488 



arsenic-, and antimony-bases would lead to the discovery of the cor- 

 responding terms, 



, 2 XAs 2 and 



c cj c 



which might be designated as diphosphines, diarsines, and distibines ; 

 and the further prosecution of this line of thought very naturally 

 suggested the idea of searching for a group of intermediate compounds 

 containing simultaneously nitrogen and phosphorus, nitrogen and 

 arsenic, phosphorus and arsenic, &c., compounds expressed by the 

 formulae 



**} 4>*\ 



>NP ; S 2 >N As ; 2 > 



cj cj 



P As, &c., 



which might be termed phosphamines, arsamines, phospharsines, &c. 



Among the several processes likely to furnish this result, none ap- 

 peared more promising than the reaction between a monamine and a 

 monophosphine of opposite chemical characters. 



In the conception of this idea, I have studied the deportment of 

 cyanic acid and some of its derivatives with phosphoretted hydrogen 

 and its homologues, in the hope of producing combinations similar 

 in constitution to the ureas, but differing from these substances by 

 containing phosphorus in the place of one equivalent of nitrogen. 



The action of cyanate and sulphocyanide of phenyl, an account of 

 which I have lately* submitted to the Royal Society, upon triethyl- 

 phosphine, seemed to include the conditions for the realization of 

 such compounds. 



On bringing cyanate of phenyl in contact with triethylphosphine, 

 a most lively reaction ensues ; the mixture begins to boil, and the 

 phosphorus-base is apt to be inflamed. On cooling, the liquid soli- 

 difies into a crystalline mass, which is insoluble in water, soluble in 

 alcohol and ether, and crystallizes from the latter solvent in beautiful 

 little square tables, tasteless, inodorous, and infusible at 100 C. On 

 submitting this compound to analysis, I was surprised to find that 

 it contained no phosphorus, and that it exhibited the composition 

 of the original cyanate of phenyl, from which it differs so essentially 

 in its properties. This substance is the cyanurate of phenyl, gene- 

 rated from the cyanate by simple transposition of the elements. The 

 * Proceedings, vol. ix. p. 274. 



