344 



STYRACE^E 



DESCRIPTION OF DRUG. It exudes from incisions in the bark, hardening 

 on exposure into agglutinated shining tears of a yellowish-brown or 

 reddish-brown color; internally milk-white; usually, however, it is 

 in various-sized pieces, having a resinous fracture, showing a mottled 

 surface of smooth, shining white spots, tears, imbedded in the 

 somewhat rough and porous, reddish-brown mass. It has a very 

 agreeable odor and a slightly aromatic taste, leaving an irritating 

 sensation in the mouth and fauces. 



FIG. 196. Sly rax benzoin Branch. 



CONSTITUENTS. Benzoin has the constitution of a balsam and is by some 

 authors considered as a solid balsam; it contains resin, benzoic acid, 

 C7H 6 O 2 , 20 to 24 per cent., which comes off in dense white vapor 

 when benzoin is heated and melted, and cinnamic acid, CgHsOg (in 

 some varieties), detected by boiling in milk of lime, decomposing 

 with HC1, and adding permanganate of potassium, when the odor of 

 bitter almonds is given off. Siam benzoin contains vanillin, CgHsOs, 

 and has a vanilla-like odor. Sumatra Benzoin. Ash, not more than 

 2.5 per cent. Siam Benzoin. Ash, not more than 2 per cent. 



