The succeeding lecture will be devoted to an examination of the doctrines of Samuel Hahnemann and his disciples; doctrines which some consider new and others old; the common title of which is variously known as Ho-moeopathy, Homoe-op-athy, Homoeo-paith-y, or Hom'pathy, and the claims of which are considered by some as infinitely important, and by many as immeasurably ridiculous. I wish to state, for the sake of any who may be interested in the subject, that I shall treat it, not by ridicule, but by argument; perhaps with great freedom, but with good temper and in peaceable language; with very little hope of reclaiming converts, with no desire of making enemies, but with a firm belief that its pretensions and assertions cannot stand before a single hour of calm investigation. II. It may be thought that a direct attack upon the pretensions of HOMOEOPATHY is an uncalled-for aggression upon an unoffending doctrine and its peaceful advocates. But a little inquiry will show that it has long assumed so hostile a position with respect to the Medical Profession, that any trouble I, or any other member of that profession, may choose to bestow upon it may be considered merely as a matter of self-defence. It began with an attempt to show the insignificance of all existing medical knowledge. It not only laid claim to wonderful powers of its own, but it declared the common practice to be attended with the most positively injurious effects, that by it acute diseases are aggravated, and chronic diseases rendered incurable. It has at various times brought forward collections of figures having the air of statistical documents, pretending to show a great proportional mortality among the patients of the Medical Profession, as compared with those treated according to its own rules. Not contented with choosing a name of classical origin for itself, it invented one for the whole community of innocent physicians, assuring them, to their great surprise, that they were all ALLOPATHISTS, whether they knew it or not, and including all the illustrious masters of the past, from Hippocrates down to Hunter, under the same gratuitous title. The line, then, has been drawn by the champions of the new doctrine; they have lifted the lance, they have sounded the charge, and are responsible for any little skirmishing which may happen. But, independently of any such grounds of active resistance, the subject involves interests so disproportioned to its intrinsic claims, that it is no more than an act of humanity to give it a public examination. If the new doctrine is not truth, it is a dangerous, a deadly error. If it is a mere illusion, and acquires the same degree of influence that we have often seen obtained by other illusions, there is not one of my audience who may not have occasion to deplore the fatal credulity which listened to its promises.