Inquiries relative to the Structure of Wood. 437 



examination and inquiry into the structure of wood. 

 In the course of a long series of researches upon heat, 

 I wished to determine the quantities of that element 

 produced by the combustion of different kinds of wood; 

 but I had scarcely begun the inquiry when I found that, 

 in order to procure satisfactory results to my experi- 

 ments, it was indispensably necessary to obtain a better 

 knowledge of wood itself; and therefore I immediately 

 devoted myself to the study. 



My first aim was to determine the specific gravity of 

 the solid parts which compose the fabric of the wood, 

 in order afterwards to determine the quantities of sap 

 or water contained in wood under various circumstances. 



Having found that very thin shavings filled with sap, 

 or even with water, could be thoroughly dried in less 

 than an hour, without injury to the wood, in a stove 

 kept at a higher temperature than that of boiling water, 

 or at about 500 of Fahrenheit's scale (= 260 French), 

 I determined on using shavings of this description in 

 my experiments. 



SECTION I. Of the specific Gravity of the solid Parts 

 of Wood. 



I began with the wood of the lime-tree, of which the 

 texture is very fine and regular. From a small board, 

 five inches long and half an inch thick, very dry, I took 

 a quantity of thin shavings with a very sharp plane. 

 These were exposed for eight days in the month ot 

 January upon a table in a large room not otherwise 

 occupied, in order that they might attract from the 

 atmosphere all that moisture which, as an hygrometric 

 body, they were capable of imbibing. The temperature 

 of the room was about 46 F. 



