Notes on pharmacognosy

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 Excerpt: ...angles to the medullary rays, or parallel with the corky layer, giving the appearance as in the diagrammatic illustration; the medullary rays are not well marked, although traces of them can be seen, and in some instances even quite plainly, but when the medullary rays make quite distinct radial lines the bark would belong in the next group; thus the stem bark of Juglans, which generally shows only the tangential lines distinctly, in some pieces shows quadratically striated, although the checkered appearance is very plain in the root bark. Nearly all barks show their characteristic markings when a piece is freshly broken across, then cut smooth with a sharp knife and examined with a Coddington lens, but some barks require soaking before cutting, and sometimes even moistening with dilute solution of potassa to increase the contrast in color between the medullary and bast rays. It is advisable, also, to cut as thin a section as possible from the end of a piece of bark previously soaked in water or diluted alcohol, place this section in a drop of liquor potassa on a slide and cover with a cover-glass, and examine, while clearing, with a lens of rather low power; the markings often appear plainer while clearing, than when the section has been completely cleared. Making such a slide need not take more than one or two minutes of time. Nearly flat massive bark, with thick corky layer deeply fissured; gray or grayish-brown on outer and reddish on inner surfaces Aspidosperma. Thin flexible bands or quilled pieces; brownish on outer and whitish on inner sur-faces; separable into thin layers Oossypil Radlcls cortex. Long, thin flexible bands, rolled into bundles, yellow-ish on outer and silky-white on inner surfaces Mt-zerenm. Quilled pieces or troughs; ash-gray outer...