76 



ON VEGETABLE EXTRACT. 



The extract 



oxicled by re- 



Action of ex 

 tract on iron, 



gelatine. 



and tin. 



red liquor with caustic lixivium. When no more sediment 

 formed, the liquor was added to the two preceding obtained 

 by alcohol and cold water. 



More than a hundred evaporations and solutions were 

 peate&ofution ma de by the help of a water-bath. Thus the pulverulent 

 and cvapara- ma tter was reduced to a 6mall quantity, and the colour of 

 the liquid became deeper. By repeated solutions almost 

 the whole was converted into powder. Of four ounces of 

 cinchona, that had furnished the extract, 15 grains [?] of 

 residuum were left, on which pure alcohol would not act. 



The infusions of cinchona then contained extract, which 

 precipitated iron of a green colour; a property that extract 

 loses, when it reaches the maximum of oxidation. 



Gelatine precipitates the extract of cinchona but in part, 

 and [the supernatant liquid comports itself in the same 

 manner as infusion of cinchona. 



Solution of tin precipitates the infusion of cinchona, 

 but the supernatant liquid has still the same properties; 

 for it forms a green precipitate with iron, and, when boiled 

 some time, the extract becomes oxided, and falls down in 

 a flocculent sediment. Tin therefore precipitates the ex- 

 tract only in part; and the same takes place with lime 

 water, or with a solution of alum. 



Pure alcohol does not dissolve extract ; and its action is 

 still farther diminished by the oxidation of the latter. 



When cinchona, or its extract, is distilled with water, 

 the product reddens litmus, without rendering the solution 

 of iron turbid. But if extract of cinchona be distilled, 

 till it becomes thick, the distilled product precipitates 

 sulphate of iron green, and comports itself like the sub- 

 stance of coffee. 



To obtain the saponaceous principle, the roots of gentian 

 and of soap-wort were treated with alcohol. The alcoholic 

 principle from tincture »f gentian Was evaporated and redissolved in water. 

 Properties of ^ resinous substance was deposited. The filtered liquor 

 the matter reddened infusion of litmus powerfully, but did not pro- 

 duce a green with solution of iron. 



Neither muriate of tjn, lime-water, nor gelatine, ren- 

 dered the liquor turbid. 



The liquid extracted by weak alcohol, and afterward 



diluted 



Insoluble in 

 alcohol. 



Distilled 

 ■water. 



Attempt to 

 obtain the sa 

 ponaceous 



eb-taiced. 



