1S4 Experiments to determine the [Sept. 



In two experiments, of March 15 and 22, following, I obtained 

 results us singular as any that had before occurred. This extraordi- 

 nary difference I conceive to be attributable to the state of the sul- 

 phureted hydrogen, which was here obtained from the sulphuret of 

 iron by sulphuric acid : in such cases the gas is generally contami- 

 nated with variable proportions of hydrogen. This gas and aqueous 

 vapour were together sent through the ignited copper tube ; the 

 product that came over blackened the inner surface of the glass 

 tube leading to the trough, as well as the inner surface of the 

 receivers in which it was collected. It did not possess the least 

 odour. The gas was found to consist per cent, of 73 volumes of 

 hydrogen and 27 residue. It contained no oxvgcn ; examined 

 W Hope's eudiometer, sulphuret of potash absorbed about 6 per 

 cent., unci a solution cf pure potash produced no change of volume 

 in the gas. I endeavoured to ascertain its specific gravity ; but 

 Unfortunately did not possess a sufficient quantity to fill the flask, as 

 a quantity of water rose with the gas into the previously exhausted 

 vessel. Making deductions, however, for the weight and measure 

 of the water, as well as of the hydrogen, the residual portion of 

 the gas was found to weigh 8 grains. We hence obtain for the 

 weight of 100 cub. inches 'JG grains. This must, however, be 

 considered only as an approximation ; for I am inclined to believe 

 that a trifle too little has been calculated as the weight of the water. 

 The gas possesses all the appearance of sulphureted azote ; but we 

 have never before known such a compound. Concluding it so, and 

 supposing it to be composed of an atom of sulphur and an atom of 

 azote, we calculate for the weight of 100 cubical inches 64'44 

 grains, an approximation not very distant. 1 have much to regret 

 that an accident deprived me of the power of making more extended 

 examinations on this gaseous product. 



The last experiment that 1 had an opportunity of making was on 

 March ()*, 1812: and it will be found to have led to results still 

 more singular, and to consequences more important. Sulphureted 

 hydrogen gas obtained from the sulphuret of iron by dilute sul- 

 phuric acid, and vapour from boiling water, were sent, as before, 

 through the copper tube, previously freed as much as possible from 

 atmospheric air. The first portion of gas that came over was re- 

 moved, in order to be certain that atmospheric air was excluded 

 from the apparatus. The remaining products were set aside for 

 examination. The gas did not possess the least smell. When tried 

 in Hope's eudiometer with hydrosulphuret of potash, four measures 

 per cent, were absorbed, which may be considered as oxygen. 

 Detonated in Volta's eudiometer with oxygen, the mean of two 

 trials indicated the presence of 52 per cent of hydrogen. The 

 residue answered to no test. The specific gravity of the gas I 

 found to be 0-4782 ; 100 cubical inches will hence weigh 1482 

 grains. Now the gas was found to consist of 



