. Cyclopedia of farm crops. Farm produce; Agriculture. 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
. Cyclopedia of farm crops. Farm produce; Agriculture. 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 Pistacia Len- tiscus is used to a much larger extent than any of the others. The stem contains but little tannin. Between 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
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectagriculture, bookyear
