292 Galvanic Apparatus, Theory of Galvanism, «^c. 



be three hundred times greater than that emitted by two thou- 

 sand pairs. The intensity produced by a single pair, must be 

 two thousand times less than that produced by the great pile, 

 and of course six hundred thousand times less than that produced 

 by a good electrical plate of thirty-two inches. Yet a single pair 

 of about a square foot in area, will certainly deflagrate more wire 

 than a like extent of coated surface charged by such a plate. 

 According to Singer, it re<juires about one hundred and sixty 

 square inches of coated glass, to destroy watch pendulum wire ; 

 a larger wire may be burned off by a galvanic battery of a foot 

 square. But agreeably to the hypothesis in dispute, it compen- 

 sates bv quantity, for the want of intensity. Hence the quantity 

 of fluid in the pair is six hundred thousand times greater, while 

 its intensity is six hundred thousand times less ; and vice versa of 

 the coated surface. Is not this absurd ? What does intensity 

 mean as applied to a fluid ? Is it not expressed by the ratio of 

 quantity, to space ? If there be twice as much electricity within, 

 one cubic inch, as within another, is there not twice the intensity?. 

 But the one acts suddenly, it may be said ; the other slowly. 

 But whence this difference ? They may both haye exactly the 

 same surface to exist in. The same zinc and copper plates may 

 be used for coatings first, and a galvanic pair afterwards. Let it 

 be said, as it may in truth, that the charge is, in the one case, 

 at!:ached to the glass superficies, in the other exists in the pores 

 of the metal. But why dees it avoid these pores in one case and 

 reside in them in the other ? What else resides in the pores of the 

 metal which may be forced out by percussion ? Is it not caloric? 

 Possibly, unless under constraint, or circumstances favourable to 

 a union between this principle and electricity, tht latter cannot 

 enter the metallic pores, beyond a certain degree of saturation ; 

 and hence an electrical charge does not reside in the metallic 

 coatings of a Leyden phial, though it fuses the wire which forms 

 a circuit between them. 



It is admitted that the action of the galvanic fluid, is upon or 

 between atoms ; while mechanical electricity when uncoerced, 

 acts only upon masses. This difference has not been explained 

 unless by my hypothesis, in which caloric, of which the influence 

 is onlv exerted between atoms, is supposed to be a principal agent 

 in galvanism. Nor has any other reason been given that water, 

 which dissipates pure electricity, should cause the galvanic fluid to 

 accumulate. From the prodigious effect which moist air, or a 

 moist surface, has in paralysing the most tf>jient machines, I am 

 led to suppose, that the conducting power of moisture so situated, 

 is greater than that of water under its surface. The power of 

 this fluid to conduct mechanical electricity, is unfairly contrasted 

 with that of a metal, when the former is inclosed in a glass tube, 

 i-he latter bare. Ac- 



