12 CONSTITUENTS OF MILK 



TABLE II 

 CASEINOGEN HYDROLYSIS PRODUCTS 



and milk serum, as determined in the usual way by direct titra- 

 tion with alkali, may be entirely fallacious because of the errors 

 introduced by titrating phosphoric acid in the presence of lime 

 salts. Cameron and Hurst 11 have shown that the following 

 reactions may occur. 



(1) CaHP0 4 +2H 2 =Ca(OH) 2 +H 3 PO 4 . 



(2) 2CaHPO4+Ca(OH) 2 = Ca 3 P20 8 +2H 2 0. 



These result in the presence of free phosphoric acid in place 

 of neutral dicalcium phosphate and the acidity is, therefore, 



