28 LIFE OF 



tions. If you think there is any prospect of my being right, I 

 will endeavour, in the course of this autumn and next spring, to 

 make further experiments and observations. My opinions on 

 this subject have been the same during the last six or seven 

 years, but I have lately been paying much attention to the 

 cause of blights, and I have reason to believe that they depend 

 much on an imperfect and irregular supply of sap. There is 

 one species of blight, the mildew, of whose nature I have 

 satisfied myself during the last month. It appears to me to be 

 evidently a plant of the cryptogamous class, as you have pro- 

 bably long since known, with oval capsules and globular seeds. 

 You were so kind as to say you had taken some copies of the 

 paper I had the honour to address to you in the spring. I will 

 not trouble you to send them to me, but I shall be much obliged 

 to you if some time in the autumn you will send a copy or 

 two to Mr. Felton, who, I believe, has the honour of your 

 acquaintance. He is Mrs. Knight's uncle, and requested me to 

 send him a copy. 



" I am, dear Sir, 



" Your much obliged obedient servant, 



" T. A. KNIGHT." 



SIR JOSEPH BANKS IN REPLY. 



" Soho Square, April 10, 1800. 



" MY DEAR SIR : 



" Your very interesting letter would not have remained so 

 long unanswered, had I not been for the last month in a state 

 of persecution from the multiplied duties of my new station in 

 the Committee for Trade. I have seldom had a day to spare : 

 and till the holy days relieved me, I thought I should never again 

 be permitted to return to my favourite pursuits ; and during 

 my absence from London, the impossibility of consulting some 

 of my friends, whose opinions upon the subject of the circulation 

 of sap I have been used to rely upon, prevented my writing. 



"Whether any of our predecessors may have been better 

 qualified to investigate the physiology of plants than you are, I 



