Russian chemist German Ivanovich Hess is born in Geneva on 7th of August, 1802 in the family of a painter, who moves to Russia soon after that. When Hess turns 15, he leaves his home for Dortpat (which is now Tartu of Estonia), enters first a private school, then a gimnasium, and graduates with honours in 1822.

After getting secondary education, Hess is admitted to medical faculty of Dortpat University, where he studies chemistry in class of professor Gottfried Wilhelm Osann, expert in inorganic and analytic chemistry. Herman Hess graduates the university in 1825 after defending his master thesis “Studies of chemical composition and healing properties of Russian mineral waters”.

Gottfried Osann helps Herman Hess, young Dorpat university graduate, to arrange a six-month duty trip to Stockholm to the laboratory of eminent Swedish chemist Jöns Jakob Berzelius, where Hess performs chemical analysis of some minerals. Swedish genius considers Hess to be a “very perspective zealous young scientist with hard-working brains and good scientific background”.

When Hess returns to Dorpat, he gets an appointment to Irkutsk, where he plans to practise medicine. While in Irkutsk, Hess studies chemical composition and healing effects of mineral waters and explores properties of rock salt in Irkutsk regional deposits. In 1828 Hess is awarded adjunct title, and in 1830 he becomes extraordinary academician of Academy of Sciences. Same year sees Herman Ivanovich’s appointment to Saint Petersburg’s institute of technology, where chemist develops a curriculum of practical and theoretical chemistry. Between 1832 and 1849 Hess occupies a position of professor in Mining institute and reads lectures in the Artillery School. In the late twenties and early thirties of 19th century Herman Hess teaches basic chemistry to prince Alexander, future Russian emperor Alexander II.

Like many other scientists of that times Hess performs research in many various fields, for example, he develops a technique for extracting tellurium from telluric silver (which was later named “hessite” after Hess); he discovers that platinum absorbs gases. Hess is the first scientist in the world to find that powdered platinum accelerates oxygen binding with hydrogen (isn’t it catalysis?); he also describes many minerals and suggests a new technology for air injection to blast furnaces. Among other things Herman Ivanovich creates a unit for degrading organic compounds, which eliminates errors in hydrogen quantification.

What makes Herman Hess world famous is thermochemistry. The scientist formulates ultimate law of thermochemistry – the “law of constant heat summation” – which is an application of energy conservation principle to chemical processes. According to this law, reaction heat depends only on initial and final states of reagents, but not on reaction pathways (Hess’s law). Description of experiments, giving ground to Hess’s law, appears in press in 1840 – two years before papers of Julius Robert von Mayer and James Prescott Joule appear in science magazines. Hess also owes the priority of discovering the second law of thermochemistry – the law of thermoneutrality, in accordance with which mixing neutral salt solution gives zero heat effect. Hess is the first to suggest an idea of possible measurement of chemical affinity on the basis of reaction heat, thus anticipating maximum work principle, which was later formulated by Marcellin Berthelot and Julius Thomsen.

Hess is also engaged in chemistry teaching methodology. His textbook “Basics of Pure Chemistry”, written in 1831, goes into seven editions (the last dates back to 1849). In this textbook Hess uses his own Russian chemical nomenclature, which comes off the press in 1835 as “Brief review of chemical names”. This nomenclature was later complemented by D. Mendeleev and is still partly used nowadays

Herman Ivanovich Hess dies December 12, 1850.

Source:
    Chemistry Online
 

Kizilova Anna