IN PRACTICAL ASTRONOMY, SPECTROSCOPICALLY EXAMINED. 835 
4, LITMUS—continued. 


Solution = 35 Shows only one narrow red band. 





frseereieye eer Re eee ne «oy eue Repion. By 
Light begins : : ‘ ‘ 2 ‘ 0 25°34 35 162 RED 
Maximum Rep Licut ; Z é ' 3 25:53 37 779 SCARLET 
Endall . ‘ : i ; : ; 0 25°61 38 700 SCARLET 



Solution 73,5, blocks all light out of spectrum. 
Solution 3455, does not redden green, but does redden Naples yellow, cadmium yellow, and 
other yellows. 
Stronger solutions redden grass-greens, but not very brilliantly. 
DIVISION V.—VIOLET MEDIA. 
1. OXALATE OF CHROMIUM AND POTASSIUM. 
A dark lilac looking powdery, lumpy matter, not easily dissolved in water; and having, 
by reflected light in solution, a dull inky blue-black colour. In the weaker solutions it shows 
by transmitted light a slatey-blue; but in stronger solutions a rich red colour. It is thus just 
the opposite of Permanganate of Potash, which is pink in weak solutions, and violet-blue in 
strong ones. 


Solutions 640 320 Té0 80 Zo. 26 
( palest pale slate blue pinkish red-_ red. ; 
Appear possible slate slate with pink blue. blue. 
1 colour, blue. tendency. 
By broadly trans- 
mitted daylight. 




COAL-GAS LUMINOUS FLAME, as foundation. 





Intensity. | | in Gute Inch. |‘ Wave-ntimber. 
First red glare . : i , : : 0 24°86 29 087 | Ultra Rep 
First true red light . F ; : : ih 25°18 33 102 | Crimson RED 
Slit, by sodium light, Ist side . : ; i 26°01 43 015 | Yellow 
, F 2d side . : ‘ 11 26:03 43 203 | Yellow 
Maximum Licut, YELLOW . ’ , : 12 26:03 43 403 | YELLOW 
End of all light at violet . 3 : : 0 28°46 62 712. | Lavender 

