168 
DR. DAUBENY ON THE ACTION OF LIGHT UPON PLANTS, 
Experiment 3. 
Proportion 
Absorption 
per cent. 
Residuum 
per cent. 
Allowance 
Calculated amount 
Date. 
Circumstances of the experiment. 
per cent, of 
caused by 
after burning 
for phospho- 
carbonic acid 
solution of 
phosphorus 
rus vapour. 
added. 
potash. 
in a portion 
of the air. 
nitrogen. 
oxygen. 
April 26. 
12 a. m. Dull day, with occasional 
gleams of sunshine, but no rain. A 
( Pelargonium ) Geranium with its 
pot introduced into the jar 
5 
5 
81 
2 
79 
21-0 
7 P. M 
0 
1 
79-5 
79-25 
2 
77-5 
77-25 
22-5 
22-75 
April 27. 
The unfavourable state of the 
weather led me to discontinue this 
experiment. 
0 
0 
2 
Experiment 4. 
April 29. 
12 a. m. Dull and stormy day, with 
occasional gleams of sunshine. A 
Geranium with its pot introduced 
into the jar, occupying together 
a capacity of about GO cubic inches 
5 
5 
81 
2 
79 
21 
6 P. M 
0 
1 
83-6 
2 
81-6 
18-4 
April 30. 
10 A. M 
5 
5 
82-5 
2 
80-5 
19-5 
5p.m. After a bright day, with clouds 
and showers occurring occasionally 
0 
0 
78-5 
2 
76-5 
23-5 
May 1. 
8 A. m. Access of the morning sun 
prevented by an opake screen co- 
vering the jar 
A diminution in the quantity of 
0 
2 
oxygen was detected, but its amount 
was not registered, as the apparatus 
was found not to be perfectly air-tight. 
'Hie experiment was therefore sus- 
pended in order to repair the defect. 
Experiment 5. 
May 8. 
12 a. m. Bright day. A Geranium 
in a pot was introduced into the jar 
5 
5 
81 
2 
79 
21-00 
H p. M 
ol 
~ 2 
0 
2-5 
79-75 
2 
77-75 
22-25 
0 
2-25 
79-25 
2 
77-25 
22-75 
H 
0 
0'05 
79 00 
2 
77-00 
23-00 
May 9. 
8 a. m. During the morning screened 
from the sun 
0 
00 
10a.m. Fine bright day 
10 
100 
11 a. m 
0 
9-50 
82 
2 
80-00 
20 00 
12 A. M 
0 
6-25 
82 
2 
80-00 
20-00 
2 P. M 
0 
G'5 
80 
2 
78-00 
22-00 
Experiment 6. 
May 10. 
Fine bright day. At 12 a. m. a fresh 
fipranium was introduced 
10'5 
10-5 
81 
2 
79 
21 
0 
10 
76 
2 
74 
26 
