w 



ACTION OF OXIDES OK ALKALINE HYDROSULPHUHETS. 



4thly, That the black oxide of raanganese is brought 

 back to a minimum, aud that no sulphuret of mauganese is 

 formed. 

 Oxide of As a second example I shall take the brown oxide of cop- 



copper and pgr, and the sulphuretted hydrosulphuret of barvtes. These 

 5ulplniieued , , , , i' -r i . 



hydrosutphu- ^^° substances act strongly oii each other; and, it they be 



ret of barytes. heated, the liquor presently loses its colour^ and no longer 

 contains any thing but barytes mixed with more or less sul- 

 phuretted sulphite. The oxide, after having been washed 

 till the water that comes off is no longer precipitated by sul- 

 phuric acid, effervesces with muriatic acid in consequence of 

 the sulphurous acid evolved, and a great deal of muriate of . 

 barytes is formed. The residuum, washed anew to remove 

 the latter salt, and then treated with very weak nitromnriatic 

 acid, leaves no other residuum than sulphur, which collects 

 on the surface of the liquid. 

 Tfte Jwo Hence we see, that the oxide of manganese and the oxide 



rNpcriments ^f copper, though exhibiting the same general result, have 

 acted differently in this, that no sulphuret of manganese was 

 formed, though sulphuret of copper was produced: but the 

 cause of this is, the oxide of raanganese was only reduced to 

 a minimum, and in this state it has little affinity to sulphur. 

 Solution of I shall not relate any more experiments of this kind, but 



^jiJphurets in gj^^jj conclude with a brief account of what happens, when a 



sulphuret is dissolved in water. 

 Sulphuret of I made some sulphuret of barytes and sulphuret of pot* 

 baiytes. ^g]^ ^^^^ ^ gentle beat. The first, dissolved in water, left a 



residuum, which, after having been washed, dissolvedcom- 

 pletely in muriatic acid, evolving a great deal of sulphurous 

 acid, 

 Sulphuret of The solution of sulphuret of potash, into which I poured 

 potash. muriate of barytes, yielded but a slight precipitate, which 



dissolved completely in muriatic acid. The mixture had 

 been heated, and on cooling a great many little crystals of 

 8ul[)haretted sulphite of barytes were deposited on the sides 

 of the vessel. 

 SuTphuretted I found »lso, that the sulphuretted sulphites were not al- 

 .ii p 1 es. tercd by exposure to the air; and that a neutral sulphite can 

 dissolve a great deal of sulphur, without becorpin^ acid or 

 ' alkaline. 



xin. 



