PROFESSOR ROSCOE’S RESEARCHES ON VANADIUM. 
687 
boat is heated to whiteness in a current of dry ammonia, dense fumes of ammonium 
chloride are given off, and on cooling after an hour’s heating, the boat contains vanadium 
mononitride in bronze-coloured pseudomorph crystals, which exhibit by reflected light 
a bright metallic lustre. 
The specific gravity of vanadium dichloride at 18° C. is 3‘23 as a mean of two well- 
agreeing determinations. Vanadium dichloride dissolves slowly in alcohol and in ether, 
giving in the one case a blue and in the other a greenish-yellow solution. 
Metallic Vanadium, V=51'3. — From what we now know of the character of vanadium, 
we learn without surprise that the metal cannot be prepared in the free state by any of 
the methods given in the books. 
Berzelius (Pogg. Ann. vol. xx. p. 1) obtained a brilliant metallic scale by heating the 
oxytrichlorides, placed in a bulb-tube, in an atmosphere of ammonia ; but this substance, 
as Schafarik observes, is mononitride, and not metal. The great Swedish chemist also 
states that the metal can be prepared in a pulverulent form by exploding fused vanadic 
acid with potassium. The black powder which is obtained by lixiviating the fused mass 
is, however, not metal but an indefinite mixture of oxides. Schafarik (Ann. der Ch. und 
Pharm. vol. cix. p. 97) describes as metal the brownish -yellow lustrous crystals obtained 
by passing the vapour of the oxytrichloride mixed with hydrogen through a red-hot tube. 
•The body thus prepared, as I have already shown, is not the metal, but a mixture of the 
lower oxychlorides of vanadium. 
Johnston (N. Edin. Journ. of Sc. vol. v. pp. 166, 318) obtained a hard brittle metallic 
globule by reducing vanadic acid with carbon at a white heat ; this was certainly not 
metallic vanadium, probably the alloy with silicon. 
Although it appeared unlikely that any compound of vanadium containing oxygen 
would yield the metal by direct reduction, 1 have nevertheless repeated the above expe- 
riments, but without success. In order to test the second method proposed by Berzelius, 
the fused pentoxide was mixed with excess of sodium, and the mixture heated in a closed 
wrought-iron crucible ; after the explosion the black mass was washed until free from 
alkali. A black powder is thus obtained which glitters when suspended in water, and 
this powder on oxidation only gained 16 per cent., showing that it contained even more 
oxygen than the trioxide. 
Johnston’s experiment was also repeated by exposing a mixture of trioxide, charcoal, 
and oil contained in a graphite crucible for several hours to the heat of a wind-furnace 
in which manganese can be fused. Not a trace of either a bead or metallic powder was 
obtained, and the black powder gained on oxidation only 16 per cent. 
In order to ascertain whether under other circumstances the trioxide can be reduced, 
a portion of this oxide was heated to whiteness in a current of hydrogen, both when 
alone and mixed with excess of sodium ; in neither case was the metal formed, a black 
residue of oxide remaining behind in the boats. The trioxide heated in a graphite 
crucible to bright redness with magnesium also yielded a black powder consisting of 
mixed oxides. 
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