The Typical Cellulose and the Cellulose Group 71 



acid. In the final result the process may be interpreted as a 

 simple hydrolysis into dextrose molecules that is, the acid plays 

 an intermediate part only, combining with the molecule by 

 simple synthesis, and interchanging with water molecules in 

 presence of excess of the latter. The intermediate terms of 

 the dissection process are not sufficiently under control to be 

 followed with that degree of precision which is possible in the 

 case of other complex carbohydrates, notably starch, which 

 are hydrolysed by relatively minute quantities of enzymes or 

 ' unorganised ferments.' Even if this were possible there appears 

 at present no prospect of building up the cellulose molecule by 

 reversal of the process, as our much more complete knowledge 

 of the starch molecule has brought with it no suggestion of a 

 constructive process following inversely the lines of its hydro- 

 lytic dissection. 



It appears, therefore, on the experimental evidence that 

 cellulose is built up of molecules of simple carbohydrates, but 

 in what manner there are none but hypothetical indications. 

 On the other hand, certain processes have been brought to 

 light which are undoubtedly direct syntheses of cellulose from 

 particular carbohydrates of low molecular weight. Of these two 

 may be cited as typical, one of which (a) is due to the action 

 of an unorganised ferment resembling diastase, the other (b) is 

 produced by a micro-organism. 



(a) As a result of a change which is observed to be set up 

 ' spontaneously ' in beet juice, a white insoluble substance is 

 formed, and separated in lumps or clots ; this substance has all 

 the characteristics of cellulose. After separating this insoluble 

 cellulose the solution gives with alcohol a gelatinous precipitate 

 resembling the hydrates of cellulose previously described. 

 These results are independent of the so-called viscous or mucous 

 fermentations. That the process by which the cellulose is 

 formed has the essential features of a fermentation process, is 



