oxide of silver, yields a powerfully alkaline solution, the nature of 

 which was determined by the analysis of the corresponding platinum- 

 salt. Transformed into the chloride and precipitated with dichloride 

 of platinum, this solution yielded beautiful rather soluble octahedra 

 which were found to contain 



C 8 H 18 AsPtCl 3 ==[(C 2 H 3 ) (C 2 H 5 ) 3 As] Cl, PtCl 2 . 

 The analysis of this salt shows that the transformation of the brom- 

 ethylated compound ensues according to the following equation, 



[(C 2 H 4 Br) (C 2 H 5 ) 3 As]Br+^ g l 0=K 2H ^ ( C * H 5\^ j O + 2AgBr. 



The idea suggested itself that the vinyl-compound obtained in this 

 reaction might be a secondary product resulting from the decom- 

 position of an oxethylated compound of limited stability formed in 

 the first instance, 



[(C 2 H 5 O) (C 2 H 5 ) 3 As] I 0= H I Q + [(C 2 H 3 ) (C 2 H 5 ) 3 As] j Q 



It was with the view of avoiding this decomposition that in one of 

 the operations the digestion was accomplished at the common tem- 

 perature ; the result, however, showed that even in this case the 

 vinyl-compound was obtained. 



Nevertheless the oxethylated body appears to exist : under cir- 

 cumstances which were not sufficiently well observed at the time, the 

 action of oxide of silver upon bromide of bromethylated triethyl- 

 arsonium yielded an octahedral platinum-salt, which on analysis fur- 

 nished exactly the platinum-percentage of the oxethylated compound. 



DIARSONIUM SERIES. 

 Dibromide of Ethylene-hexethyldiarsonium. 



The bromide or chloride of the bromethylated arsonium-compound 

 is but slowly acted upon by triethylarsine at 100 C. Two days' 

 digestion at that temperature had produced but a slight impression ; 

 at 150 the reaction is accomplished in two hours. The phenomena 

 now to be recorded presented themselves in the succession repeatedly 

 observed in the diphosphonium-series. The dibromide 



C U H 31 A B2 Br 2 =(C 2 H 4 )"g n^ 

 yielded, when debromized, the powerful alkali 



