L Zab 
flame ; that of the /aurocera/us was 
next in foulnefs to the walnut; 
then followed. the lime-tree; the 
oak had fpoiled the air the eet of 
all. 
_ One aiare of the air in “which 
Sad walnut-leaves had been, with 
one meafure of nitrous air, occu- 
pied 1.53; that of the /awrocera/us 
1.263 that of the lime-tree 1:16; 
and that of the oak i.10. 
branches of a vine generally fect 
the air much lefs by night than 
moift part of other trees. Cabbage 
among the culinary plants was, of 
all I tried, the leait difpofed to con- 
taminate ae 2 
Wa ee 
