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.
In chronic indolent or suppurating sores, even when non-specific, the "black or yellow" lotions containing the respective oxides are very good applications - the ointment of the red oxide is a valuable stimulant. Martin has strongly recommended blue ointment in whitlow, rubbing it in every hour, in intervals of poulticing. I have also used this treatment with some advantage, but the frictions need not be so frequent. Chronic indolent ulcers of the leg, whether syphilitic or not, often heal quickly with small doses of mercury, and lotions or ointment of the same, when applied to a similar condition, produce cicatrization.