O N T H E

VIRTUES of MEDICINES.

HAVING finilhed the fubjeCt of Aliments, I proceedin the next place to confider Medicines. As intro-ductory to this, I think it neceffary to tell you the mannerof inveftigating their virtues. As the fpundation of what Ihave to fay on this, I fhall take the following Canon fromLinnseus, in his Materia Medica: Syfiemate, £)ualitate } etExperientia eruitur omnis ufus Plantar urn.

What he here applies to Vegetables, will, in fome mea-fure, fuit the other Kingdoms. The two firft qualities heexplains more fully in his Philofophia Botanica, where heemploys the terms Fruftijication , which is the fame with theterm Syjiem\ for, according to the fiunification, are plantsfyftematically difpofed. In giving the qualities of Aliment,I have often alluded to its place in Natural Hiftory, andfhall be obliged hereafter to do fo more in giving the qua-lities of Medicine. This method of inveftigating the vir-tues from the Botanical Divifions, was long fince ftarted byHoffman, in his treatife De compendiofo methodo, &c. andbefore him by our countryman Dr. Blair, in the Philofo~phical Tranfaflions, &c. The Botanical Rules are, how-ever, far from being general; but, as far as they go, they fervevery well for analogy, and it is on this account we fhalloften have recourfe to them. But before you can be ac-quainted with thefe Rules, it will be neceffary to give youan idea of Method in Natural Hiftory in general.

Method in Natural Hiftory in general, is that by which aproduction of Nature being prefented, we can proceed toknow how it can be diftinguifhed from all other productionsof Nature, and the name by which IVriters have diftin-guifhed it, in order that, by this means, we may arrive at aknowledge of its nature, qualities, and virtues. This isdone by collecting natural productions into Kingdoms,

Claires,