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 of irritative dyspepsia, especially when occurring in stout and rheumatic or gouty persons, and marked by red tongue, acid eructations, or pyrosis, with nausea and discomfort after meals, the liquor potassae or bicarbonate of potash, taken at that time (after meals), often gives relief; in gouty cases, and when the urine is loaded, they are to be preferred to soda. In cases of atonic dyspepsia, however, with pale coated tongue and much weight after food, small doses of alkali are best given before a meal, and if continued for some time should be combined with a bitter infusion. In cases of "biliousness," with yellowish complexion and conjunctivae, headache, nausea, etc., and even in actual catarrhal jaundice, salts of potash are good adjuvants (Golding Bird, Bartholow). Dr. Todd recommended the sulphuret (10 gr.) when the. "mucous follicles were implicated."
In vomiting connected with the condition just described, or with other functional or even organic gastric disorder, or occurring at the commencement of inflammatory fevers, the bicarbonate of potash is advantageously given in effervescence with citric acid.
In cases of poisoning by the mineral acids, bicarbonate of potash may be employed not only to neutralize the acid, but as an emetic, by giving first a large dose of the alkali, and a suitable quantity of citric acid some minutes afterward. The amount of carbonic acid evolved distends the stomach so as to assist discharge of its contents.