126 



A. Pecller — On tlir past and present 



[No. 2, 



Also it must be remembered that Calcutta is a large shipping port ; 

 thus on the average I believe there are about 2,000 vessels annually 

 arriving and departing from the port, aggregating nearly two and 

 a half millions o£ tons ; to these must be added the very large numbers of 

 country boats, diughis, &c., which line the shores and which help to carry 

 on the great and increasing trade of Calcutta. Omitting the actual business 

 operations carried on, it must be admitted, that the crews of these vessels 

 will add a not inconsiderable amount of sewage contamination to the river 

 water. The tidal Avater, in flowing past Calcutta, must of necessity then 

 carry with it all such contamination, and will in that state be probably, if 

 not certainly, unfit for drinking, or even for domestic purposes. 



I think it cannot be disputed that, in selecting a site from which to 

 collect water for drinJcing and domestic purposes, it will be essential, that 

 at all seasons of the year, at the ordinary time of collection, (five hours' ebb) 

 there shall be practically no admixture of tidal water with river water 

 proper ; for it is evident, that the tidal water will always be contaminated 

 with various kinds of organic matter. 



The two questions which I suggested previously, thus become limited 

 to the consideration of whether at Cossipore, or at two or three miles 

 above it, the water at five hours' ebb is free from contamination with tidal 

 water at all seasons of the year. It would be bad enough to supply 

 brackish tidal water for drinking purposes, but far worse to supply tidal 

 water, which had collected all sorts of filth and abomination on its way 

 up. 



Having suggested what it appears necessary to prove, we can now 

 pass on to the consideration of the analyses which have been made on this 

 point. Most of these analyses were made from 12 to 18 years since, when 

 comparatively little attention had been given to the subject of water 

 analysis, and an important part of the method of analysis then employed 

 has been since shown to be eminently untrustworthy and unreliable. The 

 suitability of a water for domestic purposes is (as pointed out previously) 

 believed to depend principally on its freedom from organic contamination, 

 I am sorry to say that the methods for the determination of organic 

 matter in water, used in the old analyses under notice, have been since 

 shown to give at the best but very rough indications, which do not at all 

 represent the absolute amounts of organic matter present. Though these 

 methods of analysis failed to give thoroughly reliable information, yet I 

 do not think it too much to assume that, to a certain extent, they gave 

 information as to comparative purity of samples of the same variety of 

 water, and valuable information may thus be extracted from them. By 

 this I do not mean to say that the exact proportional freedom of the water 

 from organic matter will be represented by the figures given in these analyses, 



