Oct. 1, 1900.] 
THE TROPICAL AGRICULTURIST. 
231 
alao received from the Parus. The actual work of 
exploring and tapping eaucho trees is still done chiefly 
by Peruvians, even in Brazil, the Brazilians preferring 
to work the liecea. — India-Eubber and Gutta-Percha 
Trades Journal. 
Of late years the enormous consumption of rubber 
in the manafaeture of bicycle tyres has created a 
very great demand. The supply not being able to 
cope with this demand the price has steadily in- 
creaserl, and considerable attention is now being 
paid to the production of rubber all over the world. 
So great is the demand at present that although 
the supply from the Amazon Valley alone has in- 
creased from S,(3iJ5 tons in 1880, to 25,370 tons in 
1899, the approximate price of 2s. 6d. per pound in 
1889 increased to -Is. 6d, per pound in 1899. The 
British Vice-Consul at Mauaos states that the 
total world's supply to-day is about 120,000,000 to 
l:!0,Ono,000 lbs. valued at about £15,000,000, At the 
present time laticiferons plants yielding '• caoutc"houc " 
or " rubber are being worked for commercial pur- 
poses in Brazil, Bolivia, Central America, East and 
West Africa, whence come the chief supplies, while 
Guiana, the Eastern Archipelago, Bladagascar, India, 
and Ceylon contribute a small rj^uantity to the general 
stock. iVIore than half the total supply is exported 
from the iimazon district. In Brazil several kinds 
of laticiferous trees exist frorn which rubber is 
manufactured. In the State of Ceara, the Alanihot 
Glaziovii, locally known as the Manigoba, is fairly 
extensively worked, and considerable attention is 
being paid to its cultivation. In the State of Maranho 
the Rancornia speciosa or Mangabeira is beginning 
to give results. These trees, however, are unimpor- 
tant compared to the Tleveci Braziliensis or Seringueira, 
to which the Amazon Valley owes its present prosperity. 
The Hevea JSrarulieniia is found scattered through the 
forests that clothe the banks of the Amazon Kiver 
and its tributaries. It does not strike the eye among 
the innumerable varieties of trees to be met with in 
the Amazonian forests, and is often difiicult to detect. 
A peculiar glistening of the trifoliate leaves and the 
whiteness of the bark serves as a guide to the 
practised eye. The tree grows to the height of 
70 to 100 feet, and as a rule, when full grown, a girth 
of from 5 to 7 feet at a height of one yard from 
the ground. The tree flowers in January ; the seeds 
are ripe and begin to fall in March in the case of 
old trees, and in May in the case of young trees 
The seeds are contained in a hard shell, three or 
four in each shell, which hang by a short stalk 
from the upper and outer branches. When ripe 
the shell explodes, often with a loud report, scattering 
the seeds to a considerable distance. For this reason 
it is difficult to procure seeds. There are for practical 
purposes three distinct varieties of the " seringueira" 
to be tpet with in the forest. These are locally 
known as the seringueiras " casoa vermelha " (red 
bark), " barriguda " (bellied), and " casca preta " 
(black bark). The first of these, the " casca vermelha," 
grows in the higher parts of the forest which are 
seldom or never flooded. The latex which it yields 
is scanty, thick, and will not run. It is therefore 
of little value. The second of these the " barri^ii'la " 
so named because the trunk increase'-! very rapiuly 
in thickness towards the base, grows in those parts 
which are almost constantly flooded, named "iga)i'^s." 
It yields plentifully a thin, watery latex, which is 
of little value. The third variety, the " oasca preta," 
grows in those parts where a certain amount of 
drainage exists, and which form a intermediary zone 
between the permanently flooded parts and the high 
land. It is this variety which yields the latex from 
which the rubber of commerce is manufactured. The 
" latex," or as it is commonly known, the "milk'' 
of the tree, is a milky juice contained in special tubes 
running amongst the other tissues of the plant. These 
tubes, in the case of the hevea, are connected, form- 
ing what is known as the '' laticiferous system." 
The latex is quite different from what is called the 
31) 
sap," and probably does not play any part in the 
nutrition of the tree. According to some authorities 
it forms a reserve of water to be drawn upon in 
oases of drought. The actual extraction of latex 
cannot kill the tree, and the common statement that 
the trees are "bled" to death is a mistake. As a 
matter of fact, though trees, exhausted, inasmuch as 
they will not yield any more latex are common — 
actually dead trees, killed by overtapping are rarely 
met with. The latex as it exudes from the bark is 
of a dazzling whiteness, resembling milk, which it 
also resembles in composition, inasmuch as it consists 
of an emulsion in which "caoutchouc" takes the place 
of the better in the ordinary milk. The fluid part of 
the latex consists of water with very small quantities 
of albuminous matter, organic acids and phosphates 
in solution. The extraction of the latex, or as it is 
usually called the " tapping " of the tree is effected 
by making an incision in the bark of the tree. 
From this incision the latex flows for about three 
or four hours, after that it stops flowing of its own 
accord. The incision should not penetrate beyond 
the bark, which is generally about j^-inch thick, into 
the wood of the tree, and for this reason a very 
small axe, which rapidly thickens wedge like from 
the cutting edge, is used, the shape of the instrument 
preventing its entering too deep. The axe is generally 
about j-inch wide. The custom is to strike with 
it a backhanded blow upwards, thus making an 
oblique cut in the bark. It is probable that a better 
method would be to use a chisel and mallet and 
make a V shaped incision. Recent experiments at 
Henaratgoda have shown the advantage of this 
shaped incision. The incision having been made, 
a small tin cup, of a capacity of about four ounces, 
is affixed just below it to receive the latex as it 
flows. This is effected by pressing the edge of the 
cup, which is sharp, into the bark, until it gets a 
suflicient hold to remain firm. By this method, 
however, a second wound is made in the bark, which 
is injurious. No better method has yet been sug- 
gested. In some places a winding groove is cut 
in the bark of the tree, and by means of a clay 
breastwork the milk is conducted into a vessel 
placed at the foot to receive it. This method is found, 
however, to be very exhausting to the tree, and is 
falling into disuse. The usual mode of tapping is 
to make an incision with the axe at the height of 
some six or seven feet from the ground ; on a 
level with that incision and at a distance of some 
eight inches a second cut is made, and so on round 
the tree. On the next day incisions are made just 
below these, and so on day by day, until they reach 
the ground. Incisions are then made on the same 
plan, beginning as before from the top and work- 
ing downwards between the former rows. A tree 
that will carry seven cups eight inches apart is 
considered a large one and although trees that 
will carry eight or nine cups are to be met with, the 
average do not carry more than four or five. The latex 
having been obtained and collected, the caoutchouc, 
or rubber known to commerce, may be obtained from 
it in various ways. The only method, however, that 
has met with practical success is that of evaporation, 
by which the watery portion of the latex is driven 
■ If, and solid caoutchouc remains. The object to 
be secured is that as little water as possible shall 
remain in the caoutchouc, the putrefaction of the 
caoutchouc owing to the presence of these matters 
being extremely detrimental to its elastic properties, 
and therefore to its market value. In the Amazon 
district the method followed is to light a fire upon 
the ground, and to invert over it a specially-con- 
structed, funnel-shaped chimney. From the narrow 
end of this funnel, which is open, the smoke and 
heated gases pour out in concentrated form. The 
fuel used for the fire consists, as a rule, of chips 
from any hardwood tree that grows handy to the 
labourer's hut, The nuts of the " Urucury palm " 
(Attalea excelsa) are sometimes used, their smoke 
containing a trace of acetic acid, and creosote being 
