604 Research Staff of the G. E. C, London, on the 



between the wastage of the filament and the disappearance- 

 of the gas could be traced. A fraction of the gas could be 

 liberated again by baking the lamp, but the amount thus 

 liberated appeared all to be absorbed in the early stages of 

 the disappearance, and did not increase greatly with the 

 quantity of gas that had disappeared. It may be observed 

 that there was no evidence of the accumulation of gas which 

 would not disappear, and accordingly any impurities that 

 the gas may have contained must have disappeared with the 

 carbon monoxide. 



If after a quantity of gas had been caused to disappear in 

 the discharge the liquid air were removed from the trap T 

 and the trap warmed to room temperature, a marked increase 

 of pressure occurred, and much of the gas that had disappeared 

 seemed to reappear. Experiments showed that the gas thus- 

 reappearing was about half of that which had disappeared. 

 The following table gives some of the results : — 



Table I. 



Decrease of pressure Increase on -r> , • 



•i j- i • Katio, 



under discharge. warming. 



•0197 mm. -0116 mm. 059 



•1258 „ -0597 „ 0-47 



'0323 „ -0168. „ 0-52 



•0780 „ -0330 „ 042 



•0445 „ -0265 „ 0-57 



•0325 „ -0200 „ 0-62 



•1020 „ -0560 „ 0-55 



0-4348 mm. 0"2236 mm. 0515 



The first column gives the total pressure which would have 

 been exerted by the gas that had disappeared if it had been 

 present in the lamp at the same time — that is to say, it is 

 the sum of the decreases of pressure produced by the 

 discharge when several doses of gas were admitted succes- 

 sively ; the second column gives the increase of pressure 

 that occurred on warming the trap T (or the side tube A 

 — see fig. 1) ; the third column gives the ratio of the second 

 to the first. It is not certain whether the variations in this 

 ratio represent experimental error or indicate real variations, 

 but they justify the statement that about half the gas 

 reappears. 



If the trap was cooled once more, the gas that had re- 

 appeared disappeared once more completely. Accordingly 

 it is clear that by the action of the discharge the carbon 

 monoxide had been converted into some gas that condenses- 



