VEGETABLE NUTRITION. 13 



generally hold a higher rank in the scale of organi- 

 zation, than those that subsist only on vegetables. 



Thus has each created being been formed with 

 reference, not merely to its own welfare, but also 

 to that of multitudes of others which are dependent 

 on it for their support, their preservation, — nay, 

 even for their existence. In contemplating this 

 mutual relationship, this successive subordination 

 of the different races to one another, and this con- 

 tinual tendency to increased refinement, we cannot 

 shut our eyes to the magnificent unfolding of 

 the great scheme of nature for the progressive 

 attainment of higher objects ; until, in the perfect 

 system, and exalted endowments of Man, we behold 

 the last result which has been manifested to us of 

 creative power. 



Chapter II. 



NUTRITION IN VEGETABLES. 



§ 1. Food of Plants. 



The simplest kind of nutrition is that presented 

 to us by the vegetable kingdom, where water may 

 be considered as the general vehicle of the nutriment 

 received. Before the discoveries of modern che- 

 mistry, it was very generally believed that plants 

 could subsist on water alone ; and Boyle and Van 

 Helmont, in particular, endeavoured to establish 

 by experiment the truth of this opinion. The 

 latter of these physiologists planted a willow in a 

 certain quantity of earth, the weight of which he 



