ON A NEW a, 8 DIHYDROQUINOXALINE I4I 



colloidal solution of the salt in chloroform is formed, which has very 

 much the appearance of a thick starch solution. A comparatively 

 dilute chloroform solution of the base becomes semi-soUd. If water 

 is added to a portion of this in a test tube, the colloidal solution assumes 

 the form of a sphere, within the outer chloroform shell of which floats 

 a nucleus of undissolved salt. This will last a long time, even though 

 the water be hot. If the colloidal solution be allowed to evaporate 

 upon a watch-glass, a tough parchment-like residue remains behind, 

 which retains the odor of chloroform for days. This residue dissolves 

 in water to the ordinary aqueous solution of the salt. 



Comparison of the above salts of this base with those of the base from 

 orthophenylenediamine. — The halogen acid salts of this base are, Uke 

 those of the base from orthophenylenediamine, yellow and white. Their 

 aqueous solutions are, Uke those of the other base, yellow when dilute 

 and colorless when concentrated. They can serve as their ovni indi- 

 cators on titration with alkaHs, the change of color of the solution from 

 yellow, due to the complex kation, C14H22N2, to colorless being very 

 sharp. Hydrochlorplatinic acid gives with the salts of this base no 

 precipitate, the chlorplatinate being extremely soluble in water. 



Picric acid salt. — When an ether solution of the base is mixed with 

 an alcohoHc solution of picric acid, beautiful lemon yellow crystals 

 of a picrate of the base separate out. 



NITROGEN DETERMINATION 



.2102 grm. substance yielded 36.5 c.c. Nitrogen at 6i3.2m.m. and 20°. 

 Cx4H,oN,-2C6H,(OH)(N02)3 N = i6.39% Found, 16.61% Calc. 



ACTION OF NITROUS ACID 



If a potassium nitrite solution is added to a dilute acetic acid solu- 

 tion of the base, a nitroso product is formed. It becomes gummy, and 

 looks very much like the corresponding product from the base from or- 

 thophenylenediamine. In this case, however, the impurities could not 

 be removed, so that no crystals were obtained. The impure substance 

 shows the Liebermann's blue coloration, and is without doubt an 

 impure nitroso compound. 



