Which chemist brought Pasteur back to the École Normale as a laboratory assistant?

Which chemist brought Pasteur back to the École Normale as a laboratory assistant? The answer is Antoine Jérôme Balard.

Balard was one of Pasteur’s most important teachers at the École Normale Supérieure. After Pasteur was appointed to teach physics at the lycée in Tournon, Balard intervened so that the young chemist could return to Paris and work as a laboratory assistant, or préparateur, at the École Normale.

The appointment gave Pasteur access to laboratory facilities and the freedom to continue serious chemical research. In Balard’s laboratory, he developed the investigations into crystals and tartrate compounds that led to his landmark work on molecular asymmetry and the foundations of stereochemistry.

Balard himself was a distinguished French chemist, best known for discovering bromine in 1826. Pasteur’s later career is sometimes associated with Jean-Baptiste Dumas, another major influence, but Dumas was not the chemist who secured this return to the École Normale. Balard’s professional support was decisive at a formative moment.