forty centuries of ink-第69章

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nests；　that　a　paper　might　be　manufactured　from

wood。　This　idea　does　not　appear　to　have　been　acted

upon　until　many　years　later；　although　in　the　interim

inventors　were　exhausting　their　ingenuity　in　the

selection　of　fibrous　materials　from　which　paper　might

be　manufactured。



The　successful　introduction　of　wood　as　a　substitute

for　or　with　rags　in　paper　manufacture　until　about

1870　was　of　slow　growth；　since　which　time　vast

quantities　have　been　employed。　In　this　country

alone　millions　of　tons　of　raw　material　are　being　imported

to　say　nothing　of　home　products。



Its　value　in　the　cause　of　progress　of　some　arts

which　contribute　greatly　to　our　comfort　and　civilization

cannot　be　overestimated；　but　nevertheless　the

wood　paper　is　bound　to　disintegrate　and　decay；　and

the　time　not　very　far　distant　either。　Hence；　its　use

for　records　of　any　kind　is　always　to　be　condemned。



There　are　three　classes　of　wood　pulp；　mechanical

wood；　soda　process；　and　the　sulphite。　The　first　or

mechanical　wood　is　a　German　invention　of　1844；

where　the　logs　after　being　cut　up　into　proper　blocks；

were　then　ground　against　a　moving　millstone　against

which　they　were　pressed　and　with　the　aid　of　flowing

water　reduced　to　a　pulpy　form。　This　pulp　was

transported　into　suitable　tanks　and　then　pumped　to

the　〃beaters。〃



The　soda　process　wood　and　sulphite　wood　pulp　are

both　made　by　chemical　processes。　The　first　was

invented　by　Meliner　in　1865。　The　preparation　of

pulp　by　this　process　consists　briefly　in　first　cutting　up

the　logs　into　suitable　sections　and　throwing　them

into　a　chipping　machine。　The　chips　are　then　introduced

into　tanks　containing　a　strong　solution　of

caustic　soda　and　boiled　under　pressure。



The　sulphite　process　is　substantially　the　same　except

that　the　chips　are　thrown　into　what　are　called

digesters　and　fed　with　the　chemicals　which　form　an

acid　sulphite。　The　real　inventor　of　this　latter　process

is　not　known。



The　chemicals　employed　in　both　of　these　processes

compel　a　separation　of　the　resinous　matters　from　the

cell　tissues　or　cellulose。　These　products　are　then

treated　in　the　manufacturing　of　paper　with　few　variations；

the　same　as　the　ordinary　rag　pulp。



These　now　perfected　processes　are　the　results　of　long

and　continuing　experimentations　made　by　many　inventors。



The　following　paper　was　read　before　the　London

Society　of　Arts　by　Mr。　Alfred　Glyde；　in　May；　1850；

and　is　equally　applicable　to　some　of　the　wood　paper

of　the　present　day：



〃Owing　to　the　imperfections　formerly　existing

in　the　microscope；　little　was　known　of　the　real　nature

of　the　plants　called　fungi　until　within　the　last

few　years；　but　since　the　improvements　in　that　instrument

the　subject　of　the　development；　growth；

and　offices　of　the　fungi　has　received　much　attention。

They　compose；　with　the　algae　and　lichens；

the　class　of　thallogens　（Lindley）；　the　algae　existing

in　water；　the　other　two　in　air　only。　A　fungus

is　a　cellular　flowerless　plant；　fructifying　solely　by

spores；　by　which　it　is　propagated；　and　the　methods

of　attachment　of　which　are　singularly　various　and

beautiful。　The　fungi　differs　from　the　lichens　and

algae　in　deriving　their　nourishment　from　the

substances　on　which　they　grow；　instead　of　from　the

media　in　which　they　live。　They　contain　a　larger

quantity　of　nitrogen　in　their　constitution　than　vegetables

generally　do；　and　the　substance　called　'fungine'

has　a　near　resemblance　to　animal　matter。

Their　spores　are　inconceivably　numerous　and　minute；

and　are　diffused　very　widely；　developing

themselves　wherever　they　find　organic　matter　in　a

fit　state。　The　principal　conditions　required　for

their　growth　are　moisture；　heat；　and　the　presence

of　oxygen　and　electricity。　No　decomposition　or

development　of　fungi　takes　place　in　dry　organic

matter；　a　fact　illustrated　by　the　high　state　of

preservation　in　which　timber　has　been　found　after　the

lapse　of　centuries；　as　well　as　by　the　condition　of

mummy…cases；　bandages；　etc。；　kept　dry　in　the　hot

climate　of　Egypt。　Decay　will　not　take　place　in　a

temperature　below　that　of　the　freezing　point　of

water；　nor　without　oxygen；　by　excluding　which；　is

contained　in　the　air；　meat　and　vegetables　may　be

kept　fresh　and　sweet　for　many　years。



〃The　action　which　takes　place　when　moist　vegetable

substances　are　exposed　to　oxygen　is　that　of

slow　combustion　（'eremacausis'）；　the　oxygen

uniting　with　the　wood　and　liberating　a　volume　of

carbonic　acid　equal　to　itself；　and　another　portion

combining　with　the　hydrogen　of　the　wood　to　form

water。　Decomposition　takes　place　on　contact　with

a　body　already　undergoing　the　same　change；　in　the

same　manner　that　yeast　causes　fermentation。　Animal

matter　enters　into　combination　with　oxygen　in

precisely　the　same　way　as　vegetable　matter；　but　as；

in　addition　to　carbon　and　hydrogen；　it　contains　nitrogen；

the　products　of　the　eremacausis　are　more

numerous；　being　carbon　and　nitrate　of　ammonia；

carburetted　and　sulphuretted　hydrogen；　and　water；

and　these　ammoniacal　salts　greatly　favor　the　growth

of　fungi。　Now　paper　consists　essentially　of　woody

fibre；　having　animal　matter　as　size　on　its　surface。

The　first　microscopic　symptom　of　decay　in　paper　is

irregularity　of　surface；　with　a　slight　change　of　color；

indicating　the　commencement　of　the　process　just

noticed；　during　which；　in　addition　to　carbonic　acid；

certain　organic　acids　are　formed；　as　crenic　and　ulmic

acids；　which；　if　the　paper　has　been　stained　by

a　coloring　matter；　will　form　spots　of　red　on　the

surface。　The　same　process　of　decay　goes　on　in

parchment　as　in　paper；　only　with　more　rapidity；

from　the　presence　of　nitrogen　in　its　composition。

When　this　decay　has　begun　to　take　place；　fungi　are

produced；　the　most　common　species　being

Penicilium　glaucum。　They　insinuate　themselves　between

the　fibre；　causing　a　freer　admission　of　air；　and

consequently　hasten　the　decay。　The　substances　most

successfully　used　as　preventives　of　decay　are　the

salts　of　mercury；　copper；　and　zinc。　Bichloride　of

mercury　（corrosive　sublimate）　is　the　material　employed

in　the　kyanization　of　timber；　the　probable

mode　of　action　being　its　combination　with　the　albumen

of　the　wood；　to　form　an　insoluble　compound

not　susceptible　of　spontaneous　decomposition；　and

therefore　incapable　of　exciting　fermentation。　The

antiseptic　power　of　corrosive　sublimate　may　be

easily　tested　by　mixing　a　little　of　it　with　flour

paste；　the　decay　of　which；　and　the　appearance　of

fungi；　are　quite　prevented　by　it。　Next　to　corrosive

sublimate　in　antiseptic　value　stand　the　salts　of

copper　and　zinc。　For　use　in　the　preservation　of

paper　the　sulphate　of　zinc　is　better　than　the　chloride；

which　is　to　a　certain　extent　delinquescent。〃



There　are　numerous　paper　tests　which　include　the

matter　of　sizing；　direction　of　the　grain；　absorbing

powers；　character　of　ingredients；　etc。　A　few　of　them

are　cited。



SIZING。The　everyday　tests　as　to　hardness　of

sizing　answer　every　ordinary　purpose：　Moisten　with

the　tongue；　and　if　the　paper　is　slack…sized　you　can

detect　it　often　by　the　instant　drawing　or　absorption

of　the　moisture。　Watch　the　spot　moistened；　and　the

longer　it　remains　wet　the　better　the　paper　is　sized。

Look　through　the　spot　dampenedthe　poorer　the

sizing　the　more　transparent　is　the　paper　where　it　is

wet。　If　thoroughly　sized　no　difference　will　be　apparent

between　the　spot　dampened　and　the　balance

of　the　sheet。　When　there　is　a　question　as　to　whether

a　paper　is　tub　or　engine　sized；　it　can　be　usually　decided

by　wetting　the　forefinger　and　thumb　and　pressing

the　sheet　between　them。　If　tub…sized；　the　glue

which　is　applied　to　the　surface　will　perceptibly　cling

to　the　fingers。



TO　TEST　THE　INK　RESISTING　QUALITY　OF　PAPER。

Draw　a　heavy　ink　line　across　the　sheet。　If　the　paper

is　poorly　sized；　a　feathery　edge　will　appear；　caused

by　spreading　of　the　ink。　Slack…sized　paper　will　be

penetrated　by　the　ink；　which　will　plainly　appear　on

the　re