I j 2 V igetable Staticks. 
the attra&ion of the fuperior leaves, by the 
bared placed N°. 12. but alfo without any 
leaf Bud of its own, whofe branching fap 
veffels, being like thofe of other leaf Buds 
rooted downwards in the wood, might 
thence draw fap, for the nourifhment of its 
felf and the adjoining bark, N°. 13. But 
had thefe rooting fap veffels run upwards, 
inftead of downwards, ’tis probable, that in 
that cafe the upper part of each ringlet of 
bark, and not the lower, would have fwel- 
led, by having nourifhment thereby brought 
to it from the inmoft wood. 
We may hence alfo fee thereafon why, 
when a tree is unfruitful, it is brought to 
bear fruit, by the taking ringlets of bark off 
from its branches, viz. becaufc thereby a 
lefs quantity of fap arifing, it is better di- 
gefled and prepared for the nourifhment of 
the fruit ; which from the greater quantity 
of oil, that is ufually found in the feeds, 
and their containing veffels, than in other 
parts of plants, fhews that more fulphur and 
ait is requifite for their production, than 
there is for the production of wood and 
leaves. 
But the rood confiderable objeCtiou a- 
gainft this progreflxvc motion of the fap, 
without 
