342 SULPHURETTED HYDROGEN. 



(b.) Better by the aid of sulphuret of iron, to prepare which, min- 

 gle flowers of sulphur and iron filings, equal parts ;* heat them in an 

 iron pot or skillet, under a chimney, not merely till the sulphur 

 melts, which happens almost immediately, but until an intimate 

 chemical union is indicated, by incandescence pervading the entire 

 mass ; it begins with a little luminous spot or spots, and gradually ex- 

 tends through the whole, while the vessel containing the materials is 

 perhaps not even red ; at this moment, the boiling and combustion of 

 sulphur cease, for it is now detained by its affinity for the iron. 

 The sulphuret being pulverized, is fit for use, and will not disappoint 

 the experimenter.f 



(c.) To one part of the sulphuret of iron thus made, add 2 of mu- 

 riatic acid, with 4 of warm water, and when the gas begins to come 

 languidly, a little heat may be applied. 



(d.) Powdered sulphuret of antimony, with 5 or 6 times its weight 

 of muriatic acid, (sp. gr. about 1.160,) apply the heat of a lamp ; 

 this process, although strongly recommended, has not succeeded well 

 with me. 



(e.) Add diluted sulphuric or muriatic acid to almost any alkaline 

 sulphuret, preferably of potassa, but the gas comes too rapidly to be 

 easily managed ; process (c.) is the best. 



4. PROPERTIES. 



(a.) Sp.gr. 1.18, air being 1; 100 cub. inch, weigh nearly 36 

 grains. { 



(b.) Smell very offensive, like that of rotten eggs, or of sulphureous 

 mineral waters. 



(c.) When kindled in contact with air, it burns quietly, with a 

 bluish white flame, and deposits sulphur on the glass vessel. 



Sd.) Mixed with common air, it burns more rapidly. 

 e.) With oxygen, three measures to two of this gas, it detonates, 

 producing water and sulphurous acid. 



(jf.) Water absorbs its own volume or, if the gas be pure, even two 

 or three times its volume, and then resembles exactly, the native 

 sulphureous waters. 



* Or sulphur 1 part, iron 2. 



t The mere melting of iron filings and sulphur, and still more the mere mingling 

 of them will not answer ; for, when the acid is added, the gas produced will be 

 merely a mixture of sulphuretted hydrogen, and common hydrogen gas. The pro- 

 cess by rubbing roll sulphur upon a bar of iron heated to whiteness, till liquid drops 

 fall, gives also a true sulphuret which will afford the gas, but the manipulation is 

 more troublesome, and the product of sulphuret of iron is small. 



The following process was communicated. Heating the native yellow pyrites, in 

 a close crucible, till 1 proportion of sulphur is expelled ; and a fine proto-sulphuret 

 will be left. J. T. 



t 35.89, according to Dr. Thomson. Different authors have stated its sp. gr. dif- 

 ferently. 



