Excerpt from The Nucleation of the Uncontaminated Atmosphere The air to be treated in the present series of experiments is, therefore, continually approaching a state of purity so far as foreign admixtures are concerned. Hence the properties of dust-free air, or in practice of filtered air, became increasingly important. It may be proved by aid of the inclosed steam-jet that even dust-free air must be an aggregate of nuclei, whose number grows rapidly larger as their diameter de cream, with a maximum for molecular dimensions; or that size is distributed among the molecules and quasi-molecules of dust-free air in a way somewhat recalling the distribution of velocity among mole cules, and that among particles larger and smaller the air molecule represents a condition of maximum occurrence. The fog-limit of dust free air is thus a variable quantity, depending eventually on the details of the method of filtration, or other process for rendering the air dust free. In fact, as the fog-limit rises, the coronas for a given exhaustion above the fog-limit increase in aperture, up to a limit. It should always be remembered that the particles or nuclei here in question are very small, even in comparison with ions. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.