Mr Johnston on Vanadium. 323 



With proto-nitrate of mercury, chromates give a deep red ; 

 vanadiates a bright yellow precipitate. Both give with nitrate 

 of silver a ruby or vermilion red, differing only in shade. 



In these differences in the properties of these two substances, 

 having towards each other so many and striking affinities, — 

 we have ample means both of distinguishing and of accurately 

 separating them from each other, should they ever be found 

 in combination : and though, as the number of simple bodies 

 with which we are acquainted becomes greater, the properties 

 of the whole group will more and more shade into each other, 

 yet the number of points in which these two metals disagree, 

 shows us there is yet ample room for an addition to their num- 

 ber without rendering the difficulties which oppose the analy- 

 tical chemist absolutely insurmountable. 



I have not proposed to myself the difficult task of collecting 

 materials for an entire history of vanadium and its compounds, 

 knowing it to be already in far abler hands. JBerzelius has 

 been occupying himself with it during the past winter, and he 

 has in all probability already finished his researches ; but so 

 little has yet appeared in this country regarding the new me- 

 tal, and it may be yet so long before the results of Berzelius 

 find their way to our journals, that I have thought the above 

 sketch of its properties might in the meantime not be uninte- 

 resting to British chemists. 



An " Old Correspondent, 1 '' in the August number of the 

 Philosophical Magazine and Annals, p. 157, mentions my hav- 

 ing found vanadium in an ore of lead from Alston Moor, and 

 suggests that it was more probably from the neighbourhood of 

 Keswick. — On this I have only to remark, that I have never 

 found it, and never said it was to be found in any ores of lead, 

 except the two varieties described in the former Dumber of this 

 Journal, page 1G6, as formerly occurring in a now unwroughl 

 mine at Wanlockhead. 



Pohtobkllo, Hth September l'88l. 



