234 ODOROGRAPHIA. 
Bangkok. It is to the effect that the whole surface of the bark is 
incised, and that the resin which exudes accumulates and hardens 
between the wood and the bark, which is then stripped off. This 
information is confirmed by the aspect of the Siam benzoin of 
commerce, but evidently the entire supply of Siam benzoin is not 
obtained in this way. The Consul adds that the resin is much 
damaged and broken in transport to the navigable places on the 
Menam river, whence it is taken down to Bangkok. 
The finest Siam benzoin consists entirely of a mass of flattened 
tears of opaque milk-white resin tightly agglutinated together ; 
these tears are sometimes of from 1 to 2 inches in length. 
Generally, commercial benzoin is a compact mass, consisting of a 
quantity of white tears about the size of an almond, embedded in 
a translucid dark-brown resin. Sometimes the translucid resin 
predominates, and the white tears are few or almost entirely 
absent. In some consignments the tears of white resin are very 
small, and the mass presents an aspect of reddish-brown granite. 
There is always found a certain admixture of fragments of wood, 
bark, and other accidental impurities. The white tears when 
broken exhibit a certain stratified formation. The lumps of resin, 
which were exteriorly of a milky whiteness, gradually become 
brown and transparent on the surface. On the authority of 
Professor Flickiger, this opacity does not appear to be due to 
enclosed moisture, but rather to a particular molecular (semi- 
crystalline ?) condition of the resin. 
Siam benzoin is very brittle ; the fracture of the opaque tears is 
rather waxy ; the translucent part being of a glassy fracture. It 
softens quickly in the mouth and can be masticated. Its fragrance 
is very delicate, balsamic, and recalling perceptibly that of vanilla, 
but its taste is very feeble. On being heated, it.exhales a very 
strong odour and disengages irritating vapours of benzoic acid. 
It melts at 75° C. Siam benzoin is imported in cubic blocks, 
having the form of the boxes into which it was packed when in a 
soft state. 
The Sumatra benzoin is imported in the same shaped cubic 
blocks as the Siamese, but the aspect of it differs by being 
generally of a greyer tint. When of fine quality it contains 
numerous opaque trees embedded in a translucent greyish-brown 
resin, sometimes containing fragments of wood and bark. In 
inferior qualities the white tears are not present and the propor- 
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