HOFMANN, AUGUST WILHELM VON German chemist, was born at Giessen on April 8, 1818. He first read law and philosophy at Gottingen and then studied chemistry under Liebig. He acted for a short time as Privatdozent at Bonn and then, in 1845, accepted the invitation, made at the suggestion of the Prince Consort, to become the first director of the new Royal College of Chemistry, London. In 1864 he returned to Bonn, and in the following year he succeeded E. Mitscherlich as professor of chemistry and director of the laboratory in the University of Berlin. He continued his excellent work there as teacher and researcher until his death on May 5, 1892. In 1868 Hofmann founded the German Chemical Society and he was for many years its President.
Hofmann's work covered a wide range of organic chemistry; his first research, carried out in Liebig's laboratory at Giessen, was on coal-tar, and his investigation of organic bases established the nature of aniline. His perception of the analogy between it and ammonia led to his famous work on the amines and organic ammonium bases and the allied phosphorus compounds, while his researches on rosaniline, which he first prepared in 1858, formed the first of a series of investigations on colouring matters which culminated in the discovery of quinoline red in 1887. Hofmann is also known for his discovery of ally' alcohol (with Cahours), of formaldehyde, hydrazobenzene and the iso-nitriles. He dis covered a method of converting an amide into an amine contain ing one carbon atom less and this important reaction is now known by his name. Hofmann's method for determining molecular weight of liquids by means of vapour densities was an important contribution to chemistry. In addition to the investigations for which he was responsible he exercised considerable influence on chemical progress through the valuable work of his pupils. As a teacher, besides the power of accurately gauging the character and capabilities of those who studied under him, he had the faculty of infecting them with his own enthusiasm, and thus of stimulating them to put forward their best efforts. In the lecture room he laid great stress on the importance of experimental demonstrations, paying particular attention to their selection and arrangement, though, since he himself was a somewhat clumsy manipulator, their actual exhibition was generally entrusted to his assistants. He was the possessor of a clear and graceful, if some what florid, style, which showed to special advantage in his numerous obituary notices or encomiums (collected and published in three volumes, Zur Erinnerung an vorangegangene Freunde, i888).