iM UTILIZATION OF nSKK, 



on either side of it are soft and gorged with sap, so that the barfe 

 can then be separated from the wood easily. Moreover, owing to* 

 this special activity, the liber also contains at this time its maxi" 

 mum amount of tannin. 



The only portion of the bark which contains tannin in ttseful 

 quantities comprises the living layers ; the dead bark is practical- 

 ly of no value at all. Also, owing to the great solubility of tannin^ 

 the moment the periderm begins to split and a rhytidome to form', 

 rain and dew both reach the living layers through the cracks and 

 wash out a large proportion of the tannin. Hence the best stems 

 for the tanner's purpose are those of vigorous growth which have 

 still a smooth uniform shining bark. When this period of growth 

 is past, the yield of tannin diminishes considerably. According to 

 Mueller, as quoted by Gayer, the bark of young poles contains 

 twice as much again of tannic acid as the bark of full-grown trees. 

 The best stems are unquestionably young coppice poles, and coppice 

 worked for tanning bark should be exploited on short rotations-. 

 The great drawback in the case of bark which contains a consi- 

 derable proportion of dead rhytidome is that this latter must be 

 got rid of, always with immense trouble, before the bark can be 

 used. The rhytidome without appreciably increasing the amount 

 of tannic acid,, introduces a large quantity of undesirable colouring 

 matters into the tanning liquor. 



The removal of bark from standing stems (technically termed 

 peeling) is thus effectedr With a sharp broad-bladed hatchet or a 

 curved bill the bark is cut through round the base as far as th© 

 wood. A sim^ilar cut is made 3 or 4 feet higher up. Then with 

 the tool represented in Ficf. 62, which ia very sharp along the edge 

 <e, a straight incision is made from the top cut to the bottom. 

 The bark on each side of the incision may now be lifted off with 

 ease with the extremity of the same tool or with 

 °' ' the ordinary khurpa of the Indian gardener, 

 /^^e After this, the workman has only to gradually 

 strip ofi' the entire cylinder of bark, aiding him- 

 self with the tool wherever it adheres too firmly 

 to the wood. In this manner he peels off succes- 

 sive complete rolls of bark until the entire stem 

 and the thicker branches, if any, have been laid 

 bare. This method of barking is evidently unsuit- 

 ed for large trees. Moreover, it is the most trou- 

 blesome of the three methods, and should, there- 



fore, be employed only when the stems to be peeled 

 Barh scalpel. l r n i ^ ■., ■■ , 



cannot, tor some reason or other, be felled at once. 



