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.
In the ordinary form of diphtheria the sulphate of copper has also been found useful by some observers. Dr. W. Squire speaks of it as one of the most effectual emetics, and recommends a solution of 5 gr. to the ounce to be given in divided doses - a teaspoonful only to young children, so as to induce moderate vomiting ("Reynolds' System," i., p. 147, second edition). In cases of formation of diphtheritic membrane on the cutaneous, or nasal, or vulvar surface, lotions of the sulphate are found to destroy it, and to prevent its re-formation.