Galvanic Apparatus, Theory of Galvanism, &c. 2S7 



circumstances very much favour a disunion, as on the passage of 

 the compound fluid through charcoal, the air, or a vacuum. 

 In operating with the dellagrator, I have found a hrass knob of 

 about five tenths of an inch in diameter, to burn on the super- 

 ficies only; where alone, according to niv view,cah)ric is separated 

 so as to act on the mass. Having, as mentioned in the memoir 

 on my theory of galvanism, found tiiat four galvanic surfaces acted 

 v/ell in one recipient, I was tempted by means of the eighty coils 

 to extend that construction. It occurred to me that attempts of 

 this kind had failed from using only one copper for each zinc 

 phite. The zinc had always been permitted to react towards 

 the negative as well as the positive pole. My coils being sur- 

 rounded bv copper, it seemed probable, that, if electro- caloric 

 were, as I had suggested, carried forward by circulation arising 

 from galvanic polarity, this might act within the interior of the 

 coils, yet not be exerted between one coil and anotlier. 



I had accordingly a trough constructed with a partition along 

 the middle, so as to receive forty coils on one side, and a like 

 number on the other. This apparatus when in operation excited 

 a sensation scarcely tolerable in the backs of the hands. Inter- 

 posed charcoal was not ignited as easilv-ss before ; but a most 

 intense ignition took place on bringing a metallic point con- 

 nected with one pole of the series, into contact with a piece of 

 charcoal fastened to the other. It did not take place, however, so 

 speedily as when glasses were used ; but soon after the ignition 

 was effected it became even more powerful tlian before. A c\v 

 lindcr of platina nearly a quarter of an inch in diameter, tapering 

 a little at the end, was fused, and burned so as to sjjarkle to a 

 cou'iiderable distance around, and fall in drops. A ball of brass 

 <jf al)out half an iucli diameter was seen to burn on its surface 

 with a green flame. Tin foil, or tinsel rolled up into large coils 

 of about three quarters of an inch thick, were rapidly destroyed, 

 as was a wire of jdatinH of No. 1(5. Flatina wires in connexion 

 with the poles were brought into contact with sulphuric acid ; 

 there was an appearance of lively ignition, but strongest on the 

 positive side. Excepting in its power of permeating charcoal, 

 the galvanic fluid seemed to be extricated with as nnith force as 

 when each coil was in a distinct glass. Apprehending tiiat the 

 j)artition in the trough did not sufliciontiv insulate the poles from 

 each other, as they were but a few inches apart, moisture or moist- 

 ened wood intervening, 1 had two trouglis made, each to hold 

 forty pairs, and took care that there should l)e a dry space abo\it 

 four inches broad between them. Tjiey were first filled with pure 

 river water, there ijeing no saline nor acid matter to influence 

 the plates, unless the very minute (piantitv which might have re- 

 uuiiued on them from former immersions. Yet tiie sensation pro- 



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