[ S3 ] 



SECTION XIII. 



All roots, few excepted, zvhen left out 

 of the ground, yield by day and by 

 night foul air, and infecl the fur- 

 rounding air, 



THE experiments I made upon 

 this fubjedt convinced me that roots 

 have this deleterious power, and 

 fome even to fo great a degree, that 

 it would not be fafe to remain in a 

 fmall clofe room in which a great 

 quantity of roots of plants are 

 kept. The roots of ibme aquatic 

 plants are remarkably apt to foul 

 the air in which they are placed, 

 fuch as roots of rufhes, though ever 

 lb well cleaned from mud and dirt, 

 and the roots of perjicaria urens. 

 But I found the roots of bee a bung a 

 E 3 almoft 



