138 Dr. Kane on the Composition of certain Essential Oils. 



Hence there is per cent. 



A. B. C. D. 



Carbon = 86.71 86.08 86.33 86.18 



Hydrogen = 11.11 11.44 11.44 11.64 



Oxygen = 2.18 2.48 2.23 2.18 



These results are expressible by a very simple formula, c^ h^q o, or 

 10 {C5H4} -|- o, which gives 



c^= 307 86.48 



H«= 40 11.27 



0=8 2.2.5 



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

 to that generally taken by errors of experiment in organic analysis, but so 

 trivially, that I am not inclined to attribute to it any importance. From the 

 remarkable 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, attributed to oxygen, arose from the loss consequent on an im- 

 perfect combustion ; but that idea is disproved by — first, the uniformity 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 

 Oxygen = 4.72 

 being a mixture, it admits of no formula. 



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