Prof. Liveing, On the probable presence in the Sun, etc. 87 



On the probable presence in the Sun of the newly discovered 

 gases of the Earth's Atmosphere. By G. D. Liveing, M.A., 

 Professor of Chemistry. 



[Bead 2 March 1903.] 



Soon after the publication of the list of wave-lengths of the 

 rays which Professor Dewar and I found to be emitted by the 

 most volatile gases of the atmosphere, Stassano pointed out that 

 the bright rays of solar protuberances, of which the wave-lengths 

 had been measured by Deslandres and Hale, agreed closely with 

 rays in our list. The wave-lengths need to be determined with 

 very great exactness in order to prove coincidence, and neither 

 set of wave-lengths have, as yet, been measured with such nicety 

 as that. Nevertheless the agreement is sufficient to make it 

 probable that the same gases are concerned in the production 

 of the rays in question. 



When, in the Astrophysical Journal for June last, Humphreys 

 published a list of wave-lengths of 339 bright rays of the chro- 

 mosphere and corona, which he had photographed in Sumatra 

 during the total eclipse of May, 1901, I compared this list 

 with our list of the wave-lengths of rays of the most volatile 

 atmospheric gases, and with those of xenon and krypton, which 

 we had subsequently published, and with those of argon. The 

 result was that of the 339 rays in Humphreys' list 209 do not 

 differ in wave-length by more than one unit from rays emitted 

 by gases of the earth's atmosphere. In our published lists the 

 wave-lengths are given to four figures only in Rowland units, 

 those of Humphreys' list are given to tenths of a unit, so that 

 we are far from being able to prove coincidence in any case. 

 Nevertheless it is so very probable that every gas which is in 

 the earth's atmosphere is also in the sun's, and so much more 

 likely that rays appearing in the chromosphere at a height of 

 9 seconds of arc, or 4000 miles, above the photosphere, should 

 be due to gases of great volatility than to such metals as titanium 

 or strontium, that it is much safer to treat the question as an 

 open one, than to assume that titanium and other metals of high 

 atomic weight are always present in the state of vapour at such 



