686 PROFESSOR T. ANDERSON ON THE 
removal of two equivalents of hydrogen, and the addition of four of oxygen. It 
belongs to a class of substances of which there are very few examples, and for 
which we have no satisfactory system of nomenclature. I have given it the pro- 
visional name of Oxanthracene, as recalling its mode of formation. 
Binitroxanthracene—When anthracene was boiled for a long time with nitric 
acid, with occasional additions of fuming acid, red fumes continued to be given off, 
and a resinous substance was gradually produced. The substance was washed 
with water and dried. It appeared to be a mixture of some of the last substance 
with a new compound, which was obtained by heating it with a small quantity 
of alcohol, and cooling. It is deposited as a red powder which shows but little 
disposition to crystallise. A combustion gave— 
4-907 grains of nitro-binitroxanthracene gave 
10-558 grains of carbonic acid, and 
1:210 grains of water. 
Experiment. 

Carbon, ’ 4 : 58:66 56°37 oe 168 
Hydrogen, . , i 2°73 2:02 H, 6 
Nitrogen, . : : sia 9:40 N, 92 
Oxygen, : : : cee 32°21 OF 32 
100-00 298 
This isa distant approximation to the formula C,; H; (NO,), O,, and it is probable 
that this is its constitution; but as its properties showed nothing of interest, I 
did not prosecute its purification further. 
Anthracenic Acid—When the nitric acid and the washings of the preceding 
compound are carefully evaporated in the water-bath, a yellow crystalline acid, 
to which I give this name, is obtained. It is very soluble in water, and gives 
crystallisable salts with ammonia and potash, and precipitates the salts of lead 
and baryta. I reserve the further investigation of this substance for a future 
communication. 
Action of Bromine on Anthracene. 
Bromine acts somewhat slowly upon anthracene in the cold. When mixed 
together, they concrete into a resinous-looking mass, the interior of which is not 
completely saturated with bromine, and it was found most convenient to expose 
the anthracene in a thin layer under a bell glass, along with a capsule containing 
bromine. After a day or two’s exposure, the anthracene has agglutinated into a 
mass which must be removed, reduced to powder, and reintroduced; and this is 
repeated as long as bromine is absorbed. This mass, which has a brown colour, 
dissolves in benzole, and on cooling deposits hexabrom-anthracene in crystals, 
which are purified by solution in benzole or ether. It is thus obtained in small 
hard white granular crystals, apparently rhomboidal. They are sparingly soluble 
in alcohol, ether, and benzole. Nitric acid acts upon them but slightly. When 

