12 Dr. E. J. Mills's Researches on Melting-point. 



the washed mixture of liquid and solid nitrotoluol with toluol 

 thus obtained, a current of steam was passed, to remove toluol 

 first ; then a mixture of the two nitrotoluols came over ; and 

 from this the solid was almost completely extracted by solidi- 

 fication in a freezing-mixture and filtering out suddenly by 

 atmospheric pressure. For the success of this operation, 

 distillation in a current of steam is essential. 



Sample A was purified by melting with a little Nordhausen, 

 washing with water, and crystallizing from spirit: the mother- 

 liquids were evaporated for deposits, d Xy d 2 , d 3 . The results 

 were: — 



51-45 51-18 51-221 



5141 50-83 (thermometer 2) I Each result 

 51*12 (recrystallized) [ is a mean. 



51-13-51-52 (sublimed) J 



It is clear that neither crystallization from spirit (even after 

 Nordhausen) nor sublimation gives a satisfactory result. 



Sample B was purified like A, twice crystallized from spirit, 

 once from pure high-boiling-point (132°) naphtha, twice from 

 spirit, once from spirit of wine. 



Sample C was similarly purified : four successive extracts 

 (#) were taken in a mixture of 1 spirit, 2 water. Therm. 2. 

 The mean results were: — 



440.5 440.9 43 o. 8 50 o. ? 



This shows that the method of extracts is also a failure. 

 .t'i, x 2} a? 3 were united as C a ; .r 4 was set aside as C*; C a was 

 twice crystallized from naphtha, once from spirit of wine. 

 Four similar extracts were then made, united, crystallized 

 from naphtha, C 4 added, and the mixture was again crystal- 

 lized, once from naphtha, once from spirit of wine : this pro- 

 duct is termed C e . 



Sample D was thrice crystallized from naphtha, once from 

 spirit of wine; twice, thrice, and four times from spirit of wine. 

 Part of the crude substance of D had not been distilled. The 

 fractions are marked D 4 , D 5 , &c, according to the times of 

 crystallization. 



M was prepared by dropping purified toluol into twice its 

 bulk of nitrous or " fuming " nitrate of spec. grav. 1*48; 50 cub. 

 cent, of toluol were added to 100 cub. cent, nitrate in each 

 operation, which lasted 1*6 hour. It was crystallized twice 

 from naphtha and thrice from alcohol. 



