AGRICULTURE WITH CHEMISTRY. 43 



taining much vegetable matter; part of Avh"ch is dissipated 

 in a gassioiis state, and part combines with the lime, form- 

 ing insohibic compounds, which cannot promote vege- 

 tation, until brought into adion by other saline substances, 

 either on the principle of superior affinity, or on that of 



the double ele(5lric attra(5tions, as will be explained in the 

 * — ---'■ * 



senviel of this work. 



CHALK, ORUNCALCINED CALCAREOUS MATTER. 



Chalk has not the same power as lime in destroying 

 the texture of organic bodies, because it is saturated with 

 fixal)lc air: it has, however, an adion on these sub- 

 stances, or more properly speaking, these substances 

 have an adlion on chalk, so soon as by oxygenation their 

 respcflive acids are generated; in which case they will 

 combine with the chalk, and form the nearly insoluble 

 saline compounds, already described. By the adlion of 



F 2 these 



