161 Analyfis of the Air, 



Experiment CXVI. 



I bored a hole in the fide of a large wooden 

 foffet ab, (Fig. 39.) and glewed into it the 

 great end of another foffet ii, covering the 

 orifice with a bladder valve r : Then I fit- 

 ted a valve b i, to the orifice of the iron 

 fyphon f f> fixing the end of the fyphon 

 fafl: at b into the foffet a b : Then by means 

 of narrow hoops I placed four Diaphragms 

 of flannel at half an inch diftance from each 

 other, into the broad rim of a fieve, which 

 was about 7 inches diameter. The fieve was 

 fixed to, and had a free communication with 

 both orifices of the fyphon, by means of 

 two large bladders i in no. 



The inftrument being thusprepared, pinch- 

 ing my noftrils clofe, when I drew in breath 

 with my mouth at a y the valve i b being 

 thereby lifted up, the air paffed freely thro' 

 *he fyphon from the bladders, which then 

 fubfided, andflirunk confiderably : But when 

 I breathed air out of my lungs, then the 

 valve t b clofing the orifice of the fyphon, the 

 air paffed thro 1 the valve r into the blad- 

 ders ? and thereby dilated them j by which 



arti- 



