This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Polypodium vulgare C.B. & Linn Polypody: a plant with long leaves issuing from the root, divided on both sides, down to the rib, into a number of oblong segments, broadest at the base: it has no stalk, or manifest flower: the seeds are a fine dust, lying on the backs of the leaves, in roundish specks, which are disposed in rows parallel to the rib: the roots are long and slender, of a reddish brown colour on the outside, greenish within, full of small tubercles, which are resembled to the feet of an infect, whence the name of the plant. It grows in the clefts of old walls, rocks, and decayed trees: that produced on the oak has been generally accounted the best, though not sensi-bly different from the others. It is found green at all seasons of the year.
The leaves of polypody have a weak ungrateful smell, and a nauseous sweet taste, leaving a kind of roughness and slight acrimony in the mouth. They give out their smell and taste, together with a yellow colour, both to water and rectified spirit: the spirituous tincture is sweeter than the watery, but in infpiffation its sweetness is in great part destroyed or covered by the other matter; the spirituous extract, as Cartheufer observes, being to the taste only subastringent and fubacrid, with very little sweetness, while the watery extract seems to retain the full sweetness of the polypody. The root is supposed to be aperient, resolvent, and expectorant: it was formerly ranked among the purgatives, but operates so weakly, a decoction of an ounce or two scarcely moving the belly, that it has long been expunged from that class: the present practice pays very little regard to it in any intention.