Naphtha polloi]." It enters the word napalm, a contraction of the "na" of "naphthenic acid" and "palm" of "palmitic acid", originally made from a mixture of naphthenic acid combined with aluminium and magnesium salts of palmitic acid. Naphtha is the root of the word naphthalene, and can also be recognised in the word phthalate, and the paint colour phthalo blue. In older usage, "naphtha" simply meant crude oil, but this usage is now obsolete in English. It was also used for mineral spirits (also known as "Stoddard Solvent"), originally the main active ingredient in Fels Naptha laundry soap. The Ukrainian and
Incendiary ammunition night fighters for use against military zeppelins threatening the British Isles. The flammable hydrogen gas of the zeppelins made incendiary bullets much more deadly than standard ones which would pass through the outer skin without igniting the gas. Similarly, incendiary ammunition was used against non-rigid observation balloons. The British Royal Flying Corps forbade the use of incendiary ammunition for air-to-air combat with another airplane, as their use against personnel was at first considered to be a violation of the St. Petersburg Declaration. Pilots were permitted to deploy them against only zeppelins and balloons, and they were additionally restricted to shooting