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ELECTROPHORUS. 



ELEGY. 



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the armature, that however great the force required to separate 

 the armature when actually in contact with the magnet, their ten- 

 dency to approach each other when separated is so small that it seems 

 hopeless to expect mechanical effect from this source. For it is only 

 from the strong tendency in these bodies to approach each other that 

 rotation can become a source of mechanical effect. There are also 

 other objections arising from the action of induced electricity to be 

 overcome in these machines. 



In the Great Exhibition of 1851, a number'of these machines, or their 

 models, were exhibited, and the Jury Report, Class X, expresses rather 

 too flattering an opinion as to their value, especially when it is said, 

 " We cannot help flattering ourselves that the attainment of this myste- 

 rious motive force will soon be followed by making it available for 

 practical purposes." About a year or two ago there was a stormy dis- 

 cussion in the ' Times ' newspaper, as to the merits of these machines, 

 conducted chiefly by the inventors themselves. 



Professor Wheatstone, who generally hits upon the best method 

 of bringing about a result, has contrived what we consider to be the 

 best electro-motive machine. We shall perhaps be able to give a 

 sufficient idea of it in a few words of description. Conceive a number 

 of electro-magnets arranged in a circle with their poles alternating and 

 directed towards its centre. The number of electro-magnets actually 

 employed is eight, so that there are sixteen magnetic poles arranged in 

 a circle. Within this circle is placed a cylinder of iron, not quite 

 concentric therewith. A portion of the outer surface of this cylinder 

 is in contact with the poles of one of the electro-magnets, and the 

 cylinder is free to roll upon them, and to move as they attract it. 

 It is worthy of remark that in this arrangement attraction is alone 

 concerned, repulsion having been got rid of by making the inner 

 cylinder of soft iron, and the objection that the electro-magnetic force 

 rapidly diminishes with the distance is met by making the cylinder 

 roll upon the poles. Now it is ingeniously contrived that as soon as 

 the cylinder, obeying the attraction of one of the electro-magnets 

 rolls upon its poles, it acts upon certain springs, whereby the electro- 

 magnet which attracted the cylinder is unmade, and ceases to hold it, 

 while the next electro-magnet is instantly made and attracts the 

 cylinder, which rolls upon it, unmakes it, makes the next, and so on 

 in quick succession throughout the circle. Connected with the centre 

 of the cylinder, and the centre of the circle of magnets, is a crank 

 which is thus set in motion, and by which it is proposed to impart 

 motion to machinery, &c. 



ELECTROPHOKUS. An instrument invented by Volta for gene- 

 rating electricity by induction. It consists of a thick disc of resin 

 12 or 15 inches in diameter, called the plate, resting on tin-foil, or 

 cast in a tin plate called the sole. The plate is furnished with a metal 

 disc or cover, insulated by means of a glass handle. In producing 

 electricity with this instrument the cover is removed by its glass 

 handle, and the plate is excited by flapping it with dry fur or flannel. 

 On putting the cover down upon it a spark of resinous electricity 

 may be drawn from it, and on uninsulating it, and then raising it, it 

 will give a still brighter spark of vitreous electricity. On putting 

 the cover down again, another resinous spark may be obtained, and on 

 touching it and then raising it another vitreous one, and so on for any 

 number of times. In these operations the first action is to give to the 

 resin a charge of negative electricity on its upper surface, while the 

 under surface, being connected with the earth, becomes positive to an 

 equal extent, the particles of the cake being polarised. [ELECTRICITY.] 

 The cover being now placed upon the cake, and touching it only in a 

 few points, it is scarcely acted on by conduction, but induction so 

 operates as to throw the under surface of the cover into a positive 

 state, while an equal amount of negative electricity is set free on its 

 upper surface, and this passes off in the form of a spark on presenting 

 the knuckle or other conductor. On raising the cover the + electricity 

 which was retained on the lower surface by induction, is now in 

 excess, and passes off in the form of a spark when a conductor is 

 presented to it. In the mean time the plate which acts by induction 

 has lost none of its charge, and is ready to act again by induction on 

 placing down the cover. The cover must not, however, come into 

 contact with the sole, or the whole of the charge may be drawn off 

 from the plate. 



The instrument derives its name from the circumstance of the cover 

 bearing off repeated charges of electricity. The electrophorus in con- 

 nection with the condenser [ELECTRICAL CONDENSER] has had con- 

 siderable influence in enlarging our knowledge of the most important 

 feature of all electrical inquiry, namely induction. The electrical 

 plate as formed by Volta consisted of equal parts shell-lac, common 

 resin, and Venice turpentine. Pfaff recommends eight parts colophon, 

 one gum-lac, and one Venice turpentine ; while Roberts prefers ten 

 parto gum-lac, three of colophon, two white wax, two Venice turpen- 

 tine, and half a part of pitch. The materials should be well incor- 

 porated by stirring up in a pipkin, aided by a gentle heat. Harris 



remarks that small plates of glass, sealing-wax, or brimstone are well 

 adapted to serve ,is electrical plates. 



ELECTRO-STATICS. [ELECTRICITY; ELECTRO-DYNAMICS.] 



ELECTROSCOPE. [ELECTROMETER.] 



ELECTROTYPE. [ELECTRO-MET ALLUROY. ] 



ELECTRUM, from the Greek electron (faficTpov}. Pliny says this 

 term denotes two substances, namely, amber and a metallic alloy com- 

 posed of four parts of gold and one part of silver. " Ubicumque quinta 

 argenti portio est electrum vocatur." (' Hist. Nat.,' lib. xxxiii, section 

 23 ; ' Hardouin,' torn, ii., p. 619.) The term electron, in the Odyssey 

 of Homer, is supposed to mean amber. 



The metallic electrum was in use in the Roman times : it is uncertain 

 whether it was known to the Greeks. The Romans were partial to it 

 for its brilliancy. Pliny, a few sentences lower down than the passage 

 just quoted, says, " Electri natura est ad Lucernarum lumina clarius 

 argento splendere." The Romans used it frequently for what we term 

 plate. 



Lampridius, in his Life of Alexander Severus, remarks, that this 

 prince caused coins to be struck in honour of Alexander the Great, 

 both of electrum and gold. " Alexandri habitu nummos plurimos 

 figuravit : et quidem electreos aliquantos : sed plurimos tamen aureos." 

 (' Hist. Aug. Scriptores,' p. 922.) 



Isidorus, in his Origines (li. xvi., c. 23), speaks of three sorts of elec- 

 trum : 1, amber ; 2, a metal so called, found in a natural state ; and 3, 

 a metal compounded of three parts of gold- and one of silver. 



ELECTUARY, a term applied to a compound of various medicines, 

 united by means of syrup, or wine, and formed into a soft mass, nearly 

 of the consistence of honey. Substances in the state of powder or 

 extract were thus combined, and rendered capable of being swallowed 

 without their natural taste, which might be unpleasant, being per- 

 ceived. Formerly electuaries consisted of a great variety of ingredients, 

 often very unsuitable to be taken together. In the present day the 

 few electuaries which are prescribed are much simpler in their compo- 

 sition. Many compounds which were formerly preserved in a soft 

 state are now kept in a hard dry condition, and termed confections. 



ELEENCEPHOL. A substance found in the brain of man, but now 

 believed not to be a distinct chemical compound, but a mixture of 

 oleine, oleophosphoric acid, cerebric acid, and cholesterin. 



ELE'GIT, so called from the entry of its award upon the roll, " quod 

 elegit sibi executionem " (because the plaintiff hath chosen the writ of 

 execution), is a writ of execution first given by the statute Edw. I., 

 cap. 18, but the operation of which has since been greatly extended. 

 It is directed to the sheriff of the county where the defendant's pro- 

 perty lies, and commands him to make delivery of the debtor's lands 

 and all his goods (except oxen and beasts of the plough) to the 

 plaintiff. 



The sheriff, immediately upon the receipt of this writ, empanels a 

 jury, who appraise the debtor's lands as well as his goods, and if the 

 goods alone are insufficient to pay the debt, then the sheriff, upon the 

 finding of the jury, delivers the lands over to the party suing out the 

 writ, who thereupon becomes what in law is termed a tenant by eleyit, 

 and continues to occupy them until the whole of his debt and damages 

 are satisfied. The tenant's interest in the land is only a chattel, and as 

 such goes to his personal representatives. 



Before the statute of Edward I. a judgment creditor could only have 

 obtained satisfaction of his debtor's goods by the writ of fieri facias, 

 and of the present profits of his lands by a levari facias ; but as the 

 latter writ did not extend to the possession of the lands themselves, a 

 defendant might, if he thought proper, alien the property, and thus 

 oust the plaintiff of his remedy. This has, with other defects, been 

 remedied by the statute 1 & 2 Viet. c. 110. 



When the judgment is satisfied out of the estate, the defendant may 

 recover his lands either by an action of ejectment, or by a suit in equity. 

 (Blackat. Comm. Mr. Kerr's ed., vol. iii. p. 457.) 



ELEGY, from the Greek, (leyos (tAeyos, whence i\tyfiov), in English 

 commonly means a short poem composed on some person's death ; 

 also, in a more general sense, any mournful or serious poem, as, for 

 instance, Gray's ' Elegy in a Country Church-yard.' The Greek word, 

 (leyo, is properly a strain of lament ; elegeion, the form of versification 

 in which such strains were first composed by the Greeks, that is, the 

 combination of an hexameter and a pentameter (commonly called long 

 and short) verse ; eleycia, a poem made up of such verses. (Miiller, 

 ' Hist, of Lit. of Greece.') The elegiac was the first variation from the 

 hexametral, or epic, measure ; and this change of form corresponded 

 with a change of subject : the poet in epic composition keeping him- 

 self and the workings of his own mind out of sight ; while on the 

 contrary, the free and full expression of the poet's feelings, as affected 

 by external circumstances, constituted the essence of the Greek elegy. 

 Hence arises its variety ; the elegies of Callinus and Tyrtseus (the 

 earliest) being political and warlike; of Mimnermus, contemplative 

 and melancholy ; of Theognis and Solon, moral and political, &c. It 

 was at first more peculiarly appropriated to social meetings, and there- 

 fore equally fit for topics of political and local interest, and for those 

 which refer to the common feelings of our nature, as love, regret for 

 the perishableness of human tilings, exhortations to the enjoyment of 

 the present hour, and the like. The elegiac was also a favourite 

 measure for epigrams, that is, taking the word in its proper sense, 

 inscriptions. [EPIGRAM.] 



