656 PHILOSOPHICAL TRANSACTIONS. [ANNO 1600. 



The sulphuric liquor, decanted from the oxalate of mercury, was now added to 

 that with which it was edulcorated, and the whole saturated with carbonate of 

 pot-ash. As effervescence ceased, a cloudiness and precipitation followed; and the 

 precipitate, being collected, washed, and dried, weighed 3.4 gr.: it appeared to be 

 a carbonate of mercury. On evaporating a portion of the saturated sulphuric 

 liquor, I found nothing but sulphate of pot-ash ; nor had it any metallic taste. 

 There then remains, without allowing for the weight of the carbonic acid united 

 to the 3.4 gr., a deficit from the JOOgr. of mercurial powder, of 12.6gr., which 

 I ascribe to the gas separated by the action of the sulphuric acid. To ascertain 

 the quantity, and examine the nature, of the gas so separated, I introduced into a 

 very small tubulated retort, 50 gr. of the mercurial powder, and poured on it 3 

 dr., by measure, of sulphuric acid, diluted with an equal quantity of water, and 

 extricated the gas with the assistance of a gentle heat. I first received it over 

 quicksilver, the surface of which, during the operation, partially covered itself 

 with a little black powder.* 



The gas, by different trials, amounted from 28 to 31 cubical inches; it at first 

 appeared to be nothing but carbonic acid, as it precipitated barytes water, and 

 extinguished a taper, without being itself inflamed, or becoming red. But, on 

 letting up to it liquid caustic ammonia, there was a residue of from 5 to 7 inches 

 of a peculiar inflammable gas, which burnt with a greenish-blue flame. When I 

 made use of the water-tub, I obtained, from the same materials, from 25 to 27 

 inches only of gas, though the average quantity of the peculiar inflammable gas 

 was likewise from 5 to 7 inches; therefore the difference of the aggregate pro- 

 duct, over the 2 fluids, must have arisen from the absorption, by the water, of a 

 part of the carbonic acid in its nascent state. The variation of the quantity of 

 the inflammable gas, when powder from the same parcel is used, seems to depend 

 on the acid being a little more or less dilute. With respect to the nature of the 

 peculiar inflammable gas, it is plain to me, from the reasons I shall immediately 

 adduce, that it is no other than the gas, in a pure state, into which the nitrous 

 etherized gas can be resolved, by treatment with dilute sulphuric acid. 



The Dutch chemists have shown,*}- that the nitrous etherized gas can be re- 

 solved into nitrous gas, by exposure to concentrate sulphuric acid, and that, by 

 using a dilute, instead of a concentrate acid, a gas is obtained which enlarges the 

 flame of a burning taper, so much like the gaseous oxide of azote, that they 

 mistook it for that substance, till they discovered that it was permanent over 

 water, refused to detonate with hydrogen, and that the fallacious appearance was 

 owing to a mixture of nitrous gas with an inflammable gas. The inflammable gas 

 separated from the powder answers to the description of the gas which at first 

 deceived the Dutch chemists; 1st, in being permanent over water; 2dly, refusing 

 to detonate with hydrogen; and, 3dly, having the appearance of the gaseous 



• 



I cannot account for this appearance. f Journal de Physique, p. 250, Oct. 179 4 » — Orig. 



