SECTION “XIX: 
Experiments foewing that the fun by 
. iWelf, without the affiflance of 
plants, does, not improve air, but 
‘venders it rather worfe. 
aie iW e eb a Pasta Of air 
fame time, and half-full oF pump- 
water, were left by themfelves dur- 
ing four hours, the one expofed to 
a bright fun-fhine, the other placed 
Within the houfe, only two fteps . 
from a°door opening in the garden. 
The air kept in the houfe gave, - 
in fix different trials, conftantly the 
appearance of being better than 
eS = that of the jar placed in the fun. 
—- pine meafure of = air kept within © 
en 5 ~ doors 
