Station Laboratory, the per cent, of water, fat, and casein, be- 

 ing determined, the salt etc. is found by difference. 



The volatile fatty acids are also given, these are determin- 

 ed by a process in which a definite amount of the pure butter fat 

 is converted into soap by a solution of potash, to which alcohol 

 is added, after this the alcohol is driven off by heat, then water 

 and a solution of phosphoric acid are added and the mixture 

 distilled until a given amount is collected. This distilate con- 

 tains the volatile acids, this is neutralized with a solution of soda 

 of known strength, and the figures given show the number of 

 parts of this soda solution required to neutralize the acids. 

 This test is much used in detecting adulteration or in distin- 

 guishing oleomargarine from pure butter. 



Table III gives the full analysis of each sample. By some 

 error the casein was not determined in the sample made at the 

 Experiment Station. 



TABLE IIL 



The averages in the above table must closely correspand 

 with the average of the best butter made in the State. For the 

 sake of comparison I have collected data which gives the fol- 

 lowing general average composition of many samples of butter : 

 Water 12.48; Fat 84.77; Casein .73; Salt etc. 2.02; volatile 

 acids=to 14C.C. standard soda solution. 



15 



