December 1, 1911. 



THE INDIA RUBBER WORLD. 



Ill 



a 



Berba Prieto," a New Gutta Rubber. 



Bv William M. Morse. 



SUCH a change has been witnessed during the last five years 

 in the popular estimate of the value of the lesser rubbers 

 and guttas, such as Pontianak, Guayule, etc., that the trop- 

 ical forester is encouraged to bring still others to the attention 

 of the rubber world. That is why the writer is moved to tell 

 briefly what he knows of Berba Prieto. Unfortunately the pho- 

 tographic plates showing the tree in coming leaf and blossom, and 

 the processes of tapping and coagulating, were destroyed in an 

 accident to the launch as we left the rubber lands. Nor has 

 there been any report from the botanist to whom leaf and flower 

 were sent for identification. So we do not really know what the 

 tree is, but we do know that it produces abundantly a gum that 

 is certainly a high-grade chicle, and that it has a value to the 

 rubber trade even greater than to the chewing gum manufac- 

 turer. We have also proved that the tree is very abundant in 

 certain parts of Central America, hundreds of thousands of them 

 having already been located. 



The discovery of the tree, or rather of the value of its latex, 

 came about this way: Two years ago, when the CastUloa trees 

 in our region had been tapped to their limit and the last drop 

 of latex extracted, the caucheros faced a lessened production. 

 They therefore tried other milk producers in order to satisfy 

 the impatient "gringo jefe" by bringing in a full can of milk 

 each day. The cutting of wild rubber in the almost impenetrable 

 forests affords an easy chance for cheating, as the trees are 

 scattered over a large area and often hidden in the valleys and 

 "callejones." After a time it was discovered that the dishonest 

 natives were gathering something besides the regular rubber milk. 

 It showed in this way: When the soft spongy mass of rubber 

 was taken from the coagulating pans and passed through the 

 squeeze rolls, there was a pronounced tendency on the part of 

 the tortillas to stick to the rolls. Then in the course of a few 

 days a decided change came over the rubber and it gradually 

 grew black, sticky and eventually assumed the form and appear- 

 ance of treacle. 



A careful investigation conducted by a trustworthy native 

 revealed the fact that some of the tappers were adding to their 

 partly filled cans of CastUloa latex the milk of the Berba Prieto. 

 This led to an examination of the tree, which proved to be very 

 plentiful and to be found wherever the CastUloa grew. It is a 

 tall, stately tree, with a diameter of two to four feet, and a 

 trunk of forty to fifty feet high before it branches. The bark 

 is comparatively smooth, rather hard and exceedingly brittle. 

 The color in the younger trees is blackish, with irregular, round, 

 whitish areas or spots. The foot of the tree is moderately but- 

 tressed. 



Knowing that the Berba Prieto was a great producer of 

 "leche" and that its color was identical with that of the CastUloa 

 milk, the natives were able to bring in a full can of milk with a 

 minimum of work and little danger of being detected. It was 

 only the tendency to tackiness which betrayed them and opened 

 the way to the discovery of a new and valuable gum. 



The difficulties of extracting this gum proved to be many at 

 first. The native caucheros, used to working on the ground, 

 could not be induced to climb the trees or work from improvised 

 scaffolds, as they said it made them seasick. They would only 

 tap the trees from the ground. This they did for a time, cut- 

 ting irregular channels which led the rapidly flowing milk into a 

 tin basin at the foot of the tree. Even with this low tapping it 

 was easy to secure two to three gallons of milk per tree, and it 

 looked as though the caucheros could be utilized for a time to 

 good advantage, and later, little by little, taught to climb or 

 work from a ladder. 



Another trouble was that the milk did not respond readily to 

 the usual coagulating agents and soured very quickly. It was, 

 however, found that by slowly bringing the fresh milk to the 

 boiling point and keeping it there for a few minutes the gum 

 would coaHsce. It was then poured into cooling pans and 

 allowed to stand. In about thirty-six hours the mass would 

 harden from the outside toward the center, and in three to four 

 days it would become hard and brittle all through the mass. The 

 color, however, was black and the general appearance very un- 

 satisfactory. After a few e.xperiments it was found that if 

 copper kettles and copper cooling receptacles were used the gum 

 retained its white color. But when the proper method for 

 coagulating the milk had been discovered another difiiculty ap- 

 peared. It was found that the natives insisted upon following 

 the time-honored method of wiping out the cuts in the tree with 

 their forefingers. As a result, in a short time their hands 

 swelled up, owing to the stickiness of the milk, which stopped 

 up the pores of the skin. This was reason enough to discourage 

 the reluctant workers and they stopped work. 



In the meantime, samples of the gum and a five-gallon can of 

 the milk were sent to the States for expert observation and 

 opinion as to the utility of this new product. The first expert 

 reported that the gum failed to look like anything he had seen 

 and was useless ; further, that all there was to the milk was a 

 strong, pungent smell. This was discouraging, but another at- 

 tempt was made, and a sample of gum exactly like the first 

 labeled "Mariato Chicle" was sent to the judgment seat. This 

 was received with the respect due to a newly discovered chicle 

 gum, and a prominent importer agreed to take all there was up 

 to 10 tons at a very good price. Another, a large manufacturer, 

 said it was the finest chicle he had ever seen and wanted to buy 

 the forest that produced it. 



Now that Berba Prieto had come into its own and had estab- 

 lished itself as a raw product worthy of notice, the question was, 

 how to get it out in quantity? 



After various unsuccessful efforts, an experienced chicle gath- 

 erer and 10 practical "chicleros" were induced to leave their 

 homes and they were soon on the job. The Chicle Zapote 

 (Acras Sapota), the source of commercial chicle, known as the 

 "Nispero," has a bark of a different te.xture from that of the 

 Prieto. The former is not so large nor so lofty as the new 

 aspirant to chicle honors, and the "chicleros" found themselves 

 confronted with new problems. Several modifications of the 

 usual appliances were made and a camp was soon in operation. 



The Berba chiclero is equipped with a pair of climbers with 

 exaggerated spurs to hold in the thick, brittle bark of the 

 Berba. A twelve-foot piece of one-inch rope, a five-gallon kero- 

 sene tin and the usual machete completes his equipment. He 

 commences to cut a channel in the bark near the foot of the tree, 

 leading the milk downward and into the five-gallon tin. An 

 improvised spigot is made by cutting a leaf transversely and 

 slipping the straight edge into a cut made in the bark, at the 

 terminus of the channel, which conducts the white, running milk 

 safely into the can. The channel is cut upwards in an irregular 

 herring-bone form, until the operator is unable to reach higher — 

 then the rope comes into use. He throws an end of it around 

 the tree and makes a loose loop, knotting it near his body. He 

 holds his machete in his teeth, throws the loop as high as pos- 

 sible up the tree, holding on with both hands. He then steps 

 up the tree by means of the climbers, bracing himself in the 

 loop of rope which supports his back. He is thus enabled to 

 have both hands free and continues cutting the channel. In 

 this way he mounts thirty to forty feet, until one side of the 



