DEMOLITION. 115 DEMONIAC. perniitling himself to be killed by the same ex- plosion wliii'li broke in the gate. The principal ajjents used in demolitions are fire, explosives, mines, and tools. Where time allows and the material to be destroyed is in- Hammable. as in the case of crops, frame build- ings, wooden bridpres, etc., it is burned. In other eases the demolition is elfected by the use of explosives, assisted sometimes In' the pick, axe, and other tools. The explosives ordinarily used are gimpowder and fiuncotton. The materials most frequently to be demolished arc gims. rail- roads, including their bridges and tunnels, walls, doors, telegraph and telephone lines. A large gun is most readily destroyed by removing the breech-block and by exploding a charge on the chase or in the bore. Locomotives and other machinery can likewise quickly be disabled by removing or destroying some vital part. Rail- roads have been destroyed by overturning sec- tions of the track, removing and burning the ties; the rails can be placed on the piles of burning ties, heated in the centre, and then bent and twisted. If simply bent, it is a comparatively simple matter to straighten them again. If, however, they are well twisted, the rails must be re-rolled before they can be used again. Walls and doors, if there is not time for breaking them down with picks and crowbars, can be demolished by exploding charges against them. If gunpowder be used, it is necessary to tamp the charge. If guncotton, the tamping is not essential. The rules governing the amount of explosive to be used are only approximate and must be considered in connection with the class of material to be destroyed. In general the amount of explosive force varies with the square of the thickness of the wall or pier to be de- molished; and directly, as its length. For ex- ample, a brick wall two feet thick requires about two pounds i>er running foot of guncotton. while one four feet thick will require about eight pounds per running foot. A steel rail can be cut by the explosion of three-fourths of a pound of guncotton against its web. The destruction of bridges requires judgment in the placing of the charge. In the wooden bridge the destruction can be accomplished by building a fire under one or more pieces, whose failure will cause the entire bridge to drop. Similarly, an iron or steel truss bridge may be destroyed by cutting simultaneous- ly with explosives the lower chord of some ten- sion member near the centre of the bridge. Arched masonry bridges and tunnels can best be destroyed by exploding the proper sized charge on the top side of the arch near the haunches. When impracticable to reach the top side of the arch, the destruction may be effected by projiping a large charge against the crown of the areli. Wire entanglements placed as obstacles to the advance of the troops may be rendered inefTective by cutting with wire nippers, a.xes. or other edged tools. Telegiaph and telephone lines can be destroyed by cutting down and burning the poles; the wires should be removed and twisted or buried. The demolition of material which may subsequently be of service to the friendly army should only be undertaken with great caution. The denial of its use to the hostile army may frequently be accomplished in .some other way; for example, a telegraph line may be temporarilv disabled by removing some instru- nicnts or establishing faults in the line. DEMON (Lat., from Gk. ^■f|^v). A Greek writer who lived about B.C. 2S(). He is the author of Atthis CAtSis ) , a work on the history of Attica, and according to Schneidewin and Jliiller, wrote lUpi napoiiuwv. a work on proverbs; and Ilcpi 6vwv, on sacrifices. The ext.ant frag- ments of his writings are collected in Siebelis, Phanodemus (Demoitin, Vlitodemi, et Isiri) ; 'AreiSuv, Fragmcnta (1812); and in Miiller, Fragmcnia Histuricorum (Iriecorum, vol. i. (Paris, IStiS). He is considered only a second- ary iuithoritj-. DEMON ( Gk. Sai/iaf, daiinuii, of uncertain etj'mology, often tlerived from SaioOaBai, daioiis- thai, to divide; ultimately connected with SitUpai, didoiiai, Lat. dare. Skt. da, to give, or from Gk. (iai/i'iii, daCitai, to know, Skt. dasra. wise, but best connected, perhaps, if for "(^amjiwv. 'dasi-moii, with Lat. lares, tutelary deities, Skt. das, to perish). In popular usage, an evil spirit or fiend, but in allusions to the classics a tutelary deity or a godling. The development of the demon-concept is an interesting one. In Homeric usage the word denotes an indeterminate god, and often, by euphemism, a hostile divinity. In Ilesiod, however, the souls of the departed are called demons, and .Eschylus in the Persians makes Atossa apply the term to her deified hus- Ijand, Darius. Herein seems to lie the original meaning of the word., especially if the etj'mo- logical connection with the Latin lar is sound. Denoting at first the ghosts of, the benignant dead who, when duly jjropitiated, confer boons on those who observe their cult, and later godlings of the dead and hence a vague deity in general, and even fate, the concept entered by the time of Socrates and Plato upon its meaning of guardian spirit. In this sense Socrates called his indwell- ing genius dai/wvmv, and he fancied that it spoke within him to restrain him. but never to impel him. The sense of the word which is the most common one is a .Judieo-Christian develop- ment. In the reaction of Christ's teachings against the Gra>co-Roman civilization which ruled Palestine at that period, the deities of the gen- tiles became the devils of the Judiea-Christian faith. In the Xew Testament, therefore, demon always has a bad sense. The spread of Christian- ity carried the use of the word with it, and demon thus became a synonjm of devil, fiend, and maleficient spirit in general. See Demonology. DEMO'NAX (Lat., from Gk. Arindfa^). A Cynic philosopher of Athens, belonging to the second century of the Christian Era. His char- acter has been extolled by Lucian. and he seems to have been a benignant sort of person, quite as much Socratie as Cynic. Consult: Fritzsehe, Da Fragmcniis Dcmonoctis (Rostock. 1800) ; and Bernays. Lucian iind die Kyniker (Berlin, 1879). DEMONETIZATION. See Bimet.vlusm. DEMONIAC ( Lat. dwtnoniacus, Gk. oaiiionKhs, daimoiiihos, from datfiav, daimoti, denu)nl. A jjerson .su])i)osed to be possessed by a demon. The idea of such a possession is as widespread as the belief in the existence of demons. There is evidence of it in tlie ancient civilizations of Egjpt and Babylonia ; it existed in Persia and .Judea, Greece and Rome, in the most flourishing periods of their history; it held a large place in the life of the Christian nations until the end of the eighteenth century; it is cherished by
