501 



potassium with arsenic and antimony to the action of iodide of ethyl, 

 may be procured by this process as readily and as abundantly as the 

 phosphorus-bases. 



In attempting to identify the substances obtained by the new pro- 

 cess with those prepared by the old one, by the analysis of platinum- 

 and gold-salts, I have been led to the discovery of a series of com- 

 pounds of remarkable beauty. 



Since the study of these bodies, and especially of their derivatives, 

 which are particularly numerous and interesting, will involve con- 

 siderable time, I beg leave to submit to the Royal Society, before 

 the session closes, a brief sketch of those substances, the composition 

 of which I have already established by analysis. 



On adding a solution of bichloride of platinum to an alcoholic 

 solution of triethylphosphine, of triethylarsine or triethylstibine as 

 long as the colour of the platinum solution entirely disappears, the 

 liquid deposits after a few moments magnificent slightly yellow or 

 colourless crystals. The three salts thus formed may be considered 

 as the chlorides of three compound ammoniums containing platinum 

 and ethyl, united respectively with phosphorus, arsenic and antimony. 

 They have the following composition : 



ptn 



Chloride of Platophosphethylium...^ L P Cl. 



Chloride of Platarsethylium ...... As Cl. . 



EJ 



pn 



Chloride of Platostibethylium ____ ^ I Sb Cl. 



EJ 

 On substituting for the bichloride of platinum a solution of ter- 



chloride of gold, perfectly similar phenomena present themselves. 



The gold solution is entirely decolorized, and the colourless liquids 



deposit three gold compounds, which, remarkably enough, are of a 



dazzling white colour and silvery lustre. 



Analysis has proved these salts to correspond to the platinum- 



salts just mentioned, the platinum being replaced by an equivalent 



quantity of gold. 



