466 Inquiries relative to the Structure of Wood. 



proportions for the formation of water ; wherefore they 

 concluded that carbon was the only combustible sub- 

 stance contained in wood. 



It will appear in the sequel, how well the results of 

 these ingenious inquiries accord with those of my ex- 

 periments. 



But first, I shall examine what quantity of charcoal it 

 is possible to obtain from different species of woods, 

 under various degrees of dryness, pursuing the method 

 already adopted in my experiments. 



From the mode in which charcoal is ordinarily made, 

 a very considerable portion is lost and improvidently 

 burned during the operation. 



As it appears to be clearly proved, by the results of 

 the six experiments above related, that the quantity 

 of charcoal to be obtained from any given quantity of 

 wood is invariably in proportion to the quantity of 

 dry ligneous substance contained in the wood, the in- 

 quiry into the quantities of charcoal to be produced 

 from different species of woods, at various degrees of 

 dryness, becomes limited to that of the quantities of 

 wood absolutely dry, contained in the woods in question. 



It has been shown that 100 parts in weight of oak, 

 thoroughly dried, give 43 parts of charcoal. 



We have likewise seen, that 100 parts of oak as dry 

 as it can be made in summer, at the temperature of 62 

 F., contain only 91 parts of seerwood, and, conse- 

 quently, that 100 parts of such wood would furnish 

 only 39.13 parts of charcoal. 



From the results of an experiment of which I have 

 given an account in this memoir, it appears that 100 

 parts of oak, in the state wherein it is found when ex- 

 posed to the winter's air, at the temperature of 46 F., 



