12 
PLANTS. 
In the Vegetable Statics, the Doctor has recorded 
a great many experiments, the result of which tends 
to prove that he is right in his conjecture respecting 
the non-circulation of the sap ; but as these experi- 
ments are by far too numerous to be inserted in 
this place, we shall content ourselves with some of 
his general observations. 
“ In animals,” says the Doctor, “it is the heart 
which sets the blood in motion, and makes it con- 
tinually circulate; but in vegetables we can discover 
no other cause of the sap’s motion but the strong at- 
traction of the capillary sap-vessels, assisted by the 
brisk undulations and vibrations caused by the sun’s 
warmth, whereby the sap is carried up to the top 
of the tallest trees, and is there perspired off through 
the leaves : but when the surface of the tree is 
greatly diminished by the loss of its leaves, then 
also the perspiration and motion of the sap are pro- 
portionally diminished, as is plain from many of 
the foregoing experiments : so that the ascending- 
velocity of the sap is principally accelerated by the 
plentiful perspiration of the leaves, thereby making- 
room for the fine capillary vessels to exert their 
vastly attracting power, which perspiration is ef- 
fected by the brisk rarefying vibrations of warmth ; 
a power that does not seem to be any ways well 
adapted to make the sap descend from the tops of 
vegetables by different vessels to the root. 
“ If the sap circulated, it must needs have been 
seen descending from the upper part of large gashes 
cut in branches set in water, and with columns of 
