RUBBERS AND GUMS 207 



resin is removed from the crude product the remaining rubber 

 is of high grade. Jelutong is shipped in rather large quantities 

 from Singapore and is used extensively in Europe and America 

 in rubber manufacture. 



CHICLE 



The sapota tree {Acras sapota) of Mexico and British 

 Honduras is a stately tree which attains a height of 20 to 30 

 feet, bears leathery shiny leaves, and produces a latex in the 

 fruit, leaves, and bark, but chiefly in the bark. From the latex 

 of the tree a gum is obtained, known as chicle, which is used 

 as the basis of chewing gum. The wood of the sapota tree is 

 dark purplish-red and exceedingly hard and heavy when cured. 

 It is susceptible of a high polish and is very serviceable for 

 cabinet purposes. The bark of the tree contains sufficient tan- 

 nin to be utilized as a source of that product. 



The chicle industry is most highly developed in Mexico, par- 

 ticularly between Tuxpan and the southern part of Yucatan. 

 The quality of the gum obtained in Yucatan is inferior to that 

 which comes from Tuxpan. In this center of chicle production 

 trees are known to have been tapped for a period of 25 years. 

 After such a long period of tapping, however, the latex yields 

 only about 25 per cent, of gum. The tapping season begins in 

 early September and the flow of latex is greatly stimulated by 

 the occurrence of heavy rains. Trees which have not previ- 

 ously been tapped yield 15 to 25 pounds of latex. The tapping 

 process is ordinarily accomplished by V-shaped incisions so 

 arranged as to allow the latex to flow downward in a continu- 

 ous stream. The latex is caught at the base of the trunk in 

 leaves or other simple containers. The latex from the sapota 

 tree is extremely sticky. It is coagulated commonly by boiling, 

 after which the gum is kneaded to press out more of the wa- 

 ter. If carefully prepared, the gum is quite white, but it 

 usually has a dirty, dark gray color. 



The latex from the chicle tree will coagulate spontaneously. 



