360 DECAY OF WOODY FIBRE. 



of hydrogen. Viewed as a kind of combustion, it 

 would indeed be a very extraordinary process, if the 

 carbon combined directly with the oxygen; for it 

 would be a combustion in which the carbon of the 

 burning body augmented constantly, instead of 

 diminishing. Hence it is evident, that it is the hy- 

 drogen which is oxidized at the expense of the 

 oxygen of the air; while the carbonic acid is formed 

 from the elements of the wood. Carbon never com- 

 bines at common temperatures with oxygen, so as to 

 form carbonic acid. 



In whatever stage of decay wood may be, its ele- 

 ments ' must always be capable of being represented 

 by their equivalent numbers. 



The following formula illustrates this fact with 

 great clearness : 



C36 H22 022 — oak wood, according to Gay-Lussac and Th^nard.* 

 C 35 H20 O20 — humus from oak wood (Meyer).t 

 C34H18 018— " " (Dr. Will)4 



It is evident from these numbers, that for every 

 two equivalents of hydrogen which are oxidized, 

 two atoms of oxygen and one of carbon are set 

 free. 



Under ordinary circumstances, woody fibre requires 

 a very long time for its decay; but this process is 

 of course much accelerated by an elevated tempera- 

 ture and free unrestrained access of air. The decay, 

 on the contrary, is much retarded by absence of 

 moisture, and by the wood being surrounded w^ith 

 an atmosphere of carbonic acid, which prevents the 

 access of air to the decaying matters. 



Sulphurous acid, and all antiseptic substances, 

 arrest the decay of woody fibre. It is well known, 

 that corrosive sublimate is employed for the purpose 

 of protecting the timber of ships from decay ; it is 

 a substance which completely deprives vegetable or 

 animal matters, the most prone to decomposition, of 



* The calculation gives 52-5 carbon, and 47*5 water, 

 t The calculation gives 54 carbon, and 46 water. 

 t The calculation gives 56 carbon, and 44 water. 



