This moral view of events, without any regard to chronological minutiæ, may be denominated the PHILOSOPHY OF HISTORY, and should be carefully distinguished from that technical and barren erudition, which consists in a mere knowledge of _names_ and _dates_, and which is perused by the medical student with as much apathy, and as little profit, as the monk counts his bead-roll. It has been very justly observed, that there is a certain maturity of the human mind, acquired from generation to generation, in the _mass_, as there is in the different stages of life, in the _individual_ man; what is history, when thus philosophically studied, but the faithful record of this progress? pointing out for our instruction the various causes which have retarded or accelerated it in different ages and countries. In tracing the history of the Materia Medica to its earliest periods, we shall find that its progress towards its present advanced state, has been very slow and unequal, very unlike the steady and successive improvement which has attended other branches of natural knowledge; we shall perceive even that its advancement has been continually arrested, and often entirely subverted, by the caprices, prejudices, superstitions, and knavery of mankind; unlike too the other branches of science, it is incapable of successful generalization; in the progress of the history of remedies, when are we able to produce a discovery or improvement, which has been the result of that happy combination of Observation, Analogy, and Experiment,[3] which has so eminently rewarded the labours of modern science? Thus, OBSERVATION led Newton to discover that the refractive power of transparent substances was, in general, in the ratio of their density, but that, of substances of equal density, those which possessed the refractive power in a higher degree were inflammable.[4] ANALOGY induced him to conclude that, on this account, water must contain an inflammable principle, and EXPERIMENT enabled Cavendish and Lavoisier to demonstrate the surprising truth of Newton’s induction, in their immortal discovery of the chemical composition of that fluid. The history of Astronomy furnishes another illustration equally beautiful and instructive,—The Astronomer _observed_ certain oscillations in the motions of Saturn and Jupiter; by _Analogy_ he conjectured that this phenomenon was produced by the influence of a planet still more remote: a supposition which was happily confirmed by a telescopic _experiment_, in the discovery of Uranus, by Herschel.