C 62 A 



SECTION XVI. 



The pozver of plants in correcting bad 

 air is greater than their faculty 

 of improving good air* 



THE experiments already known 

 of Dr. Prieftley, by which it appears 

 that plants thrive wonderfully well 

 in air fouled by breathing and burn- 

 ing of candles, gave me a great 

 fufpicion, that the power of plants 

 in correcting bad air might furpafs 

 their faculty of improving good 

 common air. In order to put my 

 conjecture to the trial, I placed at 

 eleven o'clock, in a warm fun^-mine, 

 two jars of an equal lize, each con- 

 taining an equal quantity of fprigs of 

 pepper-mint,in pump water. In one of 

 thefe jars was let up a certain quan- 

 tity 



