ee 2 
when they remain undifturbed up- 
on their place. See alfo. experi- 
ments 51, 56, 57, 58, 59, 60. 
SECTION XVII. 
On the effec? of leaving planis kept 
in @ room. 
THO I think, that the keeping 
of a few plants in rooms is very 
indifferent as to the health of the 
perfons who live in them; yet it 
is not fo indifferent for us to know 
the effects which plants have in 
reality on the air of the room, that 
we may avoid pongcr from any 
excels, 
FF 2 The 
