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.
It is very useful for patients suffering from pain, weight, and sense of fulness at the epigastrium with flatulent distention, acidity, sour or bitter eructations, nausea or vomiting, furred tongue, foul breath, and with a tendency to loose, ill-formed motions. These stomach symptoms are usually accompanied with palpitation.
The charcoal powder, which acts by absorbing intestinal gases and neutralizing offensive products of decomposition, should be perfectly fresh and taken dry, and preferably at the commencement of a meal. The dose need not be so large as a teaspoonful, which is commonly given; in many cases I have found 2 to 5 gr. sufficient. Bismuth and magnesia are sometimes advisable at the same time.