§ 166. GLUCOSIBES OTHER THAN TANNINS. 163 



Cinclumarnova-tanrm add} jdelds, according to Hlasiwete, under 

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

 easily soluble in ether. 



For i^ecacmmfio^tanmc acid ^ see Willigh and Podwissotzki ; for 

 leditanmc add, Willigh^ and Eochleder and Schwarz;* for 

 nucUaTmic acid, Phipsonj^ for the tannin of mati, Arata;® for 

 celaslrus4annic acid, Dragendorflf.'' Information concerning .some 

 other tannins may he gained from Gmelin's ! Chemistry.' 



OTHEK OLUCOSIDES. 



§ 166. Cydopin, EMnantMn, etc. — Cydopin, ■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 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 cyclopisr 

 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 appears to be easily converted 

 intd 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 rMnOmfhin, 

 occurring in various species of- Ehinanthus, Aleetorolophus, and 

 Melampyrunu^ It can be obtained in colourless acicular crystals, 

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



1 See HIasiwetz, Annal. d. Ghem. und Pharm. Ixxre. 130, 1857. 



2 Joum. i. pract. Chem. U. 404 ; Pharm. Zeitschr. f. Russland, xix. 1. 

 Pharm. Joum. Trans. [3], x; 642. 



« Chem. Centialblatt, 790, 1852. 



* Zeitschr. f. anal. Clem. v. 668, 1869. 

 » Ibid. p. 812. 



s Jabresb. f, Pharm. 164, 1878. Compare also ByaEson, ibid. 



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



' Sitzb. d. Dorpater Naturforsoher-GeB. 345, 1880 (Phann. Jomtj. and Trans. 

 [3], xi. 549).. It is accompanied by the crystalline cyclopia-jhtore^cm, which 

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

 it witli yellow colour and production of a fine green fiuoresoence. 



* Compare Xiudwig, Archiv d. Pharm. cxlii. 199, 1870. 



11—2 



