Bunsen by boiling iodine with aqua regia and extracting with ether.
In the wet process the ores, in which the bismuth is present as oxide or carbonate, are dissolved out with hydrochloric acid, or, if the bismuth is to be extracted from a matte or alloy, the solvent employed is aqua regia or strong sulphuric acid.
This salt is prepared by precipitating a solution of gold in aqua regia by ammonia, and then introducing the well-washed precipitate into a boiling solution of potassium cyanide.
After the platinum wires have been sealed through the glass, a little aqua regia is placed in the cell legs until bubbles of gas arise from the platinum, when it is thrown out and replaced by a solution of mercurous nitrate.
The crude element is treated with aqua regia and then evaporated with an excess of hydrochloric acid, the solution diluted and the tellurium precipitated by a current of sulphur dioxide.
It is insoluble in hydrochloric, nitric and sulphuric acids, but dissolves in aqua regia - a mixture of hydrochloric and nitric acids - and when very finely divided in a heated mixture of strong sulphuric acid and a little nitric acid; dilution with water, however, precipitates the metal as a violet or brown powder from this solution.