or QUINIA**, a vegetable alkaloid discovered by modern chemistry in the yellow Peruvian bark (*Cinchona cordifolia*). It is a white powdery substance, sparingly soluble in water, but dissolved by warm alcohol, from which it is not deposited in crystals. Quinine unites with acids, and forms salts, the most important of which is the sulphate. It is soluble in water, and crystallizes. In the dose of one grain twice or thrice a day it is the most valuable of all the vegetable tonics, and in larger doses it is the best of all the antiperiodics. Quinine should not be administered where there is a tendency of blood to the head.