238

Materia Medica.

Part II.

r

I

The capsules arc prickly and triangular, and contain, undera thin, dry, grey, and black-marbled husk, a white oily ker-nel. The skin is extremely acrid ; and one or two of the seedsswallowed entire operate as a drastic purgative or emetic.

The kernels yield almost a fourth part of their weight of abland fixed oil, commonly called Castor oil. It is obtainedfrom them either by expression, or by decoction with water.The former method is practised in Europe, the latter in Ja-maica. To increase the product, it is common to parch theseeds over the fire, before the oil is extracted from them ; butthe oil thus obtained is inferior to that prepared by cold ex-pression or simple decoction, and is apt to become rancid.

Genuine castor oil is thick and viscid, of a whitish colour,insipid or sweetish to the taste, and without smell.

Medical use. —As a medicine, it is a gentle and useful pur-gative : it in general produces its effects without griping, andmay be given with safety where acrid purgatives are impro-per, as in colic, calculus, gonorrhoea, &c. : some likewise useit as a purgative in worm cases. Half an ounce, or an ounce,commonly answers with an adult, and a drachm or two withan infant.

The aversion to swallowing oil is generally considerable.

Different modes of overcoming this have been proposed___

Some prefer taking it swimming on a glass of water, or pep-permint water, others mixed with coffee, in the form of anemulsion, with mucilage, or with the addition of a little rum.

Rosa.

Willd.

Nat. ord. Scnticosce.

997. Smith, g. 232. Icosandria Polygyria __

Sp. 16. Willd. Rosa gallica. Ed. Lond. Dub.Red rose.

Off. —The petals.

Petala ros^ gallice. Ed. Lond.

Petala rosje rubra:. Dub.

This has not the fragrance of the succeeding species; butthe beautiful colour of its petals, and their pleasant astringen-cy, have rendered them officinal. It must, however, be re-marked, that their odour is increased by drying, while that ofthe damask rose is almost destroyed.

Sp. 15. Willd. Rosa centifolia.Damask rose.

Ed. Lond. Duh.