Inquiries relative to the Structure of Wood. 451 



To obtain a better knowledge of the wood in ques- 

 tion, I planed off forty shavings, 6 inches in length and 

 half an inch in breadth, from a small board cut from the 

 core ; with an equal number of shavings, of similar di- 

 mensions, from another board cut from the sap-wood. 



The forty shavings from the core, taken just as they 

 were planed off, weighed 16.37 grammes, and 10.53 

 grammes after they had been thoroughly dried in the 

 stove. 



The forty shavings of sap-wood weighed 1 6.97 grammes 

 before they were dried, and 11.99 grammes afterwards. 



Thus possessed of the specific gravity of the solid 

 parts of this kind of wood, it only remained to deter- 

 mine, from these data, the constituent parts of an inch 

 of the wood, which was readily performed, as fol- 

 lows : 



Ligneous parts. Sap. Air. 



In the core of the elm . . 0.41622 0.35055 0.23323 



In the sap-wood . . . 0.38934 0.23994 -377 2 



It appears, from the results of these experiments, that 

 the sap-wood of the elm contains rather more ligneous 

 parts in its timber than the core of the same tree ; and 

 that it contains much less sap and more air. But as 

 the tree had been felled nearly five months before it 

 became the subject of investigation, it is very possible 

 that the sap-wood had become much drier than the core 

 of the tree. 



I had purposed to repeat these experiments upon 

 wood in a growing state and upon seerwood ; but the 

 interference of other occupations has prevented a con- 

 tinuance of the inquiry. It cannot, however, but lead 

 to results curious in themselves ; and I therefore recom- 

 mend it to the notice of all students in vegetable econ- 



