4,76 Royal Society :— 



Diarsonium Series. 

 Bibromide of Ethylene-hexethyl diarsonium. 

 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 M H„ As 2 Br a =(C a HJ'g §££]" Br 2 



yielded, when debromized, the powerful alkali 



c„ii !e As 3 o 2 =K c » II ')"^ H ^ As i i;}o 2 . 



Treated with acids, this alkali produces a series of fine salts, 

 amongst which the di-iodide deserves to be mentioned ; it equals in 

 beauty the corresponding diphosphonium-compound. 



I have fixed the composition of the series by the analysis of the 

 platinum-salt and gold-salt. 



Platinum-salt. — Pale-yellow crystalline precipitate, similar to the 

 diphosphonium-compound, difficultly soluble in water, soluble in 

 boiling concentrated hydrochloric acid, from which it crystallizes on 

 cooling. It contains 



C 14 H 34 As 2 Pt a Cl 6 = [(C 2 H 4 )" gjj n^i']"^, 2 Pt Cl 2 . 



Gold-salt. — The dichloride obtained after separating the platinum 

 in the previous analysis by sulphuretted hydrogen, was precipitated 

 by trichloride of gold ; yellow slightly crystalline precipitate, soluble 

 in hydrochloric acid, from which it crystallizes in golden-coloured 

 plates. The formula of this salt is 



C u H 34 As 2 Au 2 Cl d = [(CJ-I,)" (g n^ 3 iff CL, 2 Au C1 a- 



Arsammonium Series. 

 Bromide of bromethylated triethylarsonium, as might have been 

 expected, is capable of fixing ammonia and monamines, giving rise 

 to the formation of a group of compounds not less numerous than 

 the bodies mentioned in the phosphorus-series. I have been satisfied 

 to study the action of ammonia upon the bromide. 



Bibromide of Ethylene-triethylarsammonium. 



Reaction complete in two hours at 100°. The product contains 

 the dibromide, 



C 8 II 22 As N Br 2 = [(C 2 HJ« < C * ^A*l Br 2 ; 



this salt is converted by oxide of silver into the stable caustic base 



C. H. As N O a = KC H.)» (C, H,X H, A s HJ j Q _ 



