LIGHTNING, a bright and vivid flash of fire, suddenly appearing in the atmosphere, and commonly disappearing in an instant, sometimes attended with clouds and thunder, and sometimes not. For an account of the phenomena of lightning, and of the opinions concerning it, see ELECTRICITY Index.
Artificial Lightning. Before the discoveries of Dr Franklin concerning the identity of electricity and lightning, many contrivances were invented in order to represent this terrifying phenomenon in miniature: the coruscations of phosphorus in warm weather, the accension of the vapour of spirit of wine evaporated in a close place, &c. were used in order to support the hypothesis which at that time prevailed; namely, that lightning was formed of some sulphureous, nitrous, or other combustible vapours, floating in long trains in the atmosphere, which by some unaccountable means took fire, and produced all the destructive effects of that phenomenon. These representations, however, are now no more exhibited; and the only true artificial lightning is universally acknowledged to be the discharge of electric matter from bodies in which it is artificially set in motion by machines.