This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Tacamahaca. Arefin; obtained from a tree, resembling the poplar, (Populus balsa-mifera Linn.) bearing, at the extremities of the branches, mall roundish fruits including a seed like a peach-kernel; a native of the temperate parts of the continent of America, and in a sheltered situation enduring the winters of our own country.
Two sorts of this resin are sometimes to be met with. The best, called, from its being collected in a kind of gourd-shells, tacamahaca in shells, is somewhat unctuous and soft, of a pale yellowish or greenish colour, a bitterish aromatic taste, and a fragrant delightful smell approaching to that of lavender and ambergris. This sort is very rare. That commonly found in the shops is in semitransparent grains or glebes, of a whitish, yellowish, brownish, or greenish colour, and of a less grateful smell than the foregoing. The first is said to exude from the fruit of the tree, the other from inci-sions made in the trunk. The tree, as raised among us, affords in its young buds, or the rudiments of the leaves, a resinous juice of the same kind of fragrance (a).
(a) See article Populus.
Tacamahaca is used chiefly as an ingredient in warm nervine plasters; though the fragrance and taste of the finer sort points out its being applicable to other purposes, as an internal balsamic corroborant. Both kinds dissolve in rectified spirit into a gold-coloured liquor, only a small quantity of impurities being left: they impregnate water also considerably with their smell and taste, but give out very little of their substance to this menstruum.