344 PROTEIN POISONS 



protein is used in tissue metabolism. Pick's conclusions 

 support Briicke's hypothesis. Maly 1 pointed out a possible 

 error in Pick's work, showing that while peptone may be 

 precipitated from aqueous solution by alcohol, it is not 

 wholly insoluble in this menstruum, and the increase of 

 alcohol soluble nitrogen in the blood might be due to peptone 

 and not to the conversion of this into urea. 



Evidently if Briicke's theory were true, the animal body 

 could not maintain its health and vigor if fed exclusively 

 on peptone, which according to the theory is not utilizable 

 by the animal in the repair of tissue. Plosz 2 fed animals 

 exclusively, so far as their nitrogenous 'food is concerned, 

 on peptones and found that they did not loose weight or 

 suffer in any detectable way. Maly 3 confirmed this finding 

 which has been repeated many times and under divers 

 conditions, so that now Briicke's contention that the 

 absorption of unaltered protein is essential to health has 

 no support. 



The second question, What is the fate of the absorbed 

 peptone, became for a time one of much importance. Plosz 

 and Gyergyai 4 injected from 200 to 300 c.c. of a 10 per 

 cent, solution of peptone into the stomachs of fasting dogs 

 and after periods of from one to four hours searched for 

 the peptone in the blood and tissues of various organs. The 

 method of recognizing peptone consisted in the applica- 

 tion of the biuret and Millon tests to the filtrate after the 

 removal of all the coagulable protein by acid and heat. 

 They found the largest amount of peptone in the mesenteric 

 veins and in extracts of the mesentery, much less in the 

 liver, and only traces in hepatic and carotid blood. Next, 

 they injected dogs and cats intravenously with a 10 per 

 cent, solution of peptone, employing from 100 to 200 c.c., 

 and introducing it at the rate of from 2 to 3 c.c. per minute. 

 A dog received 200 c.c. during one and one-half hours, and 

 after three hours the carotid blood showed only a small 



1 Pfliiger's Arch., ix, 605. " Ibid., 325. 



3 Loc. cit. 4 Pfliiger's Arch., 1875, x, 536. 



