STUDY OF YUCCA ANGUSTIFOLIA 
137 
By the above examination, this resin was thrown out of the 
numerous classes of described resins. It is proposed to name 
it yuccal. 1 
Yuccal was soluble in boiling absolute alcohol and acetic 
ether; incompletely soluble in benzole, carbon di-sulphide, 
alcoholic ammonia, and cold acetic ether. The red color of 
the resin was removed by cold acetic ether, a transparent sub¬ 
stance remaining, soluble in hot acetic ether. 2 Yuccal was 
dissolved by potassio-mercuric iodide. It reduced aqueous 
solutions of gold and platinum chlorides. A blood-red color 
reaction was obtained by warming a small quantity of the 
resin on a crucible lid with a crystal of ammonium molyb¬ 
date and a few drops of nitric acid. On adding to the resin 
mixture a few drops of strong sulphuric acid, and again warm¬ 
ing, it was dissolved. Warm dilute nitric acid dissolved the 
resin, colorless; cold nitric acid gave a brownish-green color 
reaction. 3 Yuccal was heated on platinum foil, and as it de¬ 
composed the fumes that were given off were pleasant and 
aromatic. Tests failed to show the presence of benzoic or 
cinnamic acids. 
1 I suggest that in future all resins be distinguished by the terminal syllable 
al, for uniformity of resin nomenclature. ‘‘Yuccal,” Science , September 11, 
1885, p. 210. 
2 I have examined the action of acetic ether as a solvent for resins. Cold acetic 
ether dissolved ordinary resin, turpentine, styrax, tolu-balsam, mastic, elemi, 
Canada-balsam, Peru-balsam, copaiba-balsam, Venice-turpentine, and, incom¬ 
pletely, spruce-gum and yuccal. In hot acetic ether, spruce-gum and yuccal 
were soluble. The following resins were insoluble in hot or cold acetic ether : 
guiacum, sandarac, shellac, benzoin, olibanum, ammoniac, myrrh, galbanum, 
and asafoetida. 
3 A reddish-yellow decomposition product resulted from the action of nitric 
acid on many resins which followed generally quite soon after adding the 
acid to a small quantity of the resin (0.1 gram of the resin and 5 c. c. of nitric 
acid, 1.4 sp. gr.). But the reaction which took place varied according to the 
conditions, i. e., strength of acid used, the application of heat to the resin 
acid mixture, or the addition of solvents to the mixture. The more concen¬ 
trated the acid the more rapid was the reaction. The application of heat also 
hastened the change, especially if a more dilute acid was used in the mix¬ 
ture. Some solvents acted like heat by increasing the energy of the reactions. 
Alcohol and ether were active solvents, and the reaction was attended by the 
escape of nitrous fumes from the combination of alcohol or ether and nitric 
acid. Chloroform and benzole were indifferent. Amyl alcohol acted feebly. 
