BACTERIA COMMONLY FOUND IN COWS* MILK. 91 



Comparing the data just given concerning the number 

 of bacteria found in milk, it will be seen that milk under 

 certain conditions may contain very few bacteria and 

 under other conditions immense numbers of these organ- 

 isms. That the latter is always the case with milk com- 

 ing from filthy stables is apparent from the data given, 

 and it is equally apparent that cleanliness and neatness in 

 the handling of the milk may cause a considerable decrease 

 in its bacterial content.* 



during May 1892, and from 10,500 to 13.6 millions, av. 2.9 millions, 

 in the same kind of milk sampled during June 1892. 



Knochenstiern (Inaug. Dissert. Univ. Dorpat, 1893) obtained the 

 following results in his investigations of the Dorpat milk supply : 

 40 samples of milk sold by milkmen : 



36,000-83 millions; av. 10.2 millions 

 25 samples of milk from village dairies : 



90,000-103 " " 12 

 35 samples of milk sold on market-place : 



137,000-287 " "25 " 

 40 samples of milk sold in milk stores : 



11,600-257 " " 30 



Gernhardt (Inaug. Dissert. Univ. Jurjew, 1893) found similar re- 

 sults for Dorpat milk. 



See also Baumann (Inaug. Dissert. Univ. Konigsberg, 1893, pp. 

 16, 17). W. 



* The number of bacteria in American milk has been studied by 

 but few investigators. Sedgwick and Batchelder examined the milk 

 supply of Boston bacteriologically (Boston Med. and Surg. Jour., 

 1892, Jan. 14) ; the average number of bacteria found in fifty-seven 

 samples in the spring of 1890 was 2,355,500 per cubic centimeter. 

 Sixteen samples obtained from groceries contained 4,577,000 per cc. 

 Ten samples collected from "well-to-do families upon the Back 

 Bay" showed an average of 1,438,000 per cc. The lowest number 

 found in Boston milk supplied in the ordinary way was 30,600 per cc. 



Dr. Russell (private communication) determined the bacteria con- 

 tent of morning milk as delivered to customers in Madison, Wis. : 



