Year-Book of Pharmacy (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: PART II. MATERIA MEDICA AND PHARMACY. Ehubarb and its Adulterants. L. E. Sayre. (Amer. Journ. Pharm., 1898, 129-135.) The author has made a careful study of U.S.P. official rhubarb (Rheum officinale and R. palmafum), and compared it with R. rJmponticnm and Rumex hymenoaepalut. Thin sections of the first showed that the lighter-coloured ground tissue was composed of thin-walled parenchyma, while the dark and contorted areas were principally fibre-vascular tissue, which was sirnetimes in regularly arranged spots having a radiate structure. In R. i-liaponticum the parenchyma was also thin- walled, but there was a distinct and plainly-marked radiate structure, unbroken by such an arrangement of vascular tissue its described abive. Starch grains, calcium oxalate crystals, and massed acicular crystals of chrysophauic acid were prominent in both specimens. Sections of canaigre root were totally different from those of rhubarb. Thin-walled parenchyma occupied the whole extent of the sections, being marked off into two areas by a concentric cambium line, and the central area occupied about two- thirds the diameter of the sections. About a dozen groups of vessels radiated from the centre to the cambium. When powdered, the two rhubarbs could not be distinguished, and the starch of canaigre was the only diagnostic feature that could be relied upon to differentiate that, root in the state of powder. The grains are described as being long and slender in form, and exhibiting a long, branching hilum, which extends throughout the major portion of the long diameter. But while official rhubarb powder turns a dark, brick-red colour with ammonium hydrate, the powder of R. rkaponticum exhibits a distinctly salmon-red shade, whilst canaigre gives a brownish colour. This test, however, also fails ...