1880.] 



Water supplies of Oalcutia. 



89 



stored for use ; then knowing that, according to the last Calcutta Census, the 

 density of the population was 109 persons per acre, it is easy to calculate 

 that each person could receive but 6'8 gallons oi fresh water daily. In all 

 probability, however, not one-fifth of the rainfall finds its way into these 

 tanks and wells, and this would leave the inhabitants less than 1^ gallons 

 oi fresh water per day during the hot season of the year. In the Coomar- 

 toUe Section of the town where the density of the population is 214 per 

 acre, this supply must be reduced to one half or to about three quarters of a 

 gallon of fresli water per day. 



If even we were to assume, that it was possible to store up the water 

 which fell during the rains, for use during the dry season of the year, 

 and gianting as before that one fifth found its way into the tanks and 

 wells, even then each inhabitant of the town could not have had more 

 than 6 or 7 gallons of fresh water daily, and an inhabitant of some parts 

 of the northern division, could not have had more than 3 or 4 gallons. 



The conclusion seems to me to be inevitable, that at the time when 

 Calcutta depended for its water supply on its tanks and wells, the 

 inhabitants must have used the same water over and over again though of 

 course without knowing it, not only for such purposes as bathing, washing 

 clothes etc., but probably also for cooking and even for drinking, and it 

 would also appear that there could have been absolutely no water for 

 necessary sanitary measures. 



That Calcutta, under these circumstances, should have had a high rate 

 of mortality is scarcely surprising. 



I will now endeavour to show that the quality of the old water supply 

 was even less satisfactory than its quantity, and that in a large number of 

 instances of tank and well water, if not in the majority of cases, the water 

 was, and still is, simply sewage, sometimes concentrated, sometimes dilute. 



That impure water may be the source of disease is, I believe, now 

 admitted on all hands, and if confirmation were required, abundant evidence 

 to this effect is given in the various reports of the Rivers Pollution Com- 

 missioners in England. The researches too of Chauveau, Burdon, Sanderson, 

 Klein and others scarcely leave room for doubt that the specific poisons of 

 the so-called zymotic diseases consist of organized and living matter • and 

 it is now certain that water is the medium through which some at least of 

 these diseases are propagated. There does not appear indeed to be any 

 doubt whatever that such diseases as cholera, typhoid fever, dysenterv and 

 diarrhoea may be produced by drinking impure or infected water. An excel- 

 lent and most conclusive instance of the propagation of typhoid fever by 

 water from one infected case near Basel in Switzerland is admirably de- 

 scribed by Dr. Hiiglcr, and is given in tlic sixth report of the Commissioners 

 above referred to. 



