STUDY OF YUCCA ANGUSTIFOLIA 155 



AQUEOUS EXTRACTS 



Extract (i), Bark of the Root. 



The residual powder was thoroughly dried from alcohol. 

 It was returned to the percolator, and cold distilled water 

 added until a definite amount had been used. The aqueous 

 extract was dark colored, and of a faintly acid reaction. A cer- 

 tain quantity of the extract was evaporated, dried, and weighed. 

 From a known weight of the aqueous residue, the ash was 

 calculated. The incineration was conducted in a covered por- 

 celain crucible of known weight. 



TOTAL SOLIDS. 



Aqueous residue dried between 100 C and 110 C 4.00 per cent. 



ash 2.65 " 



Gum. 



One volume of the aqueous extract was mixed with two vol- 

 umes of Squibb' s stronger alcohol. The mixture was kept in 

 a cool place for twenty-four hours, and the precipitate which 

 had formed was collected on a weighed filter, washed with 

 66 per cent, alcohol, dried, and weighed. The precipitate and 

 filter were incinerated in a weighed porcelain crucible, and 

 the weight of the filter being deducted, the percentage of ash 

 was determined. 



Weight of precipitate by stronger alcohol yielded 2.0 per cent. 



ash yielded 0.2 " 



Another portion of the aqueous extract was precipitated by 

 stronger alcohol, and the precipitate consisted of gum and 

 albuminous substances. It was incompletely soluble in water. 

 The soluble matter was gum ; it was recovered from solution 

 by evaporating the liquid to dryness. The gummy residue 

 was almost completely soluble in cold water. It was precipi- 

 tated from a concentrated aqueous solution by stronger alco- 

 hol; basic acetate of lead precipitated it as a flocculent preci- 

 pitate. Borax did not thicken the gum solution, and ferric 



