August Wilhelm von Hofman (1818-1892) Autograph letter, signed 2pp, with integral blank leaf, on Museum of Practical Geology [London] notepaper. Dated only Thursday morning, but probably 1864 or 1865. To 'My dear Ward'. No doubt a letter from Hofmann to the editor of his book 'Introduction to modern chemistry,'experimental and theoretic, embodying twelve lectures delivered in the royal College of Chemistry, London: Walton and Maberley, 1865'. Hofmann approves Ward's proposal to designate the 'atomicity' of the elements by Roman numerals, and indicates how this should appear in print. Hofman played a major role in the development and organisation of the 19th century chemical profession in both Germany and Great Britain. Born in Geissen, he entered the local university in 1836 to study law and philosophy, but switched to chemistry after attending Liebig's lectures. After obtaining his doctorate in 1841, he served as Liebig's assistant and taught briefly at the University of Bonn. In 1845 Hofmann was recommended by Liebig as professor and director of the newly organised Royal College of Chemistry in London. Founded by Prince Albert and modelled on Liebig's laboratory, the Royal College would, during Hofmann's 20-year tenure, train some of England's most important chemists, including W. Perkin, H. Armstrong and J.R.A. Newlands. In 1865 Hofman returned to Germany as Professor of Chemistry at the university of Berlin, where he remained until his death. In 1867 he founded the German Chemical Society (Deutsche Chemische Gesellschaft) along with its famous journal, the Berichte, which was first published in 1868. In 1865 Hofmann published his book, An Introduction to Modern Chemistry. This volume gave a brilliant summary of type theory and the newly emerging theory of structure and strongly influenced the revision of introductory textbooks in both Europe and the United States. In this book, Hofmann first introduced the term valence, under its longer variant quantivalence, to describe the combining capacity of an atom. The letter with previous folds, otherwise is bright and in near fine condition.