454 Inquiries relative 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 



1 .00000 



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 : 



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. 



