This curious phenomenon may be seen in more dense electric atmospheres accumulated by art, as in the following experiment ascribed to Mr. Canton. Lay a wooden skewer the size of a goose-quill across a dry wine-glass, and another across another wine-glass; let the ends of them touch each other, as they lie in a horizontal line; call them X and Y; approach a rubbed glass-tube near the external end of the skewer X, but not so as to touch it; then separate the two skewers by removing the wine-glasses further from each other; and lastly, withdraw the rubbed glass-tube, and the skewer X will now be found to possess resinous electricity, which has been generally called negative or minus electricity; and the skewer Y will be found to possess vitreous, or what is generally termed positive or plus electricity. The same phenomenon will occur if rubbed sealing wax be applied near to, but not in contact with, the skewer X, as the skewer X will then be left with an atmosphere of vitreous ether, and the skewer Y with one of resinous ether. These experiments also evince the existence of two electric fluids, as they cannot be understood from an idea of one being a greater or less quantity of the same material; as a vacuum of electric ether, brought near to one end of the skewer, cannot be conceived so to attract the ether as to produce a vacuum at the other end. In this experiment the electric atmospheres, which are nearly of similar kinds, do not seem to touch, as there may remain a thin plate of air between them, in the same manner as small globules of mercury may be pressed together so as to compress each other, long before they intermix; or as plates of lead or brass require strongly to be pressed together before they acquire the attraction of cohesion; that is, before they come into real contact. 2. It is probable, that all bodies are more or less perfect conductors, as they have less or more of either of the electric ethers combined with them; as mentioned in Preliminary Proposition, No. VI. as they may then less resist the passage of either of the ethers through them. Whence some conducting bodies admit the junction of these spontaneous electric atmospheres, in which the proportions or quantities of the two ethers are not very different, with greater facility than others.