The Typical Cellulose and the Cellulose Group 29 



indicates hydration to 4C G Hi O 5 .H 2 O (infra), and a corre- 

 sponding gain of 2*7 p.ct., it appears that there is a slight 

 hydrolysis of even this very pure form of cellulose. From 

 subsequent observations (p. 61) it will appear that the hydro- 

 lysis falls upon an oxycellulose, probably present in all bleached 

 celluloses. 



The cellulose regenerated from the thiocarbonate differs 

 from the original cellulose, so far as has been ascertained, in 

 the following respects : 



(1) Its hygroscopic moisture, or water of condition, is some 

 3-4 p.ct. higher, viz. from 9-10*5 p.ct. 



(2) Empirical composition. The mean results of analysis 

 show C=43'3, H=6'4 p.ct., which are expressed by the 

 empirical formula, 4C 6 H 10 O 5 .H. 2 O. 



(3) General properties, in the main, are identical with 

 those of the original, but the OH groups of this cellulose are 

 in a more reactive condition. Thus this form of cellulose is 

 acetylated by merely heating the acetic anhydride at its boiling 

 point, whereas normal cellulose requires a temperature of 180. 

 ( Vide Cellulose Acetates.) 



As regards reaction in aqueous solution we may notice that 

 it has a superior dyeing capacity, and also combines with the 

 soluble bases to a greater extent : e.g. if left some time in 

 contact with a normal solution of sodium hydrate it absorbs 

 from 4'5~5'5 p.ct. of its weight in combination. 



Towards the special solvents previously described it 

 behaves similarly to the normal or fibrous cellulose ; the 

 solutions obtained are, however, more viscous and less gela- 

 tinous. 



THEORETICAL VIEW OF THE THIOCARBONATE REACTION OF 

 CELLULOSE. The occurrence of this reaction, under what may 

 be regarded as the normal conditions, proves the presence in 

 cellulose of OH groups of distinctly alcoholic function. The 



