Selections. 



[NO. 4, NEW SERIES, 



copaiba of commerce. This hard rosin (oopaivic add) being moat pro- 



balily the active principle of balsam of copaiba, 1 am induced to think its 

 quantity ami purity in the one 1 have examined is indicative of its supe- 

 rior value as a medicament. The dark colour of the balsam may perhaps 

 limit its employment, but the large quantity of copaivic acid it contains 

 renders it valuable, as the latter may be made available by heating the 

 filtered balsam to the bofllllg point with a small quantity of caustic potash 

 or soda lye, of sp. gr< 1.3 1, and separating the resinate of potash or soda 

 from the essential oil. The alkaline resinate may then be dissolved in 

 water, giving a colourless solution (similar to Frank's specific), or the 

 balsam may be treated with magnesia to form the ordinary copaiba pill. 

 I have in conclusion remarked : — 



1st, That the essential oil obtained by the distillation of balsam of co- 

 paiba has, like several other hydrocarbons, the property of dissolving 

 indigo. 



L'ndly, The new variety of balsam above described presents the curious 

 property of becoming gelatinous (so much so that the tube may safely be 

 inverted), if heated to 230° Fah., even if a sealed tube be employed. 

 This character being dissimilar to the one given in the same circumstances 

 with such other balsams as I had at my disposal, I am induced to attribute 

 it to the large amount of " hard resin" it contains. 



Srdly, Balsams of copaiba in general give, on distillation with two per 

 cent, sulphuric acid, a beautiful blue volatile oil. Chlorine, hypochlorite 

 of lime, and bichromate of potash, give a similar character with the bal- 

 sam, which appears to me to be due to the oxidation of the hard resin, 

 as I have been unable to obtain but a small proportion of the blue-colour- 

 ed oil when I employed a balsam containing " soft resin," comparatively 

 to when I made use of the one above described, which, as I have already 

 remarked, contains only " hard resin." A further support of this view 

 is, that pure essence of copaiba assumes no blue colouration when distilled 

 as above. 



4thly, That cold sulphuric acid produces a purple colouration with bal- 

 sam of copaiba, similar to that obtained by its action on cod-liver oil. 

 Such being the case, it is probable that a small quantity of it, mixed with 

 olive or some other oil, may be sold by unprincipled persons as genuine 

 cod-liver oil. — Pharmaceutical Journal, XIV. 65. 



In 1856 the same substance was again noticed by Mr. Daniel 

 Hanbtjry under its ordinary name of Wood Oil, a substitute for 

 Copaiba. 



