COLORATION OF ANILINE: II. 



433 



During the distillations, the aniline in the apparatus was protected 

 from the action of the diffused light of the laboratory by wrappings of 

 asbestos paper and black paper. The entire work of distillation and the 

 sealing of the following described tubes were fortunately undertaken at 

 the beginning of a severe rain which lasted about ten days, so that the 

 diffused light was at a minimum and the working conditions almost ideal. 

 Since 18 different tubes were sealed, the apparatus had to be rebuilt six- 

 times. 



The methylaniline and the dimethylaniline employed were Kahylbaum's make 

 purified by fractional distillation and final drying by distillation over sodium. 

 No especial effort was made to produce absolutely pure samples and I believe that 

 the dymethylaniline contained traces of ,the monomethyl and perhaps some other 

 impurities. 



The following eighteen tubes were fastened on white paper and put 

 in the sun at the same time 2.40 p. m. on September 30, 1910. 



No. 



Labor- 

 atory 

 marks. 



Pressure, 

 in milli- 

 meters, 

 in tube 

 when 

 sealed. 



Appearance of 

 the tube at the 

 end of sixty 

 days' exposure 

 to sun. 



Aniline purified by method of Hantzsch 

 and Freese and sealed in hydrogen. 



1 



27 



761 



2 



22 



200 



3 



17 



1 



IVery dark red, 

 almost purple. 



Aniline from thiophene free benzene 

 sealed in hydrogen. 



23a 



760 



23b 



200 



23 



1 



X 



760.3 



y 



200 



z 



] 



[Darkest. 



Red_< Medium. 



[Lightest. 



{Darkest. 

 Medium. 

 Lightest. 



Aniline purified by method of Hantzsch 

 and Freese same as tubes Nos 1, 2, and 

 3 and sealed in carbon-dioxide. 



10 



14 



759.5 



11 



14a 



200 



12 



14b 



1 



Yellow. 



Reddish-yellow. 



Red. 



Monomethylaniline sealed in hydrogen. 



13 



16a 



757 



14 



16b 



200 



15 



24 



1 



I Brilliant dark 

 ( red. 



Dimethylaniline sealed in hydrogen. 



16 

 17 

 18 



26 



26a 



26b 



757.4 

 200 

 1 



Light yellow. 



