1047 



A. Mixtures of gases whicJi do not give reactions. 



Investigations were made with the binary systems argon- nitrogen, 

 neon-nitrogen, argon -hydrogen, neon-helium, and argon-mercury. 



While visual measurement by former investigators had founded 

 the opinion that for gaseous mixtures the spectral behaviour is by 

 no means an additive property with respect to the components, 

 our research has rendered a slight change of these conceptions desirable. 

 Let us first stipulate however, that the conceptions following from 

 the above mentioned non-objective investigations doubtlessly contain 

 a fundamental truth, especially there where the ionisation tensions 

 of the components are widely different ') resp. where we have to 

 do with highly electro-negative gases. In the last case however there 

 occurs complication by chemical reactions. 



Our investigations have taught us however to be careful not to 

 exaggerate the conception, that the spectral behaviour of gaseous 

 mixtures is by no means additive with respect to the components. 

 At a definite total pressure the mixing of gases gives rise to a 

 lower (partial) pressure of the components. And it proves to be a 

 general phenomenon, that a decrease in pressure causes a shift of 

 the light-emission towards the ultra-violet. With other words when 

 gases are mixed visual observations will give the impression that 

 the spectrum of one of the two gases strongly vanishes especially 

 when the emissive intensities of the components are very different. 



B. Mixtures of gases which react with each other. 



The systems nitrogen-oxygen, nitrogen-hydrogen and nitrogen-carbon- 

 monoxide were investigated. In each of these three cases the reaction 

 took place by means of an electric discharge. Each time this chemical 

 reaction was found to be accompanied by the occurrence of new 

 bands in the spectrum. As for the system N^ — H^ this had never 

 been sharply proved in a spectral tube"). We subjected it to a 

 detailed investigation, which supported the conception that the 

 "electric ammonia-synthesis" is preceded by a disintegration of the 

 reacting molecules into atoms. Further it proved possible to indicate 

 conditions under which the ammonia-yield was many times higher 



1) Gorap. J. Fhanck and G. Hertz, Verli. d. D. phys. Ges. 18, 213 (1916) 



3) Already in 1891 J. M. Eder mentioned the occurrence of new bands in the 



o 

 neighbourhood of / = 3359 A. in the spectrum of the ammonia- oxygen-flame. 



(Anzeiger d. k. Ak. d. Wiss. Wien, 1891. See also Denkschr. d. kais. Ak. d. Wiss. 



Wien 60, 5, 1893. 



