448 PKOCEEDINGS OF THE AMERICAN ACADEMY. 



salt. The alkaline solution, when poured into an excess of dilute 

 acid, gave a reddish yellow precipitate, which was filtered out, washed 

 with water, and, after purification by recrystallizatiou from alcohol, 

 dried, and analyzed with the following result : — 



0.2224 gram of the substance gave on combustion 0.5436 gram of 

 carbonic dioxide and 0.0794 gram of water. 



The substance was therefore formed from the tetraphenoxyquinone 

 by replacing two of the phenyl radicals by hydrogen, and is the 

 diphenoxyauilic acid. 



Properties of Diphenoxyanilic Acid, C(;(OCgH5)2(OH)202. — It 

 forms glistening rather thick plates, either square or in rectangular 

 oblong forms, having a dark reddish brown color like that of ferric 

 citrate ; which the substance also resembles in lustre and general 

 appearance. It melts at about 276°, but the melting point is not 

 sharp, as it shows signs of softening even at 270°. If heated some- 

 what above its melting point, it puffs up filling the capillary tube with 

 a dark liquid. It is soluble in glacial acetic acid ; sparingly soluble 

 in alcohol or hot chloroform ; insoluble in ether, benzol, carbonic 

 disulphide, or ligroine. It dissolves slightly in boiling water, imparting 

 a pink color to the solution. It has distinct acid properties dissolving 

 in sodic hydrate to form a black crystalline salt, which dissolves in 

 water with a dark purple color. It is not acted on by acids dilute or 

 strong, cold or hot. 



Tetraphenoxyhydroqicinone, Cg (OCgHj) ^ ( OH) 2. 



This body was made by reducing the tetraphenoxyquinone with 

 glacial acetic acid and zinc dust. Two grams of the tetraphenoxyqui- 

 none were warmed on the steam bath with these reagents until the red 

 color of the original substance had completely disappeared ; water was 

 then added, and the precipitated hydroquinone purified by recrystal- 

 lizing it from alcohol containing a little hydriodic acid to prevent 

 oxidation. On analysis the following results were obtained : — 



0.2015 gram of the substance gave on combustion 0.5558 gram of 

 carbonic dioxide and 0.0862 gram of water, 



