LEAVES FOR TANNING. 167 



as Butea frondosa, Semecarpus Anacardium, Diospyros Melanowylon, 

 &c., are often used in the vicinity of forests. Matting of palm leaves 

 is often placed directly over the timbers of a roof before the grass 

 thatch is put on and lasts for more than ten years. 



Section V. — Leaves foe tanning. 



The leaves of a few species, such as Anogeissus latifolia, Elms 

 Cotinus, &c., are used in tanning. The leaves should be collected 

 only when they are mature, but while they are still full of sap and 

 before their colour changes previous to their being shed. The 

 change of colour results from the appearance of colouring matters, 

 ■which have their effect on the leather. Hence for white or light- 

 coloured leathers there ought to be no delay in picking. The high- 

 est quality of leaves is obtained nearest the ends of the branches. 

 After being picked, the leaves should be first wilted, then spread 

 out and quickly dried, either in the sun or on racks arranged one 

 above another in a heated room. To accelerate the process, the 

 leaves should be frequently turned. Leaves properly dried should 

 bo greenish. For convenience of export, the leaves should be 

 ground into a coarse meal. 



The dried leaves of the various species of Rhus used for tanning 

 contain 16 — 24 per cent, of gallo-tannic acid, and make a soft, pale- 

 coloured leather. The leaves of Anogeissus give a similar leather, 

 and the samples analysed by Professor Hummel yielded 15^ per 

 cent, of tannin, while those of the leaves of Phyllanilivs Emhlica 

 gave as much as 18 per cent. The decoction of the leaves of both 

 those species obtained by the Professor was of a pale yellow colour 

 and slightly turbid. 



Section VI. — Some othek dses of leaves. 



The leaves of Melaleuca Leucadendron yield the Cajuput oil of 

 commerce. The leaves of Terminalia Caiappa, Bavcaurea sapida, 

 and some other species are used in dyeing, those of the first giving 

 a black dye. The leaves of Butea frondosa, Bauhinia VaJdii, and 

 Cordia Myxa are very largely used by Hindus in the place of plates 

 and cups. The plates are formed of several leaves pinned together 

 with long spines or stiff grass stalks, while the cups consist of one 

 or several leaves bent and pinned to the proper shape. The same 

 leaves are also used by shopkeepers to wrap round grocery and 

 other small articles that they sell. Ji'or these various purposes the 

 leaves in question are exported to great distances. The leaves of 

 the plantain are also used for plates. Both the leaves of the plan- 



