494 Experiments &3 Obfervations 
of putrefaction, by which the faculty of vege- 
tating in the atmofphere is deftroyed. We may 
now venture to explain, on rational grounds, 
a curious circumftance alluded to in my former 
Paper, (page 310): I mean a property, which 
the feeds of particular plants poffefs, of .conti- 
nuing found and uninjured in the ground for 
many years, provided it remains fallow; but 
which vegetate vigoroufly as foon as the foil is 
pulverized by the plough. For it has been 
fhewn, that an increafe of heat accelerates the 
putrefaction of seeds charged with water and 
deprived of air; from which it may be fafely 
inferred, that the prefervation of thefe bodies 
may be infinitely prolonged, by fecluding them 
from the atmofphere, ina fituation where the 
temperature never exceeds a certain degree, 
which is not the fame for all feeds, but depends 
on their refpective properties. Thus, for ex- 
ample, though peas immerfed in water lofe 
the faculty of producing in ten or twelve days, 
when the thermometer is between 40° and 50°, 
and much fooner in warmer weather, we are 
not to conclude that all other feeds are as quickly 
rendered ufelefs in fimilar circumftances. For [ 
repeated the tenth experiment in July, with feve- 
ral kinds, ina room where the thermometer was 
commonly higher than 62°; when it appeared 
that Barley began to putrify on the fourth day ; 
Wheat 
