_Balsam of Peru_ is extracted from the _myroxylon peruiferum_, a tree
which grows in Peru, Mexico, &c.; sometimes by incision, and sometimes
by evaporating the decoction of the bark and branches of the tree. The
former kind is very rare, and is imported in the husk of the cocoa nut,
whence it is called balsam _en coque_. It is brown, transparent only in
thin layers, of the consistence of thick turpentine; an agreeable smell,
an acrid and bitter taste; formed of two matters, the one liquid, the
other granular, and somewhat crystalline. In 100 parts, it contains 12
of benzoic acid, 88 of resin, with traces of a volatile oil.
The second sort, the _black_ balsam of Peru, is much more common than
the preceding, translucent, of the consistence of well-boiled syrup,
very deep red-brown colour, an almost intolerably acrid and bitter
taste, and a stronger smell than the other balsam. Stoltze regards it as
formed of 69 parts of a peculiar oil, 20·7 of a resin, little soluble in
alcohol, of 6·4 of benzoic acid, of 0·6 of extractive matter, and 0·9 of
water.
From its high price, balsam of Peru is often adulterated with copaiba,
oil of turpentine, and olive oil. One thousand parts of good balsam,
should, by its benzoic acid, saturate 75 parts of crystallised carbonate
of soda. It is employed as a perfume for pomatums, tinctures, lozenges,
sealing-wax, and for chocolate and _liqueurs_, instead of vanilla, when
this happens to be very dear.
_Liquid amber_, _Storax or Styrax_, flows from the leaves and trunk of
the _liquid amber styraciflua_, a tree which grows in Virginia,
Louisiana, and Mexico. It is brownish ash-grey, of the consistence of
turpentine, dries up readily, smells agreeably, like benzoin, has a
bitterish, sharp, burning taste; is soluble in 4 parts of alcohol, and
contains only 1·4 per cent. of benzoic acid.
Balsam of Tolu flows from the trunk of the _myroxylon toluiferum_, a
tree which grows in South America; it is, when fresh, of the consistence
of turpentine, is brownish-red, dries into a yellowish or reddish
brittle resinous mass, of a smell like benzoin; is soluble in alcohol
and ether; affords, with water, benzoic acid.
_Chinese varnish_ flows from the bark of the _Augia sinensis_; it is a
greenish yellow turpentine-like substance, smells aromatic, tastes
strong and rather astringent, in thin layers dries soon into a smooth
shining lac, and consists of resin, ethereous oil, and benzoic acid. It
is soluble in alcohol and ether; and has been employed, immemorially, in
China, for lacquering and varnishing surfaces, either alone or coloured.