viii PLAN OF THE BOOK 



The subject of bacteria and transmissible diseases is 

 treated in a simple way so as to bring it within the 

 comprehension of the pupils. While this subject is 

 not generally discussed in elementary physiologies, it 

 cannot be denied that it forms an important phase of 

 personal hygiene and public health. The schools can 

 do much to make people more intelligent on this im- 

 portant question if they will teach such simple facts as 

 are presented in these two chapters. 



The Alcohol Question. The subject of alcohol is 

 treated in the chapter on Drinks and Narcotics in the 

 early part of the book. Then in connection with the 

 discussion of each system throughout the book, there 

 is a brief statement of the specific effect of alcohol 

 upon that system. An attempt has been made to state 

 the truth so far as it is known at the present time and 

 without coloring the facts. No good can come from 

 the extravagant statements so often made by well-mean- 

 ing persons in discussing this subject in books and 

 magazines for the young. 



The treatment of stimulants and narcotics is ample 

 enough to meet the requirements of the laws of those 

 states which prescribe instruction on the effects of 

 stimulants and narcotics on the human system, and, at 

 the same time, it is scientific, being based on the latest 

 researches. 



Exercises and Experiments. This text-book is not 

 made on the laboratory plan, and yet a large number 

 of simple exercises and experiments that can be per- 

 formed with inexpensive apparatus are suggested in 



