334 ODOROGRAPHIA. 



wiutergreeii oils, depending upon variations in their power of 

 dissolving Fuchsine (Aniline red). The greater solubility of 

 fuchsine in the artificial oil is erroneously ascribed to the presence 

 of methyl alcohol. However, as fuchsine is soluble in methyl 

 salicylate, and as the natural oil, besides this body, contains 

 Terpene, which does not dissolve fuchsine, the solvent power of 

 the natural oil is consequently less than that of the artificial. 

 The difference is, however, owing to the small percentage of 

 terpene present, not important enough to distinguish the two 

 products from each other, much less to recognise a mixture of 

 them, and accept it as a test. Oils which are abundantly 

 adulterated with Kerosene, paraffine oil or turpentine will have a 

 conspicuously less solvent power for fuchsine.* This fact is 

 sufficient to characterise the test as w^orthless. 



It is considered by Dr. Power (the most eminent autliority on 

 "Wintergreen oil known) that the detection of sassafras oil with 

 nitric acid, according to the instructions of the United States 

 Pharmacopoeia, may lead to false results, and he formulates a test 

 based upon his own observations, as follows : — 



" To 1 c. c. m. of the AVintergreen oil, Birch oil or synthetical 

 methyl salicylate, under examination, 5 c. c. m. of a 5 per cent 

 sodium hydroxide solution are added, and the mixture shaken 

 together in a large test-tube. A voluminous white crystalline 

 yjrecipitate is formed, and if the corked tube be placed in hot 

 water and frequently shaken for about five minutes, solution 

 ensues, and the contents must show a clear colourless or slightly 

 yellowish liquid, with no separation of oily drops either on the 

 surface or at the bottom of the solution. This is a proof of the 

 absence of other essential oils and petroleum. If the solution is 

 then diluted with three times its volume of w^ater and slightly 

 acidulated with hydrochloric acid, a white crystalline precipitate 

 is formed, which, collected upon a filter, washed and re-crystallised 

 out of hot water, should answer all the tests for pure salicylic 

 acid — showing the absence of methyl benzoate, &c." 



Dr. Power has convinced himself that in the above manner 

 admixtures of 5 per cent, of sassafras or camphor oils can be 

 readily detected, not only by the separation of visible oily drops, 



* PoAver, ill Pharmazeutisclie Rundschau, 1889, p. 283. 



