Experimental and Applied 267 



out the results, to distinguish between the fibre-substance proper 

 and constituents easily removed by hydrolysis. Thus, to institute 

 an exact comparison of the woods with the jute fibre, both 

 should be taken after preliminary boiling out with dilute alkaline 

 solutions under the same conditions, the residue being washed 

 and dried after this treatment, and weighed in this condition for 

 the several determinations. What is required is the comparative 

 determination of the essential 'constants of lignification,' that 

 is to say, elementary composition, hydrolysis numbers, cellulose, 

 chlorine combining, furfural, methoxyl, nitration, and ferric ferri- 

 cyanide reactions. 



The Pectocelluloses. This group involves the general methods 

 of investigation of the carbohydrates of lower molecular weight, 

 for the reason that the non-cellulose constituents are easily hy- 

 drolysed to soluble bodies by alkalis, and are then further broken 

 down by acid hydrolysis to carbohydrates of definite and known 

 constitution. In the examination of these compound celluloses, 

 therefore, the methods of investigation to be found in standard 

 works on the carbohydrates must be followed. The general 

 scheme is that given in the text, p. 261 ; and as typical raw materials 

 the following should be studied : flax, esparto, and fleshy paren- 

 chyma, such as found in the turnip, apple, pear, and similar 

 fruits ; as bodies yielding the pectic acid series, and for the group 

 of mucocellulose which yield the neutral carbohydrates (hexoses 

 and pentoses), the investigations of Tollens (p. 223) should be 

 repeated. 



The Adipocelluloses. This ground is in a very undeveloped con- 

 dition, and much investigation will be required to establish the es- 

 sential chemical features of this particular compound cellulose. It 

 would be necessary to distinguish carefully between excreted by- 

 products and the essential cuticular tissue. The most promising 

 direction of investigation seems to be that resulting from previous 

 treatment of the tissue by one of the sulphite processes. The 

 drastic oxidations with nitric acid, and treatments with concentrated 

 alkalis, are too severe to enable any conclusions to be drawn with 

 certainty, from the products obtained, to the constitution of the 

 parent molecule; but a preliminary resolution into cellulose and 

 non-cellulose, by a method involving a minimum of change, affords 

 a much better basis for such investigations. As far as we know, 



