160 Analyfis of the Air. 



Which fleams have doubtlefs the fame 

 effect on the air, in the lungs of Animals 

 held ever them ; as in the Grotto di cam, 

 or when a clofe room is filled with them, 

 where they certainly fuffocate. 



It is found by Experiments 103, 106, 

 and 107, that an air greatly charged with 

 vapours lofes much of its elafticity, which 

 is the reafbn why fubterraneous damps fuf- 

 focate Animals, and extinguifh the flame of 

 Candles. And by Experiment io<5, we fee 

 that the fooner a Candle goes out, the fatt- 

 er the air lofes its elafticity. 



Experiment CXV. 



This put me upon attempting to find fome 

 means to qualify and rebate the deadly noxi- 

 ous quality of thefe vapours : And in order 

 to it, I put thro 1 the hole, in the top of the 

 air pump receiver (Fig. 32.) which con- 

 tained two quarts, one leg of an iron fyphon 

 made of a gun barrel, which reached near 

 to the bottom of the receiver : It was ce- 

 mented faft at z } I tyed three folds of wool- 

 len cloth over the orifice of the fyphon, 

 which was in the receiver. The Candle went 

 out in lefs than two minutes, tho' I conti- 



4 nued 



