Compound Celluloses 155 



products of greater complexity, up to those of indefinite 

 molecular weight (charcoal or pseudo-carbon). More definite 

 features of the condensation are the closing of the C 4 O ring 

 (furfural) and the further condensation of the hexene to 

 benzene rings. But to study these and other changes in 

 reference to the parent molecule, it would be necessary to carry 

 out an elaborate series of quantitative observations, varying 

 not only the physical conditions of the distillation (temperature, 

 time, &c.), but the chemical factors by the admixture with the 

 fibre-substance of reagents of known function. Until we have 

 such results the imagination is free to go to work upon such 

 slender materials as are available. 



General Conclusions as to the Composition and 

 Constitution of Jute Lignocellulose. Having thus set 

 forth the general chemistry of the typical lignocellulose, it is 

 important to select and bring together those facts which bear 

 more particularly upon the problem of its constitution. This 

 problem, it may be remarked, cannot be divorced from its 

 essentially physiological aspects : a plant is an assemblage not 

 merely of products, but of processes ; and in investigating a plant 

 tissue, we have not merely to ascertain the quantitative rela- 

 tionships of its constituents, but from the point of view of 

 physiology or organic function to distinguish between organic 

 and excreted products ; further, to endeavour to arrive at their 

 genetic relationships. The history of every tissue is one of 

 continuous modification, and the excreta of plants are, in many 

 cases, the last links of a long chain of transformations. Where 

 such compounds are formed as by-products of the assimilative 

 processes, we cannot as yet hope to have any definite clue to 

 their origin ; but where they originate independently, either by 

 intrinsic or extrinsic modification (e.g. oxidation) of a tissue- 

 substance, the clue may be expected to be found in the consti- 

 tution of the tissue-substance itself. Or, to put it in another 



