14 
H. N. MOSELEY. 
the alcoholic solution shows three absorption bands (PI. IT, 
fig. 15 «■). .One, an extremely intense band with well-defined 
edges, extends from a little beyond the less refrangible side 
of D to about one third of the distance between D and E. 
The next band is faint, not so broad ns the preceding, and 
situate a little to the less refrangible side of E. The third 
band is also faint, but rather darker than the last described; 
it extends from E towards the led, and shades gradually off 
towards its red edge. The position of the bands is given in 
the figure. The least refrangible band is so well marked 
that it is easily seen with a weak solution; but the two 
others, being fainter, require strong solution used in consider¬ 
able thickness, and with not too high a dispersion, to come out 
well. The red end of the spectrum is cut off as far as 
almost up to B; the blue end is visible just into the violet. 
If a drop of hydrochloric acid be added to the spirit solu¬ 
tion the colour changes at once to a clear pale blue, and the 
spectrum changes to a single band (PI. II, fig* 15 b)> dark in 
the centre, and shading ofi at the edges, which band is 
placed nearer the red than the dark band of the alkaline 
solution, and overlaps the D line towards the green by 
about one third of its breadth. The original colour and 
spectrum are restored on the fluid being again rendered 
alkaline with ammonia. 
If an ianthina be pricked and made to discharge its purple 
into a test-tube containing glycerine the colouring matter is 
dissolved, and a solution obtained which lias, a deep violet 
colour, and gives the three bands like the spirit solution. 
If the purple be treated in the same manner with ether 
a coloured solution is obtained, resembling exactly the spirit 
one in appearance, fluorescence, and spectrum. The ether 
does not become very highly tinged, but leaves a coloured 
residue, which, after the ether is poured off, may be dis¬ 
solved in absolute alcohol. A blueish solution showing one 
absorption band is the result. ... 
If the fresh purple fluid be treated with acidified ether a 
most brilliant dark blue solution is obtained, which is not 
fluorescent, and which gives the spectrum shown (11. II, 
fig. 15'c). * 
No method by which the colouring matter, which may be 
called Ianthinin, could be preserved was discovered. All 
the various solutions mentioned above faded in the course 
of a week or two, and the ethereal solutions even more 
rapidly. 
Phosphorescence .— The phosphorescent light emitted by 
three genera of deep-sea Alcyonariuns was examined spec- 
