CONSTITUENTS OF MILK 15! 



including the salt added in cheese-making, rep- 

 resents the salts of the milk even less accurately 

 than in milk. In cheese, we have a considerable 

 amount of calcium lactate, but, in obtaining the ash 

 of cheese, the lactic acid portion is destroyed and so 

 does not form a part of the ash. The percentage 

 of ash in green cheese due to constituents obtained 

 from the milk is usually between 2 and 3 per cent, 

 varying, of course, with the amount of whey retained 

 in the cheese. 



In milk, a portion of the salts is present in 

 soluble, and a portion in insoluble, form. The fol- 

 lowing portions of the salts of milk are present in 

 solution : Sodium, potassium, chlorine, and citric 

 acid compounds; amounts of phosphoric acid in 

 the form of combined phosphates varying in differ- 

 ent milks from 45 to 65 per cent of the total phos- 

 phoric acid present; 25 to 45 per cent of the calcium 

 (lime) ; and over 50 per cent of the magnesium. 

 In what specific forms of compounds these ele- 

 ments are present in milk is not known and the 

 problem is a difficult one to solve. The sugges- 

 tion has been made by Soldner that something like 

 the following arrangement may be supposed to 

 exist : 



Percentage of the total 

 Compounds salts in milk 



Calcium citrate 23.6 



Mono-potassium phosphate 12.8 



Sodium chlorid 10.6 



Potassium chlorid 9.2 



Di-potassium phosphate 9.2 



Tn-calcium phosphate 8.9 



Di-calcium phosphate 7 .4 



Potassium citrate 5.5 



Calcium oxid in casein 5.1 



Magnesium citrate 4.0 



Di-magnesium phosphate 3.7 



