January 1, 1913. 



THE INDIA RUBBER WORLD 



193 



of the trunk, a larger quantity of milk being thus obtained. 

 As soon as the tree has been felled, the rings are cut at dis- 

 tances of about 12 inches apart, around the whole of the trunk. 

 For the making of these grooved rings, a gutta percha knife 



Coagulating Gutta Perciia Milk by Boiling. 



was used by tlic expedition, such as was already in use by 

 Malay tappers in Borneo and Sumatra. These knives had in 

 general the form of a hollow chisel. 



The grooves cut out had at the upper edge a width of about 

 an inch, and were cut deep enough to reach the cambium layers 

 Otherwise a limited yield of milk would result. 



G.\THERING. 

 While some of the workers were engaged in making the rint'^ 

 on the trees, others were placing under each ring one or two 

 receptacles into which the gutta percha dropped, so far as n 

 had not begun to coagulate in the grooves. For conveniens 

 and economy, these receptacles were made on the spot from 

 palm leaves, or other leaves of leathery texture. As soon as 

 the milk ceased to fall, which usually took place in IS to 20 

 minutes, the contents of the receptacles were emptied into large 

 vessels, to be boiled, coagulated and pressed into gutta percha. 

 When water was available it was found desirable to add some 

 to the milk, as the latter was therein- to some extent washed. 



Kneading and Pressing Gutta Percha Cakes. 



and the particles of resin could thus be removed in the watery 

 residue. The milk coagulated in boiling in about ten minutes. 



CO.\GULATION. 

 After trying various methods of coagulation, Dr. Schlechter 

 was obliged to revert to the plan of boiling already in general 



use in Borneo and Sumatra, as being the only system adapted 

 for forest purposes. 



TIME OF TAPPING. 



The time of tapping was investigated on various occasions. 

 Trees tapped on the day of felling did not show any noticeable 

 difference as compared with those tapped immediately after be- 

 ing cut dow^n. Even after three days the milk flowed well, but 

 it had begun to thicken and coagulation had evidently 

 commenced. A week after felling, the yield was very small, as 

 the bulk of the milk had coagulated. Trees tapped in the morn- 

 ing gave better results than those tapped in the afternoon. 



The observation of a number of trees extending over several 

 months, indicated that after heavy rainfall, gutta percha milk 

 tlowed much more thinly than after the lapse of several warm 

 (lays without rain. 



AGES OF GUTTA PERCHA TREES. 



Owing to the fact that trees exposed to light and air often 

 form more than one ring a year, while those in dark locations 

 form less than that average. Dr. Schlechter remarks that rings 

 do not indicate with certainty the age of gutta percha trees. 

 He adds that it is unadvisable to tap young trees. He has usu- 



RuBBER Ready for Shipment (About 4 Lbs. Day's Work 

 FOR 6 Natives). 



ally tapped only such trees as have at a height of 40 inches a 

 diameter of at least 12 inches. In many cases, however, the 

 yield was small. 



PROGRESS OF GUTTA PERCHA GATHERING. 

 The gathering of New Guinea gutta percha has been con- 

 siderably developed, owing to the energy of the German govern- 

 ment, and is being carried on by natives, under the guidance 

 of Malay experts, brought for that purpose from Sumatra. 

 Ueing forced to earn so as to pay their "cottage tax," these 

 natives have overcome their natural indolence. Gathering gutta 

 percha being an occupation which brings them in money, they 

 have every inducement to follow it. The government buys all 

 the gutta percha the natives bring in at a price equaling about 

 11 cents per pound. 



ADVISABILITY OF GOVERNMENT PLANTATIONS. 

 From the results of the expedition, Dr. Schlechter advises 

 the German Colonial Government, following the example of 

 England, Holland and France, to establish gutta percha plan- 

 tations in New Guinea, the climate of which is more suitable 

 for the purpose than that of the other German colonies. These 

 plantations, when found to be profitable, might serve as a plant- 



