494 OLEO-RESINS 



ELEMI 



(Manila Elemi, Resina Elemi) 



Source, &C. The term ' elemi ' is a generic one and is applied to a 

 number of oleo-resins having certain physical properties in common. 

 Tschirch enumerates no fewer than 46 varieties, all of which are derived 

 from plants belonging to the natural orders Burseracece or Eutacece. 

 The most important and formerly official variety is exported from 

 Manila and distinguished as Manila elemi. 



Manila elemi is an oleo-resin obtained from a species of Canarium, 

 probably C. luzonicum, Gray (N.O. Burseracece). It is obtained by 

 making incisions in the tree and promoting the flow of oleo-resin 

 by the application of heat. When first obtained it is probably a 

 clear, viscid, honey-like liquid which, however, rapidly becomes 

 crystalline. It is exported chiefly from Manila, and arrives in this 

 country in tins or lead-lined cases, in a more or less solid condition. 



Description. Elemi when fresh and of good quality is pale yellow 

 in colour, soft and granular, resembling a crystalline honey, but 

 on keeping it gradually becomes darker in colour, firmer and finally 

 hard. It is soluble in alcohol and ether, partially only in petroleum 

 spirit. It has a fragrant, balsamic odour recalling fennel and mace, 

 and a spicy, rather bitter taste. Under the microscope it is seen to 

 contain an abundance of acicular crystals. 



Constituents. Manila elemi, in the soft condition in which it is 

 usually imported, contains about 20 to 30 per cent, of volatile oil 

 associated with amorphous and crystalline resin acids, bitter prin- 

 ciple, &c. 



The volatile oil (sp. gr. 0'87 to 0-91) consists chiefly of terpenes ; 

 the aromatic constituents have not been examined. 



The resin contains a- and /9-manelemic acids (soluble in solution 

 of ammonium carbonate), a- and /3-manamyrin (insoluble in am- 

 monium carbonate and in alcohol), maneleresene (insoluble in 

 ammonium carbonate, soluble in alcohol), bryoidin, and bitter principle. 

 The composition of the drug may be seen from the following table : 



a-Manelemic acid . . . . 5 to 6 per cent. 



y8-Manelemic acid . . . . . 8 to 10 



a- and /?-Manamyrin . . . . . 20 to 25 



Maneleresene . . . . . . 30 to 35 



Volatile oil 20 to 25 



Bryoidin ....... about 1 



Bitter principle and impurities . . 6 to 8 



a-Manelemic acid is crystalline and forms crystalline salts 

 a- and /3-manamyrin are both crystalline, as is also bryoidin. 



