190 



THE INDIA RUBBER WORLD 



[March i, 1906. 



stretching, is taken. After the strain has been removed, a 

 third reading is taken to show the recoil of the rubber, 

 which, in the best products, should not be far from the 

 original measurement. The whole apparatus is enclosed in a 

 copper case with a glass door and a water bath below, in or- 

 der to keep the rubber at a constant temperature, so that 

 comparative tests may be made. The measurements are 

 taken by sliding pointers moved by handles from the out- 

 side and running on a scale graduated to millimetres and 

 tenths of an inch. A large number of rubbers will be tested 

 so as to show the relative physical properties of old and 

 new, of rubber chemically pure, and of that containing small 

 proportions of resin. 



THE ZAPOTE TREE AND CHICLE GUM. 



BY A. J. LESriN.\SSK.* 



AMONG the numerous natural products abounding in this 

 fertile region [The Mexican canton of Tuxpam] the Za- 

 pote tree stands preeminent, its gum and wood during many 

 decades having formed a source of wealth to a large number of 

 individuals and corporations, native and foreign, which have 

 obtained from the state government proprietary rights or con- 

 cessions to extract Chicle gum. 



The wood of the Zapote tree t is dark purplish red, and al- 

 though exceedingly hard when first cut it is easily worked un- 

 til thoroughly seasoned, when only the finest edged tools have 

 any effect on its flint like surface. Sharp pointed nails can be 

 driven into the wood only about an inch. The fiber is so dense 

 that the wood sinks rapidly in water, and will remain immersed 

 for years without being affected in the least. Zapote door 

 frames in the ruins of Uxmal are as perfect to-day as when 

 first placed in position. The wood is susceptible of a beautiful 

 polish. The average Zapote will square 5 to 8 inches and oc- 

 casionally 2 feet. It i^ claimed that the bark is employed to 

 great advantage in tanning processes, and that leather so treat- 

 ed is superior to other kinds. 



The magnificent trees are rapidly disappearing, as the opera- 

 tors are taking no precautions to protect them from the destruc- 

 tive methods of the chicleros, who, in their greed to obtain all 

 the sap possible, cut the trees so deep that they do not recover 

 from the effects of the incisions, but gradually decay. Before 

 the trees reach this stage, and while still easy to work, they are 

 cut down and shaped into building material. 



The Chicle industry extends from this section as far as the 

 extreme southern portion of Yucatan, which produces the larg- 

 est yield, but in quality the gum is inferior to that obtained 

 from this section, especially in the Tuxpam district. The latter 

 gum commands a higher price in the United States, to which it 

 is almost exclusively shipped. 



Zapote trees thrive best on high, rolling land, and although 

 trees are found on the lowlands, they are inferior in both sap 

 and wood. Continuous tapping does not appear to have a se- 

 riously detrimental effect, provided the incisions are not too 

 deep. Trees are known to have been tapped for 25 years, but 

 after that time produced only from Yz pound to 2 pounds of 

 sap. If allowed to rest five or six years they will produce from 

 3 to 5 pounds. The average height of the trees is about 30 feet. 

 Zapotes are exceedingly slow in growth, and require from 40 to 

 50 years to attain full height. 



• United Stales consul at Tuxpam, Mexico ; extract from a fortticoming official 

 report. 



\ Achras iapota^oi the natural order Sapotacttr. The same natural order em- 

 braces the genus Isonandra, which yields Gulta-percha, and the genus Mimusops^ 

 the source of Balata. [See an article on "The Basis of The Chewing Gum Trade," 

 in Thb India Ruubkr World. November lo, 1895— page 43.] 



The Chicle season opens early in September, though the yield 

 at this period is limited, and, owing to still copious rains, the 

 chichros (laborers) are retarded in their work; but this is to a 

 great extent a benefit, as rains are favorable to an abundant 

 fl jw of the sap, provided the rainy season isnot prolonged beyond 

 October, in which case sap would contain a larger proportion 

 of water, and the loss in condensation would be heavy and the 

 product inferior. New trees will produce from 15 to 25 pounds 

 of sap, according to size. In order to produce 25 pounds a 

 tree would have to square about 2 feet and be from 25 to 30 feet 

 high. 



The process of extracting the sap is extremely primitive. 

 Open V shaped incisions are made in the tree trunks, permit- 

 ting the sap to flow in a continuous stream. At the foot of 

 each tree a palm or other appropriate leaf is fastened, which 

 acts as a leader or gutter from which the Chicle drips into the 

 receptacle placed to receive it. 



The sap as it flows into the incisions is beautifully white, has 

 the consistency of light cream, but as it runs down it gradually 

 becomes more vi cous, until, as it drips into the receiving re- 

 ceptacle, it is of the density of heavy treacle. It is very adhe- 

 sive, and is extensively employed for repairing broken articles 

 and fastening leather tips to billiard cues. When the receptacle 

 is filled it is emptied into a large iron kettle mounted on a tem- 

 porary stone foundation, with a small opening for wood, the 

 fuel used in the boiling process to evaporate the water, which 

 amounts to about 25 per cent, of the sap. As the boiling pro- 

 gresses the Chicle thickens, and when it has reached the proper 

 consistency it is allowed to settle until a trifle more than luke- 

 warm, when it is kneaded to extract more of the water content, 

 and is then shaped by hand into rough, uneven loaves weighing 

 5 to 30 pounds. If carefully cooked it is of a whitish gray 

 shade ; if carelessly handled and improperly boiled it is a dirty 

 dark gray. When prepared with extra care it is of a light pink- 

 ish color. Much deception is practiced by the chicleros. who, 

 in order to increase the weight, insert stones, bark, sand, or 

 wood in the boiling Chicle before it is formed into loaves. The 

 sap freshly extracted will weigh about 7 to 8 pounds to the 

 gallon. 



Prices in this market range from $8 to $15 Mexican currency 

 LS3.82 to $7.16] per 25 pounds; last season the average was 

 about $14 [$6.38] per 25 pounds. 



If a good worker, a chiclero can obtain 50 to 75 pounds of 

 Chicle a week, for which he receives 20 cents Mexican [9.54 

 cents] a pound. As a rule, arrangements to extract the Chicle 

 are made with capataces (contractors), who have charge of the 

 men. They receive about 40 cents Mexican [19.08 cents] per 

 pound, and from this price they must feed and pay their em- 

 ployes. 



TO TRADE IN RUBBER IN AFRICA. 



THE Tanganyika Rubber and Trading Co. of South Africa 

 was mentioned in the July i issue of this Journal (page 

 389) as having been incorporated under the laws of Montana, by 

 Roland H. Creech and others. It appears that Mr. Creech, who 

 resides at Butte, Montana, has spent twelve years in South Af- 

 rica, doing contract work for the late Cecil Rhodes and the Eng- 

 lish Chartered Co. Mr. Creech is confident of being able to deal 

 satisfactorily with the natives around Lake Tanganyika and of 

 getting' rubber at a cost which will enable his company to 

 make a good profit. Mr. Creech holds a number of concessions 

 and plans to ship produce by Mombasa, on the eastern Afri- 

 can coast. This is the first American company in the field re- 

 ferred to. 



