318 PHYSIOLOGICAL CHEMISTRY. 



the fat (as shown in women by ZALESKY, in sheep by STOLZMANN, 

 WEISKE, SCHRODT and DEHMEL and MUNK, in dogs by POGGIALE 

 and SSUBBOTIN, in cows at least in most cases by KUHN and his 

 pupils). An increase in the quantity of casein, and a decrease in the 

 albumin and the sugar in cow's milk after food containing an excess 

 of proteids has been observed by KUHIT and his pupils. The quan- 

 tity of sugar in woman's milk is found by certain investigators to be 

 increased after food rich in proteids, while others claim it is dimin- 

 ished. Food rich in fat may in sheep, as observed by STOLZMANK 

 WEISKE, SCHRODT and DEHMEL, cause an increase in the quantity of 

 fat in the milk. An increase in the quantity of fat in cow's milk be- 

 cause of an addition of fat to the fodder has only been observed after 

 a previous insufficient diet, but not after a sufficient and rich diet 

 (KiiHtf and FLEISCHMAFK). After feeding with palm-oil cake a 

 one-sided increase in the fat of cow's milk was observed by KUHK. 

 The presence of large quantities of carbohydrates in the food seems 

 to cause no constant, direct action on the quantity of the milk-con- 

 stituents. In carnivora the secretion of milk-sugar proceeds unin- 

 terrupted on a diet consisting exclusively of lean meat. Watery 

 food gives a milk containing an excess of water of little value. In 

 the milk from cows which were fed on distillers' grains COMMAILLE 

 found 906.5 p.m. water, 26.4 p.m. casein, 4.3 p.m. albumin, 18.2 

 p. m. fat, and 33.8 p.m. sugar. Such milk has a peculiar sour, 

 sharp after-taste. 



Chemistry of the Milk- Secretion. That the actually-dissolved 

 constituents occurring in milk pass into the secretion, not alone by 

 filtration or diffusion, but more likely are secreted by a specific 

 secretory activity of the glandular elements, is shown by the fact 

 that milk sugar, which is not found in the blood, is to all appear- 

 ances formed in the glands themselves. A further proof lies in 

 the fact that the lactalbumin is not identical with serum-albumin 

 (SEBELIE^ ) ; and lastly, as BUKGE has shown, the mineral bodies 

 secreted by the milk are in quite different proportions than to those 

 in the blood-serum. 



Little is known in regard to the formation and secretion of the 

 specific constituents of milk. The older theory, that the casein was 

 produced from the lactalbumin by the action of an enzyme, is incor- 

 rect and originated probably from mistaking an alkali-albuminate 



