148 MILK HYGIENE 



action of an intestinal ferment (erepsin) the splitting 

 of peptone is continued into di- and mon-amido acids. 

 Little is known as to the resorption and use of these 

 substances. 



There is a difference of opinion regarding the fate 

 of the milk sugar; some think it is absorbed from the 

 intestines unchanged, but others are convinced that it is 

 first inverted into dextrose and galactose. The absorp- 

 tion takes place more slowly than is the case with glu- 

 cose, maltose and cane sugar. 



The absorption of milk-fat takes place as that of 

 other fats, with a preceding saponification. 



It is well known that cow's milk is being used more 

 and more as food for infants and for small children. As 

 a substitute for mother's milk, there are some objections 

 to it, however, and if used for nursing babes, it must 

 receive especial treatment. This is on account of the 

 fact that it differs materially in chemical composition 

 from human milk and that it constantly contains micro- 

 organisms, and, sometimes, even pathogenic forms. 



The differences in composition of human milk and 

 cow's milk are shown by the averages given below: 



Water. Casein. Albumin. Fats. Lactose. Salts. 



Woman's milk... 87.92 0.58 0.52 3.43 7.12 0.2 



Cow's milk 87.75 3.00 0.50 3.40 4.60 .5075 



[Human milk appears to vary more in composition 

 than cow's milk. This may be due in part to the greater 

 difficulty in obtaining a fair sample than is the case with 

 cow's milk. It is known, for example, that the compo- 

 sition of the fore milk and the strippings differ consid- 

 erably, and if small samples of milk are drawn from a 

 cow's udder at irregular times during the day, before 

 and after regular milkings, the samples will be of very 

 different composition. Besides this, the less regular life 



