BY J. H. MAIDEN, F.L.S., F.C.S., ETC. 



99 



traction on cooling is great, as the resin cracks in all directions. 

 In other words it is a brittle resin, and it therefore powders with 

 great facility, forming an impalpable powder like Sandarach, 

 with the difference that it is far easier to powder than thai 

 substance. 



The exudation (henceforth in this paper to be alluded to as 

 oleo-resin), contains 26.67 per cent, of a lemon-scented volatile 

 oil which may be distilled over in the above operation. The 

 quantity of oil obtained by me was not even sufficient to deter- 

 mine its boiling point, much less its constitution. 



The melting point of the residual resin is 75'76^ C (167- 

 168*8° F). Like the original oleo-resin, it is readily soluble in 

 light petroleum, chloroform, absolute alcohol, and ether. 



It is proper to quote at this place the characters of Manila 

 Elemi as given in the B.P. of 1885 : — " When fresh, soft, granu- 

 lar, resinous, and colourless, but by keeping it becomes harder, 

 and of a pale yellow tint. Odour, strong and fragrant, some- 

 what resembling fennel and lemon. Moistened with rectified 

 spirit it breaks up into small particles, which when examined 

 by the microscope, are seen partly to consist of acicular crystals." 



(1) The most careful tests have failed to detect any acicular 

 crystals (Amyrin) in the oleo-resin of C. Muelleri, nor have 

 attempts to obtain a crystallisable resin from the same substance 

 been successful. 



(2) There is no fennel odour in the balsam of C. Muelleri. 



(3) The latter is not, at any time, whether fresii or after 

 keeping, of a granular consistence. 



The oleo-resin has in fact been very carefully worked at 

 with the view to obtain the crystallised substance (elemin or 

 amyrin) obtained by Fliickiger ■'■ from Elemi, but without success. 



With the oleo-resin of Canarium Muelleri, under the micro- 

 scope, no trace of crystalline form can be discovered either 

 from solution in alcohol, ether, cliloroform, itc. The pseudo- 

 crystalline appearance this oleo-resin assumes when treated with 

 either ether or alcohol is found, when examined under the micro- 

 scope, to be caused by minute oil-globules. 



