AN ANIMAL PIGMENT CONTAINING COPPER. 
519 
Fig. 3. Spectrum of a freshly-prepared aqueous and faintly ammoniaeal solution, 
obtained directly from a feather. The measurements, in wave-lengths, of the bands 
shading 
Eh 
70 
80 
111 
J 
’ 1 d 1 " 1 1 1' 
Sp 
4 . 
6 . 
7 . 
i r n-r 
extends back to 55(P5, is shaded off to 548. 2nd band, or f3 : is shaded feebly at 540, 
is dark at 536‘5, extends dark to 511, is shaded off to 505 ; centre of band a = 562 ; 
centre of band /3 = 523. Note, also, the faintly-shaded band S on either side of F ; 
this extends from 496 to 475. 
