Vol. X. Xo. 249. 



THE AGRICULTURAL NEWS. 



363 



A NEW METHOD OF OBTAINING 



RUBBER B'ROM CASTILLOA. 



The India Rubber World for October 1, 1911, 

 contains an account of a method for dealing with Cas- 

 tilloa, for obtaining rubber, that has been devised by 

 a planter named Gierlings, who has had a large exper- 

 ience with this })Uint in Southern Java. The account 

 contains an ilhistration of the knife with which the 

 tapping is done. The following matters of chief inter- 

 est are extracted fi-om the article: — 



Mr. Gierhngs has devoted a great deal of time to e.xperi- 

 ments in tapping. His latest metbod, tried last 3'ear, has 

 given the best results and it is well wortljy of a brief descrip- 

 tion. His method is as follows. 



With a special form of knife, which is made by the 

 native blacksmiths, horizontal incisions are made, beginning 

 about 1 foot from the ground and going around one quar- 

 ter of the circumference of the t»ee. These incisions are 

 made about 3 inches apart, being cut iinch deep, or down to 

 the cambium, and are continued until there are fifty of them, 

 reaching to tlie height of 13 feet. The same operation is 

 repeated on the next quarter of the tree, beginning at the top 

 and working down, but a narrow strip of bark about 1 inch 

 in width is left between tlie.se two series of horizontal cuts. 



After a rest of three months, the other half of the tree 

 is tapped in the same waj", and three months later the opera- 

 tion is repeated on the first half of the tree, the incisions, 

 however, being made about A-inch below the original 

 cuts. As the tree is allowed to lie idle during the three 

 months' flowering season, it is tapped only three times a year. 

 This method of tapping produces about 8 oz. of dry rubber 

 a j'ear from trees eight to nine j'ears old. 



The latex exuding from these incisions is in the form of 

 a soft mass. With every tapper is a woman, whose duty it is 

 to collect the latex. Her equipment consists of a large 

 bamboo pot, a small bamboo pot, a spoon and some bamboo 

 spatulas. The large pot is equipped with a sharp point at 

 the bottom so that it can be stuck into the ground. Both 

 this and the small bamboo pot, which she carries with her, 

 ' are partly filled with water. She mounts a ladder to the 

 uppermost incision and works her way down the tree scrap- 

 ing the latex with the bamboo spatula into the spoon and 

 pouring it into the small pot, which when full is emptied 

 into the larger one. The contents of the larger pots are 

 collected by men and carried to the factory where the latex 

 is passed through a coarse sieve and then diluted with water, 

 and passed through a finer sieve into a washing vat, usually 

 made of galvanized iron and holding from 25 to 7-5 gallons. 

 After the liquid has settled, the rubber globules come to the 

 surface and the remainder of the liquid is drained off through 

 an outlet at the bottom. Fresh water is then poured into 

 the vat, the mixture stirred and allowed to settle, and again 

 drained off. This is repeated until the latex looks pure, 

 ■which generally requires three or four washings. The wash- 

 ing of the latex is usually completed the day it is gathered. 



The latex is then coagulated in round enamelled pans. 

 About a pint of latex is poured into each pan together 

 with ^-oz. of 40 per cent, .solution of formalin, the two 

 being well stirred together. In the meantime a boiler 

 of water has been heated, containing uliout 1 grain of 98 

 per cent, acetic acid per quart of water. When the water is 

 close to the boiling point three-quarters of a quart is poured 

 into each pan of the latex In this way the latex is heated 

 to from 1.50° to 160' F., and immediately coagulates and 



floats on the top of the water in spongy cakes. These cakes 

 are pressed together and the water poured out, but is saved, 

 and the latex it contains is secured later. The coagulated 

 cakes are immediately rolled into thin sheets. These are 

 placed again in vats with clean water, to which a very little 

 formalin has been added, and allowed to remain there for 

 a few hours, and then removed to the smoking and drying 

 house — a building with perforated iron floor, on which drying 

 racks are placed. 



The temperature in the smoking house is kept at about 

 110° F., and a dense smoke is developed by means of burning 

 damp grass. The sheets of rubber remain in this smokehouse 

 for two or three days, and get about one-half dry. They are 

 then pressed into small squares weighing about 3i- lb. The.se 

 are placed in another formalin solution for a shorter time, 

 and then taken again to the smoking house for a final drying. 

 The rubber is allowed to retain about 5 per cent, of water 

 when it is shipped, experience .showing that it dries out on 

 the way, and that it keeps much better. The square blocks 

 are packed in smooth finished cases made expressly for them. 



GERMINATION OF HEVEA SEEDS 

 IN GRENADA. 



The following note on recent trials of the germina- 

 tion of He.vea seeds, conducted at the Grenada 

 Botanic Stati(jn, has been received from Mr. G. G. 

 Auchitdeck, B.Sc, Sui)erintendent of Agriculture. 

 A report of former, similar tests made by Mr. Auchin- 

 lech was given in the AgriciUtund A^ews, Vol. X, 

 p. Ill:— 



Two of the specimens of J/eixa lo-aaillensis fruited at 

 the gardens again this year, one yielding a very small crop 

 of about sixteen seeds, the other giving a crop of over 1,100 

 seeds. The total yield from the two trees was 1,191 * seeds, 

 collecting being done between August 10 and September 20. 



Contrary to the practice of former years, the fruits were 

 not allowed to dehisce upon the trees, as it was strongly sus- 

 pected that seeds from such fruits would have already lost 

 their power of germination. The capsules were this year 

 picked immediately after turning brown, and the seed set out 

 at once. 



In all 394 capsules were picked, and again the irregu- 

 larities which are common in the Euphorbiaceae showed 

 themselves. The following indicates the kinds of fruit 

 obtained and the seeds contained: — 



Bi-locular capsules 6 12 seeds 



Tri-locular „ 372 1,116 „ 



Quadrilocular ,, 16 64 ,, 



Total 



1,192* 



All seeds were planted in the sand-beds, whether 

 rejected on the weight test or not, and the plants as they 

 came up were potted in bamboo joints and watered Avhen 

 necessary. Up to October 13, 607 strongly growing plants 

 have been sold to local planters, these being probably all that 

 will be obtained. The germination works out as 67'7 per 

 cent. — a fair percentage, considering that light seeds were not 

 rejected. 



These results show, however, that even when the pre- 

 caution of collecting fruits before delifscence is e.xercised, 

 a loss of .some 30 per cent, may be expected. 



* One seed lost in handling. 



