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least al 0°. Alter some time, the mixture was shaken repeatedly in 

 a large separation tunnel with water until no more acid reaction 

 could be observed. 



Being dried over sodium sulphate, the product was distilled in 

 vacuo. The temperature was first kept for some time at 40', to 

 remove any unattacked toluene: at a pressure of 1 to 2 m.m. 

 and a temperature of 90° — 10() D the whole distilled over leaving but 

 a very small residue. Towards the end of the distillation much of' 

 the p-nitrotoluene passed over, which deposited in the exit tube as 

 a yellow crystalline mass. 



The distillate consisted of a clear pale yellow liquid. 



After the solidifying point and the sp.gr. of such a nitration- 

 mixture had been determined the distillation in vacuo was once 

 more repeated and the solidifying point and the sp. gr. determined 

 again. These did not differ perceptibly from the first ones. 



The end solidifying points could also be determined pretty sharply ; 

 the subjoined table shows the results obtained : 



Nitration at : Spec. Gr. 



initial solidifying point -f 4°.l 1.1026 



16°.6 

 + 2°.8 1.1026 



16°.8 

 + 1°.4 1.1027 

 16'. 9 



— 0\s 1.1028 



— 17°.4 



The specific gravities were again determined at the temperature 

 of' boiling benzene and reduced to 80\0. They have been corrected 

 for vacuum and expansion of the glass. 



I have had these observations repeated in part by Messrs Caland, 

 van Dorssen and de Leeuw who have themselves purified toluene 

 in the manner described, nitrated the same, and determined the 

 initial and end solidifying point, also the sp.gr. of their nitration 

 product. They found : 



17* 



