CENTRAL AMERICJAN.—The Central American, Cartagena, and Guayaquil rubbers are yielded chiefly by the ule (Castilloa elastica), a lofty tree with a trunk 8 ft. diam., found in Mexico, GuatemaLa, Salvador, Honduras, Nicaragua, Costa Rica, Panama, the W. coast of S. America down to Guaya quil, and the slopes of Chimborazo, as well as in Cuba and Hayti. This extensive geographical range shows the tree to be capable of existing under considerably varied climatic' conditions. The forests in which it grows are usually at or near sea-level, but it has been observed at an elevation of 1500 ft. on the Pacific coast. The soil is various, but the tree avoids marshy or boggy land, and manifests a preference for warm, deep loam or sandy clay, and it especially affects the margins of small running streams, where it occurs in little groups. A moist climate and high equable temperature are essential ; the trees thrive best in dense, steaming„ hot forests, and are particularly abundant where it reins during 9 months of the year, and the tempera ture ranges between 75° and 88° F. A second smaller species, C. Marlthamia, also ocoure in Panama.
In Panama, the usual method of collecting the milk is by felling the tree, and then making deep notches around the trunk at distances of about 1 ft. apart, as shown in Fig. 1174. Broad leaves placed beneath the notches receive the milk, which is afterwards collected in a large cala bash or other vessel, poured into a hole in the ground, and thatched over with leaves, where it coagulates in about 2 weeks. Another plan is to bruise a handful of the leaves of the Ipowca bona twx, and stir them about in the milk, which is thereby thickened in about an hour to a jelly-like porous mass, profusely exuding a black ink-like water when touched. The article thus produced is inferior. It is sometimes sliced into flakes 1 in. thick and sun-dried. In Nicaragua, it is found that though the tree yields the juice at all seasons, the best time for tapping is April, when the old leaves begin to fall and the new ones appear. During the rainy season, May-September, the rich ness of the juice diminishes. From that time till January, the rains decrease, the milk increases in richness, the tree prepares to flower, and the fruit appears in March, during which month and the succeeding one the milk contains the greatest proportion of rubber, the difference amounting to 60 per cent. more in April than in October. A tree about 18 in. diam. (probably 6 years old) tapped skilfully in April will yield some 20 gal. of milk capable of giving 50 lb. of rubber. This is a maximum figure, and the average is somewhat less. A tree of 20-30 ft. to the first branches is
expected to afford 20 gal, of milk, and each gallon of milk to reuder 2 lb.-2 lb. 2 oz. of good dried rubber, By the Panama system of destroying the tree, the produce often amounts to 100 lb. of rubber from a tree. The Nicaraguan mode of tapping is as follows. The collector ascends the tree by climbers or a ladder as high as possible, and then commences a series of incisions with a sharp machete or axe in one of two ways. One is to make a long vertical cut, with diagonal cuts running into it, as in Brazil ; the other is by encircling the tree with spiral cuts at an inclination of 45° ; if the tree be large, two such spirals are inade, either crossing or parallel with each other. At the bottom of the trunk, an iron spout is driven in, and the milk is received into iron pails. In the evening, the milk is freed from foreign matters by passage through a sieve, before transference to the barrels in which it undergoes coagulation. This last condition is brought about by the addition of plant-juices, notably that of the acliete (Iponixa bona nox), as in Panama. The plant is collected, moistened with water, and bruised, and the juice, after straining, is added to the milk, in the pro portion of 1 pint to 1 gal. After this operation, the rubber appears as a soft mass floating in a brown fluid, and smelling like new cheese. The mass is pressed under a plank or iron roller into a tortilla or cake, usually weighing about 2 lb. when dry, and representing 1 gal. of milk. When the acheM or other suitable plant is not procurable, water in the propoition of 2 to 1 is added to the milk, and the whole is allowed to stand for 12 hours. The residue which separates from the water is poured into underground vats and left to dry for 12-14 days. Sometimes the milk is shnply poured on a prepared spot of ground, and the watery portion left to evaporate or disappear as it may ; the rubber, when outwardly dry, is pressed to remove bolsas or bubbles of watery liquid. Slabs made in this way are sometimes called meros. The rubber which is allowed to dry in the iron spout conducting from the tree trunk is rolled into balls, and called cubezza ; that which dries in the wounds on the tree is termed bola or burucha, and is esteemed in New York. The loss by drying (inerma) is estimated at about 15 per cent. A recent traveller in Central America states that the u/g tree " yields many gallons every 2 years ;" but in Panama, the tree is totally destroyed in obtaining the milk, and elsewhere the tapping is said to be so injuriously done as to be little better than immediate destruction.