Hess Herman I. (Herman Hess)

(7.IIX 1802 (Geneva) - 30.XI 1850 (St. Petersburg))
In his honor named silver telluride hessite.
Russian chemist, academician of the Petersburg Academy of Sciences (since 1830). Born in Geneva. He graduated from the University of Dorpat (Doctor of Medicine, 1825).
Improve education at Stockholm University (1825). Since 1830, Mr.. - Professor of St. Petersburg Institute of Technology, in 1832-1849 he. - St. Petersburg Mining Institute.
One of the founders of the thermochemistry. Much earlier X. Thomsen and P. Berthelot nominated (1840) a provision that the magnitude of thermal effects of reactions may serve as a measure of chemical affinity. Open (1840), the fundamental law of thermochemistry - the law of constancy of the amount of heat which the heat of reaction depends only on the initial and final states of the reactants, rather than the number of stages of the process (Hess's law).
Proved (1842) that the mixing of neutral salt solutions the thermal effect is absent (usually termoneytralnosti). Found that the neutralization of 1 mole equivalent of any strong acid, strong base always allocated the same amount of heat (13.5 kcal). Opened and identified (1830-1834 gg.) Composition of four new minerals - vertita, uvarovita, gidroboratsita and folbortita. Offered (1833) method for silver telluride from tellurium - a mineral which was the first time they studied.
He studied (1832) cobalt oxides. Established catalytic and adsorptive properties of finely divided platinum. One of the first studied the composition of the Caucasian oil. He opened the sugar acid.
Posted textbook "Foundations of pure chemistry" (1831), which went through seven editions.
In his honor silver telluride named hessite.
On materials of biographical reference book "Eminent chemists of the world" (by Volkov VA, etc.) - Moscow, "High School", 1991