STUDY OF YUCCA ANGUSTIFOLIA 147 



they were decomposed and melted, leaving a dark-colored 

 liquid. Several attempts were made to dry these crystals, with- 

 out success. A few of the crystals were recovered from the 

 solution, and tested for alkaloids; no reactions were obtained 

 with the usual reagents for them. 



Glucose was estimated from the aqueous extract. The liquid 

 was heated over a water bath with Fehling's solution, and the pre- 

 cipitated red cuprous oxide was thrown upon a weighed filter, 

 dried, and incinerated. The glucose was estimated gravimetri- 

 cally by calculating the amount of cupric oxide. It yielded 

 0.619 P er cent - A portion of the aqueous extract was boiled 

 with acid, neutralized, and heated over a water bath with Feh- 

 ling's solution to calculate, by difference, saccharose or other 

 reducible compounds, and by this method 0.18 per cent, was 

 obtained. 



The alcoholic extract was described as being deeply colored. 

 This coloring principle * was completely precipitated by sub- 

 acetate of lead. The lead precipitate was collected on a 

 filter, suspended in water, and decomposed by sulphuretted 

 hydrogen, filtered, and the filtrate freed from all odor. It was 

 allowed to evaporate slowly over sulphuric acid. The residue 

 was a brownish-gray mass, interspersed with fine crystals 

 which radiated from a nucleus. The mass was weighed and 

 gave 3.27 per cent, of solids. Another portion of the alcoholic 

 extract was agitated with water and acetic ether. The color- 

 ing matter was taken up by the acetic ether, and on evapo- 

 rating a red-colored substance was recovered. It was dried 

 and weighed, yielding 2.2 per cent. This red-colored residue 

 was perfectly soluble in cold water. This solution was tested 

 with the following reagents: It gave with potassium bichro- 

 mate a creamy-colored precipitate; ferric chloride, a yellow- 

 ish-green precipitate; ferrous sulphate, a reddish-brown pre- 

 cipitate; stannous chloride, no precipitate, a yellow cloudy 

 liquid; alum, a cloudy solution; neutral acetate of lead, a 

 slight precipitate. The red color of the coloring matter was 

 brought out on addition of alkalies. It was destroyed by 

 acids. 



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



