78 (ECONOMY 
prepared offers again to plants from its bo- 
fom, what it has received from them. For 
when feeds are committed to the earth, they 
draw to themfelves, accommodate to their 
nature, and turn into plants , the more fub- 
tile parts of this mould by the co-operation 
of the fun, air, clouds, rains, and winds j fa 
that the talleft tree is, properly fpeaking, no- 
thing but mould wonderfully compounded 
with air, and water, and modified by a vir- 
tue communicated to a fmall feed by the 
Creator. From thefe plant j, when they die, 
juft the fame kind of mould is formed, as 
gave birth to them originally ; but in fuch a 
manner, that it is in greater quantity than 
before. Vegetables therefore increafe the black 
mould, whence fertility remains continual- 
ly uninterrupted. Whereas the earth could 
not make good its annual confumption, un- 
lefs it were conftantly recruited by new fup- 
plies. , 
The cruftaceous liverworts are the firft foun- 
dation of vegetation , and therefore are plants 
of the utmoft confequence in the oeconomy 
of nature, though fo defpifed by us. When 
rocks firft emerge out of the fea, they are fo 
polifhed by the force of the waves, that 
fcarce 
