kinds; it is rational so far as the curative effect is sought through a primary influence on some or other of the natural functions followed by consecutive changes thence resulting; empirical, when from obscurity in the modus operandi, and failure in discerning the series of vital actions through which the cure takes place, this the ultimate effect can be alone perceived. Blood-letting, when employed for relief of diseases occasioned by plethora or congestion, may serve as an instance of the former; the use of bark in stopping a paroxysm of intermittent fever, will exemplify the latter. The enlightened practitioner will, so far as science and experience can guide him, lean to the use of the former class of remedies as most intelligible in their operation, more manageable under varying circumstances, and, on these accounts, more certain in their results; but he will not despise the aid of empirical means for doing whatever good they may be able to accomplish.
It is clear that, if, in the operation of remedies which, through our ignorance, we are compelled to use empirically, we could discover the series of physiological changes through which the curative effect is produced, our knowledge would be most valuably extended, and our capability of administering such remedies with precision and certainty, be greatly increased. And this suggests one course of medical enquiry, worthy the attention of every cultivator of the science, and which will not be speedily exhausted, namely, to ascertain the primary impression and consecutive functional changes through which each remedy, employed for the cure of disease, acts, ultimately, on the pathological derangements for which
