410 Researches on 



action of water about one cubical inch and -j-g- of hydrogen is 

 made to act upon about half a grain of sulphur, some sulphur 

 sublimes during the combination, which always takes place 

 with heat and light, and from t 't t0 tV °* a cubical inch of 

 sulphuretted hydrogen is evolved. The compound acted 

 on by muriatic acid, saturated with sulphuretted hydrogen, 

 affords from -j 9 - to -f-^ of a cubical inch of pure sulphuretted 

 hydrogen. 



When more sulphur is used so as to be from twice to 

 ten times the weight of the potassium, the quantity of sul- 

 phuretted hydrogen evolved by the action of the acid, is 

 from T 7 - to T 9 y-; but if heat be applied to the combination, 

 so as to drive- off the superfluous sulphur, the quantity of 

 gas collected is very little inferior to that produced from the 

 combination in which a small proportion of sulphur is used; 

 and I am inclined to believe, from the phenomena pre- 

 sented in a great number of experiments, that sulphur and 

 potassium, when heated together under common circum- 

 stances, combine only in one proportion, in which the metal 

 is to the sulphur nearly as three to one in weight; and in 

 which the quantities are such that the compound burns into 

 neutral sulphate of potash. 



When a grain of potassium is made to act upon about 

 J'l cubical mches of sulphuretted hydrogen, all the hydro- 

 gen is set free, and a sulphuret of potassium containing one- 

 fourth of sulphur is formed, exactly the same as that produced 

 by the immediate combination of sulphur and the metal. 



When sulphuretted hydrogen is employed in larger quan- 

 tities, there is an absorption of this gas, and a volume is 

 taken up about equal to the quantity of hydrogen disen- 

 gaged, and a compound of sulphuretted hydrogen and sul- 

 phuret of potash is formed, which gives sulphuretted hy- 

 drogen by the action of an acid, nearly double in quantity 

 to that given by the sulphuret of potassium. 



From a number of experiments I am inclined to believe 

 that potassium and phosphorus, in whatever quantities they 

 are heated together, combine only in one proportion, a grain 

 of potassium requiring about f of a grain of phosphorus to 

 form a phosphuret; which when acted upon by muriatic 

 acid, produces from -*f to ±% of a cubical inch of phosphu- 

 ret ted hydrogen. 



Haifa gram of potassium decomposes nearly three cubical 

 inches of plmsphuretted hydrogen, and sets free rather more 

 than four cubical inches of hydrogen ; and the phosphuret 

 formed seems to be of the same kind as that produced by 

 direct combination of the metal with phosphorus. 



if, 



