Germain Henri Hess - Definition and Overview

Germain Henri Hess (1802-08-07 - 1850-11-30) was a Swiss chemist and doctor who formulated Hess's Law, an early principle of thermochemistry.

Born in Geneva, Switzerland, his father was an artist and in 1805 moved the family to Russia to find work. Hess studied at the University of Tartu and qualified as a doctor in 1825.

Hess turned to chemistry after a meeting with Jöns Jacob Berzelius, the famous Swedish chemist, and went to Stockholm University to study under him. On his return to Russia, Hess joined an expedition to study the geology of the Urals before setting up a medical practice in Irkutsk.

In 1830, Hess took up chemistry full time, researching and teaching, and later became a professor at the Technological Institute of the University of St. Petersburg. His most famous paper, outlining his law on thermochemistry, was published there in 1840.

Hess's other work concerned the investigation of minerals, including analysis of silver telluride (Ag₂Te), which was named Hessite in his honour. He also discovered that the oxidation of sugars yielded saccharic acid.