Analyfis of the Air. 147 



Which fudden and fatal effed of thefe 

 noxious vapours, has hitherto been fuppofed 

 to be wholly owing to the lofs and wafte of 

 the vivifying fpirit of air $ but may not 

 unreafonably be alfo attributed to the lofs 

 of a confiderable part of the air's elafticity, 

 and the groffhefs and denfity of the vapours* 

 which the air is charged with 5 for mutu- 

 ally attracting particles, when floating in fo 

 thin a medium as the air, will readily coa- 

 lefce into groffer combinations : Which 

 efFed of thefe vapours, having not been duly 

 obferved before , it was concluded, that 

 they did not affecl: the air's elafticity , and 

 that confequently, the lungs muft needs be 

 as much dilated in infpiration by this* as 

 by a clear air. 



But that the lungs will not rife, and di- 

 late as ufual, when they draw in fuch noxi- 

 ous air, which decreafes faft in its elafticity, 

 I was affured by the Experiment I made on 

 my felf in Exper. 107- for when towards 

 the latter end of the minute, the fuffocating 

 quality of the air in the bladder was grea- 

 teft, it was with much difficulty that I 

 could dilate my lungs a very little, 



R 4 From 



