Vlll PREFACE 



the chief remedy of the evil undoubtedly lies partly in the continuance 

 of certain of the laboratory courses into the clinical years, and partly 

 in the study of medical literature in which the application of physiology 

 and biochemistry in the practice of medicine is emphasized. 



Notwithstanding the sufficient number of excellent textbooks in phys- 

 iology available to the medical student, there is none in which partic- 

 ular emphasis is laid upon the application of the subject in the routine 

 practice of medicine. In the present volume the attempt is made to 

 meet such a want, by reviewing those portions of physiology and bio- 

 chemistry which experience has shown to be of especial value to the 

 clinical investigator. The work is not intended to be a substitute, 

 either for the regular textbooks in physiology, or for those in functional 

 pathology. It is supplementary to such volumes. It does not start like 

 the modern test in functional pathology, with a consideration of the 

 diseased condition, and then proceed to analyze the possible causes and 

 consequences of this disturbances of function which this exhibits; but 

 it deals with the present-day knowledge of human physiology in so far 

 as this can be used in a general way to advance the understanding of 

 disease. In a sense it is therefore an advanced text in physiology for 

 those about to enter upon their clinical instruction, and at the same 

 time, a review for those of a maturer clinical experience who may- desire 

 to seek the physiological interpretation of diseased conditions. 



In attempting to fulfil these requirements, it has been deemed essen- 

 tial to go back to the fundamentals of the subject, and to explain as 

 simply as possible the physical and physicochemical principles upon 

 which so large a part of physiological knowledge depends. Physiology 

 may be considered as an application of the known laws and facts of 

 physics and chemistry to explain the functions of living matter, and it is 

 only after the extent to which this application can be made has been 

 appreciated, that the knowledge may be used to serve as the foundation 

 upon which a superstructure of clinical knowledge can be built. 



In order that the volume might be maintained of reasonable size, it 

 has been necessary to select certain parts of the subject for particular 

 emphasis, the basis of selection being the degree to which our knowledge 

 clearly shows the value of the application of physiological methods both 

 of observation and of thought in the study of diseased conditions. This 

 has not been done to the extent of omitting the apparently less essential 

 parts, for these have been treated in sufficient detail to link the others 

 together so as to preserve a logical continuity, and show the bearing of 

 one field of knowledge on another. There are however certain parts 

 of the science, particularly the physiology of nerve and muscle, of the 

 special senses, and of reproduction, for which application in the general 

 fields of medicine and surgery is limited, and these parts have been 



