84 



easily procured in commerce, Professor Kane considered 

 that the determination of the composition of the products of 

 certain members of a botanical group, whose natural con- 

 nexion is among the best marked, might tend to throw some 

 light upon the question at issue. He, therefore, examined 

 the oils of the origanum vulgare, lavandula spica, mentha 

 piperita, mentha puleghium, and mentha sativa. Great diffi- 

 culty was found in obtaining the specimens so absolutely 

 pure as to fit them for analysis, as all such oils contain small 

 quantities of solid matters, (camphors of the essential oils, 

 stearoptens,) which render impure the later products of the 

 rectification. 



Repeated analyses of the oil of the mentha puleghium, 

 gave for its composition the same formula as for oil of tur- 

 pentine, or oil of lemons, that is c^h^, or per cent. 



Theory. Experiment. 



Carbon zz 88,45 - 88,56 

 Hydrogen =11,55 - 11,87 



Its boiling point is about 814° F., the same as that of tur- 

 pentine. 



The oil of mentha sativa, boiling at 320° F., gave, by 

 several accordant analyses, the formula, 



C35H28O or VjCsHJ+Oj and per cent. 



Theory. Experiment. 



Carbon = 85,67 - 85,66 

 Hydrogen =11,15-11,38 

 Oxygen zz 3,18 - 2,96 



The oil of the origanum vulgare, boiling at 3^4*^ F., gave 

 as the result of five analyses, which varied very Uttle from 

 one another, the formula, 



CsoH.oO or lOlc^Hj-f 0, and per cent. 



