354 



The World's Commercial Products 



per cent. 



Canaigre or " Tanner V 

 Dock" 



This product is one of the 

 few roots used as a tanning 

 material. The plant is a 

 native of Mexico and the 

 Southern parts of the United 

 States, and is now exten- 

 sively cultivated in those 

 regions for the sake of its 

 root. It is best grown 

 from tubers, which should be 

 planted out in the autumn, 

 but may be also raised from 

 seed. The roots are har- 

 vested in the second year, 

 and are cut into slices, which 

 are dried in the sun or made 

 into " canaigre extract." 

 Good canaigre may contain 

 from twenty-six to thirty 

 of tannin, and yields a firm heavy leather of a bright orange colour. 



mangrove thicket 



Quebracho 



This material, which owes its name to its exceptional hardness, quebracho being a corrup- 

 tion of the Spanish word for " axe-breaker," consists of the wood of a South American tree, 

 Quebrachia (Loxopterygium) Lorentzii. The tree is a fairly large one, and is grown on an 

 enormous scale in the Argentine Republic. The wood contains about twenty per cent, of 

 tannin, and yields a firm but rather reddish leather. 



Myrabolans 



This, one of the most important Indian tanning materials, especially for export purposes^ 

 consists of the unripe fruits of Terminalia chebula or T. belcrica, trees which are common in 

 India, especially in Madras and the Central Provinces. The fruits are collected when full 

 grown but still unripe, and are prepared for the market merely by drying in the sun. 



Gambier 



This material is also known as " white catechu." It is an extract prepared from the leaves 

 and branches of a climbing plant, Uncaria gambier, which grows in the East Indies, especially 

 in Malaysia. For the production of gambier, the trees are cropped almost bare of twigs four- 

 times a year from the. time when they are three years old, so long as they bear well. The 

 twigs with the leaves are chopped small and extracted by being boiled with water in copper 

 pans until a syrupy liquor is formed. This is strained and allowed to flow into tubs, m 

 which it sets to a brownish-white, semi-crystalline solid, which while still soft is cut into' 

 approximately one-inch cubes. 



Mangrove Bark 



''"/'The mangroves are an interesting group of trees, which inhabit the swampy foreshores of 

 tropical countries where they form forests frequently of vast extent. The barks of all the 

 mangroves appear to contain more or less tannin, but the species, which have so far been 



