Analyfis of the Air. 249 



I cut afunder the bodies of feveral young 

 and fmall animals juft below the ^Diaphragm, 

 and then taking care not to cut any vefiel 

 belonging to the lungs , I layed the Thorax 

 open by taking away the TDiphragrn, and 

 fo much of the ribs, as was needful to ex- 

 pofe the lungs to full view, when blown 

 up. And having cut off the head, I faftned 

 the windpipe to a very fhort inverted leg of 

 a glafs fyphon 5 and then placed the inver- 

 ted lungs and fyphon in a large and deep 

 glafs veffel at full of water (Fig. 32.) un- 

 der the air pump receiver p p, and palling 

 the longer leg of the fyphon thro' the top of 

 the receiver, where it was cemented faft at 

 z,, as I drew the air out of the receiver, the 

 lungs dilated, having a free communica- 

 tion with the outward air, by means of the 

 glafs fyphon % fome of which air would 

 here and there pafs in a few places thro' 

 the fubftance of the lungs , and rife in fmall 

 ftreams thro' the water , when the receiver 

 was exhaufted no more than to make the 

 Mercury in the gage rife lefs than two inch- 

 es. When I exhaufted the receiver, fo as 

 to raife the Mercury 7 or 8 inches, tho' it 

 made the air rafh with much more violence 



thro' 



