{93} 
CiC TT Oe XXin: 
in planting trees for rendering the air 
wholefomer, it fees not to be quite 
indifferent what kind of trees are 
made use of. 
AFTER what is already faid 
on the fubject, there will be no 
doubt left, that vegetables have a 
remarkable fhare in cleanfing and 
purifying our atmofphere. But as 
it feems to follow from my experi- 
ments, that fome trees yield by the 
day a purer dephlogitticated air than 
others, and that fome feem to be 
lefs difpofed to infect common air 
by night, it can fcarce be confidered | — 
as a matter entirely indifferent og 
kind of trees ones to be planted, 
