609 



lastly with dichloride of platinum. The latter compound was ana- 

 lysed in order to fix the composition of the series. 



Platinum-salt. The product of the reaction of triethylarsine 

 upon the bromethylated bromide was treated with oxide of silver in 

 the cold, and the alkaline solution thus obtained, saturated with 

 hydrochloric acid and precipitated with dichloride of platinum. An 

 exceedingly pale-yellow, apparently amorphous precipitate of diphos- 

 phonic appearance was thrown down, almost insoluble in water, but 

 dissolving in boiling concentrated hydrochloric acid. The hydro- 

 chloric solution deposited, on cooling, beautiful orange-red crystals, 

 resembling those of the diphosphonium-platinum-salt. The crystals, 

 according to the measurement of Quintino Sella, belong to the tri- 

 metric system. The analysis of the platinum-salt led to the formula 



C M H 31 PA s Pt 2 Cl 6 =r(C 2 H 4 )" %%>* l"ci 2) 2PtC! 2 . 



L (C 2 H 5 ) 3 As J 



The phospharsonium-compounds, and more especially the hydrated 

 oxide of the series, are far less stable than the corresponding terms 

 of the diphosphonium- and even of the phosphammonium-series. If 

 the product of the action of triethylarsine upon the brominated bro- 

 mide be boiled with oxide of silver instead of being treated in the 

 cold, not a trace of the phospharsonium- compound is obtained. 

 The caustic solution which is formed, when saturated with hydro- 

 chloric acid and precipitated with dichloride of platinum, furnishes 

 only the rather soluble octahedral crystals of the oxethylated triethyl- 

 phosphonium-platinum-salt *. The nature of this transformation is 

 clearly exhibited when a solution of the dioxide of phospharsonium 

 is submitted to ebullition. Immediately the clear solution is rendered 

 turbid from separated triethylarsine, which becomes perceptible, 

 moreover, by its powerful odour, the liquid then containing the 

 oxide of the oxethylated triethylphosphonium, 



[(C 2 H 4 )"(C 2 H 5 ) 6 PAs]"1 [(C 2 H 5 0)(C 2 H 6 ) 3 P]1 



J^-^AJsAs- 



* See the following Abstract. 



H 2 -s- H 



2T2 



