124 



Profs. G. D. Liveing and J. Dewar. [June 15, 



for other purposes, together with some new observations on the 

 genesis of the cyanogen spectrum during combustion. 



The remarkable discovery of Dr. Hug gins, regarding the occur- 

 rence of two of the most marked series of cyanogen bands in last 

 year's comet, adds considerable interest to this question, and has 

 induced us to make a further study of the chemical reactions in 

 flames which cause this particular spectrum to appear at a relatively 

 low temperature. 



Electric Discharge betioeen Carbon Poles in different Gases. 



In order to facilitate reference the general appearance of the 

 portion of the cyanogen spectrum to which we shall refer is given in 

 the following diagram : — 



