40 CHEMICAL DIFFERENCES. 



and laws of nature : where such endowments exist, 

 the power is also given of seeking the good and 

 avoiding the evil. 



The leading differences between animals and 

 plants may therefore be summed up, by observing, 

 that all animals possess an internal cavity for the 

 reception and digestion of food; that, with some 

 exceptions, they have organs of locomotion, sym- 

 metrically disposed; that they are endowed with 

 sensation or feeling ; that the greater number have 

 additional senses, as of sight, hearing, taste, and 

 smell, a condition connected with a high degree of 

 organization and nervous development ; and that in 

 such as are thus gifted, there are exhibited various 

 instincts, and a diversity of affections and passions. 

 We might detail the chemical differences which 

 have been discovered in the elementary structure of 

 animals and of plants ; but to what do these differ- 

 ences amount ? Plants, we are told, as it respects 

 their solid parts, contain carbon, oxygen, hydrogen, 

 with scarcely a trace of azote, and that silica is 

 sometimes incorporated with their outward covering. 

 The solid parts of animals consist of lime or mag- 

 nesia, united with carbonic or phosphoric acids ; but 

 if we compare the beings of the animal kingdom, 

 destitute of solid parts, as the medusa* * with mu- 

 cilaginous vegetables, we shall find that the gum or 

 mucilage of the plant affords no azote, but that azote, 



* The round masses of jelly so often observed on the sea-shore. 



