A newly discovered metal by M. Sefstrom. It has been briefly described in a letter from M. Berzelius to M. Dulong, from which the following is an extract; - " M. Sefstrom, director of the School of Mines at Fah-lun, whilst engaged in examining a variety of iron, remarkable for its extreme softness, observed the presence of a substance, the properties of which differed from all other known bodies, but its quantity was so small as would have rendered it tedious and expensive to collect sufficient for a correct examination of its properties. This iron was from the mine of Taberg, in Smoland; the ore merely contained sources of the substance. Finding that the pig iron contained far more of this principle than the wrought iron, M. Sefstrom thought that the scoriae formed during the conversion of the pig iron into wrought metal might be a more abundant source; a conjecture confirmed by experience; so that sufficient having been procured, he went to M. Berzelius to complete its examination."
Vanadium combines with oxygen to form an oxide and an acid. The acid is red, pulverent, fusible, and on solidifying becomes crystalline. It is slightly soluble in water, reddens litmus, and forms yellow neutral salts, and orange bisalts. Its combinations with acids or bases have the singular property of suddenly losing their colour; they resume it only on becoming solid again, and being then re-dissolved, preserve their colour. Hydrogen at a white heat, reduces vanadic acid, leaving a coherent mass, having a feeble metallic lustre, and being a good conductor of electricity, but it is not certain that the reduction is complete. The oxide of vanadium is brown, or nearly black, and dissolves readily in acids. The salts are of a deep brown colour, but by the addition of a little nitric acid, effervesce and become of a fine blue colour. The oxide and acid of this metal together produce other combinations, green, yellow, and red, all soluble in water.
When the oxide of vanadium is produced in the humid way, it is soluble both in water and alkalies. The presence of a salt renders it insoluble, and upon this effect may be founded a process for its preparation. Before the blowpipe, vanadium colours fluxes of a fine green, in this respect resembling chrome.