earth, whence flames, but oftener vast quantities of water, are discharged. Flames tud smoke are also emitted from spots of ground where no chasms are perceptible; and though the abysses formed in the earth are in general not extensive, yet in violent earthquakes they are frequently so large as to bury whole cities. 8. The water of the ocean is, on such occasions, affected perhaps still more than the land; the sea now rising to a prodigious height, now divided to a considerable depth, and emitting great quantities of air, flames, and smoke. Similar agitations occur in the waters of ponds, lakes, and even rivers.
Lastly, the effects of earthquakes are not confined to one particular district or country, and frequently extend to very distant regions; though there is no instance of the whole globe having been convulsed at the same time.
The cause of earthquakes, or the theory of this tremendous phenomenon, is but imperfectly understood. It is, however, certain, that they arise from the confinement of air within the bowels of the earth, where it is generated by sulphureous vapours acting on different metallic ores, the principal and most copious of which appears to be iron. In confirmation of this theory, we shall only observe, that artificial earthquakes may be easily produced, by burying equal quantities of iron-filings and sulphur, mixed in a moist state, and confined in a vessel, so as to exclude the access of external air, and prevent the escape of the inflammable gas thus generated. In a few days (and, if large quantities be employed, in a few hours) this composition grows remarkably hot, and will explode with a violence and impetuosity resembling the natural phenomenon:—but we do not advise our junior readers to attempt such dangerous experiments. As it would be deviating from our plan to enter into farther particulars, we can only refer the inquisitive to the 73d vol. of the "Philosophical Transactions" of the Royal Society for 1783, where they will find an ample account of the latest and most awful earthquake that has happened in Europe, within the memory of man.
EARTH-WORM, or Lumbricus, L. a well known insect, which is destitute of feet; it is of an oblong form; round shape, and covered with a soft, slender skin, marked with annular ridges and furrows. It is common in all parts of this country, at little depths beneath the surface of the earth; and is not unfrequently found in the human intestines, as well as in those of the lower animals; in which state it has been supposed to be a different creature, and is therefore called by various names.—See Worms.
Earth-worms were formerly reputed to be of great virtue in medicine; but are at present more usefully employed in feeding poultry and other birds.
EAU-DE-LUCE, a kind of liquid volatile soap, of a strong pungent smell, which is prepared in the following manner: Ten or twelve grains of white soap are dissolved in four ounces of rectified spirit of wine; after which the solution is strained. A dram of rectified oil of amber is then added, and the whole filtrated: with this solution should be mixed such a proportion of the strongest volatile spirit of sal-ammoniac, in a crystal
