472 COPAIBA-EESIN. 



turbid ness remains, crystals separate in a few hours, 

 consistin of 





Sylvic acid (Abietie acid), C 20 H 30 2 . Crystallizes 

 from alcohol in pointed, oval laminse. Insoluble in 

 water, soluble in alcohol, ether, benzene, and chloro- 

 form ; fuses at 120 ; monobasic acid. The alkaline 

 salts are yellowish, brittle masses ; easily soluble in 

 water and alcohol. The magnesium, calcium, and 

 barium salts are white, flocculent precipitates; diffi- 

 cultly soluble in water, more easily in alcohol. 



An acid, isomeric with sylvic acid, 



Pimaric acid, C 20 H 30 2 , forms the principal ingre- 

 dient of the resin from Pinus maritima (Galipot). It 

 is deposited from its alcoholic solution in hard crusts. 

 Fusing point, 149; perfectly insoluble in water, diffi- 

 cultly soluble in cold alcohol and ether, easily in the hot 

 liquids. Monobasic acid. Yields crystallizable salts. 

 Boils above 320, and, when distilled, is converted into 

 sylvic acid. 



2. Copaiba-resin. From species of Copaifem, in- 

 digenous in Brazil, is obtained, by means of incisions, 

 balsam of copaiba, a bright-yellow, clear, thick liquid, 

 resembling oil of turpentine, which consists of resin 

 and a turpene. 



The resin, freed of oil by distillation with water, is 

 an acid, copaivic acid, C 20 II 30 2 (?), isomeric with sylvic 

 and pimaric acids; it can be obtained in exceedingly 

 regular, clear, colorless crystals by dissolving the resin 

 in alcohol and allowing it to evaporate spontaneously; 

 or by shaking the balsam for a long time with a con- 

 centrated solution of ammonium carbonate, and then 

 acidifying the lower aqueous solution of the ammo- 

 nium salt with acetic acid. On the other hand, the 

 different varieties of balsam appear to contain some- 

 what different or altered resins, and hence the resin 

 cannot always be obtained in a crystalline form. In 

 Maricaibo balsam there is contained an acid, mcta- 

 copaivic acid, C 22 H 34 4 , very similar to copaivic acid ; it 

 crystallizes in laminae, and fuses at 205-206. 



