60 



ME. A. FOWLER ON THE SPECTRUM OP SCANDIUM, 



part of the scandium absorption in the solar spectrum originates at a higher level 

 than that at which the greater part of the iron absorption is produced. 



5. The discussion of scandium lines indicates that while in the case of some elements 

 solar identifications are to be based chiefly on arc lines, in others it is the enhanced 

 lines which may be expected to show the most important coincidences. 



6. The flutings which occur in the arc and arc-flame spectra do not appear when 

 the arc is passed in an atmosphere of hydrogen. As suggested by THALEN, they are 

 probably due to oxide of scandium. 



In concluding this paper the author is anxious to express his great indebtedness to 

 Sir WILLIAM CJIOOKES, without whose aid in providing purified scandia the greater 

 part of the investigation would not have been possible. Valuable assistance in taking 

 the photographs, and in checking some of the determinations of wave-lengths, has also 

 been rendered by Miss L. ALUOCK, A.ll.C.S., B.Sc., H. SHAW, A.K.C.S., and 

 A. EAGLE, A.E.C.S. 



TABLE I. Arc Spectrum of Scandium. 



