EOSEMARY. 411 



No. 1 was examined when about 6 months old and again about 9 

 months after, with the same result.* 



Chemical chaeacters. Freedom from Petroleum, Besin, and other 

 non-volatile srchstances. — 1 c. c. of each sample was evaporated in a 

 platinum basin on a water-bath. Neither sample left any 

 weighable residue, only just sufficient to render the dish slightly 

 sticky. 



Freedom from alcohol. To each sample a fragment of magenta 

 was added (before the addition of chloride of calcium). Samples 

 1 and 4 remained free from pink coloration. Nos. 2 and 3 were 

 very faintly coloured, but not more so than would be due to the 

 trace of moisture present. 



Reaction with Nitric acid. Two drops of the oil are added to 6 

 drops of nitric acid (sp. gr. I'o). With each sample the following 

 reaction occurred : — A bright orange-brown colour, then brisk 

 effervescence, becoming at the same time paler in tint ; No. 4 

 reacted much more violently than Nos. 1 and 2 and hissed slightly. 

 No. 3. being intermediate. Dragendorff says, " Eed, then brown, 

 no hissing." 



Reaction with Sidphuric acid. Two drops of the oil with 4 

 drops of sulphuric acid (sp. gr. 1-843) in each case assumed a pale 

 orange-brown colour, becoming darker and redder by standing. 

 Dragendorff says, " brown, then red-brown." 



Reaction with Hydrochloric acid. This and the two following 

 tests are taken from a paper by Charles Noel which appeared in 

 L' Union Pharmaceutique, 1886-1887. They are modifications of 

 tests originally proposed by Dragendorff.f Five drops of oil are 

 mixed with 1 c. c. of hydrochloric acid (sp. gr. 146) and heated to 

 ebullition ; 4 c. c. of chloroform are added, the whole agitated, and 

 then allowed to stand, the colour of the two layers of liquid being 

 observed. With each of these oils the liquids remained almost 

 colourless, the acid layer being faintly yellowish. 



* Schimmel says (Bericlit, April, 1891), foreign Rosemary oil dissolves at a 

 temperature of 20° C. in ^ to U parts of 90 per cent, alcohol, forming a clear 

 solution. Further, on the addition of a larger quantity of the same alcohol the 

 solution remains clear. Oil adulterated with American turpentine "will be 

 dextrogyre, but this sophistication will be readily recognised by the anomalous 

 specific gravity and the difficult solubility in 90 per cent, alcohol. 



t " Studies upon Essential oils," Pharm. Journ. [3], vi., p. 681. 



