414 



CHEMISTRY OF THE DIGESTIVE PROCESSES. 



formed from protoalbumose and that from heteroalbumose are distinct bodies, 

 being distinguished by the fact that the deutero-compound formed from 

 protoalbumose is to some extent soluble in saturated solution of ammonium 

 sulphate. 1 



Starting with fibrin, and forming albumoses from it both by the 

 action of acids and by peptic digestion, Neumeister also showed that in 

 order of time proto- and Ae&roalbumoses first appeared, to be followed 

 later in the process by efewforoalbumose. 



Fibrin was boiled for three-quarters of an hour with 1 per cent, 

 sulphuric acid, after which the fluid was neutralised, and the neutralisa- 

 tion precipitate removed. In the filtrate both proto- and heteroalbu- 

 moses were found, but not a trace of cleuteroalbumose ; the latter first 

 appeared after some hours' boiling, and by a continuance of the process 

 increased at the expense of the pr<5to- and hetero-compounds so as to be 

 present finally in preponderating quantity. 



In accordance with these experiments, Nemneister 2 considers that 

 the peptic digestion of proteids takes place as represented in the follow- 

 ing scheme, in which the preponderance of any group is shown by a 

 dark line, while its presence in small quantity is signified by a light 

 line : 



Proteid Molecule, 



consisting of 

 Hemigroups Autigroups 



Protoalbumose 

 (Amphoalbumose) 



Deuteroalbumose 

 (Amplioalbumose) 



Amphopeptone 



Heteroalbumose Antialbumid 



(Ainphoalbumose) 



mlbt 



Deuteroalbumose Deuteroalbumose 

 (Ainphoalbumose) (Antialbumose) 



Amphopeptone Antipeptone 



TRYPTIC DIGESTION OF PROTEIDS. 



The proteolytic action of the pancreatic juice has not been known 

 for nearly so long a period as that of the gastric juice ; it was first 

 clearly proclaimed by Corvisart 8 in 1857, although this author refers to 

 an earlier statement, by Purkinje and Pappenheim in 1836, that extracts 

 of pancreas possess a dissolving action on proteids. 



Claude Bernard 4 knew that pancreatic juice in the presence of bile 

 had the power of dissolving proteids, but stated that when alone it 

 had no such action, unless the proteid matter had previously been sub- 

 jected to the action of bile. This error was removed by Corvisart, who 

 clearly proved that pancreatic juice alone at the temperature of the 



1 Ztschr.f. Biol., Miiiichen, 1888, Bd. xxiv. S. 267. 



2 Ibid., Miinchen, 1887, Bd. xxiii. S. 381. See also Neumeister, " Lehrbuch der 

 physiologischen Chemie," Jena, where Neumeister concludes: "The expression 

 hemipeptone has, according to this representation, only a theoretical meaning, and the 

 term hemialbumose corresponds to older notions and ought to be allowed gradually to 

 disappear from the text-books." 



3 ' ' Collection de memoires sur line fonction peu connue du pancreas, la digestion des 

 aliments azotes," Paris, 1857. 



4 "Lecons de physiologic experimental e," 1856, tome ii. p. 440. 



