Oxides of Carbon and Iron, 279 



This contrast is quite sufficient to show that the different 

 carbonating powers of charcoal of wood depend upon a 

 principle different from any that has been developed in the 

 foregoing experiments. 



From the same experiments, however, we are warranted 

 to conclude, that the carbonating powers of the matter of 

 carbon contained in different woods in their natural state, are 

 greater than when the same is reduced to charcoal by distil- 

 lation or any other mode of operation. This curious fact, 

 the reverse from what might have been expected, may be ac- 

 counted for in three different ways. 



1st, From the decomposition of the oleaginous or resi- 

 nous juices of the wood by the oxide of iron ; part of the 

 carbonaceous matter of which, being set free, may either 

 unite itself to the iron, or unite with the oxygen of the ox- 

 ide, and by this means leave greater scope to the carbonating 

 powers of the concrete carbon. 



2dly, From a large surface being exposed by wood in the 

 state of fine sawdust to the same bulk and weight of oxide. 



3dly, And what seems to be the most permanent cause, 

 this fact may arise from a certain degree of oxidation being 

 necessary in the carbon, which facilitates its union with 

 the oxygen of the oxide; and as the degree of oxidation in 

 raw wood is greater than in charcoal, so in proportion to 

 this degree of oxidation we find the affinity more speedily 

 and more extensively exerted. 



The following Table will prove a convenient summary and 

 contrast of the foregoing experiments. 



S 4 ' Tatte 



