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.
There is much evidence as to the value both of oxide and sulphate of zinc in this malady, more perhaps in favor of the latter; it requires to be given in gradually increasing doses up to 15 to 20 gr. (Barlow). In recording many cases, all of which derived some benefit, Mr. Marsh, of the Children's Hospital, remarks that no definite indication for the sulphate could be verified, but that a harsh, dry skin became soft during its administration (Lancet, ii., 1871); it was well borne. In chorea affecting strumous children, I can speak well of the iodide of zinc. Dr. Barlow was the first to recommend it (Medical Times, ii., 1857).