Frederick Thomas Trouton: the man, the rule, and the ratio

Trouton was a multifaceted theoretician and experimentalist who left his name in several fields. Here, his many contributions to science are described and analyzed with particular emphasis on Trouton’s rule and its further development, his contributions to rheology (Trouton’s ratio), and the famous Trouton—Noble experiment, which is related to the absolute movement of the Earth through the æether.

Chemists and chemical engineers are familiar with Trouton through the rule that carries his name. Trouton’s rule states that at the normal boiling temperature the entropy of vaporization is constant. They are generally unaware of his rich contributions in other scientific areas, such as rheology, osmotic pressure, and physics. Here we describe his personal life and career, his scientific achievements, and, in particular, how his rule has been further developed by others.