study of the action of drugs, poisons and other substances which may alter normal function. Its early development corresponds to the period of the application of exact experimental methods to physiology which, as has been shown in an earlier lecture, dates from about 1840. Buchheim, professor of materia medica at Dorpat, established in his own house, in 1849, a laboratory for the study of pharmacological problems; somewhat later this laboratory became a part of the University of Dorpat and was, therefore, the first laboratory to procure for pharmacology, recognition as a science of university rank. Furthermore, Buchheim in 1876 in the Archiv f. experimentelle Pathologie und Pharmakologie, (founded in 1873) defined the methods and aims which have guided pharmacological work for the past thirty-five years. He also made the first classification of drugs according to their physiological action.
The proper study of pharmacology is all-embracing. It includes not only the study of the mode of action of remedial agents in healthy individuals and the influence on such action of various abnormal or pathological conditions, but, also, the effect of a great variety of substances, as bacterial toxins, the secretions of venomous serpents and the products of metabolism, in short, all animal, vegetable or mineral substances in any way capable of altering normal physiology. Moreover, the study of the effect of these various substances is not limited to man and the higher animals, but includes the use of the lower invertebrate forms, bacteria and protozoa. It is, therefore, an all-inclusive branch of biology, dealing with the "comparative study of the action of chemical bodies on invertebrate and vertebrate animals." Its achievements are of interest to physiology, to which science it has contributed much, both in method and in fact; to chemistry, in that pharmacology has added largely to the data concerning the interaction of cell and chemical substance; and to practical therapeutics, in that it presents new remedies, explains the action of old remedies and defines the limitations of drug-therapy. Finally it has a definite relation to the general public welfare in that, by its methods, it establishes procedures for determining the potency of therapeutic remedies, thus preventing, on the one hand, ill effect from a drug of unusual power, and, on the other, guaranteeing a remedial agent of standard strength.
Experimental Pathology and Pathological Physiology are branches of pathology and physiology which, combining the methods of both these sciences with those of chemistry, attempt, by the study of abnormal conditions experimentally produced, to explain the disturbance in function consequent upon cell or tissue injury or disturbances in physiological or chemical equilibrium. Combining as they do the methods of several of the medical sciences, and having for their object the elucidation of definite problems in clinical medicine, they are essentially the