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.
The friction of rheumatic limbs with sulphur is as ancient at least as Pliny (lib. xxxv.), and attention was specially directed to it again some years ago by Dr. Fuller, Dr. O'Connor, and others (Medical Times, i., 1858). They found it useful also in sciatica and lumbago, adding to the frictions close and constant covering with flannel. Renard found it very serviceable in rheumatism affecting tendinous parts, in his own person, after an acute attack; it produced some degree of heat and increase of perspiration when it acted well. It should certainly be tried in all obstinate forms of rheumatism, and especially that form which attacks the soles of the feet in those who are exposed to damp and cold.
The therapeutical action of sulphur and the sulphides is somewat similar, but the former is commonly used in small doses to produce an "alterative," and in large doses a laxative effect, and the latter to modify some acute conditions, especially when they are connected with suppuration in various stages.