SINCE an atom consists of a number of electrons distributed around a positive nucleus, its electrical effect at a distant point would be equivalent to an electrical doublet. The force between two atoms, which may be either an attraction or a repulsion, depending on the way the representative doublets face each other, would, accordingly, be proportionate to the product of the electrical moments of the atoms, and inversely proportional to the fourth power of their distance of separation. When the atoms or molecules are free to move about as in a gas or liquid their electrical doublets would tend to arrange themselves with respect to each other, as the writer has pointed out, 1 so that the potential energy would be a minimum. The outstanding force would therefore be attraction, and if repulsion occurs, it would be as small as possible. Thus there would be an association between the directions of the axes of the atomic doublets at every instant, though all directions of the axis of each doublet are equally probable, since the substance as a whole does not possess any polarity. But the attraction between two atoms or molecules in a substance at constant temperature would not follow the inverse fourth power law, since the orientation of the molecules with respect to each other at any instant would depend on the nature and number of collisions they undergo per second, which would depend on the density and temperature of the substance. The attraction between two atoms or molecules of electrical moment M corresponding to the average distance of separation ~ of the molecules of the substance would accordingly be given by M ~ ~,(~, v). ~-, * Communicated by the Author.