CHEMICAL COMPOSITION OF MILK 7 



high, and allowed some Shorthorn milk to stand for twelve 

 hours, after which the fat globules at different stages were 

 examined by the microscope and so measured. The result was 

 as follows : — 



Lloyd has also made observations, as we have seen, on the size 

 of fat globules in the milk of various species of cows. He finds a 

 marked uniformity in the size of the globules in each sample, the 

 milk from Jerseys having a narrow range of size and that from 

 Shorthorns a wider range. 



The Salts present in cow's milk have been represented by 

 Soldner thus : — 



Sodium chloride (NaCl) 

 Potassium chloride C^t^O 

 Monopotassium phosphate (KH.2PO4) 

 Di-potassium phosphate (KoHPO^ 

 Potassium citrate, K3(CgH507) 

 Di-magnesium phosphate, MgHPO^ 

 Magnesium citrate, Mg3(CgH707).2 

 Dicalcium phosphate, CaHCOj 

 Tricalcium phosphate, Ca3(C04)2 

 Calcium citrate, Ca3(C8H50-)2 

 Lime combined with proteids . 



IC-62 



9-i6 



12.77 



9*22 



5-47 

 371 

 4-05 

 7.42 

 8-90 

 3-5S 

 5-13 



Of the total phosphoric acid from 36 to 56 per cent, and of the 

 lime from 53 to 72 per cent, is not simply dissolved in the fluid, 

 but is united more or less firmly in the caseinogen. It will be 

 noted that 1 3 per cent, of the mineral ingredient is constituted of 

 compounds of citric acid. Besides the bodies mentioned above, 

 milk also contains certain organic compounds of the nature of urea, 

 hypoxanthine, and other nitrogenous basic substances. Bechamp 

 has described a starch-liquefying enzyme, and Babcock and Russell 

 a proteolytic enzyme, in milk. 



Chemical composition of milk products. — We may briefly 

 summarise the chemical characters of the various products of 

 milk, of which what has been said already applies as a general 



