156 LECTURE IV. 



tually descends to the roots, to nourish and 

 increase them, and in various instances, to 

 form means and materials, for the future 

 production of vegetables of the same kind. 



Such is the view of the nourishment of 

 vegetables, exhibited of late by Mr. Knight, 

 in his papers published in the Philosophi- 

 cal Transactions, and which has been drawn 

 from the results of numerous well contrived 

 and satisfactory experiments. The ascend- 

 ing sap. has in it no marked peculiarity, 

 being equally fitted to form the leaf, the 

 flower, and the fruit ; for he has engrafted 

 the stalk, upon which each of these has 

 been produced, upon the same kind of 

 stem. Also, by dividing the descending 

 vessels, he has stopped the formation of 

 the parts below ; and by performing this 

 experiment in the root, he has prevented 

 the growth of the potatoe, and even caused 

 it to be injected from these descending 

 vessels by which it is formed and supported. 



In viewing the subject, according to this 

 sketch, we cannot but feel surprize, that 



