22 INTRODUCTION. 



attempt be made confusion and loss of time would inevitably 

 result. As an illustration we may refer to the function or series 

 of functions by which the food is prepared for absorption that is, 

 digestion. Food is the material which is taken into the body to 

 supply the waste of its tissues, and it must be of such a composi- 

 tion as will meet this want. To select the proper food-materials 

 we must know of what the body is composed, and what are the 

 changes which take place in its composition what parts are 

 wasted. For these reasons a study of physiologic chemistry must 

 precede a study of the functions of digestion. This is but one of 

 many illustrations which might be given to show the importance 

 of prefacing the study of physiology proper with a study of the 

 chemistry of the body and of the food. 



Arrangement of Topics. The topics treated of in this work 

 will therefore be arranged in the following order : I. Histology 

 of the Human Body ; II. Physiologic Chemistry ; III. Nutritive 

 Functions; IV. Nervous Functions; V. Reproductive Functions. 



