Denham. — The Temperature of Combustion of Methane. 39 



clayey and talcose matrix of the remarkable lode-formations 

 of Kalgoorlie ; of the rich horn- silver and embolite found in 

 the kaolin clay of Broken Hill Lode ; of the silver in the 

 silver-sandstones of Utah ; and of the copper in the copper- 

 bearing shales of Mansfield and elsewhere. Rock-impregna- 

 tion by magmatic water in the zone of metamorphism con- 

 nected with an igneous intrusion may also be traced to the 

 same cause. 



Art. VII. — The Temperature of Co?nbustion of Methane <n 

 the Presence of Palladiumised Asbestos. 



(Abstract.) 



By H. G. Denham, M.A. 



[Read before the Canterbury Philosophical Society, 7th June, 1905.] 



A considerable doubt appears to envelop the question as 

 to the temperature at which methane combines with oxygen 

 in the presence of palladiumised asbestos. Winkler states 

 that the action scarcelv takes place under a red heat. Phillies 

 (Chem. Soc. Jour., 66^ 2, 194) gives 404°-414° C. ; Hempel, 

 200° ; whilst Richardt has quite recently determined 500° C. 

 as being the temperature at which an appreciable oxidation 

 takes place. it was to throw light on this question that this 

 set of experiments has been carried out. 



Scope of Work. 



1. Determination of the temperature of combustion of 

 methane and oxygen when in proper volume for complete 

 combustion. 



2. The influence of a change of rate at which the gases 

 were passed over the palladiumised asbestos. 



3. The influence of a change in the proportion of the 

 gases. 



4. The effect on the temperature of combustion of methane 

 w 7 hen varying proportions of hydrogen were added. 



5. A brief inquiry into the question as to how far the 

 catalytic action of the palladium is due to a superficial oxida- 

 tion. 



Apparatus and Method. 



Pure methane was prepared by the method of Parker and 

 Tribe from zmc-copper couple and methyl iodide ; and the 

 oxygen and hydrogen by the electrolysis of pure dilute 

 sulphuric acid. 



A heavy iron vessel containing lead, shielded with asbestos 

 walls, was used as a bath, and gave extremely satisfactory 



