C 811 j 



6 parts charcoal. 



3 Muriate of soda and sulphate of potash, 



with a trace of vegetable alkali. 

 9 Oxide of iron. 

 And the remainder the earths. 



In this instance, as in the other, finely divided 

 charcoal was found ; the solubility of which would be 

 increased by the presence of the alkali. 



The third instance was, that of a stiff clay, from 

 Mount's Bay Cornwall. This land had been brought 

 into cultivation from a heath by burning about ten 

 years before ; Imt having been neglected, furze was 

 springing up in different parts of it, which gave rise 

 to the second paring and burning. 10O parts of the 

 ashes contained 



8 parts of charcoal. 



2 of saline matter, principally common salt, 

 with a little vegetable alkali. 



7 Oxide of iron. 



2 Carbonate of lime. 

 Remainder alumina and silica. 



Here the quantity of charcoal was greater than in 

 the other instances. The salt, I suspect, was owing 

 to the vicinity of the sea, it being but two miles offl 

 In this land there was certainly an excess of dead ve- 

 getable fibre, as well as unprofitable living vegetable 

 matter ; and I have since heard, that a great improve- 

 ment took place. 



Many obscure causes have been referred to for 

 the purpose of explaining the effects of paring and 

 burning ; and I believe they may be referred entirely 



