Analyfn of the Air. 255 



no more than to make the Mercury in the 

 gage rife lefs than two inches. When I ex- 

 haufted the receiver, fo as to raife the Mer- 

 cury feven or eight inches, though it made 

 the air rufli with much more violence thro* 

 thofe fmall apertures in the furface of the 

 lungs, yet I did not perceive that the num- 

 ber of thofe apertures was increafed, or at 

 leaft very little. An argument that thofe 

 apertures were not forcibly made by exhauil- 

 ing the receiver lefs than two inches, but 

 were originally in the live animal. And 

 that the lungs of living animals are fome- 

 times raifed with the like force, efpecially in 

 violent exercife, I found by the following 

 Experiment; viz* 



Experiment CXIII. 

 I tied down a live Dog on his back, near 

 the edge of a table, and then made a fmall 

 hole through the intercoftal mufcles into his 

 Thorax, near the Diaphragm. I cemented 

 faft into this hole the incurvated end of a 

 glafs tube, whofe orifice was covered with a 

 little cap full of holes, that the dilatation 

 of the lungs might not at once flop the ori- 

 fice of the tube. A fmall phial full of fpiric 

 of Wine was tied to the bottom of the per- 



pendicular 



