148 TANNING- MATERIALS. 



ground, inside down, and in ranges on piles 18 Inches deep, the top being 

 covered with the largest pieces, as a shelter from rain. Bark while dry- 

 ing is much injured by rain. 



When it has been three or four days on these stages, it should be 

 stirred and opened a little to prevent molding. It takes from two to 

 three weeks, according to the weather, to dry the bark of such coppice 

 oak; but under very favorable circumstances it will dry in eight days. 

 Properly cured bark is of a light cream-color, and breaks freely. If 

 damaged by the weather it is of a brownisli color, indicating a part of 

 the tannin has been taken out. When dried it is taken to sheds, broken 

 into small pieces, and sold in sacks to the tanners. The bark should be 

 peeled the same day the tree is cut, or at latest the next day. A genial 

 shower after cold weather makes the bark peel more easily. Much of 

 the peeling, especially of the small pieces, is done in Scotland by women. 

 The larger sticks of peeled wood are sold for spoke timber and other 

 industries, and the smaller to the chemical works for fuel. 



The European larch thrives extremely well with the oak, and is often 

 planted to fill up vacant places. The bark is easily stripped, and 

 when taken from young trees brings nearly as high a price as second 

 quality of oak bark. It thrives best on dry soil, and its foliage is open, 

 admitting much light. No other timber does so well with oak as the 

 larch. 



By the common method of procuring the bark of young oak coppice 

 wood, it can only be peeled in summer, when the sap is up, and accord- 

 ing to the above experiments, when the tannin is in relatively smaller 

 amount, and the wood of the least value. But by a process first pro- 

 posed a few years since by M. J. Le Maitre, the peeling may be done 

 at all seasons, instead of the brief and variable season formerly allowed. 

 This consists in steaming the wood in an air-tight receiver of any con- 

 venient size and form. The inventor died before seeing his process 

 adopted as a branch of industry, but it has since been perfected by M. 

 de Nomaison.^ 



According to the researches of M. Wohmann, oak wood cut in the 

 •winter, or while the sap is at rest (September to January), is denser, all 

 circumstances being equal, than in summer. He found that a cubic me- 

 ter of young oak in winter weighed 1.097 kilograms, and that it yielded 

 1G5 kilograms of bark, while, if cut in summer, it weighed only 892 kil- 

 ograms, and yielded but 148 kilograms of bark. This interesting result 

 confirms very satisfactorily the theory of alimentary reserve in the phys- 

 iology of timber growth. A notable advantage is gained, if the cop- 

 pice for peeling can be cut in winter, because the stumps will sprout 

 again for a new growth with much more vigor and certainty than if cut 

 in early summer. But a disadvantage is met, in the steaming process, 

 by the fact that the tannin is less soluble and more difficult to extract 

 than when peeled in the sap season. In fact, this appears to be the 

 only weak point in M. Le Maitre's method. 



'The Director-General of forests in France, wishing to iktermme with exactness 

 the results obtained by the apjiaratus of the latter, some months since appointed a 

 commission of forest agents, wood merchants, and tanners to examine and report upon 

 this invention. This commission was placed under the presidency of M. Meynier, ad- 

 ministrator of forests, and consisted in all of eight professional foresters, three wood 

 merchants, and two tanners. Their labors began in January, 187G, in the domainal 

 woodland of Viroflay. They were at once able to see that the bark was readily loos- 

 ened ; but it remained to be shown by careful study how tl^ results compared, as to 

 quality with those of bark peeled in the ordinary way. A rrussian commission has 

 also been appointed to examine its merits. The process is deemed too new, and the 

 r^ults too uncertain, to aflford a safe basis for estimating its real value. 



