68 Report of Schimmel $ Co. April 1913. 



chapter "Oil-Resins", he refers to two gurjun balsams, one of which is derived from 

 Dipterocarpus turbinatus and the second from D. tuberculatus. 



Through the courtesy of Mr. C. G. Rogers, Conservator of Forests at Rangoon, 

 Burma, we were able to procure samples of these two balsams, of which the following 

 particulars may be given: — 



Dipterocarpus turbinatus, Gaertn. fil. is a large tree which is found throughout 

 tropical Burma, in Bengal, and on the Andaman Islands. Its balsam is specially 

 known there by the name of "gurjan oil". It is collected in large quantities and is 

 used as a paint for houses and ships, as well as a preservative for articles of bamboo. 

 The balsam is exported from Chittagong (Bengal). The sample received by us consists 

 of a faintly acid, milky liquid; acid v. 10,9; sp. gr. 0,9811 (15°). When allowed to 

 stand, especially in the warmth, it separates out into a brown oil which floats on 

 the surface and a viscous, whitish-grey, emulsion-like mass. The constants of the 

 oily layer were as follow: di 5 o 0,9706, « D — 10°8', n D20 o 1,51200, acid v. 7,3, ester v. 1,9. 

 By steam distillation we succeeded in separating out from the total balsam 46 p. c. of 

 a pale-yellow oil of a balsamic odour, possessing the following constants: di 5 o 0,9271, 

 « D — -37°, n D20 o 1,50070, acid v. 0, ester v. 1,9, sol. in 7 vols a.m. 95 p. c. alcohol. 



Dipterocarpus tuberculatus, Roxb. yields a balsam of very different appearance. It 

 is known in Burma as "in oil", and plays a very subordinate part compared with 

 "gurjan oil". The balsam is of a pale-brown colour; its consistency is that of turpen- 

 tine and its sp. gr. at 15° is 1,029; acid v. 17,8; ester v. 0. The oil which was separated 

 out from it by steam-distillation (yield 33 p. c.) was of a yellow-brown colour, and 

 dissolved in 6 vols. a.m. of 95 p. c. alcohol. Its constants were as follow: di 5 o 0,9001, 

 « D — 99° 40', n D20O 1 ,50070. It did not contain saponifiable constituents (sap. v. 0). With 

 Turner's colour-reaction both the balsams and the oils gave the characteristic violet 

 colour. This test consists 1 ) in dissolving 3 or 4 drops of the balsam or oil in 3 cc. 

 of glacial acetic acid, adding to the solution 1 drop of freshly-prepared 10 p. c. sodium 

 nitrite solution, and layering the mixture very carefully on 2 cc. of concentrated sulphuric 

 acid. The test has been somewhat modified by Deussen and Eger. 



Another balsam, which is greatly esteemed in Burma, and of which we have also 

 received a sample, was derived from Melanorrhoea usitata, Wall. (N. O. Anacardiacece). 

 It consisted of a thick, viscous, brown mass with an odour of train-oil. It turned black 

 when exposed to air. This balsam, which is known as "thitsi oil" is of no interest 

 for us, as it contains no essential oil whatever. 



Juniper berry Oil. A few claims due to the imperfect solubility in weak alcohol, 

 of extra-strong juniper berry oil, give us occasion to point out once more that the 

 solubility of juniper berry oil 2 ) soon begins to diminish during storage, and that 

 extra-strong juniper berry oil possesses the same peculiarity. It is not impossible, 

 however, that oils of the 1912 crop may possess the property of resinification in an 

 exceptionally high degree, because in that year the yield of oil and of juice, as com- 

 pared with the yield from raw material of other seasons, was quite abnormal, and the 

 sugar-content of the juice was low, no doubt as a result of the cold and rainy summer. 



We are now engaged in making experiments with the keeping-properties and 

 solubility of extra-strong juniper berry oil, and we intend to return to the subject in 

 due course, and to give practical hints for the storage of juniper berry oil. 



*) Comp. Report April 1909, 41 ; October 1912, 49. — -') Gildemeister and Hoffmann, The Volatile Oils, 

 I Ed. pp. 271 and 272. 



