Analyfis of the Air. 163 



which was fufpended by a cord, Co as to 

 have its mouth r r three or four inches un- 

 der water 5 then with a fyphon I fucked 

 the Air out of the glafs vefiel till the water 

 rofe to z z. But when any noxious thing, as 

 burning brimftone, aquafortis, or the likc> 

 were placed under the glafs 3 then by affix- 

 ing to the fyphon the nofe of a large pair of 

 bellows, whofe wide fucking orifice was 

 clofed up, as the bellows were enlarged, 

 they drew the Air briskly out of the glafs 

 z z a a thro' the fyphon ; the other leg of 

 which fyphon I immediately drew from un- 

 der the glafs veffel, marking the height of 

 the water z z. 



When the materials on the pedeftal ge- 

 nerated Air, then the water would fubfide 

 from z z to aa, which fpace z z a a was 

 equal to the quantity of Air generated : 

 But when the materials deftroyed any part cf 

 the Air's elafticity, then the water would 

 rife from a a ( the height that I in that cafe 

 at firft fucked it to ) to z z, and the fpace 

 a a z z was equal to the quantity of Air, 

 w 7 hofe elafticity was deftroyed. 



I fometimes fired the materials on the 

 pedeftal by means of a burning glafs, viz. 



M z fuch 



