^ A TREATISE ON THE CONNECTION OF 



these acids on chalk fixable air is disengaged. This gas 

 is absorbed by the roots of vegetables, decomposed in the 

 process of vegetation, affording the carbonaceous prin* 

 ciple to vegetables ; whilst vital air, the other constituent 

 part of fixable air, is thrown off by the respiratory power 

 of vegetables. 



The different effeds of lime and of chalk on vege- 

 table and animal substances, shew, that when either of 

 those materials is applied with a view to promote the 

 fertility of the ground, they should be used according 

 to circumstances, and the nature of the soil. 



PAR 



