In 1943, chemists at Harvard came up with a cheap and simple way to thicken petrol into a gel. Not only was it easier to use in flame-throwers in this non-drip form, but it would conveniently stick to things - wood, metal, flesh - as it burned. The thickener was originally made with coprecipitated aluminium salts of naphthenic and palmitic acids, which is how it came to be known as napalm. The first napalm incendiary bombs were dropped on a fuel depot near St Lô during the Allied invasion of Normandy in 1944. The stuff was later used by the United States against the Japanese, by the Greek government against the Communists in 1946-49, as well as by UN forces in Korea and French troops in Indochina during the 1950s. But it was the Americans in Vietnam who made napalm famous.

LRB 29 November 2007 | PDF Download