194  _ DIPTEROCARPE. 
. acid which colours it of a beautiful blue. DeVrij states that 
the essential oil after this treatment deviates the ray to the 
right. 
“The resin contains, like that of copaiba, a small proportion 
of a crystallizable acid, which may be removed by warming it 
with ammonia in weak aleohol. That part of the resin which is 
insoluble even in absolute alcohol, we found to be unerystal- 
_ lzable. The gurjunic acid may consequently be prepared by ; 
extracting the resin with alcohol (838) and mixing the solution 
with ammonia. From the ammoniacal solution gurjunic acid is _ 
precipitated on addition of a mineral acid, and if it is again 
dissolved in ether and alcohol it may be procured in the form 
of small crystalline crusts. Gurjunic acid, C+* H6® O08, accord- 
ing to Werner, melts at 220°C, and concretes again at 180° — 
C.; it begins to boil at 260° C., yet at the same time decom- 
position takes place. By assigning to this acid the formula 
c™ He O05 +: 8 H*O, which agrees well with Werners 
_ analytical results, we may regard it as a hydrate of abietinic 
acid, the chemical behaviour of which is perfectly analogous. 
Gurjunic acid is soluble in alcohol 0-838, but not in weak 
alcohol ; it is dissolved also by ether, benzol, or bisulphide of 
carbon. 
‘Tn copaiba from Maracaibo, Strauss discovered metacopaivic 
acid, which is probably identical with gurjunic ; the former 
however fuses at 206° C. The amorphous resin forming the 
chief bulk of’ the residue of distillation of the balsam has not 
yet been submitted to exact analysis. We find that after com- 
plete dessication it is not soluble in absolute alcohol.” Fluckiger 
has since discovered (1878) in Garjan Balsam a crystallizable 
indifferent resin, formula C28 H46 Oz ; it melts at 258°8° F. and 
dissolves in sulphuric acid with an orange colour. 
Commerce.—Garjan Balsam is not an article of commerce i? 
most parts of India, but small quantities may be sometimes 
obtained in the native drug shops. In Calcutta its price is 
from 3 to 5 rupees per maund of 80 Ibs. Large quantities are 
exported from Moulmein to Europe. The Government supplies ° 
_ * have been obtained from the Andaman Islands. ao 
gris 
Fd 
; 
hs Noes 
