170 
DR. DAUBENY ON THE ACTION OF LIGHT UPON PLANTS, 
Experiment 9. — 'Continued. 
Proportion 
Absorption 
per cent. 
Residuum 
per cent. 
Allowance 
Calculated amount 
Date. 
Circumstances of the experiment. 
per cent, of 
caused by 
afterburning 
for phospho- 
per cent, of 
carbonic acid 
solution of 
phosphorus 
rus vapour. 
atlded. 
potash. 
in a portion 
of the air. 
nitrogen. 
oxygen. 
May 22. 
S a. m. Before uncovering the jar. . 
9 a. m. Fine bright cloudless day. 
0 
0-5 
79-75 
2 
77-75 
22-25 
Thermometer 6S° 
8-5 
9-0 
.... 
.... 
14 P.M 
0 
6-0 
75-75 
2 
73-75 
26'25 
5 P. M 
0 
3-0 
74-5 
“2 
72-5 
• 27-5 
May 23. 
8 a. m. Before the screen had been 
removed 
0 
2 
75 
2 
73 
27 
8 p. m. After a fine bright day .... 
0 
0 
76 
2 
74 
26 
May 24. 
8 a. m. Before removing the screen. . 
0 
0 
75-5 
2 
73-5 
26-5 
4 p. m. After a fine bright day .... 
0 
0 
76-5 
2 
74-5 
25-5 
May 25. 
S a. m. Before removing the screen. . 
0 
2 
76-75 
2 
74-75 
25-25 
6 p. m. Fine bright day, like yesterday 
0 
0 
77-25 
2 
75-25 
24-75 
May 27. 
10 A. M . 
0 
1 
80-75 
2 
78-75 
21-25 
Experiment discontinued, as most of 
the leaves had dropped off, and the re- 
mainder looked decayed and withered. 
The decay of the leaves began to date 
from the 24th, at which time the 
amount of oxygen will be seen to have 
begun to diminish. 
Observations . — This experiment shows how erroneous a 
conclusion we might deduce, if we contented our- 
selves with examining the air after an interval of some days, and how soon, even under the most favourable 
circumstances, confinement interferes with the healthy functions of 
a plant. 
Experiment 10. 
Aug. 20. 
12 a. m. Day dull and cloudy, with a 
few occasional gleams of sunshine. 
Therm. 70°. A young Cedar with 
its pot was introduced under a jar 
having a capacity of about 800 cu- 
bic inches 
75 
7“5 
81 
2 
79 
21 
I 
10 P. M 
2-75 
80 
2 
78 
22 
I Aug. 21. 
10 a. m. Day overcast, but with oc- 
casional gleams of sunshine. Ther- 
mometer 70° 
0 
2-0 
82-5 
2 
80-5 
19-5 
104 
7 P. M 
7“5 
0 
9“5 
5-0 
80 
2 
78 
220 
Aug.22. 
11 a. m. Windy day, but with a 
bright sun till about 4 p. m. Ther- 
mometer 70° 
0 
4-0 
80 
2 
78 
22-0 
7 P. M 
0 
00 
78-75 
2 
76-75 
23-25 
Aug. 23. 
8 a. m. Windy and cloudy day, with 
occasional showers, and few gleams 
of sunshine. Therm. G4° 
0 
2-0 
80 
2 
78 
22 
10 A. M 
75 
95 
80 
2 
78 
22 
7 P. M 
0 
4“0 
78-50 
2 
76-50 
23-50 
Aug. 24. 
10 a. m. Cloudy day, without sun. 
24-75 
Therm. G6° 
0 
1 
77-25 
2 
75-25 
12 A. M 
7“5 
7 P. M 
0 
5 
78-20 
2 
76-20 
23-80 
Experiment discontinued. 
