1910] on Tonisatioii of Gases and Chemical Change, 793 



open silica tulje. The containing vessel was provided with a vacnnm 

 gauge, 1)7 means of Avhich the combination of soVotli part of the 

 gases could be easily detected. No action whatever was observed, 

 although the substances Avere left in contact for two months. A 

 further experiment showed that, as was to be expected, very dry air 

 undergoes electromerism when subjected to the action of radium. 

 Two more tubes were then set up, similar to the first, containing 

 mixtures of carbon monoxide and oxygen, one very dry, and the 

 other containing traces of moisture, and although the radium 

 l)romide was in contact with them for more than three months not 

 the slightest contraction could be observed. In these cases therefore 

 electromerism produces no chemical change. 



There, was, however, a possibility that electromerism might bring- 

 about a chemical action in a mixture of gases which was under 

 conditions which were nearly, but not quite, suitable for chemical 

 action to take place. The gaseous mixtures mentioned only combine, 

 even when moist, at a red heat. Since the experiments were done 

 at 20", they only show that electromerism does not produce chemical 

 action in gases Avhich are otherwise unable to combine. 



There remained the possibility that if gases were just on the 

 point of combining, increasing the electromerism might accelerate 

 the rate of action. I sought for a case of simple chemical union 

 which would proceed at a manageable temperature, and at a rate 

 which could be measured. Of those tried, the reaction between hydro- 

 gen and nitrous oxide was found to be the most suital:)le. The gases 

 used were as pure as possible, l)ut dried only by passing through 

 phosphorus pentoxide tubes. They were found to coml)ine with great 

 uniformity when heated in clean Jena glass tubes to 530°. An 

 electric resistance furnace was used, consisting of a wide silica tube 

 which formed the heated chamber. It is known that many substances 

 when heated, produce electromers in a gas ; lime is fairly efficient, 

 thoria more so, and, of course, radium bromide most of all. In the 

 first experiment two tubes of the same Jena glass, containing the 

 hydrogen and nitrous oxide mixture, were heated side by side. One 

 contained some lime and in order to make the conditions as similar as 

 possible, an equal quantity of powdered Jena glass was introduced 

 into the other. As soon as the requisite temperature was reached, 

 the action proceeded rapidly in the tube containing lime, the rate in 

 the first five minutes being five times the rate of combination in the 

 tube containing only powdered glass. After fifteen minutes the 

 second tube had caught up the first, and the rates of union were 

 equal up to the completion of the action. With thoria the effect was 

 still more marked, the rate increasing to twenty times the rate in the 

 tube containing the glass. Finally about 2 mg. of radium bromide 

 was heated in the mixture of gases. As soon as the combining tem- 

 perature was reached the gases in the radium bromide tube exploded. 



From these three experiments it is seen that as the amount of 



