84 Galvanism compared with Electricity < 



laid in the circuit, the same number of revolutions caus'ed 

 the discharge, and the wire was deflagrated and fused into* 

 balls in the same manner as in the 8th experiment. Hence 

 I conclude, that 340 square inches of coated glass, properly 

 constructed, will l>ear a charge equal to a galvanic battery 

 of 1080 square inches surface. 



I compared the above experiments with others gone 

 before, particularly Mr. Wilkinson's, in Nicholson's Jour- 

 nal, vol. vii. p.- 297* wherein he says that one trough of 10O 

 pairs of plates ignited one half- inch of wire of one-seven- 

 teenth of an inch in diameter* If this is not a mistake (as 

 I am inclined to think), it is well worthy of notice; because, 

 to ignite one half-inch of steel-wire of the above diameter 

 would require a power sufficient to ignite 120 inches of wire 

 of 7375th part of an inch in diameter by common electrical 

 discharges, which is a power equal to two of mv common 

 electrical batteries. See Nicholson's- 4to Journal, vol. 

 p. 525. 



The greatest power of CO pairs of 6-inch square plates 

 that has ever been hitherto known, is that of igniting \(y 

 inches of wire ofV^th part of an inch in diameter. Mr. Wil- 

 kinson's trough of 100 pairs of plates of 4 inches square is 

 of much less surface, and, as he says, it is a less favour- 

 able size; from which, and from the above experiments, I 

 conclude, that such a battery has not the power of igniting 

 one half-inch of wire of one-seventeenth of an inch in dia- 

 meter, unless galvanic discharges act upon metals in some 

 manner different from common electrical discharges, but with 

 which I am unacquainted: perhaps Mr. Wilkinson will be 

 kind enough to clear up this remark. 



From the experiments, mentioned in the above letter, and 

 others since made with the same result, I concluded, that 

 double quantities of galvanic fluid only burn double lengths 

 of wire ; but on examining some of my notes of experiments,/ 

 I find that, on the 6th of June 1803, I had made a Volta's^ 

 pile of \Q pairs of plates of 10 inches diameter, 8 of 

 which laid upon each other in the usual manner, with cloths' 

 wetted with diluted muriatic acid, burned one half-inch of 

 \vire0f-r-i\3th part of an inch in diameter } and when the other 

 8 were added they burned 4 inches of the same wire. This" 

 was repeated witli the 8 in pairs with the same result, ^with 

 respect to burning of metals ; but it gave strong and loud 

 sparks from metal to metal, sufficient to be heard at 300 

 yards distance; which result, I believe, has never been ob- 

 tained from troughs, to be heard at any distance. , For thi* 

 3 last 



