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 w T as 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 yellow-colored residue recovered, of a semi-solid con- 
