40 



ATLAS OF ABSORPTION SPECTRA. 



111. Eosine, bluish. (B.) Sodium salt of 



tetraiodo-fluoresceine. 



Similar to fig. 58, pi. 15; No. 517, 

 S. & J. 



Lavender powder. In solution red, 

 pink. 



15 g. per liter. 



Angle 21.3'. Depth o to 0.18 mm. 



Intense absorption in the blue-green. 

 Similar absorption to that of solu- 

 tion No. 108. The yellowish-green 

 fluorescence only appears in dilute 

 solutions. Absorption decreases 

 gradually from 0.20/i to 0.36/^. In- 

 tense absorption from 0.45 5/t to 

 o.555/i. Maximum of absorption at 

 o.52;u. There seem to be two unre- 

 solved bands of which the more re- 

 frangible is a little less intense than 

 its companion. This region of ab- 

 sorption is sharper and steeper at 

 its yellow border. Transparent from 

 0.555/* to 0.63/1. 



112. Erythrosine. (M.) Sodium salt of 



tetraiodo-fluoresceine. 



Fig. 59, pi. 15; No. 517, S. & J. 



Dark-red powder. In solution red, 

 pink. 



15 g. per liter. 



Angle 21.3'. Depth o to 0.18 mm. 



Intense absorption in the blue and 

 green. A strong hand in the middle 

 with a slightly weaker, unresolved 

 companion on each side. The yel- 

 lowish-green fluorescence only ap- 

 pears in dilute solutions. The re- 

 gion of visible absorption is from 

 0.455^ to 0.562/i. The chief maxi- 

 mum is about 0.518/i. The yellow 

 edge of this group of bands is very 

 sharply defined. Transparent from 

 0.562/* to 0.63/*. 



113. Cyanosine. (M.) Alkaline salt of 



tetra - bromodichloro - fluoresceine- 

 methyl-ether. 



Fig. 18, pi. 5; No. 519. S. & J. 



Brownish-red powder. In solution red, 

 bluish pink. 



Saturated (boiled). 



Angle 25.4'. Depth o to 0.23 mm. 



Band in blue-green and green. Faint, 

 yellowish fluorescence. Strong ab- 

 sorption from 0.493/1 to o.553/i"with 

 its maximum at 0.525/*. Transpar- 

 ent from 0.553/1 to 0.63/1. 



114. Rose Bengal. (B.) Alkaline salt of 



tetraiododichloro-fluoresceine. 



Similar to fig. 59, pi. 15; No. 520, 

 S. & J. 



Brown powder. In solution red, orange. 



15 g. per liter. 



Angle 21.3'. Depth o to 0.18 mm. 



Double, unresolved pair of bands in 

 green. In amyl alcohol the bands 

 were nearly resolved. Strong ab- 

 sorption from o.20/t to about 0.33/t, 

 except a slight weakening at 0.295/1. 

 Transparent from 0.33/1 to 0.48/1. 

 Strong absorption from 0.48/1 to 

 0.575/t. Transparent from 0.575/t to 

 0.63/t. 



115. Phloxine. (B.) Sodium salt of tetra- 



bromotetra-chloro-fluoresceine. 



Fig. 60, pi. 15; No. 521, S. & J. 



Brick-red powder. In solution cherry 

 red, pink. 



12.5 g. per liter. 



Angle 42.5'. Depth o to 0.36 mm. 



Intense absorption in the green. Dark- 

 green fluorescence. Visible band lies 

 between 0.458/1 and 0.57/1. The max- 

 imum is near 0.525/1. For dilute so- 

 lutions the absorption is very much 

 like that shown by fig. 18, except 

 that the contour of the band in the 

 green is sharper than for solution 

 No. 113. 



116. Galleine. (By.) Pyrogallol-phthalein. 

 Similar to fig. 1 1, pi. 3 ; No. 525, S. & J. 

 Violet brown powder. In .solution very 



dark brown, brown. 



Saturated (heated). 



Angle 58.5'. Depth o to 0.54 mm. 



Ilazy-edged absorption in the blue- 

 green and green. Absorption is com- 

 paratively strong at 0.20/1 and de- 

 creases very gradually to semi-trans- 

 parency about 0.435/t. Only partial 

 transparency exists between 0.435/1 

 and 0.485/4. A V-shaped band ab- 

 sorbs from 0.485/4 to o.553/t. The 

 maximum is about 0.52/t. The end 

 of the negative slants a good deal, 

 showing general absorption in the 

 yellow-orange. The spectrogram is 

 like that which would be obtained 

 with a more concentrated solution of 

 No. 47 if it were possible to produce 

 such a condition. 



