262 A CHEMICAL STUDY OF 



TOTAL SOLIDS. 



Ethereal residue dried at 100° C 1.70 per cent, of solids. 



" " 110°C 1.45 " '• 



0.23 " " loss. 



The resin Avas examined by Hirschsohn's scheme* with a view to classify it 

 ■with known resins. It was imperfectly sohible in 95 per cent, alcohol and chloroform ; 

 soluble in ether. The alcoholic solution gave a turbidity with lead acetate, not cleared 

 upon boiling, and with ferric chloride formed a clear mixture. Concentrated sul^jhuric 

 acid dissolved the resin, leaving a dark yellow-brown liquid which faded to a dull yel- 

 low color. The sulphuric acid solution when mixed with alcohol, changed to a pale 

 gray coloi-. On addition of water to the acid solution, there was no coloration nor 

 separation of the resin. Alcohol containing hydrochloric acid gave no color reaction 

 with the resin. Bromine solution added to the chloroform-resin extract, and iodine 

 solution to the ether-peti'oleum-resin extract, gave no reactions. Sodium carbonate at 

 the ordinary temperature had no effect on the lesin, but on boiling the liquid was 

 colored yellow. 



By the above examination, this resin was thrown out of the numerous classes of 

 described resins. It is proposed to name it yuccal.t 



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 substance 

 remaining, soluble in hot acetic ether.J Yuccal Avas dissolved by potassio-mercuric 

 iodide. It reduced aqueous solutions of gold and platinum chlorides. A blood-red 

 color reaction Avas obtained by Avarming a small quantity of the resin on a crucible lid 

 with a crystal of ammonium molybdate and a few drops of nitric acid. On adding to 

 the resin mixture a few drops of strong sulphui'ic acid, and again Avarming, it Avas dis- 

 solved. Warm dilute nitric acid dissolved the resin, colorless ; cold nitric acid gave a 

 brownish-green color reaction. § Yuccal was heated on platinum foil, and as it decom- 



*E. llirschsolin. AVatts Clicm. Diet. Vol. viii, Pt. ii, p. 1743. 



fl suggest that in future all resins be distinguished by the terminal syllable al, for uniformity of resin nomencla- 

 ture. Yuccal ; Science, September 11, 1885, p. 310. 



X 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 

 incompletely spruce gum, and yuccal. In hot acetic ether spruce gum and yuccal were soluble. The following resius 

 were insoluble in hot or cold acetic ether, guiacam, sandarac, shellac, benzoin, olilianum, ammoniac, myrrh, galba- 

 num, and asafatida. 



^A reddish-yellow decomposition product resulted from the action of nilric^ acid on many resins which fol- 

 lowed 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 l.-l sp. gr.). But the reaction which took place varied according to the conditions, i. c, strength of acid used. 



