838 PROFESSOR PIAZZI SMYTH ON COLOUR, 
2. Judson’s Dyes—VIOLET —continued. 

Solution of strength = z},: shows 1 red band and 1 violet; each pure, strong 
and distinct. 

Wave-number | Colour Region by 


Intensity. tr in Brit. inch. | Wave-number. 
Light begins. : : : ; . 0 25.28 Crimson RED 
Maximum Rep LicHt 3 25°55 SCARLET 
Ends 0 25°70 ORANGE 
Begins again 0 27:28 GLAUCOUS 
Maximum VIOLET 2. 25:73 VIOLET 
End all 0 28°33 LAVENDER 
Solution of strength = z4>. 
| Light beginay i bie-gz < apee «ox | |-O | Spee pose genialceen 
Maximum Rep LicHt , : : 3 2 25°47 387 064 | ScARLET 
Ends ; ' F : 3 2 2 0 25°57 38. 226 SCARLET 
A separate faint band seen here : ¥ 0 28°15: 60-709 | LAVENDER 
Solution of strength = 3. Its red band is remarkably red and pure. 
Light begins. . : 4 ; - 0 25°28 34 364 | Crimson RED 
Maximum Rep LicHt : ‘ é : 2. 25°39 35 868 RED 
Rndsally : : : ; , , 0) 25°47 37 064 | ScARLET 
3. Judson’s Dyes—LAVENDER. 
A dark strong colour in itself by daylight; and in the spectrum, more of an obscurer 
of all rays, than a transmitter of some. 
Solution of strength = 34,: produces broad dulling of the yellow, resulting in a long 
faintly, but nearly evenly, illuminated triple spectrum of red, green and blue. 

: Wave-number | Colour Region by 
Intensity. r in Brit. inch. | Wave-number. 

25°45 36 765 | RED 
25°83 41 271 | AMBER 
26°46 47 ‘710 | GREEN 
Dio 56 561 BLUE 
28°10 60 372 LAVENDER 
Light begins 
Maximum Rep Licut 
Fainter Maximum Green 
Still fainter Maximum Blue 
End all : . : 

onw FP © 

