! 



U 





z 5 6 



when 

 filled, 



Anahjfis of the Air. 



* 



> 



gj* 



the bladder was at any time ncwiy 

 than when it was near empty. aW 



From thefe violent and fatal effe6h oi^c^ 

 very noxious vapours on the refpiration and^j* 

 life of animals, we may fee how the refpi-' 

 ration is proportionably incommoded, wheJ 

 the air is loaded with lefier degrees of va- m & 

 poursj whicjj vapours do in fome meafure 

 clog and lower the air's elafticity > which it 

 belt regains by having thefe vapours dif- 1 ^^ 

 pclled by the ventilating motion of the 

 free open air, which is rendered wholefomc * 

 by the agitation of winds : Thus what wc 

 call a clofe warm air, fuch as has been lon£ * ■ 

 confined in a room, without having the va 

 pours in it carried off by communicating, 

 with the open air, is apt to give us more 

 or lefs uneaftnefs, in proportion to the quan 

 tity of vapours which are floating in itjo,^ 

 For which reafon the German (loves, whicl 

 heat the air in a room without a free 

 admittance of frefh air to carry off the va*^ 

 pours that are raifed, as alfo the moderr 

 invention to convey heated air into room: 

 thro' hot flues, feem not fo well contrived 

 to favour a free refpiration, as our common 



method of fires in open chimneys, which 



fires*** 







, 



