iv THE CARBOHYDRATE RADICALS 163 



He further suspects a carbohydrate-acid. In serum-globulin 1 he 

 found grape-sugar ; an animated hexose, which was not glucosamin and 

 still other substances resembling carbohydrates. But as serum-albumin 

 contains only 0'5 per cent, and serum-globulin a little more than 1 

 per cent of these bodies, the proof is yet wanting that these substances 

 are really derived from albumins and globulins, and that they are not 

 simply admixtures, linked perhaps chemically to the albumin (compare 

 with p. 222). Abderhalden, Bergell, and Dorpinghaus 2 state that 

 they prepared serum -albumin which gave no trace of Molisch's re- 

 action. Langstein 3 observes that he never had so pure a specimen, 

 and that in his case the serum-albumin may ' perhaps ' have contained 

 traces of non-coagulable albumins, which according to Zanetti 4 always 

 contain glucosamin. Langstein has certain evidence, not yet pub- 

 lished, that pure serum-albumin does contain some glucosamin. 



Although, then, no exact proof has been so far adduced in support of 

 the view that, with the exception of egg- albumin, mucins, and other 

 glycoproteids, a carbohydrate radical is contained in proteids, there 

 is a whole series of other facts (apart from the results of Langstein, 

 Krakow, and Frankel discussed above) which show that a carbo- 

 hydrate group is present in most albumins, for the following reasons : 

 1. The reaction of Molisch (see p. 8) is a furfurol reaction, and 

 is admitted by every one to demonstrate the presence of carbo- 

 hydrate. Pick 5 has shown that Molisch's reaction is present 

 only in some of the dissociation-products resulting from peptic 

 digestion. He has isolated amongst the deutero-albumoses a 

 gluco-albumose, and further a gluco-peptone or ' Peptone A.' 

 These substances, in addition to giving the reaction of Molisch, 

 are further characterised by a high oxygen and a low carbon 

 and nitrogen percentage. Gluco-albumose has so far been 

 prepared only from Witte's peptone, and as it is not known 

 from what material Witte's peptone is made, the possibility of 

 mucin albumoses being present must not be lost sight of. A 

 glyco-peptone has, however, on the other hand, been prepared 

 by Umber 6 from serum-albumin and serum-globulin. 



1 L. Langstein, Sitzungsber. der Wiener Akad. ct. Wissensch., math.-nat. Kl., Part 

 2 & , 112. (May 1903). 



2 Emil Abderhalden, Peter Bergell, and Theodor Dorpinghaus, Ztitschr. /. physiol. 

 Cliem. 41. 530 (1904). 



3 Leo Laugstein, ibid. 42. 171 (1904). 



4 Zanetti, La Chim. Ital. 1. 160 (1903). 



5 E. P. Pick,Zeitschr.f.phy*ioL Ghem. 28. 219 (1899); Hqfineister's Beitr. ' 2. 481 

 (1902). 



6 F. Umber, Zdtschr.J.-physiol. Chan.- 25. 258 (1898). 



