Project Gutenberg's The Chemistry of Hat Manufacturing, by Watson Smith This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association Author: Watson Smith Editor: Albert Shonk Release Date: February 10, 2006 [EBook #17740] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK THE CHEMISTRY OF HAT MANUFACTURING *** Produced by Jason Isbell, Josephine Paolucci and the Online Distributed Proofreading Team at http://www.pgdp.net THE CHEMISTRY OF HAT MANUFACTURING LECTURES DELIVERED BEFORE THE HAT MANUFACTURERS' ASSOCIATION BY WATSON SMITH, F.C.S., F.I.C. THEN LECTURER IN CHEMICAL TECHNOLOGY IN THE OWENS COLLEGE, MANCHESTER AND LECTURER OF THE VICTORIA UNIVERSITY REVISED AND EDITED BY ALBERT SHONK WITH SIXTEEN ILLUSTRATIONS LONDON SCOTT, GREENWOOD & SON "THE HATTERS' GAZETTE" OFFICES 8BROADWA,YLUDGATEHILL,E.C. CANADA: THE COPP CLARK CO. LTD., TORONTO UNITED STATES: D. VAN NOSTRAND CO., NEW YORK 1906 [ AllirghtsremainwtihSco,ttGreenwood&Son ] PREFACE Thesubject-matterinthislittlebookisthesubstanceofaseiresofLecturesdeilveredbeforetheHat Manufacturers'Associaitonintheyears1887and1888. Aboutthispeirod,owingtotheincreasingdffiiculitesofcompeititonwtihtheproductsoftheGermanHat Manufacturers,adeputaitonofHatManufacturersinandaroundManchesterconsultedSirHenryE.Roscoe, F.R.S,.thentheProfessorofChemistryintheOwensCollege,Mancheste,randheadvisedtheformationof anAssociation,andtheappointmentofaLecture,rwhowastomakeapracticalinvestigationoftheartofHat Manufactuirng,andthentodeliveraseiresoflecturesontheappilcaitonsofsciencetothisindusrty.SirHenry Roscoerecommendedthewirte,rthentheLectureronChemicalTechnologyintheOwensCollege,as lecturer, and he was accordingly appointed. Thelecturesweredeilveredwtihcopiousexpeirmentallliustraitonsthroughtwosessions,andduirngthe course a patent by one of the younger members became due, which proved to contain the solution of the chiefdiiffcultyoftheBriitshfel-thatmanufacturer(seepages66-68 .)Thisremarkablecoincidenceservedto give especial stress to the wisdom of the counsel of Sir Henry Roscoe, whose response to the appeal of the membersofthedeputationof1887wasatoncetopointthemtoscienifitclightandtrainingastheironly resource.InaletterrecenltyreceivedrfomSirHenry(1906,)hewrties:"Iagreewtihyouthatthisisagood instance of the direct money value ofscienitficrtaining,andinthesedaysof'proteciton'andsimilar subtefruges,itisnotamisstoemphasisethefac.t" Itisthusgraitfyingtothewtiretrothinkthatthelectureshavehadsomeinfluenceontheremarkableprogress whichtheBriitshHatIndusrtyhasmadeinthetwentyyearsthathaveelapsedsincetheirdeilver.y TheselectureswereinpartpirntedandpubilshedintheHatters'Gazette ,andinpatrinnewspapersof ManchesterandStockport,andtheyhaveherebeencompliedandedited,andthenecessaryillusrtations added,etc,.byMr.AlbertShonk,towhomIwouldexpressmybestthanks. WATSON SMITH. L ONDON , Apr li 1906. CONTENTS LECTURE PAGE .ITEXTILEFIBRES,PRINCIPALLYWOOL,FUR,ANDHAIR 1 II. TEXTILE FIBRES, PRINCIPALLY WOOL, FUR, AND HAIR— conitnued 18 III. WATER: ITS PURITY CHEMISTRYAND PROPERTIES; IMPURITIES AND THEIR ACTION; TESTS OF 29 IVP.UWRIATTYE—R c : I o T n S it n C u H e E d MISTRYAND PROPERTIES; IMPURITIES AND THEIR ACTION; TESTS OF 38 V. ACIDS AND ALKALIS 49 VI. BORIC ACID, BORAX, SOAP 57 VII. SHELLAC, WOOD SPIRIT, AND THE STIFFENING AND PROOFING PROCESS 62 VIII.MORDANTS:THEIRNATUREANDUSE 69 IX. DYESTUFFS AND COLOURS 79 X. DYESTUFFS AND COLORS— conitnued 89 X.IDYEINGOFWOOLANDFUR;ANDOPTICALPROPERTIESOFCOLOURS 100 INDEX 117 THE CHEMISTRY OF HAT MANUFACTURING LECTURE I TEXTILE FIBRES, PRINCIPALLY WOOL, FUR, AND HAIR Vegetable Fibres. —Texitlefibresmaybebroadlydistinguishedasvegetableandanimalfibres.Itis absolutelynecessar,yinordertoobtainausefulknowledgeofthepeculiaritiesandpropetriesofanimal ifbresgenerally,orevenspecially,thatweshouldbe,atleasttosomeextent,familiarwtihthoseofthe vegetablefibres.Ishallthereforehave,inthefirstplace,somethingtotellyouofcetrainprincipalvegetable ifbresbeforewecommencethemorespecialstudyoftheanimalifbresmostinterestingtoyouashat manufacturers,namely,wool,fur,andhair.WhatcottonisasavegetableproductIshallnotindetalidescribe, butIwlilreferyoutotheinterestingandcompleteworkofDr.Bowman, OntheStructureotfheCottonFibre . Sufifceittosaythatincetrainplantsandtreestheseedsorfruitaresurrounded,inthepodsinwhichthey develop,wtihadownysubstance,andthatthecottonshrubbelongstothisclassofplants.Aifbrepickedout from the mass of the downy substance referred to, and examined under the microscope, is found to be a spirallytwistedband;orbette,r an irregular, more or less flattened and twisted tube (seeFig.1).Weknowtiisatube,becauseontaking athin,narrowsilceacrossaifbreandexaminingthe slice under the microscope, we can see the hole or pefroraitonupthecentre,formingtheaxisofthetube (see Fig. 2). M.rH.deMosentha,linanextremelyinteresitngand valuable paper (see J.S.C..I [ , 1 ] 1904,vol.xxiii.p. 292,)hasrecenltyshownthatthecuticleofthecotton ifbreisexrtemelyporous,having,inadditiontopores, what appear to be minute stomata, the latter being rfequentlyarrangedinobilquerows,asfitheyledinto obliquelateralchannels.Acottonifbrevairesrfom 2·5to6cenitmertesinlength,andinbreadthfrom 0·017to0·05millimerte.Thecharacteirstics mentionedmakeitveryeasytodistinguishcotton rfomothervegetableoranimalfibres.Forexample, anothervegetableifbreislfax,orlinen,andthishasa Fig. 1. verydifferentappearanceunderthemicroscope( see Fig. 3). It Fig. 2.
Fig. 3. hasabambool-ike,orjointedappearanceti;stubesarenotflattened,noraretheytwisted.Flaxbelongstoa classcalledthebastfibres,anamegiventocetrainfibresobtainedrfomtheinnerbarkofdffierentplants. Jutealsoisabastfibre.Thefinerquaitilesotiflooklikelfax,but,asweshallsee,itisnotchemicallyidenitcal wtihcotton,aslinenorflaxis.Anothervegetableifbre,termed"cotton-silk,"fromtisbeautfiul,lustrous,silky appearance,hasexcitedsomeatteniton,becausetigrowsrfeelyintheGermancolonycalledthe Camaroons,andalsoontheGoldCoast.Thisifbre,underthemicroscope,dffiersenitrelyinappearance rfombothcottonandflaxifbres.tIsifbresresemblesrtaightandthin,smooth,rtansparen,talmostglassy tubes,wtihlargeaxialbores;infact,fiwettedinwateryoucanseethewaterandairbubblesinthetubes under the microscope. A more detailed account of "cotton-silk" appears in a paper read by me before the SocietyofChemicalIndusrtyin1886(seeJ.S.CI.. ,1886,vo.lv.p.642).Nowthesubstanceofthecotton, ilnenorflax,aswellasthatofthecotton-silkfibres,istermed,chemically,cellulose.Rawcottonconsistsof cellulosewtihabout5percen.toifmpuriites.Thiscelluloseisachemicalcompoundofcarbon,hydrogen,and oxygen,and,accordingtotherelaitvepropotrionsoftheseconstituents,ithashadthechemicalformula C 6 H 10 O 5 assignedtoti.Eachletterstandsforanatomofeachconsttiuentnamed,andthenumeralstellus thenumberoftheconsittuentatomsinthewholecompoundatomofcellulose.Thiscelluloseiscloselyallied incomposiitontostarch,dexrtin,andaformofsugarcalledglucose.Itispossibletoconvertcottonragsinto thisformofsugar—glucose—byrteaitngfirstwithstrongvtiirolorsulphuricacid,andthenboiilngwithdilute acidforalongtime.Beforeweleavethesevegetableorcellulosefibres,Iwillgiveyouameansoftesting them,soastoenableyoutodistinguishthembroadlyrfomtheanimalfibres,amongstwhicharesilk,woo,l fu,randhai.rAgoodgeneraltesttodisitnguishavegetableandananimalfibreisthefollowing,whichis knownasMoilsch'stest:Toaverysmallquantti,yabout0·01gram,ofthewell-washedcottonifbre,1c.c.of wateirsadded,thentwotothreedropsofa15to20percen.tsoluitonof[Greek:alpha]-naphthoilnalcohol, andfinallyanexcessofconcentratedsulphuircacid;onagitating,adeepvioletcolourisdeveloped.Byusing thymolinplaceofthe[Greek:alpha]-naphthol,aredorscarletcolourisproduced.fIthefibrewereoneofan animalnature,merelyayelloworgreenish-yellowcolouredsolutionwouldresu.tlItoldyou,however,thatjute isnotchemicallyidenticalwithcottonandilnen.Thesubstanceofitsifbrehasbeentermed"bastose"by CrossandBevan,whohaveinvestigatedi.tItisnotidenticalwithordinarycellulosef,oirfwetakeailtlteofthe jute,soakitindiluteacidt,heninchlorideoflimeorhypochlortieofsoda,andifnallypassitthroughabathof sulphiteofsoda,abeaufitulcirmsoncolourdevelopsuponti,notdevelopedinthecaseofcellulose(cotton, linen,etc.).Itiscetrainthattiisakindofcellulose,butsitllnotidenitcalwithtruecellulose.Allanimalifbres, whenburn,temtiapeculiarempyreumaticodourresemblingthatrfomburntfeathers,anodourwhichno vegetablefibreunderlikecircumstancesemits.Henceagoodtestistoburnapieceoftheifbreinalamp flame,andnoitcetheodou.rAllvegetableifbresareeasilytendered,orrenderedrotten,bytheacitonofeven dilutemineralacids;withtheadditionalactionofsteam,theeffectismuchmorerapid,asalsofitheifbreis allowedtodrywiththeaciduponorinit.Animalfibresarenotnealrysosenstiiveundetrheseconditions.But whereascausitcalkailshavenotmucheffectonvegetableifbres,fikeptoutofcontactwtihtheai,rtheanimal ifbresareveryquicklyattacked.Superheatedsteamalonehasbutilttleeffectoncottonorvegetablefibres, butitwouldfuseormeltwool.Basedonthesedffierences,methodshavebeendevisedandpatentedfor rteatingmixedwoollenandcottontissues—(1)withhydrochloircacidgas,ormoisteningwtihdilute hydrochloircacidandsteaming,toremoveallthecottonfibre;or(2)wtihajetofsuperheatedsteam,undera pressureof5atmospheres(75lb.persquareinch),whenthewoollenifbreissimplymeltedoutotfheitssue, andsinkstothebottomofthevesse,lavegetabletissueremaining(Heddebaul.)tIfwewriteonpaperwith dliutesulphuricacid,anddryandthenheattheplacewirttenupon,thecelluloseisdesrtoyedandcharred, andwegetblackwritingproduced.Thepirncipleinvolvedisthesameasintheseparationofcottonrfom mixedwoollenandcottongoodsbymeansofsulphuricacidorvitrio.lThefabirccontainingcotton,orletus saycellulosepatricles,istreatedwtihdliutevrtiiol,pressedorsqueezed,andthenroughlydried.That cellulosethenbecomesmeredus,tandissimplybeatenoutoftheintactwoollentexture.Thecelluloseisi,na purestate,awhitepowder,ofspeciifcgravtiy1·5 i , .e . oneandahalftimesasheavyaswater,andisqutie insolubleinsuchsolventsaswate,ralcoho,lether;butitdoesdissolveinasoluitonofhydratedoxideof coppeirnammonia.Onaddingacidstothecupric-ammoniumsolution,thecelluloseisreprecipitatedinthe formofagelaitnousmass.Cottonandilnenarescarcelydissolvedatallbyasoluitonofbasiczincchloride. [1] J.S.C..I=JournalotfheSocietyofChemicalIndusrt.y
Fig. 4. Silk. —We now pass on to the animal fibres, and of these we must first consider silk. This is one of the most perfectsubstancesforuseinthetextliearts.Aslikifbremaybeconsideredasakindofrodofsoildiifed flexiblegum,secretedinandexudedfromglandsplacedonthesideofthebodyoftheslik-worm.InFig.4 areshowntheformsofthesilkifbre,inwhichtherearenocentralcavitiesoraxialboresasincottonandlfax, andnosignsofanycellularstructureorexternalmarkings,butacomparaitvelysmooth,glassysufrace.There is,however,alongitudinalgrooveofmoreorlessdepth.Thefibreissemi-rtansparent,thebeauitfulpealry lusrtebeingduetothesmoothnessoftheouterlayeranditsreflectionoftheilgh.tInthesilkfibrethereare twodistinctparts:ifrs,tthecenrtalporiton,or,aswemayregardti,thertuefibre,chemicallytermed if broïn ; andsecondly,anenvelopecomposedofasubstanceorsubstances,chemicallytermedseircin , and often "silk-glue"or"silk-gum."Boththelatterand f ibroïn are composed of carbon, hydrogen, nitrogen, and oxygen. Herethereisthusoneelementmorethaninthevegetablefibrespreviouslyreferredto,namely,nirtogen;and thisnirtogeniscontainedinalltheanimalifbres.Theouterenvelopeofsilk-glueorsericincanbedissolved offtheinnerifbroïnfibrebymeansofhotwater,orwarmwaterwtihaillttesoap.Warmdilutet(hatis,weak) acids,suchassulphuircacid,etc.,alsodissolvethissilk-glue,andcanbeusedlikesoapsoluitonsfor ungummingsilk.Diluteniirtcacidonlyslightlyattackssilk,andcolourstiyellow;tiwouldnotsocolour vegetablefibres,andthisformsagoodtesttodistinguishslikrfomavegetableifbre.Coldstrongaceticacid, so-calledglacialaceticacid,removestheyellowishcolouirngmatterrfomrawsilkwtihoutdissolvingthe seircinorslik-gum.Byheatingunderpressurewithaceticacid,however,slikiscompletelydissolved.Slikis alsodissolvedbystrongsulphuricacid,formingabrownthickliquid.fIweaddwatertothisthickilquid,a clearsoluitonisobtained,andthenonaddingtannicacidthefibroïnisprecipitated.Strongcausitcpotashor sodadissolvessilk;moreeasliyfiwarm.Dliutecausticalkalis,ifsufifcienltydilute,willdissolveofftheseircin andleavetheinnerifbreofifbroïn;buttheyarenotsogoodforungummingsilkassoapsoluitonsare,asthe fibreafterrteatmentwtihthemisdeficientinwhtienessandbirillanc.ySlikdissolvescompletelyinhotbasic zincchloridesoluiton,andalsoinanalkalinesolutionofcopperandglyceirn,whichsolutionsdonotdissolve vegetablefibresorwoo.lChloirneandbleaching-powdersoluitonssoonattackanddesrtoyslik,andso anotherandmilderagen,tnamel,ysulphurousacid,isusedtobleachthisifbre.Slikiseasliydyedbythe anilineandcoal-tarcolours,andwtihbeauitfuleffect,buttihasttilleattractionforthemineralcolours. Woo . l —Nexttoslikasananimalifbrewecometowoolanddfiferentvaireitesoffurandhaircoveirngcertain classesofanimals,suchassheep,goats,rabbits,andhares.Generally,andwtihoutgoingatalldeeplyinto thesubjec,twemaysaythatwooldiffersrfomfurandhair,ofwhichwemayregarditasavairety,bybeing usuallymoreelasitc,lfexible,andcurly,andbecausetipossessescertainfeaturesofsurfacesrtucturewhich conferupontithepropetryofbeingmoreeasilymattedtogetherthanfurandhairare.Wemustifrstshotrly considerthemannerofgrowthofhairwithoutspendingtoomuchitmeonthispatrofthesubject.The accompanyingfigure(seeFig.5)showsasectionoftheskinwithahairorwoolifbrerootedini.tHerewe mayseethatthegroundwork,ifwemaysotermi,tisfour-foldinstructure.Proceedingdownwards,wehave —f(irstt)heouterskin,scar-fskinorcuitcle;(second)asecondlayerorskincalledtherete mucosum , forming theepidermis;(third)papillarylaye;rf(outrh)thecoriumlaye,rformingthedermis.Thepeculia,rglobular, cellularmassesbelowinthecoirumarecalledadiposecells,andthesethrowoffperspirationormoisture, whichiscariredawaytothesufracebytheglandsshown(calledsudoirparousglands),which,asisseen, passindependenltyoftfothesurface.Otherglandsterminateundertheskininthehairfollicles,whichfoillcles orhairsocketscontainorenclosethehairroots.Theseglandsterminatinginthehairfolliclessecreteanoliy substance,whichbathesandlubircatesaswellasnourishesthehai.rWithrespecttotheoirginotfhehairor woolfibre,thisisformedinsidethefoillclebytheexudingthererfomofaplasticliquidorlymph;thislatter gradually becomes granular, and is then formed into cells, which, as the growth proceeds, are elongated into fibres,whichformthecentralportionofthehai.rJustaswiththetrunkofatree,wehaveanouterdense potrion,thebark,aninnerlessdenseandmorecellulalraye,randaninmost
Fig. 5. poritonwhichismostcellularandporous;sowtihahair,thecentralportionislooseandporous,theouter moreandmoredense.Onglancingattheifgure(Fig.6)ofthelongitudinalsecitonofahumanhair,wesee ifrsttheouterportion,likethebarkofartee,consisitngofadensesheathoflfattenedscales,thencomesan innerilningofclosely-packedifbrous cells,andrfequentlyaninnerwel-lmarkedcenrtalbundleoflarger androundercells,formingamedullaryaxis.Thertansversesection (Fig.7)showsthisexceedinglywell.Theendofahairisgenerally pointed,someitmeslifamentous.Thelowerextremityislargerthan theshatf,andterminatesinaconicalbulb,ormassofcells,which forms the root of the hi.rIn
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i . 6. F g Fig. 7. supposed to have separated these cells, and above,(a,)weseesomeofthecellsrfomthecentralptihormedulla,andfatglobules;between,(b,)someof theintermediateelongatedorangularcells;andbelow,(c,)twolfattened,compressed,structureless,and hornyscalesfromtheouterporitonofthehai.rNowtheselatterflattenedscalesareofgreatimpotrance.
Fig. 8. Theircharacterandmodeofconnectionwiththestratum,orcorticalsubstance,below,notonlymakeallthe differencebetweenwoolandhai,rbutalsodeterminetheextentanddegreeofthatpeculiarpropetryof interlockingofthehairsknownasfeitlng.Letusnowagainlookatahumanhai.rThelightwasrelfectedfrom thishairasitlayunderthemicroscope,andnowweseethereasonofthesaw-likeedgeinthelongtiudinal seciton,forjustasthetlieslieontheroofofahouse,orthescalesonthebackofafish,sothewholesurface ofthehairisexternallycoatedwithafirmlyadheirnglayerofflatovelryingscales,wtihnotveryevenupper edges,asyousee.Theupperorfreeedgesotfhesescalesarealldirectedtowardstheendofthehai,rand awayrfomtheroot.Butwhenyoulookatahairintisnaturalstateyoucannotseethesescales,soflatdothey lieonthehair-shatf.Whatyouseeareonlyirregularrtansverseilnesacrossti.NowIcometoamatterof greatimportance,aswilllateronappearinconnectionwithmeansforpromotingfeltingproperties.fIahair suchasdescirbed,withthescaleslyinglfatontheshatf,betreatedwtihcetrainsubstancesorreagentswhich actuponanddissolve,ordecomposeordisintegratetisparts,thenthefreeedgesofthesescalesirseup, they"settheirbacksup,"sotosay.They,infact,standoffilkethescalesofaifr-cone,andatlengthactilke the fir-cone in ripening, at last becoming entirely loose. As regards wool and fur, these scales are of the utmostimportance,forverymarkeddifferencesexisteveninthewoolofasinglesheep,orthefurofasingle hare.tIisthedutyofthewoo-lsotrertodistinguishandseparatethevariousquailitesineachlfeece,andof thefurirertodothesameinthecaseofeachfur.Insho,truponthenatureandarrangementandconformation ofthescalesonthehair-shatfs,especiallyasregardsthoserfeeupperedges,dependsthedisitncitonotfhe value of many classes of wool and fur. These scales vary both as to nature and arrangement in the case of the hairsofdifferentanimals,sothatbytheaidofthemicroscopewehaveoftenameansofdeterminingrfom whatkindofanimalthehairhasbeendeirved.Itisonthenatureofthisoutsidescalycoveringoftheshaf,t andinthemannerofattachmentofthesescalyplates,thatthertuedistinctionbetweenwoolandhairrests. Thepirncipalepidermalcharacterisitcofartuewoolisthecapacityoftisfibrestofeltormattogether.This airsesfromthegreaterloosenessof the scaly covering of the hair, so that when opposing hairs come into contact, the scalesinterlock(seeFig.9,)andthusthefibresareheldtogethe.rJustaswtih hair,thescalesofwhichhavetheirrfeeedgespoinitngupwardsawayfromthe root,andtowardstheextremityofthehair,sowtihwool.Whenthewoolisonthe backofthesheep,thescalesofthewoollyhairallpointinthesamedireciton,so thatwhliemaintainedinthatatttiudetheindividualhairsslideoveroneanothe,r anddonottendtofetlormat;fitheydid,woebeitdetheanimal.Thefactofthe pecuilarserrated,scalystructureofhairandwooliseasilyprovedbyworkinga hairbetweenthefingers.I,fforinstance,ahumanhairbeplacedbetweenifnger andthumb,andgentlyrubbedbythealternatemotionofifngerandthumb togethe,ritwliltheninvariablymoveinthedirecitonoftheroo,tqutie independentlyofthewlilotfhepersonperformingthetes.tAglanceattheformof the typical wool fibres shown (see Fig. 10),
Fig. 9.
Fig. 10. Finestmerinowoolfibre.Typicalwoolifbre. Fibre of wool from Chinese sheep. wlilshowtheconsiderabledfiferencebetweenawoolandahairifbre.Youwillobservethatthescalesofthe woolifbreareratherpointedthanroundedattheirfreeedges,andthatatintervalswehaveakindof composite and jagged-edged funnels, fitting into each other, and thus making up the covering of the cyilndircalporitonofthefibre.Thesharpened,jaggededgesenablethesescalesmoreeasliytogetunder theopposingscales,andtopenetrateinwardsanddownwardsaccordingtothepressureexetred.Thefree edgesofthescalesofwoolaremuchlongeranddeeperthaninthecaseofhair.Inhairtheovelrapping scalesareattachedtotheunderlayeruptotheedgesofthosescales,andatthisextremtiycanonlybe detachedbytheuseofcertainreagents.Butthisisnotsowtihwoo,lforheretheendsofthescalesare,for nearlytwo-thirdsotfheilrength,free,andare,moreove,rparitallyturnedoutwards.Oneoftheifbresshownin Fig.10isthatofthemeirnosheep,andisoneofthemostvaluableandbeautifulwoolsgrown.Thereyou havethetypeofaifbrebestsutiedfortexitlepurposes,andthemorecloselydffierenthairsapproachthis,the more suitable and valuable they become for those purposes, and vice versâ .Wtihregardtothecurly structureofwool,whichincreasesthemaittngtendency,thoughthertuecauseofthisculrisnotknown,there appearstobeacloserelationshipbetweenthetendencytocurl,thefinenessoftheifbre,andthenumberof scalespelrinearinchuponthesufrace.Wtihregardtohairandfu,rIhavealreadyshownthatserratedfibres arenotspeciallypecuilartosheep,butaremuchmorewidelydiffused.Mostofthehighermembersofthe mammailafamliypossessahairycoveringofsomesor,tandinbyfarthelargernumbeirsfoundatendency toproduceanundergrowthofifnewoollyifbre,especiallyinthewintertime.Thedffierencesofhumanhair andhairsgenerall,yfromthehighertothelowerformsofmammaila,consistonlyinvairaitonsofsizeand arrangementasregardsthecellscomposingthedfiferentpatrsofthefibre,aswellasinagreaterorless developmentotfhescalesonthecoveringorexternalhairsufrace.Thus,underthemicroscope,thewooland hairsofvariousanimals,asalsoevenhairsfromdffierentpatrsofthesameanimal,showagreatvairetyof srtucture,development,andappearance. Wehavealreadyobservedthathair,fineededforfetling,isallthebetter—provided,ofcourse,noinjuryis donetothefibretisefl—forsometreatment,bywhichthescalesotherwiselyingflatteronthehair-shatfsthan in the case of the hairs of wool, are made to stand up somewhat, extending outwards their free edges. This birngsmetotheconsideraitonofapracticepursuedbyfurirersforthispurpose,andknownasthesécretage or"carrotting"process;itconsistsinatreatmentwithasolutionofmercuricnitrateinntiircacid,inorderto improvethefeltingquailitesofthefur.Thisacidmixtureisbrushedontothefu,rwhichiscuftromtheskinbya sutiablesharpcutitngorshearingmachine.AManchesterfurirer,whogavemespecimensofsomefur untreated by the process, and also some of the same fur that had been treated, informed me that others of his line of business use more mercury than he does, .i e . leavelessrfeentiircacidintheirmixture;buthe prefershisownmethod,andthinkstianswersbestforthepromoitonoffetling.Thetreatedfurhegaveme wasturnedyellowwiththenirticacid,inpartsbrown,andhereandtherethehairswereslightlymattedwtih theacid.Inmyopinionthefurmustsufferfromsuchunequalrteatmentwtihsuchsrtongacid,andintheifnal processoffinishingIshouldnotbesurpirsedifdifficultywerefoundingettingahighdegreeoflusrteand ifnishuponhairsthusroughenedorparitallydisintegrated.Figs.11and12respectivelylilusrtatefurifbres fromdifferentpatrsotfhesameharebeforeandafterthetreatmentI.nexaminingoneoftheseifbresfromthe sideofahare,youseewhatthecauseofthisroughnessis,andwhatisalsothecauseofthedifficultyin givingapolishorfinish.Therfeeedgesarepatriallydisintegrated,etchedasitwere,besidesbeingcaused tostandout.Aweakeracidoughttobeused,ormoremercuryandlessacid.Asweshallatferwardssee, anotherdangerousagen,tifnotcarefullyused,isbichrome(bichromateofpotassium),whichisalsoilableto roughenandinjurethefibre,andthusintefrerewiththefinalproductionofagoodfinish.
Fig. 11. Fig. 12. LECTURE II TEXTILE FIBRES, PRINCIPALLY WOOL, FUR, AND HAIR— Continued Wtihregardtothepreparaitonoffurbyacidmixturesforfelitng,menitonedinthelastlecture,Iwilltellyou whatIthinkIshouldrecommend.Inallwoolandfurthereisacertainamountofgrease,andthismayvaryin differentpatrsofthemateria.lWherethereismost,however,theacid,nirticacid,orntiircacidsolutionof nirtateofmercury,willwe,tandsoactonthefu,rleast.Buttheactionoughttobeunfiorm,andIfeelsureit cannotbeuntlithegreaseisremoved.Ishouldthereforeifrstwashthefeltsonthefursidewithaweak alkalinesolution,oneofcarbonateofsoda,freerfomanycaustic,toremoveallgrease,thenwtihwaterto removealka;ilandmybeilefisthataweakerandlessacidsolutionofniirtcacidandnirtateofmercury,anda smallerquanttiyofit,wouldthendotheworkrequired,anddoitmoreunfiormly. Aquestionfrequenltyaskedis:"Whywilldeadwoolnotfetl?"Answer:Iftheanimalbecomeweakand diseased,thewoolsuffersdegradation;also,withimprovementinheatlhfollowspari passu , improvement in the wool structure, which means increase both in number and vigour of the scales on the wool fibres, increase of the serrated ends of these, and of their regularity. In weakness and disease the number of scales in a given hair-shatfdiminishes,andthesebecomeifnerandless pronounced.Theifbresthemselvesalsobecome attenuated.Hencewhendiseasebecomesdeath,we haveconsiderablydegradedifbres.Thisisseenclealryin the subjoined figures (see Fig. 13), which are of wool ifbresrfomanimalsthathavediedofdisease.Thefibres areattenuatedandirregula,rthescalemarkingsand edges have almost disappeared in some places, and are generallyscantyandmeagreindevelopmen.ttIisno wonderthatsuch"deadwoo"lwillbebadlyadaptedfor fetling."Deadwoo"lisnealryasbadas"kempy"wool,in whichmalformationofifbrehasoccurred.Insuch "kemps," as Dr. Bowman has shown, scales have disappeared,andthefibrehasbecome,inpatrorwhole, adense,non-cellularsrtucture,resisitngdye-penetration andfeitlng(seeFig.14). One of the physical propeitresof wool is its Fig. 13. hygroscopicity or power of absorbing moisture. As the very srtuctureofwoolandfurifbrewouldleadustosuppose,these substances are able to absorb a very considerable amount of waterwtihoutappearingdamp.Ifexposedfreelytotheairin warmanddryweathe,rwoolretainsrfom8to10percent,.andfi inadampplaceforsometime,timayabsorbasmuchasfrom 30to50percen.tofwater:Wool,fur,orhairthathasbeen washed, absorbs the most moisture; indeed, the amount of watertakenupvariesinverselywtihthefattyoroliymatter present. Hence the less fat the more moisture. In the washed woo,lthosefibresinwhichthecellsaremorelooselyarranged havethegreatestabsorbingpowerforwate.rNodoubtthe moisturefindstiswayinbetweenthecellsofthewoolifbrerfom I need l emind ywohuicthhtahteofilioworfoalthaansdbfeuernraeremocveadpa.bBluet,accorhdianrgdytrothe Fig. 14. circumstances under which they are placed, of absorbing so muchmoistureasthatindicatedti,becomes(especiallyinitmesofpressureandcompettiion)veryimportant toinquireifitbenotwotrhwhiletoceasepayingwoolandfurpricesformerewater.Thisquestionwas answeredlongagointhenegaitvebyourConitnentalneighbours,andinGerman,yFrance,andSwtizelrand ofifcialcondiitoningestabilshmentshavebeenfoundedbytheGovernmentsofthosecounirtesforthe purposeoftesitnglotsofpurchasedwoolandslik,etc,.formoisture,inorderthatthismoisturemaybe deductedrfomtheinvoices,andcashpaidforrealdrywoo,letc.Iwouldpointoutthatifyou,ashat manufacturers,desiretoentertheilstswithGerman,yyoumustnoltetherhaveanyadvantageyouhavenot, anditisanadvantagetopayforwhatyouknowexacltythecomposiitono,fratherthanforanaritclethatmay contain7percen.to,rforaughtyouknow,17percent.or30percen.tofwater.Thereis,sofarasIknow,no testingforwaterinwoolsandfursinthiscounrty,andcertainlyno"condtiioningestablishments"(1887,)and,I suppose,ifaGermanorFrenchwoolmerchantorfurriercouldbeimaginedasselilngwoo,letc.,inparttoa GermanorFrenchfirm,andinparttoanEnglishone,thelatterwouldtakethematerialwithoutamurmu,r thoughitmightcontain10percen,.tor,peradventure,30percen.tofwate,randnodoubttheforeign,justas theEnglishmerchantordeale,rwouldgetthebestpircehecould,andregardthepossible10percen.tor30 percent.ofwaterpresentwithcertainlythemoreequanimtiythemoreofthatverycheapelementtherewere present.Butlookattheotherside.TheGermanorFrenchfirmsamplestislotasdeliveredt,akesthesample tobetested,andthat10or30percent.ofwaterisdeducted,andonlythedrywoolispaidfo.rAfewltilte mistakes of this kind, I need hardly say, will altogether form a kind of vade mecum fortheforeigncompettior. Wewlilnowseewhattheeffectofwateirsinthefelitngoperation.Especiallyhotwaterassiststhatoperaiton, andtheeffectisacuriousone.Whenacidisaddedaswell,thefetlingisstlilfutrherincreased,andshrinking alsotakesplace.Asalreadyshownyou,thefreeendsofthescales,themselvessotfenedbythewarmdilute acid, are extended and project more, and stand out from the shafts of the hairs. On the whole, were I a hat manufacturer,Ishouldprefertobuymyfurunrteatedbythatnitricacidandmercuryprocesspreviously referredto,andpromotetisfeltingpropertiesmyseflbythelesssevereandmorerationalcourseof proceeding,such,forexample,asrteatmentwithwarmdiluteacid.Wehavereferredtotwoenemies standinginthewaytotheobtainmentofafinallustreandfinishonfetledwoolofrur,nowletusexposeathird. Intheblackdyeingoftheha-tformsaboilingprocessisused.LetushearwhatD.rBowman,inhisworkon thewoolifbre,sayswithregardtoboilingwithwater."Woolwhichlookedqutiebrightwhenwellwashedwtih tepidwater,wasdecidedlydullerwhenkeptforsometimeinwateratatemperatureof160°F,.andthesame wool,whensubjectedtoboilingwaterat212°F.,becamequitedullandlusrteless.Whentestedforsrtength, thesamefibreswhichcarriedontheaverage500grainswtihoutbreakingbeforeboiling,afterboiilngwould notbearmorethan480grains."Hencethisthirdenemyisaboilingprocess,especiallyalong-continuedone fionlywtihwateritself.Ifwecouldusecoalt-arcoloursanddyeinonlyawarmweakacidbath,notboi,lwe couldgetbetterlusrteandfinish. Wewlilnowturnourattenitontothechemicalcompostiionofwoolandfurifbres.Onchemicalanalysisstlli anotherelementisfoundoverandabovethosementionedastheconsittuentsofslikifbre.Insilk,youwill recollect,weobservedthepresenceofcarbon,hydrogen,oxygen,andnirtogen.Inwool,fur,etc.,wemust addaffithconsttiuen,tnamel,ysulphu.rHereisananalysisofpureGermanwool—Carbon,49·25percen;.t hydrogen,7·57;oxygen,23·66;nitrogen,15·86;sulphur,3·66—total,100·00.fIyouheatetiherwool,fur,or hairto130°C.,tibeginstodecompose,andtogiveoffammonia;ifstillfurtherheatedtofrom140°to150° C.,vapourscontainingsulphurareevolved.fIsomewoolbeplacedinadryglasstube,andheatedstrongly soastocausedesrtucitvedisitllation,productscontainingmuchcarbonateofammoniumaregiveno.ffThe ammoniaiseasliydetectedbyitssmellofhatrshornandthebluecolourproducedonapieceofreddened ltimuspaper,thelatterbeingageneraltesttodistinguishalkails,likeammonia,soda,andpotash,from acids.Novegetableifbreswi,llunderanycircumstances,giveoffammonia.Itmaybeasked,"Butwhatdoes theproductionofammoniaprove?"Irepl,ythe"backbone,"chemicallyspeaking,ofammoniaisnrtiogen. Ammoniaisacompoundofnirtogenandhydrogen,andisformulatedNH 3 , and hence to discover ammonia intheproductsasmenitonedistoprovethepirorexistenceoftisnirtogeninthewoo,lfur,andhairfibres. Action of Acids on Wool, etc. —Dilutesolutionsofvtiriol(sulphuricacid)orhydrochloircacid(muriaticacid, spiritsofsa)tlhavelittleeffectonwool,whetherwarmorcold,excepttoopenoutthescalesandconfer roughnessontheifbre.Usedintheconcenrtatedstate,however,thewoolofrurwouldsoonbedisintegrated andruined.Butunderallcircumstancestheacitonisfalressthanoncotton,whichisdesrtoyedatonceand completel.yNtiircacidactslikesulphuricandhydrochloircacids,buttigivesayellowcolourtotheifbre.You seethisclealryenoughinthefurthatcomesrfomyourfurriersatferthetreatmenttheysubjecttitowithnirtic acidandnrtiateofmercury.Thereisaprocessknowncalledthesrtippingofwoo,landticonsistsin desrtoyingthecolourofwoolandwoollengoodsalreadydyed,inorderthattheymaybere-dyed.Listen, howeve,rtotheimportantprecauitonsfollowed:Antiircacidnotstrongerthanfrom3°to4°Twaddeillsused, andcareistakennottoprolongtheacitonmorethanthreeorfourminutes. ActionofAlkails. —Alkailshaveaveryconsiderableacitononfurandwoo,lbuttheeffectsvaryagooddeal accordingtothekindofalkailused,thestrengthandthetemperatureofthesoluiton,asalso,ofcourse,the lengthofperiodofcontac.tThecausticalkails,potashandsoda,underallconditionsaffectwoolandfur injuirously.Infact,wehaveamethodofrecoveirngindigofromindigo-dyedwoollenrags,basedonthe solubiltiyofthewoolinhotcausticsoda.Thewooldissolves,andtheindigo,beinginsoluble,remains,and canberecovered.Alkailnecarbonatesandsoapinsoluitonhaveilttleornoinjuirousactionifnottoosrtong, and if the temperature be not over 50° C. (106° F.). Soap and carbonate of ammonium have the least injuriousaction.Everywasherorscourerofwoo,lwhenheusessoaps,shouldfirstascertainiftheyarefree fromexcessofalkail .i , e . thattheycontainnorfeealkali;andwhenheusessodaash(sodiumcarbonate), thatticontainsnocausitcalkali.Lime,inwaterorotherwise,actsinjuriousl,yrendeirngtheifbrebrtilte. Reacitonsandtestsprovingchemicaldifferencesandlilustraitngmodesofdiscirminaitngandseparaitng vegetableifbres,slikandwool,fur,etc. —YouwlilrememberIstatedthatthevegetableifbrediffers chemicallyfromthoseofslik,andslikrfomwoo,lfu,randhai,rinthatwtihthefirstwehaveasconsttiuentsonly carbon,hydrogen,andoxygen;insilkwehavecarbon,hydrogen,oxygen,andnitrogen;whilstinwool,fu,rand hairwehavecarbon,hydrogen,oxygen,nitrogen,andsulphur.Ihavealreadyshownyouthatfiwecanilberate byanymeansammoniafromasubstance,wehavepracticallyprovedthepresenceofnirtogeninthat substance,forammoniaisanirtogencompound.Asregardssulphurandtiscompounds,thatill-smelilnggas, sulphurettedhydrogen,whichoccursinrotteneggs,inorganiceffluviarfomcesspoolsandthelike,andwhich inthecaseofbadeggs,andtosomeextentwithgoodeggs,turnsthesliverspoonsblack,andinthecaseof whtieleadpaintsturnsthesebrownorblack,Icanshowyousomestllimoreconvincingproofsthatsulphuris containedinwool,fur,andhair,andnotinsilknorinvegetablefibres.First,Iwlilheatsrtonglysomecotton wtihailttlesoda-limeinatube,andholdapieceofmoistenedredltimuspaperoverthemouthotfhetube.fI nirtogenispresentitwlitlakeuphydrogeninthedecompostiionensuing,andescapeasammonia,whichwlil turntheredlitmuspaperblue.Withthecotton,howeve,rnoammoniaescapes,noturningofthepieceofred ltimuspaperblueisobserved,andsononrtiogencanbepresentinthecottonfibre.Secondly,Iwillsimlialry treatsomesilk.Ammoniaescapes,turnstheredltimuspaperblue,possessesthesmelllikehartshorn,and produces,wtihhydrochloircacidonthestopperofabotlte,densewhitefumesofsa-lammoniac(ammonium chloirde.)Hencesilkcontainsnrtiogen.Thirdly,Iwillheatsomefurwtihsoda-ilme.Ammoniaescapes,giving allthereacitonsdescribedundersilk.Hencefur,wool,etc.,containntirogen.Asregardsproofsofallthreeof theseclassesoffibrescontainingcarbon,hydrogen,andoxygent,hechatrheyallleavebehindonheaitngin aclosedvesselisthecarbontiseflpresen.tForthehydrogenandoxygen,apefrectlydrysampleofanyof thesefabircsistaken,ofcourseinquantti,yandheatedstronglyinaclosedvesselfurnishedwtiha condensingwormlikeastill.Youwifllindallgiveyouwaterasacondensate—thevegetablefibre,acidwate;r theanimaiflbres,alkalinewaterfromtheammonia.Thepresenceofwaterprovesbothhydrogenandoxygen, sincewaterisacompoundoftheseelements.fIyouputapieceofpotassiumincontactwiththewater,the latterwillatoncedecompose,thepotassiumabsorbingtheoxygen,andsettingfreethehydrogenasgas, whichyoucouldcollectandignitewtihamatch,whenyouwouldfinditwouldburn.Thathydrogenwasthe hydrogenformingpartofyourcotton,slik,orwool,asthecasemightbe.Wemustnowattackthequestionof sulphu.rFirst,wepreparealtiltealkailneleadsolution(sodiumplumbate)byaddingcausticsodatoa solutionofleadacetateorsugaroflead,untlithewhtiepreciptiateifrsftormedisjustdissolved.Thatisoneof ourreagents;theotherisasoluitonofared-colouredsaltcallednirtoprussideofsodium,madebytheaction ofntiircacidonsodiumferrocyanide(yellowprussiate.)Thefirs-tnamedisverysensitivetosulphur,andturns blackdireclty.Toshowthis,wetakeaquanttiyoflfowersofsulphu,rdissolveincausticsoda,andaddtothe leadsolution.Itturnsblackatonce,becausethesulphuruniteswtihtheleadtoformblacksulphideoflead. Thenitroprusside,however,givesabeauitfulcrimson-purplecoloraiton.Nowontakingalittlecottonand heatingwiththecausticalkailneleadsolution,fisulphurwerepresentinthatcotton,thefibrewouldturnblack orbrown,fortheleadwouldatonceabsorbsuchsulphu,randformintheifbresoakedwithti,blacksulphide oflead.Nosuchcoloraitonisformed,socottondoesnotcontainsulphur.Secondl,ywemusttestsilk.Slik containsnitrogen,likewoo,lbutdoesticontainsulphur?Theanswerfurnishedbyourtestsis—no!sincethe ifbreisnotcolouredbrownorblackonheaitngwiththealkalineleadsolution.Thirdly,wetrysomewhtieBeriln woo,lsothatwecaneasilyseethechangeofcolourifittakesplace.Inthehotleadsoluitonthewoolturns black,leadsulphidebeingformed.Onaddingthentiroprussidesoluitontoafreshportionofwoolboliedwtih causitcsoda,todissolveoutthesulphur,asplendidpurplecoloraitonisproduced.Furandhairwould,of course,dothesamething.Leadsolutionshavebeenusedfordyeingthehairblack;notcausticalkailne soluitonsilkethis,however.Theywoulddosomethingmorethanturnthehairblack—probablygiveriseto somevigorousexerciseofmuscularpowe!rSitllithasbeenfoundthateventheleadsolutionsemployed have,throughgradualabsorptionintothesystem,whlistdyeingthehairblack,alsocausedcolicsand conrtactionsoftheilmbs. Havingnowfoundmeansforprovingthepresenceofthevairouselementscomposingcotton,silk,andwoo,l furorhai,rwecometomethodsthathavebeenproposedfordistinguishingtheseifbresmoregenerall,yand for quantitatively determining them in mixtures. One of the best of the reagents for this purpose is the basic zincchloirdearleadyreferredto.Thisismadeasfollows:100patrsoffusedzincchloirde,85patrsofwate,r and4patrsofzincoxideareboliedtogetheruntilaclearsoluitonisobtained.Thissolutiondissolvessilk slowlyinthecold,quicklyfihot,andformsathickgummyilquid.Wool,fur,andvegetableifbresarenot affectedbyi.tHenceifwehadamixture,andrteatedwiththissoluiton,wecouldstrainofftheilquid containingthedissolvedsilk,andwouldgetcottonandwoolleft.Onweighingbeforeandatfersuch treatmen,tthedffierenceinweightswouldgiveustheslikpresen.tTheresidueboiledwithcausticsoda wouldloseatillswool,whichissolubleinhotsrtongcausticalkali.Againstrainingoff,weshouldgetonlythe cottonorothervegetablefibrelef,tandthusourproblemwouldbesolved.Ofcoursetherearecetrain additionalnicetiesandmodfiicationsstlilneeded,andImustreferyouforthemethodinfulltotheJournal of theSocietyofChemicalIndusrty ,1882,page64;also1884,page517.Iwlilnowconcludewithsometests withalkailneandacidreagents,takeninorde,randfirsttheacids.Thesewillalsoimpressuponourminds theeffectsofacidsandalkalisonthedifferentkindsofifbres.