156 VOLATILE OILS. 
The fruit of the Bead-tree (Melia) also furnishes a consider- 
able quantity of oil. . 
2. VOLATILE OILS. 
595. These are not confined to any particular part of the 
plant, but are found in the root, the stem, the leaves, the 
flowers, or the rind of the fruit. They are characterized 
by possessing some strong and peculiar odour; and the 
odours of different plants seem to depend upon some volatile 
oil. They are obtained by placing the vegetable in water, 
and distilling ; the oil rising in vapour along with the water, ~ 
and being condensed in the receiver. 
596. They have a strong and fragrant odour, and a hot 
and acrid taste, and are yolatilized by a temperature of 320° ; 
when distilled along with water, rising in vapour at 212°. 8 
Little attention has been paid to the composition of volatile 
oil. “According to Dr. Ure, oil of turpentine consists of— 
Carbon, ; : = z 82.35 
Oxygen, . : ‘ é 9.80 
Hydrogen, . . : Z 7.85 
100 parts. 
When purified by distillation, it has been found by some che- 
mists to contain no oxygen. Sa! 
597. The number of vegetables which afford volatile oil is 
very great. Almost every plant possessing any marked odour 
owes it to a volatile oil. The following are the principal 2 
volatile oils : : 
Caryophyllus aromaticus. 
Melaleuca minor. 
Laurus cinnamomum. 
Citrus limonum. tS 
Citrus aurantium, et vulgaris- 
ee ; : 
