260 



5.. Acetylisatin (Table E. II). 



1.89 gr. acetylisatin were dissolved in 100 cm' alcohol. 1 cm' 

 of this solution bas been mixeci with 60 cmä of alcohol and 1 cm* 

 of this latter solution diluted furtlier as foUovvs: 

 a.. 1 cm* -j- 1 cm* alcohol. corresponding to 0.000157 gr. in 1 cm* 

 b.', 1 „ + 3 „ , „ „ 0.0000787 „ „ , 



c, 1 „ + 7 „ „ „ „ O.OOOOoyS „ „ „ 



d., 1 „ + 15 „ „ „ „ 0.0000197 „ „ „ 



6.. Sodium sait of isatic acid (Table E. I) 

 1"47 gr. isatin were dissolved in boiling caustic potash solu- 

 tion and then filled up tu 100 cm*. Taken 1 cm^ of this -\- 60 cm* 

 of water and diluted further as follows: 



a., 1 cm* -j- 1 cm* Hg 0, correspond, to 0.000120 gr. in 1 cm* 

 b., 1 „ + 3 „ „ ' „ „ 0.000060 „ „ „ 



c, 1 „ + 7 „ „ „ „ 0.000030 „ „ „ 



d, 1 „ + 15 „ „ „ „ 0.000015 



V n 



7., N-toly 1-ps-i ndophenazine (Table G. II) 



1,546 gr. were dissolved in 200 cm* alcohol. 1 cm* of this 



solution was mixed with 25 cm* of alccjhol and then diluted 



further as follows: 



a., 1 cm* -{- 31 cm* alcohol, corresp. to 0.0000096 gr. in 1 cm* 



b., 1 „ + 63 „ „ „ „ 0.0000048 „ „ „ 



8., N-methyl-ps-indophenazine (Table Gr. I) 

 0.1166 gr. were dissolved in 20 cm* alcohol and then di- 

 luted as under 7. 



Ail the N-alkyl-(aryl)-ps-indophenazines hitherto examined 

 show, besides the two bands in the ultraviolet, an ill defined band 

 in the green and blue part of the spectrum. 



