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flame ; that of the laurocerafus was 

 next in foulnefs to the walnut ; 

 then followed the lime-tree ; the 

 oak had fpoiled the air the leaft of 

 all. 



One meafure of the air in which 

 the walnut-leaves had been, with 

 one meafure of nitrous air, occu- 

 pied 1.53 ; that of the laurocerafus 

 1.26 ; that of the lime-tree 1.16; 

 and that of the oak 1.10. 



120. I have obferved that the 

 branches of a vine generally infect 

 the air much lefs by night than 

 moll part of other trees. Cabbage 

 among the culinary plants was, of 

 all I tried, trie leafl difpofed to con- 

 taminate air. 



SEC- 



