36 



ATLAS OF ABSORPTION SPECTRA. 



90. Crystal Violet Continued. 



Cantharides glistening crystals. In so- 

 lution violet, violet. 



1.38 g. per liter. 



Angle 42.5'. Depth o to 0.36 mm. 



The absorption is the same as that ex- 

 hibited by solution No. 92, hence see 

 the description given below. 



91. Ethyl Violet. (B.) Hydrochloride of 



hexaethyl pararosaniline. 



Fig. 64, pi. 16; No. 453, S. & J. 



Green, crystalline powder. In solution 

 pure, deep blue, pinkish blue. 



2.73 g. per liter. 



Angle 27.3'. Depth o to 0.25 mm. 



Intense absorption in the green. Very 

 sharp and abrupt on the blue side 

 but indefinite on the red border. 

 Strong lines in the ultra-violet are 

 transmitted pretty freely. Relative 

 transparency in the vicinity of 0.265/^. 

 Absorption ceases about 0.31/* and 

 from this wave-length to 0.495/1 

 transparency obtains. At 0.495^11 an 

 intense band having its maximum at 

 o.525(Li begins. About 0.585/i the ab- 

 sorption becomes relatively weak and 

 diffuse and continues thus to 0.63^4. 



92. Methyl Violet 6 B. (A.) Chiefly a mi.x- 



ture of the hydrochlorides of benzyl- 

 pentamethylpararosaniline and hexa- 

 methylpararosaniline. 



Fig. 66, pi. 17; No. 454, S. & J. 



Metallic, glistening powder. In solu- 

 tion blue, reddish blue. 



2.5 g. per liter. 



Angle 31.2'. Depth o to 0.29 mm. 



Transmits only blue and pure red in 

 concentrated solution. The solution 

 described below showed two bands, 

 the more intense in the green-yellow 

 and the weaker in the orange. All 

 strong ultra-violet lines are trans- 

 mitted. The chief band starts at 

 0.50/4, has its maximum at 0.535/1, 

 and joins its companion about 0.57/x. 

 The weaker band has its maximum 

 at 0.595/4 and fades away at 0.615/1. 

 Transparent from 0.62/1 to beyond 

 0.6^/4. 



93. Methyl Green 00. (By.) Zinc-double- 



chloride of hepta-methyl-pararosani- 



line-chloride. 

 Similar to fig. 47, pi. 12; No. 460, 



S. & J. 

 Green crystals. In solution greenish 



blue, greenish blue. 



93. Methyl Green OO Contimied. 



6 g. per liter. 



Angle 19.5'. Depth o to 0.18 mm. 



Band in violet and blue, also strong 

 absorption in orange and red. The 

 band in the orange is partly sepa- 

 rated from the stronger band whose 

 intensity increases to, and beyond, 

 0.63/t. With due allowance for dif- 

 ferences in concentration, it ap- 

 pears that the absorption is, in 

 toto, the same as that shown by 

 solution No. 94. Absorption de- 

 creases from 0.20/4 to a region of 

 less intense absorption at 0.28/4. 

 Then follows a strong band with 

 maximum at 0.315/1. A band from 

 0.375/4 to 0.445/1 has its maximum 

 at 0.415/4. The yellow and orange 

 band begins at 0.515/4. 



94. Methyl Green. Zinc-double-chloride of 



ethylhexamethyl - pararosaniline bro- 

 mide. 



Fig 47, pi. 12; No. 461, S. & J. 



Moss-green, crystalline powder. In 

 solution bluish green, bluish green. 



20 g. per liter. 



Angle 19.5'. Depth o to 0.18 mm. 



Band in violet and blue, also strong 

 absorption in orange and red. Trans- 

 mits green and yellow-green. Band 

 from 0.36/1 to 0.45/1 with maximum 

 at 0.415/4. This band is steeper on 

 its green side. Very transparent 

 from 0.45/t to 0.495/4. From 0.495/1 

 the absorption is intense and no re- 

 turn to transparency can be seen at 

 0.63/1. The band at 0.415/1 disap- 

 pears first on dilution. 



95. Fuchsine S. (B.) Mixture of the so- 



dium or ammonium salts of the tri- 

 sulphonic acids of rosaniline and 

 pararosaniline. 



Fig. 53, pi. 14; No. 462, S. & J. 



Metallic, green, glistening powder. In 

 .solution red, red. 



3 g. per liter. 



Angle 23.4'. Depth o to 0.21 mm. 



Strong absorption in the blue-green 

 and green. The middle of the first 

 transparent region is about 0.265/t. 

 A weak absorption band has its 

 maximum near 0.295/4. The visible 

 band commences at 0.475/4, has its 

 maximum about 0.535/4, and ends at 

 o. 575/4. Transparent from 0.575/4 to 

 0.63/4. 



