Inquiries relative to the Structure of Wood. 467 



contain only 83.36 parts of seerwood ; consequently, 

 100 parts of such wood would yield no more than 35.84 

 parts of charcoal. 



From the examination we have made of the oak in 

 that state in which it is deemed fit for burning, we 

 have found that 100 parts of this kind of wood contain 

 only 76 parts of absolutely dry wood ; whence we con- 

 clude that 100 parts of such wood would produce 32. 68 

 parts of charcoal. 



It has been shown that 100 parts of an oak felled on 

 the 6th of September, while in a growing state, contained 

 only 62.56 parts of seerwood, and that, consequently, 

 100 parts of such wood would yield only 26.9 parts of 

 charcoal. 



In making these calculations, no account has been 

 taken of the quantity of wood, or other combustible, 

 burned in order to heat the closed vessel in which the 

 wood was carbonized, pursuant to the process here 

 adopted. But it may be remarked that such quantity 

 will be increased or diminished according to the con- 

 struction of the furnace and the arrangement of the 

 other parts of the apparatus ; and it will always be too 

 considerable to be omitted in the list of expenses. 



As M. Proust obtained only 19 or 20 parts of char- 

 coal in 100 of oak, it is probable that some waste 

 occurred in the process ; but as it is certain that in the 

 carbonization of wood some loss will happen, so in 

 the ordinary method of making charcoal there is always 

 a considerable reduction of the quantity that ought to 

 be produced, arising from the quantity of wood con- 

 sumed, either wholly or in part, to obtain heat sufficient 

 to char the portion of wood that is reduced to a coal. 



Messrs. Gay-Lussac and Thenard found from 52 to 



