150 BURSERACE^. 



If the essential oil of elemi (8 parts) is shaken with alcohol, 0'816 

 sp. gr. (2 parts), nitric acid, 1-2 sp. gr. (1 part) and water (5 parts), the 

 mixture, on exposure to air in a shallow capsule soon yields large 

 crystals, which were found to agree crystallographically^ perfectly with 

 terpin,e»H-'0' + OH^from oil of turpentine. 



Maujean,^a French pharmacien, examined Manila elemi as long ago 

 as 1821 and proved it to contain two resins, the one soluble in cold, the 

 other only in hot spirit of wine. The former, which appears to consti- 

 tute by far the prevailing part of all varieties of elemi, has not yet been 

 satisfactorily examined. Bonastre^ a little latter made a more complete 

 analysis, showing that the less soluble resin which he obtained to the 

 extent of 25 per cent, is easily crystallizable, and apparently identical 

 with a substance obtainable in a similar manner from what he regarded 

 as true elemi, which the Manila resin was not then held to be. Baup 

 (1851) gave it the name of Amyrin. According to our experiments, it 

 is readily isolated to the extent of 20 per cent, when Manila elemi is 

 treated with cold spirit of wine, in which the crystals of amyrin are 

 but slightly soluble. If the elemi is pure, the amyrin may be thus 

 obtained (by Avashing with spirit and pressure between bibulous paper) 

 in a cake of snowy whiteness, which may be further purified by crystal- 

 lization from boiling alcohol. The fusing point of the crystals is 177°C.; 

 their composition has been ascertained by Buri'' to agree with the 

 formula C'^H^'O, which may be written thus: (C'H')' OH^. Amyrin at 

 16° C. dissolves in 27"5 parts of alcohol 0"816 sp. gr., being readily 

 soluble also in all the usual solvents for resins. The alcoholic solution 

 is slightly dextrogyre. Amyrin is a neutral substance, and may be 

 sublimed in small quantities by very carefully heating it. 



By heating amyrin with zinc dust Ciamician* obtained chiefly toluol, 

 methyl-ethyl- benzol and ethyl-naphtalin. 



By allowing an alcoholic solution of the amorphous resin of Manila 

 elemi "^ to evaporate, Baup obtained in very small quantity crystals of 

 Breine, a substance fusing at 187'' C, which he considered to be distinct 

 from amyrin. In our opinion it was impure amyrin ; it is extremely 

 difficult, or rather practically impossible to extract all the crystallizable 

 resin from the amorphous. If the latter, perfectly transparent, is kept 

 for several years, an elegant crystallization at last begins to make its 

 appearance throughout the bulk of the resin. 



Baup further extracted from Manila elemi a crystallizable substance 

 soluble in water to which he gave the name of Bryoidin^ and in smaller 

 quantity a second also soluble in water which he called Breidine. 

 From the experiments of Baup it appears that bryoidin is soluble in 360 

 parts of water at 10° C, and melts at 135° C; whereas breidine requires 

 for solution 260 parts of water and fuses at a temperature not much 

 over 100° C. 



We have also obtained Bryoidin^ by operating in the following 



^ Examined at my request by Prof. Groth. " I am indeLtecl for a specimen of the 



— F.A.F. material that Baup worked upon and which 



■•^ Journ. dePharm. ix. (1823) 45. 47. he called Resin of Arbol a brea, to M. Roux, 



3 Id. X. (1824) 199. pharmacien of Nyon, Switzerland — F.A.F. 



* Pharm. Journ. vii. (1876) 157, also ^ From the Greek /S^^uoi/, in allusion to the 



Yearbook of Ph. 1877. 21. moss-like aspect sometimes assumed by the 



" Berichte der deutschen chemischen crystals. 



Gesellschafl, 1878. 134:7. » Fluckigcr, Pharm. Jouin. v. {1874 142. 



i 



