THE CHEMICAL COMPOSITION OF MILK 29 



Potassium oxide 25.02 



Sodium oxide 10.01 



Calcium oxide 20.01 



Magnesium oxide 2.42 



Iron oxide 0.13 



Sulfur trioxide 3.84 



Phosphoric pentoxide 24.29 



Chlorine 14.28" 



Soldner considers that the following more nearly represents 

 the mineral constituents as they exist in cow's milk : 



Sodium chloride, NaCl 10.62 



Potassium chloride, KC1 9.16 



Mono-potassium phosphate, KH2PO4 12.77 



Di-potassium phosphate, K 2 HPO 4 9.22 



Potassium citrate, K 3 (C6H 5 O 7 )2 5.47 



Di-magnesium phosphate, MgHPCh 3.71 



Magnesium citrate, Mg 3 (C 6 H 567)2 4.05 



Di-calcium phosphate, CaHPO 4 7.42 



Tri-calcium phosphate, Ca 3 (PO 4 )2 8.90 



Calcium citrate, Ca 3 (C 6 H 5 O7)2 ' 23.55 



Lime, combined with proteins 5.13 



Other constituents of milk 



Minute quantities of urea, lecithin, iodine, acetic acid, car- 

 bon dioxide, and other gases have been reported as existing in 

 milk, but they are present only in traces and are probably of 

 little practical significance. 



Condition of casein and salts in milk (Van Slyke and Bosworth) 



The chemistry of milk has been studied by many investi- 

 gators. Numerous facts have been accumulated relating to 

 the amounts and properties of the more prominent constituents 

 of milk, including various conditions affecting the composition ; 

 but much less attention has been given to thorough study of 

 individual constituents, owing largely to the difficulties in- 

 volved in making such investigations. . . . 



