OILS AND FATS. 373 



stalks, and fruits, which in some cases is very decided. 

 Some plants in South America and China contain so much 

 wax that it is obtained from them by boiling and pressure, 

 and is sold under the name of vegetable or Chinese wax. 

 But most of the wax in use in the world is made by bees. 

 It has been supposed that the bees simply gathered the 

 wax from flowers as it exists in the pollen; but this is 

 certainly not true in regard to all of it, for it has been sat- 

 isfactorily proved that the bees actually convert the sug- 

 ary substance into wax in their abdominal sacs. 



524. Volatile Oils. The oils which we have already no- 

 ticed are called faced oils, because they have no tendency 

 to pass off into the air. The volatile oils, of which oil of 

 turpentine, oil of peppermint, and oil of lemons are familiar 

 examples, nearly all possess the same chemical composition 

 C 10 H 16 ; they differ from the fixed oils in three important 

 respects : 1. As their name imports, they are readily dissi- 

 pated in the air. Some of them are exceedingly volatile. 

 Sometimes a volatile oil is adulterated with some fixed oil; 

 but this can be readily detected by dropping some of the 

 specimen on paper, for if it be adulterated it will leave a 

 grease spot upon it. 2. Volatile oils dissolve in alcohol. 

 Such solutions form the bases of essences and cordials and 

 perfumed waters, such as the Eau de Cologne. 3. They are 

 hydrocarbons, and not salts of fatty acids like the fixed oils. 

 The volatile oils are very numerous, as you -may readily 

 see from the fact that all the varied odors of plants are 

 due to their presence. They are most frequently pro- 

 duced in flowers and seeds, sometimes in the stalks and 

 leaves, and in some plants in the roots. Sometimes there 

 are several sorts of oil in the same plant. Thus there are 

 three different kinds of oil in the orange-tree one in the 

 leaves, another in the blossom, and still another in the peel 

 of the fruit. 



