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

APPENDIX. 449superficially from ono to tlio other, parallel to the axis of the includediron, instead of pursuing the circuitous channel afforded by the helix withthe intensity requisite to the polarization of the ponderable atoms.The extreme Dircrsttjj, ast rcsj)ccts strikiiKj Distance, hctween the directEffects of Frictional Electricity and those directly arisinj from GalvanicReaction.46. The intensity of the excitement produced by different electricalmachines is estimated to be as the relative lengths of the sparks whichproceed from their prime conductors respectively. Admitting that therelative intensity were merely as the length of the spark, not as the squareof that length, still there would be an infinite difference between the intensityof a voltaic scries and that of electrical machines, if measured bythis test. Large electrical machines, like that at the Polytechnic Institution,London, give sparks at twenty inches and more ; while, agreeably toGassiott's experiments, a Grovcs's battery of 320 pairs, in full power, wouldnot, before contact, give a spark at any distance, however minute. Itfollows, that, as respects the species of intensity which is indicated bylength of sparks, or striking distance, the diflFerence between the electricityof the most powerful voltaic series and electrical machines is not to berepresented by any degree of disjmrify; it proves that galvanism properand electricity proper arc heterogeneous.47. It should be recollected that the intensity of galvanic action in aseries of 320 pairs, excepting the loss from conduction, would be to thatof one pair as 320 to 1.* Of course, the striking distance of a batteryof one pair would be 320 times less than nothing : 320 below zero.48. We may infer that the undulatory polarization of ethereo-ponderablematter is the primary, direct, and characteristic effectof galvanic excitement,in its more energetic modifications. Yet, that by peculiar carein securing insulation, as in the water batteries of Cross and Gassiott,ethereal undulations may be produced, with the consequent accumulationof ethereal polarity requisite to give sparks before contact, agreeably to theexperiments of those ingenious philosophers.49. Hence it may be presumed that, during intense ethereo-ponderablepolarization, superficial ethereal waves may always be a secondary effect,although the conducting power of the reagents, requisite to the constitutionof powerful galvanic batteries, is inconsistent with that accumulationof ethereal polarity which constitutes a statical spark-giving charge.50. As all the members forming a voltaic series have to be discharged* According to Colomb's experiments, electrical attraction and repulsion arc invcrselj'as the squares of the distances: ought not the inductive power of statical charges whichis produced by those forces, and which precedes and determines the length of the resultingspark, to obey the same law ?If this calculation be correct, the intensity must be as the squares of the striking distances,as indicated by sparks.It may be urged that the striking distances, as measured by the length of the sparks,is in the compound ratio of the quantity and intensity. As to the quantity, however,galvanic sources have always been treated as pre-eminent in efficacy, so that on that sidethere could be no disparity. Moreover, I have found, that in galvanic apparatus of onlyone, or even of two pairs, as in the calorimotors, the intensity lessened as the surfaceswere enlarged. IJy a pair of fifty square feet of zinc surface, a white heat could not beproduced in a wire of any size, however small. The calorific power of such apparatuscan only be made evident by the production of a comparatively very low temperature, ina comparatively very large mass.29