This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Zedoaria Pharm. Lond. & Edinb. Ze-doaria longa & Zedoaria rotunda C. B. Ze-doary: the root of an Indian plant, (Amomum scapo nudo spica laxa truncata, Berg, Mat, Med,) brought over in oblong pieces, about the thick-ness of the little finger and two or three inches in length; or in roundish ones † about an inch in diameter; of an ash-colour on the outside, and white within. The long sort is said by some to be the strongest, but the difference, if any, is very inconsiderable, and hence the college allows both to be used indiscriminately.
This root has an agreeable smell, and a bitterish aromatic taste. It impregnates water with its smell, a slight bitterness, a considerable warmth and pungency, and a yellowish brown colour: the reddish-yellow spirituous tincture is in taste stronger, and in smell weaker, than the watery. In distillation with water, it yields a thick ponderous essential oil, smelling strongly of the zedoary, in taste very hot and pungent: the decoction, thus deprived of the aromatic matter, and concentrated by infpiffation, proves weakly and disagreeably bitter and subacrid. A part of its odorous matter rises also in the infpiffation of the spirituous tincture: the remaining extract is a very warm, not fiery, moderately bitter aromatic, in flavour more grateful than the zedoary in substance.
† Zerumbeth Ph. Paris.
Zedoary root is a very useful warm stomachic, It was employed by some as a succedaneum to gentian root; at a time when a poisonous article, mixed with the gentian brought from abroad, rendered its use hazardous; but from the above analysis it appears to be not entirely similar to that simple bitter; its warm aromatic part being the prevailing principle, in virtue of which, its spirituous extract (the most elegant preparation of it) is made an ingredient in the cordial consection of the London pharmacopoeia.