OF ARTS AND SCIENCES. 97 



The phosphoric anhydride residue from which the benzol solu- 

 tion of o-nitro acid and anhydride had been decanted, yielded only 

 a small amount of the acid on being extracted with fresh benzol. 

 As a considerable quantity of insoluble residue still remained 

 after repeating the operation, we substituted absolute alcohol for 

 benzol as an extracting agent. With this we obtained a clear so- 

 lution which was evaporated to dryness, washed with cold water 

 until free of phosphorus, and recrystallized from alcohol. The 

 product consisted of small tablets which melted at 30°, and is 

 in all probability the ethyl ester of orthonitrobenzoic acid. The 

 amount was too small for an analysis. 



III. Action of Phosphorpentoxide upon Meta Nitrobenzoic Acid 



in an Excess of Benzol. 



10 grams m-nitrobenzoic acid were dissolved in about 200 c.c. 

 dry benzol, 10 grams of phosphorpentoxide added to the hot solu- 

 tion, and the whole boiled for three to four hours on the steam bath 

 under a reverse condenser. As in the previous experiments, the 

 phosphorpentoxide did not dissolve, but settled to the bottom of 

 the flask as a thick, gummy mass, which, as the boiling continued, 

 became rapidly darker-colored. 



The supernatant liquid was decanted hot through a plaited filter, 

 the residue in the flask boiled with fresh benzol, and this extract 

 added to the first. The solution immediately threw down a pre- 

 cipitate of fine white needles, which, after drying, showed a melt- 

 ing point of 161°, which was not raised by recrystallization from 

 benzol. Dried at 110° the substance analyzed as follows : — 



0.3051 grm. gave 0.5871 grm. C0 2 and 0.0548 grm. H 2 0. 

 0.2032 grm. gave 0.3904 grm. C0 2 and 0.0611 grm. H 2 0. 

 0.2166 grm. gave 0.4160 grm. C0 2 and 0.0608 grm. H 2 0. 

 0.3875 grm. gave 28.6 c.c. nitrogen at 6.6° and 748 mm. 

 0.4021 grm. gave 32.6 c.c. nitrogen at 4.2° and 755.7 mm. 



c 



H 2.53 2.00 3.34 3.14 



N 8.86 8.82 8.70 



VOL. XXVII. (n. S. XIX.) 7 



