The Harmony of Creation. 643 
without giving a fresh supply from time .to time, these 
marine animals die. But by the addition of a few plants, 
ulve or conferve, the equilibrium maintains itself, and the 
animals would live a long time without the addition. of 
water, because the plants absorb the effete matters thrown 
off by the animals, and having digested these matters, re- 
turn to the water the life-sustaining elements which have 
been extracted. 
In like manner, an admirable paeceanicns is maintained 
between the animal and vegetable kingdoms which flourish 
in the atmosphere. The carbonic acid which is evolved in 
the process of respiration of all animated nature, is ab- 
sorbed by every leaf and every blade, and the oxygen is 
returned to the air, while the carbon is consumed by the 
tree, plant, or grass. A large amount of the carbonic acid 
is absorbed by water, and carried in a state of solution, by 
means of vapour, rain, river or sea, to the vegetable king- 
dom. The water forms the vehicle, and the gas poisonous 
to man and all animal life is extracted, the oxygen being 
thrown back into the circumambient air, or the surround- 
ing waters. A circulation of life is thus maintained by the 
play of the animal and vegetable kingdom. ‘The immense 
oceans which cover the greater part of our globe, absorb 
from the air all deleterious vapours which the vegetable 
kingdom is unable to appropriate, and the low order of 
plants and marine insects which live in the ocean, without 
doubt absorb the gaseous poisons and digest them, as the 
higher order of plants on land have been proved to purify 
the air of its carbonic acid gas. By a harmonious play of 
wonderful laws, the vegetable kingdom is rendered sub- 
servient to the production of food and purification of the 
air. The food of the plant is formed from the effete mat- 
ters thrown off by the animal kingdom. Yet, in spite of 
this admirable antagonism between these two kingdoms of 
Nature, the purity of the air would have been but imper- 
fectly maintained, if the atmosphere had not been kept in 
a state of constant motion by winds, which force the air to 
wander in perpetual currents from the equator to the pole, 
and from the pole to the equator. 
The unequal influence of the heat of the sun upon the 
atmosphere between the tropics and in the higher latitudes, 
is the first grand cause of this immense aérial circulation. 
Columns of cold air from the freezing poles, sweep into the 
heated regions of the earth, the heated air ascends, and 
- pours its floods in the upper strata towards the poles. 
NEW SERIES.-—VOL I.  B 
