146 THE GRAPE. 
similiar in structure, if not positively of the same gen.1s— 
are most prevalent when a slow steady under current of 
dry air is passing in hot weather, which, by exciting to 
an extraordinary degree of evaporation, leaves a dam 
clamminess upon the surface of all plants by drawing out a 
f rtion of their collected juices, which then becomes food 
for the sporules to vegetate upon. This may be considered 
somewhat similar to the bottom draft in a hot-house—a 
very different thing, by the way, to a healthy and free 
ventilation overhead, where the air is made to circulate 
evenly over the whole cubie bulk, without that continual 
stream from small apertures below. In our present case, 
moisture combined with heat will counteract the fungus, 
and it may he effectually got rid of by syringing with 
water, in which a portion of sulphur is mixed; one pound 
of the latter will be enough for ten or fifteen gallons of the 
former. If the fruit be approaching to maturity, this kind 
of application will disfigure it, and the same purpose may 
be as effectually gained by dusting a small quantity on 
the heating apparatus where it will not ignite; or if a cold 
use, by strewing it over the floor in the same quantity 
as before advised. 
The peculiar cireumstances under which parasitica! 
fangoids luxuriate, are wonderfully dependent on the state 
of the atmosphere. This is demonstrated, not only by the 
different sorts of grape mildew, but in all othe 
