December, 1911.] 



497 



Saps and Exudations. 



with Para. The accompanying shows a 

 young Ceara tree having been tapped 

 by the Lewa method. 



The tree is fit for tapping when tha 

 rough and papery outer bark has been 

 removed. If this hastaot been recently 

 done, the surface may contain dirt con- 

 veyed up the tree by little ants, so it is 

 therefore advisable for the tapper to 

 carry a stiff scrubbing-brush for the pur- 

 pose of cleaning the surface. The portion 

 of the tree to be tapped is then painted 

 over with a weak acid solution— either 

 acetic, citric, carbolic or fluoric acid. 

 The juice of citrus fruits, such as limes, 

 lemons or oranges, or seeds of the baobab 

 tree soaked in water will also serve the 

 purpose ; but clean solutions only should 

 be employed and absolute cleanliness 

 practised throughout. In the portion 

 to be tapped almost point-like incisions 

 should be made, and the latex oozes out 

 and flows down and coagulates in thin 

 ribbons on the bark. (See Illustration.) * 

 These incisions should be made 4 in. 

 apart, as each incision drains the latex 

 from 1 in. to 2 in. in every direction from 

 the wound. An ordinary pruning knife 

 is suitable, but every care must be 

 taken that the incisions do not reach 

 the cambium layer ; a very narrow 

 chisel, or a flattened bradawl will also 

 serve the purpose; but it is better to 

 use a knife with a guard to prevent the 

 incisions being made too deep, If the 

 latex does not coagulate quickly the 

 acid solution is not strong enough. In 

 damp weather the acid will be required 

 to be stronger than in cold weather. 

 The requisite strength will soon be found 

 from experience. 



Formerly, when the system was first 

 started in German East Africa, the rub- 

 ber was rolled off the tree into round 

 balls. It followed, of course, that 

 particles of bark and dirt became 

 mixed with the rubber, and the product 

 was consequently of poor quality. 

 Latterly, however, this method has been 

 improved upon, and instead of rolling 

 the rubber into a ball it is now rolled off 

 from the tree on to a small wooden 

 roller (see illustration)* in such a way as 

 to form a sheet when cut open from the 

 roller lengthways. The latter method is 

 a great advance on the method of collect- 

 ing in the form of balls, as the tapper 

 can from time to time dip the roller into 

 a pail of water and wash off particles of 

 bark and dirt, and subsequently put the 

 sheet through a washer. 



The tapper should be provided with a 

 rough scrubbing-brush, acid and a small 

 hand whitewash-brush, for applying the 



* Not reproduced. 



63 



acid, a wooden roller about G in. 

 long by 2£ in. in diameter, and a pail 

 or calabash of clean water. In addition 

 to the tapper it is advisable to have a 

 second boy to follow him to collect the 

 rubber, for if too many tiees are tapped 

 at a time the rubber from the first trees 

 will not be so easy to roll off. When 

 rolling the ribbons off they should be 

 distributed over the roller as evenly as 

 possible. It is desirable that the sheets 

 should not be too thick, so the rubber 

 should be removed at intervals accord- 

 ing to the desired thickness. The size 

 of the sheets would vary, of course, 

 according to the size of the roller used. 

 It is desirable that the sheets should be 

 of uniform thickness and size, so the 

 rollers should be all the same size. The 

 rubber should not be exposed to light 

 more than is possible, so whenever the 

 roller is not in use it should be kept in a 

 pail of water, aud the sheets that have 

 been collected should also be kept in 

 water and brought in from the plant- 

 ation twice a day, after the morning and 

 evening tapping. 



The sheets should then be at once 

 thoroughly washed by passing through 

 a wooden roller or washer. They should 

 be first immersed in hot water at about 

 170° Fahr. for about 10 or 15 minutes and 

 then taken out and put through the 

 roller. This process should be repeated 

 until the sheets are perfectly clean. 

 They should then be placed in a wooden 

 tub of water containing 5 % of formalin, 

 and remain there from one to two hours. 

 They are then ready to be laid out in a 

 drying or smoking house. If cleanliness 

 is practised throughout and the rubber 

 thoroughly washed, a good marketable 

 product will be the result. 



The Ceara tree gives forth its latex 

 more freely at night and in the very 

 early morning, so tapping operations 

 should be commenced as early in the 

 morning as it is possible to see, and 

 discontinued in sunny weather in the 

 middle of the day, being resumed again 

 in the afternoon or evening. The Ceara 

 tree takes a period of rest every year in 

 the dry season and loses its leaves ; it 

 should then never be tapped. With the 

 Ceara there should be two tapping 

 periods a year ; the first after the rains 

 and the second after the dry season, 

 when the trees have revived and broken 

 into new leaf. 



In the next issue of the Journal it is 

 proposed to follow up this article with 

 an account of other methods of tapping 

 which are being followed at Tambarara 

 and Chibabava. It is yet too early to 

 give an opinion on the relative merits of 

 the methods under trial, but the Lewa 



