RESEARCHES ON SULPMITR AND FH0SPR0RU8. ^5 



rated with sulphuretted hidrogen over mercury. I have era- experiments, 

 ployed sulphur distilled from iron pyrites in vacuo, which limedfrom 

 did not in the slightest degree affect litmus paper, and 1 pyrites inva- 

 have combined it with potassium in retorts of green glass, <^"o "^ot acid. 

 or plate glass lined with sulphur, and filled with very pure 

 nitrogen or hidrogen. In making potassium act upon sul- 

 phuretted hidrogen, I have employed the gas only in the 

 quantities of from 1 to 3 cubical inches, and have made 

 the combination in narrow curved tubes of green glass over 

 dry mercury. With all these precautions, and after having Results not 

 made a great number of experiments, I am not able io-P^^^'^^h^oi- 

 gain perfectly uniform results. Yet there is a sufficient 

 correspondence between them, to enable me to form con- 

 clusions, which 1 may venture to say cannot be far from the 

 truth. 

 When 1 grain of potassium, which would give by the Action of pot- 



action of water about 1 cubical inch and tV of hidrosen, is a^^^"™ °" ^^^' 

 I 1 1 w . i. . 1 Phur, in small 



made to act upon about halt a gram of sulphur, sornt* proportion^ 



sulphur sublimes during the combination, which always 

 takes place with heat and light ; and from yV *o tV <>^ a 

 cubical inch of sulphuretted hidrogen is evolved. The 

 compound acted on by muriatic acid, saturated with sul- 

 phuretted hidrogen, affords from -fij to l-^ of a cubical inch 

 of pure sulphuretted hidrogen. 



When more sulphur is used, so as to be from twice to and iu larger 

 ten times the weight of the potassium, the quantity of sul- P'"oporii«»« 

 phuretted hidrogen evolved by the action of the acid is 

 from T-V to T^^; but if heat be applied to the combina- 

 tion, so as to drive off the superfluous sulphur, the quan- 

 tity of gas collected is very little inferior to that produced 

 from the combination in whirh a small proportion of sul- 

 phur is used ; and I am inclined to believe, from the phe- 

 nomena presented in a great number of experiments, that 

 sulphur and potassium, when heated together under com- 

 mon circumstances, combine only in one proportion, in Ttrey combine 

 which the metal is to the sulphur nearly as 3 to 1 in weight; only in ona 

 and in which the quantities are such, that the compound ^'^P**' ^* 

 burns into neutral sulphate of potash. 



When a grain of potassium is made to act upon about Action of pot- 

 1*1 cubical inches of sulphuretted hidrogen, all the hidrosjen ^^J'"'" °" ^V^* 



Vou^XXVIII.-^Jan. 1811, D is ^" 



