(Pierre Eug

Chemist and French statesman, born in Paris, France. He became the first professor of organic chemistry at the Collège de France (1865), and was foreign minister (1895–6). He helped to found the study of thermochemistry, introducing a standard method for determining the latent heat of steam. His syntheses of many fundamental organic compounds helped to destroy the classical division between organic and inorganic compounds.

In 1854, he made his reputation by his doctoral thesis, Sur les combinaisons de la glycérine avec les acides, which described a series of beautiful researches in continuation and amplification of M.E. In 1859 he was appointed professor of organic chemistry at the École Supérieure de Pharmacie, and in 1865 he accepted the new chair of organic chemistry, which was specially created for his benefit at the Collège de France.

The fundamental conception that underlay all Berthelot's chemical work was that all chemical phenomena depend on the action of physical forces which can be determined and measured. When he began his active career it was generally believed that, although some instances of the synthetical production of organic substances had been observed, on the whole organic chemistry must remain an analytical science and could not become a constructive one, because the formation of the substances with which it deals required the intervention of vital activity in some shape. To this attitude he offered uncompromising opposition, and by the synthetical production of numerous hydrocarbons, natural fats, sugars and other bodies he proved that organic compounds can be formed by ordinary methods of chemical manipulation and obey the same laws as inorganic substances, thus exhibiting the "creative character in virtue of which chemistry actually realizes the abstract conceptions of its theories and classifications--a prerogative so far possessed neither by the natural nor by the historical sciences."

His investigations on the synthesis of organic compounds were published in numerous papers and books, including Chimie organique fondée sur la synthèse (1860) and Les Carbures d'hydrogène (1901). This branch of study naturally conducted him to the investigation of explosives, and on the theoretical side led to the results published in his work Sur la force de la poudre et des matières explosives (1872), while on the practical side it enabled him to render important services to his country as president of the scientific defence committee during the siege of Paris in 1870-71 and subsequently as chief of the French explosives committee.

In later life he turned to the study of the earlier phases of the science which he did so much to advance, and students of chemical history are greatly indebted to him for his book on Les Origines de l'alchimie (1885) and his Introduction à l'étude de la chimie des anciens et du moyen âge (1889), as well as for publishing translations of various old Greek, Syriac and Arabic treatises on alchemy and chemistry (Collection des anciens alchimistes grecs, 1887-1888, and La Chimie au moyen âge, 1893). He was also the author of Science et philosophie (1886), which contains a well-known letter to Renan on "La Science idéale et la science positive," of La Révolution chimique, Lavoisier (1890), of Science et morale (1897), and of numerous articles in La Grande Encyclopédie, which he helped to establish.