38 PROTEIDS. 



confirmation of this probability in the work of Schiitzenberger 1 . 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.' Convinced 

 thus of the double nature of the proteid molecule, and seeing but little 

 hope of separating from each other in a mixture the two peptones 

 which must presumably result from the gastric peptonisation of a 

 proteid, Kiihne endeavoured to establish their existence by trying to 

 discover the primary products intermediate between the proteid and 

 the peptones, antipeptone on the one hand and hemipeptone on the 

 other 2 . 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, and hence called by 

 his name 3 . 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 4 . It was in fact the product inter- 

 mediate between the original proteid and the hemipeptone, and to it 

 Kuhne gave the name of hemialbumose. It now was only necessary to 

 obtain the corresponding albumose precursor of the antipeptone, to 

 peptonise this and shew that the peptone thus obtained would yield no 

 leucin or tyrosin by even prolonged treatment with trypsin. This 

 Kiihne succeeded in doing by a fractionated peptic digestion 5 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 

 detailed description of the several products of the decomposition of 

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

 fundamental notion then of Kuhne's view is that an ordinary 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-residue antipeptone, and on the part of 

 the hemi-residue hemipeptone, the latter being distinguished from the 

 former by its being susceptible of further change by tryptic digestion 



1 Bull, de la Soc. chim. Paris, T. xxm. (1875), pp. 161, 193, 216, 242, 385, 433. 

 T. xxiv. pp. 2, 145. See abst. Maly's Jahresb. Bd. v. (1875), S. 299. 



2 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, ' antipeptone ' on the 

 other hand that it is that form of peptone which withstands or is opposed to (avri) 

 any further decomposing action of the agents which led to its appearance. 



3 Phil. Trans. Eoy. Soc. Pt. i. 1848. Ann. d. Chem. u. Pharm. Bd. LXVII. (1884), 

 S. 97. 



4 Kiihne, Zt. f. Biol. Bd. xix. (1883), S. 209. 



5 Kuhne u. Chittenden, Ibid. S. 171. 



