CHAPTER I. 



MATTER AND BNEEGY. 



r 



'N this series of Essays I intend to proceed, according 

 to the law both of nature and of thought, from the 

 simple to the complex. Consequently, I shall treat of the 

 laws of Matter before those of Life; and, in treating of 

 the laws of Matter, I shall treat of those which are 

 common to all matter, and to matter in all its actions, 

 before the special laws of chemistry and crystallization. 



It is not my purpose to write a regular treatise on 

 elementary dynamics. In this and the following chapters 

 I only intend to give a statement of some of the most 

 important results of modern dynamical science, in a form 

 that shall be at once theoretically complete and suitable 

 for future reference. I shall employ as few mathematical 

 terms as possible ; but I fear it will be impossible to 

 make the subject perfectly intelligible except to those 

 who are acquainted with the fundamental conceptions of 

 mathematics. 

 Four laws There are in nature four, and only four, laws of con- 

 vation!*^^' servation which we can assert to be absolutely and without 

 exception true. These are the laws of the Conservation of 

 Matter, of Momentum, of Rotation, and of Energy. These 

 must be explained seriatim,.. 



Conserva- I. The CONSERVATION OF MATTER. — Matter can he neither 



matter. ]?rocluccd nor destroyed hy any process whatever. This truth 



],ias been long known, and is familiar ; but it is ver}'' far 



