THE POL YSA CCHARIDES. 1 3 



they are precipitated from their solutions by saturation with certain 

 neutral salts, such as ammonium sulphate. 1 



FIG. 4. Crystals of phenyl-lactosazone. 



By hydrolysis they are finally split up into simple sugars ; various 

 dextrins and disaccharides being intermediate products. The dextrins 

 are of various kinds, and are differently named by different observers. 

 The reaction cannot be represented by equations with certainty as long 

 as the molecular weights of the members of the group are unknown. 



Brown and Morris suggest the following series, indicating the successive 

 steps of the hydrolysis, in the case of starch under the influence of diastatic 

 ferments : 



(C 6 H 10 5 )n + H 2 T (C 6 H 10 5 ) n _ 2 + C 12 H 22 O n 



(starch) (dextrin) (maltose) 



(C c H 10 5 ),,- 2 + H 2 = (C 6 H lo 5 ) n _ 4 + C 12 H 22 O n 



(dextrin) (dextrin) (maltose) 



(C, ; H 10 5 )n-4 + H 2 = (C 6 H 10 5 ) n _ 6 + C 12 H 22 O n 



(dextrin) 



(dextrin) 



(maltose) 



assigned to dextrin and soluble starch the formulae (C 6 H 10 5 ) 12 and (C 6 H 10 5 ) 30 re- 

 spectively. The same method applied to starch, though not so satisfactorily, points to a 

 molecular weight of between 20,000 and 30,000 ; that is, about three times greater than that 

 of soluble starch. Sabanejeff, Cham. Ccntr.-BL, Leipzig, 1891, S. 10 ; Journ. Russian Chem. 

 Soc., vol. xxi. p. 515, by the same method assigns to glycogen the formula (C 6 H 10 5 ) 10 . 



1 Pohl, Ztschr. f. physiol. Chem., Strassbtirg, Bd. xiv. S. 151 ; Young, " Proc. Physiol. 

 Soc.," Feb. 13, 1897, in Journ. Physiol. , Cambridge and London, vol. xxi. 



