I purposely refrain from entering into any details as to the character of the technical work done at the Virchow Institute, because the subject of pathology, despite its directly practical bearings, is in itself necessarily somewhat removed from the knowledge of the general reader. One cannot well understand the details of changes in tissues under abnormal conditions unless one first understands the normal conditions of the tissues themselves, and such knowledge is reserved for the special students of anatomy. For the nonprofessional observer the interest of the Virchow Institute must lie in its general scope rather than in the details of the subjects there brought under investigation, which latter have, indeed, of necessity, a somewhat grewsome character despite the beneficent results that spring from them. It is quite otherwise, however, with the work of the allied institution of which I now come to speak. The Institute of Hygiene deals with topics not very remote from those studied in the Virchow Institute, part of its work, indeed, falling clearly within the scope of pathology; but it differs in being clearly comprehensible to the general public and of immediate and tangible interest from the most strictly utilitarian stand-point, hygiene being, in effect, the tangible link between the more abstract medical sciences and the affairs of every-day life. The Institute of Hygiene has also the interest that always attaches to association with a famous name, for it was here that Professor Koch made the greater part of those investigations which made his name the best known, next to that of Pasteur, of any in the field of bacteriology. In particular, the researches on the cholera germ, and those even more widely heralded researches that led to the discovery of the bacillus of tuberculosis, and the development of the remedy tuberculin, of which so much was at first expected, were made by Professor Koch in the laboratories of the antiquated building which was then and is still the seat of the Institute of Hygiene. More recently Professor Koch has severed his connection with the institution after presiding over it for many years, having now a semi-private laboratory just across from the Virchow Institute, in connection with the Charité Hospital; but one still thinks of the Institute of Hygiene as peculiarly the "Koch Institute" without injustice, so fully does its work follow the lines laid out for it by the great leader.