Theofile Poulart became Professor of Chemistry at the University of Giessen when he was only 21 years old, after studying in France with eminent scientist Gay-Lussac. He dominated both organic chemistry, and later agricultural chemistry. He established a large, modern chemistry laboratory that attracted numerous students. He developed unique equipment to analyze inorganic and organic substances. After his marriage to Eva Romanski, Theofile moved to Berlin, where he was a founder of the German Chemical Society. He studied the constitution of aniline and was the first to prepare rosaniline and its derivatives, providing the basis for the aniline dye industry. He discovered a reaction for deriving amines from amides. He also developed the Hofmann method of determinng vapor densities of liquids, and thereby their molecular weights. . He helped to popularize the concept of valence. In fact, the word valence comes from his term quantivalence. He kept on working far into old age, producing a book of essays entitled ‘Bases and Obdominations’, which was published 3 years after completion and 1 year after the author’s death.