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of air oozes out of the plant, and of 

 what quality this air is ; for any air 

 iffuing out of a plant incorporates 

 immediately with the furrounding 

 air, and makes a compound whofe 

 conftituent parts are an intimate 

 mixture of air from the plant and 

 common air; and it would be as 

 difficult to judge accurately how 

 much dephlogifticated air fuch a 

 plant has communicated to the or- 

 dinary air which was already in 

 the jar, as it would be for a chymifl 

 to judge accurately what quantity 

 of di (tilled Water was mixed with a 

 certain quantity of common water, 

 if fome of it was really added to it 

 on purpofe to puzzle him. It may, 

 however, be afcertained, in an in- 

 accurate way, what quantity of this 

 beneficial air a plant, placed in a j ;r 

 full of common air, has communi- 

 D cated 



