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 cases where there occur well-marked paroxysms, terminating in the ejection of quantities of mucus, small doses of sulphate of copper repeated frequently until vomiting occurs will usually give relief; but independently of vomiting, in asthma of more purely nervous type, I have observed benefit from 1/6 gr. and upward, given every one to three hours during the attacks, and continued night and morning in the intervals, so as to secure a tonic effect on the nervous system.
Whooping - Cough, in the early spasmodic stage, is often relieved by the same remedy, especially if moderate emesis be produced.