The Principles of Leather Manufacture

by H. R. Procter

Eucalyptus longifolia bark, the “woolly-butt” of Australia, contains 8·3 per cent. of tannic acid, and 2·8 of gallic. The “peppermint” tree contains 20 per cent. of tannic acid in its bark. The “stringy-bark” (E. obliqua) gives 13¹⁄₂ per cent. of kinotannic acid. The Victorian “iron-bark” (E. leucoxylon) contains 22 per cent. of kinotannic acid, but is available only for inferior leather.

Myrtus communis, and several other myrtle species, contain a considerable amount of tannin in the bark and leaves.

GRANATACEÆ.

Punica Granatum, Pomegranate. Peel of fruit employed in Spain and the East as substitute for sumach, containing up to 25 per cent. of tannin. Bark said to contain 22 per cent. tannin. Balaustines, wild pomegranates, East Indies. Fruit, said to contain 46 per cent. tannin.

ROSACEÆ.

Tormentilla erecta, Potentilla tormentilla. Root variously stated to contain 20-46 per cent. tannin. Red coloured leather, formerly used in Orkneys, Shetland, and Faroe Islands, and in some parts of Germany.

Sorbus or Pyrus Aucuparia, Mountain Ash. Bark said to be stronger than oak.

Many other plants of the family contain tannin, among others the strawberry.

PAPILIONACEÆ.

Butea frondosa.[147] This (with Pterocarpus marsupium)[148] furnishes East Indian kino. The flowers are used in India as a dye, under the name of Tesu. Bark fairly rich in tannin.