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sojohanic acid, which is one of the colouring matters of offici- 

 nal rhubarb ; several alimentary principles, as gliadine, starch, 

 sugar, gum; several medicinal substances, as resin, bitter 

 matter, gallic acid, and a peculiar ethereal oil ; besides wax, 

 stearine, chlorophyll, and some salts, as carbonate of lime. 

 In young plants we have met with bundles of acicular crys- 

 tals, resembling the rhaphidian bundles of many phanero- 

 gamic plants, which consist generally of phosphate or car- 

 bonate of lime. Its yellow colouring matter has been abun- 

 dantly employed by the peasantry in various countries of 

 northern Europe for dyeing woollen goods. The late Dr. 

 Johnston of Berwick, in his interesting ' Botany of the East- 

 ern Borders/ mentions that about Wooler children collect 

 it at Easter, for dyeing their Pasque eggs. So lately as 

 1815 it was commended as a substitute for quinine and 

 cinchona bark in intermittent fevers ; and it has in many 

 other diseases been employed as an astringent and febrifuge.* 

 This Lichen occurs sparingly in the Arctic regions, and is 

 found in South America and other foreign countries. Under 

 the name of " Common yellow Wall-moss/' it is to be met 



* Sander : Die Wandflechte em Arzneymittel welches die Peruv. Kinde 

 nicht nur entbehrlich macht, sondern die auch an gleichart Heilkniiften iiber- 

 trifft. 4to, Sonderhausen, 1815. 



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