THE SOIJECES OE THE OTTEOGEN OE VEGETATION, ETC. 
489 
T.\ble III. — Showing the amount and composition of the Gas given off into 
a Torricellian vacuum, by plants exposed to sunlight. 
Date, 
How manured, &c. 
Total 
Gas col- 
lected, 
cub. 
cents. 
Nitro- 
gen. 
Per 
Oxygen. 
cent. 
Car- 
bonic 
acid. 
Oxygen 
and 
Carbonic 
acid. 
Wheat (whole plant), 1858. 
June 
22. 
Unmanured 
44-4 
73-65 
21-17 
5-18 
26-35 
June 
23. 
Unmanured 
34-8 
77-01 
21-26 
1-73 
22-99 
June 
30. 
Unmanured 
44-1 
72-79 
20-86 
6-35 
27-21 
June 
22. 
Mineral and Ammoniacal manure 
54-5 
73-76 
21-29 
4-95 
26-24 
June 
23. 
Mineral and Ammoniacal manure 
42-1 
78-15 
15-44 
6-41 
21-85 
June 
25. 
Mineral and Ammoniacal manure ... 
37-2 
78-76 
19-09 
2-15 
21-24 
Grass (whole plants), 1857. 
August 15. 
Mineral and Ammoniacal manure : second crop 
39-0 
82-10 
16-19 
1-71 
17-90 
August 15. 
Mineral and Ammoniacal manure: second crop 
47-8 
77-08 
15-35 
7-57 
22-92 
August 15. 
^^ineral and Ammoniacal manure: second crop 
41-6 
76-56 
21-46 
1-98 
23-44 
August 1 7. 
Mineral and Ammoniacal manure: second crop 
39-9 
75-07 
23-39 
1-54 
24-93 
August 18. 
Mineral and Ammoniacal manure : second crop 
36-8 
79-88 
15-19 
4-93 
20-12 
August 18. 
Mineral and Ammoniacal manure : second crop 
42-3 
80-23 
15-97 
3-80 
19-77 
Beans, 1858. 
July 
12. 
Mineral manure ; almost podding 
44-3 
71-11 
18-28 
10-61 
28-89 
July 
12 . 
Farm-yard manure; almost podding 
45*8 
73-14 
10-26 
16-60 
26-86 
July 
15. 
Unmanured ; almost podding 
25-9 
82-63 
15-83 
1-54 
17-37 
July 
15. 
Mineral and Ammoniacal manure; almost podding... 
30-9 
70-55 
20-71 
8-74 
29-45 
The general accordance in the proportions of Nitrogen found throughout this Series, 
together with their general approximation to the amounts observed in Series 2 (Table II.), 
and the consequent similarity in range of the sums of the two remaining gases — carbonic 
acid and oxygen — point to the character of the change which has taken place, by virtue 
of which the proportion of carbonic acid is diminished, and that of oxygen increased. 
The variations in the amounts are, nevertheless, somewhat considerable ; and w'e feel 
that it would be requisite to exercise considerable caution in attempting to refer them 
to any other than accidental circumstances beyond our control. There can be no doubt, 
however, that the carbonic acid, showm to exist in the plants in the shade, has yielded 
the oxygen evolved w'hen in the sunlight. But the mutual relations of the two gases will 
be more clearly brought to \iew by a consideration of the results yet to be adduced. 
Experiments, Series 4. 
These experiments, as well as those of the succeeding Series, were arranged to show 
the influence of the time of action of the sunlight on the plant, upon the relative pro- 
portions of carbonic acid and oxygen. 
In the Series of experiments now under consideration, duplicate quantities of the 
3x2 
