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.
By boiling together arsenious acid and carbonate of potash, and adding to the solution (when cold) tincture of lavender, and sufficient water to preserve a proportion of 4 gr. in the ounce.
A reddish, alkaline liquid, with the odor of lavender: it contains a mixture of arsenite and carbonate of potash.