THE OBJECTS OF PHYSIOLOGY. 27 



living beings only, and therefore we must not assume that any 

 such exist. We must rather endeavor to explain all the so- 

 called " vital phenomena " by means of the laws known to chem- 

 ists and physicists. By this means we shall certainly get a closer 

 insight into the processes of life, and if there be laws governing 

 the living beings we may learn to know them. This method of 

 working has already given good results, for within comparatively 

 recent times many of the processes which were regarded as spe- 

 cially vital in character have been shown to be within the power 

 of the experimenter and to depend on purely physico-chemical 

 processes. 



It is therefore necessary for the physiologist, before he attempts 

 to explain the activities of any organism, to be familiar not only 

 with the structure of its body, but also the various laws which, 

 as chemists and physicists teach us, control the operations of 

 inanimate matter. 



The sciences of chemistry and physics may, in fact, be re- 

 garded as the physiology of inorganic matter, just as, when chem- 

 istry and physics are applied to the elucidations of the functions 

 of living creatures by the biologist, the study is called physiology. 

 When we consider how far the chemist and the physicist still are 

 from thoroughly grasping and interpreting all the phenomena 

 presented by the various kinds and conditions of matter, we 

 cannot be surprised that those who attempt to explain the 

 actions of living beings find many processes that they are 

 unable to comprehend. So that when physiologists make use 

 of the convenient term " vital phenomena," it must be re- 

 membered that they do not thereby imply the existence of 

 a special living force or any kind of energy peculiar to living 

 creatures. 



The final end of physiology is, then, not yet within the reach 

 of our modern methods of research. To explain the mode of 

 activity of living beings, and grasp the exact relation borne by 

 their living phenomena to the laws which govern them, is a task 

 of enormous difficulty. Indeed, the manifestations of certain en- 

 ergies in living organisms are so complicated that it is often, if 

 not generally, impossible to say exactly how they are brought 



