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.
Sulphate of copper is an excellent remedy in these disorders, given in doses of 1/2 to 1 gr., three or four times daily. Elliotson highly recommended it in somewhat larger doses, and generally combined with opium in a pill ("Medico - Chirurgical Transactions," vol. xiii.), but if opium be really required for pain, I find it better given separately, especially in the form of Dover's powder, at bedtime. Morehead also recommends this treatment ("Diseases of India," i.). In infantile diarrhoea, objection has been taken to the use of copper, but I have seen it act most beneficially in obstinate cases, not only when chronic, but also when acute in character, and especially when connected with dentition - the dose may vary from 1/20 to 1/4 gr. several times daily. Pereira specially recommends the remedy in 1/12-gr. dose. Eisenmann has also recorded its value in the diarrhoea of dentition, and of weaning, and states that he has seen many cases treated by it and cured, when others, not so treated, have become chronic and ended in marasmus (Bulletin, June 30, 1859).
In the diarrhoea of phthisis, dependent, as it commonly is, on ulceration of the intestine, we often require to use different forms of astringents, and the sulphate of copper is a valuable alternative. Small doses only should be used, in order to avoid nausea and irritation - 1/4 gr. with the same quantity of opium is advised by Sir T. Watson ("Lectures," ii., p. 21G).
In Enteric Fever with severe diarrhoea, a similar combination is highly praised by Dr. John Harley ("Reynolds' System," i., p. 419), who "considers it more efficacious than any other medicine." The dose may be increased up to 1 gr., but must be kept small enough to avoid vomiting; quite small doses rather allay gastric irritability.