Gums, Resins, 



200 



[March 1908. 



The distance from Rio Sao Francisco 

 is not too great and the roads are fair, 

 and good means of communication are 

 afforded by the river and from Joazeiro 

 onwards by jail. We shall not be in 

 danger of over-estimating the present 

 export of rubber from this species of 

 Manitoba at least 600 tons a year. 



Harvesting and the Yield of Rubber. 



In the method of collecting, Manihot 

 dichotoma resembles Hancornia speciosa 

 most closely. In the Catinga woods the 

 thickets of this Manicoba are usually 

 found near villages and close together, 

 so that special huts for the collectors 

 are only required in the more distant 

 parts. The Borrageiro starts in the 

 morning, and just as with the Manga- 

 beira he taps the stronger trees with a 

 sinuous cut using a knife which is either 

 bent at the point or truncated. Some- 

 times a straight cut is used with or 

 without lateral cuts— a kind of herring- 

 bone tapping. At the lower end a zinc 

 cup is attached to the bark in order to 

 catch the milk. When this milk is col- 

 lected in vessels it begins at once to 

 coagulate and is moulded with the hands 

 into balls which are usually pressed be- 

 tween rollers and afterwards thoroughly 

 dried. 



This method of collecting caoutchouc is 

 carried out by the inhabitants of the 

 neighbouring regions or by people 

 specially enlisted, and this branch of 

 industry is only incumbent upon the 

 collectors who wander round certain so- 

 called reversionary landed property 

 which belongs to the Government. 



If the tapping is carried out carefully 

 the wound heals after a time and the 

 tree can be tapped again so that rubber 

 can be gathered three, and, under favour- 

 able circumstances, as many as ten, times 

 from a single tree. In the wild state, 

 however, M. dichotoma is often carelessly 

 cut by unaccustomed workmen, so that 

 the wood is laid bare. In these cases the 

 stem rots very quickly and the tree dies. 

 In the neighbourhood of Tambury very 

 many dying and dead Manicoba trees 

 are already to be seen, and it is certain 

 that within a few years the rubber crop 

 will fall off very considerably. In my 

 opinion the wild thickets oj Manihot 

 dichotoma will very soon cease to have 

 any importance as a source of rubber. 



The amount of rubber which a man 

 can gather and prepare in one day varies 

 from one to several pounds. The yearly 

 amount is difficult to determine because 

 very few Borrageiros occupy themselves 

 continuously with gathering rubber, 

 although the trees yield latex through- 

 out the whole year. 



In the case of both the other species 

 M. heptaphylla and M. piauhyensis, the 

 method of obtaining the rubber is almost 

 identical. In these cases it is found that 

 the shorter stem as well as the some- 

 what thinner bark are not suitable for 

 cutting, and, treated in this way, yield 

 little latex ; on the other hand scratching 

 just above the root gives a very good 

 result. 



For this purpose a depression is made 

 by removing the earth on one side at 

 the base of the stem, and at this point, 

 just above the insertion of the root, the 

 Manicoba tree is scarified with a round 

 pointed knife. The latex flows into the 

 hole prepared for it and there coagulates, 

 whence it is gathered by the rubber 

 collectors. Since the rubber obtained 

 in this way is liable to become very 

 much contaminated with sand, the 

 bottom of the hole is often covered with 

 a thin layer of clay, for which purpose 

 that obtained from termite nests is 

 well adapted. This clay can easily be 

 washed away from the small threads of 

 rubber, and thus a fairly, pure product is 

 obtained. After gathering, the rubber 

 requires to be dried in the air for some 

 time before it can be packed in sacks 

 and sent away. 



The weight of these rubber threads 

 obtained from a single tapping usually 

 varies from 10 to 100 g. oz. to 3 oz.). 

 But I have seen balls of rubber up to 

 150 g., and it is said that as much as 1 

 k.g. (2| lbs ) is sometimes obtained. The 

 Manitoba tree is always scratched at 

 the same spot, and endures this method 

 of tapping very well. The yield of rub- 

 ber from a good tree may be put at 5 

 k. g. a year.* 



The method of obtaining rubber from 

 the Manicoba in Piauhy is adapted from 

 that employed in the case of Hevea 

 brasiliensis on the Amazon, and here 

 too the people concerned with it are 

 called Seriugueiros. 



Here also so-called Estradas— primitive 

 paths— are laid out, from which 300 to 

 1,000 trees can be got at. By cutting 

 do wn the lianes which block the way 

 a sufficient line of passage through the 

 jungle is laid open, and, if possible, the 

 path returns in a circle to the point of 

 departure, whilst it must pass a sufficient 

 number of Manicoba trees on either side. 

 A Seringueiro taps about 200 trees a day, 

 and it is so arranged that each tree 

 comes upon his route not more than 

 twice a week 



* Or 11 lbs., a figure that one is hardly disposed 

 to accept, even from Dr. Ule, without further 

 evidence. — Ed. 



