1180 PROTEIDS. 



of two parts, of which each yielded its corresponding peptone 

 during the hydration which leads to the formation of peptones. 

 He found also further confirmation of this probability in the 

 work of Schiitzenberger (1875). This observer, decomposing 

 proteids with acids at 100 C., came to the conclusion that half 

 the proteid molecule is readily decomposable by the acids, while 

 the other half is peculiarly resistent and is obtained in the final 

 products as an extraordinarily indigestible but true proteid, to 

 which he gave the characteristic name of 'hemiprotein.' Con- 

 vinced thus of the double nature of the proteid molecule, and 

 seeing but little hope of separating from each other in a mix- 

 ture the two peptones which must presumably result from the 

 gastric peptonization of a proteid, Kiihne endeavoured to estab- 

 lish their existence by trying to discover the primary products 

 intermediate between the proteid and the peptones, antipep- 

 tone on the one hand and hemipeptone on the other. 1 In this 

 his endeavours were at once assisted by his being in possession 

 of a large amount of a proteid identical with that first described 

 and carefully examined by Bence-Jones (1848), and hence called 

 by his name. A renewed examination of this substance revealed 

 that it was capable of conversion by pepsin into a peptone which 

 was readily further decomposed by trypsin. It was in fact the 

 product intermediate between the original proteid and the hemi- 

 peptone, and to it Kiihne gave the name of hemialbumose. It 

 now was only necessary to obtain the corresponding albumose 

 precursor of the antipeptone, to peptonize this and shew that 

 the peptone thus obtained would yield no leucine or tyrosine by 

 even prolonged treatment with trypsin. This Kiihne succeeded 

 in doing by a fractionated peptic digestion and thus established 

 his own views, and in doing so shewed how accurate as a whole 

 Meissner's statements were. This will be evident from the de- 

 tailed description of the several products of the decomposition 

 of proteids by pepsin, trypsin, and acids, which is given below. 

 The fundamental notion then of Kiihne's view is that an ordi- 

 nary native albumin or fibrin contains within itself two residues, 

 which he calls respectively an anti-residue and a hemi-residue. 

 The result of either peptic or tryptic digestion is to split up the 

 albumin or fibrin, and to produce on the part of the anti-resi- 

 due antipeptone, and on the part of the hemi-residue hemipep- 

 tone, the latter being distinguished from the former by its being 

 susceptible of further change by tryptic digestion into leucine, 

 tyrosine, &c., each peptone being preceded by a corresponding 

 anti- or hemi-albumose. Antipeptone remains as antipeptone 



1 The name ' hemipeptone ' was given in order to convey the idea that it is 

 the peptone formed from one half of the original proteid molecule, 'antipep- 

 tone ' on the other hand that it is that form of peptone which withstands or is 

 opposed to (&vri) any further decomposing action of the agents which led to its 

 appearance. 



