THE NITROGEN QUESTION—-MUNROE. DOS 
address made by Sir William Crookes before the British Associa- 
tion for the Advancement of Science in 1898, when, in dealing with 
the problem of meeting the rapidly increasing demand for food, 
he pointed out that while the average yield of wheat was but 12.7 
bushels per acre it had been demonstrated that the yield could be 
increased to 20 bushels by the use of 14 hundredweight of nitrate 
of soda on each acre annually. 
This increasing use, however, tends to exhaust the supply. Crookes 
estimated that if the nitrate were used over the whole area under culti- 
vation at the rate he proposed, the Chilean deposits would be ex- 
hausted in four years. Vergara“ estimated that at the rate that the 
nitrate had been mined and exported between 1840 and 1903, as shown 
in Table 5, the Chilean deposits would be exhausted by 1938. Albert 
Hale, however, in a more recent review of the situation,’ points out 
that these estimates were based on the contents of the deposits then 
known in the province of Tarapaca, and the extent to which they 
could be profitably worked, and states that deposits of such magnitude 
have since been discovered in the provinces of Antofogasta and 
Atacama, and the processes of recovery of the nitrate from low-grade 
ore (caliche) have been so improved that, at a rate of consumption of 
5,000,000 tons annually, which he expects will be the normal demand 
in a few years, there is enough nitrate in these deposits to last three 
hundred years. 
This is a more encouraging outlook, but, nevertheless, from what 
has been said it is evident that the world has for long been largely de- 
pendent on these Chilean deposits for the greater part of its supply of 
nitrate and the substances derived from it. In time of prolonged war, 
in case nitrate has become contraband, most countries have been obliged 
to resort to the vicious policy of niter farming, or, as our Navy De- 
partment has done since 1863, have accumulated in advance consider- 
able stores of niter, and this condition would have continued to hold 
but for important advances recently made in the production of nitrate 
from atmospheric nitrogen, and through other developments in 
chemistry. 
We have in our atmosphere an abundant supply of this element. It 
is estimated that the air over each acre of ground contains 33,880 
gross tons of nitrogen. It is, however, free, and to be available for 
use it must be combined. The methods for effecting the fixation of 
this nitrogen have proceeded along three lines: (1) The production 
of nitric acid and nitrates; (2) the production of cyanides; and (3) 
the production of amids, and the first and last have now been brought 
to commercial success. 
@ Loe. cit. 
> Bull. International Bureau of American Republics, p. 27, July, 1908. 
