490 
C. A. MAC MUNN. 
Sp. 14. — The same blood in aqueous solution after the addition of sulphide 
of ammonium and caustic soda. Compare Sp. 3. 
Sp. 15. — Spectrum 1 of the gills of some Serpulm. 
Sp. 16. — Spectrum of an operculum. In the gills of some Serpulae this 
band is seen. 
CHART II. 
Sp. 1. — The colouring matter of the perivisceral fluid of Strongylocen- 
trotus lividus with caustic potash (in the solid state). 
Sp. 2. — The “serum” of this fluid, after standing in contact with the clot 
for a considerable time. 
Sp. 3. — Action of stannous chloride on the same. Reduced echinochrome. 
Sp. 4. — Spectrum of the brownish clot (of same fluid). 
Sp. 5. — The same treated with caustic soda. 
Sp. 6. — Absolute alcohol extract of fresh clot. 
Sp. 7. — The same with acetic acid (acid echinochrome). 
Sp. 8. — Absolute alcohol extract of fresh clot with stannous chloride. 
Sp. 9. — Chloroform extract of residue from the evaporation of an alcohol 
solution of echinochrome. 
Sp. 10. — What was left untouched by the chloroform went into ether, 
giving this spectrum. 
Sp. 11. — An absolute alcohol solution was evaporated down, residue dis- 
solved in chloroform ; this was evaporated, and the residue dissolved in ether 
gave this spectrum, which differs from Sp. 10. 
Sp. 12. — Bisulphide of carbon solution of the residue left from the evapora- 
tion of a chloroform solution. 
Sp. 13. — Dried clot in ether. 
Sp. 14. — Dried clot in chloroform. 
Sp. 15. — Dried clot in bisulphide of carbon. 
Sp. 16. — Dried clot in benzene. 
Sp. 17. — Glycerin extract of fresh echinochrome. 
Sp. 18. — The same with stannous chloride. 
A comparison of these spectra shows how remarkably unstable echino- 
chrome is ; it is on this instability that its usefulness as a respiratory substance 
depends. 
1 This band is rather too dark. 
