ISO VEGETATION. [LesSOH XXXIV. 



Dr. Hunter, so well known and so justly cele- 

 brated both as an anatomist and a naturalist, is in- 

 duced, by a number of experiments accurately con* 

 ducted, to believe, ttfat all Vegetables receive their 

 principal nourishment from oily particles incor- 

 porated with water by means of an alkaline salt$ 

 or absorbent earth. Till oil is made miscibk-, it 

 cannot enter the radical vessels of Vegetables! 

 and on that account, Providence has bountifully 

 supplied all natural soils with chalkv or other ab-> 

 sorbent particles : and those soils which are as- 

 sistfd by art are full of materials for that purpose;. 

 as lime, marl, and the volatile alkaline salt of pu- 

 trid dunghills. 



The argument in favour of oil being the prin- 

 cipal food of Plants is confirmed by the observa- 

 tion, that all Vegetables, whose seeds are of an 

 oily nature, are found to be remarkable impoverish- 

 ers of the soil ; as hemp, rape, and flax : and the 

 best manures for lands worn out by these crops 

 are such as have a good deal of oil in their com- 

 position, provided that they are laid on with lime, 

 chalk, marl, or soap-ashes, so as to render the oily 

 part f les miscible with water. 



But Plants not only receive nourishment by. 

 their roots, but also by their leaves. Vegetables- 

 that have a succulent leaf, such as peas, beans, and 

 buck wheat, draw much of their nourishment from 

 the air; and on that account impoverish the soil 

 less than wheat, oats, barley, or rye, the leaves of 

 which are of a firmer texture. The leaves of al] 

 kinds of grain are succulent for a time, during 



which . 



