158

Materia Medica.

Part II.

its dose may be gradually increased from half a grain. Col-in pushed it to the length of 30 grains for a dose.

The extract of henbane has been lately much used by ocu-lists for dilating the pupils of the eyes, in order to facilitatethe extraction or breakin . down of the cataract, to diminishsensibility, to destroy adhesions, to reduce protrusions of theiris, and to dilate contraction of the pupil. The mode of ap-plication is by dropping a few drops of solution of the extractinto the eye, or applying them with a camel's hair brush.The greatest effect is produced in about four hours, and it isgenerally over in twelve. Vision is not impaired during itsaction.

Hyssopus officinalis. Ed. Dub.

Willi, g. 1096, sp. 1. Didynamia Gymnospermia. —Nat.ord. Verticillatce.Hyssop.

Off. —The herb and leaves.Herba hyssopi officinalis. Ed.Folia hyssopi. Dub.

Hyssop is a perennial herb which grows wild in Germany-Its leaves have an aromatic smell, and a warm pungent taste.Their virtues depend entirely on an essential oil which risesin distillation both with water and with alcohol. Besides thegeneral virtues of aromatics, they were formerly recommend-ed in humoral asthmas, coughs, and other disorders of thebreast and lungs, and were said to promote expectoration.

Inula helenium. Dub.

Willd. g. 1489, sp. 1. Smith, g. 369, sp. 1. Syngenesis-superflua. —Nat. ord. Composite radiates.Elecampane.

Off— The root.

Radix enul;e campan^e. Dub.

This is a very large downy perennial plant, sometimesfound wild in moist rich soils. It flowers in July and Au-gust. The root, especially when dry, has an agreeable aro-matic smell : its taste, on first chewing, is glutinous, and, asit were, somewhat rancid ; in a little time it discovers an aro-matic bitterness, which by degrees becomes considerably acridand pungent.

Neumann got from 480 grains of the dry root, 390 watery,and 5 alcoholic extract ; and inversely, 1 50 alcoholic, and"300 watery. In distillation, alcohol elevated nothing, but the