THE GROWTH OF OUR KNOWLEDGE OF HELIUM. 279 



HELIUM. 



GAS X. 



my results, and had extended them, called upon me, I thought it right to 

 suggest to them that, sinking the priority of my own results, we should all 

 three combine in suggesting a name. Professor Runge (under date 20th 

 October) wrote me : " The inference that there are two gases is a spectro- 

 scopical one, being based on the investigation of the ' series '. Now, though 

 we think this basis quite sound, we must own that the conclusion rests on 

 induction. . . . For this reason we do not want to give a name to ' gas 

 X '." I have so far suggested no name, though Orionium and Asterium 

 have been in my mind. 



