IN PRACTICAL ASTRONOMY, SPECTROSCOPICALLY EXAMINED. 837 
1. OXALATE OF CHROMIUM AND POTASSIUM—continued. 


Solution 31. The fixed, black line in the red band is now exceedingly intense, and is 
in the middle of light of said band. 




Light begins at . ' 0 25°24 33 830 | Crimson RED 
The black, fixed line . 3 25°42 30 311. .|| RED 
Maximum Licut REGION also 3 25°42 36 311 | Rep 
Red light ends, hazily 0 25°56 38 124 | SCARLET 
Ghost of a narrow green band 0 26°97 52 274 | GLAUCOUS 


Solution 3'5. Fixed line very black, symptoms of other lines on right-hand side. 


Light begins. : e ‘ ; ‘ 0 25°22 33 591 | Crimson RED 
Maximum Rep Licut 5 3 ; 5 ‘2 | 25:35 35 298: | RED 
Black, fixed line : , B ‘ : be 25°42 36 311 | Rep 
Light line . ; ‘ : . , : 0 25°53 37 779 | SCARLET 


The black, fixed line in the red, is the chief feature here of Oxalate of Chromium and 
Potash. It is a true spectrum analysis line, constant in spectrum place by the above measures. 
And it assists the measures again, in showing that luminous bands are totally different things ; 
for they shift in place, both as tested by the measures and by this line, with the strength of the 
solution. This line, or lines, to be examined again with Prism 3 or 4. It was subsequently 
so examined and found to be a bundle of finer lines. 
2. Judson’s Dyes—VIOLET. 
A very strong colour, staining all the glass vessels sadly. This colour is antipathic to yellow 
chiefly ; knocking it out by a narrow dark band; even when the solution is very weak. 





Solution of strength = y257: offers 1 narrow luminous red band and 1 blue and violet band, 
but knocks out orange, yellow, and citron. 
b Wave-number | Colour Region by 
Intensity. T. in Brit. inch. | Wave-number. 
Light begins 0 25°32 34 892 | Crimson RED 
Maximum Rep Licut 4 25:62 38 820 | ScARLET 
Ends : 0 25°82 41 152 | AmBER 
Begins again 0 26°77 | 50 454 | GLaucous 
Maximum light Violet 3 27:58 56 948 | BLUE 
End all 0 28°25 61 380. | LAVENDER 




VOL. XXVIII, PART III. 10 k 
