(10) 
AN ACCOUNT 
OF SOME 
Bek <P Hh RAL MM RoNeTss 
TO DETERMINE THE QUANTITY OF 
CARBONIC ACID IN THE ATMOSPHERE. 
By WILLIAM HADFIELD. 
(Read December 24th, 1830.) 
Tue Gas denominated Carbonic Acid is found 
diffused through the Atmosphere, but in a very 
small quantity, in every part of the world. We 
find it at the surface of the earth, and in the most 
elevated situations. It is generated in certain 
caverns, mines, and deep covered wells ; and be- 
ing nearly fifty per cent heavier than common 
air, it does not make so great an effort to escape 
from those subterraneous abodes as it would 
otherwise do. The gas is formed in immense 
quantities in large towns from the combustion 
of fuel, and from the respiration of animals ; 
but such is the still greater immensity of the 
atmosphere that the whole quantity of acid gas 
