HORSEBACK RIDING. 9 



of that activity. In the other, on the contrary, life 

 is a principle of the activity of matter, a force which 

 necessitates certain acts, indeed, a cause of the first 

 phenomena of the living being, outside of all qualities 

 of structure. 



This latter view of the question is advocated by 

 Plato, Hippocrates, and Galen, as well as by Stahl, 

 Boerrhave and Hoffman, that great triumvirate of the 

 eighteenth century, to whom the most immediate ex- 

 pression of life was motion. 



We find the first principle of the system of the lat- 

 ter to be that the human body, as well as all other 

 bodies in nature, possesses material forces by means 

 of which it moves. A body, simply because it is a 

 body, has forces of cohesion and of resistance which 

 are given it by the Creator. 



That imponderable material agent, ether, the ac- 

 tive mot 07' force, animates all the properties of bodies, 

 and presides over all the physical phenomena in the 

 unity of the creation. Thus the living mechanism 

 performs the functions which are peculiar to it, by 

 virtue of the properties assigned to animal matter ; 

 and the activity of those properties resides essentially 

 in the power of a special ether secreted by the brain, 

 and carried to all the parts of the organism by a very 

 complicated organic apparatus. 



That ether is the primary and efficient cause of all 

 vital movements. // it is which animates all the 

 organs, and each of them ceases to perform its func- 



