NATURAL EESOURCES LITTLE. 235 
With a possible exception of steel, no metal is more vitally essential 
to the conduct of modern warfare than platinum, though there is 
probably not more than 10,000,000 ounces — approximately 425 tons — 
in use in the world to-day, and of this probably 95 per cent came from 
Russia. The importance of platinum is chiefly due to its extensive 
use as a catalyst in the synthetic production of such fundamentally 
basic supplies as sulphuric acid and ammonia, and it functions sim- 
ilarly in the manufacture of many other compounds. It is indis- 
pensable for certain chemical equipment, and a light film of platinum 
on glass is an essential part of Navy range finders. 
The importance of mercury as a war metal is altogether dispropor- 
tionate to the small amount used. It finds employment in periscope 
mirrors, thermostats, clinical and technical thermometers, and as mer- 
cury fulminate in priming charges. Corrosive sublimate, which is 
vitally important in surgery, is mercuric chloride, and the red oxide 
of mercury finds effective use in paints for ships' bottoms. We de- 
pend chiefly upon California for our mercury, and the Central Powers 
drew upon Austria and possibly Asiatic Turkey for their supply. 
Graphite crucibles are essential to the industries employing non- 
ferrous metals, and for such crucibles we have heretofore depended 
upon the flake graphite coming from Ceylon, our own supplies of 
graphite being of the amorphous variety. Under the stress of neces- 
sity, however, entirely satisfactory mixtures composed in large part 
of domestic graphite were developed. 
The whole structure of modern chemical industry, with all the 
ramifications arising from military demands, is based upon sulphuric 
acid, made either from pyrites or from native sulphur. Of the latter 
our immense deposits in Louisiana and Texas made it possible to 
increase our 1913 production of 3| million tons of 50° acid and 23,000 
tons of acid above 66° to 6,000,000 tons of 50° acid in 1917 with 760,000 
tons of the stronger acid, which finds its chief use in the production 
of explosives. Sulphuric acid is also largely used in the refining of 
petroleum and the pickling of metals. 
Portland cement, made from limestone and clay or clay-bearing 
limestone, is obviously a military supply of the first importance, en- 
tering into foundations and construction of all sorts — roads, dugouts, 
" pill boxes," and even ships, well named Faith. Fortunately, both 
our producing capacity and our supply of raw materials proved ade- 
quate to all demands. 
Similarly, it may be pointed out that crushed stone for road con- 
struction proved so vitally important to military operations that 
it is said that in France, next to the transportation of troops and 
ammunition, the transportation of crushed stone had priority over 
practically everything else. 
