r 



THE PARENTERAL INTRODUCTION OF PROTEINS 347 



proteins in large amounts: Syntonin and albuminate from 

 egg albumen, syntonin from ox flesh, crystalline phyto- 

 vitellin from pumpkin seed, and pure serum albumin from 

 the ox. 



According to Neumeister, Salviolo was the first to show 

 that peptone is transformed by the living intestinal wall, 

 but this investigator only demonstrated that peptone 

 disappears when placed in an intestinal loop and cannot 

 be found in either the blood from the part, or within the 

 loop. The nature of the transformation was not determined. 

 The fact that peptone is synthesized into albumin seems 

 to have been first suggested by two women, students of 

 Kronecker, Nadine Popoff and Julia Brinck. It was thought 

 by these investigators that this synthesis is accomplished 

 partly by the epithelial cells of the intestinal wall, and 

 partly by a microorganism, to which Julia Brinck gave 

 the name micrococcus restituens. 1 Hofmeister 2 suggested 

 that the leukocytes in the intestinal wall might combine 

 with peptone much as hemoglobin does with oxygen in the 

 lungs, and Heidenhain 3 thought that the leukocytes might 

 play a part in the absorption of peptones, but that it could 

 not be as suggested by Hofmeister, 4 otherwise the leuko- 

 cytes in the circulating blood would combine with peptone 

 injected intravenously. 



As early as 1874 Tschiriew, 5 working under Ludwig's 

 direction, found that dog serum transfused into another 

 dog increased the elimination of urea much more slowly 

 than when given to the dog by mouth, but Forster 6 found 

 that horse serum affects the urea output in dogs equally, 

 both in amount and time, whether given intravenously or 

 by mouth. 



Zunz and von Meering 7 injected solutions of peptone 



1 Zeitsch. f. Biol., 1889, vii, 427, 453. 



2 Zeitsch. f. phys. Chemie, 1881, v, 151. 



3 Pfluger's Arch., 1888, liii. 4 Loc. cit. 



5 Arb. a. d. phys. Inst. zu Leipzig. 



6 Zeitsch. f. Biol., 1895, ii, 496. 



7 Pfluger's Archiv, 1883, xxxii, 173. 



