Hess, Hermann Heinrich

died in 1850 g.Uchilsya at Tartu University, then worked in Stockholm at Berzelius. Accompanying Professor geognosy Engelhardt in the scientific journey through the Urals and then served as a doctor in Irkutsk, where he wrote his memoirs: "Sur les sels communs du gouvernement d'Irkoutsk" (1830). Appointed assistant professor at the Academy of Sciences, he made an analysis of the Neva water and gas lamps Baku, gave geognosticheskoe description of neighborhoods near Lake Baikal and has published extensively on new minerals. In the newly founded Institute of Technology and Mining Institute took the chair of chemistry, in the Main Pedagogical Institute - Chemistry and Technology. The most outstanding discovery of new organic acid, which he called sugar. In 1833, Mr.. Hess issued a "Foundations of pure chemistry". In 1834, Mr.. Hess approved the rank of ordinary academician. In 1836, Mr.. Hess published his work on the thermochemistry, the true founder of which is it, these works Hess continued until the end of life. In 1840, t. e. two years before the promulgation of the work of Mayer and Joule, Hess, in his article in the 50-m m. "Poggendorffs Annalen", expressed the basic principle of thermochemistry, represents the application of the law of conservation of energy to chemical phenomena. "The amount of heat, . - Wrote Hess, . - Developing with any chemical process, . always the same, . occurs whether the chemical transformation immediately, . or gradually, . through several stages, in other words, . heat of reaction depends only on the initial and final states of the reactants,
. With this basic principle Hess made it possible to calculate the thermal effect of chemical phenomena that are not available in this regard, direct measurement. Hess was installed another, equally important law thermochemistry - Law termoneytralnosti, t. e. absence of heat exchange with the reactions of decomposition of salts. In 1840, he taught chemistry Tsarevich Alexander Nikolaevich. His writings have appeared in "Memoirs of the Imperial Academy of Sciences.