144 BURSERACEiE. 



Bruckner (1867) found this portion to yield 75-6 per cent, of carbon and 

 9 '5 of hydrogen. The resin which the bisulphide refuses to dissolve, is 

 freely soluble in ether. It contains only 5 7 "4 per cent, of carbon. The 

 resin of myrrh to which, when moistened with alcohol, a small quantity 

 of concentrated nitric or hydrochloric acid is added, assumes a violet 

 hue, but far less brilliant than that displayed by resin of galbanum 

 when treated in a similar manner. But a most intensely violet liquid 

 may be obtained by adding bromine to the resin dissolved in bisulphide 

 of carbon. If the resin of myrrh as afforded by alcohol is warmed 

 with petroleum (boiling at 70° C)., only a small amount of resin is 

 dissolved. This liquid becomes turbid if vapours of bromine are 

 added ; a violet flocculent matter deposits, whereas the just above- 

 mentioned solution in the bisulphide continues clear on addition of 

 bromine. 



The resin of myrrh is not capable of affording umbelliferone like 

 that of galbanum. By melting it with potash, pyrocatechin and pro- 

 tocatechuic acid are produced in small amount. 



Myrrh yields on distillation a volatile oil which in operating on 

 25 lb. of the drug, we obtained to the extent of f per cent.^ It is a 

 yellowish, rather viscid liquid, neutral to litmus, ha\Ting a powerful 

 odour of myrrh and sp. gr. 0'988 at 13° C.^ In a column 50 mm. long, 

 it deviates a ray of light 30'1° to the left. By submitting it to dis- 

 tillation, we obtained before the oil boiled, a few drops of a strongly acid 

 liquid having the smell of formic acid. Neutralized with ammonia, this 

 liquid produced in solution of mercurous nitrate a whitish precipitate 

 which speedily darkened, thus indicating formic acid, which is de- 

 veloped in the oil. Old myrrh is in fact said to yield an acid distillate. 

 The oil begins to boil at about 266° C, and chiefly distills over between 

 270° and 290°. 



On combustion in the usual way it afforded carbon 84*70, hydrogen 

 9"98. Having been again rectified in a current of dry carbonic acid, it 

 had a boiling point of 262-263° C, and now afforded ^ carbon 8470, 

 hydrogen 10'26, which would nearly answer to the formula C^-H^^O. 

 The results of Ruickholdt's analysis (1845) of essential oil of myrrh 

 assign it the formula C"II"0, which is widely different from that indi- 

 cated by our experiments. 



The oil which we rectified displays a faintly greenish hue ; it is 

 miscible in every proportion with bisulphide of carbon, the solution 

 exhibiting at first no peculiar coloration when a drop of nitric or sul- 

 phuric acid is added. Yet the mixture to which nitric acid (1'20) has 

 been added, assumes after an hour or two a fine violet hue which is 

 very persistent, enduring even if the liquid is allowed to dry up in a 

 large capsule. If to the crude, oil dissolved in bisulphide of carbon 

 bromine be added, a violet hue is produced ; and if the solution is 

 allowed to evaporate, and the residue diluted with spirit of wine, it 

 as.sumes a fine blue which disappears on addition of an alkali. The 



iRuickholdt got 2-18 per cent.; Bley ^ Gladstone (1863) found the oil a little 



and Diesel (1845) from 1'6 to 3 4 per cent. heavier than water. 



of an acid oil. We are kindly informed * Analyses performed in my laboratory 



by Mr. Fritzsche of Leipzig (Messrs. Schim- by Dr. Buri, February, 1874. See also my 



mel & Co.) that good myrrh distilled on a paper on Carvol, Pharm. Journ. vii. (1876) 



large scale yields as much as 4"4 per cent. 75, or Yearbook of Pharraacy (1877) 51 — 



of oil. (Letter dated 13th June, 1878.) F.A.F. 



