This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Prepared by saturating a solution of potash carbonate with sulphurous acid gas, and crystallizing. It occurs in white opaque fragments or powder, with slight odor of the gas - very soluble in water (1 in 3). Taste saline and sulphurous.