Raoul Pictet

Raoul-Pierre Pictet
Raoul-Pierre Pictet
Born	4 April 1846 (1846-04-04) Geneva
Died	Paris
Nationality	Swiss
Fields	Physics
Institutions	University of Geneva
Known for	Liquid nitrogen
Notable awards	Davy Medal (1878)

Raoul-Pierre Pictet (4 April 1846 – 27 July 1929) was a Swiss physicist and the first person to liquefy nitrogen.

Biography

Pictet was born in Geneva and served as professor in the university of that city. He devoted himself largely to problems involving the production of low temperatures and the liquefaction and solidification of gases.

On December 22, 1877, the Academy of Sciences in Paris received a telegram from Pictet in Geneva reading as follows: Oxygen liquefied to-day under 320 atmospheres and 140 degrees of cold by combined use of sulfurous and carbonic acid. This announcement was almost simultaneous with that of Cailletet who had liquefied oxygen by a completely different process.

Works

• Mémoire sur la liquéfaction de l'oxygène, la liquéfaction et la solidification de l'hydrogène et sur les théories des changements des corps (1878)
• Synthèse de la chaleur (1879)
• Nouvelles machines frigorifiques basées sur l'emploi de phénomènes physicochimiques (1895)
• Étude critique du matérialisme et du spiritualisme par la physique expérimentale (1896)
• L'acétylène (1896)
• Le carbide (1896)
• Zur mechanischen Theorie der Explosivstoffe (1902)
• Die Theorie der Apparate zur Herstellung flüssiger Luft mit Entspannung (1903)

• Pictet, Raoul; Cellérier, Gustave. Méthode générale d'intégration continue d'une fonction numérique quelconque...

Pictet died in Paris in 1929.

See also

• Liquefaction of gases
• Timeline of low-temperature technology
• Pictet Family Archives (French)

•Pictet’s apparatus • Production of oxygen under pressure in a retort. Two pre-cooling refrigeration cycles:

1. first stage SO2(-10°C) 2. second stage CO2(-78°C) oxygen flow is pre –cooled by the Means of heat exchangers and Expands to atmosphere via a Hand valve