NAPHTHA  , a word originally applied to the more fluid kinds of

petroleum, issuing from the ground in the Baku district of Russia and in Persia . It is the va4Ba of Dioscorides, and the naphtha, or bitumen liquidum candidum of Pliny . By the alchemists the word was used principally to distinguish various highly volatile, mobile and inflammable liquids, such as the ethers, sulphuric ether and acetic ether having been known respectively as naphtha sulphurici and naphtha aceti . The term is now seldom used, either in commerce or in science, without a distinctive prefix, and we thus have the following: I . Coal-tar Naphtha.—A volatile commercial product obtained by the distillation of coal-tar (see COAL-TAR) . 2 . Shale Naphtha.—Obtained by distillation from the oil produced by the destructive distillation of bituminous shale (see PARAFFIN) . 3 . Petroleum Naphtha.—A name sometimes given (e.g. in the United States) to a portion of the more volatile hydrocarbons distilled from petroleum (see PETROLEUM) . 4 . Wood Naphtha.—M ethyl alcohol (q.v.) . 5 .

Bone Naphtha.—Known also as bone oil or 'Dippers oil . A volatile product of offensive odour obtained in the carbonization of bones for the manufacture of animal charcoal . 6 . Caoutchouc Naphtha.—A volatile product obtained by the destructive distillation of rubber . (B .