368 DECOMPOSITION OF WOOD, COAL, ETC. 



its oxygen. The proportion of these numbers is 

 expressed by the formula C33 H21 016.* 



When these numbers are compared with those 

 obtained by the analysis of oak, it would appear 

 that the brown coal was produced from woody fibre 

 by the separation of one equivalent of hydrogen, 

 and the elements of three equivalents of carbonic 

 acid. 



1 atom wood , C36 H22 022 



Minus 1 atom hydrogen and 3 atoms car- ^ r; q h i q 6 

 bonic acid S 



Wood Coal . . CSS H21 016 



All varieties of wood coal, from whatever strata 

 they may be taken, contain more hydrogen than 

 wood does, and less oxygen than is necessary to 

 form water with this hydrogen ; consequently, they 

 must all be produced by the same process of decom- 

 position. The excess of hydrogen is either hydro- 

 gen of the wood which has remained in it unchanged, 

 or it is derived from some exterior source. The 

 analysis of wood coal from Ringkuhl, near Cassel, 

 where it is seldom found in pieces with the structure 

 of wood, gave, when dried at 212^, 



Carbon 

 Hydrogen 

 Oxygen 

 Ashes 



100-00 100-00 



The proportions derived from these numbers cor- 

 respond very closely to the formula C^^ H^* 0% or 

 they represent the constituents of wood, from which 

 the elements of carbonic acid, water, and 2 equiva- 

 lents hydrogen, have been separated. 



C36H22 022=Wood. 

 Subtract C 4 H 7 OlS = 4 atoms carbonic acid + 5 atoms of water 



-|- 2 atoms of hydrogen. 



C32 H15 O 9 = Wood coal from Ringkuhl. 

 The formation of both these specimens of wood 



* The calculation gives 57-5 carbon, and 5'98 hydrogen. 



