THEIR MODE OF ACTION. 383 



of fulminating silver and mercury, that is, to effect 

 another arrangement of their elements, in conse- 

 quence of which, new compounds are formed. 



We know that electricity and heat possess a de- 

 cided influence upon the exercise of chemical affi- 

 nity ; and that the attractions of substances for one 

 another are subordinate to numerous causes which 

 change the condition of these substances, by alter- 

 ing the direction of their attractions. In the same 

 manner, therefore, the exercise of chemical powers 

 in the living organism is dependent upon the vital 

 principle. 



The power of elements to unite together, and to 

 form peculiar compounds, which are generated in 

 animals and vegetables, is chemical affinity; but 

 the cause by which they are prevented from arrang- 

 ing themselves according to the degrees of their 

 natural attractions the cause, therefore, by which 

 they are made to assume their peculiar order and 

 form in the body, is the vital principle. 



After the removal of the cause which forced their 

 union that is, after the extinction of life most 

 organic atoms retain their condition, form, and 

 nature, only by a vis inertitz ; for a great law of 

 nature proves that matter does not possess the 

 power of spontaneous action. A body in motion 

 loses its motion only when a resistance is opposed 

 to it ; and a body at rest cannot be put in motion 

 or into any action whatever, without the operation 

 of some exterior cause. 



