CHAPTEE IX. 



THE MILK-SUPPLY OF THE LONDON WOEKHOtTSES. 



HATING had occasion to examine a large number of specimens 

 of milk during the year 1871, 1 have made some observations 

 on the subject, which, possibly, may not be deemed to be 

 unworthy of the attention of those chemists who may have 

 a like task before them. 



The two common forms of malpractice which occur in the 

 milk-trade are the practice of removing the cream from the 

 milk, and the practice of diluting the milk with water; and 

 the testing of milk resolves itself into the detection of skim 

 ming and watering, and the measurement of the extent to 

 which these operations have been carried. 



The possibility of detecting whether or not a specimen of 

 milk has undergone impoverishment, depends obviously on 

 the possibility of assigning a normal composition to milk, or, 

 at any rate, on the possibility of fixing limits beyond which 

 the composition of milk does not vary. 



From the observations of Alexander Muller and Eisen- 

 etuck, who carried out an investigation for the Royal 

 Agricultural Society of Sweden, it appears that the milk 

 yielded by a herd of cows remains very constant in composi 

 tion throughout the year. A daily analysis of the milk given 

 by fifteen cows, of different breeds, but uniformly well-fed, 

 exhibited the percentage of solids in the milk as never once, 



