290 Cellulose 



numbers obtained were C 75*5, H 13*0. (c) Pectic acid, a 

 gelatinous acid body, having the composition and properties of 

 the acid described by Fremy. (d) Two colouring matters 

 (i) soluble in alcohol, (2) insoluble having the following 

 composition ; 



d) (> 



C 58-48 577 



H 5-80 6-05 



N 5-30 874 



(Mem. Lit. and Phil. Soc. Manchester, [3] 4.) 



In addition to these substances, which are constituents of 

 the fibre proper including residues of cell-contents the 

 alkaline treatment breaks down the residues of the seed 

 envelopes (motes) which survive the mechanical operations of 

 preparing, and find their way into the yarn. The proportion 

 of these by weight is, however, relatively insignificant, though 

 they are a source of some difficulty to the bleacher. 



There can be little doubt that the cotton cellulose under- 

 goes certain molecular changes during the process of a normal 

 bleach. From what we know of its constitution and reactions 

 we may affirm that it does not remain inert under treatments 

 of this severity ; but our methods are not sufficiently refined for 

 differentiating the product from the cellulose as contained in 

 the raw cotton. There is perhaps one exception to be noted, 

 which is, that the bleached cotton yields from o'2-o'6 p.ct. of 

 furfural on boiling with hydrochloric acid, which may be taken 

 as an indication of the presence of a small proportion of 

 oxycellulose. 



As already pointed out, cotton is very easily oxidised to 

 oxycellulose under the joint action of calcium hypochlorite (in 

 dilute solution) and carbonic acid. The researches of Witz, 

 who established the general conditions of these oxidations, 

 were carried out at a date (1882 -85) when there were none but 



