D 564 K 015614

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ANNEX
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CORNELL
UNIVERSITY
LIBRARY
The Library of
EMIL KUICHLING,
C. E.
The Gift of
Sarah
L.
Kuichling
1919
ENGINEERING
f^0ntr0n
^o^vitxi
€annt]s
Cornell University Library
TD 564.L8A22
Bacterial treatment of crude
sewage (sec
3 1924 004 275 024
BACTERIAL TREATMENT OF CRUDE
SEWAGE
(SECOND REPORT).
BY
De/I
CLOWES
AND
De.
HOUSTON.
EXPERIMENTAL INTERMITTENT TREATMENT
OF
LONDON CRUDE SEWAGE
IN
THE COKE-BEDS AT CEOSSNESS.
PRESENTED BY
PROFESSOR FRANK CLOWES,
(Ghief Chemist
D.Sc.
(LoND.),
F.LC.
ta the Council),
To THE Main Drainage Committee of the Council.
JAS.
TRUSOOTT AND SON, PRINTERS, SUFFOLK LANE, CANNON STREET,
E.G.
S^uu^.
- „
^^
^
^t^
=^
Cornell University
Library
^^1
The
original of this
book
is in
the Cornell University Library.
There are no known copyright
restrictions in
the United States on the use of the
text.
http://www.archive.org/details/cu31924004275024
DIVISION I.-CHEMICAL
AND GENERAL.
BY
PROFESSOR PRANK CLOWES,
(Ohief Chemist
to the
D.Sc. (Lond.), F.I.C.
Council).
———
CONTENTS.
AND GENERAL.
DIVISION I.-OHEMIOAL
Section
General Objects and Conclusions.
I.
1.
Introductory.
2.
Objects of the Coke-bed Experiments.
3.
General results obtained.
4.
General Conclusions.
5.
Advantages of Bacterial over Chemical Treatment.
Section
Construction and Working of the Coke-beds.
II.
1.
Construction and Details of the Coke-beds.
2.
Method of Working the Beds, and
3.
History of each Coke-bed.
4.
Experimental proof of the Aeration of the Coke-beds.
5.
Variation in the Condition of the
6.
Comparative purity of clear Sewage, Bacterial Effluent and Chemical Effluent.
their present condition.
Eaw
Sewage, and
its effect
upon the
Effluent.
Tables and Curves, showing the Eesults of the Chemical Examination of
Section III.
THE Crude Sewage before and after Treatment in the Coke-beds.
Table
I.
—Results obtained by the
Chemical Determination of the Relative Amoxints of
Dissolved Oxidisable Matter in the
Raw Sewage
before
and
after
the
Bacterial
Treatment.
Diagram
1.
—Curves showing the Variation
in the Relative
Amount
of Dissolved Oxidisable
Matter in the Crude and in the Treated Sewage from July, 1898, to February, 1899,
and the Rainfall
at corresponding times.
Weekly Averages
of
Percentage
Bacterial Treatment, as measured
Diagram
the
2.
Also Curves showing the Variation in the
Purification effected
Raw Sewage by
the
by the removal of Dissolved Oxidisable Matter.
—Curve showing the Daily Variation in the
Raw Sewage by
on the
Percentage Purification efiected on
the Bacterial Treatment.
(The Diagrams will be found immediately following page 41 of the
text.)
—
—
DIYISIOIsr
I-CHEMICAL.
SECTION
I.
GENERAL OBJECTS AND CONCLUSIONS.
1 .— Intkoddctoby.
After duly considering the different methods of sewage treatment which have been at present
proposed (see pages 19, 20), it appeared to me that the intermittent treatment in bacteria coke-beds was
the one most likely to be suitable to the conditions at the Council's Northern and Southern Outfalls.
Much information has already been laid before the Main Drainage Committee on this method, but
chiefly with respect to the results obtained by treating the effluent from the chemical precipitation of
London seiwage. I considered that further information and experience was desirable before the
Committee could be advised to embark on the scheme of treating the whole or even a considerable
portion of the raw sewage by this process, which is usually called that of " intermittent filtration
through coke-beds." This treatment undoubtedly depends upon the action of bacteria, and the term
" filtration," which implies mechanical removal of suspended impurity should be abandoned.
On the loth of February, 1898, the Council approved, on the recommendation of the Main
Drainage Committee, my proposal that further experiments should be made on this process of
intermittent bacterial treatment in coke-beds, and the chief engineer. Sir Alexander Binnie, willingly
accorded his cooperation. Dr. Houston was retained for the purpose of conducting bacteriological
investigations during the first year of the experimental work, and a grant was voted by the Council for the
purpose of laying down coke-beds on a small scale at Crossness and for maintaining their working.
Thanks to the cooperation of Mr. E. J. Beal, the superintendent, and of Mr. J. W. H. Biggs, the
assistant chemist at Crossness, these experimental coke-beds have been constructed and worked to
'
my entire
'
satisfaction.
In the present report the details of construction and the method of working the coke-beds are
explained, and the general results arrived at, after about ten months experience of the filtration, are
stated.
c
It appeared' to me to be necessary that the crude sewage at the Northern Outfall should be
subjected to similar experimental treatment, and a further sum was accordingly voted by the
Main Drainage Committee on 21st July, 1898, to equip small experimental coke-beds at the Northern
The full particulars of these coke-beds and of the results obtained by them, will be included
Outfall.
in a special report in due course.
The Committee has already received, in a Report which they ordered to be printed and
circulated on the 16th June, 1898, the results obtained by Dr. Houston from a bacteriological
examination of the crude sewage as it arrives at Crossness and at Barking. "In the present Report
the results are stated, which were obtained by Dr. Houston from a bacteriological examination of the
Crossness sewage after its passage through the coke-beds (pages 17 to 41).
It should be explained that the experiments on intermittent treatment in the coke-beds have
been carried out by filling the coke-beds with sewage until the coke is just submerged, then allowing
the sewage to remain in contact with the coke for several hours, and finally draining the liquid away
The coke is then allowed to remain for some time in contact with the air, which fills the
completely.
This series of processes is repeated at
interstices of the coke-bed when the liquid has flowed away.
regular intervals.
Fuller details as to the construction and working of the coke-beds will be found in Section II.
(pages 7 to 10) of this. Report.
2.
Objects of the so-called "filtration" experiments.
The process of " filtration " of raw sewage, or of its bacterial treatment in coke-beds, is already
in use for purifying the sewage of several towns containing a population less numerous than that of
But in order to render this process adaptable to the treatment of London sewage it
London.
appeared to be necessary to use coke-beds which were deeper and which could be more rapidly filled
and emptied than those usually employed elsewhere.
And
further,
since
London sewage
is
of.
a
special character, consisting not only of domestic drainage but of manufacturing refuse of the most
varied description, it seemed advisable to ascertain by a lengthened experience whether its purification
was possible, and whether it could be regularly maintained by the process of bacterial treatment.
With these objects in view, coke of fairly large size was employed, and the coke was introduced into
tanks of considerable depth so as to enable the layer of coke to be progressively increased in
thickness during the progress of the experiments.
The main objects of the experiments M'ere to ascertain
(a) The effect of using the coke in fragments about the size of a walnut.
(b) The effect of increasing the depth of the layer of coke beyond the usual limit.
(c) The extent to which the raw sewage underwent purification by the treatment.
(d) The practicability of maintaining the constant passage of raw sewage through the
same coke-bed, without deterioration occurring, either in the bed or in the effluent.
'
—
—
(e)
the cokeof sewage which could be treated daily by a superficial unit of
The amount
l^ed.
, ^
underwent further improvement by
.
(/)
The extent
to
which the
effluent
.,
passage
its
through a second similar coke-bed.
(g)
The
The
suitability of the effluent for
maintaining the life of fish.
number and nature of the bacteria which were
the treatment on the
present in the raw sewage.
(h)
efiect of
3.
General results obtained.
It may be stated that the general results obtained from about 10 months' experience of the
coke-bed treatment point to the following conclusions
(a) Size of coke.
The use of ordinary gas coke, in pieces about the size of walnuts, seems to be attended with the
The larger coke enables the bed to
following advantages, as compared with the use of smaller coke.
hold a larger volume of sewage. The beds now in use had an original capacity for sewage which was
nearly equal to the volume of the coke which they contained, in place of only 20 or 30 per cent, of
that volume, as is shown by beds containing smaller coke. The use of the larger coke also allows the
bed to be more rapidly filled and emptied, and to be more completely emptied and aerated.
(b)
Depth ofcohe.
Coke-beds similar in character, but differing in depth, have been found to give practically
identical purifying effects.
At present experience has been obtained only with a four-foot and with a
six-foot bed ; but I am arranging to extend these depths considerably.
[June 21st, 1899 A bed 18 feet in depth has now been working satisfactorily for over nine
weeks, and has given a purification approximately equal to that effected by the four-foot bed.]
—
(c)
Chemical purifisation
effected
hy a single treatment.
The sewage had been roughly screened before reaching the coke-beds, and it was free from
larger matter usually described as " filth," and from coarse sand and heavy mineral road detritus, but
it contained all the suspended solid matter usually termed " sludge."
During part of the period reported on, the coke-beds received only one charge of this raw
sewage daily but latterly all the coke-beds have received two charges daily of raw Crossness sewage.
The coke-beds have removed the whole of the suspended matter or " sludge " from the crude
sewage and they have yielded an effluent which occasionally shows a slight turbidity, apparently due
in ordinary flow, mainly to the presence of bacteria, but which is increased in storm flow by fine
clay and mud.
Not only has the suspended matter been removed, but the removal of the dissolved oxidisable
and putrescible matters of the raw sewage has been secured to the average extent of 51-3 per cent, by
the single process, the four-foot coke-bed giving 62-7 and the primary six-foot coke-bed 49-9
per cent. The effluent thus produced remains free from objectionable odour when it is kept
in open or in closed vessels, provided the bacteria present in it are not removed or killed by
special
subsequent treatment. This effluent could, therefore, produce no offensive smell when it is introduced
;
;
into the river.
{d) Permanency of coJce-heds.
Since the coke-beds have become regular in their action, neither the effluent nor
the coke itself
has become foul. The coke which has been in use for upwards of 12 months has shown
no general
tendency to break up, but the surface of each piece of coke has become partially covered
with soft
matter which consists mainly of fine particles of coke with some fine sand, woody
and vegetable
tisRue, cotton and woollen fibres and diatoms.
Below this thin film the coke is perfectly hard and no
sand has penetrated two millimetres below the surface. The sand when examined
by polarised light
was found not to be granite sand derived from road detritus. The ash in the coke
has been reduced
in amount by about 25 per cent, during its exposure to sewage in the coke-bed
capacity of the four-foot coke-bed has during the period in
revi'ew been reduced from
Kr^ .
-.T"^
per cent, of the whole volume of the bed, and this reduction of capacity
to 33
50
appears to be mainly
due to fragments of straw and chaff, apparently derived from horse-dung, and to
woodv-fibre derived
from the wear of wood pavements. The treatment of raw sewage by this coke-bed
is biina continued
order to ascertain whether the decrease in the capacity continues.
It has been ascertained that
the original capacity is not restored in any degree by prolonged aeration,
which proves that the denosit
on the coke surface was not organic matter of animal origin but it has been
found that the vegetable
tissue, which appears to be the main cause of the decrease
in capacity, can be in great
measure
^
^^^ '^^^^^
°^ sedimentation before the sewage is allowed
^
to flow
into the
m
;
coSef
^
(e) Amount of sewage which can be treated daily hy
a superficial unit of the coke-bed
The volume of sewage which can be passed through the coke-bed
per unit nf si t. "fl
i
•^^has not yet attained its maximum, since the depth of the coke-bed is being
furtherinorPo«t^
Tf
^^T
gallons
amounted to 555,000
per acre per day for the four-foot
^
^d
to 832 Sn '^T
per acre per day for the six-foot coke-bed.
^
This represents in each
case one filial
i"""'
but, as has been already stated, two fillings have been made successfully
fr .i?„n..^^ ^^'/f/-'
corresponds to 1,665,000 gallons per acre per day for the six-foot
^""^ *^''
^oke bed
?^?™*s are
reduced after ten months' working of the coke-beds to 370 000 ffalln,i« r,.!
^""'^ ^°' "" ''^^^° ^"^°g
^
of the four-foot coke-bed, and to 673,400 for the six-foot coke-bed!
•
cX-C
Tw'
/
—
—
7
The maximum possible rate of treatment by each coke-bed is possibly not yet reached. This
an important point to be determined, since the practicability of applying this method to the
treatment of the whole of the London sewage depends largely upon the superficial area which will
be required for the laying down of the coke-beds.
The above daily rate of treatment will
naturally be augmented as the depth of the coke-bed is increased, and if the satisfactory working of
the 13-foot bed is maintained, it will treat a volume of raw sewage equal to at least three-and-a-half
is
million gallons per day.
if)
Secondary treatment.
been stated that the purification efiected by a single treatment of the raw sewage in the
coke-beds amounts to a complete removal of the suspended matters, and to a further removal of an
average of at least 5r3 per cent, of the dissolved putrescible oxidisable matter. The primary sixfoot coke-bed actually removed on the average 49-9 per cent, of dissolved impurity, and a second
process has effected thus far an additional purification of about 19-3 per cent., giving a total average
purification of the clarified raw sewage amounting to about 69*2 per cent.
It has
(g) Hffed of the effluent on fish.
Pish die at once when they are placed in the present effluent produced by chemical precipitation,
probably because there is a serious deficiency of dissolved oxygen in the impure liquid, and therefore
their respiration cannot be maintained.
Not only goldfish, but roach, dace and perch have lived for
months in the first eflluent from the coke-beds, and they apparently would live and thrive in this
liquid for
an
indefinite period.
(Jh)
Bacteriological character of the
efflue7ht.
The results obtained by the
bacteriological examination of the effluent by Dr. Houston (see pp. 1
seem to indicate that the coke treatment does not by any means remove the bacteria from
the crude sewage, and indeed does not materially reduce the number. It shows that the presence of many
of the bacteria in the effluent is possibly unobjectionable, and is probably necessary for the purpose of com-"
pleting the purification of the effluent when it has flowed into the river but it further shows that
some of the bacteria whose presence might be looked upon as undesirable in drinking water pass
through the coke-beds.
to 41) thus far
;
4.
General Conclusions.
The above considerations show that neither on chemical, not possibly on bacteriological grounds
can any serious objection be raised to the introduction of the effluent from the coke-beds into a portion
of the river Thames which is cut off by locks from the Intakes of the Water Companies, and the water
from which is not employed for drinking purposes, and cannot be used for drinking on account of its
" brackish " nature. The effluent certainly will not cause any deposit upon the river-bed, and will
even tend to render the turbid water of the lower river more clear and transparent. At the same
time, the liquid discharged from the outfall into the river will be sweet and entirely free from smell.
Further, it will carry into the river the bacteria necessary for completing its own purification in contact
with the aerated river water, and under no conditions can it therefore become foul after it has mingled
with the stream. The effluent will in no way interfere with fish-life in the stream..
5.
As compared with
Advantages of bacterial over chemical treatment.
the present process of chemical precipitation and sedimentation, the
bacterial
process presents the following advantages-^
(a) It requires no chemicals.
(b) It produces no offensive sludge, bui only a deposit of sand or vegetable tissue which
is free from odour.
(c) It removes the whole of the suspended matter, instead of only about 80*0 per cent,
thereof.
(tZ) It effects the removal of 5r3 per cent, of the dissolved oxidisable and putrescible
matter, as compared with the removal of 17 per cent, only, effected by the present chemical
treatment.
(e) Further, the resultant liquid is entirely free from objectionable smell, and does not
become foul when it is kept ; it further maintains the life of fish.
SECTION
II.
CONSTRUCTION AND WORKING OF THE COKE-BEDS*
1.— Constkuction and details of the coke-beds.
For the purposes of the present experiments three brick-lined tanks with brickwork bottoms
were specialty provided with suitable outlets and with means of chargmg them with raw sewage by
series of parallel loose-jointed stoneware drain pipes
means of a pump and distributing troughs.
A
on the bottom of the tanks, and were connected with
served to draw off the effluent.
were
laid
suitable outlets j this arrangement
Two of these tanks (A, B) are precisely similar in dimensions, being 22 feet 6 inches long,
10 feet 8 inches wide, and 12 feet deep, and the superficial area of each is T^^gS^*^ '^^ ^^ acre. 'JTie
third tank (C) is of less regular shape, but of the same area as (A) and (B), and 6 feet in depth.
—
—
8
.
.
The
,
Single. Ooke-lei,
-
i
of uniform size, each fragmenr.
of the tanks (A) was filled to. a depth of four feet with coke
retorts of the gasworks at the;
from
the
being about as large as a walnut. The coke was drawn
absorb
15 per cent, of its weight ot,
to
water
in
soaking
Crossness Outfall, and was found by long
equal to 50 per cent, of the volume
water. The eoke-bedhad a sewage capacity of 3,000 gallons, which is
cubic teet.
occupied by the coke and air space ; the volume of the coke amounts to_ 960
it has been used for the
"
since
Ooke-oed,"
Single
The
as
best described
One
.
.
i
This coke-bed is
purpose of subjecting the sewage to a single process only.
The Double Coke-bed;
The other two tanks (C, B) have been filled to a depth of six feet with precisely similar coke,
of each of these,
which was obtained from the South Metropolitan Gasworks. The sewage capacity
bed is therefore
the
of
capacity
the
coke-bed,
tanks is 4,500 gallons. As compared with the single
contains.
it
which
coke
of
volume
increased
the
increased in proportion to
Tank C is at a higher level than tank B, and the two coke-beds have been, therefore, easily
rendered available for a process of double treatment. The raw sewage has been pumped into tank 0,
[
and the effluent from this tank has been allowed to flow by gra,vitation into tank B and there to
undergo a second treatment.
j
i,
and B, have been called " The Double Coke-bed,'
In order to avoid confusion the two tanks,
"
the
Secondary
B
tank
ajid for purposes of distinction tank C has been called the "Primary," and
,
i
Coke-Bed."
It should be stated that the effluent from the Primary Coke-bed was passed through a small
This laboratory coke- vessel
laboratory coke- vessel pending the preparation of the Secondary Coke-bed.
consisted of a glass bottle of 275 gallons capacity, which was filled with small coke, and_ which
had a sewage capacity of 1-25 gallons, or about 45 per cent, of that of the coke which it contained.
2.
Method of wokkikg and present condition of the
coke-beds.
After each coke-bed has been filled from above to the level of the upper surface of the coke, a
process which occupies about seven minutes for the four-foot bed, the sewage remains in contact
with the coke for three hours. The liquid is then allowed to slowly flow by. gravitation from the;
bottom of the coke-bed, the process of emptying requiring an hour for the four-foot bed, and the cokebed is then allowed to stand empty for about eight hours in order that the surface of the coke fragments may become aerated. In the case of the secondary coke-bed the aeration process lasted only
seven hours.
The coke-bed requires to be daily filled and emptied and aerated for about four weeks before it is
"matured " and begins to exert its full purifying efiect upon the sewage. During this interval the,,
coke is doubtless becoming sown with bacteria, which are the active purifying agents, and which are
present in large numbers in the raw sewage. This process of " maturing " the coke-bed has usually been
carried on during its construction, by constantly treating the coke with sewage while it is being intro-
duced into the tank.
In the earlier experiments with the " single coke-bed," when it was being filled twice a day, and
before it was fully " matured," the coke-bed evidently became overworked, and accordingly returned a foul
effluent, and the coke itself became foul. A fortnight's rest in an empty condition restored its activity,
and it has not again given any unsatisfactory results whilst being filled with sewage once a day, and
when
has again been, filled twice a day.
are not filled on Sundays. They have also rested for four consecutive days, including
Sunday, during the Whitsun recess, and on July 30th and August 1st, 5th, 6th and 7th, the latter rest
bbing partly due to the necessity of repairing the sewage pump. The coke-beds rested on five other
With these exceptions the coke-beds have been continuously at work since the date when they
days.
latterly
it
The coke-beds
were
started.
The surface of each working coke-bed is broken up to a depth of several inches twice a week
by being raked over; this keeps the surface open, and there is no appearance of its becoming
clogged.
At longer intervals a hole extending from the surface of the coke-bed to the bottom of the tank
has been dug in the coke. The whole of the coke has on every occasion been found to be perfectly
sweet when it has been thus exposed, arid possesses only a slight earthy odour. The surface of the
upper portion, to a depth of three or fjur inches, is not quite bright, but it emits no foul smell.
The use of comparatively large pieces of coke in constructing the coke-bed enables the bed
to hold a charge of sewage which is considerably greater than that which would fill a similar bed
constructed of the smaller coke which was formerly employed.
single daily filling of the coke-bed
deals, therefore, with almost as large ah amount of sewage as the double daily filling
of an ordinary
The larger size of the coke will doubtless also admit of the coke-bed being considerably
bed.
deepened without .losing the possibility qf fully aerating the coke. It may be confidently anticipated
that the larger coke and greater depth of the bed will thus enable the necessarily
large amount
of sewage to be dealt with.
Since the single colce-bed settled down to a steady rate of working,
the number of daily fillings
Has been increased to two, and the depth of one of the coke-beds has been
increased from six to
thirteen feet in order to ascertain the possibility of working with deeper
coke-beds.
A
jo
.
3.
History of each coke-bed.
The Single Oohe-bed.
The
single coke-bed
was
filled with coke to a depth of of 4 ft.
It was first charged with sewage
on April 22pd, and from that dat^ until June 23rd it was charged with crude sewage
twice daily,
—
;
with the exception of Sundays when
it
rested entirely,
and of Saturdays when
it
received one filling
only.
On June 23rd it was decided to give the coke-bed complete rest for a fortnight, since both the bed
and the effluent were becoming foul. There is little doubt that this foulness arose from the fact that
undue work was thrown upon the bed before it had become " matured." The impurities, therefore,
gradually collected in the coke, since they could not be dealt with by the bacteria, which were not
established in the bed at that period in sufficient number.
Ultimately the impurities accumulated in
the bed in such qua,ntity as to render the purification insufficient.
There is no doubt that this
state is unlikely to arise in a coke-bed which is not overworked in its immature state.
After the fortnight's rest, the bed was filled only once a day, and efiected satisfactory
purification of the crude sewage continuously until November 7th, 1898.
During this period the coke-bed was stopped on certain public holidays and for the repair of the
sewage pump, these stoppages amounting in all to 12 days.
On November 8th, 1898, a commencement was made with two fillings a day, and this was maintained until February 18th, 1899.
The results obtained by two fillings have been perfectly satisfactory.
Up to the present date (February 18th) this coke-bed has been charged with raw sewage 339 times,
and the one layer of coke has dealt with about 847,500 gallons of the raw sewage. The coke-bed has,
therefore, removed from the sewage an amount of solid matter which in the dry condition would weigh
32-4 cwt. This solid matter would represent 20-25 tons of sludge, containing 92 per cent, of moisture
or taking one ton of sludge as occupying 33 cubic feet, the sludge removed by the coke-bed would fill
the empty coke-bed tank to a depth of 2 feet 9 inches.
The Prima/ry Colce-bedfor
the first stage of Bouble Treatment.
This coke-bed was charged with coke somewhat slowly owing to the difficulty of procuring coke at
the time when the bed was being constructed. From July 12th to September Isb, the period over
which the introduction of coke extended, the coke-bed was, however, frequently charged with crude
sewage, in order to carry on the " maturing " process during the lengthened process of construction.
The bed started its regular work in the treatment of crude sewage on September 1st, and from
that date until February 18th it has been filled 213 times.
This coke-bed, which is six feet in depth, is now producing an effluent in which the purification is
practically the same as that eff^ected by the single coke-bed, which is four feet in depth.
It may therefore be inferred that the purification efiected by the bed will not be diminished when its depth
is still further augmented.
TJie
Secondary Colre-bed for the second stage of Double Treatment.
The Secondary Coke-bed was " matured " by treatment with sewage during its construction. It
received its first charge of raw sewage on June 21st, and was worked until August 31st as a single
crude sewage coke-bed. During that period it received 60 fillings of raw sewage, and 244,200
gallons of sewage in all were passed through it.
It removed during this period an amount of solid
matter from the sewage, which in the dry condition would weigh 9 '35 cwt. This solid matter would
be equivalent to 5'85 tons of sludge containing 92 per cent, of moisture.
Since September 1st this coke-bed has been used as a secondary bed, and has received
the effluent from the primary coke-bed and subjected it to a second process of treatment.
Since the
primary effluent is usually clear, this secondary bed has been spared the process of removal
of solid suspended matter and has exerted all its purifying action upon the dissolved oxidisable
Since the secondary coke-bed has been in operation the use of the small laboratory vessel
matter.
has been stopped.
4.
Experimental proof of the aEration of the coke-beds.
In order to ascertain whether the surface of the fragments of coke became fully aerated
throughout the bed between the successive chargings with raw sewage, two vertical pipes were
After the sewage had
inserted into the bed reaching to the depths of 6 feet and 1 3 feet respectively.
flowed away from the bed samples of air were drawn oS" from the interspaces between the coke
fragments at stated intervals, and the percentage proportions of oxygen and carbonic acid were
estimated in this air. The results, which in the case of the 13-foot depth were only of a preliminary
character, indicated that even after the air had been in contact with the lower strata of the coke for
seventy hours, the air still contained an average of about 75 per cant, of its original oxygen, and the
average amount of carbonic acid did not exceed 3 per cent., as is indicated by the tabulated results
below.
This evidently represents an entirely satisfactory condition of aeration of the coke surfaces.
Six-foot depth.
—
10
the effluent.
the crude sewage and its effect upon
5 -Variation in the condition of
The sewage wHch ha. been suhjeci^d ^^o
fc^^s!
•
J^/^^^^^^^
'"'
purification effected by the coke-beds more
the variations in the degree of
the
as a curve in Diagram I and
out
dra-Wn
evident the percentage daily purification has been
has
purification
I'litarthfa^erage^^^^^ percentage
the efiiuent ^l^^.J^^,^/^^^ ^^tte^V^^^^^
amounts of oxidisable matter in the crude sewage and in
^J'^^'^tjf^
with the dissolved °^
It will be understood that the results deal only
J^^
coke-bed
f^^^^^\^
in the ,o^^^^^^^^
matters of the sewage wholly disappear
^t'Sef to'eVder-
m
^™
^^^llZZtll
jff
Ve
The solid suspended
in the eflauent.
are therefore not taken into account.
j
.•
.^
,r^T.o^T. in
ar-irl
due tn
to an acid
be Hne
to hf>
does not appear
The occasional diminution in the percentage purification
alkalme
or
either
always
since the sewage is
reaction of the sewage hindering the bacterial action,
the
presence
to
referred
be
to
apparently
neutral in reaction. Neither is this diminished purification
and
and
*.
from gas works and chemical works,
"n^he sewage of undue proportions of chemical refuse derived
the coke-bed from such can es.
ko evidence\as been obtained of interference with the normal action of raw sewage is most complete
the
of
purification
very probable that the
It appears, however,
It is of interest to consider the rainfall
in a fairly dilute and fresh condition.
results were obtained during the hot
curve on the diagram in this connection. The least satisfactory
Crossness in a less dilute condition
at
arrived
sewage
the
dry weather of the recent summer, when
condition owing to the high
putrescent
and
offensive
an
in
and
rain,
of
absence
the
owing to
in this offensive condicoke-beds
the
upon
poured
temperature of the air. Even when the sewage was
it did not become offensive
and
character,
in
offensive
not
was
beds
the
tionf the efluent from
containing a larger amount ot
It differed from better effluents only by
when it was kept.
dissolved oxidisable matter.
when the sewage
is
6.— Eelative purity of clear sewage, chemical effluent, coke-bed effluents, and lower
river water.
matter in the sewage, the chemical effluent, and the
putrescible
dissolved
of
amounts
The relative
from permanganate,
coke-bed effluent, as measured by the oxygen which they absorb
are as follows
Percentage
Impurity of
liquid.
purification calculated
on raw sewage.
Raw
sewage
Chemical effluent
Coke-bed effluent (single treatment)
Coke-bed effluent (double treatment)
River water, high tide
River water, low tide
...
...
...
...
...
—
3-696
3-070
1-799
1-137
16-9
513
69-2
—
—
0'350
0-429
A comparison of these numbers with one another shows that by substituting a single coke
treatment for chemical treatment, the effluent sewage discharged into the river would be completely
free from suspended impurity, and would possess a purity, as regards dissolved putrescible matter,
of 51-3 as compared with 16-9 in the present effluent, representing an improvement of 67-1 per cent.
If discharged after double treatment in the coke-beds the percentage improvement on the chemical
The bacterial action continuing in the river would rapidly bring the purity
effluent would be 75-6.
of such a liquid into a condition equalling that of the river water itself.
SECTION
III.
TABULATION OF RESULTS OP CHEMICAL EXAMINATION OF THE
THE BACTERIALLT-TREATED SEWAGE.
RAW AND
The results of the examination of the sewage before and after its passage through coke-beds were
obtained by estimating the amount of dissolved oxidisable matter in the crude sewage, which had been
clarified by passage through a paper filter, and then making a similar estimation in the same sewage
after it had passed through the coke-bed.
The oxidisable matter was estimated by exposing the liquid, which had been clarified by
filtration if necessary, to the action of acidified potassium permanganate, in closely stoppered bottles,
for four hours at a temperature of 80° Fahr.
The oxidisable matters are measured by stating the number of grains of oxygen per gallon of
the liquid which are required for their oxidation.
When the coke-bed has been filled twice in a day, a
sample of each effluent is collected, and these equal samples are mixed for the chemical estimation.
This method of estimation is not appreciably affected by the small amount of nitrite which is
occasionally present in the effluent.
The Table which includes the numerical results will be found on pages 11 to 14. Thei results
obtained will be more readily appreciated by a consideration of the curves in the Diagrams which
immediately follows page 41.
11
TABLE I.— SINGLE COKE-BED
June
,,
,,
„
„
1
2
3
4
6
„
7
„
8
9
10
11
13
»
»
„
„
„
„
„
„
„
,,
U
15
16
17
18
20
,,
21
22
,.
23
„
(4 feet).
.
12
TABLE I.-SINGLE AND DOUBLE
Number
Raw
sewage.
Effluent from the
single coke-bed
(4 feet).
1898.
August
„
2
3
4-000
2-500
4
3131
Eest on
August
10
11
12
13
15
16
17
18
19
20
22
23
24
25
26
27
29
30
31
1
2
3
5
6
9
10
12
13
14
15
16
17
19
20
21
22
23
24
26
27
28
29
30
OctoTaer 1
3
„
„
„
4
5
]0
11
12
13
14
15
17
18
19
20
21
22
and
6tli
while the spindle of the
3-956
3-333
4-207
2-841
1-938
2-264
3-211
3-750
3-333
2-680
2-010
3-933
2-746
4-211
2-263
3-044
4-400
2-128
5-319
6-809
6-145
3-617
4-574
3-191
5-417
4-632
3-152
4-616
4-193
4-946
5-319
3-830
6-774
3-298
2-234
5-745
4-574
4-239
6-129
4-444
2-258
3-936
2-766
2-447
3-617
3-656
3-391
3-898
3-643
4-265
3-978
3-991
3-391
2-447
3-587
3-763
2-717
3-696
3-696
3-614
2-909
3-622
4-830
4-146
-967
860
1-506
2-903
1-916
1-596
3-548
1-277
1-277
1-809
2-128
2-174
1-936
1-778
1-183
2-128
sample
1-489
2-340
2-558
1-522
1-809
1-848
2-234
2-258
2-340
1-739
1-277
1-550
2-161
1-413
1-729
1.522
1-932
1-682
1-870
2-043
2-312
of
from the Effluent from the
secondary cokeprimary coke-bed
bed (6 feet).
(6 feet).
pump was
2-234
1-383
3-229
1-064
1-596
1-489
2-187
2-211
1-196
No
by one gallon
2-400
1-600
1-515
1-260
1-636
1-343
1-640
1-296
1-052
1-052
1-177
1-875
1-666
1-400
-982
1-641
1-112
2-000
1-118
1-236
1-717
r
in 4 hours
Effluent
1-900
1-600
1-717
2166
8
9
September
5tli
oxygen absorbed
of grains of
Date.
GOKE-BEBS-(,continued)
1-100
•700
•920
being repaired.
1-374
1-450
1-343
1-759
1-295
1-295
1-176
1-400
1-666
1-666
1-284
1-006
1-422
1-317
2-000
1-010
1-010
1-994
1-383
2-340
1-702
683
•802
-644
1-077
•647
•490
565
•818
•737
1-010
-752
-642
•834
•834
1^196
•660
•749
•997
•745
1-064
•851
Stopped working
1-596
2-708
2-316
1-848
1-828
2-043
2-258
2-447
1-915
4-086
1-596
1-809
2-234
2-128
1-957
3-222
1-889
1-398
2-234
1-916
1-277
2-447
2-688
1-304
2-021
2-391
2-660
2-366
2-840
1-7.39
1-809
1-820
2-581
1-957
2-065
2-009
1-932
1-909
2-234
2-903
2-312
•064
•562
-684
-978
-605
-605
-398
-596
-170
-118
-064
-170
-702
-489
-304
-258
-889
•290
-489
-170
-064
-809
-290
-978
-383
-522
-702
-605
-596
•196
170
196
•720
-304
-304
-196
-136
-341
-596
-505
•525
13
TAETiF. I.-
14
(contiWed).
TABLE I.— SINGLE AND DOUBLE COKE-BEDS—
Number
of grains of
Date.
Raw
1899.
January 17
19
20
21
23
24
25
26
27
28
30
31
Tebruary
1
„
2
„
3
„
4
sewage.
oxygen absorbed in 4 hours by one gallon of
15
DIVISION
II.-BACTERIOLOGICAL.
BY
A. C.
HOUSTON,
M.B, D.So.
—
—
—
16
CONTENTS,
A
Introduction.
.
Summary of Contents of First Report.
B.
I.
Biological Treatment of Sewage.
—The
9th, 1898).*
II.— General Results obtained (May 9th to August
III.— Summary of Results shewn in Table
number
1.
of Bacteria.
1.
Total
2.
Number
of Spores of Bacteria.
3.
Number
of Liquefying Bacteria.
4.
Species of Micro-organisms.
(a) B. Enteritidis
Sporogenes (Klein).
Communis.
(h)
B. Coli
(c)
Other species of Bacteria.
of the Bacteriological Examination
lY. -Tables and Diagrams dealing with the Results
Coke-beds, of the Effluent from
OF THE Crude Sewage, of the Effluents from the
of Thames Water.
Samples
THE Chemical Precipitation Works, and of
(The Diagrams will be found following page 41 of the text.)
v.— Description
of some of the
Bacteria found
in
the
Crude
Sewage, and
in
the
Effluents from the Coke-beds.
1.
B. Coli Communis.
2.
B. Mesentericus.
Sewage
variety E.
Sewage
variety
3.
Sewage Proteus.
4.
B. Prondosus.
5.
B. Fusiform is.
6.
B. Subtilissimus.
7.
B. Subtilis.
Sewage
I.
variety A.
Sewage variety B.
VI.
Membraneus Patulus.
8.
B.
9.
B. Capillareus.
Description
of Micro -photographs and Diagrammatic Drawings
accompanying the
REPORT.f
"VII.
Addenda A,
December
B,
C, D, E.
Further Bacteriological Records from August 9th to
31st, 1898.
(These
Addenda
follow
Diagram 9
at the
end of the Report.)
was written (August 9tli, 1898) circumstances arose delaying its publication for several
To have brought it up to date would have necessitated rewriting the whole report and reconstructing
Under these circumstances it was considered best to incorporate some of the later
all the Diagrams and Tables.
results in the form of addenda (Add. A, B, 0, D, E), so that anyone interested in the progress of the coke-beds might
follow their history a stage further. All the results, however, are not given, and it is hoped that in the future
an opportunity may present itself of recording the work done since August 9th, 1898, in a more complete form.
t The micro-photographs were specially taken by Dr. Albert Norman. I wish to record my thanks to him
for the great skill which he has shown in photographing my cultures and microscopic preparations, both for this
and for my previous report. A. 0. H.
* Since this report
months.
—
—
f;
17
DIVISION II-BACTERIOLOaiCAL.
RESULTS OF THE BAOTERIOLOGIOAL EXAMINATION OF CROSSNESS
CRUDE SEWAGE AND OF THE EFFLUENTS FROM THE COKE-BEDS.
A.—INTRODUCTION.
It has been stated (Division I., Section I., Sub-section 2h) that one of the main objects of the
eiperiments was to ascertain
" The effect of the treatment on the number and nature of the bacteria which were
present in the raw sewage."
This portion of the Eeport contains a record of the work which has been done in this direction
from May 9th to August 9th, 1898.*
It will be readily understood that, notwithstanding the large amount of work which has been
carried out in obtaining data for this preliminary statement, the period during which the coke-beds have
been in operation is too short to allow of anything in the nature of a final opinion being given as to
their efficiency from the view-point of the bacteriologist.
What follows then must be regarded as in
a sense provisional, although it is probable that many of the results which have been obtained, and
some, at all events, of the conclusions that have been arrived at will hold good in future work.
In what follows reference will be repeatedly made to the effluent from the 4-foot coke-bed, to
the effluent from the 6-foot coke-bed, and also to the effluent from the laboratory coke-vessel. This last
is the effluent from the 6-foot coke-bed which has again been treated in the small laboratory vessel at
_
Crossness.
A
description of the construction
and history of these coke-beds, together
vrith all other
essential particulars relating to them, will
be found in Division I. of this Report (pages 7 to 9).
The Committee will remember that they have already received a report dealing with the
bacteriology of London crude sewage as it is delivered at the Barking and Crossness Outfall Works.
Before proceeding further it is desirable to give a brief summary of the contents of this first report.
B.— SUMMARY OF CONTENTS OF THE FIRST REPORT.
Under the heading "Description of some of the Methods used in the Bacteriological Examination of
Sewage," information was given as to (1) collection of samples (2) dilution of sewage; tlie best way of estimating
;
the total number of bacteria; (4) the number of spores of bacteria; (5) the number of liquefying bacteria; and
how to search for (6) special micro-organisms such as B. coli, typhoid bacillus, diphtheria bacillus, staphylococci
and streptococci, and B. enteritidis sporogenes.
Under the heading " Summary of Eesults shown in Table I.," it was shown that (1) the total number of
bacteria in 1 c.c. of Barking crude sewage averaged 3,899,259 (19 cultures of 9 samples), and in 1 c.c. of Crossness
crude sewage 3,526,667 (11 cultures of 6 samples) (2) the number of spores of bacteria in 1 c.c. of Barking crude
sewage averaged 332 (excluding certain extreme results), and in 1 c.c. of Crossness crude sewage 365 (excluding
extreme results), which gives a ratio of spores to total number of bacteria of 1 to 11,744 and 1 to 9,662 respectively
(3) the number of liquefying bacteria in 1 c.c. of Barking crude sewage averaged 430,760, and in 1 c.c. of Crossness
crude sewage 400,000, which gives a ratio of liquefying bacteria to total number of bacteria of 1 to 9 and 1
to 8'8 respectively. As regards (6) the species of micro-organisms, it was shown that in Barking and Crossness
crude sewage the spores of B. enteritidis sporogenes were present in numbers varying from at least 10 to about 1,000
per c.c, and B. coli was present in numbers usually exceeding 100,000 per c.c. Notes were also given of the
occurrence of other bacteria such as proteus-like forms, bacillus fluorescens liquefaciens and non-liquefaciena B.
mycoides, B. mesentericus, B. suhtilis, &c.
In Table I. were given the results of the bacteriological examination of 9 samples of Barking and 6
samples of Crossness crude sewage as regards the total number of bacteria, the number of spores of bacteria and
the number of liquefying bacteria, and as regards the species of micro-organisms present.
A number of micro-photographs illustrating the work accompanied the Report.
It was said (page 1, A., First Keport) that the Eeport was only to be regarded as a preliminary statement
By this it was not meant that the amount of work that had been carried out was of
of the progress of the work.
an insignificant character, the contrary was the case, but the subject was one of such a complex nature, and one
about which so little is known, that it might well occupy the energies of not one but many workers for a very
considerable period of time. Had the work merely covered the ground taken up by earlier observers it would
still have been a most desirable thing from a scientific point of view to have confirmed or modified the results
obtained in the past, particularly in an enquiry dealing with a subject which is still in its infancy, namely, the
bacteriology of crude sewage.
But to a very considerable extent the research covered new ground, as, for exaniple, the determination not
only of the presence but of the relative abundance of a number of different micro-organisms, but more particularly
of the B. coli and the spores of B. enteritidis sporogenes. B. coli is an example of an aerobe peculiarly abundant
in crude sewage, and B. enteritidis sporogenes is an example of a pathogenic anaerobe less abundant, but perhaps
more characteristic of sewage. The importance of obtaining records of the number of these germs in raw sewage
preparatory to a study of their numbers in the eflSuents from the coke-beds needs no commeut to show its
importance. Moreover, such records are highly important from the point of view of the bacterioscopic analysis of
(3)
;
drinking water.
in
of the report will be found further bacteriological records (9th August to 31st December, 1898).
C, D, E.
, t
j
j
tt
-r.
of London crude sewage,
i! irst Report
t Filtration of sewage. Report on the bacteriological examination
* At the end
addenda A, B,
(P. S.
King
.
.
and Son, 2 aud4, Great Smith-street, Westminster, S.W.).
[3]
18
I— THE BIOLOGICAL TREATMENT OF SEWAGE.
treatment of sewage by natural processes, although
apt to be misleading. It is meant to denote the endeavour to obtain, under
control, results similar -to those which are constantly being produced in nature, and to employ processes
which have been in operation for unknown ages. The term, however, is misleading because it might
give the erroneous impression that sewage does not contain in itself the living organisms which are
necessary to effect its decomposition, and that some new discovery had been made by which sewage
was artificially treated with foreign bacteria, in order to bring about its destruction. This, however,
is not the case.
Sewage already contains all the organisms which are necessary for its decomposition and final
purification.
In order to discover a method- of biological treatment all that has to be done is to
discover the best and the most practical way of allowing the natural purification by the action of the
bacteria to take place without nuisance or danger.
In brief, the so-called biological treatment of sewage is neither more nor less than the attempt
to imitate nature's own methods of effecting the decomposition and finally the purification of the
effete matter of the animal and vegetable kingdom.
In this connection the testimony of Duclaux may be quoted
" Whenever and wherever there
is a decomposition of organic matter, whether it be the case of a herb or an oak, of a worm or a
whale, the work is exclusively done by infinitely small organisms.
They are the important, almost the
only, agents of universal hygiene they clear away more quickly than the dogs of Constantinople or
the wild beasts of the desert the remains of all that has had life ; they protect the living against the
dead. They do more
if there are still living beings, if, since the hundreds of centuries the world has
The term
biological, as applied to the
manifestly convenient,
is
:
—
;
:
continues, it is to them we owe it."
To describe the steps which have brought our knowledge to such a point that sanitarians now
dare to look forward to a possible solution of the problem of sewage disposal would be to outline th&
history of bacteriology.
Here it is permissible only to indicate in a few sentences some of thediscoveries which have paved the way towards a scientific knowledge of the true nature of putrefactive
processes.
been inhabited,
life
One of the most important discoveries of recent times was that made by Schloesing and Muntz
They proved that nitrification, or the oxidation of ammonia to nitric acid, is due to the vital
activity of bacteria, and thus carried a stage further the important discovery by Schwann and Schultze
(1839) that micro-organisms are the true agents of decomposition.
Later, Winogradsky and others
in 1877.
described and isolated, in pure culture, nitrifying organisms.
Pasteur, following up the researches of Gagniard and Schwann, demonstrated, in
1857, the
relation between lactic, acetic, and butyric fermentations and special organisms.
Later, he erroneously
assumed that putrefaction was brought about solely by anaerobic bacteria.
Since 1857 the scienc©
of bacteriology has advanced by leaps and bounds, and increased knowledge of the nature
of putrefactive processes has, during the last decade, led to the serious attempt to bring
about putrefaction,
under control, as a means of disposing of excremental matters.
Putrefaction has been called putrid fermentation, but putrefaction is rather to be
looked upon
as a fermentation which is putrid or otherwise, according to the conditions under
which it is conducted
and the degree of its completeness.
The products of decomposition by so-called putrefaction are of the most varied kind
and there
IS no doubt that putrefaction is brought about, not by a single germ, but by
a large number' of difierent
bacteria, some aerobic, others anaerobic.
Each one of these germs may produce intermediary products
of widely difierent character, but all of them, perhaps, tend in the direction
of finally resolving hiehlv
'
complex organic substances into their simplest component parts.
Although the study of fermentation and the proper understanding
of the true nature of
putrefactive processes are attended with great difficulties, the aim and
object of the biological treatment
^
of sewage is sufficiently plain and simple.
f°il.°^;"g5=y°l« «f. transformation takes place :-Dead organic
matter decays as
,. result of
""f the
Jr'vital
T^ activity of bacteria, and ammonia is liberated.
the
The nitrifvine organisms brin^
about the oxidation of the ammonia, first to nitrous and then to nitric
acid.
These acids bv reaction
uponthe bases, always present, form nitrites and nitrates, and these nourish
the living nlant
Whilft
the nitrogen IS undergomg these changes, the carbon of the organic
matter is converted into carbonic
-'''' "° ^"^^ ^^*^^* ^^^ *^« ^^*-^^^drogen"-
^Ju
-^
SatTd'inlteTsrstt^e.^'^
Although organic matter
ultimately resolved into innocuous,
inorganic substances bv these
processes, the intermediary products of decomposition, as has
been already indfcated.t^X of a h^^^^^
''' ''' *^^ most pVt
n
is
Scter tTrtdVSSk^
unsSf
"T'r '^YT''
Novv the organic matters found in sewage are partly in
suspension and partly in solution and
sewage contains
itself the necessary living germs for the
destruction of both^^ese fSms
of oi^^c
m
^. s:nttt?a°:dt
s';£^?piyr::;tn^n:f:i\
f-rS^lyl
dfsso^ed and the organic compaunds;which^
tlnX'n t^^^^^^^^^^
In the final process of purification, these substances should
undergo oxidation
by the life
processes of nitrifying organisms, and an effluent should
be P™'^^"^^
producfd ^^i°^
whipff«f?
is free from putrescible
matter and contains only inorganic or mineral substances.
Of course it will be argued that there is oTRnt i1ar.™<»>
°^
micro-organisms which are lafgely derived from^The
exerftrof TiZf^^^^^
^ ^^^^^^^on is
certainly justifiable.
But in this connection it is to be noted
^° °® °°ted in
in the fl^'ffirst place that the biological
[r.dSKTv7'
•
t^
,
^^1
—
19
treatment of sewage is conducted under control
secondly, that the process always gradually secures
the destruction of the pabulum on which bacteria
feed, and hence leads to their death
thirdly, that
the balance ot evidence points to the probability that some, at all events,
of the pathogenic organisms
;
;
°"*,/" ^^^ struggle for existence in a nutritive medium containing a mixed bacterial
being weakened or destroyed by the enzymes of the saprophytic species
f
lourthly, that while it is true that bacteria
produce poisonous substances in their growth, it also is true
that their chemical poisons are toxic in proportion
to the dose, and, moreover, are highly unstable and
readily break down into their elementary and
innocuous constituents and, lastly, that in some cases
it may not be necessary to attempt
the complete purification of the sewage, the solution of the
suspended matters and partial destruction of the putrescible matter in solution being
all that i
IS
urgently called for, as, for example, where the eflBaent is of relatively small bulk
and is turned into a
stream the water of which is not used for domestic purposes
(as is the case in the lower Thames) or
else when the effluent is to be subsequently
treated by land irrigation.
It has been said that the processes of putrefaction
and nitrification are dependent
"^IT
f^
flora,
their
.
vitality
;
;
on the vital
and that the destruction of the organic matters in sewage can be efiected by the
hfe_ processes of living germs.
But it will be asked under what conditions the bacteriological
purifacation of sewage can be best carried out, and
whether there is any process known which in point
of economy, practicability and freedom from obvious danger compares with the methods
ordinarily in
use—namely, chemical treatment and land irrigation. These are questions which cannot be fully
_
activity of bacteria,
answered in the present state of our knowledge.
As regards the conditions essential to the successful biological treatment of sewage, it may be
«aid atthe outset that the presence in the sewage of any substance inimical to microbial life
must, if
possible, be guarded against.
Thus, it is well known that acidity inhibits the growth of bacteria, and
that slight alkalinity is a favourable condition.
Again, many of the waste products of manufacturing
processes are poisonous to bacteria, and in the preliminary treatment of the sewage with
certain
chemicals it may also be rendered unfit for bacterial life. But whether the sewage is best placed
primarily under aerobic or under anaerobic conditions is a question still open to discussion.
All,
however, are agreed that the final treatment must be aerobic.
As regards a comparison between the bacteriological treatment of sewage and its treatment by
chemical precipitation or by land irrigation, it may safely be said that even the most powerful
advocates of treatment with chemicals or treatment on land are dissatisfied with the general results that
have been obtained in the past, and it is a significant fact that the believers in the possibility of the
so-called self-purification of sewage are rapidly increasing in numbers.
Moreover, the records, which
are daily accumulating, of the practical trials of bacterial coke-beds in different parts of the country tend in
the direction of demonstrating the possibility of purifying sewage biologically, although the conditions
under which such treatment is best carried out are not yet fully known.
One point which has been rather lost sight of is that there is probably no bacterial process in
practical operation at the present time which is not eminently successful in that it places the sewage
in a most favourable state for its final purification by land irrigation, or by other methods.
The mere
solution of the great mass of the suspended matters by bacterial agencies, which is, perhaps, common
to all the different processes at present under trial, is a sufficient vindication of the enormous advantage
to be gained by the biological treatment of sewage.
And, even when an effluent is excessively foul, it
IS, perhaps, not wholly justifiable to condemn it in unmeasured terms, because such foulness may
possibly
be a step, although not of the most direct character, leading towards ultimate purification.
The scope of this report permits only of a brief allusion to some of the methods which are in
operation for dealing bacteriologically with raw sewage and partially purified effluents. No attempt,
however, will be made to describe their respective merits.
To the State Board of Health of Massachusetts belongs the honour of having carried out a
laborious series of experiments upon the purification of sewage at a time when the -whole subject was
enshrouded in mystery. The publication of the valuable results of this investigation at once aroused
the interest of sanitarians in this country.
In 1892 Mr. Scott-Moncrieff introduced his cultivation bacteria-bed. He founded his system on
the following well-recognised truths
(1) That bacteria under favourable conditions are capable of indefinite multiplication.
(2) Tliat there exist in sewage, bacteria which are capable of peptonizing solid organic
matter, or in other words, of preparing it, by a process comparable to that of digestion, for
its final
disintegration.
That in nature the purification of the refuse of the organic world
history of these or similar micro-organisms.
(3)
life
is effected
by the
In this system the crude sewage passes into the bottom of a bed filled with flint, coke and
and fitted with a false bottom. The liquid portion rises through this bed and the suspended
matters are held back at the bottom and undergo solution by the action of bacteria. In order to still
further improve the quality of the effluent, by oxidation and by the action of micro-organisms, the
effluent from this primary bed is afterwards passed down nitrifying channels.
Since 1892
Mr. Moncrieff has modified his original plans in a number of important respects.
gravel,
*Iii this connection reference may be made to certain interesting experiments carried out by Lawes and
Andrewes, and published in their joint report to the London Councy Council on Mioro-orgamsms in Sewage, 1894.
fit must be distinctly understood that I do not imply that such organisms as the typhoid bacdlus or the
cholera vibrio would necessarily lose their vitality, or even suffer a diminution in virulence under tbe conditions
prevailing in a biological filter. In the absence of actual experiments with the particular sewage in question, I am
not prepared to say more than that I believe that if these germs did gain access to the sewage they would suffer
a diminution in numbers primarily in the sewers, and secondarily in the coke-beds. A. 0. H.
—
—
20
While Mr. MoncriefF was engaged in demonstrating the possibility of disposing of sewage by
In particular, Messrs. Adeney and Parry
the agency of bacteria, other workers appeared in the field.
commenced a long series of investigations which has finally resulted in the formation of a company
This so-called oxygen system of sewage purificacalled The Oxygen Sewage Purification Company.
tion possesses three main features of interest, namely
I. The
use of crude manganese compounds for the purpose of clarification or
precipitation.
The principle of recovering the chemicals employed for the precipitation.
The use of nitrate of soda as a substitute for air (and therefore of the coke-bed)
supplying oxygen to the organisms in the manner required by them.
II.
III.
for
Mr. Cameron's system was brought forward in 1895 at Exeter. In this system the sewage is
passed into a closed tank with the object of producing liquefaction of the solid matters by
anaerobic bacteria.
The efiBuent from this anaerobic tank is next passed over an aerating weir and
thence to a series of coke-beds. The arrangement is such that each bed in turn is filled, remains
full for a period, is then emptied, and finally is allowed a rest before being again filled.
first
In 1897 Colonel Ducat introduced his "aerated bacterial self-acting coke-bed." This is a continuous
raw sewage falling on the surface of the open bed, the walls of which are made
of open drain pipes, and after passing through the body of the bed, which is composed of coarse
material at the top and fine at the bottom, finally escapes without having been exposed to any
filtration process, the
anaerobic treatment.
It is unnecessary to describe the system of sewage disposal advocated by Messrs. Dibdin
and Thudichum, because the Committee have from time to time received the records of their pro-
longed investigations.
Messrs. Waring and Lowcock, although working on different lines, attempt to bring about
the oxidation of the organic matter in their beds by pumping operations.
_
At Davyhulme, near Manchester, an interesting series of experiments have been carried out
under the direction of Sir Henry Eoscoe with coke, cinder, coal, and sand beds, the treatment
of the
effluent from the sewage precipitation tanks being
some cases continuous and in others
m
intermittent.
II.—GENERAL
RESULTS OBTAINED AT THE CROSSNESS OUTFALL
(May
Aug. 9th, 1898*).
9tli to
Under the above heading are given the chief results which have been obtained
from the
The records of the examination of the effluent from the
other beds are too small m number to allow of their being
included here, but reference is made to
them m the body of the report.
effluent of the experimental 4-foot coke-bed.
Total number of Bacteria per
JwnXT^ffl-.
ti:i:^:lS^:'
z
:
z
z
c.c.
6,140,000 (average of 10 experiments)
^^''-^^^ ''
^^''-'--^^>
4-foot
cX-bed effluent
.'::
...
:::
Percentage reduction
...
;;;
fj,
i^^^'""^^ °S^o^
-^52 (average
of 8 experiments)
;_';
;;;
Liquefying Bacteria per
4-foot cokl-bed effluent
c.c.
860,000 (average of 10 experiments)
^'^'^'^^H^y^^^ge o{ 8 ex^erimenU)
;;'.
;;;
Spores of B. Enteritidis per
'ScTeTed effluent
- ^™"
Z
Percentage reduction
„
cc
''
to'''' ^^'^^''^T'
*^-
m
Practically no reduction
(H experiments)
(10 experiments)
B. CoLi per c.c.
,
Crude sewage
c.c.
experiments)
Z.
Percentage reduction
'
'''''^A'
Number of Spores of Bacteria per
...
...
4-foot coke-bed effluent']
,„„
More i,
than 100,000 (10 experiments)
tu-
;;.
...
'
'"
Percentage reduction
-n
.•
,,
i Tactically
"
(8 experiments)
no reduction
Micro-organisms other than B. Enteritidis
and B. Ooli.
comparing
the
cultures
no
distinct
Crude sewage
C l^
difference could be" made out as
regards
4-footcoke-bedseffluent|f;/Pe-of^-^^^^^^^^^^^
be
worthyVfTciert Te
reduction of lique^ing
^S S
s^g^g^^gj^^
^S^^
bleriaj
Nevertheless, the general results
toL^lff f'^'''^'^' ^^^"^ ^---
obtainKnc^t£ 1 ^'ot
^^^
^^
-^
^;te?^lVel^rt£ '^^SUZt.,^^^- '''
—
21
It
might reasonably be inferred that in the coke-beds there was a relative increase in the liquefying
and a relative decrease in the number of spores, as a result of the biological treatment of the
bacteria,
sewage.
must be admitted that the above results are not satisfactory from the bacteriological point
when it is remembered that an effluent ought to be judged, not only by the
percentage amount of purification efiected, but also by the actual state it is in. Yet it is to be
considered that these results assume a different complexion when viewed side by side with the
It
of view, particularly
chemical data.
It has been shown in Division I. of this report that the percentage purification, as judged by the
dissolved oxidisable matter removed by the treatment, was on an average 51-3 per cent, and that the
suspended matter was entirely removed. It has been stated that the results thus obtained surpass
considerably those yielded by chemical treatment and appear to justify the claims put forward by the
supporters of the biological treatment of sewage, especially since, so far as can be seen, no nuisance
or danger arises as a result of the treatment.
In the body of the report a number of reasons are given, showing that it is unwise in the
present state of our knowledge to recklessly condemn an effluent on bacteriological ground alone,
without fuU^ knowledge of all the requirements of the case. In the attempt to treat sewage on
biological lines it is to be noted that the solution of the suspended matter and even the partial
destruction of putrescible matters by microbial agencies afford sufficient ground for justifying the
process, at all events as a preliminary measure.
Whether this preliminary treatment is to be
supplemented by further treatment, either by passage through other coke-beds, or by land irrigation or
by any other method, is a matter largely dependent on circumstances.
In^ the present case there are practical points which first of all demand consideration, and
although it may be most desirable to obtain an effluent chemically pure and bacteriologically above
suspicion of danger it is to be thought of that an effluent not altogether satisfactory in one or other, or
even in both, of these respects may yet fulfil all necessary requirements without passing out of the
range of practicability. In certain cases it may be imperative to obtain an effluent bacteriologically
sound, but it does not follow that a similar result is urgently called for in other cases, as, for example,
where an effluent is turned into a watercourse which is not used for drinking purposes, and which
already may contain practically all the bacteria that are found in sewage.
It might reasonably be argued that where an effluent is turned into a river already grossly
polluted and below the lowest level of "intake" for waterworks purposes, that the chemical state of
such effluent was (from the practical point of view, at all events) of possibly even greater importance
than the bacteriological. Some such state of things pertains in the case of London sewage and the
river Thames.
Here the initial consideration is to avoid fouling the river with putrescible matters to
such an extent as to constitute a grave public nuisance. From this point of view it is evident that an
effluent rich in putrescible matter is not permissible, but it is not as certain that an effluent rich in
bacteria is equally to be condemned on practical grounds.
In conclusion, it must not be considered from what has been said that any attempt is made to
minimise the importance of the bacteriological state of the effluent, or to disguise the true significance
of the results that have been obtained.
No doubt the question will eventually have to be faced
Are the advantages gained by chemical purification sufficiently great to outweigh the possible danger arising
from, the discharge of an effluent bacteriologically unsound into the river Thames ?
That the water itself of the Thames is in an unsatisfactory state from the bacteriological point
This table also shows that the effluents
of view may be deduced from the results shown in Table 2.
from the Barking and Crossness precipitation-tanks are no better, if indeed they are not worse, than
average samples of the raw sewage.
III.—
SUMMARY OF RESULTS* SHOWN
IN TABLE
The
I.
results are those derived from the bacteriological examination of Crossness crude sewage, and
of the effluents respectively from the 4-foot coke-bed, from the 6-foot coke-bed, and from the laboratory
coke-vessel (see pages 28 to 31).
1.— Total numbbe of bactbeia in
1898.
I
c.c.
(table
I.,
col. 2).
22
the total number of bacteria in the crude
It will be noted that in these comparative experiments
On three separate^ o^^^^^^^
^^^^^'^^ds
the
from
effluents
sewage usually exceeded those fo.nd in the
organisms than the crude sewage, namely,
however the effluent from the 4-foot coke-bed contained more
numbers the averages were over six
round
In
9.
and
expts.
3,
1,
expts 2 4, and 10, as compared with
the effluent from the 4-foot bed,
sewage,
crude
million, over four million, and over four million in the
reduction of bacteria was on an average
percentage
The
respectively.
bed
6-foot
and th^ effluent from the
6-foot coke-bed effineut^
27-7 in the case of the 4-foot bed effluent and 32-4 in the case of the
is fairly satisfactoj i* ^i^st be
Although the percentage reduction in the total number of bacteria
the
large, namely, 4,437,500
very
is
effluent
the
in
left
of microbes
m
conceded that the average number
6-foot coke-bed.
case of the 4-foot coke-bed, and 4,150,000 in the case of the
may have been satisfactory as regards
coke-beds
the
in
prevailing
conditions
It is probable that the
destruction of dissolved organic
partial
the
the solution of suspended organic matter and even as regards
In the
nitrification and total purification
active
to
of
leading
short
have
fallen
yet
and
matter,
satisfactory and
was
matter
orgamc
of
amount
the
in
Massachussets experiments, when the reduction
a marked diminution
nitrification was in active progress, the total number of bacteria suffered
the point of view of solution of
from
efficient
highly
were
coke-beds
the
that
In brief, it may be,
substances, and as a preoffensive
and
suspended organic matter and partial destruction of dissolved
ultimate punfacation of the
liminary measure tending in the direction of complete disintegration and
the organic matter if
crude sewage, but that they were unable to bring about the complete resolution of
of the contmued growth
this were the case, sufficient pabulum may have, been left in the effiuent to allow
;
of the sewage bacteria.
i.as
li- ii
t
the efliuent, multiplication of
Indeed, so long as organic matter in an assimilable form remains
these
bacteria,
of
products
existing micro-organisms may be expected to take place until the self injurious
their destruction
or a lack of nutritive material, or some other conditions adverse to microbial life lead to
or to a cessation of their powers of multiplication.
The presence of bacteria in enormous numbers in an effiuent does not perhaps necessarily unply that
the effluent is of a degraded character and highly putrescible it may only mean that the liquid has passed
through a previous stage of putrefaction, preparatory to its purification, in which case the danger so far as
nuisance is concerned may be regarded as potential and not actual. It is as certain on the one hand that
the addition of an infinite number of bacteria to a pure liquid, would be followed by a decrease in their
number owing to the lack of nutritive material, as it is on the other hand that the removal of all the
bacteria from a foul liquid would be a useless precaution, since Nature has always at her command a host
and multiplication
m
i.
.
;
of micro-organisms ready to attack the effete matter of the vegetable and animal kingdom, and effect directly
or indirectly its purification.
Nevertheless, a liquid swarming with living bacteria is usually a liquid still undergoing putrefaction,
and is likely also to contain germs of a harmful nature.
It may be worthy of note that out of the sixteen samples of Crossness and the nine samples of
Barking crude sewage examined during a period extending from February to August, 1898, on no occasion
was it found that the total number of bacteria was other than very large. It is evident then that the
various substances, such as waste matters from manufactories, which are discharged in large quantities
into the London sewers, and yet may be regarded as foreign to sewage, do not inhibit the growth of the
It is important to note this fact, because if the bacterial
sewage bacteria to any marked extent.
purification of sewage should be adopted on a large scale, disastrous results might arise if the sewage
was at one time rich in microbial life and at another almost sterile owing to the presence of foreign
substances inimical to bacteria.
In conclusion, it must be borne in mind that the coke-beds at Crossness were purposely constructed
so as not to lead to mere mechanical filtration of the suspended matter, much less of the bacteria in the
crude sewage.
In estimating the total number* of bacteria gelatine plates were used. From O'l to I'O c.c. of crude sewage
or effluent diluted with 10,000 times its volume of sterile water (i.e., O'OOOOl to O'OOOl c.c. of the origmal fluid) was
added to 10 c.c. of sterile gelatine contained in a test tube. A.iter the gelatine had been melted, it was poured
into a Petri's capsule, and after solidification had taken place the plate was inverted, incubated at '20 0.,
and the colonies subsequently counted at as late a date as the liquefaction of the gelatine and the crowding
of the colonies allowed of.
23
In these comparative experiments the number of spores of bacteria in the crude sewage usually
exceeded those found in the effluents from the coke-beds, but on three separate occasions the number in the
effluent from the 4-foot coke-bed was greater than in the crude sewage
namely, experiments 6, IC, and 16
as compared with experiments 5, 9, and 15.
The averages were 407, 252, and 390 in the crude sewage, in
the effluent from the 4-foot bed and in the effluent from the 6-foot bed respectively. The percentage
reduction of spores of bacteria was on an average 38 in the case of the 4-foot coke-bed effluent, and 4 in the case
In the latter case, however, the average is based on two experiments only.
of the 6-foot coke-bed effluent.
In the case of the 4-ft. coke-bed effluent, the percentage reduction in the number of spores was slightly
greater than the percentage reduction of the total number of bacteria.
Yet the number of spores
remaining in the effluent, namely, 252 on an average, was large. Spores of bacteria are peculiarly
resistant to unfavourable physical conditions fortunately, however, the majority, at all events, of the spores
of aerobic micro-organisms found in sewage belong to species which are believed to be harmless.
Taking the figures 6,140,000, 4,437,500 and 4,150,000 as representing the total number of bacteria,
and 407, 252 and 390 as representing the number of spores in one cubic centimeter of an average sample of
Crossness crude sewage, of effluent from 4-ft. bed, and of effluent from 6-ft. bed respectively, the ratios of
—
;
spores to bacteria are as 1 to 15,086, 1 to 17,609, and 1 to 10,641 respectively. It appears, then, that
there was a slight diminution in the number of spores, relative to the total number of bacteria, as a result
of the treatment of the sewage in the 4-ft. coke-bed
The opposite is the case as regards the 6-ft. bed,
but here only two sam.ples of effluent were examined.
Comparing diagrams 3 and 4 as regards crude sewage, no direct parallelism appears to exist between
the total number of germs and the number of spores, although to some extent a rise or fall in the total
number of bacteria was associated with a rise or fall in the number of spores. When, however, a similar
comparison is made in the case of the 4-ft. coke-bed effluent, it will be noted that a parallelism does exist
between the total number and the number of spores of bacteria.
—
In estimating the number of spores of bacteria, * the following plan was adopted
To 10 c.c. of sterile
was added 1 c.c. of diluted sewage or effluent (1:10), and the mixture heated to 80° C. for
ten minutes and then poured into a Petri's capsule. After the gelatine had become quite solid the plate was
:
gelatine in a test tube
inverted and incubated at 20° C.
—
f
24
Further, it has been said as regards the
the nnmljer of liquefyincr germs and the number of spores.
total number of bacteria and the number
the
between
exists
crude sewage, that no distinct parallelism
number of liquefying microbes is not well
of spores and the relation between the total number and the
relation between
marked. Neither, on comparing diagrams 4 and 5, does there appear to be any distinct
the crude sewage.
the number of spores and the number of liquefying bacteria in
and 7, which show
In order to observe these facts more closely reference may be made to diagrams 6
sewage and effluent from the 4-ft.
the percentage deviation from the mean in the different samples of crude
and 6-ft. beds as regards total number of germs, number of spores, and number of liquefying bacteria.
definite relation between the
Firstly, as regards the crude sewage, diagram 6 shows that there is no
To some extent, however, there is a relation between
total number of bacteria and the number of spores.
the total number of bacteria and the liquefying germs.
,.
Secondly, as regards the effluents from the coke-beds, diagram 7 shows that there is a distinct relation
between the to'bal number—the number of spores and the number of liquefying bacteria. Although,
however, a rise or fall above or below the mean in the total uumber was nearly always coincident with a
liquefying bacteria, the
rise or fall above or below the mean in the number of spores and the number of
parallelism.
no
showed
case
each
percentage deviation in
Lastly, comparing diagrams 6 and 7, no relationship can be made out between the total number,
the number of spores and the number of liquefying bacteria in the crude sewage, as compared with the
.
.
from the 4-ft. bed.
In the first report it was stated (page 4, c. 3) that " It must not be concluded, however, that
because a micro-organism liquefies gelatine, it will also liquefy all the various and complex kinds of organic
matter existing in sewage. But it is safe to assert that a liquid rich in bacteria of varied species, many of
which are capable of producing liquefaction of gelatine, is likely also to be rich in ability to dissolve solid
or suspended oiganic matter."
As illustrating the complex behaviour of different germs to different albuminoids, and also of the
same organism to different albuminoids, it may be noted that some bacteria liquefy gelatine, others do not;
some coagulate the casein in milk and then dissolve it, others coagulate it and do not further peptonize it,
others peptonize it directly again some organisms which liquefy gelatine coagulate milk, others coagulate
milk but do not liquefy gelatine again an organism which liquefies gelatine may or may not produce
liquefaction of fibrin, of blood serum or of egg albumen, and an organism capable of peptonizing fibrin
—
effluent
;
;
may
fail to liquefy gelatine.
In a description of some of the bacteria found in the crude sewage and in the effluents which
accompanies this report, will be found details relating to their behaviour when grown in milk, gelatine,
blood serum, etc. For example, "sewage proteus" quickly liquefies gelatine and blood serum, and apparently
peptonizes milk without first coagulating it. B. coli produces no liquefaction of gelatine or blood serum,
but clots milk in 24 hours at 37°C. B. mesentericus I. rapidly liquefies gelatine and blood serum, and
apparently peptonizes milk without previous coagulation. B. mesentericus E. liquefies gelatine very slowly,
but liquefies blood serum fairly rapidly at 37°0., and produces a weak clot in milk which appears to he
subsequently dissolved.
In estimating the number of liquifying organisms the following plan* was adopted— The contents of a test
tube containing 10 o.c. of sterile nutrient gelatine were melted and poured into a sterile Petri's capsule. After
the gelatine had become quite solid the surface of the medium was inoculated with O'l c.o. of diluted sewage or
effluent (1: 10,000). The diluted sewage or effluent (representing O'OOOOl c.o.) was then spread over the entire
surface of the gelatine with a platinum instrument. The plate was next inverted and incubated at 20° C. in this
position until the colonies were sufficiently advanced in their growth for observation. Although this method is
the best one available, it must be remembered that some bacteria liquefy the gelatine so very slowly that they
might readily escape being counted as liquefying germs under the above conditions of experiment. This matters
the less since bacteriologists are in the habit of classing some, at all events, of these bacteria as non-liqueflers.
4.
Spscies of Micko-oeganisms peesent in Crossitess
Ceude Sewage and
the Epplubnts feom the
in
Coke-Beds.
(a)
Bacillus enteritidis sporogenes (Klein).
In the First Report the result
of a considerable number of experiments were given, showing that the
spores of B. enteritidis may be present in London crude sewage;]: in numbers varying from 10 to 1,000 per
Further, it was pointed out that Dr. Klein's researches tend to show that this organism is causally
c.c.
That its cultures are extremely virulent may be seen by referring to col. 5 expt.
related to diarrhoea.
6,
Table I., and col. 5, expts. 4 and 5, Table II., and also expts. 1 and 2, col. 5, Table I., of First Report.' Again!
it was stated that this pathogenic anaerobe is most important from the point of view
of the bacterioscopic
analysis of water, and lastly the hope was held out that future work would show what was
the fate of
B. enteritidis during the passage of the sewage through the biological coke-beds at the Outfall
Works.
The following is a summary of the results shown in col. 5 of Table I.
Crossness crude
sewage.
Date.
from
Effluent
4-foot Effluent
coke-bed.
from
6-foot
coke-bed.
Effluent from 6-foot
coke-bed again
passed through the
laboratory vessel
at Crossness.
1898.
11th
May
+
—
0-1
+
c.c.
0-01,
O'OOOl
O'OOl and
c.o.
sewage
(expt. 1)
18th
May
-f 0-1,
0"001
0-01
c.c.
and
sewage
0-01
c.c.
— O'OOI and 0-0001
effluent
(expt. 2)
c.c.
+ 01
and 0-01
— 0-001
c.c.
c.o.
effluent
(expt. 3)
(expt. 4)
* See B 5, page 2. First Report.
t See figure 2, Plate I., of this report, and Nos. 3 and 14 (Plate I
J See page 6, and also Table I., of First Report.
—
)
''
First Report.
Rpnnrt
26
Effluent
Crossness crude
sewage.
Date.
Effluent
from 4-foot Effluent from 6-foot
coke-bed.
coke-bed.
from 6-foot
coke-bed again
passed through the
laboratory vessel
at Crossness.
1898.
+
—
O'OOl
26t]iMay
and 001 c.c.
c.c. sewage
0-1
+
(expt. 5)
9th.
+
June
c.c.
+
sewage (expt. 7)
+
15th June
0-1
c.c.
+
sewage
c.c.
and 0-01
0-1
c.c.
+
0-1
c.c.
effluent
(expt. 10)
0-01
0-1,
0-001
and
effluent
effluent (expt. 8)
(expt. 9)
22nd June
c.c.
(expt. 6)
and 0-01
0-1
0-01
0-1,
0-001
and
sewage
(expt. 11)
+
0-1 c.c.
— 0-01
and 0-001
c.c. effluent
(expt.
12)
6th July
-1-
0-1 c.c.
+
— 0-01
c.c.
and 0-001
sewage (expt.
0-001
c.c. effluent
(expt.
13)
14)
+
—
0-001
20th July
0-1
and 0-01
c.c.
c.c.
(expt. 15)
27th July
0-1 c.c.
-0-01 and
+
0-1
and 0-01
— 0-001
c.c.
c.c.
+
effluent
0-1
and 0-01
c.c.
effluent (expt. 17)
0-1 and 0-01 c.c.
sewage (expt. 19)
+ 0-1 and 001 c.c.
—0-001 c.c. effluent
+
0-1
and 0-01
c.c.
effluent (expt. 20)
(expt. 21)
9th August
..
..
+
0-1 and 001 c.c.
sewage (expt. 23)
—+ O'Ol
0-1
+
sewage
0-1
and 0-01
c.c.
+
0-1
and 001
c.c.
0-1
c.c.
effluent
(expt. 25)
-I-
signifies the presence,
The above
c.c.
+ 10 and 0-1
— 001
c.c.
c.c.
effluent
+
effluent (expt. 29)
0-1
+
0-1
effluent
c.c.
(expt. 26)
and 0-01
c.c.
effluent (expt. 28)
(expt. 27)
(The sign
and 0-01
(expt. 22)
effluent (expt. 24)
+
c.c.
c.c.
0-1
effluent (expt. 18)
(expt. 16)
-1-
4th August
+
+
0-1 C.C.
— 001
effluent
c.c.
(expt. 30)
—
the absence of the spores of B.
and the sign
shown in graphic form in Diagram 8.
enteritidis sporogenes.)
results are
As
regards the crude sewage and the effluents from the 4-foot bed, it is to be noted that the number
In the case of both the 6-foot coke-bed
of B. enteritidis varied from 10 to 1,000 per c.c.
effluent and the effluent from the laboratory vessel the numbers were found to vary from 10 to 100
per c.c, but there may have been more spores present, as the minimum amount of the liquid added to
the milk-tubes was 0-01 c.c.
In comparing the various results, it is noteworthy that although the number of spores of
B. enteritidis in the crude sewage exceeded those found in the 4-foot coke-bed effluent on two separate
occasions, the number on three other occasions was greatest in the 4-foot coke-bed effluent.
In the
remaining five comparative experiments the numbers were approximately equal. As regards the crude
sewage and the 6-foot coke-bed effluent, the numbers were equal on July 6th, 20th, and 27th. On August
4th the number was greater in the crude sewage, and on August 9th greatest in the 6-foot coke-bed effluent.
The laboratory coke-bed effluent and the crude sewage gave an equal number on July 20th and August
9th, but on July 27th and August 4th the crude sewage contained a larger number of spores.
Judging these results as a whole, it cannot be said that the biological processes at work in the
coke-beds produced any significant alteration in the number of spores of this pathogenic anaerobe. This
is the less to be regretted since the effluents are discharged into a large tidal river* below locks, the water
StUl, it is to be thought of that the cultures of B. enteritidis
of which is not used for drinking purposes.
sporogenes are extremely virulent, and that Dr. Klein's results seem to prove that this anaerobe may be
causally related to acute diarrhoea. At all events, it is highly important from a practical as well as from
a scientific point of view to continue these observations on the number of spores of B. enteritidis in crude
sewage and in the effluents from the coke-beds.
of spores
—
for detecting the presence of the spores of this bacillus is as followsf Dilute 1 part of crude
may be, with 99 parts of sterile water ; of this dilution add 1-0, 0-1, and 0-01 c.c.
Heat the tubes to 80° 0. for ten minutes, and cultivate anaerobically by
Buchner's method at a temperature of 37° 0. In certain cases it is necessary to add as much as 0-1 c.c. of the crude
sewage or effluent directly to the milk tube. When B. enteritidis is present the casein is precipitated, the whey
remains nearly colourless, and there is a marked development of gas.J These changes in the milk commonly take
guinea-pig inoculated suboutaneously with 1 c.c. of the whey, usually dies in less
place in less than 24 hours.
than 24 hours, and presents, on post-mortem examination, appearances which are typical of enteritidis (extensive
The method
effluent, as the case
severally to three sterile milk tubes.
sewage or of
A
gangrene, sanguineous exudation full of
bacilli, etc.).
(a) Bacillus Coli
Oommwnis.^
In the First Report the results of a considerable number of experiments were given, showing that
B. coli was presen t in the crude sewage in numbers exceeding 100,000 per c.c, and it was stated Lhat in future
* That Thames water
itself contains
the spores of B. enteritidis sporogenes
Table II
t See page 3 of First Eeport.
§ In the First Eeport a number of illustrations
characters of this micro-organism,
may
be seen by referring to
First Report.
J See No. 14, plate I. of
were shown, illustrating the morphological and biological
[
4
]
—
26
the ^o^^f-^^^;.
^,^^^5^° P°^.^^^^^
micro-organism would be searched for in the effluents from
a denvation of the liquid from
showing
as
considered
be
might
effluent
an
such
out that its presence in
and, perhaps dangerous bacteria which had
sewage, and hence as indicating the possible°presence of other
but did not signify that the liquid was
coke-beds,
the
in
work
at
processes
biological
survived the
character.
putrescible
^.,. ct
necessarily of a degraded, offensive, and
^
a- x.
characteristic of fsecal discharges,
Although it has been long known that B. coli is an organism
of
crude
sewage
samples
of these germs
no accurate record exists of the determiation of the number
when
it is
understood
be
will
record
a
The importance of establishing such
periodically examined.
of potable waters. If, their,
pollution
of
source
dangerous
most
chief
and
the
is
remembered that sewage
pure waters do not contain
we know the number of germs of B. coli in crude sewage, and if we find that
position to Jtidge of the importance of
this organism, or contain it only in few numbers, we are in a
nature is capable
It is true that B. coli is widely distributed
its presence in a given sample of water.
other excreta
present
under certain circumstances of multiplying outside the animal body, and is
the value of the mere
lessen
extent
some
to
doubt
facts
no
These
human
beings.
besides those of
the relative abundance of
demonstration of B. coli in water, but sink into comparative insignificance when
crude sewage
present
It has already been shown that B. cdli may be
this micro-organism is considered.
any
likelihood of
from
free
water
in
a
that
affirmed
be
safely
in numbers exceeding 100,000 per c.c, and it may
minimal quantity oi sewage
pollution B. coli is not discoverable, or is present in very few numbers.
water very greatly and it
gaining access to a large bulk of water would increase the number of B. coli
in any way comparable.
result
a
producing
is difficutt to conceive of any Substance other than sewage
nature producing this result.
It is particularly difficult to conceive of a substance of an unobjectionable
No doubt in certain cases the presence of B. coli in water may arise from indirect pollution with sewage,
gains access to a supply. Yet,
as, for example, where the surface drainage from manured or polluted soil
even here, the danger so far as potability is concerned could hardly be considered remote. It is not the
presence of B. coli in water, but its relative abundance, which entitles the bacteriologist to assume pollution
direct or indirect with sewage, or to avoid all controvarsial points with a substance of an objectionable
Certainly, in view of the fact that this organism is not discoverable in waters free from any
natui-e.
likelihood of sewage pollution, and is found to be present in great numbers in waters which are known to
be fsecally contaminated, and is present in crude sewage in numbers vastly exceeding any other substance
at all likely to contaminate a water supply; it seems justifiable to conclude that its presence in
considerable numbers in a given sample of water indicates pollution of an objectionable kind, and,
in all probability, points to contamination with sewage.
Enough, at all events, has been made out to show the importance of a large number of observations
having for their object the collection of data dealing not only with the presence, but with the relative
abundance of B. coli in sewage. Of the importance of experiments having for their aim the estimation of
the number of B. coli in the effluents from the biological coke-beds as compared with the number in the crude
sewage applied to the coke-beds there cannot be a doubt. Ajid here it may be stated that much that has been
said in the above sentences applies with perhaps even greater force to B. enleritidis sporogenes. B coli.
is an example of an aerobic, and B. enteritidis sporogenes of an anaerobic micro-organism, the former
being peculiarly abundant in crude sewage, and the latter less abundant, but perhaps more characteristic. The
estimation of their numbers in the effluents as compared with the crude sewage needs no comment to show
work
J*
this
m
m
m
m
A
m
its
importance.
The following
Date.
is
a summary of the results, as regards B.
Crossness crude sewage.
coli
shown
;
in col. 5, Table
Effluent from 4-foot
coke-bed.
I.
Effluent from 6-foot
coke-bed.
1898.
11th
May
No
colonies of B.
coll in
phenol gelatine plate
containing O'OOOOl c.c.
per
200,000 B. coli
c.c.
(expt. 2)
sewage (expt. 1)
18th
May
Gas forming
300,000 per
25th
May
coli bacteria,
c.c.
(expt. 3)
Gas forming coli, 1,500,000
per
9th June
(expt. 5)
c.c.
Gas forming
per
15th June
c.c.
22nd June
c.c.
per
c.c.
300,000
coli,
300,000
coli,
300,000 per
at least
(expt.
15)
27th July
B.
coli,
c.c.
c.c.
coli,
100,000
coli,
600,000
(expt. 10)
coli,
300,000
(expt. 12)
Gas forming
300,000
700,000
(expt. 8)
Gas forming
per
c.c.
c.c.
coli,
(expt. 6)
Gas forming
per
coli,
c.c.
Gas forming
per
(expt. 11)
Gas forming
20th July
200,000
(expt. 9)
Gas forming
Gas forming
per
(expt. 7)
Gas forming
per
coli,
200,000 gas forming coli
per c.c. (expt. 4)
coli,
per
at least
c.c.
(expt.
16)
500,000 per
c.c.
B.
(expt. 19)
4th August
,
B.
coli,
200,000 per
c.c.
(expt. 23)
9th August
.
B.
coli,
1,000,000 per
coli,
600,000 per
c.c.
(expt. 20)
B.
coli,
300,000 per
c.c.
(expt. 24)
c.c.
(expt. 27)
These results are shown in graphic form
in Diagram
B.
coli,
200,000 per
(expt. 28)
9.
c.c.
f
27
be noted ttat on three separate occasions the nnmher of B. coli in the crude sewage exceeded
in the 4-foot coke-bed effluent, and on three other occasions the conditions were reversed
In the two comparative experiments remaining the numbers were approximately equal.
in this respect.
As regards the 6-foot coke-bed effluent, on one occasion the number in the effluent was somewhat
greater than the number in the crude sewage on the other occasion the crude sewage contained a much
larger number.
JNidging the experiments as a whole it cannot be said that the biological processes at work in the
coke-beds effected any marked alteration in the number of B. coli. It must not, however, bo too lightly
considered that this implies that the effluent was necessarily of an offensive and putresoible character.
B. coli and other putrefactive bacteria no doubt work in the direction of purifying the sewage, and their
presence in the effluent might only mean that the purification had not been carried sufficiently far to allow
of a decrease in their numbers, owing to the incomplete reduction of the organic matters on which they
feed and which allow of their continued multiplication. Yet, when this has been said, it must also be
admitted that the passage of an aerobic non-spore-forming bacillus typical of excremental matters through
the coke-beds, in practically unaltered numbers, is not a desirable state of things. It is trae that B. coli is
not pathogenic in the ordinary meaning of the word, but its presence in the effluents implies the possible
presence of other bacteria— it might be of dangerous sort. Still, on the whole it may be said that the
balance of evidence points to pathogenic aerobic bacteria being liable to be crowded out in the struggle for
existence in a nutrient fluid containing a mixed bacterial flora and one rich in saprophytic micro-organisms.*
Lastly, it must be remembered that the effluent is discharged into a large tidal river at a point far below
the lowest " intake " of water for waterworks purposes. Moreover, the Thames before it reaches the
Outfalls of the Sewage Works is already grossly polluted with excremental matters.
It is to
the
number found
;
—
In searching for B. coli in the crude sewage and in the effluents the follovring plan was adopted^ 10 c.c.
of sterile gelatine, contained in a test tube, were melted, 01 c.c. of five per cent, phenol added, and then the
gelatine was poured into a Petri's capsule and allowed to become quite solid. O'l c.c. of diluted sewage, or else
of effluent (1 10,000) was next added and spread over the entire surface of the gelatine with a platinum spreader.
Colonies which were typical of B. coli in their microscopical appearance and in the manner of their growth were
then subcultured in broth (for diffuse cloudiness and indol reaction), in litmus milk (for acidity and clotting), and
in gelatine shake culture (for gas formation). It was not, however, found possible in all of the experiments to
apply all of these tests, although, in the majority of oases the gas test in gelatine was applied.
:
'(c)
Othee Species
of Bacteeia.
Besides searching for JB. enteritidis and B. coli the attempt was also made to estimate the number
Notes under
as well as the character of other microbes present in the crude sewage and in the effluents.
this heading will be found in col. 5 of Table I. Thus the organism called " sewage proteus," of which a
description appears in this report, was found to be present in great numbers (usually over 100,000 per c.c.)
Other microbes found in the crude sewage and effluents
in both the crude sewage and in the effluents.
were B. fluorescens liquefaciens and its varieties, B. fluorescens non-liquefaciens, B. mesentericus (a description
of two varieties of this bacillus is given in this report), B. suhlitis, B. mycoides, B. pyocyaneus.^
streptococci, staphylococci, &c.
In experiments 3 and 5 (col. 5, Table I.) the number of bacteria in the crude sewage capable of
growing at 37° C. in agar was estimated. The numbers were 1,260,000 and 1,171,000 per c.c. as compared
with 3,670,000 and 6,400,000 obtained by gelatine plate cultivation at 20° C. A similar experiment
(experiment 4) with the effluent from the 4-foot filter bed gave 1,630,000 (agar, at 37° 0.) as compared with
4,100,000 (gelatine, at 20° C.) bacteria per c.c.
In experiments 9 and 10 (col. 5, Table I.) it was sought to discover the smallest amount of crud'
sewage and of effluent which in broth cultures at 20° 0. would produce growth, indol reaction and
offensive smell. No growth occurred in either case, when as little as 0,0000001 c.c. was inoculated into
the broth but when 0-000001 c.c. was used, growth occurred both in the case of the crude sewage and of
the effluent, and the cultures had an offensive smell and gave indol reaction.
In concluding this section of the report it may be said that when making comparative cultivations
liquids the trained observer can often detect differences in the characters of the colonies
different
from
developing in the nutrient media which are none the less real because they cannot always be put into
Speaking from this point of view, it must be admitted that little or no real distinction
definite language.
made from the effluents,
could be made out between the cultures made from the crude sewage and those
reduction in the total number of
other than those points of difference already considered namely, a slight
number of liquefying aerobic bacteria
aerobic bacteria, the number of spores of aerobic bacteria, and the
found in the effluent, as compared with the crude sewage.
;
—
* See however, notes under heading— The biological treatment of sewage.
J See pages 3 and 6 of First Keport.
t See results shown in Table II.
proved to be extremely
cultivation of B. pyocyaneus isolated from a sample of Crossness crude sewage
S
Thus 1 c c. of a 24 hours' broth culture (at 37° 0.) injected subcutaneously into a gumea-pig, killed the
virulent
in pure culture from the heart's blood, spleen, &c.
animal in less than 24 hours, and the organism was recovered
A
28
IV.
-TABLES AND DIAGRAMS DEALING WITH THE RESULTS OF THE
BACTERIOLOGICAL EXAMINATION OF THE CRUDE SEWAGE,
OF THE EFFLUENTS FROM THE COKE -BEDS, OF THE EFFLUENTS
FROM THE CHEMICAL PRECIPITATION WORKS, AND OF SAMPLES
OF THAMES WATER.
showing the results of the bacteriological examination of Crossness crude sewage, the
and the effluent from
effluent from the 4-foot coke-bed, the effluent from the 6-foot coke-bed,
laboratory at Crossness).
the laboratory vessel (effluent from 6-foot coke-bed again treated in the
Table I
Number
Number
Total
Expt.
Description of
the eamples.
number
of
bacteria in
1 o.c. of
the sample.
of
spores of
bacteria in
1 c.c. of the
sample.
of
bacteria
causing
liquefaction
Bemarks.
of the
gelatine in
1 c.c. of
the sample.
3,930,000
Crossness
crude sewage. (average of
May
11, 1898.
two
expts.
with 0-0001
460
(one expt.
with O'l c.c.
sewage).
and O'OOOOl
c.c.
4.
3.
2.
1.
sewage).
Spores of B. enteritidis present in milk culture
400,000
containing 0-1 c.c. sewage; absent in cultures
(one expt.
with 0-00001 containing 0-01, 0-001, and 0-0001 c.c. sewage.
In phenol gelatine plate containing 0-00001 o.c.
c.c. sewage).
sewage, no colonies of B. ooli.
B. fluoreseena liquefaciens, 200,000 in 1 c.c.
" Sewage proteus," 200,000 in 1 c.c.
In cultivation for spores (0-1 c.c. sewage, col. 3)
10 colonies of B. mesentericus and several of
jB. subtilis.
At least 6 different
0-00001 CO. sewage.
Crossness
effluent
4-foot
bed,
4,800,000
from (average of
coke two eipts.
May
11,
with 0-0001
260
(one expt.
with
O'l c.c.
effluent).
of
bacteria in
Spores of B. enteritidis present in O'Ol c.c.j
absent in 0-001 and 00001 c.c. effluent.
In phenol gelatine plate containing 0-00001 c.c.
effluent) effluent, at least two colonies of B. coli.
No fluorescent colonies noted in any of the
cultures on the fifth day.
1,300,000
(one expt.
with 0-00001
c.c.
and 0-00001
1898.
species
c.c. eflBuent)
" Sewage proteus," 400,000 in 1 c.c.
In cultivation for spores (O'l c.c. effluent,
col. 3)
20 colonies of JB. mesentericus.
At least four different species of bacteria in
0-00001 c.c. effluent.
300
100,000
Spores of B. enteritidis present in 0-1, 0-01, and
0-001 o.c. sewage.
one expt.
(one expt.
two expts. with 0-1 c.c. with 0-00001 An agar plate culture incubated at 37° C.
with 0-0001
sewage).
c.c. sewage). yielded only 1,260,000 bacteria per c.c. sewage as
and 0-00001
compared with 3,670,000 by gelatine plate culture
o.c. sewage).
at 20° 0.
Gas-forming coli bacteria, 300,000 in 1 c.c.
sewage.
B. fluorescens liquefaciens, 100,000 in 1 c.o.
3,670,000
Crossness
crude sewage. (average of
May
18, 1898,
"
4,100,000
Crossness
effluent from (average of
coke- two expts.
4-foot
bed.
May
18,
with 0-0001
140
(one expt.
with
0-1 c.o.
effluent).
and 0-00001
1898.
0.0.
effluent)
1 c.c. sewage.
Spores of B. enteritidis present in O'l and 0-01
absent in 0-001 c.c. effluent.
An agar plate culture incubated at 37° C.
effluent) yielded only 1,630,000 bacteria per c.c. effluent as
compared with 4,100,000 by gelatine plate culture
at 20° 0.
Gas-forming coli, at least 200,000 per c.c. effluent.
700,000
(one expt,
with 0-00001
c.c.
Sewage proteus," 100,000 in
c.c.
;
B. fluorescens liquefaciens 10,000, and B. fluorescens non-Uquefaciens 10,000 in 1 o.c. effluent.
" Sewage proteus," 100,000 in 1 c.c. effluent.
370
6,400,000
(one expt.
(one expt.
25, 1898. with 0-00001 with 0-1 c.c,
c.c. sewage).
sewage).
Crossness
crude sewage.
May
900,000
The liquefaction of the gelatine with O'OOOl c.c.
(one expt.
sewage (col. 2) was so great that this culture
with 0-00001 could not be counted; the cultivation, however,
c.o. sewage). containing 0-00001 c.c.
sewage was counted.
Spores of B. enteritidis in
absent in 0-001 c.c. sewage.
01 and
0-01 c.c;
Gas-forming coli, 1,500,000 in 1 c.c. sewage (see
photo 1, Plate I., First Report).
An agar plate culture incubated at 37° C.
yielded 1,171,000 colonies per o.c sewage.
"
Sewage proteus," at least 100,000per o.c. sewage.
No
fluorescent colonies noted in culture contain-
ing 0-00001
c.c.
sewage.
In cultivation for spores
(0-1 c.c.
several colonies of B. mesentericus
sewage,
col. 8)
29
Expt.
30
Number
bacteria, in
1 c.c. of
of
spores of
bacteria in
1 c.c. of the
Expt.
the sample.
sample.
number
Description of
the samples.
of
of
bacteria
Number
Total
causing
liquefaction
Hcmarks.
of the
gelatine in
1 c.c. of
the sample.
6.
2.
13
14
Crossness
crude sewage,
July 6, 1898.
This sam pie was exam ined for B.
nteritidis onl
Crossness
15
0"1
Spores of B. enteritidis present in
absent in O'Ol and O'OOl c.c. sewage.
do.
effluent from
6-foot
coke-
bed, July
1898.
Spores of B. enteritidis present in
absent O'Ol and O'OOl c.c. sewage.
O'l
c.c.
c.c;
6,
Crossness
12,800,000
400
1,700,000
The liquefaction of the gelatine with O'OOOl c.c.
crude sewage,
(one expt.
(one expt.
(one expt.
sewage (col. 2) was so rapid that the colonies
July 20, 1898. with 0-00001 with O'l c.c. with O'OOOOl could not be counted. The cultivation containing
c.c. sewage;.
sewage).
c.c. sewage). O'OOOOl c.c. sewage was, however, counted.
Spores of B. enteritidis present in O'l and
O'Ol c.c. absent in O'OOl c.c. sewage.
Gas-forming coli, at least 300,000 per c.c. of
sewage.
B. fluorescens liquefaciens, 100,000 in 1 c.c.
sewage.
" Sewage proteus,'' several colonies in O'OOOOl
c.c.
sewage.
Spores of S. mesenterictts and JB. suibtilis present
in O'l c.c. sewage.
;
16
Crossness
effluent from
4-foot
coke-
bed, July 20,
1898.
9,200,000
(one expt.
with O'OOOOl
c.c. effluent).
430
1,000,000
(one expt.
with O'OOOOl
with
The
liquefaction of the gelatine with O'OOOl c.c.
was so rapid that the colonies
could not be counted the cultivation, however,
c.c. effluent). containing O'OOOOl c.c. sewage was counted.
Spores of B. enteritidis present in O'l and O'Ol;
absent in O'OOl c.c. effluent.
Gas-forming coli at least 300,000 per c.c. of
(one expt.
O'l c.c.
effluent).
effluent (col. 2)
;
effluent.
B. fluorescens
liquefaciens,
100,000 in
]
c.c.
effluent.
Spores of B. meseniericus and B, suUilis present
in O'l
17
This sam pie was exam ined for B.
Crossness
effluent from
6-foot
coke-
e nteritidis
onl
c.c. effluent.
Spores of B. enteritidis
O'Ol c.c. effluent.
present
in O'l and
Spores of B. enteritidis
present
in O'l and
bed, July 20,
1898.
18
Crossness
effluent
do.
from
001
laborat ory
c.c. effluent.
vessel (6-foot
coke
-
bed
effluent again
treated
in
laboratory),
July
19
20, 1898.
Crossness
crude sewage,
July
27, 1898.
7,200,000
(one expt.
with O'OOOOl
c.c. sewage).
870
900,000
(one expt.
(one Gxpt.
with
O'l c.c.
sewage).
with
c.c.
00001
sewage).
Spore of B. enteritidis in O'l and O'Ol c.c. sewage.
B. coli, 600,000 in 1 c.c. sewage.
Several colonies of " sewage proteus" in O'OOOOl c.c.
sewage.
B. fiuorescens liquefaciens 100,000 per c.c.
sewage.
One colony of B. mycoides in plate culture
spores (0-1 c.c. sewage, col. 3).
20
Crossness
6,600,000
(one expt.
with O'OOOOl
bed, July 27, CO. effluent).
1898.
effluent from
6-foot
coke-
21
Crossness
effluent from
4-foot
coke-
bed, July 27,
1898.
480 (one
expt. with
300,000 (one
O'l c.c.
expt. with
O'OOOOl c.c.
effluent).
effluent.
This sam pie -ivas exam ined for
£.
e nteritidis
onl y.
Spores of B. tnteritidis in
O'l
and
0-01
for
c.c.
effluent.
B.
coli,
Spores
O'Ol c.c.
;
600,000 in 1
c.o. effluent.
of B. enteritidis present in
absent in O'OOl c.c. effluent.
O'l
and
•
31
32
from the Crossness
Table 2.— Showing the results of the bacteriological examination of the effluents
Thames.
River
and Barking Outfall Works and the water of the
Expt.
33
Number
Total
Description of
the samples.
Ezpt.
number
of
bacteria in
1.
Thames
water,
1 c.c.
2.
3.
3,000
18
sample taken
in mid-stream
at Twickenham, opposite
Ham
Number
of
spores of
bacteria in
1 c.c.
of
bacteria
causing
Eemarks.
liquefaction
of the gelatin
in 1 0.0.
4.
No
record.
Spores of B. enieritidis sporogenes present in
10 CO., 5 c.c, 1 c.c, 0-1 c.c of the water absent
m 0-01 cc
;
In a phenol gelatine plate culture containing
O'Ol c.c. of the water, one colony indistinguishable
from B. coli. Subcultures from this colony gave
the following results Gas in 24 hours in gelatine
shake culture incubated at 20° C. DifCuse cloudiness in broth in 24 hours at 37° C. No indol in
five days.
Slight acidity but no clotting in
litmus milk in 48 hours at 37° C. In 96 hours,
however, the milk showed a solid clot.
In an ordinary gelatine plate culture containing
house,
about
half-way betweenGiover's
i.e.,
:
island
and
Eel Pie island.
11 a.m., Nov.
22, 1898 (very
wet weather).
O'Ol c.c. of the water,
one colony indistinguishable
Subcultures from this colony gave
the following results Gas in 24 hours at 20° C.
in gelatine shake culture, diffuse cloudiness in
broth in 24 hours at 37° C; acidity but no clotting
in litmus milk culture in 24 hours at 37° 0. No
indol in broth culture, fourth day, at 37° C.
from B.
coli.
:
V.-DESCRIPTION OF SOME OF THE BACTERIA FOUND IN THE CRUDE
SEWAGE AND IN THE EFFLUENTS FROM THE COKE-BEDS.
2.
B. Coli Communis.
B. Mesentericus.
3.
Sewage Variety E.
Sewage Yariety I.
Sewage Proteus.
1.
Prondosus.
7.
B.
B.
B.
B.
8.
Sewage Variety A.
Sewage Variety B.
B. Membraneus Patulus.
9.
B. Capillareus.
4.
6.
6.
1.
PusiroRMis.
SUBTILISSIMUS.
SUBTILIS.
Bacillus Coli Communis.
[.4w aerobic, non-chromogenie, slightly motile, non-liquefying hacillus.}
—
Source. The excreta of human beings and many of the lower animals. Very abundant in
London crudesewage usually more than 100,000 per c.c. of sewage.
Morphologyf. Small bacilli with rounded ends, hardly longer than broad solitary, often in pairs
rarely
in chains containing more than two segments.
Motility.
Usually only feebly motile.
;
—
•
;
'
—
—
—
Spore formation. No spores are formed.
Flagella. Dr. M. H. Gordon gives the flagella average as 1 to 3.
Temperature. Grows best at 37° C, but also very well at the ordinary temperature.
Gelatine plate cultureb%. The colonies develop in from 24 to 48 hours at 20° C. The deep colonies are notcharacteristic, the surface colonies peculiarly so, appearing as delicate, slightly granular films, of an irregularly
circular shape, which are bluish-white by reflected and of an amber colour by transmitted light
they are
transparent, and sometimes iridescent, especially towards the periphery, but at the centre and over the entire
surface in old cultures an opacity due to a greater thickness of the bacterial growth is observed later these
surface colonies may become marked by concentric, or radiating, or irregular markings. The surrounding
gelatine frequently acquires a dull, cloudy, faded appearance. The gelatine is not liquefied.
Gelatine " stab " cultures. The growth on the surface is like a surface colony in a plate culture, but tends
to be more luxuriant, due to the greater thickness of the medium.
white growth extends to the foot of the
stab, and gas fissures frequently appear in the gelatine.
The gelatine, as already stated, is not liquefied.
Gelatine " streak " cultures. The growth is like an elongated surface colony in a gelatine plate culture
but is, perhaps, more luxuriant. Briefly, a delicate faintly-granular film forms, with transparent and irregular
margins. Down the centre, longitudinally, the growth is more opaque. Sometimes the film shows iridescence,
and in old cultures it may become irregularly thickened. The gelatine, which is not liquefied, becomes often
clouded. The growth, which is bluish-white by reflected light, has a yellowish-amber colour by transmitted
—
—
;
;
—
A
—
light.
—
Potato-gelatine plate, " stab " and " streak " cultures. The growth is somewhat similar in appearance to the
above, but tends to be more circumscribed, is slower, and of a characteristic brown colour.
Phenol (0'05 per cent.) gelatine cultures. These do not differ from ordinary gelatine cultures except that
—
growth
delayed.
Gelatine "shake " cultures.* ^Numerous gas bubbles are formed, usually in 24 hours, at 20° C.
Agar plate cultures. The growth is not so characteristic as in gelatine. The superficial colonies have a
moist glistening white appearance.
is
—
1 1 * See
figs. 6, 4,
13 and
—
6,
Plate
I.
of First Keport.
[5J
34
Agm
"stab" cultures.—Growth occurs all the
way down the
developed.
stab,
and on the
BuriEaoe a wliite layer
is
.
Agar "streak" cultures.— At 37°
very rapid, and occurs as an abundant moist and
C. the gi^owth is
white layer.
:
Potato cultu^es.^—A rich yellowish-brown layfir quickly developes.
Broth cultures.— The growth is characteristic. In less than 24 hours,: at_ 37° 0., the broth is uniformly
turbid. Later, a heavy bacterial deposit collects at the foot of t^ie tube. There is no distinct pellicle formajtion,
but sometimes an imperfect scum forms on the surface.
Phenol (0'05 j)er ceril.) broth cultures.— The growth idthe sa,me as.ib an oj-dinary-.brotL cultivation.
Litmus milk cultures. The growth is extremely characteristic. Usually, an acid solid clotting of the milk
"
takes place in 24 hours at 37° C. Occasionally the clotting is somewhat delayed. First of all, the bluishmilk,
except
at
the
free
surface,
the
becomes
occurs,
and
purple colour changes to pink then clotting
whifcp.
Later, the redness extends from the surface downwards until the Whole contents of the tube are bright red in ocjloiir.
Blood serum cultures. An abundant white layer is quickly developed at 37° 0. there is no liquefaoticjn.
Indol reaction. Indol reaction is usually well marked in biroth cultures kept at 37° C. for five days.
Reduction of nitrates. In 24 hours, at 37° 0., reduction of nitrates to nitrites well marked.
[Broth 6 per
O, O'l per cent., water 94'9 per cent.]
cent.
Widal's test. Typhoid blood serum gives a negative result.
Bemcvrks. BacillUiS coli com/munis is one of the most abundant and most characteristic of sewage bacteria.
In this and a previous report it has been shown that its number may exceed 100,000 per c.c. of London crude
sewage. It has likewise been shown that it survives the processes at work in the biological filters at the Outfall
Works. Apart from its function as one of nature's scavengers, the B. coli is of great importance from the point
of view of the bacteriosoopic examination of water. In the first report a photograph (plate I, figure 1) was given
showing that even in so minute an amount as j-oTOoo o.c. of Crossness crude sewage, B. coli and closely aUied
forms were present, and it was pointed out that a bacterial process of great delicacy exists for the detection
of pollution of water with minimal quantities of sewage.
It has been asserted that B. coli is abundant everywhere, that it multiplies outside the animal body, that
it is present in the intestinal contents not only of human beings but of the higher maramals and birds,
and
that, therefore, its value as an indication of pollution of water of possibly dangerous sort is nil.
The fact remains
that in crude sewage B. coli is present in numbers exceeding 100,000 per c.c, and is absent, or present in but few
numbers in a corresponding amount of a water free from suspicion of recent pollution. Moreover, if B. coU
multiplies outside the animal body under favourable conditions, it also loses its vitality under unfavourable
conditions, and we have yet to learn that the excrement of healthy, much less of diseased, mammals and
birds
is altogether harmless to man.
The Bacillus coli may be pathogenic, but can hardly be considered pathogenic in the ordinary sense of the
term. Its presence serves rather as an index of the possible presence of other and more objectionable
kinds of
.
'
'
i
:
—
,
;
—
—
—
KN
;
——
bacteria.
No apology is needed for describing B coli in a report dealing with the bacteriology of sewage. Its
prevalence in sewage, its relation to the proper bacterioscopic examination of drinking water, and the
important
part it plays as one of Nature's scavengers, all make it desirable to record its chief morphological
and biological
characteristics.
This is the more necessary as the published descriptions of this microbe are often
incomnlete
"^
'
and in some cases even misleading.
It will be noted that not only the presence of B. coli in the various samples of crude
sewage and effluents
has been determined, but that, as well, a record has been kept of its relative abundance. Until
such records are
obtained, not only as regards B. toli, but as regards many other species of micro-organisms,
the usefnlnesA
of
"^^^am ui
bacteriology is restricted.
2.
Bacillus Mesentbeicus,
Sewage variety E.
iAn
Sewage variety
aerobic, non-chromogenic, actively motile, slowly
liquefymg bacillus.2
[An
I.
aerobic, non-chromogenic, activelu motile
ramdUi
liquefying badllus.y
^
Source.
to 8S°
OX™10 m3I'
^''^''^'' "'"'' °""'^''" ""'^''^
to 8^°
cXw m3I'
^'"^'"^^ ^'^^^ '^^^^^^^ ^^^'^^
Morphology.
tnlcS'
^''^ '"''"'^'^ ""^'
an*d long unains.
Buu
'
'°^'*^''^' '""
^''^'
^^^'^'^-f-fdliacilli. with rounded ends
m pairs and chains.
;
solitary.!
'
Motility.
Actively motile.
Exceedingly rapid movement.
Spore formation.
Readily forms spores.
Readily forms spores.
Flagella,
t
A multi-flagellated organism.
A multi-flagellated organism.
||
Temperature.
Grows well
at the
37° C.
rapidly
' at
^
• See
fig. 3,
room temperature, and «xoeeaingiy
exoeedinelv
Plate
L
f See
fig. 6.
Plate II.
Ornwo ^r^^.^
«
-ji
^ ^i
l^rows
very rapidly
at the room temperature, and
with great rapidity at 37° 0.
J See
fig. 4,
Plate
I.
y
See
fig. 6.
Plate II.
35
'Gelatine plate cultures.
The growth is not very rapid. The deep colonies
have a somewhat starlike appearanee the superficial
;
appear
colonies
as
bluish-white,
delicate
granular
which are almost coli-like in character. These
surface colonies are somewhat irregular in shape, and
from the wavy, transparent edge irregular processes
films,
are given
ofB.
_
Under a lower power of the microscope the deep
colonies show a central darkish yellow spot, from which
root-like processes are given off. The surface colonies
are transparent, granular, and striated, and from the
spreading edge delicate processes are given off, which
spread over the surface of the gelatine, forming often
curious and intricate patterns. The colonies do not
attain a large size, and liquefaction only slowly sets in.
The growth is characteristically rapid. The deep
colonies quickly reach the surface, to form large areas
of liquefied gelatine, which become saucer-shaped, and
are greyish-white in colour and almost translucent-IT
From the edge of these saucer-shaped surface colonies
may be given off which are almost of the
nature of " swarming islands." These almost transt
lucent areas of liquefied gelatine are rendered greyishwhite by the presence of innumerable bacteria, and
these bacteria may be gathered together in clumps so
as to give rise to a mottled appearance.
thin
bacterial film tends to form on the surface of the
liquefied gelatine.
In a very few days the whole
plate is completely liquefied.
Under a low power of the microscope the deep
colonies are dark in colour and granular. The surface
colonies at first may be almost completely translucent
and of an irregular, star-shaped form, but soon form
large circular areas of liquefied gelatine, in which the
extraordinarily rapid movement of the individual
bacilli can be clearly watched.
processes
A
Gelatine " stab " cultures.
The growth at the surface is slow, and resembles the
growth of a superficial colony in gelatine plate culture,
Growth takes place all the way down the stab, accompanied by slow liquefaction delicate tuft-like filaments
are given off all down the line of the inoculation. These
extend more and more deeply into the solid gelatine as
growth proceeds. Gradually at the surface liquefaction
sets in, showing itself at first merely by a slight central
pitting of the bacterial film. Later, the liquefaction
spreads, and the delicate details of growth are lost.
;
'
Rapid liquefaction takes place nearly if not quite to
the foot of the stab and in funnel form.§ Very soon
the liquefaction spreads to the walls of the tube and
increases rapidly from above downwards as well as from
the stab in an outward direction. The liquefied gelatine
has a greyish-white translucent appearance, and has
also a somewhat flocculent appearance due to aggregation of little masses of bacteria. Very soon the whole
contents of the tube are completely liquefied and converted into a greyish- white turbid fluid.
Gelatine " streak " cultures.
A
delicate granular film forms on the surface of the
gelatine which is of somewhat limited extent. Liquefaction slowly sets in and shows itself as a longitudinal
furrow. After some days the film changes its appearance and shows numberless fine processes radiating
outwards and upwards from the central line. Tuft-like
processes also extend into the solid gelatine. As
liquefaction proceeds all the delicate details of growth
become
No
Gelatine " shake " cultures.
gas bubbles are formed
;
the gelatine
is
No
slowly
gas bubbles are formed
;
the gelatine
is
rapidly
liquefied.
Agar plate
In agar plate cultures at 37° 0. the growth is so rapid
and the colonies spread so much laterally, that frequently the whole plate is covered with a granular
dirty yellowish- white film in 24 hours. The spreading
edge is often broken up into processes of most varied
and which frequently form
tree-like patterns.
Agar
In 24 hours at 37° C. there
is
growth
all
and the surface
cultures.
0. the growth is so rapid
obtain discrete colonies.
The
yellowish-white, granular, and often of un-
In agar plate cultures at 37?
that
difficult to
it is
growth
is
equal thickness.
dency
.B.
to
form
mesentericus
The spreading edge has
tree-like patterns
less
tenof
than in the case
JS.
" stab " cultv/res.
down the
of the medium is covered
yellowish- white granular layer, which later may
stab,
is not characteristic, as the liquefaction
rapid that the peptonised gelatine runs down the
oblique surface to the foot of the tube, and in a few
days the whole of the contents are converted into a
turbid greyish-white liquid,
lost.
liquefied.
shape,
The growth
is so
with a
becpme
In 24 hours at 37° 0. there is growth all down the
and the surface of the medium is covered with a
yellowish-white granular layer, which later may become
stab,
wrinkled.
wrinkled.
Agar
" streak " cultures.
In 24 hours at 37° 0. a dirty yellowish- white fihnhas
covered nearly the whole oblique surface. The spreading
edge may extend as irregular processes forming leaf -like
patterns. Later the film darkens in colour and becomes
In 24 hours at 37° 0. a dirty yellowish-white film has
covered nearly the whole oblique surface. The spreading
edge may be lobed or fissured and of unequal thickness,
The film darkens in colour and becomes wrinkled,
wrinkled.
Potato cultures.
The growth is extremely characteristic. In 24 hours
extremely characteristic. At 37° C.
at 37° 0. the whole surface of the potato is covered with
covered
is
potato
the
of
surface
whole
the
in 24 hours
a thick greyish-white moist skin, which is thrown into
with a thin yellowish-white film, which has a charactermultiple folds, creasmgs and wrinkles.** The colour
There
istic folded, creased and wrinkled appearance.
rapidly changes from greyish-white to yellow, and then
these dry up,
is an appearance also as of blisters:
to brown The growth, it touched withaplatmum needle,
leaving deeply wrinkled skins. The substance of the
is found to be held to the potato by a viscous substance
film
the
Later
colour.
pink
bright
on
a
takes
potato
which can be drawn out into long threads.
becomes thicker, mori deeply pitted and wrinkled, and
the colour becomes brown.
Broth cultures.
The growth at 37° 0. is characteristic even in 24
in 24
even
37*
characteristic
is
0.
at
The growth
greyish-white wrinkled film is formed at the
hours.
the
at
formed
is
film
wrinkled
greyish-white
hours
the liquid below is nearly quite clear,
tnd the liquid below is nearly quite clear. surface,theand
film thickens, and the wrinkled appearance
Later
pitted and
liter the film thickens and becomes deeply
becomes more marked. It acquires a reddish-brown
tl H
wrmkled.
colour, and the liquid below, which remains nearly
q uite transparent, also takes on a reddish-brown colour.
The growth
,
•
See
is
A
A
•
1 See fig.
7,
Plate
IL
§
See
fig. 8,
Plate II.
* * See
fig. 9,
Plate
IIL
—
36
Idtmus milk
cult/u/res.
colour of the
In 24 hours at 37° 0. the bluish-purple
milk is changed to a dirty yellowish-white .no clot,
In 48 hours no clot but the mil^k is rapidly becommg
transparent. In 72 hours the whole of the contents of
of a dirty yeliowiah
the tube are semi-transparent and
On gently shaking the tube, the liquid assumes
colour.
a crushed strawberry colour,
at 37° C. slight discolouration has taken
place. In 48 hours the liquid is of a dirty yellowish-white
colour, with a tinge of red ; no clot. In 72 hours a weak
clot has formed, and the liquid near the surface is semitransparent.
On gently shaking the tube, a pinkish
tinge develops. In five days the clot lies at the foot of
In 24 hours
the tube as a dirty white mass above this the liciuid is
transparent and of a faint yellow colour, which on
shaking changes to a pink tint.
;
Blood serum cultures.
At 37° C. decided liquefaction takes place in less than
24 hours, and on the surface of the liquid, at the toot ot
the tube, a wrinkled skin is formed. Later, the blood
serum is completely liquefaed.
and in less than 24 hours, nearly the whole
of the oblique surface of the medium has become covered
with a deeply wrinkled skin. Later, slow liquefaction
sets in, and in about 16 days the blood serum is com-
At
37'^ 0.,
pletely liquefied.
Indol reaction.
No
indol
is
No
formed.
Reduction of nitrates
[Broth 5 per
cent.,
K N 0,
0-1
per
is
formed.
to nitrites.
water 94-90 per cent.]
reduction of nitrates to nitrites in 24 hours at
cent.,
No
Great reduction of nitrates to nitrites in 24 hours at
37° C.
indol
37° 0.
Bemarles.
The micro-organism is constantly present in sewage
in the form of spores 10, 20, 30, or more spores per c.c.
of London crude sewage may be found. It is present in
considerable number in the effluents from the biological
It resembles closely B. mesentericus vulgatus,
filters.
B. mesimtericus fuscus, and 5. liodermos, and is perhaps
most closely allied to, if it is not identical with,
B. mesentericus vulgatus.
not identical with,
Eesembles very
closely, if it is
Bacillus meaentericus ruber.
;
Sewage Pboteus.
3.
[_An a'erohic, non-chromogenic, actively m,otile, rapidly liquefying haoillus.}
Source. ^Very abundant in London crude sewage ; frequently as many as 100,000 per c.c. of crude sewage.
Morphology.* Small bacilli, with rounded ends solitary, in pairs, or sometimes in short chains; involution
—
may
—
;
occasionally be seen.
Actively motile.
Motility.
Spore formation. No spores are formed.
Flagella.f Bach rod is possessed of a single flagellum.
'Temperature. The original culture grew better at 20° 0. than at 37° 0.^
Gelatine plate cultures.X In less than 24 hours at 20° 0. the surface colonies appear as delicate granular films
In two days the colonies look like "punched out" circles containing liquefied gelatine, and
of irregular shape.
greyish-white bacterial deposit. The masses of bacteria lying in the liquefied gelatine usually give a mottled
appearance to the colonies. Viewed under a low power of the microscope the individual bacilli can be made out,
and their active movement watched the colonies appear darkest centrally and at the circumference, and here and
there darker spots may be seen in the liquefied and granular-looking gelatine. The colonies are usually exactly
circular in shape with well-defined borders, and no " swarming islands " appear to be given off, as in proteus
vulgaris.
By the third or fourth day the plate is completely liquefied, the gelatine being converted into a turbid
greyish -white liquid.
The growth is very characteristic. In 24 hours at 20° 0. liquefaction has occurred
Gelatine " stai" cultures.^.
all the way down the path of the needle, and minute bubbles of gas may be watched rising through the turbid,
In 4'8 hours the liquefaction is very much more pronounced;
greyiah-white liquefied gelatine to the surface.
numerous bubbles of gas may be seen at the surface, and also bubbles in the solid gelatine. The bacteria collect
at the foot of the liquefied portion as a greyish-white deposit. In four or five days the whole of the gelatine is
converted into a greyish-white liquid. If such a culture be heated to 80° C. for 20 minutes the bacilli are kUled,
but if, after cooling, a portion of the fluid be added to another tube containing solid gelatine, the gelatine in this
forms
—
—
—
—
—
:
—
second tube becomes liquefied.
—
—
Gelatine " streah " cultures. The gelatine is liquefied so rapidly that all details of growth are lost.
Gelatine " shake " cultures.— In 24 hours at 20° 0. numerous gas bubbles are formed, and the gelatine is
liquefied near the surface.
Agar plate cultures. The growth is not characteristic. The colonies are more or less circular in shape,
they are greyish-white in colour, and have a somewhat moist, glistening appearance.
Agar " stal " cultures.—There is growth all down the stab gas bubbles may form in the medium on the
surface the growth is like a surface colony in an agar plate culture. In old cultures the surface growth becomes
of a brownish colour.
Agar "streah" cultures.— The growth is rapid, but not specially characteristic.
greyish-white layer
having a moist glistening appearance is formed, which may extend nearly to the walls of the tube
Potato cultures.— The growth is not characteristic a slimy, thin, yellowish-white growth
appears
on the
^^
surface of the potato.
Broth cultures. Abundant diffuse cloudy growth in 24 hours at 20° C.
Utmus milk cultures -The growth at 20° 0. in litmus milk culture may be described as an acid change from
an opaque bliiish-purple coloured liquid to a semi-transparent reddish-coloured fluid. The redness is chiefly near
the surface, but if the tube be shaken the whole of the contents of the tube assume a crushed
strawberrv tint
If clotting occurs, it is imperfect in character and possibly is dissolved as soon as it is formed
\\
—
;
;
A
;
—
'
—
Blood serum cultures. Eapid growth, accompanied by liquefaction
Indol r6aoiw«.-Usually no indol is formed in broth cultures, but in one such
culture, kept
for
urrcivc uajo,
days,
'^
" twelve
was observed.
'
a feeble mdol reaction
Reduction of ntiroto.— Rapid reduction of nitrates to nitrites in 24 hours at 20°
C
TBrnth b^ per
npr cent.,
fPnt
^- Li^rotn,
O3 0-1 per cent., water 94-9 per cent.]
Bemarks.-This organism difiers from Proieus vulgaris and has little or no
resemblance either to Praters
mrraUhs or to Proteus .enken. It differs from Proteus vulgaris in many respects, for
example 'a/tt^g
^
KN
epS
* See
fig. 10,
t See
Pate III.
J See
fig. 11,
fig. 12,
Plate 111.
Plate III.
II
Kg.
%
See however notps iTi^^wuTTJ^
^''^'
§ See fig 13 (&T (I) Rate IV
13 (al, Plate IV.
^
""^'^'•
i
——
37
'^^'^^^ ^''•oieus shows no '-swarming slands"" unlike
pXT^Lris ™™n^fl^!\
"^"l/i*'^'*^'''
' been called sewage proteus owing to its prevalence in crude sewage, and
wir/p!^ ,?r«;T.3fi -T^ ^1
i^«2^an8, and to other member^ of the proteas group
It^i not
SSv that tZSrno?<r •''''''is Vfrequently
^""^'"f
mistaken for the true Proteus vulgaris It also differs in a
«Sjof imnort«^t ..J^pff /
P™*^™
=XvW lZ^nl=Kf- lPn^4^T
^"''"-^"o'"?*f
'"^''' ^^^
'^^a/^DecTmber,
K"
"'•^'»"«' ^1^
''^^^^'^^^^
organism isolated from the urine of a patient
^-''"^^'^ ^^
^^ -
*^^
^"—^ of Fathololj and
*^^*
^^^ff'*"'* ^^ 1^°* P'-^^*'"* ^^ London crude sewage, bat that
nnmbSB"are''not^«°™Tt 1" I'^PP'T u
^^f'""
^^ generally
supposed. In figure 1, Plate L, a micro-photograBh is shewn
I -^
^%^'f^J'°
^""""^.^
""^1
l^?"Pl^ °* Crossness raw sewage. The preparation was obtained by
lli
'r'^*'n
°^ ^''^^ micro-organism, and then making "impressions" from the
^^^ZLJ^.tZ5^
A Pf^
•l'^'''''^
swarming islands produced
by its
growth on the surface of the gelatine in 20 hours at 20° 0.
A culture of sewage proieus proved to be very virulent. Thus, 1 c.c. of a 24 hours' broth culture was
guinea-pig. The animal was found dead on the second
day, but had probaWy
i?pdoAhe™Ht^^^^^^^
^^- ^^^ organism was recovered from the heart's blood in pure culture. [Subsequent
1-t^l^
I
work yielded
some measure anomalous results. Thus, as freshly isolated from
sewage, "sewage proteus"
sometimes grew well at 37°
and sometimes in an imperfect manner. Moreover, the cu tures were^in
lii ouiiio
some
^-^ „ ci
cases virulent and in others not.]
it«
if
t^o?™p Lr»n=
•
J ^surtTi"
m
^
<=
4.
Bacillus Fhonbosus.
^^'"' O'^'Tobic,
non-chromogenic, motile, slowly liquefying lacillus.]
bource.—Jjondon crude sewage gelatine plate cultures heated to 80° G. for 10 minutes.
oaoilh, with rounded ends ; solitary, in pairs, and in chains of varying
length.
:
MMt
—u'tT^^^
Spore formation*.— ¥orma spores readily at the
Temperature.— No growth at 37" 0.
room temperature.
Grows
fairly rapidly at the room temperature.
Gelatine plate cultures:^.—The surface colonies appear as white, coarsely granular
films of irregular shape,
which send out curious processes of varied form. These erotesquely-shaped processes resembles bits of
seaweed flattened out. Liquefaction sets in very slowly and shows itself by a slight pitting near the centre of each
colony. The deep colonies are not characteristic. Under a low power of the microscope the superficial
colonies
have a granular and laminated appearance, and show at the spreading edge processes which are of the most
varied shapes, and which often form patterns of great delicacy and beauty.
Gelatine "stab " cultures.— The growth at the surface is like a superficial colony in gelatine plate
culture.
The growth down the stab is not characteristic. Liquefaction slowly sets in at the surface, and eventually all
the delicate details of growth are lost.
Gelatine "streak" cultures.— The growth is like an elongated surface colony in plate culture. Brieflv, a
white coarsely granular film forms on the sloping surface of the medium which peripherally shoots out processes
of very irregular shape. Liquefaction first shows itself as a longitudinal and central pitting of the bacterial film.
Gelatine " shake " cultures. No bubbles of gas are formed.
Agar plate cultures. The colonies are white in colour; they do not grow in the same characteristic way as
the colonies in gelatine plate culture.
Agar "stab " cultures. Growth occurs all the way down the stab, and at the surface a greyish white-layer is
formed of irregular shape which resembles somewhat a surface colony in gelatine plate culture.
Agar " streak " cultures. The growth extends over the surface of the medium as a greyish-white film. The
growth at the periphery in some mea sure simulates the corresponding growth on gelatine.
Potato cultures. The growth is characteristic from a negative point of view as it is of a transparent
colourless character.
Broth cultures. Grows slowly; a white bacterial deposit collects at the foot of the tube, leaving the
—
—
—
—
—
—
above fairly clear.
Litmus milk cultures. In milk at 20° C. No change is visible in three days. Later the milk turns slightly
acid, no clotting is visible even after one month.
Blood serum cultures. At 20° C. a greyish-white, somewhat gi-anular and film-like growth develops in a
few days. The edge is irregular. Apparently, no liquefaction takes place.
Indol reaction
No indol is formed in broth cultures, after 6 days incubation at 20° C.
Reduction of nitrates to nitrites. No reduction takes place in 4 days at 20°. 0. [Broth, 5 per cent.,
N O3 O'l
per cent., water 94'9 per cent.]
Remarks. This micro-organism has been compared with the descriptions of all the aerobic, motile,
non-chromogenic, liquefying bacteria, and it resembles none of them sufficiently closely to suggest identity. It
has been called B. Frondosus because the spreading edge of the colonies sometimes have a leafy appearance.
liquid
—
—
—
—
K
—
5.
Bacillits PusiroKMis.
l_An aerobic, non-chrom,ogenic, m,otile, non-liguefying bacillus.']
—London crude sewage gelatine plate cultures heated to 80° C. for ten minutes.
—Large
with rounded ends solitary, in pairs, and in chains.
Motility. —Motile.
Spore formation.X — Forms spores at the room temperature. These are large, and give a spindle-shaped
appearance to the
Temperature. — No growth at 37° C. Grows slowly at the room temperature.
very slow. The surface colonies are circular, of an opaque porcelainGelatine plate cultures. — The growth
Source.
:
Morphology.
bacilli,
;
cells.
is
white, glistening appearance.
The periphery is slightly transparent. By transmitted light the colonies are
yellowish in colour. In old cultures the white colour takes on a yellowish tint. The deep colonies are not
characteristic.
Microscopically, under a low power, no delicate details of growth can be made out. No
liquefaction of the gelatine takes place.
white growth appears along
Gelatine "stab" cultwres. Tardy growth, no liquefaction of the gelatine.
—
A
the line of the stab, and on the surface a scanty yellowish-white layer very slowly develops.
glistening porcelain- white layer is slowly formed, which is opaque, except at
Gelatine " streak " cultures.
the margins, which are slightly transparent. By transmitted light and by reflected light in old cultures a slight
yellowish tint may be seen.
The growth does not extend far from the actual line of inoculation. No
liquefaction occurs.
Gelatine " shake " cultures. No gas bubbles are formed.
Agar plate cultures. The colonies are white and more or less circular in shape the growth is not
—A
—
—
characteristic.
Agar " stab" cultures. —The growth
stab,
;
A whitish line appears along the line
is slow and imperfect.
and on the surface a thin white layer slowly develops.
Agar " streak" cultures.—A. thin whitish layer is slowly formed the growth is not characteristic.
;
* See
fig. 14,
Plate lY.
t See
fig. 16,
Plate IV.
J See
fig. 16,
Plate IV.
cf the
——
'
38
colour becomes dirty'
Potato culture!.—
porcelain-white growth slowly developes afterwards the
yellowish- white and the bacterial layer becomes unequally thickened.
Broth cultv/reg. The growth is very scanty and not characteristic.
lAtmMS milk cultures.— Eo clotting occurs, and the change in the medium is hardly visible, even after
16 days. Apparently a feeble acidity of the milk results.
i.
iBlood serum cultures.— JjittlQ or no growth on the surface, even after the lapse of some time ; some growth,
X
;
—
.
however, takes place in the fluid at the foot of the tube.
Indol reaction. No indol is formed in broth cultures.
t?- at n
JN Oj 01 percent.,,
Reduction of nitrates to wiWfes.— Negative after 12 days at 20° C. [Broth 5 per cent.,
water 949 per cent.]
iJemorfca.— This micro-organism has a somewhat negative character of growth in aU the nutrient media'
ordinarily in use. It has been called B.fusiformis. owing to the shape of the spores, spindle-shaped. So far as,
could be ascertained it belongs to a new species.
—
m
K
BaCILLITS SUBTILISSIMITS.
6.
[An aerobic, non-chromogenic, non-motile, non-liquefying hadllus ( ? micro-coccus).']
Source. Crude sewage.
Morphology.* In most cultures it appears as a large micro-coccus, but if " impression " preparations be made
—
—
.
_
.
.
from surface colonies in a gelatine plate, it will be seen that at the spreading edge the elements are distinctly longer
than broad, nearer the centre they are oval and frequently united in pairs, and at or about the centre they are
perfectly spherical.
—
No motility has been observed even in recent broth cultures.
Spore-formation. None.
Tem,perature. Does not grow at 37° C, but grows with extreme rapidity at 20° 0.
Gelatine plate cultures. The deep colonies are not characteristic, either on naked eye examination when
viewed with a hand-lens, or when examined under a low power of the microscope. The surface colonies are
peculiarly characteristic, and grow so rapidly and extend so widely, that a single colony may cover nearly a whole,
plate in two days. The growth is film-like in character and extremely thin and transparent. It is dull grey in
colour and very faintly granular. When viewed under a low power of the microscope, the appearance is not unlike,
-6. coli, but the details of the growth are so much more delicate that it is difficult to perceive the shght granulation,
faint creasing and delicate veining of the bacterial film. The surface colonies are usually of a more or less circular
shape, but the spreading edge is nearly always markedly irregular.
Gelatine " streak " cultures.^ The growth is like an elongated surface colony. In less than 24 hours a delicate
film has spread nearly to the walls of the tube. The spreading edge is very irregular, and in older cultures may
present a terraced appearance.
Gelatine "shake" cultures. No gas bubbles are formed in the gelatine.
Agar "streak" cultures.
white film is formed on the surface having a markedly irregular edge. The
lateral expansion is less than in the case of gelatine cultures.
Broth cultures. Uniform turbidity occurs in 24 hours at 20° C, and a very faint scum forms on the
surface. No motility could be made out.
Blood serum,.
thin film forms of a faint yellowish-white colour. No liquefaction occurs.
Litmus milk cultv/res. No visible change in 48 hours at 20° 0. Later the purple colour of the milk changes
to a reddish purple, and later still to a buff colour.
On shaking the tube gently the liquid does not assume a
red tint. There is no clotting produced and no transparency of the medium occurs even in old cultures.
Indol. No indol is formed even after 20 days at 20° C.
Remarks. This microbe has been called B. subtilissimus on account of the thin almost gauze-like character
of the surface colonies in gelatine plate culture.
No micro-organism hitherto described appears to correspond
with the above.
Motility.
—
—
—
—
—
—A
—
—A
—
—
—
7.
Bacillus Subtilis.
Sewage Yakiett A.
lAn
Sewage Vakiett B.
^An
aerobic, non-chromogenic, rapidly liquefying, spore-
forming, matile badllus.]
aerobic non-chromogenic, ra/pidly liquefying, sporeforming, motile bacillus.']
Source.
Crude sewage and
effluents
Grows luxuriantly
from coke-beds.
at 37°
C,
also at the
Crude sewage and
Optimum
room tern-
from coke-beds.
temperature.
perature.
Little or
no growth
at 37°
C, grows
luxuriantly at
20° C.
Morphology.
with rounded ends, frequently
Large and long bacilli with rounded ends, frequently
long chains.
associated in long chains.
Large and long
associated
effluents
m
bacilli
Spore formation.
Forms spores
readily.
Forms spores
.
readily.
Motility.
Waddling sluggish movement.
Waddling sluggish movement.
Gelatine plate cultures.
Forms
in two days at 20° 0. circular greyish-white
areas of liquid gelatine which rapidly increase in
diameter. The white masses of bacteria lying
the
liquefied gelatme may present a mottled appearance,
or may be arranged in stellate fashion
Under a low
m
power
microscope (about 80 diam.) the individual
bacilli can be clearly seen
the more liquid portion,
and their movements watched. At the edge of the
colonies the bacilh bore side by side into the nonliquefied gelatme
a highly characteristic way.J
of the
m
m
See fig.
17,
Plate V.
t Kg.
18,
Rapidly froms greyish- white circles of liquefied
The mastes of bacteria lying in the liquefied'
gelatine may present a rosette or star - shaped or
radiating appearance. Under a low power of the microgelatine.
scope (about 80 diam.) the movement of the individual
bacTui can be clearl/ seen. The parallel arrangement
of the bacilli at the peripherv of the colonies islbsent
or not so well marked
cLe of
ety
skin forms on the surface of the
li^fied geh^tine.'
The growth is not so rapid as in the case of va^rlty A.
Sometimes the colonies are not exactly circular in shape.
TKe
Plate V.
t Fig. B, plate VII.
Tr
A A
—
39
Agar
" streak
'"
cuUures.
Wo
days, at 37° C, an abundant creamy white
layer, covering nearly the whole surface, which on close
inspection shows 'numerous minute circular areas where
the growth, instead of being opaque, is semi-trans-
In
parent.
In 20 hours, at 20°
0.,
a greyish-white layer, not
In 48 hours, growth somewhat dry and granular looking. In four days, curious
wrinkled appearances. Eidges, formed by the unequal
rate of growth, or by the contraction of the bacterial
skin, stand out from the surface of the medium about
one-sixteenth of an inch, and usually are arranged in
more or less transverse folds.*
specially
characteristic.
Gelatine " stab " cultures.
2 days, at 20° C, liquefaction has occurred right
down to the foot of the stab. White flocculent masses
of bacteria sink through the liquefied and grey-coloured
The liquefaction
gelatine to the foot of the stab.
extends rapidly from the line of inoculation outwards
A, scum
as well as from the surface downwards.
forms on the surface, but no distinct skin is formed.f
In
Eapid
>
liquefaction
all
way down
the
the stab,
but as the growth proceeds the liquefaction spreads
in cylindrical fashion from above downwards rather than
from within outwards from the region of the line of
inoculation. A distinct skin forms on the surface,
which eventually sinks in the liquefied gelatine.J
Liquefaction.
Rapidly liquefies gelatine and blood serum.
serum
Liquefies gelatine and blood
fairly rapidly.
Oas formation.
Forms no gas in gelatine " shake
''
Forms no gas
cultures.
in gelatine " shake " cultures.
Broth cultures.
A
scum
DifEuse cloudiness in 24 hours at 37° 0.
forms on the surface which readily falls to the foot of
the tube on shaking.
Diffuse cloudiness: a skin forms on the surface
is brittle and sinks on shaking the tube,
which
Indol.
Forms no
Forms no
indol.
Litmus milk
In 2 days, at 37° C, there is complete discoloration
and a clot has formed no redness is visible. In 5 days
a white clot occupies about one-third of the bulk of
medium, which appears to be slowly peptonised. The
liquid surrounding the clot is pale yellow in colour,
and semi-transparent without pink coloration.
;
indol.
cultures.
of the litmus milk gradually
but no clotting or redness occurs. In 8 days the
milk is almost transparent and of a pale dirty yellow
colour on shaking the tube the liquid assumes a faint
pink tinge. By the 21st day the milk has changed to a
semi-transparent dirty yellow liquid on shaking the
tube the contents assume a reddish tint.
The purple-blue colour
fades,
;
;
Potato cultures.
In 2 days, at 378 0., a dirty-white layer
with a yellowish tint.
is
formed
A
white, rather dry-looking coat is formed. Later
portions of the growth become upraised, and sometimes
present a worm-like appearance.
Blood serum cultures.
In 24 hours, at S?*?, a white layer develops, accompanied with liquefaction of the medium.
In 20 hours, at 20° C, a thin whitish layer is formed,
In 48 hours commencing liquefaction and markedly
wrinkled
— Several varieties of B.
Remarks.
—
euhiilis
occur in sewage.
skin.||
For the purpoee of description I have named
however, of the latter organism not growing at
Sewage variety A, and sewage variety B. The fact,
these two
87° 0. makes it doubtful whether it should be considered a variety of B. suUiUs.
:
8.
Bacillus Membraneus
Pattjltjs.
[_An a'erohi&, non-chromogenic, slowly liquefying, spore-forming
{?),
non-motile hacillus.]
coke-beds.
— Crude sewage and effluent from
temperature. — Grows well at 37° C, and at the room temperature.
Morphology. —A very large bacillus which forms long chains.§
80°
for ten minutes, and the microbe has
Sou/rce.
Optimum
,
.
m
,
been found
C.
Spore formation.— Old culture resist heating to
satisfactory doublecultures made from sewage which had previously been heated to 80° 0. for ten minutes.
stained preparation, however, has not been obtained.
Motility.— No motility could be made out, even in a 20 hours' broth culture.
films of somewhat
Gelatine plates.—The surface colonies appear as coarsely granular greyish-white
From the spreading edge of the colonies processes extend in a tortuous fashion over the
irregular shape.
the surface film-like growth,
surface of the mediums often forming patterns of great delicacy and beauty. Beneath
Under a low power of the microscope the
slow liquefaction of the gelatine occurs. The growth is rapid.
.
.
colonies present a characteristic granular and striated appearance.^
granular film forms on the surface of
Oblique gelatine cultures.—In less than two days, at 20° C, a coarsely
tube.
From
the
spreading
the
of
the gelatine which spreads rather rapidly and may extend nearly to the walls
a characteristic way. Soon a
edge processes are given off which wind over the surface of the gelatine
and later on as liquefaction
longitudinal pitting of the bacterial film along the line of inoculation is observed,
A
m
are lost. The growth is like an
proceeds, the growth sUps down to the foot of the tube, and all delicate details
**
elongated surface colony in gelatine plate culture.
,
i
i
^
a coarsely granular, semi-transparent,
Oblique Agar cultures.— In one night, at 37° C.,the growth appears as
In old
less granular looking.
and
transparent
less
is
growth
the
day
second
By
the
greyish -white film.
cultures the surface assumes a tuberoulated appearance.
^ .
.it
c,.->
is liquefaction down the line of the stab
Gelatine "stab" cwZ/Mres. ft— The growth varies, as sometimes there
no
liquefaction
almost
along
there
is
times
other
with tuft-like processes extending into the solid medium, and at
tube, gmng rise to an appearance of
the line of inoculation, and the processes extend nearly to the walls of the
gelatine plate culture.
colony
surface
of
a
growth
the
like
is
surface
the
growth
on
great beauty. The
liquefaction of blood serum
slight
very
only
Produces
rapidly.
not
Liquefaction.—Lique&ea gelatine, but
even in cultures kept at 37° 0. for 16 days.
Gas formation.— Forma no gas in gelatine " shake" cultivations.
•
j.
_
ma
• Fig.
20,
Plate V.
§ Fig. 2i; plate
VL
'
t Fig. A, plate VII.
t
Fig. F, plate
VIIL
t Fig.
** Fig.
C,
and Fig. 19, plate V
and Fig. E, plate VIIL
plate VII.,
22, plate VI.,
Fig^ D.. Plate "Vll.
J Fig. 23, Plate
ft
VL
—
40
The cloudiness throughout the medium is flocculent
Broth CH?/Mres.— Grows very rapidly at 37^ C.
rather than diffuse. An abundant white bacterial deposit collects at the foot of the tube. On the surface a skin
is formed, which sinks on shaking the tube, but is re-formed in one night.
Indol formation. Forms no indol in broth cultures.
Litmus milk culturet.—ln 24 hours, at 37" C, the milk has become slightly discoloured later, a weak
gelatinous clot is formed, and the medium turns faintly acid.
The growth is not characteristic a dirty, faint yellowish-grey coloured growth in 24 hours
JPotato cultures.
at 37" 0.
Blood serum cultures. ^A granular greyish-white film is formed. Only very slight liquefaction occurs, even
in old cultures.
Reduction of nitrates. Great reduction of nitrates to nitrites in one night at 37° C. (Bouillon 5 per cent.
0, 0-1 per cent).
liemarhs. This organism does not appear to resemble at all closely the descriptions of any of the bacteria
found in sewage and elsewhere. On account of its spreading, film-like character of growth, it has been termed
B. membraneus patulua.
—
;
—
;
.,,..
—
—
KN
—
9.
Bacillus Capillakeus.
[_An aeroiic, non-chromogenic, rapidly liquefying, spnre-forming
(
?),
motile bacillua.']
— Crude sewage and efiBuents from coke beds.
also at room temperature.
Optimum temperature. — Grows luxuriantly at 37°
Morpliology.* — A large bacillus, forming long chains.
tipore formation. — Old cultures resist heating to 80° C, and this microbe commonly occurs in cultivations
80°
Source.
0.,
made from sewage which have
previously been heated to
preparation, however, has not been obtained.
—
A satisfactory double-stained
C. for 10 minutes.
Motility.
This organism is motile.
Gelatine plates cultures.^ The colonies in the depth have a characteristic fluffy appearance. They rapidly
increase in size, and reaching the surface quickly liquefy the gelatine. The growth is filamentous in the depth,
and on the surface from the spreading edge of the colonies, delicate film-like processes are given off, which extend
over the surface of the medium to form irregular patterns. Later, the finer details of growth are lost, owing to
the rapid liquefaction of the gelatine, the colonies eventually appearing as large, more or less circular, areas of
liquefied gelatine with greyish-white contents.
Agar " streak " cultures. In 24 hours an opaque-white growth of limited extent appears, which along the
spreading edge is slightly transparent and granular-looking. Later, the growth may extend laterally to cover
a wide extent of surface.
Gelatine "streak" cultures.
longitudinal furrow appears due to the liquefaction of the gelatine, but from
the edge of the furrow delicate processes may be seen extending in irregular fashion over the surface of the solid
gelatine.
The furrow is nearly clear as the bacteria slip down the sloping surface with the liquid gelatine, and
collect at the foot of the tube.
Soon all details of growth are lost, owing to the progressive liquefaction of the
—
—
—A
medium.
—
Gelatine "stab " cultures. Liquefaction takes place in funnel form, and extends down the stab to an extent
varying in different cultures. Along the line of the inoculation feathery processes are given off, which extend
into the solid gelatine for a short distance. The masses of bacteria gradually sink to the foot of the liquefied
medium.
—
Liquefies gelatine rapidly, blood serum less rapidly.
Gas formation.— i^o gas is formed in gelatine "shake" cultures. Sometimes the colonies in "shake"
cultures have a beautiful star-shaped appearance, but at other times they are globular.
Broth cultures.— In broth at 37'' U. there is diffuse cloudiness with flocculent masses scattered throughout
the medium. Later, a skin forms on the surface, and an abundant white bacterial deposit collects at the foot
of
the tube, leaving the liquid above fairly clear.
Indol.
ISIo indol is formed in broth cultures.
Litmus milk cultures.— No decided change, even after 72 hours at 37° 0. In five days weak Gelatinous
clot
"
but no apparent acidity.
Botato cultures.— Bj the second day at 37" 0. a fairly abundant creamy coating has formed
on the surface of
the medium, and later this becomes of a dirty-brown colour.
Blood serum culture^i.-Bj the second day, at 37" C, a white-coloured growth, having no special
characters
Liquefaction slowly sets in, and by the 16th day is practically complete.
Beduction of nitrates. Reduces nitrates to nitrites.
Bemarks.—'Vhis microbe has been called B. capillareus because of the hair-like character
of its growth in
gelatine plate cultures.
It resembles in some respects B. mycoides, B. subtilis and
B. mesentericus. but
lAguefaction.
—
'
—
not
suinoieutly to suggest a similarity of species.
VI.-DESOEIPTION OF MICRO-PHOTOGRAPHS
AND DIAGRAMMATIC
DRAWINGS ACCOMPANYING REPORT.
at 20°
?^'
'"'^^'"'''
'
i'^P^'ession preparation
X ToOO*'"'
from
"
swarming islands
"
on gelatine
sporogenes (Klein); microscopic double-stained
preparation
showin'^^'f'orei^' x"2'oO?'''
^~"^' ™'''"*'""''' ^"^"""^ ^^"^*y
X
^
;
20 hours' growth,
from a serum
culture,
microscopic preparation from a 20 hours' agar culture at 20° C.
;
1 OOO'"'
Fig.4.-B. mesentericits sewage variety E microscopic preparation stained
by V. Ermengem's
method
o
="
and showing numerous flagella, from a
hours agar culture at 20'^ C
x 1 000
^'~'^' ™"'"'"'''™ "'''^-^ ^^"''^y ^ mi'^roscopic preparation from
a
'
M
X
1,000.'*^'
;
>=
20 hours' agar culture at 20° C.
'
Fig. 6.-B. mesentericus sewage variety I microscopic preparation
stained by V. jjiiuBiigem
Ermengem'sb method,
mui^nuur
showing numerous flagella from a 20 hours' agar culture at 20"' C
x 1 000
Fig. 7.—B. mesentericui sewage variety I gelatine plate culture.
About natural size
Fig. 8.-B. mesenterwus sewage variety I
gelatine " stab " cultures.
From left to '^^^^
right-three
days',,
umctj uaj-o,
two days one day s growth at 20° 0. About natural size
^'~^' '"'''"^'"""^ ^^^^f^" ^^"^'^ ^' P"^^'^" culture, one day's
growth at 37° C. Very slightly
enlargS"'
'
;
;
;
;
,
iQj'S-10-"'5s»<;a^«i^''°i'^«'-"
X
Microscopic preparation from an agar
culture; 24 hours' growth at 20° 0.
^^X^^^^^, Wr2rCJ^^^S';g^^c:JSeIi g^!^Tir
*I^ig-
24
plate
VL
t Fig. G.
^°^- ^^-^"^^ ^ ^^"^^'
platelEI
"
——
— ——
'
—
41
—
Fig
"
12.
" Sewage proteus " ; gelatine plate culture, two days' growth at 20° C.
About natural size.
Vig,.!?!.—" Sewage proteus." From left to right gelatine "shake" culture, 24 hours at 20° C. ; gelatine
stab " culture, 24 hours' growth at 20° 0. ; gelatine " stab " culture, 48 hours' growth at 20° 0. About natural
—
size.
Fig.
X 1,000.
Fig.
Fig.
Fig,
Fig.
14.
B.frondosus.
15.
Fig.
Fig.
Fig.
Fig.
B.fmiformis.
17.
18.
—
About natural
size.
B.
B.
B.
B.
B.
20.
21.
22.
23.
Fig. 24.
X
Gelatine plate culture. About natural siz;e.
Microscopic double-stained preparation, showing spores.
X 1,000.
B. subtilissimus. Impression preparation from a gelatine plate culture.
X 1,000.
B. suhtilissimus. Gelatine " streak " cultures, 24 hours' growth at 20° 0. Natural size.
8. subtilis.
Sewage variety B. gelatine "stab" cultures. 1 day's and 3 days' growth at 20° 0.
B.frondosus.
16.
Fig. 19.
Microscopic double-stained preparation from an agar culture showing spores.
Sewage variety B. Obhque agar culture, 3 days' growth at 20° C. About natural size.
membraneus patulua. Impression preparation from gelatine plate culture. X 1,000.
membraneus patulus. Oblique gelatine culture. About natural size.
membraneus patulus. Gelatine " stab " culture, 3 days' growth at 20° 0. About natural size.
oapillareus.
Impression preparation from a gelatine plate culture, 20 hours' growth at 20° C.
suhtilis.
1,000.
sewage variety A. Gelatine " stab " culture
days' growth at 20° C.
(6) Three days' growth at 20° 0.
(c) Four days' growth at 20° G.
Fig. B. B. subtilis, sewage variety A. Colony in gelatine plate, under low power of microscope
Two days' growth at 20° 0.
Fig. C. B. suhtilis, sewage variety B. Gelatine " stab " cultures
(a) Two days' growth at 20° C.
(6) The same as (a) but at a later stage.
Fig. D. B. subtilis, sewage variety B. Blood serum culture
48 hours' growth at 20° G.
Fig. B. B. m,embraneus patulus. Oblique gelatine culture.
Showing the appearance, under a low power of the microscope, of the
Fig. F. B. membraneus patulus.
delicate film-like processes which extend over the surface of the medium in gelatine plate cultures.
Fig. G. B oapillareus. Under a low power of the microscope.
{a) Deep-seated colony in gelatine, 20 hours' growth at 20° 0.
(b) Colony partly deep and partly superficial, 20 hours' growth at 20° 0.
(c) Colony at a later stage of growth, and after liquefaction had set in.
Fig. A.
B.
(a)
—
subtilis,
Two
—
^^
'
!
^ --L-
r
r
-^
T
ri
rn
T
7
T
t
+++
BE.
--H-
-•-r
-r-~-f-*-^-
r-izmxtr It
i-+-rt._.:
-++
M
'
I
J .j-_t^-+-
I
-I
!
I
'
i-
I
'^-f-~
!
:
-r+-r!
I
h
i
i
'
-+:
i
^4-
[E
T-+-^i-
ME- CPFtBENT -Mr GHE1IICAI"1F TOE^^
-H-
— V^
arcROsm
:*^if?Aef^
by " oxygen absorbed from Permanganate!'
represent in every caSe the dissolyed oxidisable matter only, and
do not include the suspended matter. The coke-bed efi9n^nt wa»-
l^OTB^lie
results obtained
.^
alwiys free from suspended" matter^ siiice the raw sewagejiras]^
all suspended inattei^l^-tbe bacterial treatme it.
deprived of
i^-^^
a±^:E3E£l£±3zHiizziil
ml
+^4-
lis
1gri^-2S
VII.-FURTHER BACTERIOLOGICAL RECORDS FROM AUGUST
Addendum A.
Total
Date.
number
— Showing the
of bacteria in
total
1 c.c.
number
of bacteria
m
l
c.c. ot
Crossness crude sewage
:
and
in
1
c.c.
9tli
TO DECEl
of effluents from
4-ft., 6-f
ICAL RECORDS FROM AUGUST
)t
CrossneBS crude sewage; and in
1
c.o.
9th
TO DECEMBER
of effluents from
Total
4-ft., 6-ft.
31st,
1898.
(primary), and 6-ft. (secondary) Coke-ted.
1
8
J
Addendum
Number
B,
showing the number of bacteria causing liquefaction of gelatine in
of bacteria causing liquefaction of gelatine in
Date.
1
cc-
1 cc.
of Crossness crude sewage
;
and in
1 cc.
of effluents
ssness crude sewage
;
and in
1 cc.
JVumberof
of effluents from 4-foot, 6-foot (primary),
|£
and 6-foot Csecondary) Coke beds.
AiiDENDtiM C.
— Showing
the
number
Number of Spores of Bacteria
Date.
of spores of bacteria in
in 1 c.c.
1 c.c.
of Crossness crude sewage
;
and
in
1
c.c.
of effluent
froi
IS
crude sewage; and in
1 c.c.
of effluent from
Jfumfjer
C7f
4-ft.,
6-ft.
(primary), and
6-ft.
(secondary) CokE-bed.
Addendum
—
D.
Showing the number of B. coli (or closelj^ allied forms) in 1 c.c. of Crossness crude sewage (16 samples) in 1 c.c. o
[Calculated from the numbe
coke-bed (6 samples); and in 1 c.c. of effluent fiom 6-ft. (secondary) coke-bed (2 sample.s).
plate cultures containing O'OOOOl c.c. of sample.]
from
Number of
Date.
;
G-ft. (jirimarj')
B. coli (or closely allied forms) in
1
1 cc. of Crossness crude sewage (16 samples)
in 1 cc. of effluent from 4-ft. coke-bed (7 samples); in 1 cc. of effluent
idary) coke-bed (2 samples).
[Calculated from the number of colonies indistinguishable from B. coli in phenol gelatine
;
B. Coll
per cc
Addendum
— Showing the number of spores of B.
K.
from G-ft. (primary) coke-bed (17 samples)
coke-bed (15 samples).
ettluent
;
in
1
enteritidis sporogenes (Kleiii) in
c.c of effluent
1
c.c.
of Crossness crude sewage (17 samples) ii
6-ft. coke-bed again treated in laboi
;
from laboratory vessel (effluent from
Scores of 6
Er>tf;r/hd/s
Sporogef?e3
per
Number of spores of
c.c
coke-bed
effluent again
primary
(j-ft-
]
Effluent from
laboratory vessel
Effluent from
Effluent from
4-ft. coke-bed.
Crude sewage.
Date.
B. enteritidis sporogenes (Klein) in
(6-ft;
ookt-lped.
Effluent from
6-ft.
secondary
coke-bed.
treated).
1S98.
Aug. 19
„
24
Sept. 14
&0-01
-1-01
-fO-1 &0-01;
—0-001 c.c.
0-01
-1-0-1,
&
+
0-1
&
0-01
C.C.
+
0-1
&0-0]
c.c.
;^i
„
28
+ 0-1,
0-01
-1-0-1,
0-01
0-001
o.c.
5
12
c.c.
+
0-1, 0-01
+ 0-1,
0-01
0-1, 0-01
&
0-1
+
0-1, 0-01
+
;
0-1
&
—0-01
0-01
;
;
c.c.
+
0-1;
—0-01
c.c.
+
0-1
&0-01
C.c.
+
0-1
&
0-01
C.C.
+
0-1
&
0-01
c.c.
+
0-1
&
0-01 c.c.
+
0-1;
c.c.
&
+
0-1
+
0-1, 0-01;
0-01
c.c.
c.c.
0-01
c.c.
—0-001
& 0001
+
;
c.c.
+ 0-1, 0-01
—0001 c.c.
c.c.
c.c.
0-01
-t-0-1,
+
+ 0-1;
;
c.c.
+
-0-001
c.c.
—0-001
,.
0-001
;
—0-001
Oct.
&
0-1
—0-001
-0-001
,.
+ 0-1
+
0-1,0-01
& 0-001
c.c.
+
c.c.
&0-01
0-1
c.c.
—0-01
..
„
Nov.
..
21
+
0-01;
0-001 c.c.
-1-0-1,
0-1
&0-01
—0-1 &
2
+ 0-1
+
0-1 c.c.
y
+ 0-1,0-01 & 0-001
c.c.
+
0-1,0-01
16
+ 0-1, 001 & 0-001
c.c.
+
0-1
;
0-01
+
c.c.
&
0-1
„
Dec.
23
c.c.
30
7
+ 01.
0-01
+ 0-1,
+ 0-1
01
14
+ 0-1,
21
0-001
c.c.
+ 0-1,
0-0001
&
& 0001
c.c
0-01 c.c.
+
0-1
+
0-1,
+
0-1
&
0-01
0-1 c.c.
4-
0-1
+
0-1, 0-01
&
0-01;
001 c.c.
—
&
+
0-1
&
0-01 c.c.
?0-01
+
0-01
&
c.c.
&
+
0-1
+
0-1, 0-01
— 0-001
+
c.c.
0-1
&
c.c.
+
c.c.
0-1,
0-01
&
0-01
c.c.
0-01
+
—
0-1;
c.c.
0-1, 0-01
001
+
c.c.
0-1, 0-01;
—0-001
0-001
c.c.
+
0-1,0-01
&
0-001
c.c,
? 0-1
signifies the presence
and the sign
? 0-1
;
c.c.
;
c.c.
0-1;
-0-01
c.c.
0-01 c.c.
+ 0-1 &0-01
+
;
c.c.
?
c.c.
—0-01
c.c.
c.c.
+ 01 &
+
;
c.c.
c.c.
0-01
&0-01
+ 01
+
-0-01
The sign
0-01
+ 0-1 &0-01
c.c.
c.(.-.
0-01;
—0-001
„
&
0-001. c.c.
;
—001 &
„
&
0-1
c.c.
0-001
—0-001
„
+
0-1, 0-01;
—0-001
-1-0-1, 001
—0-001 c.c.
26
+
c.c.
c.c.
— 0-01
c.c.
;
c.c.
— the absence of spores of B. enteritidis sporogenes (Klein).
c.c.
cc-
sample.s); in 1 c.i:;. of
B. enheritidis sporogenes (Klein) in 1 c.c. of Crossness crude sewage (17 samples) in 1 c.c. of effluent from 4-ft. coke-bed (17
c.c.
fi-om 6-ft. secondary
1
of
effluent
and
in
samples)
laboratory)
treated
in
(2
c.c of effluent from laboratory vessel (effluent from 6-ft. coke-bed again
;
;
Spofcsof
m) in
C.C
]
Effluent from
laboratory vessel
(6-ft; coke-beJ
Effluent from
6-ft.
secondary
coke-bed.
effluent ae;ain
treated).
+ 0-1
+
0-1;
—0-01
c.c.
—
-f
0-1
&
0-01
c.c.
+
0-1
&
0-01
c.c.
B
W.„ cI'S'^jiZ^XT'^^' ^T^?*''-!
»f "»<ie sewage
'hTeStfperJ'; "Xat:*^^"
"""
by coke-beds.
These percentages have
by
""^ ""^ Pe™-g-te by the i.e.aja„d
Diagram
'T^S W
3,
"""
showing the
f
'f
coke-bed (two samples).
Td^l munber
total
''^''* ^'''"'
number of
^"^^^'^
^-^"°*
bacteria in 1 cc. of Crossness crude sewage (b,en
(«ight samples)
and in 1 cc. of effluent from 6-fc
foot
r
/
ipqo
;
>
^^7
Diagram
samp es); in
1
4,
showing the number of spores of
bacteria in
from 4-foot coke-bed (8 samples)
coke-bed (2 samples).
,'
jVurnier of
Spores ofBac/ena
in J cc
1
cc. of effluent
;
cc. of
and in
Crossness crude sewage (10
1 cc. of effluent from 6-foot
Diagram 5, showing the nutnber of bacteria causing liquefaction of gelatine in 1 cc. of Urossness
(ten samples; in 1 cc. of effluent from 4-foot eoke-bed (eight samples)
and in 1 cc. of
sewage
crude
effluent from 6-foot coke-bed Ctwo samples).
;
J^ofBacteria.
;
1898.
jV" of Bac/cni/
AngrMS^.
of Geiatinem Ice.
/
700,000
1,600,000
/,
600,
000
1,500,000
I,
SOO,
000
/,
700, 000
WO, 000
I,
I,
wo. 000
300,
000
/,
300,000
I,
200,
000
/,
200,000
/,
/OO,
000
I,
/OO,
/,
/,
000,000
I,
000,000
900,
000
800,
000
000
900,000
800,
000
700,
000
700,000
eoo,ooo
600.
000
500,
000
4-00,
000
300,
000
SCO,
000
wo, 000
300,
000
200,000
200,000
/OO,
/OO.
000
= ^ossne^s O^ide. ^^^^^, '1";^
Red = EffUoervbfrorw^fj'/^M&lf
£lacJo
OMerage of dEocpts)
000
t
-P
o
•i-i
o
8
.S|
§
C3
<c
bo
il
O
rH
t+,
d
^<
f?
a
O
03
.S -p
-p
o
(S
la
MH
^,
"I
o
-p
O
12
to
CO
"^
CO
u
^
a
^
r
bo
£
bo
.a
o
CD
eg
s
Diagram 8, showing the numl)er of spoivs of B. Enteritidis Sporogmes (Klein) lu 1 cc. of
Crossness crude sewage (eleven «;unples)
1 cc. of effluent from 4-foot coke-bed (ten samples)
in
1 cc. of effluent from 6-toot coke-hed (five samples)
and in 1 cc. of effluent from laboratory coke-bed
(effluent from 6-foot cok.-bed again treated in laboratoiy at Crossness— four samples).
;
m
:
;
Mtmber
ofSpores
Diagram 9, showing the number of B. Coli (or closely allied forms) in 1 cc, of Crossness crude
sewage (ten samples) in 1 cc ,of effluent from 4-foot coke-bed (eight samples) ; and in 1 cc. of effluent
from 6-foot coke-bed (two samples). [Calculated from the number of colonies in phenol gelatine plate
culture containing 0-00001 cc. sample, which were indistinguishable from B. Coli in the characters of
their growth.]
;
/?
(yjj
,
PLATE
I.
/^^^
—
PLATE
II.
Fig.
Fig.
6—B.
raesentericus.
Sewage variety I. Microscopic preparation from a 20 hours' agar culture at
20*= C. X 1,000.
Fig. 7
—B. mesentericus.
Sewage variety I.
plate culture, about natural size.
6—
B. mesentericus.
Sewage variety I. Microscopic preparation stained
by V. Ermengem's
method, showing numerou.s flagella
hours' agar culture at 20° C. x 1,000.
Gelatine
Fig. 8
— B.
mesentericus.
" stab " cultures,
(a)
(h)
(o)
Sewage variety
about natural size
Three days' growth at 20° 0.
Two day.s' growth at 20° C.
One days' growth at 20° (1.
from a 20
;
I.
Gelatine
PLATE
HI.
Fig.
—
10 " Sewage proteus."
Microscopic
preparation from an agar culture
24
hours' growth at 20° C. X 1,000.
;
—
Fig. 9 B. mesentericup.
Sewage variety I. Potato
culture, one day's growth at 37° C, very slightly
enlarged.
Fig.
—
" Se\page proteus."
Microscopic
11
preparation stained by V. Brmengem's
method, showing one flagellum at the end
of each rod
from a 24 hours' growth agar
culture at 20° C. X 1,000.
;
Fig. 12
— " Sewage proteus."
days' growth at 20°
Gelatine plate culture, two
C about natural
,
size.
—
PLATE
IV.
—
Fig. 14 B. frondosus.
stained preparation
showing spores X
Fig.
18—" Sewa.ge
(a)
(6)
(c)
proteus."
About natural
Microscopic double-
from an agar culture
1,000.
size
Gelatine •' shake " culture. 24 hours' growth at 20° C.
Gelatine " stab " culture. 24 hours' growth at 20° 0.
Gelatine " stab " culture. 48 hours' growth at 20° C.
Fig. 16
—B. fusiformis.
Microscopic double-stained
preparation, showing spores
Fig.
15— B.
frondosus.
Gelatine plate culture, about natural
size.
X
1,000.
PLATE V.
Fi8.
17— B.
aubtilissimus. Impression preparation
from a gelatine plate culture x 1,000.
Fig. 18
— B. subtilissimus.
Gelatine " streak " cultures,
0., natural size.
24 hours' growth at 20°
—
Pig. 19
B. subtilis.
" stab " cultures,
(a)
(6)
Sewage variety
day's growth at 20° C.
Three days' growth at 20° 0.
One
B.
about natural size—
Gelatine
—
Yio. 20 B. subtilis.
culture, 3 days'
Sewage variety B. Oblique agar
growth at 20° C, about natural
PLATE
VI.
Fig
B. membraneus
patulus.
Impression
preparation from a gelatine pbite culture x
1,000.
Fig.
Fig.
—
i-I
B. membraneus patulus.
Oblique
gelatine culture, about natural size.
—B.
24
capillareus.
Impression
preparation
from a gelatine plate culture, 20 hours' growth
at 20° 0.
—
"
Gelatine " stab
Fig. 23 B. membraneus patulus.
culture, 3 days' growth at 20° 0., about natural
X
1,000.
—
PLATE
VII.
-4
V
">^V^
i
\
'•
(tlM
',
.
'';
..;!
'
!
tVi
,
>
I
i
^B
|i'^i|
Wl
Fig
Fig. a.
—
A
Gelatine " stab
Sewage variety A.
B. subtilis.
''
cultures
Two days' growth at 20° C. (b) Three days' growth at 20° C. (o) Four days' growth at 20° C.
Sewage variety A. Colony in a gelatine plate under a low power of the
Fig. B.— B. subtilis.
microscope. Two days' growth at 20° C.
{a)
(Diagrammatic.)
K#'-^
..
,-
\r
\,f¥
^'^'^''4k^P'
v^'
"t
^^r^
K
...
1^
,
\i'>^
..Mi
1,1
y
(i))
(a)
FigC.
Fig.
C—
B.
cultures—
(a)
(b)
Fig
D —B
'culture.
Sewage variety B.
subtilis.
Two
Gelatine " stab
"
n f oao p
days growth at ^0 Kj.
,
The same
at a later stage.
Sewage variety B. ^ Blood
Forty-eight hours' growth at 20 0.
subtilis.
(Diagrammatic.)
serum
—
PLATE
VIII.
m
1
.y^/j
Fig. B.
JFlG.
F.
Figfc.
—B. membraneus patulus.
— B. membraneus patulus.
Oblique gelatine culture.
Showing the appearance under
a low
power
of the microscope, of the delicate film-like processes which
extend over the surface of the medium in gelatine plate cultures.
(Diagrammatic.)
r
(a)
M
(cj
FioG".
— B. capillareus.
(h)
Under a low power of the microscope
Deep-seated colony in gelatine. Twenty hours' growth at 20*^ C.
Colony partly deep and partly superficial. Twenty hours' growth at
(c)
Colony at a
Fig. G.
(a)
•20°
C,
later stage of
growth and
after liquefaction
(Diagrammatic.)
had
set in.
'"%
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