t « 74 3 



SECTION XIX. 



Experiments Jhewing that the fun hy 

 itfelf without the ajjijlance of 

 plants y does not improve air, but 

 renders it rather worfe. 



124. TWO jars, half-full of air 

 taken from the atmofphere at the 

 fame time, and half-full of pump- 

 water, were left by themfeives dur- 

 ing four hours, the one expofed to 

 a bright fun-ihine, 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 

 that of the jar placed in the fun. 

 One meafure of the air kept within 

 5 d oors 



