BALSAMUM DIPTEROCARPI. 91 



may regard it as a hydrate of abietinic acid, the chemical behaviour of 

 which is perfectly analogous. Gurjunic acid is soluble in alcohol 0\S38> 

 but not in weak alcohol ; it is dissolved also by ether, benzol, or sulphide 

 of carbon (Werner). 



In copaiba from Maracaibo, Strauss (1865) discovered Metacopaivic 

 Acid which is probably identical with gurjunic; the former, however, 

 fuses at 20G' C. 



The amorphous resin forming the chief bulk of the residue of the 

 distillation of the balsam, has not yet been submitted to exact analj^sis. 

 We find that after complete desiccation it is not soluble in absolute 

 alcohol. A crystallized constituent of Gurjun, which we obtained from 

 a balsam of unknown origin, has been shown^ to answer to the formula 

 Q2sjj46Q2^ Its crystals, belonging to the asymmetric system, melt at 

 126'' — ISO^'C; they are entirely devoid of acid character. A comparative 

 examination of the product of each of the above named species of 

 Dipterocarpus would be highly desirable. 



Commerce — Gurjun balsam is exported from Singapore, Moulmein, 

 Akyab and the Malayan Peninsula, and is a common article of trade 

 m Siam. It is likewise produced in Canara in Southern India. It is 

 occasionally shipped to Europe. More than 2000 lb. were offered for sale 

 in London under the name of East India Balsam Capiviy 4th October 

 1855; and in October 1858, a no less quantity than 45 casks appeared 

 in the catalogue of a London drug-broker. It is now not unfrequent 

 in the London druor sales. 



Uses— In medicine it has hitherto been employed only as a substi- 

 tute for copaiba, and chiefly in the hospitals of India. 



In the East its great use is as a natural varnish, either alone or 

 combined with pigments ; and also as a substitute for tar as an applica- 

 tion to the seams of boats, and for preserving timber from the attacks 

 of the -white ant. To the first application it is often made better 

 appropriated ^ by boiling it, so that the essential oil is evaporated. 



Wood Oil of Cliina — The oleo-resin of Dipterocarpus must not be 

 contounded with the so-called Wood Oil of China, which is of a totally 

 ^merent nature. The latter is a fatty oil expressed from the seeds oi AUu- 

 ^tf€8 co?'cZato Mull. Arg. (Dryandra cordata Thunb. Elaeococca Veniicia 

 ^|P^^J; Prodromus xv. part 2, p. 724), the well-known Tung tree of 

 e_ l/hmese. It is a large tree of the order EiipJiorbiacecey found in 

 ^ ina and Japan. The oil is an article of enormous consumption 

 aS^ ^^^^ Chinese, who use it in the caulking and painting of junks 

 boats, for preserving woodwork, varnishino; furniture, and also in 



)-65 

 tremel ^^ ^^^^'^^^ countries. The oil of the Timor tree is also ex- 



ecucine. In the comiiiercial reports of H.M. Consuls in China (No. 5, 

 iQh ^.P- ^' -^) we find that this oil is laro-elv exported from Hankow : 



l^Oft'i ' ""u i^iiau LUIS ou is largely tjApuiucv.!. nwiii a.xu,..±i^w. . 



^„;„i *.Peculs in 1874, and forms an article of import at Ningpo : 15-123 



peculs 



8hi 



Hi 1874 (peculr=l:33-33 lb. avoirdupois). It is, however, not 



bv ni ■■ ^^^^rkable on account of its chemical properties as shown 

 ^y Uoez (1875—1877). 



fjg^ ^^^gQv, Pharm, Joimu (1878) 725, with ^ Catalogue of the French Colonies, Paris 



Exhihltion, 1878, 101, quoted above. 



