IN PRACTICAL ASTRONOMY, SPECTROSCOPICALLY EXAMINED. 
DIVISION III—GREEN MEDIA. 
1. SULPHATE COPPER. 
829 
A faint colouring material, its } giving a tint only as deep as ,35 of amm. sulph, copp. 
It is an impure blue, destroying the red, no doubt, but dulling the violet and favouring the 
citron far too much, 

COAL-GAS LUMINOUS FLAME as foundation. 


Intensity. 
False red glare : : “ : A 0 
First true red light . te - a ; il 
Slit, by sodium light, Ist side . : : 1a 
a 5 2d side . ; ; 11 
Maximum Licut, YELLOW ; ; : 12 
End of all light at violet . . ; : 0 
Solution=,;5. Shortens the red, and dulls the orange slightly. 
~ 24°86 
. 2518 
26°01 
26°03 
26:03 
28°46 
‘Wave-number | Colour Region by 
in Brit. inch. 


Red light begins ; . 
Maximum Licut, yellowish 
oF FP SO 
Green ends, blue begins . : 
Endall .. = : ; 

25°58 
26:09 
26°77 
28°12 
Wave-number, 
Ultra Rep 

29 087 
33 102 | Crimson RED 
43 015 | YELLoOw 
43 203 © | YELLOW 
43 403 | YELLOW 
62 712 | LAVENDER 
38 344 | SCARLET 
43 975 | YELLow 
50 454 | GLaucous 
60 518 | LAVENDER 

Solution=;}). Shortens the red much, and dulls the orange and yellow, 

Red light begins 
Maximum Licur 
ow ao co 
Green ends, blue begins 
Bnd ales... ‘ 


25°72 
26:20 
26°77 
28:17 

40 016 
45 045 
50 454 
60 846 
AMBER 
CITRON 
GLAUCOUS 
LAVENDER 
Solution=4. Red reduced to merely a red-brown edging on left of green. 

Light brown-red begins, 
Maximum LicHtT 
Green ends, blue begins ; 5 
Endall , > : , . : , 
om WwW O&O 
25°92 
26:30 
26°85 
28°12 


42 265 
46 062 
Sil by 7¢ 
60 518 
AMBER 
CITRON 
GLAUCOUS 
LAVENDER 

This tint is so weak as to be next to useless as a colour; but should be preserved for com- 
parison and contrast. 
VOL, XXVIII. PART III. 
10 
