372 Observations and Experiments 



genated muriatic acid gas. The apparatus was again emptiftil, 

 and filled with the acid gas until we concluded that it could 

 contain nothing but oxygenated muriatic acid gas; when we ob- 

 served the temperature of the interna! air bv means of a thermo- 

 meter which was immersed in it. Adapting the siphon to the 

 stopcock, we observed the stationary point of the mercury in its 

 two arms. Lowering the platina cup containing the hydroge- 

 nated sulphur by means of the screw, we noticed in an hour the 

 following appearances, having the stopcock shut. The tempera- 

 ture of the inside of the vessel rather increased, and afterwards 

 returned to its original state. The gas confined in the vessel 

 had no colour, although at the ccmmcneement of the experiment 

 it vvas greenish yellow. The hydrogenated sulphur from a fluid 

 became a little pasty, from a perfect transparency to a somewhat 

 milky appearance. The stopcock being opened, the mercury in 

 the siphon evinced an increase of volume in the air of the re- 

 ceiver, the barometer indicating no diminution of pressure. Af- 

 ter another hour we found the same things, only the increase of 

 volume of the internal air was greater. At the end of a third hour 

 we observed no change. We then resolved to try a higher tem- 

 perature in the balloon glass, exposing it for a few moments to 

 a bar of iron heated, but not shining. With this heat the paste 

 in which the hydrogenated sulphur had been converted, became 

 dry, and the sulphur remained in the cup in a white powder ; 

 some of this powder was sublimed on many parts of the sides of 

 the vessel ; this happened without the mass being melted, and it 

 is evident that it was a sublimate from undecomposed hydroge- 

 nated sulphur, which abandoning its hydrogen had left this pow- 

 der adhering to the sides. We left all to repose a little, and 

 when it resumed its original temperature we observed a new in- 

 crease of air. At this period we introduced a small quantity of 

 oxygenated muriatic acid gas, the driest and purest possible. 

 This was effected by means of a bladder, which threw into the 

 apparatus oxygenated muriatic acid gas without permitting the 

 condensed air to escape. After a few minutes the stopcock was 

 opened, to see if there vvas any increase in the air, as it seemed 

 there should be in proportion to the quantity of gas added; but 

 instead of this we found a diminution, and the temperature of the 

 gas as much raised : restored to its original degree, we added 

 some new oxygenated muriatic acid gas, and after a certain re- 

 pose found a diminution of air, an increase of temperature, and 

 the white powder of sulphur had assumed its ordinary yellow co- 

 lour. After a little repose we added more oxygenated muriatic 

 gas, but we then observed an increase of the air and no change 

 of colour. 



We deemed it suj>erfluous to continue longer these experi- 

 ments, 



