[ 217 ] 



SECTION VII. 



Experiments Jbewing that the damage 

 done to common air by the night 

 is very inconfiderable compared to 

 the benefit it receives in the day. 



52. TWO handfuls of Elm-tree*^™- 



*-> Lity or 



leaves were put in a jar full of wa-^2 

 ter, as in the former experiment, cro > ed * 

 and expofed to the open air from 

 the 14th of Auguft to the 16th, 

 when the air difengaged from them 

 was examined, and found to be good 

 dephiogiiiicated air ; its teft was 



1-95; *- 8 5 ; 1-77; 2 -4° ; 3-s°- 350 



53. Some graft, kept in a green 

 bottle from the evening till next 

 day at eleven o' clock, had yielded 

 fome air, whofe teit was 1.80 ; 

 I.64; 1.54; 2.31 ; 3.26. 374 



54. A 



