Dr. Stenhouse on the Oils of Hyssop, Assafcetida, S^c. 275 



it is evidently a mixture of several oils. In order to deter- 

 mine this more certainly, the anhydrous oil was rectified, and 

 the product of its distillation at different temperatures collected 

 separately and subjected to analysis. The following are the 

 results: — 



(1.) 0-289 gramme, boiling at 288° F., gave 0-8794' carbonic 

 acid, and 0-2875 water. 



(2.) 0-3022 gramme, boiling at 299° F., gave 0-8885 car- 

 bonic acid, and 0-298 water. 



(3.) 0-2838 gramme, boiling at 335° F., gave 0-8243 car- 

 bonic acid, and 0-2671 water. 



It will at once be perceived from these results, that the por- 

 tion of the oil richest in carbon and hydrogen distils over at 

 a comparatively low temperature, and that as the quantity of 

 oxygen in the oil increases, its boiling point rises. This is 

 what usually takes place with oils which consist of a mixture 

 of a carburetted hydrogen, and more or less oxygenated oils. 

 I was induced therefore to try if these different oils could be 

 separated by treating them with fused potash — the method so 

 successfully employed by Messrs. Gerhardt and Cahours with 

 oil of cumin, and which promises to be extremely useful in 

 the investigation of this class of bodies. The oil of hyssop 

 was dropped upon the potash through a capillary opening in 

 the tubes of a retort. As soon as the oil came in contact with 

 the melted potash, the greater portion of it was converted into 

 a brownish resin, but a part of it passed into the receiver. 

 This portion was again subjected to the action of the potash, 

 when still more of it was converted into resin. What di- 

 stilled over was considerably different in taste and smell from 

 ordinary oil of hyssop. When subjected to analysis, 

 0-3047 gramme gave 0-955 carbonic acid, and 0*313 water, = 



Carbon 86-65 



Hydrogen 11-41 



Oxygen 1-94 



Too-00 



It is evident, therefore, that I did not succeed in converting 

 oil of hyssop into a pure carburetted hydrogen, though the 

 quantity of the oxygenated oil was considerably diminished. 



Oil of Assafcetida . 

 It is to this oil that assafcetida owes its highly offensive 



