J81 1.] On Sulphur el of Carbon, IS* 



chesnut brown colour, and is readily attracted by the magnet. It 

 dissolves witli great difficulty in the acids by long digestion and 

 concentration. During this solution no sulphureted hydrogen is 

 disengaged, the sulphur remains undissolved, and the oxidule com- 

 bines with the acid. The oxidulated sulphuret of iron is very 

 inflammable ; it takes fire at a temperature much interior to a red 

 heat; and it continues to burn till it is wholly reduced to the state 

 of red oxide of iron. It is owing to the formation of tins oxidulated 

 sulphv.ret that, when we try to expel by heat, in vessels imperfectly 

 closed, the excess of sulphur from common pyrites, the sulphuret 

 obtained is, but with great difficulty, dissolved by acids. The ox't- 

 dide of cerium equally combines with sulphur, and forms an oxidu- 

 lated sulphuret, which is pulverulent, and of an apple- green colour. 

 It is doubtful whether the green sulphuret of manganese obtained in 

 a similar manner is not an oxidulated sulphuret, rather th;ui a 

 metallic sulphuret of manganese. It is evident that those oxidulated 

 sulphurets bear to the metallic sulphurets the same ratio as the 

 sulphuret of potassium to the sulphuret of potash. 

 . 3. On the Comhination of the triple Acid, or Acidum Muriattcurn, 

 Sulphuroso-Carbonicum (Phil. Trans, same paper, p. 199) ivitk 

 Ammonia. — The triple acid, when put in contact with ammoniacal 

 gas, slowly absorbs a considerable quantity of the gas. It seems, at 

 fii-st, to become liquid; but soon afterwards it forms a saline mass, 

 which contains ammonia in excess. This subsalt presents the pecu- 

 liar combination of a triple salt, with three acids, but with one single 

 base, in the same way as the fluoborates present double salts, with 

 'VO acids, but with a single base. 

 This triple salt is not deliquescent, though it gradually absorbs 

 from the air some water of crystallization. It has first an acrid, and 

 then a sulphureous taste, like the sulphite of ammonia; it is easily 

 soluble in water, and this solution precipitates carlx)nate ot lime 

 from lime water. If the solution be acidulated by muriatic acid, 

 muriate of barytes docs not occasion any precipitate from it, proving 

 (hat it does not contain any sulphuric acid. 



When the triple salt is distilled previous to its having attracted 

 any moisture from the atmosphere, it melts, bubbles, and gives out, 

 first, aunnoniacal gas, and afterwards a mixture of sulphureous acid 

 gas and an etherial liquid, which is extremely volatile, and has a 

 smell very analogous to that of the prussic acid, though it did not 

 appear to pioduce any Prussian blue with solution of Iron. After 

 this etherized liquid, tliere comes over a saline sublimate, which is a 

 mixture of muriate and sulphate and sulphite of anmionia, contain- 

 ing some water of crystalli/alioii. This water seems to be formed 

 at tlie expense of the amnionic and carbonic acid, the etherial liquor 

 containing the carbon of the latter, and also the azote with a portion 

 of the hydrogen of tiie former. This salt is very curious in piany 

 nsfwcts, aud well deserves to be more minutely examined. 



