642 PHILOSOPHICAL TRANSACTIONS. [ANNO 1800. 



great exactness. The action of the electric fluid itself, as a decomponent, is ex- 

 tremely powerful; for it is capable of separating from each other, the constituent 

 parts of water, of the nitric and sulphuric acids, of the volatile alkali, of nitrous 

 gas, and of several other bodies, whose components are strongly united. I began 

 therefore with examining attentively the effects of the electric fluid on the muriatic 

 acid gas, without admixture*. 



§ J . On the Effects of Electricity on Muriatic Acid Gas. 



When strong electrical shocks were passed through a portion of muriatic acid 

 gas, confined in a glass tube over mercury, the following appearances took place. 

 The bulk of the gas, after 20 or 30 shocks, was considerably diminished; and a 

 white deposit appeared on the inner surface of the tube, which considerably obscured 

 its transparency. In some instances, both the contraction and deposit were much 

 more remarkable than in others. The gas which issued from muriate of soda, 

 soon after the affusion of sulphuric acid, and while the charge was yet warm, ex- 

 hibited these appearances in an eminent degree. Of this gas, 307 measures were 

 reduced, by 20 shocks, to 227, or were contracted nearly \. Gas from the same 

 materials, after they had continued working for some hours, was diminished, by 

 similar treatment, only about a 12th. These effects therefore it seemed probable 

 depended in some measure on the presence of moisture; and I accordingly found 

 that muriatic acid gas, after more than a week's exposure to muriate of lime, 

 brought into contact with it immediately after cooling from a state of fusion, was 

 scarcely -diminished at all; and that the deposit, though it still occurred, was less 

 copious in quantity. This deposit was not, like corrosive sublimate, soluble in 

 water; but had every property of the less saturated salt, calomel. The mercury 

 by which the muriatic acid was confined, was therefore evidently oxidated; and to 

 the combination of a part of the gas with the oxide thus produced, the diminution 

 of bulk was doubtless to be ascribed. But it was uncertain from whence this 

 oxygen was derived. It might either result from the decomposition of the acid 

 gas, or of the water chemically combined with it. The following experiments 

 were therefore made, to determine this point. 



Exper. 1. Through 1457 measures of muriatic acid gas, 300 electrical shocks 

 were passed. There remained, after the admission of water, 100 measures of 

 permanent gas, or not quite 7 from each 100 of the original gas, which on trial, 

 appeared to be purely hydrogenous. — Exper. 2. Of the gas, dried by muriate of 

 lime, 176 measures received 120 shocks. The residue of hydrogenous gas amounted 

 to 1 1 measures, or rather more than 6 per cent. 



These experiments, and other similar ones, made on comparative portions of 



* The gases submitted to the action of electricity, in the following experiments, were confined in 

 straight glass tubes of various diameters, armed at the sealed end with a conductor of gold, or platina, 

 but generally of the latter metal. The shocks were as strong as could be given without breaking the 

 tubes, which, notwithstanding every precaution, were often shaitered by the force of the explosion. 

 Each measure of gas is equal to the bulk occupied by 1 gr. of mercury. — Orig. 



