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.
After what has been stated above, little remains to be said on this point. Belladonna may be given in substance, infusion, extract, or tincture; and there are two officinal preparations intended exclusively for external use, namely, the plaster and ointment. Atropia is also among the officinal preparations.
The commencing dose of the powdered leaves is one or two grains, to be repeated two or three times daily, and to be gradually increased until the effects of the medicine are produced. When the leaves have not been injured by time, ten or twelve grains daily can rarely be exceeded without inconvenient effects.
The Infusion may be prepared by macerating a scruple of the dried leaves in ten fluidounces of boiling water. The dose at first is one or two fluidounces two or three times daily, to be increased as in the case of the powder.
The medicine, however, in this country, is much more used in the form of extract than in any other way. The U. S. Pharmacopoeia directs two extracts, one of which is the inspissated juice, and the other is prepared by means of diluted alcohol.