THE NITROGEN QUESTION—MUNROE. 229 
and excreta of bats are the chief source of the.organic matter, and 
about stables. 
Since the amount of niter procurable from these sources was lim- 
ited it became necessary, as the demand for saltpeter increased, to 
resort to other sources of supply, and consequently niter plantations 
were established in many countries where, following the principles 
set forth above, the niter was formed and protected from the weather. 
Desortiaux ® describes in detail the saltpeter plantations of Hungary, 
Switzerland, France, and Sweden. Such farms have been carried 
on in this country, especially in the Southern States during the civil 
war, and the means resorted to by John Harrolson, of Selma, Ala- 
bama, to secure the necessary nitrogenous organic matter for these 
farms became particularly widely known. In emergencies, as in 
Sweden in 1520, the earth of cemeteries has been lixiviated to obtain 
niter, and in this last-mentioned country a tax was imposed in 1642 
which had to be paid in saltpeter.? 
About 1821 the naturalist Mariano de Rivero found on the Pacific 
coast of South America, in the province of Tarapaca, immense de- 
posits of sodium nitrate.“ As this salt had prior to this been known 
only as a laboratory product, the discovery was of marked scientific 
interest, which became an economic one when, in 1830, the material 
was mined for exportation and 8,348 tons were shipped in that year. 
Investigation has shown that this deposit extends for some 450 miles 
north and south in the arid plains which he between the western slope 
of the Andes Mountains and the coastal range on the Pacific, at alti- 
tudes of from 3,600 to 13,000 feet and at distances of from 15 to 93 
miles from the sea. The exploitation of this deposit has been pushed 
to such an extent that in the year ending December 31, 1908, there were 
shipped from the various South American ports contiguous to this 
field 1,993,000 tons of the nitrate of soda, and because of the export 
taxes levied upon this material and the payments required for con- 
cessions to operate in this desert tract, this industry has been and 
still is a rich source of revenue to the Chilean Government. The 
extent to which this industry has grown and its rate of growth are 
clearly set forth in the following table prepared by F. V. Vergara,’ 
collector of customs at the port of Valparaiso: 
4Traité sur la poudre, les corps explosifs et la pyrotechnic, vol. 1, pp. 15-117, 
1878. 
6’ The Manufacture of Explosives, O. Guttmann, vol. 1, p. 24, 1895. 
¢ Principles and Practice of Agricultural Analysis, H. W. Wiley, vol. 1, p. 16, 
1894. 
@Monthly Bulletin International Bureau of American Republics, November, 
1903, p. 1290, 
