THE POLYSACCHARIDES. 
i3 
they are precipitated from their solutions by saturation with certain 
neutral salts, such as ammonium sulphate. 1 
Fig. 4. — Crystals of phenyl-laetosazone. 
By hydrolysis they are finally split up into simple sugars ; various 
dextrine 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 O 5 ) n + H 2 = (C 6 H 10 O 5 )n_ 2 + C 12 H 22 O n 
(starch) (dextrin) (maltose) 
(C 6 H 10 O 5 ) n _ 2 + H 2 O: 
(dextrin) 
(C,/H,o0 5 )n-4 + C 19 H 22 0„ 
(dextrin) (maltose) 
(C fi H 10 O 5 ) n _ 4 + H 2 = (C,H 10 O 5 ) n _ + C 12 H 22 O n 
(dextrin) (dextrin) (maltose) 
assigned to dextrin and soluble starch the formulae (C G H 10 O s )j„ 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, Chem. Centr.-Bl., Leipzig, 1891, S. 10 ; Journ. Russian C'hem. 
Soc, vol. xxi. p. 515, by the same method assigns to glycogen the formula (C ft H 10 O 5 ) 10 . 
1 Pohl, Ztschr. f. physiol. Chem., Strassburg, Bd. xiv. S. 151 ; Young, " Proc. Physiol. 
Soc," Feb. 13, 1897, in Journ. Physiol., Cambridge and London, vol. xxi. 
