Gun Cotton, a cellulose product discovered by Schönbein in 1845. It is prepared by drying cotton-wool at 100 degrees, and then leaving it for 24 hours in a mixture of one volume of nitric acid, specific gravity 1.5, and three volumes of sulphuric acid, specific gravity 1.85, the mixture being cooled to 10 degrees. It is then washed with water, and, if required pure, again with a mixture of one part alcohol and three parts ether to remove the lower nitrates. Gun cotton finely divided explodes between 160-170 degrees. It keeps best if washed in soda. Compressed gun cotton burns like tinder, but is exploded by mercuric-fulminate.

Entry from Everybody's Cyclopedia, 1912.