[ 146 ] 

 XIX. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from p. 73.] 



June 17, 1869. — Lieut. -General Sabine, President, in the Chair. 



r T^HE following communications were read : — 

 ■*■ "Researches on Vanadium." — Part II. By Henry E. Roscoe, 

 B.A., Ph.D., F.R.S. 



On the Chlorides of Vanadium and Metallic Vanadium. 



In the first part of these researches (' Bakerian Lecture,' Phil. 

 Trans. 1868, pt. i.) the author stated that the chlorides of vana- 

 dium, and probably also the metal itself, could be prepared from 

 the mononitride, the only compound of vanadium not containing 

 oxygen then known. The process for obtaining the mononitride de- 

 scribed in the last communication was that adopted by Berzelius for 

 preparing the substance which he conceived to be metal, but which 

 in reality is mononitride. This method consists in the action of 

 ammonia on the oxy trichloride; but it cannot be employed for the 

 preparation of large quantities of nitride, owing to the violence of 

 the action and consequent loss of material. The author, seeking for 

 a more economical method, found 'that if the ammonium meta- 

 vanadate (NH 4 V0 3 ) be heated for a sufficiently long time at a white 

 heat in a current of dry ammonia, pure vanadium mononitride re- 

 mains behind. Analysis of a sample thus prepared gave 79*6 per 

 cent, of vanadium and 20*2 per cent, of nitrogen, theory requiring 

 78*6 and 21*4 per cent, respectively. The mononitride may likewise 

 be directly prepared by igniting vanadium trioxide (V 2 3 ) in a cur- 

 rent of ammonia at a white heat in a platinum tube, and also by 

 subjecting the dichloride to the same treatment. 



The Chlorides of Vanadium. — Three chlorides of vanadium have 

 been prepared, viz. : — 



Vanadium tetrachloride .... VC1 4 



Vanadium trichloride VC1 3 



Vanadium dichloride VCl a 



1. Vanadium Tetrachloride, VC1 4 , molec. wt. = 193*3, V.d., = 96-6 

 (H=l) v . — This chloride is formed as a dark reddish brown volatile 

 liquid, when metallic vanadium or the mononitride is burnt in excess 

 of chlorine. The first method adopted for the preparation of this 

 chloride was to pass dry chlorine over the mononitride heated to 

 redness ; the whole of the nitride volatilizes and a reddish-brown 

 liquid comes over. In one operation 44 grammes of the crude tetra- 

 chloride was thus prepared ; the liquid is purified by distillation first 

 in a current of chlorine and then in a stream of carbonic acid gas. 

 On fractionating, the liquid was found to boil at 154° C. (corrected) 



