Experiments ta decompofe the Muri tic Add. 213 



nat of foda, foon after the afifufion cf fiilphuric acid, and 

 while the charge was yet warm, exhibiled thefe appearances. 

 in an eminent degree. Of this gas, 307 nieafures were re- 

 duced, by 20 fliocks, to 237, or were contracled nearly one- 

 fourth. Gas from the fame materials, after they had con- 

 tinued working for fome hours, was diininiflied, by fimilar 

 treatment, only about a twelfth. ThcTe ellecls, therefore, it 

 feemed probable, depended in fome meafure on the prefence 

 of moifture; and I accordingly found, that muriatic acid 

 gas, after more than a week's expofure to miu'iat of lime, 

 brought into contavft with it immediately after cooling from, 

 a ftate of fiifion, was fcarcelv diminillied at all ; and that the 

 depofit, though it ftill occurred, w-as lefs copious in quantity. 

 This depofit was not, like corrofive fublimat, foluble ia 

 •water; but had every property of the lefs faturated fait, 

 calomel. 



The mercury by which the muriatic acid was confined 

 was therefore evidently oxvdated ; and to the combinatioa 

 of a part of the gas with the oxyd thus produced, the dimi- 

 nution of bulk was doiibtlefs to be afccibed. But it was un- 

 certain from whence this oxygen was derived. It might 

 either refult from the decompofition of the acid gas, or of 

 the water chemically combined with it. The following er- 

 periments were therefore made to determine this point. 



Experiment i. Through 1457 nieafures of muriatic acid 

 gas 300 eleftrical fliocks were pafled. There remainedj 

 after the admiihon of water, 100 meafiires of permanent 

 gas, (or not quite feven from each hundred of the original 

 gas,) which, on trial, appeared to be purely hydrogenous. 



Exper. 2. Of the gas dried by miiriat of lime, 176 mea- 

 fares received 120 fliocks. The refidue of hydrogenous gas 

 amounted to 11 meafiucs, or rather more than 6 per cent. 



Thefe experiments, and other fimilar ones, made on com- 

 parative portions of muriatic acid gas in its recent fl:ate, and 

 after expofure to muriat of lime, convinced me that it was 

 impoflible, by this method, wholly to deprive the muriatic 

 gas of water. The recent gas, however, when eleftrified in 

 fmaller quantity than in experiment i, gave a larger propor- 

 tion of hydrogenous gas ; which fljows, that fome portion of 



its 



