Laurent, Auguste

In 1830 he graduated from the Paris Mining Institute with an engineering degree, after which in 1830-1831. worked as an assistant to J. B. Dumas at the Central School of Arts and Crafts in Paris. In 1832, Laurent moved to the laboratory of the Sevres Porcelain Factory, where, despite the lack of equipment for work in organic chemistry, he carried out his outstanding research. In 1837, Laurent received a Ph.D., and the following year became a professor of chemistry at the University of Bordeaux . Having received the title of Corresponding Member of the Academy of Sciences in 1846 , Laurent again came to Paris, where from 1846 to 1847 he worked at the Higher Normal School in Paris, and in 1848 , having no opportunity to take up any teaching position and was left without a livelihood, was getting a probationer at the Mint. Despite the difficult financial situation, Laurent still continued to engage in science. He died in complete poverty, from consumption , when he was not yet 46 years old.

While working in the Dumas laboratory, Laurent began studying the properties of substitution products of various compounds in comparison with the properties of the starting materials. One of the first works of Laurent was his classic study of the effects of chlorine and nitric acid on naphthalene ( 1835 ). He also carried out the chlorination of ethylene and other hydrocarbons and came to the conclusion that the chemical structure of the compounds was preserved in hydrogen substitution reactions with chlorine. According to the data obtained by Laurent, not only halogens , but also complex groups are able to replace hydrogen hydrocarbons. This statement, consistent with Dumas' replacement theory, has become part of a more general “nuclear theory” first formulated by Laurent in 1836 . In his opinion, organic substances are obtained from the main "radicals" (nuclei) containing carbon and hydrogen atoms in simple atomic relations by replacing hydrogen with other elements or atomic groups. All derivative radicals of one basic radical must have the same number of atoms as the main radical, and belong to the same type (row). In his "theory of nuclei," Laurent first suggested that all organic compounds are reducible to hydrocarbons, and on this basis proposed a system for classifying organic substances originating from "typical" hydrocarbons by substituting or joining other atoms or molecules. This "unitary" system did not meet the sympathy of famous chemists of that time - Berzelius and Liebig , supporters of the idea of ​​"binary", who believed that any chemical compound is a combination of "electropositive" and "electronegative" components, but found understanding from another French chemist, Charles Gerard , author of the new "type theory". The views of Laurent and Gerard were so close that in historical sketches their names as creators of this theory stand side by side. The exceptionally fruitful collaboration between the two scientists lasted from 1843 until the death of Laurent. Gerard and Laurent very successfully complemented each other; according to S. A. Würz , “Laurent was strong in his analytical genius and ability to classify phenomena, Gerard, in the highest degree, possessed the genius of generalization.” Laurent owns a large number of other experimental works in organic chemistry: he discovered phthalic acid ( 1836 ), studied fat oxidation with nitric acid, obtained isatin by indigo oxidation ( 1841 ), studied coal tar anthracene , phenol and its derivatives, etc. Laurent's merit was that he, like Gerard, was one of the first to come to the realization of the need for a clear delineation of the concepts of atom , molecule and equivalent , which contributed to the revival of Avogadro's law . Already after the death of the scientist, the work “Method of Chemistry” ( 1854 ) was published, where his thoughts on molecules, atoms, and the structure of organic compounds are stated.

• Biographies of the great chemists. Translation from it. edited by Bykov G.V. - M.: Mir, 1981. 320 p.
• Volkov V.A., Vonsky E.V., Kuznetsova G.I. Outstanding chemists of the world. - M .: VSH, 1991.656 s.
• Jua M. , History of Chemistry, trans. with ital., Moscow: Mir, 1966

• Laurent, Auguste // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.