OILS 
201 
Still firmer fatty bodies, used as grease or butter, occur in 
Bassia, Butyrospermum, Caryocar, Pentadesma, Sapium, &c.; 
while wax is obtained from Ceroxylon, Copernicia, Myrica, 
Rhus, &c. 
Volatile oils are distilled from Andropogon (citronella, 
lemon-grass, &c.), Calamintha, Cananga, Cinnamomum 
(cinnamon, &c.), Citrus (lemon, &c.), Eucalyptus, Eugenia 
(clove), Gaultheria, Jasminum, Lavandula (lavender), Lippia, 
Melaleuca, Mentha, Moringa, Nardostachys, Origanum, Pelar- 
gonium, Pogostemon (patchouli), Reseda, Rosa, Rosmarinus, 
Santalum (sandalwood), Sassafras, Thymus, Viola, and many 
others. 
III. Dyes and Tanning-stuffs. Many vegetable 
dyes are now superseded by artificial products, e.g. madder by 
alizarin, but a large number are still in use. In some cases 
the colouring matter exists in the plant as such, in other 
cases it is prepared by oxidation or otherwise. Among the 
more important plants yielding dyes are Alkanna, Bixa 
(annatto), Carthamus (rouge), Chlorophora (fustic), Clad- 
rastis, Crocus (saffron), Crozophora, Curcuma (turmeric), 
Garcinia (gamboge, cf. resins), Haematoxylon (logwood), 
Indigofera (indigo), Isatis (woad), Lawsonia, Madura (fustic), 
Morinda, Nopalea (used for feeding cochineal insects), 
Peganum (turkey red), Reseda, Rhamnus, Rhus, Rubia 
(madder), &c. 
* Tannin is contained in many plants and parts of plants ; 
it often occurs in the cells of growing parts, and is then 
apparently useful in the metabolism. It very often occurs 
as an excretum in the bark and elsewhere, and it is such 
parts that are chiefly used as sources of it for commercial 
purposes. Among the more important genera yielding 
tan-stuffs may be mentioned Acacia (cutch), Betula, Butea, 
Byrsonima, Castanea (chestnut), Caesalpinia (dividivi), 
Gordonia, Pterocarpus (Malabar kino), Eucalyptus, Quercus 
(oak), Rhizophora, Rhus, Rumex, and many others. 
IV. Fibres. Fibres are usually the mechanical 
tissues of plants (pp. 43, 48), and are arranged at the 
places where strains occur, the amount of the mechanical 
tissue developed depending to a considerable extent upon 
the strain to which the part is subjected. Superficial 
fibres occur on seeds, leaves, &c. 
