CONTENTS. 



CHAPTER I. Pack 



THE VITAL PRINCIPLE— THE BLOOD . .5 



CHAPTER II. 



THE PURIFICATION OK THE BLOOD . . . .31 



CHAPTER III. 



ORGANIC AND INORGANIC MATTER COMPARED , . 64 



CHAPTER IV. 



RErOSE, OR SLEEP ......... 94 



CHAPTER V. 



HYBERNATION 109 



