626 



TANNING MATERIALS 



TANNING MATERIALS 



Ohio and Indiana, and in the mountains to Alabama and 

 west to Michigan. The wood contains 3 to 10 per cent of 

 tannin, giving blue-black with iron salts. The older trees 

 contain the highest percentage of tannin. The bark con- 

 tains about 8 per cent. The wood is used for making 

 extracts which give a firm leather, with a good deal of 

 bloom if used strong, and a more reddish tint thanvalonia. 

 The extract often contains dark coloring matters, and the 

 color of leather tanned with it is readily darkened by 

 traces of lime. Like all wood extracts it tans rapidly, the 

 color penetrating first and the tan following. Decolorized 

 chestnut extracts, sometimes mixed with quebracho and 

 other materials, are often sold as " oakwood " extracts. 

 There were 187,000 barrels of chestnut extract made in 

 1905, and the use of this material is steadily increasing. 



Spanish chestnut {Castanea vesca) bark contains up to 

 17 per cent of tannin. The wood contains 3 to 6 per cent 

 of tannin and is used abroad for making extract. 



Sumac and related plants. 



Sicilian sumac (Rhus Coriaria) leaf contains 20 to 35 

 per cent of tannin which is principally gallotannic, with 

 some ellagitannic acid, and is the best tanning material 

 known for pale color and soft tanning, and hence is used 

 for moroccos, roans, skivers and the like. Sumac is fre- 

 quently adulterated with ground leaves and twigs of Pis- 

 tacia Lentiscus, Ailanthus glandulosa, Vitis vinifera, and 

 some other species of the Rhus family, but Pistaeia Len- 

 tiscus is used to a much larger extent than any of the 

 others. The stem contains but little tannin. Between 

 S00,000 and 400,000 tons of sumac leaf are imported 



annually. The Sicilian 

 sumac is cultivated 

 in Italy and Sicily. 

 The best leaf grows 

 on stony calcareous 

 mountain soils near 

 the sea and is known 

 as "Masculine," 

 while the leaf which 

 contains much less 

 tannin is called 

 feminella. 



Smooth sumac 

 (Rhus glabra, Fig. 

 ZS&Zii^ 850), Dwarf sumac 

 ^^SSSs* (B. copallina) and 

 Staghorn sumac (R. 

 hirta or R. typhina) 

 are native from the 

 St. Lawrence river 

 to the Gulf of Mexico 

 and west to the Mis- 

 sissippi river, in poor 

 soils, waste places, 

 and on the hills and 

 mountain sides. The 

 leaf contains 15 to 

 30 per cent of tan- 

 nin and makes leather of a rather darker color than 

 Sicilian sumac because it contains more coloring matter. 

 The leaf is extensively gathered in the mountains of 

 Pennsylvania, Maryland and Virginia and sells to the tan- 

 ners at $35 to $45 per ton. The leaf should be gathered 

 in July before it begins to turn red, as the percentage of 

 tannin is higher and it produces a lighter colored leather 

 than the leaf gathered in August and September. Better 

 prices would be realized if the leaf were gathered earlier 

 than it now is. After drying, the leaf is ground under 

 mill-stones, sifted to get out stems, and the leaf bagged or 

 baled for market. Sumac is not cultivated in this coun- 

 try. It is possible, however, that the American sumac 

 could be cultivated as a profitable farm crop. 



Fig. 850. 

 Smooth sumac {Rhus glabra). 



Other tannin-bearing species of Sumac or Rhus are : 

 B. aromatica, 13 per cent tannin ; R. Metopium, 8 per 

 cent; R. pumila; R. Canadensis; R. Toxicodendron. 

 Venetian or Turkish sumac (R. Cotinus) is more impor- 

 tant as a dyeing than as a tanning material. The leaves 

 contain about 17 per cent of tannin. Kliphout (R. 

 Thunbergii), from the Cape of Good Hope, contains 28 

 per cent of catechol tanning matter of reddish color. R. 

 semialata, containing 5 per cent of tannin, yields Chinese 

 and Japanese galls, containing up to 70 per cent of gallo- 

 tannic acid. They are caused, not by a fly, but by the 

 attack of an aphis, as are those of the allied Pistaeia. 



Japanese or Chinese galls, made on leaves of Rhus 

 semialata by the sting of a plant-louse, contain 70 per cent 

 of tannin. 



French sumac (Coriaria myrtifolia) is a poisonous 

 shrub of the south of France; the leaves contain about 15 

 per cent of tannin and are used for tanning and as a 

 sumac adulterant under the name of " stineo." Tutu {Co- 

 riaria ruscifolia) bark, of New Zealand, contains 16 to 17 

 per cent of tannin. 



Quebracho {Loxopteryngium Lorentzii). The wood 

 contains about 20 to 28 per cent of a red, difficultly 

 soluble tannin, yielding " reds," and containing catechol 

 and phloroglucol. It gives a firm, reddish leather. Que- 

 bracho is obtained from Argentina, whence large 

 quantities of logs, or extracts made therefrom, are 

 exported to Europe and the United States. 



Pistaeia Lentiscus, grown in Sicily, Cyprus and Algeria. 

 The leaves contain 12 to 19 per cent of a catechol tannin, 

 and are used chiefly in the adulteration of sumac. Leather 

 tanned with sumac adulterated with lentiscus darkens and 

 reddens on exposure to light and air, and for this reason 

 its use in cases where a good color is desired is objection- 

 able. P. orientalis, Terebinthus-, vera, and others of India 

 and the Mediterranean region, bear various aphis galls 

 yielding 30 to 40 per cent of tannin. 



Pepper Tree or Molle (SchinusMolle),of Buenos Ayres. 

 The leaves only are used, and are said to contain 19 per 

 cent of tannin. The wood contains less than 3 per cent, 

 and the bark 5 to 10 per cent of tannin. S. Aroeira, of 

 Brazil, is said to contain 14 per cent of tannin. 



Palm tannins. 



Saw palmetto, Dwarf palmetto (Sabal Adansoni, S. 

 serrulata), grows freely in the southern states and is 

 especially abundant on the east coast of Florida. The 

 plant is an evergreen, the stem of which grows flat along 

 the ground and is held in place by numerous small roots. 

 The leaves are fan-shaped and ribbed. The plant is very 

 hardy and the leaves may be cut without damaging the 

 plant. The average yield is stated to be about one-half 

 ton of stems to the acre, but in good seasons and with 

 rich land over a ton per acre has been secured. The air- 

 dried stems contain 5 to 20 per cent and average about 

 13 per cent of tannin, and are used in making an extract 

 which produces a very soft and mellow leather of good 

 color. The extract contains noticeable quantities of 

 common salt and organic salts of soda. The leaf also con- 

 tains tannin. There were 3,500 barrels of extract made 

 in 1905. 



Coconut palm (Cocos nucifera) contains tannin in the 

 roots. 



Gambler extract. 



Gambier or " Terra Japoniea," also called Pale " Cate- 

 chu," is a solid extract made from Uncaria (or Nauclea), 

 Gambier, an Bast Indian climbing shrub. The plant is 

 crudely cultivated but yields rapid returns. As the plants 

 do not receive proper attention, a plantation is exhausted 

 in ten to fifteen years. Cropping begins three years 

 after planting, and is continued two to four times annually. 

 In preparing the extract, the leaves and twigs are put in a 



