184 



Sarinamensis (from Cascarilla maguifolia), in the seeds and leaves 

 of CoÖea Arabica, in species of Galium (G. Mollugo, &c.); in species 

 of Vaccinium (V. Myrtilhis, &c.), and probably in the following 

 plants, the leaves of which yield kinon (quinon) on heating with 

 sulphuric acid and peroxyd of manganese, viz.: — Cyclopia lati- 

 folia, and others; Fraxinus excelsior, and others; Hedera Helix, 

 Ilex Aquifolium, Ilex Paraguayensis, Ligustrum vulgare, and 

 other species; Quercus Ilex, Quercus Robur, and other oaks; 

 Ulmus campestris, and other species. It appears hereby that 

 Quinic acid is not confined to the genus of Cinchona, as formerly 

 stated, but that it belongs largely to the family of Rubiaceae, 

 and to many other ordei'S of j »hints widely distant in natural 

 affinities. 



Pre])aration from the quina bai'k: Evaporate the liquid ob- 

 tained in the pi-epai'ation of quinin, by }»recipitating the sulphuric 

 acid exti'act with milk of lime to the consistence of a syrup, 

 decant from the lime-sulphate, evaporate over the water-bath to 

 honey consistence, boil with alcohol several times and dissolve the 

 i-emnant in little water. The solution yields, after a few days, 

 a crystalline mass, which has to be strongly pressed, and is purified 

 by recrystallisation. From the bilberry herb: Boil the gi'een 

 herb, gathered in si)ring, with water and lime, evaporate the 

 decoction, and tlu-ow down the Quinate of lime with alcohol. 

 Dissolve the glutinous pi-ecipitate in water mixed with some 

 acetic acid, free fi-om dyeing matters by means of acetate of lead 

 and evaporate the filtrate, after i-emoving the lead, to the density 

 of a syrup, when Quinate of lime will form in crystals after a few 

 days. The Quinate of lime, obtained by any of these methods, is 

 purified by repeatedly recrystallising or by precipitating with alcohol 

 of 36° B., and by dissolving in alcohol of 18° B. In order to isolate 

 the acid, the Quinate of lime is dissolved in water and decomjjosed 

 by oxalic acid. The filtei'ed liquid is freed from the excess of 

 oxalic acid by means of acetate of lead, the excess of the latter by 

 sulphuret of hydrogen, and the filtered liquid is then allowed 

 to crystallise. 



Forms large, hard, tabular, klino-rhombic crystals with a 

 characteristic hemitropism on the right side of the horizontal axis ; 

 has a pure and strong acid taste; loses at 100° nothing of its 

 weight, fuses at 161°, and decomposes by more heat; dissolves in 

 2-^ parts cold and in less hot water, more readily in aqueous 

 than in strong alcohol, scarcely in ether. By heating with super- 

 oxyd of manganese and sul])huric acid an orange coloured, needle- 

 shaped sublimate of Quinon (C12 H4 O4) is obtained. The 

 Quinates are mostly ci-ystallisable and of neutral reaction; with 

 the exception of the basic Quinate of lead, soluble in water, not in 

 strong alcohol ; yield by the destructive distillation tannic acid and 

 Quinon. 



