108 Hare's J\'ew Galvanic Apparatus, Theory, ^c. 



with the other hypothesis, which supposes it to be electri- 

 city alone. The finest needle is competent to discharge 

 the product of the most powerful machines without detri- 

 ment, if receiv^ed gradually as generated by them. Platina 

 points, as small as those which were melted like wax in my 

 experiments, are used as tips to lightening rods without in- 

 jury, unless in sudden discharges, produced under peculiar 

 circumstances.* 



The following experiment I conceive to be very unfa- 

 vourable to the idea that galvanic ignition arises from a 

 current of electricity. 



A cylinder of lead of about a quarter of an inch diameter, 

 and about two inches long, was reduced to the thickness of 

 a common brass pin for about three quarters of an inch. 

 When one end was connected with one pole of the appara- 

 tus, the other remained suspended by this filament ; yet it 

 was instantaneously fused by contact with the other pole. As 

 all the calorific fluid which acted upon the suspended knob, 

 must have passed through the filament by which it hung, 

 the fusion could not have resulted from a pure electrical 

 current, which would have dispersed the filament ere a 

 mass fifty times larger had been perceptibly affected. Ac- 

 cording to my theory, caloric is not separated from the 

 electricity until 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 deflagrator, I 

 have found a brass knob of about five tenths of an inch in 

 diameter, to burn on the superficies only ; where alone ac- 

 cording to my view, caloric is separated so as to act on the 

 mass. Having, as mentioned in the memoir on my theory 

 of galvanism, found that four galvanic surfaces acted well in 

 one recipient, I was tempted by means of the eighty coil? 

 to extend that construction. It occurred to me that attempts 

 of this kind, had failed from using only one copper for each 

 zinc plate. The zinc had always been permitted to react 

 towards the negative, as well as the positive pole. My coils 

 being surrounded by 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 another. 



' See Adams's Electricily, on points. 



