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 acidity, pyrosis, and allied symptoms of irritative dyspepsia, such as heartburn, flatulence, colic, or constipation, magnesia and its carbonate are very useful, and their efficacy may be increased by the addition of bismuth or of carminatives: such symptoms are often brought on by food containing too much fat, and this point should be attended to. Headache, accompanied with nausea and mental depression, often occurs in the conditions described, and may be relieved by magnesia. When vomiting is a troublesome symptom in the dyspepsia either of children or adults, and in the vomiting of pregnancy, magnesia often acts well. An effervescent solution of the carbonate or citrate is a good form, but 5 to 10-gr. doses of the sulphate will sometimes act better. I have known this succeed in the vomiting of albuminuria, and in cases where hepatic derangement was more marked than acidity.