880 CHEMICAL TRANSFORMATIONS. 



CHAPTER IV. 



On the Transformation of bodies which do not contain Nitrogen as * 

 constituent ; and of those in which it is present 



When oxygen and hydrogen, combined in equal equivalents, as 

 in steam, are conducted over charcoal, heated to the temperature 

 at which it possesses the power to enter into combination with one 

 of these elements, a decomposition of the steam ensues. An 

 oxide of carbon (either carbonic oxide or carbonic acid) is under 

 all circumstances formed, while the hydrogen of the water is 

 liberated. This proves that the attraction between carbon and 

 oxygen is more powerful, at a high temperature, than that be- 

 tween oxygen and hydrogen. The carbon here is not shared 

 between the elements of the water; for no carburetted hydrogen 

 is formed. 



Acetic and meconic* acids suffer a true transformation under 

 the influence of heat, that is, their component elements are dis- 

 united, and form new compounds without any of them being 

 singly disengaged. Acetic acid is converted into acetone and 

 carbonic acid C 4 H 8 8 =C 3 H s + C0 2 ), and meconic acid 

 into carbonic acid and komenic acid ; whilst, by the influence 

 of a higher temperature, the latter is further decomposed into 

 pyro-meconic acid and carbonic acid. 



Now, in these cases, the carbon of the bodies decomposed is 

 shared between the oxygen and hydrogen ; part of it unites with 

 the oxygen and forms carbonic acid, whilst the other portion en- 

 ters into combination with the hydrogen, and an oxide of a hydro- 

 carbon is formed, in which all the hydrogen is contained. 



In a similar manner, when alcohol is exposed to a gentle red 

 heat, its carbon is shared between the elements of the water ; 



* An add existing in opium, and named from the Greek for poppy. 



