JOg STRUCTURE OP WOOD, &C. 



discover the difference between the quantities of sap and air 

 wood at diffe- ^ ouncl in tne wood composing the trunk of a large tree, in 

 rent seasons, winter and in summer. 



On the 20ih of January, 1812, I had a lime-tree felled, of 

 about 25 or 30 years growth, which had stood among several 

 others of the same age in my garden at Anteuil. On taking 

 a piece of wood from the middle of the trunk, at about three 

 feet above the ground, it appeared to be filled, and even drowned 

 in sap. Its specific gravity was 76Q\7 > 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 to 472 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 follow : 



Ligneous parts 0*25353 cubic inch. 



Sap 044549 



Air 30098 



1 00000 



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 ano- 

 ther lime, of equal age with the former, (from 25 to 30 years) 

 at the height of three feet above the earth. This tree was in a 

 growing state, ?nd the piece taken from it, after it had been 

 trimmed by the joiner, weighed 87'8 grammes, and displaced 

 1158 grammes of water, at the temperature of 62° F. conse- 

 quently, its specific gravity was 75820. In the month of 

 January, the specific gravity of this same species of wood had 

 been found to be 796 17- 



From the piece of wood taken from the tree on the 8th of 

 September, I had 14"19 grammes of their shavings planed off, 

 which, after they bad been thoroughly dried in the stove, 

 weighed only 7 35 grammes. Hence we have, as the consti- 

 tuent parts of a cubic inch of this wood — 



Ligneous 



