640 UTILIZATION OF J5AI5K VXD ITS CONSTITUENTS. 



20 in cooler districts ; fertile soil has a similar influence in 

 shortening the rotation. If, however, some timber also must 

 be produced, as in many communal and private forests of 

 Franconia and Wurtemberg, the rotation is raised to 25 to 30 

 years, obviously at the expense of the bark. The shoots are 

 felled close to the ground, the area being left clean -felled, and 

 new shoots spring from the stools. If a few standards are 

 left, or if some of the coppice-shoots (stannels) are left to grow 

 for two or more rotations of the underwood, the shoots under 

 their shade produce little tannin, so that such a system is not 

 calculated to yield a profitable return. 



(g) Condition of Crop. A pure crop of oak gives the best 

 quality and greatest quantity of bark ; all other species, 

 especially rapidly growing ones, such as poplar, birch, pine, 

 larch, certainly yield valuable timber, but they prejudice the 

 quantity and quality of the bark. Grass or broom denote 

 either a poor soil, that should be devoted to a more profitable 

 crop, or bad management. Preference should be given not to 

 a very dense crop, nor to a very open one ; 1,600 to 1,800 

 stools per acre form the ordinary crop. After two-thirds of 

 the rotation are over, cleanings should be made to remove all 

 other species except oak, also bent, poor oak-shoots that 

 contain little tannin, as well as the weaker shoots in the 

 stronger clumps. The evils of the removal of litter is not 

 exhibited so readily in other forest systems as in oak coppice ; 

 even without this disastrous practice, many oak coppices on 

 bad soil are soon exhausted by the repeated fellings, and by 

 intermediate agricultural crops ( Jhumes) . Pasture also injures 

 the crop, but the lopping of leaves for fodder, practised in a 

 few districts in the Upper Ehine, is worse. 



From numerous data it appears that the bark of the best 

 oak coppices in South Germany and Austro-Hungary yield 

 15 to 20 per cent, of tannin, second-class coppices 10 to 15 per 

 cent., and third-class ones 8 to 10 per cent. In North Germany 

 the yield is 6 to 10 per cent, of tannin. 



2. Ilttrrt'titiiuj the 



The work of harvesting the bark may be divided into three, 

 parts, preparatory work, peeling and drying. 



