ELECTRICITY

Page 402 "TT ELECTROMETER. •wire n p conveying the electric current twisted round it; the darts at the ends of which show the ingre and egre of the electricity, and the transverse darts the direction of the magnetic current. If the cylinder round which the wire conveying the electric current is twisted be of steel, it becomes a permanent magnet; if of pure soft iron, it becomes a temporary magnet, so long as the electric current is in motion, and s and n are powerfully opposed poles. If the bar be bent, as in the annexed cut, a powerful horse -shoe magnet is obtained when the ends p n of the copper wire twisted round it are connected with the voltaic circle; and a single pair of plates is sufficient for the purpose. ELECTRO'METER. (Gr. nXtxrfiov, and f^ir^ov, a measure.) An instrument for ascertaining the presence and intensity of electric excitation. The simplest form of electrometer consists of two very small pith balls suspended from a small conductor by very fine wire or thread; upon the principle that bodies similarly electrified repel each other, these diverge upon the reception of very minute quantities of electricity. Two thin slips of gold leaf are also similarly applied; and, to prevent the influence of the agitation of the air upon them, they are suspended in any convenient way under a gla shade. The other forms of electrometers generally act upon the same principle, being respectively adjusted to the varying degrees of quantity and intensity. ELECTRO'PHORUS. (Gr. yMxreovy and ipiPU, I carry.) This instrument consists of a flat smooth cake of resin A, which is rendered negatively electrical by friction; a plate of bra with a gla handle is then placed upon it, and becomes electropolar by induction. The bra plate, having been touched bv the finger whilst lying upon the resin, is afterwards lifted off by its gla handle, and gives a spark of positive electricity. The same operation maybe indefinitely repeated. This instrument is sometimes a convenient substitute for the electrical machine, and is elegantly applied to inflame a jet of hydrogen gas in Volta's inflammable air lamp. ELE'CTROPO'LAR. A term applied to conductors, one end or surface of which is positive, and the other negative; a state which they commonly exhibit when under the influence of induction. ELE'CTROSGOPE. (Gr. tiXtxreev, and irxoinu, I see.) An instrument for rendering electrical excitation apparent by its effects. The gold leaf electrometer, and other similar arrangements, are electroscopes. ELE'CTRUM. {Gr. rM»r^ov.) A term applied by the ancients to various substances; but especially to the substance now called amber, or to a certain metallic alloy consisting of four parts of gold and one part of silver. (See Plinj/, lib. xxxiii. and xxxvii.) ELE'CTUARY. (Lat. electuarium.) This term is generally applied to powders which are mixed up with syrup, so as to be of about the consistency of treacle. The confections of the present Pharmacopoeia are substi. tuted for the former electuaries. ELE'DONE. (Gr. tAsSovjj.) A name applied by Aristotle to a genus of Malakia or Cephalopods having a single row of suckers on each arm, and without any musky odour; it is applied in modern zoology to the same genus. E'LEGANCE. (Lat. elegant i a.) In the Fine Arts, a quality indicating grace and lightne , but especially the latter. In painting and sculpture it greatly depends on good selection and delicacy of execution, and these again upon taste. Heavine , and leanne or extrepae lightne , are the boundaries between which elegance is a mean. ELE'GIT (Lat. he has chosen), in Law, is a writ of execution, which lies for one who has recovered debt or damages; or upon a recognizance in any court against one not able in his goods to satisfy the same, directed to the sheriff, commanding him to make delivery of a moiety of the party's land, and all his goods except beasts of the plough. The creditor holding the moiety of the land until satisfaction is termed tenant by elegit. E'LEGY, is the name given in modern times to a species of poetical composition of a mournful character. But though this signification of the term tallies with its etymology (Gr. e, and Xtyttii, to cry alas), the expre ion elegy among the Greeks, with whom it originated, and among the Romans, by whom it was a iduously cultivated, had a much wider signification. Thus among the former it embraced equally the warlike verses of Tyrtaeus, the melancholy effusions of Mimnermus, and the moral and political aphorisms of Tiieognis and Solon;.md among the latter it comprehended the miscellaneous themes of Ovid, Pro pert i us, TibuUus, and Catullus. The form of verso in which it was composed was the alternate hcxaroi'^er and pentameter. (6Ve Pentameter.) Inmo389 ELEVATION. dern times almost all the nations of Europe have practised this species of composition; but if we except the Elegies of Hammond, Milton's Lycidas, and Gray's Elegy among ourselves, and Mat this son's Elegie among the Germans, itjloes not appear with great succe . E'LEMENTS. The old chemists applied this term to certain imaginary principles or e ences of matter; such as fire, water, earth, and air. The elements of the alchemists are salt, sulphur, and mercury. The term element is now used as synonymous with simple or undecomponnded body; that is, a substance which we cannot resolve into simpler forms of matter. The present list of elements includes all the metals, and the following substances — oxygen, chlorine, iodine, bromine, fluorine, hydrogen, nitrogen, sulphur, phosphorus, carbon, selenium, and boron; amounting in all to fifty-four, exclusive of the imponderable forms of matter. See Equivalents, Chemical. E'LEMI. The resinous exudation of the Amyris elemifera, brought from the West Indies: it yields a volatile oil on distillation. It is used in ointments, giving them a gently stimulating character, and adding to their viscidity. The compound elemi ointment of the Pharmacopoeia is a good preparation of this kind, and resembles the yellow basilicon of old pharmacy. ELE'NCHUS. See Sophism. ELEPHANT I'ASIS. a disease which chiefly aflTects the legs and feet, which become rough, scaly, and swollen, and have been compared to the feet of the elephant: the skin gets thick, unctuous, and insensible, and the limb occasionally attains an enormous size. E'LEPHANT, WHITE. A Danish order of knighthood of great antiquity: the number of knights is limited to thirty, besides members of the royal family. E'LEPHAS, or ELEPHANT. (Gr. iXifcts, an elephant.) The generic name of the most gigantic of existing quadrupeds. They are characterized e entially by having grinders composed of alternating vertical plates of ivory, enamel, and caementum, and two tusks in the upper jaw: they are also the only living Mammal i a which have a proboscis or trunk longer than the head. It is inferred from the structure of the skull that the extinct Mastodons, which have grinders of a more simple structure, also po e ed a long proboscis; and accordingly Cuvier includes the genus Elephas and Mastodon in a particular family of Pachyderms called Proboscidians. Of the true genus Elephas there are two living and a greater number of extinct species. The Indian elephant {Elephas Indict is, Cuv.) differs from the African species in its greater size, in the skull being higher in proportion to its length, and with a more concave forehead. The Indian elephant has also comparatively smaller ears; the skin is of a paler brown colour; and it has four nails on the hind feet instead of three. The elephant will breed in confinement; its period of gestation is twenty months and some days. It brings forth one young at a birth, which derives its nourishment from two nipples placed on the inner side of the setting in of the fore-legs. The perpendicular height of the Indian elephant, measured from the top of the shoulder, has not been found to exceed ten feet six inches: the ordinary height is from seven to nine feet. The Indian elephant varies as to the length of the tusks; their ends only are visible externally in the females, and there Is also a race (Mooknah) in which they are straight and short in the males. In other races the males have the tusks long and curved, especially in that called " Dauntelah." The anecdotes of the docility, sagacity, and tenacious memory of the elephant are numerous and generally known. The characteristics of the African elefhant may be inferred from the account of those of the ndian species. It is usual to describe it as having a forehead convex instead of concave; but the projection is caused by the nasal bones, which are higher placed than in the Indian species; and the true front is in reality concave in the African species, but in a le degree than in the Indian. The chief external character of the African elephant is his huge ears. It is a remarkable fact that no African nation has ever subdued the elephant, or made it available for any useful purpose. For an account of the fo il elephants, see Mammoth. ELEUSl'NIAN MYSTERIES. The secret religious rites performed every year in honour of Ceres and Proser pine at the Attic town of Eleusis. To these mysteries all Greeks of both sexes, if unpolluted by crime, were admitted; and as persons thus initiated were considered to be peculiarly under the protection of the gods and to enjoy their favour, it was a privilege much sought after. It has been thought that many pa ages of ancient cla ical writers refer in a covert manner to these mysteries, and the doctrines disclosed in them: thus, the whole sixth book of the JEneid has been interpreted by War burton and others as an allegorical exposition of them, a notion controverted by Gibbon in one of his early works. See Mysteries. ELEVA'TION. (Lat. e,/>-ow, and levo, Jra«e.) In Architecture, a geometrical representation of a building measured vertically in respect of the horizon; by the an  Page 403