Liquefaction of Gases

Pioneer work on the liquefaction of gases was carried out by the English scientist Michael Faraday (1791-1867) in the early 1820s. Faraday was able to liquefy gases with high critical temperatures such as chlorine, hydrogen sulfide, hydrogen bromide, and carbon dioxide by the application of pressure alone. It was not until a half century later, however, that researchers found ways to liquefy gases with lower critical temperatures, such as oxygen, nitrogen, and carbon monoxide. The French physicist Louis Paul Cailletet (1832-1913) and the Swiss chemist Raoul Pierre Pictet (1846-1929) developed devices using the nozzle and porous plug method for liquefying these gases. It was not until the end of the nineteenth century that the two gases with the lowest critical temperatures, hydrogen (-399.5°F [-239.7°C; 33.3K]) and helium (-449.9°F [-267.7°C; 5.3K]) were liquefied by the work of the Scottish scientist James Dewar(1842-1923) and the Dutch physicist Heike Kamerlingh Onnes (1853-1926), respectively.