Areca catechu, Betel-Nut Palm of India. Yields a species of cutch of no importance for tanning.
Sabal serrulata, Saw Palmetto of Florida (Trimble). (“Dwarf” palmetto is S. Adansonia.) Palmetto root has been much talked of as a tanning material; and makes a light-coloured leather.
An extract is now made from the roots of the Saw Palmetto, which grows freely in the Southern States of America, and is especially abundant on the east coast of Florida. The plant is an evergreen, the stem growing flat along the ground, being held in place by numerous roots each the size of a pipe-stem. The leaves are fan-shaped and ribbed, and two to three feet in diameter. In its hardihood the palmetto resembles a weed, as the leaves may be cut off quite close to the stem without damaging the plant, which will grow freely on poor sandy land which is worthless for other purposes. The average yield is stated to be about 10 cwt. to the acre, but in good seasons and with rich land, over a ton per acre has been obtained.
The air-dried leaves contain about 13 per cent. of tannin, but the results obtained by different chemists vary from 5 to 20 per cent. Possibly these variations are caused by the different amounts of moisture in the various samples.
The leaves must be treated with a solution of caustic soda, to remove the glossy siliceous shield which covers them and prevents their being easily extracted. After the tanning matter has been extracted the remaining fibre can be profitably disposed of to paper and rope manufacturers.
As the supply of palmetto is very large it is likely that it will, to a considerable extent, substitute the employment of gambier, and in the United States the extract has already met with a considerable sale. Samples of the extract examined by the Author analysed from 16-22 per cent. of tanning matter, and several per cent. of mineral matter, and produced a very soft and mellow leather of good colour. The extract contains noticeable quantities of common salt, and organic salts of soda which leave sodium carbonate on ignition.
Cocos nucifera, the Cocoa-nut Palm, also contains tannin in roots.
CASUARINÆ.
Casuarina equisetifolia L. (laterifolia Lam.); Filao bark, Reunion; Tjamara laut, Java; Casagha or Tinian Pine, Ceylon. Widely distributed in Southern Asia, bark used for tanning and dyeing. Tannin gives blue-blacks with iron. Several other species very similar in structure and properties. (Von Höhnel.) Hooper found 11-18 per cent. of tannin.