On the Law of the Diffusion of Gases

Abstract

It is the object of this paper to establish with numerical exactness the following law of the of gases: The or spontaneous intermixture of two gases in contact, is effected by an interchange in position of indefinitely minute volumes of the gases, which volumes are not necessarily of equal magnitude, being, in the case of each gas, inversely proportional to the square root of the density of that These replacing volumes of the gases may be named volumes of diffusion, and are as follows: Air, 1; Hydrogen, 3.7947; Carburetted hydrogen, 1.3414; Water-vapour, 1.2649; Nitrogen, 1.0140; Oxygen, 0.9487; Carbonic acid, 0.8091; Chlorine, 0.6325, c numbers which are inversely proportional to the square roots of the densities of these gases, being the reciprocals of the square roots of the densities, the density of air being assumed as unity. If the two gases are separated at the outset by a screen having apertures of insensible magnitude, the interchange of equivalent volumes of diffusion takes place through these apertures, being effected by a force of the highest intensity; and if the gases are of unequal density, there is a consequent accumulation on the side of the heavy gas, and loss on the side of the light gas. In the case of air, for instance, on the one side of the screen, and hydrogen gas on the other, a process of exchanging 1 measure of air for 3.7947 measures of hydrogen, through the apertures, is commenced, and continues till the gases on both sides of the screen are in a state of uniform mixture. Experiments on this principle can be made with ease and precision, as will