168 On Mildew. — . 
stalk, and most where itis slenderest, Hae there he 
on a stagnation. | 
But the earth, being deeply nite 1 by the long io 
intense heat, not cooling so soon as the stalk, continues 
the violent ascent of the juices as before; and if there 
be an obstruction or stoppage above, in the slenderest 
part of the stalk, what must, what can be the conse- 
quence of this but an eatravasation, or as the vessels 
burst ? sa 
That in fact mildews in New-England always come 
in cool nights, after intense and continued heats, lam 
sure from near 40 years observation, and from these 
symptoms I have often known a mildew prognosticated 
by observing persons, in the evening preceding. 
Such a cold, succeeding heat, every philosopher, and 
almost every man, knows will occasion a great dew. 
And this no doubt is the reason why this rust has been 
ascribed to the dew and called meldew or mildew. 
Whereas I suppose it was the cold, properly speaking, 
which occasioned both; and that the dew had no other 
effect in occasioning the rus¢ than, as by hanging on the 
stalk, it may increase the chill. 
Another fact which, I think, confirms this hypothesis 
is this: that the thin leaves and the slenderest parts of 
the stalk are always first affected; on the stalk the spots 
first appear just below the ear. Here the stalk being 
smallest and the vessels narrowest, is the first stoppage 
by the chill, as might be expected. And accordingly 
just below this the first eruption appears; and so lower 
and lower, till, without relief, it covers the whole and 
entirely ruins the grain if not already filled. 
