205 GALVANIC AND ELECTRICAL EXPERIMENTS. 



Eight inches of the fame fort of wire were laid in the circuit, 



57 revolutions of the plate caufed the eledlrometer to dif- 



charge the jars which ignited the wire perfediy, as in the 



ninth experiment. Then fix inches of the wire were laid in 



the circuit, and the above nnmber of revolutions caufed the 



difcharge, the wire being deflagerated and fufed into balls 



in the fame manner as in the eighth experiment. 



Dedu(5t)on as to Hence I conclude, that 340 fquare inches of coated glafs 



ei/ftridty l'"a° P^op^rly conftruded, will bear a charge equal to a galvanic 



jar and a pile. battery of 1080 fquare inches of furface. 



Probability that The refult of the above experiments gives me reafon to 



llilrewasSnJr''^'"^' that there is amiftake refpeding the diameter of the 



than ftated. wire ignited by Mr. Wilkinfon's batteries, as mentioned in 



your Journal, Vol. VII. p. 297, to which you refer, becaufe 



to ignite one half inch of fleel wire of one fcventieth of an inch 



in diameter, will require a power fufficient to ignite 120 inches 



of wire -j-i^ part of an inch in diameter, by common ele6lrical 



difcharges, which is a power equal to two of my common 



cleftrical batteries, (fee your Quarto Journal, Vol. II. p. 525.) 



The greateft power of 60 pairs of 6 inches fquare plates 



that ever has been known, was that of igniting 16 inches of 



wire of i-y^ part of an inch in diameter. Mr. Wilkinfon's 



trough of 100 pairs of plates of 4 inches fquare is of much 



lefs furface, and as he fays, it is a lefs favourable fize, from 



which, and from the above experiments, I conclude, that fuch 



a battery has not the power of igniting one half an inch of 



wire of one feventieth of an inch in diameter, unlefs galvanic 



difcharges ad upon metals in feme manner ditTerent to common 



elc-6tfical difcharges, but with which I am unacquainted; 



perhaps Mr, Wilkinfon will be kind enough to clear up this 



remark. 



I am, with due refped, ' 



Dear Sir, Your very humble Servant, 



JOHN CUTHBERTSON, 



Poland Street, Snho, 

 June 19, 1804. 



Chemical 



I 



