IN CONTACT WITH WATER. 319 



contact with water, is produced in the way just 

 mentioned. 



An analysis of wood of this kind, obtained from 

 the interior of the trunk of an oak, yielded, after 

 having been dried at 212, 



Carbon 47-11 . . 48'14 



Hydrogen 6*31 . . 6'06 



Oxygen 45-31 . . 44'43 



Ashes 1-27 . . 137 



100-00 100-00 



Now, on comparing the proportions obtained 

 from these numbers with the composition of oak 

 wood, according to the analysis of Gay-Lussac and 

 Thenard, it is immediately perceived, that a certain 

 quantity of carbon has been separated from the 

 constituents of wood, whilst the hydrogen is, on the 

 contrary, increased. The numbers obtained by the 

 analysis correspond very nearly to the formula 

 C33 H27 O24. (The calculation from this formula 

 gives in 100 parts 47*9 carbon, 6'1 hydrogen, and 

 46 oxygen.) 



The elements of water have, therefore, become 

 united with the wood, whilst carbonic acid is dis- 

 engaged by the absorption of a certain quantity of 

 oxygen. 



If the elements of 5 atoms of water and ,3 atoms of 

 oxygen be added to the composition of the woody 

 fibre of the oak, and 3 'atoms of carbonic acid 

 deducted, the exact formula for white mouldered 

 wood is obtained. 



