TRANSACTIONS OF SECTION B. 627 



In the case of ethane we are able to distinofiiish the successive formations of 

 (1) acetaldehyde, and (2) formaldehyde, as intermediate products. The experi- 

 mental results are consistent with the following view of the case, namely : — 



1. That the primary oxidation involves the formation of acetaldehyde and 

 steam — 



CHj-CIL, + O, = CH3OIIO + H,0. 



2. That the acetaldehyde is further rapidly oxidised to carbon monoxide, 

 steam, and formaldehyde — 



H H 



O 



3. That the formaldehyde suffers further oxidation as indicated above. 



These views, it may be stated, are supported by experiments on the oxidation 

 of acetaldehyde. 



I wish it to be understood that I have provisionally adopted the explanations 

 just given of the oxidation stages of methane and ethane as a convenient working 

 hypothesis because they express most simply the observed facts. Professor 

 Armstrong has recently given ns ' a very suggestive general theory of combustion 

 which embodies his dictum that chemical interchange and electrolysis must be 

 regarded as interchangeable equivalent terms. Applied to hydrocarbons {e.g. 

 methane) the theory involves the successive ' hydroxylation ' of each hydrogen by 

 an indirect process, the oxygen being transferred electrolytically across ' conduct- 

 ing ' water, as indicated by the following scheme : — 



(1) CH, + OH, + 0., =CH3(OH) + H..O, 



(2) CH3OH + OH, + O. = CH4OH)., + H,,d., 



(3) OH.(OH).. + 0H„ + a = CH(OH),j*+ H.O., 



^4-) ch(oh);+oh;+o;-c(oh)^+h2o; "" 



The hydrogen peroxide formed being in part decomposed by heat, and in part 

 acting as depolariser. 



The hydroxylated molecules thus produced may decompose, as for instance : — 



(5) CH^COH), = CH,0 + H,0 

 formaldehyde ; 



and then the formaldehyde is further indirectly oxidised to (I) formic acid 

 (2) carbonic acid, thus : — 



(6) : : H, + 0H„ + 0. = ^^§>G : + H,,0, 



(7) ^§>C : O + OH, + 0. = 2q>C : + H,0, 



The formic and carbonic acids thus produced then decompose, as follows : — 



(8) ^H>C : = CO + H,0 



(9) §Q>C : = C0, + H20 



It does not come^within the province of this paper to discuss this electrolytic 

 theory of chemical change; it should, however, be pointed out that Professor 

 Armstrong's views demand the formation of an alcohol in the priinary oxidation 

 of a saturated hydrocarbon. Although I have never failed to obtain a marked 



> Trans. Chem. Soc. 1903, 83, 1088. 



s 3 2 



