THE AIR OF THE SOIL. 219 
Boussingault and Lewy. (Mémoires de Chimie Agricole, 
etc., p. 369.) 
Cubse feet of carbonic 
Composition of the 
air in the soil in 100 
parts by volume. 
—_—-*-——— 
14 énches. 
Car- | Oy. | Witro- 
acid, | YIM: | gen. 
to depth of 14 inches. 
acid in acre to depth of 
Cubie feet of air in acre} 
Sandy subsoil of forest. 
Loamy ry “a “ 
Surface soil ‘“ “  ... 
Clayey ‘ of artichoke fi \: 
Soil of asparagus bed not manurced for one year} 11182) 86 | 0.74 | 19.02] 80.24 
ths cy “newly mannred.......... 11182) 172 | 1.54 
Sandy soil, six days after manuring....[of rain] 11783] 257 | 2.21 
“ws oh ten “a be oe 9.44 
3.64 
three days} 11783} 1144 10.35] 79.91 
Vegetable mold-compost..............ceeeeees 21049} "72 16.45] 79.91 
we [ss 
S$ /§8 
Q . 
S5 leh s 
$x 3s 
Bay a 8 eS 
= 8 $3 Composition of air 
ped x , 
SS [SE] above the soit 2n 100 
ss 3 <3 parts. 
Be (SSS| £05 | ow. |aitro- 
8 BS | acia. | yen | gen. 
50820! 12 | 0.025/20.945/79.030 
The percentage, as well as the absolute quantity of car- 
bonic acid, is seen to stand in close relation with the or- 
ganic matters of the soil. The influence of the recent 
application of manure rich in organic substances is strik- 
ingly shown in case of the asparagus bed and the sandy 
soil. The lowest percentage of carbonic acid is 10 times 
that of the atmosphere a few feet above the surface of the 
earth, as determined at the same time, while the highest 
percentage is 390 times that proportion. 
Even in the sandy subsoil the quantity of free carbonic 
acid is as great as in an equal bulk of the atmosphere; 
and in the cultivated soils it is present in from 6 to 95 
