Natural philosophy is highly necessary, independent of its connection with matter and motion. We are advancing rapidly into these branches, where, as in the human body, we see effects without being able to comprehend causes; we mean in the sciences of electricity and galvanism, and have reason to suppose that the discoveries in these will, at no great distance, materially illustrate the functions of the human system. It is disgraceful not to be intimately acquainted with each, and in the acquisition of either mathematics are useful, if not necessary. The great supports of this position are the papers of Columb and Van Swinden. Another assistant in acquiring this habit of close reasoning is logic, a science essentially useful, though, in conse-quence of its abuse, too much neglected. When properly regulated, it gives the distinctions so necessary to the clear enunciation of a proposition, and the conduct of the reasoning cither in support or in opposition; and it leads the mind, by easy steps, to detect the fall; a too unlimited statement, of an unsuspected subterfuge, or of inconsequential reasoning. Were logic more generally studied, many bulky volumes would neither have tired our patience, nor disgusted our judgment. Fatal as its neglect has been in every science, it has not been more severely felt than in medicine.

Of chemistry we need not now speak: it is acknowledged to be an essential part of the physician's education; nor should any science which is supposed ornamental in a gentleman be omitted. Geography, for instance, may appear far from a necessary branch of medical knowledge; but it would be disgraceful to speak of the ipecacuanha as a production of Russia, or the cortex peruvianus of the arctic circle. A knowledge of botany is highly necessary, especially an intimate acquaintance with the natural families, as it will often enable a physician to apply his indigenous species of plants to useful purposes where the exotic is wanting.

All these arc, or should be, preparatory sciences, for medicine itself is a study which Trill fill all the time usually allowed for its attainment. Where then can this varied knowledge be acquired? not behind the counter; not in dispensing the prescriptions of others; not in staring at diseases, without information, or without principles. In this way, the student cither attains no knowledge or crude imperfect ideas, which he can scarcely ever correct; or, if correction is in his power, it will require more trouble than the acquisition of juster notions. This kind of education also narrows the mind in another view. We look with some partiality to our earliest instructor; our first ideas stick to us with peculiar force, so that it is of consequence where they are acquired. Those who are accustomed only to a narrow circle cannot easily expand their ideas beyond it, as the native of Switzerland thinks his valley scarcely less than the whole world. We do not indeed contend, that able and enlightened physicians have not, at times, escaped from the shop; or, on the other hand, that the deepest and most profound philosophers have been the best practitioners. Exceptions prove a general rule; but some distinctions arc requisite in the full discussion of this question, which we shall soon consider.

We have, in different parts of this work, hinted that a physician should be, from his earliest years, educated with the view to his future profession. If the best parts of his life have been directed to other pursuits, he will seldom acquire that extent of information, and readiness of application, which the practice of his profession requires. In the most advanced period of his life, what he may have seen at his first entrance into the study may happen to be applicable, though, through the whole interval, it has been never necessary. It must not be supposed, that the most splendid abilities or the deepest knowledge are always requisite. Many diseases are obvious in their causes, appearances, and treatment; but, on the other side, many serious complaints assume, at first, a common form, and it requires no little sagacity to trace them in their bud; no little knowledge to obviate the fatal consequences. Were it always possible to say whether a disease was common, great abilities or extensive knowledge might not be necessary; and we thus find physicians, with little real skill, but with policy and address, pass through life with credit, sometimes with the highest applause. . It is not, however, enough to possess knowledge, but the mind should be ready and active in its application. It is often necessary to adopt at once a plan, and to pursue it with active decision: it is necessary to weigh contending difficulties, and at once to seize the path where the fewest or the least important appear, or where the inconveniences are counterbalanced by the advantages. This rapidity of decision, the result of great and extensive knowledge, as well as readiness of resource, is often equally the offspring of ignorance. No difficulty can be experienced by those who are unable to anticipate danger; and doubt, the consequence of different plans contending for superior eligibility, can scarcely be felt by those who have none. Physicians are called on, in general, to act with this prompt decision; and to hesitate is usually accounted a mark of ignorance. A man must have merited the confidence of the world before he can require time for consideration, and his reputation be firmly established before he can own himself at a loss.

Readiness of resource is partly owing to habit and long experience; but it may be easily acquired by a ready arrangement of ideas, and clear distinct views. The able and experienced physician, who can at once comprehend the object to be attained, will, at the same moment, perceive the various methods by which it may be effected, and he has only to choose the most convenient and the best adapted to the habit or idiosyncra-cy of his patient. In his progress new views will generally open, and the soundest judgment is shown in steering between the opposite extremes of varying the plan according to" the variety of symptoms, or obstinately persisting in it, notwithstanding every change of appearance. The first is pleasing to common observers, as it shows diligent attention; but it is a proof of weakness and indecision. The last, perhaps the most venial error, is the effect of too great confidence; and, unless accompanied with extensive knowledge which dictated the first opinion, and an acute sagacity in discerning the effects of the medicines, is scarcely less injurious.