454 Inquiries /-dative to the Structure of Wood. 



the atmosphere, could never become more dry, on 

 account of its hygrometric quality, which it constantly 

 preserves. 



The following are the constituent parts of a cubic 

 inch of firewood employed in this experiment : 



Ligneous parts, or seerwood 



Sap, or water 



Air 



0.40166 cubic inch. 

 . 0.18982 

 0.40852 



Thus we are enabled clearly to demonstrate the differ- 

 ence 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 eighteen months : 



Dry wood, i Water. 



By comparing the relative quantities of seerwood 

 contained in a piece of timber while in a growing state, 

 and in the same timber after it has been dried, we may 

 ascertain how much its fabric has shrunk by desicca- 

 tion. 



It appears from these experiments, that the oak sold 

 in the timber-yards of Paris for firewood contains 

 rather more than one half of the sap which it formerly 

 had in a growing state. 



I have made several similar experiments upon other 

 species of wood ; but their results are better calculated 

 for exhibition in a table than for circumstantial detail. 



