BALSAM PERU. 251 
withdrawn from the boiler they are submitted to strong pressure, 
and the balsam which is extracted from them returned to the 
boiler. When the decoction is cold the water is decanted and the 
balsam poured into gourds ready for transport to the coast. The 
next year the Indians again visit the same trees and perform the 
same operation on the portion of bark which was left untouched 
the year before. 
The tree begins to be productive in its fifth year, and continues 
to yield for 30 years or more*. In 1861 the tree was introduced 
in Ceylon, with complete success. 
As the tree is said to be capable of reproducing its bark in two 
years, a harvest can be gathered for many years, provided that 
from time to time it be allowed a few years of rest. Sometimes 
the naked wood is covered up with clay as a protection. 
When Balsam Peru arrives at Acajutla and La Libertad, the 
ports on the “ Balsam Coast” from which it is chiefly shipped, 
it is in a crude state, usually of a grey-green to a dirty yellow 
colour, and requires to be purified before it is fit for exportation. 
A first clarification is effected by allowing the crude balsam to 
stand in a large iron vessel capable of holding six or seven 
hundred pounds during a week or a fortnight, by which time the 
heavier impurities sink to the bottom and the lighter ones float as 
a scum on the surface. The clear balsam, which has already 
attained its characteristic black-brown colour, is then drawn off 
through a tap fixed about four inches from the bottom of the 
vessel and run into a tinned iron boiler set over an open fire and 
boiled moderately for two or three hours. All scum is removed 
as it makes its appearance, and the boiling is continued as long as 
any continues to be formed. It can easily be understood that the 
physical properties of the balsam will differ according to the 
temperature to which it is submitted during this boiling, and it is 
alleged that the lower specific gravity observed in balsam of Peru 
during recent years is attributable to a modification it undergoes 
in this operation, and is quite consistent with the genuineness of 
a given sample { ; this may be so, but it would seem preferable to 
refine the balsam in Europe by a more careful process. 
The sp. gr. of pure balsam Peru at 15° C. varies from 1:140 to 
* Am. Journ. Pharm. xxxii. p. 303. 
t Gehe & Co.’s Market Reports, 1884. 
