In medical, as in every other science, the increase of knowledge so widened the field that it became impossible for one mind to grasp all the facts, and a division of labor took place, the part of the work which related to the collection, preservation and dispensing of drugs being assigned to a class of men who had displayed peculiar aptitude for that branch. Thus was constituted as a distinct occupation, the specialty of the apothecary, which, beginning as a department of medical science, is inherently honorable, and has been so developed that it gives scope for a lifetime of fascinating research, elevating study, and profitable endeavor, independently of any proper work of the modern physician. The two callings are, for the purposes of this discussion, as in their best actual operation, practically distinct; and yet they are not independent, but interdependent. The greater part of the physician’s labor would be vainly spent, were it not supplemented by the service of the pharmacist; the latter’s business would cease to have a reason for existence but for the vocation of the former. In this paper it will be taken for granted that the physician is well educated and experienced in his profession, that the apothecary knows his business thoroughly, and that both are actuated by high moral purposes. The grievance of neither, therefore, will result from the intentional wrong-doing of the other, but from his thoughtlessness or conservative adherence to long-established custom. The honesty of each being presupposed, such a charge as the substitution of an inferior article for some ingredient in a prescription, or the false insinuation that a mistake in the medicine is due to the compounder’s carelessness need not be raised. Let us consider the grievances of each against the other.