Gerard Charles Frederick

Gerard, Charles Frц?dц?ric (Gerhardt, Charles Frdric) (1816-1856), French chemist. Born August 21, 1816 in Strasbourg, in the family of banker. He graduated from high school at age 15, he entered the Polytechnic Institute in Karlsruhe. In 1833 continued his education at the Higher Commercial School in Leipzig. In 1835, Gerard moved to Giessen, where for years he worked in a university laboratory for Yu Liebig. In 1839-1841 he attended lectures on chemistry J. Dumas at the Sorbonne and also worked in the laboratory of M. Chevrel. In 1841, a thesis, received a professorship at the University of Montpellier. In 1848 he moved to Paris, worked together with O. Laurent in his laboratory at the Mint. In 1851 founded a private school laboratories - the school of practical chemistry. In 1855 Gerard received the chair of chemistry at Strasbourg and the laboratory.

For the first time an independent approach to the theoretical problems of chemistry showed a Gerard in 1939, in the work of 'theory of residues'. In contrast to the radicals (in the representation of Berzelius and Liebig), the remnants of Gerard - a group of atoms, not preexistent in the compounds, but only formed during the chemical interactions. However, depending on the nature of the interaction of 'remnants' of the compounds may be different, but their combinations always give the same molecule. Fundamentally new theory of the molecule as a single system of atoms - 'unitary system' - Gerard formulated in the textbook "Introduction to the study of chemistry in the unitary system" (Introduction sur l'tude de la chimie sur la base du systeme unitaire, 1848). Contributed to the 'revival' Avogadro's law, which is sometimes called Avogadro's Law - Gerard. As Laurent, Gerard came to the need to distinguish between the concepts of atoms, molecules, and the equivalent. Introducing a new system equivalents, . he found the correct formula for water, . potassium oxide, . potassium chloride, . sulfuric acid, etc., . indicated, . that the hydrogen molecule, . oxygen, . chlorine and some other elements are composed of two atoms, . was improved table of atomic weights,
.

In 1851 came the work of Gerard, dedicated to the basicity of acids, in which he developed his 'theory of types'. According to this theory, all chemical compounds can be classified as derivatives of four types - hydrogen, hydrogen chloride, water and ammonia. So, . the type of hydrogen were hydrocarbons and organo-metals, . the type of hydrogen chloride - halogenated, . to the most numerous and most studied type of water belonged oxygenated substances - alcohol, . acids and their anhydrides, . ethers and esters, etc.,
. Assign a connection to this type - hence, by Gerard, to establish that this compound enters into the same reaction, the substance selected as the type. His system of classification Gerard called unitary, . because every connection it was considered as a whole, and excluded the principle of opposites within him, . which was the basis of the dualist system Berzelius ( 'electropositive' and 'electronegative' Components),
. Insisting on the use of unitary empirical formulas of compounds, Gerard distributed substance through the ranks in accordance with the chemical analogy. On the concept of homologous series, have already introduced earlier in "Sketches of Organic Chemistry" (Precis de chimie organique, 1844-1845), he added two others: izologichesky and heterologous.

Considering the organic compounds as derivatives of the four inorganic substances, Gerard pointed to the close relationship between the organic and inorganic worlds, contrary to prevalent at that time, vitalism.

The ideas of promoting bilateral Gerard got in the works of DI Mendeleev and AM Butlerova.

Gerard died at Strasbourg, 19 August 1856.