VI INTRODUCTION. 



the mysteries of vegetation. Before the time of Newton, 

 there were many men who had seen apples fall to the ground 

 without ever reflecting on the cause of their fall. Newton 

 saw the same, and thought. The result of his reflections was 

 the production of his immortal work, the Principia, and the 

 development of the theory of gravitation. He showed with 

 what small means Nature attains the most magnificent results. 

 It was the mutual attraction subsisting between the earth and 

 apple that brought the apple to the earth's surface; and the 

 same mutual attraction retains the moon and planets in their 

 orbits, causing them to sweep out in immensity those sublime 

 curves with which the mind of the geometer is familiarized. 

 It is by the attraction of other suns that our own sun, or rather 

 star, is upheld in space; whilst all the stars that sparkle on 

 the roof of night, and whose light comes to us from the most 

 distant regions of the universe, are upheld by mutual attrac- 

 tion. Such was the sublime discovery of the illustrious New- 

 ton. What though the means which Nature employs in the 

 construction of the various forms of plants is at present only 

 imperfectly understood — if the law that regulates the motion 

 of masses of matter has been discovered, why not the law 

 which governs the motion of atoms of matter, and causes them 

 to colkct around every germinating seed or growing plantlet, 

 so as to develop it with such unchanging constancy and regu- 

 larity into the same definite form of life and beauty ? Man 

 is not destined to continue forever hopeless and helpless 

 amidst the forces of nature. It is his prerogative " to subdue 

 the earth," and " have dominion." 



The law of material attraction may be thus expressed : Mat- 



