134 
Proceedings of the Royal Society 
No. 12. H.M.S. “ Triton ” 516 fathoms. St. 10. 24/8/82. 
Colour of liquid as seen in tube, brownish shade of orange colour. 
No. 7. Off Arrou Isle, 23d Sept. 1874, 800 fathoms. Colour, 
brownish-orange. 
The close agreement of the measurements of the hand in the red 
with those of the same hand in fresh chlorophyll is evidence of the 
nature of the substance. It may be of interest to point out that 
the green colouring matter from liquid No. 10 was insoluble in 
water, but soluble in alcohol and ether ; boiling with dilute 
sulphuric acid showed that it was not a glucoside, as it had subse- 
quently no action on Fehling’s solution. The yellow colouring 
matter from the same specimen was soluble in water • it had a very 
feeble action on Tehling’s solution. Both specimens No. 12 and 
No. 7 yielded yellow residues soluble in water, which reduced copper 
solution at once on boiling. 
According to Sorby, blue chlorophyll in strong solutions shows 
three bands at the red end of the spectrum, the least refrangible 
being the most intense ( Proc . Roy. Soc<, vol. xxi. p. 442). I have 
observed only one band in solutions corresponding in strength 
to the liquids numbered 12, 10, and 7, when examined in the same 
way, and it is that which is figured in the paper just quoted ; the 
bands in the yellow and green are due to the colouring matters 
derived from chlorophyll. 
An examination was made of living green sea-weed brought out 
of the Irish Channel by trawlers. The fronds being thin and filmy, 
can be easily laid upon glass and placed before the slit of the spec- 
troscope to be examined in layers of different thicknesses by direct 
sunlight. One thickness showed a dark band in the red, with an 
extension towards the orange, which was undoubtedly the second and 
weaker band of blue chlorophyll ; but there were no traces of bands 
in the orange and green. The spectrum ended just beyond the 
magnesium green triplet h. Two thicknesses caused the band to be 
much increased in density ; no band in the orange ; green practically 
unaltered, the end of the spectrum nearly approaches the triplet in 
the green. Three and four thicknesses transmitted no trace of red, 
but only the green and part of the yellow rays. No band in the 
green was observed at all. 
When the sea- weed was rapidly dried and extracted with pure dry 
