104 ON WOOD AND CHARCOAL. 



however, for, though deeply browned, they burned with a 

 very fine flame. 



Of these brown shavings I made three parcels, each weigh* 

 ing 2*3 gr. The first was placed in the stove on a white 

 china plate, supported by a tile, but not covered. The 

 second was put into it in a similar manner, except that it was 

 covered with a glass jar, six inches in diameter, and six inches 

 high. 



The third parcel was p«,t into a glass vessel, six inches 

 high, but only an inch and a quarter in diameter. This nar- 

 row vessel was put into a glass three inches in diameter, and 

 seven inches high ; which, being slightly closed with its glass 

 cover, was also placed in the stove on a tile. 



As the door of the stove (which is double, the better to 

 confine the heat) does not shut so close as to prevent the free 

 passage of air; and as the china plates, on which two of the 

 parcels were placed, were flat ; every circumstance was fa- 

 vourable for the free transmission of the carbonic acid gas 

 arising from the decomposition of these two parcels by slow 

 combustion, and there was nothing to prevent the progress 

 of this operation. But the third parcel being enclosed in a 

 narrow vessel, as this gas is much heavier than atmospheric 

 »ir, the first portion of this gas arising from a commence- 

 ment of combustion of the wood could not fail to descend in 

 the vessel toward its bottom, gradually expel the air, and at 

 length fill the vessel completely : and as this sort of inunda- 

 tion by carbonic acid gas could not fail to stop the com- 

 bustion, I expected to find that this parcel of shavings would 

 be preserved, at least in part, even though both the others 

 should be entirely consumed. 

 Stesults. The stove having been heated in the usual manner, I 



found the next day, that the results of the experiment had 

 been such as I anticipated. The two parcels of shavings 

 placed on the china plates had disappeared entirely j nothing 

 at all remaining, except a very small quantity pf ashes, of a 

 white colour inclining a little tq yellow. 



The yellow ashes in the plate that was not covered with a 

 glass jar were deranged and dispersed by the wind, occasioned 

 by opening the door of the stove too suddenly : but those in 

 the other plate, being protected by the glass, were found all 



together, 



