1900 ] Capt. L. Uogevs— Malaria North of Calcutta. 93 



more than two and a half times as f^reat in the latter, wliich strikingly 

 confirms the local opinion as to the relative immunity of filtered water 

 drinkers from malaria. 



Tittagarh, two out of the four wards of which have a partial 

 filtered water supply from mills, afforded a good opportunity of putting 

 the matter to a crucial test, so a note was made of the water drunk 

 by nearly all the people examined. The results are shown in the 

 following tables. 



TABLE II. 



Ground Water Level. 

 Area. February. Rains, 1899. 



Ward IV. 10 ft. 1 in. 1 ft. 3 in. 



Ward in. 10 ft. 6 in. 1 ft. 6 in. 



Ward II. 



Ward I. 18 ft. 4 in. 6 ft. in. 



Drinking Water Supply. Spleen Percentage. 



River and tank water ... ... ... 48 



One-th'-,d drank filtered water ... ... 30 



82 per cent, drank filtered water ... 19 



River and tank water ... ... ... 54*8 



The much lower spleen rates in Wards II and III which had a 

 partially filtered water supply, and that too in proportion to the number 

 of persons examined who had drunk the filtered water is evident. But 

 this is not all for it will be seen from Table III below that the spleen rate 

 among 140 filtered- water drinkers is 26*4 per cent., that among 179 river- 

 water drinkers was 418, while out of 55 tank-water drinkers (who it 

 should be noted form a minority here), it was no less than 67*2 per cent. 

 Further, only 38 per cent, of filtered water drinkers in which the spleen 

 was enlarged, was it considerably (two finger-breadths below the ribs) 

 or markedly so, while in 62 per cent, it was only just felt between below 

 the ribs. In river-water drinkers it was much enlarged in 67 per cent, 

 and slightly so in 43 per cent., while in tank-water drinkers it was much 

 enlarged in 73 per cent., and slightly so in only 27 per cent. Not only, 

 then, is the spleen much more frequently enlarged in river and tank 

 water drinkers than in those who drink filtered water, but the degree of 

 enlargement is also much greater in the former than in the latter. 



