1877.] 69 
{Smith, 
plates separate out. By distilling the acid with barium oxide dichlorphenol 
(Acide Chlorophénésique) was produced, with liberation of carbon di- 
oxide. 
Recently, Rogers (Inaugural Disseitation, Gottingen, 1875) published the 
results of an investigation upon a similar acid. By conducting a calculated 
amount of chlorine gas into a solution of salicylic acid in glacial acetic 
acid, and applying heat, he produced dichlorsalicylic acid, which crystal- 
lized from the above solution in small white needles. The acid was purified 
by converting it into its barium salt, and this then recrystallized. The acid 
from the purified salt fused at 224°C. It was entirely insoluble in cold, 
soluble in an excess of hot water and very soluble in hot alcohol. 
The following salts were made and analyzed : 
Dichlorsalicylate of Barium.—(C, H, Cl, OH COO), Ba+5 H,0. 
Long needles, colored slightly brown. 
Dichlorsalicylate of Potassium—C, H, Cl, OH. COOK. Showed a 
tendency to crystallize in small white needles, which lost, by exposure to the 
air, any water of crystallization they may have possessed. 
Dichlorsalicylate of Copper.—(C, H, Cl, OH C O O), Cu. Green, in- 
soluble precipitate. 
Some time ago I had occasion to make dichlorsalicylic acid, but as I ob- 
tained a compound not corresponding to any known analogous derivative, 
I submit to the Society the following results of my investigation upon the 
new dichlorine product. 
ForMATION OF DICHLORSALICYLIC ACID. 
About 40 Grm. of pure salicylic acid (fusing point 156°C) were placed in 
a flask and upon this was poured a rather large quantity of concentrated 
acetic acid. While applying a gentle heat to effect solution, a calculated 
amount of dried chlorine gas was introduced into the liquid, which grad- 
ually assumed a deep yellow color. Without waiting for the new acid to crys- 
tallize out Iadded to the yet warm solution a large quantity of water, where- 
upon the dichlorsalicylic acid fell out in large white flocks. The liquid 
was filtered off and the acid washed with cold water and then boiled with 
an excess of barium carbonate. The salt thus obtained was redissolved 
and recrystallized until it was obtained in almost colorless needles, which 
crystallize in aggregated masses from an aqueous solution. Upon several 
occasions monochlorsalicylate of barium was produced, but as this salt is 
much more soluble than the corresponding compound of the dichlor acid it 
was easily removed. 
Properties —The dichlor acid separates in large flocculent masses upon 
the addition of dilute hydrochloric acid to a solution of the barium salt. Cold 
water does not dissolve the acid, an excess of boiling water being neces- 
sary to effect its solution. After many recrystallizations the acid fused at 
2120-21490. It separates from an aqueous solution in white arborescent 
masses. In cold alcohol it is very soluble. By the slow evaporation of 
such a solution stellated masses consisting of large colorless needles were 
obtained. The fusing point of these was the same as that of the white 
