THE AQUARIUM. 59 
UY ef “f HI AHN THN oe 
= To aS 
The Aquarium. 
into the lungs is deprived of a large amount of oxy- 
gen gas, while at the same time it becomes charged 
with carbonic acid gas, which is incapable of support- 
ing animal life. This noxious principle is absorbed 
by the leaves of plants, where it appears to undergo 
Jecomposition ; the carbon being retained for the use 
of the plant, and the oxygen liberated to assist in 
restoring the atmosphere to its original purity. This 
