INTRODUCTION xiii 



" What is abnormal ? " " Why is it abnormal ? " Perhaps it is 

 wiser not to enquire too curiously into the position of the physician 

 of the present. 



The development of physiology on the lines indicated has also 

 made possible the growth of the sciences of experimental path- 

 ology, of experimental medicine and of pharmacology ; and the 

 knowledge of disease and of its treatment has thus been put 

 upon a sounder basis. 



All this has followed the adoption of physics and chemistry 

 as the guides of the physiologists. 



In the present volume, Dr. Burns attempts to show the part 

 which physics has come to play in the solution of the problems 

 of physiology. A science of bio-physics has evolved in the same 

 way as that of bio-chemistry. Perhaps some attempt should 

 have been made in the title to indicate that it is the problems of 

 the physiology of vertebrates rather than the basic problems of 

 life generally which are dealt with. 



The book is intended for students of human physiology, although 

 it cannot fail to interest all workers in biology. 



It demonstrates what a very large number of the characteristic 

 reactions of living matter may be explained in terms of ordinary 

 physical processes, and it thus shows the reduction which is 

 taking place in the number of phenomena which some are still 

 content to explain as due to a mysterious vital action instead of 

 simply confessing that they are yet not understood. 



As the application of physics and chemistry to physiology is 

 extended, it is safe to predict that fewer and fewer of these vital 

 manifestations will remain unexplained. 



The origin of living matter, its increase and dispersion all over 

 the globe, its marvellous and endless developments and evolutions, 

 and its reactions with its surroundings may all be explained in 

 terms of physics and chemistry. But consciousness and its 

 association with living things will ever remain the mystery it 

 has been and is. 



