ABSTRACT
The extraction of essential oils from the plants which contain them is accomplished in most cases by a process of distillation with water. An essential oil is distinguished from the fatty oils first by a strong and characteristic odour; it usually floats on water, but it is slightly soluble, for the odour is commonly communicated to the water, as in such instances as the familiar rose-water or orange-flower water. The use of perfumes is a form of luxury which in ancient times was probably limited to the rich but in own day they are used more or less unconsciously by everybody. Common camphor is a natural constituent of several essential oils, especially those of lavender, rosemary, and sage. As may be imagined the prices of the individual oils differ greatly. The history of essential oils would not be complete without at least a passing reference to the extensive class of hydrocarbons called terpenes.
