This experiment I formerly tried various ways, as I had conceived, if the electric matter would displace air, it might have been applied to answer the end of steam in the steam-engine, and many other great mechanical purposes. But as from the above it appears, that the contrary is true, it is evident, that electric matter surrounding particles of vapour must, in fact, increase their specific gravity, and cannot any-ways be imagined to facilitate their ascent. I may add further, that if this be true, that it pervades the pores of air, its specific levity cannot, by any means I know, be compared with that of air. Its particular attraction to some bodies, at least to much the greater part of the terraqueous globe, is abundantly greater than that of air to those bodies: and hence its gravitation to the whole globe would appear, at first view, to exceed that of air. But the more I consider this, the more perplexing and amazing it appears to me: and thence must leave it to the investigation of my very ingenious antagonist, or some other able philosopher. I come now to the experiments, that are given us to show all vapour to be electrifed. In these Mr. Eeles seems to have been led into error, by not having observed, that many bodies electrifed will retain that electricity for some time, altho’ in contact with conductors. The Leyden phial may be touched three or four times by a quick finger before the whole is discharged. Almost all light dry animal or vegetable substances, such as feathers and cork, do this in a much greater degree: and in general I have observed, the more slow any bodies are to acquire electricity, the more avaritious they are to keep it. Part of the plume of a feather, hanging to a green line of silk about a foot long, which was suspended from the midst of an horizontal line of the same, about four yards in length, was electrified with a dry wine-glass, according to the method of Mr. Eeles; and, after being touched nine times with my finger, at the intervals of two seconds of time, still manifested signs of electricity, by being attracted at the tenth approach of it.