24 LIFE OF 



" This is almost the first hour of leisure that I have had 

 since I received your letter. I am here at grass for two or 

 three days, in the midst of fine woods, but without a Teme or 

 a Downton." 



The paper " On the Functions of the Alburnum," alluded to in 

 Sir H. Davy's second letter, was published by the Royal Society, 

 but has not been included in the selection of papers for the 

 present work, because the theory it presents has not been 

 established, and it will be seen, that at a subsequent period, 

 Mr. Knight himself was disposed to adopt the opinions of M. 

 Dutrochet, who ascribes the ascent of the sap to electrical agency. 

 A letter addressed to Sir Joseph Banks on this subject will show 

 what were his views at that time, and the observations on 

 which they were founded. 



" August 14, 1799. 

 " MY DEAR SIR : 



" I am very much obliged to you for my ram, which arrived 

 very safe, and in perfectly good condition. I shall try different 

 crosses with him this autumn, and I shall have great pleasure 

 in sending you the results of such trials as I shall make. You 

 may depend on the statements I shall send being perfectly 

 accurate, if without any other merit. 



" I will take this opportunity of mentioning the observations 

 and opinions I spoke of in my last letter, relative to the ascent 

 of the sap in trees, though I fear it will occasion me to trouble 

 you with an epistle of immoderate length. If I become a trou- 

 blesome scribbler to you, I must claim your pardon on the 

 ground that you have made me such ; for without the attention 

 I have been honoured with from you, I am certain I should 

 never (in print) have scribbled at all. In the observations I 

 am going to state, there will probably be little, perhaps nothing, 

 new to you ; but as I do not know how much will be new, I will 

 state the whole as if I supposed it such. 



" It is, I think, easy to prove every theory I have seen on the 



