This section is from the book "Materia Medica And Therapeutics - Vegetable Kingdom", by Charles D. F. Phillips. Also available from Amazon: Materia Medica And Therapeutics: Vegetable Kingdom.
Active Ingredients. - The dried inner bark of the cinnamon tree possesses a warm, sweet, and aromatic taste, and evolves a corresponding odor. These qualities are referable to a volatile oil, C9H7OH, which, when separated, varies a little in color, when good is bright yellow, but by keeping becomes red. The odor and taste are pleasant, and resemble the corresponding qualities of the bark; it is heavier than water, and on exposure to the atmosphere absorbs oxygen, and forms cinnamic acid, two resins, and water. Cinnamon bark also contains tannic acid in considerable quantity, a resin, and an acid called cinnamic acid.
Physiological, Action. - Cinnamon is warm and cordial to the stomach, astringent, and carminative. The essential oil is devoid of the astringency found in the bark, and taken in moderate doses becomes an agreeable stimulant, producing a sensation of warmth in the epigastrium, and promoting assimilation. The too constant use of cinnamon has a tendency, however, to produce costiveness.
In full doses cinnamon acts as a general stimulant to the nervous and vascular systems. Some practitioners believe that it exerts a specific influence over the uterus.
Therapeutic Action. - Being cordial, stimulant, and tonic, cinnamon is useful in many cases characterized by feebleness and atony. As an astringent it checks diarrhoea, for which purpose it is best combined with chalk, opium, or some vegetable infusion. In the later stages of low fever it is also employed with advantage; and in flatulent and spasmodic affections of the alimentary canal it may often be used to good purpose. Nausea and vomiting are checked by the administration of cinnamon. It has also been employed with excellent effect in uterine haemorrhage, and is an ingredient in various powders, infusions, and tinctures. The oil is sometimes employed as a powerful stimulant in cases of paralysis of the tongue, in syncope, and in cramp of the stomach. The principal value, after all, as with the bark, is to modify the flavor of bitter infusions, and, when combined with purgatives, to check their griping action.
Preparations and Dose. - Ol. Cinnamomi, mj. - v. (.05 - .25); Tinct. Cinnamomi, 3 j. - ij. (4. - 8.); Spts. Cinnam., 3j. - ij. (4. - 8.).