and neglected duty for which minds were given them, the duty of thinking for themselves.

Caution. Let me repeat to you respecting lectures the same caution that was suggested in relation to books. In listening to lectures you should be neither too easy nor too hard of faith. You should view your minds with respect, but at the same time with distrust. You should not believe without reason every thing that you hear; and you should not reject without reason the instructions of those who have gone before you in science, and whom you have chosen as your teachers. "The pupil," says Bacon, "should believe; when he has been taught sufficiently, he should then exercise his own judgment: oportet discentem credere; oportet jam edoctum judicio suo uti.”* Yet it may be said, under correction, that the pupil, however young and inexperienced, should not suffer his opinions and judgment to be, in all cases, decided by the mere authority of his instructors. But on the other hand, being young and inexperienced, he should be guarded against that petulance and folly

* De Augmentis Scientiarum, Lib. 1.

+ Obest plerumque iis qui discere volunt, auctoritas eorum qui se docere profitentur: desinunt enim suum judicium adhibere; id habent ratum quod ab eo quem probant judicatum vident.

CICERO, De Nat. Deorum, Lib. 1—5.

which under the guise of liberty of thought sometimes incline the young to reject without examination the doctrines inculcated by their teachers, and which may be the result of careful observation and of mature study and reflection.

LECTURE IV.

CLINICAL EXPERIENCE.

The student of Medicine requires the assistance of other means of instruction besides books and lectures, before his professional education can be completed. As an important and indispensable part of that education, he requires to be furnished with opportunities for personal observation and experience.

Medicine is in part a practical art, and in order to be learned, it must be seen in its practical applications. Lectures and books are useful means for preparing the student to observe with accuracy and advantage; but they are not sufficient by themselves to make him a physician. Before he can be qualified for the active duties of his profession, he must have opportunities for observation; and he must use those opportunities with attention and diligence.

It is on this account that a Hospital forms a necessary part of the apparatus of medical instruction; a part so necessary that without it no School of Medi

cine can be even moderately well qualified to do justice to its pupils.

There are two conspicuous advantages which the student may expect, if he improve to the best of his ability the opportunity for acquiring knowledge which is presented to him in the wards of a hospital.

In the first place, there are many things in the natural history of diseases which you can learn much more easily and more perfectly by seeing them than by any other means. No verbal description, however accurate and faithful, of the eruptions of Typhus and Typhoid fever, of the agitated muscles of Delirium Tremens or Chorea, or the Fine Crepitation of Pneumonia, or the Bellows-Murmur of Endocarditis, can give you so correct an idea of those symptoms as you can obtain in a few moments from observing them as you stand by the bed-side. "True knowledge of things," says Julius Scaliger, "cometh from things themselves-rerum ipsarum cognitio vera a rebus ipsis est." Consider how much more complete and exact is your impression of the size and appearance of a foreign animal or a new plant when you have examined it with your own senses, than when you have depended upon the most elaborate description given by the ablest zoologists or botanists. When

you have seen the Giraffe, or the Victoria Lily, you

have an infinitely better conception of the figure and colour of the beast, or of the flower, than could be given you by all the perspicuity and eloquence of Buffon or Cuvier, or of De Candolle or Linnæus. The same thing is true in relation to diseases. If you desire to understand them so as readily to detect their existence, and distinguish their character, you must not depend exclusively upon the accounts given by others. You must see them for yourselves. You must live with them in habits of constant and familiar intercourse. You must spend your days and nights, your months and years, in their melancholy but edifying society. It is thus, and thus only, that you can become thoroughly acquainted with their phenomena, and learn to interpret the language of their symptoms.

By frequenting the wards of a Hospital, you may obtain all the benefits of experience, without encountering the anxiety, pain, and sorrow which usually imbitter that acquisition. You may there study the varying and complicated symptoms of disease, and observe the effects of remedial means, and exercise your judgment respecting the treatment employed, and compare what you have heard in the lectureroom, or read in your closets, with what you find written in the book of nature.