This fire gives elasticity: and elasticity or vibration is the mother of electricity. We don't so much wonder at phosphorus arising from animal substances; for this fire is in water, and betrays itself to our senses, in salt water. Many a time when I have passed the _Lincolnshire_ washes, in the night time; the horse has seem'd to tread in liquid flames. The same appearance is oft at the keel of a ship. Fire exists in water, says _Pliny_, as well as in human bodies. _nat. hist._ II. 107. Loaf sugar beaten in the dark is luminous. Many vegetables, as indian cane, and rotten wood the like, as _Bartholin_ largely recites, _de luce hominum_ c. 4. All electric bodies have this privilege: that is, they more easily discover it. Amber, gum lac, naptha, bitumens, some precious stones. My old friend Mr. _Stephen Gray_ the father and great propagator of electricity, show'd me experiments therein, in the year 1705, then at _Corpus Christi_ college in _Cambridge_. Afterward in the year 1719, he show'd by experiments before the Royal Society, that paper, ribbands, silk, sattin, cloth, shavings, linen, goldbeaters skin, and in short, almost all kind of substances discover electrical sparks of fire in the dark: especially when well warm'd before the fire, or in a cold, dry, nitrous air, and in a room where there is no company. This same quality is found _in vacuo_, as Dr. _Desaguliers_ show'd before the Royal Society, _march_ 31, 1720. He took an exhausted glass globe, and caused it to be turn'd round violently, in an engine: by rubbing the hand upon it, it was illuminated within side, with purple streams. This gave foreigners the idea of using a glass globe, in electrical experiments. The operation of the ethereal fire is various, nay, infinite, according to its quantity, and degree of incitement, progress, hindrance, or furtherance. One degree keeps water fluid, says the learned bishop of _Cloyne_: another turns it into elastic air, and air itself seems nothing else, but vapors, and exhalations render'd elastic, by this fire. This fame fire permeates, and dwells in all bodies; even diamond, flint, and steel. Its particles attract with the greatest force, when approximated. Again, when united, they fly asunder, with the greatest force, and celerity; it resists nothing quiescent, but when put into motion, it disdains all resistance. All this is according to the laws prescrib'd by the sovereign architect. This is the life, and soul of action, and reaction, in the universe. Thus has the great author provided against the native sluggishness of matter! light, or fire in animals, is what we call the animal spirits; and is the author of life, and motion. But we know not the immediate mode of muscular motion; any more than how, in inanimate matter, it causes the vibrations of an earthquake. Of this fire, the excellent _Manilius_ thus writes, who liv'd in the time of _Augustus_. _Astronom._ I.