Page:Popular Science Monthly Volume 85.djvu/589

Rh the disadvantage that the ammonia must be converted into nitric acid by processes which are not yet completely worked out. Undoubtedly, however, the economical manufacture of nitric acid from ammonia will soon become an accomplished fact, as recent publications seem to indicate that the problem is almost solved. During the present war all the saltpeter in the German Empire has been requisitioned by the government for the manufacture of nitric acid and the production of ammunition, while sulphate of ammonium obtained by the Haber synthesis and that recovered from the by-product of the coking industries takes its place for fertilizing purposes. The output of the existing Haber plant was doubled at the beginning of the war in order to provide sufficient sulphate of ammonium for the coming crops, and it is said that since that time another unit is in course of construction which will definitely secure Germany's requirements for nitrogenous fertilizers.

Another great benefit which, while the war lasts, will accrue to German agriculture from scientific farming is that the large acreage devoted to the cultivation of the sugar beet—usually the most fertile soil—will be directly available, without the use of additional fertilizers, for the raising of rye, oats, potatoes, etc. During the war Germany will not be able to export beet sugar which she does at other times on an extremely large scale, and will, therefore, not raise so many sugar beets. Utilizing this fertile soil for cereals, potatoes, etc., means an additional supply of food stuffs for the nation.

The industry for the recovery of the by-products from the coking process, which we already mentioned as a source for sulphate of ammonium, has also been highly developed because German militarism needed some of the resulting coaltar products for the manufacture of explosives. Benzol, toluol, carbolic acid, metacresol and diphenylamine are starting materials used in the manufacture of ammunition. Formerly, most of these substances were imported from England, where they were produced from coaltar obtained in the manufacture of illuminating gas by the distillation of coal, while in most other countries, for example, in the United States, illuminating gas is made from water gas. By developing the coking industry, that is, by suitably and economically heating coal, Germany has made herself independent of England, and now produces all the materials required for explosives and ammunition within her own borders.

Germany is also the only country which has made itself independent of England as far as its consumption of carbolic acid, one of the most important coaltar products, is concerned. This substance, employed both for explosives and as a disinfectant in general hygiene and surgery, is a material of war of the highest value. It was not considered wise nor profitable to remain dependent on foreign sources for such an indispensable article. Soon the ever watchful and resourceful chemist