, 1875-04-10
SPARKS OF SCIENCE.


OF trceH belonging to different fAn,,Eies, M tho
1foraccr, Artocdrpaeca, EupaortidcrH, ApocY- |
nacea, Ascieptaducetr, md lnpnyacCr. II cx-
in.b in tim milky juice aoctetcd by Tho plants OF
tcso osdera throug, whicl, It ia tl,ruAcd in tho
fnsn OF minute gioh,llos. When tito 3ulco Ia c1-
tractcd from tho plants, and allowed tn slan for
q short limo, tho gobnleH rise to tho top like
rort If cream. Tho treo from which caoutcliouc
In chtoly derived tn the East In1es Is rpec'cs
of Zig (Ficas cjasfca, OF tho ordor Moracer),
that grows abundantly on rocky dtcliv't!ca III
tho forcsta Of Asxaul, L1chim pur, md Sylbcs.
ll!a tEoo nttains ,reat nse, aud has large, OVAL
thick. MID Glossy leaves. lit ANAL fruit IS In
edible. Fifty o,stccs OF Tho Juicn OF this troo
Yield fully Is ounces Of caou,cllouc. Tho sacred
ns of lnlia 4. uliqio.a) also aIlorda tho tanac
gum.
III !;nu!!, America. c,outchoao IL furnished
mainly bg tho siphont7 elas'ira 4rce common
In tho forcs.s Of 1,tazt aud tiulana and bclo,is-
Ing to Tho order Euphorbiacer. Tits trcc rcara
ts straight. scsly trunk to tho height Of froln 10
to GO feet, heturo irving OF Its branches. Other
trees In Roltll America TINT yiofd caoutchcuc
nte tho Co!opaora Mills, md Camcrarid lo jolia,
OF tho order Apocyaaccfe. In Madagascar, the
substance ia found IN tho 1nico Of tho = dIta
gtnlmtf tfrn: and aCan III tho East Iia!cs It in
furnished by lE9f'HfJhtciu etinlls, and Crce0ld
eMsiica.-all plants Ut the order Apof:ytaectf.
The t.rEt SPECIMENS Of caolittl1ouc wero tronEl,t
to Europe from the EaRt Indtes; but III 179j, tue
earliest nceount Of its nature ard properties waH
communicated to tho Frouc!l Academy Ivy n. tio
Ia Constamlttc who Ind examined tic substance
In South Amclica. In 1757, Ftctnea, discovered
elastic Gum, Lut rccciscd the nanlo Of India
rubber from itn use IN rubbing out baea-
lead rcncil.mnrhs. For this purroto /. was
Imported III el!,nll quantities at tho close Of tho
=. IL Il, ,~tH
was not nntil 1870 ih.t ita uscH eAtonlca beyond
tho erasurc Of pcncil.maras, although the it-
crcaso in Its importation lad reduced tho cest 20
that IL wan accessible to oyory otn
Tho nauuor oi obtaining caoutehonc in South
America Is IA follows: Will! sharp Instrument,
straight aud slopflg iucteions aro tunto in tho
bulk of tho tree, nno above tho otllor, to the
height of d mans head. Under tho inclslona aro
placed vcssels Of clay, holding about a tun.bler
full. 1ho }ulco is wl,lts wl,c 1t llrst Aows from
tho trcc hut a brown color is impaired to 1t BY
foreign matters mixed viii, it, aud nleo By sub
joctIns 1t to tho thick oils stnoke Of fires fnado
Of nruca1i nnts. Tho natives havo clay nlolds
Of hottlsa, animals, ctc., winch they dip into tic
milk md hold ovtr the pmoko until dry. ioreat-
ing tho proco ~ till tho 1uIbcris OF fsntficictt thek
nest. N!leh It Ia removed from tho n1o!tl and
Ia ready for tho market. Caoutchonc from tho
East Indies Is generally In the fo,m of Eall. nDl
jun'p, and tH OF light color, o'lnt; to ta being
dried in tho pun.
On reaching tho manufacturer, tho frat thing
tiouo With tho ctutle raoltchouc Ia to cloanEo It
OF Impurities. It II cut Into e',reds and thor
ouShly waslled by tho aid OF ulachnrry. Wbno
purified. It Is placed OH trays. and dried by
Etonn. 1t Is Afterwards kllcaIcd into solid
nass unaor hcavs rollers. OF sufficient weight to
cloEo all alr-ho!ea nhd to compress ihc substance
into a compact block. This block ia then cut
under water into allccs by powerful knivos Or
rhcara, and tic alccs alo divided iuto piecea
suitable for tho trade OF tho a:atloncr, or they
arc manufactured into bnnas or thread.
-. t.M
by cuo1i,isal process cai!od 7ulce'ixa.on.
dos,lyear 'S i'''Dib but 4Sep. by Lin accre
it waa independently discovered by 1Iau-
coci, Of England, and patented By him. lilo
subl!mcd sulphur. 1lns trcntcd, tho Eubannco
retains elasticity nt nll degrees Of temperature,
Is not dissolved by auy known solvent, mud rc-
s!sts compression tn tho highest degree. mix
turo nf tar and cnnutcholc with rnoia than their
weight of kn!plsnr ploducos material 70 lIard
a,l bIac.s that 1t tynls ebony OF jot, ard, bnint.
susceptible Of n 0no polish, il manufactured INTO
MI cilllcsa variety or ornamental artcle8, Eucil
0utta-pelclla il often corfonudod will, caout-
c1louc. but IL h quito different substance. 1t Is
tho dried Juice OF tho fsononfra gua, treo be-
longing to tue o.dcr Sapofacer, mud growing III
tic Peninsula OF NafaccR aud tic hialayan Ar
clupoaso. Tho tree nttalus q largo Hze, tue
trunk sometimes measuring , fec. in t1ianeter.
10 obtain tho Juice. tho trco IL cut down nsd
stripped Of ita ba1If, aud tho Juice, wl,iel,
lEes no1t tho wood, in eerapol up into l:tlo
and in thon slt for expottstioit. From tfnlo to
time, drinking cups tnato Of Ibis material had
been brought to Europe by travellers from tho
East Inites; but lts properties were not known
brought it to tho nutico Of the Socioty OF Arts.
London. and waa rewarded with tho gold 1uolat
for his valuable service.
TITO grltta-percha Of commerce has 10 to
clenuBcd by about tho Eamo PROCESS aH that applied
to caoutcouc. before ills fit to 10 manufactured.
It IN imported III Jumps Of from 3 to 1T pounde.
aud is OF q light brown color, nnd full Of pores,
1t 10! omlcB cork "hcn cut, ami haH NIL odoy
Like cheese. The snbttatce nas littlo or ITO eias-
tcie', and In thia dtiorn euucntially FROM
caoutchouc. :
ENEMIES o. THE AppLG.TrrE.
Tho a,pio-trca nllmbcrA among It's enemies
not Ices than Aoyenty-Aye different spoclea Of In
sects. OF these tho blisht.tusect (sriosoma
pyrr, and tho young Of tho cicata, prey OF liz
roots. Tho former Ia o near ally OF Tho phyl-
lo1cra that docs such great harm to tho vine.
Tho roots Of y ttoo iufcslcd with IL should bo
dipped In soap-suIs, and when rerlantcd, n
ehnyeiful Of sfLcs should bc mixed WITH tho
dirt. The young OF tho cicala--cn.nmonly
called lncust st-l,yes sixteen years In tho ground.
and, though usually sucking tho sap from tho
roots Of tlle oals It sometimes astacks tho alpto-
tree, aud, during this long period, proves q &C.
ronn drain OF the tree.
Tho trunk OF tho npplc-treo Is subleet to a.
tacka from nulnhcr Of beetles tina.
boro into tho bark and wool Among
these pesta tho 1noat prominent is tho
common nrple-srco.borcr (Snpcrda candila).
This may 10 kent down by cutting out lilo
worms or by pouring hot water Into thtir l,oleH,
in the autumn; by applying Roap to tho tr,,nl.
or surrounding 1t with t:s.red lapors, III tlo
spring. Two l}trrustid borors, tho Lhrysotos.,i,
tt,moTata nnn tic q. Norrte1., arc nlso cos.nlrl-
oua foes. a'isl aro 10 DO treated III tho eamo way
Oh tho Saperda. Ulor hottns beetles A.fodt.ng
the app!c-srco aro tho whtto-iincd ]'sei.oee'rts
the cylindrical hark-boror, Or 1o'aicns nsali .hu
rttcAly !crtohtyiua (Leptostyias achlJsrus); aud
to apple faiopns.
Eo1s to tho borors, tho most destructive enemy
OF ths arnle,tfee " tho scab-lasees tlIy!iaYix
DoMo,tn. Douctoj. Tho beat romcly for TIN,
evil Ia to scIare tho tarA OF tho tteo III autumn
and again In Juno, when It should bo washcd III
wilalo oil soap.
The leaves Ut tho applo-.rco arc liah'o to tho
rnyages OF tho American tons.castrpIlar (titai.
u