286 PHILOSOPHICAL TRANSACTIONS. [aNNO 1787. 



XXX. On Hepatic u4irs or Gases; by Mons. Hassenfratz. From the French. 



p. 305. 



Having made some experiments on the different species of hepar sulphuris, in 

 1785, Mons. H. resolved to investigate the nature of the inflammable hepatic 

 air, which is let loose when those hepars are decompounded by the nitrous 

 acid. The sulphur which is seen to be precipitated after every combustion of 

 inflammable hepatic gas, led him to believe that this substance (viz. sulphur) 

 might be one of its constituent parts; but it taught him nothing more; and 

 this was almost the only experiment which had at that time been made relative to 

 its analysis. He therefore determined to have recourse to synthesis, and the 

 more so, as he knew that M. Monges, by causing some fixed air to pass over 

 sulphur in fusion, had obtained, as the result, fixed air which had a sulphureous 

 smell, and which actually held some sulphur in solution. Mr. H. repeated this 

 experiment, and he moreover instituted the following: 



He first caused some fixed air to pass over sulphur in fusion, whereby he ob- 

 tained a sulphureous fixed air, which threw down a precipitate from lime-water, 

 uniting with the lime so as to form a [mild] calcareous earth, and disengaging 

 the sulphur, part of which swam on the surface of the water, and part settled at 

 the bottom. He made a similar experiment with nitrous gas, and obtained a sul- 

 phureous nitrous gas, which, during its combination with vital air [oxygen gas] 

 so as to form nitrous acid, let go the sulphur. 



Azotic gas [la mofete atmospherique] yielded, by a similar treatment, a sul- 

 phureous azotic gas, which, after it had stood some time over water, deposited 

 its sulphur. 



By the same treatment vital air [oxygen gas] was converted into sulphureous 

 vital air, mixed with some volatile sulphureous acid, which the water absorbed. 

 Nitrous gas being mixed with this sulphureous vital air, a redness ensued, together 

 with a disengagement of sulphur. Also, when the sulphureous vital air was 

 detonated with inflammable air, sulphur was precipitated. 



Atmospheric air gave nearly the same result as vital air, except that the ob- 

 tained air (as might easily be inferred from the previous experiments) was a 

 mixture of sulphureous vital air and sulphureous azotic gas [mofete sulfureuse.] 

 When nitrous gas was combined with this vital air* or when it was detonated 

 with inflammable air, in both cases a precipitation of sulphur took place. 



Lastly, when inflammable gas was made to pass over sulphur in fusion, a 

 sulphureous inflammable air was obtained, exactly resembling the hepatic gas 

 which is procured by pouring nitrous acid on liver of sulphur. Hence it may 

 be inferred, that the inflammable air which is obtained by pouring nitrous acid 



* That is, with the vital air of the atmospheric air so treated. 



