138 BURSERACE^. 



writes thus : — " The gum is procured by making longitudinal incisions 

 through the bark in the months of May and December, when the 

 cuticle glistens with intumescence from the distended state of the parts 

 beneath ; the operation is simple, and requires no skill on the part of 

 the operator. On its first appearance the gum comes forth white as 

 milk, and according to its degree of fluidity, finds its way to the 

 ground, or concretes on the branch near the place from which it first 

 issued, from whence it is collected by men and boys employed to look 

 after the trees by the different families who possess the land in which 

 they grow." According to Captain Miles,^ the drug is not collected by 

 the people of the country, but by Somalis who cross in numbers from 

 the opposite coast, paying the Arab tribes for the privilege. The 

 Arabian Lubdn, he says, is considered inferior to the African. 



It would even appear that the collection of the drug has ceased in 

 Arabia, and that the names of Luban Maheri or Mascati or Sheehaz, 

 referring to the coast of Arabia between Ras Fartak (52° 10' E.) and 

 Ras Morbas (54° 34') are now applied to the olibanum brought there 

 from the opposite African coast.^ Hildebrandt informed one of us 

 (letter dated 2Gth Dec, 1878) that he has ascertained at Aden, that all 

 the frankincense imported in Aden comes from Africa. 



Description — Olibanum as found in commerce varies rather con- 

 siderably in quality and appearance. It may in general terms be 

 described as a dry gum-resin, consisting of detached tears up to an 

 inch in length, of globular, pear-shaped, clavate, or stalactitic form, 

 mixed with more or less irregular lumps of the same size. Some of 

 the longer tears are slightly agglutinated, but most are distinct. The 

 predominant forms are rounded, — angular fragments being less fre- 

 quent, though the tears are not seldom fissured. Small pieces of the 

 translucent brown papery bark are often found adliering to the flat 

 pieces. The " Luban Fasous Bedow " as exported from the Mijjertheyn 

 district, in the eastern part of the Somali Country, is in very fine 

 large tears. 



The colour of the drug is pale yellowish or brownish, but the finer 

 qualities consist of tears which are nearly colourless or have a greenish 

 hue. The smallest grains only are transparent, the rest are trans- 

 lucent and somewhat milky, and not transparent even after the 

 removal of the white dust with which they are always covered. 

 But if heated to about 94° C, they become almost transparent. 

 When broken they exhibit a rather dull and waxy surface. Exa- 

 mined under the polarizing microscope no trace of crystallization is 

 observable. 



Olibanum softens in the mouth ; its taste is terebinthinous and 

 slightly bitter, but by no means disagreeable. Its odour is pleasantly 

 aromatic, but is only fully developed when the gum-resin is exposed 

 to an elevated temperature. At 100° C. the latter softens without 

 actually fusing, and if the heat be further raised decomposition begins. 



Chemical Composition — Cold water quickly changes olibanum 

 into a soft whitish pulp, which when rubbed down in a mortar forms 

 an emulsion. Immersed in spirit of wine, a tear of olibanum is not 



^ Loc. cit. yah, in Journ. of R. Geograph Society, 



' On the neighbourhood of Bunder- Mura- xxii. (1872) 65. 



