Ryan and Ryan — Action of Acids on Dipheny famine. 20 1 



colourless, leafy crystals, which melted at 132-133°C, gave an intense 

 violet coloration with concentrated sulphuric acid, and, when boiled with 

 alcohol containing a small amount of aqueous potash, formed A-nitro-diphenyl- 

 amiiie with a small quantity of higher melting constituents. The former 

 when recrystallized from diluted alcohol, separated in sulphur-yellow, platy 

 crystals, which melted at 131-132° C, and gave a nearly colourless solution 

 with concentrated sulphuric acid. 



8. To another solution of 2 grams of diphenylnitrosaniine in I00c.cs of 

 glacial acetic acid we added T2c.es (2 mols.) of nitric acid, and, as before 

 allowed the solution to remain in a stoppered flask at the ordinary tempe- 

 rature for three weeks. On the first day the solution had an orange colour, 

 on the second day deep orange, and from it yellowish-white crystals had 

 separated. From the third to the twenty-first day the solution was orange 

 in colour. 



The solution was filtered from the yellowish-white crystals, which weighed 

 1*7 grams, and the filtrate was mixed with several volumes of water. The 

 deep-yellow solid, which separated, weighed IT gram, and partially melted on 

 the water-bath. This solid, which had separated from the acetic acid solution 

 on dilution with water, dissolved easily in chloroform ; and on evaporation of 

 the chloroform a deep-yellow, somewhat oily, residue remained. This was 

 extracted with boiling alcohol, leaving a dark-coloured, tarry substance. The 

 alcoholic solution on evaporation gave an orange solid, which, after several 

 recrystallizations from chloroform and alcohol, separated as yellow prisms, 

 melting at 213-214°(J., and consisted of i'10-dinitro-diphenylamine. A dilute 

 solution of it in alcohol (cold) gave a violet colouration with a trace of alkali. 

 The crystals were coloured orange-red by contact with concentrated sulphuric 

 acid, in which they dissolved, forming a faintly yellow solution, the colour of 

 which was scarcely affected by addition of a crystal of potassium nitrite. 

 The orange solid contained in the mother liquids was mixed with a tarry 

 substance from which we were unable to separate it in a pure condition. 



9. In another experiment we added 1*8 c.cs (3 mols.) of nitric acid to the 

 diphenylnitrosaniine solution which developed an orange-yellow colour on the 

 first day, and from which yellowish-white crystals separated. The separation 

 of the crystals continued for several days, the colour of the solution becoming 

 gradually lighter until the seventeenth day, when it was orange-yellow. At 

 the end of the third week the solid, which was filtered off and reserved, 

 weighed about I - 4 grams. The filtrate, on dilution with water, gave an 

 orange-yellow precipitate which weighed 1*3 grams. 



This precipitate was dried, washed with chloroform, and recrystallized 

 from acetic acid. It melted at 192-195° (J., and consisted of slightly impure 



