50 Dairy Bacteriology. 



filth of all kinds are so intimately associated with each 

 other that the presence of one rightly presupposes that 

 of the other. 



As to the numerical bacterial content of any milk, 

 there is such a wide variation under different conditions 

 that figures are of little worth. No exact relation can be 

 maintained between number of bacteria in milk and the 

 development of fermentative products. 



The studies by different observers have been carried 

 on under such diverse conditions that no comparison of 

 the results can well be made. Under American conditions 

 but little work has been done in this direction, yet milk 

 as it is sold here to the consumer usually contains less 

 bacteria than that retailed in European cities, although as 

 Conn has pointed out, it is materially older. As he in- 

 timates this fact is explained by the relatively free use of 

 ice in this country. A few determinations of the bac- 

 terial contents of European milks that have been analysed 

 biologically will illustrate this point. 



Renk 1 found in Halle milk- supply 6-30,000,000 germs 

 percc.; Cnopf 2 in Munich milk- supply 200, 000-6, 000,- 

 000 per cc.; Uhl 3 in Giessen milk 83,000-170,000,000 

 per cc. ; Clauss 4 in Wurzburg 222,000-23,000,000 per cc. ; 

 Bujwid in Warsaw an average of 4,000,000 per cc. and 

 Knochensteirn 5 in Dorpat 25,000,000 per cc. 



Sedgwick and Batchelder 6 report fifty- seven samples 

 of Boston milk as containing from 30,000-4,220,000 per 

 cc. In the country, they found in the milk fresh from 



iRenk, Cent. f. Bakt., 10: 193. 

 5 Cnopf, Ibid. 6: 553. 



3 Uhl, Zeit. f. Hyg., 12: 475 (1892). 



4 Clauss, Diss. Wurzburg, 1889. 



5 Knochensteirn, Chem. Cent., 11: 62. 



6 Sedgwick & Batchelder, Boston Med. Surg. Journ., Jan. 14, 1892. 



