Experimental investigation of the spirit manifestations, [electronic ...

384 OF MATTER, MIND, AND SPIRIT.resume their natural relative position by a contrary application of a similaragent. Although steel differs from iron only in containing, as an ingredient,one-fiftieth of carbon, this gives it the highly valuable property ofhardening, when suddenly refrigerated; a result which may be accountedfor by supposing that, in consequence of the sudden exposure to a powerfulconducting medium, there is a sort of a jerk by which theparticlesloose from their midst an undue portion of their ethereal constituents, andcannot recover their normal arrangement after the refrigeration. Whenthis effect is reached to a maximum, the steel is so brittle as sometimes tofly into two or more pieces when left to itself. AVhen soft iron is subjectedto the magnetizing process, it exchanges one polarity for the otherwith such speed, that, in some electro-magnetic instruments, this reversalis effected more than one hundred times in a second; but precisely in proportionas the magnetism is readily received, it is more readily lost. Onthe other side, when hardened to a maximum, steel can scarcely be magnetizedat all. Thus, to have a permanent magnet, we must employ themetal in a state of induration between the extremes. These facts tend tocorroborate the inference that magnetism isdependent on the relative positionof the ferruginous particles. It is presumed that the ferruginous particlesof which the filings consist indicate, by their direction, as seen externally,the direction in which the constituent particles of the magnetare situated beneath the metallic surface.*••'Explanation of the Galvanic Pile, Battery, or Series.—When pieces of zinc andsilver are so placed in the mouth as to have their surfaces separated by the tongue, theirextremities extending beyond it externally, on allowing the lattlr to touch each other, ametallic taste is perceived by the person Avhose tongue is subjected to the process thusdescribed. It has been ascertained that at the same time a minute portion of the zinc isoxydized at the expense of the water which exists in the saliva.Suppose a pile of plates of zinc and silver, or copper, alternating, tobe separated intocouples by the interposition of moistened cloth ; each plate will on one side touch itspartner, on the other side the moistened cloth. Every couple of zinc and copper separatedby the cloth are situated as the pair above described, when separated by tho tongue, andarc equally capable of giving a discharge which would be sensible to the taste, under thosecircumstances. Tho plates which arc in metallic contact havo no such disposition to discharge,because there is no moisture to act upon them, and no diversity of electrical statecan be excited on account of their great conducting power, which would neutralize anysuch excitement as soon as it could be created. The surfaces separated by the cloth cannotdischarge to each other, because there is no conductor extending from one to the other.But as the whole pile is a conductor of electricity, to dis;chargc every pair entering intoits constituency it is only necessary to touch each end simultaneously with a good conductor—awire, for instance. The whole series will then bo discharged at once, and theenergy of the discharge is proportional to tho number to be thus discharged. There is anuncertainty and obscurity as to tho i^recise rationale of tho effect thus obtained.There isas much difference about this as there is about tho nature of matter. It will not be expedient,therefore, in presenting a popular view, to enter upon that intricate question, andwill be enough to state the laws and facts which are admitted generally by men of science.It is universally admitted that, if each of tho terminal plates, in such a pile or series, havoa platina wire soldered or otherwise well connected with it, the other ends of the wiresextending into some water, this liquid will be decomposed, and a similar decomposition