DIRT- AND GERM-CONTENT IN MILK. 



201 



Sample No. 



1: 



Number of Germs. 



Per c.c. 



12,897,600 



7,079,820 



3,338,775 



the dirt is separated, and collects, along with casein, bacteria, &c., 

 as a coating, sometimes granular, at others mucinous, on the walls 

 of the inner drum, and is generally known as milk-sludge. It con- 

 sists of about 26 per cent, of albuminoids, 67 per cent, of water, &c., 

 and is relatively much richer in bacteria than the milk. O. WYSS (I. ) 

 was the first to investigate this mud, and the quantity separated 

 was found, in a case examined by NIEDERSTADT (I.), to amount to 

 43 grams per hectolitre (slightly more than 30 grains per gallon). 



The connection between the content of dirt and of germs in 

 milk was shown in particular by UHL (I.), a few of whose figures 

 are now given : 



Dirt. 



M.g. per Litre. 

 36.8 

 20.7 



5-2 



Sundry researches on the germ-content of cow-dung, and on 

 its dependence on the dietary, were carried out by E. WUTHRICH 

 and E. VON FREUDENREICH (I.). They found up to as many as 375 

 millions of bacteria per i gram of fresh faecal matter, the majority 

 consisting of Bacterium coli commune, along with some 3 millions 

 of hay bacilli and others. An equal weight of the hay used for 

 fodder contained about 7^ millions of germs, of which about one- 

 fourth were hay bacilli. Sour brewers' grains (forty-eight hours 

 old) yielded 375 million colonies. 



The germ- content of freshly drawn milk increases very rapidly 

 during transport to the centres of consumption, as also during stor- 

 age, e.g. in milkshops. A number of estimations have been made 

 in this connection, a few of which, by FREUDENREICH (II.), are 

 subjoined. In these, the influence of the length of storage in 

 conjunction with the prevailing temperature is taken into account. 



Number of Germs per c.c. : 



On arrival in the laboratory (two and a half hours after milking), 9300. 



A milk with an initial germ-content of 9300 will be reckoned 

 poor in bacteria when it is known that J. v. GEUNS (I.) found 2.5 

 million bacteria per c.c. in fresh samples of Amsterdam milk. The 

 reproduction can be moderated, but not arrested, by cold, because, 



