#GI!. IU, 193s CHEMISTRY AND ZNDUSI’RY 177

with alchcniy ; hit Iic niny Iiavc IJcen a Scots corrc- spondent of Coiint Xchnel Mnier, thc author of A h - Iwfa higie,is, nnd composer of the alclicmical musio coritaincd in t h n t work rind recently sung nt thc ltoynl Institution, T.ondon, by a student-clioir from the University of St. Andrcws. ’JIIicrc is n fine brass of Liddcl in S t . Nicliolns’ Kirk nt Abcrtlcen, aflordiiig an iiniisiinl rcprcscntntion of n man of scicncc of that period, attired in :iciidernic costume mid scntcd in his study amidst his instruincnts and books.

Jolin Nnpicr, of Jlcrcliiston (1550--1 G l ’ i ) , thc in- ventor of lognrithnis, wlio prsucd liis cnrly studies in thc University of St. hd rcws , wns keenly iutcrcstcd in ~ilcl~ciny. Jliinuscript copies of Xiipicr’s own nccount o f his discussions with tt Geriiiiiii iitlcpt of i~lchciiiy nt JStlinbitrgli arc still cstniit, and form very interesting rciiiling. Niipier, likc Newton, Iind tlircc iu:iin intcrcsts : inntliematics, irlchcniy, nntl rcligion. Nnpicr’s fnthcr, initl also liis son Rolmt,, w r c likewise rtctirc cxponcnts of nlchcmy. Hobcrt Nnpicr left n ninnuscript treatise 011 thc subject,.

Sir David Linclsny, first h r l of Biilciirrcs (1587- 1641), wns nil ciithusiiistic studcnt of niiturnl philosophy, uiid 11 seeker lifter thc Philosoplicr’s Stone niid Elixir of Life ; iitid SO’\VRS lus contenipornry, Sir Gcorgc Erskine, who left a rcninrkablc collectioii of nlchcniicnl innnu- scripts. Among scvcral nicmbcrs of the noljlc family of‘ Ruthvcn who w r c distii~guishcd for tlicir study of the niiturirl ncietices, Patrick Hiitlives (1584-1652) cnlls for spcciul notice : his iilchciiiicnl commonplace- hook, contnining a coiiipendium of cxtrncts from i i l c h ~ ~ ~ i i ~ a l writers, is still extant.

Probably tlic most discerning of rill Scottish cxponcnts of ttlcherny during thc 17th century i m s thc dbcrcloiiiiin, \Villinm Dnvidson, or Dnvisson (1593-1669 ?), who hccnnie physician to tlic King of Frnncc iind first

inciinibeiit of the chair of chctiiist,ry i i t the Jardin dtc Roi i n Pitris. The tencliing of this first Scots professor of clieinistry itthictcd pupils from iiiiiiiy countries, and i t was for tlicir bcncfit thnt Dnvidson publishcd, in 1633-35, what, w i s cssciitially tin early test-book of chemistry, uudcr thc titlc Philoso~~liiu Pyro!cch)tin, sell C‘t i rsus clpticdricits ( ‘ I Pyrotccliiiic Philosophy, or :t Coiirsc in JIcdical Chemistry ”). Thc foourth pnrt of this book dciils with t.hc nppnratus iuiid opcriitioiis of chemistry, cspccirilly as applied to medicine, and also contains one of tlic cnrliest contributions to crystallo- graphy-‘‘ n IICW subject,” ns Dnvidsoii says, “ wliicli, RO fiir :is I know, iionc before hns elnborntcd.”

l)i~vidson has clniuis to be cdlcd it cliciiiist ruther t.Iinn nn nlchcmist, nnd in this rcspcct hc r:iitks with his contenipornry, Glnubcr. After thc tu rn of tlic 17th century, indeed, thc ent,husinsm for alchemy bcgnn to wnnc in Scotland, as elsewhcrc ; iind the extrnvagnnt clniins and uuintclligiblc mysticisins of nlchcmy grndu- nlly gave wrty to n wiic nnd sober considerntion of thc facts and npplicntions of chcniistry. Thiis, a t the beginrtiiig of thc 18th century n coitrsc of what would now bc cnlled phnrninceuticnl chemistry wns given r r t Edinburgh uiidcr the nuspices of thc Incorporntion of Surgeons ; and in 1713 the first professor of physic ant1 chemistry was nppojnted t i t Ediiiburgh. Fifteen years later, hi 1728, nppenrcd tlic first-born hitrbingcr of scieiitific chcinist.ry, in the person of the erninciit Sc0t.s chemist., Joseph 13lnck.

‘ J k iiiccting ntljourncd with the ;iccorditnce of i L

1icitrt.y votc of t.linnks to the lcctmcr. ‘l‘hc inccting wns followed by s n inforinn1 dinner n t

thc l’nlncc Hotel, where Prof. Rend wns the gucst of thc owning. Scvcrnl of the iiienibers and their guests cont,ril,ut.cd to the gnicty of thc eveniug with song nnd story.

COLLOID CHEMISTRY IN THE PAPER INDUSTRY By ALEXANDER KING, M.Sc., D.I.C.

Assistant Lecturer, Imperial Collcge, S.W.7

Tltc funtlitniclititl process ill‘ p ~ w r iiiiiliiiig is still too oftcii rcgtirdcil iis t,lic iiierc iIq)t)siLioii of’ ccll~tlosc f i lms UJI the hirtlriiiicr wires f‘roni iiii itcj~ico\is suq)eiisioii, u process susceptiblc to soiiic dcgrct! of clic!iiiic~iI cotit.rol, but etill csliciitiiilly tiiccltrtiiicitl. Yvt, the oliiel‘ riiw lniitcriul of tlic pipcrniuker, celldose, is i i colloid, iind ita I)rodiict.ioii IJY orgiuiic growt.li essciitictlly ii clictiiicnl ndsorption proccss, wliilc tho i i i o n t i l l l~J~~t i t l l t iiusiliaty ~nrrtcrials, rosiii, Htiircli, wiitcqliiss, cliiy, t:iiscin, dye- tltullij, ctc. iire IIISO colloitlitl i i i mitiire. A i l untlcrstcintl- ing of t,lic siiiiplcr iispeets of t.lic intwiotions 01’ tlicsc colloitls-it subject, wliioli still rcqiiirw 1111tc1t rcsc11rc~11- ehoultl bc of help to the ~~riictioril ptip~riiiiiI;cr t i n i l is of piicr111 oltcinit:iil ititcrcut,.

THE SWELLING OF CELLULOSE ~!clliilosc, wliilc cotttiiiiiing otily SOIIIC! Gyo of nioiutiirc

iii tlic itir-ilrictl condition, liirs II grciit tcndciicy to bccoitic Irytlrntctl i inr l c d e t s i n thc forni of gcliitiiioiia lydrntcs in vcgct iililc tisaiics, cspcciililly during tlic cnrly stages of growtli. In tlic wet-tnilliiig 1)roccss gciicrnlly used i n the p i i p iidustry, tho berrtt!ii cellulose bcconics proyrcs- sivcly iiioro hyilrittccl w i t 1 tho l ropr t ies of tlic piper p r d i w t dcpiid oil tho tlcgrco of liydrrrtioii thus iioquircd. ‘flic fluxibility of tlic liyilriitctl cclliilose librcs is iicccssciry for t1it:ir c~onibinnt,ion to I‘onii i t closc \WIJ wlicu tlic pulp is Jriiiiirtl oil t h o wires. The Iiytlrittioii of ccllulovo hiie

Clicni. I!)!?& 124, 352, also i i i lrcss : Cliciiiiu tlcr Celldosc, IJCCli l’ollo\Vcti by -y-I’iiJ’ Illcthodt; 1,)’ J. It. h t Z (z. 1’h)’S.

B I

178 CIIE.\(IS'l'RY AND WDUSTRY F O ~ . LO, iom

1). W), wlio fiiicls tlint tlic S-rny I)iittti.rii t low iiot. c1iit1igu tliiriiig t.lic! proi:css, itidiaithg t.liiitt Iiytlrrttioii is iiitcr-niicelliir. llydrii thii ol' cclliilost~ prow& eveii in t h nl)seiic:(: of I)ivitiiig, its is often iiot,ic.ctl i i i tlic iiiills wl~eti pitlp is left i i i thr hitters ovvr tlic \vcck-r.iitl. Aftw proloiigctl bc;it.iiig, t.lic ccllulosc tlis~icrses to i t hoiiio- p i c o i i y gelittinous iiiiiss (hccoincs tlcritl-lwnten), iii which t,he origiiinl films Iiiivc lost. blicir itiilivitliiiilit,y. This iiintcrial is used for t l i v iiiitiiiif'nct~iri~ of iiiiitiit ioii piircli- ineiit wliic*li is to soiiic ~ s t c w t grciiscproof i i i i t l is tiset1 Jiii. writyping food, nni l :is '' ccllulitli," :I Iiiirtl iiiiiteriiil l'oriiiecl liy dcltytlriitioii of t.lic cclliilosc: jelly. 1 to shoultl IN! tiotcd tliirt IJ~LPWS iiinrli! I'roiii highly hyilriitcd piilli itre riitlicr hygroscopic. Thc greater t.hr tlcgrcc of hydrirtion of t,lic " st,uF," tlic Icss siriiig is rcqiiiretl iiiid the stronger (within liinits) is tlio rc!sultinp pitper. Quiiiit,itics of this ccllulosc jclly iiiity oftctii lie iit l i lctl with adv111ltngc to a less Iiyclriitetl p d p for t,lw ~iiirposc of streiigtbcning rind rctluctioii of t31te siriiig. It iiiust be reineiubcrcd, of wiirsc, t81int t,lic art., of pit lp bertting cwuuists not only i i i tlic Iiyclriitioii of tlic lilircs hi t also in tlicir subtlivisioii ; Iioth procesxcs rirc siisccptililc of indepentlent cooiit.rol.

ACTION OF ELECTROLYTES ON CELLULOSE It is well knorw tliiit tlie inorgnnic sii1t.s i i i soliitioii

Iiiivi! :L p i t iitfliicncc 011 t.ltc swclliiig ol' liydro~~liilic gels w d on tlicir evcntuiil ~)elitiznt.ioii. !L'lir c:lliciciicy of tlifl'crci~b ions i n this coiiiicsioii dcpentls oil r h i r Iiytlrri- tion. \\'hen the wrious srilts of i i pivcii iiietiil :ire iirningcd in orrh of their pcptieiiig or c.oii\-cr~cly of their " saltiiig out '' iictioli on Lydropliilic colloids, t l i v I-Iofnicintibr or 1yot.roliic series of tlie iiiiiotis is obtninctl. \\'hen t h siiiiie salts of titiother nictiil itre coiisidcretl, t,he same nnioii order is foiind t.o cincrge. At ono ctitl of the scrirs itrr Iluoritlos, siilphiites, wid citriitos which all possws i i iiinrkctl coitguliitirtg ii~lliic~iicc, while :it. tlic other end {ire fount1 tliiocyiiri:itCs niit l iotlidcs which swc4 i i i i d dislicrsc Iiydropliilic substnticcs. Althigli tlir Iyotropic scrics iviis first lbuiitl to ripply to g~liitiiic iind otlier proleitis, voii \Vciiiicrii (I<olloitl %., I!)%, 40, 120, 1027, 41, 14s) cstnblis1ic:d it for crIIitIow, licriitiii fihroin, chitin, uiid otlicr orguiiic HtriIctIII.itI iiiatcrjiils. ' l ' h n R celllilosc :iiitl silk coiild IIC l~ptirittl by incitue ol' iiiditlrs niitl tliiocyriii;ites ctntl prrcipitiitcd I'roiii suvh tlispcrsioiis by fluorides. S-riiy rcsultr; pint to t,lii!

swelliiig of cellnlosc in dilute clcctrolytc solut.ioiis (q., ZnCI,) 11s hciiig pliysic:iI iii nnturc, wliili~ in coiici!iit,rntcd solution there is soiii(l cvidciicc of coiii~ioiiiid l'oriii* '1 t ' 1011. ZriC'I, solitt.ioiis of 1~4iiloac~ pivr ii violct c ~ o l o i i r i i t i c i t i with iotlinr.

'I'hc swlling of ii colloid is gencrtilly II i i i i t i i i t i i i t i i tit t,lie iRoclvct,ric poiiit, liot.li Iiyclroprri i i i i t l ltyilroxyl ioiis producitiy it grciitcr srvclliiig tlinii piirp wnfer . \ Y I i i k it, is often titntetl thrrt. tlic swclliiig o l ' ~ ~ ~ ~ l l i i l o s ~ ~ is i i i l i i l ) i t td by ~ U I I I riitd o h r acidic ~id)st~atircs, tliir; cll'cch is p i i c + itlly to IJV nsc!ril~c!tl to t,lit! congultrtiiig iiilliic!iicc ol' t.lir wition ( i i i tliis L'IIBC triwlciit d i i ~ i i i i i i u ~ i i ) i i i cotijiinctioii with HII nnioii lit. tlie .' d t i i i g oiit. " cwl of !.lit! IIol'inc~iritw wries. The srwlliiig of ccllulosc i i i piire nc:irls is wry einrked, biit Iiydrrition is followed l)y Imt Ii hydralysin iiiirl esterjficritjon if t.hc ticid c:oiiccritriit.ioii i, high. IJI t bc gclatinizntion of celliilosc Iiy ucids, clicwicvtl rriidoii is iilwlrys p c r d 4 1)y s\vclliiig.

'l'lic iiiIliiciicc of' sodiiitii hyrlroxidc ou' cclluloee is cspccirilly iin1iort8riiit, both froiii tlic point of view of iiicrccriziitioii iiiid, i i i grcatcr tliliition, thc yitper iiidus- try. Cclllilosc swells \?cry rcridily in CiiiistiC sodti solii- tioii. !I!Iicrc lins bccii inucli discussion :is to t h t,lieorcn- t k 1 criiisc of tliie, i i i i t l t.lic csiriteiicc of virrious alkali- cclliilosc coiii~~oniiils hiis Iicc!n iiirokctl. S-ray studies t ciitl to coiifiriii t.liiit salt I'oriiiiitioii hiis occiirrc:rl. Baii- c:roft (.T. I'liys. Chcili., 1995, 39, I ) itltcr n criticril cxuni- inntimi of t,lic litcrntmc oil t,lic iiitcr~ictioii o f cclliilose iuicl iilkiili, coiicliidcs that thcrc is no cvidciicc I'or coiii- poiitid foriiiiit.ioii, cvcii itt ~iicrccrixiiig coiiccntnitioim of nlknli. I3vcn if tlicrc is i~ltciiii~iil retiction, the eimi- Iarity of' t.lic :ictioii of ciiustic sodit oii cellulose to that of iicids i i i id snlts would iiidiciitc that the chief factor is t.lie lyotropic itiflucnci! of blic ioiis. Whcii iinpurc ccllulosc in tlic foriii of 1iii11i is coiisitlcrccl, cheniicul iiiternctioii iiiny triko pliice I)ctwcen tlic rilkdi wid iiiipiirities, sucli 11s l i y i i i i .

!l!lic tccliuiail xlipliodoiis of. liytlriited cclltilouu arc itunt~*riiiis-iii tlic jirc~ii~riitioii of' 111crccrixc0 cottoil, ~~iircliiiicrits of' vririoiis kititls, viilc;i iiizctl Iilwrs, Willesdcii Ih1iric.s (cloth, piipcr, ctc. siirliicc trwtetl with ciiprani- iiioiiiiiiii solut~ioii) and ot,licr iiirittriiils. I t i t h pupw industry, tlie use ol' iilkitli to s\vcll or hytlnitc t,lic pulp h i s long IJCL'I~ ktioivii. 1 i i tlir! ii~iiiit~l';tctiirc of certriiii '' kriil't: " piiprs, for csiiiitplc, soiiic ol' t.lic rtlkitli liquor i i i wliicli t.lic! wood hiis IJCCil Iioilcd i n blic nulplinta pro- owe, is Icft. i i i thc! ])itlJ) to :is& in tlio clisiutcgrutioii und rlisprrsioii proccss ; it is eubseqiiciitly iicutralizcd. The rcsultiiig piipcr is c:liiircictcrizctl Iiy its great strcngth, due iiot only to t h tlcgwc of 1iytlriit.ioii of tlic ccllulom but rilso to tlic ] i ~ ~ ) t ~ Z i l t i O i l ol' rosin i t i i t l ot.lirr impuritirB i n the stufl'. Tliu prcsciici: of :ilkali i n t h Iicitkrs during t.lic! Liiziiig ])roccss i n of grwt. iiiiportiiiici! :is will prcscnt,ly bc SCCII.

:\lthougli tlic ~ iro~iort io i i ol' clcc:t~rolytcs jircwmt in tlic Iwii1c.r is Itsuiilly low, t,licy iirc iiot \ritIioiit iiiflucncc. 'I'liiis, iiiiiiiy wlts prcsctit i i i t,lic! l i i i l f sttill', introdiiccd iii t.lic lilciirhiiig ~iroccss o r d s c hy t.hc iisc of' linrtl waters iiiriy Iiirvc 1 1 1 1 iiiliiliitiiig ell'cct. n i i Iiydriitioii iuvl JICCCS-

sititt i! leii~t~ltciiiiig of' tho I ~ e ~ i t h g process with coiiscquciit, i l i ( : r c i i d riicrgy esl~ciiditurc. A etiidy of' tlic ~pccific salt t.lfccts i i i ciioli i i i i l l is rrqiiirctl, iis t.lic!ro iirt! so iiiiiiiy viiriiilh! liictore.

SIZING I Ire f i i u t l ~ ~ ~ ~ i c r ~ t ~ ~ l I I~I IWSS oi' piipertiiiikitig iti t.lw coil-

soliiliitioti of tlic Iiytlrrttcd ~i!lltil~sc! filircu with rositi

ri!pdIcrib, sliectp o i i tleliyclrritioii. ' t ' l i ~ tlimovory of 1111-

sized (Llottiiig) ]iiipr C ~ I I I I I : litti: i i i t h IiiHtory ol' p p r - iiittkitig, prolmbly iicc:itlcntrilly. U i i s i m l piijicr, itpart, froiii it,s porous iititiirc, w1iit:Ii p i w i t s it, froin beiiig ueed for IwintiiiK, is Iiickiiig i i i iiicclirt iiicitl strciigt.Ji. Tire iict~ioii of sizing rigciit.s is to *' i!losc " tho slicct. Iiy filling i i p tlic Iwrw Iict~cc!ii t.ho Iilircs ( i i i i i i w t l fillws i i lH(i help to do this) rii id to iiiiprirt to it, ii WiiIi:r-ri!siHt,iiiit cjt i i i l i ty.

1iosiii is t,lic iiiiliytlritli! ol' iiliic!t.ic iicitl (C,,o'I~t~~oO~) rind rcndily ( ~ ~ H H ~ ~ V C H in dkiiliti to Ibriii soliihlc. sdtn which II ILVC propcrLics w r y siiiiiliir to tliosc of t h alknli metal sonp, c.g., t h t or l'oriiiiiig i i ~ ~ o l ~ i l i l ~ ! sti1t.H with di- and trivalent iiictiils (notion of Iiitrtl wiitcr !). ltosin is ndded to t1w r!clluloso i i i t,hr h i t w iiid I I tioliit ioii of eluni then

, I

i i i i c l I I I I I I I I to give it C(lllCI'cIlto r i i i t l , to soiit(! cxtciit. \\*i&tCr-

Web. 19,1988 CHEBflSTRY AND INDUSTRY 170

~ O U T C ~ in. Thc obvious rcnctioii to cxpect is thc for- inittion of insoleblc nleiiiinium rcsinate :-

iiud to tjliis substiincc thc sizing action i~iis fornicrly iiycribcd. 111 1575, liowcvcr, C. Wurstcr concl~iilcrl t,liiit. sized piper coritniiictl its rosin ns tlic frcc acid niitl not iis tlic nluininiuni salt. Etlicr, which is n solreiit for both frcc rosiii iiiid iiiicliiiiigcd sodiuiii rcsiiiiitc, dissolvcs I'rom i~ sizcd pip- free rosiii but no nluiiiiiiiiiiii coiii- poiind. Tlic frcc rosin was tlicn s i i~q~oscd to lw sct. f r w hy the action of csccss iiluni on thc rcsiiintc :-

iigent, i t lins thus bccoiric ciistoiiinry to iisc :i sizc whicli contains frcc rosin IIS well ns tlic sodiuni siilh. \\'lietIicr frec rosin iicitl hiis ri grciit,cr cfiicicncy t,liriii its sodn solut.ioii s c c ~ ~ ~ s doulMu1, lmt ccrt:tiiily ii grriit den1 tlcpciidv on tlic tlcgrcc of dispcrsioii of tlic rosiii when i t 1)ccomcs cniulsifictl in tlic bciitcr. A conrsc cinulsioii will tciid to sepnrritc out nnd iiiiiy collect iii liimps to

But this is by no iiiciiiis t,llc \vliolc story. The fipccific cfl'cct of tlic iLluIii hrtv yct to lie considerctl. Mniiy other ~ubet~incce, euch ns irciils niicl calciiiin nnd miigiiesiuiii s:iltB, conguliitc t . 1 ~ rcsiiintc soliit ion nnd linvc rit tiiiicfi Iwcn usctl to do SO i n tlic bciltcr. It is found, howcvrr, I hat the cffcct of sulpliuric iicid or niiy siibstnncc frcc I'rom uluiiiiniuiii, iis 11 rosin corigrilont gives only 11

tciiipornry sizing. +in, if i i rosin dispersion is iidtlctl to tlic betiter, thc piirt,iclcs iirc \viislicd away in the wiist.c water without bciiig fiscd to tlic ccllulosc fibres. On tlic 0 t h hnnd, the iiiiiouiit of diii i i found i i i pmct.icc to givc thc best rcsults, is iiiirch in csccss of t,he rosin Iimsent, yet no nluniiiiiiiiii is wiislicd ~wi ty in tlic wnstc! watcr. Thcsc fricts lrt l It. Lorcnz (Jcronic Alesander, ( 'olloid CLeiiiist.ry IV, 85) to postulutc (I sizing inccli- i t nisni in which t h uliiiiiiriiuiii plnys nu iiiiportciiit piirt.. I Ic aesumcd t h t thc liytlrolysis of tlic iiluiii took plncc in tlic prcsciicc of t,lic liytlrosyl ioris of tlic rosiii sonp, gelatinous aliiiiiiiiiriiii Iiytlrositlc being formcd :-

A12(S0,), -1- (il-120 = 2AI(OB), -b S€12S04 Tho high ndaorptivc propcrtics of geliitinoiis uluiiiinii arc well known itiitl t,litir iippliciitioii in iiiortlnntiiig nnd hi wntcr piirificiition \vitlcsprc;itl. Aluiiiiiiiuiii hydrosido is positivcly churgcd wit.li rcspcct. to wntcr, wliilo both rosin niitl ccllulosc iirt! iicgiitivc, wliicli gives 11 rcnsoii for I Iic Iitck of rc!tciit,ion of rosin diflpcrsioiis by cclluloRe. ,t\ccording to Lorciiz, tlicrcforc, t,lic gcliit,iiioue nluiniiin wliicli is set frtv 1)y IiytlrolyRis in t.lw bcciter brc!oiiics t~l~:ctrostiit~ic~iill~ Ii t ! l t l to I l i t ' celliilosc libres rind iii its tririi 1irlsor1)s the rosin ; i i i his own wards, the nluiiiina foriiis 1 1 1 1 " clcctrostiitit: c i m c i i ~ " 10 1)iiitl t,lic colloitliil piirt,icles ol' rosin to the cclliilost~. l'iipcr i H tJiiis t i t*olloitliil coin- plcs of ccllulosr, t i l u i i i i i i i i , i ~ i i t l rasiii, t l l c ! Iiydrosiclo liiiviiig iiiiicli tlti! siiiiit: fiiiiot.iori IIS whrii iiscil IIS i t iiiorfiuiit. l'lic iitltlit.ioii of frcc ii l i ir i i i i i i ir i i i Iiytlrosidc to the bcntcr is iilso ktiowii to give i i i i ~ i r o v ~ ~ l qiiiilit.ics to 1,lic 1)iiI)cr ( I I . \\'. l h v l i i r i t l , Pitper Il'rntlc , I . , 1!133, 97, No. 21, 37).

I l it! iiiost. olisc:iiro point i i i t , l itr I,orciii! tlrcory is th: rtwoii for t h : t w i i p I t ! l (1 I~ytlroly~is of t . l i t 8 rosin sorip.

" spot " the paper.

f ,

13y niinlogy with tlic otlicr rilktili iiictiil sotips wc should cspcct t,liat this iiin tcrinl woiiltl not I)c hydrolysed to nny iiinrked cstciit, cvcii n t tlic grcnt dilutioiis cinployed in tlic bcatcrs. N c ~ e r t l i c l e ~ ~ , 11i1ugli (Pnpcr Tradc J., l!)23,77, No. 2,50) niit l Iv~iiioff (?Xd., 1923,76, No. 11,45) both find almost coiiiplctc hydrolysis i n N/1000 solution. l31i~lko~~~slcy (Paper Triidc .I., 1833, 97, No. 13, 28), how- ever, has rcociitly sliowii by :in iiiiprowd tiictliod t l in t tlierc is only 4.3% Iiyrlrolysis :it 56" C. with nii N/3M solution. 13. W. 1~owl:iiid (J. I'lrys. Cliciii., l937,41, 1000) hos clucidntetl the iiiiittcr hy sliowiiig that hydrolysis docs tnkc pliice i n tlic prc'sciicc of ccllulosc fibrcs, different pulps haviiig diKcrcnt cflccts, prcwinin1)ly tluc to vnria- tions i i i Iiy(lriition and to iiiipiiritics. This cffcct is undoribtcdly doc to hydrolytic idsorptioii niitl sclcctivc rctciitioii of it lLii l i by thc pulp, ns tlic relative nctivity of tlic vnrioiis pdps iii Iiydrolysing rosin soap is tlic siililc as t l i i t t of tlicir n l l x l i iitlsorptioii cnpacity. Row- l i i i i t l tlicn prnccctls to rcprcseiit tlic colloid chciiiistry of siziiip hy tlic followiiig cliopraiii :-

This iiitliciitcs, first,, tlii. Iiytlrolysis of tlic rcsiiiiite by tJic iirt,ioii of the ccllulosc films. !t'lic iitIdit,ioii of nluiii n t p l r = 8.0 will hriiig tlic Iiydrolysis to nil r i d by prc- cipitiit,iiig tiny ii~iIiy~lroly~c'tI iiinteriril iis AIRp (iicgntivc1~- cliiirgcd), Al,03 (positivcly cli~irgcd), iiiitl sotliuiir sulphntc rilso bciiig foriiicd. Alost of tlic rosin I ind previously bceii colivcrtctl to tlic frcc iicid (1icgiitircly chiirgcd) OW- cvcr, i i i id thc frcc iilkiili t,lius libcriitcd oii the ccllulosc* siirfiicc prccipitiitctl ~ ~ ~ 1 i i t i 1 ~ 1 1 ~ iiliiiiiiiin. Thc rclntivo :iiiioiiiits of free rosin, ~ ~ I U I I I ~ I I I L , iiid i i l iI i i l i i l i i i i l i rcsiriatr wlijcli fiiiitlly UI)l)ciir, will dcpcnil, not o d y 011 the ill- grctliciits iitldctl, b ~ t ; illso O N tlic liydr~itioii of tlic pi lp iuid tlia impurities i t (wiitrtiiis (1)otli of wliicli factors coiitrol it,s iiclsorl~tivc powers) i i l i t l nlso on tlic coiigiilating iullucnccs of ot,licr ions which iiiity be ~)rcsciit,, 11s for instance, from lirirtl wiitcr.

t\s t,lic iiiiiiii sizing agent, tlic piire rosin iicitl is pro- tliiccrl by hydrolysis o i i t l i c t:clliilosc IilJrcs ; i t is proli- iibly tlct frrc i n i i wry liw stritc of siibdivisioii which would c'spliiiii t,Iw 1)t)or rcsrilts o1)tiiiiictl l y t,lir ridditioii

rcliitivcly coiirst! rosiii riiiiilsioiis. Aiiotlicr iiiiportiiiit fiictor iii pnI)criiiiikiiig is the rctca-

tioii of t,hc miiicriil Lillcrs hy t.lir porous tiygrcgntc. It is kiiowii tliiit R high clegrcc of Iiydriitioir of t,lic pulp pro- tlucce ciihii~iccd powers of iitlsorptioii i i i i t l rct,ciitioii ol' iiiiiicrnls niitl pigiiic1iitw. 'I'h iiiost iiiiportiiiit; fiictor hcrr y i i i i , lio~vcwr, is prohribly t.lir Iiytlroux iiliiiiiiiin with its high specific surfiicc wliicli is ccil)iililc of fkiiig cltiyy, pigiiiciits, 1iii11 tlyestiillk l'liis hiis bccii discruscd by b'riccliiiiiiiii (L'iipcr 'l'rritlc J., 1030,90, No. 25, 55) iiiid by Albcrt (/ l id., 1037, 105, No. ti, 73). 1'1ic tlizo cuid shape of tho fillcr dry . prirtic:ICs, 1)iiso oxoliniigc uiid tho pit of tlic siityeiisioii rill pliiy I I pnrt in t,Lc fisritioii of i t Iiiiiiinii.

II :1

180 CHEhIlSTRY AND XNDU8TRY Rib. 10,1938

OTHER COLLOIDAL EFFECTS Colloidnl conditions prcvnil nt every Rtnge in the

manufacture of paper from pulping to finishing. The effect of drying sized paper on tlic hot rollcrs is, for example, a coniplicntcd nnd little understood collcctioii of colloidnl reactions, amongst wliicli, cliangcs in the nature of the drying iiluniina have grcnt influence on the printing qunlitics of tlic p p c r . Agiiin, other sizing methods may be cniployed, sue11 as the use of stiirch and materglnss solution, precipitated once again by ulum ; there is no need to point out the colloidnl i1:iturc of this system. Among iicwcr sizing :igcnts, wnx emulsions have coine into proniinence (Cobb, Clitiiiibcrliiiii iiiid Donibrow, Pnper Trade J . , 1033,97, No. 10, 35). Finely divided wax, when efficiently distribntetl in the pnper, gives nn enhanced hnndlc, flexibility, arid cxccllciit printing qualities. In oddition, rosin, stnrch, wisein, niid rubber latex inny be suitnbly incorpor:rtetl.

In thc finishing of pnpcr by gclatinc or ciisciii filnis the drying of these hydropliilic substances is n matter of importance ns is the colloidnl effcct of lirirdcning ngcnts

(formalin, chrome alum) on them Amongst recent dcvelopnicnts must be mentioned thc use of nitrocellu- lose ciiiulsions which, by a suitable admixture of plns- ticizcrs, dyes, ctc. cnn give to t,lic pnpcr almost any desired appearance.

I n the production of niiiicrnl coated papers and wnll- pnpcrs, II suspension of ii iiiincrnl siicli iis kaolin in a liytlrophilic ndhcsivc, gcncrnlly ctisciu, is cniploycd. Thc problcnis of dispersion of tlic cnsciii by nieaus of nlltnli, niniiionin, bornx, etc. nrid of control of tlic viscosit,y of tlic rcsirltnnt inis nrc iisunlly nttacked by eiiipiricnl nietliods niid wit.lioiit; undcrstnnding of the colloidiil principles invol\wl. W c iire only beginning to rccogiiiee thc infinitc iiiinibcr of possiblc colloidal rc- uctions I)et,\rccii the iiintcrinls of tlic coiitctl paper mnnu- facturcr : p p r s of ivitlcly tliffcring properties, illinern1 pigincnts of diflcrcat clicinicril rind :itlsorptivc propertieu, dycstuffs, bindcrs, softcning ngents, nnti-frothing agents, Aiiisliing ngciits, iind so on. ,The colloidnl iispccta of paper iiiaiiufiictiirc 11nrc heen discussed before : they will hnvc to be stressed ngnin !

THE EARLY DEVELOPMENT OF CHEMICAL INDUSTRY IN BRISTOL

By a Number of Contributors (Summarized by Mr. Stanley Robson)

(Co/t/i,t 1Wd)

111. TOBACCO,* CHOCOLATE, AND SUGAR

Our survey uow brings 11s to the wry plcnsrint trades of tobncco Innking, chocolatc ntitl siigir. The cnrly development of the tobncco industry is \vriipl)cd in historical interest. Tobacco is bcli~vctl to hove bccli introduced into Europc by Hoiiiiino Piiiic, IL Spiiiisli iiionk who ncconipanictl c‘olunibus on his voyngc to America. The first tobiicco plnnt. \VIIS brought to Europe nbout 1560 by Prluisisco lIcriiuiidw, i i pliysicitin, who had been sent by Philip 11 of Sptiili to invcstignte the products of blesico.

Jean Nicot., thc Prcncli A iiibiissndor to l’ortiignl, cultivated tlic plant in his girrtlcn, tind mit sonic sccds to Catharine dc Mcdici of Friiiicc i i i 1561. Ciiptnin Ralph Laiic tint1 Sir Frirncis 1)rnkc brouglit toblicco home from Virginia iti 1686. tit lirst tlic usc! of tobiicco for smoking excited violent oppositioii. Proliibition and persecution liowcwr iiiiidc little inipressioii up011 nu ever increti&ig npprecintion of its use, lint1 by tlic end of the sevciitcciitli century the usc of tol~iicco Iind sprcnd throughout the civilized world. Tlic cignrcttc, as we know it today, wis IL Covernulent iiionopoly in Rrancc in 1843 and i t bcciiiiic fnsliionablc in tllis country

Dr. bl. Niorenstein Ilns written R lottcr in whioli 110 diseliiinis nny oontribution t o the n b o w nrtiolo o i i tho t ~ l ~ ~ i c o o industry in Bristol. In oiir issiio of 1~’oIi. d it \VIM Rttilctl tllnt Dr. h’ioronhtoin Jind contrib~rtctl iihrrtliitiort on tlrie topjc.

\vhcii the h o p s returned froiii tlic Criniean War of lf35&-185(i,

Ikistol hns heen coniicctcd wit,li tobacco iiianufncturc froiii thc ciirlicst dnys irntl the processes of Lnw were eiiiploycd i n 11 tobncco cnsc in this City as ‘cnrly ns OctolJcr 9, 1503. ‘Illic iniinufiicturc of clay pipes bcgiin

workiiicii. Tlic bowls of tliesc pips werc nt first littlc larger than ii Iritly’s tliiniblc bccausc tlic price of tobricco wtis very Iiigli iriid wiis bii1iiiic:cd iigliinst its weiglit in silver on thc sciilcs in tlic Jlrrrkcts of Jl~ilnicsbury aid Chippciiliani.

In 16% IL lioyiil Proclaiiiirtiou iviis issued estriblishing u iiionopoly i i i tlie niiiiiufiict;urc of tobncco pipes in fnvour of i i coiiipany in Londoii.

I n 1631 iiiiotlar Proclainatioii \vns iseucd by tlic King proliibiting Uristol nwrchants from cultivciting tol~ncco and forbitldiiig it,s iinportritioii froin the plnntu- tions iiito nny port save Loiitloii. Tlicsc l’roclirmntions wcrc ruct with grcat rcsistrrncc! rriid evnsioii, but in 1039 tlic Arbitrirry Ortlcrs werc \r~ithtlrewii and grniits of iniporttit.ioti were pcrniittcd to the fiorts of J3rieto1, l’lymoutli, Diirtaiouth, untl Southiimpt~on. A greet 8tjniulus wan this iinpnrtcd to lociil coiiiiiiercc and, tlic trade rapidly dcvclopcd.

In 1652 the I.lousc of Coiiitnoiis p i w d n fresh ordiirriicc ititcrdict~ing cultiviit ion, but cvnsion cont.i~iacd ns bcforc,

i ~ i 13ristol :it U. very ciirlp dntc illid cillploycd many