This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
The dried root of Gentiana lutea. Collected in the mountainous districts of central and southern Europe.
Characters.-From half an inch to one inch in thickness, several inches in length, often twisted, much wrinkled, or marked with close transverse rings; brown externally, yellow within, tough and spongy; taste at first sweetish, afterwards very bitter.
Composition.-Gentian contains •1 per cent. of an active bitter glucoside, gentiopicrin, C20H30O12, which is crystalline, readily soluble in water and dilute spirit, and yields, by decomposition, glucose and gentiogenin. It is united with an inert non-bitter body, gentianic acid, sugar, gum, and a trace of a volatile oil.
Preparations. 1. Extractum Gentianae.-Aqueous. Dose, 5 to 10 gr.
Infusum Gentianae Compositum. 1 in 80, with Orange and Lemon Peel. Dose, 1 to 2 fl.oz.
Mistura Gentianae. 1 in 40, with Bitter-Orange Peel,
Coriander, Water, and Proof Spirit. Dose, 1/2 to 1 fl.oz.
Tinctura Gentianae Composita. 1 in 13 1/3, with BitterOrange Peel, Cardamoms, and Proof Spirit. Dose, 1 to 2fl.dr.
Gentian possesses the action of other bitters, as described under Calumboe Radix. The uses made of it correspond. It is, perhaps, the most extensively used and popular of all bitters, because (1) it is agreeable, being very slightly aromatic; (2) its bitter is not intense, and its astringency but slight; and (3) it is more stimulant to the bowels, and more disinfectant than some bitters. A drawback to its usefulness is the liability of the sugar which it contains to ferment in simple infusions.