( 254 ) 



The end solidifying points were found to be a little lower; as 

 regards the initial solidifying point of -f- 3°.l in the nitration at 60° 

 it should be observed that t lie mixture of toluene and nitric acid 

 had been left over night and separated into two layers which was 

 not the case in van den Arend's experiment. With an initial solidi- 

 fying point of 0\8 corresponds 37.5° of /Miitrotoluene , with 

 that of -j-"3°.l, 40.7% > disregarding, for the moment, the small 

 quantity of wi-nitrotoluene present in the nitration product. As a 

 content of 40.7° „ of /Miitrotoluene corresponds with a sp. gr. of 

 1. 10*20 it seems that no higher nitration products are formed, even 

 at -f- 60°, when the nitration is carried out in the manner indicated. 

 This is also shown by the position of the cm\ solidifying point 

 which is but little lower than that found with the nitration products 

 obtained at lower temperatures. 



In order to determine the o-, m- and /Miitrotoluene content of the 

 nitration product it must be regarded as a ternary mixture, and the 

 lowering which the initial and end solidifying points undergo, on 

 adding a small quantity of »i-nitrotoluene, should be determined, as 

 Nolting's investigation had shown that the latter is present only to 

 the extent of a few " . 



A mixture of pure o- and /Miitrotoluene weighing 2.8319 grains, 

 composed of 35.5°/ para- and 1)4.5" „ onf/ttf-nitrotoluene, had an 

 initial solidifying point 3 .8 and an end solidifying point - - J4°l). 



If now 0.0860 grams of 2.9° „, of wwfanitrotoluene were added, 

 the initial solidifying point fell to 6°.0, the v\u\ solidifying point 

 to — 16°.7. 



The percentage <>f o- and /Miitrotoluene in the mixed nitration 

 product at 0°, with an initial solidifying point -f- 2°.8 and an end 

 solidifying point — L6°.8 could now be determined in the following 

 manner, keeping account of the meta-comipound formed. 



On addition of 2.9% of meta the end solidifying point falls from 



- 14°. 9 to — 16°. 7 = i°.8. Owing to the presence of mc/a-mtvö- 



toluene, the end solidifiying point of the mixed nitration product 



has been found to be 16°.8 instead of 14°.9 (the eutectic point 



of the mixture ortho -\- para), therefore 1°.9 lower. From this it 



1.9> 2.9 

 follows that in the mixture at D there is present — — r— = 3.1 % 



l.o 



of meta. 



Owing to the presence of those 2.9" „ of meta-compound, the 



initial solidifying point of the artificial mixture has fallen from 



-3°.8 to -6°.0, therefore 2 3 .2. For 3.1% of meta the fall must 



amount to 2 3 .4. If for the mixed nitration product is found an initial 



