iS2 PLANT AND ORGANIC CHEMISTRY 



sodium carbonate solution was colored pale brown when cold 

 or on warming. 



SUMMARY III. ALCOHOLIC EXTRACTS 



Extracts (i). 



My attention was not directed to the presence of saponin 

 in extract (i), for the characteristic properties which it im- 

 parted to extracts (2), (3), and (4) were absent; but it was 

 evident that saponin was present in the bark, for on boiling 

 the latter in distilled water, the presence of the compound was 

 indicated. The solution frothed on shaking, and by adding 

 a concentrated solution of caustic baryta, saponin-baryta was 

 precipitated. 1 



A coloring matter 2 contained in the bark was extracted, 

 and imparted to the alcoholic extract a brilliant red color. It 

 was precipitated by sub- acetate of lead, and the lead precipi- 

 tate suspended in water and decomposed by sulphuretted 

 hydrogen. The lead sulphide nitrate was evaporated over a 

 water bath until the odor of sulphuretted hydrogen was ex- 

 pelled, and the concentrated liquid was placed over sulphuric 

 acid to evaporate slowly. A crystalline residue was obtained. 

 On addition of alkalies to the colorless lead sulphide nitrate 

 the red color of the original solution was developed. Acid dis- 

 discharged the color. Acetic ether took up the red colored 

 substance. The acetic ether residue was a red uniform solid, 



1 "Saponin in the Bark of Yucca Angustifolia" Science, September u, 

 1885. 



2 "A Red Crystalline Coloring Matter," Science, September n, 1885. 





