Jnalyfis of the Ah. 165 



fyphon S S y fixing the end of the fyphon faft 

 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 feven 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 i n n 0. 



Linen would probably be more proper to 

 make thefe Diaphragms of than flannel, be- 

 caufe oil or greafe is ufed in the making of 

 flannel : And as I have heard, it is whitened 

 by the fumes of burning Brimjtone; which I 

 was not aware of, when I made uie of flannel 

 in thefe Experiments. 



The inftrument being thus prepared, 

 pinching my noftrils clofe, when I drew in 

 breath with my mouth at ft the valve i b 

 being thereby lifted up, the air pafled freely 

 through the fyphon from the bladders, 

 which then fubfided, and fhrunk confider- 

 ably: But when I breathed air out of my 

 lungs, then the valve i b clofing the orifice 

 of the fyphon, the air pafled thro' the valve 

 r into the bladders, and thereby dilated 

 them j by which artifice the air which I ex- 

 pired muft neceffarily pafsthro' all the Dia- 

 phragms, 



