t66 Nodcas respecting Neu- Books. 



colourless. If sulphuric, muriatic, or anj' other acid which 

 does not act upon hydrogen, be added to this solution whilst 

 recent and colourless, the sulphuretted hydrogen exhales, 

 hut no precipitate is formed ; but when, by standing, de- 

 composition has taken place, and tlie solution is become of 

 a greenish colour, hydrogen having escaped in union with 

 the oxygen of the atmosphere, the sulphur thus abandoned 

 by hydrogen is increased in its proportion, and is gradually 

 converted into sulphurous acid : if then sulphuric or muri- 

 atic acid be added, sulphuretted hydrogen gas is exhaled, 

 and sulphur is thrown down. 



" Sulphuretted hydrogurct of soda is obtained in a similar 

 manner, and possesses similar properties. 



" Sulphuretted hydrogurets of lime, barvteSjStrontia, mag- 

 nesia. See. luay also be formed, possessing analogous pro- 

 perties. 



" Sulphuretted hydroguret of ammonias formed by passing 

 sulphuretted hydrogen through ammonia. It does not pos- 

 sess the fetid odour of sulphuretted hydrogen, and is capa- 

 ble of crystallization. 



** By pouring hydrosulphuret of potash gradually into 

 muriatic acid, a portion of the sulphur combines with the 

 sulphuretted hydrogen, and forms a substance resembling a 

 yellow oil, which tails to the bottom, and is a supersulj)hu- 

 retted hydrogen, or the hydroguretted sulphur of Chenevix. 

 Immediately on the solution of sulphurcts taking place in 

 water, a decomposition of the water commences, and sul- 

 phuretted hydrogen is formed ; and this acquiring an addi- 

 tional dose of sulphur, forms the hydroguretted sulphur, 

 which, by uniting with the base, forms an hydroguretted sul- 

 phuret ; the sulphurets being thus changed, by solution, into 

 hydroguretted sulphurcts. On this principle are formed hy- 

 droguretted sulphurets of the different alkalies and earths. 



" Hydroguretted sulphuret of potash may be obtained by 

 boiling the alkali and sulphur together in water. The solu- 

 tion is of a greenish colour, of an acrid and bitter taste. It 

 rapidly absorbs oxygen, and in close vessels deposits sulphur. 

 It acts powerfully on the metals, it often reduces them to 

 the state of sulphuret^ being capable even of dissolving gold. 



" Hydro- 



