Naphthenic acid by a general formula CH O, where "n" indicates the carbon number and "z" specifies a homologous series. The "z" is equal to 0 for saturated, acyclic acids and increases to 2 in monocyclic naphthenic acids, to 4 in bicyclic naphthenic acids, to 6 in tricyclic acids, and to 8 in tetracyclic acids. Salts of naphthenic acids, called naphthenates, are widely used as hydrophobic sources of metal ions in diverse applications.Aluminium salts of naphthenic acid and palmitic acid were combined during World War II to produce napalm. The word "napalm" is derived from the words naphthenic acid and palmitic acid.
Incendiary ammunition VI incendiary were used until production increased to sufficient levels. By 1942 the standard loading for fixed .303s was half loaded with AP and half with incendiary bullets. One fighter pilot who was shot down by incendiary ammunition while flying in the Battle of Britain describes his experience: The British Mk VI bullet was copied by the United States in simplified form, for both their .30 and .50 aircraft bullets. The British then adopted the simplified design as the Mk VII bullet. Incendiary projectiles, in particular those intended for armor penetration, are more effective if they explode after penetrating a