RESINA BENZOE. 407 



has the aspect of a reddish-brown granite. There is always a certain 

 admixture of bits of wood, bark, and other accidental impurities. 



The white tears when broken, display a stratified structure with 

 layers of greater or less translucency. By keeping, the white milky 

 resin becomes brown and transparent on the surface. 



Siam benzoin is very brittle, the opaque tears showing a slightly 

 waxy, the transparent a glassy fracture. It easily softens in the mouth 

 and may be kneaded with the teeth like mastich. It has a delicate 

 balsamic, vanilla-like, fragrance, but very little taste. When heated it 

 evolves a more powerful fragrance, together with the irritating fumes 

 of benzoic acid ; its fusing point is 75° C. The presence of benzoic acid 

 may be shown by the microscopical examination of splinters of the 

 resin under oil of turpentine. 



Siam benzoin is imported in cubic blocks, which takes their form 

 from the wooden cases in which they are packed while the resin is 

 still soft. 



2. Sumatra Benzoin — Prior to the renewal of direct commercial 

 intercourse with Siam in 1858, this was the sort of benzoin most com- 

 monly found in commerce. 



It is imported in cubic blocks exactly like the preceding, from 

 which it difters in its generally greyer tint. The mass however, when 

 the drug is of good quality, contains numerous opaque teais, set in a 

 translucent, greyish-brown resin, mixed with bits of wood and bark. 

 When less good, the white tears are wanting, and the proportion of 

 impurities is gieater. We have even seen samples consisting almost 

 wholly of bark. In odour, Sumatra benzoin is both weaker and less 

 agreeable than the Siam drug, and generally falls short of it in purity ^ 

 and handsome appeai-ance, and hence commands a much lower price. 

 The greyish-brown portion melts at 95°, the tears at 85° C. 



A variety of Sumatra benzoin is distinguished by the London drug- 

 brokers as Penang Benjamin or Starax-smelling Benjamin. We have 

 seen it of very fine quality, full of white teai-s (some of them two inches 

 long), the intervening resin being greyish.- The odour is very agree- 

 able, and perceptibly different from that of Siam benzoin, or the usual 

 Sumatra sort. Whether this drug is produced in Sumatra and by 

 Styrax Benzoin we know not ; but it is worthy of note that S. subden- 

 ticulata Miq., occun-ing in Western Sumatra, has the same native 

 name (Kajoe K^minjan) as S. Benzoin, and that Miquel remarks of 

 it — "An etiani henzoiferuin I " ^ 



Chemical Composition — Benzoin consists mainly of amorphous 

 resins perfectly soluble in alcohol and in potash, having slightly acid 

 properties, and differing in their behaviour to solvents. If two parts of 

 the drug are boiled with one part of caustic lime and 20 parts of water, 

 benzoin acid is removed. From the residue the excess of lime is 

 dissolved by hydrochloric acid, and the remaining resins washed and 

 dried. About one-third of them wiU be found readily soluble in ether, 

 the prevailing portion dissolves in alcohol, and a small amount remains 

 undissolved. 



^ Id the Public Ledrjer, May 2, 1874, the - There were 8 cases of this drug oflFered 



prices are quoted thus : — Siaui Gum Ben- at Public Sale, 13 April 1871. 



jamin, 1st and 2nd qualities, £10 to £28 per ' Prod, Florae Sumatrance, 1860. 47'4. 

 cwt.; Sumatra, 1st and 2nd, £7 lOs. to £12. 



