Guncotton is an explosive. It is obtained when cotton or purified wood cellulose is soaked in a mixture of sulfuric and nitric acids. By 1846, C. F. Schonbein, a German chemist, had discovered the process for making guncotton. After the cotton is soaked in the acid mixture, it is drained and washed. Then, it is boiled in water to remove the acid and impurities. The cotton is ground to a pulp and drained. It is pressed into small slabs, or blocks, while damp. It may be dried in air, either after boiling, or after it has been made into blocks.
When ignited, dried guncotton burns very rapidly. A blow from a hammer will cause it to explode. Wet guncotton is safer to handle. It will not burn, can be kept in storage indefinitely, and will not explode unless another explosive sets it off. Ordinary guncotton burns too fast to be used as an explosive in firearms. When it is colloided (gelatinized) in nitroglycerin or other solvents, its burning rate can be controlled. Colloided guncotton is a major ingredient of smokeless gunpowder and is used in certain rocket propellants.
Guncotton is a kind of cellulose nitrate, a chemical that is also known as nitrocellulose. It is the most highly nitrated form of nitrocellulose. Nitrated celluloses that have less nitration than guncotton are usually called collodion cotton. These materials are widely used in lacquer and plastic products.
