NATURE OF THE PROCESS. 269 



that carbon in certain other conditions shows a 

 much greater affinity for oxygen than either of 

 those substances. 



In putrefaction, the conditions are evidently 

 present, under which the affinity of carbon for 

 oxygen comes into play ; neither expansion, cohe- 

 sion, nor the gaseous state, opposes it, whilst in ere- 

 macausis all these restraints have to be overcome. 



The evolution of carbonic acid during the decay 

 or eremacausis of animal or vegetable bodies, 

 which are rich in hydrogen, must accordingly be 

 ascribed to a transposition of the elements or dis- 

 turbance in their attractions, similar to that which 

 gives rise to the formation of carbonic acid in the 

 processes of fermentation and putrefaction. 



The eremacausis of such substances is, therefore, 

 a decomposition analogous to the putrefaction of 

 azotised bodies. For in these there are two affini- 

 ties at play ; the affinity of nitrogen for hydrogen, 

 and that of carbon for oxygen, which facilitate the 

 disunion of the elements. Now there are two 

 affinities also in action in those bodies which decay 

 with the evolution of carbonic acid. One of these 

 affinities is the attraction of the oxygen of the air 

 for the hydrogen of the substance, which corre- 

 sponds to the attraction of nitrogen for the same 

 element ; and the other is the affinity of the 

 carbon of the substance for its oxygen, which is 

 constant under all circumstances. 



When wood putrefies in marshes, carbon and 



