37 6 Dr. ingenhousz 0 # the Salubrity 
It feems alfo probable, that the air will be found in 
general much purer far from the land than near the 
fhore, the former being never fubject to be mixed with 
land air. 
It appears alfo, that the air in frofty weather is in ge- 
neral wholefdmer than it is in winter when it does not 
freeze ; and that uncommon warm weather, happening 
in the winter feafon, is apt to render the atmofphere very 
unwholefome ; the feafon of which I apprehend to be, 
that the fro ft totally checks that general tendency to cor- 
ruption, which being revived by warmth again increafes 
the infedlion of the common air, which at that time is fo 
much the greater, becaufe the plants (which are deprived 
of their leaves in winter) have no power in them to 
counteract it. 
It feems alfo probable, that thofe countries which are, 
by their local fituation, expofed to noxious exhalations, 
are in general much wholefomer in the winter; and that 
it is much fafer to crofs fuch countries in fummer time 
when it is windy weather than in a calm, See. 
How far thefe deductions are founded upon experi- 
ence may appear by applying them to fuch places as 
they may be found to have a relation to. 
My old friend Dr. damman, an eminent phyfician 
and profeftor royal in midwifry at Ghent, told me, that 
when 
