far exceed the narrow limits of the life of man, as is the case with most of the liberal arts as well as with medicine. The number of authors is not small by whose labours the art has attained its present growth; and yet one may hope to master the monuments of their industry within the space of a few years. Let us suppose that, in the course of a thousand years, a thousand authors had made improvements in the profession; and then a person who has diligently studied their works may improve his mind as much in knowledge as if he had devoted a thousand years to the study of medicine. But, when an acquaintance with former authors is despised, what need be expected from the efforts of a single person? For, however much he may surpass others in abilities, how is it to be supposed that his private stock of knowledge should be at all worthy to compare with the accumulated treasures of antiquity? In a word, he who has never turned over the pages of the ancient physicians, nor has formed to his mind a distinct conception of the nature of diseases before he enters the chambers of the sick, will find that, from ignorance and misapprehension, he will confound one complaint with another, for this obvious reason, that he has come to his task unprepared and uninstructed.” And here I would beg to call the attention of my readers to the fact that there is no legitimate mode of cultivating medical knowledge which was not followed by some one or other of the three great sects into which the profession was divided in ancient times. The Empirics held that observation, experiment, and the application of known remedies in one case to others presumed to be of a similar nature, constitute the whole art of cultivating medicine. Though their views were narrow, and their information scanty, when compared with some of the chiefs of the other sects; and although they rejected, as useless and unattainable, all knowledge of the causes and recondite nature of diseases, it is undeniable that, besides personal experience, they freely availed themselves of historical detail, and of a strict analogy founded upon observation and the resemblance of phenomena. To this class we may refer Scribonius Largus, Marcellus, Plinius Valerianus, and a few others, frequently quoted by us. The sect called the Rational, Logical, or Dogmatical, holding that there is a certain alliance and connexion among all the useful and ornamental arts, maintained that it is the duty of the physician not to neglect any collateral science or subject. They therefore inquired sedulously into the remote and proximate causes of diseases, and into the effects of airs, waters, places, pursuits, food, diet, and seasons, in altering the state of the human body, and in rendering it more or less susceptible of morbid changes. Looking upon general rules as not being of universal application, they held that the treatment ought to be modified according to the many incidental