pe : = 
It is another well known fact, that grounds in our 
new settlements are much less exposed to mildews than 
in our old plantations which have been often dunged. 
The reason of this is plain upon this hypothesis, for 
dung heaps are known in summer, to receive and retain 
a much greater degree of heat than common earth. 
There ean be no doubt therefore, but that dunged 
lands do the same in proportion to the dung, especially 
the new dung, laid upon them. And if so, It must oc- 
casion a more violent ascent of the juices, and so the 
stalk will be proportionably in more danger of bursting, 
and of an extravasation of the juices, upon a sudden 
chill in the stalk. 
Another fact commonly observed is, that high grounds 
are not so exposed to mildews as lower. The reasons 
are plain upon this hypothesis. Ist. Because there is | 
not so much difference between the weather in the day 
and night on high grounds, as im the lower. 2d. Because 
the greater motion of the air in the high land, may in 
some measure prevent the stagnation of the juices. 
But most of these things are very hard to account 
for, upon any other hypothesis I have ever seen. 
Upon this plan too, an /igh wind will be likely to 
prevent a mildew; and accordingly, I think, they are 
never known to come ina windy night, though cold. 
And a shower, or a rope passed over the fields, at this 
time may do some service : as the washing and cleans- 
ing a sore on an animal, or as any kind of motion in 
case of stagnation of the blood and juices of our bo- 
dies. 
But though I take this, for the reasons given, to be 
the true cause of what are called mi/dews; from the 
VOL. II. Y 
