July 1, 190B,] THE TROPICAL 
AGRICtTLTURtST. 
16 
kilos, of an esaence which, when pare, ia sold in 
France and Egypt at 500 to 550 franca an oanoe 
(31 grammes) or 16 to 17,000 francs the kilo. A 
woman can gather 1 to 2 kilos, of flowers daily. 
In Algiers 100 plants give 150 ki)o9. of flowers 
annually. A hectare may carry 5,000 plants, the 
daily produce of whioh may be 50 to 60 kilos, of 
flowers, or 7,000 to 9,000 kilos, annually. One 
hundred kilos, of flowers yield 12 to 14 grammes 
of essential oil. One hundred plants yield 25 to 28 
grammes. The oil obtained by distillation has al- 
ways a strong and somewhat empyreumatic odour, 
and will bear no comparison with that whioh has 
been obtained by enfleurage or by ether extraction, 
much leas with that of the natural flowers. The 
gathering should be done up to 9 a.m., and from 
5 to 7 P.M. When it raina the wetted flowera have 
to be thrown away, because they lose their perfume 
and turn brown. The rainfall ia thus a consider- 
ation. 
Vetyver or Khushhus (Andropogon muricatus). — 
The roots are worth 2 to 3. and very exceptionally 
6 franca the kilo. According to Jeanneney'a rough 
teats, the roots contain 1-3 per cent, of essential 
oil. A clump two years old may have 800 grammes 
of dried roots. The essence ia brownish, soluble in 
alcohol, and worth 25 to 30 francs the kilo. 
(7iYron«ZZa (Andropogon Schoeaanthus). — The essence 
ia worth 40 to 50 francs the kilo. It ia much used 
in England (lemon-grass oil. — Transl.) and is ob- 
tained by distilling the leaves, which yield 500 
grammes of essence per 100 kilos, of leaves. 
There are many other plants not recognised in 
the trade as yet, but perfectly likely to give pro- 
fitable results ; for instance, the following : — 
Lantana camara and aculeata, the unarmed and 
the thorny species. The latter especially is more 
free-grown than welcome, and as it cannot be 
exterminated might as well be utilised. The leaves 
and twigs are aromatic and might be distilled, aa 
they furnish 250 grammes of eseonce per 1,000 kilos. 
This product might be used either in perfumery or 
in medicine. The leavea are used for colds aad 
fevere. 
Carica papaya, the male flowers of the papaya. 
Beilschmtedia lanceolaia, or musk sandal. — The bark 
and seeds yield an essential oil smelling somewhat 
like Euaaia leather, 'J5i) grammes of essence from 
1,000 kilos of bark or seeds worth about 12 frauca 
the kilo. 
Santalum album and austtv-caledonicum, wall known. 
Thespena populnea, or Oceania rosewood. — The 
timber is valuable for cabinet work, and yields a 
fine brownish essence which would be excellent in 
perfumery. Worth about 30 franca the litre. — Indian 
Forester, 
RUBBER IN BOLIVIA. 
The frequent reference in these pages to estradas 
in conneotlon with rubber gathering may make of 
Interest acme word of explanation, with which ii 
presented on this page a diagram of a small rubber 
ooncesBion embracing 32 estradas, giving employment 
to 15 men, lodged in three bnts, the whole being 
convenient to a water course navigable by a steam 
launch. This ia a rough sketch of a rubber con- 
cession actually being worked in Peru, and is pro- 
bably the first plan of the kind to be presented in 
print. The word eatrada ia Spanish for path. A 
collection of rubber trees is called a aeringal, from the 
Portuguese name of the Biazilian rubber tree 
'"seringa," whence also comes the word leringuierv — 
a rubber worker. When a new seringal is to be 
opened, generally in a dense forest rendered almost 
impassable by the luxuriant undergrowth, an expert 
rubber hunter ia employed who, starting from a 
given point, proceeds through the forest until a 
rubber tree ia located. Calling back to his assiatanti, 
he waits until they reach him, blazing out ft path 
on the way and the tree is marked so that it may 
be recognised. Ue then proceeds until another tree 
is found, when the path is similarly extended, and 
so on until, having gone far enough in his judgment, 
he turns and proceeds again toward the starting 
point, still locating and marking rubber trees while 
his assistants blaze out the path. The work of 
opening the path ia then completed, after which it 
is the duty of each seriiiguiero to keep open the 
estrada (path) which he is detailed to work. The 
idea is to make the estradas each of a convenient 
length for one man to tap all the trees included in 
it, and carry the rubber milk back to the hut and 
cure it, in one day. Two estradas are assigned to 
each man, who " works " them on alternate days. 
As will be seen, the number of trees embraced in 
the estradas varies widely, the numbers in the dia- 
gram ranging from 95 to 160. It will be seen also 
that this seringal embraces three groups of estradas, 
with considerable open spaces intervening, the 
reason for whioh is that the rubber trees are found 
in groups, and that in the open spaces indicated, 
the rubber trees are so scattered aa not to repay 
location and working. 
YIELD OF THE PABA RUBBEE THEE. 
It must be understood that the product of the 
rubber tree varies greatly with its locality and also 
with its size. For instance, on the Acre it is not 
uncommon to find estradas of 100 trees giving 12 to 
15 kilograms of green rubber— i. e., on the same day 
as cut. On the Badajos, on the other hand, a 
similar estrada will yield only 3 or 4 kilograms. Be- 
sides, the yield from the same estrada will vary at 
times, and one man may extract 8 or 10 kilograms 
from an estrada that will give only 3 or 4 to another 
and less skillful operator. 
This is the yield per day. Any attempt to es- 
timate the yeai'ly yield is complicated by the vary- 
ing length of the working season, which may be 
60, 90, or even 180 days, in different localities. The 
same estrada, as a rule, is not worked daily, bat 
every other day. 
It must also be remembered that many seringu- 
ieros adulterate their rubber with the latex of the 
pitch tree, which, when carefully mixed, 1 fraco of 
pitch latex to 2 of rubber latex, is not easily de- 
tected the rubber being sold at MansJos as " fine " 
at market pricea. If, therefore, a really good man 
who cut rubber at night, thereby getting 40 per 
cent, more, mixed the product with pitch latex, he 
would get 10x5-=l5 kilograms of rubber from au 
estrada which would yield only 6 kilograms to an 
innocent rubber cutter who cut by day-light and 
sold pure rubber only. Then the statistics of pro- 
duction usually given do not include "scrap," which 
is scraped off the trees and mixed together until it 
is impossible to reckon the total yield for any day, 
aa nearly always the same man works two estradas 
on alternate days. 
The almost universal practice of heating the lates 
before smoking in order to hasten the cure of the 
rubber doubtless has an injurious effect, in detracting 
from the elasticity of the finished product. [This 
ia a subject ou whioh The India Rubber World would 
like further details, j 
The Oauoho tree is now generally affirmed in these 
regions to be Castilloa elastica, but in view of some 
remarks in The India Rubber World on the Mexican 
rubber tree (the species first designated aa Castilloa 
elastica), it would seem that the classification of the 
Brazilian rubber species should be revised. Among 
the Eeveas I am acquainted with at least twelve well 
marked species, which give a very different product, 
and there is a kind of Manihot here which gives a 
rubber very different from that from the manicoba 
(Manihot Olaziovii) of Oe&xa.— India Euhber World, 
ManaOB, August 16, 1902. L. Q, 
