346 MOULDERING OF BODIES. 



CHAPTER XIII. 



On the Mouldering of Bodies. — Paper, Brown Coal, and Mineral Coal. 



The decomposition of wood, woody fibre, and all vegetable bodies 

 when subjected to the action of water, and excluded from the air, 

 is termed mouldering. 



Wcod (or brown coal) and mineral coal, are the remains of 

 vegetables of a former world ; their appearance and characters 

 show that they are products of the processes of decomposition 

 termed decay and putrefaction. We can easily ascertain by ana- 

 lysis the manner in which their constituents have been changed, 

 if we suppose the greater part of their bulk to have been formed 

 from woody fibre. 



But it is necessary, before we can obtain a distinct idea of the 

 manner in which coal is formed, to consider a peculiar change 

 which woody fibre suffers by means of moisture, when partially 

 or entirely excluded from the air. 



It is known that when pure woody fibre, as linen, for example, 

 is placed in contact with water, considerable heat is evolved, and 

 the substance is converted into a soft friable mass, which has in 

 a great degree lost its coherence. This substance was employed 

 in the fabrication of paper before the use of chlorine, as an agent 

 for bleaching. The rags employed for this purpose were placed 

 in heaps ; and it was observed, that on their becoming warm a 

 gas was disengaged, and their weight diminished from 18 to 25 

 per cent. 



When sawdust moistened with water is placed in a closed 

 vessel, carbonic acid gas is evolved in the same manner as when 

 air is admitted. A true putrefaction takes place, the wood as- 

 sumes a white color, loses its peculiar texture, and is converted 

 into a rotten friable matter. 



The white decayed wood found in the interior of trunks of 



