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.
Both the oxide and the sulphate of zinc, especially in conjunction with belladonna, have been found to relieve spasmodic cough, whooping-cough, etc. (Fuller: Lancet, ii., 1860). In the intervals of spasmodic asthma, they are given as prophylactics (Symonds: British Medical Journal, i., 1868). The valerianate has been successfully used for obstinate hiccough and for hysterical cough (G. Harley: Medical Times, ii., 1863), but although of some value, is uncertain in its action. In laryngeal spasm, sometimes, 5 to 6-gr. doses will succeed when smaller ones fail (Medical Times, i., 1858, p. 475).