102 



Prof. V. B. Lewes. 



[Feb. 1, 



high to check the polymerisation of the acetylene, and many attempts 

 were made to find conditions under which the acetylene could be 

 liberated and prevented from polymerising, and it was found that 

 this could apparently be, to a certain extent, effected either by dilut- 

 ing the ethylene with a considerable volume of an inert gas, or else 

 increasing the rate of flow through the heated tube. 



On passing a mixture of 75 per cent, hydrogen and 25 per cent, 

 ethylene through the tube, heated as before, 3'43 per cent, of acetylene 

 was produced, which would be equivalent to 13' 72 on the ethylene 

 present, whilst the following results show the effect of increasing 

 the rate of flow of the gas through the tube. The original gas taken 

 was a bad sample containing 87'49 per cent, of ethylene and 12-51 of 

 nitrogen, and the rate of flow was increased to 15 c.c. per minute, the 

 tube being heated to 1250 C. 



Unsaturated hydrocarbons 10'41 



containing acetylene . 4*49 



Saturated hydrocarbons 34'00 



Hydrogen 41'99 



Nitrogen 9'11 



100-00 



Increase in volume Large 



Carbon and oil deposited. . . . O'OOG gram per 100 c.c. 



showing a very marked increase in the amount of acetylene formed. 



Before it was possible to trace the primary action taking place 

 during the heating of ethylene, it was necessary to find how the 

 temperatures and methods I was employing affected pure methane, 

 which plays so important a part amongst the products of decom- 

 position. 



Methane was prepared by acting on methyl iodide by means of the 

 copper zinc couple in the presence of alcohol and water. 



Table IV. The action of Heat upon flowing Methane. 



