170 CHEMISTRY OF THE PROTEIDS CHAP. 



sociable, perhaps somewhat more highly oxidised form. But this whole 

 conception is erroneous, apart from the existence of the A- and B-cystin 

 which have been described on p. 56, since the symmetrically built cystin 

 and the cystein containing only one atom of sulphur behave exactly as 

 do albumins, and since Morner has found cystin in sufficient amounts to 

 account for the whole or for the greater part of the sulphur occurring 

 in albumins. Morner, however, still makes use of the old view, for he 

 calculates from the amount of sulphur which is readily split off how 

 much cystin is actually present, and thence concludes as to whether any 

 given albumin contains only cystin or whether it is necessary to assume 

 the existence of still another sulphur-containing dissociation-product. 

 He arrives at the conception that the keratin of cow's horn and of hair, 

 that serum-albumin and serum-globulin, contain only cystin, while the 

 shell -membrane of hens' eggs, egg-albumin, and fibrinogen contain, 

 besides cystin, yet other sulphur bodies. These calculations are, how- 

 ever, not very certain. That we do not yet understand all the ins and 

 outs of this question is shown by the following considerations. Accord 

 ing to Maly, 1 Low, 2 and Bernert, 3 the lead sulphide reaction is no1 

 given by oxyprot-sulphonic acid, which is formed when albumins an 

 oxidised with an alkaline solution of potassium permanganate ; it con 

 tains, however, the whole of the sulphur, and will split off sulpljurettec 

 hydrogen if oxidation is prevented (Schulz 4 ). An analogous behavioui 

 is shown by the iodine-containing albumins (according to Hofmeister 5 ) 

 and by the salts which denaturalised albumins form with many heavj 

 metals (Harnack 6 ). Even when dissociating albumins slowly witl 

 dilute alkalies, some sulphur is split off quite early. 7 The author! 

 assume a partial oxidation, but other explanations are possible. 



Pick, 8 on the other hand, has shown that primary albumoses pre 

 pared from the cystin -containing fibrin give off the whole of thei: 

 sulphur in the form of sulphuretted hydrogen, and that therefore thi 

 sulphur cannot be contained in these albumoses as cystin. Morner 

 states further that the sulphur of glutin, which cannot be split off, i 

 not even oxidised if aqua regia be used. 



1 R. Maly, Monatshefte /. Chemie, 6. 107 (1885), 9. 258 (1888). 



2 0. Low, Journ. f. prakt. Chem. [2], 5. 433 (1872), 31. 129 (1885). 

 8 R. Bernert, Zeitschr. /. physiol. Chem. 26. 272 (1898). 



4 F. N. Schulz, ibid. 29. 86 (1899). 



5 F. Hofmeister, ibid. 24. 159 (1897). 



6 E. Harnack, Ber. d. deutsch. chem. Ges. 31. II. 1938 (1898). 



7 N. Lieberkuhn, Arch.f. Anat., Physiol. u. wissenschaftl. Medizin, 1848, pp. 28 

 and 323. 



8 E. P. Pick, Zeitschr. f. physiol. Chem. 28- 219 (1899). 



9 C. T. Morner, ibid. 28. 471 (1899). 



