Section III. 1913 [161] Trans R S.C. 



The Formation of Carbon Monoxide during the Rapid Combustion of 



Carbon. 



By F. M. G. Johnson and D. McIntosh, F.R.S.C. 



Presented by D. McIntosh, F.R.S.C. 



(Read May 28, 1913) 



When carbon or a compound containing carbon mixed with an excess 

 of an oxidizing agent is ignited the carbon is, in general, completely 

 oxidized to carbon dioxide. Thus in the residual gases of black or 

 smokless powder, only a trifling amount of carbon monoxide is found. 

 In some analyses which we have made of the gases resulting from the 

 combustion of a mixture of potassium chlorate and carbon, a considerable 

 amount of carbon monoxide associated with much free oxygen was 

 noticed. This is surprising, since at 1027°C the decomposition of carbon 

 dioxide amounts to only 0-004%; while at 1000° carbon monoxide in 

 the presence of carbon is in equilibrium with 0*4% carbon dioxide. 



We have made a few experiments on this incomplete combustion 

 by mixing an excess (about 35%) of potassium chlorate with wood 

 charcoal, pressing into lumps and igniting, either in a vacuum or in a 

 vessel containing air. The gases were then withdrawn and analysed 

 by the ordinary Hempel methods. 



The carbon monoxide was determined in some cases by cuprous 

 chloride; in others by oxidation with a hot platinum spiral after removal 

 of carbon dioxide; and occasionally by explosion with electrolytic 

 gas, and subsequent absorption of the carbon dioxide. Carbon monoxide 

 was found in all cases as the following results show. 



1 (vacuum) 2 (air) 



CO2 43-6% 51-4 



46-9% 37.9 



CO 8-9 6-2 



N — 4-5 



The gases were further tested for carbon monoxide by passing 

 them into a chamber containing a white mouse. In a few minutes 

 the mouse showed all the symptons of carbon monoxide poisoning. 



Blood shaken with the gases showed the shifting of the absorption 

 bands when treated with yellow ammonium sulphide, so that the pres- 

 ence of carbon monoxide may be looked as certain. 



