168 CHEMISTRY OF THE PROTEIDS CHAP. 



another example of a reversible process, for formaldehyde may be 

 built up into hexoses, and the latter be reconverted into formaldehyde. 

 Many physiological data of the highest importance will also be 

 found in the two papers by Neuberg, 1 who discusses the physiology of 

 the pentoses and of glycuronic acid, and by Langstein, 2 who deals with 

 the formation of carbohydrates out of albumins, and special attention 

 is also drawn to the paper by Roux, 3 in which new amino-sugars are 

 described. 



The occurrence of alcohol in the tissues is discussed by Landsberg. 4 



The formation of fat from albumins has been fully discussed by 

 Slosse. 5 The existence of long carbon chains in the albumin-molecule, 

 as discovered by Skraup (see p. 45), brings us nearer the higher fatty 

 acids ; but there is a good deal of evidence against fat-formation from 

 albumins in the case of phosphorus-poisoning, judging by the account 

 Boruttau 6 gives. 



THE SULPHUR -RADICALS OF ALBUMINS 



With the exception of the protamins, peptones, and mycoproteid 

 (see p. 172), sulphur is contained in all albumins. The sulphur-con- 

 taining dissociation-products cystin, cystein, and a-thiolactic acid have 

 already been referred to (pp. 56 and 83). The following substances 

 occur also : Ethyl-sulphide, found by Abel 7 in urine, and by Drechsel 8 

 after dissociation with acids ; methyl- and ethyl-mercaptan and sul- 

 phuretted hydrogen, discovered by Sieber and Schoubenko after fusion 

 with alkalies, and similarly by Rubner, 9 who also obtained them when 

 employing dry distillation. During putrefaction these three substances 

 are also met with. 5 (See p. 104). 



Drechsel observed that the compound from which ethyl-sulphide was 



1 Neuberg, Ergebnisse d. PhysioL 3. fasc. 1, p. 373 (1904). 



2 Leo Langstein, ibid. p. 453. 



3 M. Roux, Ann. de chim. et de phys. 8. 72. 



4 Georg Landsberg, Zeitschr. f. physiol. Chem. 41. 505 (1904). 



5 A Slosse, Annales de la Soc. roy. des sciences medicates et naturelles de Bruxelles, 

 13. fasc. 2 (1904). 



6 H. Boruttau, Arch. ital. de Biol. 36. 157 (1901) ; and in Fano's Arch. d. Fisid. 

 2. 26 (1904). 



7 J. J. Abel, ibid. 20. 253 (1895). 



8 E. Drechsel, Zentralbl. /. Physiol. 10. 529 (1896). 



9 N. Sieber and G. Schoubenko, Arch, des Sciences biol. de St. Pttersbourg, 1. 314 

 (1892) ; M. Rubner, Arch. f. Hygiene, 19. 136 (1893) ; E. and H. Salkowski, Ber. d. 

 deutsch. chem. Ges. 12. I. 648 (1879) ; E. Baumann, Zeitschr. f. physiol. Chem. 20 

 583 (1895). 



