August Wilhelm von Hofmann (8 April 1818 – 5 May 1892[2]) was a German chemist who made considerable contributions to organic chemistry.

[7] As president of the Royal Society in London, Albert, Prince Consort to Queen Victoria, was determined to foster scientific advancement in Britain.

Hofmann felt the loss deeply, writing in 1863, "[Albert's] early kindness exercised so powerful an influence upon the destinies of my existence.

Hofmann's decision to return to Germany can be seen as a symptom of that decline, and with him gone, the Royal College of Chemistry lost its focus.

While taking his time to decide which offer to accept, Hofmann designed laboratory buildings for both universities, which were both subsequently built.

Following his return to Germany Hofmann was the principal founder of the German Chemical Society (Deutsche Chemische Gesellschaft zu Berlin) (1867) and served 14 terms as its president.

Hofmann was a major contributor to the development of techniques for organic synthesis, which originated at Liebig's laboratory in Giessen.

A subsequent paper, Muspratt and Hofmann's "On Toluidine", described some of the first "synthetical experiments" (synthetische Versuche) in the field of organic chemistry.

[9] Hofmann's first research investigations, carried out in Liebig's laboratory at Giessen, was an examination of the organic bases of coal tar.

In his first publication (1843) he demonstrated that a variety of substances which had been identified in contemporary chemical literature as obtainable from coal tar naphtha and its derivatives were all a single nitrogenous base, aniline.

These included Kyanol, Carl Julius Fritzsche's Anilin, Otto Unverdorben's Krystallin, and Nikolai Zinin's Benzidam.

His method became extremely significant as a tool for examining the molecular structures of alkaloids, and was eventually applied to morphine, coca amine, atropine, and tubocurarine, among others.

[3][21] In 1856, Hofmann's student William Henry Perkin was attempting to synthesize quinine at the Royal College of Chemistry in London, when he discovered the first aniline dye, mauveine.

[22] The discovery led to the creation of a wide range of artificially created colourful textile dyes, revolutionising the fashion world.

[3] Hofmann studied nitrogen bases, including the development of methods for separating mixtures of amines and the preparation of large numbers of "polyammonias" (diamines and triamines such as ethylenediamine and diethylenediamine).

Hofmann isolated sorbic acid from rowanberries' oil in 1859, a chemical compound that is widely used as a food preservative.

At a Friday Evening Discourse at London's Royal Institution on April 7, 1865, he displayed molecular models of simple organic substances such as methane, ethane, and methyl chloride, which he had had constructed from differently colored table croquet balls connected together with thin brass tubes.

[25] After 1874, when van't Hoff and Le Bel independently suggested organic molecules can be three-dimensional, molecular models began to assume their modern appearance.

The inner cylinder is open at the top to allow addition of water and an ionic compound to improve conductivity, such as a small amount of sulphuric acid.

A platinum electrode is placed inside the bottom of each of the two side cylinders, connected to the positive and negative terminals of a source of electricity.

In 1865 Hofmann published An Introduction to Modern Chemistry, summarising type theory and emerging ideas about chemical structure.

[27] In addition to his scientific works, Hofmann wrote biographical notices and essays on the history of chemistry, including a study of Liebig.

[4] In 1900, the German Chemical Society built the "Hofmann-Haus" at Berlin and in 1902 created the August Wilhelm von Hofmann Gold Medal in his honour, to be awarded for outstanding achievements in chemistry.