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



In determining the melting-points of Z„, Z f , and Y, the 

 thermometers were protected by two glass cylinders ; in the 

 other three cases the cylinders were not used. 



Crystallization, powdering, desiccation, and filling of capil- 

 lary tubes had to be effected either in total darkness or in a 

 deep shade. /3 dinitrophenol is very nearly white ; but by- 

 two hours' exposure to a somewhat gloomy atmosphere it 

 becomes deep turmeric yellow. 



/3 dinitrophenol melts with moderate sharpness. 



Table XXI. 





Z„. 



Z C . 



Y. 



T. 



Z e . 



Z e . 





o 



o 



o 





o 









116 60 



111-63 



111-46 



111-57 



11L-66 



111-05 





•60 



•63 



•57 



•57 



•64 



•55 





•46 



•49 



•63 



•49 



•61 



•65 





•52 



•58 



•68 



•60 



•61 



•58 





•55 



•63 



•82 



•57 



•64 



•53 





•63 



•60 



•60 



•60 



•80 



•63 





•46 



•58 



•49 



•57 



•61 



•60 





•43 



•68 



•57 



•52 



•66 



•58 





•52 



•52 



•60 



•54 



•53 



•53 





•63 



•55 



•57 



•54 



•66 



•65 



Mean 



111-54 

 •015 



111-59 

 •012 



111-60 

 •020 



111-56 

 •007 



111-64 

 014 



111-59 

 •010 



Probable error ... 



Thermometer ... 



2 



2 



2 



2 



2 



3 



5. Trinitrophenol. — Sample A was a commercial specimen. 

 It was crystallized twice from water, once from alcohol, and 

 again from water. 



Z was prepared from dinitrophenol made by Griiner's pro- 

 cess (v. supra); the material employed was very pure, having 

 been precipitated from a 12th (Z^) cold aqueous extract of 

 the crude basic salt. This was evaporated to dryness on the 

 water-bath with a very large excess of hydric nitrate, and crys- 

 tallized once from naphtha, once from ethylic alcohol, and 

 twice from w T ater. 



O was made from phenol, containing minute amounts of the 

 two modifications of dinitrophenol, by evaporation, as with Z. 

 It was crystallized thrice from water, once from alcohol, and 

 a first (Oi), second (0 2 ), and third (0 3 ) time from water. 



M was similarly prepared from sodic a nitrophenate (E 

 under a nitrophenol), and was crystallized thrice from water. 



F was derived from sodic /3 nitrophenate (the analysis is 



