VI PREFACE 



Heat, Air, and Light in the House," "The Weather," 

 "Rocks and Soil," "Plants," and "Animals." Chapters 

 XVII to XX are given to elementary Physiology and 

 Sanitation. The book therefore contains the material 

 needed by schools that desire to give a short course in 

 Physiology at the end of the first year. Coming, as it 

 does, after the elementary Physics and Chemistry of the 

 earlier half of the book, and immediately after the 

 chapters on "Plants" and "Animals," the work in 

 Physiology ought to mean far more to the pupil than if 

 it were an isolated appendix to the first year's work. 



The illustrations of the "First Year of Science" are 

 unusually numerous and especially adapted to the text. 

 They have been prepared with great care, for they are 

 intended, by their direct appeal to the eye, to enlarge 

 materially the teaching power of the text. To this end 

 descriptive matter has been added to them and they 

 have been made very simple. The parts of drawings 

 have usually been designated by names rather than by 

 letters. 



Exercises are given at the end of each chapter and 

 also in the body of each chapter except the first. The 

 exercises are questions taken from the chapter; they en- 

 courage the pupil to apply to common phenomena what 

 he has learned in the text and the laboratory work. 



Summaries are placed at the end of each chapter to 

 bring together in a bird's-eye view the leading topics of 

 the chapter. 



An appendix contains useful tables and a reference 

 Glossary of terms used in the book. 



The laboratory exercises are such as can be per- 



