[ ai6 ] 



So that the fame air which the 

 plants had fouled in the night was 

 again reftored to its former purity, 

 and even by fome of thefe plants 

 rendered better than common air, 

 principally by the walnut-leaves, 

 lime-tree, and vine, the teft of 

 the common air being at the time 

 that one meafure of it with one of 

 nitrous air occupied 1.07, 



SEC- 



