1823.] of several Gases into Liquids. 91 



and pushed in, and upon that were put fragments of sulphuret 

 of iron, until the tube was nearly full. In this way action was 

 prevented until the tube was sealed. If it once commences, it 

 is almost impossible to close the tube in a manner sufficiently 

 strong, because of the pressing out of the gas. When closed, 

 the muriatic acid was made to run on to the sulphuret of iron, 

 and then left for a day or two. At the end of that time, much 

 protomuriate of iron had formed, and on placing the clean end 

 of the tube in a mixture of ice and salt, warming the other end 

 if necessary by a little water, sulphuretted hydrogen in the 

 liquid state distilled over. 



The liquid sulphuretted hydrogen was colourless, limpid, 

 and excessively fluid. Ether, when compared with it in similar 

 tubes, appeared tenacious and oily. It did not mix with the 

 rest of the fluid in the tube, which was no doubt saturated, 

 but remained standing on it. When a tube containing it was 

 opened, the liquid immediately rushed into vapour ; and this 

 being done under water, and the vapour collected and exa- 

 mined, it proved to be sulphuretted hydrogen gas. As the 

 temperature of a tube containing some of it rose from to 45, 

 part of the fluid rose in vapour, and its bulk diminished ; but 

 there was no other change : it did not seem more adhesive at 

 than at 45. Its refractive power appeared to be rather 

 greater than that of water ; it decidedly surpassed that of sul- 

 phurous acid. A small gauge being introduced into a tube in 

 which liquid sulphuretted hydrogen was afterwards produced, 

 it was found that the pressure of its vapour was nearly equal 

 to 17 atmospheres at the temperature of 50. 



The gauges used were made by drawing out some tubes at 

 the blowpipe table until they were capillary, and of a trumpet 

 form ; they were graduated by bringing a small portion of 

 mercury successively into their different parts ; they were then 

 sealed at the fine end, and a portion of mercury placed in the 

 broad end ; and in this state they were placed in the tubes, so 

 that none of the substances used or produced could get to 

 the mercury, or pass by it to the inside of the gauge. In esti- 

 mating the number of atmospheres, one has always been sub- 

 tracted for the air left in the tube. 



The specific gravity of sulphuretted hydrogen appeared to 

 be 0-9. 



