[2] In a few months military life became equally distasteful, and he purchased his discharge with the assistance of the German chemist Justus von Liebig.

[1] In Paris, he attended Jean Baptiste Dumas’ lectures and worked with Auguste Cahours (1813–1891) on essential oils, especially cumin, in Michel Eugène Chevreul’s laboratory at the Jardin des Plantes, meanwhile earning a precarious living by teaching and making translations of some of Liebig’s writings.

In 1845 he and his opinions were the subject of an attack by Liebig, unjustifiable in its personalities but not altogether surprising in view of his wayward disregard of his patron’s advice.

The two were reconciled in 1850, but his faculty for disagreeing with his friends did not make it easier for him to get another appointment after resigning the chair at Montpellier in 1851, especially as he was unwilling to go into the provinces.

Gerhardt is usually linked with his contemporary, Auguste Laurent, with whom he shared a strong and influential interest in theories of chemical combination.