The Chemistry of Powder and Explosives - Sciencemadness Dot Org

EARLY HISTORY OF NITRATED CARBOHYDRATES 251
cotton in it for several minutes at ordinary temperature. Dumas
stated that satisfactory guncotton could be obtained without
observing any great exactitude in the proportion of the two acids
or in the duration of the immersion. Dr. Bley of Bernberg had
discovered that sawdust, treated in the same way as cotton,
yielded an explosive which, he believed, might replace gunpowder
in firearms and in blasting.
1846. Pelouze 83 made clear distinction between xyloidine and
guncotton. "I shall call pyroxyline or pyroxyle the product of the
action of monohydrated nitric acid on cotton, paper, and ligneous
substances, when this action has taken place without having
caused the solution of the cellulose." Braconnot in 1833 had prepared
xyloi'dine from starch; Pelouze had prepared pyroxylin in
1838. He pointed out that xyloidine dissolves readily in strong
nitric acid and, in the course of a day, is destroyed by it and
converted to a deliquescent acid. Pyroxylin does not dissolve in
concentrated nitric acid. Xyloidine is very inflammable and
explodes when struck, but it leaves a considerable residue of
carbon when heated in a retort and may be analyzed like an
ordinary organic substance by heating with copper oxide. Pyroxylin
explodes when heated to 175° or 180° and cannot be
distilled destructively. Pelouze found that 100 parts of starch,
dissolved in nitric acid and precipitated immediately, yielded at
most 128 to 130 parts of xyloidine. One hundred parts of cotton
or paper, after a few minutes' or after several days' immersion in
concentrated nitric acid, yielded 168 to 170 parts of washed and
dried pyroxylin. The acid mother liquors, both from the nitration
of the starch and from the nitration of the cotton, contained not
more than mere traces of organic matter.
1846. Schonbein's process soon became known through the
publication of the English patent to John Taylor (cited above).
He carried out the nitration by means of a mixture of 1 volume
of strong nitric acid (1.45 to 1.5) and 3 volumes of strong sulfuric
acid (1.85). The cotton was immersed in this acid at 50-60°F. for
1 hour, and was then washed in a stream of running water until
free from acid. It was pressed to remove as much water as possible,
dipped in a very dilute solution of potassium carbonate
(1 ounce to the gallon), and again pressed as dry as possible,
83 Ibid., 809, 892 (1846); MacDonald, op. at., pp. 17-20.