222 Intelligence and Miscellaneous Articles, 



with alcohol. The evaporation of the filtered liquor gives a deep 

 yellow-coloured residue of a crystalline appearance, and containing 

 much resin ; to deprive it of which it is to he repeatedly washed with 

 small portions of cold aether. In this operation, the aether acquires a 

 yellowish-brown colour, and is most intensely bitter : by evaporation 

 it leaves an uncrystallizable residue. 



The gentianin thus obtained has a decidedly bitter taste, derived 

 from a small quantity of resin. It is to be dissolved in a small quan- 

 tity of alcohol, to be crystallized, and again washed with cold aether. 

 The crystals, after each washing, are to be pressed between filtering 

 paper. Two pounds of gentian yielded only about 120 grains of 

 gentianin. 



Gentianin is in the state of fine silky needle-form crystals, and of 

 a sulphur-yellow colour ; it is but very slightly bitter, and this bit- 

 terness is entirely got rid of by repeated solutions in, and crystal- 

 lizations from alcohol, after which it is insipid, even when in solution. 



Gentianin is insoluble in cold water, very slightly dissolved by 

 boiling water, and much more soluble in alcohol and aether. When 

 heated to a temperature of above 212°, it sublimes entirely, and con- 

 denses into silky yellow crystals. 



The subacetate of lead and nitrate of silver do not precipitate it 

 from solution. The chloride of iron and the salts of copper give a 

 precipitate. It strongly resists the action of acids. Some very con- 

 centrated mineral acids only appear to decompose it. Some seem 

 also to render it more soluble in water. It does not act upon litmus 

 paper. 



The most remarkable circumstance is, not only that it dissolves 

 with the utmost facility in alkaline solutions, and becomes of a bright 

 golden colour, but it combines with the alkalies in several definite 

 proportions. These compounds are yellow, crystallizable, and pos- 

 sess an alkaline reaction. This acid (for it is one) decomposes the 

 alkaline carbonates, expelling the carbonic acid.-— Jbwr^a/ de Chimie 

 Medicate, December 1837. 



ON QUASSIN. 

 Wiggers gives the name of quassin to the bitter principle of the 

 Quassia amara and Quassia excelsa. The following is the process which 

 he employed to obtain it ; boil the wood, cut into thin slices, in water; 

 filter and evaporate the solution to three quarts ; afterwards allow it 

 to cool, and add some lime water to it, and leave them together for 

 a day. The lime separates the pectin and the other substances. 

 Filter and evaporate to drj^ness, and add to the residue about 80 or 

 90 per cent, of alcohol. This menstruum dissolves the quassin, a 

 little chloride of sodium, nitrate of potash, and an organized brown- 

 ish matter. By distillation a residue of a light yellow is obtained ; 

 this is to be treated with a mixture of absolute alcohol and aether, 

 until the quassin appears pure. A little water is to be added to this 

 solution, and it is to be allowed to evaporate in the air. A fresh 

 quantity of quassin may be obtained by collecting the substances 

 separated by the rether, and by treating them afresh with absolute 



