$ 1GG. GLUCOSIDES OTHER THAN TANNINS. 163 



Cinckona-nova-tannic acid 1 yields, according to Hlasiwetz, under 

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

 easily soluble in ether. 



For ipecacuanha-tannic add 2 see Willigli and Podwissotzki ; for 

 leditannic acid, Willigh 3 and Eochleder and Schwarz; 4 for 

 acid, Phipson; 5 for the tannin of mate, Arata; 6 for 

 acid, Dragendorff. 7 Information concerning some 

 -other tannins may be gained from Gmelin's 'Chemistry.' 



OTHER GLUCOSIDES. 



166. Cyclopin, Rhinantliin, etc. Cyclop in, which, however, 

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

 is a glucosidal substance found by Greenish, 8 in the so-called Cape 

 or Bush tea. It is freely soluble 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 liberated 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 

 iicid, 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 appears 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 rhinanthw, 

 occurring in various species of Rhinanthus, Alectorolophus, and 

 Melampyrum. 9 It can be obtained in colourless acicular crystals, 

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



1 See Hlasiwetz, Annal. d. Chem. uncl Pharm. Ixxix. 130, 1857. 

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

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

 a Chem. Centralblatt, 790, 1852. 

 4 Zeitschr. f. anal. Chem. v. 668, 1869. 

 Ibid. p. 812. 

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



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



8 Sitzb. d. Dorpater Naturforscher-Ges. 345, 1SSO (Pharm. Journ. and Trans. 

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



-ible in ether and alcohol but sparingly soluble in water. Potash dissolves 

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



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



112 



