Raoul Pictet

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Raoul-Pierre Pictet
Pictet Raoul.jpg
Raoul-Pierre Pictet
Born 4 April 1846 (1846-04-04)
Died 27 July 1929(1929-07-27) (aged 83)
Nationality Swiss
Known for Liquid nitrogen
Awards Davy Medal (1878)
Scientific career
Fields Physics
Institutions University of Geneva
Pictet Raoul signature.jpg

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


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.[1]

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.

Pictet died in Paris in 1929.


See also[edit]

•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


  1. ^ For biographical details, see Sloan, T. O'Connor (1920). Liquid Air and the Liquefaction of Gases. New York: Norman W. Henley. pp. 152–171.