MASTIC. 



473 



3. Elemi, from several species of Amyris in East 

 and West Indies. Yellow, translucent, soft, smelling 

 somewhat of volatile oil. It contains a non-crystal- 

 lizable resin, easily soluble in cold alcohol, and a crys- 

 tallizable resin, soluble only in boiling alcohol. The 

 latter can be obtained only in fine needles, and does 

 not combine with bases ; takes up water from the air 

 and from alcohol, and becomes amorphous. It is also 

 contained in anime-resin and in euphorbium. 



4. Betulin, in birch-bark. Appears as a fleecy vege 

 tation in the bark when gradually heated. ^ Obtained 

 most readily by boiling the outer bark with water, 

 drying and boiling with alcohol, from which it crys 

 tallizes in nodules. Colorless ; fuses at 200, emitting 

 an odor like that of the bark ; is sublimable in a cur 

 rent of air. 



5. Lactucone, in the juice of Lactuca virosa.Fine, 

 colorless prisms, solidifying after fusion in an amor 

 phous form; very similar to betulin. 



6. Copal, from Africa, East Indies, etc., of various 

 origin. Large (externally opaque, on a fractured sur 

 face clear), slightly yellowish or yellow pieces, fre 

 quently inclosing insects; hard, brittle, heavier than 

 water. Fusible, but undergoing a change at the same 

 time. Insoluble in alcohol ; soluble in ether ; soluble 

 in caustic potassa, There are different varieties of 

 copal; they consist of several difficultly separable 

 resins. 



7. Dammara resin, from Pinus Dammar a, in the 

 Moluccas. Very similar to copal; fusible, however, 

 without decomposition, and soluble in hot alcohol. 



8. Mastic, from Pistada Lentiscus in Greece. Small, 

 yellowish, translucent, round grains, of a slight 

 aromatic odor and taste, Consists of several amor 

 phous compounds, of different solubility in aqueous 



alcohol. 



40* 



