This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Caranna: a concrete resinous juice; exuding from a large tree, of which we have no particular account; brought from New Spain, and some other parts of America, in little masses, rolled up in leaves of flags; externally of a dark brownish colour, internally brown with a casl of red, variegated with irregular white streaks; somewhat loft and tenacious as it first comes over, but in length of time growing dry and friable.
Unguentum epispasticuin ex infuso cantharidura Ph. Ed.
Unguentum cantharidis Ph. Lond.
This juice has an agreeable smell, especially when heated, and a bitterish and slightly pungent taste. Water dissolves about one fourth of it, and rectified spirit above three fourths: what is left by the one menstruum dissolves in the other, a small quantity of impurities excepted: both solutions are of a bright yellow colour, the spirituous deepest.
The watery tincture smells agreeably of the caranna, and is in taste bitterish and somewhat warm. In distillation with water, there separates from the aqueous fluid a considerable quantity of an orange-coloured essential oil, of a very fragrant smell, and a moderately pungent taste: the remaining decoction, infpiffated, leaves an extract of an ungrateful, though weak, bitter-ishness.
The spirituous tincture is both in smell and taste stronger and more agreeable than the watery. Infpiffated, it yields a very tenacious adhesive resin, with an oily matter which separates and floats on the surface: the resin has very little smell, and scarcely makes any im-pression on the organs of taste: the oil is considerably aromatic, and moderately bitter, in which last respect it differs from the purer oil obtained by distillation with water.
Caranna has been chiefly employed as an ingredient in vulnerary balsams, corroborant and discutient plasters, and other external applications. It has very seldom been given internally, and is now, in this country, almost wholly in difuse.