example and persistent asseveration, only precise scientific concepts and a critical appreciation of the nature and limits of actual demonstration can protect the young physician. The laity has in this matter more to fear from credulous doctors than from advertisements themselves: for a nostrum containing dangerous drugs is doubly dangerous if introduced into the household by the prescription of a physician who knows nothing of its composition and is misled as to its effect.[1] Experimental physiology and pharmacology must train the student both to doubt unwarranted claims and to be open to really authoritative suggestion: for it is equally important to reject humbug and to accept truth. Fortunately, even a brief concrete experience may teach one to be wary in weighing evidence.
The course in pharmacology need include, therefore, actual experimental determination by the student himself of the effect on animals of a relatively small number of carefully selected agents; demonstration of others by the instructor; and a critical survey of the rest by means of lectures and recitations.[2] Materia medica, now much shrunken, need concern itself only with the pharmaceutical side, aiming to familiarize the student with drugs of proved power and the most agreeable and effective forms in which these may be administered. Therapeutics subsequently adds to these agents whatever other resources the clinician has accumulated,—baths, electricity, massage, psychic suggestion, dietetics, etc.,—approaching the subject from the standpoint of disease, as opposed to the pharmacological approach from the standpoint of the drug itself.
The last division of the medical sciences—and the most extensive—includes pathology and bacteriology. The three subdivisions of pathology are symmetrical with anatomy, physiology, and physiological chemistry. To the first corresponds pathological anatomy; to the second, pathological physiology; to the third, chemical pathology.
In its modern form the study began on a comprehensive basis when Virchow, called from Würzburg, established the first pathological institute in Berlin in 1856. His plans went far beyond the gross morbid anatomy then current. He conceived pathology not only as a descriptive but as an experimental science, whose laws are the laws of general biology. The pathological is not, in this view, an anarchic, extralegal freak; it is the product of agencies and forces, operating on regular and inevitable lines. The problem of the pathologist is through observation and experiment to get the key to the pathological process, in order that he may understand its origin and significance, and, if necessary, avert or control it. The pathological is abnormal from the standpoint, not of biological law, but of the human interests that it sometimes thwarts—sometimes, only; for not infrequently it is a beneficent, compensa-
