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lity. One hundred leaves of this 

 plant, which are very thin, yielded, 

 in two hours time, as much dephlo- 

 gifticated air as would fill a cylindri- 

 cal glafs four inches and a half deep, 

 and one inch and three quarters dia- 

 meter ; of which quantity gathered 

 again afterwards from the fame 

 leaves, without taking them out of 

 the water, fee exp. 30 — 35. This 

 quantity furpafles by far the bulk of 

 the leaves themfelves, and fhews to 

 how amazing a quantity the air may 

 amount yielded in a fair day by a 

 lofty tree. 



The leaves being: more or lefs 



o 



crouded together, being expofed 

 for a longer or fhorter time, or 

 fooner or later in the day, will occa- 

 iion fome difference in the quality 

 and quantity of this air. 



It 



