Part II.

Materia Medica.

16/

Medical me. —Both the bark and buds of cassia possess thesame properties with cinnamon, though in an inferior degree.

The bark is very frequently, and sometimes unintentionally,substituted for the more expensive cinnamon; and the pro-ducts obtained from cassia bark and buds, by distillation, arein no respect inferior to those prepared from cinnamon.

Sp. 3. Laurus camphora. Ed. Lond. Dub.Camphor tree.

Off". —The camphor.Camphora lauri camphors. Ed.■ Camphora, cohcretum sui generis distillationeparatum. L.Camphora, resina. Dub.

The camphor laurel grows in great abundance, and to avery considerabie size, in the forests of Japan. It is not un-common in greenhouses in England. Every part of the treesmells strongly of camphor, which is obtained from the trunk,branches, and root, by distillation. They are cut down intosmall pieces, and put into a still, with a proportion of water.After the water has been kept boiling forty-eight hours, thecamphor is found adhering to the straw with which the headof the still is lined. In this state it is imported by the Dutch,and is called crude camphor. It is very impure, consisting ofsmall brownish or dirty grey grains, mixed with straw, wood,hair, and other impurities. From these it is purified, inHolland, by a second sublimation in glass vessels ; being pre-viously mixed with quicklime, to combine with and preventany empyreumatic oil with which it may be contaminatedfrom subliming, while the camphor concretes in the upperpart of the vessel into cakes, convex on the one side, and con-cave on the other, about two or three inches thick, thinnerat the edges, and generally perforated in the middle.

Pure camphor is lighter than water, very white, pellucid,somewhat unctuous to the touch, brittle, yet tough and elas-tic, so as to be scarcely pulverizable; shining in its fracture,and crystalline in its texture; of a bitterish, aromatic pun-gent taste, yet accompanied with a sense of coolness, of astrong and very penetrating smell; very volatile, inflammable,burning entirely away, without leaving any coal or ashes ; ca-pable of combining with the resins and balsams, soluble in al-cohol, ether, fixed and volatile oils, and the concentrated sul-phuric, nitric, muriatic, fluoric, and acetic acids; separablefrom these alcoholic and acid solutions by water ; insoluble inwater, alkalies, and the weaker acids; decomposed by heat,when mixed with alumina, into an essential oil and charcoal \