-O CRITERION OF M1RBEL. 



table life, who attribute the phenomena of which we 

 have been speaking to a power which the artist possess- 

 es, to the agency of chemical and mechanical causes. 

 We have seen that they possess most of the properties 

 which distinguish living from inanimate matter, and 

 that like animals they owe their existence to a power 

 which we can neither comprehend nor explain. 



This analogy might be traced still further, and we 

 at last should be obliged to resort to a criterion which 

 for wantof a better has of late been defended with great 

 ingenuity by Mirbel, and adopted by the most eminent 

 naturalists of Europe. The food of animals is found to 

 consist of organized materials, whose peculiar proper- 

 ties were produced by the action of life. With the 

 single exception of salt, which is used as a condiment 

 and not as food, 1 believe this is a rule of universal ap- 

 plication, and that there is not an article of food which 

 has not been the tenement of life. Vegetables on the 

 other hand are nourished by inorganic materials, by 

 earth, by air, and by water. They constitute the great 

 manufactory of life, in which the dead elements of cre- 

 ation are converted into living solids, capable of sus- 

 taining the lives of animals. In this respect the former 

 possess a power denied to the latter, and if they could 

 speak, they would tell us how entirely, how immedi- 

 ately we are dependent on them for existence. Is not 

 then the position tenable, that life is the same wherev- 

 er it is found, and that it derives its peculiar modifica- 

 tions from the form and structure of the tenements 

 which it inhabits ? Even in the same body it assumes 

 a great multiplicity of forms, and enables the eye to 

 see, the ear to hear, and the tongue to taste and tell, 

 while other organs equally important and equally alive 

 are almost denied the power of sensation. 



