ORCIN. 307 



Diacetylresorcin, C 6 H 4 (O.C 2 H 3 0) 2 , is ^ produced by 

 the action of acetyl chloride on resorcin. Colorless 

 liquid, insoluble in water. 



Trinitroresorcin (Oxypicric acid, Styphnic acid), 

 C 6 H(K&quot;0 2 ) 3 (OII) 2 . Is produced by the action of nitric 

 acid on morintannic acid, a number of gum-resins, 

 (galbanum, sagapenum, ammonia-gum), and a number 

 of vegetable extracts (of sapon-wood, Brazil-wood, etc.) 

 Is obtained from orcin by the action of nitric acid at 

 a low temperature. Pale yellow prisms or lamellae; 

 sublimable when carefully heated; difficultly soluble 

 in water; fusing point, 175.5. Strong, bibasic acid ; 

 yields salts that crystallize well and explode violently 

 when heated. 



Thiores orcin, C 6 H 4 (SH) 2 . Is produced when para- 

 disulphobenzolchloride (p. 270) is heated gently with 

 tin and hydrochloric acid. Crystalline mass, easily 

 volatile with water- vapor; fusing point, 27; boiling 

 point, 243. 



TJmbelliferone, C 6 H 4 2 (or C 9 H 6 3 ). Isomeric with 

 quinone. Is produced in the destructive distillation of 

 a number of resins, chiefly of umbelliferous plants, as 

 galbanum. Colorless, rhombic prisms, sparingly solu 

 ble in cold water, easily soluble in alcohol, and ether. 

 The aqueous solution exhibits, by reflected light, 

 a splendid blue color. Melts at 240 ; sublimes with 

 out decomposition. Yields resorcin when fused with 

 caustic potassa. 



2. Orcin. 



It appears to be ready formed in a number of lichens. 

 Is formed from orsellic acid and other acids (lecanoric, 

 evernic, erythric acids) that occur in various lichens, 

 and bear a close relation to orsellic acid, either by 

 heating them alone, or by boiling them with strong 

 bases. It is further produced when aloes is melted 



