§ 16G. GLUCOSIDES OTHER THAN TANNINS. 163 



ClncJioua-nova-tannic acid''- yields, according to Hlasiwetz, under 

 the same conditions, sugar and cinchona-nova-red ; the latter is 

 easily soluble in ether. 



For ipecacuanhaAannic mid ^ see Willigh and Podwissotzki ; for 

 Uditannic acid, Willigh' and Rochleder and Schwarz;* for 

 nucitannic acid, Phipson;'' for the tannin of mate, Arata;*^ for 

 celastrus-tannic acid, DragendorfF.'^ Information concerning some 

 other tannins may be gained from Clmelin's 'Chemistry.' 



OTHER GLUCOSIDES. 



§ 166. Cyclopin, FJiinanthin, etc. — Cyclopin, which, however, 

 cannot, without some consideration, be classed with the tannins, 

 is a glucosidal substance found by Greenish,^ in the so-called Cape 

 or Bush tea. It is freely solul^le in water, and is precipitated from 

 solution by acetate of lead, as well as by digestion with the 

 oxyhydrate of that metal ; from the combinations with lead thus 

 obtained, it can be liljerated by sulphuretted hydrogen. Ether 

 precipitates it from alcoholic solution. Boiled with 4 per cent, 

 hydrochloric acid, cyclopin decomposes into glucose and cyclopia- 

 red, which latter is insoluble in ether. With strong hydrochloric 

 acid, the solution turns rapidly red. Cyclopin is not precipitated 

 by gelatine or tartar emetic, and does not possess an astringent 

 taste. In the plant producing it, it ajopears to be easily converted 

 into oxycyclopin, which is insoluble in alcohol, and undergoes a 

 similar decomposition to cyclopin itself. 



Another glucoside that yields a deeply coloured decomposition- 

 product when boiled even with very dilute acids, is the rhinanthin, 

 occurring in various species of lihinanthus, Alectorolophus, and 

 Melampyrum.^ It can be obtained in colourless acicular crystals, 

 soluble in water and alcohol, insoluble in ether, and not preci- 



^ See Hlasiwetz, Annal. d. Chem. und Pharm. Ixxix. 130, 1857. 



2 Journ. f. pract. Chem. li. 404 ; Pharm. Zeitschr, f. Russland, xix. 1. 

 Pharm. Journ. Trans. [3], x. 642. 



■^ Chem. Centralblatt, 790, 1852. 



•* Zeitschr. f. anal. Chem. v. 668, 1869. 



Ö Ibid. p. 812. 



^ Jahresb. f. Pharm. 164, 1878. Compare also Byasson, ibid. 



7 Archiv d. Pharm. [3], xii. 113, 1878. 



s Sitzb. d. Dorpater Naturforscher-Ges. 345, 1880 (Pharm. Journ. and Trans. 

 [3], xi. 549). It is accompanied by the crystalline cijdopia-fluorescm, which 

 is soluble in ether and alcohol but sparingly soluble in water. Potash dissolves 

 it with yellow colour and production of a fine green fluorescence. 



3 Compare Ludwig, Archiv d. Pharm, cxlii. 199, 1870. 



11—2 



