542 



Sir N. Lockyer and Mr. F. E. Baxandall. [Jan. 3 r 



@ccur amongst the most widened lines observed during the last 24 years. 

 Four of them, however, have only been recorded a few times. The 

 remaining one, X 5672'047, is a very persistent widened line and is. 

 nearly always greatly affected. It is, of course, quite possible that 

 the solar line in question, although weak, may be a compound one, 

 and that an additional chemical element is involved in its formation. 

 No origin other than scandium has been suggested by Rowland, and 

 no alternative origin has been found for it by reference to Kensington 

 spectra of metals. It must, therefore, be accepted provisionally as. 

 being really due to scandium. 



Scandium Lines in Stellar Spectra. 



It is quite probable that, as the stronger scandium lines occur in 

 the solar spectrum, they also appear in the spectra of stars resembling 

 the sun, such as those of the Aldebarian and Arcturian types. The 

 closeness of the lines in these stars with the dispersion usually employed 

 on stellar spectra makes it difficult to establish definitely whether the 

 scandium lines are really present. At the next higher stage (Polarian, 

 e.g., y Cygni) those scandium lines previously given as occurring in the 

 chromospheric spectrum at least, those in the ordinary photographic, 

 region, say X 3900 to A. 4700 occur as well marked lines, as has been 

 shown in a previous paper.* 



At the next higher stage Cygnian (a Cygni) the only line which can 

 with certainty be ascribed to scandium is that at X 4247 '00, corre- 

 sponding to the strongest line of the element. Its stellar intensity,, 

 has, however, decreased considerably from that of the Polarian stage. 

 At the higher stages represented successively by Rigelian (ft Orionis), 

 Taurian (f Tauri), Crucian (y Orionis), and Alnitamian (f Orionis) types, 

 scandium lines are entirely lacking. 



The photographs of the metallic spectra involved in the discussion 

 were taken by Mr. C. P. Butler, A.E.C.Sc. 



'Phil. Trans.,' A, vol. 201, p. 205. 



