1880.] 



Water supplies of Calcutta. 



87 



after use be thrown on the surface of the ground, or into the nearest ditch, 

 from which it would either run or percolate into the tank or well a 

 second time, and would naturally be in a still more impure condition. Such 

 ■would appear to be the natural conclusions as to su^^plies of water derived 

 from rivers, and from tanks and shallow wells in towns, and it will be sub- 

 sequently seen that the quality of the Hooghly river water, and of the 

 water of the tanks and wells within Calcutta, as deduced from numerous 

 analyses fully bears out the above suggestions. 



In speaking of the former supply of water to Calcutta, I have assumed 

 that it was confined to the various tanks and wells distributed throughout 

 the town ; for though there is no doubt that the river water was used consi- 

 derably by the inhabitants who lived near the banks of the river, yet the 

 greater number of the inhabitants living as they did at a distance from the 

 river, must have depended for their supply of household water on the tanks 

 and wells nearest to them. The modern water supply of Calcutta which we 

 have to consider is of course the Hooghly water collected at Pultah and, 

 after filtration, etc., distributed through the ordinary mains. 



For the purposes of this paper I have not thought it necessary to analyze 

 all the tank and well waters in the town, which amount to many hundreds, 

 but as I have examined 200 samples, some from the crowded districts of the 

 northern part of the town, and some from the open maidan, I think a fair con- 

 clusion can be derived from them. I have also to mention, that a very large 

 number of the well and tank waters which I have analyzed, have been 

 noticeable for their bad quality, and for having apparently given rise to 

 disease of one kind or another to tlie persons who were living in the neigh- 

 bourhood. Therefore the numbers usually obtained represent the bad 

 rather than the good waters of the old supply. I should however wish 

 to point out, that there is every probability, that the water in the tanks and 

 wells now, is of a much better quality then formerly it was, for by the present 

 system of drainage and conservancy, a vast amount of excreta and filth of 

 all kinds is removed from the town, which informer days must have remain- 

 ed to choke up the soil, and to render the tank and well water very much 

 more impure than at present. 



I will attempt first to shew, that, when the inhabitants of this town 

 depended for their water supply on the tanks and wells, the quantity was 

 decidedly insufficient during at least one half of the year. 



With regard to the necessity of a sufficient supply of water being given 

 to a town for domestic and sanitary purposes, a well known author on Hy- 

 giene, writes — * 



" It was there shown that want of water leads to impurities of all 

 kinds ; the person and clothes are not washed, or are washed repeatedly in 

 * Parkcfs' Hygiene, 5th edition, p. 37. 



