1879.] on the Reversal of the Lines of Metallic Vapours. 371 



Lines in 

 wave-lengths. 



Frequency 

 in chromo- 

 sphere. 



Behaviour. 

 Reversal in our 

 tubes. 



Remarks. 



Lithium . 6,705 



6,101 



4,972 

 4,603 

 4,130 







3 

 

 

 



Difficultly reversed. 

 



Readily reversed. 



Most characteristic, 

 at low temperature 

 and low density. 



Described hy Bois- 

 baudran. 



Magnesium 5,527 

 by 5,183 

 6 2 5,172 



C>4 0,1D/ 



4,703 

 ? 4,586 



4,481 



40 

 50 

 50 

 30 

 

 







Expanded. 



JJimcultiy reversed. . . 

 Much expanded. 



35 33 .... 



Not seen either bright 

 or reversed. 



> Most characteristic. 

 J 



Doubtful whether 

 due to magnesium. 



Characteristic of 

 spark absent in arc. 



Barium . . . 6,677 

 6,496 

 6,140 



K C Q A 

 0,Oo4 



5,518 

 4,933 

 4,899 

 4,553 



25 



18 



25 

 50 

 15 

 30 

 30 

 10 





 







Readily reversed .... 

 Reversed. 







Pretty readily re- 

 versed. 



May be either Ba or 

 Sr. 



May be either Ba or 

 Sr. 



Most persistent. 

 Well-marked ray. 



Strontium . 6,677 

 6,496 

 4,607 



4,215 

 4,077 



25 

 18 



40 

 25 







o 



Readily and strongly 



reversed. 

 Readily reversed .... 



35 55 .... 



May be Sr or Ba. 



33 JJ 33 



Most characteristic. 

 Well marked. 



33 3 5 



Calcium... 6,161 

 6,121 

 5,587 

 5,188 

 4,587 

 4,576 

 4,453 

 4,435 

 4,425 

 4,226 

 4,095 (?) 

 3,968 

 3,933 



8 

 5 

 2 



10 



2 



4 

 

 1 



2 

 3 

 

 75 

 50 



Reversed difficultly . . 



3 5 35 



Doubtful reversal. 

 Reversed. 











Readily reversed. 



3) 35 



55 35 



Most easily reversed . 

 Strongly reversed. 

 Well reversed. 

 Rather more readily 

 than the last. 



Very bright. 



Very characteristic. 



Aluminium. 6,245 ' 

 6,237 

 3,961 1 

 3,943 J 



8 

 8 















Strongly reversed. . . . 



Strong lines. 

 Very marked. 



