The Chemistry of Powder and Explosives - Sciencemadness Dot Org

258 NITRIC ESTERS
heat and pressure, was patented by J. W. and I. S. Hyatt 9i in
1870. Worden 95 states that collodion for the manufacture of celluloid
is made by nitrating tissue paper with a mixed acid which
contains nitric acid 35.4%, sulfuric acid 44.7%, and water 19.9%.
Twenty-two pounds of acid are used per pound of paper. The
nitration is carried out at 55° for 30 minutes, and the product
contains 11.0-11.2% nitrogen. Ether-alcohol solutions of collodion,
to which camphor and castor oil have been added in
order that they may yield tough and flexible films on evaporation,
are used in pharmacy for the application of medicaments
to the skin in cases where prolonged action is desired. Two per
cent of salicylic acid, for example, in such a mixture makes a
"corn remover." Collodion for use with nitroglycerin to make
blasting gelatin is generally of higher nitrogen content. Here the
desideratum is that the jelly should be stiff, and the higher
nitrogen content tends in that direction, but the collodion dissolves
in the nitroglycerin more slowly, and the product becomes
stiffer on prolonged storage, and less sensitive, and may cause
misfires. The nitrogen content of collodion for use in the manufacture
of blasting explosives is generally between 11.5 and
12.0%, The official definition in England of collodion for this
purpose gives an upper limit of 12.3% nitrogen.
Two kinds of nitrocellulose were used in France at the time of
the first World War, coton-poudre No. 1 (CPi), insoluble in
ether-alcohol and containing about 13% nitrogen, and cotonpoudre
No. 2 (CP2), soluble in ether-alcohol and containing
about 12% nitrogen. 96 CPx thus contained a little less nitrogen
than the material which we are accustomed to call guncotton,
and CP2 contained a little more than the material which we are
accustomed to call collodion, CPi and CP2 were not respectively
wholly insoluble and wholly soluble in ether-alcohol; their compositions
were approximate, and CP2 always contained a certain
amount of material soluble in alcohol alone. A mixture of CPi
and CP2 colloided with ether-alcohol was used for making pou-
»*U. S. Pat. 105,338 (1870).
95 /. Soc. Chem. Ind., 29, 540 (1910).
96 The French are accustomed to report their analyses of nitrocellulose,
not as per cent nitrogen, but as cubic centimeters of NO (produced in
the nitrometer and measured under standard conditions) per gram of sample.
Per cent nitrogen times 15.96 equals number of cubic centimeters of
NO per gram of nitrocellulose.