SUMAC : THE CORK OAK. 



153 



manner, " average bark " dried in the free air agrees almost with that dried in the 

 forest, it being 0.G9 for the trunk and 0.78 for the branches. 



4. The volume of a given weight of bark dried in the free air scarcely differs from 

 that dried in the forest, a quintal having the following contents in cubic meters : 



Glossy bark from branches 



Avf rage bark from branches 



B.irk from trees 16 years old 



Bark from trees 24 years old 



Bark from trees 38 years old 



Bark from trees 55 to 62 years old 



0. 0610 

 0. 0620 

 0. 0575 

 C. 0635 

 0. 0675 

 0. 0725 



THE SUMAC AS A MATERIAL FOR TANNING. 



Next after the oak and hemlock, we should mention the sumac, of which 

 several species of the Blms, but chiefly the B. glabra and B. tyhina, afford 

 with us the principal supplies. 



The sumac best suited for tanning and dyeing purposes grows wild in 

 a belt of country extending from Maryland, down through the Atlantic 

 States to Georgia, and through Alabama, Mississippi, Louisiana, and 

 Texas, and in portions of Kentucky and Tennessee. The northern cli- 

 mate appears too cool for developing the tanning properties of this 

 plant to the best advantage, although large quantities of the leaves 

 gathered in Pennsylvania and New York are sold to the tanners of goat- 

 skins, who put it in v^ts to strengthen up and keep the sewed skins 

 from leaking, and it is used by many tanners to brighten the color of 

 their leather. 



The State of Virginia at present takes the lead in the production of 

 sumac, and the business of collecting, grinding, and packing is carried 

 on at Eichmond, Fredericksburg, Alexandria, Culpeper, Winchester, 

 and perhaps other places. The season for picking begins about the first 

 of July and ends the last of September, or with the first frost, for when 

 the leaves turn red in autumn, they are no longer of value. The tan- 

 ning properties of the sumac reside in the leaves, and only these should 

 be gathered, and the difference of value in this article is found often to 

 depend very much upon the care with which the leaves are gathered 

 and dried. The blossoms and berries, as well as the stems, should be 

 thrown out. It should be dried in the shade. When cured, it is taken 

 to the mills and ground by being placed under heavy wooden wheels, 

 rolling in circles, at the ends of axles attached to a revolving shaft. 

 These grindingwheels are inclosed in a close covering to keep in the 

 abundant dust that rises. Those used in Virginia are somewhat expen- 

 sive, but in Sicily they grind the leaves in a very primitive manner under 

 stone wheels on a stone bed. 



CULTIVATION OF THE CORK-TREE IN THE UNITED STATES. 



In 185^, and, it is believed, at an earlier period, quantities of acorns 

 from the cork-oak were procured from the south of Spain, and distrib- 

 uted from the Patent Office to those sections of the country where it 

 was thought they would thrive. A report made at the close of 1875, 

 from Winnsborough, S. C, shows that all the acorns planted in 1859 



