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.
From the effect of arsenic in improving the coat of horses, it has been plausibly thought to have a special power in promoting hair-growth, and certainly after any sources of baldness, such as syphilis, dyspepsia, or local irritation, have been treated and removed, the internal administration of small doses may be carefully carried out for a time with advantage. Hunt practised this treatment successfully.
Chronic Urticaria is often relieved under arsenic, but any evident intestinal disorder should, if possible, be remedied in the first instance.