Aniline.
Among the events which gradually led to the production of artificial compounds for which physiological properties and action have been claimed, the discovery of aniline is prominent. The substance, now so well known by that name, was first separated from indigo in 1826 in the course of a dry distillation of that dye by a pharmacist of Erfurt, named Unverdorben. He named his product "crystalline," from its character. In 1834 the same substance, as it was later known to be, was obtained from coal tar by Runge, who, observing the violet colour which bleaching powder caused in its aqueous solution, designated the product "kyanol." Ten years subsequently Hofmann continued the investigations which Runge had pioneered. Meanwhile Fritzsche had obtained anthranilic acid from indigo, and from that he had produced an oily base which he called "aniline." This term was derived from the specific name of the indigofera anil, which was the Sanskrit designation of the famous blue dye. Hofmann's researches ultimately proved that Unverdorben's crystalline, Runge's kyanol, and Fritzsche's aniline were all chemically identical. Hofmann would have preferred to retain the first of these names, but the more definite aniline prevailed.
The colour producing power of aniline had been observed (as has been already mentioned) by Runge in 1834, but it was not until 1856 that this property became of practical importance, when W. H. Perkin, at the time a pupil of Hofmann's, commenced the
