( 250 ) 



preparation and found to be - 3°. 7 and - - 9°.4. According to his 



observation the unstable modification with the higher m.p. is formed 

 most readily when the liquid substance is cooled rapidly to about 

 30 . First, a solid yellowish mass is formed, which, on further 

 lowering of the temperature, begins to show white spots and then 

 turns quite white, with production of a crushing sound ; the crystal- 

 line mass thus obtained melts at about —4°. 



wi-Nitrotoluene is obtainable from ni. IIakn in a very pure condition. 

 It was fractionated a few times when the melting point was found 

 to be -\- 1Q° and the boiling point 230—231° at 756 mm.; it may 

 therefore, be taken as pure. 



p-Nitrotoluene from Kahlbaum was recrystallised twice from alcohol 

 and then distilled in vacuo: its solidifying point was found to be 54°. 4. 



Solidifying curve of <>- <ui<l p-nitrotoluene. 



" n para-nitrotoluene initial solidifying point end solidifying point 



100.0 -r- 54°.4 



<)7.5 50°.0 



1)1. i; 46°.2 



79.0 38°.5 



72.1» 33°.8 



67.5 30°.4 



60.5 24°.4 — 



46.6 U°.6 15°.0 

 42.3 5°.4 15°.2 



39.8 1°.8 15°.7 



°/'o para-nitrotoluene initial solidifying point end solidifying point 



37.2 — 1°.2 14°.6 



33.5 6°.8 



30.6 14°.8 



24.9 14°.4 15°.6 



16.3 J2°.l 

 11.2 11°.3 



0.0 0°.4 



mean — 15°. 2 



Fig. 1 represents the solidifying curve constructed with the aid 

 of these figures. 



