Marcellin Berthelot

Marcellin Berthelot was a French chemist who became one of the founders of the field of thermochemistry, the study of the heat absorbed or released during chemical reactions, coining the terms exothermic and endothermic to describe reactions that release or absorb heat. Working through the 1850s and 1860s, Berthelot synthesized numerous organic compounds directly from their basic elements, at a time when many chemists still believed organic substances could only be produced by living organisms, and his systematic synthetic work helped establish that organic chemistry followed the same fundamental laws as the rest of chemistry. Beyond laboratory research, Berthelot held senior positions in French public life, serving as a government minister and as permanent secretary of the French Academy of Sciences, and he wrote extensively on the history of ancient and medieval chemistry, publishing detailed studies of the surviving texts of Greek and Arabic alchemy. His combination of prolific experimental synthesis with foundational thermochemical measurement made him one of the most prominent chemists in nineteenth century France.