Page:Popular Science Monthly Volume 90.djvu/606

 War Time Uses of Wood

Great guns are fired with chemically transformed wood, and whole nations are kept alive by it

By A. W. Schorger

Chemist in Forest Products, Forest Products Laboratory, Madison, Wisconsin

���ONE of the mysteries of the present war is the source from which Germany obtains the gun cotton used in the manufacture of smokeless powder. A well- defined belief exists in England that at least part of the nitrocellulose (gun cotton) needed by German powder factories is being made from wood.

When England declared cotton contra- band of war, it was maintained by many that Germany would not be greatly incon- venienced, since she was already making explosives from wood cellulose. The dis- cussions that followed even developed the silly suggestion that the forests of Germany be destroyed by an enormous fleet of aero- planes armed with bombs. One English editor dryly remarked: "This would scarcely be feasible since about one-third of Germany is forested."

It is an interesting fact that the first successful smokeless powder was made from wood, about 1865. This powder, in- vented by Schultze, consists of a mixture of saltpeter and nitrated purified wood. While inferior to gun cotton in power, it still retains high favor among sportsmen. Vari-

��A brick charcoal kiln. Here great quantities of stump wood and wood of poorer grade are used

ous Other explosives, known as "white powder," "yellow shooting powder," an<^ "Bautzen blasting powder" are trans- formations of wood.

The propellant explosive used in both large caliber guns and small arms is some form of nitro-cellulose or nitro-glycerine. On the caliber of the gun depends the size of the grain required; for the powder must burn uniformly and not too fast. Grains of any desired size may be obtained by mechanical processes, provided the original structure of the nitrated fibers has been destroyed so that they are reduced to a gelatinous mass. Thus the successful use of nitrocellulose powders depends upon the possession of proper solvents.

In the production of solvents the de- structive distillation of hardwoods plays a highly important part. It yields methyl alcohol and acetic acid. From the latter is made acetone. The lower cellulose nitrates are soluble in a mixture of alcohol and ether, but when the nitrogen content reaches about thirteen per cent they are insoluble in this mixture but are soluble in acetone. It requires from seventy-five to one hundred

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