Mountains, among which we are now travelling with philosophic discrimination, are, in truth, the surest beacons we can trust to. They are old, but they are firm; they are clothed, indeed, in the wisdom of ages, but they are vigorous and universally instructive. How awfully the clouds roll down the sides of the eminences which surround you; how powerfully the winds rush; how frightfully the thunder roars! Whence the cause of such warfare? Are the elements, here one and all, to exhibit themselves in their sublimest form? Or, are similar strifes more common; but, is man less attentive to them in other situations? A momentary enquiry, will throw some light upon the subject. In the clouds, and in the regions above the clouds, we must search for the elucidation of these phænomena. Electricity presents itself before us, and that mighty agent we must investigate and trace, in its favourite ethe.. rial mansion. The most wonderful discovery of modern times relative to the earth, has been electricity, which is a principal and constant agent in the works of nature; and extends its influence to all bodies without exception, whether mineral, vegetable, or animal. By its effects, contrary to the principles of gravitation, we see bodies attracted, repelled, and held suspended by others, and through no other means than a slight friction; while another body, by the very same friction, shall reverse all its effects. We see a piece of cold metal, or even water or ice, emitting strong sparks of fire, so as to kindle many inflammable substances; and in vacuo, its light to resemble what it really is, lightning. Flashes of lightning are always crooked, so are flashes of electricity. Lightning strikes the highest and most pointed objects in its way, preferably to others, as high hills and trees, towers, spires, masts of ships, &c. In like manner, all pointed conductors receive or throw off the electric fluid, more readily than those which are terminated by flat surfaces. Lightning burns, so does electricity. Lightning dissolves metals, so does electricity. Lightning rends some bodies, so does electricity. Lightning destroys animal life, so does electricity. All the operations of electricity depend upon one fluid, sui generis, extremely subtile and elastic, dispersed through the pores of all bodies; by which the particles of it are as strongly attracted, as they are repelled by one another. It is, most probably, a real vapour ignited. It is highly visible in vacuo : One of the principal rea | reasons, why flashes of lightning sometimes make a very long rumbling, is the vast length of the vacuum, made by the passage of the electric matter, although the air collapses the moment after it has passed; and the vibration (on which the sound depends) commences at the same moment, through the whole length of the tract. : This vacuum, Beccaria says, is very observable upon great explosions of thunder, when animals have been struck dead, without being touched by the lightning; a vacuum being only suddenly made near them, and the air immediately rushing out of their lungs to fill it, whereby they are left flaccid and empty; whereas, when persons are immediately killed by lightning, their lungs are found distended. Lightning may be considered in three states: The first, that in which it explodes and flashes, without any force to do harm; the second, when it explodes with greater force and density, striking people with blindness, setting fire to combustibles, &c.; and the third, the thunderbolt, which is a compact and undissolved body of ignited matter, which has not time to explode in the air, but is darted with the velocity of light itself, striking objects with an inconceivable and irresistible force. Beccaria establishes it, that great quantities of electric matter, at times rush out of particular parts of the earth, and rise through the air into the higher regions of the atmosphere. Attracting and carrying with them sand, ashes, and other like substances; together with the watery particles which are dispersed in the atmosphere, and that thus vapours are raised to cause storms. But, what can be more miraculous than to find, that a common glass phial or jar, shall after a little preparation, (which, however, leaves no visible effect, whereby it can be distinguished from other phials or jars) be capable of giving a person so violent a sensation, as nothing else in nature can give, and even of destroying animal life, and this shock attended with an explosion like thunder, and a flash like that of lightning? Even Newton himself would have wondered at this discovery. The electric fluid, as I have already said, exists in all the bodies of the earth; and is repulsive of its own particles, but attractive of the particles of other matter. Thus, when a body does not shew any electrical appearance, it is then supposed to contain its natural quantity of the electric fluid, and is then said to be in its non-electrified state: but, if it shews any electrical appearance, it is then said to be electrified. And hence a body having received an additional quantity of electric fluid, is said to be overcharged or positively electrified; and a body that has lost part of its natural quantity, is said to be undercharged, or negatively electrified. From all experiments, says Priestley, it appears, that the electric matter either is, or contains phlogiston, since it does the very same thing that phlogiston does. It is also probable, that the sulphureous smell occasioned by electricity, being very different from that of fixed air, may be produced by the phlogiston in the electric matter itself. The substances capable of transmitting the electric fluid, whilst others are impervious to it, we likewise are to suppose, are rendered so by the phlogiston which they possess, as is eminently the case with metals and charcoal, which are the best conductors. And yet, the electric fluid, is of a different principle from that of fire. A metal may have a great degree of heat, without appearing at all electrified; and on the other hand, |