STUDY OF YUCCA ANGUSTIFOLIA 131 



acid slowly dissolved the fixed oil; the former colored it dark 

 green, and on stirring the mixture the color was changed to 

 a brown. Concentrated sulphuric acid dissolved and changed 

 it to a very dark brown color; on adding concentrated nitric 

 acid, the liquid was changed to a reddish-brown color. 



The following reactions were noted: The fixed oil changed 

 to a hard greenish-yellow substance on heating it with anhy- 

 drous borax on platinum foil. When rubbed on a crucible 

 lid with powdered rosaniline, it was colored red, showing the 

 presence of free fatty acids. It did not emulsify with calcium 

 di-sulphide nor with syrupy antimony chloride, but it was 

 colored dark-green by the latter. It was imperfectly dissolved 

 by phosphoric acid, and slowly soluble in equal parts of 

 cane sugar and concentrated hydrochloric acid; more rap- 

 idly soluble in equal parts of cane sugar and nitric acid. An 

 aqueous solution of picric acid made alkaline by sodium car- 

 bonate colored the fixed oil a light reddish-brown color ; cane 

 sugar added to the solution facilitated dissolving it. It was 

 instantly dissolved by equal parts of picric acid and acid am- 

 monium phosphate, and on warming with stannous chloride, 

 leaving a turbid yellow-colored liquid. It was insoluble in 

 aqueous barium hydrate; soluble in alcoholic ammonia with 

 no coloration, and in sulphurous acid. It was colored brown 

 when mixed with sulphuric acid of 1.634 specific gravity, and 

 incompletely dissolved; it was also colored brown by ferric 

 chloride. On adding to the fixed oil sulphuric acid of 1.475 

 specific gravity, and a small quantity of zinc, hydrogen was 

 generated, and the solubility of the oil in the acid liquid was 

 accompanied by a rosy tint given to the solution. 



Extract (4), Yellow Part of the Leaf. 



The extract was obtained by a similar process to that used 

 for the other petroleum spirit extracts. The extract was a pale 

 yellow-colored liquid. The reaction was slightly acid. A uni- 

 form spot was left on blue paper as the drop evaporated. The 

 petroleum spirit was evaporated at the ordinary temperature, 

 and a vellow-colored residue recovered, of a semi-solid con- 



