viii PREFACE 



obtain a bird's-eye view of all, and a day's lesson in some one 

 of the elementary sciences ceases to be a blind alley, or a path 

 which must be followed with complete faith that the teacher 

 knows where it will lead. The pupil can see the interrelation 

 of all sciences, and can reason from many points of view. 

 The other value lies in awakening the mind to the vast pos- 

 sibilities of scientific knowledge and mental attainments. A 

 course in general science should reach every pupil in at least 

 one science and stimulate his ambition to learn more of it. 

 If this be true, we must have two purposes in the presenta- 

 tion of such a course, to overcome narrowness, and to 

 stimulate ambition. 



If there is not a definite plan for the year's work, a goal 

 toward which the class is to strive, there must be waste of 

 time and loss of interest. This book is offered in the hope 

 that it may aid and guide the teacher, as well as help the 

 pupils, always allowing for initiative on the part of both. 

 Such a course is elastic and can never be limited by an outline, 

 however full. While a large proportion of the experiments 

 are standard, it has been the author's endeavor to require 

 simple apparatus and chiefly qualitative work. Several of 

 the experiments are believed to be new, and the element of 

 play has been brought in wherever it seemed feasible. The 

 numbering of ' the reference books is arbitrary, but must 

 necessarily be so, as the Dewey system is not sufficiently 

 graduated for exact reference. Local conditions should by 

 all means be emphasized, for, to be valuable, the course must 

 touch the lives of the pupils in as many places as possible. 



The book may be used without any of the reference books 

 except the publications of the United States government. 

 However, the references have been divided into two groups: 

 one contains fourteen books for general supplementary work; 



