The Conclufion. 3 67 
earth, compote that nutritive du&ile matter, 
out of which the parts of vegetables are form- 
ed, and without which the watry vehicle a- 
lone cannot render a barren foil fruitful. 
Nor is this the only care, the thriving 
and fertility of plants and trees depends much 
upon the happy influence and concurrence 
of a great variety of other circumftanccs. 
Thus many trees are unfruitful by being 
planted too deep, whereby their roots being 
in too moifl: a ftate, and too far from the 
proper influence of the Sun, whofe power 
greatly dccreafes the deeper we go, as we 
fee in Experiment zo. they imbibe too much 
crude moifture, which tho’ produ&ive of 
wood, is yet unkindly for fruit. 
Or if when not planted too deep, they 
are full of crude fap, either by being too 
luxurious, or too much fhaded; or are 
planted in a moifl, when they delight in a 
dry foil, then the fap is not fo fufficiently 
digefted by the Sun’s warmth, as to be in 
that du&ile ftate, which is proper for the 
producing of fruit. 
And thus the Vine, which is known to 
thrive well in a dry, gravelly, rocky foil, 
will not be fo fruitful in a moifl, ftiflf, clay 
ground: And accordingly we may obferve 
a in 
