Pine Bark—­Is well distributed and is a very important tanning material.  It bears the same relation to oak bark here as does hemlock in America, but its effects are quite different from hemlock.  The best Austrian sorts are those of Styria and Bohemia, but that of Karuthen is also of good quality.  The German pine comes from Thuringia to a great extent.  The countries that consume the greatest amount of pine bark are Austria, Germany, Russia and Italy.  The tannin contained varies from 5 to 16 per cent.  Its use is almost wholly confined to the handlers, as its weight returns are not so satisfactory as oak or valonia.  In case it should be used for layers it is always in combination with some better weight-giving tannic.  For upper leather its use is limited.

The bark is always peeled from the felled tree, and often the woodman accepts the bark in part payment for his labor; he then sells the bark to the tanner or agents who go about the country collecting bark.  It is generally very nicely cleaned.  I would here like to correct a mistake which tanners often make in their estimations of the value of barks.  A tanner usually buys the bark of southern-grown trees in preference to that of trees grown in northern countries, as it is a common idea that southern vegetation contains more tannin than that of the north.  This is a fallacy, as has not only been proved by careful analyses, but may also be found to be an incorrect conclusion after a moments’ thought.  Those trees which flourish in southern countries grow very rapidly, and as tannin is necessary to the development of leaf structure, etc., it is absorbed to a greater extent than is the case with the slower-growing tree of the north.  The tannin contained in the sap does not increase in the same ratio as does the rapid growth, and it follows that the remainder in the bark is less than in the tree of slower growth.

Birch Bark—­Is at home in Russia, Norway, and Sweden.  It is used for both upper and sole leather, but seldom alone.  The bark is usually peeled from the full grown tree, and contains 4 to 9 per cent. tannin.

Willow Bark—­May also be found in the above mentioned countries and also in Germany.  This material is used for both upper and sole leather, and contains 6 to 9 per cent. tannin.  It is a very delicate material to use, as its tannin decomposes rapidly.

Erlen Rinde—­Is also a native of Germany, but is not used to any great extent.  The same may be said of the larch, although this variety is also to be met with in Russia.

Mimosa Bark—­Is obtained from the acacia of Australia.  It is a favorite in England.  The varieties are as follows:  Gold wattle, silver wattle (blackwood, lightwood), black wattle, green wattle.  The gold wattle is a native of Victoria.  Its cultivation was tried as an experiment in Algeria and met with some success.  The trees are always grown from seeds.  These seeds are laid in warm water for a few hours before sowing.  The acacia may be peeled at eight years’ growth and carries seeds.  The Tasmania bark is very good; that from Adelaide likewise good.