75 



these four elements alone. These four 

 elements are contained in carbonic acid, 

 water, and ammonia. ^ Throughout all 

 organic nature, during life, combina- 

 tion from the constituents of these 

 three goes on, and after death the de- 

 composition of those combinations into 

 the constituents of these three. That 

 is, carbonic acid, water, and ammonia 

 furnish the constituents from which, by 

 combination, result all the exquisite 

 living forms which we admire and love ; 

 and into these three those forms are 

 by decomposition eventually resolved. 

 Throughout the realms of vitality the 

 actual living are the late dead freshly 

 combined ; and from the decomposition 

 of one generation of plants and animals 

 the recomposition of another generation 

 results. 



I should doubt the supposed excretion 

 from the roots of substances unnecessary 

 to the growth of the tree. If this were 



