Note 53 — Chapter VIII · SCIENTIFIC WORK—MOLECULAR THEORY.
Reading edition
Another supposition which might be made, and which is necessary in order to explain various actions observed in a compound gas under electric force, is that the parts of which a molecule is composed are continually changing. Thus a molecule of steam consists of two parts of hydrogen, one of oxygen, but a given molecule of oxygen is not always combined with the same two molecules of hydrogen; the particles are continually changed. In Maxwell’s paper an hypothesis of this kind is not dealt with.