JACKSON AND KOCH. — DERIVATIVES OF ORTHOBENZOQUINONE. 227 



It is obvious that the decision can be made between these formulas only 

 by the chemical study of the substance, but unfortunately we have not 

 succeeded as yet in decomposing it by any of the reagents we have tried, 

 so that we must leave this question undecided for the present, with the 

 statement that we consider the formula C 14 H 2 Br 8 5 the most probable. 

 The study of the substance will be continued in this Laboratory next 

 year. 



Properties of the Substance C 14 H 2 Br s 5 . — When crystallized from 

 glacial acetic acid it forms small, almost square rhombic plates with a 

 pearly lustre, which melt at 230°. It is easily soluble in ether, benzol, 

 chloroform, acetone, or ethyl acetate ; almost insoluble in glacial acetic 

 acid, but its solubility is increased by heat, as the boiling acid takes up 

 from two to three per cent of the substance. Its solubility in ethyl alco- 

 hol is similar to that in glacial acetic acid ; curiously enough, when first 

 formed, the crude mass is rather freely soluble in alcohol, but, as the 

 purification continues, it becomes less and less so, until, when pure, it is 

 nearly insoluble in cold alcohol, as already stated. It is essentially in- 

 soluble in ligroin or in water, hot or cold. The best solvent for it is 

 glacial acetic acid. None of the strong acids dissolve it when cold ; nor 

 does even a hot solution of sodic hydrate show any perceptible action 

 with it. 



This substance is decidedly stable, as is shown by the following exper- 

 iments, which were tried in the hope of decomposing it into simpler 

 bodies, in order to throw some light on its nature: 0.5 gram of the 

 white substance were treated with sodium amalgam and water in an atmos- 

 phere of carbonic dioxide for eight days. At the end of this time the 

 substance was recovered unaltered, as shown by its melting point. The 

 filtrate was acidified, and extracted with ether, but yielded no pyrocate- 

 chine. 0.2 gram of the substance were dissolved in boiling glacial acetic 

 acid, and mixed with 5 c.c. of fuming nitric acid also diluted with glacial 

 acetic acid ; no visible reaction took place, and upon dilution with water 

 the original substance was obtained, as shown by the melting point. 

 0.2 gram were dissolved in cold chloroform, and 3 c.c. of bromine added ; 

 after standing for twenty-four hours the chloroform was evaporated, 



