The present age, unlike any that has preceded it, is peculiarly one of rigid, radical and fundamental examination. Everything in the Heavens above, or in the Earth beneath, is tested and retested; analyzed, synthetized and submitted to the crucible of stern reason, and the logical conclusion of experience; even to the extreme of possibility. This is true not only of the material universe, but of all mental and moral conditions, of social, political and even religious institutions. Nothing, in this day, and especially in this country of free thought and liberty of speech, is taken for granted merely because it can lay claim to the honors of a great antiquity, or can number thousands or millions of adherents. Vast differences are to be observed in governments, churches, creeds and social practices; and all, however opposite and apparently antagonistic, are working out a solution to the problem-- "WHAT IS TRUTH?" Conservatism is fast dying out, hidden and smothered by the ever-flowing tidal-waves of progression. Radicalism ceases to become radical, by the daily and hourly recurrence of startling discoveries, and new, unheard-of, and unexpected adaptations of old laws. The mistakes of to-day will be found to be mistakes, and will be rectified. Whenever and wherever freedom holds her sway, evil must work out its own destruction, and good enthrone itself in the hearts of those benefitted by its benign influence. In this spirit, and with such views, let us look at the progress of Medical Science that we may learn from the experience of the past to correctly estimate the developments of the present and aid wisely in the working for a more glorious future. Medicine has been--not inaptly styled--"The daughter of dreams." From the time of Hippocrates until now, the great body of the profession has been swayed by conflicting theories, founded upon either the wholly unsupported fancies and conjectures of their authors, or unwarrantably built upon isolated facts, often accidental in their occurence, partial in their observation, and improperly understood in their inherent nature and theoretical significance, pointing to a law of action widely different from the one in support of which they had been adduced. All branches of medicine have been involved in these crude absurdities; nor has the nomenclature of any department of science, even in our day, been entirely purged from the errors and misleadings with which the past so fruitfully abounds.