on the Muriatic and Oxymuriatic Acids. 341 



ing attained, we only, by continuing the electrization, 

 work in a circle. 



It may now be inquired, what is the limitation to the 

 action of electricity on muriatic acid gas which is con- 

 fined over mercury? In this case, it was suggested to me 

 bv Mr. Dal ton, who favoured me with his presence at most 

 of the experiuients, that the evolved hydrogen might pos- 

 sibly in some way prevent the effect from being carried 

 bevond a certain amount. Availing mvself of this hint, 

 I mixed SO measures of hydrogen gas with 400 of muriatic 

 acid gas in its ordinary stare, and passed fjOO discharges 

 through the mixture. It soon became evident that the ad- 

 dition of the hydrogen had produced an important dif- 

 ference in the results of the experiment; for the surface of 

 the mercury, over which the gas rested, was untarnished 

 after some hundred explosions, and was scarcely changed 

 at the close of the process. When the res_iduary gas, the 

 volume of which remained unaltered, was analysed, it was 

 found to contain the same quantity of muriatic gas as at 

 the outset, and neither more nor less hydrogen. To ex- 

 plain the event of this modification of the experiment, on 

 the old theory, we may suppose that by the action of 

 electricity a particle of water is decomposed, and that 

 the atom of oxygen, forcibly repelled from that of hy- 

 drogen with which it was associated, finds another atom 

 of hydrogen uninfluenced bv the electric fluid, and within 

 the sphere of its attraction. With this it unites, and recom- 

 poses water. On the theory of Sir H. Davy, the same series 

 of decompositions and recombinations may be assumed to 

 take place between the oxymuriatic acid and hydrogen*. 



It still, however, remains to be determined, what is the 

 eource of the hydrogen gas, which, in a limited proportion, 

 is always evolved by the electrization of muriatic acid ? 

 Does it result from the decomposition of water, existing as 

 an element of the gas ; or from the disunion of the oxy- 

 muriatic acid and hydrogen, which, according to Sir H. 

 Davy's view, compose nmrialic acid ? The limitation to 



• I am aware that there !s an apparent inconsistency in supposing changef 

 of precisely an opposite kind to be eflectcd by the same means. But in- 

 utar.cci arc not wanting, in which the very same elements arc brought into 

 combination by electric discharges, and arc again disunited by the same 

 agency. As examples, it may be sufficient at present to state, tliat nitrous 

 acid and nitrous <;as are geiierateil by tlie action of ihc electric spark on 

 mixtures ot tpxy;;e.i and ni;rL',;en giscs; and that, by the same power, they 

 are aj^ain resolved into their cleiiiciits. If this were the proper place, it 

 migh;, I think, be rendered probable liy several arguments, that electricity, 

 wlieu tlms applied, acts rather by mei.haiiic.il collision, th«u by inducing a 

 change iu tiic electrical states of the elements of bodies. 



Y 3 its 



