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PREFACE 



THE author of this intermediate grade of Applied Physi- 

 ology has designed the work to be not merely an intro- 

 duction to the study of anatomy and physiology, but a 

 complete elementary work in itself, giving a clear picture 

 of how each organ of the body performs its work. 



In presenting hygienic facts to pupils before they 

 have an elementary knowledge of anatomy and physiology, 

 there is a violation of pedagogical principles. The laws 

 of healthful living cannot be grasped without this elemen- 

 tary knowledge of the human machine to which the laws 

 apply. Advice to a pupil will have an effect in direct pro- 

 portion to the confidence reposed in the teacher. New 

 environments and duties demand new applications of laws. 

 Every business man is often compelled to break common 

 hygienic laws in regard to eating, exposure, and overwork. 

 Thus mere advising conduces but little toward intelligent 

 living. On the other hand, prohibition arouses in children 

 a desire to do the forbidden thing, especially if it be a rule 

 insisted upon at school. Moreover, the unavoidable incon- 

 sistencies of teachers themselves will upset the pupil's 

 confidence in all laws. For these reasons dogmatic hygi- 

 enic advice is avoided, but anatomical and physiological 

 facts are simply stated and developed. 



By way of example, however, it has seemed wise to indi- 

 cate detailed hygienic applications of physiology and anat- 

 omy along a single line, leaving it to teachers to apply the 

 same principles to other abuses of the body in answer to 



