414 C. S. WILLIS. 



(a) Of the 37 cases occurring in the twelve months, 30 

 occurred on premises where there were wells ; 



(b) A large number of the cases occurred amongst people 

 who, it is reasonable to suppose, had access to the 

 wells actually condemned. 



Reference to attached map will show the relative 

 positions of cesspits, wells and houses in which typhoid 

 occurred. 



Summary : 



(1) Personal inspection of the cesspits and the wells, com- 

 bined with local evidence, proved that seven of the 

 condemned wells were being polluted by soakage from 

 cesspits. 



(2) Epidemiological evidence supported the conclusion that 



these wells were being contaminated by the cesspits. 



(3) Chemical evidence of the pollution of seven of the wells 



was furnished mainly by the large and the varying (in 

 different wells) quantity of N as nitrates present in 

 the well waters. 



