135 
of Edinburgh, Session 1884 - 85 . 
ether, no other hands were seen with distinctness ; hut an alcoholic 
solution of the colouring matter from the same specimen, and much 
stronger, exhibited three absorption hands. 
Pure dry ether does not take up so much colouring matter as alcohol, 
and it appears as if the ethereal solution contained hut two substances, 
namely, blue chlorophyll, and a yellow body which causes absorption 
only beyond the b group. The spectrum of the ethereal solution 
very closely resembles that of the fronds of the living sea-weed, 
while the alcoholic solution differs therefrom. 
The Absorption Spectrum of Chlorophyll as seen in the Fronds of 
living Sea- Weed. 
Description of Spectrum. 
Arc measure- 
ments. 
Oscillation 
frequencies. 
Wave- 
lengths. 
Termination in the red, . 
41°- 
1390 
7194 
Absorption band in the 
red, .... 
41°T5' to 41° -35' 
1466 to 1560 
6820 to 6410 
Termination in the blue, 
43° -39' 
) 
2010 
4975 
A sec 
ond series of Measur 
ements. 
Absorption band in the 
red, .... 
41° T 6' to 41° -37' 
1468 to 1568 
6812 to 6377 
The Absorption Spectrum of Chlorophyll extracted from the dried 
Sea- Weed by Alcohol. 
Description of Spectrum. 
Arc measure- 
ments. 
Oscillation 
frequencies. 
Wave- 
lengths. 
Termination of spectrum 
in red, 
41' • 
1390 
7194 
Absorption band in red, 
41° T7' to 41° -39' 
1475 to 1576 
6779 to 6343 
Feeble Absorption band 
in the orange, 
41° *52' to 42° • 
1631 to 1664 
6131 to 6008 
Feeble Absorption band 
in the green, 
42° '23' to 42° *57' 
1753 to 1875 
5702 to 5333 
The bands in the orange and green were much weaker in the 
green colouring matter extracted from sea-weed than they usually 
appear when an alcoholic extract of leaves is examined, as they are 
caused in the latter case by substances of the xanthophyll group 
(Sorby, loc. cit.) and alteration products. 
I am indebted to Mr John Murray for the following note, in 
