ON THE VITAL PR&CIPLE. 7 



ing indeed, or increasing by the mechanical 

 addition of extraneous substances, or by the 

 laws of chemical attraction, but not fed by 

 nourishment taken into an organized struc- 

 ture. Their curious crystallization bears some 

 resemblance to organization, but performs 

 none of its functions, nor is any thing like a 

 vital principle to be found in this department 

 of Nature. 



If it be asked what is this vital principle, so 

 essential to animals and vegetables, but of 

 which fossils are destitute, we must own our 

 complete ignorance. We know it, as we know 

 its Omnipotent Author, by its effects. 



Perhaps in the fossil kingdom heat may 

 be equivalent to a vital principle ; but heat is 

 not the vital principle of organized bodies, 

 though probably a consequence of that prin- 

 ciple. 



Living bodies of animals and plants produce 

 heat ; and this phenomenon lias not, I think, 

 been entirely explained on any chemical 

 principles, though in fossils the production of 

 heat is in most cases tolerably well accounted 

 for. In animals it seems to have the closest pos- 

 sible connexion with the vital energy. But the 



