$64 On some Comlinatlons of Platink. 



phoretted hydrogen gas on solutions of this metal. I have 

 since made an experiment of" this kind; and though it 

 offers but little novelty of result, it may not be improper 

 briefly to describe the effects produced. 



when phosphoretted hydrogen gas is passed through an 

 aqueous solution of muriate of placina, the gas appears to 

 be partially decompounded at the surface, it loses the pro- 

 perty of spontaneous inflamniation. The globules are de- 

 tained at the surface of the fluid, and arrange themselves 

 somewhat in the form of a honeycomb; and a yellowish- 

 brown substance is at lencth deposited, which shortly after 

 acquires a gray colour. If the gas is rapidly passed through 

 the solution, it inflames as in other cases ; but the moment 

 this eff'fct is produced, a grayish metallic-like substance 

 partially covers the surface, which appears to be a phos- 

 phoret of platina. 



The mode I adopted to procure this substance was similar 

 to that used in the case of the hvdrosulphuret of platina. 

 It is necessary to use some precautions, in operating on this 

 gas in considerable qiiantities, and therefore the retort 

 should be previously exhausted twice from hydrogen gas. 

 A short time after the retort had been filled with phos- 

 phoretted hydrogen gas, a gradual absorption of the gas 

 took place, and a yellowish-brown coloured substance 

 partially lined the sides of the retort, and the surface of the 

 fluid, which slowly increased in quantity, and after some 

 time acquired a gray colour. Whether this yellow sub- 

 $tance is a distinct compound, or for the most part phos- 

 phorus, I have not ascertained : the latter idea appears the 

 more probable. Whilst the hydrogen is employed in re- 

 ducing the metallic oxide, the phosphorus seems to be de- 

 posited in a minute state of division, and t(> combine slowly 

 ■with the revived metal. After the gray-coloured substance 

 had been well washed with distilled water, and dried in hy- 

 drogen gas at a temperature about 212^, I examined it so 

 far as to satisfy myself respecting its constitution. It was 

 in the form of small curved laminne. It had a slightly acid 

 taste, evidenlb owing to the presence of a little uncombined 

 phosphorus, which had absorbed oxygen during its exposure 

 to the atmosphere. It was for (he most part insoluble in 

 the mineral acids. When heated to redness in close vessels, 

 it furnished a gray semifuscd porous mass having the me- 

 tallic lustre, water, and a little hydrogen gas. The hydro- 

 gen, it would seem, must have residted from the decomposi- 

 tion of a htlle water. The gray-coloured substance in its 



general 



