1^6 Anahjfis of the Air. 
when the bladder was at any time newly 
filled, than when it was near empty. 
From thefe violent and fatal efFeSs of 
very noxious vapours on the refpiration and 
life of animals, we may fee how the refpi- 
ration is proportionably incommoded, when 
the air is loaded with leffer degrees of va- 
pours, which vapours do in fome meafure 
clog and lower the air’s elafticity 5 which it 
beft regains by having thefe vapours dif- 
pcllcd by the ventilating motion of the 
free open air, which is rendered wholefomc 
by the agitation of winds : Thus what we 
call a clofe warm air, fuch as has been long 
confined in a room, without having the va- 
pours in it carried off by communicating j 
with the open air, is apt to give us more { 
or lefs uneafinefs, in proportion to the quan- 
tity of vapours which are floating in it. 
For which reafon the German ftoves, which i 
heat the air in a room without a free | 
admittance of frefli air to carry off the va- i 
pours that arc raifed , as alfo the modern | 
invention to convey heated air into rooms 
thro' hot flues, feem not fo well contrived, 
to favour a free refpiration, as our common 
method of fires in open chimneys, which 
4 fires 
I 
