Abstract
The critical temperature of glass surface for condensation of mercury vapor as a function of density of atoms striking the surface has been found. The results indicate a large nucleus composed of many atoms is necessary for condensation to start; the heat of vaporization of an atom from the nucleus is 13.2 kcal. per mole. Some qualitative observations are reported, showing both rapid and slow adsorption of mercury atoms on glass and metal, and a considerable adsorption of mercury ions.