CHEMISTRY OF MILK SECRETION. 637 



extirpated. This glycosuria is explained simply by the. fact that the 

 lactose-forming action of the gland was removed at the time of delivery, 

 when large amounts of dextrose were produced, but it must not be for- 

 gotten that MARSHALL and KIRKNESS found with similar experiments 

 upon guinea-pigs no passage of sugar into the urine. The experiments 

 of KAUFMANX and MAGXE 1 upon cows indicate a formation of lactose 

 from dextrose. They found that during secretion the glands took sugar 

 from the blood, so that the venous gland-blood was poorer in sugar than 

 otherwise. 



The passage of foreign substances into the milk stands in close connec- 

 tion with the chemical processes of milk secretion. 



It is a well-known fact that milk acquires a foreign taste from the 

 food of the animal, which is in itself a proof that foreign bodies pass into 

 the milk. This fact becomes of special importance in reference to such 

 injurious substances as may be introduced into the organism of the nursing 

 child by means of the milk. 



Among these substances may be mentioned opium and morphine, 

 which after large doses pass into the milk and act on the child. Alcohol 

 may also pass into the milk, but probably not in such quantities as to 

 have any direct action on the nursing child. 2 Alcohol is claimed to have 

 been detected in the milk after feeding cows with brewer's grains. 



Among inorganic bodies, iodine, arsenic, bismuth, antimony, zinc, 

 lead, mercury, and iron have been found in milk. In icterus neither 

 bile-acids nor bile-pigments pass into the milk. 



Under diseased conditions no constant change has been found in woman's 

 milk. In isolated cases SCHLOSSBERGER, JOLY and FILHOL 3 have indeed 

 observed a markedly abnormal composition, but no positive conclusion can be 

 derived therefrom. 



The changes in cow's milk in disease have been little studied. In tuber- 

 culosis of the udder STORCH 4 found tubercle bacilli in the milk, and he also noted 

 that the milk became more and more diluted, during the disease, with a serous 

 liquid similar to blood-serum, so that the glands finally, instead of yielding milk, 

 gave only blood-serum or a serous fluid. HUSSON 5 found that milk from murrain 

 cows contained more proteins but considerably less fat and (in severe cases) less 

 sugar than normal milk. 



The milk may be blue or red in color, due to the development of micro- 

 organisms. 



The formation of concrements in the exit-passages of the cow's udder is often 

 observed. These consist chiefly of calcium carbonate, or of carbonate and phos- 

 phate with only a small amount of organic substances. 



1 Porcher, Compt. rend., 138 and 141; Marshall and Kirkness, Bioch. Journ., 2; 

 Kaufmann and Magne, Compt. rend., 143. 



2 See Klingemann, Virchow's Arch., 126, and Rosemann, Pfliiger's Arch., 78. 



3 Schlossberger, Annal. d. Chem. u. Pharm., 96; Joly and Filhol, cited from 

 v. Gorup-Besanez, Lehrb., 4. Aufl., 438. 



4 See Bang, Om Tuberkulose i Koens Yver og om tuberkulos Miilk, Nord. med. 

 Arkiv, 16, and also Maly's Jahresber., 14, 170; Storch, Maly's Jahresber., 14. 



5 Compt. rend., 73. 



