ZT4 Experhncnts to iecompoje the Muriatic Acict, 

 its' moifture was removed by expofure to muriat of lime. lu 

 order, if poffible, to procure llie gas perfc(ftly dry, another 

 mode of preparing jt was rcforted to. Alum and common 

 fait were firll well calcined, feparately, to expel their water 

 of crvftallifation, and, being tl-.en mixed, were diftUled to- 

 gether in an earthen retort. The gas proceeding from thefe. 

 materials was received over dry mercurv ; but, though only 

 the laft portion that came over was rcfervcd for experiment, 

 it ftill, after the ufual electritauon;, afiurded a produft of hy- 

 drogenous gas. 



In the courfe of the preceding experiments, I obferved 

 that the diminution of the mur-alic acid gas ftoppcd always 

 at a certain point, beyond which it could not be carried by 

 continuing the fliocks. Gas alfo, which had been thus 

 treated, when transferred to another tube, and again elec- 

 tritied, did not exhibit any further depolit. It became in- 

 tercfting, therefore, to know whether the produftion of hy- 

 drosenous o-as had a {imilar limitation : becaufe the dccifion 



DO 



of this queftion would go far towards afcertaining its fource. 

 If the evolved hydrogenous gas arofe from the decompofition 

 of the acid, it might be expected to be produced as long as 

 any acid remained undecompofed. But if water were the 

 origin of this gas, it would ccafc to be evolved, when the 

 whole of the water contained in the gas had been refolved 

 into its conllituent principles. 



Experhncnls 3 and 4. Into two feparate tubes I paffed 

 known quantities of muriatic acid gas. Through the one 

 portion 200 difcharges were taken, and through the other 

 400. On comparing the quantities of hydrogenous gas pro- 

 duced, it proved to bear exactly the fame proportion, in each 

 tube, to the gas originally fubmitted to experiment. Hence 

 it may be inffvrcd, that the hydrogenous gas, evolved by 

 eleftrifying the muriatic acid, has its origin, not from the 

 acid, but from the v.ater which is intimately attached to it. 

 The agencv of the c1e6l.ric fluid appears alfo, from the follow- 

 ing experiments, to be exerted, not only in difuniling the 

 elements of water, but in promoting the union of the evolved 

 fcxygcn with muriatic acid. 



flxper. ^. A mixture cf commou air and muriatic acid 



9 £'''■> 



