210 PROCEEDINGS OF THE AMERICAN ACADEMY. 



I. 0.1275 gram of the substance gave on combustion 0.2910 gram of 

 carbonic dioxide and 0.0436 gram of water. 

 II. 0.0608 gram of the Bubstance gave 0.1401 gram of carbonic dioxide 

 and U.U230 gram of water. 



Found. 



II. 



G2.85 

 4.20 



The substance is obviously the same as that previously analyzed, although 

 not bo pure. 



We bare, therefore, four analyses of three samples of this substance 

 prepared or purified in different ways, and, as these agree, there can be 

 no doubt that the black alteration product of the orthoquinone is a deli- 

 nit, compound, and has the composition Ci 2 II s 5 . 



Properties of the Black Alteration Product of Orthobenzoquinone 

 ( Orthodioxyphenyloxyorthoquinone,* ( ,1 [ 8 | < )11 (..CV.ILOIIOj. — It forms 

 an almost black amorphous powder, which does not melt, but decomposes 

 gradually at temperatures above 170°. It is easily soluble in cold alco- 

 hol, ether, or glacial acetic acid; insoluble in benzol or chloroform, 

 whether cold or hot. Strong acids have no apparent action on it, but 

 alkalies dissolve it. 



The fallowing experiments were undertaken to determine the constitu- 

 tion of the black alteration product. 



Reduction of the Alteration 1 'rod act. 



The formula of the substance C',. I U< >- indicates that it contains two 

 benzol rings, and these may cither be united directly, forming a diphenyl 

 compound, or they ma) be united h\ two atoms of oxygen, forming a 

 substituted pyrocatechine ether, [(',-. I b<>l I ]O s [C 6 l I,.<<)1 1 1, ]. The di- 

 phenyl formula, (HO)0 8 H 8 C 9 -CeH 8 (OH) a , is rendered probable by the 

 formation of the dinaphthyldiquinhydrone "f under Bomewhal similar cir- 

 cumstances from beta-naphthoquinone, which has been proved to be a 

 dinaphthyl compound;! the pyrocatechine ether formula, on the other 

 hand, is in harmony with a derivative of tetrabromorthoquinone, which is 

 ribed later in this paper. Reduction Beemed the easiest waj to de- 



• This name and formula n>r the substance are established by the «.>rk 



bed later in tlii* paper. 



. m. <Ii-ii.. (I.i. in i. i V [V 206 

 I Ibid. 206. K'.m Ber. d. cbem. Ges., XVII 8020. 



