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1 he Supplement to the Tropical Agriculturist 



A great variety of tools have been devised for 

 removing the shaviogsof bark. With regard to 

 these the most important point is that any tool 

 used should have a razor-like edge, so as to re- 

 move with a clean cut the thinnest possible 

 shaving of bark, and at the same time obtain a 

 free flow of latex. Blunt tools clog the small 

 tubes, take ofl a thicker shaving than is neces- 

 sary, and leave a ragged ledge, down which the 

 latex fails to run properly. Some of the tools 

 proposed are weird engines of considerable com- 

 plexity, but as in other trades, so in rubber tap- 

 ping, the best results are often obtained with 

 the simplest instruments, and very good tap- 

 ping is performed on many estates with a 

 slightly modified gouge or farrier's knife. After 

 an extensive trial of the patent tools, public 

 opinion in Ceylon now shows signs of a return to 

 the more primitive types of knife. 



When the latex has ceased to flow, the con- 

 tents of the cups arc usually collected in ena- 

 melled iron pails, every precaution being taken 

 to ensure the utmost cleanliness ; and, indeed, 

 from this stage onwards the processes of rubber 

 preparation have much in common with those 

 obtaining in an up-to-date dairy. 



Further observations on both the theoretical 

 and practical aspects of paring will be fouud in 

 Circular No. 2 of Vol. VI., published in October, 

 1911, 



A Digression in Methods of Pricking. 



So far we have confined our remarks to the 

 method of paring or excision. The alternative 

 group of methods by which the tree is tapped 

 by incision or pricking has many pointsto recom- 

 mend it, at least in theory. If we are to credit 

 the dictum of Mr Herbert Wright that the best 

 method of tapping is the one which leads to the 

 largest flow of latex with the least possible re- 

 moval of bark, a pricking system in which no 

 bark is removed should be superior to any 

 method of paring. There are, however, maDy 

 other points to be taken into consideration, be- 

 sides the flow of latex and the removal of bark. 

 It may, therefore, prove instructive to discuss 

 the disadvantages under which some systems of 

 pricking labour as compared with good paring. 

 From such a discussion we may hope to arrive 

 at some idea of the features which should 

 characterize the perfect system of pricking. 



The fact is that no method of large incisions 

 truly conforms to the definition given above, 

 since such incisions entail the destruction, if not 

 the removal, of a considerable mass of living 

 cortex ; and this destruction goes much deeper 

 than that caused by careful paring, and often 

 involves the cambium itself. On the other hand, 

 a small clean prick, such as may be made with 

 the point of a penknife, generally heals up com- 

 pletely without any sloughing off of cortical 

 tissue, in spite of the fact that the blade has 

 actually penetrated the cambium. Such a priok 

 also leads to a considerable flow of latex in com- 

 parison with the size of the wound inflicted. 



The writer has been shown on an estate in the 

 Southern Province of Ceylon a method of prick- 

 ing which seems to avoid most of the drawbacks 

 hitherto described. The trees are tapped on a 

 herring-bone system, and each rib of the herring 



bone is represented simply by four small pricks 

 inflicted by a single insertion of a serrated knife. 

 The teeth of this pricker and the intervals be- 

 tween them are practically identical with the se 

 of Macadam's comb pricker exhibited at the 

 Rubber Exhibition of 1906, but the number of 

 teeth is only four. The herring bone occupies 

 an area about 3 inches wide, over which the bark 

 is previously scraped clean. A shallow vertical 

 channel is cut down the centre of this area from 

 a height of 5 or 6 feet to the bottom of the tree, 

 and the knife is then pressed into the bark with 

 its blade at an angle of 45 with the channel, the 

 pricks being made at vertical intervals of a foot. 

 In performing this operation care has to be ex- 

 ercised to keep the pricker vertical to the surface 

 of the tree so as not to induce a strain which 

 might cause the cambium to split. With a little 

 assistance from the tapper the latex flows into 

 the channel and down the tree. On each day 

 following a similar set of incisions is made half 

 an inch below the old ones. When the first area 

 is completed after twenty-four days' tapping the 

 •whole operation is repeated on the opposite side 

 of the tree. Subsequently similar figures are 

 intercalated between the old ones until the 

 whole circumference has been tapped. A return 

 is then made to the original area after a period 

 of rest, which is more or less extended according 

 to the freedom with which the latex is found to 

 flow. 



As a practical amendment to the method as 

 here described, we would venture to suggest 

 that it is desirable to leave one or more vertical 

 areas untapped ; and these, in our opinion, 

 should aggregate not less than 6 inches width, 

 and consist of individual strips not less than 2 

 inches wide. 



The method here described is open to the same 

 abuse as all other pricking systems, in the temp- 

 tation which it presents of ovettapping small 

 trees. But if no trees under ISinches are tapped, 

 and if the method is adopted of resting any field 

 which shows a falling-off in yield, the system 

 appears to be practically free from theoretical 

 disadvantages. No sign of injury could be seen 

 in the renewed bark of trees which had been 

 tapped for three years by the method described. 

 We are informed that the yield from considerable 

 areas tapped by this system is fully equal to the 

 average from pared trees of the same age in 

 Ceylon, and that the cost of obtaining the rubber 

 is no greater, 



In the fact of thegenerally expressed opinion 

 which favours paring, we hesitate to recommend 

 the universal adoption of this method without 

 further trial, especially as there, is good 

 evidence to show that a system of tapping 

 which suits one district is sometimes quite 

 unsuccessful in another. We think, however, 

 that all estates which desire to be abreast of 

 the times would do well to give the method 

 a trial on a limited number of trees. 

 Work in the Factory. 



The latex has still to undergo treatment in 

 the factory before it is ready to appear in one 

 or other of the forms familiar on the market 

 as crepe, sheet, biscuit, or block, as the case 

 may be. Where large quantities of latex have 

 to be dealt with, crepe is perhaps the most 



