HEALTHY HUMAN MILK. 53 



The salts of woman's milk appear, according to my own ob- 

 servations, and those of Meggenhofen, to range at about from 

 i to 5 per cent, of the fluid; of these, usually about are insoluble, 

 and ~ soluble in water : the former consist of phosphate and 

 carbonate of lime, with a little magnesia, and a very small 

 quantity of (phosphate of ?) peroxide of iron ; the latter, of chlo- 

 rides of sodium and potassium, with a little chloride of calcium, 

 carbonate of soda, (corresponding with the lactate in the milk,) 

 and a little sulphate of potash, the acid of which does not pre- 

 exist in the milk, but is produced during incineration. Pfaff 

 and Schwartz 1 found a larger proportion of salts in woman's 

 milk, namely, 0-4407g; they were composed of phosphate of 

 lime, O25 ; phosphate of magnesia, O05 ; phosphate of iron, 

 O0007 ; phosphate of soda, 0*04 ; chloride of potassium, 0*07 ; 

 and soda originating from lactate of soda, O03. Carbonate of 

 lime, sulphate of potash, and chloride of sodium are not noticed, 

 although all other observers concur in finding them in the milk. 



Chevallier and O. Henri have instituted some researches on 

 the milk ; they precipitated the casein by acetic acid, evaporated 

 the fluid portion, and determined the salts by the incineration 

 of the residue. They estimated the part that was consumed as 

 sugar of milk, and removed the fat from the precipitated casein 

 by means of ether. By this process they obtained much too 

 small a quantity of casein from woman's milk, (since this con- 

 stituent is only imperfectly precipitated by acetic acid,) and too 

 large a quantity of sugar, which was thus made to include all 

 the destructible constituents, with the exception of the casein 

 and fat. In the other sorts of milk, the precipitation of the 

 casein by acetic acid is also imperfect. The following is the 

 result of their analysis of woman's milk : 



Water . . . 879-8 



Solid constituents . . 120-2 



Butter . . . 35-5 



Dried casein . . 15-2 



Sugar of milk . . 65-0 



Salts . . .4-5 



1 Dissert, inaug. sistens nova experimenta circa lact. princip. constit. Kiel, 1833. 



