98 THE ROYAL SOCIETY OF CANADA 



temperature some decomposition takes place into carbon monoxide 

 and hydrogen. The decomposition is complete at 700°. This fact 

 probably accounts for the presence of carbon monoxide in the latter 

 experiments of this series and for the poor yields obtained throughout. 

 A further series of experiments was carried out using silver 

 oxide, thorium oxide, platinum, borosilicate glass, vanadium oxide 

 and uranium oxide, at temperatures from 250° to 500°, with varied 

 mixtures of methane and oxygen, and space velocities ranging from 

 150 to GOO. The same general results were obtained as for copper 

 oxide and traces of formaldehyde were detected at temperatures of 

 400° and above. It is not thought worth while including similar 

 tabular statements of these experiments. 



Several qualitative tests were made on the formation of formalde- 

 hyde when a natural flame impinged on a cooled surface. One arrange 

 ment was to have a flame, two inches long, playing on the circum- 

 ference of a large iron fly wheel, slowly rotated. • Traces of formalde- 

 hyde were detected in the water resulting from combustion which 

 had condensed on the cold surface. A similar flame was allowed to 

 play on a large cake of ice and the water formed then examined. 

 This gave negative results. 



Conclusion 



These experiments prove that slight traces of formaldehyde can 

 be formed by the passage of natural gas and oxygen over metallic 

 oxides, but due to the greater liability of the formaldehyde to decom- 

 position at the temperatures necessary for its formation it is improbable 

 that this method could be developed as a means of preparation of the 

 aldehyde. 



Method II — Oxidation with Ozone 



Several observers have studied the efifects of ozone on the satur- 

 ated hydrocarbons, especially M. Otto^ in 1898 and J. Drugman^ in 

 1906. When methane and ozonized oxygen were mixed at 15° and 

 at 100° some formaldehyde and higher oxidation products resulted, 

 but the quantity was small even though 200 litres of methane were 

 used. Hauser and Herzfeld^" state that small amounts of methane 

 are quantitatively oxidised to formaldehyde by ozone. 



8M. Ottlo Ann. Chim. Phys. (Ser. 7) 13, 109, 1898. 

 «J. Drugman, Jour. Chem. Soc. Trans. 89, 939, 1906. 

 "Berichte, 45, 3575, 1912. 



