NOTES ON TANNING SUBSTANCES. 293 



to some other kinds. This tree grows to the height of 70 or 80 feet, and has 

 a diameter of 3 or 4 feet. The rock chestnut oak is seldom found in the 

 Southern States, but abounds in elevated districts having a broken rocky 

 surface. On some of the Alleghany mountains it constitutes nine-tenths of 

 the forest growth ; hence the name rock oak by which it is known on the 

 banks of the Hudson and the shores of Lake Champlin. It has received 

 in Pennsylvania, Maryland, and Virginia, the name of chestnut oak. Its 

 bark is thick, hard and deeply furrowed, and differs from other barks in 

 that the epidermis or outer layer contains a large proportion of tannin, 

 which is usually in other kinds confined chiefly to the under layers. In 

 Pennsylvania and New York it abounds, but only the bark of the small 

 branches and young trees is used in tanning. 



" The Quercitron or black oak grows throughout the States below the 

 latitude of 43 deg. N., and in the more elevated sections of Georgia and the 

 Carolinas. Its bark is not very thick, but is bitter, deeply furrowed, and of a 

 deep brown or black colour. It also imparts a yellow colour to the liquor, 

 and leather tanned with it is apt to give a yellow tinge to the stockings : 

 this inconvenience, however, may be obviated by an inexpensive chemical 

 process. Quercitron bark is much used, as it is abundant and cheap, and 

 rich in tannin. This tree often attains a height of 90 feet, and a 

 diameter of 4 or 5 feet. (Quercitron bark is used in England for a 

 dye, where it is much valued on account of the various shades of colour 

 that can be produced with it ; it is imported ground very fine.) 



" Besides these four kinds are others less known. The white oak chiefly 

 grows in Florida, and to the south of 46 deg. N. Its bark is preferred for 

 leather, for saddles, and similar purposes. The scarlet oak is found as far 

 north as latitude 43 deg. N. — its bark is very thick ; the grey oak, in Maine, 

 New Hampshire, and Vermont ; and the live oak is never found more 

 than 20 miles inland, its bark being black, hard, thick, and replete with 

 tannin. Other kinds of oak bark are occasionally used, but not to any 

 great extent, in the United States." 



Cork Tree Bark (Qtiercus Suber). — The cork tree grows in the South 

 of Italy, the Isle of Sardinia, Spain, and the more temperate parts of 

 Europe and Africa. 



The exterior bark of this tree is the substance usually known as cork, 

 and the bark used by tanners is the inner bark, the cork containing no 

 tannin. Cork bark is imported to this country from the Isle of Sardinia, 

 Tuscany, and Barbary ; the largest quantity is obtained from the Island of 

 Sardinia. 



The Sardinian cork-tree bark may easily be distinguished by its colour 

 and weight, being of a pinkish hue throughout and weighing heavier 

 than the other two varieties ; it is considered the best imported to this 

 country. The Tuscan is the next best ; it is considerably lighter than the 

 Sardinian, and of a whiter colour. The African is more like the Tuscan, 

 though not quite so good. 



But very little i^ imported from other places ; though after a while it is 



