94 Capfc. L. Rogers— il/oZana North of Calcutta. [July, 



TABLE III. ENLARGEMENT. 



Spleen Percentage and water supply. 



Filtered water. 



River water. 



Tank water. 



Total. 



Spleen not enlarged ... 



103 



105 



18 



226 



Spleen just felt 



23 (627,) 



32 (437o) 



10 (277,) 



65 



Spleen considerably 











enlarged 



9 (247o) 



26 (367J 



15 (407o) 



50 



Spleen markedly 











enlarged 



5 a37o) 



16 (217 J 



12 (337o) 



33 



Total examined ... 



140 



179 



55 



374 



Percentage of enlarged 











spleens 



264 



41-8 



672 



39-5 



If now the spleen 



rates for the different municipalities as 



shown 



in Table I (and in the Map), be now examined in the light of the figures 

 just given it will be evident that the difference in the water supply 

 will explain all the facts in a way that no other hypothesis will do. 

 Thus, Chitpore-Oossipore has *the lowest spleen rates, and it has the 

 double advantage of botli a full filtered water supply and close proximity 

 to the river. The influence of the latter is well illustrated by the fact 

 that the spleen rate of the two riverine wards is only 7 per cent., while 

 that of the other two wards which are from one to two miles from the 

 river, is 15 per cent., or just about the same as that of Maniktolla, 

 which is similarly situated. The obvious explanation is that those who 

 do not take the trouble to get the filtered water will drink river water in 

 the wards on its bank, while in those at a distance they will drink tank 

 water. The same point is illustrated by the differences between the 

 spleen rates of the western portions of Kamarhati and South Barrack- 

 pore and the eastern portions of the same municipalities, the former 

 with a water supply from the river having just about half the spleen 

 rate as the latter with only tank water for drinking purposes. In short 

 the much lower rate of the riverine parts is due to the difference in the 

 water supply, for as will be shown presently, there is no essential differ- 

 ence in the ground water level which can explain this distribution. The 

 good effect of even a partial water supply is once more shown by the 

 ward variations of the spleen rate in Baranagar and South Dum Dura. 

 In the former the lowest spleen rate, namely, 116, is met with in the 

 most southerly of the riverine wards, which borders on Cossipore, and I 

 found that many of the inhabitants of the small ward were getting their 

 filtered water from Cossipore, Again the only ward which is at a little 

 distance from the river in this municipality has the highest spleen rate, 

 being dependant on tank water to a great extent. 



