Before them, Hippocrates writes in the ſame ſenſe, I. de victûs ratione, that this fire moves all in all. This ethereal fire is one of the four elements of the ancients. It lies latent, and diſperſed thro’ all the other three, and quieſcent; till collected into a quantity, that overbalances the circumjacent; like the air crouded into a tempeſt: or till it is excited, by any proper motion.
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 palled 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 bominum 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 experi-
