The fundamental reason for laboratory work in any subject, not entirely observational, is the training it gives in systematic observation. One of the best possible methods for developing adequate apprehension of the essentials of a problem is to require the student to record his observations in an orderly, systematic manner. To serve so valuable an end, this Manual is provided with definite leaders and spaces for recording the relatively more important data. The student thus works with directed purpose to discover important pharmacologic facts for himself.

To the possible objection that set formulae might tend to cramp the student's powers of expression, it may be replied that these early years of a medical course represent a formative period in which should be developed accurate, systematic methods of observation; and such formulae as prevent fruitless dissipation of energy thereby promote increased efficiency, both of thought and action.

This book has been prepared with the constant thought in mind that the great majority of medical students are not preparing to become specialists in Pharmacology, but practitioners of general medicine. Therefore the knowledge gained derives its chief value in proportion to its relation to medicine. The interests of the student are in such a case paramount to the interests of the specialist, though the difference in needs in the two cases is "less in matter and method than in proportion and emphasis." So, to paraphrase the words of an honored preceptor, Dr. Ganong, the real test of the value of this Manual will be found not in whether my colleagues deem it a well-proportioned compendium of pharmacologic fact, but whether it leads students to pursue the subject with an interested spirit, and to adopt spontaneously its methods and teachings in their later activities.

Materia Medica has always been a bugbear subject to most medical students, largely because of its dry, dictionary-like presentation. It is helpful to the student if he be given personal contact with the various drugs and preparations, with some clews as to their utilities, by way of introduction to the experimental and applied uses. This can be carried out very successfully in a laboratory, where the examination and testing of drugs is the means whereby he gains knowledge instead of information. If it be desirable for the medical student to know the physical properties and the principal incompatibilities of drugs, then the best way to acquire such knowledge is by personal investigation.

In Pharmacodynamics, it is impossible for the students, through lack of time, to study many of the drugs experimentally; so an intensive study may well be made of the more important ones, especially those which produce registerable reactions. In such a study, a graded method is pedagogically superior. Hence the student is directed to first observe the way and manner in which simple tissue reacts to drug influence, for this purpose using the common frog. Next, he studies the reactions to that same drug of one of the mammals, like the cat, or rabbit, or dog. Then, because of sundry divergencies between the reactions of the lower animals and the higher, he tests this same drug on a human being - his fellow-student - gaining thereby also invaluable experience in observational methods. Next, inasmuch as thus far his information has not had that definite application necessary for conclusiveness, he makes further investigation of the Pharmacodynamics of that same drug at the hospital, in an attempt to learn how much and in what manner the toxins of disease may modify the apparent action of drugs. Finally, he checks up his accumulated observations by comparing them with the recorded observation of others, as presented in current literature. Thus the student acquires a training in method and procedure of inestimable value in his future work as a scientific physician.

A. D. Rush.