4 EXPERIMENTAL PHYSIOLOGY. 



While admitting these principles some have averred that the 

 technical difficulties of experimental physiology are such as to 

 make it impossible for the average medical student to secure a 

 sufficient number of results to justify the expenditure of time and 

 energy required in the laboratory. This is a fallacious criticism 

 for it assumes that every experiment to be of value should be 

 crowned by results that are technically flawless, and it fails to 

 recognize that the performance of the work, if carefully and in- 

 telligently done, affords that personal experience without which, 

 in a highly practical science like medicine, theoretical knowledge 

 by itself is valueless and without meaning. 



There is, however, no subject of the medical curriculum in 

 which the organization and arrangement of laboratory courses is 

 more difficult for classes of average size than in physiology. In 

 physics and chemistry, as well as the various morphological sub- 

 jects, the material for the laboratory course is constantly available, 

 and can be stored away for future use, whereas in physiology living 

 material must be provided afresh for each experiment and there 

 must be constant supervision of the practical work to see that the 

 material is properly used. This requires that the student be 

 adequately directed as to how he should proceed with the experiment 

 without at -the same time stifling originality on his part by re- 

 quiring him explicitly to follow detailed directions in every step. 

 The experiment is of no value unless it is performed with an inquir- 

 ing attitude of mind, and laboratory directions and instruction 

 should be no fuller than is necessary to guide the student in its 

 general performance. 



It is with these requirements in view that the present volume 

 has been compiled, and while the authors realize full well its many 

 shortcomings they hope that the practical instruction, not only in 

 their own laboratories, but also in those of other institutions may 

 be assisted by its publication. 



The work is arranged in sections, each of which deals with 

 some special part of the subject, this plan being adopted because 

 it has been found the most practicable for courses designed for 

 large elementary classes, as well as for smaller groups of more 

 advanced students. The first section deals with the fundamental 

 experiments in the physiology of isolated muscle and nerve, placed 



