many cases the artifical products cannot be distinguished from the natural original ones. Benzoic acid, obtained by subliming gum benzoin, has been in use since the latter part of the sixteenth century, when under the name of fleurs de benzoin, soon anglicised into flowers of benjamin, they were introduced by a French physician, named Blaise de Vigenère, who was secretary to Henri III. [The name benjamin was not a bad corruption after all, as the Arabic term from which the European designations were derived was Lu-ban Jawa, the incense of Java. The Spaniards first dropped the first syllable under the mistaken impression that it was the Arabic article. Old etymologies traced the name to a supposed Ben-jui, or tree of the Jews.] The artificial benzoic acid is obtained by the oxidation of toluene, a hydrocarbon distilled from coal-tar.
Comparatively recent achievements of synthetic chemistry are the artificial production of camphor and of adrenaline, the active principle of the suprarenal gland. The synthetic products can be distinguished from the originals by their behaviour towards polarised light.
Salicylic acid, prepared by acting on carbolic acid by carbon dioxide in the presence of an alkali, became a practical commercial product in 1874, but its discoverer, Kolbe of Leipzig, had prepared it in his laboratory since 1859. The natural product, prepared from willow bark or oil of wintergreen, was worth twelve guineas a pound; the artificial salicylic acid in a few years came to be sold at not so many shillings per pound. Kolbe's theory was that the compound he devised would decompose within the organism into phenol and carbon dioxide, and thus exercise an anti-putrefactive effect.
