382 INVESTIGATION, ETC., OF MILK-BORNE EPIDEMICS 



no cases were traced to their supplies except on rounds associated 

 with the X supply. 



" Distribution of the inilkr 



" The dealer X, bringing in only milk from his own farm, distri- 

 buted it first outside the city, with a record of two cases ; the milk 

 then entered Clifton : — 



X. 



Houses supplied 

 Houses attacked 



>2i-o 



per cent. Cases, 8. 



" The distributor Y, receiving milk in churns from farms X and 

 A, affirmed his habit of mixing it before delivery, a statement 

 borne out by the uniform implication of his three delivery 

 rounds : — 



Yi. Houses supplied 

 Houses attacked 



Y2. Houses supplied 

 Houses attacked 



Y3. Houses supplied 

 Houses attacked 



Y. Total houses supplied 

 Total houses attacked 



o 1-25-0 per cent. Cases, 13. 

 M7-0 per cent. Cases, 11. 



7 f2i-7 per cent. Cases, 13. 

 [21-7 per cent. Cases, 37. 



" The distribution of Z milk, over an extensive round, is more 

 complicated. 



" The supply from farm X, about 50 quarts, was usually reserved 

 for the supply of the district W, the chief incidence of the disease 

 was upon two out of four streets in this district. 



" The milk was always distributed in this order : — 



Wi. The hand-can (holding 

 about 2 gallons) filled 

 by dipping from the 

 churn — usually X 

 milk, occasionally B 

 milk . . .^ 



W2. The hand-can filled a^ 



second time, always I Houses supplied 29) t- r 



from X milk and 'Houses attacked 5 j^Z-o per cent. Cases, 7. 



carried round. .) 



W3. The hand-can filled al tt r j 



third time, always 1^°"^^^ ^^P?'-'^^- ^4 



from X milk . 



W4. The hand-can filled a 



Houses supplied ii) .. <- 



'tt ^5 1 J f 9'0 per cent. Cases, 2. 



Houses attacked ij ^ ^ ' 



>20-0 



per cent. Cases, 6. 



third time, always ^^""^-^ .f^V^ . 

 from X milk . M Houses attacked 5. 



filled a" 



Houses supplied 29) i^y ^ 



i-i^. ^^r. r.4.^K,i ^A Ji }-None. Cases, none. 



Houses attacked o) ' 



fourth time, usually 

 from X milk, but 

 when this ran short 

 from B or C . 



" The immunity of W4 street seemed at first remarkable, as it 

 was on the supply from X churn, but as this street is invariably 

 dealt with last, and as the infection probably occurred upon a 



