ling, it has passed beyond the domain of a conjectural science, and taken its place among the most positive of the sisterhood. And a system of medical logic has grown out of it, showing conclusively that the laws upon which it is founded are not based upon hypothesis alone, but have their origin in the immutable canons of nature. In this respect it is in advance of all the physical sciences; for it deals not simply with the materialities of the universe, but enters the domain of the passions, and deals with problems affecting our moral nature. And I cannot help feeling in this connection, that the labors of Pinel, Esquirol, and Conolly, have elevated it into an atmosphere beyond where even Harvey or Bacon had placed it. Slowly, and with the procession of the centuries, it has freed itself from dogmas of superstition, has cast aside alchemy and astrology, talismanic traditions and routine methodism, and now stands upon a pinnacle of reason, both founded upon, and justified by, experience. In this tendency towards rationalism it has never forgotten that God rules in all, and over all, things. And its best apostles have never failed to put upon record their solemn asseveration of a constant dependence upon the Deity, as well for the least, as for the greatest of their achievements. Under such convictions as these we cannot fear that the rationalism of any science will offend the Great Author of them all; nor that our little systems, as ephemeral as the sunshine, can cloud His glory among men. For one, I prefer to consider them only as so many stepping-stones with which He has provided us for a higher, and more exhaustive comprehension of the laws of His universe; and as they are offshoots of His omniscience, so does He smile upon every devout laborer, in whatever field engaged, who seeks with finite mind to approach Him through a study of His works. "Our little systems have their day, They have their day, then cease to be, "We have but Faith- -we cannot know, It is this constant growth in positive knowledge, beginning with the earliest civilized nations, and transmitted by each generation in successive waves to posterity, that has made the physical sciences the handmaids of commerce, legislation, and religion. And today, but for them, the Bible would not be found disseminating the comforts of a Christian belief in the distant isles of the sea, nor anæsthetics exist to rescue life from the shocks of pain, or the torture of inevitable operations. But the practice of a science, limited as it is to the exigencies of particular cases, must ever fall behind the philosophy of that science. Even as the hand, however cunning in execution, must always fall behind the brain in scope of power; so, a sedulous cultivation of a true system of philosophy in medicine, has done more to advance that science than the labors of thousands of simple practitioners. Professional experience is personal, and dies with its possessor; philosophy is cumulative and immortal, and descends unaltered to posterity. And without the development of such a philosophy, knowledge being only traditional, we should be standing little in advance of our fathers in any science. Every age has perceived and acknowledged this law of genesis, and consequently every age has produced its own philosophy. Yet, inasmuch as no great events happen prematurely, each in the fulness of time taking its appointed place, so, even amid the infancy of science, we perceive germs of thought and glimmerings of truth which have only fructified in after ages. For, if it requires centuries, and changes of government and laws to build great cities, or found empires, no less so is it with the establishment of a true system of philosophy. Battles must be fought between contending factions, persecutions be endured by defeated minorities, and schools be convulsed and overthrown, before the equilibrium of truth can finally be obtained; and whether in theology, metaphysics, or medicine, history ever consecrates the victory in language teeming with painful significance. In the separate characteristic of every age we find one dominant idea. And that of our own, under the best sanctions of Christian belief, is the tendency everywhere manifested to convert dogmatic into rational philosophy, and to substitute a knowledge of the positivism of universal laws for that of empirical observation. In law, medicine, theology, and government, radical changes are being effected, because the educated mind of the world gives, as by a preconceived intuition of its truth, universal assent to this proposition. It accepts it as a step forward, made in its own proper time and season, and the result of all those cumulative agencies of development which the art of printing and the Reformation inaugurated. In searching for fields of activity, it renounces at the start the idea of discovering new forces, and new worlds in which to employ them. All the physical forces existed at the dawn of creation as they do now. Light, heat, moisture, electricity, magnetism, gravitation, and matter, have never changed their character. It is only in the variety of their combinations that changes occur; but the elements behind remain as first created-simple, unvarying, absolute. Hence the wisdom of ages has taught us that the true field of employment for finite intelligence is inside, and not outside, of this realm. Under Providence, we are permitted to exercise ourselves illimitably within it, knowing that only fools or infidels seek to go beyond. Convinced of this great law, which inexorably limits the human mind to the unfolding of new relations between physical forces, and not to the discovery of new forces, philosophy is constantly taking up the seed-thoughts of different ages, and endeavoring to develop them further. The astronomy of the Chaldeans and Egyptians has been used and verified in many of its computations by that of modern times; the mechanical forces by which the pyramids were built and obelisks raised have been further enlarged in the range of their activities; the medicine of the Arabs, and Greeks, and Romans, has furnished some data upon which to unfold new laws of disease and treatment, so that no age has been completely barren of fruit useful to posterity. And every day, in recognition of this fact, we are searching for some one of those mysterious lost Arts, which we feel was the triumphal measure of a success achieved by a past age. Now, in medicine, the great undeveloped seedthought of every age and school has been, not the treatment of disease, which must be more or less empirical and personal, but the prevention of disease, which is philosophical, impersonal, and therefore overpeers it. And to-day, as by a spasm of remorse, that much-neglected goddess Hygeia, whose worship has heretofore been left to the caprice of individuals, has suddenly been reinstated, not in private houses alone, but in legislative halls, as one of the Dii Majores of our civil establishments. To-day, it is recognised judicially, that State medicine is a science and deserves a priesthood, and a place in the government of every commonwealth, as one of the chief safeguards to life. Truly, the world moves, the pendulum of the ages continues to swing, the arc of progress increases its diameter, and we may soon hope to reach a pinnacle in statesmanship corresponding to the Alpine heights upon which physical science has reared her last temples. The prevention of disease, the seed-thought of many a past age, has always been recognised as a legitimate branch, a coequal system with therapeutics in the science of medicine. In fact, it constitutes the first and best chapter in its philosophy. All the fathers in medicine either allude to it, or incorporate some of its laws in their treatises. Even St. Clement, one of |