BALSAxMUM COPAIBA. 231 



dextrogyre,and also several samples imported in 1877 fromMaturin (near 

 Aragua, Venezuela), and Maracaibo into Hamburg, whereas we found Para 

 balsam to be levogyre.^ 



The Para and Maranham balsams are regarded in wholesale trade as 

 distinct sorts, and experienced druggists are able to distinguish them 

 apart by odour and appearance, and especially by the greater consistence 

 of the Maranham dmg. Maracaibo balsam is reckoned as another 

 variety, but is now rarely seen in the English market. West Indian 

 copaiba is usually said to be of inferior quality, but except that it is 

 generally opalescent, we know not on what precise grounds. 



Chemical Composition — The balsam is a solution of resin in 

 volatile oil; the latter constitutes about 40 to 60 per cent, of the balsam," 

 according to the age of the latter and its botanical origin. The oil 

 has the composition C^^H^ ; its boiling point is 245° C. or even higher. 

 It smells and tastes like the balsam, and dissolves in from 8 to 30 parts 

 of alcohol 0830 sp. gr. The oil exhibits several modifications differing 

 in optical as well as in other physical properties, but numerous samples 

 of the drug, either dextrogyre or levogyre, invariably afforded us essential 

 oils deviating to the left; their sp. gr. varies fi'om about 0*88 to 091. 



After the oil of copaiba has been removed by distillation, there remains 

 a brittle amorphous resin of an acid character soluble both in benzol 

 and amylic alcohol, and yielding only amorphous salts. Sometimes 

 copaiba contains a small amount of crystallizable resin-acid, as first 

 pointed out in 1829 by Schweitzer. By exposing a mixture of 9 parts 

 of copaiba and two parts of aqueous ammonia (sp. gr. 0'95) to a tempera- 

 ture of — 10° C, Schweitzer obtained crystals of the acid resin termed 

 Copaivic Acid. They were analysed in 1834 by H. Rose, and exactly 

 measured and figured by G. Rose. Hess (1839) showed that Rose's and 

 his own analyses assign to copaivic acid the formula C^ff-Ol It agrees 

 with Maly's abietic acid from colophony in composition, but not in any 

 other way. Copaivic acid is readily soluble in alcohol, and especially in 

 warmed copaiba itself ; much less in ether. We have before us crystals, 

 no doubt of copaivic acid, which have been spontaneously deposited in 

 an authentic specimen of the oleo-resin of Copaifera offi^cinalis from 

 Trinidad, which we have kept for many years. The crystals may be 

 easily dissolved by warming the balsam ; on cooling the liquid, they 

 again make their appearance after the lapse of some weeks. After 

 recrystallization from alcohol they fuse at 116-117 C°., forming an 

 amorphous transparent mass which quickly crystallizes if touched with 

 alcohol. 



An analogous substance, Oxycopaivic Acid, C'^H'^O^, was examined in 

 1841 by H. von Fehling, who met with it as a deposit in Para Copaiba. 

 And lastly Strauss (1865) extracted Metacopaivic Acid, C--H340*, from 

 the balsam imported from Maracaibo. He boiled the latter with soda- 

 lye, which separated the oil ; the heavier adjacent liquid was then 

 mixed with chloride of ammonium, which threw down the salts of the 

 amorphous resin-acid, leaving in solution those of the metacopaivic acid. 

 The latter acid was separated by hydrochloric acid and recrystallization 

 from alcohol. We succeeded in obtaining metacopaivic acid by washing 



^ Fliickiger in Wiggers and Husemann's - Or 18 to 65 per cent., sp. gr. 0915 to 



./aAresftencAi for 1867. 162, and for 1868. 140. 0-995, according to Siebold (1877). 



