This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
Quassiae Lignum - Quassia Wood. - The wood of Picraena excelsa. From Jamaica.
Characters. - Billets varying in size, seldom thicker than the thigh. "Wood dense, tough, yellowish white, intensely and purely bitter. Also chips of the same.
Substance resembling quassia: Sassafras, which is aromatic, and not bitter.
Composition. - The active principle of quassia is quassin, C10H12O3, a white crystalline, neutral bitter principle. Quassia contains no tannin.
Extractum Quassiae. Aqueous. 48 in 1. Dose, 3 to 5 gr.
2. Infusum Quassiae - 1 in 80 of cold water. Dose, 1 to 2 fl.oz.
Tinctura Quassiae. 1 in 27. Dose, 1 to 2 fl.dr.
Quassia is a pure or simple bitter, and possesses the various properties fully described under Calumbae Radix. It is very extensively used. The special points to be noted respecting it are: (1) that its preparations contain no tannin, and may be combined with salts of iron; (2) that it is entirely devoid of flavour, and intensely bitter, i.e. less agreeable than gentian and chiretta; and (3) that the infusion is an excellent anthelmintic enema.