72 Cellulose 



seen from the fact that when the lumps or clots are transferred 

 to a solution of pure cane sugar, or beet molasses, a further 

 formation of the cellulose ensues. When the process proceeds 

 in neutral solution no carbonic anhydride is evolved ; but in 

 presence of acids this gas is evolved, and at the same time 

 acetic acid is formed in the solutions. 



E. Durin, by whom these phenomena have been investigated, 

 (Compt. Rend. 82, 1078; 83, 128), regards the ferment as 

 allied to diastase, and states that fresh solutions of diastase itself 

 act on solutions of sugar to form the soluble cellulose, precipit- 

 able by alcohol. There is also some evidence that cellulose 

 may be formed from cane sugar in the plant by processes of 

 this kind. It may be noted here that the general view current 

 amongst plant physiologists has been that ' starch is the material 

 from which plants elaborate their tissue substances or cellulose.' 

 The recent researches of Brown and Morris, however, have rather 

 discredited this view, their elaborate and ingenious experiments 

 going to show that cane sugar is probably the immediate 

 mother substance from which the plant cell builds up cellulose, 

 starch being rather a reserve form for what may be regarded as 

 the excessive energy of assimilation in sunlight, being in turn 

 hydrolysed as required to feed the more continuous process of 

 tissue formation. 



(b) A. J. Brown has more recently made observations upon 

 * An Acetic Ferment which forms Cellulose ' (J. Chem. Soc. 

 49, 432). The ' vinegar plant ' takes a membranous form, 

 which in microscopic examination is seen to be clearly differen- 

 tiated from the zooglcea form of the Bacterium Aceti. It is, in 

 fact, composed of bacterial rods of 2^ length contained in a 

 membranous envelope. This envelope has the properties and 

 composition of cellulose. 



Pure cultures of the organism placed in solutions of levulose, 

 mannitol, and dextrose, reproduce the growth in question, com- 



