BREAD FROM AIR.

Manawatu Herald, Volume XXX, Issue 434, 10 September 1908, Page 4

BREAD FROM AIR.

Writing in the London Daily News Mr L. G. Chizzo-Money describes briefly the methods by which scientists are seeking to restore to the earth the nitrogen of which the human race deprives it. Without nitrogen flesh cannot be formed, he says ; without nitrogen man is impossible. With the preservation and rapid multiplication ot men the call for nitrogenous food has led to the rapid exhaustion of soils and manure beds. Fortunately, the scientist has come to the rescue of mankind, and various methods of nitrifying the soil are in use. There is a beautiful process by which Oswald and Brauer, two German chemists, obtain nitric acid from the ammonia waste of gasworks. It consists essentially in the decomposition of ammonia vapour by platinum, the amount being exposed to the platinum for one-five hundredth part ot a second of time. If the exposure were longer than this unfixed nitrogen would be created, and, of course, lost. The ammonia vapour has to pass like a gale ot wind, so that decomposition goes far enough to produce nitric acid and not free nitrogen. The area of the decomposition used is but that of a teacup, but it produces zoolb of nitric acid in a day. In Norway, nitrogen is drawn directly from the air, and is made available tor manuring purposes. An electric furnace is employed, the electricity being obtained from waterfalls. The air is led into the furnace and put to an electric disc flame with a diameter of about seventy inches. Sweeping this terrible flame on both sides, the air is momentarily heated to a point at which the nitrogen is oxidised. Immediately the gas coming from the furnace is cooled down to avoid loss of nitrogen, and led over limestone sprinkled with water, with the result that nitrate of lime is obtained. It is a scientific triumph, which looks prosaic enough when the stuff leaves the factory in wooden barrels, adds Mr Money. A third and still more interesting process by which soils are charged with nitrogen is the now well-known one of infecting the earth with nitrogen fixing bacteria. It is said that by this method waste lands may be reclaimed at a cost of about sixpence an acre.