PREFACE TO THE FIRST EDITION 



PHYSIOLOGY, though dealing with the phenomena of living organisms, 

 has to use the same tools, whether material or intellectual, as the sciences of 

 physics and chemistry. Any advances which are made in these sciences 

 not only increase our powers of attack upon physiological problems but at 

 the same time alter the intellectual standpoint from which we view them. 

 On the other hand, the investigation of the phenomena of living beings 

 is continually attracting our attention and that of workers in the other 

 branches of science to unexplored regions in physics and chemistry. This 

 mutual stimulation and co-operation among the different sciences have as 

 their result a continual modification of our attitude with regard to the 

 fundamental problems of physiology. The present time has seemed to me, 

 therefore, fitting for the production of a textbook which, while not neglecting 

 the data of physiology, should lay special stress on the significance of these 

 data, and attempt to weave them into a fabric representing the principles 

 which are guiding physiologists and physicians of the present day in their 

 endeavours to extend the bounds of the known and to increase their 

 powers of control over the functions of living organisms. 



In a science such as physiology, based on so wide a discipline and with so 

 diverse a technique, it is almost impossible for any one man to attain to a 

 personal acquaintance with all its branches. In the present book I have 

 therefore not hesitated to avail myself of the work of masters of the science 

 in fields which I had not myself explored. Thus, in the physiology of the 

 nervous system, which has been transformed and built up on a new basis 

 by the researches of Sherrington, I have endeavoured to follow this author 

 as closely as possible. I am also deeply sensible of my obligations to 

 the writings of Tigerstedt, Leathes, and Lusk on general metabolism, of 

 Abderhalden and Plimmer on physiological chemistry, of Bayliss on general 

 physiology, as well as to various authors of articles in the Ergebmsse der 

 Physiologic, in Nagel's Handbuch der Physiologic, and in Dr. L. E. Hill's 

 Recent and Further Advances in Physiology. 



Although I have endeavoured to confine my demands on the previous 

 knowledge of the student within the narrowest possible limits, I should 

 recommend him in every case to read some primer on physiology in order to 

 obtain a bird's eye view of the subject before beginning the study of this 

 work. He will then be able to vary the order of chapters in this book 

 according to the part of physiology which he is hearing about in his lectures 

 or working at in his practical classes. Those of my readers who are entirely 



