THE INDIA RUBBER WORLD 



The Editor's Book Table. 



rUVSIOLUC.ICAL I'RINCIPI.KS FOR DKTKRMINlXr. TIIL \ ALLF. 

 of the Various Ruhber Tapping Methods. By Professor Dr. Hans 

 Fitting (translated by .1. H. Renton). Capper & Sons, or Times of 

 Ceylon, office 27 MincinR Lane, both London, E. C, England. [Paper, 

 8vo, 51 p.iges.1 



THE rubber planter is interested in bringing his plantation 

 quickly into a prolitable condition as a commercial enter- 

 prise and maintaining it in that state as long as 

 possible. Doctor Hans Fitting has made a very careful 

 study of the many questions involved and has indicated the 

 way to be followed in investigating practical methods of 

 tapping. 



-After explaining the functions of the root, stem and crown, 

 the circulation of water, and showing that the ascending 

 movement of water and the inorganic salts takes place in 

 the wood, and the descending movement of the organic sub- 

 stances, chiefly in the bast, he reports the result of his ex- 

 periments. Believing with Kneip that in all probability latex 

 is not a nutrient juice, and, consequently, is of no importance 

 as regards the circulation of the sap, he assumes that the 

 latex is produced almost entirely, in the stem, however, it is also 

 found to a small extent in the leaves, and therefore the nutritive 

 substances required for this purpose must exist in the stem in suf- 

 licient quantities. If there is a deficiency of them, the renewal of 

 latex must necessarily suflfer and the supplementary latex 

 may possibly deteriorate in quality. 



It may be concluded that in rubber trees cuts made very 

 deep in the corte.x and in the bast disturb some very im- 

 portant vital functions of the tree. As the lactiferous vessels 

 are situated chiefly in the bast, tapping should penetrate to 

 the inner parts of the bast in order to secure a sufficient flow 

 of sap, but must neither reach nor cut through the cambium. 



Dr. Fitting's first tapping expeiiment • was a spiral incision 

 one and one-half times around the tree. This had the same 

 effect as girdling because the circulation of organic nutrients 

 in an oblique direction proceeds too slowly to provide the 

 food supply required by the base of the tree. The tree is, 

 therefore, obliged to draw on the reserve material from its 

 reservoirs in the bark and wood. 



In the second experiment the tapping cuts extended only 

 over a quarter of the stem's circumference. There were 

 six tapping areas, with bridges of bark between each. On 

 three of these areas, the Bowman parer alone was used, and 

 on the alternate three, the Bowman parer and Bowman 

 pricker. The tapping period extended from November 8 

 to .April 11. The tree was then cut down and examination 

 showed that tapping cuts of this description can at most 

 have only a local influence on the descent of organic food 

 substances toward the base. 



In the case of young trees, planters are warned against 

 the use of all those tapping cuts by which the rectilinear 

 connection of the vertical channels for the circulation of 

 organic substances in the cortex and bast suffer a complete. 

 or almost complete, interruption at any spot between the 

 crown and the base of the tree. 



Therefore, the spiral cut should be rejected, not because 

 a great quantity of bark is in course of time removed from 

 the tree, but because it completely destroys the food chan- 

 nels. .'Mso. all those tapping methods are unsuitable, by 

 means of which straight strips of bark are at first left be- 

 tween incisions and are removed in the second tapping 

 is advisable to avoid all tapping methods, 

 i are of such length that the nutrient and 



period. Lastly. 

 where the incisi 

 constructive substances 



.-ithi 



the tapping system must 



travel too great a distance in an oblique or even horizontal 

 direction. 



In reviewing the value of tapping methods, the demands 

 of practice must be considered, namely, that the latex should 

 run easily and be easily collected, and the incisions be easily 

 made. The herringbone incision must be given preference, 

 here, as long as it embraces only a small part of the tree's 

 circumference. The tapping system should extend only over 

 a quarter of the tree's circumference. Successive tapping 

 periods are to be confined respectively to the second, third 

 and fourth quarters. Preference should be given to the half 

 herringbone incision because of the short channels for flow 

 of the latex. 



The use of the pricker, as a tapping tool, cannot be rec- 

 ommended. Wherever the teeth of the pricker penetrate to 

 the neighborhood of the cambium, the latter forms a new 

 bark with many stone cells, but practically without lacti- 

 ferous vessels. Where the pricker teeth did not penetrate 

 through the inner cortex, new bark forined containing lacti- 

 ferous vessels arranged irregularly. Bark on the tapping 

 spots is renewed much more evenly if the knife is used 

 exclusively, and is sooner ready for re-tapping. 



The author's conclusions are summed up thus: "Do not 

 begin to tap the trees till they are six or eight years old 

 and are twenty inches in circumference, at three feet from 

 the ground. Adopt the half, or the full herringbone V-shaped 

 incision. Angle of sixty degrees is best. The tapping sys- 

 tem must cover only a vertical strip cf bark not exceeding 

 a quarter of the tree's circumference. Tap daily, or on al- 

 ternate days, with knife only. Prolong the tapping to five 

 or six months. .Avoid mixing latex of different quality, that 

 from young and old trees, or from trees at different stages 

 of tapping. 



"It will be found advantageous to tap for two or three 

 months, removing at most half the strips of bark between 

 two incisions: after that pause for one or two months and 

 then finish tapping the remainder of the bark in two or 

 three months." 



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 of use to heads of purchasing departments in all factories using 

 oils and chemicals. 



THE .MEDICAL WHO'S WHO. 1916. THE FULTONMA.VDERS PUB- 

 lishing Co., London. England. |16mc, l.UO pages. Price, lOi. 6rf.) 



The many members of the rubber trade who know A. 

 Staines Manders and his able secretary. Miss D. Fulton, may 

 be aware of the fact that the Fulton-Manders Publishing 

 Co., of London, is publishing a number of important works 

 concerning the medical profession and other lines, including 

 several in the rubber field. The latest publication of this 

 company is the one named above, a compact volume contain- 

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 are given of the many thousand physicians. There are 



