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cannot be ascertained with sufficient accuracy. According to their 
intensities they may be put in the following order: 
III > IV > II > I 
Band I is indeed extremely faint. 
In alcohol containing some hydrochloric acid the crystals dissolve 
easily with a reddish violet colour. Concentrated solutions show 
three bands of which the one situated in the green is extremely 
faint: 
Band I X 623 — X 605 
„ II X 592 — X 546 
„ III X 523 — X 515 
Scale of intensity II > I > III. 
On further dilution band II splits up into two new bands: 
Band I X 617 — X 606*5 
„ II a X 590 — À 580 
„ II b X 571 — X 557 
the third is scarcely visible. 
Still another absorption spectrum is shown by the crystals dis¬ 
solved in a 12°/ 0 aqueous HC1 solution. In this case only two 
distinct bands are visible: 
Band I X 617*5 — 606 
„ II X 573 — 546 
on further dilution 
Band I X 615 — 607*5 
„ II X 566 — 559. 
As regards the absorptions in the ultraviolet all the described 
colouring matters behave in exactly the same manner. Their neutral 
ethereal solution cause a strong band situated on the Hg = 405^0 
line. A much less distinct absorption band follows in the region of 
about 380 \i\i, besides a total absorption in the extreme ultraviolet. 
Having described the optical properties of colouring matters 
obtained according to the method ofWilstätter and M i e g which 
these authors call phytorhodines we may now proceed with the 
