Gun Cotton
2 of the 7 encyclopedias on this shelf carry an entry for Gun Cotton. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
Important: Safety Warning This page contains instructions involving gunpowder or other explosive or pyrotechnic compositions. Preparing explosives as described has caused severe injuries and deaths, and is illegal in most places. In addition, this page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes. This information has been left in for historical purposes but should not be acted upon. pyroxylin. Trinitrocellulose, C&H (NO2) 30%, more probably a nitric ether of cellulose, C12H14 (ONO2) 604, as by the action of reducing agents as hydric potassium sulphide, KHS, and iron and acetic acid, it is converted into cellulose. Boiled with ferrous sulphate and concentrated hydrochloric acid, it gives off all its nitrogen as N2O2. Gun cotton was discovered by Schönbein in 1845. It is prepared by drying cottonwool at 100 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°. 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°. It keeps best if it is washed with soda. Compressed gun cotton burns like tinder, but is exploded by mercuric-fulminate. See EXPLOSIVES.
Aiton's Encyclopedia (1910)
a violent explosive. It is prepared by soaking cotton waste in the same acids that form nitroglycerin. After washing and treatment too detailed for description, it may be used loose, or it may be compressed into small cakes like gun wads by a pressure of from four to six tons per square inch. It is almost smokeless, and is used as a substitute for gunpowder. It is the forerunner of dynamite by which it has been supplanted for purposes of blasting. See Dynamite