452 
THE TROPICAL 
AGRICULTURIST. 
[Jan. ], 1900. 
these mixtures are said to be greatly enhanced by 
mixing 100 grammes (about 3| ounces) of soda crystals 
with each litre (l ? pints) of diluted juice. Regaiding 
the use of this product in the Alpes Maritinies, the 
United Slates Consul at Nice says that it is rapidly 
coming into general favour for all the purposes men- 
tioned above. He has seen it used with complete 
success in curing what is popularly called " le noir." 
This pnasitic affliction is not confined to orange, 
lemon, olive, and other trees, but has been most dis- 
astrous to such vegetables as potatoes, beans, peas, 
tomatoes, &o. He has also seen whole rows of orange 
trees so thickly coated with parasites that every leaf 
appeared coated with soot (hence the popular 
appellation, " le noir,") and he has been enabled 
to verify the fact that three or four applications of 
the lotion have prevented the disease from attacking 
new leaves, and have caused the disappearance of the 
black deposit upon those attacked. A proprietor of 
an olive grove in Nice has recently stated that the 
use of the juice in combating " le noir," which 
has destroyed many thousands of olive trees in the 
department, is most costly, but at the same time 
very efficacious. The spraying machines used to 
spread the mixture are the same as those employed 
in applying sulphate of copper to vineyards. Efforts 
have been made to ascertain whether the use of 
tobacco juice would not be more desirable in treating 
vines for the cure of the oidium — a parasitic disease 
of the vine leaves — than sulphate of copper, but it 
appears impossible to discover anyone who has ex- 
perimented with the tow treatments. It would appear, 
at first sight, that tobacco juice would be preferable, 
as sulphate has always been considered a preventive 
of attacks upon the grapes themselves, especially 
after the bunches are completely developed, whereas 
the oidium attacks only the bases and indirectly the 
vitality of the plant. 
♦ 
FUMIGATION UF TREES. 
The fumigation of trees for the destruction of insect 
pests has for some time been extensively used in 
California and other parts of the United States. 
The process will probably soon come into use in 
New South Wales, for Mr. W. J. Allen describes 
in the A(/ricultural Gazette of the Colony some very 
successful experiments in spraying and fumigating 
for red and other scales on orange trees. The tree 
to be treated, is completely covered with a tent, 
and is subjected for netrly an hour to the fumes 
of hydrocyanic acid, produced by the combination 
of sulphuric acid and potassium cyanide. The 
number of men generally employed in a fumigating 
gang is four or five, according to the size of the 
tree. One man introduces the chemicals, another 
looks out for the generator and measures the acid, 
and two or three handle the tents. Such a gang 
ean handle from th'rty to forty medium-sized tents, 
and cover four to six acres of orchard in a night. 
Fumigation is to be preferred above spraying, be- 
cause the trees are not in any way damaged by the 
fumes, except in the case of a few of the tender 
leaves, while the solution used in the sprays musk 
to a certain extent close the pores of the tree and 
slightly weaken it. — Nature. 
MANGABEIRA RUBBER, 
The current number of the Kern Bulletin contains 
an important article on the source of Mangabeira 
rubber {Ilancornia speciosa). In consequence of cer- 
tain objections to its use, the price has been but 
half of Para rubber. Recently, however, the price 
of Mangabeira rubber has advanced by reason of the 
improvement in the purity, and on account of its 
great suitability, when pure, for certain purposes. 
In consequence, the disparity between the price of the 
best sorts and that of Para rubber is much diminished. 
At the end of last year, a kilogramme ('21b. 3oz.) 
of the hest Mangabeira rubber sold for upwards of 
12 milreis (almost 8s.), a price not far short of that 
of Para rubber. An additional cause of the advance 
in price is to be sought in the change in makinR 
up the rubber ; for, owing to the constant watch 
which is necessary to guard against adulteration by 
addition of iron or stones put in to make weight, 
pieces of rubber only half to three-quarters of an 
inch thick and two feet long by ten inches broad, 
the so-called ■' theets " of commerce, are welcome in 
the trade. 
Of recent years, the exploitation of this source of 
rubber has taken a considerable extension. While 
the intelligent collectors, who start from Bahia and 
work towards the interior, have only tapped mature 
trees, improvident itinerant collectors, making their 
own profit out of the presssing demand of the time, 
have in many places mischievously drawn on the 
supply and threatened its continuance. 
The chief centres for export of Mangabeira rubbel 
are Bahia and Pernambuco. A large supply is 
brought down the river Sio Francisco, and so to 
Bahia; and from this town, in 1889, 131 tons were 
exported: in 1892, 4,362 bales, to the value of 
£22,820 ; and in 1893, 3293 bales, to the value of 
£20,362. From Pernambuco were exported, in 1896 
64 tons to the vahis of £1,800.* A small amount of 
caoutchouc from the Province of Matto Grosso 
(probably Mangabeira rubber) is exported down the 
Parana through Paraguay, and great quantities from 
Minas Geraes are shipped through Kio de Janeiro. 
Recently the Province of Sao Paulo has begun to 
demand a place in the consideration of rubber export. 
Regions here, such as that through which the 
Mogyaoa railway runs, are exploited, even by persona 
coming from Bahia for the purpose, the owners of 
the land receiving, in return for the permission they 
grant, one-third of the clear profits. A worker can 
collect about 6i lbs. of rubber per diem, and receives 
on the spot 7-5 mileris £(2 9s. approximately) (per 
arroba 32| lbs.). The arroba is sold in Loudon for 
200 milreis. In the first half of the year 1898 no 
less than 76,498 kilogrammes (approximately 78 tons) 
of rubber were passed over this railway, and yet the 
railways of Paulista and Sorocaba equally traverse 
the country where the Mangabeira tree grows. In 
consequence of the increasing trade, Santos has 
become an important centre for rubber, and there, as 
at the town of Sao Paulo, now exist mercantile 
houses whose principal concern lies in this business. 
In this Province an idea of the importance of culti- 
vating and protecting the tree is arising. Many 
coffee-planters are turning their attention to the 
sowing of Uancoynia, and seed is already hard to 
procure. The Govrnment hoping, by means of the 
duty on rubber (now standing at 13 per cent, ad- 
valorem), to recuperate its fiances, which have 
become disordered by the depreciation of coffee, has 
instructed Dr. A. Uchoa Cavalcanti, Acting Director 
of the Agircultural Institute at Campinas, to inspect 
the territory in question ; and, further, the Congress 
of the State has decreed that the Mangabeira trees 
shall be protected, and its cultivation extended, as is 
advisable. 
Although but little is known so far of the cultiva- 
tion of Mangabeira, it may be said that there is a 
considerable probability of it becoming an important 
tree in rubber-culture. The apparently easy accom- 
modation of the tree to soil and climate, its early and 
considerable yield, together with the fact that even 
under thorough treatment of the Indians it preserves 
its fruitfulness, and also the facility with which it can 
be cultivated, promise a future. And, taking a wide 
view of its possibilities, from its presence in the red 
coffee-growing soils of the west of the Province of 
Sao Paulo, it appears suitable! for the red earths of 
the German colonies of Africa, Usambara and Togo- 
land alike, such, for instance, as occur at Misahohe, 
in the latter colony. For these soils it promises to 
be considerably better suited than the Ceara rubber 
plant (Maniltot Glaziovii), and the Para rubber 
(Hevea), and will probably give better results than 
Ciistilloa, than which it is more hardy, earlier maturing, 
and smaller. — Journal of Society of Arts. 
* Probaly an error for £18,000. 
