Henri-Victor Regnault. The heat man

Regnault was a skillful, thorough, and patient experimenter that carefully determined (or redetermined) the specific heat of many solids, liquids, gases, the vapor pressure of water and other volatile liquids, as well as their latent heat at different temperatures. He proved conclusively that all gases have a different coefficient of expansion and that the ideal gas of Mariotte and Boyle is a model only approximately true for real gases. His results on the properties of water and steam should be considered the first version of the steam tables. Although an outstanding experimentalist, Regnault did not possess the brilliant originality of manyof his fellow physicists and did not leave us with lasting theoretical results. He devoted all his life to perform very accurate measurements and placed in the hands of the modern physicist and chemist an in-valuable collection of constants, which presently are in daily use not only in the laboratory but also for a large variety of industrial purposes. Regnault was the victim of an implacable fatality that filled his life with personal tragedy, but only in the last years of his life he let it overcome him