170 



TRUE OR ETHYL ALCOHOL AND ITS .MANUFACTURE— ARTIFICLAL SILK .MADE FROM CELLULOSE 



(G) STATISTICS. In the United States during 1909. 116 distilling etablishments consumed 

 1,150,000 cords of hardwoods, costing a-3'32 per cord upon an average. 



PARAGRAPH XXXVI. 

 TRUE OR ETHYL .ALCOHOL AND ITS M.AXUFACTURE. 



(A) PRIXCIPLE UXDERLYIXG THE PROCESS. Wood heated under pressure in the presence of 



acids yields sugar (dextrose). This sugar, freed from the acid admixture and allowed to ferment under the 

 influence of yeast, is transformed into ethyl alcohol. 



(B) RAW MATERIAL. Cottonwoods, linden, yellow poplar are said to be superior to the heavy 

 hardwoods as well as to conifers. Unless sawdust is available, the wood is prepared as if it were to be 

 used in the manufacture of chemical fiber. 



(C) PROCESS. The acid used does not enter into any chemical combination with the wood. It 

 merely acts by its presence and is said to be most efficient when in statu nascendi. Sulphuric acid, 

 sulphurous acid, hydrochloric acid or a mixture of these and similar acids are used. 



The temperature of the lead -coated vats containing acid and wood is gradually raised to about 

 250 degrees P. Hydraulic pressure in also applied, either before or after the heating process. As a matter 

 of fact, the partial conversion of cellulose into sugar seems to be due to pressure, not to heating. The 

 acid is then neutralized and the temperature reduced to about 85 degrees F. By the addition of yeast (fed on 

 phosphates of potash and of ammonia) a violent fermentation of the sugar is started, ending within 36 hours, 

 when the yeast has dropped down to the bottom of the vat while the sugar has been converted into alcohol. 



The liquid is distilled and redistilled, yielding alcohol of any desired concentration. 



The refuse remaining- merely a small percentage of the raw material seems convertible into sugar - 

 might be used as fuel for the boilers. 



Classen claims, after his method, to obtain at least 30 per cent dextrose from absolutely dry wood. 

 .■\fter T. Koerner, not more than 6 per cent of the weight of air -dry wood can be thus converted. 



(D) OUTPUT. One hundred pounds of dry- wood are said to actually yield about five pounds of 

 90 per cent alcohol. The process of manufacture is far from being perfect. .A number of chemists, notably 

 Classen, are hard at work to further improve and to cheapen the process. Cheap alcohol -a fuel, a 

 source of light, and a source of technical energy- manufactured from wood will be a boon for household, 

 industry and forest. 



PARAGRAPH XXXVII. 

 ARTIFICLAL SILK MADE FROM CELLULOSE. 



(A) HISTORY. Artificial silk was first prepared by Hilaire de Chardonet in 1884. To-day, many 

 patents and numerous factories to exploit them exist in the Old Country. 



(B) QUALITIES OF PRODUCT. Artificial silk has an exquisite shine and is easily colored. .Artificial 

 silk is thicker, less flexible, more brittle, and weaker than natural silk. It distends perceptibly in water. 

 The tearing strength of silk obtained from nitro- cellulose is only 35 per cent of that of true silk, its 

 toughness only 45 per cent. 



Under the microscope, the thread produced by the silkworm shows a hollow cross section, whilst 

 that of artificial silk is solid. C smically, there is no difference between the composition of natural and 



r 



