44 MURIATIC AND OXYMURIATIC ACIDS* 



has attracted moisture, either from the atmosphere or the 

 mercury, and is then owing to a condensation of a part of the 

 gas. 

 Muriatic acid Essentially, the changes produced by electrifying muriatic 



Srr when***" ac ' ,J over mercur y are tnose which I have stated ; viz. a con- 

 tler'tiified, traction of the volume of the gas, the formation of muriate of 

 w^rfmulv- mercur .v (calomel,) and the evolution of hydrogen. Recent 

 cirogen ; hut experiments, also, have confirmed the accuracy of the obser- 



10 a certain ex- vation*, that when a certain effect has been produced by elec- 

 tee only. .. . . , .,, .. , - . , 



tricity, nothing is gained by continuing the process j for neither 



is more hydrogen evolved, nor can the contraction of bulk be 



carried any farther. 



Muriatic acrd I have lately applied, to experiments on muriatic acid, an 



jjas-, electrified ...» , ■> - • t. . ' » 



in a vessel, apparatus which 1 used advantageously for the analysis of 

 without the ammoniaf . It consists of a spherical glass vessel, into which 



T2r£!3CnCC of 



any other are hermetically sealed two small tubes containing platina 

 *»"d» wires, the points of which approach within the striking dis- 



tance. To the globular part is attached a neck, which may 

 be closed, as occasion requires, either by a glass stopper, or by 

 a metal cap and stop-cock. Into a vessel of this kind I intro- 

 duced A\ cubic inches of muriatic acid gas, and passed through 

 whin™ ]t 300 ° dischar g es from a Leyden jar ; at the close of the 

 process, no traces of moisture could be perceived on th& 

 inner surface of the vessel ; nor could I discover, on opening 

 hut when the the stopper, that any change of bulk had taken place. After 

 sas was ah- absorbing the unchanged muriatic acid gas by a small quan- 



stracted, the tity of water, a volume of gas remained, in which there were 



small residue , * - , . 



was oxymuria- P resent 10 ° measures (each equal to one gram of mercury) 



tic acid gas of oxymuriatic acid gas, and 140 measures of hydrogen. Two 

 i) rogen. cauges m igh^ perhaps, contribute to diminish, in some degree, 

 the proportion of the former. Jt was difficult to exclude from 

 the apparatus, on admitting the muriatic acid gas into it, two 

 or three very minute globules of mercury, which became tar- 

 nished during the experiment, exactly as they would have been 

 by oxymuriatic acid ; and a small portion of the latter gas waa 

 probably also taken up by the water employed to absorb the 

 muriatic acid. 



Repetition on With the intention of giving greater effect to the electricity, 



* Phil. Trans. 1800. p. 192. i Ibid, 1809. 



I re* 



