Boltzmann offered a demonstration of the law of osmotic pressure in dilute solutions, based on the idea that the mean energy of translation of a molecule should be the same in the liquid as in the gaseous state.
Boltzmann Suggested That A Diatomic Molecule Regarded As A Rigid Dumb Bell Or Figure Of Rotation, Might Have Only Five Effective Degrees Of Freedom, Since The Energy Of Rotation About The Axis Of Symmetry Could Not Be Altered By Collisions Between The Molecules.