STRUCTURE OF WOOD, &C. 



S23 



I planed off some thin shavings, and exposed them to the air Specific gra- 

 for eight days, in the month of January, in a large room, vitie* ofwood, 

 where the temperature, which varied but littje, was about 

 40° to 45° F. 



When these shavings had acquired their ordinary degree of 

 dryness under existing circumstances, ten grammes of each * 

 sort were weighed off, and. being hid separately in China 

 plates, were thoroughly d/ied in the stove. 



On being taken out of the stove, they were again weighed, 

 and then thrown into boiling waier, to expel the air from their 

 pores, and to moisten them thoroughly. Wh«n they had 

 boiled for an hour, they were suffered to remain in the liquor 

 till it was sufficiently cool ; and after they had been weighed 

 in the water, the specific gravity of their solids was calculated 

 in the usual way. 



The following table gives the details and results of this in- 

 quiry. 



Weight. 



The specific weight of the solid matter which composes 

 the fabric of these woods is so nearly alike in them all, that 

 the small variations to be observed in the different experiments, 

 may, perhaps, be accounted for otherwise than by supposing 

 the ligneous substance to be essentially different in the several 

 species. 



The charcoal obtained from the various kinds of wood, if 

 carefully prepared, has no sensible difference ; and all the 



seer-woodi 



