658 PHILOSOPHICAL TRANSACTIONS. [ANNO 1800. 



alcohol, yield 00 cubical inches only of gas : whereas, without the intervention of 

 mercury, they yield 210 inches. On the whole, I trust it will be thought reason- 

 able to conclude, that the mercurial powder is composed of the nitrous etherized 

 gas, and of oxalate of mercury with excess of oxygen. 1st. Because the nitric acid 

 converts the mercurial powder entirely into nitrous gas, carbonic acid gas, acetous 

 acid and nitrate of mercury. 2dly. Because the dilute sulphuric acid resolves it into 

 an uninflammable oxalate of mercury, and separates from it a gas resembling that 

 into which the same acid resolves the nitrous etherized gas. 3dly. Because an un- 

 inflammable oxalate is also left, after the muriatic acid has converted a part of it into 

 sublimate. 4thly. Because it cannot be formed by boiling nitrate of mercury in 

 dulcified spirit of nitre ; though a very inflammable oxalate is by this means pro- 

 duced. 5thly. Because the difference of the product of gas, from the same mea- 

 sures of alcohol and nitrous acid, with and without mercury in solution, is not 

 trifling ; and, 6thly. Because nitrogen gas was generated during its combustion in 

 the glass globe. 



Should my conclusions be thought warranted by the reasons I have adduced, the 

 theory of the combustion of the mercurial powder will be obvious to every chemist. 

 The hydrogen of the oxalic acid, and of the etherized gas, is first united to the 

 oxygen of the oxalate, forming water ;* the carbon is saturated with oxygen, form- 

 ing carbonic acid gas ; and a part, if not the whole of the nitrogen of the etherized 

 gas, is separated in the state of nitrogen gas ; both which last gases, it may be re- 

 collected, were after the explosion present in the glass globe. The mercury is re- 

 vived, and I presume thrown into vapour ; as may well be imagined, from the im- 

 mense quantity of caloric extricated, by adding concentrate sulphuric acid to the 

 mercurial powder. I will not venture to state with accuracy, in what proportions 

 its constituent principles are combined. The affinities I have brought into play are 

 complicated, and the constitution of the substances I have to deal with not fully 

 known. But, to make round numbers, I will resume the statement, that 100 gr. 

 of the mercurial powder lost 16 gr. of its original weight, by treatment with dilute 

 sulphuric acid : 84 gr. of mercurial oxalate, mixed with a few minute globules of 

 quicksilver, remained undissolved in the acid. The sulphuric liquor was saturated 

 with carbonate of potash, and yielded 3.4 gr. of carbonate of mercury. If 1.4 gr. 

 should be thought a proper allowance for the weight of carbonic acid in the 3.4 gr. 

 I will make that deduction, and add the remaining 2 gr. to the 84 gr. of mercurial 



oxalate and quicksilver ; I shall then have, of oxalate and mercury 86 gr. 



and a deficit, to be ascribed to the nitrous etherized gas and excess of oxygen 14 



100 

 It may perhaps be proper to proceed still further, and recur to the 48.5 gr. sepa- 

 rated by nitrate of lime from the 84 gr. of mercurial oxalate and globules of quick- 



* Drops of water were observed on the internal surface of the globe, the day after several explosions 

 had been produced in its centre.— Orig. 



