ii CONTENT 5, 
Se&t. XVII. Experiments towards inveftigating 
-gybat plants or trees infect the wh 
the air leaft by night, 
ates Sp hig a foewing that eee aes 
logifticated air, and the greate/t quantity, 
is oh by full-grown leaves, 272 
pi nts foewing that the fun Ss 
il, without the affijtance of plants, does 
ot improve air, but renders it rather — 
XX. Experiments tending to invefticate the nop 
- accurate and expeditious gay of putting coim- 
“mon air to the te/t, on purpofe to judge as the 
_ fabubrity of any couniry, 
ijcript, “388 
ae : 
