This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Quassia Pharm. Lond. & Edinb. Lignum Quaffiae Amaenit. Acad. vol. vi. Bois de Coiffi Fermin Surinam. Quassy root: the woody root of a tree growing in Surinam, called by Linnaeus, Quaffia amara, of the class and order decandria monogynia in his system. This root is as thick as a man's arm. Its wood is whitish, hard, solid, and tough, becoming yellowish on exposure to the air. It is covered by a thin grey, fissured, and brittle bark.
(a) Dr. Slare, Philosophical transactions, numb. 213.
Quassi root has no sensible odour. Its taste is that of a pure bitter, more intense and durable than that of almost any other known substance. Its watery infusions and decoctions, and its spirituous tinctures, are all almost equally bitter, of a pale yellowish hue, which is not blackened by the addition of martial vitriol. The watery extract is from a sixth to a ninth of the weight of the wood; the spirituous about a twenty-fourth. The bark of the root is reckoned in Surinam more powerful than the wood. The flowers alio are a strong bitter.
The medical use of the quassi has been a con-siderable time known in Surinam. The flowers were long ago employed by the natives as an excellent stomachic. The root was a secret remedy used by a negro, named Quaffi, in the fatal fevers of that country, from whom it was purchased by Dan. Rolander, a Swede, who returned from thence in 1756. Some speci-mens of the wood and of the fructification were, in 1761, presented by M. Dahlberg to the celebrated Linnaeus-; who drew up a botanical description of the plant, with an account of its virtues, and published it in the sixth vol. of the Amaeni. Acad, A confirmation of its medical powers appeared in a letter from Mr. Farley, a practitioner in Antigua, printed in the Phil. Transact. vol. Iviii. He found it remarkably efficacious in suppressing vomitings, flopping a tendency to putrefaction, and removing fevers. It seemed capable of producing all the good effects of Peruvian bark, without heating. Some further experiments on the quassi are contained in a late medical thesis by Dr. Ebeling. He confirms the general account of its virtues, with this additional circumstance, that though its general antiseptic powers were inferiour to those of Peruvian bark, yet it preserved bile a longer time from putrefaction. In this circumftance it agrees with another pure bitter, the columbo root.
From these relations, the quassi appears to be a valuable addition to our tonic remedies, and has therefore obtained a place in the last Edinburgh and other pharmacopoeias. It may be used either in infusion, or extract: the latter, made into pills, on account of the intense bitter-ness of the drug, is preferable for delicate stomachs.