2 COPISAROW, Carbon : its nioleadar structure, etc. 



II. A carbon atom is always tetravalent. (Gomberg's 

 experiments on tri-phenyl methyl and Nef's on the poly- 

 methylene compounds do not necessarily imply the 

 non-tetravalency of a carbon atom.) 



III. Carbon exists in three allotropic modifications 

 (several new modifications suggested by Brodie, Berthelot, 

 Luzi and others have been proved by Moissan and Le 

 Chatelier to be either compounds or solutions and 

 mixtures of carbon with some other element). 



As we have to deal with the combination of carbon 

 with oxygen, it is obvious that the knowledge of the 

 mechanism of such a combination must be of essential 

 importance. It seems to me that there are two, and only 

 two possible hypotheses, which can explain the process : — 



1, The carbon molecule disintegrates at the first 

 instant into single atoms, which combine subsequently 

 with oxygen. 



2. Oxygen combines at the first instant with the 

 atoms inside the carbon molecule, next follows a disruption 

 of the complex and the formation of the known oxides. 



Which of these two hypotheses is the correct one ? 

 Can we reasonably suppose that by the mere presence of 

 oxygen, which has not yet reacted chemically, the carbon 

 molecule falls to atoms, which would imply the volatility 

 of carbon at a temperature below red heat ? 



I think that the first hypothesis is, at least, improbable. 



Now what can be said about the second ? 



(a) It is in complete agreement with the most recent 

 experimental evidence. 

 {b) It is quite logical. 

 {c) It explains facts. 

 {d) It is the only one left. 



