Chemical Notes

Abstract

WE have already mentioned M. Konovaloff's researches into contact actions, published in the Journal of the Russian Chemical Society (1885, vii. and viii.) The following conclusions of his inquiry are worthy of being noticed:—The capacity of solid bodies for condensing gases on their surfaces is generally recognised, but their capacity of dissociating them under certain conditions must also be recognised now as a property of all solid bodies, although shared in by them in different degrees. Platinum enjoys this property to a high degree, but also many other solid bodies, glass among them, the intensity of its contact action obviously depending upon several circumstances: its chemical composition, the structure of its surface, and its temperature, as also upon the density of the gas it is brought in contact with. It being so, it appears possible, in the author's opinion, that in the dissociation phenomena studied by Sainte Claire Deville (and having so great an importance for the theoretical discussions upon the dynamics of chemical reactions), the dissociation observed was a consequence of the contact action of the solid body. Contact action seems also to have played its part in the researches of M. Lemoine on the dissociation of hydrogen iodide. On the whole, in all those cases where the process of chemical transformation in a gaseous medium offers an uninterrupted character, there is reason to suppose that a contact action has been taking place. But if this supposition proved to be correct, we should be compelled to admit that the chemical transformation, even in its simplest shape in a gaseous medium, is intimately connected with the action of molecular forces—that is, with such actions which do not have the characters of determinated chemical combinations. Molecular forces ought to be taken into account even in the transformations going on in a gaseous medium; both factors—tbe chemical affinity and the cohesion—appear so intimately connected that it would be impossible to delimitate them: the chemical reaction would appear as a result of both the forces which unite atoms in molecules and those which are at work between the molecules.