THE JOY OF GUNCOTTON

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Nitrocellulose essentially consists of cotton exposed to nitric acid and sulfuric acid. It was discovered around 1845 by Christian Friedrich Schönbein when he used a cotton apron to wipe up an acid spill. His curiosity became piqued when the apron spontaneously disappeared in a ball of flame after drying out. Fortunately, he no one was wearing it at the time.

Nitrocellulose, a high explosive, is also called "guncotton," as it has been a significant ingredient of many formulas for smokeless gunpowders and other stuff which goes boom since the 19th century. It is fairly inert when wet but extremely unstable and unsafe when dry. 

It is still used in the manufacture of guitar picks and  paint for guitars. Until the EPA stepped in, it was also a component of lacquer paints used on automobiles.

X-rays, movie films, and photo negatives were for several decades made from plasticized nitrocellulose (also called "nitrate" film). As anyone who watched the 2009 movie Inglourious Basterds or the Simpsons parody thereof knows, nitrate film is extremely inflammable and will continue burning intensely even under water. After several hospital and movie theater disasters, safer alternatives were introduced for X-rays in the 1930s and for movie, negative, and slide film in the late 1940s. If you look at a photo negative from about 1950 or later, it will probably have "SAFETY FILM' printed on it, which denotes that it is not nitrate film and is thus unlikely to burn down your house. The government now has extreme safety protocols, including asbestos projection booths and special film projectors containing holes in which to insert fire extinguisher spray, imposed on anybody who will actually be showing movies on nitrate stock.  If you would like to see film archivist Geoffrey Rayle perform a nitrate burn, please click here.

Even if it does not catch fire, nitrate film will decompose unless stored under very controlled conditions. Many early movies are no longer available as a result.

Photo courtesy of  Library of Congress

For a while, nitrocellulose was used in the manufacture of artificially ivory for billiard balls. However, this practice died out after players made complaints about being distracted by their balls exploding during the course of a game.

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