Inquiries relative to the Structure of Wood. 473 



it is evident that the seerwood is at least partially de- 

 composed when the charcoal is produced in the process 

 of carbonization, that is to say, when the skeleton of 

 the wood is deprived of its flesh, and left naked ; and 

 it is well known that a great quantity of pyroligneous 

 acid is formed in the carbonization of wood, and this 

 acid contains carbon. 



From the process employed by Messrs. Gay-Lussac 

 and Thenard, in their learned analysis, there can be no 

 doubt that they discovered and kept an account of all 

 the carbon found in the woods analyzed by them ; and 

 as there was no pyroligneous acid formed in my experi- 

 ments when the wood was totally consumed without 

 either smoke or smell, it is manifest that in this case all 

 the carbon contained in the wood was burned. 



According to the analyses of Messrs. Gay-Lussac and 

 Thenard, 100 parts of oak, perfectly dry, contain 52.54 

 parts of carbon ; and 100 parts of beech contain 51.45. 



Now, as it seems to me extremely probable that the 

 dry ligneous substance is palpably the same in all woods, 

 I shall take the medium term of the results of these 

 two analyses, and consider it as an indubitable fact, that 

 100 parts of perfectly dry wood contain 52 parts of 

 carbon. 



Therefore, as 100 parts of seerwood furnished me 

 with only 43 of charcoal, we must conclude, if dry char- 

 coal be considered as carbon, that of the 52 parts of 

 carbon contained in 100 parts of seerwood, 9 are taken 

 up in the composition of the pyroligneous acid formed 

 in the carbonization of the wood, which 9 parts make 

 more than 17 per cent of all the carbon contained in 

 the wood. 



Though charcoal should not be purely carbon, we 



