222 PROCEEDINGS OF THE AMERICAN ACADEMY. 



action in this case being allowed to continue for a week, but, as we had 

 reason to expect from our observations in our first reduction, the sub- 

 stance remained essentially unaltered, not more than a ti'ace of pyrocate- 

 chine being formed. Meanwhile we had discovered that the purplish 

 white product was converted by nitric acid into the original red substance, 

 and, therefore, we oxidized the unaltered body from the last reduction, 

 and on reducing this again with sodium amalgam, obtained a fiesh amount 

 of pyrocatechiue with the purplish white product again. By repeating 

 these alternate oxidations and reductions we have succeeded in convert- 

 ing a sample of the red substance completely into pyrocatechiue ; a result 

 which, it seems to us, proves that this red body is a pyrocatechine ether 

 and not a diphenyl derivative. 



The purplish white product of the reduction of hexabromorthoquino- 

 pyrocatechine ether by sodium amalgam mentioned frequently in the 

 preceding paragraph proved to have the same solubilities as the mother 

 substance ; that is, it was insoluble in all the common solvents except 

 uitrobenzol. It was accordingly recrystallized three times from boiliiio' 

 nitrobeuzol, when, as it does not have a definite melting point, it was 

 assumed to be pure. After extraction with alcohol to remove adher- 

 ing uitrobenzol it was dried at 100°, and analyzed with the following 

 result : — 



0.1215 gram of the substance gave by the method of Carius 0.1974 gram 

 of argentic bromide. 



Calculated for ^ , 



C„Bro(OH),0,. ^"""^d. 



Bromine 69.56 69.16 



Properties. — The substance crystallizes from hot uitrobenzol in very 

 small chocolate brown crystals, which appear to be short, rather blunt 

 needles. As obtained from reduction it has a purplish white color and a 

 characteristic silky lustre. It does not melt at 300°. It is insoluble in 

 all the common solvents except uitrobenzol. An aqueous solution of 

 sodic hydrate does not dissolve it ; fuming nitric acid converts it back 

 into the red substance, from which it was made, as is proved by the 

 following experiment : — 



Three grams of the chocolate-colored crystals of the reduction product 

 were mixed with 20 c.c. of glacial acetic acid, and 5 c.c. of fuminf nitric 

 acid were added. The solid immediately turned red, and, after the mix- 

 ture had been thoroughly stirred, it was poured into water, and washed. 



