2: VEGETABLE PHYSIOLOGY. 



Fixed to the soil they are expanded either therein,, 

 or in the air or water. The tribes of trees and herbs 

 which eover the face of the earth, though more 

 varied in form and colour, are scarcely more nume- 

 rous than the JPuci* which inhabit the shores and 

 depths of the ocean. 



Vegetables are said to perform an important office 

 in the scheme of creation, in maintaining an equili- 

 brium among the constituents of the atmosphere, by 

 which its salubrity is improved for the purposes of 

 animal life. 



In describing the elementary matter or membrane 

 of vegetables, it will not be necessary to notice its 

 various disposition as presented to us by the micro- 

 scope, in the different stages of its advancement 

 from primitive indistinctness to its perfect form in 

 the organisation : suffice it to notice in this place, 

 that it is not a homogeneous solid, but an areolated 

 mass, composed of innumerable vesicles arranged in 

 different forms : either extended into filaments 

 and fibres spread out into tissues depressed into 

 horizontal layers compressed into perpendicular 

 partitions or disposed in regular columns. 



Vegetable element is said to be composed of 

 oxygen, hydrogen, carbon, and some other bodies 

 detectible by chemical analysis. This combination 

 0f immaterial bodies, forming a visible and tangible 

 substance, is of itself a mysterious circumstance ; 

 but when we see that the most concrete and durable 



* Son-weed?,. 



