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.
Chlorate of potash in full doses, either alone or combined with iodide, has seemed very useful to many observers (Squire, Hillier, Perrin, Henoch, Vogel). I quite agree with them; I have for twenty years used it more or less with advantage. In America, it is commonly given with chloride of ammonium. Recently Dr. Ciattaglia (Rome) has recorded his very successful results with doses of 10 to 15 grammes daily; but in addition he thoroughly applied to the affected part a wash of chloral - 1 dr. in 5 of glycerin (Lancet, i., 1876).
The permanganate of potash has also proved useful in diphtheria, as well internally as locally (Copland: Lancet, i., 1863, p. 151, and Ranking, i., 1865, p. 55). I can add my testimony to its value, though it is right to recognize the statements of Dr. H. C. Wood, that he "has never seen the chlorate do a particle of good in such maladies as scarlet fever, diphtheria, etc.," and with regard to the permanganate, "as immediate decomposition of it must occur in the stomach, the absurdity of its internal use needs only to be pointed out" ("Elements of Therapeutics," 473-586).