iQ05\ Wheeler— Problems in Cellulose Field. 107 



with the cell wall, but modern investigation has demonstrated 

 the error of this belief by showing- that the ultimate products 

 of hydrolysis of different cell walls are not the same. Cotton, 

 for instance, yields dextrose; the cell walls of the seeds of 

 Lupinus lutevs, and many other plants give galactose, while 

 the seeds of the cereals and leguminous plants yield arabinose 

 and xylose. It is clear that cell walls are not of uniform com- 

 position. How they actually differ has not yet been deter- 

 mined, their differentiation being- an extremely difficult prob- 

 lem. The name cellulose does not apply to a sing-le individual, 

 existing in only one form, like ethyl alcohol. Analyses of 

 various bodies regarded as cellulose give figures leading- to 

 the empirical formula (C 6 H I0 O s )n in which the carbon percent- 

 age is 44.2 and the hydrogen is 6.3. The highest percentage 

 of cellulose is obtained from cotton, the yield being approxi- 

 mately ninety per cent. Most of the remainder is water, and 

 there are very small amounts of ash and complex organic 

 compounds. Flax, hemp and ramie also give large yields of 

 cellulose. Again, cellulose is used to designate combinations 

 of the body already mentioned with highly complex radicals 

 of unknown constitution. These are compound celluloses and 

 are more specifically termed lignocelluloses, muco-celluloses, 

 pectocelluloses, adipocelluloses and cutocelluloses. Some pro- 

 gress has been made in the constitutional study of these com- 

 pounds, more especially the lignocelluloses. Cross and Bevan 

 have studied the lignocellulose of jute, selecting this form 

 because it seemed likely to be the simplest representative 

 since jute matures in one season. They recognize the follow- 

 ing general constituents: (a) a-cellulose, an oxidized cellulose; 

 (b) /3-cellulose, a less resistant form and yielding a large 

 amount of furfural on hydrolysis; (c) lignone, a radical con- 

 taining the carbonyl group and about one-third of which is of 

 the benzeneoid type. 



The difficulties surrounding the experimental study of the 

 celluloses are very great. Their insolubility in the ordinary 

 solvents precludes purification in the usual way and renders 



