Nicolas-Théodore de Saussure

Nicolas-Théodore de Saussure
250px Nicolas-Théodore de Saussure
Born	(1767-10-14)14 October 1767 Geneva, Switzerland
Died	Geneva, Switzerland
Nationality	Swiss
Fields	chemistry, phytochemistry, plant physiology
Institutions	University of Geneva
Influences	Antoine Lavoisier
Author abbrev. (botany)	N.T.Sauss.

Nicolas-Théodore de Saussure (14 October 1767 – 18 April 1845) was a Swiss chemist and student of plant physiology who made seminal advances in phytochemistry. He is considered to be one of the major founders in the study of photosynthesis.

Biography

Nicolas-Théodore de Saussure was born in Geneva on 14 October 1767 into a wealthy aristocratic family, as the first child to Horace-Bénédict de Saussure, a Swiss aristocrat, physicist and Alpine traveller, and Albertine-Amélie Boissier (1745-1817). He lived quietly and avoided society; yet like his ancestors he was a member of the Genevan representative council, and gave much attention to public affairs. During the French Revolution he fled to England. In 1802 he returned to Geneva and eventually became an honorary professor of mineralogy and geology at the University of Geneva, where he stayed until 1835. In the latter part of his life, he became increasingly reclusive, and died in the city of his birth.

His sister, Albertine Necker de Saussure, is a noted early writer on the education of women. He is also the grandfather of Ferdinand de Saussure, an important linguist and semiotician.

Career

While a young man, Nicolas-Théodore accompanied his father in his Alpine journeys and assisted him by the careful determination of many physical constants. He was attracted to chemistry by Lavoisier's discoveries, but he never became as great. He took a leading share in improving the processes of ultimate organic analysis; and he determined the composition of ethanol, ether and some other commonly occurring substances. He also studied fermentation, the conversion of starches into sugars, and many other biochemical processes. The majority of his 36 published papers dealt with the chemistry and physiology of plants, the nature of soils, and the conditions of vegetable life, and were republished under the title Recherches chimiques sur la végétation ("Chemical investigations of vegetationism").

Saussure showed that the increase in mass of the plant as it grows could not be due only to uptake of water, but also to the uptake of CO₂. Thus the basic reaction by which photosynthesis is used to produce food (such as glucose) was outlined. Because of that, Saussure is considered to be one of the major founders in the study of photosynthesis. He also showed that plants are dependent upon the absorption of nitrogen from soil.

In March 1792, he named the mineral dolomite after Déodat Gratet de Dolomieu. In 1815 he was one of the founding members of Société Helvétique des Sciences Naturelles.

Honours

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• 1812 Member of the Royal Institute of the Netherlands.
• 1820 Member of the Bavarian Academy of Sciences and Humanities.
• 1837 Plant genera Saussurea and Saussuria are named after him.
• 1842 Elected president of the Congrés Scientifique of Lyons.

Works

• Chemische Untersuchungen über die Vegetation . Vol.1&2 . Engelmann, Leipzig 1890 Digital edition by the University and State Library Düsseldorf

References

•  This article incorporates text from a publication now in the public domain: