It is a remarkable fact that some diseases should disappear from among us, while others, again, should continue to prevail, colic[1] for example. It was only in the reign of Tiberius Cæsar that this malady made its appearance in Italy, the emperor himself being the first to be attacked by it; a circumstance which produced considerable mystification throughout the City, when it read the edict issued by that prince excusing his inattention to public business, on the ground of his being laid up with a disease, the very name of which was till then unknown. To what cause are we to attribute these various diseases, or how is it that we have thus incurred the anger of the gods? Was it deemed too little for man to be exposed to fixed and determinate classes of maladies, already more than three hundred in number, that he must have new forms of disease to alarm him as well? And then, in addition to all these, not less in number are the troubles and misfortunes which man brings upon himself!

The remedies which I am here describing, are those which were universally employed in ancient times, Nature herself, so to say, making up the medicines: indeed, for a long time these were the only medicines employed.

(2.) Hippocrates,[2] it is well known, was the first to compile a code of medical precepts, a thing which he did with the greatest perspicuity, as his treatises, we find, are replete with information upon the various plants. No less is the information which we gain from the works of Diocles[3] of Carystus, second only in reputation, as well as date, to Hippocrates. The same, too, with reference to the works of Praxagoras, Chrysippus, and, at a later period, Erasistratus[4] of Cos. Herophilus[5] too, though himself the founder of a more refined system of medicine, was extremely profuse of his commendations of the use of simples. At a later period, however, experience, our most efficient instructor in all things, medicine in particular, gradually began to be lost sight of in mere words and verbiage: it being found, in fact, much more agreeable to sit in schools, and to listen to the talk of a professor, than to go a simpling in the deserts, and to be searching for this plant or that at all the various seasons of the year.