THAT department of medical science which treats of the nature, effects, and uses of those remedies that are employed for the prevention or removal of disease is called MATERIA MEDICA. It comprises the natural history of the articles, or an account of those circumstances by which they may be distinguished, and of the means of procuring and preserving them; their chemical history, or an account of the changes which they undergo from the action of various reagents, the mode of analyzing them, of separating their most useful principles, and of ascertaining their purity; and their medical history, or an account of their sensible effects on the animal system both in the healthy and morbid state, with their application to the practice of medicine.
The art of collecting, and preserving the various substances employed in medicine, and of reducing them to those forms that are best suited to the various purposes for which they are exhibited, is called PHARMACY. This art is practised by the trading chemist and the apothecary; and at least the principles of it form a necessary part of education to every member of the medical profession.
In the present edition of our ENCYCLOPÆDIA, it is proposed to treat of these two subjects together, since
they are intimately connected, and when considered under the same treatise, will occupy much less room.
We shall divide this article into four parts; in the first of which we shall briefly treat of those articles that are employed to support life, or of diet; in the second we shall treat of remedies in general, and shall arrange them into classes according to their action on the animal economy; in the third we shall consider the methods of preparing them for exhibition, or shall lay down the general principles of pharmacy; and in the fourth we shall briefly notice each of the articles employed in medicine, whether simple or officinal, and mention the most important circumstances necessary to be known respecting them.
As the limits which have been assigned to this article are extremely confined, it cannot be expected that the subject will be treated at any great length. Contrary to usual practice, we shall dwell most on the general circumstances of materia medica and pharmacy, and shall be as brief on the individual articles, as is consistent with perspicuity and practical utility.
We shall not at present enter on a historical account of the writers on the materia medica and pharmacy. If we find room for such an account, we shall introduce it at the end of this article, where we conceive it would be most properly placed. It will be expected, however, that we should mention some of the most approved