OLIBANUM. 139 



altered much in form, but it becomes of an almost pure opaque 

 white. In the first case the water dissolves the gum, while in the 

 second the alcohol removes the resin. We find that pure olibanum 

 treated with spirit of wine leaves 27 to 35 of gum,^ which forms a 

 thick mucilage with three parts of water. Dissolved in 5 parts of water 

 it yields a neutral solution, which is precipitated by perchloride of iron 

 as well as by silicate of sodium, but not by neutral acetate of lead. It 

 is consequently a gum of the same class as gum arable, if not identical 

 with it. Its solution contains the same amount of lime as gum 

 arable affords. 



The resin of olibanum has been examined by Hlasiwetz (1867), 

 according to whom it is a uniform substance having the composition 

 Q2JJJ30Q3 -y^T-g gjj(j jT^Q^ ji; jg jjQ^ soluble in alkalis, nor have we suc- 

 ceeded in converting it into a crystalline body by the action of dilute 

 alcohol. It is not uniformly distributed throughout the tears ; if they 

 are broken after having been acted upon by dilute alcohol, it now and 

 then happens that a clear stratification is perceptible, showing a con- 

 centric arrangement. 



Olibanum contains an essential oil, of which Braconnot (1808) 

 obtained 5 per cent., Stenhouse (1840) 4 per cent., and Kurbatow 

 (1871-1874) 7 per cent. According to Stenhouse it has a sp. gr. of 

 0'8G6, a boiling point of 179"4° C, and an odour resembling that of tur- 

 pentine but more agreeable. Kurbatow separated this oil into two 

 portions, the one of which has the formula C'"H^*, boils at 158° C, and 

 combines with HCl to form crj^stals; the other contains oxygen. The 

 bitter principle of olibanum forms an amorphous brown mass. 



The resin of olibanum submitted to destructive distillation affords no 

 umbelliferone. Heated with strong nitric acid it develops no peculiar 

 colour, but at length camphretic acid (see Camphor) is formed, which 

 may be also obtained from many resins and essential oils if submitted 

 to the same oxidizincj aofent. 



Commerce — The olibanum of Arabia is shipped from several small 

 places along the coast between Damkote and Al Kammar, but the 

 quantity produced in this district is much below that furnished by the 

 Somali Country in Eastern Africa. The latter is brought to Zeyla, 

 Berbera, Bunder Murayah, and many smaller ports, whence it is 

 shipped to Aden or direct to Bombay. The trade is chiefly in the 

 hands of Banians, and the great emporium for the drag is Bombay. A 

 certain portion is shipped through the straits of Bab-el-Mandeb to 

 Jidda, — Von Kremer^ says to the value of £12,000 annually. The 

 quantity exported from Bombay in the year 1872-73 was 25,100 cwt., 

 of which 17,446 cwt. were shipped to the United Kingdom, and 6,184 

 cwt. to China.^ 



Uses — As a medicine olibanum is nearly obsolete, at least in 

 Britain. The great consumption of the drug is for the incense used 

 in the Roman Catholic and Greek Churches. 



^ I obtained 32 "14 per cent, from the ^ Aerpjpten, Forscfningen iiber Land und 



finest tears of the kind called Fasous Volk, Leipzig, 1863. 



Bedowi, with which I was presented by ^ Statement of the Trade and Navigation 



Capt. Hunter of Aden.— F.A.F. of the Presidency of Bombay for 1872-73, 



pt. ii. 78. 



