Es Sy} 
reCting the mafs of air contaminated 
by their refpiration, and perhaps 
too by their perfpiration. The fol- 
lowing pages will fhew, whether 
the pains J took, in the courfe of this 
fummer, to inveftigate this impor- 
tant fubject, have een attended with 
fome. degree of fuccefs. I am far 
from thinking that I have difco- 
‘vered the whole of this falutary 
operation of the vegetable kingdom; 
but I cannot but flatter myfelf, thas 
Thave at leait proceeded a ftep far- 
‘ther than others, and opened a new 
path for penetrating deeper into Bs | 
~myfterious labyrinth. 
Among the various ufeful difco- 
veries with which Dr. Prieftley has 
already enriched, and ftill continues - 
: to enrich, natural knowledge, none, 
in 1 my opinion, are of more import- 
ance 
Pr 
