at variance as to what it is,-whether it be itsell something or only a property of something; and not a few of them can sympathise strongly with the spirit of Milton's address to it, even when entirely differing from him in sentiment:

“Hail, holy Light, offspring of Heav'n first-born,
Or of the eternal co-eternal beam,

May I express thee unblamed? since God is Light,
And never but in unapproached light

Dwelt from eternity, dwelt then in thee,
Bright effluence of bright essence increate.
Or hear'st thou rather pure ethereal stream,
Whose fountain who shall tell? Before the Sun,
Before the Heav'ns thou wert, and at the voice
Of God, as with a mantle, didst invest

The rising world dark and deep,

Won from the void and formless infinite."

CHAPTER IV.

ELECTRICITY.

THE ORIGIN AND PROGRESS OF ELECTRICAL SCIENCE THE ELECTRIC MACHINE THE NATURE AND VARIETIES OF ELECTRICITY—LIGHTNING THUNDER-BALL LIGHTNING-EXTRAORDINARY LIGHTNINGSTROKES SHEET LIGHTNING-ELECTRIC METEORS-AURORA BOREALIS SUMMARY VIEWS OF MANY OTHER WONDERS OF ELECTRICITY -THE GALVANISING OF A CORPSE.

WHAT electricity or the electric fluid is, no man knows. The earliest notion of it was obtained through amber, called by the Greeks electron, and by the Romans electrum. This substance was observed by the ancients to possess so curious a capacity that, by being rubbed, it became able to draw to itself, and to hold for a short while in suspension, any light loose substances, such as small pieces of feather, which happened to be in its vicinity. Many other substances, such as resins, gums, glass, sulphur, and silk, were in the course of time observed to possess the same capacity, and, in allusion to amber, were designated electrics. Their peculiar power the power put into them by friction-was very long regarded as a mystery, an amusement, or a thing merely to be wondered at; but eventually, it was accumulated in large quantity, and found to emit crackling sounds and sparkling light, and to give off smart instantaneous energetic shocks; and then it was

assumed to be a distinct though obscure element, and called electricity.

In

The first thought of any consequence which occurred in connection with it was to use it for the cure of diseases. A particular kind of friction machine was constructed for obtaining quantities of it at will, and for pouring them upon invalids at a touch; and this acquired rapid, general overtowering fame as one of the grandest inventions ever known in the healing art,—— but was so abused by quacks, and so enormously overestimated by physicians, that it soon became little more than a means of philosophic experiment. this character, however, it led the way to amazing discoveries. The power obtained by it was easily proved to be got out of the ground; for, when the machine stood on any substance which could not become electrically affected by friction, it was useless; and ever while standing on the ground, it retained all its susceptibility. Either the crust of the earth, or perhaps the solid globe, was hence inferred to be one vast reservoir of electricity. A suspicion by and by arose that the air is full of it too, or at least that the lightning of thunderstorms and the crackling, sparkling, energetic power of the electric machine, were the same thing; and this suspicion was traced on to truth, in a series of masterly experiments, by several distinguished philosophers of Europe, and most of all by the celebrated Franklin of America. Electricity henceforth was recognised as a grand agent in weather,and particularly as the presiding power in thunderstorms, sultriness, and outbursts of typhoon and hurricane; and, in the course of later, manifold, and highly curious investigations, it came to be identified also—

at least as to its essential characteristics, though under great differences of intensity and of some other characters, with several sorts of luminous appearances in the air, with the formation of hail-showers, with the occasional luminosity of fogs and snow, with the peculiar power of magnets, with the peculiar power of the galvanic pile or voltaic battery, with certain energies of steam and gun-cotton and other remarkable things or conditions of things, and with the subtle agencies over animal physiology and animal life which have obtained the designations of mesmerism, electro-biology, animal magnetism, and odyle.

Still no man can tell what electricity is. It may be a material fluid of the closest possible similarity which a material thing can possess to an immaterial,and therefore prodigiously versatile, prodigiously subtle, and without any appreciable weight; or it may be two such fluids, most curiously related to each other, yet mutually repulsive, and rushing off to opposite poles. It may be a substance or substances strictly peculiar; or it may be a primal element identical in some way with the matter of light and heat, and possibly alsɔ with the matter of some of those seemingly undecomposable things which chemists call elements. Or it may be not a fluid or substance or primal element at all, but only a condition of something else so subtle and recondite as hitherto to have escaped all detection or recognition by man. Yet here is a wonder that, nevertheless, it displays itself to all eyes, and works magnificently and mightily as one of the sublimest powers of nature, and behaves according to laws of the most perfect precision and not difficult to be ascertained, and is altogether as well known by its

F

properties and effects as many of the grossest substances which lie thoroughly open to man's investigation. And another wonder is that, in spite of all diversities of character, it is essentially and absolutely the same in the crashing thunderbolt, the beauteous aurora, and the tiny machine-spark,-the same in the tornado, the magnet, and the dewdrop,-the same in shivering the lightning-rod, in playing on the mariner's compass, and in gliding along the telegraphic wire,-the same in creating a hail-storm, in producing an electrotype, in mesmerising a man, and in convulsing a corpse.

Lightning leaps either from cloud to cloud, from clouds to the ground, or from the ground into the air. It sometimes flashes without showing any precise form; sometimes forks or runs zigzag, with sharply defined outline; sometimes leaps crookedly and obliquely, and goes to pieces like a broken chain; and sometimes rolls along the ground in a series of balls, or with a continuous glow. The flashes occur most commonly in leaps from cloud to cloud; the forkings, in leaps from clouds to the ground; and the obliquities and chain-like appearances, in leaps from the ground into the air. The ball lightning is the only kind which does not evanish at a glance; and probably owes its more than instantary duration to a continuous series of discharges from a moving cloud.

All lightnings-as also other evolutions of electricity which are not visible to observers-make sudden and overwhelming upsets among the clouds, and all therefore affect the world of plants and animals through the medium of onfalls, winds, and other changes of weather. But only lightning which leaps to the ground is dangerous, or answers to the popular idea