PERSPIRATION OF LEAVES. 141 



The above is certainly a veiy sPxiall part of the use 

 of leaves. Yet the observations of tliis writer, the 

 father of botanical philosophy among the moderns, are 

 so far correct, that if the leaves of a tree be stripped 

 off, the fruit comes to nothing, which is exemplified 

 every year in Gooseberry bushes devoured bv cater- 

 pillars; and though the fruit-trees of warm climates, 

 partly naturalized with us, Grapes and Peaches for , 

 instance, ripen their fruit sooner perhaps if partially 

 deprived of their leaves ; yet if that practice be carried 

 too far, the fruit perishes, as gardeners who tried it 

 soon discovered. The White r\Iul berry indeed, culti- 

 vated in the south of Europe for the food of silkworms 

 only, bears wonderfully the loss of its foliage three or 

 four times a year. How far the fruit is injured nobody 

 thinks it worth while to inquire, as it is never eaten, 

 but it certainly does not fall off prematurely . 



That Leaves imbibe and dve out moisture has been 



o 



loni; known, this being one of the most obvious facts 

 belonmncp to them. Dr. Hales thouo;ht thev miffht 

 probably imbibe air; but since his time, more certain 

 discoveries have been made concerning this point, as 

 well as the effects of light upon leaves, vrhicli also did 

 not escape the consideration of that great philosopher. 

 AJl these subjects we shall mention in their turn. 



That Leaves give out moisture, or are organs of in- 

 sensible perspiration, is proved by the simple experi- 

 ment of gathering the leafy branch of a tree, and im- 

 mediately stopping the wound at its base with maslick, 



