204 PROCEEDINGS OF THE A.MEBICAN ACADEMY. 



none, and of hydrochloric acid at 1G0° to 17.3° on the red pyrocatechine 

 ether. There seems no doubt, therefore, that it is formed from the red 

 body by the conversion of two orthoquinone oxygen atoms into liydroxyl 

 groups ; in other words, that it is the pyrocatechine corresponding to the 

 red orthoquinone ; and this view is confirmed by the oxidation of the 

 brown substance to the red by nitric acid. The reaction of the hydro- 

 chloric acid is especially instructive in regard to the constitution of these 

 two bodies, as it is the familiar conversion of a quinone to a hydroqui- 

 none by this reagent. The red color of the original substance also points 

 to the presence of orthoquino oxygen in it, whereas the lighter color 

 of the reduction product (brown when crystallized, but purplish white 

 when amorphous) confirms the view that it is the hydroxy compound. 

 We therefore assi<m the following formulas and names to these suit- 

 stances, — red compound, Br 4 C 6 = On (',, Br 8 < ).., hexabromorthoquinopyro- 

 catecbine ether; the brown reduction product, Br 4 CVOo=C c Br 2 (OII | s , 

 hexabromdiorthoxypyrocatechine ether. The only observed fad not in 

 accordance with this last formula is that the substance does not dissolve 

 in a solution of Bodic hydrate, as we should expect it to do considering 

 that it contains two phenol bydroxyls; this may, however, be explained 

 by the very slight solubility of the substance (soluble only in warm 

 nitrobenzol). which might prevent the solution of sodic hydrate from 

 comin" into sufficiently close contact with it to react. 



The hexabromorthoquinopyrocatechine ether was formed when acetic 

 acid or alcohol was used as the solvent, but none of it was obtained 

 when the tetrabromorthoquinone and tetrabrompyrocatechine were mixed 

 in solution in chloroform or ether. In this latter case the residue left 

 after the evaporation of the solvent was a reddish white mass, apparently 

 a mixture of the unaltered reagents, which contained none of the hexa- 

 bromorthoquinopyrocatechine ether. This is strange, as Zincke by mix- 

 in- the two Bubstances in ethereal solution obtained a black crystalline 

 itance. An attempt will be made in this laboratory nexl year to find 

 the conditions under which this lda«;k compound is formed. 



W< have Buccei led also in obtaining a reaction Bimilar to thai jnst 

 ribed from tribromresorcine and tetrabromorthoquinone. The other 

 phenols tried acted -imply as reducing :i_ r <'nt>. The product proved to 

 be i ditribrommetoxyphenyldibromorthoquinophenylene ether, 



HBr.OHO < Br,O a . 



Thi instance melts at 217 , and like the reduction product just de- 

 scribed, does not di-solvc in a Bolution of Bodic hydrate, in Bpite of the two 



