818 PROFESSOR PIAZZI SMYTH ON COLOUR, 
1. POTASH PERMANGANATE, Watery SoLutTions—continued. 

Solution = g7sz, colour of 1 inch thickness by daylight, appears a darker bluish pink. 



ee 1st Obser. . 2d Obser. | Mean. W. L. Colour Region. 
Red light begins. : |) aea5 25 o529 25°27 | 34 223 | Crimson RED 
25°77 2568 | 25°72 | 40 016 | AmpER 
Hazy ending into black . 26°02 26:03 26°02 | 43 309 | YELLOW 
Light begins again . 27°32 27°30 27°31 | 54 885 | GLaucous 
Maximum Licut, RED 4 
0 
emiMO) 
Greenish black shade ends. A Wes as 27°58 27-58 |.56 948 | BLUE 
3 
0 

Maximum VIOLET LIGHT . 27:80 27:79 2780 | 58 480 | ViIoLET 
Endall . 28°42 28°35 28°38 | 62 2477 | LAVENDER 



Solution = z757, colour of 1 inch thickness by daylight, appears a violet pink. 

25:28 25°30 25:29 | 34 495 | Crimson RED 
25°63 25°62 25°62 | 38 820 | ScaRLET 
25°97 25°99 25°98 | 42 882 | AMBER 
27°50 27°55 2752 | 56 497 | BLUE 
27:86 27:88 27:87 | 58 893 | VIOLET 
28:37 28°21 | 28:29 | 61 667 | LAVENDER 
Red light begins 
Maximum Licut, RED 
Hazy ending into black 
Light begins again . 
Maximum VIOLET LIGHT . 
Se GF) oe TS l= 

Ends broadly and uncertainly . 


Solution = z755, colour of 1 inch thickness, by daylight = violet. 

Red light begins. : | Om) 620926 25°33 25°30 | 34 '722 | Crimson RED 
Maximum Licut, Rep 25°40 25°41 25-40 | 36 010 | Rep 
3 
Ends 5. . ; i> OT) 2oo69) 25752 25°54 | 37 879 | Rep SCARLET 
Light begins again . : Ne OR) Baer 27°80 27°76 | 58 241 | VIoLEr 
2 
0 
2797 | 2797 | 2797 | 59 524 | Vioter 
28°16 28°16 28:16 | 60 779 | LAVENDER 
Maximum LIGHT, VIOLET. 
Ends 





Solution = ;757, colour of 1 inch thickness by daylight = blue violet, and in depth = an 
ordinary sun-glass. 


Red light begins Only Zoe 33 102 | Crimson RED 
Maximum (RED) LIGHT 2) 2530 | 34 626 | Crimson RED 
Red light ends ; : .| O | 25:44 36 603 | Rep 
Violet light begins . Othe 2rGno | 58 241 | VioLEr 
Maximum VIOueT Licut . {15 | 2805 60 049 | LAVENDER 
Violet light ends 0 | 28:25 | 61 380 | LAVENDER 
N.B—Curious that the violet band becomes so much fainter than the red band with increased 
thickness of solution, when its colour to the eye, if thin, is red, and if thick is violet. 
NV.B.—Also, with every increased thickness, maximum of red moves more to red, and maximum 
of violet moves more to violet; so that at last, all the visible red band is beyond, or farther 
to the red, than any of the red light when thinner solution was employed, 

