Chestnut (Castanea Americana, Fig. 849) is native from southern Maine and Ontario to Delaware, Maryland, 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 than valonia. 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 (Rh us 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 Pistacia Len llama is used to a much larger extent than any of the others. The stem contains but little tannin. Between 300,000 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. 850), Dwarf sumac (R. copallina) an d 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 dry ing, 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.
Other tannin-bearing species of Sumac or Rhus are : R. aromalirs, 13 per cent tannin ; R. Jtetopiom, 8 per cent ; R. pumila; R. Canadensis; R. Toxieodendren. 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 (I?. Thunbergii), from the Cape of Good Elope, 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 Pistacia.
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 myrt(olia) 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 " stinco." Tutu (Co riaria ruseifolia) bark, of New Zealand, contains 16 to 17 per cent of tannin.
Quebracho (Loxopteryngium Lorentzit). 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.
Pistacia Len(iscus, 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.