Sulphur a7id Phosphorus w'dh Platina. 37 



the results of my inquiries should admit of immediate use- 

 ful applications. 



If the ammonia-muriate of platina be regarded as a com- 

 pound of oxide of platina and muriate of ammonia, I do 

 not see how the preceding facts can be explained. If its 

 composition is such as I have stated, Sir H. Davy's theory 

 happily applies to all the phasuomena. 



I have made some experiments on those substances 

 which are considered as triple compoimds of oxide of 

 platina, acids and fixed alkali ; and they all appear to me 

 to be compounds of chlorine, platina and alkali : thus they 

 are decomposed when heated with sulphur and phosphorus, 

 and furnish substances which Sir H. Davy has denomi- 

 nated sulphurane and phosphorane ; compounds precisely 

 similar to those obtained when these inflammable bodies 

 are heated directly in chlorine gas. 



At Sir H. Davy's request, I made a number of experi- 

 ments on those substances which have been considered as 

 oxides of platina, and the evidence of facts obliges nie to 

 regard almost all the statements in our elementary books, 

 relative to the oxides and salts of platina, as incorrect. It 

 is unnecessary in this place to detail the experiments on 

 which these opinions are founded ; they will more properly 

 form the subject of a distinct paper. 



It is also said to be a distinguishing property of platina, 

 that it is precipitated by sulphuretted hydrogene in the me- 

 tallic state. This is not the case. It is obtained in the form 

 of a black pov\dcr resembling the super-sulphuret in some 

 properties, but ditfering from it in others ; thus, it is soluble 

 in nilro-mtiriatic acid, and contains a large quantity of sul- 

 phur. Sulphuret of potash likewise precipitates platina \n 

 combination with sulphur; but I have not yet satisfied my- 

 self a.s to the true constitution of these compounds. 



In forming the combinations of platina with sulphur and 

 phosphorus, it was not easy to obtain uniform results, 

 owing it seems to their partial decomposition at high de- 

 grees of heat, and the ditBculty of regulating the tempera- 

 ime with precision. 'Ihc doctrine of definite proportions, 

 which has been so amply illu-jtrated by the researches of 

 the most eidightened chemists, served in some measure to 

 direct me in my experiments, and the results I have obtained 

 appear to harmonize with this doctrine. Thus, the sub- 

 6ul[)liurtt and sub phosphuret of platina contain one pro- 

 portion, and the super-sulphuret and super-phosphurtt 

 two proportions of the mflammable jirinciples. A tabular 

 view of ihcbc combinations v^ill exhibit ihvm in a more di- 

 C 3 stinct 



