CORTEX CINCHONiE. 361 



rated from the other alkaloids of bark by a solution of iodide of 

 potas 



w^ Hesse 



(1873), quinidine is further characterized by the fact that its sulphate 



is soluble in 20 parts of chloroform at 15° C, the sulphates of the other 



cinchona-alkaloids being far less soluble in that liquid. The common 



medicinal sulphate of quinine, €,g,, requires for solution 1000 parts of 

 chloroform. 



3. Cinchonine, — This alkaloid forms crystals which are always 

 anhydrous ; they fuse at 257^ C, and require about 400 parts of ether 

 and 120 of spirit of wine for solution. Cinchonine further differs from 

 quinine by its dextrogyre power, its want of fluorescence, and its non- 

 susceptibility to the thalleioquin test. Its hydriodate is readily soluble 

 m water, and still more so in alcohol whether dilute or strong:. 



4 Cinchonidme — forms anhydrous crystals melting at 206° C, 

 soluble in 76 parts of ether, or 20 of spirit of wine, then affording 

 levogyre liquids, devoid of fluorescence, and not acquiring a green 

 colour (thalleioquin) by means of chlorine water and ammonia. Hydro- 

 chlorate of cinchonidine forms pyramidal crystals of the monoclinic 

 system, very different from the hydrochlorates of the allied alkaloids. 



5. Qiiinamine, — The crystals are anhydrous, fuse at 172' C, and 

 form at a temp, of 20°, with 32 parts of ether or 100 parts of spirit of 

 >vine,^a dextrogyre solution. Quinamine is even to some extent soluble 

 m boiling water, and abundantly in boiling ether, benzol, or petroleum 

 ether. The solutions of quinamine do not stand the thalleioquin test, 

 nor do they display fluorescence ; in acid solution, the alkaloid is liable 

 to^ be transformed into an amorphous state. Quinamine moistened 

 ^ith concentrated nitric acid, assumes like paytine a yellow coloration. 

 Its hydriodate is readily soluble in boiling water, but very sparingly 

 in cold water, especially in presence of iodide of potassium, in which 

 respect it is allied to quinidine as well as to paytine. 



The more important properties of the Cinchona-alkaloids may be 

 summarized as follows :— 



a. Hijdrated crystals are formed by . , . Quinine, Quinidine, (or Conquinine). 

 -A'o hydrated crystals by Cinchonine, Cinchonidine, Quinamine. 



b. M..„a,ul, soMe in ether , . . . j ^ro^^Sidi""^""' "" "" 



Sparingly soluble in ether Cinchonidine. 



Almost insoluble in ether Cinchonine. 



c. Levogyre sohitions afforded by . . . Quinine, Cinchonidine. 



n^w , . , ( Cinchonine, Quinidine, Quinamine, Con- 



^e^rofirj/re solutions by p quinamine, and the amorphous alkaloids. 



d- Thalleioquin is formed by Quinine, Quinidine, and also by Quinicine. 



Thallpmn,,; * 1- u. • J f i Cinchonine, Cinchonidine, Quinamine, nor 



i iialleioquin cannot be obtained from j ^^^^ Cinchonicine. 



«• Fluorescence is displayed by solutions of Quinine, Quinidine. 



No fluorescence in solutions of pure . . Cinchonine, Cinchonidine, Quinamine. 



Proportion of Alkaloids in Cinchona Barks— This is liable to 

 very great variation. We know from the experiments of Hesse (1871), 

 w?at the bark of G. puhescens Vahl is sometimes devoid ^of alkaloid.' 

 Similar observations made near Bogota upon G. pitaijensis Wedd., G. 



^ Ba-klde der Deut^chen Chan. GeselUcha/t s« Berlhi, 1871. 818. 



