Vanadium: Dichloride Reduced in Perfectly Pure Hydrogen at Bright Red Heat (Roscoe, Treatise 1913)

Roscoe first made pure vanadium this way. Hydrogen is cleaned of every trace of air and moisture and passed for days over vanadium dichloride in a platinum boat at bright red heat; the chlorine leaves as hydrogen chloride and vanadium remains. Result: metallic vanadium, a light whitish-grey powder (1 to 4 g per run, 40 to 80 hours). Source: Roscoe and Schorlemmer, A Treatise on Chemistry vol. 2 (1913), pp. 914-917, Fig. 184 (shown above). Hydrogen chloride comes off; hydrogen is flammable.