England was now free to get nitrates for her munition factories, but
Germany was still bottled up. She had stored up Chilean nitrates in
anticipation of the war and as soon as it was seen to be coming she
bought all she could get in Europe. But this supply was altogether
inadequate and the war would have come to an end in the first winter if
German chemists had not provided for such a contingency in advance by
working out methods of getting nitrogen from the air. Long ago it was
said that the British ruled the sea and the French the land so that left
nothing to the German but the air. The Germans seem to have taken this
jibe seriously and to have set themselves to make the most of the aerial
realm in order to challenge the British and French in the fields they
had appropriated. They had succeeded so far that the Kaiser when he
declared war might well have considered himself the Prince of the Power
of the Air. He had a fleet of Zeppelins and he had means for the
fixation of nitrogen such as no other nation possessed. The Zeppelins
burst like wind bags, but the nitrogen plants worked and made Germany
independent of Chile not only during the war, but in the time of peace.

Germany during the war used 200,000 tons of nitric acid a year in
explosives, yet her supply of nitrogen is exhaustless.

[Illustration: World production and consumption of fixed inorganic
nitrogen expressed in tons nitrogen

From _The Journal of Industrial and Engineering Chemistry_, March,
1919.]


Nitrogen is free as air. That is the trouble; it is too free. It is
fixed nitrogen that we want and that we are willing to pay for; nitrogen