104 Dr. Hart^s Defiagrator and Calorimoior. 



power of the latter instrument was found to be completely 

 destroyed — a similar result was obtained by a battery con- 

 sisting of fifty triads of plates two inches square, each 

 zinc surface being coated by a copper plate after the man- 

 ner of Dr. WoUaston — the object of this arrangement, was, 

 to ascertain, whether a battery, in which the arrangement 

 of metals was similar, to that in the defiagrator, would pro- 

 duce a result in any respect ditTerent from that of the com- 

 mon battery ; the effect however was precisely the same. 

 In most of the experiments the connexion of the poles was 

 tjccasionally reversed. This circumstance however made 

 no difference in the result; a feeble spark was obtained as 

 before. Every thing tended to countenance the opinion 

 that the interposition of the common galvanic battery opera-^ 

 ted simply as an impediment — that it was completely inert in 

 relation to the dejlagrator^ and the dejlagrator in relation to it, 

 that thepower of neither icould pass through the other, and 

 consequently that each was to be regarded^ with respect to the 

 t^ther^ simply as so much interposed matter ^ constituting a con- 

 ductor more or less, imperfect. To bring this conjecture to a 

 decision, the number of interposed plates Was constantly di- 

 minished, until the connexion was formed by no more than 

 twenty pairs. In this state of things, the power of the de- 

 fiagrator passed freely, although somewhat diminished. 

 The connexion was now formed with smaller and smaller 

 numbers of pairs ; the activity of the defiagrator in the 

 mean time rapidly increased, until the moment, when only 

 one pair was employed (this pair being, however, like the 

 Others, immersed in an acid fluid,*) then there was no per- 

 ceptible impediment, and the effect was as brilliant as when 

 nothing was interposed. 



I have thought these curious facts worthy of being pre- 

 ierved, and I have addressed them to you with the hope 

 that you will be able to throw some light upon this singular 

 anomaly, which to me appears to be incapable of explana- 

 tion, in consistency with the received theories of galvanism- 

 iloping that you will, through the medium of this journalt 

 ;fevour the public with your views upon this subject. 



I remain with very great respect, 



Your friend and servant, 



B. SILLIMAN. 



* When this one pair was surrounded by air alone the power of the deSa- 

 »rator passed freely as might hare been expected* 



