446 Inquiries relative to the Structure of Wood. 



sap and air found in the wood composing the trunk of 

 a large tree, in winter and in summer. 



On the 2oth of January, 1812, I had a lime-tree felled 

 of about twenty-five or thirty years' growth, which had 

 stood among several others of the same age in my gar- 

 den at Auteuil. On taking a piece of wood from the 

 middle of the trunk, at about 3 feet above the ground, 

 it appeared to be filled and even drowned in sap. Its 

 specific gravity was 76,617 ; consequently, one cubic 

 inch of the wood weighed 15.788 grammes. 



Having planed off 10 grammes of thin shavings from 

 this piece, and dried them thoroughly in the stove, I 

 found their weight reduced 4.72 grammes. 



Thus in possession of the specific gravity of the solid 

 part of this wood, it was easy to determine, with the aid 

 of these data, the constituent parts of a cubic inch, 

 which were as follows : 



Ligneous parts .... 0.25353 cubic inch. 



Sap 0.44549 



Air . 0.30098 



On the 8th of September, in the same year (1812), I 

 had a piece of wood (= 5.84 cubic inches) cut from the 

 trunk of another lime, of equal age with the former 

 (from 25 to 30 years), at the height of 3 feet above the 

 earth. This tree was in a growing state, and the piece 

 taken from it, after it had been trimmed by the joiner, 

 weighed 87.8 grammes, and displaced 115.8 grammes of 

 water, at the temperature of 62 F. ; consequently, its 

 specific gravity was 75,820. In the month of January 

 the specific gravity of this same species of wood had 

 been found to be 79,617. 



