On the Power of Ho bit in Vegetables. 67 



mer, one week's rain, every day, would scarcely 

 afford as much moisture as one common nightly 

 dew." 



XVIII. Observations on the Power of Habit in Vege- 

 tables . In a L etter to the E d i t o r , from W i l l i a m 

 Barnwell, M. D. 



Sir, 



I WAS highly gratified with the subject of your 

 lecture* to-day, on more than one account. In the 

 first place, because the physiology of vegetation has 

 hitherto been, in my opinion, too much neglected. 

 Secondly, because the effects of the change of climate 

 on vegetables, &c, is a mode of investigating their 

 physical properties which is almost new, although it 

 is, certainly, a subject of much importance with res- 

 pect to agriculture, as well as medicine. And, lastly, 

 as it has some connection with a subject which my 

 own employment, for some years of my life, has led 

 me to investigate, that is, the effects of the changes 

 of climates on animals, and particularly on man. 



The fact which I mentioned to you, of the Goose- 

 berries and Currants, &c, when carried to warm 

 climates, turning evergreens, and ceasing to bear 

 fruit, I learned in the island of St. Helena, in the 

 year 1789, being then surgeon of the Royal Char- 

 lotte-Indiaman, in the employ of the Honourable 



* On the Power of Habit in Vegetables. Editok. 



