334 



STRUCTURE OF WOOD, &C. 



Saj) and vola- 

 tile par s in 

 dry wood. 



This piece, after being trimmed by the joiner, weighed 

 126*2 grammes, and displaced 157'05 grammes of water j its 

 specific gravity was consequently 80357, and a cubic inch 

 weighed 15*939 grammes. 



Forty-three shavings of this wood, six inches long, and hilf 

 an inch broad, weighed 17'Q grammes ; but when thoroughly 

 dried in the stove, they were reduced to 13*7 grammes. They 

 were, therefore, prior to being put into the stove, composed of 

 13*7 grammes of solid parts, that is to say, of dry, or seer- wood, 

 and 4-2 grammes of water. 



The results of this experiment indicate, that 100 kilogrammes 

 of this excellent fire-wood contained 76 kilogrammes of seer- 

 wood, and 24 of water ; which is, probably, the ordinary state 

 of the best fire-wood sold in the timber-yards of Paris, and all 

 other places. 



Were the wood to be kept for several years, in a dry place, 

 secured from the rain, it is possible, that it might become dry to 

 such a degree as to contain only about 12 per cent, of water, 

 and 88 of seer-wood. But it will appear in the sequel, that 

 wood of any kind, exposed to the atmosphere, could never be- 

 come more dry, on account of its hygrometric quality, which it 

 constantly preserves. 



The following are the constituent parts of a cubic inch of 

 fire-wood employed in this experiment : 



Ligneous parts, or seer-wood 0401 66 cubic inch, 



Sap, or water 0-18982 



Air , 040852 



00000 



'J'hus we are enabled clearly to demonstrate the difference, 

 between the oak in a growing state, and the same kind of wood 

 after it has been felled and dried in the air, secured from the 

 rain, for 18 months. 



In a cubic inch of oak, in a 

 growing state 



In a cubic inch of the same 

 kind of wood, after it had 

 been felled and dried for 

 J 8 months*... ., . , 



} 



Air. 



0.24525 



0*40852 



By 



