Mr Johnston on Vanadium. 321 



ish red volatile liquid. As it escapes into the air the vapour 

 is decomposed, forming white fumes of muriatic acid and va- 

 nadic acid (?), which deposits itself in the form of a red crust 

 round the mouth of the tube by which the vapour escapes. 

 Confined in a moist receiver, it is changed into a muriate, and 

 a beautiful blue liquid is formed, which is a solution of the 

 oxide in muriatic acid. 



6. Heated in atmospheres of sulphur and iodine, it under- 

 goes no change. 



7. In nitric acid it dissolves rapidly, with effervescence and 

 evolution of red fumes, forming a deep indigo-blue solution, 

 which, by spontaneous evaporation, gives an amorphous partly 

 steel-grey and partly brownish crust, which is a mixture of the 

 vanadic acid with theoxideof vanadium. Evaporated todryness 

 by a gentle heat continued till fumes of nitric acid cease to be 

 given off", it leaves a beautiful vermilion red vanadic acid, 

 which is slightly soluble in water and forms a yellow solution.' 

 Heated further, in the open air, this red substance fuses into 

 the red liquid already mentioned. 



8. Neither the sulphuric nor muriatic acids act upon it sen- 

 sibly in the cold, whether dilute or concentrated, and very 

 slightly even when aided by heat. The oxide is dissolved by 

 both acids, giving beautiful blue solutions resembling those of 

 the salts of copper. 



III. Distinctive Characters of Vanadium. 

 This metal is most nearly allied to chromium, and it cannot 

 easily be confounded with any other. It differs from chro- 

 mium as follows. 



1. The protoxide of chromium is green and insoluble in 

 water, that of vanadium is dark brown and soluble. Thedeu- 

 toxide of chromium, or the compound of oxide and acid i.-. 

 brown; vanadium appears to give a similar compound, which 

 is of a beautiful indigo-blue. * 



2. Newly precipitated oxide of chromium dissolves very 



- r hum pe .1. a! a ; ii m oxide, ( hi. </ Chitn. -I in. l».i\.J Thi I 

 have not obtained, unless, indeed, w< il :■■ nl i" 'I"' 



Imltoii occasionally obtained in icids, and which I nixture 



of iii blu< solution of Hi oxide uid the ion of ill 



