22 Mr. Charles F. Cross [March 2, 



non-cellulose components. The esparto compound celluloses are 

 resolved by alkaline treatment (caustic soda solution at 120°-130°), 

 the wood substance (ligno-cellulose) by treatment with acid com- 

 pounds (bi-sulphites) in solution at 140°-160^ 



The soluble by-products, derivatives of the non-cellulose complex, 

 amounting in either case to 50 per tsent. of the original raw material, 

 are in effect waste products. In the case of the esparto they are 

 burned incidentally to the recovery of the soda ; but the " wood 

 liquor " by-product is still in the main a waste, and a colossal one. 



The " positive " chemical technology of cellulose is necessarily 

 based upon its reactivity, and the industries w^hich exploit the 

 reaction changes of cellulose are of widely divergent character ; those 

 of Group A are based upon reactions of decomposition ; those of 

 Group B are based upon the properties of synthetical derivatives. 



Of Group A, the resolution of cellulose into sugar (dextrose) by 

 acid hydrolysis is the basis (1) of a process for the preparation of 

 industrial (ethyl) alcohol from wood, and more economically from 

 wood w^astes. According to our latest information the technical 

 difficulties presented by this apparently simple process have been so 

 far overcome that the alcohol is produced on the large scale at a cost 

 of 2^d. per gallon, exclusive of the small cost of the w^aste wood 

 material. Under these most favourable conditions, however, the 

 yield of alcohol is only 5 per cent, of the weight of the wood sub- 

 stance, or say 8 per cent, of its cellulose content, leaving therefore 

 a very large item of final Avaste to the debit account of the chemist.* 



(2) Saw^dust, or other wood waste, fused — i.e. heated at high 

 temperatures — with the caustic alkalis is destructively oxidized, and 

 the main product of the oxidation is oxalic acid ; this process is in 

 effect the main source of the acid, as an industrial product. 



(3) Waste w^ood subjected to destructive distillation in closed 

 retorts is resolved into gaseous and volatile liquid products, with a 

 solid residue of charcoal or pseudo-carbon. The liquid products con- 

 tain acetic acid, acetone, and methyl-alcohol as main constituents, and 

 have been the main source of supply of these chemical individuals, 

 which, as reagents especially, are indispensable in modern chemical 

 industry. 



In this direction, however, cellulose material and its wasteful 

 treatment by destructive distillation are being supplanted by a direct 

 and controlled synthesis from calcium carbide, acetylene being quanti- 

 tatively transformed into acetaldehyde, and this into acetic acid. In 

 this new industry the pioneers in this country are the British Cellulose 

 and Chemical Manufacturing Company, Spondon, Derby. 



(4) Cellulose heated in full contact with oxygen is burned with 

 the familiar flame combustion ; but from all the natural structural 

 forms there is a residue of inorganic matter (ash) which when present 



* See Journ. Soc. Chem. Ind., X300-1916. 



