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.
Cases of this disease affecting the lip, the tongue, the scrotum (chimney-sweep's cancer), etc., are stated to have been cured by its internal administration; and although Hirtz concludes that all reports of true cancer being cured by arsenic internally are founded on mala fides, or bad diagnosis, yet there is some trustworthy evidence of its relieving cancerous pain in the stomach and in the uterus. Sir C. Locock mentions his own confidence in it, together with cases from his practice, and from that of Brodie and Sir A. Cooper (Lancet, 1837), and Mr. Hunt records a marked instance of relief under small doses frequently repeated, not amounting to more than 10 min. in twenty-four hours. The case was said to be undoubted uterine cancer, and the relief given was greater than from morphia: as a rule, a pill was preferred, containing 1/20 gr. or less. Fordyce Barker also speaks highly of its power to relieve pain and improve the general condition, in doses of about 3 min. of Fowler's solution (American Journal of Obstetrics, November, 1870). Dr. Walshe has written specially to recommend the iodide of arsenic as most valuable (Dublin Quarterly Journal, August, 1857, v., p. 9). I have given Fowler's solution internally in many cases of epithelioma, when the disease was extending rapidly, and have known it apparently retard for a considerable time the progress of the malady, relieve the pain, and improve the general condition. Cases where the lower lip or the scrotum was affected have given me the best results: the dose usually prescribed was 5 min. thrice daily.