354 Abstract of Mr, Faraday'' s Experiments on the 



all its characters was like that prepared by the former pro- 

 cess. 



" Sulphurous acid vapour exerts a pressure of about two 

 atmospheres at 45°F. Its specific gravity was nearly 1,42. 

 " Sulphuretted Hydro gen. -A. tube being bent, and sealed at 

 the shorter end, string muriatic acid was poured in through a 

 small funnel, so as nearly to fill the short leg without soilingfthe 

 long one. A piece of platinum foil was then crumpled up and 

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

 ir*-<n, 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 outof 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 pla- 

 cing the clean end of the tube in a mixture of ice and salt, 

 warming the other end if necessary, by a little water, sul- 

 phuretted hydrogen in the liquid state distilled over. 



"The liquid sulphuretted hydrogen was colourless, lim- 

 pid, and excessively fluid. It did not mix with the rest of 

 the fluid in the tube, which was no doubt saturated, but re- 

 mained 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 

 examined, it proved to be sulphuretted hydrogen gas. As 

 the temperature of a tube containing some of it rose from 

 0° to 45°, part of the fluid arose in vapour and its bulk di- 

 minished; but there was no other change : it did not seen 

 more adhesive at 0° than at 45°. Its refractive power ap- 

 peared to be rather greater than that of water: it decidedly 

 surpassed that of sulphurous ac»d. The pressure of its va- 

 pour was nearly equal to seventeen atmospheres at the tem- 

 perature of 50°. 



" The specific gravity of sulphuretted hydrogen appeared 

 to be 0.9. 



" Carbonic Acid. — The materials used in the produc- 

 tion of carbonic acid, were carbonate of ammonia and con- 

 centrated sulphuric acid ; the manipulation was like that 

 described for sulphuretted hydrogen. Much stronger tubes 

 are however required for carbonic acid than for any of the 

 former substances, and there is none which has produced so 



