A CONTRIBUTION TO THE HISTORY OF BALSAM OF PERU. 
205 
surface of the trunk, until they have imbibed as much of the resin as they 
will hold, when they are removed and boiled in water. This causes the sepa¬ 
ration of the resin, which, after some mechanical purification, constitutes the 
liquid known in Europe as Balsam of Bern. The chemistry also of the com¬ 
mercial balsam has been tolerably well ascertained, and with Fremy, we may 
regard it as a mixture of volatile oil, crystalline cinnamic acid, and resin. 
But with regard to the state in w hich the balsam exists in the tree, and the 
extent to which it may be altered by the manipulations of extraction and ex¬ 
posure, we know nothing. 
It w'as in the hope of supplying some of these deficiencies in the pharmaco¬ 
logy of Balsam of Peru that I recently examined a small branch of Myroxy- 
lon Pereirce, sent to me by Mr. Hanbury, and a portion of a section of the 
trunk of the tree from the Museum of the Pharmaceutical Society. The 
branch was so young that it contained no heart-w T ood, but the trunk, which 
had apparently been about twelve inches in diameter, had dark mahogany- 
coloured heart-wood, nine inches thick. The bark of the trunk was about 
a quarter of an inch thick. 
The bark, white-wood, and heart-w r ood of the specimens were each finely 
rasped and examined separately. In imitation of the method of extraction 
actually adopted, each was subjected to the action of heat very gradually 
raised, but no exudation was obtained in either case, nor even any odour 
emitted at all resembling that of Balsam of Peru. On continuing the appli¬ 
cation of heat destructive distillation was at last effected, but the product 
was onl} r the usual acid water and tar obtained on heating any kind of 
wood. 
The characteristic constituents of Balsam of Peru being soluble in ether, 
the several portions of the specimens were each boiled with that liquid 
for some time, and after filtration the ether removed by evaporation. By this 
treatment the bark of the large specimen yielded a soft resin of light-brown 
colour, the white-wood a similar but less soft residue of lighter colour, and 
the heart-wood a reddish-brown soft resin, on which, after a day or two, a 
light-brown oil floated. The odour of these three residues was alike, but 
strongest in that from the heart-wood ; it did not resemble that of Balsam of 
Peru. On heating these resinous products with water, an odorous steam was 
evolved, least odorous from the white-wood, most so from the heart-wood, 
but in each case this odour was also unlike that obtained when Balsam of 
Peru is similarly treated. Nor had the water an acid reaction on blue 
litmus paper, as water warmed in contact with Balsam of Peru invariably 
has, a reaction due to the presence of cinnamic acid. The bark and wood of 
the small branch yielded small quantities of similar products. The volatile 
oil of Balsam of Peru being very well characterized by its odour, its absence 
from the resinous products, obtained as above, may be fairly inferred. The 
absence of cinnamic acid ia the products is also indicated by these experi¬ 
ments, but was confirmed by boiling the several resins with solution of carbo¬ 
nate of soda, neutralizing the resulting liquid by hydrochloric acid and filter¬ 
ing while hot; on cooling, no crystalline plates of cinnamic acid separated 
out as would have occurred in the case of Balsams of Peru or tolu. Finally, 
to detect the third characteristic constituent of Balsam of Peru, the resin, 
each of the products was moistened with concentrated sulphuric acid, which 
gives a persistent dark-purple colour with Peru and tolu balsams, but in 
neither case was any such coloration produced. 
From these experiments it is obvious that the Balsam of Peru tree 
contains an oily resin, which is either perfectly distinct from the exudation 
known as Balsam of Peru, or else is a product of the alteration of the balsam ; 
a production which no trace of the constituents of Balsam of Peru remains. 
