85 



queiit chemical examination in the laboratory, which includes, in 

 the first place, an accurate determination of the fat, and determina- 

 tion of the specific gravity of the milk after skimming. Differ- 

 ences in the properties of the milk for sale and the milk thus obtain- 

 ed, indicate the use of adulterants, and the rest of the sample should 

 then be given to a chemist for further examination, to insure a 

 good case when it should be brought before the courts. Water, 

 solids and fat should be determined. 



The taking of samples, and the examination in the stable, should 

 he done in the presence of witnesses. 



Estimation of the quality of the milk by the specific 

 gravity: The determination of the specific gravity of the whole 

 and skimmed milk, establishes the degree of adulteration by water. 



The percentage of fat establishes the fact whether we have a 

 normal or abnormal milk before us. 



The percentage of water added may be inferred by the use of 

 the table previously given (p. 83). Wliole milk sliould have a 

 specific gravity ranging from 1.02S) to 1.033. If the specific grav- 

 ity be less than 1.029, the milk must be considered adulterated if 

 a sample taken from the stable should show a different (higher) 

 gravity. If the specific gravity should be found higher than 1.033, 

 it may indicate the partial removal of the cream. 



If the milk, skimmed after 24 hours' standing, shows a specific 

 gravity of less tlian 1.032, while unskimmed its specific gravity 

 appears normal, we conclude that the milk under examination had 

 been skimmed and watered. 



The quantity of cream removed is inferred from a 



Determination of the Fat. 



It is to be regretted that as yet for the estimation of fat in 

 milk, Chevalier's creamometer is frequently used. When using 

 this apparatus, the milk is allowed to stand for 24 hours, after 

 which the amount of cream which has risen to the surface, is de- 

 termined. The results obtained from this instrument are very 

 uncertain, and should never be used in proceedings before a court 

 of justice, for the following reasons : 



1. The cream, even under the same conditions, does not rise 

 evenly. 



