| C₆H₄ |  | CHO |
| C₃H₇ , |
a liquid of sp. gr. 0·972, boiling point 237° C. It has also been met with, in 1858, by Trapp in the oil of Cicuta virosa. By boiling cuminol with potash in alcoholic solution, cuminalcohol,
| C₆H₄ | | CH₂OH |
| C₃H₇ , |
as well as the potassium salt of cuminic acid,
| C₆H₄ | | COOH |
| C₃H₇ , |
are formed.
The oil of cumin, secondly, contains a mixture of hydrocarbons. That which constitutes about one-half of the crude oil has been first obtained in 1841 by Gerhardt and Cahours, just from the oil under notice, and therefore called Cymene (or also Cymol). It is a liquid of 0·873 sp. gr. at 0° (32° F.), boiling at 175°; neither cymene nor cuminol have the same odour and taste as the crude oil. Many other plants have been noticed as containing cymene among the constituents of their essential oils. Thus for instance Cicuta virosa L., Carum Ajowan (page 304), Thymus vulgaris (see art. Folia Thymi), Eucalyptus globulus Labill.
| Cymene, C₆H₄ | | CH₃ (Propylmethyl-benzol), |
| C₃H₇ |
may also be artificially obtained from a large number of essential oils having the composition C₁₀H₁₆, or C₁₀H₁₄O, or C₁₀H₁₆O, or C₁₀H₁₈O. It differs very remarkably from the oils of the formula C₁₀H₁₆, inasmuch as cymene yields the crystallizable cymen-sulphonic acids when it is warmed with concentrated sulphuric acid.
Lastly, there is present in the oil of cumin a small amount of a terpene, C₁₀H₁₆, boiling at 155·8° C., as stated in 1865 by C. M. Warren, and in 1873 by Beilstein and Kupffer.