Inquiries relative to the Structure of Wood. 443 



specific gravity was 96,515, and, consequently, that a 

 cubic inch of it weighed 19.134 grammes. 



When the piece of wood had been reduced to the 

 shape of a small board, about half an inch in thickness, 

 I took from it forty very thin shavings weighing 19.9 

 grammes, but when thoroughly dried in the Stove, at 

 a temperature of 262 F., they weighed only 12.45 

 grammes. 



From this experiment, it is evident that the wood in 

 question, being full of sap, was composed of 12.45 

 ligneous parts, and 7.45 parts of water, or of sap, whose 

 specific gravity is nearly the same as that of water. 



Now, as one cubic inch of this wood weighed 19.134 

 grammes, it is very certain that it was composed of 

 11.971 grammes of ligneous parts, which were conse- 

 quently solids, and of 7.163 grammes of sap. 



But we have already seen, from the results of the 

 experiments detailed in the former part of this memoir,* 

 that a cubic inch of the solid parts of the wood of the 

 oak weighs 30.42 grammes : 



Consequently the 11.971 grammes of solid parts 

 found in one cubic inch of this wood, when the 

 tree was alive, could have no greater bulk 

 than . -39353 cubic inch. 



As one cubic inch of water weighs 19.83 

 grammes, the 7.163 grammes of sap found in 

 the cubic inch of this wood must have occu- 

 pied a bulk equal to ..... 0.36122 



Consequently a cubic inch of the wood in ques- 

 tion contained a quantity of air whose bulk 

 was equal to ...... 0.24525 



Making together .... l.ooooo 

 * See the table, page 440. 



