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



with the climate. Thus, in the oil from the south of Europe (Murcia), it is said to 

 amount to more than one-half its weight, and I have often found a fourth of the 

 English oil to remain behind on distillation, so loaded with stearopten as to be- 

 come quite solid on cooling. These circumstances, — the quantity of solid matter, 

 and its not differing very much in volatility from the oil, — present great obstacles 

 to the obtaining oil of lavender In an absolutely pure condition. 



The oil examined by Mr. Brande, and which probably contained much 

 stearopten, was found by him of a specific gravity 0.9206. In the specimen 

 which I tried the specific gravity was 0.9174. By repeated rectifications, by 

 which as much of the solid matter as possible was separated, it was obtained 0.8865, 

 and then boiled at 370° F. Another portion equally rectified had a specific 

 gravity 0.8745, and boiled at 365° F. Saussure, who likewise examined this 

 oil, states its specific gravity, when pure, to be 0.877. 



A specimen of the commercial oil, the specific gravity of which was 0.9172, 

 was rectified, and the product received in four different vessels, stopping when 

 the residue in the retort appeared to become thick. 



No. 1 had sp. gr. = 0.8864 1 



2 =0.8879 AU boiled between 360° and 370°. 



3 = 0.8884 J 



4 = 0.9050 boiled at 390°. 



The residue solidified by cooling. The difficulty of pronouncing on the absolute 

 purity of any one portion of oil of lavender is thus evident. 



The analysis of this oil was conducted in the usual way. Different portions 

 of oil were selected, in consequence of their boiling points and specific gravities 

 not being in accordance. 



A. Specimen sp. gr. = 0.8865 ; boiling point = 370° F. 



Material = 0.4333 gramme gave 



Water = 0.441 



Carbonic acid = 1.245 



B. Specimen sp. gr, = 0.8745 ; boiling point 365°. 



Material = 0.2835 gramme gave 



Water = 0.299 



Carbonic acid = 0.819 



