SECTION XI. 
‘Experiments fbewing that roots of 
plants when kept out of ihe ground 
yield, in general, bad air; and {potil 
common air at aul times, oe Jen 
ts encepied, — 
Cesta Es THREB haridfals‘of. foot 
on the of muftard plants, wafhed clean, 
"y*were put in a jar full of water in 
‘the ordinary way, and expofed to 
the fun - ae fix, hours r eee 
72. Two handfuls of roots of 
‘common rufbes, well cleaned:from — 
-dirt, were in the fame manner ex- 
pofed to the fun durin g feven hours; 
_ when a {mall quantity of air was 
: — Me So obtain Say 
