concerned in the Phenomena of ordinary Electricity, fyc. 451 



tensity of a Leyclen battery will kill an animal ; but reconvert tbat 

 intensity into quantity by causing the animal to draw off the 

 charge by a sharp point, and no sensation will be experienced. 

 If then intensity be thus proved to be the effective condition for 

 giving the shock and spai'k, how is the fact reconcileable with 

 the violent one which may be taken from a voltaic series in which 

 the electric intensity is of the most feeble character ? 



The views which I suggested at the commencement of this 

 essay, relative to the compound nature of the electric fluid, and 

 the variable ratio of its constituent elements, would, in my 

 opinion, accord better with the circumstances of the charge of a 

 Leyden battery, by a voltaic series, than the assumed agency of 

 quantity of electricity. Were I to offer an explanation, it would 

 be based on the following notions. 



That ordinary chemical agency developes electricity has long 

 been known ; combustion, evaporation, effervescence, and some 

 other processes evolve this fluid. The solution of a metal in an 

 acid is a case in point, and some instances have been supplied 

 by Lavoisier and La Place* In one experiment some iron-filings 

 were introduced into a wide-mouthed bottle, and sulphuric acid 

 diluted with three parts of water was poured on. A brisk dis- 

 engagement of hydrogen ensued, and in a few minutes the con- 

 denser of Volta became so highly charged with electricity that it 

 afforded a brilliant spark. 



Electricity of this kind has been always recognised as identical 

 with common frictional electricity. In a voltaic series, a number 

 of pieces of metal are subjected to the chemical action of an acid 

 or some other menstruum ; it is therefore quite an analogical 

 fact that electricity of the ordinary kind is developed ; but when 

 one state of electricity is produced in one situation, the opposite 

 state must exist somewhere near it. It is so in the voltaic series ; 

 the opposite poles are brought into opposite states and so main- 

 tained by some agency which I do not profess to comprehend, 

 and which, notwithstanding the explanations hazarded by philo- 

 sophers, seems as little understood as ever. In this state of 

 electrical tension the poles remain, while the balance between di- 

 spersion and generation is preserved ; such is the state of the open 

 circuit. 



But when the circuit is closed by connecting the poles, the 

 case is very much altered ; the two opposite states of electricity 

 neutralize and destroy each other ; hence all symptoms of free 

 electricity cease, and a new set of phenomena are produced. A 

 new mode of generation of electricity also seems to come into 

 operation, constituting voltaic excitement ; an electric fluid, which 

 possesses more intense properties, is developed by the altered cir- 

 * Mtmoires de VAcademie Roy rile des Sciences, 1781, p. 293. 



2G2 



