ON FALLOWING. 185 



surface, the adhesion is counteracted, and the 

 rain-water, with the soluble manure, more per- 

 fectly distributed among the roots ; and the con- 

 traction of the surface in drying, being pre- 

 vented, or the fissures and clefts being closed or 

 filled up, the water raised by evaporation is 

 more equally diverted among the roots. A pro- 

 per attention to, and comprehension of, those 

 principles, can alone enable a person to judge of 

 the eligibility of paring and burning, and to es- 

 timate its probable value when applied to parti- 

 cular soils. 



It is evident, that the most important and per- 

 manent effects of fire consists in its imparting 

 calcareous quality to the earth ; it must therefore 

 be as evident that soils which naturally contain a 

 due proportion of calcareous earth, such as chalk, 

 limestone, marie, &c. cannot be so much im- 

 proved by burning. The effect of dressing lands 

 with lime and marie, is to ? certain degree the 

 same as fire; and therefore those lands only, 

 which are deficient in calcareous matter can be 

 permanently benefited by the addition of those 

 substances. Calcareous earths also anticipate 

 the effects of putrefaction, by reducing vegetable 

 and animal substances to soluble oxydes, and 

 thus they prevent a loss of carbon in the forma- 

 tion of carbonated hydrogen gas. 



