NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
152
SAMPLE V.—RESERVOIR WATER—FIRST TAP AFTER RESERVOIR.
C o l o n y n u m b e r . L a c t o s e . S a c c h a p o e e .
D u l c i t e .
A d o n i t e . I n u l i n .
V o g e s e a n d P r o s k . I n d o l .
M o t i l i t y .
Gr oup.
Bacillus.
Groups and
remarks.
(a) Total colonies per cc on agar at 37°—210.
(b) Bile salt lactose, medium.
+
— 1 + — — — — — +
— IV B. Vesiculosus .. Group I, 9
2 + — — — — — + — IV
Do ..
,, II, nil,
1 tube 20 cc. of water taken..
..
1
. . 3 + — — — — — + — IV
Do. .. ,, III, n i l .
1
..
4 + — — — — — + — IV
Do. ..
,, IV, 1,
2 tubes 10 cc.
, ,
.. . .
2
. .
5 + — — — — — + — IV
Do.
3 ,, 5 cc.
, ,
. .
.
...
. .
1
6 + — — — — — + — IV
Do.
3
, ,
1 c c .
, ,
. .
. . ..
3
7 + — — — — — + — IV
Do. .. Class I, n i l .
3 „ •1cc.
, ,
. .
. .
. .
3
8 + + — + — — + — IV
,, II, nil.
3 „ •01 cc.
, ,
. .
. .
9 + — — — — — + — IV B. Vesiculosus .. ,, III, 9.
1 0 + — — — — — — — IV B. Mutabilis .. Undetermined, 1,
(c) Fœcal bacilli in 5 cc. and upwards.
(d) Glucose fementers in ·01 cc. and upwards.
SAMPLE VI.—ONE OF THE FOUR TAPS IN FRONT OF COLLECTOR'S
OFFICE ABOUT TWO MILES FROM HEAD-WATER WORKS IN
BUDARPET.
(a) Total colonies on agar at 37º—3,780.
1 + + + + — + — — III B. 67.
.. Group I, 5,
(b) Bile salt lactose, medium.
„ II, nil,
+
— 2 + + + + — + — — III Do. ..
„ III, 5,
3 + + + + — + — — III Do. ..
4 + + + + — + — — III Do. ..
, , I V ,
n i l
.
1 tube 20 cc. of water taken..
.. 1
. . 5
+ + + + — + — — III Do.
6 +
—
— — — — — — I B. Mutabilis
2
2 tubes 10 cc.
, , . . . .
. .
Class I, nil,
7 + — — — — — — — I
Do. ..
3 „ 5 cc.
,, ..
..
1
2
I
,, 11, 5.
Do. ..
3
8 + — — — — — — —
3 „ • 1 cc.
,, .. ..
..
Do. .. „ III, 5.
9 + — — — — — — — I
3 ,, • 1 cc.
,, .. ..
. . 3
Undetermined, n i l
.
10 + — — —
— — — —
I
Do. ..
3
3 ,, ·01 cc. ,, .. ..
. .
(c) Fœcal bacilli in 10 cc. and upwards.
(d) Glucose fermenters in 1 cc. and upwards.
SAMPLE VII.—FOUNTAIN No. 12 IN BASTION ROAD TERMINUS IN
KURNOOL FORT, TWO MILES FROM HEAD WORKS.
1 +
— — — — —
+
—
I B. Vesiculosus
Group I, 10.
(a) Total colonies per cc. on agar at 37°—
5,040.
(b) Bile salt lactose, medium.
+
—
2 +
— — — — —
+
—
I
D o . . .
, , I I I
n i l .
3 + —
—
— — — + — I
Do.
,, III n i l .
4 + —
—
— —
—
+
—
I
D o . . .
, , I V ,
n i l ,
1 tube 20 cc. of water taken.. ..
1
. . 5 +
— — — — —
+
—
I
Do.
2 tubes 10 cc.
, ,
. .
..
2
. . 6 +
—— — — — —
+
—
I
Do
3
„
5 c c .
. .
. .
2
1
7 +
— — — — —
+
—
I
Do. .. Class I, Ni l.
3
, ,
1 c c .
, ,
. . . .
. .
3
8 + —
—
— —
—
+ — I
D o . . .
, , I I
ni l .
3
„·1 cc.
, ,
. .
. .
. .
3
9 + — — — — —
+
—
I
D o .
„ I I I 1 0
3
, ,
· 0 1 c c .
, ,
..
. .
. .
3 10 +
— — — — —
+
—
I
Do. .. Undetermine
d, nil.
(a) Fœtal bacilli in 5 cc. and upwards.
(d) Glucose fermenters in 1 cc. and upwards.
------
153
Chemical Analyses.
SAMPLE No. I.
SAMPLE NO. II.
Physical
appearances.
Colour and
Transparency.
Brownish and opaque.
White and opaque.
Smell.
None.
None.
QUANTITATIVE.
Total solids.. .. .. .. .. Parts per 100,000 ..
136.600
41.000
Temporary hardness
.. .. ..
Do. ..
3.500
3.000
Permanent hardness.. .. .. ..
Do. ..
2.000
2.000
Total hardness .. .. .. ..
Do.
5.500
5.000
Chlorine
.. .. .. ..
Do. ..
1.065
1.065
Ammoniacal Nitrogen .. .. ..
Do. ..
0.002
0.004
Albuminoid Nitrogen .. .. ..
Do. ..
0 . 0 1 7
0.012
Oxygen absorbed (Tidy's Process)
..
Do. ..
0 . 3 7 3
0.147
Nitric Nitrogen .. .. .. ..
Do. ..
0.025
0.025
QUALITATIVE.
Nitrites
. .
. .
. .
. .
N i l .
Nil.
Sulphates.. .. .. .. .. .. .. ..
.
Present.
Present.
Phosphates
.. .. .. .. .. .. .. ..
Nil.
Nil.
Iron, poisonous metals .. .. .. ..
..
Nil, Nil.
Nil, Nil.
SAMPLE NO. III.
SAMPLE NO. VII.
Physical
appearances.
Colour and
Transparency.
Brownish and opaque.
White and opaque.
S m e l l .
None.
None.
QUANTITATIVE.
Total solids ..
.. .. .. Parts per 100,000 ..
32.000
13.600
Temporary hardness
.. .. ..
Do.
..
3.000
2.500
Permanent hardness.. .. .. ..
Do.
. .
2.000
1.500
Total hardness .. .. .. ..
Do.
5.000
4.000
Chlorine .. .. .. .. ..
Do.
..
1.065
1.065
Ammonical Nitrogen
.. .. ..
Do.
Trace.
0.003
Albuminoid Nitrogen .. .. ..
Do.
..
0.008
Trace.
Oxygen absorbed (Tidy's Process)
..
Do.
..
0 . 1 2 7
0.033
Nitric Nitrogen .. .. .. ..
Do.
0.037
Trace.
QUALITATIVE.
Nitrites .. .. .. .. ..
..
Nil.
Nil .
Sulphates .. .. .. .. .. .. .. ..
Present.
Present.
Phosphates .. .. .. .. ..
..
..
Nil.
Nil .
Iron, poisonous metals .. .. .. .. .. .. ..
Nil, Nil.
Nil, Nil.
89
154
REPORT.
The flooded condition of the canal accounts for a fairly high total number of microbes per
cc. and for the presence of fœcal bacilli in so small an amount of water as 1/100th of a cc.
Thes e l at t er however al l bel ong t o t he mor e r es i s t ent var i et i es and t hi s s hows t hat t he f i r s t and
most dangerous part of the surface pollution has been got rid of. None of the samples show
signs of recent pollution.
Sample 2 shows a somewhat curious state of affairs. The excremental bacilli have been
decreased a hundredfold but the total count of micro-organisms has been very largely increased,
which is exactly the opposite of that which we would expect to occur in a settling tank.
Probably there was some local and temporary cause to account for this.
Sample 3 from the southern tank is quite different, and shows the improvement expected
from sedimentation in a marked degree.
The water has not been improved by filtration ; the total count is very high and no
reduction of the lactose fermenters has been brought about. The filters are probably both
dirty and inefficient.
The water from the reservoir again shows a great improvement which forces the conclusion
on us that sedimentation is a far more valuable measure than filtration as the latter is carried
out at Kurnool.
Passage through the pipes of the distributary system has not altered the water from the
point of view of excremental pollution from which we may gather that the pipes are sound. A
very large increase has however taken place in the total number of microbes present. This
would seem to point to accumulated silt in the pipes.
Chemically the water is satisfactory, the large amount of total solids in the water of the canal
is due to the condition of the flood. Throughout the figures for hardness and salinity remain
much the same, while sedimentation in the reservoirs and pipes has reduced the total solids
tenfold.
156
SAMPLE V.—WESTERNMOST TAP NEAR RAILWAY STATION
COMPOUND.
C o l o n y n u m b e r .
L a c t o s e .
S a c c h a r o s e .
D u l c i t e .
A d o n i t e .Inulin.
V o g e s a n d P r o s k . Indol.
M o t i l i t y .
Group.
Bacilus.
Group and
remarks.
(a) Total colonies per cc. on agar at 37°—
1 , 8 9 0 .
_
+
(b) Bile salt lactose, medium.
1 tube 20 cc. of water taken
1
. .
1
+ + + + — + — — III B. 67 ..
..
.. Group I, nil.
2 tubes 10 cc. "
..
2 ..
2 + + — + — — — — IV B. Gasoformans
. .
" II, nil.
3 „ 5 cc. "
2
1
3 + + + + _ + _ _ III B. 67
• •
..
,, III, 8
3 „ 1 cc. " • •
1
2
4 + + +
+
_ + _ — III Do.
• .
..
,, IV, 2.
3 „ .1 cc. " ..
..
3
5 + +
+
+ _ + — — III Do.
....
3 „ .01 cc. ,, .. ..
3 6 + +
+
+ — + _ — III Do.
• •
• •
....
7 + + +
+
_ + _ — III Do
..
.. Class I, nil.
8 + + + + _ + _ — III Do.
..
..
,, II, 10.
(c) Fœcal bacilli in 5 cc. and upwards.
9 + + + + — + — — III Do.
..
..
„ III, nil.
(d) Glucose fermenters in .1 cc. and upwards.
10 + + _ + — - - — IV B. Gasoformans ..
SAMPLE NO. 1.
SAMPLE NO. V.
157
Chemical Analyses.
Physical
appearances.
Colour and
Transparency.
Yellowish and opaque.
White and opaque.
Smell.
None.
None.
QUANTITATIVE.
Total solids ..
..
..
..
.. Parts per 100 , 000
28...400
1 7 . . . 0 0 0
Temporary hardness
..
..
..
Do.
3...500
5 . . . 5 0 0
Permanent hardness
..
..
..
Do.
. .
2...000
2...500
Total hardness
..
..
..
..
Do.
•
5.500
8.000
-Chlorine
. ,
..
..
..
..
Do.
. .
1...420
1 . . . 4 2 0
Ammoniacal Nitrogen
..
..
..
Do.
0...002
0.006
Albuminoid Nitrogen
..
..
..
Do
..
0...016
0.004
Oxygen absorbed (Tidy's Process)
..
Do.
. .
0...097
0...028
Nitric Nitrogen
..
..
..
..
Do.
Trace.
Trace.
QUALITATIVE.
Nitrites
..
..
..
..
..
..
..
Nil.
Nil.
Sulphates ..
..
..
..
..
..
..
..
..
Present.
Present.
Phosphates
. .
..
. .. ..
..
..
. .
..
Nil.
Nil.
Iron, poisonous metals ..
. .
..
..
..
..
Nil.
Nil.
REPORT.
On the whole the results obtained from this quarter's analyses can be regarded with some
satisfaction. The total count of microbes per cc. is far too high in the unfiltered water, but this
is probably due to the heavy rainfall. The very small proportion of microbes of animal origin
shows that the gathering ground is clean. In the filtered water the total count of organisms
is also very high, and this seems due to the post filtration passages being foul. That the
filters are moderately good may be seen from the fact that the excremental microbes have been
reduced by eighty per cent. The samples taken from the more distant parts of the distributary
system show reduced numbers for the total counts though none of them are what can be called
good in this respect. There is no very obvious explanation for the varying quality and quantity
of the microbes found in the water from different parts of the system. There are too many
varieties in the waters taken from the taps near the filter beds and near the harbour. The east-
ern tap near the beach yields the best water from this point of view, as there is pratically only
one variety, and that of the most resistent kind. On previous occasions the water from the tap
in the railway compound was worse than the others, and it alone on this occasion shows all the
varieties of microbes examined belonging to the more susceptible class II—certainly a step in
the wrong direction. The particular microbes however are not in themselves objectionable, and
the limited number of species present does not suggest contamination being drawn into the
pipes at this point. ..
Chemically the water is satisfactory. Filtration here also has brought about some improve-
ment in the reduction of the total solids, most probably that portion of them associated with the
heavy rainfall.
4 0
40
159
SAMPLE V.—FOUNTAIN IN FRONT OF VETERINARY HOSPITAL
(a) Total colonies on agar at 37°—
(b) Bile salt lactose, medium.
–
C o l o n yn u m b e r .
L a c t o s e . S a c c h a r o s e . Dulsite. A D o n i t e . I n u l i n . V o g e s a n d P r o s k . Indol.
M o t i l i t y
Group.
Bacilli.
Group and
remarks.
+
–
1 + + - + - + - - IV B. Lactis ærogenes ..
Group I, nil.
1 tube 20 cc. of water taken ..
1
. . 2
+ + - + - + - - IV
Do
„ I I ,
n i l .
2 tubes 10 cc.
,,
1
1 3 +++ - + - - - - IV B. Gasoformaus ..
,, III, nil.
3 ,,5 cc.
,,
3
. .
4 ++ - - + - + - + IV B. 102 ..
..
, ,
I V , 1 0 .
'
3 „
1 cc.
,, ..
1
2 5 ++ + - + - + - - IV B. Lactis ærogenes ..
. . . .
3 „
...1 cc.,, .. ..
. .
3
6 +,- + - + - + - + IV B. 102
.. Class I, nil.
3 ,, ...01 cc. ,, .. ..
. .
3
7 + + - + -
+- - IV B. Lactis ærogenes ..
„ II, 9.
(c) Fœcal bacilli in 5 cc. and upwards.
8 ±- + - + - - - IV
Do.
„ III, nil.
9 +- - + - - - IV
1 1 6 . .
Undetermined,
10 ++ - + - + - + IV
1 0 2
1.
a
(d) Glucose fermenters in .1 cc. and upwards.
I
SAMPLE No. II.
SAMPLE No. IV.
160
Chemical Analyses.
Physical
appearances.
Colour an
d Transparency.
Yellowish and hazy.
Yellowish and hazy.
Smell
None.
None.
QUANTITATIVE.
Total solids ..
..
..
..
.. Parts per 100,000 ..
14...000
13...600
Temporary hardness
..
..
..
Do...
3...500
3...500
Permanent hardness
..
..
..
Do.
..
2...000
2...000
Total hardness
..
..
..
..
Do.
..
5...500
5...500
Chlorine
..
..
..
..
Do.
..
1...420
1...420
Ammoniacal Nitrogen
..
..
..
Do.
..
0...003
Trace.
Albuminoid Nitrogen
..
..
Do.
..
0...022
0...014
Oxygen absorbed (Tidy's Process) . .
Do.
..
0...201
0...125
Nitric Nitrogen ..
..
..
..
Do.
..
Trace.
0 . . . 0 2 5
QAULITATIVE.
Nitrites
..
..
..
..
..
..
..
..
..
Nil.
Nil.
Sulphates ..
..
.. ..
..
..
..
..
Present.
Present.
Phosphates..
..
..
..
..
Nil.
Nil.
Iron, poisonous metals ..
..
..
..
..
..
..
Nil, Nil.
Nil, Nil.
REPORT.
Considering the very considerable rainfall that has taken place since the water was last
examined, it is not very surprising to find evidence of extensive pollution in the samples taken
on the 27th September. There is in the water taken from the Samalkota canal a very large
total count and excremental microbes in one hundredth of a cc. These latter also show a con-
siderable variety of species which farther confirms the extensive nature of the pollution, but the
species present show that the recent and dangerous pollution has probably been washed away
leaving the gathering grounds harmless if not so clean as they might be.
The results got with sample II, taken from the storage tank show what a very valuable
measure storage is The excremental germs have been reduced a hundred fold and the total
count- is also much lower.
Sample III shows that filtration has not improved the water. The variety of fœcal germs
has been reduced but not the number. On the other hand the total count has been largely
increased. Probably the filters are efficient enough, but the post filtration passages are dirty.
Sample IV drawn from the pillar fountain near the Port Railway Station is not materially
different from the filtered water.
Sample V is better and shows the effect of sedimentation in the service pipes. A multipli-
cation of species has however crept in which is difficult to account for. Otherwise this sample is
quite satisfactory.
Chemically the water is quite fair, though the figures for albuminoid nitrogen both actually
and in relation to those for absorbed oxygen are on the high side.
163
Report on the Town Water Supplies of the Madras Presidency
for the quarter ending 31st December 1909 being Part
III of Appendix II to the Annual Report of the King
Institute of Preventive Medicine, Madras, for the year
1909
167
s u r r o u n d i n g s c a n h a r d l y b e t h e c o r r e c t o n e . T h e c o n d i t i o n o f t h e p i p e s a s r e g a r d s
leaks should be carefully examined. If polluted subsoil water were being sucked into
them and pumped into the reservoir, the mystery would be explained.
Vizagapatam.—The quaiity of the Vizagapatam water is fairly consistent and
pretty good. It is better after there has been a good deal of rain, though perhaps
not very recent rain. An agreeable feature of the installation is that the water is
always improved by filtration. This indicates good management. The water in the
distributary pipes has improved of late.
Kurnool.—There are several curious features about the management of the
Kurnool. supply. The supply from the canal seems to be pretty constant and. yet the
supply to the town is intermittent. If this be due to a desire for economy in
pumping, it is likely to prove a very expensive luxury. Unless absolutely necessary
the strain of intermittent service is not one to which the best laid of pipes should be
subjected. The results got from the settling tanks are highly contradictory and
were exceedingly bad on the last occasion. With an unfailing supply of water and
well constructed and conserved settling tanks, improvement in the water should
result as regularly as clockwork. There is probably faulty management somewhere.
The pipes, as a natural result of having such water run into them, are very dirty.
Vellore.—The tendency in the water of Vellore is distinctly towards betterment,
and the latest analyses showed very good results indeed. The weakest point in the
system seems to be the filtration which, though it usually improves the water to some
extent, does not do so to the extent we expect from properly constructed and managed
sand filters. The efficient filtration is absolutely necessary is shown by the highly
contaminated condition of the unfiltered water in July 1909. It is evident that such
purity as was displayed by the unfiltered water in December of 1909 cannot always
be counted. on.
KING INSTITUTE,
F. MAITLAND GIBSON, M.B.,
B.Sc.,
GUINDY, 25th February 1910. Acting Director.
169
Chemical Analyses.
SAMPLE No. I.
SAMPLE No. IV
Physical
appearances.
Colour and
Transparency.
White and opaque.
Colourless and clear.
Smell.
None.
None.
QUANTITATIVE.
Total solids
..
..
..
Parts per 100,000.
16.400
16.400
Do.
6.500
7.000
Temporary hardness ..
..
Do.
1.500
1.500
Permanent hardness
..
..
..
Do.
7.000
8.500
Total hardness
..
..
..
..
Do.
1.065
1.065
Chlorine .. .. .. .. .. ..
Do.
0.003
0.003
Ammoniacal Nitrogen .. ..
..
Do.
0.012
0.003
Albuminoid Nitrogen..
..
..
..
Do.
0.087
0.014
Oxygen absorbed (Tidy's Process)
..
..
Do.
Trace.
Trace.
Nitric Nitrogen ..
..
..
..
..
QUALITATIVE.
Nitrites ..
..
..
..
..
. .. .. ..
Nil.
Nil.
Present.
Present.
Sulphates ..
..
..
..
..
..
..
..
..
Phosphates
..
..
..
..
..
..
Nil.
Nil.
Iron, poisonous metals ..
..
..
..
..
..
..
Nil.
Nil.
REPORT.
The condition of flood in which the river Cauvery was at the time the samples were taken
precludes the possibility of the water showing good results. The total number of microbes was
so large as to be uncountable, and it is therefore gratifying that the organisms of animal origin
are so few as one in a cc. Probably all the more objectionable kinds also had been washed away
at the time, but of this we cannot be quite certain as a large proportion of the varieties found
belonged to species whose resistance to natural purifying agencies has not been determined. Still
none of the better-known varieties usually associated with recent objectionable pollution was
found.
Passage through the infiltration gallery produced a very marked change in the bacterial
content of the water. The total count is still far too high, but the excremental microbes are
greatly reduced in number and are practically confined to one species. This species was not
however represented in the river water, so it has probably been derived from the gallery and
conducting channels. This idea is borne out by the results shown on examining Sample III from
the distributary system. Here we find the same germ in preponderating and greatly increased
amount. There must be a good deal of deposit in the pipes to account for this. Sample IV is
quantitatively very like Sample III, but there has been a complete change in the varieties present.
These changes in different parts of the same distributary system are difficult to account for
. P r o b a b l y s i l t h a s a g o o d d e a l t o d o w i t h t h e m b u t w h y t h e d e p o s i t s h o u l d b e d i f f e r e n t i n t h e
different pipes is not quite so clear.
Chemically the water is excellent.
43
171
Chemical Analyses.
SAMPLE No. I.
SAMPLE No. IV.
Physical
appearances.
Colour and
Transparency.
White and opaque.
Colourless and clear.
Smell.
None.
None.
Q U A N T I T A T I V E .
Total solids ..
..
..
..
.. Parts per 100,000 ..
35.400
17.400
Temporary hardness
..
..
..
Do.
..
6 . 5 0 0
7.000
Permanent hardness
..
..
..
Do.
..
1 . 0 0 0
1.000
Total hardness ..
..
..
..
Do.
..
7 . 5 0 0
8.000
Chlorine ..
..
..
..
..
Do.
..
1.065
1.065
Ammoniacal Nitrogen ..
..
. .
Do.
..
0.002
0.002
Albuminoid Nitrogen ..
..
. .
Do.
. .
0.017
0.002
Oxygen absorbed ( Tidy's Process) ..
Do.
. .
0 . 1 1 6
0.009
Nitric Nitrogen ..
..
..
. .
Do.
..
T r a c e .
0.037
Q U A L I T A T I V E .
Nitrites ..
..
..
..
..
..
..
..
Nil.
Nil.
Sulphates ..
..
..
. .
. .
. .
. .
. .
Present.
Present.
Phosphates
..
..
..
..
..
..
..
Nil. Nil.
Iron, poisonous metals ..
..
..
..
..
..
..
Nil.
Nil.
REPORT.
The river Coleroon being partially flooded at the time the samples were taken, it is not
surprising to find a very large number of microbes in the water,.’and that one-tenth of a cc. shows
the presence of fœcal bacilli. These latter however are of the more resistant types which shows
that a considerable amount of cleansing of the drainage area or of the water has taken place.
From the point of view of efficiency the filters must be held to be good, as passage through
them has reduced the excremental organisms one hundred and fifty fold, but a countless number
of organisms of other kinds is not what we look for in filtered water. The post-filtration passages
must be very foul to account for this.
The water taken from a tap in Kodikkal street is considerably improved by its three-mile
passage through the pipes. If this be mainly, or even largely, due to sedimentation it is difficult
to believe that it can go on indefinitely, so that it is likely that the pipes will in time become
sources of pollution. As noticed in previous analysis the water from the tap near the railway
station compound is not so good as that from other parts of the system, but on this occasion
it is not bad and it is only by comparison with the other samples that it does not show to
advantage.
Chemically the water is good. The higher total solids in the river water is largely
suspended matter, present owing to the flooded condition of the river.
173
Chemical Analyses.
SAMPLE No. I.
SAMPLE No. IV.
Physical.
appearances.
Colour and
Transparency.
Reddish and opaque.
White and hzy.
Smell.
None.
None.
QUANTITATIVE.
Total solids ..
..
..
..
.. Parts per 100,000 ..
63.400
20 200
Temporary hardness
..
Do.
..
5.000
7.500
Permanent hardness
..
..
Do.
3.000
2.500
Total hardness
..
..
Do.
..
8.000
10.000
Chlorine
..
..
..
..
..
Do.
. .
1.420
1.952
Ammoniacal Nitrogen
..
..
..
Do.
..
0.006
0.003
Albuminoid Nitrogen
..
..
Do.
..
0.058
Trace.
Oxygen absorbed ( Tidy's Process )
Do.
. .
0.560
0.049
Nitric Nitrogen ..
..
..
..
Do.
..
0 . 0 2 5
0.037
Q U A L I T A T I V E .
Nitrites ..
..
..
..
..
..
..
..
Nil. Nil.
Sulphates ..
..
..
..
..
..
..
..
Present.
Present.
Phosphates
..
..
..
..
Nil.
Nil.
Iron, poisonous metals ..
..
..
..
..
.. . .
. .
Nil.
Nil.
REPORT.
In respect to the purity of its water-supply Madura evidently leads a very up and down
existence, and at the time these samples were taken down and very much so was the order of the
day. The water could hardly be worse. At this season last year and under very similar con-
ditions, that is with a small stream of water in the Vaigai river, the state of affairs was very
different. Then as always the river water was bad, but the water taken from the distributary
system was so good as to give rise to the conjecture that the subsoil water and not the river was the
real source of supply. On the present occasion some support is given to this idea by the result
of the chemical analyses, those obtained from the river and supply water respectively being very
different, and in a sense not likely to have been brought about by simple filtration. Chemically
the supply water is much the better, but bacteriologically it shows signs of even more recent
pollution than the river water. If it be really subsoil water that is being pumped from the in-
filtration gallery, then the subsoil water is liable to serious and what might at any time become
dangerous pollution. A drinking-water supply, that without any obvious cause, shows the
presence of oxytoccus perniciosus and coli communis can only be regarded with the gravest sus-
picion, and if any other supply be available it should be investigated in order to see if something
more satisfactory cannot be got. The huge total count of microbes in the sample drawn from
the tap in Block No. 1, Railway Station road, Mungammal Chattram points to a dirty condition
of the pipes. All the samples, river and supply water alike show the presence of the susceptible
microbes of class I, indicative of recent pollution, and the number of species present shows that
the pollution in addition to being recent and objectionable is extensive.
44