TESTS OF THE PURITY OF BALSAM OF COPAIBA. 187 
truum, causes the separation of a little resin and oil, and a 
ittle extractive; and it is requisite that the mixture should 
stand, with occasional agitation, for three or four hours be- 
fore being filtered, after which it should measure a pint. 
When thus prepared, fluid extract of valerian is a dark 
brown transparent liquid, with the taste and odour of 
valerian strongly developed, and a decided acid reaction. 
One fluid ounce represents half a troy ounce of the root, 
which is the same proportion as in the published formula. 
ART. LV. — NOTE ON THE TESTS OF THE PURITY OF BALSAM. 
OF COPAIBA. By Mr. Redwood, Professor of Pharmacy to the 
Pharmaceutical Society. 
Some observations which have recently been made at a 
meeting of this Society, with reference to the adulteration 
of copaiba, especially that used for filling the cheap capsules, 
have induced many of our members to examine their co- 
paiba capsules with the view of determining whether or not 
the contents were genuine. In these examinations the or- 
dinary tests, mentioned in works on Materia Medica, have 
of course been resorted to, and in some instances results 
have been obtained indicating, according to the tests used, 
that the copaiba was not genuine. 1 have been applied to 
for my opinion in two or three cases of this kind, and after 
examining several samples of copaiba obtained from differ- 
ent sources, and trying the action of all the tests upon them, 
I have come to the conclusion that no satisfactory method, 
applicable in all cases, for determining the purity or impu- 
rity of this oleo-resinous substance by the application of a 
