602 SYSTEMATIC BOTANY. 



tainty as to the species from wMch our supplies are derived ; bnt they are 

 chiefly, if not entirely, obtained from Fraxinus Ornus or Ornus europcea, and 

 F. roiundifolia or Ornus roiundifoUa. These plants are natives of the south 

 of Europe and Asia Minor, but our supplies of Manna are chiefly derived 

 from Calabria and Sicily, where the trees are cultivated for the purpose. 

 Manna is a mild agreeable laxative. It owes its properties to mannite, and 

 a peculiar resin. Fraxinus chinensis is the tree upon which the insect 

 {Coccus Pe-la) producing the AYhite Wax of China feeds. 



Olea. — Oha eixrvpcea, the Olive. — The ripe fruit has a very fleshy pericarp ; 

 this yields by expression the fixed oil, known as Olive Oil, and which 

 is so largely used for dietetical purposes, in the arts, and in medicine. 

 In medicine it is principally employed externally, either by itself, or in com- 

 bination with other substances. When administered internally, it is nutrient, 

 emollient, demulcent, and laxative. The olives used as a dessert are prepared 

 by first soaking the green unripe fruits in water to deprive them of a portion 

 of their bitter flavour, and then preserving them in a solution of salt slightly 

 aromatised. The leaves and bark of the Olive-tree have been highly extolled 

 by some writers for their tonic and febrifugal properties, and they certainly 

 deserve more attention as remedial agents than they have hitherto obtained 

 in this country. The substance called olive gum or olivile is a resinous exu- 

 dation from the Olive-tree. It was formerly employed in medicine, biit at 

 present is not applied to any useful purpose. The wood of the Olive is much 

 used for cabinet-work. The flowers of Olea fragrans are employed in China 

 to give odour and flavour to a particular kind of tea. 



Syringa vulgaris, the Lilac, has a bitter tonic, and febrifugal bark. 



Natural Order 157. Jasminackte. — The Jasmine Order, — 

 Character. — Shrubs, often twining. Calyx persistent, with 

 5 — 8 divisions. Corolla regular, 5 — 8-partite ; cedivation imbri- 

 cated. Stamens 2, included. Ovary 2-lobed, 2-celled, with 1 — 4 

 erect ovules in each cell. Fruit a capsule or berry. Seeds 

 with very little or no albumen ; embryo erect. 



Distribntmi, ^'c. — Chiefly natives of the East Indies, but a few 

 species are found in several other warm regions of the globe. 

 Examples of the Genera : — Jasminum, Nyctanthes. There are 

 about 100 species. 



Pro2)erties and Uses. — The flowers are generally fragrant. 

 The volatile oil of jasmine, which is used in perfumery, is chiefly 

 obtained by distillation from the flowers of Jasminum officinale 

 and J. grandifloritm. The fragrant flowers of J. Samboc 

 are used as votive offerings in India; they are also said to 

 have much power in arresting the secretion of milk. The leaves 

 and roots of some species of Jasminum are reputed bitter, and 

 have been employed for various purposes, but generally speaking 

 the order contains no active medicinal plants. The flowers of 

 Nyctanthes arbor-tristis are employed in India for dyeing yellow. 



Natural Order 158. SALVADOEACEiE. — The Salvadora Order. — 

 Character. — Shrubs or small trees. Leaves opposite, entire, 

 leathery. Flowers small, panicled. Calyx of 4 sepals. Corolla 

 4-partite, membranous. Stam.ens 4. Omr?/ 1 -celled ; stigma sessile. 

 Fruit fleshy, 1 -celled, with a solitary erect seed. Albumen none. 



Distribution, ^-c. — Natives of India, Syria, and North Africa. 

 Examples of the Genera: — Salvadora, Monetia. 



PropertiiS and Uses. — Some are acrid and stimulant. The 



