S6 THE PHILOSOPHY 



and nourifliment of animals and vegetables are effeded. But 

 I fhall confine myfelf, at prefent, to fuch remarks as are pure- 

 ly analogical, and may be fully imderflood without a minute 

 knowledge of the different ways by which growth and nour- 

 Khment have been fuppofed to be accomplifhed. 



Animals,like vegetables, gradually expand from an embryo 

 or gelatinous ftate, and, according to their kinds, arrive foon- 

 er or later at perfedlion. This expanfion and augmentation 

 offubftance is the idea conveyed hj the word groivth. With- 

 out fome nutritious matter taken into the body, and aflimila- 

 ted, by the adion of veiTels, to the fubftance of the being 

 that receives it, growth cannot take place. Moifture is the 

 chief food of plants. But the food of animals, in general, va- 

 ries with the fpecies. This fact led fome philofophers to con- 

 clude, that every plant extracted from the foil a food peculiar 

 to its ov^^i nature. It was, however, afterwards difcovered, 

 by repeated experiments, that vegetables can grow, and ac- 

 quire a very confiderable degree of bulk and weight, without 

 exhaufting a perceptible quantity of the earth in which 

 they are planted. Thefe experiments are a fufficient 

 proof, that moifture conilitutes the chief nourishment of 

 plants. They likewife indicate, that vegetables, however di- 

 verfified in their figure, denfity, and fibrous arrangement,are 

 more fimple in their texture than animals. But, notwith- 

 llanding thefe feeming differences in the nourifhment of 

 plants and animals, Nature fails not to obferve the famecourfe 

 in both kingdom.s. The food of the animal, before it is con- 

 verted into nourifliment, muft go through the intricate 

 procefs of digeftion. But, after the food has been con- 

 verted into chyle, and the chyle into blood, this blood be- 

 comes a common fluid, from which all nourifliment and all 

 animal fluids are derived. Here the analogy is apparent. 

 Moifture is to the plant precifely what blood is to the animal. 



