[ 44 ] 

 It feems that, in general, the 

 fineft air is obtained when the fun 

 has palfed the meridian. 



SECTION XL 



The faculty which plants pejfefs of 

 yielding dephlogifticated air, of cor- 

 recting foul air, and improving or- 

 dinary air, is not owing to the a£i 

 of vegetation, 



IF this wonderful faculty of plants 

 depended upon their vegetation, 

 they would exert it at all times, and 

 in all places in which the vegetation 

 goes on. A plant may vegetate, 

 and even thrive very well, in the 

 utmoft darknefs; and yet in fuch a 



place 



