Contamination of Milk. 51 



the cow 30,000 and in the milk as used on the table, 

 about 70,000 organisms per cc. Loveland and Watson 1 

 found in the supply of Middletown, Conn., from 11,000 

 to 85,500,000 per cc. McClatchie 2 found in Los Angeles, 

 Cal., supply, an average of 11,700 per cc. in twenty-six 

 trials. In my experience, the mixed milk of a herd that 

 is kept with any reasonable degree of cleanliness, if ex- 

 amined immediately after it is milked, usually will not 

 contain more than 520,000 germs per cc. The number 

 present in any milk is due to the influence of so many 

 factors that it is practically impossible to establish any 

 number as a normal, although Bitter 3 sets 50,000 germs 

 per cc. as a maximum limit for a milk intended for hu- 

 man food. The milk as delivered by the milkmen to 

 their private customers in the city of Madison, Wis., 

 ranges from 15,000-2,000,000 organisms per cc., varying 

 mainly with the season of the year. 



The presence of such large numbers in a food product 

 need not necessarily occasion alarm from a hygienic stand- 

 point, although it is quite certain that putrefactive forms 

 may have an irritating effect upon a deranged digestive 

 tract, and thus produce intestinal disturbances, especially 

 with infants during the summer months. 



If we compare the bacterial flora of milk with that of 

 sewage, a fluid that is popularly and rightly supposed to 

 be teeming with germ life, it will almost always be ob- 

 served that milk when it is consumed, is richer in bacte- 

 ria by far than the sewage of our large cities. Sedgwick 4 

 found that the sewage of Lawrence, Mass., contained at 



1 Loveland and Watson, 7th Report, Storrs Sta. (Conn.), 1894, p, 72. 



2 McClatchie, Bull. 3, Agr. Expt. Stat. (So. Cal. Acad. Sc.), Aug. 

 1897. 



3 Bitter, Zeit. f. Hyg\, 8: 240. 



4 Sedgwick, Kept. Mass. Bd. Health, 1890, p. 60. 



