PREFACE. 



EVERY human being is appointed to take the charge of 

 his own body. He must supply its wants, direct its powers, 

 regulate its actions, and thus sustain his life. This respon- 

 sibility for the care of health takes precedence of all others, 

 and requires the earliest attention to prepare <o meet it. 

 Before any one can have any use for other knowledge, he 

 must know how to live. He should, therefore, learn the 

 nature and the wants of his frame, and of its various 

 organs, even earlier than he studies the features of the 

 earth, the science of numbers, or the structure of language ; 

 for, before he can put these to any practical use, he must 

 eat, and breathe, and move, and think. Physiology should, 

 then, be included among the subjects of all school educa- 

 tion, and thus preparation be first made for the fulfilment 

 of the first responsibility of life. 



The great and sole object of this work is to teach the 

 laws of health, the powers of the several organs, the limit 

 of their strength, the way in which they are to be developed 

 and sustained, their proper uses, and the certain and evil 

 consequences that follow their misapplication. 



For these purposes, it is necessary to learn, first, the 

 general structure of the organs and parts which are sub- 

 mitted to our management ; second, the law of their being 



