183 



(Jll6rcit=:Ci2 Hi2 Oio. Peculiar kind of sugar of the fruits of 

 Quercus racemosa and sessiliflora. Throw down, hot, with lime 

 the tannic acid from an aqueous extract of acorns, filter, destroy 

 any fermentable sugar by fermentation with yeast, evaporate to a 

 syrup-consistence, wash the ciystals which will form with cold 

 alcohol, and recrystallise in water or in weak alcohol. — Forms 

 hard, permanent, klinorhombic crystals of sweet taste, unaltered 

 at 215°, fusing at 235°, partly sublimating, soluble in 8 to 10 parts 

 cold water, also in hot weak alcohol, does not ferment with yeast, 

 yields with nitric acid, on heating, oxalic but no mucic acid, dis- 

 solves in concentrated sulphuric acid colourless, is not altered on 

 boiling with alkalies,- acetate of copper, or with alkaline tartarate 

 of copper. 



(^liercitl'ill = C70 H36 O40. Yellow glucosid of the bark of 

 Quercus tinctoria. Formerly confounded with rutin. Boil the 

 bark with water, leave the decoction to stand cold, collect the 

 Quercitrin which has formed, triturate it with a little alcohol of 

 35° B. to a pulpy state, heat over the water-bath, collect on 

 calico, remove impurities by pressing, dissolve the remnant in a 

 larger quantity of boiling alcohol, filter hot, mix with boiling 

 water until it becomes turbid, and allow to stand cold. Collect 

 the ciystals of Quei'citrin, and purify by again submitting them to 

 the same treatment. — Foi-ms sulphur or chrome-yellow, microscopic, 

 rhombic, tabular crystals, inodorous and tasteless, slightly bitter 

 when dissolved; fuses after desiccation at 168°; yields in higher 

 temperatures crystals of quercetin under decomposition ; dissolves 

 in 2485 parts cold and in 143 parts boiling water, the straw-yellow 

 solution becoming colourless by acids; dissolves in 23 parts cold 

 and in 4 parts boiling alcohol, little in ether, most readily in 

 diluted alkalies, these sohitions turning dark at the air; breaks 

 lip on boiling with diluted acids into sugar and quercetin. 



Quilia-l{ed=Ci2 H7 O7. In the bark of the genus Cinchona, 

 produced by the Oxydation of tannic acid. Draw out with diluted 

 liquor of ammonia, precipitate the red-brown solution with hydro- 

 chloric acid, wash and heat the deposit (Quinovin and Quina-red) 

 with thin milk of lime, dissolving the quinovin and leaving 

 Quina-red lime undissolved, wash the latter with hot water; de- 

 compose with diluted hydrochloric acid, wash the deposit of 

 Quina-red, redissolve in ammonia, precipitate with hydrochloric 

 acid, wash the precipitate, dissolve in alcohol, filter and evaporate 

 to diyness. — Red-brown, inodorous and tasteless, not fusible, in- 

 soluble in water and in diluted acids, readily soluble in alcohol, 

 ether, alkalies with dark-red colour; the ammoniacal solution 

 after a rather long time throws down the glue on addition of water. 



(^Uillic Acid = Cu Hn On + HO. In the genuine quina- 

 barks (from Cinchona), in the Quina Maracaibo, Quina nova 



