

Sir William Crookes. Phil. Trans., A, vol. 209, Plate 1. 



THE SCANDIUM SPECTEUM. SELECTED GROUPS OF CHARACTERISTIC LINES. 



i'o economise space and avoid unnecessary complications, I give photographs of only those parts of the spectrum containing the most 

 i ninent scandium groups. The upper half of each strip shows the iron lines used as standards, with their wave-lengths according to 

 VIAND'S measurements. The lower halves contain the scandium linos, with their wave-lengths calculated from the iron standards. 

 1'here are also many strong lines in the ultra-violet spectrum of scandium between A 3535 -865 and A 2300. I have not completed the 

 , .suremcnts of these lines, and their description must form the subject of a subsequent communication. 



Ss 

 & s 



II 



a 



s 



i is 





pi I 



III I 



I 



8.f-pectrum of crude rare earths from keilhauite, also photographed 7. Spectrum of crude rare earths from enxenite, also photographed 

 in the same position as in Spectrum 5. It was from the rare earths in the same position as in Spectrum 5. It was from euxenite that 



from keilhauite that CLEVE prepared scandium. NII.SON" first extracted scandium. 



at 



1 P S ^ 



] IN r-*j , 



!S 3 S 



5. 



Sp& trum of crude rai'e earths from wiikite, photographed in the 5. Group of linos between A. :5(;.">I '.)()] and A 3535 -si;."). This is the part 



Set " ' 



01 



ill' 



me position as in Spectrum 5. In addition to the dominant and 

 :uer lines of scandium, which are marked in wave-lengths, there 

 ! seen lines of yttrium and one strong line of ytterbium. 



of the spectrum which I photograph when minerals are being 

 examined for scandium. The "dominant line.'' A 3(1 1 .'i Ulj.j occurs 

 here between the iron lines A 36 1 S !) 1 !J and A .'((>( )'J -(J(J8. 





4. 3 



s a i 



4. Group of lines between A 4082 '590 and A 3843-163. 



3. Group of lines between A 44 15- 722 and A 4122-613. 



2. Group of lines between A 5087-1 and A 4672-590. 





ssss 



1. 



1. Group of visible lines between A 6305-231 and A 5527-033. 



In the part of the spectrum shown on strips 1 and 2 there are no iron lines suitable for standards. Here, therefore, I have used some good 

 ies of zinc, cadmium, and mercury. Attention is drawn to the comparative intensities of the yttrium lines and the dominant line of scandium 



tl e spectra from the wiikite, euxenite, and keilhauite earths. The spectrum of the earths from gadolinite is not given, as the dominant line 

 t sc andium in it is too faint to be reproduced. 



