This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
The oleo-resin obtained by cutting deeply or boring into the trunk of Copaifera Langsdorfti, and other species of Copaifera. Valley of the Amazon.
Tests. - Perfectly soluble in an equal volume of benzene. Does not become gelatinous after having been heated to 270° F.. Is not fluorescent (wood oil). After heating on paper it does not leave a greasy ring round the stain (fixed oil).
The absence of turpentine is shown by the smell of it not being given off on heating, and after distilling off the volatile oil the residue, when cool, should be hard and friable (absence of fixed oils). The essential oil distilled off from the oleo-resin, when rectified, should not begin to boil below 200° C. (392° F.). On adding 1 drop of copaiba to 19 drops of disulphide of carbon, and shaking the mixture with 1 drop of a cold mixture of equal parts of sulphuric and nitric acids, it should not acquire a purplish red or violet colour (absence of gurjun balsam).