Sept. 1,
1870.]
THE POTABLE
WATEBf^OF
CALCUTTA?BY W. J. PALMEE.
ON RECENT IMPROVED METHODS OF ANALYSIS OF POTABLE WATERS, AND ON THE DRINKING WATERS OF CALCUTTA. By Surgeon W. J. Paxmek, M.D.
analyses of the drinking "water of Calcutta having recently made, and the new water-supply being now in full operation, a favourable opportunity is afforded for collecting some of the most important results obtained, and observations on the recent presenting them together, with such into this branch of analysis as "will introduced improvements render the facts more generally available. In the ordinary been distilled from the ocean course of nature, water, having by the sun, is stored on mountain heights, in the form of snow, or descends as rain, to supply the wants of man; in both cases it is delivered in a state of purity, and at the same time, at such an elevation above the level of human habitations, that if conducted directly by suitable means, every house might be supplied A numbee of been
with
a
perpetual
and unlimited flow of pure water, without tbe or pumping machinery of any kind
intervention of purifying
ordinarily obtained, however, water is always both by organic and inorganic impurities, the former being by far the most important from a sanitary point of view. Until recently, no better method of estimating the proportion of this kind of impurity in water was known, than that afforded by the loss of weight which occurred when the solid residue, remaining after the evaporation of the water, was burned or 'incinerated' : so recently indeed as the year 1867, Dr. Frankland, the Government analyst of metropolitan whatever. or
more
As
less
contaminated
cent, of sewage matter waters, asserted that less than one per in a litre (If pints) of water could not be satisfactorily determined ; one year later than this the processes had been Frankland himself, that in so far improved, chiefly by Dr. be detected and estimated 1868, he said ^foth per cent, could these processes have with certainty ; and still more recently and accuracy. been further improved, both in simplicity By the of Messrs. "Wanklyn and Chapman the different and
system
organic matter are by chemical means ammonia, and by the justly celebrated test 'Nessler's,' one part of this compound can be correctly
ever-changing
forms of
which i3 absorbed " immediately" by cold water; and 2nd, that which it will absorb after being acidified and heated to a
temperature 122?F. (50?c). The first indicates the amount of organic matter which is actually ptitrescent at the time of examination ; the second, that which is putrescible or just about to become putrescent. This test is valuable, not only as indicating the condition of the water itself, but also that of the superincumbent air which is being contaminated and rendered unwholesome by the impure water. The faint depressing smell of foul water in hot weather, and the bracing' effects of pure ocean air denote, to ordinary observation, the two extremes of this condition; while sea-water only requires O'lO per million parts to neutralize all its putrescent and putrescible mattert, and the water of mountain streams or lakes only 0*15, some of the Calcutta tank waters have lately required 2'00, and even as much as 3'00 to purify the same quantity. The depressing effects of such foulness on the general health is probably a great predisposing, even though it may not be an immediate cause of disease. Some experiments have been made to estimate the amount of oxidizable organic matter represented by a given consumption of oxygen, from which it appears that one part of this body corresponds to about 20 parts of the putrescible matter. =
'
" Free Ammonia and Ammonia of Urea."?This column in the tables indicates that portion of organic matter which in the natural course of change and decay forms ammonia, viz., sewage and other refuse animal matters. Ammonia when
formed, rapidly disappears again, wherever the water is freely exposed to sun and air, especially where it is also in motion a high temperature ; all these conditions prevail rivers; so that the ammonia formed in them is very evanescent, disappearing partly by escaping into the surrounding air, and partly by becoming chemically united with in the water, forming in the first place oxygen while still nitrous acid, and afterwards, when more fully oxidized, nitric
and
exposed
known
estimated, even when it is diluted with the enormous proportion of twenty million (20,000,000) parts of water; even this remarkable result however does not represent the limit of attain-
delicacy, for ammonia, being a very volatile body, can easily concentrated; the whole amount contained in any a process of distillation obtained in given solution being by one-tenth part of that solution, so that one part of ammonia means be detected, even when diluted with as may by this much as two hundred million (200,000,000) parts of water. it must be admitted that Thus, as far as quantity is concerned, of delicacy almost the processes have attained a degree inconthe quality of this ceivable ; to the sanitarian, however, organic than its gross matter is of far greater importance bulk; for minute ova of fish conexample, the chemist would classify the able
be
tained in the water as organic matter, which the sanitarian would regard as health-giving, rather than infecting germs. Until the smell of the incinerating organic matter
recently almost the only
was test by which its quality could be estimated; now, however, the improvements in this direction are almost as wonderful as those above detailed concerning its quantity. of the several heads under An examination of the
significance
which these results are noted in the analytical this apparent?thus " Oxygen required." or
tables,
The amount of oxygen which water is capable of assimilating is estimated under two conditions:
will make
acid and nitrates.
proportion, therefore, of these three bodies in water affords indication of the present condition of this portion of the organic matter, and also of that which has already passed The
an
"
into
something rich and strange."
"Where only nitric acid or nitrates are detected, all the conmatters have, by the beneficient laws of nature,
taminating nitrous acid or nitrites are already become innocuous; where found to co-exist, evidence is afforded that these changes are still in active operation; and where free ammonia is also found, it is known that the contamination is of quite recent date.*
The absence of nitrites does not appear to shew that water contained this particular kind of may not have previously refuse; some of the vegetation so common in the tanks
organic
about Calcutta having the power of assimilating these salts, and so causing them to disappear entirely. " Albuminoid Ammonia."?This is perhaps the most import-
headings, representing as it does that portion of matter which is not prone to decay, which possesses and which theresome inherent power to resist decomposition, fore probably includes all those bodies which are capable of or multiplying disease ; it is not to be supposed that ant of all the
the
organic
propagating
the whole of this portion is made up of disease producing germs, all the refinement of nor does it appear possible, with analysis hitherto attained, to infer'even how much is either harmless or to obtain water dangerous ; it is possible, however,
so
free from
All tie nitre or nitrate of potash found in and around the village* certain parts of the Bengal Presidency has, so far as I have been able observe, been thus formed by the decomposition of refuse, organic am) urinary matter, with the addition of wood-ash. also deriv?d especially ofrefuse. The presence of lime or kunkur in the soil apnear* to from village of this salt. formation the facilitate ?
in to
consuming 1st, that
to
in the Indian
converted into as
179
THE INDIAN MEDICAL GAZETTE.
180 it, that
million parts only yield
a
five hundredth of a part of (0'05 per 1,000,000 parts) ; the rule laid down by Messrs. "Wanklyn and Chapman, therefore, that "No drinking one
ammonia
water should
yield more than 0 08 per million," should be guide. The new Calcutta water-supply has yielded at different times, proportions varying from 0-05 to 0-17 per million; and the different drinking-water tanks, from 0-14 in the month of
accepted
as our
October when filled with fresh rain water, collected on wellgathering grounds, to 1*60 parts per million in the
washed
months of
May and June. It may be assumed that every part of ammonia under this head represents about ten parts of the organic matter from which it has been formed. "
Chlorine
?when the flow of water from up-country
was
1S70.
abundant,
the
sea-water had very little influence on that at Pultah; while in May, when the downward flow had almost ceased, the proportion of sea-chlorides rose to 165 per million.
important indication of the condition of the new scarcely be carried up to Pultah without a corresponding proportion of the refuse so constantly thrown into the river opposite the city. Of the remaining inorganic impurities; the " total solids" and the "hardness" alone require notice. As pure water contains no solids of any kind, the proportion of total solids aiforas a true measure of the amount of impurity ; but as water is only rendered unwholesome when these are very excessive, they may be passed over as comparatively unimportant. The hardness" is of importance to manufacturers, representing that part of inorganic matter which destroys soap, and deposits in boilers as ' fur'; thus causing increased outlay to those who use soap, and excessive expenditure of coal to those who use steam-power. It thus appears that organic matter in water can be estimated with certainty when there is a sufficient amount in 200,000,000 parts to yield one part of ammonia, and further that the following details concerning the quality of this matter can be discovered with tolerable certainty, viz.:? This is
supply,
an
for sea-salts can
"
calculated
places far from proportion of
the sea
or
Chloride of
as
Sodium."?In
other natural source of
chlorine,
ingredient affords a most useful indication of the amount of previous sewage pollution, whether recent or otherwise; in the Calcutta river, however, as well as in all tanks which are liable to be replenished to any extent with river-water, the chlorine derived from sewage cannot be distinguished from that of sea-salts. There are many tanks, however, in which the water is totally uninfluenced by that of the river, and in these the proportion of chlorine may be regarded as an index of the amount of organic pollution, and also as affording a tolerably safe means of judging how far the organic matter may have had a vegetable or animal origin. Normal urine contains about seven parts of chlorides in a thousand, and as these salts are tolerably permanent, it may be affirmed with safety, that the quantity of water whicn contains seven parts of chlorides could not have been polluted with more than 1,000 parts of urine, though the converse of this could only be stated after proving that no other source of chlothe
[September 1,
this
ls?.?What
proportion
i3
already putrescent,
and
2nd.?How much is about to become so.
3rd.?"What proportion has changed into, come
or
is about to be-
ammonia.
4 th.?What
proportion having passed through
the ammonia
stage has just become oxidized, and 5th.?How much has
passed through this stage
some
time
previously. 6th.?How much is in
a
condition to resist decomposition ;
rides existed.
and in most cases,
water-supply in Calcutta yielded in the month of May, occasions, respectively, 56, 60, 165, and 152 parts of chloride per million; in June, the proportion decreased to 44 parts; and in the preceding month of January, it had been as low as 21 parts per million. This varying proportion affords a tolerably correct indication of the extent to which the river at Pultah is effected by tides. In January,
a vegetable or origin. The following tabular statement shews the relative purity, as far as the moat important ingredients are concerned, of the Calcutta new water-supply, and that *of those cities ia Groat Britain where much time, intellect, and money have been expended to procure a good supply :?
7th.?Whether the organic matter has had
The new on
animal
four separate
Haedness.
TABLE I. Name ok Source WaIBB WAS
Date of
Analyses,
Oxygen
Total Solids.
required
1,000,000 [perPARTS.
Chloeiwe as
Chloride
of
S6dium. s
prom which
?
XAKJiX.
I
si ?-
?2
ca
COo
a
i'a
J3 c8
So
2o
?3
o
s-g3 ?
?
West Middlesex Water
1867
Com-} > Average ...)
pany's water, Grand Junction,
Chelsea
...
...
Soutliwark and Vauxhall Lambeth ...j River Company's water New Aug. June, July,
July 1S67
...
...
...
...
June 1867 August 1867 Sept. and Oct., 1867. October 1870 January 1870 ...
...
...
May 1870,
age June 1870, age
East
London Water
Company
Manchester Water-Supply
Edinburgh Water-Supply Glasgow Calcutta Water-Supply
New
Average Average Average Average
Average ...
...
15-4'
...
3-46
309-0
f2
o-oio
0-071
68-0
?>
a-012 0066 0-030 0-089 o-oii 0 075
6-2
32-8 166-0
11-42 0-085
0-45
21-4
0-31 0-65
0-022 0-075 0-004 0080 0-050 0-100
...
aver-
Ditto
Ditto
12-0
7-0
268-0
0-070
0-27
107-0
2-30
0-090 0-140
Ditto
Ditto
16-0
6-4
315'0
0-063
0-45
07-0
1-40
0-086
aver-
From the above table it appears that the Calcutta water is better in quality than that supplied by the worst London companies, though still inferior to that of the best; this, it must be confessed, is a great result, and if the municipal authorities had made no other improvements whatever, they might be
already
5 ?
3 61 0-01
...
'
Remarks,
0-017 0-15
... ...
ri
o
?2 s&
?4
July
_
'53
0-110
having conferred the greatest possible earthly congratulated blessing upon the poor of this great tropical city. The present degree of purity in the London water-supply has only been attained after years of improvements suggested by the results of successive analyses, and there is every reason on
Sept. 1,
1870.]
ON THE INFLUENCE OE THE POISON OE BUNGAKUS CCEEULEUS.
to believe that the Calcutta water may, in like manner, be
improved until it is as good as that of any city in the world. To gain any notion, however, of the advantages already attained, comparison should rather be made with the only watersupply formerly available, than with that at present existing in the healthiest large city in the world. Practically, the only water hitherto available in Calcutta was that supplied by the tanks, which are mere excavations in the earth of varying dimensions, scattered about in different parts of the town. During the rainy season these tanks become filled, nominally with rain-water, really to a very slight extent with that which falls directly into them, but chiefly by water which, having previously washed the surrounding surface soil, is conducted into them by ditches or drains made for the contained in them is therefore purpose y the water necessarily less impure: firstly, in proportion to the cleanliness or otherwise of the gathering grounds; and secondly, to the more
more or
or
less
filthy condition
of the soil in which
they
TABLE II.
were
Where this latter has been sewage soaked for generathe gathering grounds are merely densely-
excavated.
tions,
and where
populated streets, innocent of all drainage but that carried on at the surface, the kind of fluid which has to do duty for drinking water can scarcely be contemplated without feelings of
cholera, dysentery, and fevers should never city, ought not to excite surprise. The tanks in the open part of the town have this one advantage, that their gathering grounds are somewhat cleaner than those within the city, but in all other respects they are little better. One of those situated on the cleanest part of the glacis of the Fort has been lately deepened, and some of the earth removed was so black and foul, that the purest water would be rendered totally unfit for use after lying in contact with it for a time. The following table of analyses of some of the tank waters, contrasted with the new water-supply, will convey a notion of the advantages obtained :? that
repulsion;
have been absent from the
orginally
Habdness.
Total Solids.
Oxygen EE- Chlorine as ChloQUIRED PEE ride op
1,000,000
Sodium.
Pabts.
e
Name of Sottbce ebom which Wateb was taken.
Date of
Analyses.
181
.
3!
Remabks,
11 a
so
o
November 1869 December ,, February 1870 ^November 1869 December ,, February 1870
New Calcutta WaterSupply Tank opposite Bengal Club Ditto Ditto Ditto Ditto Tank near the Grand Stand Lall Diggie, Tank Square Ditto Ditto Water from the Seven Tanks General Hospital Tank Ditto Ditto New Tank on the Fort Glacis Ditto Ditto Ditto Ditto Old Tank on the Fort Glacis Ditto Ditto Ditto Ditto
November 18G9 March 1870
Fort Hydrant Water Ditto Ditto
June
May
1870 ,,
November 1869 ?>
December
it ,,
February 1870
December 1869 January 1870
February
October
January
,,
1869 1870
March 129 th
,,
May
,,
... ...
...
...
...
_
...
...
_
...
...
Tank in Alipore Parade Ground Ditto Ditto Ditto Ditto Ditto Ditto Tank ea9t of the LieutenantGovernor's Camp, Alipore J Diglah Tank, Dum-Dum
16-0 9-5 11-0 8-5
9-6 1-5 6-0 4-7
i'i:o
5:8
140 8-7 7-0 9-3 10-3 131 12-0 6-7 5-2 8-7 8'2 12-6
4-7 5-0 4-8
7-2 7-1 7-4 5-8
5-4
6-4 8-0 6-0 3-8 6-2 9-3 3-7
2-2 2-1 3-2 5-7 6-2
7-2
e-s
0-063 0-160 0-130
315-0 207-0 216-6 260-0 108-0 286-0 206-0 173-0 1900 146-0 260-0 200-0 220-0 170-0 266-6
0-080
a a
0-45 1-75 0-85 0-70 0-47 0-75
a
eg
1870.]
THE POTABLE
WATEBf^OF
CALCUTTA?BY W. J. PALMEE.
ON RECENT IMPROVED METHODS OF ANALYSIS OF POTABLE WATERS, AND ON THE DRINKING WATERS OF CALCUTTA. By Surgeon W. J. Paxmek, M.D.
analyses of the drinking "water of Calcutta having recently made, and the new water-supply being now in full operation, a favourable opportunity is afforded for collecting some of the most important results obtained, and observations on the recent presenting them together, with such into this branch of analysis as "will introduced improvements render the facts more generally available. In the ordinary been distilled from the ocean course of nature, water, having by the sun, is stored on mountain heights, in the form of snow, or descends as rain, to supply the wants of man; in both cases it is delivered in a state of purity, and at the same time, at such an elevation above the level of human habitations, that if conducted directly by suitable means, every house might be supplied A numbee of been
with
a
perpetual
and unlimited flow of pure water, without tbe or pumping machinery of any kind
intervention of purifying
ordinarily obtained, however, water is always both by organic and inorganic impurities, the former being by far the most important from a sanitary point of view. Until recently, no better method of estimating the proportion of this kind of impurity in water was known, than that afforded by the loss of weight which occurred when the solid residue, remaining after the evaporation of the water, was burned or 'incinerated' : so recently indeed as the year 1867, Dr. Frankland, the Government analyst of metropolitan whatever. or
more
As
less
contaminated
cent, of sewage matter waters, asserted that less than one per in a litre (If pints) of water could not be satisfactorily determined ; one year later than this the processes had been Frankland himself, that in so far improved, chiefly by Dr. be detected and estimated 1868, he said ^foth per cent, could these processes have with certainty ; and still more recently and accuracy. been further improved, both in simplicity By the of Messrs. "Wanklyn and Chapman the different and
system
organic matter are by chemical means ammonia, and by the justly celebrated test 'Nessler's,' one part of this compound can be correctly
ever-changing
forms of
which i3 absorbed " immediately" by cold water; and 2nd, that which it will absorb after being acidified and heated to a
temperature 122?F. (50?c). The first indicates the amount of organic matter which is actually ptitrescent at the time of examination ; the second, that which is putrescible or just about to become putrescent. This test is valuable, not only as indicating the condition of the water itself, but also that of the superincumbent air which is being contaminated and rendered unwholesome by the impure water. The faint depressing smell of foul water in hot weather, and the bracing' effects of pure ocean air denote, to ordinary observation, the two extremes of this condition; while sea-water only requires O'lO per million parts to neutralize all its putrescent and putrescible mattert, and the water of mountain streams or lakes only 0*15, some of the Calcutta tank waters have lately required 2'00, and even as much as 3'00 to purify the same quantity. The depressing effects of such foulness on the general health is probably a great predisposing, even though it may not be an immediate cause of disease. Some experiments have been made to estimate the amount of oxidizable organic matter represented by a given consumption of oxygen, from which it appears that one part of this body corresponds to about 20 parts of the putrescible matter. =
'
" Free Ammonia and Ammonia of Urea."?This column in the tables indicates that portion of organic matter which in the natural course of change and decay forms ammonia, viz., sewage and other refuse animal matters. Ammonia when
formed, rapidly disappears again, wherever the water is freely exposed to sun and air, especially where it is also in motion a high temperature ; all these conditions prevail rivers; so that the ammonia formed in them is very evanescent, disappearing partly by escaping into the surrounding air, and partly by becoming chemically united with in the water, forming in the first place oxygen while still nitrous acid, and afterwards, when more fully oxidized, nitric
and
exposed
known
estimated, even when it is diluted with the enormous proportion of twenty million (20,000,000) parts of water; even this remarkable result however does not represent the limit of attain-
delicacy, for ammonia, being a very volatile body, can easily concentrated; the whole amount contained in any a process of distillation obtained in given solution being by one-tenth part of that solution, so that one part of ammonia means be detected, even when diluted with as may by this much as two hundred million (200,000,000) parts of water. it must be admitted that Thus, as far as quantity is concerned, of delicacy almost the processes have attained a degree inconthe quality of this ceivable ; to the sanitarian, however, organic than its gross matter is of far greater importance bulk; for minute ova of fish conexample, the chemist would classify the able
be
tained in the water as organic matter, which the sanitarian would regard as health-giving, rather than infecting germs. Until the smell of the incinerating organic matter
recently almost the only
was test by which its quality could be estimated; now, however, the improvements in this direction are almost as wonderful as those above detailed concerning its quantity. of the several heads under An examination of the
significance
which these results are noted in the analytical this apparent?thus " Oxygen required." or
tables,
The amount of oxygen which water is capable of assimilating is estimated under two conditions:
will make
acid and nitrates.
proportion, therefore, of these three bodies in water affords indication of the present condition of this portion of the organic matter, and also of that which has already passed The
an
"
into
something rich and strange."
"Where only nitric acid or nitrates are detected, all the conmatters have, by the beneficient laws of nature,
taminating nitrous acid or nitrites are already become innocuous; where found to co-exist, evidence is afforded that these changes are still in active operation; and where free ammonia is also found, it is known that the contamination is of quite recent date.*
The absence of nitrites does not appear to shew that water contained this particular kind of may not have previously refuse; some of the vegetation so common in the tanks
organic
about Calcutta having the power of assimilating these salts, and so causing them to disappear entirely. " Albuminoid Ammonia."?This is perhaps the most import-
headings, representing as it does that portion of matter which is not prone to decay, which possesses and which theresome inherent power to resist decomposition, fore probably includes all those bodies which are capable of or multiplying disease ; it is not to be supposed that ant of all the
the
organic
propagating
the whole of this portion is made up of disease producing germs, all the refinement of nor does it appear possible, with analysis hitherto attained, to infer'even how much is either harmless or to obtain water dangerous ; it is possible, however,
so
free from
All tie nitre or nitrate of potash found in and around the village* certain parts of the Bengal Presidency has, so far as I have been able observe, been thus formed by the decomposition of refuse, organic am) urinary matter, with the addition of wood-ash. also deriv?d especially ofrefuse. The presence of lime or kunkur in the soil apnear* to from village of this salt. formation the facilitate ?
in to
consuming 1st, that
to
in the Indian
converted into as
179
THE INDIAN MEDICAL GAZETTE.
180 it, that
million parts only yield
a
five hundredth of a part of (0'05 per 1,000,000 parts) ; the rule laid down by Messrs. "Wanklyn and Chapman, therefore, that "No drinking one
ammonia
water should
yield more than 0 08 per million," should be guide. The new Calcutta water-supply has yielded at different times, proportions varying from 0-05 to 0-17 per million; and the different drinking-water tanks, from 0-14 in the month of
accepted
as our
October when filled with fresh rain water, collected on wellgathering grounds, to 1*60 parts per million in the
washed
months of
May and June. It may be assumed that every part of ammonia under this head represents about ten parts of the organic matter from which it has been formed. "
Chlorine
?when the flow of water from up-country
was
1S70.
abundant,
the
sea-water had very little influence on that at Pultah; while in May, when the downward flow had almost ceased, the proportion of sea-chlorides rose to 165 per million.
important indication of the condition of the new scarcely be carried up to Pultah without a corresponding proportion of the refuse so constantly thrown into the river opposite the city. Of the remaining inorganic impurities; the " total solids" and the "hardness" alone require notice. As pure water contains no solids of any kind, the proportion of total solids aiforas a true measure of the amount of impurity ; but as water is only rendered unwholesome when these are very excessive, they may be passed over as comparatively unimportant. The hardness" is of importance to manufacturers, representing that part of inorganic matter which destroys soap, and deposits in boilers as ' fur'; thus causing increased outlay to those who use soap, and excessive expenditure of coal to those who use steam-power. It thus appears that organic matter in water can be estimated with certainty when there is a sufficient amount in 200,000,000 parts to yield one part of ammonia, and further that the following details concerning the quality of this matter can be discovered with tolerable certainty, viz.:? This is
supply,
an
for sea-salts can
"
calculated
places far from proportion of
the sea
or
Chloride of
as
Sodium."?In
other natural source of
chlorine,
ingredient affords a most useful indication of the amount of previous sewage pollution, whether recent or otherwise; in the Calcutta river, however, as well as in all tanks which are liable to be replenished to any extent with river-water, the chlorine derived from sewage cannot be distinguished from that of sea-salts. There are many tanks, however, in which the water is totally uninfluenced by that of the river, and in these the proportion of chlorine may be regarded as an index of the amount of organic pollution, and also as affording a tolerably safe means of judging how far the organic matter may have had a vegetable or animal origin. Normal urine contains about seven parts of chlorides in a thousand, and as these salts are tolerably permanent, it may be affirmed with safety, that the quantity of water whicn contains seven parts of chlorides could not have been polluted with more than 1,000 parts of urine, though the converse of this could only be stated after proving that no other source of chlothe
[September 1,
this
ls?.?What
proportion
i3
already putrescent,
and
2nd.?How much is about to become so.
3rd.?"What proportion has changed into, come
or
is about to be-
ammonia.
4 th.?What
proportion having passed through
the ammonia
stage has just become oxidized, and 5th.?How much has
passed through this stage
some
time
previously. 6th.?How much is in
a
condition to resist decomposition ;
rides existed.
and in most cases,
water-supply in Calcutta yielded in the month of May, occasions, respectively, 56, 60, 165, and 152 parts of chloride per million; in June, the proportion decreased to 44 parts; and in the preceding month of January, it had been as low as 21 parts per million. This varying proportion affords a tolerably correct indication of the extent to which the river at Pultah is effected by tides. In January,
a vegetable or origin. The following tabular statement shews the relative purity, as far as the moat important ingredients are concerned, of the Calcutta new water-supply, and that *of those cities ia Groat Britain where much time, intellect, and money have been expended to procure a good supply :?
7th.?Whether the organic matter has had
The new on
animal
four separate
Haedness.
TABLE I. Name ok Source WaIBB WAS
Date of
Analyses,
Oxygen
Total Solids.
required
1,000,000 [perPARTS.
Chloeiwe as
Chloride
of
S6dium. s
prom which
?
XAKJiX.
I
si ?-
?2
ca
COo
a
i'a
J3 c8
So
2o
?3
o
s-g3 ?
?
West Middlesex Water
1867
Com-} > Average ...)
pany's water, Grand Junction,
Chelsea
...
...
Soutliwark and Vauxhall Lambeth ...j River Company's water New Aug. June, July,
July 1S67
...
...
...
...
June 1867 August 1867 Sept. and Oct., 1867. October 1870 January 1870 ...
...
...
May 1870,
age June 1870, age
East
London Water
Company
Manchester Water-Supply
Edinburgh Water-Supply Glasgow Calcutta Water-Supply
New
Average Average Average Average
Average ...
...
15-4'
...
3-46
309-0
f2
o-oio
0-071
68-0
?>
a-012 0066 0-030 0-089 o-oii 0 075
6-2
32-8 166-0
11-42 0-085
0-45
21-4
0-31 0-65
0-022 0-075 0-004 0080 0-050 0-100
...
aver-
Ditto
Ditto
12-0
7-0
268-0
0-070
0-27
107-0
2-30
0-090 0-140
Ditto
Ditto
16-0
6-4
315'0
0-063
0-45
07-0
1-40
0-086
aver-
From the above table it appears that the Calcutta water is better in quality than that supplied by the worst London companies, though still inferior to that of the best; this, it must be confessed, is a great result, and if the municipal authorities had made no other improvements whatever, they might be
already
5 ?
3 61 0-01
...
'
Remarks,
0-017 0-15
... ...
ri
o
?2 s&
?4
July
_
'53
0-110
having conferred the greatest possible earthly congratulated blessing upon the poor of this great tropical city. The present degree of purity in the London water-supply has only been attained after years of improvements suggested by the results of successive analyses, and there is every reason on
Sept. 1,
1870.]
ON THE INFLUENCE OE THE POISON OE BUNGAKUS CCEEULEUS.
to believe that the Calcutta water may, in like manner, be
improved until it is as good as that of any city in the world. To gain any notion, however, of the advantages already attained, comparison should rather be made with the only watersupply formerly available, than with that at present existing in the healthiest large city in the world. Practically, the only water hitherto available in Calcutta was that supplied by the tanks, which are mere excavations in the earth of varying dimensions, scattered about in different parts of the town. During the rainy season these tanks become filled, nominally with rain-water, really to a very slight extent with that which falls directly into them, but chiefly by water which, having previously washed the surrounding surface soil, is conducted into them by ditches or drains made for the contained in them is therefore purpose y the water necessarily less impure: firstly, in proportion to the cleanliness or otherwise of the gathering grounds; and secondly, to the more
more or
or
less
filthy condition
of the soil in which
they
TABLE II.
were
Where this latter has been sewage soaked for generathe gathering grounds are merely densely-
excavated.
tions,
and where
populated streets, innocent of all drainage but that carried on at the surface, the kind of fluid which has to do duty for drinking water can scarcely be contemplated without feelings of
cholera, dysentery, and fevers should never city, ought not to excite surprise. The tanks in the open part of the town have this one advantage, that their gathering grounds are somewhat cleaner than those within the city, but in all other respects they are little better. One of those situated on the cleanest part of the glacis of the Fort has been lately deepened, and some of the earth removed was so black and foul, that the purest water would be rendered totally unfit for use after lying in contact with it for a time. The following table of analyses of some of the tank waters, contrasted with the new water-supply, will convey a notion of the advantages obtained :? that
repulsion;
have been absent from the
orginally
Habdness.
Total Solids.
Oxygen EE- Chlorine as ChloQUIRED PEE ride op
1,000,000
Sodium.
Pabts.
e
Name of Sottbce ebom which Wateb was taken.
Date of
Analyses.
181
.
3!
Remabks,
11 a
so
o
November 1869 December ,, February 1870 ^November 1869 December ,, February 1870
New Calcutta WaterSupply Tank opposite Bengal Club Ditto Ditto Ditto Ditto Tank near the Grand Stand Lall Diggie, Tank Square Ditto Ditto Water from the Seven Tanks General Hospital Tank Ditto Ditto New Tank on the Fort Glacis Ditto Ditto Ditto Ditto Old Tank on the Fort Glacis Ditto Ditto Ditto Ditto
November 18G9 March 1870
Fort Hydrant Water Ditto Ditto
June
May
1870 ,,
November 1869 ?>
December
it ,,
February 1870
December 1869 January 1870
February
October
January
,,
1869 1870
March 129 th
,,
May
,,
... ...
...
...
...
_
...
...
_
...
...
Tank in Alipore Parade Ground Ditto Ditto Ditto Ditto Ditto Ditto Tank ea9t of the LieutenantGovernor's Camp, Alipore J Diglah Tank, Dum-Dum
16-0 9-5 11-0 8-5
9-6 1-5 6-0 4-7
i'i:o
5:8
140 8-7 7-0 9-3 10-3 131 12-0 6-7 5-2 8-7 8'2 12-6
4-7 5-0 4-8
7-2 7-1 7-4 5-8
5-4
6-4 8-0 6-0 3-8 6-2 9-3 3-7
2-2 2-1 3-2 5-7 6-2
7-2
e-s
0-063 0-160 0-130
315-0 207-0 216-6 260-0 108-0 286-0 206-0 173-0 1900 146-0 260-0 200-0 220-0 170-0 266-6
0-080
a a
0-45 1-75 0-85 0-70 0-47 0-75
a
eg
