SALTS 



19 



iodine (brown), and the xantho proteic reaction. On hydrolysis 

 with hydrochloric acid it yields a quantity of a substance* capa- 

 ble of reducing Fehling's copper solution. 



This proteid is probably identical with the /3 casein of 

 Strewe who separated it from a casein (caseinogen) by dissolving 

 out the latter with ammonium hydrate. 



Salts. In addition to the various acids and bases which 

 form part of the caseinogen complex, the serum of milk contains 

 various salts in solution. The average percentage of ash in 

 milk is about 0.75 per cent but fluctuates considerably. The 

 average composition of the ash of milk, as obtained by igni- 

 tion is given in Table V. 



TABLE V 

 COMPOSITION OF ASH OF MILK (RICHMOND) 



Per Cent. 



Lime 20 . 27 



Magnesia 2 . 80 



Potash 28.71 



Soda 6.67 



Phosphoric acid 29 . 33 



Chlorine .' . 14.00 



Carbon dioxide . 97 



Sulphuric acid Trace 



Ferric oxide . 40 



103.15 

 Less oxygen = Cl 3 . 15 



100.00 

 Distribution of the phosphoric acid. 



Grams per 100 c.cms. 



P 2 O 6 as caseinogen combined with NaCa . 0605 



P,O 5 as Ca-P 2 O 8 0.0625 



P 2 O 8 as R 3 HPO 4 0.0770 



P 2 O 5 as RH 2 PO 4 0.0200 



Total.. . 0.2200 



