•« 1 1 Experiments to decompcfe the Muriatic Ai id. 



limitation ; bccaufe, the decifion 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 expedled to be produced, as long as any acid remained undecompofed. But, if water 

 were the origin of this gas, it would ceafe to be evolved, when the whole of the water 

 contained in the gas had been refolved into its conftituent principles. 



Experiments 3 and 4. Into two feparatc tubes, I paffed known quantities of muriatic acid 

 gas. Tlirough the one portion, 200 difcharges were taken ; and through the other, 400. 

 On comparing the quantities of hydrogenous gas produced, it proved to bear exa£i:ly the 

 fame proportion, in each tube, to the gas originally fubjnitted to experiment. Hence it 

 may be Inferred, that the hydrogenous gas, evolved by elc^rifying the muriatic acid, has 

 Its origin, not from the acid, but from the water which is intimately attached to it. The 

 agency of the eleftric fluid appears alfo, from the following experiments, to be exerted, not 

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

 oxygen with muriatic acid. 



Exper. 5. A mixture of common air and muriatic acid gas, in the proportion of 143 of 

 the former to 116 of the latter, was rapidly diminiftied by elcdrical fliocks; 30 of which 

 reduced the whole to in*. The remainder con fifted of muriatic acid and azote gafes, 

 with a fmall proportion of oxygenous gas. The depofit formed on the tube was of the 

 fame kind as before, but much more abundant. 



Exper. 6. The fame appearances were occafioned, much more remarkably, by eleflrify- 

 ing muriatic acid with oxygenous gas : and the contradtion continued, till the mercury 

 rofe fo as to touch the extremity of the platina condudlor. At each explofion, a denfc 

 white cloud was feen in the tube, which foon fettled on its inner furfacc, and was of 

 exaftly the fame chemical compofition as the one already defcribed. Nitrous gas and 

 muriatic gas, when eleftrified together, underwent a fimilar change. 



In order to afcertain whether the mercury by which the gafes were confined, in the 

 above experiments, had any influence on their refults, they were repeated in an inftrument 

 made, purpofely for the occafion, by Mr. Cuthbertfon, of London. It confifted of a glafs 

 tube> ground at each end, with the view of receiving two Hoppers, each perforated with 

 platina wire, which proje£led into the cav>y of the tube. When the (toppers were in 

 their places, the extremities of the wires were at the diftance of about half an inch ; and, 

 by properly difpofing the apparatus, eleftrical fhocks might be paflTed, through any gas or 

 mixture of gafes, with the contadl only of glafs and platina. 



Exper. 7. In this tube I eleftrificd the muriatic acid gas, and then admitted to it an 

 infuGon of litmus. The fudden deftrudlion of its colour evinced the formation of oxy- 

 genated muriatic acid. Not the fmalleft depofit appeared on the tube. 



* This experiment fuggefts an additional reafon, to that already given, for the greater diminution of 

 the firft, than of the fubfequent portions of the muriatic acid gas ; for the former may be prefumed to have 

 keen much roore adulterated than the latter, with the atmofpherical air of the relTcls. 



Experiments 



