4.4'0 Dr. Kane on the Composition of certain Essential Oils. 



The first analysis deviates a little from this result, in the 

 direction opposite to that generally taken by errors of ex- 

 periment in organic analysis, but so trivially, that I am not 

 inclined to attribute to it any importance. From the re- 

 markable relation of the formula to that of oil of turpentine, 

 it may, perhaps, be thought that possibly the oil of origanum 

 had the same composition, and that the two per cent, attri- 

 buted to oxygen, arose from the loss consequent on an imper- 

 fect combustion ; but that idea is disproved by — first, the uni- 

 formity of the analyses which were made at different times 

 and on different quantities of oil ; and secondly, by the fact 

 that in only the fourth analysis does the hydrogen amount to 

 what oil of turpentine should yield, that is 11*55 per cent., 

 the general error in analysis being to give too high a value 

 for the hydrogen. The stearopten of this oil would appear 

 to contain much more oxygen than the oil itself; as a quantity 

 of oil which contained some, and had consequently a boiling 

 point of 344°, gave the following results : 



Material = 0*360 gramme gave 

 Water = 0-350 



Carbonic acid = 1*100 

 Hence per cent. 



Carbon = 84-48"| 

 Hydrogen = 10-80 ^100 

 Oxygen = 4-72 J 

 being a mixture, it admits of no formula, 



III. Oil of Peppermint. 



This oil had been submitted to analysis by Blanchet and 

 Sell *, but their results having been communicated without 

 any detail, and the analyses being exceedingly discordant, I 

 was obliged to re-examine its constitution before I could satisfy 

 my mind. The result has been, that I have obtained a for- 

 mula differing from that of the chemists before named. 



The oil of peppermint of commerce, particularly that sold 

 as American, is often adulterated by a large quantity of oil of 

 turpentine, from which, if once mixed, no number of rectifi- 

 cations can completely purify it. The rough oil, when pure, 

 has, according to Brande, a specific gravity 0"907 ; I found it 

 0-9083. It contains a certain quantity of stearopten, though 

 not so much as the generality of oils; when freed from this 



* Jourml de Fhannacic, vol. xx. 1834. 



