This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Coffee may be used in medicine in the form of powder, decoction, or infusion. Of the powder, a drachm or two may be taken for a dose; but it is very seldom used in this way. The decoction may be made by boiling an ounce of the coarse powder in a pint of water for a short time, and then clarifying by the white of an egg. The infusion is best prepared by the process of percolation. A cupful of either may be given for a dose, and repeated, if necessary.
Caffein, in the form of citrate, has been recommended as a remedy or preventive of sick-headache, in the dose of a grain every hour, before or during the paroxysm. Caffein itself, in doses varying from two to ten grains, was found by Lehmann to produce vehement excitement of the nervous and circulatory systems, with palpitations, oppression of chest, headache, perversion of hearing and sight, sleeplessness, erections, and delirium. Prof. II. T. Campbell, of Georgia, administered twenty grains of it, dissolved in infusion of coffee, by enema, in a case of poisoning by laudanum in which the patient could not swallow, with the apparent effect of rescuing him from impending death. (Am. Journ. of Pharm., xxxii. 321, from South. Med. and Surg. Journ. for May, 1860.) Tea is always given in infusion. It is probably preferable to coffee, especially the green variety, when given very strong, as a preventive or cure of sick-headache. As a refreshing drink in febrile diseases it is also preferable, being much more agreeable to the patient and acceptable to the stomach. In diarrhoea, too, it might be expected to prove more effectual than coffee, through its astringeney. In consequence of the tannic acid it contains, it might be used as an antidote to tartar emetic; and I have often employed it, on the same account, as a gargle in mercurial sore-mouth.
There are several other substances which merit a brief notice here, either from former reputation, or from their greater or less efficiency, though at present not much employed as nervous stimulants, at least in this country.