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.
Simpson recommended for indolent "menstrual" acne, a decolorized iodine paint made by mixing tinct. iodin. co. 1 part, with liq. ammoniae 2 parts, to stand forty-eight hours (Medical Times, i., 1861). I have not found this preparation so effective as ordinary iodine when applied to glands, etc., and for acne there are several better remedies. The ointment of iodide of mercury is more valuable in acne rosacea, and that of iodide of sulphur in indolent acne and sycosis.