ii 6 Vegetable Staticfa. 



But when towards the latter end of April 

 the fpring advances, and many young moots 

 are come forth, and the furface of the Vine 

 is greatly increafed and inlarged by the ex- 

 panfion of feveral leaves, whereby the per- 

 fpiration is much increafed, and the fap more 

 plentifully exhaufted, it then ceafes to flow 

 in a vifible manner, till the return of the 

 following fpring. 



And as in the Vine, fo is the cafe the 

 fame in all the bleeding trees, which ceafe 

 bleeding as foon as the young leaves begin 

 to expand enough to perfpire plentifully, and 

 to draw off the redundant fap. Thus the 

 bark of Oaks, and many other trees, moft 

 eafily feparates, while it is lubricated with 

 plenty of fap : But as foon as the leaves 

 expand fufficiently to perfpire off plenty of 

 fap, the bark will then no longer run, (as 

 they term it) but adheres moft firmly to 

 the wood. 



Ex periment XXXIX. 



In order to try if I could perceive the item 

 of the Vine dilate and contract with heat or 

 cold, wet or dry, a bleeding or not bleeding 

 feafon, fome time in February, I fix'd to the 



ftem 



