Gentian may be administered in the form of infusion, tincture, or extract. The compound mixture of gention of the London pharmacopoeia, consisting of six parts of compound infusion of gentian (Ph. L.), three parts of compound infusion of senna (popularly known as black draught), and'one part of compound tincture of cardamoms, forms, in doses of from 1 to 2 ozs., a safe and moderately agreeable tonic and purga tive medicine in cases of dyspepsia with constipation. An imitation of the compound tincture of gentian, known as Stoughton's elixir, is very much used in the West Indies before meals as a pleasant bitter, to give tone to the languid stomach. The extract of gentian is very commonly used as the vehicle for the exhibition of metallic substances (such as salts of iron, zinc, etc.) in the form of pill. Powdered gentian is one of the chief constituents of an empirical medicine known as the Duke of Portland's gout powder. The bitter principle on which its virtue depends exists also in other species of this genus, probably in all, and appears to be common to many plants of the same order. The roots of G. purpurea, G. punctata, and G.pannonica, are often mixed with the gentian of commerce. They are deemed inferior. Several species are natives of Britain, but
none are at all common except G. campestris. and G. amarella, plants of a few inches in height, with small flowers, both of which are in use as tonics, although only in domestic medicine.—G. Cateskel, a North American species, is extensively used in its native country, as a substitute for common gentian, and G. Karroo is employed in the same way in the Himalaya.—Several species of gentian are common ornaments of our gar dens, particularly G. acaulis, a small species with large blue flowers, a native of the continent of Europe and of Siberia, often planted as an edging for flower-borders. Of North American species, G. crinita is particularly celebrated for the beauty of its flowers, which are large, blue, and fringed on the margin. It has a branched stein, and grows in wet ground. The brilliancy of the flowers of the small Alpine species has led to many attempts to cultivate them, which have generally proved unsuccessful, apparently from the difficulty of imitating the climate and seasons of their native heights.