viii PREFACE 



ble that at the age children usually undertake the 

 intensive study of physiology, habits of eating, breath- 

 ing, and care of the body are too firmly fixed to be 

 changed without persistent effort, of which the great 

 majority are incapable. Certain it is that many 

 people who are familiar with the benefits of plain 

 food and the bad effects of that which is indigestible 

 do not allow this knowledge materially to affect their 

 daily diet. Carelessness in regard to ventilation is 

 perhaps still greater, even though the injurious effects 

 of impure air are commonly known. In both cases 

 the lack of care is probably a natural result of having 

 gained knowledge of physiology and hygiene at a 

 time or in a way that did not lead to practical appli- 

 cation in daily habits. 



The aim in the pages that follow r is to present some 

 generally recognized important facts about the care 

 and building of the body in a way that will interest 

 and impress children enough to help in forming daily 

 habits most likely to insure future health and use- 

 fulness. The author believes that the reading and 

 discussion of these facts in the fifth or sixth year of 

 school, and again in perhaps the seventh or eighth, 

 will greatly help in familiarizing children with the 

 use of food, air, and water in body building. It 

 should also impress the fact that health and strength 

 are not due to luck, but to the w r ise use of these 

 common things. 



Throughout the book much is made of the fact 



