ANIMALS AND VEGETABLES. 41 



oxygen, hydrogen, and azote, together with alkaline and 

 earthy salts. These ingredients are variously combined, 

 according to the species ; but, when examined in a general 

 view, they appear to unite according to a different plan in 

 each kingdom. 



The solid parts of all plants, termed the woody fibres, 

 contain carbon, oxygen, and hydrogen, with scarcely a 

 trace of azote. Sometimes there is a quantity of silica in- 

 corporated with the common integuments. The solid parts 

 of animals consist of lime or magnesia, united with carbonic 

 or phosphoric acids. In those beings, of both kingdoms, 

 which appear to be destitute of solid parts, the points of 

 difference are still numerous. We find the mucilage or 

 gum of soft plants, differing widely from the gelatine or 

 albumen of soft animals ; the former being destitute of 

 azote, which enters as a constituent in the latter. In 

 some plants, substances of an animal nature, (or abound- 

 ing in azote,) have been detected; not, however, consti- 

 tuting a whole plant, but only occurring in certain situa- 

 tions, and always in company with other substances of a 

 decidedly vegetable nature ; or consisting only of carbon, 

 hydrogen, and oxygen. In the soft animals, there is no 

 extensive combination of carbon, hydrogen, and oxygen, 

 into which azote does not enter ; or, in other words, 

 no substance of a vegetable kind. In consequence of this 

 difference of composition, animal and vegetable matters 

 may be easily distinguished, when burning. The odour 

 of each is so peculiar, that the test may be safely employed 

 by the most inexperienced. Besides, as vegetables abound 

 in oxygen, they have a tendency, after death, to become 

 acid by its new combinations with carbon and hydrogen ; 

 whereas, the soft parts of animals, after death, are disposed 

 to become alkaline, the azote entering into new combina- 

 tion with the hydrogen, and forming ammonia. 



