Daily press. [volume] (Newport News, Va.) 1896-current, 1906-01-28


! agascar also has produced excellent
rubber within comparatively recent
| period. In eastern and central Africa
| several new rubbcr plants have been
| discovered in recent years Even Mex
| leo has yielded Il new rubber. called the
gauyule but this is of inferior value
The milk of the rubber tree is not
| simply liquid caoutchOuc. hut contains
the latter rs an like matter, which
| is suspended i'm the milk as an emul-
sion. Gntherers of this Juice when
making iucisious i'm the tree With n pick
OF Ratchet must take the greatest care
bark. as that would provide means
of entrance for boring insects, which
would destroy the life Of the tree.
There are various methods of effect
ing the coagulntiou of the milk. but the
Para gatherers depend almost wholly
upon the operation Of smoking. Nari-
Gus palm nuts are commonly used as
n fuel. aud the qnicknesS with which
the smoke from these produces coagu-
lation has been attributed to the pres.
cnco in it OF ncetic acid. The shells of
brazil nuts have also been used for
The same purpose with fairly good re.
suits.
In burning the fuel il is sought to
prevent perfect combustion SO ns to
secure greater quantity of smoke.
and an inverted clay pot with hole
I'm the bottom is placed over the fire.
The milk is exposed to the smoke issu-
ING from thn nttfinp a tu111n yyhiIl,
has been dipped into large vessel of
the liquid. heing held in the cloud of
! smoke. which SO quickly coagulntcs the
milk that the paddle can be dipped
again almost Immediately. This proc
| ess is repeated until the mass Of india
rubber on the paddle becomes I'M
wicldy. when il is removed
Despite the extensive production of
rubber in various countries. the de-
mand for il has Increased more rapidly
| than the supply. The better the quality
of the rubber the longer is the growth
Of the tree producing it and the longer
| 1t takes To yield the material. The
poorer rubbers can be obtained much
more quickly. AS il comes to market
! the bulk Of crude rubber contains n
large percentage Of impurities. espe-
CHILLY resins. Para rubber WA former
| ~ substantially free from resin and
dirt but IL ia said that some of the
rubber now produced on plantations is
even superior to the best Para. In gen
ernl, however. the cultivation of rubber
| on plantations has not been very sue
| cpssful. though II has been carried on
| TO considerable extent in Ceylon and
the Dutch East Indies. II is said that
| all the South American companies or
ganized to operate such plantatio
have hitherto failed to produce much
rubber. In explanation it Is pointed
| out that from sixteen to twenty years
are required for n Para rubber tree TO
become productive. from the time its
seed is planted. and even then its yield
Of milk ia scanty. Moreover. the vigor
OF tree especially n Young one. is
Injured by much tapping Full matu-
rity. it is believed. is not attained 10y a
| Para tree in less than fifty years.
To increase the supply rubbers have
| been largely ndulternted. great vuri.
| ETY. Of resins being uscd. giving the mn
terial more body. but impairing its
strength and making; it brittle Many
attempts have been made to manufar.
turc substitutes for rubher. commonly
with OXitliZed linseed or corn oil as q
| basis. but all such efforts are averred
| TO have been failures. As one OF thu
| experts at the botanical garden said.
The alleged substitutes for rubber are
not rubber, and science has not yet
succeeded in producing anything which
| cnn be called caoutchouc.' a story
| has been told that an English chemist
some years ago achieved the produc.
| ton of compound. with turpentine ms
basis. which comprised all the prop
critics of genuine india rubber, but wa7
unable for some unexplained reason tC
| duplicate the experiment. This tale Is
discreditcd by botnnists ut the garden
Any one who could produce nrtiticially
the equivalent Of renl india rubber nj
n reasonable cost would secure Dr.
Johnson's ''potentality of growing rich
beyond tho dreams of avarice."
The ordinary vulcanizcd material
contains only from one half to per
| cent of sulphur, but if enough more is
added it produces the hornlike sub
stance called hard rubber, used for
| combs. penholdcrs knife handles. eve
glass rims. watch chains and many 9th.
er articles. This hard rubber, which
takes fine polish, is valuable to the
electrician for its insulating properties
and to the chemist and photographer
because vessels made Of 1t are unafrect-
ed by most chemical reagcnts.-New