,transcrib]'s ,note3 ,m9or typographical errors & inconsi/5cies h be5 correct$4 ,"s words _h inconsi/5t hyph5ation ?r\gh\t ! book2 ^! h be5 made consi/5t4 ,9 ! ma!matical & *emical expressions1 ! c>et "* repres5ts to ! p[] (1 e4g4 e#b means e-squ>$4 ,curly braces are us$ to repres5t und]scores1 e4g4 n#a means n ) a subscript ( #a4 ,equal signs are us$ to repres5t bold words1 & und]scores are us$ to repres5t italics4 ,on page #aeb ,na,c,o#bc has be5 correct$ to ,na#b;,,co#c4 ,on page #bab1 ! v>iable n has be5 replac$ ) ! correctly subscript$ =ms n#a & n#b4 ,! index entry = ,hemlock b>k _h no page numb] 9 ! orig9al text1 s ! correct page numb]1 #cd1 has be5 suppli$4 ,ions are %[n z ,fe1 in/ead ( us+ sup]scripts4 ,!re is "s inconsi/5cy 9 ! notation us$ 9 ! orig9al text = *emical =mulae su* z ,na#b;,cr#b,o#g7b;,h#b,o74 ,^! h be5 regul>iz$ to use ! mod]n mid-dot1 = example1 ,na#b;,cr#b,o#gb;,h#b,o4 ,greek lett]s 9 ! orig9al h be5 repres5t$ 9 ?is v]sion by ! "n ( ! lett] enclos$ 9 squ>e brackets1 e4g4 alpha4 ,,animal ,,prote9s ,,by ,,hugh ,,g>n] ,,b5nett1 ,m4,sc4 7,,le$s7 ,,memb] ,,( ,,! ,,society ,,( ,,lea!r ,,trades' ,,*emi/s2 ,,=m]ly ,,assi/ant ,,lectur] ,,& ,,demon/rator ,,at ,,! ,,lea!r ,,indu/ries ,,dep>tm5t ,,( ,,! ,,univ]sity ,,( ,,le$s ,,au?or ,,( ,,! ,,manufacture ,,( ,,lea!r ,,london ,,bailli,,re1 ,,t9dall ,,& ,,cox #h1 ,,h5rietta ,,/reet1 ,,cov5t ,,g>d5 #aiba 7,all rights res]v$7 ,,g5]al ,,preface ,! rapid developm5t ( ,appli$ ,*emi/ry 9 rec5t ye>s has br\ght ab\t a revolution 9 all bran*es ( te*nology4 ,?is gr[? has be5 accel]at$ dur+ ! w>1 & ! ,briti% ,empire has n[ an opportunity ( increas+ its indu/rial output by ! application ( ?is k to ! raw mat]ials available 9 ! diff]5t p>ts ( ! _w4 ,! subject 9 ?is s]ies ( h&books w be treat$ f ! *emical r ?an ! eng9e]+ /&po9t4 ,! indu/rial aspect w also be m prom95t ?an t ( ! laboratory4 ,ea* volume w be complete 9 itself1 & w give a g5]al survey ( ! indu/ry1 %[+ h[ *emical pr9ciples h be5 appli$ & h affect$ manufacture4 ,! influ5ce ( new inv5tions on ! developm5t ( ! indu/ry w be %[n1 z also ! effect ( indu/rial requirem5ts 9 /imulat+ inv5tion4 ,hi/orical notes w be a feature 9 deal+ ) ! diff]5t bran*es ( ! subject1 b !y w be kept )9 mod]ate limits4 ,pres5t t5d5cies & possible future developm5ts w h att5tion1 & "s space w be devot$ to a comp>ison ( indu/rial me?ods & progress 9 ! *ief produc+ c\ntries4 ,!re w be a g5]al bibliography1 & also a select bibliography to foll[ ea* section4 ,/ati/ical in=mation w only be introduc$ 9 s f> z x s]ves to illu/rate ! l9e ( argum5t4 ,ea* book w be divid$ into sections in/ead ( *apt]s1 & ! sections w deal ) sep>ate bran*es ( ! subject 9 ! mann] ( a special article or monograph4 ,an attempt w1 9 fact1 be made to get away f ! or?odox textbook mann]1 n only to make ! treatm5t orig9al1 b also to appeal to ! v l>ge class ( read]s already possess+ good textbooks1 ( :i* !re are q suffici5t4 ,! books %\ld also be f\nd useful by m5 ( affairs hav+ no special te*nical k1 b :o may require f "t to "t to ref] to te*nical matt]s 9 a book ( mod]ate compass1 ) ref]5ces to ! l>ge /&>d works = full] details on special po9ts if requir$4 ,to ! advanc$ /ud5t ! books %\ld be especially valuable4 ,8 m9d is (t5 cramm$ ) ! h>d facts & details ( 8 subject :i* cr[d out ! p[] ( realiz+ ! indu/ry z a :ole4 ,^! books are int5d$ to rem$y su* a /ate ( affairs4 ,:ile recapitulat+ ! ess5tial basic facts1 !y w aim at pres5t+ ! reality ( ! liv+ indu/ry4 ,x has long be5 a drawback ( our te*nical education t ! college graduate1 on comm5c+ 8 indu/rial c>e]1 is positively h&icapp$ by 8 academic k because ( 8 lack ( in=mation on curr5t indu/rial conditions4 ,a book giv+ a compreh5sive survey ( ! indu/ry c be ( v mat]ial assi/ance to ! /ud5t z an adjunct to 8 ord9>y textbooks1 & ?is is "o ( ! *ief objects ( ! pres5t s]ies4 ,^? actually engag$ 9 ! indu/ry :o h specializ$ 9 r n>r[ limits w probably f9d ^! books m readable ?an ! l>g] textbooks :5 !y wi% to refre% _! memories 9 reg>d to bran*es ( ! subject ) :i* !y are n imm$iately conc]n$4 ,! volume w also s]ve z a guide to ! /&>d lit]ature ( ! subject1 & prove ( value to ! consultant1 s t1 hav+ obta9$ a compreh5sive view ( ! :ole indu/ry1 he c g at once to ! prop] au?orities = m elaborate in=mation on special po9ts1 & ?us save a c\ple ( days sp5t 9 hunt+ ?r\gh ! libr>ies ( sci5tific societies4 ,z f> z ?is c\ntry is conc]n$1 x is believ$ t ! g5]al s*eme ( ?is s]ies ( h&books is unique1 & x is confid5tly hop$ t x w supply m5tal munitions = ! com+ indu/rial w>4 ,i h be5 =tunate 9 secur+ writ]s = ! diff]5t volumes :o are specially connect$ ) ! sev]al dep>tm5ts ( ,indu/rial ,*emi/ry1 & tru/ t ! :ole s]ies w contribute to ! fur!r developm5t ( appli$ *emi/ry ?r\gh\t ! ,empire4 ,,samuel ,,rideal4 ,,au?or',s ,,preface ,x has be5 ! au?or's *ief conc]n t ?is volume %\ld fulfil its own "p 9 ! programme set =? 9 ,dr4 ,rideal's ,g5]al ,preface4 ,! lea!r1 glue1 & k9dr$ trades h be5 = _m ye>s recogniz$ z *emical indu/ries1 b ! great developm5t ( colloid *emi/ry 9 ! la/ few ye>s has giv5 ^! trades a m def9ite /atus z su*1 & !y c n[ be plac$ 9 ! category ( appli$ physical *emi/ry4 ,! "t is probably n f> di/ant :5 "s k ( pure physical *emi/ry w be a fir/ ess5tial to /ud5ts1 *emi/s1 *emical eng9e]s1 & to all engag$ 9 ^! indu/ries 9 sup]vision1 adm9i/ration1 or control4 ,x is hop$ t ?is volume w /imulate ! /udy ( ^! indu/ries f t /&po9t4 ,z ! au?or has previ\sly writt5 ^u "o ( ! indu/ries involv$ h]e9 7,! ,manufacture ( ,lea!r3 ,con/able ,co471 he has1 r inevitably1 f\nd x difficult to avoid altoge!r 8 own phraseology4 ,! *anges ( a decade1 h[ev]1 toge!r ) ! wid] field & new] view-po9t1 h made possible a radical diff]5ce ( treatm5t4 ,! au?or desires to ackn[l$ge ! help he has receiv$ f ! _m books1 essays1 & rese>*es :i* are m5tion$ 9 ! ref]5ces at ! end ( ea* section1 especially to ,proct]'s ,pr9ciples ( ,lea!r ,manufacture1 & also to ?ank ,dr4 ,rideal = _m useful sugge/ions4 ,! au?or w\ld l also to ackn[l$ge "h 8 indebt$ness 7z well z t ( ! trade g5]ally7 to ! "w ( ,dr4 ,j4 ,gordon ,p>k]1 :o1 ?r\gh 8 rese>*es1 lectures1 & tea*+ "w1 has done m ?an any o!r man to dissem9ate a k ( practical me?ods ( tann+4 ,! au?or's ?anks are also due to 8 bro!r1 ,mr4 ,w4 ,gordon ,b5nett1 ,m4,sc41 ,a4,i4,c41 ,m4,c41 = assi/ance 9 pro( revision1 & to 8 fa!r1 ,rev4 ,john ,b5nett1 = "s lit]>y criticism4 ,h4 ,,g>n] ,,b5nett4 ,,bev]ly1 ,june1 #aiba4 ,,cont5ts ,,g5]al ,,preface ,,au?or',s ,,preface ,,cont5ts ,,introduction 99 99 99 99 99 ,,"p ,i4 ,,hides ,,= ,,heavy ,,lea!rs4 ,,section #a4 ,,! ,,raw ,,mat]ial ,,( ,,heavy ,,lea!rs #b4 ,,! ,,prep>ation ,,( ,,pelt #c4 ,,vegetable ,,tannage #d4 ,,f9i%+ ,,process #e4 ,,sole ,,lea!r #f4 ,,belt+ ,,lea!r #g4 ,,h>ness ,,lea!r #h4 ,,upp] ,,lea!rs #i4 ,,bag ,,lea!r #aj4 ,,pick+ ,,b& ,,butts 99 99 99 99 99 ,,"p ,,ii4 ,,sk9s ,,= ,,light ,,lea!rs4 #a4 ,,pr9ciples ,,& ,,g5]al ,,me?ods ,,( ,,light ,,lea!r ,,manufacture #b4 ,,goatsk9s #c4 ,,sealsk9s #d4 ,,%eepsk9s #e4 ,,calfsk9s #f4 ,,japann$ ,,& ,,enamell$ ,,lea!rs 99 99 99 99 99 ,,"p ,,iii4 ,,*rome ,,lea!rs4 #a4 ,,! ,,nature ,,( ,,*rome ,,lea!rs #b4 ,,g5]al ,,me?ods ,,( ,,*rome ,,lea!r ,,manufacture #c4 ,,*rome ,,calf #d4 ,,*rome ,,goat ,,& ,,%eep #e4 ,,heavy ,,*rome ,,lea!rs 99 99 99 99 99 ,,"p ,,iv4 ,,miscellane\s ,,tannages4 #a4 ,,alum ,,tannages #b4 ,,fat ,,tannages #c4 ,,oil ,,tannages #d4 ,,=maldehyde ,,tannage #e4 ,,syn!tic ,,tann+ ,,mat]ials #f4 ,,comb9ation ,,tannages #g4 ,,! ,,evolution ,,( ,,! ,,lea!r ,,indu/ry 99 99 99 99 99 ,,"p ,v4 ,,gelat9e ,,& ,,glue4 #a4 ,,prop]ties ,,( ,,gelat9e ,,& ,,glue #b4 ,,raw ,,mat]ials ,,& ,,prelim9>y ,,treatm5t #c4 ,,extraction #d4 ,,cl>ification ,,& ,,decolorization #e4 ,,blea*+ #f4 ,,evaporation #g4 ,,cool+ ,,& ,,dry+ #h4 ,,uses ,,( ,,gelat9e ,,& ,,glue #i4 ,,! ,,evolution ,,( ,,! ,,gelat9e ,,& ,,glue ,,indu/ry 99 99 99 99 99 ,,"p ,,vi4 ,,miscellane\s ,,prote9s ,,& ,,bye-,,products4 #a4 ,,bye-,,products ,,( ,,! ,,lea!r ,,trades #b4 ,,bye-,,products ,,( ,,! ,,gelat9e ,,& ,,glue ,,trades #c4 ,,food ,,prote9s #d4 ,,miscellane\s ,,animal ,,prote9s ,,index ,,animal ,,prote9s ,,introduction ,prote9s are organic comp\nds ( natural orig91 be+ f\nd 9 plants & 9 animals1 ?\gh mu* m pl5tifully 9 ! latt]4 ,!y are comp\nds ( great complexity ( composition1 & ( v high molecul> weight4 ,! con/itution ( none ( !m is fully und]/ood1 b al?\gh !re are a great numb] ( diff]5t individual proteids1 !y pres5t typical resemblances & div]g5ces :i* s]ve to diff]5tiate !m f o!r gr\ps ( organic bodies1 & also f "o ano!r4 ,prote9s resemble "o ano!r 9 bo? proximate & ultimate analysis4 ,!y conta9 ! usual elem5ts 9 organic comp\nds1 b 9 proportions :i* d n v>y ov] v wide limits4 ,?is range ( v>iation is giv5 approximately bel[3-- ,elem5t4 ,p] c5t4 ,c>bon #di to #ee ,hydrog5 #f4d to #g4c ,oxyg5 #ag to #bf ,nitrog5 #ac to #ai ,sulphur #j4c to #c4j ,! mo/ *>act]i/ic feature ( ! prote9 gr\p is ! am\nt ( nitrog5 usually pres5t4 ,?is is g5]ally ne>] ! high] limit1 seldom fall+ bel[ #ae p] c5t4 ,?is range = ! nitrog5 cont5t is det]m9$ l>gely by ! nature ( con/itu5t gr\ps :i* g to =m ! proteid molecule4 ,r\ghly speak+1 prote9s consi/ ( *a9s ( amido-acids & acid amides ) small] proportions ( aromatic gr\ps1 c>bohydrate gr\ps & ?io comp\nds atta*$4 ,9 ^! *a9s an acid radical may comb9e ) ! amido gr\p ( ano!r amido acid1 ! acid gr\p ( ! latt] comb9+ ) an amido gr\p ( ano!r amido acid1 & s on4 ,hydrog5 may be sub/itut$ 9 ^! *a9s by alkyl or aromatic gr\ps4 ,!re is obvi\sly inf9ite possibility ( v>iation 9 con/itution = comp\nds ( ?is "*1 ! g5]al nature ( :i* v>ies v little4 ,practically all ( ! prote9s are f\nd 9 ! colloid /ate1 & ?is makes !m v difficult to purify & r5d]s ! ultimate analysis 9 _m cases d\btful4 ,x is1 = example1 (t5 difficult to asc]ta9 _! moi/ure cont5t1 = _m are easily hydrolyz$ ) wat] only1 & _m "p easily ) ! elem5ts ( wat]1 :il/ on ! o!r h& _m are lyophile colloids & practically _c be dehydrat$ or dri$4 ,a few1 su* z gelat9 & "s album9s1 h be5 cry/alliz$4 ,! con/itu5t gr\ps h be5 inve/igat$ *iefly by hydrolytic me?ods4 ,! *a9s ( amido acids are split up dur+ hydrolysis1 & individual amido acids may ?us be sep>at$4 ,! hydrolysis may be assi/$ ei!r by acids1 alkalies or f]m5ts1 b foll[s a diff]5t c\rse accord+ to ! nature ( ! assi/ant4 ,"u approximately con/ant conditions ( hydrolysis1 ! products obta9$ are 9 approximately con/ant proportions1 & ?is fact has be5 utiliz$ by ,van ,slyke 9 devis+ a me?od ( proximate analysis4 ,x is n possible 9 ?is volume to ent] deeply into ! con/itution ( ! diff]5t proteids4 ,ref]5ce mu/ be made to works on pure *emi/ry1 especially to ^? on advanc$ organic *emi/ry4 ,x w be int]e/+1 h[ev]1 to m5tion "s ( ! amido acids & gr\ps commonly occurr+ 9 proteids4 ,^! comprise orni?9e 7#a3d diamido val]ic acid71 lys9e 7#a3e diamido-caproic acid71 arg99e 7#a amido1 #d guanid9e val]ic acid71 hi/id9e1 glyc9e 7amidoacetic acid71 alan9e 7amido propionic acid71 amido-val]ic acid 7amido-iso-caproic acid71 liac9e1 pyrollid9e c>boxylic acid1 asp>tic acid1 glutamic acid 7amido-glut>ic acid71 ph5yl-alan9e1 s]9e 7hydroxy-amido propionic acid71 pur9e d]ivatives 7e4g4 guan9e71 indol d]ivatives 7e4g4 tryptophane & skatol acetic acid71 cy/9e 7a ?ios]9e anhydride71 glucosam9e1 & urea4 ,!re are a few g5]al reactions :i* are typical ( all prote9s1 & :i* c usually be trac$ to def9ite gr\p+s 9 ! molecule4 ,among/ ^! is ! biuret reaction3 a p9k col\r obta9$ by add+ a trace ( copp] sulphate & an excess ( cau/ic soda4 ,?is is caus$ by ! biuret1 ,,nh7,,conh#b7b radical or by simil> diacidamide gr\ps1 e4g4 malonamide1 oxamide1 glyc9e amide4 ,ano!r g5]al reaction is ) ,millon's reag5t1 a solution ( m]curic nitrate conta9+ nitr\s fumes4 ,on w>m+ ! proteid ) ?is reag5t1 a curdy p9k precipitate or a r$ col\r is obta9$4 ,?is reaction is caus$ by ! tyros9e gr\p 7p4 oxy alpha amido ph5yl-propionic acid74 ,ano!r g5]al reaction is to boil ! prote9 ) #a3b nitric acid = "s days4 ,a yell[ floccul5t precipitate ( xan?oproteic acid is obta9$1 & ?is dissolves 9 ammonia & cau/ic alkalies ) a br[n or orange-r$ col\r4 ,ano!r *>act]i/ic ( prote9s is t on dry di/illation !y yield mixtures ( pyrid9e ,c#e;,h#e,n1 pyrrol ,c#d;,h#e,n1 & _! d]ivatives4 ,on ! subdivision1 classification & nom5clature ( ! prote9s mu* ink has be5 spill$1 & x is impossible 9 ?is volume to g into ! v>i\s sy/ems :i* h be5 sugge/$4 ,x %\ld be not$1 h[ev]1 t "s writ]s habitually use ! t]ms proteid or album9oid z synonyms = prote94 ,! classification ( prote9s adopt$ 9 ?is "w is us$ because x is ! mo/ suitable = a volume on indu/rial *emi/ry & has ! additional m]its t x is simple & is already us$ 9 sev]al /&>d works on indu/rial *emi/ry4 ,x is bas$ ^u ! behavi\r ( ! prote9s t[>ds wat]1 a matt] ( obvi\s mom5t 9 manufactur+ processes4 ,on ?is basis prote9s may be divid$ into album9s1 k]at9s & gelat9s4 ,cold wat] dissolves ! album9s1 does n affect ! k]at9s1 & only swells ! gelat9s4 ,! behavi\r 9 hot wat] confirms & elaborates ! classification4 ,:5 heat$ 9 wat]1 ! album9s coagulate at temp]atures ( #gj-ge ,c41 ! gelat9s 7if swoll57 dissolve readily1 :il/ ! k]at9s only dissolve at temp]atures above #ajj ,c4 ,album9s & k]at9s may be di/+ui%$ also f gelat9s by add+ acetic acid & potassium f]rocyanide to _! aque\s solutions4 ,album9s & k]at9s give a precipitate1 gelat9s d n4 ,ano!r di/+ui%+ reaction is to boil ) alcohol1 wa% ) e!r1 & heat ) hydro*loric acid 7,s4,g4 #a4b74 ,album9s give a violet col\r1 k]at9s & gelat9s d n4 ,album9s may be fir/ discuss$4 ,!y are typifi$ by ! case9 ( milk & by :ite ( egg4 ,_! solutions 9 wat] are fa9tly alkal9e1 optically active1 & lvorotatory4 ,!y are coagulat$ by heat & also by m9]al acids1 alcohol1 & by _m poisons4 ,! temp]ature ( coagulation 7usually ab\t #gb ,c47 is affect$ by m9]al salts1 ! effect be+ 9 lyotrope ord] 7see ,"p ,v41 ,section ,i474 ,! coagulat$ album9 behaves 9 mo/ respects l a k]at94 ,"s ( ! album9s 7globul9s7 are1 /rictly speak+1 n soluble 9 cold wat]1 b readily dissolve 9 weak solutions ( salt4 ,! album9s are coagulat$ f ^! solutions1 z usual1 :5 heat$4 ,into ?is special class fall myos9 7( ! muscles71 fibr9og5 7( ! blood7 & vitell9 7( egg yolk74 ,by a g5tle or limit$ hydrolysis ( ! album9s ) dilute acids 9 ! cold1 a gr\p ( comp\nds call$ album9ates are obta9$4 ,!y dissolve 9 ei!r acids or alkalies1 & are precipitat$ by exact neutralization4 ,!y may also be salt$ out by add+ sodium *loride or magnesium sulphate4 ,!y are n coagulat$ by heat4 ,aft] fur!r hydrolysis ) ei!r acids1 alkalies or f]m5ts1 v soluble comp\nds are obta9$ call$ album9 peptones or albumoses4 ,^! are soluble 9 alkalies1 acids & wat]1 & are readily hydrolyz$ fur!r into amido acids & acid amides4 ,!y are v simil> to ! peptones obta9$ f k]at9s & gelat9s4 ,!y are n coagulat$ by heat4 ,k]at9s are typifi$ by ! hair ( animals4 ,!y s(t5 some:at 9 cold wat] & ev5 m 9 hot wat]1 b are n dissolv$ until dige/$ = "s "t at temp]atures exce$+ #ajj ,c4 ,) "s k]at9s1 h[ev]1 ! cy/9e gr\p is to "s ext5t easily split (f by w>m wat]1 & on boil+ ) wat] hydrog5 sulphide is evolv$4 ,! sulphur cont5t ( k]at9s is (t5 great] ?an ! av]age = proteids4 ,all k]at9s are dissolv$ ) great read9ess by solutions conta9+ sulphydrates & hydrates1 e4g4 a solution ( sodium sulphide4 ,9 solutions ( ! hydrates ( ! alkali & alkal9e e>? metals1 k]at9s behave diff]5tly4 ,"s dissolve ) great ease1 "s ) difficulty1 "s only on heat+ & "s n ev5 if dige/$ ) hot cau/ic soda4 ,!y are dissolv$ 7) hydrolysis7 by heat+ ) m9]al acids1 yield+ peptones & ev5tually amido acids1 acid amides1 etc4 ,_m k]at9s h a comp>atively l[ cont5t ( nitrog54 ,gelat9s are v difficult to di/+ui% f "o ano!r1 _! behavi\r be+ closely simil> to reag5ts4 ,!y are also v readily hydrolyz$ ev5 ) wat]1 & ! products ( hydrolysis are ev5 m simil>4 ,! gelat9s are kn[n toge!r1 comm]cially1 "u ! g5]al "n ( gelat9e4 ,gelat9s ( diff]5t orig91 h[ev]1 h und\bt$ly a diff]5t composition1 ! nitrog5 cont5t be+ v>iable4 ,if ! gelat9s are n blea*$ :il/ !y are be+ manufactur$ into comm]cial gelat9e1 !y are call$ glue4 ,gelat9e is col\rless1 transp>5t1 devoid ( ta/e & smell4 ,x is usually brittle4 ,its ,s4,g4 is ab\t #a4db1 & x melts at #adj ,c4 & decomposes4 ,x is insoluble 9 organic solv5ts4 ,:5 swell+ 9 cold wat] x may absorb up to #ab times its own weight ( wat]4 ,! swoll5 product is call$ a jelly4 ,jellies easily melt on heat+ & a colloidal solution ( gelat9e is obta9$4 ,?is sets aga9 to a jelly on cool+1 ev5 if only #a p] c5t4 gelat9 7or less7 be pres5t4 ,! solution is optically active & lvorotatory1 b ) v v>iable specific rotation4 ,"s obs]v]s h ?\ght t ! diff]5t gelat9s h diff]5t specific rotations & may s be di/+ui%$4 ,gelat9s are precipitat$ f solutions by _m reag5ts1 su* z alcohol1 =mal91 qu9one1 metaphosphoric acid1 tann9s1 & _m salt solutions1 e4g4 ^? ( alum9ium1 *romium & iron1 & ( m]curic *loride1 z9c sulphate1 ammonium sulphate1 potassium c>bonate1 acidifi$ br9e4 ,_m ( ^! precipitations h analogies 9 lea!r manufacture 7see ,p>ts ,i4 to ,,iv474 ,! gelat9 peptones or gelatoses are =m$ by hydrolysis ) acids1 alkalies1 f]m5t or ev5 by dige/ion ) hot wat] only4 ,a m detail$ description ( ! prop]ties ( gelat9e is giv5 9 ,"p ,v41 ,section ,i4 ,gelat9e is sometimes call$ glut9 & osse94 ,animals are mu* ! mo/ important s\rce ( prote9s1 especially ( ^? :i* are ( importance 9 indu/rial *emi/ry4 ,prote9s occur 9 ne>ly e "p ( all animals1 & ! protoplasm ( ! liv+ cell is itself a prote94 ,! k]at9s include ! horny tissues ( animals3 ! epid]mis prop]1 ! hair1 horns1 ho(s1 nails1 claws1 ! sebace\s & sudorif]\s gl&s & ducts1 & also ! ela/ic fibres4 ,! gelat9s are obta9$ f ! collag5 ( ! sk9 fibres1 ! bones1 t5dons1 ligam5ts1 c>tilages1 etc4 ,fi% bladd]s yield a /rong gelat94 ,! album9s are obta9$ f ! ova1 blood1 lymph1 muscles & o!r int]nal organs ( animals4 ,! classification ( prote9s h]e9 adopt$ fits 9 well ) ! scope & purpose ( ?is volume4 ,! k]at9s are ( little importance 9 *emical indu/ry1 b are ( imm5se importance 9 me*anical indu/ry1 e4g4 ! wooll5 trade1 :i* is bas$ ^u ! k]at9 compris$ by %eep wool4 ,! collag5 ( ! hide & sk9 fibres is ( va/ importance to *emical indu/ry1 & is ! basis ( ! ext5sive lea!r trades discuss$ 9 ,p>ts ,i4 to ,,iv4 ,! wa/e pieces ( ^! trades1 toge!r ) bones1 =m ! raw mat]ial ( ! manufacture ( gelat9 & glue1 z discuss$ 9 ,"p ,v4 ,! proteids ( animals' fle% & blood1 milk & eggs =m ! s\rce ( ! food prote9s discuss$ 9 ,"p ,,vi4 ,! food prote9s embrace *iefly album9s1 b gelat9s & ev5 k]at9s are involv$ to "s ext5t4 ,,"p ,i4--,,hides ,,= ,,heavy ,,lea!rs ,section ,i4--,,! ,,raw ,,mat]ial ,,( ,,heavy ,,lea!rs ,! t]m hide possesses sev]al %ades ( mean+4 ,9 its wide/ s5se x applies to ! ext]nal cov]+ ( all animals1 & is sometimes us$ d]ogatively = human sk94 ,9 ?is wide s5se1 x is almo/ synonym\s ) ! t]m sk94 ,! t]m hide1 h[ev]1 has a n>r[] mean+1 9 :i* x applies only to ! out] cov]+ ( ! l>g] animals1 & 9 ?is s5se is us$ r 9 contra/ ) ! t]m sk94 ,?us we speak ( horse hides1 c[ hides1 camel hides1 & buffalo hides4 ,x is us$ 9 ?is s5se 9 ! title ( ,"p ,i4 ( ?is volume4 ,z su* hides are f l>ge animals1 ! lea!r :i* is manufactur$ !refrom is ?ick & 9 l>ge pieces1 & is !re=e comm]cially designat$ z heavy lea!r4 ,f ! /&po9t ( *emical indu/ry hides are among/ ! mo/ important ( animal prote9s1 & _! trans=mation into lea!r = boots1 %oes1 belt+1 /raps1 h>ness1 & bags comprises ! heavy lea!r trade1 :i* is "o ( ! l>ge/ & mo/ vital indu/ries ( ! c\ntry4 ,! heavy lea!r trade pr$om9ates ov] o!r bran*es ( lea!r manufacture1 n only because ( ! comp>atively l>ge weight & value ( ! mat]ial h&l$1 b also because ! result+ products h a m ess5tial utility4 ,!re is also a /ill n>r[] use ( ! t]m hide1 9 :i* x applies only to ! dome/icat$ cattle--! ox1 heif]1 bull & c[--:i* use arises f ! fact t ! hides ( ^! are bo? ! l>ge/ & mo/ valuable portion ( ! raw mat]ial ( ! heavy lea!r indu/ries4 ,9 a v n>r[ s5se ! t]m is also sometimes appli$ only to ox hides1 :i* = mo/ heavy lea!rs are ! ideal raw mat]ial4 ,! ,home ,supply ( hides =ms a l>ge important proportion ( ! total raw mat]ial4 ,its importance1 moreov]1 is rapidly increas+1 = ! excell5ce & abundance ( ! home supply det]m9es ! ext5t to :i* x is necess>y = ! indu/ry to pur*ase its raw mat]ial abroad4 ,! position ( our national f9ances makes ?is an increas+ly s]i\s matt]1 = hides are comp>atively a v exp5sive mat]ial4 ,! quality ( our home supply ( hides is v valuable1 be+ det]m9$ by ! conditions ( ! animal's life1 its precise bre$1 & by o!r factors su* z age & sex4 ,! be/ hides are usually obta9$ f animals :i* h be5 mo/ expos$ to extremes ( w9d & cold1 z su* conditions t5d naturally to develop a ?ick] & m compact cov]+4 ,broadly speak+1 ^! include ! hides f cattle ( ! nor!rn & hilly di/ricts4 ,! age ( ! animal :5 kill$ is also a dom9at+ factor4 ,calf sk9s are v s(t1 f9e gra9$ & compact1 ! /ate ( rapid gr[? fav\r+ ! exi/5ce ( mu* int]fibrill> sub/ance4 ,! y\nge/ animals supply suitable raw mat]ial = v>i\s light lea!rs 7see ,"p ,,ii41 ,section ,v471 & are also v suitable = *rome "w 7see ,"p ,,iii41 ,section ,,iii474 ,bull & c[ hides1 on ! o!r h&1 are f animals ^: gr[? is complete1 & %[ 9 consequ5ce a lack ( int]fibrill> sub/ance1 co>se fibres & a r\gh & (t5 wr9kl$ gra94 ,! result+ lea!r t5ds consequ5tly to be spongy1 ?91 empty & non-wat]pro(4 ,int]m$iate betwe5 ^! extremes are ! hides ( ! ox & heif]1 l>ge1 yet ( good texture1 & well suppli$ ) int]fibrill> sub/ance4 ,^! hides are mu* ! be/ = sole lea!r1 a firm1 smoo?-gra9$ & well-fill$ lea!r be+ ne$$4 ,! t]m kip is (t5 appli$ to small hides & to hides f l>ge calves4 ,9 ! trade1 h[ev]1 kip is sometimes us$ also = l>g] hides1 z a v]bal enhancem5t ( value2 j z a man ) a few old f[ls is said to keep *ick5s4 ,c[ hides t5d to be spready1 i4e4 to h a l>ge area p] unit weight1 & are !re=e m suitable = dress+ lea!r4 ,bull hides are ?ick] 9 ! neck & belly1 & ?9n] 9 ! back1 :i* *>act]i/ics r$uce _! comm]cial value4 ,m>ket hides are sold by weight1 & are !re=e classifi$ *iefly by _! weight1 :i* is m>k$ on ne> ! tail by a sy/em ( knife-cuts4 ,! animals are flay$ aft] cutt+ ! hide d[n ! belly & on ! inside ( ! legs4 ,( ! v>i\s bre$s1 ,%or?orns yield a l>ge supply ( useful hides4 ,! "n1 h[ev]1 cov]s a v>iety ( simil> bre$s1 & ! hides !refrom are r v>iable 9 texture & quality4 ,!y t5d to be greasy ow+ to high fe$+4 ,! ,h]e=ds1 obta9$ f ,midl& m>kets1 are g5]ally excell5t hides = sole & h>ness lea!rs4 ,!y give a good yield ( butt pelt1 a /\t & smoo? %\ld]1 & are n (t5 greasy4 ,devons yield a good-textur$ & well-gr[n hide1 b are (t5 badly w>bl$4 ,! ,sussex cross bre$s yield some:at l>g] hides4 ,suffolk ,r$ ,polls1 common 9 ,ea/ ,anglia1 yield a good butt1 & ! c[ hides make good dress+ lea!r4 ,*annel ,isl& cattle yield v ?9 hides1 b ) a f9e undamag$ gra94 ,scot* hides possess des]v$ly ! v highe/ reputation4 ,! climatic conditions fav\r ! production ( a h>dy race ( cattle ) ?ick well-gr[n hides1 yield+ a l>ge proportion ( butt4 ,^! hides are among/ ! be/ obta9able = heavy lea!r1 & p>ticul>ly = sole lea!r4 ,highl&]s1 ,ab]de5 ,angus1 ,gall[ays are typical bre$s1 ) %ort neck1 legs & /raight backs4 ,cross bre$s are also excell5t 7e4g4 ,scot* ,%or?orns74 ,! natural value ( ^! hides is fur!r enhanc$ by ! usual c>e 9 flay+4 ,ayr%ires yield good mil* c[s & consequ5tly yield (t5 a m spready hide4 ,! ,wel% bre$s = r simil> reasons also yield valuable hides4 ,! ,iri% ,k]rys are small b /\t1 & yield hides suitable = light sole lea!r4 ,iri% cross-bre$s1 ,%or?orns1 h a r bad reputation1 & are (t5 ill flay$4 ,all ! v>ieties ( ! home supply are subject to v>i\s defects1 :i* influ5ce s]i\sly _! comm]cial value4 ,"o ( ^! defects is w>ble holes or m>ks1 caus$ by ! ,ox ,w>ble fly 7,hypod]ma bovis74 ,?is is a two-w+$ fly ab\t half an in* long4 ,! l>va ( ?is fly1 ! ,w>ble maggot1 lives & ?rives 9 ! sk9 ( cattle1 & causes a sore & swell+4 ,! life-hi/ory ( ?is insect is /ill 9 dispute1 b x is g5]ally ?\ght t ! eggs are laid 9 ! hair on ! animal's back1 & ! "y l>va eats its way ?r\gh ! hide until j bel[ ! d]mis1 & !re fe$s until mature4 ,x !n creeps out ( ?is w>ble hole1 falls to ! gr\nd1 pupates = a mon?1 aft] :i* ! imago or p]fect insect em]ges f ! *rysalis4 ,hides :i* h be5 ?us infect$ h1 9 consequ5ce1 (t5 q a numb] ( holes ?r\gh ! mo/ valuable "p ( ! hide1 !reby r5d]+ x unsuitable = _m k9ds ( lea!r4 ,ev5 old w>bles :i* h m or less heal$ up are a weakness1 & w>bl$ hides & lea!r fet* a decid$ly l[] price ?an undamag$4 ,ano!r ( ^! defects is bad flay+4 ,cle>ly ! hide %\ld be z little cut z possible1 b _m ( our m>ket hides are abom9ably ga%$ & (t5 cut "r ?r\gh4 ,?is1 ( c\rse1 (t5 r$uces s]i\sly ! comm]cial value ( ! hide4 ,c>eless treatm5t aft] flay+ also results 9 ano!r common defect1 viz4 ta9t4 ,z ! t]m implies1 ! hide is p>tly putrefi$1 sometimes only 9 pat*es1 b sometimes also s ext5sively z to r5d] ! hide q rott5 & q incapable ( be+ made into lea!r at all4 ,hides are ( c\rse putrescible1 & dirt1 blood1 dung & w>m wea!r enc\rage rapid putrefaction4 ,z m>ket hides are usually uncur$1 ?is defect is con/antly appe>+1 & is a cause ( consid]able loss4 ,o!r defects are due to injuries to ! animal be=e x is kill$1 e4g4 br&s1 scrat*es due to h$ges & b>b$ wire1 old scabs1 goad & t> m>ks4 ,all ^! r$uce ! value ( ! hide4 ,all ! defects 9 hides involve a v s]i\s loss to ! community1 & ! "t is rapidly approa*+ :5 _! cont9uance is insuff]able4 ,! loss is n usually v consid]able to any individual1 ?\gh v l>ge 9 ! aggregate4 ,! hide is a m9or "p ( ! bea/'s value1 & a some:at damag$ hide does n involve a v s]i\s loss to ! f>m]4 ,"s ) typical /upidity reg>d a few w>bles z ! sign ( a heal?y bea/4 ,^! defects involve practically no loss to ! hide m]*ant1 tann] or curri]1 z ea* pays less = damag$ mat]ial4 ,! loss falls ^u ! community1 & ! "t is ripe = ! community to insi/ ^u ! elim9ation ( ^! defects4 ,! national res\rces w be = "s ye>s /ra9$ to _! utt]mo/1 & prev5table damage mu/ be consid]$ intol]able4 ,! pr9cipal defects 9 hides are prev5table1 & ought to be prev5t$4 ,! w>ble fly c\ld1 by a unit$ ef=t1 be r5d]$ be=e long practically ext9ct1 a task :i* is facilitat$ by ! fact t x is n migrative4 ,bad flay+ & c>eless treatm5t ( hides result+ 9 putrefaction are /ill m easily rem$i$4 ,! communal slaught]-h\se is long ov]due f ! /&po9t ( public heal?1 & w\ld1 "u conditions ( cleanl9ess & skill$ workman%ip & ov]sight1 also solve ! problem ( ill-flay$ & ta9t$ hides4 ,! "q ( ! raw mat]ial is ( fir/ importance to ! lea!r trades4 ,!re 01 be=e ! comm5cem5t ( ! ,european ,w>1 a /eadily increas+ sc>city ( hides1 caus+ a con/ant increase 9 _! price4 ,?is 0 due p>tly to ! fact t cattle 7 increas+ at a less rate ?an ! population1 p>tly to ! gr[? ( civilization1 & m ext5sive use ( lea!r 9 proportion to ! _w's population1 & p>tly to ! con/ant discov]y ( new uses = lea!r1 e4g4 = motor c>s1 a]onautics1 etc4 ,! "q ( raw mat]ial 0 "u ^! conditions s]i\s en\gh4 ,! t]rific slaught]1 necess>y at ! same "t to provide ! bellig]5ts ) food & ! army ) lea!r1 is b\nd to result 9 a s]i\s crisis = ! lea!r indu/ries2 & 9 conjunction ) ! c\ntry's f9ancial condition1 w make x absolutely necess>y t all c>e %\ld be tak5 ) ! raw mat]ial ( "o ( our mo/ important indu/ries4 ,! f>m] :o pays no he$ to ! w>ble fly1 ! man :o ga%es ! hide 9 flay+ & :o all[s ! hide to putrefy1 are equally crim9al ) ! man :o ?r[s bread cru/s into ! du/b94 ,x is impossible to =esee1 z yet1 any?+ 9 ! nature ( a satisfactory solution to ! problem ( raw mat]ial1 especially 9 respect to heavy lea!r production1 = ! food "q w rank fir/ 9 ! popul> m9d1 & ! e>li] slaught] enjo9$ = ! m economical production ( meat w sc>cely t5d to increase ! proportion ( heavy hides4 ,! ,=eign ,supply ( hides is also ( great importance & value4 ,9 ! case ( import$ hides precautions to prev5t putrefaction are ess5tial1 & "s me?od ( cur+ is always us$4 ,salt+ ! hides is "o ( ! mo/ satisfactory me?ods = tempor>y pres]vation4 ,! action ( salt is hygroscopic1 & mildly antiseptic4 ,moi/ure is )drawn f ! hides1 :i* are !n "u conditions no long] fav\r+ ! gr[? ( bact]ia4 ,well-salt$ hides w keep = ye>s1 especially if q clean4 ,a light salt+ is also useful = a %ort pres]vation1 & is becom+ common 9 hide m>kets & tann]ies dur+ ! summ] & autumn mon?s4 ,salt+ is a me?od us$ ext5sively 9 ! ,unit$ ,/ates4 ,! pack] hides ( ! /ocky>ds are c>efully & sy/ematically salt$ ) ab\t #be p] c5t4 ( salt & /or$ 9 cool cell>s4 ,! hides are s pil$ up 9 heaps1 t br9e easily dra9s away4 ,! great disadvantage ( salt+ is ! s-call$ salt /a9s4 ,^! /a9s h be5 ascrib$ to ! iron 9 ! salt1 to ! iron 9 ! blood1 to calcium sulphate 9 ! salt1 & also to *romog5ic bact]ia1 ^: developm5t is fav\r$ by salt+4 ,! relative importance ( ^! factors is n yet satisfactorily det]m9$1 b cleanl9ess & pure salt t5d to elim9ate ! tr\ble4 ,dry+ ! hides is a less satisfactory cure4 ,! pr9ciple is simil>1 viz4 removal ( moi/ure4 ,dri$ hides are1 h[ev]1 mu* dri] ?an salt$1 & are q h>d & horny1 h5ce ! "n fl9t hides4 ,! hides also lose mu* weight1 a consid]able advantage 9 r$uc+ freight4 ,tropical hides are (t5 fl9t-dry1 & :]e pres]vatives are exp5sive or unprocurable1 x is (t5 ! only practicable me?od ( cure4 ,nev]!less1 ! me?od has _m s]i\s disadvantages1 & is difficult to execute4 ,if dri$ too sl[ly ! hides putrefy p>tially2 if too quickly !y dry on ! outside1 & ! int]ior is left to putrefy4 ,! fact t hides are ( unev5 ?ickness1 & ! climate (t5 hot1 increases ! difficulty1 & (t5 results 9 p>tial de/ruction ( ! fibr\s /ructure ( ! hide4 ,:5 dri$1 moreov]1 ! hides are /ill subject to ! attacks ( insect l>v1 = ! prev5tion ( :i* ! usual spr9kl+ ( naph?al5e or ars5ic is only an imp]fect rem$y4 ,?is me?od ( cure is also a nuisance to ! tann]1 :o has to employ lab\r1 pits & "t 9 attempt+ to re/ore ! hides to _! orig9al condition1 & (t5 loses up to t5 p] c5t4 ( ! goods 9 s do+4 ,dri$ hides are also subject to ! pres5ce ( an?rax4 ,dry ,salt+ ! hides is an excell5t me?od ( cur+4 ,z ! "n implies1 x comb9es me?ods ( dry+ & salt+ :i* are us$ alt]natively4 ,! me?od is us$ ext5sively 9 ,s\? ,am]ica4 ,a modifi$ =m ( x is also us$ = pres]v+ ! ,e4,i4 kips1 :i* are cur$1 h[ev]1 n ) common salt1 b ) e>? conta9+ up to #gj p] c5t4 ( sodium sulphate4 ,dry-salt$ hides are l>gely free f ! defects ( dri$ hides1 b ( c\rse are m tr\ble to ! tann] 9 ! process ( soak+ 7see ,section ,,ii47 ?an ! wet-salt$ goods4 ,freez+ ! hides is n[ a comm]cial process4 ,on ! :ole ! process is satisfactory1 b ! expansion ( wat] aft] freez+ may t5d to damage ! hide fibres4 ,/]iliz+ ! hides has be5 frequ5tly sugge/$1 b no me?od has yet be5 advocat$ :i* does n int]f]e ei!r ) ! tann+ processes or ) ! quality ( ! f9i%$ lea!r4 ,hides f ! ,european ,cont95t1 usually wet salt$ & well flay$1 exhibit mu* ! same v>iable quality z ! home supply1 ^? f highl& di/ricts t5d+ to be ?ick1 yet ev51 well gr[n1 tight textur$ & smoo? gra9$1 :il/ ^? f l[l& regions are less satisfactory4 ,?us hides f ! ,swiss ,alps & ,sc&9avia h rank$ high1 :il/ ! spready ,dut* c[s are typical ( a l[l& hide4 ,9 ! hides :i* once came f ,g]many ! same features appe>4 ,bav>ian highl& hides _h an excell5t reputation1 :il/ ^? f ,b]l91 ,cologne1 etc41 t5d$ to be long 9 %ank & n well gr[n4 ,fr5* hides are (t5 ill flay$1 & ,spani% & ,portuguese are (t5 subject to scrat*es4 ,italian hides h a v good "n1 be+ small b /\t 9 butt4 ,! ,am]ican supply is important4 ,s\? ,am]ica yields an excell5t class ( hide1 salt$ or dry-salt$4 ,!y are f an excell5t bre$ ( animals1 slaught]$ & flay$ ) e c>e1 & effici5tly cur$4 ,a mo/ s]i\s defect 9 ?is class ( hide is ! br&1 :i* is bo? deep & l>ge & 9 ! mo/ valuable "p ( ! hide4 ,"o side1 h[ev]1 is usually unbr&$1 s t ea* hide yields "o good b5d4 ,^! hides1 e4g4 ,frigorifics1 h rec5tly be5 mu* m ext5sively tann$ 9 ,brita9 because ( ! %ortage 9 ! home supply ( m>ket hides caus$ by ! ,european ,w>4 ,s\? ,am]ica also yields good horse hides4 ,nor? ,am]ican hides are usually wet-salt$ 7e4g4 pack] hides74 ,!y are usually good4 ,c5tral ,am]ica yields mo/ly dri$ hides exhibit+ usual defects4 ,! ,asiatic supply comprises ! froz5 ,*9a hides1 :i* are clean b small1 ) flay+ ( unc]ta9 quality4 ,!re are ! buffalo hides f ,asia & ,ea/ ,europe1 :i* are suitable = *eap & sole & /rap lea!r1 & also ! dry-salt$ ,e4,i4 kips1 obta9$ f a small bre$ ( ,indian cattle1 & ext5sively made into upp] lea!r4 ,! ,asiatic hump$ cattle also provide a limit$ supply4 ,! ,african supply is ( increas+ importance4 ,! tropical p>ts yield dri$ hides ( unc]ta9 quality1 b ! m temp]ate p>ts ( ,s\? ,africa yield a gr[+ supply ( good quality4 ,,ref]5ces4 ,! ,manufacture ( ,lea!r 7,b5nett71 pp4 #bg-cg4 ,pr9ciples ( ,lea!r ,manufacture 7,proct]71 pp4 #cc-ef4 ,! ,ox ,w>ble or ,bot ,fly 7,e4 ,orm]od74 ,! ,mak+ ( ,lea!r 7,proct]71 pp4 #b-bb4 ,section ,,ii4--,,! ,,prep>ation ,,( ,,pelt ,be=e hides are tann$ x is necess>y = !m to pass ?r\gh a s]ies ( prep>atory processes4 ,! object ( ^! processes is to obta9 f ! hide ! true hide sub/ance 9 a pure & suitable condition4 ,ea* class ( lea!r has its own appropriate processes1 ! adju/m5t ( :i* l>gely det]m9es ! quality ( ! f9i%$ article4 ,s prom95t is ! influ5ce ( ^! prep>atory me?ods t ! p>adox good lea!r is made be=e tann+ is 9 trade circles almo/ a platitude4 ,^! processes1 sometimes lump$ toge!r "u ! g5]al "n ( ,wetwork1 comprise soak+1 lim+1 beam h\se "w & delim+4 ,^! w be discuss$ 9 turn4 ,! t]m appli$ to ! hide aft] ^! processes1 b be=e tannage1 is pelt4 ,soak+ has = its object ! cleans+ & s(t5+ ( ! hides1 *iefly by means ( wat]4 ,x aims at ! removal ( dirt1 blood1 dung1 & cur+ mat]ials by wa%+4 ,! process is usually simple1 & is mu* ! same = all classes ( lea!r4 ,! ideal to be aim$ at is to re/ore ! hide to its condition :5 x left ! animal's back4 ,cleanl9ess 9 lea!r manufacture is z ess5tial at ! comm5cem5t z any:]e1 = ! hide is 9 its mo/ putrescible /ate4 ,! soluble proteids 7blood1 lymph1 "p ( dung1 etc47 :i* always adh]e to hides enc\rage ! rapid gr[? ( putrefactive bact]ia1 & _c be wa%$ away too soon4 ,dung is (t5 difficult to remove1 be+ cak$ on ! butt end among/ ! hair4 ,soak+ only s(t5s x1 & me*anical removal is usually necess>y4 ,if su* sub/ances are n remov$1 !y g =w>d ) ! goods into ! lime liquors1 caus+ /a9s1 loss ( hide sub/ance1 & c\nt]act+ plump+4 ,! detail$ me?od & "t ( soak+ are det]m9$ ma9ly by ! nature ( ! cure4 ,"o ( ! purposes ( ! soak liquors is to dissolve ! salt us$ 9 cur+ hides & to rehydrate ! hide & make x aga9 s(t & pliable4 ,z a #aj-p]-c5t4 salt solution ex]ts a solv5t effect on hide sub/ance1 x is necess>y soon to *ange ! fir/ soak liquor ( salt$ goods4 ,m>ket hides1 :i* are uncur$1 require ! lea/ soak+1 ! cleans+ effect be+ mo/ ne$$4 ,! hides are ins]t$ into pits 7wat] dykes7 ( wat] = a few h\rs1 & ! wat] *ang$ once or twice4 ,! soak+ %\ld n be prolong$ z ! hides are s putrescible1 & :]e x is cu/om>y to leave ! goods 9 a soak liquor ov]night1 x is advantage\s to add a little slak$ lime to ! wat] be=e ins]t+ ! goods4 ,?is n only s(t5s h>d wat]1 b is mildly antiseptic & plump+1 & =ms a suitable introduction to ! lim+ prop]4 ,ea* pit conta9s a pack ( #cj-ej hides1 accord+ to its capacity1 :i* v>ies 9 diff]5t tann]ies f #ajjj to #bjjj gallons4 ,ta9t$ goods1 :i* are indicat$ by a *>act]i/ic :ite col\r on ! fle% side & by loose hair1 ne$ a prelim9>y wa%+ ei!r 9 a drum1 tumbl] or 9 a paddle4 ,?is ensures a rapid *ange ( liquor & ! removal ( mo/ ( ! putrefactive ag5cies4 ,bad cases may ne$ ! application ( antiseptics1 su* z imm]sion 9 #j4a p] c5t4 c>bolic acid2 b if possible ^! %\ld be avoid$1 z !y l5g!n ! "t requir$ = lim+4 ,aft] drumm+ or paddl+1 ta9t$ goods %\ld be plac$ directly into a lime liquor4 ,salt$ hides ne$ v simil> treatm5t to uncur$ hides1 b ! soak+ is long]1 because ( ! dehydration caus$ by salt+4 ,h5ce !y receive also a great] numb] ( *anges ( wat]1 ?ree or f\r usually1 b (t5 m4 ,z mu* loose salt z possible %\ld be %ak5 f ! hides be=e ins]tion into any liquor4 ,! employm5t ( drum or paddle be=e pit soak+ is extremely useful to effect ! rapid removal ( sup]ficial salt1 & is also useful aft] pit soak+ to remove ! la/ traces4 ,dri$ & dry-salt$ goods ne$ a soak+ /ill m prolong$1 up to "o week if wat] alone be us$4 ,) ! assi/ance ( cau/ic soda1 h[ev]1 ! process c be %ort5$ to ab\t two days4 ,! fir/ soak liquor %\ld consi/ ( a #j4a p] c5t4 solution ( cau/ic soda1 & aft] ! goods h be5 ins]t$ tw5ty-f\r h\rs1 !y w be mat]ially improv$ by a few h\rs' drumm+ or paddl+4 ,ano!r cau/ic soda soak w complete ! process4 ,sodium sulphide cry/als may replace cau/ic soda1 b ab\t ?ree times ! weight w be ne$$4 ,c>bonate ( soda & cau/ic lime also are a conv5i5t comm]cial sub/itute = cau/ic soda4 ,= #aj lbs4 cau/ic soda1 use #cf lbs4 c>bonate & #g lbs4 lime4 ,extra lime %\ld be add$ 9 all cases :5 ! wat] is h>d4 ,acid liquors w also s(t5 dri$ & dry-salt$ goods1 b su* processes d n fit 9 s well ) ! subsequ5t lim+4 ,! use ( putrid soaks & /ocks may be n[ consid]$ out ( date4 ,lim+ foll[s soak+1 & consi/s ess5tially 9 imm]s+ ! hides = #g-aj days 9 milk ( lime4 ,! *ief object 9 view is to loos5 ! hair & prep>e = its me*anical removal4 ,lim+ takes place 9 pits1 ! tops ( :i* are level ) ! limey>d floor4 ,! lime is slak$ completely & mix$ well ) wat] 9 ! pit1 be+ p>ticul>ly well plung$ j be=e ! ins]tion ( a pack ( goods4 ,saturat$ limewat] is only a #j4ac-p]-c5t4 solution4 ,! goods are occasionally h&l$ i4e4 haul$ out ( ! pit & re9s]t$ aft] plung+ 7haul+ & sett+74 ,?is is necess>y to keep ! liquor saturat$ ) lime4 ,! hides are ins]t$ "o by "o1 ea* be+ pok$ d[n to ensure its contact ) ! liquor4 ,! goods are inv>iably imm]s$ fir/ 9 a previ\sly us$ lime liquor4 ,mo/ tann]ies n[ c>ry ?is out 9 a sy/ematic way1 s z to ensure regul>ity 9 ! process4 ,z ! goods are l>ge & heavy x is less labori\s to c>ry out ! :ole process 9 "o pit4 ,9 ?is "o-pit sy/em ! goods are ins]t$ = 7say7 f\r days 9 an old us$ lime liquor1 ) occasional h&l+2 ?is liquor is !n run to ! dra9 & a new liquor made up 9 ! same pit1 into :i* ! goods are ins]t$ = 7say7 five days4 ,!y are !n haul$ & s5t to ! unhair]s4 ,ea* pack ?us gets two liquors1 old & new4 ,a bett] me?od is ! ?ree-pit sy/em4 ,9 ?is case ea* pack receives ?ree liquors & has 7say7 ?ree days 9 ea*1 fir/ an old lime1 !n a m$ium lime1 & f9ally a new lime4 ,?is sy/em ensures a great] regul>ity ( treatm5t1 & is des]v$ly ! mo/ popul> me?od = lim+ hides = sole lea!r4 ,aft] be+ us$ once z a new lime1 a liquor !n becomes a m$ium lime1 & aft] be+ ?us us$ becomes ! old lime :i* receives ! gre5 hides f ! soaks4 ,! sy/em involves ! goods be+ %ift$ twice to ano!r pit1 :i* is m labori\s ?an re9s]tion into ! old pit1 b if ! limey>d be arrang$ 9 sets or r\nds ( ?ree pits1 ! %ift is usually only to ! adjac5t pit4 ,"o special advantage ( ?is sy/em is t ! top hides 9 "o pit become ! bottom hides 9 ! next pit1 & vice v]s4 ,r\nds ( m ?an ?ree pits are sometimes us$4 ,_m factories h n[ adopt$ sy/ems 9 :i* !re is no h&l+ at all4 ,! hides are susp5d$ 9 lime liquors :i* are agitat$ by me*anical contrivances 7e4g4 ,til/on-,melb\rne process71 or by jets ( compress$ air 7e4g4 ,=s>e process74 ,! goods are soak$ & lim$ mell[ to fre% by *ang+ ! liquors by means ( pumps1 air ejectors1 etc4 ,?us ! hides ne$ no lab\r f fir/ be+ ins]t$ until drawn = depilation4 ,9 lim+1 ! :ole ( ! epid]mis z well z ! hair is loos5$1 & is subsequ5tly remov$ 9 depilation4 ,! corium or true hide sub/ance becomes mu* m swoll5 by imbibation ( wat]1 & :5 tak5 out ( ! new lime is plump$ to v firm jelly4 ,?is plump+ is a matt] ( prime importance to ! tann]4 ,! co>s] fibres are !reby split up into ! f9] con/itu5t fibrils1 :i* fact assi/s v mat]ially 9 obta9+ a quick & complete tannage1 good weight1 & a firm lea!r4 ,dur+ ! lim+1 ! natural grease ( ! hide is saponifi$ or emulsifi$1 :i* prep>es = its removal 9 scudd+4 ,lim+ is ?us a complex process3 ! hair is loos5$1 ! hide is plump$1 & ! grease is kill$4 ,all ^! results may be ha/5$ by ! use ( o!r alkalies 9 addition1 & mo/ heavy lea!r y>ds assi/ ! lim+ by add+ also sodium sulphide or cau/ic soda or bo?4 ,sodium sulphide is a p[]ful depilatant1 & w alone unhair hides easily 9 /rong solutions ev5 9 a few h\rs4 ,z 9 solution x =ms cau/ic soda by hydrolysis1 x possesses also ! p[]ful plump+ & saponify+ p[]s *>act]i/ic ( ! latt]4 ,! addition ( ars5ic sulphide 7,z#b,s#b7 7realg>7 to ! lime :5 slak+ causes ! pres5ce ( calcium sulphydrate 9 ! lime liquors ?us made4 ,?is is also a p[]ful depilatant1 b n mu* us$ = heavy lea!r4 ,! function ( ! lime 9 depilat+ is complex & has occasion$ mu* discussion4 ,its ma9 purpose1 h[ev]1 is t ( a p>tial antiseptic4 ,:5 hides putrefy1 "o ( ! fir/ results is t ! hair is loos5$4 ,9 ,am]ica depilation by sweat+ is c>ri$ out comm]cially by su* a mild putrefaction1 ! lime liquor p]mits a simil> f]m5tation at a sl[] rate1 & all tann]y lime liquors are sw>m+ ) putrefactive bact]ia4 ,lim+ is ?us a saf] me?od ?an sweat+1 :i* may be easily c>ri$ too f>4 ,v>i\s work]s h isolat$ specific organisms--,wood a bacillus1 ,s*mitz-,dumont a /reptococcus--b x seems highly probable t ! limey>d bact]ia are j ! common organisms ( putrefaction sort$ out or select$ by ! exact nature ( ! liquor & ! me?od ( work+ ! limes4 ,_m putrefactive bact]ia are v adaptable & c\ld easily accommodate !mselves 9 ?is way4 ,x is kn[n t ! exact nature ( ! culture m$ium has a great influ5ce on ! rate ( developm5t ( su* organisms1 & :i* p>ticul> species ?rive & obta9 pr$om9ance 9 any limey>d w dep5d ^u ! am\nt & nature ( ! dissolv$ organic matt] available z food1 & ^u ! exact alkal9ity & ! conc5tration ( o!r app>5tly in]t sub/ances1 su* z common salt & sodium1 calcium & ars5ic salts4 ,h5ce no two lime liquors op]ate alike1 & approximate regul>ity is only assur$ by sy/ematic me?od4 ,9 h&l+ & %ift+1 ! organisms are subject$ to fur!r selection1 & ! mo/ adaptable survive4 ,x is probable t diff]5t species may act symbiotically4 ,! depilat+ organisms ( lime liquors are probably mo/ly anrobes1 b "s may be anrobic by adaptation4 ,x is probable t robic f]m5ts comm5ce ! depilation1 b ?is w be done be=e ! goods are put into "w1 or at any rate be=e !y rea* ! limes4 ,m /rictly1 x is ! enzymes secret$ by bact]ia :i* are directly responsible = ! hydrolytic "w2 ^! enzymes are *iefly proteolytic 7proteid splitt+71 b ! lipolytic 7fat splitt+7 enzymes h also a place4 ,! lime1 h[ev]1 n only limits & selects ! c\rse ( ! putrefaction1 b also af=ds m positive assi/ance4 ,lime plays its own hydrolytic "p & assi/s ! depilation by purely *emical action4 ,lime w unhair )\t ! assi/ance ( bact]ia1 b its action is sl[ & =ms a m9or "p ( ! op]ation 9 ! av]age limey>d4 ,?is action is due *iefly to its progressive =mation ( calcium sulphydrate f ! cy/9e gr\p ( ! s(t] k]at9s4 ,lime also plays an ess5tial "p 9 assi/+ ! putrefactive f]m5tation4 ,x s(t5s ! k]at9s & ?us assi/s ! bact]ial attack1 x hydrolyzes o!r proteids & provides ! bact]ia ) food 9 solution1 ! calcium ion increases ! proteolytic action ( c]ta9 enzymes1 & f9ally ! app>5tly in]t excess ( undissolv$ lime has an accel]at+ effect on ! bact]ial activity4 ,9 ! av]age limey>d ^! v>i\s functions are inextricably mix$ up1 & x is impossible to assign any def9ite proportion ( ! total depilatory effect to any ( ! factors at "w4 ,lime alone w unhair1 bact]ia alone w unhair1 & sulphides w also unhair )\t lime or bact]ia1 b 9 ! limey>d all ?ree ag5cies are at "w4 ,putrefactive f]m5tation1 h[ev]1 obta9s a good />t4 robic f]m5tation comm5ces ) ! slaught] ( ! animal1 & ! anrobic organisms soon comm5ce _! "p1 & are at "w 9 ! hide h\se & soaks4 ,on ent]+ ! limes1 ! purely *emical hydrolytic action ( lime is add$ to t ( ! bact]ial enzymes z well z ! action ( lime z bact]ial assi/ant1 & ! ?ree cont9ue to op]ate side by side4 ,ea* gives rise to ! =mation ( calcium sulphydrate1 ^: own special solv5t effect is sup]add$4 ,if sulphydrates be delib]ately add$ to ! liquors !re is yet ano!r factor assi/+4 ,speak+ broadly1 ! bact]ial enzymes h _! maximum activity 9 ! old limes1 & ! *emical action ( sulphydrate =m$ f ! k]at9 cy/9e is also at a maximum 9 ^! liquors4 ,! *emical action ( add$ sulphide1 & ! simple hydrolytic action ( calcium hydrate h _! maximum activity 9 ! new limes4 ,mo/ obs]v]s w\ld agree t 9 practice ! bact]ia %\ld] ! great] "p ( ! "w4 ,f ! limey>d is tak5 ab\t ! only wa/e bye-products ( ! tann]y1 viz4 ! residues f ! soak & lime pits4 ,^! consi/ ma9ly ( lime & *alk1 ) "s hair & dung1 & possibly a little sulphide4 ,! sludge possesses "s value z a manure1 especially if f ! soak pits on acc\nt ( ! great] nitrog5 cont5t4 7,"p ,,vi41 ,section ,i47 ,! ,beam ,h\se ,"w consi/s 9 ! me*anical removal ( ^? p>ts ( ! hide n want$ = lea!r manufacture4 ,unhair+ removes ! hair & ! epid]mis made loose 9 lim+4 ,! hides are plac$ ov] a slop+ beam ) a convex surface1 & ! hair scrap$ (f ) a blunt concave & d\ble-h&l$ knife4 ,! hides are !n ?r[n into a pit ( wat]4 ,! hair is c>efully collect$1 wa%$ well ) wat]1 pref]ably c5trifug$1 & !n dri$ out by a curr5t ( w>m air4 ,x =ms a valuable bye-product4 ,:ite hair is usually kept sep>ate & fet*es a high] price4 ,fle%+ is ! next process4 ,! hides are aga9 plac$ ov] a beam1 ) ! fle% side 7i4e4 ! side ne>e/ ! fle%7 upp]mo/4 ,skill$ workm5 !n cut (f1 ) a %>p convex knife1 ! fat1 fle% & connective tissue left 9 flay+4 ,r\nd+ is usually ! next process4 ,! unhair$ & fle%$ hide is spread out flat & cut up into butt1 %\ld] & a pair ( bellies4 ,^! p>ts h diff]5t comm]cial values1 & may aft]w>ds be tann$ by diff]5t me?ods = v diff]5t purposes--= dress+ lea!r1 & sometimes ev5 = sole lea!r4 ,scudd+ is ! la/ piece ( beam "w4 ,! fle%$ hides 7:e!r r\nd$ or n7 are wa%$1 or at lea/ r9s$1 ) wat]1 & aga9 plac$ on ! beam gra9 side up4 ,!y are !n scrap$ ) a r %>p concave knife1 to remove scud1 :i* consi/s ( hair roots & %ea?s1 lime soaps1 fat1 pigm5t & o!r dirt4 ,%ort hair is %av$ (f by a v %>p h& knife4 ,! beam "w dem&s a c]ta9 am\nt ( skill f ! workm51 especially f ! fle%]1 ^: %>p knife may prove v wa/eful 9 incompet5t h&s4 ,h& lab\r 0 sl[ly b surely be+ replac$ by ma*9]y be=e ! w>1 & w>-"t conditions h greatly accel]at$ ! rate ( transition4 ,beam h\se ma*9]y is rapidly becom+ univ]sal4 ,! ma*9es are cumbr\s & exp5sive 9 co/ & 9 p[]1 b ma*9e "w is quick]1 less labori\s1 & ne$s mu* few] workm54 ,_m types ( ma*9e h be5 sugge/$1 b ! mo/ useful are ^? 9 :i* ! hides pass ov] roll]s & are simultane\sly act$ ^u by a rapidly revolv+ cyl9drical knife ) spiral blades1 "o half be+ a left-h&$ & ! o!r a "r-h&$ spiral1 s t ! hide is scrap$ outw>ds z well z 9 ! direction ( motion4 ,! "p ( ! hide be+ act$ ^u re/s on a pneumatic roll]4 ,by *ang+ ! type ( spiral knife cyl9d] ! ma*9e w unhair1 fle% or scud4 ,delim+ is a g5]al "n cov]+ a numb] ( simil> op]ations ^: prim>y object is ! neutralization & removal ( ! cau/ic lime & soda 9 ! plump$ pelt1 or at any rate on ! surface ( ! hide4 ,?is is a prep>ation = ! tan liquors4 ,all ! tann9s & _m associat$ sub/ances d>k5 rapidly ) oxidation :5 9 alkal9e solution1 s t to place ! fully lim$ hide 9 a tan liquor w\ld give a d>k-col\r$ lea!r4 ,a %ort ins]tion 9 a ba? ( weak acid w\ld secure ! elim9ation ( surface lime & ! disappe>ance ( ?is difficulty1 b !re are o!r purposes 9 delim+4 ,! m completely lime is remov$ ! m ! plump$ pelt falls into a s(t1 pliable1 unswoll5 & relax$ condition1 & ?is *ange assi/s v mat]ially 9 ! production ( a s(t dress+ lea!r1 suitable = boot upp]s1 bags1 etc4 ,= su* lea!rs1 !re=e1 ! delim+ mu/ be mu* m complete ?an = sole lea!r1 9 :i* ! object is to obta9 a firm & plump lea!r4 ,9 ! case ( ! s(t] dress+ lea!rs1 exp]i5ce indicates ! advisability ( all[+ "s fur!r bact]ial action on ! int]fibrill> sub/ance 9 ord] to produce ! requisite pliability & s(tness4 ,?is is secur$ by bat+ ! hides4 ,?is process consi/s 9 imm]s+ ! goods into a cold f]m5t+ infusion ( h5 or pigeon dung4 ,! infusion is made 9 a special tub or pit ) w>m wat] & all[$ to /& = a day or two until ! f]m5tation has comm5c$1 & !n run into ! bat+ pit ?r\gh a co>se filt] su* z sack+4 ,! hides are imm]s$ = "s days1 b are h&l$ frequ5tly to ensure an ev5 effect4 ,! bate is always slightly alkal9e4 ,! cau/ic alkal9ity increases rapidly at fir/ ow+ to ! diffusion ( cau/ic lime1 !n at a sl[] rate1 aft]w>ds sl[ly decl9+4 ,?is is expla9$ by ! production ( organic acids1 & _! salts ) weak bases f ! dung infusion by ! action ( bact]ia4 ,! total alkal9ity ( ! bate liquor increases rapidly at fir/ ow+ to ! diffusion ( lime & its lib]ation ( organic bases1 !n v sl[ly1 b t[>ds ! end ( ! op]ation ! total alkal9ity increases v rapidly inde$1 ow+ probably to ! comm5cem5t ( a viol5t anrobic f]m5tation :i* produces ammonia & o!r organic bases1 & :i* h]alds ! approa* ( a putrefactive action1 :i* if all[$ to cont9ue = ev5 a %ort "t w ru9 ! hides4 ,bat+ is consequ5tly a risky process1 & ne$s exp]i5c$ ov]sight4 ,= goods :i* ne$ only a mild bat+1 !re is ! alt]native ( giv+ a long] lim+ 9 old] limes4 ,?is ( c\rse involves m bact]ial hydrolysis1 & p]haps does x 9 a saf]1 m economical & c]ta9ly 9 a less (f5sive mann]4 ,bat+ is (t5 foll[$ by a fur!r delim+ by acids4 ,boric1 lactic1 acetic1 =mic & butyric acids are all us$1 & ) c>e ev5 hydro*loric & sulphuric acids may be employ$4 ,innum]able artificial bates h be5 put on ! m>ket1 b mo/ are m]ely weak acids1 acid salts or salts ( /rong acids ) weak bases4 ,an ,am]ican bact]ial bate consi/s ( a lactic f]m5tation ( glucose 9 ! pres5ce ( glue4 ,closely simil> to bat+ is pu]+1 inve/igat$ by ,wood4 ,dr5*+ is ano!r f]m5tive delim+ process4 ,9 ?is ! goods are ins]t$ into an infusion ( bran4 ,?is is made by scald+ ! bran ) hot wat]1 & all[+ x to /& until x is ab\t #gj-ij ,f4 ,! infusion is !n inoculat$ ) a few gallons ( old dr5* liquor1 & ! goods are imm]s$4 ,?is f]m5tation has be5 exam9$ c>efully by ,j4 ,t4 ,wood4 ,fir/ ! enzyme c]eal9 conv]ts bran />* into glucose1 :i* is !n f]m5t$ by ! dr5* bact]ia ) ! production ( lactic acid1 "s acetic acid & small am\nts ( =mic & butyric acids4 ,! butyric f]m5tation is liable to become too viol5t4 ,^! acids1 z !y are =m$1 neutralize ! lime 9 ! hides & plump ! pelt slightly4 ,v>i\s gases 7c>bon dioxide1 hydrog51 nitrog51 me?ane & sulphurett$ hydrog57 are involv$1 & ! proportion produc$ 9 ! pelt itself has a peculi> op5+ effect on ! hide fibres4 ,! activity ( ! dr5* c be decreas$ by dilution & by us+ a less />*y bran1 & c be increas$ by add+ pea meal or rye meal4 ,dr5*+ usually foll[s bat+4 ,scudd+ sometimes foll[s delim+4 ,! !ory ( ! volume & ela/icity *anges ( pelt dur+ prep>ation w be bett] und]/ood aft] consid]+ ! behavi\r ( gelat9e gels4 ,! det]m9+ factors are ! nett *>ge ( hydroxyl ions on ! disp]se phase1 result+ f ionic adsorptions1 & ! lyotrope influ5ce ( dissolv$ sub/ances on ! cont9u\s phase4 ,9 s(t5+ dri$ hides ! swell+ may be due to ei!r influ5ce1 b ! latt] t5ds to loss ( hide sub/ance & ! production ( s(t lea!r4 ,9 lim+1 ! nett adsorption ( hydroxyl ions is ! pr9cipal factor1 b ! lyotrope influ5ce ( ! alkali cations & ( ! impurities is important4 ,plump pelts are ^? 9 :i* ! conta9$ wat] is 9 a relatively great] av]age /ate ( compression4 ,few sub/ances c assi/ plump+1 b _m c h9d] x4 ,9 plump+ all lyotrope influ5ce is objectionable1 & %>p 7pure7 alkali solutions are requir$4 ,mell[ limes r$uce ela/icity & plumpness by lyotrope influ5ce4 ,9 bat+ & pu]+ ! ess5tial *ange is t be=e ! process ! swell+ is due *iefly to adsorption ( hydroxyl ions1 :]eas aft]w>ds x is due *iefly to a composite lyotrope influ5ce4 ,,ref]5ces4 ,pr9ciples ( ,lea!r ,manufacture1 ,proct]1 pp4 #ajh-ahd4 ,! ,manufacture ( ,lea!r1 ,b5nett1 pp4 #di-aac4 ,lyotrope ,influ5ce & ,adsorption 9 ! ,!ory ( ,wetwork1 ,b5nett1 ,j4,s4,l4,t4,c41 #aibj1 pp4 #ge-hf4 ,analytical ,exam9ation ( ,bat+1 ,b5nett1 ,lea!r ,trades ,review1 #aiaa1 p4 #igb1 & #aiab1 p4 #bh4 ,! ,bat+1 ,pu]+ & ,dr5*+ ( ,sk9s1 by ,j4 ,t4 ,wood4 ,,section ,,iii4--,,vegetable ,,tannage ,all tannages h = _! object ! conv]sion ( ! readily putrescible hide tissue ( ! corium 7! pelt7 into an imputrescible1 insoluble & p]man5t mat]ial call$ lea!r :i*1 possess+ consid]able /r5g? & pliability1 is capable ( application to a v>iety ( useful purposes4 ,! conditions necess>y = ?is trans=mation h be5 cle>ly /at$ by ,proct]4#a ,= ! production ( lea!r f pelt x is n only necess>y to dry ! fibres 9 a sep>ate & non-adh]5t condition1 b s to coat !m or alt] _! *emical "* t !y are no long] capable ( be+ swell$ or r5d]$ /icky by wat]4 ,:atev] sub/ance w secure ?is p]man5t dehydration ( ! hide fibres 9 a sep>ate condition is call$ a tann+ mat]ial4 ,! *ange f pelt to lea!r is kn[n z tannage1 ! process is t]m$ tann+1 & ^? :o und]take x are tann]s4 ,footnote #a3 ,pr9ciples ( ,lea!r ,manufacture1 p4 #ahd4 ,9 vegetable tannage ! tann+ mat]ials are ( vegetable orig91 & conta9 a gr\p ( organic comp\nds call$ tann9s :i* are extract$ by ! infusion ( ^! mat]ials ) wat]4 ,pelt1 :5 imm]s$ 9 ^! infusions1 is conv]t$ into lea!r1 r sl[ly2 b a gelat9 solution gives an imm$iate precipitate ( amorph\s lea!r1 ev5 if ! tann9 infusion be exce$+ly dilute4 ,! tann9s are aromatic comp\nds ( ph5olic "*1 & conta9 c>bon1 hydrog5 & oxyg5 only1 b our k ( _! *emical con/itution is exce$+ly small ow+ to _! in/ability & colloid nature1 :i* make impossible _! prep>ation 9 a pure /ate4 ,!y are all1 h[ev]1 d]iv$ f ei!r cate*ol or pyrogallol1 & yield ^! sub/ances if c>efully heat$ to ab\t #bjj ,c4 ,! tann9s are soluble 9 wat]1 alcohol1 acetone1 e?yl acetate & acetic acid1 b insoluble 9 b5z5e1 *lor(orm1 c>bon disulphide1 petroleum e!r1 dilute sulphuric acid & pure e?yl e!r4 ,! aque\s infusions ( ! tann9s are 9 reality colloidal solutions2 i4e4 het]og5e\s sy/ems ( two phases4 ,! sy/ems are lyophile1 or1 m p>ticul>ly1 hydrophile1 i4e4 !re is an aff9ity betwe5 ! two phases4 ,z usual ) lyophile sy/ems ! two phases may be consid]$ z bo? liquid1 & an aque\s infusion ( tann9 =ms an emulsoid sol1 :i* !re=e is subject to ! ph5om5on ( adsorption4 ,! tann9s are all precipitat$ by solutions ( basic lead acetate & copp] acetate1 & _m ( !m ) v>y+ complet5ess by solutions ( _m o!r metallic salts & hydroxides1 ( basic dye/uffs & ( alkaloids4 ,!y give d>k colorations ) f]ric salts4 ,! tann9s are widely di/ribut$ 9 plant-life1 b only 9 a limit$ numb] ( cases d ! plants conta9 suffici5t tann9 to r5d] !m ( comm]cial importance4 ,tann9 is f\nd 9 all p>ts ( plants1 b usually 9 greate/ am\nt 9 ! b>k or fruit4 ,! tann9s are classifi$ into pyrogallol tans & cate*ol tans1 accord+ to ! p>5t ph5ol4 ,?is classification is confirm$ by _! *emical1 analytical & practical behavi\r1 & ! vegetable tann+ mat]ials may be classifi$ into ! same two gr\ps1 =1 al?\gh ev5 ! same plant conta9s bo? pyrogallol & cate*ol tans1 x is usual to f9d 9 any "o "p ( ! plant t "o gr\p is pr$om9ant4 ,pyrogallol tans1 :i* are (t5e/ obta9$ f fruit or leaves1 conta9 usually ab\t #eb p] c5t4 ( c>bon4 ,us$ alone !y produce a r s(t & por\s lea!r4 ,associat$ ) !m--9 _m cases probably z decomposition products--are c]ta9 o!r sub/ances ( well-kn[n prop]ties & con/itution4 ,^! sub/ances are n only typical ( ! gr\p1 b also =m ! mo/ valuable clue to ! *emical con/itution ( ! gr\p & ! key to _! *emical behavi\r4 ,"o ( ^! sub/ances is gallic acid 7#c3d3e trihydroxy-b5zoic acid ,c#f;,h#b7,,oh7#c;,,cooh71 :i* possesses prop]ties v simil> to ! tann9s1 b does n precipitate gelat9 & w n itself make lea!r4 ,ano!r ( ^! sub/ances is ellagic acid ,c#ad;,h#f,o#h1 a d\ble lactone ( a hexa-hydroxy-diph5yldic>boxylic acid4 ,?is is deposit$ z an insoluble yell[ p[d] f infusions ( _m pyrogallol tans1 by boil+ ) dilute acids only1 all[+ !m to /& = a few days4 ,9 practice ! deposit is f\nd z mud at ! bottom ( ! tan pits1 & also ^u ! lea!r1 to :i* x /rongly adh]es4 ,x is te*nically kn[n z bloom4 ,x is insoluble 9 acids & cold alcohol1 b soluble 9 alkalies4 ,x is a feeble dye-/uff4 ,! pyrogallol tans yield v diff]5t am\nts ( bloom4 ,o!r associat$ sub/ances are ! sug>s4 ,9 practice ^! sug>s f]m5t to lactic1 acetic1 & o!r acids :i* cause s\r liquors4 ,su* liquors plump ! hides & t5d to give firm1 ?ick lea!r4 ,^! acids also probably cause increase ( adsorption ( tann9 by ! hide & !re=e assi/ 9 giv+ good weight4 ,solutions ( pyrogallol tans all give a blue-black col\r ) a dilute solution ( f]ric alum4 ,if a solution ( sodium ars5ate be add$ to an infusion ( pyrogallol tan dilut$ until no long] di/9ctly col\r$1 & ! mixture all[$ to /& = ab\t two h\rs1 a gre5 col\r develops at ! surface ( ! liquid4 ,! reaction is due to gallic acid or a simil> gr\p+1 & is1 9 ! au?or's exp]i5ce1 ! mo/ satisfactory qualitative te/ = ! gr\p4 ,ano!r te/ is to mix equal volumes ( a #j4d p] c5t4 infusion ( tan & a #aj p] c5t4 solution ( sodium bisulphite2 a few drops ( #aj p] c5t4 potassium *romate are add$1 & ei!r a transi5t blood-r$ col\r or a m p]man5t deep purple is obta9$4 ,! =m] col\r is due to gallic acid4 ,if a tann9 infusion be l>gely dilut$ ) h>d wat] & a little iod9e solution add$1 ! pyrogallol tans yield ei!r a purple-r$ or a d>k blue col\r1 ! =m] be+ a reaction ( gallic acid4 ,pyrogallol tans yield no precipitate ) brom9e wat]4 ,!y yield a yell[ or br[n col\r :5 "o drop ( infusion is add$ to conc5trat$ sulphuric acid4 ,myrabolans is "o ( ! mo/ important ( ! pyrogallol tann+ mat]ials4 ,x is a "n giv5 to ! dri$ fruit ( ,t]m9alia *ebula & o!r species ( ,indian trees4 ,! nuts resemble an elongat$ walnut4 ,!y are dri$ & export$ f _m p>ts ( ,india to all p>ts ( ! _w1 b l>gely to ?is c\ntry4 ,! v>ieties ( comm]ce are nam$ accord+ to orig9 & quality3 ?us we h ,j#a's1 i4e4 ,jubbelpore1 ,no4 #a quality1 ,r#a's 7,rajpore1 ,no4 #a71 ,b#a's 7,bhimley1 ,no4 #a71 etc4 ,! little diff]5ce 9 tann9 /r5g? 7ab\t #cb p] c5t47 9 ^! v>ieties is usually comp5sat$ by correspond+ diff]5ces 9 price4 ,! quality ( myrabolans _c be safely judg$ by appe>ance4 ,mu* bloom is deposit$ by myrabolans liquors1 especially by ,j's4 ,myrabolans are among/ ! mo/ sug>y ( tann+ mat]ials1 conta9+ up to #e-a_/b p] c5t4 ,x is !re=e "o ( ! be/ mat]ials = giv+ a plump lea!r4 ,broadly speak+1 ^? v>ieties :i* yield mo/ sug> yield lea/ bloom1 & vice v]s4 ,myrabolans tann9 has a small aff9ity = hide sub/ance & p5etrates ! hide v sl[ly4 ,x gives a mell[ tannage1 b a bright1 good col\r1 :i* *>act]i/ics are imp>t$ to ! lea!r :5 ! mat]ial is bl5d$ ) o!r mat]ials conta9+ d>k or a/r+5t tann9s4 ,:5 us$ alone x yields a r spongy lea!r1 & x is n consid]$ a good weight-giv+ mat]ial1 ?\gh its acid-produc+ p[]s are v helpful to o!r m a/r+5t tann9s4 ,valonia has be5 ! o!r /aple tann+ mat]ial ( ! heavy lea!r trade4 ,x is ! acorn cup ( oaks common 9 ,asia ,m9or & ,greece1 *iefly ! ,turki% oak 7,qu]cus gilops74 ,! fruit is ga!r$ :5 ripe & dri$ 9 lay]s ( ab\t "o foot deep until ! acorn drops out1 ,smyrna is ! great export c5tre4 ,greek valonia is obta9$ f _m p>ts ( ! ,ar*ipelago & ma9l&4 ,x is ga!r$ 9 a m immature condition & includes ! acorn4 ,x is consid]$ slightly inf]ior 9 /r5g? & col\r to ! ,smyrna valonia4 ,! ext]ior ( ! acorn cup is cov]$ ) r scaly protub]ances kn[n z be>d1 :i* conta9s usually ab\t #dj p] c5t4 ( tann94 ,! cup alone conta9s usually ab\t #be p] c5t4 tann91 & ! :ole ab\t #cj p] c5t4 ,! valonia tann9 has be5 ?\ght to conta9 two *emical individuals1 only "o ( :i* produces bloom4 ,p>k] & ,lea*#b f\nd t ! tann9 ( ! cup produces m bloom ?an t ( ! be>d1 & t ,smyrna valonia yields m bloom ?an ,greek4 ,! m bloom is deposit$1 ! less acid w be produc$4 ,"u all conditions ! yield ( bloom is l>ge1 & its deposition 9 & on ! lea!r assi/s mat]ially 9 giv+ ! weight & wat]-resi/+ p[]s associat$ ) sole lea!r :i* has be5 l>gely tann$ ) valonia4 ,! valonia tann9s h only a mod]ate aff9ity = hide1 :i*1 l myrabolans1 !y p5etrate v sl[ly4 ,:5 us$ alone ! lea!r is less yell[ ?an t f myrabolans1 & is also dull]4 ,aft] mo/ ( its bloom has be5 deposit$ valonia makes a v suitable tannage = dress+ lea!r1 & 9 conjunction ) gambi] has be5 l>gely ?us us$4 ,s9ce ! outbreak ( w> ! ,turki% product has1 ( c\rse1 n be5 available = importation4 ,footnote #b3 ,j4,s4,s4,i41 #aijc1 #aahd4 ,suma*#c is ! o!r pyrogallol tan ( comm]cial importance4 ,x consi/s ( ! leaves & small twigs ( ! ,sicilian suma* 7,rhus cori>ia7 cultivat$ 9 ,italy ext5sively = export4 ,! leaves are h& pick$1 dri$ & (t5 gr\nd to p[d]4 ,x conta9s #bf-bh p] c5t4 ( a tann9 :i* yields little or no bloom1 b mu* gallic acid4 ,x is an un/able tann91 & its infusion rapidly f]m5ts4 ,suma* is a v valuable tann+ mat]ial1 & :5 us$ alone gives an exce$+ly durable lea!r ( excell5t light col\r4 ,x gives a s(t mell[ tannage1 & is !re=e mo/ suitable = light lea!r tann+1 & is ext5sively us$ = ?is purpose4 ,x is us$1 nev]!less1 9 l>ge quantities by ! heavy lea!r tann]s = f9i%+ purposes1 = x conta9s "s organic r$uc+ ag5t :i* ex]ts a p[]ful blea*+ action on o!r tannages1 & :i* assi/s to bright5 z well z light5 ! r dull appe>ance ( lea!rs l>gely tann$ ) valonia4 ,x is r an exp5sive tann91 b mo/ manufactur]s f9d t its results are wor? its co/4 ,footnote #c3 ,also spelt ,sumac & ,%umac1 & always pron\nc$ l ! latt]4 ,o!r pyrogallol tans are also us$ to a limit$ ext5t4 ,alg>obilla & divi-divi are ! fruit pods ( sev]al species ( ,am]ican csalp9a4 ,!y are /rong 9 tan 7#de p] c5t47 & yield a light-col\r$ & bright lea!r1 b are un/able tans1 yield+ mu* bloom4 ,babla is a small pod yield+ a mell[ tannage & mu* gallic acid4 ,celav9ia is ano!r pod conta9+ no col\r+ matt] & giv+ an almo/ :ite lea!r4 ,! tann9 is closely simil> to t ( oak galls4 ,^! la/ 7 once ext5sively us$ = tann+ 9 ,au/ria4 ,will[ b>k is us$ = tann+ 9 ,russia & ,d5m>k4 ,valuable pyrogallol tann9s are obta9$ f oak wood & *e/nut wood1 b ! woods are n us$ 9 tann+ z ! p]c5tage ( tan is s small4 ,cate*ol tans1 (t5 obta9$ f b>ks1 conta9 usually ab\t #fj p] c5t4 ( c>bon4 ,!y are seldom us$ alone1 = !y usually h little or no sug> associat$1 & h5ce _! liquors d n ei!r s\r or plump4 ,!y c be us$ alone if artificially acidifi$1 b )\t acidify+ or bl5d+ w\ld give a r flat lea!r1 ?\gh possibly firm4 ,!y yield no bloom or gallic acid1 b h associat$ ) ?is o!r *>act]i/ic sub/ances4 ,( ^! ! cate*9s are ! mo/ typical1 & h be5 consid]$ z ! p>5t sub/ances ( ! cate*ol tans4 ,! cate*9s are :ite cry/all9e sub/ances1 app>5tly isom]s ) ! g5]al =mula ,c#ae;,h#ad,o#f4 ,!y h diff]5t melt+-po9ts1 & v>y+ am\nts ( wat] ( cry/allization1 b are o!rwise exce$+ly simil> 9 prop]ties4 ,!y are sp>+ly soluble 9 cold wat]1 b freely 9 hot1 & 9 alcohol & e!r4 ,!y are precipitat$ by lead acetate1 m]curic *loride & album91 b n by gelat91 t>t> emetic or alkaloids4 ,9 gambi] liquors !y are especially /rong1 & sometimes cry/allize on ! side ( ! pits1 be+ ?us kn[n z :ites4 ,! phlobaph5es or r$s are also typical ( cate*ol tans f :i* gr[ cate*9s2 !y c be =m$ by boil+ ) dilute m9]al acids4 ,!y are consid]$ to be anhydrides ( ! cate*ol tans4 ,!y are difficultly soluble 9 cold wat]1 b freely 9 hot1 & 9 cold alcohol & dilute alkalies4 ,!y are true tann9s & alone are capable ( mak+ a r$ lea!r1 b 9 practice are (t5 f\nd z mud 9 ! tan liquors ow+ to _! limit$ solubility4 ,!y naturally influ5ce ! col\r ( lea!r made ) cate*ol tans1 :i* is usually di/9ctly r$d] ?an ! lea!r made f pyrogallol tans4 ,infusions ( cate*ol 7cp4 cate*97 give a gre5-black col\r ) iron alum4 ,! sodium ars5ate te/ gives a r$ col\r due to cate*94 ,! *romate & iod9e te/s m5tion$ = pyrogallol tans give negative results ) ! cate*ol tans1 b brom9e wat] gives a precipitate1 & sulphuric acid a crimson col\r4 ,mimosa b>k is "o ( ! mo/ important cate*ol tans4 ,x is usually obta9$ 9 ?is c\ntry f ,natal 7,natal b>k72 b ! tree 7,sydney gre5 wattle1 ,acacia mollissima7 is a native ( ,au/ralia4 ,x is be+ cultivat$ n[ ext5sively 9 ,s\? ,africa1 & =ms a mo/ valuable portion ( ! ,empire's /ock ( tann+ mat]ial4 ,its m ext5sive use has be5 long recomm5d$ by ! au?or1#d b its gradually increas+ employm5t 9 ,briti% tann]ies has be5 greatly accel]at$ by ! w>1 :i* has prev5t$ its deliv]y 9 ,g]many & has cut (f ,turki% valonia f ,brita94 ,x yields ab\t #cj p] c5t4 ( a /able & excell5t tann91 & w produce a firm1 durable lea!r1 ) a col\r mu* less r$ ?an t obta9$ f _m o!r cate*ol tans4 ,x is an a/r+5t tan1 & if c>elessly us$ yields a h>% or ev5 drawn gra94 ,mo/ ( ! tann9 is easily extract$1 yield+ a cle> infusion :i* p5etrates fairly quickly & gives good weight4 ,x conta9s less ?an #a p] c5t4 ( sug>1 :i* un=tunately rapidly f]m5ts to c>bonic acid1 s t x is n a good plump+ mat]ial4 ,x makes 9 all respects an excell5t bl5d ) myrabolans4 ,l all cate*ol tans1 ! result+ lea!r d>k5s on exposure to sunlight4 ,footnote #d3 ,j4,s4,c4,i41 #aijh1 #aaic4 ,oak b>k1 f ,qu]cus robur1 is ! anci5t tann+ mat]ial ( ,brita91 & is /ill us$ to a limit$ ext5t4 ,x conta9s ab\t #ac p] c5t4 ( tann9 & is ma9ly a cate*ol tan1 b also conta9s a pyrogallol d]ivative4 ,x yields cate*91 & gives a r$ col\r ) ! sodium ars5ate te/1 b also w yield "s bloom & gallic acid1 & gives a blue-black ) f]ric salts4 ,! tann9 itself is exce$+ly simil> to t ( mimosa b>k1 b ! mat]ial conta9s ab\t #b-a_/b p] c5t4 ( sug>1 :i* makes x possible to employ oak b>k alone = mak+ sole lea!r4 ,x is not$ = yield+ a s\nd1 durable lea!r ( good typical tan col\r4 ,its tann9 comb9es well ) hide & p5etrates quickly4 ,! fatal disadvantage ( oak b>k is its weakness 9 tann9 /r5g? comp>$ ) o!r mat]ials4 ,?is results 9 heavy freight & heavy co/ p] unit tann91 bulky /orage1 exp5sive h&l+ 9 ! factory1 comp>atively l>ge bulk ( sp5t tan1 aft] relatively great] tr\ble 9 extract+1 & ! impossibility ( mak+ ! /rong liquors s necess>y 9 ^! days to produce good weight 9 a %ort "t4 ,no satisfactory extract has yet be5 made f x4 ,p9e b>k1 f ,p9as abies1 is "o ( ! /aple mat]ials ( ! ,cont95t4 ,x conta9s up to #ad p] c5t4 ( a cate*ol tan1 &1 unlike mo/ ( ?is gr\p1 conta9s a high proportion ( sug> & w give good results alone4 ,hemlock b>k has be5 ! /aple tann+ mat]ial ( ,nor? ,am]ica4 ,x is obta9$ f ! hemlock1 or ,p9us canad5sis4 ,x conta9s up to #aa p] c5t4 ( tan & mu* phlobaph5e1 & yields a *>act]i/ic r$ lea!r ( good quality1 b :i* rapidly d>k5s ) sunlight4 ,x conta9s "s sug>1 b is usually employ$ 9 conjunction ) sulphuric acid or ) sug>y mat]ials4 ,mallet b>k yields ano!r cate*ol tan simil> to t ( mimosa1 b some:at less a/r+5t & m yell[ 9 col\r4 ,quebra*o wood & mangrove b>k h be5 us$1 b are n[ made into extracts4 ,lea*+4--,:atev] class ( lea!r is be+ made1 & :atev] bl5d ( tann+ mat]ials is be+ employ$1 ! tann9s mu/ be effici5tly extract$ by wat] 9 ord] to make ! tann+ liquors4 ,?is process is call$ lea*+4 ,! tann+ mat]ials1 aft] be+ gr\nd1 cru%$ or %r$d$1 are plac$ 9 l>ge pits arrang$ 9 r\nds1 sets1 or batt]ies ( #f1 #h or #aj units1 ?r\gh :i* wat] is p]colat$ sy/ematically1 s z to secure a cont9u\s extraction4 ,wat] itself is add$ to only "o ( ! pits ( mat]ial4 ,! liquor produc$ is pass$ on to ! next pit1 & !n to ! next1 & is cont9ually ga!r+ /r5g?4 ,aft] pass+ ?us ?r\gh ! s]ies1 ! liquor becomes ! s\rce ( ! /rong extract$ tan liquors :i* are us$ 9 ! tann]y prop]4 ,) ?is sy/em ! /rong] lea* liquors are be+ act$ ^u by fre% mat]ial1 & ! ne>ly sp5t mat]ial is be+ act$ on by ! weake/ liquors1 & f9ally by wat]1 ?us ensur+ a complete extraction4 ,9 ! press lea* sy/em1 :i* is n[ practically univ]sal1 ! bottom ( "o pit communicates ) ! top ( ! next1 & ! liquor presses r\nd by gravity fl[ caus$ by a few in*es fall4 ,liquor is ?us con/antly p]colat+ d[nw>d ?r\gh ! mat]ial 9 ea* pit4 ,! head lea* & tail lea* are always adjac5t 9 a d\ble r[ ( pits1 & :5 ! mat]ial 9 ! latt] is q sp5t1 x is ca/1 & ! pit is fill$ ) fre% mat]ial4 ,! liquor is !n press$ r\nd into ?is pit by add+ wat] to ! tail lea*4 ,hot wat] is us$ to secure bett] diffusion4 ,at lea/ two su* sets ( lea*es 7taps & sp5d]s7 are necess>y to sp5d ! mat]ial ( ! av]age tann]y & to obta9 liquors ( ! necess>y /r5g?4 ,! ,manufacture ( ,extracts4--,9 addition to ! use ( ! natural tann+ mat]ials describ$ above1 mod]n lea!r manufactur]s employ also a v>iety ( tann+ extracts1 i4e4 vegetable tann+ mat]ials 9 :i* ! tann9 has be5 already extract$1 & :i* are suppli$ 9 =m ( a solid or conc5trat$ liquid4 ,su* extracts only ne$ to be dissolv$ 9 w>m wat] 9 ord] to make a tan liquor1 & ! co/ & tr\ble ( lea*+ is avoid$4 ,!y are a great conv5i5ce z mak+ /rong liquors ( def9ite /r5g?4 ,_m vegetable tann+ mat]ials are too weak 9 tan = ! tann] to lea*1 & inde$ to ju/ify ! co/ ( importation h be5 made available by manufactur+ an extract at ! s\rce ( ! mat]ial4 ,) su* weak mat]ials ! extract manufactur] has _h to secure a mu* m complete extraction ?an 9 ord9>y lea*+1 & to conc5trate 8 infusions by means ( /eam-heat$ vacuum pans4 ,) su* exp]i5ce he has naturally begun to make extracts also f ! /rong] mat]ials1 su* z myrabolans & mimosa b>k1 & x is n[ possible to h a tann]y )\t any lea*es at all4 ,tann]s also h begun to realize ! advantages n only ( m rapid & complete extraction1 b also ( do+ ! "w = !mselves1 & extract factories are beg9n+ to appe> z an adjunct to ! l>g] tann]ies4 ,! m complete extraction ( tan also involves a great] extraction ( unwant$ col\r+ matt]s1 h5ce decolorization is a feature ( extract manufacture4 ,*e/nut ,extract is f ! wood ( ! ,spani% *e/nut 7,ca/anea vesca71 :i* conta9s #c-f p] c5t4 ( a valuable pyrogallol tan v simil> to t ( valonia4 ,its weight-giv+ & wat]-resi/+ p[]s are z good z valonia1 & its p5etrat+ p[] is ev5 bett]1 s t x =ms an exce$+ly suitable mat]ial = ! mod]n %ort tannage1 & also = drum tannages4 ,! extract is manufactur$ ext5sively 9 ,france4 ,! wood is /ripp$ ( b>k & usually pil$ = "s mon?s to dry & to all[ ! res9s to become insoluble4 ,"s factories1 h[ev]1 use ! gre5 wood direct4 ,!re are two me?ods ( extraction1 viz4 9 op5 vats & 9 clos$ vats "u pressure4 ,! two me?ods yield extracts :i* diff] 9 composition & prop]ties4 ,9 ei!r case ! vats h a capacity ( up to #c1jjj gallons1 & hold up to #f-a_/b tons ( wood4 ,!y are arrang$ 9 s]ies1 z 9 lea*+1 & ! liquor passes 9 succession ?r\gh all ! vats ov] wood less & less sp5t4 ,! temp]ature is highe/ 9 ! vat conta9+ ! fre% wat] & ne>ly sp5t wood4 ,9 op5 vats ( wood or copp] ! temp]ature is ne> boil+-po9t1 :il/ 9 ! clos$ autoclaves 7copp] or bronze7 ! pressure rea*es ab\t two atmosph]es & ! temp]ature ab\t #acj ,c4 7#bff ,f474 ,! s]ies may conta9 #e1 #g1 #i or ev5 #ab vats1 & ! liquor obta9$ has a /r5g? ( #c to #d-a_/b ,beaum 7#bb to #cc ,bkr474 ,aft] extraction ! liquor is all[$ to /&1 & mu* insoluble matt] settles out--res9s1 wood1 fibre1 etc4 ,! cl>ifi$ & settl$ liquor is !n pass$ ?r\gh a cool] up to ab\t #ee ,c41 & !n run into ! decoloriz+ plant1 a deep vat fitt$ ) a copp] /eam coil & me*anical /irr] atta*$ to p[]4 ,! be/ decoloriz] is bullock's blood1 :i* is run into ! vat & well mix$4 ,! temp]ature is next rais$ to ab\t #gj ,c41 caus+ ! blood album9 to coagulate4 ,x c>ries d[n ) x a little tann91 b mu* col\r+ matt]4 ,aft] /&+ a few h\rs ! settl$ liquor is run (f direct to ! evaporator4 ,a multiple-effect evaporator is usually employ$1 & ! conc5trat$ liquor1 :i* has a /r5g? ( ab\t #be ,beaum1 is run into suitable oak casks4 ,! extracts conta9 #bg-cb p] c5t4 tann94 ,an extract made ) op5 vats has ab\t #g p] c5t4 soluble non-tann+ matt]s1 :il/ a pressure extract may conta9 up to #ab p] c5t4 ( ^! non-tans4 ,pressure extracts obta9 also a bett] yield ( tann91 :i* m ?an comp5sates = ! slightly l[] price4 ,op5 extraction yields1 h[ev]1 ! pur] product & an extract ) bett] p5etrat+ p[]s1 & is consequ5tly ! m suitable = drum tannages4 ,*e/nut extract is ext5sively us$ by ! heavy lea!r tann]s4 ,oakwood ,extract is manufactur$ f ! wood ( ! common oak 7,qu]cus robur74 ,! c5tre ( ! indu/ry has be5 ! oak =e/ ( ,slavonia4 ,! wood conta9s #b-d p] c5t4 ( a tann9 v simil> to t ( *e/nut wood1 b some:at m a/r+5t4 ,! manufacture is also simil> to t ( *e/nut extract1 b decolorization is (t5 omitt$1 & great] c>e has to be tak5 & 9 o!r ways to keep ! col\r )9 limits4 ,"o ( ^! is to /rip ! wood m completely ( b>k4 ,ano!r is to op]ate at z l[ a temp]ature z possible1 ab\t #aaj ,c4 ,! extraction is made 9 l>ge circul> vats ab\t #ad feet high & hold+ ab\t two tons mat]ial4 ,a batt]y is compos$ ( ab\t eight vats or extractors4 ,op5 extraction is us$1 & ! liquor is pass$ =w>d aft] #b-c h\rs' boil+1 s t ! mat]ial is sp5t 9 ab\t #bd h\rs4 ,a liquor ( ab\t #e ,b 7#cf ,bkr47 is obta9$1 & ! /r5g? ( ! mat]ial r$uc$ f #d to #a_/d p] c5t4 ( tann94 ,gett+ rid ( insoluble matt] is a difficulty1 & is atta9$ by settl+1 by rapidly cool+1 & !n pass+ ?r\gh a filt] press ( wood4 ,= evaporation a d\ble-effect vacuum pan is pref]r$1 :i* op]ates fir/ at ab\t #aac ,f41 & aft]w>ds at #adj ,f4 ) a high] vacuum4 ,! liquor is conc5trat$ f #e to #be ,beaum 7s4g4 #a4jcf & #a4baj respectively74 ,! extract has a mu* high] col\r ?an *e/nut1 & is n us$ n[ z mu* z "s ye>s ago4 ,z ! pr9cipal supply 0 ,g]man1 x has be5 unavailable4 ,quebra*o ,extract is made f ! wood ( ! ,s\? ,am]ican tree ,loxopt]yngium ,lor5zii1 :i* conta9s ab\t #bj p] c5t4 ( a typical cate*ol tan4 ,x is associat$ ) a little cate*91 mu* phlobaph5e1 b practically no sug>4 ,! tann9 is v a/r+5t1 p5etrates quickly & gives a firm r$ lea!r :i* d>k5s on exposure to light4 ,x is n not$ = weight-giv+ p[]s4 ,! wood itself1 z *ips or %av+s1 has be5 us$ 9 ,briti% tann]ies1 to a limit$ ext5t1 b ! great bulk ( ! mat]ial is made into extract *iefly 9 ,s\? ,am]ica4 ,! crude extract1 made by evaporat+ aque\s infusions ( ! wood1 is l>gely export$ = ref9em5t 9 ,europe4 ,x is also ref9$ on ! spot to a l>ge ext5t & conv]t$ into solid extract conta9+ #fj p] c5t4 ( tann94 ,! great difficulty ) quebra*o has be5 ! disposal ( ! phlobaph5es1 & a great v>iety ( quebra*o extracts are n[ available :i* deal ) ?is problem 9 diff]5t ways4 ,9 "s ! m soluble r$s are simply left 9 ! extract "u ! idea t !y are really tann9s & may be ( "s use 9 "s "p ( ! tann+ process2 9 o!rs !y h be5 remov$ by settl+ & filtration at appropriate temp]atures & conc5trations2 9 mo/1 h[ev]1 !y h be5 solubiliz$ by treatm5t ) alkalies1 9 ! pres5ce ( r$uc+ ag5ts1 notably by heat+ ) sodium bisulphite 9 clos$ vats4 ,! base comb9es ) ! phlobaph5es1 :i* are made completely soluble & available = tann+4 ,sulphur\s acid is evolv$1 & its r$uc+ p[]s assi/ mat]ially 9 reta9+ & promot+ a good col\r 9 ! product4 ,su* sulphit$ extracts are n[ ext5sively manufactur$ 9 ?is c\ntry f ! import$ crude extract1 & sold z liquid extracts conta9+ #cj1 #ce or #dj p] c5t4 ( tan accord+ to ! requirem5ts ( ! buy]2 mix$ extracts :i* are solubiliz$ quebra*o bl5d$ ) ab\t #ae p] c5t4 ( myrabolans1 are also us$4 ,by solubiliz+ quebra*o ) excess ( bisulphite an extract is obta9$ :i* possesses consid]able blea*+ p[]s1 & su* extracts are also ext5sively manufactur$ = ! vatt+ or blea*+ ( heavy lea!r aft] tannage4 ,! excess ( sulphur\s acid n only blea*es ! lea!r1 b also swells x up & ?us p]mits a fur!r absorption ( /rong tan liquor1 :i* is conducive to good weight4 ,^! blea*+ extracts are usually ( #cf-ch p] c5t4 /r5g? 9 tan4 ,gambi] is an extract ( ! leaves & twigs ( ! ea/]n %rub ,nauclea gambir4 ,x is a cate*ol tan ( peculi>ly mell[ quality & great practical value4 ,x conta9s mu* cate*91 b little phlobaph5e1 & yields a beautifully s(t lea!r1 b )\t weight4 ,x is an exce$+ly suitable mat]ial = ! e>ly /ages ( tann+1 & is mu* lik$ = tann+ lea!rs t h to be curri$1 & is widely us$ 9 ! manufacture ( upp] lea!r4 ,x is1 h[ev]1 an exce$+ly exp5sive tann91 & ! extract is made 9 a v crude way by ,*9ese & ,malays )\t mu* sup]vision4 ,h5ce its /r5g? 9 tan & g5]al quality is extremely v>iable4 ,! plant is cultivat$ = ! purpose ( extract manufacture1 & prun+s are tak5 9 ! plant's ?ird ye>4 ,!y are bruis$ & boil$ ) wat] 9 ! op54 ,! infusion is /ra9$1 conc5trat$1 & p\r$ into cool+ vessels 9 :i* x sets to a pa/e4 ,two v>ieties ( gambi] are well kn[n1 cube gambi] & block gambi]4 ,9 ! latt] ! extract rema9s z a pa/e conta9+ #be to #dj p] c5t4 ( tann94 ,x is sold 9 oblong blocks ( #a or #b cwt41 ei!r wrapp$ 9 cocoanut matt+ or 9 wood5 boxes4 ,cube gambi] is made by runn+ ! conc5trat$ syrup into trays #b in*es deep & dry+ 9 ! sun4 ,:5 p>tly dry1 x is cut up into #a-a_/b-;94 cubes & dri$ fur!r on cocoanut matt+4 ,! r\gh cubes z import$ conta9 #dj-ej p] c5t4 ( tann94 ,myrabolans ,extract is n[ l>gely manufactur$ 9 ?is c\ntry4 ,a liquid extract ( #be1 #cj or ev5 #ce p] c5t4 /r5g? is made = home consumption1 & a solid extract = export4 ,! light col\r1 high /r5g? & easy extraction ( ! natural mat]ial h all facilitat$ ! task ( ! manufactur]4 ,! mat]ial is extract$ 9 op5 vats or /ills ( copp]1 :i* take "o ton or m ( nuts4 ,a batt]y ( #d1 #f or #h ( su* /ills is usually employ$1 & ! temp]ature is kept well bel[ boil+-po9t except 9 ! vats conta9+ ! ne>ly sp5t mat]ial4 ,! liquors move =w>d quickly1 & ! mat]ial is q sp5t 9 #bd h\rs4 ,! mat]ial :5 ca/ conta9s less ?an #a_/b p] c5t4 ( tann94 ,! liquor obta9$ is #dj-ej ,bkr4 7#f - #g-a_/b p] c5t4 tan71 & aft] settl+ is conc5trat$ at #dj-ej ,f4 9 a s+le effect vacuum pan1 :i* ?\gh m co/ly 9 /eam is quick] ?an ! multiple effects1 & gives ! l[ temp]ature requir$4 ,= solid extract ! m conc5trat$ liquor is run direct into t>r$ bags1 9 :i* x soon solidifies4 ,hemlock ,extract is manufactur$ f ! ,nor? ,am]ican p9es & import$ into ?is c\ntry to "s ext5t4 ,x gives a v r$ col\r4 ,mangrove ,extract is made f ! b>k ( ,rhizophona ,mangle & o!r species ( mangrove :i* gr[ freely 9 ! tropical swamps ( ,we/ ,africa1 ,borneo1 etc4 ,mu* solid & liquid extract has be5 made f ?is mat]ial1 b is n v popul> on acc\nt ( its h>% tannage & d>k r$ col\r4 ,p9e ,b>k ,extract 7,l>* extract7 is made 9 ,sw$5 f ! ,norway spruce 7,p9us abies74 ,x is slightly sulphit$ & gives a good col\r4 ,x is a liquid extract ( ab\t #cj p] c5t4 /r5g?1 & is sometimes us$ z a *e/nut sub/itute4 ,x %\ld n be confus$ ) ! s-call$ spruce or p9e wood extract1 :i* is a pap] trade bye-product & conta9s ligne\s matt]s r ?an tann94 ,am]ican ,*e/nut ,extract1 made f ! *e/nut oak1 is ei!r a liquid or a solid extract 9 p[d] =m4 ,x gives a wret*$ br[n-black col\r1 :i* is q unsuit$ to ! usual ,briti% ne$s4 ,,!ory ,,( ,,vegetable ,,tannage4 ,vegetable tannage is a ph5om5on ( colloid *emi/ry4 ,! old argum5ts z to :e!r tann+ 0 a *emical or a physical process h be5 r5d]$ obsolete by ! adv5t ( a new set ( explanations1 :i*1 ?\gh %$d+ light on _m obscure po9ts1 h enorm\sly increas$ ! complexity ( ! problem4 ,9 vegetable tannage an emulsoid gel 7pelt7 is imm]s$ 9 a complex emulsoid sol 7tan liquor71 :i* imm]sion results1 n 9 simple reaction or *ange1 b 9 a s]ies ( *anges4 ,"o ( ^! *anges is adsorption4 ,pelt is a gel :i* possesses a great developm5t ( surface4 ,x n only exhibits l gelat9e ! ph5om5on ( imbibition & dehydration to a v m>k$ ext5t1 b also possesses a v f9e fibr\s /ructure due to its organic orig92 ?us pelt possesses an enorm\s specific surface1 fur!r int5sifi$ by ! prep>ation processes previ\sly discuss$1 :i* split up ! hide fibres into small] bundles & into mu* f9] con/itu5t fibrils4 ,tann9s1 on ! o!r h&1 are hydrophile colloids :i* 9 wat] =m emulsoid sols1 & :i* may ?us be expect$ to exhibit ! ph5om5on ( adsorption4 ,a tan liquor usually conta9s sev]al tann9s 9 addition to o!r closely simil> sub/ances1 also 9 colloidal solution1 & is !re=e a sol ( consid]able complexity4 ,! imm]sion ( pelt into a tan liquor results 9 an adsorption1 :i* consi/s ess5tially 9 an inequality ( conc5tration 9 ! sol1 ! great] conc5tration be+ at ! int]face4 ,?is inequality betwe5 ! surface conc5tration & ! volume conc5tration ( ! sol1 is due prim>ily to consid]ations ( surface t5sion & surface en]gy1 & exi/s be=e ! imm]sion ( ! pelt4 ,! surface lay] hav+ excess ov] ! volume conc5tration1 any consid]able ext5sion ( surface 9 a fix$ volume ( sol mu/ produce a v consid]able decrease 9 ! volume conc5tration4 ,?is is :at occurs :5 pelt is imm]s$ 9 a tan liquor1 ! imm]sion be+ ! consid]able ext5sion ( surface4 ,x %\ld be especially rememb]$ t ! inequality ( conc5tration is 9 ! sol1 on ! liquid side ( ! int]face4 ,9 adsorption1 ! sub/ance adsorb$1 i4e4 ! excess at ! surface1 is too frequ5tly reg>d$ z b\nd to ! solid imm]s$4 ,?is is because ! excess is 9 ! lay] :i* wets ! solid & rema9s wett+ x :5 ! solid is remov$4 ,?us ! imm]sion ( pelt produces prim>ily only a *ange 9 ! di/ribution ( ! tann9s 9 ! liquor4 ,x foll[s f ?is t ! adsorption is an equilibrium1 & t if ! sol be dilut$1 ! equilibrium w become ! same z x w\ld h be5 by imm]s+ ! pelt directly into ! dilute solution4 ,?us1 if pelt be fir/ imm]s$ 9 "o tan liquor & !n into a weak] "o x w yield tan to ! latt] solution4 ,! *ief object 9 heavy lea!r tann+ is to obta9 ! maximum possible adsorption 9 ! m9imum possible "t1 or 9 o!r words1 to obta9 good weight quickly4 ,! am\nt adsorb$ is proportional to ! actual ext5sion ( surface1 i4e4 ! adsorption is a function ( ! specific surface ( ! adsorb5t4 ,h5ce1 to obta9 good weight x is necess>y to develop 9 ! pelt its maximum possible specific surface4 ,?is is "o ( ! objects ( plump+1 :i* splits up ! fibres4 ,x is atta9$ also by ! solution ( int]fibrill> sub/ance 9 limes & bates4 ,! am\nt adsorb$ is also a function ( ! volume conc5tration 9 ! sol aft] equilibrium is rea*$4 ,h5ce ! bett] weights are obta9$ ) /rong] liquors4 ,! adsorption law is y_/m ac7#a_/n7 :]e y is weight adsorb$ by ! weight m ( adsorb5t1 & c ! volume conc5tration aft] adsorption2 a & n are num]al con/ants4 ,h5ce weight is det]m9$ by ! /r5g? ( ! liquor :i* ! goods f9ally leave4 ,! comm5cem5t ( tannage is necess>ily 9 weak infusions1 9 ord] to secure ! maximum diffusion into int]ior ( ! fibres be=e !y become heavily coat$ on ! ext]ior4 ,z ! equilibrium is be+ e/abli%$ 9 su* liquors ! volume conc5tration dim9i%es1 & ?us makes x less likely t good weight w be atta9$2 h5ce x is necess>y 9 practice to move ! goods con/antly into fre% liquors ( gradually increas+ /r5g?1 & s ma9ta9 ! rate ( adsorption & save "t4 ,a fur!r consequ5ce ( ! adsorption iso!rm is t z y v>ies z c7#a_/n7 & n is #a1 y is increas$ appreciably only by a relatively l>ge increase 9 c4 ,h5ce1 ?\gh /rong] liquors give bett] weight1 !re is a limit beyond :i* any fur!r ga9 9 weight is n ju/ifi$ by ! enorm\s increase 9 ! conc5tration necess>y to atta9 x4 ,su* great increase 9 c is impracticable n only on ! gr\nd ( exp5se1 b also on acc\nt ( ! great viscosity ( ! sol4 ,! am\nt ( adsorption dep5ds also ^u ! exact nature ( ! sol4 ,x has be5 previ\sly po9t$ out t ! tann9s diff] l>gely 9 _! p5etrat+ & weight-giv+ p[]s4 ,"s are readily adsorbable & are deposit$ 9 great conc5tration at ! surface ( ! fibre1 b = good weight x is necess>y to use also ! less adsorbable & m diffusible tans1 :i* p5etrate ! fibre itself4 ,h5ce x is necess>y = good weight to use a bl5d ( mat]ials1 & s supply _m grades ( liability to adsorption4 ,x is p>ticul>ly advantage\s to bl5d judici\sly ! two ma9 types ( mat]ial1 ! pyrogallol & cate*ol tans4 ,x is also necess>y = good weight to pres5t to ! pelt ! m diffusible & less adsorbable tann9s fir/1 9 ord] to secure ! maximum diffusion into ! int]ior ( ! fibre be=e ! ext]ior ( ! fibre is heavily coat$ ) ! heavily adsorbable & a/r+5t tans4 ,! lea/ adsorbable mat]ials are !re=e us$ 9 ! e>ly /ages ( tann+1 & ! mo/ adsorbable mat]ials at ! end ( ! tann+ process4 ,?us gambi] is add$ to ! e>ly liquors 7susp5d]s71 solubiliz$ quebra*o to ! lat] liquors 7h&l]s71 & mimosa b>k extract to ! f9al liquors 7lay]s74 ,!re is also ano!r excell5t way ( ensur+ ?is progressive a/r+5cy ( ! liquors2 ?is consi/s 9 lea*+ ! requir$ bl5d ( mat]ials toge!r 7or mix+ !m 9 ! case ( extracts7 & pres5t+ ! mix$ infusion to ! ne>ly tann$ goods1 :i* adsorb *iefly ! m a/r+5t tann9s4 ,! liquor is !n us$ = goods at a less advanc$ /age ( tann+1 :i* aga9 take ! mo/ adsorbable con/itu5ts4 ,?is is repeat$ until ! /age is rea*$ :5 ! fre% pelt is ins]t$ into ! ne>ly exhau/$ liquor1 :i* naturally conta9s only ! lea/ adsorbable sub/ances4 ,?is sy/em is almo/ univ]sal1 & 9 practice is kn[n z work+ ! liquors d[n ! y>d4 ,x has ! additional advantage ( be+ a sy/ematic me?od ( economically exhau/+ 7sp5d+7 ! tan liquors4 ,:5 free acid is pres5t 9 ! tan liquors1 x t5ds to di/5d ! fibres compos+ ! pelt by a /rong & rapid adsorption4 ,?us di/5d$ or plump$ ! fibres pres5t a /ill great] surface = adsorptive op]ation1 b ! di/5sion naturally leaves less space betwe5 ! fibres = ! diffusion ( ! sol4 ,h5ce acid or s\r tan liquors give 9 ! long run m weight1 b tan m sl[ly4 ,pelt tann$ :il/ ?us plump$ =ms naturally a ?ick] & less pliable lea!r4 ,?is occurs 9 tann+ sole lea!r1 to a less ext5t ) heavy dress+ lea!r1 & to a v small ext5t 9 ! case ( s(t] dress+ lea!rs4 ,9 addition to adsorption1 !re is ano!r ph5om5on ( colloid *emi/ry 9 op]ation1 viz4 ! mutual precipitation ( ! sols 9 ! liquid by ! gels 9 ! hide4 ,9 mo/ sols ! disp]se phase is electrically *>g$4 ,! sol !re=e possesses electric conductivity1 & migration occurs 9 ! electric field to ! ca?ode or anode accord+ to ! nature ( ! *>ge4 ,oppositely *>g$ sols precipitate "o ano!r1 ! precipitate conta9+ bo? colloids4 ,! maximum precipitation occurs :5 ! *>ge ( "o sol exactly equals & neutralizes ! - *>ge ( ! o!r4 ,!re is ?us an electrical equival5ce2 an am\nt ( sol :i* is equival5t to a giv5 am\nt ( ! o!r4 ,?is is n a *emical equival5ce1 h[ev]1 & ! precipitate is n a *emical comp\nd 9 spite ( its fairly con/ant composition4 ,! composition ( ! precipitate1 inde$1 is n q con/ant1 = ! optimum precipitation may n correspond exactly ) ! electrical equival5ce1 be+ influ5c$ by ! numb] ( p>ticles requir$1 _! size 7disp]sity71 ! rate ( mixture1 & ! relative conc5trations ( ! sols4 ,?is mutual precipitation is exhibit$ by emulsoids z well z susp5soids1 b ! *>ge 7 or -7 on an emulsoid is 9 _m in/ances l>gely an accid5tal matt]1 be+ det]m9$ by ! m$ium 9 :i* x happ5s to be1 its normal condition be+ electrical neutrality4 ,gelat9 & pelt are su* emulsoids1 & a positively *>g$ gelat9 sol has be5 obs]v$ to precipitate a negatively *>g$ gelat9 sol4 ,x is ?\ght1 h[ev]1 t gelat9 is prim>ily a positive sol4 ,pelt 7:e!r delim$ or n7 is rapidly acidifi$ by ! quickly p5etrat+ & /rongly adsorb$ organic acids ( ! old tan liquors & becomes positively *>g$ be=e ! tann9s are adsorb$4 ,! positive *>ge increases ) ! acidity ( ! liquor4 ,o!r emulsoids are n electrically neutral1 b are electrically *>g$ & exhibit consid]able conductivity4 ,into ?is class fall ! tann9s1 & 9 tann+ x is ?\ght t !re is a mutual precipitation ( ! negative tann9 sol ) ! positive hide gel1 ! precipitation ( ! negative sol be+ fav\r$ by ! acid condition ( ! liquor4 ,! effect ( increas+ acidity soon falls (f1 h[ev]1 z a saturation limit is soon rea*$4 ,?is mutual precipitation ( colloids 9 tann+ is 9 reality b an ext5sion ( ! adsorption !ory1 :i* expla9s ! pr$om9ant effect ( ,h1 & ,,oh- on ! electric *>ge by /at+ t ^! ions are m readily adsorb$ ?an o!r ions1 & t z ,,oh- is m readily adsorb$ ?an ,h mo/ sols are negative to wat]4 ,9 addition to ! adsorption ph5om5a describ$1 !re are 9 vegetable tannage second>y *anges :i* are sl[ & irrev]sible4 ,^! *anges are obscure & are difficult to inve/igate4 ,oxidation1 dehydration & polym]ization h all be5 sugge/$1 b !re is little direct evid5ce4 ,c]ta9 x is1 h[ev]1 t "t r5d]s ! tannage m p]man5t4 ,x p]haps %\ld be po9t$ out t 9 ! v /ronge/ tan liquors ! viscosity ( ! tann9 sol is s great t adhesion w\ld be a bett] t]m ?an adsorption4 ,!re is no abrupt division betwe5 ! two ph5om5a4 ,9 ! !ory ( vegetable tannage !re is ano!r factor ! importance ( :i* has be5 /rongly emphasiz$ by ! au?or1 viz41 lyotrope influ5ce4 ,?is has be5 mo/ conv5i5tly discuss$ 9 connection ) gelat9 gels1 b its effect on hide gels is analog\s4 ,x has also an effect ^u ! diffusion & gelation ( ! tann9 & non-tann9 sols4 ,me*anical ,op]ations4--,9 ! tany>d ! liquors are almo/ inv>iably divid$ up into sections1 call$ r\nds or sets1 9 :i* ! me*anical op]ations are diff]5t 9 aim & me?od4 ,9 ! fir/ pits ent]$ by ! goods !re is rapid adsorption 9 spite ( ! l[ conc5tration & small a/r+5cy1 & ! great aim is to obta9 ev5ness ( action & a good level col\r4 ,x is also necess>y to ma9ta9 ! rate ( adsorption4 ,all ! aims are atta9$ by frequ5tly mov+ ! goods4 ,heavy lea!r is susp5d$ v]tically 9 ! pits ( tan liquor & h&l$ up & d[n z well z =w>d f pit to pit4 ,su* pits are t]m$ susp5d]s4 ,9 ! e>lie/ susp5d]s x is inde$ advantage\s to h ! goods 9 con/ant motion4 ,?is is done by susp5d+ on wood5 frames :i* are rock$ g5tly by me*anical p[]2 su* pits are t]m$ rock]s4 ,= dress+ lea!r 9 :i* firmness & smoo? gra9 are n s ess5tial1 ! goods may be paddl$ 9 ! fir/ liquors4 ,?is is occasionally done ) /rong] liquors = ! express purpose ( work+ up ! gra9 patt]n4 ,! goods aft] pass+ ?r\gh ! susp5d]s are usually pass$ to h&l] r\nds1 9 :i* !y are mov$ less frequ5tly4 ,9 ^! pits ! goods are laid horizontally "o above ! o!r4 ,"o advantage ( h&l]s is t ! goods flatt5 ?or\ghly & /raight5 "o ano!r by _! own weight2 ano!r is t m goods c be plac$ 9 "o pit ?an 9 susp5d]s4 ,!y are n s conv5i5t to "w1 h[ev]1 z susp5d]s1 & ! goods d n fe$ s rapidly4 ,h5ce ! t5d5cy is n[ to tan m 9 susp5sion1 & to economize lab\r by an ext5sion ( ! rock]s4 ,! h&l+ ( ! goods is also sav$ by pump+ ! liquors & by work+ r\nds ( susp5d]s or rock]s l ! press lea* sy/em1 ) ! diff]5ce t ! /rong] liquor is pump$ 9 to ! head pit1 & ! liquor passes upw>ds ?r\gh ! goods4 ,f9ally ! goods are plac$ 9 lay]s or layaways1 9 :i* !y rema9 undi/urb$ = a decid$ly long] "t4 ,^! pits conta9 ! /ronge/ liquors ( ! y>d1 & _! pr9cipal function is to complete ! tannage & give weight & firmness by ! adsorption ( bloom1 r$s1 etc41 9 ! int]ior ( ! hide4 ,! goods are plac$ 9 horizontally1 & are du/$ 9 betwe5 ) fre% tann+ mat]ial :i* ma9ta9s ! local /r5g? ( ! liquor & keeps ! goods some:at ap>t4 ,drum tann+ atta9s a m rapid p5etration ( ! pelt by giv+ con/ant motion 9 /rong] infusions4 ,x is ( c\rse liable to result 9 an "u-tannage ( ! int]ior ( ! fibre4 ,aft] ! goods h be5 /ruck ?r\gh 9 ! ord9>y way1 h[ev]1 drumm+ 9 extract is increas+ly us$ z a sub/itute = mu* lab\r 9 h&l+1 & also to save ! "t sp5t 9 ! e>ly lay]s4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #bbj-cej4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #aac-agi4 ,b5nett1 ,celavima & ,babla1 ,l4,t4,r41 #aiad1 #abb4 ,dumesny & ,noy]1 ,manufacture ( ,tann+ ,extracts4 ,!ory3-- ,meuni] & ,seyewetz1 ,collegium1 #aijh1 #aie4 ,/iasny1 ,collegium1 #aijh1 #aag-aei1 #bhi1 #bid1 #ccg4 ,proct] & ,wilson1 ,collegium 7,london71 #aiag1 #c4 ,wilson1 ,collegium 7,london71 #aiag1 #ig1 #ajj1 #aje4 ,moell]1 ,collegium 7,london71 #aiag1 #ac1 #ch1 #df1 #ajc2 & ,j4,s4,l4,t4,c41 #aiag1 #bb1 #ef1 #ib4 ,b5nett1 ,j4,s4,l4,t4,c41 #aiag1 #acj-acc1 #afi-ahb2 #aiah1 #dj2 #aibj1 #ge-hf2 ,s4,l4,r41 #aiaf1 ,m>*4 ,,section ,,iv4--,,f9i%+ ,,processes ,aft] ! tannage is complete1 lea!r is hung up to dry4 ,9 ! case ( heavy lea!r ?is dry+ mu/ be v c>efully c>ri$ out 9 ord] to obta9 a product ( satisfactory appe>ance & saleable qualities4 ,associat$ ) ! dry+ are _m me*anical op]ations 7sc\r+ & roll+7 :i* assi/ v mat]ially 9 imp>t+ ! desir$ qualities4 ,aft] tann+1 h[ev]1 ! quality ( ! f9al product is mo/ /rongly influ5c$ by ! am\nt ( grease add$ 9 f9i%+4 ,"s grease is always us$ 9 f9i%+1 p>tly because ev5 sole lea!r requires "s measure ( pliability & p>tly because a coat+ ( oil ov] ! lea!r dur+ dry+ prev5ts ! loose tann9 f be+ drawn to ! surface ( ! lea!r by capill>ity1 !reby caus+ d>k & unev5 pat*es & a cracky gra94 ,! add$ grease is also a contribution to ! weight ( ! f9i%$ article--a prim>y consid]ation = heavy lea!r1 :i* is usually sold by weight4 ,! f9i%+ processes1 inde$1 t5d to be dom9at$ by ?is consid]ation1 & become a s]ies ( ef=ts to reta9 z mu* tann9 & add z mu* grease z are consi/5t ) ! requirem5ts ( ! class ( lea!r be+ manufactur$4 ,sole lea!r does n conta9 m ?an ab\t #b p] c5t4 grease1 or its firmness is impair$4 ,belt+ lea!r1 9 :i* consid]able pliability is ne$$1 may conta9 ab\t #i p] c5t41 :il/ h>ness lea!r1 :i* mu/ be exce$+ly t\gh & durable1 may conta9 up to #ac p] c5t4 ( fatty matt]s4 ,upp] lea!rs1 :i* ne$ to be s(t & pliable z well z wat]pro( & durable1 are v heavily /uff$ & (t5 conta9 up to #cj-dj p] c5t4 ( grease4 ,sole lea!r is ?us r di/9ct f ! re/1 :i* are call$ curri$1 /uff$1 or dress$ lea!rs4 ,! actual dry+ out be=e1 aft] & betwe5 ! v>i\s me*anical op]ations1 ea* h an appropriate degree ( wetness4 ,9 ?is c\ntry ! dry+ is usually "u ! prevail+ atmosph]ic conditions & is kn[n z wea!r dry+4 ,! goods are susp5d$ by hooks or /r+s or by lay+ ov] poles 9 special %$s fitt$ ) l\vre bo>ds by :i* ! rate ( dry+ c be r\ghly controll$4 ,wea!r dry+ is *eap1 b exce$+ly sl[1 & 9 unfav\rable wea!r is v unreliable4 ,! goods1 moreov]1 ne$ con/ant att5tion to obta9 an ev5 result4 ,/eam pipes are usually laid along ! %$ floors1 & are us$ 9 w9t] & damp wea!r to accel]ate ! dry+1 & also 9 ! f9al %$ /ove to remove ! la/ traces ( moi/ure4 ,wet wea!r1 h[ev]1 w n /& a high temp]ature1 & /eam dry+ is bett] avoid$ :5 possible4 ,air-dri$ lea!r /ill conta9s ab\t #ad p] c5t4 ( moi/ure4 ,_m sy/ems ( %$ v5tilation h be5 sugge/$ to ha/5 ! dry+ & to secure a bett] control ( ! process4 ,9 "o sy/em a screw fan is fitt$ at "o end ( a %$ 7)\t l\vre bo>ds7 & sucks air ?r\gh ! goods f an inlet at ! o!r end4 ,! air c be heat$ by a /eam coil ne> ! inlet4 ,9 ano!r sy/em a c5trifugal fan bl[s air ?r\gh an arrangem5t ( pipes :i* di/ributes x to ! dry+ %$s1 & dis*>ges x close to ! floor by v>i\s bran* pipes4 ,! outlets are ne> ! ro(4 ,a sy/em ( damp]s p]mits hot air1 w>m air & ! us$ wet air to be bl5d$ 9 ! desir$ proportions4 ,9 ,am]ica turret dry+ has be5 us$4 ,! %$s are v]tically above "o ano!r & h lattic$ floors4 ,heat$ air is admitt$ at ! bottom & rises ?r\gh ! goods up ! build+ j z 9 a *imney4 ,= _m ( ! f9i%+ op]ations x is important to obta9 ! lea!r 9 a uni=mly half dry or samm$ condition4 ,?is may be done by c>eful dry+1 & wett+ back ! p>ts t h become too dry ) tepid wat] or weak sumac liquor1 & !n leav+ ! goods 9 pile until ( uni=m humidity4 ,x may also be done by wett+ back lea!r :i* has be5 completely dri$ out4 ,!re are also samm+ ma*9es :i* by means ( roll]s squeeze out ! excess liquor4 ,sole lea!r is dri$ out & f9i%$ imm$iately aft] tann+1 b dress+ lea!r is (t5 r\gh dri$ out ( tan liquors & wet back = f9i%+ :5 requir$4 ,dress+ lea!r is (t5 treat$ 9 diff]5t factories2 tann]s sell+ x z r\gh lea!r & curri]s f9i%+ x4 ,sc\r+ is "o ( ! fir/ op]ations 9 f9i%+ lea!r4 ,! gra9 side is wet & work$ ) bru%es & /ones until ! bloom & loose tann9 are remov$4 ,?is process aims at produc+ a good ev5 col\r & level surface1 b is liable to cause a loss ( weight4 ,dress+ lea!r is (t5 sc\r$ on bo? gra9 & fle%1 & weak soap or borax solutions are us$ to assi/ ! process4 ,9 ?is op]ation h& lab\r has be5 n[ q sup]s$$ by ma*9e "w4 ,a great v>iety ( ma*9es h be5 devis$4 ,! me*anical work+ ( lea!r takes place 9 v>i\s p>ts ( f9i%+4 ,^! op]ations1 kn[n z /rik+1 sett+1 p9n+1 jack+1 may be c>ri$ out (t5 by ! same ma*9e z us$ = sc\r+1 b ) a *ange ( tool4 ,! object ( ^! op]ations is to get rid ( wr9kles & creases1 to produce s(tness1 pliability & area1 & to remove sup]flu\s moi/ure1 grease1 dirt4 ,! tools are ( /eel1 brass1 slate or vulcanite4 ,sc\r+ is (t5 effect$ by putt+ ! goods into rotat+ drums toge!r ) extract & suma*4 ,! bloom is remov$ by friction1 ! col\r is improv$ by ! suma*1 :il/ ! extract keeps up ! weight4 ,9 f9i%+ sole lea!r firmness is enhanc$ by roll+4 ,a brass roll] passes to & fro ov] ! goods ) ! ex]tion ( consid]able pressure4 ,! op]ation is c>ri$ out by ma*9]y4 ,%av+ is an important op]ation 9 ! case ( _m dress+ lea!rs4 ,its object is to produce a uni=m ?ickness ( ! lea!r & an ev5 surface on ! fle% side4 ,! samm$ goods are laid ov] suitable beams & %av$ ) special %>p knives :i* possess a turn$ edge4 ,?is h& process1 :i* dem&$ consid]able skill1 is fa/ becom+ ext9ct1 & ma*9e %av+ is already almo/ univ]sal on acc\nt ( its great] spe$4 ,! ma*9es consi/ ess5tially ( two roll]s1 "o ( :i* is smoo?1 :il/ ! o!r is a spiral knife-blade cyl9d] 7cp4 ,section ,,ii474 ,! samm$ goods are held 9 ! h&s & plac$ ov] ! smoo? roll]1 :i* is rais$ to ! cutt+ roll] by a foot treadle4 ,a numb] ( simil> op]ations 7flatt+1 :it5+1 buff+7 are c>ri$ out by a suitable *ange ( tool4 ,9 all ^! op]ations good samm+ is important4 ,splitt+ is ano!r important op]ation on tann$ lea!r4 ,9 ?is process ! lea!r is cut p>allel to its gra9 surface1 ?us yield+ two pieces ) ! same area z ! orig9al1 ! gra9 & ! fle% split4 ,x is ess5tially a ma*9e op]ation1 & is c>ri$ out by pres5t+ ! c>efully samm$ lea!r to a %>p knife-edge1 t[>ds :i* x mu/ be con/antly press$4 ,! b& knife ma*9e is ! mo/ popul> arrangem5t4 ,! knife is an endless belt1 :i* cont9ually revolves r\nd two pulley :eels ( equal size4 ,9 betwe5 ^! ! knife is horizontal1 & is !n us$ = splitt+4 ,! samm$ lea!r is pu%$ t[>ds ! blade by two fe$ roll]s1 & ! gra9 passes above ! knife on to a small plat=m1 :il/ ! fle% or split passes bel[ & falls to ! gr\nd4 ,em]y gr9d]s & ?ick felt clean]s 9 ! l[] "p ( ! ma*9e keep ! knife 9 good condition4 ,! adju/m5t ( ! ma*9e is delicate & requires consid]able exp]i5ce4 ,) c>e splits may be obta9$ d[n to #a_/af ?ick1 & sometimes z _m z #f or #g splits are obta9$ f "o hide4 ,oil+ is /ill usually done by h&1 & cod oil is /ill pref]r$ = _m classes ( goods4 ,( rec5t ye>s !re has be5 a great ext5sion ( ! use ( sulphonat$ oils1 :i* h ! valuable prop]ty ( =m+ an emulsion ) wat] or tan liquor4 ,) ^! mat]ials x is easi] to ensure ! goods be+ completely cov]$ ) oil4 ,! p5etration ( ! oil into ! lea!r is also quick] & m complete4 ,^! oils h (t5 ! disadvantage ( leav+ solid fats on ! ext]ior ( ! lea!r1 :i* gives x an ugly sme>$ appe>ance4 ,/uff+ ! dress+ lea!rs is c>ri$ out 9 a v>iety ( ways & ) a v>iety ( mat]ials4 ,! old process ( h& /uff+ employs a mixture ( tall[ & cod oil call$ dubb94 ,?is is made by melt+ ! +r$i5ts toge!r & all[+ !m to cool ) con/ant /irr+ to a ne>ly homog5e\s salve4 ,! dubb9 is bru%$ ?ickly on to ! fle% side ( ! samm$ lea!r1 :i* is !n hung up to dry4 ,z ! moi/ure dries out ! oils & s(t fats p5etrate ! lea!r & leave ! m solid fats on ! outside4 ,! proportions ( tall[ & oil are v>i$ ) ! "t ( ye> & ) ! me?od ( dry+1 = if ! dubb9 be too s(t x w run (f ! lea!r1 & if too h>d w n p5etrate x s well4 ,drum /uff+ is a m mod]n developm5t 9 :i* a high] temp]ature is employ$1 ab\t #adj ,f4 ,! drum is heat$ up by /eam or by hot air1 & ! samm$ goods are !n ins]t$ & drumm$ = a few m9utes until !y are w>m$4 ,! drum is fitt$ ) a heat$ funnel conta9+ ! melt$ grease1 :i* is run 9 ?r\gh ! holl[ axle4 ,aft] a half to ?ree-qu>t]s ( an h\r's drumm+ ! grease is completely absorb$ by ! lea!r4 ,! drumm+ is cont9u$ = a :ile until ! goods h cool$4 ,:il/ /ill w>m !y are set out to remove creases & sup]flu\s grease4 ,drum /uff+ is n only quick] ?an h& /uff+1 b also makes x possible to use ! h>d fats1 & s make a lea!r :i* c>ries m grease )\t appe>+ greasy4 ,?us 9 drum /uff+1 p>aff9 wax & wool fat are us$1 & _! p5etration assi/$ by small proportions ( cod oil or dgras4 ,if ! lea!r be too wet ! grease is n absorb$1 :il/ if x be dri] ?an usual ! lea!r w take m grease1 b ! result+ col\r is n s good4 ,!re is also ano!r me?od ( /uff+ :i* orig9ates f ! ,cont95t4 ,x is kn[n z burn+ 9 & involves ! use ( /ill high] temp]atures 7#aie to #bab ,f474 ,wet lea!r w1 ( c\rse1 n /& ?is temp]ature1 s t x is fir/ necess>y to make ! lea!r absolutely dry4 ,?is is effect$ by dry+ 9 /oves at temp]atures up to #aaj-aae ,f4 ,!re are two ways 9 :i* ! grease is appli$4 ,9 "o me?od ! melt$ grease is p\r$ by a ladle on to ! fle% side & bru%$ ov] until ev5ly di/ribut$4 ,a second application ( grease is made to ! ?ick] p>ts4 ,! hides are !n put into w>m wat] 7#abj ,f47 = ab\t a qu>t] ( an h\r1 & !n drumm$ = half an h\r4 ,9 ! o!r me?od ! goods are completely imm]s$ 9 ! melt$ fats = a few m9utes 9 a /eam-jacket] tank at a temp]ature ( #aie ,f4 ,aft] s(t5+ 9 wat] at #abj ,f4 ! goods are drumm$4 ,burn+ 9 is us$ = ! heavi] dress+ lea!rs su* z belt+ & h>ness4 ,x does n give good col\r1 b p]mits ! employm5t ( /ill m h>d fats4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #bbc1 #cgh4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bea-cab4 ,b5nett1 ,pr9ciples ( ,lea!r ,/uff+1 ,lea!r ,trades ,review1 #aiaa1 #ahf4 ,,section ,v4--,,sole ,,lea!r ,lea!r = ! soles ( boots & %oes is a matt] ( ess5tial int]e/ to all1 & =ms "o ( ! be/ appreciat$ applications ( animal proteids to useful purposes4 ,me?ods = its manufacture are z num]\s z ! factories produc+ x1 h5ce all t c be done is to describe broadly ! g5]al me?od :i* is typical ( our "t1 to classify ! _m v>ieties into types1 & to indicate ! rec5t *anges & pres5t t5d5cies4 ,sole lea!r is ma9ly manufactur$ f butt pelt1 & ! great aim is to produce a firm1 ?ick1 wat]pro( & smoo? gra9$ lea!r :i* w b5d )\t crack+4 ,x mu/ h a light tan col\r to be saleable1 & conta9 z mu* weight z possible to be pr(itable4 ,! mod]n mix$ tannage ( sole butts or sc\r$ b5ds g5]ally utilizes ox-hides ( ! ,scot* & ,engli% m>kets1 ?\gh salt$ ,cont95tals & ,s\? ,am]icans are also employ$4 ,aft] ! usual soak+ a %ort & %>p lim+ is giv54 ,! special aim 9 lim+ sole hides is to obta9 ! maximum plump+ effect ) ! m9imum loss ( hide sub/ance4 ,bo? ^! a*ievem5ts are necess>y to obta9 good weight4 ,! limes %\ld be kept z clean z possible1 :i* is be/ obta9$ by putt+ clean hides into "w4 ,?is r$uces bact]ial activity & loss ( hide sub/ance4 ,! %ortness ( ! process is atta9$ by ! use ( sodium sulphide 7f #b to #af ozs4 p] hide ( sulphide cry/als71 by :i* depilation may be accompli%$ easily 9 ab\t n9e days4 ,! am\nt ( sulphide %\ld be increas$ some:at 9 ! %ort-hair season & 9 cold wea!r4 ,"s factories take up to ab\t #ab days us+ less sulphide1 :il/ o!rs w lime 9 ab\t a week by us+ ! l>g] quantities4 ,! am\nt ( lime us$ v>ies enorm\sly1 & is inv>iably 9 great excess ( ! actual requirem5ts4 ,probably #b-c p] c5t4 on ! gre5 weight ( ! hides is all t c be really utiliz$1 ! rema9d] be+ wa/$4#e ,?is am\nts to ab\t #b-a_/b lbs4 lime p] hide1 b 9 practice x is m frequ5t to f9d #g1 #h1 #i or ev5 #aj lbs4 p] hide be+ us$4 ,! excess is innocu\s1 ow+ to ! limit$ solubility ( lime4 ,"s excess is desirable1 to replace 9 ! liquor ! lime adsorb$ by ! goods 9 plump+1 to assi/ bact]ial activity1 & also because 9 %>p lime liquors ! undissolv$ portions d n rema9 s long 9 susp5sion4 ,! use ( sulphide & o!r alkalies does n make x possible to r$uce ! am\nt ( lime us$1 x m]ely r5d]s ! excess m sup]flu\s4 ,! use ( sulphide n only %ort5s ! process1 b also %>p5s x1 on acc\nt ( ! cau/ic soda produc$ by hydrolysis4 ,usually = sole lea!r1 h[ev]1 x h>dly %>p5s x suffici5tly1 & x is v common to add also cau/ic soda 7or c>bonate ( soda7 to ! limes4 ,ab\t #b ozs4 cau/ic soda 7or its equival5t 9 c>bonate7 is us$ p] hide4 ,! hides are lim$ g5]ally by ! ?ree-pit sy/em1 giv+ ab\t ?ree days 9 ea* pit4 ,!y %\ld be h&l$ ea* day 9 ! fir/ pit 7old lime7 & once 9 ! o!r pits4 ,footnote #e3 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #abi4 ,unhair+ & fle%+ by h& lab\r is /ill common1 9 ord] to avoid great pressure on ! plump$ hide4 ,scudd+ %\ld be v light1 & 9 "s y>ds is entirely omitt$4 ,only ! lime on ! surface ( ! hide %\ld be remov$ by delim+1 & ?is imm$iately prior to ! ins]tion ( ! butts into ! tan liquor4 ,?is is to ensure good col\r & yet keep ! butts plump4 ,boric acid is ! be/ = ?is purpose1 us+ #aj-ae lbs4 p] #ajj butts4 ,! goods are ins]t$ 7& pref]ably rock$7 9 a dilute solution = a few h\rs only4 ,ab\t ! same quantity ( comm]cial lactic acid may be sub/itut$ = ! boracic4 ,?is delim+ c also be accompli%$ by add+ ! acid to ! wor/ susp5d] 9 ! tany>d4 ,to obta9 firmness & plump+ x is necess>y t ! e>ly liquors 9 tann+ %\ld be m acid ?an = o!r lea!rs4 ,) old me?ods ( tann+ "o c\ld tru/ to ! natural s\rness ( ! liquors to complete ! delim+ & replump ! goods ) acid4 ,9 su* cases any delim+ 0 also unnecess>y4 ,9 ! mod]n y>d1 h[ev]1 we get sweet liquors com+ d[n ! y>d1 p>tly on acc\nt ( ! great] proportion ( extract us$ & p>tly because ! liquors !mselves are n s old4 ,h5ce x is n[ practically always necess>y to acidify artificially ! tan liquors4 ,?is may be done by add+ a few gallons ( lactic1 acetic1 =mic1 or butyric acid to ! h&l]s & susp5d]s1 especially 9 ! w9t] & spr+4 ,x is n[ increas+ly common to place sole butts 9 a special acid ba? aft] !y h be5 9 tan liquor = ab\t a week4 ,?is ba? is (t5 made f sulphuric acid1 & may be #a or #b or ev5 #d p] c5t4 9 /r5g?4 ,! actual tann+ ( sole butts la/s ?ree to f\r mon?s1 & j prior to ! w> ! tannage consi/$ (t5 ( ab\t "o-?ird myrabs1 "o-?ird valonia1 & "o-?ird extract4 ,! myrabs & valonia 7 lea*$ toge!r1 & ! extract add$ to ! be/ lea* to make lay] liquors ( ! requir$ /r5g?4 ,"s mimosa b>k 0 g5]ally us$ also1 & n[ x is ext5sively employ$ to replace ! valonia4 ,! mo/ widely pref]r$ extract is *e/nut1 b quebra*o1 myrabs extract & mixtures h also a prom95t place1 & mimosa b>k extract an increas+ importance4 ,x is recogniz$ t ?is tannage is if any?+ too mell[1 & t if only a smoo? gra9 & plump butt c be ensur$ 9 ! fir/ weeks ( tann+1 x is mu* bett] = sole lea!r to employ ! mo/ a/r+5t tans possible & ! %>pe/ liquors 7i4e4 liquors ) a small relative proportion ( soluble non-tann9 matt]s74 ,h5ce !re is ! t5d5cy 9 sole-lea!r tann+ to employ fre% cle> liquors = ! butts & use up ! m mell[ liquors on ! (fal 7%\ld]s & bellies74 ,f\r types ( sole butt tannage w n[ be describ$1 all ( :i* illu/rate ! me?ods employ$ 9 a mod]n mix$ tannage4 #a4 ,! fir/ type consi/s 9 a f\r-mon?s tannage1 9 :i* ! liquors are work$ d[n ! y>d4 ,! butts pass fir/ ?r\gh ! susp5d]s 7#bj-dj ,bkr47 9 ab\t a week1 & are rock$ 9 ! fir/ liquors4 ,!y next ent] ! h&l]s 7#dj-ee7 r\nds ( eight pits1 six float]s & two du/]s4 ,myrabs1 or a mixture ) alg>obilla is us$ z du/+ mat]ial4 ,! goods rema9 9 ?is set = two weeks1 & %\ld !n be /ruck ?r\gh4 ,! susp5d] h&l]s 7#ee-fe7 are next ent]$1 9 :i* !y rema9 up to ?ree weeks 9 susp5sion1 be+ %ift$ =w>d on alt]nate days4 ,! goods n[ ent] ! lay]s1 ( :i* f\r are giv53 fir/ #gj = "o week2 second #ge = two weeks2 ?ird #hj = ?ree weeks2 & f\r? #ij = a mon?4 ,! goods ?us take sixte5 weeks to tan1 ( :i* t5 weeks 7#fb-a_/b p] c5t47 are 9 lay]s4 ,! sy/em ( work+ ! liquors is exp5sive1 & is only possible if ! butt liquors c be sp5t out by ! (fal4 ,! be/ or f\r? lay]1 #ij1 is made f ! be/ lea* liquor1 #fe1 & extract 7*e/nut ) "s oakwood or mimosa b>k74 ,aft] use x becomes ! second lay]1 #ge4 ,! ?ird lay]1 #hj1 is also made f fre% lea* liquor & extract 7*e/nut ) "s myrabs or mix$ extract74 ,aft] be+ us$ ?us x is us$ = ! fir/ lay]1 #gj4 ,! us$ fir/ & second lay]s are mix$ toge!r & us$ p>tly to =m ! belly lay]s1 & p>tly to make a %>p liquor = ! h&l]s 7#ee-dj7 by dilut+ ) #dj lea* liquor & add+ quebra*o extract4 ,! old h&l] liquor is run to ! susp5d]s 7#dj-bj71 & f9ally us$ = col\r+ (f ! (fal 9 drum or paddle #ah4 ,! susp5d] h&l]s 7#fe-ee7 are made f fre% lea* liquor & *e/nut extract4 ,!y are aft]w>ds us$ to make %\ld] lay]s4 ,! c\rse ( ! liquors is %[n 9 ! diagram bel[4 ,x w be se5 t fre% lea* liquor & fre% mat]ial are us$ to ea* set except ! susp5d]s1 :i* mu/ h "s mell[ness to ensure plump+ & smoo? gra94 ,lay] liquors are us$ twice only1 & !n 7:5 only five weeks old7 pass to ! h&l]s4 ,^! are fur!r %>p5$ by fre% lea* liquor & fre% extract & dry mat]ials4 ,! =w>d h&l]s are fre% liquors ) fre% extract4 ,?is tannage is fairly typical ( high-class sole lea!r1 9 :i* ! liquors are work$ d[n ! y>d1 b work$ t[>ds ! (fal1 :i* ?us receives liquors ) relatively great] proportions ( mell[ tans & soluble non-tans4 ----------,lea* liquor------------------- _/ ,v #d? lay]1 #ij ,v ,v #crd lay]1 #hj #bnd lay]1 #ge ,v #a/ lay]1 #gj _/ _/ ,v ,v 7mixture7--bellies _/ ,v ,v ,v ,susp5d] h&l]s--7#fe-ee77%\ld]s7 ,h&l]s1 #ee-dj ,v ,susp5d]s --(fal #b4 ,! second type consi/s 9 a tannage ( ab\t f\r mon?s1 9 :i* ! liquors are n work$ d[n ! butt y>d4 ,9 ?is me?od also !re is an attempt to save mu* ( ! lab\r 9 h&l+1 fir/ by %ort5+ ! "t 9 ! h&l]s by "o week 7z comp>$ ) ! above71 & second by fus+ ! two progressive h&l] sets into two sets ( equal /r5g?1 ?r\gh :i* ! goods pass m sl[ly & ) less di/urbance4 ,! goods g ?r\gh ! susp5d]s 7#aj-be7 9 ab\t a week1 rock+ 9 ! e>ly liquors1 & !n into l>ge r\nds ( h&l]s 7#cj-de7 = "o mon?4 ,! h&l]s consi/ ( float]s & sev]al du/]s1 9 :i* ! butts are laid away ) #a-c cwt4 myrabs4 ,! goods next ent] ! lay]s1 ( ! same /r5g? z 9 ,type #a1 & 9 :i* !y rema9 ! same "t4 ,! total tannage is ?us #ae weeks1 ( :i* #aj weeks 7ne>ly #fg p] c5t47 are 9 lay]s4 ,! be/ or f\r? lay] is made up f lea* liquor & extract1 & is !n us$ successively z a ?ird1 second & fir/ lay]1 & !n passes to ! (fal lay]s4 ,! h&l] liquor is made entirely f fre% lea* liquor & quebra*o extract1 & is a %>p liquor ( great] /r5g? ?an its ,bkr4 /r5g? w\ld indicate4 ,! old h&l] liquor is run to ! butt susp5d]s4 ,! c\rse is repres5t$ ?us3-- ,lea* liquor _/ _/ #d? lay]1 #ij _/ _/ #crd lay]1 #hj _/ _/ #bnd lay]1 #ge _/ _/ #a/ lay]1 #gj--(fal lay]s ,v ,h&l]s 7#de-cj7 ,v ,susp5d]s 7#be-aj7 #c4 ,! ?ird type consi/s ( a %ort ?ree-mon?'s tannage 9 :i* ! liquors are work$ /raight d[n ! y>d4 ,to comp5sate = ! %ort "t x is necess>y to h /rong] lay] liquors 9 :i* ! goods sp5d a /ill great] proportion ( _! total "t4 ,! /rong] liquors involve a great] proportion ( extract1 p>ticul>ly ( quebra*o1 :i* fact causes ! :ole ( ! liquors to be %>p] ?an _! ,bkr4 /r5g? indicates1 & ju/ifies !m be+ work$ /raight d[n ! y>d4 ,! goods g ?r\gh susp5d]s 7#bj-dj7 z usual "o week1 & !n pass into susp5d]-h&l]s 7#dj-fj7 = two weeks1 & !nce to ! lay]s4 ,9 ! fir/ two ( ^! 7#fe & #gj7 !y are actually 9 susp5sion1 a week 9 ea* liquor4 ,!y are !n du/$ d[n = t5 to elev5 days1 fir/ 9 #he & !n 9 a #ie liquor1 & f9ally = a mon? 9 a liquor ( #aaj4 ,! total tannage is ?us twelve weeks1 ( :i* n9e weeks 7#ge p] c5t47 are 9 lay]s4 ,!re is consid]ably less h&l+ ?an 9 ,type #b1 & x is m conv5i5t1 ! goods be+ 9 susp5sion4 #d4 ,! f\r? type is also a ?ree-mon?'s tannage4 ,9 ?is x is attempt$ to obta9 ev5 great] weight ) /ill less lab\r4 ,! lay] liquors are kept mu* /rong] by ! m ext5sive use ( extract1 & ?is makes x impracticable z well z too co/ly to run ^! liquors d[n ! y>d4 ,!y are !re=e repeat$ly /r5g!n$ ) extract & us$ aga94 ,! goods g ?r\gh susp5d]s 7#bj-dj7 z usual "o week1 & !n ?r\gh a r\nd ( susp5d]-h&l]s 7#dj-ee7 consi/+ ( fre% %>p liquor f ! lea*es toge!r ) quebra*o extract4 ,!y are 9 ?is set two weeks1 & !n are laid away4 ,!y receive ?ree lay]s3 fir/1 #aje = #b weeks2 second1 #aaj = ?ree weeks2 & f9ally1 #abj = a mon?4 ,( ! twelve weeks1 !re=e1 n9e weeks 7#ge p] c5t47 are sp5t 9 lay]s4 ,9 ?is me?od ! goods are imm]s$ 9 #c p] c5t4 sulphuric acid aft] pass+ ?r\gh ! susp5d]s4 ,!re is possible1 ( c\rse1 a trem5d\s numb] ( v>iants ( ! above types4 ,! numb] ( h&l] r\nds is det]m9$ by ! numb] ( butts be+ dealt )4 ,) a l>ge numb] x is m easily possible to arrange = !m to be 9 progressive /r5g? z 9 ,type #a4 ,!re are also _m sy/ems ( work+ ! lay]s1 ( :i* ! mo/ notable is to make ! second or ?ird lay] f fre% lea* liquor & extract1 & /r5g!n x ) extract = ! succe$+ lay]s4 ,x is !n us$ z a fir/ lay] & work$ d[n ! y>d4 ,! bellies & %\ld]s (t5 g ?r\gh sep>ate sets ( liquors1 b x is common to put !m ?r\gh susp5d]s1 & ev5 h&l]s toge!r4 ,!y receive1 ( c\rse1 a di/9ctly %ort] tannage1 & are (t5 drumm$ ) extract be=e lay+ away or aft] ! fir/ lay]4 ,by way ( illu/ration1 ! c\rse ( ! (fal & _! liquors may be giv5 9 ! case ( ,type #a4 ,! %\ld]s & bellies are col\r$ (f 9 a paddle or drum ) old butt susp5d] liquor1 :i* is !n q exhau/$4 ,!y !n pass ?r\gh susp5d]s 7#ah-dj7 toge!r 9 #d-e days1 & g ?r\gh a h&l] r\nd 7#dj-ee7 = #c weeks1 includ+ "o du/]4 ,! bellies are remov$ aft] #b weeks1 & giv5 ?ree lay]s 7#fj1 #gj1 #hj7 ( a week ea*4 ,!y receive1 !re=e1 ne>ly #f weeks 9 all4 ,! %\ld]s also h ?ree lay]s 7#fj1 #fe & #hj7 ( #b1 #c & #d weeks respectively4 ,! c\rse ( ! liquors is %[n ?us3-- ,butt lay]s ,butt susp5d] ,butt susp5d]s 7& extract7 ,h&l]s 7 extract7 ,v ,v ,belly lay]s ,%\ld] lay]s 7#hj-fj7 7#hj-fj7 _/ ,v ,v ,(fal h&l]s 7#ee-dj7 ,v ,v ,(fal drums ,(fal susp5d]s 7#dj-ah7 7#ah7 _/ _/ _/ _/ _/ _/ ,v ,v ,dra9 ,! tann$ butts are pil$ = #b-c days1 sometimes r9s$ to remove du/+ mat]ial1 & !n sc\r$ ei!r by ma*9e or by drumm+ ) sumac & extract4 ,?is removes bloom1 b causes "s loss ( weight4 ,vatt+ or blea*+ n[ foll[s1 9 :i* x is attempt$ n only to blea* ! col\r ( ! lea!r1 b also to imp>t z mu* weight z possible4 ,! vat liquor is made sev]al degrees /rong] ?an ! la/ lay] by means ( quebra*o blea*+ extract & good col\r$ *e/nut or myrabs extract4 ,! liquor is kept w>m by a /eam coil1 at ab\t #ajj ,f41 b n mu* m )\t risk4 ,! goods rema9 9 ! blea* liquor #b-c days & are !n hors$ or susp5d$ to dra94 ,suma* is sometimes us$ 9 ! vats4 ,a new vat liquor mu/ be made up aft] "s weeks' use4 ,! goods are sometimes r9s$ 9 weak sumac liquor be=e vatt+ to get good p5etration1 & sometimes aft] to ensure good col\r4 ,! butts are next oil$ & hung up 9 a d>k %$ & all[$ to dry sl[ly & ev5ly to an india-rubb]y consi/5cy & r slimy feel4 ,!y are !n /ruck out by ma*9e1 wip$1 re-oil$ & aga9 hung up to dry1 pref]ably ) sulphonat$ oil4 ,aft] a %ort dry+ to a suitable & ev5 condition !y are roll$ on1 &1 possibly aft] fur!r dry+1 roll$ (f ) great] pressure1 & !n dri$ = a day or two ) ! help ( a little /eam4 ,f9ally !y are ma*9e-bru%$ & s5t to ! w>eh\se1 :]e !y are weigh$ & classifi$4 ,! (fal is (t5 drum oil$4 ,x ne$s m /rik+ & is m difficult to obta9 9 suitable condition = /rik+1 roll+4 ,x is treat$ simil>ly to butts1 b (t5 also goes = dress+ lea!r1 & may be split4 ,x is ( "s int]e/ to comp>e ! above processes ) t once v popul> manufacture ( bloom$ butts 9 ! ,we/ ( ,engl& f ,s\? ,am]ican salt$ hides4 ,^! receive a lim+ f #ab-ad days1 us+ #ab-af lbs4 ( lime p] hide4 ,!y receive !n a tannage ( ab\t #i mon?s1 compris+ #c weeks 9 susp5d]s 7#bj-dj7--v s\r & mell[ liquors--#d weeks 9 h&l]s 7#dj-ee71 #d weeks 9 du/]s 7#fj71 #d weeks 9 r\nd made f hemlock extract 7#fj71 & #bj weeks 9 six lay]s 7#fj-ij7 9 :i* !y 7 du/$ heavily ) valonia4 ,oakwood extract 0 us$ = ! lay]s1 :i* took #eg p] c5t4 ( ! total "t4 ,! butts 7 sc\r$ 9 a mu*-dri$ condition1 s t only ! loose & surface bloom 0 remov$4 ,no blea*+ 0 giv5 9 ! mod]n s5se4 ,9 ! old oak-b>k tannage ( sole lea!r up to #ab mon?s 7 tak5 = tann+1 two-?irds to f\r-fif?s ( :i* "t ! goods 7 9 lay]s4 ,! /ronge/ liquor r>ely exce$$ #ej ev5 :]e valonia & gambi] 7 also us$1 & r m ?an #cj if n4 ,x w be und]/ood f ! above t ! t5d5cy = _m ye>s has be5 to %ort5 ! "t & ! lab\r requir$ = tann+4 ,drum tann+ is obvi\sly ! next /age 9 %ort5+ ! "t4 ,9 "o su* process ! butts are put ?r\gh susp5d]s 7#be-dj7 = #b weeks1 drumm$ = #ab h\rs 9 an #hj extract liquor1 & f9ally 9 a neat extract #bjj = #cf h\rs4 ,drum tann$ sole lea!r1 h[ev]1 is n z yet ( good quality2 ! gra9 is n smoo?1 & ! heavy weight f9i% 7/rik+ & roll+7 ne$$ to c\nt]act ?is t5d5cy is liable to cause poor sub/ance4 ,! lea!r1 too1 readily wets & goes out ( %ape4 ,possibly "s drumm+ may be adopt$ to save "t 9 ! e>ly lay]s1 b ! mo/ s]i\s rival to ! #c mon?s' tannage is ! wat]pro( *rome sole lea!r 7,"p ,,iii41 ,section ,v474 ,,ref]5ces4 ,p>k]1 ,j4,s4,c4,i41 #aijb1 #hci4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #bbj4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #agi1 #bei4 ,b5nett1 ,j4,s4,c4,i41 #aiji1 #aaic4 ,,section ,,vi4--,,belt+ ,,lea!r ,! manufacture ( belt+ lea!r is well illu/rat$ by ! tann+ & f9i%+ ( /rap butts4 ,9 g5]al1 ! tannage pres5ts _m po9ts ( great simil>ity ) ! tannage ( sole lea!r2 inde$1 ! resemblance is s close t 9 "s factories !re is little diff]5ce obs]v$1 & ! curry+ & f9i%+ op]ations are reli$ on to produce ! desir$ diff]5ce 9 f9al results4 ,nev]!less1 !re is consid]able diff]5ce 9 ! type & ideal ( ! two lea!rs1 :i* may be express$ 9 trade p>lance z a great] mell[ness = ! belt+ lea!r1 & 9 ! be/ me?ods ( manufacture ?is fact is 9 evid5ce ?r\gh\t ! :ole process ( manufacture4 ,9 lim+1 !re ne$ be little diff]5ce betwe5 sole & belt+ hides1 & a %>p treatm5t ( #i-aj days1 by ! ?ree-pit sy/em1 ) a day or two extra 9 ! colde/ wea!r1 w\ld meet ord9>y ne$s4 ,= ! cons]vation ( hide sub/ance & = ! sav+ ( "t a %ort] lim+ is sometimes giv51 9 :i* m sulphide is employ$ ?an is usual = sole lea!r4 ,ev5 ! v %ort processes ( lim+1 #a to #c days1 :i* involve ! use ( /rong solutions ( sodium sulphide1 h be5 successfully employ$ = belt+ lea!r4 ,! t5d5cy to h>% gra9 ) su* processes is n s s]i\s a defect ) belt+ z ) sole lea!r1 & c be m9imiz$ by c>eful delim+4 ,am]ican & ,cont95tal factories t5d to fav\r ! use ( ^? quick processes :i* employ w>m wat] 9 addition to sulphide4 ,! hides aft] a %ort lim+ 9 sulphide limes are imm]s$ 9 w>m wat]1 :i* greatly accel]ates bo? ! *emical & bact]ial actions4 ,= example1 aft] ab\t #c days' lim+1 9 :i* bo? old & new limes are us$ z usual1 ! hides may be ?r[n into wat] f #ajj-aje ,f41 & w be ready = depilation 9 #g or #h h\rs4 ,ev5 a /rong] lim+ may be giv51 especially if ! soak+ is unusually prolong$4 ,su* processes und\bt$ly save hide sub/ance1 & ! pelt is obta9$ m free f lime1 b !y h ! disadvantage t ! natural grease ( ! hide is only imp]fectly kill$ 7i4e4 saponifi$ or emulsifi$71 & may int]f]e ) ! normal c\rse ( ! tannage4 ,! plump+ is also apt to be insuffici5t4 ,on ! o!r h&1 lim+ processes are also us$ 9 :i* a mell[] lim+ or a long] lim+ is pref]r$ 9 ord] to produce ! desir$ degree ( s(tness & pliability 9 ! f9i%$ lea!r4 ,belt+ mu/ n be too s(t1 ( c\rse1 & x w be cle> t ! requir$ diff]5ce f sole lea!r c be produc$ ei!r 9 lim+ or tann+ or p>tly 9 bo?4 ,^! consid]ations also decide :e!r bat+ is to be omitt$ or n4 ,a h>d a/r+5t tannage 9 s\r liquors aft] a %>p lim+ might make bat+ ess5tial1 b 9 ^! days x is usual to avoid x & produce ! effect 9 o!r ways4 ,a light bat+ ( a few h\rs is sometimes giv51 b x is m unusual to delime ! gra9 ?or\ghly ) boric acid1 us+ up to #bj lbs4 p] #ajj butts4 ,crack9ess is a fatal defect 9 /rap butts1 s t a s\nd gra9 mu/ always be obta9$4 ,g5]ally speak+1 !re=e1 /rap butts receive m wa%+ 9 wat]1 & r m delim+ ?an sole lea!r1 ev5 :5 !y are n bat$4 ,x is also usual to scud mu* m ?or\ghly1 & to r\nd a l>g] proportion ( butt1 especially 9 l5g?4 ,! tannage is usually c>ri$ out ) a bl5d :i* includes a mu* great] proportion ( ! fruit tans1 & correspond+ly less ( extract4 ,di/9ctly m myrabs are us$ ?an 9 sole lea!r tannages1 9 ! dry mat]ial1 & among/ ! extracts *e/nut is pref]r$ to quebra*o1 & myrabs to mimosa b>k1 ?\gh all ^! may be us$ 9 "s degree4 ,9 ! pa/ ! mo/ fav\r$ extract has be5 und\bt$ly gambi]1 :i* gives a tannage :i* is easily curri$ & imp>ts ! requir$ mell[ness to ! uncurri$ lea!r4 ,! great exp5se ( ?is mat]ial1 h[ev]1 toge!r ) ! adv5t ( drum /uff+ & %ort] tannages 9 /rong] liquors1 h t5d$ to cause a consid]able r$uction 9 ! proportion us$ = /rap butts1 & to limit its employm5t to ! e>li] /ages ( tann+4 ,! same t5d5cies = r$uc+ ! "t tak5 to tan1 employ+ /rong] liquors1 & secur+ economy ( lab\r 9 h&l+1 h be5 evid5c$ 9 ! tannage ( /rap butts z 9 sole butts4 ,x is nev]!less true t1 broadly speak+1 /rap butts receive r m h&l+ & r weak] liquors ?an sole butts4 ,a great] am\nt ( me*anical assi/ance is also employ$ ) e>ly /ages 7paddl+1 drumm+1 rock+74 ,?is is less objectionable = curri$ lea!r ?an = sole butts4 ,! h&l+ is m usually 9 susp5sion4 ,! liquors are usually work$ /raight d[n ! y>d z a great] mell[ness is ne$$ 9 ! e>ly liquors ?an = sole butts4 ,! (fal is giv5 a sep>ate tannage & (t5 us$ = diff]5t purposes1 e4g4 ! %\ld]s = welt+ & ! bellies = fancy goods4 ,plump+ ) sulphuric acid is g5]ally consid]$ inadmissible = /rap butts4 ,x has be5 %[n t lea!r conta9+ sulphuric acid t5ds to p]i% aft] ! lapse ( a numb] ( ye>s4 ,sole lea!r w be worn up be=e ?is effect is obs]v$1 b belt+ is an article :i* is int5d$ to la/ mu* long]1 & ! use ( sulphuric acid is consequ5tly inadvisable4 ,plump+ mu/ be obta9$1 to a consid]able ext5t1 b mu/ be a*iev$ by ! organic acids 7lactic1 acetic1 =mic & butyric acids74 ,a few gallons ( su* acids are consequ5tly add$ to ! h&l]s1 especially 9 ! w9t] & spr+4 ,less may be us$ 9 ! autumn1 :5 ! lay] liquors :i* f]m5t$ 9 ! summ] mon?s h work$ d[n to ! susp5d]s4 ,a mixture ( ^! acids is usually bett] ?an any "o alone1 = !y n only diff] v consid]ably 9 price1 b also h diff]5t p[]s ( neutraliz+ lime & plump+ ! goods4 ,lactic acid 7,m4,w4 #ij71 ,acetic acid 7,m4,w4 #fj71 & =mic acid 7,m4,w4 #df7 are ea* monobasic acids2 consequ5tly #c lbs4 =mic w neutralize z mu* lime z #d lbs4 acetic or #f lbs4 lactic4 ,_! plump+ p[]s are some:at influ5c$ by ! anion4 ,9 det]m9+ :at quantities to take1 ! comm]cial /r5g? ( ! acids mu/ also be consid]$4 ,=mic is (t5 #hj-ij p] c5t4 pure1 acetic #fj-hj p] c5t41 & lactic #dj-fj1 b may be z l[ z #be p] c5t4 ,! bl5d mu/ be adju/$ accord+ly4 ,z /rap butts d n ne$ ! firmness ( sole lea!r1 less ( ^! acids may be us$ ?an = sole butts4 ,! exact nature ( ! tannage & ! /r5g? ( ! liquors is l>gely influ5c$ by comm]cial consid]ations4 ,if ! manufactur] is bo? tann] & curri]1 he ne$ n g to su* great exp5se 9 /rong liquors & 9 "t 9 lay]s1 = he c obta9 "s ( ?is weight 9 curry+4 ,if1 h[ev]1 ! tann] sells ! butts r\gh dri$1 he mu/ naturally aim at obta9+ great] weight 9 tann+4 ,! actual details ( ! tann+ processes are z usual v v>i$1 b may be classifi$ accord+ to type1 j z 9 ! case ( sole butts4 ,illu/rations w n[ be giv54 ,type #a1 :i* may be comp>$ ) ,type #a = sole butts1 is a tannage ( ab\t #e mon?s4 ,! goods pass ?r\gh susp5d]s 7#h-cj7 9 #b-a_/b weeks1 & !n pass to ! h&l]s 7#cj-ej71 9 :i* !y rema9 a mon?2 !y are !n put into susp5sion aga9 & pass ?r\gh ! susp5d] h&l]s 7#dj-ee71 :i* takes #b-a_/b weeks4 ,9 ?is r\nd mu* gambi] is add$1 & ! goods are frequ5tly h&l$4 ,f\r lay]s are usually giv51 viz4 fir/ lay] #ee1 "o week2 second lay] #fj1 two weeks2 ?ird lay] #fe1 f\r weeks2 & f\r? lay] #ge1 f\r weeks4 ,! tannage is ?us #bj weeks1 ( :i* #aa weeks 7#ee p] c5t47 are 9 lay]s4 ,extra lay]s may be giv5 to heavi] goods1 us+ /rong] liquors made up ) extract4 ,all liquors "w /raight d[n ! y>d4 ,! tannage consi/s ( #ce p] c5t4 myrabs1 #ce p] c5t4 valonia1 #aj p] c5t4 ,natal b>k1 & #bj p] c5t4 extract1 *iefly gambi]1 ?\gh "s *e/nut & quebra*o are us$4 ,type #b repres5ts ! mod]n t5d5cy to use /rong] liquors & a %ort] "t4 ,! /rap butts pass ?r\gh ! susp5d]s 7#bb-ej7 9 #a-a_/b weeks1 dur+ ab\t a ?ird ( :i* "t !y are rock$4 ,!y next pass ?r\gh two sets ( susp5d]-h&l]s 7#ej-fg & #fg-hj71 :i* takes a mon?1 & !nce to ! lay]s4 ,?ree lay]s are giv5 7#he1 #ij & #ajj71 9 :i* ! goods rema9 "o1 ?ree & f\r weeks respectively4 ,! tannage is ?us #ac-a_/b weeks1 ( :i* #h weeks 7ne>ly #fj p] c5t47 are 9 lay]s4 ,! liquors "w d[n ! y>d4 ,long] "t may be giv5 to heavi] goods4 ,! tannage consi/s ( #dj p] c5t4 myrabs1 #ce p] c5t4 valonia or ,natal b>k1 & #be p] c5t4 extract1 *iefly *e/nut1 ?\gh "s gambi] may be add$ to ! susp5d]s4 ,h[ev] tann$1 /rap butts are fir/ dri$ out r\gh ov] poles4 ,?is assi/s 9 mak+ ! tannage p]man5t1 on acc\nt ( second>y *anges discuss$ 9 ,section ,,iii4 ,!y are next wet back = curry+ by soak+ 9 wat] or suma* liquor = a few h\rs & pil+ to become s(t & ev54 ,! fir/ op]ation is skiv+1 :i* is a light %av+ on ! fle% side1 c>ri$ out by a %>p slick] ) a turn$ edge4 ,! butts are next sc\r$ ?or\ghly by ma*9e on bo? fle% & gra91 & suma*$ 9 a vat = sev]al h\rs at #ajj ,f41 aft] :i* !y are slick$ out & hung up 9 a cool %$ to samm = /uff+4 ,h& /uff+ is (t5 /ill pref]r$1 ) tall[ & cod oil4 ,! butts are next set out1 & x is important t ?is %\ld be ?or\ghly done4 ,ma*9es are n[ g5]ally us$1 & ! goods are (t5 reset aft] fur!r dry+4 ,aft] dry+ out completely !y are giv5 a light coat+ ( tall[ & laid away till want$ = cutt+ up into /raps1 :i* is n[ done by ma*9]y4 ,a ,cont95tal me?od = mak+ belt+ lea!r is to give #f weeks 9 a susp5d] set 7#gj-bd7 ( twelve pits arrang$ on ! press sy/em1 runn+ two fre% liquors a week1 & to give !m two lay]s 7#bd & #bh7 ( #f & #h weeks4 ,! mat]ial is *iefly p9e b>k1 b "s oak b>k1 valonia1 myrabs & quebra*o are also us$4 ,! goods are /uff$ by burn+ 91 molt5 fat be+ p\r$ on ! fle% side4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp #aid1 #bie4 ,,section ,,vii4--,,h>ness ,,lea!r ,:5 discuss+ ! "q ( oak b>k 7,section ,,iii471 reasons 7 advanc$ = its decreas$ use & popul>ity4 ,^! 7 quickly appreciat$ 9 ! sole lea!r trade1 b ! obsolesc5ce ( oak b>k 9 ! dress+-lea!r section 0 mu* m prolong$1 p>tly because !re 0 less press+ ne$ to obta9 good weight 9 ! actual tann+1 & p>tly because 9 "s bran*es ( dress+ lea!r1 su* z belt+ & h>ness1 a lea!r 0 requir$ ( great durability & t\ghness1 = :i* qualities oak b>k tannage _h a des]v$ly high reputation4 ,h5ce h>ness lea!r manufacture af=ds a good illu/ration ( ! transition betwe5 ! me?ods ( ! late n9ete5? & ^? ( ! tw5tie? c5tury4 ,) ! use ( oak b>k l+]$ ! old me?ods ( lim+1 bat+ & tann+ 9 weak liquors = a long "t ) pl5ty ( gambi]4 ,h5ce 9 ?is section x w be necess>y to obs]ve a gradual transition ( me?od1 bo? 9 wet "w & tann+4 ,x %\ld be po9t$ out t ?is transition has n be5 & is n go+ on 9 all factories at ! same rate4 ,_m factories rema9 9 :i* ! old me?ods are /ill pref]r$ at "s /ages ( ! manufacture1 & "s rema9 9 :i* _m ( ! *anges indicat$ bel[ h n tak5 place at all4 ,! lea!r trade has always be5 consid]$ cons]vative 9 its me?ods1 b x %\ld be realiz$ t mu* ( ! prejudice 9 fav\r ( old me?ods is due to ! public1 & t aft] all tann]s & curri]s1 l o!r bus9ess m51 h to suit _! cu/om]s4 ,! m>* ( indu/ry is n l a regim5t 9 l9e2 x is r m l nature1 a survival ( ! mo/ adaptable4 ,hides = h>ness lea!r are lim$ 9 v>i\s ways1 ( :i* ! foll[+ are types4 #a4 ,a r mell[ lim+ ( #aj-ae days 7long] ?an = sole lea!r71 9 :i* no?+ b lime is us$1 & a c]ta9 am\nt ( old liquor us$ 9 mak+ up ! new limes4 ,! lim+ 0 c>ri$ out by ! "o-pit sy/em1 b ! goods & liquors 7 kept clean by a good soak+ process4 ,h5ce ! loss ( hide sub/ances 0 n v great2 goods s treat$ 7 bat$ be=e tann+4 #b4 ,a %ort] lim+ ?an ! above by ! ?ree-pit sy/em4 ,?is sav$ "t 7tak+ #i-aj days71 sav$ hide sub/ance1 & ensur$ great] regul>ity ( treatm5t4 ,! limes 7 ab\t z mell[1 b a little sulphide 7#b-d ozs4 p] hide7 0 us$ to assi/ ! depilation1 especially dur+ ! %ort-hair season4 ,^! goods 7 also bat$4 #c4 ,a di/9ctly long] lim+1 #ae-af days1 9 mell[] limes4 ,?is diff]$ f ,type #a also 9 ! respect t great] regul>ity 0 ensur$ by ! ?ree-pit sy/em2 a foot or two ( old liquor 0 us$ 9 mak+ up ! new lime4 ,m hide sub/ance 0 lo/ ?an 9 ei!r ( ! above processes1 b ?is 0 delib]ate1 ! object be+ to disp5se ) bat+1 :i* is always light = h>ness hides4 ,?us a long] & mell[] b sy/ematic lim+ 0 us$ z a sub/itute = %ort] lim+ & bat+4 ,no sulphide 0 us$ 9 ?is process4 #d4 ,a %ort lim+ ( #f-g days1 us+ up to #ab ozs4 ( sulphide p] hide4 ,! object "h is to save "t & hide sub/ance4 ,! ?ree-pit sy/em is pref]r$4 ,bat+ aga9 becomes necess>y1 b ! pigeon-dung bate is replac$ by artificial bates1 less objectionable1 quick]1 & m sci5tific 9 managem5t4 #e4 ,a /ill %ort] process ( ab\t five days1 us+ /ill m sulphide 7ab\t #af-bj ozs4 p] hide71 toge!r ) "s calcium *loride to r$uce h>%ness4 ,9 su* a me?od !re is a t5d5cy to rev]t to ! "o-pit sy/em1 :i* involves r less lab\r4 ,! ?ree-pit sy/em %[s to a great advantage 9 ! long] processes ( lim+ :5 ! process is r$uc$ to five days2 !re is little diff]5ce betwe5 ! two1 = a "o-pit sy/em is a two-liquor me?od4 ,h5ce aga9 an artificial bate is us$4 ,! v>i\s me?ods ( lim+1 toge!r ) analog\s v>iations 9 tannage1 h result$ 9 great v>iety 9 bat+4 ,sometimes up to ?ree days' bat+ has be5 giv5 at #gj ,f41 b m (t5 ! goods are m]ely imm]s$ ov]night1 & !n delim$ ) boric acid1 b ) sulphide processes x is an advantage to use "s ( ! comm]cial bates ( ! ammonium *loride type1 & f9i% (f ) boric acid4 ,scudd+ is always m ?or\gh ?an = sole or belt+1 ! hides are r\nd$ into long butts :i* include mo/ ( ! %\ld] h>ness backs4 ,! goods are sometimes bate %av$4 ,a few tannages w n[ be outl9$1 9 ord] ( hi/oric type4 ,type #a may be tak5 to repres5t ! s-call$ high-class process 9 :i* oak b>k myrabs & valonia are ! /aple mat]ials4 ,a good deal ( gambi] is also us$1 & a little myrabs & *e/nut extract are helpful 9 atta9+ ! desir$ /r5g? ( liquor4 ,! backs g fir/ ?r\gh susp5d]s 7#h-cj71 :i* takes up to ?ree weeks1 & !n 9 to h&l]s 7#cj-dj7 = f\r weeks1 consi/+ ( r\nds ( cle> liquor4 ,!y next g ?r\gh a du/] r\nd1 9 :i* !y are put = a week ) oak b>k & myrabs into a liquor ( #de4 ,f\r lay]s are giv5 7#ej1 #ee1 #fj & #fe71 9 :i* ! goods rema9 = two1 ?ree1 f\r & five weeks respectively1 oak b>k be+ ! *ief du/+ mat]ial4 ,! tannage is ?us = tw5ty weeks4 ,light backs receive less "t 9 ! lay]s 7only #aa weeks74 ,if ! tann] is also ! curri]1 ! f\r? lay]s are omitt$4 ,he !n saves five weeks & gets ! weight 9 ! /uff+4 ,type #b is a tannage 9 :i* oak b>k & valonia are replac$ by myrabs1 mimosa b>k & *e/nut extract4 ,x is !re=e consid]ably *eap] & probably no less durable4 ,exp5se is also curtail$ 9 h&l+4 ,! h>ness backs g ?r\gh susp5d]s 7#af-cj7 9 two weeks1 h&l]s 7#cj-de7 9 f\r weeks1 & !n receive f\r lay]s ( ! same /r5g? z 9 ,type #a1 b only "o1 two1 ?ree & f\r weeks respectively4 ,! la/ lay] is omitt$ = light h>ness1 & an extra lay] ( #ge is giv5 if ! tann] is n ! curri] also4 ,?us ! usual tannage is #af-bj weeks1 ( :i* #aj-ad weeks 7#fc-gc p] c5t47 are 9 lay]s4 ,type #c is a tannage :i* may consi/ ( myrabs 7#ee p] c5t471 valonia or mimosa b>k #be p] c5t41 & extract 7#bf p] c5t474 ,! extract is *iefly quebra*o1 ?\gh "s *e/nut may be us$4 ,m valonia & less myrabs may be us$ if desir$ 7& :5 possible71 & myrabs extract w !n replace quebra*o & *e/nut4 ,! goods are col\r$ (f 9 drums or paddles1 & !n pass ?r\gh two sets ( susp5d]s h&l]s 7#bj-ee & #ee-ge74 ,!y are h&l$ up & d[n v frequ5tly 9 ! fir/ set & rapidly pass into /rong] liquors4 ,! backs !n receive ?ree float]s at #hj1 9 ea* ( :i* !y rema9 "o week4 ,! tannage is complet$ by ?ree lay]s3 fir/1 #he = "o week2 second1 #ij = "o week2 ?ird1 #ie = two weeks4 ,! tannage is ?us #aa weeks1 ( :i* #g weeks involve little lab\r4 ,if ! tann] is n ! curri]1 /ill /rong] liquors may be us$4 ,9 all ^! tannages little or no acid is us$ = plump+1 z ! natural acids ( ! liquors are suffici5t to ensure :at is necess>y 9 ?is direction = ?is class ( lea!r4 ,a little organic acid or ev5 boric acid may be us$ 9 ! e>lie/ liquors = delim+ purposes1 :5 necess>y4 ,aft] tann+ ! goods are dri$ out & sort$ 9 ! r\gh /ate4 ,h>ness is a some:at broad t]m1 & !re is scope = consid]able v>iety 9 classification4 ,! hides are sometimes n r\nd$ until aft] tann+4 ,! f9i%$ article may be any grade betwe5 heavy h>ness = artill]y & lea!r = ord9>y bridles4 ,9 curry+ heavy black h>ness1 ! backs are soak$ & samm$ = %av+4 ,light] goods may be ma*9e-%av$1 b ! heavie/ are %av$ lightly by h& ov] ! beam or m]ely skiv$ ) ! %av+ slick]s4 ,! neck ne$s mo/ att5tion1 & x is (t5 advisable to /one by ma*9e & split4 ,! sc\r+ %\ld be ?or\gh1 on fle% & gra94 ,?is is done by ma*9e1 & n only cleans ! goods f bloom1 dirt & sup]flu\s tan1 b also assi/s 9 sett+ out4 ,suma*+ may be = sev]al days1 m]ely ov]night or ev5 only = a few h\rs1 be+ /on$ aft] wett+ back to temp]4 ,h&-/uff$ goods get a coat ( cod oil fir/1 & dur+ ! dry+ are (t5 well set out4 ,drum-/uff$ goods are well set out by ma*9e1 & aft] "s dry+1 /on$ & reset by h&4 ,x is n[ usual to buff ! gra91 i4e4 remove ! co>s] p>ts by light %av+4 ,?is prev5ts crack+ 9 ! f9i%$ article4 ,! goods are black$ ) logwood1 iron & ammonia1 ?9ly dubb9$ aga91 aga9 well set out & tall[$4 ,sett+ out1 inde$1 may be done at any conv5i5t opportunity4 ,! sup]flu\s grease is remov$ by slick+1 scrap+1 bru%+ ) a /iff bru%1 & f9ally ) a s(t bru%4 ,= br[n h>ness ! goods are m c>efully select$1 m ?or\ghly sc\r$ & suma*$1 & blea*$ frequ5tly ) oxalic acid4 ,!y are h& /uff$1 /a9$ twice1 & aft] ! usual sett+ out1 glass+ & bru%+1 are f9ally rubb$ ) flannel4 ,= bridle lea!r ! goods are c>efully %av$ b are n /uff$1 be+ m]ely oil$ ) cod oil on fle% & gra94 ,!y are dri$ out be=e sc\r+1 & !n siz$1 set out1 /a9$ & resiz$4 ,! goods are heavily glass$ dur+ ! f9i%+4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #aie1 #big4 ,section ,,viii4--,,upp] ,,lea!rs ,! manufacture ( lea!r = ! upp]s ( boots & %oes embraces a bewild]+ v>iety ( goods1 suitable = any?+ betwe5 a baby's %oe & a man's %oot+ boot4 ,almo/ all degrees ( lightness1 s(tness1 & wat]pro(ness are 9 dem&4 ,a great v>iety ( f9i% is also involv$1 det]m9$ by ! +5uity ( ! curri] & ! ev]-*ang+ fancy ( ! public4 ,ev5 great] is ! v>iety ( me?ods by :i* all ^! results are obta9$ by me?ods :i* sup]ficially seem q diff]5t2 ! desir$ qualities be+ imp>t$ 9 "o case l>gely by ! tannage & 9 ano!r case almo/ entirely by ! curry+4 ,"u su* circum/ances ! selection ( types becomes a problem4 ,! v>iety1 moreov]1 comm5ces f ! e>lie/ /ages1 ! selection ( ! raw mat]ial4 ,upp] lea!r may be made f light calfsk9s1 heavy calfsk9s1 kips 7home & =eign71 light dress+ hides & heavy dress+ hides1 :i* la/ may replace any ( ! =m] aft] splitt+ to ! requir$ sub/ance4 ,9 ?is section x w be necess>y to take kips z typical ( ! re/1 & to use x 9 a r broad s5se1 includ+ heavy calf & light dress+ hides4 ,speak+ q g5]ally1 kips = upp] lea!r receive usually a long & mell[ lim+1 a ?or\gh bat+ & a sweet & v mell[ tannage 9 weak liquors4 ,9 curry+ !y are well sc\r$ & set out1 heavily /uff$ & /a9$ black1 be+ sometimes f9i%$ on ! gra9 & sometimes on ! fle%4 ,^! out/&+ features ( upp]-lea!r me?ods w be fur!r illu/rat$ by a brief acc\nt ( ! tann+ ( kips 7light hide & heavy calf71 & outl9+ ! be/ kn[n types ( f9i% = butt1 %\ld] & belly4 ,! goods receive usually a long & mell[ lim+ ( #ad-af days1 us+ only lime z a rule4 ,9 "s factories lime liquors are us$ repeat$ly = successive packs to an almo/ indef9ite ext5t4 ,dissolv$ hide sub/ance1 ammonia1 mud & du/1 & bact]ia accumulate = mon?s & sometimes = ye>s4 ,x is obvi\s t 9 su* liquors putrefaction is a m correct t]m ?an lim+ = ! depilation4 ,su* me?ods h be5 us$ ev5 9 rec5t ye>s1 b !re has n[ be5 a t5d5cy = "s "t to make ! lim+ m me?odical4 ,su* old limes make a lea!r :i* is empty1 loose1 & dull gra9$1 b ! defects are m9imiz$ by ! sy/em ( /uff+ heavily & f9i%+ ! fle%1 & h5ce ! anci5t lime rema9$ ) surpris+ t5acity4 ,ev5 s late z #aijc we f9d t ,proct] ) *>act]i/ic caution c\ld write1 ,probably no lime ought to be all[$ to g = m ?an ?ree mon?s at ! outside limit )\t at lea/ a p>tial *ange ( liquor4 ,x is )9 ! writ]'s exp]i5ce to f9d an upp] lea!r factory ) limes :i* _h nev] be5 empti$ = ov] ?ree ye>s4 ,9 o!r factories1 h[ev]1 !re has be5 a revulsion ( feel+ ) reg>d to su* processes1 & x has be5 f\nd advantage\s to adopt a m sci5tific r\t9e1 9 :i* ! lime pits are clean$ out at regul> int]vals4 ,!re is little d\bt t a mell[ lim+ is desirable1 b ?is c be secur$ by bl5d+ "s old lime liquors ) fre% lime liquor 9 a sy/ematic mann]4 ,simil> consid]ations apply to ! "q ( work+ ! v>i\s packs ?r\gh ! limes4 ,x is cle> t ) a mell[ lim+ a "o-pit sy/em is q possibly satisfactory1 b ! revulsion ( feel+ aga9/ a lack ( me?od produc$ a me?od ( lim+ m elaborate ?an usual1 & x is n[ n uncommon to f9d kips lim$ 9 a r\nd ( #f-h pits1 ! goods pass+ ?r\gh ea* pit4 ,!y rema9 9 "o pit ab\t two days1 & are %ift$ =w>d4 ,9 ! gre5 or old limes ! goods are h&l$ up & d[n4 ,! old limes are1 ( c\rse1 mell[] ?an ! new & ex]t ! desir$ s(t5+ effect4 ,! work+ is q analog\s to t ( a r\nd ( h&l]s4 ,unhair+ is sometimes assi/$ by ! use ( ars5ic sulphide4 ,e4,i4 kips ne$ a ?or\gh soak+ be=e any lim+2 sev]al days are usually ne$$4 ,! old me?ods involv+ putrid soaks & /ocks may be consid]$ out ( date1 & x is usual to s(t5 back 9 cau/ic soda or sulphide soaks ) "s assi/ance by drumm+4 ,a little sulphide is sometimes add$ to ! old] limes to cont9ue ! treatm5t4 ,! goods are next ?or\ghly bat$ & delim$4 ,! h5 or pigeon dung bate is /ill usual1 & probably gives ! be/ results1 ?\gh clos] approximations h be5 made ( rec5t ye>s on artificial l9es4 ,"s bat+ ) solution ( hide sub/ance seems necess>y = ^! goods4 ,! light] goods are (t5 dr5*$ also to complete ! delim+1 us+ #f p] c5t4 bran on ! weight ( pelt4 ,! heavi] goods are m (t5 treat$ ) boric acid aft] bat+1 :i* n only delimes completely & gives a s(t relax$ felt1 b also acts z antiseptic & /ops ! action ( ! bate1 a matt] ( "s importance 7see ,section ,,ii474 ,lactic acid may sub/itute boric1 9 :i* case ab\t #b p] c5t4 on ! pelt weight ( #ej p] c5t4 acid may be requir$4 ,x is important to avoid a /rong solution & local excess1 h5ce lactic acid mu/ be add$ gradually s t ! liquor is nev] /rong] ?an #j4b p] c5t4 ,drumm+ & paddl+ is an advantage 9 delim+4 ,! tannage is light 9 mo/ cases1 p>tly because "s ( ! f9i%$ goods are sold by area1 b p>tly also because ev5 if sold by weight1 ! weight is obta9$ quick] & m easily by /uff+1 :i* c\rse is also (t5 pref]able to obta9 ! desir$ mell[ feel1 wat]pro(ness & durability4 ,h5ce x is seldom t /rong liquors are employ$4 ,! tannage is also mell[1 on acc\nt ( ! s(tness & pliability requir$2 no acids are consequ5tly employ$1 & no mat]ial :i* is liable to yield s\r liquors4 ,gambi] is easily ! fir/ fav\rite among/ ! tann+ mat]ials1 :il/ oak b>k comes second4 ,x %\ld be obs]v$1 h[ev]1 t a hypo!tical tannage ( equal weights ( cube gambi] & oak b>k is 9 reality a tannage by f\r-fif?s gambi] & "o-fif? oak b>k1 on acc\nt ( ! relatively great] /r5g? ( ! =m]4 ,?is obs]vation is s apposite ) respect to "s tannages t x is ne>ly correct to say t ! tannage is gambi] & ! oak b>k an excuse = hav+ lea*es ?r\gh :i* ! gambi] liquors may be run occasionally to cle> & to %>p5 slightly4 ,no s]i\s !oretical objection to su* a me?od is possible if ! liquors are weak & ! sy/em ( work+ ! liquors is sci5tific & ! process c>efully regulat$4 ,upp]-lea!r tannages1 h[ev]1 h sc>cely m]it$ sci5tific praise4 ,x is (t5 a case1 n ( poor me?ods1 b ( no me?od at all4 ,! same lack ( sy/em1 pr9ciple1 & regul>ity obs]v$ ) reg>d to ! limey>d has be5 equally obvi\s 9 ! tany>d1 :5 p]haps ! ne$ 0 ev5 great]4 ,ev5 a mell[ tannage has v>y+ degrees ( mell[ness possible to x2 !re /ill rema9s ! "q ( ! soluble non-tans4 ,h[ev]1 me?od 9 ! upp]-lea!r tany>d has (t5 be5 conspicu\sly abs5t4 ,!re has be5 _m a factory :]e any "o tan liquor 0 z good z any o!r 9 ! y>d4 ,9 ! writ]'s exp]i5ce are two su* cases3 9 "o ! liquors 7 all #be ,bkr41 9 ! o!r !y 7 all #j ,bkr4 ,9 su* cases1 h&l+ ! goods f pit to pit is some:at futile1 & h&l+ =w>d f set to set /ill m s4 ,h5ce x is possible to f9d dress+ lea!r tann$ by putt+ x sl[ly ?r\gh "o r\nd ( h&l]s1 add+ a few buckets ( gambi] :]e x app>5tly is necess>y4 ,x is1 f "o po9t ( view1 surpris+ to see :at s]viceable & excell5t-look+ upp] lea!r c be manufactur$ by su* happy-g-lucky processes4 ,x is1 h[ev]1 also possible to see h[ ?is may occur4 ,gambi] is a /able tan1 & no s\r+ & little decomposition take place 9 gambi] liquors4 ,x is also extremely mild & non-a/r+5t1 & is always us$ 9 weak liquors4 ,! hides1 moreov]1 are completely delim$1 & !re is little dang] ( bad or unev5 col\r4 ,tann+ "u ^! conditions is at its easie/2 x is almo/ m difficult to spoil ! goods ?an make !m "r4 ,"u su* conditions tann+ det]iorat$ r ?an improv$ 9 me?od4 ,:5 neglect+ x made little diff]5ce to ! f9i%$ lea!r1 x 0 neglect$4 ,?is /ate ( affairs1 h[ev]1 0 emb>rass+ :5ev] a tann] wi%$ to try any o!r tann+ mat]ial4 ,! exp5se ( gambi] & oak b>k made valonia & mimosa b>k into obvi\sly desirable alt]natives & sub/itutes4 ,me?ods :i* w\ld tan ) gambi]1 h[ev]1 w\ld n "w ) ,natal b>k or valonia1 & _m a tann] has _h to revise 8 me?od ( tann+ f end to end4 ,! use ( myrabs also rais$ ! problem ( s\r+1 & x has become evid5t t work+ ! liquors d[n ! y>d is z desirable a me?od = dress+ lea!r z aft] all o!r tannages4 ,x w be cle> f ! above t types ( upp]-lea!r tannages are less typical ?an = o!r lea!rs1 b nev]!less ! m progressive manufactur]s h = "s ye>s n[ be5 work+ on s\nd] l9es1 economically & sci5tifically4 ,9 su* cases x is n[ usual to pass ! goods ?r\gh at lea/ two sets ( h&l]s1 & ?r\gh liquors ( gradually increas+ /r5g?4 ,occasionally du/]s or lay]s are giv51 especially = ! heavi] goods4 ,! tannage is ne>ly always comm5c$ n[ by paddl+ ! goods 9 ! olde/ liquor4 ,?is paddl+ may be any?+ f half an h\r up to tw5ty-f\r h\rs4 ,x is sometimes desir$ to "w up a gra91 & ! old liquor is !n (t5 %>p5$ by ! addition ( fre% gambi] or lea* liquor4 ,! same t5d5cy to save lab\r 9 h&l+ is to be obs]v$ 9 upp] lea!r tannages z 9 sole & o!r dress+ lea!r factories4 ,!re is also a t5d5cy to obta9 r m weight 9 tann+ by us+ /rong] liquors1 & 9 ! heavi] goods to %ort5 some:at ! "t tak54 ,! foll[+ me?ods may be tak5 to illu/rate mod]n processes1 9 ord] ( evolution4 ,!y all la/ ab\t sev5 weeks4 ,type #a4--;,9 ?is process ! kips are fir/ paddl$ 9 an old liquor 7#c71 & pass$ to ! fir/ h&l]s 7#c-cj7 = ?ree weeks4 ,aft] work+ ?r\gh ?is set !y pass ?r\gh ! second h&l]s 7#bj-cj71 9 :i* !y are n h&l$ q s frequ5tly4 ,!y are 9 ?is set also ?ree weeks4 ,heavy goods may !n receive a float] 7#cj7 = ano!r week4 ,type #b4--;,9 ?is process ! goods are paddl$1 & !n ent] a l>ge h&l] r\nd 7#h-cj71 ?r\gh :i* !y pass 9 five weeks4 ,! goods are h&l$ frequ5tly 9 ! e>ly /ages4 ,! tannage is complet$ by "o lay] ( two weeks 7#cj74 ,! lay] is made by ! anci5t me?od ( putt+ ! goods & du/ alt]nately into an empty pit1 & !n fill+ up ) liquor f ! be/ lea*4 ,oak b>k1 valonia & myrabs are us$ z du/1 ?\gh suma* & gambl] h be5 us$4 ,type #c4--;,9 ?is process an attempt is made to save h&l+ & obta9 m complete tannage4 ,! goods are paddl$ = ?ree to five h\rs 9 a r %>p liquor ( #aj1 & are !n h&l$ well = a week 9 ! fir/ h&l]s 7#e-bj74 ,! goods !n g ?r\gh ! second h&l]s 7#bj-de7 9 six weeks1 & heavy goods may !n receive an extra float] 7#de7 = "o week4 ,9 type #a ! lea*+ mat]ial is two-?irds oak b>k & "o-?ird valonia2 9 type #b x is half oak b>k & half mimosa b>k2 9 type #c x is "o-?ird oak b>k1 "o-?ird valonia or ,natal b>k1 & "o-?ird myrabolans4 ,9 all cases ! /ronge/ h&l] is obta9$ f ! lea*es1 & made up to ! requir$ ) /rong infusion ( gambi]4 ,:5 ! liquor has pass$ ?r\gh ! =w>d h&l]s1 x is return$ to ! lea*es to cle> & %>p51 & !n run to ! gre5 h&l]s4 ,aft] pass+ ?r\gh ?is r\nd x is return$ to ! paddle1 f :i* x passes to ! dra94 ,! re/ ( ! paddle liquor may be f ! =w>d h&l]s4 ,x is (t5 cu/om>y to obta9 ! be/ liquor f ! second lea*1 & all[ ! be/ lea* to /& = a few days4 ,?is all[s ! bloom to deposit 9 ! lea*es4 ,! sy/em secures ! result desir$1 b ! deposition ( bloom involves a loss ( tann91 :i* wa/e makes ! sy/em exp5sive4 ,heavi] dress+ hides are tann$ by me?ods simil> to ! above1 b ) float]s1 du/]s & occasionally lay]s add$ aft] !y h pass$ ?r\gh two sets ( h&l]s4 ,?us !y may h fir/ h&l]s 7#h-ah7 two weeks2 second h&l]s 7#dj-de7 = six weeks1 mak+ twelve weeks 9 all4 ,light] goods may receive two r\nds1 be+ two weeks 9 ea*4 ,aft] tann+1 ! kips are r\nd$ usually into butts1 %\ld]s & bellies1 to :i* diff]5t f9i%es are giv54 ,! curry+ may be illu/rat$ by select+ types1 b x mu/ be borne 9 m9d t !re is mu* ela/icity 9 ?is matt]4 ,?us kips may be made into wax$ butts1 sat9 %\ld]s & l9+ bellies1 b also may be cut d[n ! back 9 sides1 bo? ( :i* are f9i%$ lim+s4 ,wax$ kip butts are a type ( _m simil> upp] lea!rs 7wax$ %oe butts1 wax$ calf1 wax$ splits1 etc474 ,! f9i% is on ! fle% side4 ,! kip butts are soak$ c>efully1 & %av$ by ma*9e4 ,!y are !n drumm$ 9 suma* = an h\r or two1 slick$ out & samm$ = /uff+4 ,! suma*+ is also ! sc\r+ unless ! goods be too heavily bloom$4 ,! samm+ is (t5 done by ma*9e4 ,drum /uff+ foll[s1 wool fat & /e>9 be+ /aple greases1 ) v>y+ am\nts ( degras & cod oil1 & ( tall[ & cod oil4 ,a little p>aff9 wax & res9 are also us$ sometimes4 ,! goods are well slick$ out & dri$4 ,!y may be n[ dubb9$ & laid away to mell[ = :it5+1 :i* consi/s ( a c>eful %av+ ( ! fle% by a turn$-edge slick] or by ma*9e4 ,! gra9 is /on$1 set out & />*$1 & ! butts gra9$ by bo>d+ ! fle%4 ,9 ! wax+1 "o ( two c\rses may be adopt$4 ,! butts may be black$ ) lampblack & oil1 bottom siz$ ) glue1 soap & logwood1 & !n top siz$ ) glue1 dubb91 beeswax & turp5t9e2 or !y may be giv5 a soap-black+ ( soap & logwood & lampblack1 appli$ by ma*9e1 & siz$ once only4 ,dress+ hide butts may also be giv5 a gra9 f9i%1 su* z ! memel butts = heavy upp]s4 ,! butts are soak$1 %av$ or split1 suma*$ 9 drum1 & pref]ably ?or\ghly sc\r$ on fle% & gra94 ,!y are !n samm$ & heavily /uff$ 9 ! drum4 ,! gra9 is buff$ & /a9$ black ) logwood1 ammonia & iron solution 7curri]s' ink74 ,! butts are !n dri$1 set out1 ?9ly siz$ & sl[ly dri$4 ,:5 dry on ! face !y are pr9t$ or emboss$ by ma*9e to give ! *>act]i/ic memel patt]n & dri$ out completely4 ,!y are !n gra9$ f\r ways4 ,! gra9 is f9i%$ by a coat+ ( l9se$ oil conta9+ res91 & ! fle% is :it5$1 ,fr5* *alk$ & glass$4 ,%\ld]s = sat9 receive a curry+ :i* /rongly resembles ! wax$ f9i%es1 b ! smoo? f9i% is on ! gra9 side4 ,! gra9 is buff$1 & black$1 dubb9$1 set & reset1 ) int]m$iate dry+1 & is siz$ & f9i%$ by compositions simil> to ^? us$ = wax$ lea!rs4 ,! fle% is :it5$4 ,sat9 hide & sat9 calf are dress$ simil>ly4 ,%\ld]s may also be f9i%$ = levant4 ,aft] soak+1 splitt+1 & %av+ to sub/ance1 !y are drum-suma*$1 ma*9e-samm$1 & oil$ up to dry4 ,!y are /a9$ ) logwood on ! gra91 & at once pr9t$ ) ! typical levant gra91 black$ & dri$ out4 ,!y are !n s(t5$ by ma*9e1 season$ ) logwood & album51 glaz$1 gra9$ & oil$ lightly ) m9]al oil4 ,x w be obs]v$ t /uff+ is omitt$4 ,bellies may be dress$ = l9+s4 ,aft] soak+ & splitt+ to ! requir$ sub/ance1 !y are blea*$ 9 a weak & w>m solution ( oxalic acid1 & drum-suma*$ at #aaj ,f4 ,aft] slick+ well out !y are h&-/uff$ on ! gra9 ) dubb9 & wat]1 or m]ely oil$1 & hung up to samm4 ,!y are !n set-out fle% & gra94 ,if ! gra9 be co>se1 x is buff$ & reset4 ,aft] dry+ out ! fle% is fluff$ & ! gra9 du/$ ) ,fr5* *alk4 ,9 ?is section may be conv5i5tly discuss$ ! manufacture ( legg+ lea!r4 ,:il/ 9 _m respects a typical dress+ lea!r !re are "s r important diff]5ces f ! av]age upp] lea!r4 ,broadly speak+1 ! diff]5ces are t legg+ lea!r ne$s a smoo? gra91 great] firmness & m ?or\gh tannage on acc\nt ( ! abs5ce ( /uff+4 ,! lim+ & bat+ are some:at simil> to dress+ lea!r1 ?\gh a %ort] lim+ ) sulphides & a mild] bat+ w\ld be 9 ord]4 ,! tannage is mell[1 b n s mu* z is usual = upp] lea!r4 ,?us gambi] is us$1 b m valonia & myrabs are employ$1 & ! liquors may be /r5g!n$ ) *e/nut & quebra*o extracts4 ,! hides are r\nd$ be=e tann+ into long butts or backs1 & ! tannage is comm5c$ 9 susp5d]s 7#ah-dj71 :i* are kept acid by ! addition ( lactic or acetic acid1 9 ord] to obta9 ! requir$ firmness2 ! goods are ?ree weeks 9 ^! liquors4 ,! backs next g ?r\gh r\nds ( du/]s 7#dj-ej71 9 :i* !y are put d[n ) oak b>k & ,natal b>k4 ,!y are six weeks 9 ?is section1 & !n pass to ! lay]s4 ,?ree lay]s are giv51 fir/ #ej = "o week2 second #ee = two weeks2 & ?ird #fj = two weeks4 ,! tannage ?us takes f\rte5 weeks4 ,9 f9i%+1 ! goods are soak$ & split1 & !n sc\r$ fle% & gra94 ,!y are heavily suma*$1 slick$ out ?or\ghly1 oil$ up ) l9se$ oil & dri$ out4 ,!y are !n next damp$ back1 /on$ & flatt$4 ,aft] fur!r wett+ & temp]+ !y are dress$ ) ,iri% moss & tall[ on ! fle%1 & ) gum tragacan? on ! gra94 ,!y are glass$ :il/ dry+ out1 & !n /a9$ twice & glass$ aga94 ,!y are aga9 bru%$1 season$ & glass$ by ma*9e4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #aig-bja & #cja-cjh4 ,,section ,,ix4--,,bag ,,lea!r ,hides to be tann$ = bag lea!r receive a treatm5t :i* is little diff]5t 9 fundam5tal pr9ciple f t ( dress+ hides = upp] lea!r1 except t ! tannage is usually %ort]4 ,hides = bags & portmanteaux repres5t a type ( dress+ lea!r 9 :i* ! out/&+ features are t ! goods are split b n r\nd$4 ,! splitt+ is done at all /ages1 accord+ to ! requirem5ts ( ! tann]4 ,"s tann]s split gre51 i4e4 split ! pelt itself4 ,! advantage ( ?is is t ! fle%es may !n be treat$ 9 q a diff]5t way1 e4g4 pickl$ or giv5 a mu* *eap] tannage4 ,o!r manufactur]s split aft] tann+1 ! advantage be+ t !re is mu* less mat]ial to h&le4 ,! g5]al op9ion1 h[ev]1 fav\rs a middle c\rse 9 :i* ! hides are split aft] be+ 9 ! tan liquors = a %ort "t4 ,! advantage ( ?is c\rse is t ! hides are easie/ to split "u ^! conditions--a great consid]ation--be+ col\r$ ?r\gh ) tan1 j a little plump$1 b n h>d4 ,a smoo!r fle% is obta9$ toge!r ) m ev5 sub/ance4 ,"h aga91 h[ev]1 are diff]5ces2 "s tann]s pref] to split aft] two days1 o!rs aft] two weeks 9 tan4 ,mu* dep5ds ^u ! nature ( ! tan & ! /r5g? ( ! liquors4 ,= ?is class ( "w1 flat1 spready & ev5ly gr[n c[hides are obvi\sly ! mo/ suitable mat]ial1 & are inv>iably us$4 ,x is important1 h[ev]1 t ! gra9 be good1 & free f scrat*es & simil> defects4 ,! tannage mu/ be sweet & mell[1 i4e4 conta9 no acid & little a/r+5t tan4 ,h5ce myrabolans & gambi] h always be5 ! fav\rite tann+ mat]ials4 ,a s(t & mell[ tannage is ! m important1 inasmu* z ! lea!r is n heavily /uff$ ) grease 9 f9i%+4 ,^! types ( me?od = tann+ split hides w n[ be outl9$1 & ! nature ( ! curry+ !n indicat$4 ,type #a4--;,9 ?is a long mell[ lim+ ( #ae-af days is giv51 mu* l t describ$ = h>ness lea!r 9 ,section ,,iii41 ,type #c4 ,only lime is us$1 b ! liquors are n all[$ to get dirty4 ,! ?ree-pit sy/em is mu* ! be/4 ,! hides are trimm$ at ! r\nd+ tables1 & !n bat$ 9 h5 or pigeon dung = ?ree days at #ge-he ,f4 ,! delim+ is comm5c$ by wa%+ 9 tepid wat] be=e bat+1 & is complet$ by a ba? ( boric acid1 us+ up to #cj lbs4 acid p] #ajj hides z necess>y4 ,9 ?is & o!r processes = split hides x is ess5tial to obta9 all ! lime out1 b to d no plump+ ) acid4 ,lactic acid may also be us$1 b x is n s conv5i5t to hit ! neutral po9t ) x4 ,! tannage consi/s ( oak b>k & myrabs toge!r ) gambi]4 ,^! may be p>tly replac$ by ,natal b>k1 valonia1 & quebra*o respectively4 ,x is sometimes desir$ to h a smoo? f9i%1 b sometimes to "w up a gra94 ,9 ! latt] case ! hides are fir/ put ?r\gh col\r+ pits conta9+ fre% lea* liquor4 ,9 ^! !y are con/antly h&l$ = a few h\rs4 ,a little exp]i5ce indicates :i* lea* liquor w s]ve ! purpose4 ,! hides !n g ?r\gh ! gre5 h&l]s 7#h-bj7 9 two weeks4 ,! liquor is ! old =w>d h&l] liquor made up ) gambi]4 ,! hides may be samm$ & split up at ?is /age1 b ! heavi] goods may be tann$ fur!r4 ,^! heavies & ! gra9s ( ! split hides n[ g ?r\gh ! =w>d h&l]s 7#bj-dj7 = f\r weeks1 & ! heavie/ goods giv5 two lay]s 7#dj7 ( two weeks ea*1 & mak+ t5 9 all4 ,type #b4--;,9 ?is a %ort] lim+ ( #h-i days is giv5 ) ! help ( sulphide4 ,no dung bate is us$1 b ! goods are wa%$ ) wat] & bat$ ) ammonium *loride & boric acid4 ,! tannage is *iefly ( myrabs1 b "s valonia or ,natal b>k may be us$ toge!r ) *e/nut extract & "s quebra*o4 ,gambi] is us$ 9 ! e>ly liquors4 ,! goods are col\r$ (f 9 drum or paddle & tann$ 9 sev]al sets ( h&l]s1 viz4 gre5 h&l]s 7#ae-ce7 ?ree or f\r days2 second h&l]s 7#ce-fj7 two weeks2 =w>d h&l]s 7#fj-hj7 #a-a_/b weeks2 & float]s 7#hj-ij7 = ?ree weeks4 ,! tannage is ?us #f-a_/b weeks 9 all4 ,! arrangem5t ( pits is a matt] ( local conv5i5ce1 & ! numb] ( sets ( equal /r5g? is det]m9$ by ! numb] ( hides be+ tann$4 ,! hides are split gre5 or aft] pass+ ?r\gh ! gre5 set4 ,aft] tann+ !y are oil$ ) cod oil & dri$ out4 ,type #c is illu/rat$ by ,am]ican me?ods4 ,! goods are tack$ on la?s or racks ) copp] nails 9 ord] to ensure smoo? gra94 ,!y are !n susp5d$ 9 tan liquors4 ,! tannage is l>gely ) gambi] & 9 weak liquors1 :i* also help to give smoo? gra94 ,! t5d5cy is to employ h&l] r\nds involv+ a r l>ge numb] ( pits1 & to "w ^! on ! press sy/em4 ,h&l+ is also sav$ by plump+ ! liquors in/ead ( %ift+ ! goods =w>d1 & by rock+ ! susp5d]s in/ead ( h&l+ up & d[n4 ,! hides are split aft] ab\t a mon?1 & ! heavi] gra9s laid away 9 hemlock liquors4 ,type #d4--,?is is a rapid process ?r\gh\t4 ,! hides are lim$ 9 #f-g days ) ! help ( sulphide1 & bat$ by wa%+ 9 w>m wat] & !n 9 cold to :i* hydro*loric acid is gradually add$1 f9i%+ (f aga9 9 tepid wat]4 ,! hides are n[ col\r$ (f 9 paddles1 put ?r\gh a small h&l] r\nd 7#aa-bj7 = half a week1 & !n split4 ,! gra9s are drum tann$ 9 a mixture ( *e/nut & quebra*o extract1 ov] a p]iod ( ab\t ?ree days 9 :i* ! liquor is /r5g!n$ gradually f #cj to #ej4 ,! fle%es are drum tann$ ) ! old gra9 liquors aft] /r5g!n+ ) quebra*o4 ,! split hide gra9s = bag "w1 aft] tann+1 are drumm$ 9 suma*1 r9s$1 dra9$1 & oil$ up to dry out1 ) "s sett+ out4 ,aft] wett+ back !y are %av$ if necess>y1 h& sc\r$1 & heavily suma*$ aga9 to get a light ev5 col\r4 ,! goods are slick$ out1 oil$ up to samm1 reset & dri$ out4 ,!y are next /a9$1 samm$1 pr9t$ by ma*9e1 dubb9$ or tall[$1 gra9$ 7see ,"p ,,ii41 ,section ,i471 bru%$ & rubb$ ) flannel4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bjb1 #cjh4 ,,section ,x4--,,pick+ ,,b& ,,butts ,x is ! p>adox ( vegetable tannage t ! less ! pelt is tann$ ! /rong] is ! lea!r produc$4 ,! manufacture ( butts = pick+ b&s af=ds a good illu/ration4 ,:at is requir$ is a lea!r ( maximum t\ghness1 pliability & durability4 ,any factor r$uc+ ! t5sile /r5g? ( ! lea!r is fatal4 ,h5ce1 comp>$ ) mo/ o!r tannages1 pick+ b& butts are "u-tann$4 ,to ensure ! desir$ s(tness & pliability1 moreov]1 x is necess>y to h a mell[ lim+1 r heavy bat+1 & a s(t mell[ tannage 9 sweet & weak liquors4 ,! requir$ durability & ! necessity = weak liquors bo? po9t to oak b>k z ! mo/ suitable tann+ mat]ial1 assi/$ by "s gambi] 9 ! e>ly /ages4 ,a good quality hide is *os51 & giv5 a long & mell[ lim+ ( ab\t #ae-af days4 ,! "o-pit sy/em may be us$1 & ! hides are put into an old lime = ab\t five days ) frequ5t h&l+ & !n plac$ 9 a new lime :i* is made up 9 a pit conta9+ ab\t a foot dep? ( ! old liquor4 ,aft] ab\t twelve days ano!r #a_/c cwt4 ( lime may be add$4 ,aft] unhair+ & fle%+ ! goods are bat$ 9 pigeon dung = f\r days at a temp]ature ( ab\t #gh ,f41 h&l+ twice on ! fir/ & la/ days4 ,! bat+ is /opp$ & ! delim+ complet$ by paddl+ ) boric acid 7#ae lbs4 p] #ajj butts74 ,! tannage is comm5c$ by paddl+ 9 a sp5t h&l] liquor 7#d7 to :i* a little gambi] has be5 add$4 ,! butts !n g ?r\gh ! fir/ h&l]s 7#e-ae71 :i* are r\nds ( t5 pits 9 :i* ! goods are h&l$ e day 9 ! fir/ week1 & alt]nate days 9 ! second week1 & are %ift$ =w>d twice a week 9 ! next pit4 ,! goods are !re=e 9 ?is set = five weeks4 ,gambi] is add$ to ^! liquors z ne$$4 ,! butts next pass to du/] r\nds ( f\r pits1 9 :i* !y are du/$ d[n 9 a liquor ( #bj = f\r weeks ) #a-b cwt4 ( oak b>k4 ,! liquor is obta9$ f ! lea*es1 & aft]w>ds run alt]nately to ! lea*es & to ! fir/ h&l]s4 ,z _m z six lay]s are n[ giv5 ( #bj-be /r5g?1 9 :i* ! butts are du/$ d[n ) #b-c cwt4 oak b>k = ?ree weeks4 ,! lay] liquors are receiv$ f & return$ to ! lea*es1 :i* are made f ! fi%+s f ! lay]s4 ,! tannage la/s1 !re=e1 #bg weeks1 ( :i* #ah weeks 7two-?irds7 are 9 lay]s4 ,%ort] tannages are n[ (t5 giv51 us+ /rong] liquors1 mu* z 9 ord9>y dress+ lea!r4 ,! tann$ butts are r\gh dri$1 & !n wet 9 = %av+4 ,!y are ?or\ghly sc\r$1 fle% & gra94 ,!y are next drumm$ = ?ree-qu>t]s ( an h\r 9 suma*1 /ruck out & hung up to samm4 ,h& /uff+ is be/1 to avoid any t5d]+ ow+ to high temp]ature1 b drum /uff+ is also us$4 ,aft] sett+ out & /on+ on ! gra9 !y are /uff$ ) w>m cod oil & laid away 9 grease = sev]al weeks1 re-oil+ occasionally4 ,!y may be /a9$ be=e /uff+4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bjc1 #caj4 ,,"p ,,ii4--,,sk9s ,,= ,,light ,,lea!rs ,,section ,i4--,,pr9ciples ,,& ,,g5]al ,,me?ods ,,( ,,light ,,lea!r ,,manufacture ,! t]m sk91 l ! t]m hide1 9 its wide/ s5se applies to ! natural cov]+ = ! body ( any animal1 b is g5]ally us$ ) a n>r[] mean+ 9 :i* x applies only to ! cov]+ ( ! small] animals4 ,?us we speak ( %eep sk9s1 goat sk9s1 seal sk9s1 pig sk9s1 de] sk9s1 & porpoise sk9s4 ,x is 9 ?is s5se t x w be us$ 9 ?is volume4 ,! treatm5t ( su* sk9s to fit !m = useful purposes comprises ! light lea!r trade4 ,:il/ ?is bran* ( ! lea!r indu/ry is c]ta9ly utilit>ian1 ! arti/ic elem5t is a great deal m prom95t 9 x ?an 9 ! heavy lea!r bran*4 ,?us ! light lea!rs are (t5 dy$ & arti/ically f9i%$1 & _! f9al purposes 7su* z fancy goods1 uphol/]y1 bookb9d+1 slipp]s1 etc47 h r m ( ! elem5t ( luxury ?an ( ess5tial utility4 ,! total weight & value ( ! sk9s prep>$1 & ( ! mat]ials us$ 9 _! prep>ation1 are naturally consid]ably small] ?an ^? ( ! heavy lea!r trade4 ,9 ! latt]1 moreov]1 "o has to consid] ! purpose 9 view f ! v comm5cem5t ( manufacture & v>y ! process accord+ly1 b 9 light lea!r manufacture "o aims r1 9 ! factory1 at a type ( lea!r su* z morocco lea!r1 & only aft] manufacture is x fitt$ to su* purposes z may be p>ticul>ly suit$ to ! actual result4 ,^! results dep5d v l>gely ^u ! gra9 patt]n :i* is natural to ! sk9 ( any "o species ( animals4 ,h5ce 9 ,"p ,,ii4 ( ?is volume x has be5 f\nd mo/ conv5i5t to deal ) ! diff]5t classes ( sk9s 9 diff]5t sections4 ,j z ! hides ( ox & heif] 7 mu* ! mo/ num]\s & important ( hides1 s also naturally are %eepsk9s ! mo/ prom95t section ( ! raw mat]ial ( ! light lea!r trade4 ,?is is ! m true because ! sk9 is valu$ = its wool z well z = its pelt2 inde$1 ! wool is (t5 consid]$ ( prim>y importance1 & receives fir/ consid]ation 9 fellmong]+4 ,un=tunately = ! light lea!r trade1 %eepsk9s1 ?\gh mo/ num]\s1 d n give ! be/ class ( light lea!r1 ! quality be+ easily surpass$ 9 /r5g?1 beauty & durability by ! lea!r f goat or seal sk9s4 ,9 ! wet "w = ! prep>ation ( sk9s = tannage mu* ! same g5]al pr9ciples & me?ods are embodi$ z 9 ! case ( hides1 b ) appropriate modifications4 ,z s(t lea!rs are *iefly want$1 a mell[ lim+ is q ! usual requirem5t = all sk9s4 ,x is also usual to h a long lim+1 = "s sk9s 7l ^? ( %eep & seal7 h mu* natural fat :i* ne$s ! saponify+ influ5ce ( lime & lipolytic action ( ! enzymes ( ! lime liquors2 :il/ o!r sk9s 7l ^? ( goat & calf7 are v close textur$ & ne$ ! plump+ action ( ! lime & a c]ta9 solution ( int]fibrill> sub/ance4 ,9 consequ5ce ( ! long mell[ lim+1 sulphides are n usually necess>y1 & inde$ sodium sulphide is n usually desirable1 on acc\nt ( its t5d5cy to make ! gra9 h>%4 ,x is us$1 h[ev]1 = unwooll+ %eepsk9s1 9 su* a mann] t ! gra9 is n t\*$4 ,simil>ly cau/ic soda is seldom requir$1 & ! yield ( pelt by weight is usually a small consid]ation4 ,sy/ems ( lim+ %[ "s v>iety4 ,! "o-pit sy/em is v common1 & is less objectionable = a long mell[ lim+1 b r\nds ( sev]al pits are also us$1 & 9 "s cases ev5 m ?an "o r\nd4 ,?is is obvi\sly conducive to regul>ity ( treatm5t1 & z ! "w involv$ 9 %ift+ ! goods is mu* less labori\s ?an 9 ! case ( heavy ox hides1 x w\ld seem a pref]able alt]native4 ,! depilation ( %eepsk9s involves v special me?ods ( treatm5t 7sweat+ & pa9t+7 on acc\nt ( ! importance & value ( ! wool1 ! quality & value ( :i* w\ld be impair$ by putt+ ! sk9s ?r\gh ord9>y lime liquors4 ,! pelts1 h[ev]1 are lim$ aft] unwooll+4 ,9 delim+ light lea!rs ! process ( pu]+ is widely us$4 ,?is consi/s 9 imm]s+ ! sk9s aft] depilation 9 a w>m f]m5t+ infusion ( dog-dung4 ,9 pr9ciple ?is disgu/+ process pres5ts a close analogy ) bat+1 & inde$ ! two t]ms are bo? us$ some:at loosely1 b !re are nev]!less sev]al po9ts 9 :i* ! two processes are radically diff]5t4 ,! dog-dung pu] is a process c>ri$ out at a high] temp]ature ?an ! f[l-dung bate2 x is also a mu* quick] process1 & ! infusion employ$ is g5]ally m conc5trat$4 ,:il/ ! f[l-dung bate is always slightly alkal9e to ph5olph?ale9 ! dog-dung pu] is always acid to ?is indicator1 & ! c\rse ( ! pu]+ may be conv5i5tly foll[$ by te/+ ! pelts ) x4 ,! me*anism ( ! two processes is also probably some:at diff]5t4 ,! me*anism ( ! dog-dung pu] has be5 l>gely made cle> by ! rese>*es ( ,wood & o!rs1 & be5 f\nd due p>tly to a delim+ action by ! am9e salts ( weak organic acids & p>tly to ! action ( enzymes f a bacillus ( ! coli class1 :i* receiv$ ! "n ( ,b4 erodi5s1 & :i* effects a solv5t action on ! int]fibrill> sub/ance4 ,z we h not$ 7,"p ,i41 ,section ,,ii471 ! f[l-dung bate involves two f]m5tations1 9 ea* ( :i* 7robic & anrobic7 sev]al species ( bact]ia are probably active4 ,wood f\nd ! bact]ia ( ! bate to be *iefly cocci1 & ascrib$ "p ( ! diff]5ce 9 me*anism by ! nature ( ! m$ia1 :i* 9 ! bate includes also ! ur9>y products4 ,9 ! dog-dung pu]1 also1 a lipolytic action is probably an ess5tial "p ( ! total effect4 ,! pu] gives a mu* m complete delim+ & a mu* s(t] & m relax$ pelt ?an ! bate1 x is !re=e p>ticul>ly suit$ to ! ne$s ( light lea!r manufacture4 ,! pu]+ action has be5 imitat$ fairly successfully by artificial me?ods4 ,erod9 7,wood1 ,popp & ,beck]7 involves ! use ( ,b4 erodi5s & a suitable culture m$ium includ+ organic delim+ salts3 ,oropon1 ,pancreol & o!rs involve ! use ( ammonium *loride & tryps91 toge!r ) "s in]t matt]4 ,light-lea!r goods are usually dr5*$ aft] pu]+4 ,!y are also (t5 split gre5 aft] ! wet "w4 ,%eepsk9s ?us yield skiv]s 7! gra9 split71 :il/ ! fle% split is (t5 giv5 an oil tannage 7see ,"p ,,iv41 ,section ,,iii474 ,! greasy nature ( %eep & seal sk9s necessitates ! processes ( degreas+4 ,9 ! case ( sealsk9s ?is is done l>gely be=e lim+1 b ) %eepsk9s ei!r aft] be+ /ruck ?r\gh ) tan1 or aft] tannage is complete4 ,%eepsk9s are (t5 pres]v$ 9 ! pelt by pickl+ ) sulphuric acid & salt1 :i* process =ms a tempor>y lea!r4 ,! fibres ( ! pelt are dri$ 9 a sep>ate condition1 b ! adsorption is easily rev]sible & ! pelts may be depickl$ by weak alkalies & aft]w>ds giv5 an ord9>y vegetable tannage4 ,9 ! vegetable tannage ( sk9s = light lea!rs1 ! same !oretical consid]ations h =ce z 9 ! heavy-lea!r section1 b ! =m] has its own r special requirem5ts & aims4 ,g5]ally speak+1 a s(t] & m flexible lea!r is requir$1 b ^! qualities mu/ n be imp>t$ by /uff+ ) grease z 9 ! curry+ ( dress+ lea!r1 because a bright & grease-free result is usually requir$4 ,h5ce x is important t a sweet mell[ tannage be giv54 ,! durability ( ! lea!r is also a prim>y consid]ation = goods int5d$ = bookb9d+1 uphol/]y1 etc41 & ! tannage mu/ be arrang$ to imp>t ?is quality & avoid any?+ t5d+ to cause ! p]i%+ ( ! fibre4 ,?us oak b>k is a popul> tann+ mat]ial1 & sulphuric acid v def9itely avoid$4 ,! tannage mu/ be fa/1 & take ! dye/uffs well1 & = ! production ( light %ades ( col\r 9 dye+ mu/ be a light-col\r$ tannage4 ,all ^! qualities are imp>t$ by suma*1 :i* also fits 9 excell5tly ) ! o!r g5]al requirem5ts1 su* z s(tness1 brightness & durability4 ,h5ce suma* is ! pr9cipal light-lea!r tann+ mat]ial1 b ! t5d5cy is to employ o!r mat]ials--oak b>k1 myrabs1 & *e/nut extract--to d mu* ( ! int]m$iate tann+1 s t ! exp5sive & useful suma* may be us$ = sett+ ! col\r & gra9 at ! comm5cem5t1 & = bright5+1 blea*+ & mordant+ ! lea!r at ! end ( ! tann+ process4 ,weight is g5]ally no consid]ation1 b area is (t5 a def9ite aim1 p>tly because "s goods are sold by area & p>tly because ! /rik+ out1 sett+ out & simil> op]ations improve ! quality ( ! lea!r by giv+ ev5ness ( f9i%4 ,lea!r well /ruck out1 moreov]1 is less liable to g out ( %ape4 ,z ! gra9 patt]n is s important 9 ! f9i%$ lea!r1 appropriate c>e mu/ be tak5 dur+ tannage4 ,if a smoo? or a f9e gra9 f9i% is want$1 = example1 ! goods mu/ n be all[$ to get wr9kl$1 creas$1 d\bl$ or unduly b5t to & fro dur+ ! tann+4 ,= su* goods1 susp5sion1 c>eful h&l+ & ev5 ! bag tannage may be desirable1 :il/ = co>s] & l>g] gra9s paddles or drums may be m ext5sively us$4 ,among/ ! f9i%+ processes dye+ holds an important position4 ,! nature ( ! process has _m po9ts ( simil>ity ) t ( tann+4 ,! great specific surface ( pelt is probably m enhanc$ ?an o!rwise dur+ tannage1 at any rate ) light lea!rs1 ow+ to ! isolation ( fibres1 & consequ5tly lea!r is z liable z pelt to exhibit adsorption4 ,! dye/uffs1 on ! o!r h&1 are sub/ances v easily adsorb$4 ,"s 7l eos9 & me?yl5e blue7 are cry/alloids1 "s 7l fu*s9 & me?yl violet7 are semi-colloids1 :il/ o!rs 7l ,congo r$ & night blue7 are und\bt$ colloids =m+ sols 7usually emulsoid7 ) wat] z disp]sion m$ium4 ,! cry/alloids & semi-colloids may also be obta9$ 9 colloidal solution1 sometimes be+ s *ang$ on ! m]e addition ( salts to ! solution4 ,9 addition1 ! pelt has be5 mordant$ ) tann94 ,if1 h[ev]1 lea!r has be5 kept long 9 ! r\gh-tann$ or cru/ /ate1 ?is may n be s effective1 ow+ probably to ! second>y *anges 9 tann+ 7,"p ,i41 ,section ,,iii471 b su* lea!rs are usually retann$ or prep>$ = dye+ by suma*+ 7:i* process also incid5tally blea*es74 ,! tann9 mordant assi/s mat]ially 9 ! fixation ( ! dyes4 ,9 ! case ( basic dye/uffs1 lakes also are =m$1 i4e4 !re is a mutual precipitation ( oppositely *>g$ colloids 7dye1 -tann974 ,! dye+ ( lea!r is ?us a case ( colloid reactions ev5 m complicat$ ?an t ( tann+4 ,ano!r f9i%+ op]ation typical ( ! light lea!rs is gra9+ or bo>d+4 ,9 ?is ! sk9s aft] dye+ & dry+ are work$ by a bo>d :i* is cov]$ by cork1 rubb]1 p]=at$ t9 or o!r mat]ial1 & s grips or bites ! lea!r4 ,! object ( gra9+ is to "w up ! gra9 patt]n by pu%+ or pull+ a fold on ! sk9 ) ! bo>d4 ,! nature ( ! gra9 v>ies ) ! ?ickness & ! h>dness ( ! sk91 ) ! am\nt ( pressure appli$1 ) ! nature ( ! bo>d1 ) ! direction ( ! bo>d+ & ) ! total numb] ( directions bo>d$4 ,!re is ?us inf9ite scope = v>iety ( f9i%1 & h5ce arise bold gra91 f9e gra91 h>d gra91 /raight gra91 cross gra91 long gra91 etc4 ,! op]ation requires consid]able skill & exp]i5ce4 ,9 ! case ( sk9s ) little natural gra9 7su* z %eepsk97 emboss+ & pr9t+ ma*9es impress ! desir$ patt]n4 ,9 season+1 a dress+ is appli$ conta9+ ess5tially album9s & emulsifi$ fats1 e4g4 egg album9 & milk4 ,col\r+ matt]s are also (t5 add$ to int5sify or modify ! %ade4 ,aft] season+ ! goods are usually glaz$ by a ma*9e :i* rubs ! season$ gra9 ) consid]able pressure1 by a glass or h>dwood tool1 & s produces a high gloss1 = :i* ! season+ is v l>gely a prep>ation4 ,light lea!rs are v lightly oil$ ) l9se$ or m9]al oil4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #bbj1 #cid4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #cf-da1 #ee1 #he-ij1 #ib-aab1 #cab1 #ccb4 ,wood1 ,pu]+1 ,bat+ & ,dr5*+ ( ,sk9s4 ,lamb1 ,lea!r ,dye+ & ,f9i%+4 ,,section ,,ii4--,,goatsk9s ,goatsk9s are among/ ! mo/ valu$ raw mat]ial = ! manufacture ( light lea!r4 ,! lea!r obta9$ f !m is ( ! v f9e/ quality 9 respect to durability & adaptability to ! pr9cipal purposes 9 view4 ,! texture ( ! fibres 9 goatsk9 is exce$+ly compact & v /rong1 :il/ ! gra9 exhibits naturally a *>act]i/ic patt]n :i* r5d]s x mo/ suitable = a gra9$ f9i%4 ,h5ce = purposes l uphol/]y1 bookb9d+1 slipp]s1 x =ms almo/ an ideal mat]ial4 ,! tann+ & f9i%+ ( goatsk9s into morocco lea!r may inde$ be tak5 z a q typical example ( light lea!r manufacture4 ,! sk9s are obta9$ f all qu>t]s ( ! globe :]e goats exi/1 & ! excell5t quality ( ! lea!r produc$ has creat$ a dem& :i* is great] ?an ! supply4 ,?is is due n only to ! dem& = morocco lea!r1 b also to ! popul>ity ( ! goatsk9 *rome upp] lea!rs su* z glac kid 7see ,"p ,,iii41 ,section ,,iv474 ,! l>ge ,am]ican trade 9 ! latt] has produc$ ! say+ t :]ev] !re is a goat !re is an ,am]ican wait+ = x to die6 ,! ,european supply ( sk9s is some:at limit$4 ,!y are obta9$ f ! ,balkans & ,bav>ia1 9 :i* case !y are small1 f9e-gra9$ & plump sk9s4 ,! ,swiss goatsk9s are l>g]1 & h also a f9e gra92 !y are well gr[n & well flay$4 ,sc&9avian sk9s h a poor reputation1 be+ v flat4 ,! ,african supply is important2 ,abyss9ian sk9s are exce$+ly compact & t\gh1 & are v suitable = bold gra9 f9i%es4 ,! ,cape sk9s are p>ticul>ly l>ge1 /rong & ?ick1 b _! quality is (t5 impair$ by ! cure1 ! sk9s be+ fl9t-dry1 &1 l hides s cur$1 prone to uns\ndness4 ,l>ge quantities ( goatsk9s also come f ! ,ea/4 ,_m ( ^! are import$ 9 a tann$ /ate 7,e4,i4 ,goat74 ,^! sk9s are tann$ ) turw> b>k1 :i* conta9s a cate*ol tann94 ,!y are also heavily oil$ ) sesame oil1 & ne$ degreas+4 ,! tannage is also /ripp$ z f> z practicable1 & ! sk9s retann$ ) suma* be=e f9i%+4 ,!y make good morocco lea!rs = _m purposes1 b ! prim>y cate*ol tannage r5d]s !m ineligible = f9i%+ "u ! specifications ( ! ,committee ( ! ,society ( ,arts4 ,! sk9s h a ,p]sian or ,indian orig94 ,india also supplies a l>ge numb] ( raw dri$ goatsk9s :i* are small & ( v>iable quality4 ,^!1 h[ev]1 are m ext5sively us$ = *rome upp]s4 ,goatsk9s are import$ 9 ei!r a salt$ or a dri$ condition4 ,! great aim ( soak+ is to obta9 ! sk9s 9 a ?or\ghly s(t condition4 ,h5ce ! soak+ is prolong$1 & "s me*anical treatm5t is desirable 9 addition to v>i\s /eep+s 9 wat]4 ,to be c]ta9 ( s(tness x is desirable to avoid ! use ( alkalies 9 ! soak wat]s1 = al?\gh !y cause hydration ( ! fibres by imbibition1 !y also h a plump+ effect :i* is n want$ at ?is /age4 ,salt$ goatsk9s are fir/ imm]s$ 9 wat] & left until ! foll[+ day4 ,?is dissolves ! salt4 ,!y are !n /ret*$ & giv5 a fre% soak liquor ( wat] only to s(t5 fur!r1 clean1 & remove ! re/ ( ! salt4 ,?is second wat] la/s only a few h\rs1 & ! goods are !n drumm$ well 9 runn+ wat]4 ,?is n only cleans quickly1 b has an excell5t s(t5+ effect4 ,!y are aga9 return$ to a soak liquor1 !n s(t5$ me*anically by work+ !m ov] a beam4 ,?is treatm5t mu/ be repeat$1 drumm+ aga9 if necess>y1 until ! sk9s are p]fectly relax$ & ?or\ghly s(t5$4 ,if ! treatm5t be v prolong$ x becomes advisable to use antiseptics 9 ! soak wat]s aft] ! fir/ drumm+4 ,solubiliz$ 7or emulsifi$7 cresols ( ! ,jeyes fluid type are ! mo/ suitable antiseptics1 b too mu* mu/ n be us$ or ! /]ilization affects ! lim+1 9 :i* bact]ial action is ne$$4 ,fl9t-dry sk9s are left long] 9 ! fir/ soak1 :i* %\ld be ( wat] only4 ,!y are !n giv5 a fre% soak liquor conta9+ #j4b p] c5t4 ( sodium sulphide4 ,sometimes a #a4j p] c5t4 solution ( borax is us$ in/ead2 x s(t5s excell5tly1 is antiseptic1 & avoids ! plump+ effect1 b is r exp5sive4 ,! goods are next drumm$ well1 & resoak$ & work$ z = salt$ sk9s4 ,9 ei!r case ! soak+ takes ab\t a week4 ,! lim+ ( goatsk9s pres5ts "s po9ts ( contra/ ) ! me?ods us$ = o!r sk9s4 ,^! diff]5ces are due to ! exce$+ly tight & compact nature ( ! sk9 fibres4 ,?is compactness ( texture makes x q necess>y to dissolve ! int]fibrill> sub/ance to a great] ext5t ?an usual1 & also to plump ! fibres & split !m into ! con/itu5t fibrils4 ,^! effects are ess5tial to obta9 a rapid & complete tannage & a s(t lea!r4 ,too mu* bact]ial action %\ld be avoid$1 h[ev]1 or ! brightness & s\ndness ( ! gra9 may be impair$1 :i* w\ld be a fatal defect 9 su* a lea!r4 ,h5ce ! lim+ is long r ?an mell[1 & %>p limes r simil> to ^? requir$ = sole lea!r are (t5 us$4 ,ano!r result ( ! tight texture ( goatsk9 is t depilation is n easily effect$4 ,?is feature is r int5sifi$ by ! deepness ( ! hair-root4 ,h5ce x is usual to employ sulphides to assi/ ! depilation4 ,9 "o me?od two r\nds ( five pits are us$4 ,! sk9s are giv5 ab\t two days 9 ea* pit1 s t ! lim+ la/s approximately ?ree weeks4 ,9 ! fir/ r\nd1 :i* consi/s ( r mell[ limes1 ars5ic sulphide is us$ to assi/ depilation4 ,up to #f p] c5t4 on ! weight ( lime is add$ dur+ slak+4 ,?is is a comp>atively l>ge am\nt ( ars5ic sulphide1 & ! depilation is consid]ably ha/5$2 ! sk9s inde$ are unhair$ aft] pass+ ?r\gh ?is r\nd1 i4e4 aft] ab\t #aj days' lim+4 ,9 ! next r\nd ! object is plump+1 & cau/ic soda 7or c>bonate7 is add$ to ! lime liquors 9 quantities comp>able to ^? sugge/$ = sole lea!r 7,"p ,i41 ,section ,v474 ,9 ?is r\nd ! goods /ay also = ab\t #aj days4 ,an alt]native to ! above process is to ha/5 ! e>li] "p ( ! lim+ by employ+ sodium sulphide in/ead ( realg>4 ,m sulphydrate may be obta9$ 9 solution 9 ?is way1 & ! unhair+ may be 9 ab\t half ! "t4 ,! sulphide ( soda also comm5ces ! plump+ action :i* foll[s 9 ! next r\nd1 b ?is alt]native has ! disadvantage t ! sk9s are unhair$ :il/ ! pelt is swoll5 ) sulphide1 :i* r5d]s ! gra9 bo? h>% & t5d] & consequ5tly m liable to damage by ! unhair]'s knife4 ,delim+ is by pu]+ & dr5*+1 & is (t5 associat$ ) a fur!r me*anical work+ ( ! goods4 ,! sk9s are ins]t$ into a pu] liquor at #he ,f4 & ?or\ghly pull$ d[n4 ,! cau/ic alkalies %\ld be completely neutraliz$4 ,a slight cut into a ?ick "p at ! butt end %\ld develop no p9k col\r ) ph5olph?ale94 ,! sk9s %\ld be ?or\ghly relax$1 & ! swell+ s mu* elim9at$ t !y are q s(t1 weak & fall54 ,! resili5ce & ela/icity ( ! plump$ sk9s %\ld h q disappe>$1 & ! impressions ( h& or ?umb %\ld be readily reta9$ by ! pelt4 ,! gra9 %\ld appe> :ite & possess a s(t & silky feel4 ,9 ?is condition !y are aga9 work$ ov] ! beam to s(t5 fur!r if possible4 ,!y are !n r9s$ & aga9 work$ ov] ! beam4 ,dr5*+ foll[s ) #aj p] c5t4 ( bran on ! pelt weight1 ! op]ation comm5c+ at #he to #ie ,f41 & la/+ till next morn+4 ,! sk9s are next scudd$ ?or\ghly to remove all dirt1 b c>efully s z n to damage ! gra94 ,9 tann+1 suma* & oak b>k are ! /aple mat]ials4 ,suma* gives a mu* light] col\r1 & h5ce x is us$ alone = goods t are to be dy$ ! light] %ades1 b oak b>k is a fa/] tannage & m pref]able = dye+ 9 ^? cases :]e blacks & v d>k %ades are want$4 ,= ord9>y purposes a bl5d is usually employ$4 ,a feature ( oak b>k1 also1 is t x t5ds to make a firm] lea!r1 s t ! proportion us$ mu/ be adju/$ ) ?is fact 9 m9d z well z ! "q ( col\r4 ,= firm] moroccos ! sk9s may pass ?r\gh a h&l] r\nd ( oak-b>k liquors 7#aj-bj7 9 :i* a c]ta9 am\nt ( suma* is add$ to ! liquors4 ,! suma* is lea*$ & assi/s bo? 9 tann+ & blea*+ z ! liquor works ?r\gh ! r\nd4 ,! old liquor is run to a paddle1 & ! tannage is comm5c$ by paddl+ ! dr5*$ sk9s 9 ?is liquor4 ,x is advantage\s bo? = ! tannage & = ! effici5t sp5d+ ( ! suma* if ?is liquor be slightly w>m$4 ,9 ! e>ly pit liquors ! goods are v frequ5tly h&l$4 ,!re is1 h[ev]1 ! usual t5d5cy ( ! times to save lab\r 9 ?is direction1 & h5ce x is common to h sev]al paddles ) liquors ( gradually increas+ /r5g?1 foll[$ by a %ort] r\nd ( h&l]s 9 :i* ! h&l+ is m infrequ5t4 ,in/ead ( paddles lattic$ drums may be ins]t$ into pits conta9+ liquors4 ,^!1 h[ev]1 are n q s conv5i5t4 ,9 "s tann]ies1 especially :]e suma* only is employ$1 ! tannage is 9 paddles ?r\gh\t4 ,a new liquor is made up ) fre% suma* & is us$ repeat$ly until exhau/$4 ,a ?ree-paddle sy/em sometimes obta9s1 9 :i* case ! op]ation closely resembles ! ?ree-pit sy/em ( lim+ 7,"p ,i41 ,section ,,ii471 & ! sk9s pass ?r\gh an old liquor1 a m$ium liquor & a fre% liquor4 ,! goods ne$ n be paddl$ ! :ole day ?r\gh1 & inde$ 9 ! lat] /ages ?is is undesirable4 ,! packs rema9 sev]al days 9 ea* liquor & take up to #ad days to tan4 ,two to ?ree bags ( suma* are ne$$ = ab\t #bj doz5 goatsk9s4 ,?is me?od ( tann+ is effici5t & conv5i5t = bold-gra9 f9i%es1 on acc\nt ( ! con/ant tumbl+ & b5d+ ( ! sk9s :i* t5ds to "w up a gra94 ,= v s(t lea!rs & f9e-gra9 f9i%es1 h[ev]1 ! bag-tannage or bottle tannage is fav\r$4 ,9 ?is me?od ! pelt is /it*$ up by ma*9e to =m a bag1 gra9 outw>ds1 leav+ a neck 9 ! h9d %ank4 ,! bag is ne>ly fill$ ) a fairly /rong infusion ( suma*1 inflat$ ) air & ti$ up at ! neck4 ,! bags are !n plac$ into a vat ( w>m suma* liquor1 9 :i* !y j float4 ,! bags are pu%$ d[n & ! liquor /irr$ up1 s t ! goods are 9 con/ant motion4 ,aft] a few h\rs !y are pil$ on a rack1 & ! tan liquor ( ! int]ior is caus$ to diffuse ?r\gh ! sk9s by ! pressure due to ! weight ( ! pile4 ,! bags are refill$ ) fre% & /rong] suma* liquor & ! process is repeat$4 ,! sk9s are ?us lightly b effectively tann$ 9 ab\t #bd h\rs1 & ! lea!r has v f9e gra9 & s(t feel4 ,h[ev] tann$ ! sk9s are dri$ out aft] tann+1 & sort$ 9 ! cru/ accord+ to size & col\r4 ,! l>g] sk9s are pref]r$ = uphol/]y & ! small] = fancy goods & bookb9d+4 ,to illu/rate ! c\rse ( f9i%+ op]ations1 ! case ( h>d-gra9 morocco = bookb9d+ may be giv5 z typical4 ,! goods are wet back ) w>m wat] & drumm$ = #a-b h\rs 9 w>m sumac to prep>e = dye+4 ,!y are !n /ruck out by ma*9e1 samm$ & %av$4 ,dye+ foll[s1 ) acid col\rs1 9 a drum4 ,! goods are run fir/ 9 a little wat] & ! dye/uff add$ v gradually ?r\gh a holl[ axle4 ,! acid requir$ 7pref]ably =mic7 is add$ lat] to develop ! full %ade4 ,w>m solutions are us$1 & ! dye ba? is practically exhau/$4 ,! goods are next plac$ 9 cold wat] to wa% (f sup]flu\s liquor & free ! sk9s f acid4 ,!y are !n hors$ to dra91 /ruck out & hung up to samm4 ,!y are season$ ) milk & wat] & pil$ to temp]4 ,!y are too? roll$ 9 ! glaz+ ma*9e two ways3 "r-h& %ank to left =e %ank & vice v]s1 & pil$ aga94 ,aft] wett+ back aga9 !y are wet gra9$ by h& ) a cork bo>d 9 f\r directions3 belly to belly1 %ank to %ank1 & across z be=e1 & f9ally f neck to butt4 ,!y are imm$iately hung up 9 a w>m %$ to dry1 & to fix ! gra94 ,!y are !n s(t5$ by break+ d[n ) a rubb] bo>d1 top season$1 pil$ to temp] & dry1 bru%$ lightly1 pil$ aga91 bru%$ m heavily1 & dri$ out4 ,!y are f9ally s(t5$ by gra9+ 9 ?ree directions3 %ank to %ank & across1 & neck to butt4 ,!y are !n bru%$ aga94 ,if ^! sk9s are want$ = uphol/]y !y are %av$ aft] dye+1 & nail$ on bo>ds to samm4 ,!y are also dri$ out 9 a cool] %$ or /ove1 to ensure s(tness4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #ci1 #ee1 #hi1 #aaa1 #bjd1 #cdd1 #cif4 ,,section ,,iii4--,,sealsk9s ,a special class ( morocco lea!r is manufactur$ f ! sk9s ( seals4 ,?is %\ld n be confus$ ) ! sealsk9 ( popul> p>lance1 :i* is manufactur$ f ! sk9 ( a diff]5t animal4 ,all ! f9-foot$ mammals 7,p9nip$ia71 except ! walrus1 are t]m$ seals1 b !y are divid$ into two families4 ,! ,ot>iid are kn[n by _! possession ( small b di/9ct ext]nal e>s3 into ?is class fall ! fur-seals ^: sk9 is dress$ ) ! fur on1 = wom5's jackets1 muffs & caps4 ,! ,phocid are t family )\t ext]nal e>s3 ! sk9s ( _m species 7,phoce ,gre5l&ica1 ,phoco b>bata1 etc47 ( ?is family are unhair$ & giv5 a vegetable tannage1 ?us =m+ ! raw mat]ial ( sealsk9 morocco lea!r4 ,x is ) ! latt] t ?is section w deal4 ,z ! seal is a m>9e animal & is p>tial to ! cold] seas1 its sk9 is v oily4 ,! sk9s are import$ 9 a salt$ condition f bo? ! ,arctic & ,ant>ctic regions4 ,nor? ,europe1 ,nor? ,am]ica & ,newf\ndl& supply _m sk9s1 & ! s\!rn mat]ial is suppli$ *iefly ?r\gh ! ,cape4 ,sealsk9 %>es ) goatsk9 ! prop]ties ( compact texture1 /r5g? ( fibre1 & great durability1 all ( :i* fit x = ! manufacture ( moroccos = uphol/]y1 bookb9d+1 etc4 ,x is1 h[ev]1 readily di/+ui%able f goatsk9 by its *>act]i/ic gra9 patt]n4 ,9 soak+ sealsk9s ! object is n only to s(t5 ?or\ghly1 b also to effect ! recov]y ( z mu* seal oil z possible be=e ! lim+ comm5ces4 ,?is is desir$ because ! oil is 9 itself a valuable bye-product1 & because its removal is ess5tial to a satisfactory lim+ & tannage4 ,! removal ( ! oil is mat]ially assi/$ by rais+ its temp]ature1 s t ! soak+ ( sealsk9s is (t5 done ) w>m wat] 7#he-hh ,f471 aft] :i* treatm5t !y are laid ov] ! beam & scrap$ ) a blunt knife on bo? fle% & gra94 ,! oil fl[s away into a special receptacle4 ,?is treatm5t is repeat$ until ! bulk ( loose oil is remov$4 ,! process is kn[n z blubb]+ or bru%+ ov]4 ,aft] "s soak+ ! sk9s are drumm$ to ensure s(tness4 ,! sk9s are !n fle%$4 ,m oil may be obta9$ f ! fle%+s4 ,by fle%+ be=e lim+ a m regul> action ( ! lime is obta9$4 ,?is is necess>y to kill ! grease /ill rema9+ 9 ! sk94 ,a long & mell[ lim+ is giv5 = ! same reason4 ,fully ?ree weeks are giv51 & old limes are mu* pref]r$1 p>tly to obta9 ! maximum lipolytic action & p>tly to avoid ! int5se ribb+ ( ! pelt :i* new limes s easily imp>t to ! old] animals4 ,^! ribs are v difficult to elim9ate 9 ! subsequ5t "w4 ,"s factories f9d x necess>y to f9i% up 9 new limes1 h[ev]1 9 ord] to plump & split ! compact fibre bundles into _! compon5t fibrils4 ,! plump$ pelt is also easi] to split gre54 ,no sulphides are usually employ$4 ,sweat+ 7see ,section ,,iv47 is sometimes us$ = depilation1 & 9 ?is case ! ribb+ ( ! pelt does n take place4 ,! pu]+ is unusually ?or\gh ) sealsk9s4 ,?is is to obta9 ! maximum s(tness & take full advantage ( ! lipolytic action4 ,! pu] liquor is fully #ie ,f41 & ! sk9s are paddl$ = ab\t ?ree h\rs1 or until fully pull$ d[n & completely delim$4 ,scudd+ foll[s1 n[ usually by ma*9e4 ,! sk9s are !n well dr5*$4 ,! action is int5sifi$ by ! use ( peameal 9 addition to ! bran4 ,ab\t #aj p] c5t4 ( ! mixture on ! weight ( pelt is us$4 ,x is cu/om>y1 h[ev]1 to dr5* at a l[] temp]ature 7#fh-gj7 ?an 9 ! case ( goatsk9s 7,section ,,ii471 b ! goods are left 9 ! dr5* ov]night only1 z is usual 9 dr5*+4 ,x is q possible t dr5*es work$ diff]5tly may h also a some:at diff]5t f]m5tation & be due to o!r organisms ?an ! symbiotic bact]ia discov]$ by ,wood4 ,x is equally possible t ! acids produc$ are also diff]5t1 9 relative proportion1 if n 9 nature1 & t consequ5tly !re is a real diff]5ce 9 ! practical effect4 ,9 ! ,au?or's op9ion1 ! great probability is t 9 ! dr5* are sev]al f]m5tations1 & t if ! action be r$uc$ by l[]+ ! temp]ature1 b int5sifi$ by add+ peameal to ! bran1 "s ( ^! f]m5tations are enc\rag$ at ! exp5se ( o!rs4 ,! tannage ( sealsk9s dep5ds ^u ! size ( ! sk9s1 ! purpose = :i* !y are int5d$1 & :e!r !y h be5 split or n 9 ! lim$ /ate4 ,! l>ge/ & co>se/ sk9s int5d$ = boot upp]s1 & ^? :i* h be5 heavily scrat*$ on ! gra9 & are only suitable = enamels1 are giv5 a tannage :i* may la/ ab\t #e weeks4 ,! liquors are made f oak b>k & mimosa b>k1 & are made up to #ce ) gambi] & possibly myrabolans extract4 ,= fancy "w also heavy sk9s are us$1 b a s(t] tannage is ne$$4 ,if = blacks ! tannage is ) gambi] & *e/nut extract4 ,two sets ( h&l]s are giv5 7#aj-ae & #ae-bj71 us+ only gambi] 9 ! gre5 sets4 ,!y are well suma*$ aft] tann+ to blea* & to mordant4 ,if = col\rs1 only suma* & oak b>k are employ$4 ,! sk9s are fir/ paddl$ = #c-d days 9 suma* liquors1 9 :i* !y are col\r$ ?r\gh4 ,! liquors may be w>m$2 ?is quick5s ! tannage & also lea*es ! suma*4 ,! sk9s are !n split1 & ! gra9s pass ?r\gh a h&l] set ) liquors made f oak b>k 7#h-bd74 ,! sk9s are 9 ?is set = #c weeks1 9 ! fir/ half ( :i* !y are v frequ5tly h&l$4 ,!y are f9i%$ (f by paddl+ = #a or #b days 9 a fre% liquor conta9+ mu* suma*1 :i* mordants ! sk9s & blea*es ! b>k tannage4 ,! fle% splits are giv5 a drum tannage 9 *e/nut & quebra*o extracts4 ,if small sk9s are be+ tann$ = bookb9d+ purposes1 suma* only is employ$1 & usually ! tannage is entirely 9 paddles4 ,9 f9i%+ _m types ( gra9 may be obta9$1 9 blacks & 9 col\rs4 ,! f9i%+ ( black levant may1 h[ev]1 be select$ z a typical case4 ,! sk9s are soak$ back1 temp]$1 & ei!r split or %av$1 accord+ to _! sub/ance & ! size ( gra9 want$4 ,! ?9 sk9s ( c\rse give ! f9e gra9s4 ,mix$ tannages ne$ sc\r+ & possibly suma*+4 ,! sk9s are !n oil$ up ) l9se$ oil1 samm$1 set out & black$4 ,9 ?is la/ op]ation ! gra9 is bru%$ ov] ) a solution ( logwood & ammonia1 & aft]w>ds ) ! iron mordant :i* (t5 conta9s glue4 ,!y are next hung up = a :ile & !n wet gra9$ 9 f\r directions--belly to belly1 %ank to %ank1 across1 & neck to butt4 ,aft] hang+ up 9 a hot /ove to set ! gra91 !y are cool$1 fluff$ on ! fle%1 & season$ on ! gra9 ) a solution ( milk & blood4 ,a little black dye/uff may be add$ to ! season4 ,! season is well bru%$ 91 ! sk9s dri$ some:at1 & !n glaz$4 ,!y are !n gra9$ f\r ways aga9 z above1 dri$ out 9 ! /ove1 & lightly oil$ ) w>m l9se$ oil on ! gra94 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 #dj1 #ef1 #ij1 #aab1 #bjf1 #bea1 #cab1 #cdf1 #chc4 ,,section ,,iv4--,,%eepsk9s ,! mo/ num]\s class ( sk9s = light lea!rs is f ! common %eep4 ,^! sk9s h p>ticul> value inasmu* z !y include ! wool z well z ! pelt4 ,?is wool1 :i* is actually ! mo/ valuable "p ( ! %eep's sk91 is ! raw mat]ial ( our wooll5 indu/ries1 & is "o ( ! mo/ important ( animal proteids4 ,we h1 !re=e1 9 ?is section to consid] ?is dual value ( %eepsk9s1 ! proteid ( ! epid]mis 7wool71 & ! proteid ( ! d]mis 7pelt72 "o ! raw mat]ial ( ! wooll5 indu/ry1 ! o!r ! pr9cipal raw mat]ial ( ! light lea!r trade4 ,! fir/ problem is to sep>ate ! two proteids4 ,) o!r sk9s & hides ! ord9>y lim+ processes 7 suffici5t & appropriate1 b 9 ! case ( %eepsk9s ! me?od is unsuitable1 because ! exposure ( ! wool to ! action ( cau/ic lime & possibly o!r alkalies w\ld s]i\sly impair its quality & r$uce its comm]cial value4 ,h5ce ?is sep>ation ( wool f pelt is usually q a sep>ate bus9ess1 viz4 t ( ! fellmong]1 ^: occupation x is to collect ! %eepsk9s f but*]s & f>m]s1 to sep>ate ! two important con/itu5t proteids1 & to h& ! wool 9 "o direction to ! wool /apl]1 :o sorts x accord+ to quality1 & to h& ! pelt 9 ano!r direction to ! light lea!r tann]1 :o tans & f9i%es ! pelt to fit x = light upp] "w1 fancy goods1 etc4 ,9 ! fir/ in/ance1 !re=e1 we h to consid] ! "w ( ! fellmong]1 ! sep>ation ( wool & pelt4 ,9 ?is "w ! wool receives fir/ consid]ation1 & ! raw mat]ial ( ! fellmong] is usually classifi$ accord+ly into long wools1 %ort wools1 & m\nta9 bre$s4 ,! sk9s v>y v l>gely 9 quality ( wool & 9 quality ( pelt1 be+ influ5c$ v /rongly by ! conditions "u :i* ! %eep liv$1 & by ! precise bre$ ( animal f :i* ! sk9 has be5 tak54 ,z 9 ! case ( hides 7,"p ,i41 ,section ,i471 animals expos$ to extremes ( wea!r develop ! be/ pelts1 :]eas ^? %eep :i* h be5 c>efully br$ & re>$ = ! sake ( _! wool yield a ?9 & poor class ( pelt4 ,9 ,brita91 & m especially 9 ,engl&1 are re>$ ! f9e/ & mo/ valuable %eep4 ,?is is evid5t f ! prices paid = !m by =eign]s & colonial bre$]s :5 seek+ new blood = _! flocks & fre% /ock = _! l&s4 ,z mu* z #ajjj gu9eas h be5 paid by an ,arg5t9e firm = a s+le ,l9coln ram4 ,long wools are obta9$ f "s ( ! be/ & mo/ ext5sively br$ animals4 ,! ,cotswolds are ! l>ge/1 & probably ! orig9al bre$ ( ,engl& are /ill f\nd on ! ,cotswold ,hills4 ,!y h long wool1 :ite fleeces1 :ite faces1 & :ite legs1 & h no horns4 ,! wool is f9e1 b ! pelts are p>ticul>ly greasy1 especially along ! back4 ,a lat] bre$ orig9at+ 9 ! ,midl&s 0 call$ ! ,leice/] long wool4 ,?is bre$ gives a great cut ( wool & mu* co>se mutton4 ,x is v ext5sively di/ribut$ 9 ! ,nor? ( ,engl& & has be5 mu* cross$1 s t _m sub-bre$s are n[ well kn[n1 e4g4 ! ,bord] ,leice/]--! g5]al utility %eep ( ,scotl&--& ! ,york%ire ,leice/] or ,ma%ams1 mu* br$ 9 ,w5sleydale4 ,l9colns are ano!r long wool f\nd only on ! ,l9coln%ire ,wolds4 ,!y also h :ite faces & %anks & yield a l>ge pelt ) f9e gra94 ,!y give a big crop ( wool4 ,devons are a small] bre$ common 9 ,som]set1 ,devon & ,cornwall4 ,!y yield a fairly long wool ( great /r5g?1 b n q :ite4 ,romney ,m>% %eep 7,k5ts7 are also long wools4 ,!y h :ite legs1 :ite faces1 a tuft ( wool on ! head1 & no horns4 ,! pelt is l>ge & good4 ,roscommons are an ,iri% cross bre$ ) mu* ,leice/] blood4 ,!y yield a long wool & a spready pelt4 ,%ort wools are typifi$ by ! ,d[n %eep4 ,^! %eep are ext5sively br$ on ! *alk l&s :i* comprise a v l>ge p]c5tage ( ! s\!rn c\nties ( ,engl&4 ,! ,s\? ,d[ns are ! be/ & mo/ important1 ! bre$ be+ ! g5]al utility %eep ( ,engl&4 ,!y are small b well-%ap$ animals ) grey faces1 no horns & f9e close wool4 ,! pelt is only fair1 b ! mutton is excell5t & provides ! meat sold 9 our be/ %ops4 ,?is bre$ has l>gely /ock$ ,new ,zeal&4 ,! ,s\? ,d[n is a some:at delicate animal1 & has !re=e be5 l>gely cross$ ) ,cotswolds & o!r bre$s4 ,_m well-kn[n cross-bre$s are f\nd 9 ! ea/]n & s\!rn c\nties4 ,! ,suffolks1 = example1 are f\nd 9 ! ea/]n c\nties4 ,!y h black heads1 faces & legs4 ,ox=ds & ,hamp%ires are simil>1 b l>g]4 ,%rop%ires are ano!r h>dy cross-bre$1 :i* yield a heavi] fleece4 ,all ! cross-bre$s are l>g] ?an ! ,s\? ,d[n & yield bigg] pelts4 ,m\nta9 bre$s yield wool ( v>y+ quality b give ! be/ pelts4 ,! ,*eviots--mu* fav\r$ by ! ,scot* f>m]s--h a wool ( m$ium l5g? b ) mu* hair 9 x4 ,!y h :ite faces & legs & no horns1 & yield excell5t pelts4 ,! ,black-fac$ ,m\nta9 ,%eep h long] wool b co>se1 & yield good pelts4 ,!y are kept 9 ! hilly p>ts ( ,nor? ,engl& & 9 ! ,scotti% ,highl&s4 ,lonks yield a l>ge & good pelt1 b v co>se wool4 ,! mutton is good4 ,!y are a v l>ge bre$ ) mu* curv$ horns & black faces4 ,!re are also "s small bre$s1 s(t wools1 ,%etl&s1 & ,wel% ,m\nta9 ,%eep4 ,! wool ( ! la/ two is poor1 b ! ,wel% pelts are valu$ = _! f9e gra94 ,!re are l>ge numb]s ( %eepsk9s also import$1 f ,s\? & ,c5tral ,am]ica1 & f ,au/ralia1 ,new ,zeal& & ! ,cape4 ,! colonies1 h[ev]1 h (t5 done _! own fellmong]+1 & we h import$ pickl$ pelts4 ,!y n[ tan ! sk9s also1 & _m tann$ %eepsk9s are n[ import$4 ,!re are also _m ,indian sk9s import$ aft] tannage ) turwa% b>k 7cp4 ,e4,i4 ,goat1 ,section ,,ii474 ,! depilation is br\ght ab\t by sweat+ 7or /al+7 & by pa9t+4 ,! imm$iate object ( bo? ^! types ( me?od is to avoid us+ any ?+ :i* w affect ! wool4 ,! sweat+ process is ! mo/ anci5t me?od ( unhair+ & is us$ 9 ,am]ica = hides z well z %eepsk9s4 ,x consi/s ( a m or less regulat$ putrefaction4 ,! loos5+ ( hair or wool has long be5 accept$ z evid5ce t putrefaction _h comm5c$ 9 a hide or sk91 & x is ! aim ( ! sweat+ process to /op ! action at t /age1 be=e any damage has be5 done to ! pelt4 ,?is aim is a*iev$ r imp]fectly by susp5d+ ! goods 9 clos$ *amb]s & regulat+ ! temp]ature & humidity by means ( /eam & wat]4 ,su* *amb]s are kn[n z sweat pits or ta9t+ /oves4 ,9 ! case ( %eepsk9s ! w>m-sweat sy/em is g5]ally us$1 & ! op]ation is c>ri$ out at #ge-hj ,f4 ,a satisfactory yield ( wool is obta9$ 9 good condition1 b ! pelt is v liable to suff] bact]ial damage & %[ weak gra94 ,! sk9s are fir/ clean$ by a few soaks 9 clean fre% wat]1 ) int]m$iate help f a burr+ ma*9e :i* pres5ts a rapidly revolv+ set ( spiral blades to ! wool1 & 9 ! pres5ce ( a good /ream ( wat] quickly removes all dirt f ! wool4 ,! sk9s !n ent] ! ta9t+ /ove1 & ! op]ation is comm5c$ by a slight injection ( live /eam4 ,9 summ]1 ab\t a week is suffici5t to loos5 ! hair1 b 9 w9t] up to two weeks may be necess>y4 ,little control ( ! process is possible1 & all t c be done is to wat* ! goods c>efully ne> ! end ( ! op]ation4 ,9 "o v>iety ( ?is me?od ( unwooll+ ! sk9s are pa9t$ on ! fle% side ) a creamy mixture ( lime & wat] & pil$ = a day or two until ! pelt is di/9ctly plump$4 ,!y are !n wa%$ ) fre% wat] to remove ! excess ( lime1 dra9$1 & !n ent] ! ta9t+ /ove4 ,by ?is me?od ! pelts are obta9$ 9 bett] condition & are less liable to damage by local excess ( putrefaction4 ,9 unwooll+ ! sk9s are plac$ ov] a beam & ! true wool is pull$ out by h&4 ,! wool is grad$ z x is pull$ & diff]5t qualities kept sep>ate3 ewe wool1 lamb wool1 hog wool1 etc4 ,! hair is next remov$ f face & %anks by means ( a blunt rubb+ knife1 & ! pelt !n imm]s$ 9 wat]4 ,9 ! o!r me?od ( depilation1 by pa9t+1 advantage is tak5 ( ! loose texture ( ! %eepsk9 fibre & ( ! fact t ! wool root is ne>ly halfway ?r\gh ! sk94 ,! fle% side ( ! clean sk9 is pa9t$ ) a creamy mixture ( lime 9 a /rong solution ( sodium sulphide 7#ad-bd ,beaum74 ,c>e is tak5 to keep ! depilatant (f ! wool4 ,! sk9s are fold$ fle% to fle% & left = a few h\rs or until next day be=e unwooll+1 accord+ to ! /r5g? ( ! sulphide solution4 ,! depilatory action is entirely *emical1 be+ due to ! solv5t action ( ! sulphide on ! hair root4 ,! lime is sometimes omitt$4 ,aft] pull+1 ! sk9s are op5$ up & wa%$ 9 fre% wat]4 ,! v>i\s classes ( wool are sold to ! wool-/apl] & s to ! wooll5 indu/ry4 ,z ?is is a me*anical r ?an *emical indu/ry1 its discussion is beyond ! scope ( ?is volume4 ,h[ev] unwooll$1 ! pelt /ill ne$s fur!r treatm5t by ! fellmong]4 ,x ne$s lim+ & unhair+4 ,?is is done 9 ! ord9>y way 9 pits ( milk ( lime1 ?r\gh :i* ! goods pass f old to new limes 9 ! c\rse ( ab\t a week4 ,?is plumps ! fibres1 sep>ates ! fibrils & kills ! grease4 ,paddles are us$ also to save h&l+4 ,%e>l+s are sometimes lim$ #i-ad days & unwooll$ )\t sweat+ or pa9t+4 ,aft] lim+ ! sk9s are unhair$ & fle%$1 & plac$ 9 clean /rong limes until sold to ! tann]4 ,%eepsk9 pelts are sometimes pres]v$ by pickl+4 ,?is consi/s 9 plac+ !m fir/ 9 a solution ( sulphuric acid 7ab\t #c_/d p] c5t47 toge!r ) "s common salt4 ,! pelts swell up & imbibe ! acid solution4 ,!y are !n plac$ 9 saturat$ br9e1 :i* causes a v complete repression ( ! swell+1 ! pelts be+ app>5tly lea!r$4 ,9 ?is condition or p>tly dri$ out !y may be kept = ye>s4 ,! =ces at "w 9 ?is ph5om5on are some:at complex 7see ,"p ,v41 ,section ,i474 ,! sk9s may be depickl$ by paddl+ 9 a #aj p] c5t4 salt solution to :i* weak alkalies su* z borax1 :it5+1 c>bonate & bic>bonate ( soda1 etc41 h be5 add$4 ,! lea!r manufactur] classifies %eepsk9s accord+ to ! size ( ! pelts4 ,! l>ge sk9s are tann$ = light upp] lea!rs & simil> "w4 ,^! are call$ basils4 ,_m l>ge sk9s are also split gre5 into skiv]s :i* aft] vegetable tannage are f9i%$ = fancy goods1 bookb9d+1 etc4 ,! fle%es are (t5 oil-tann$ = *amois lea!r 7,"p ,,iv41 ,section ,,iii474 ,m$ium-siz$ sk9s su* z are obta9$ f ! ,d[n %eep are tann$ = roans1 & f9i%$ z a k9d ( morocco lea!r4 ,small sk9s are mo/ly taw$ 7,"p ,,iv41 ,section ,i47 = glove lea!rs1 b "s are made into roll] lea!r by vegetable tannage4 ,basils1 :i* repres5t ! heavie/ %eepsk9 "w1 are tann$ & f9i%$ 9 ! foll[+ mann]4 ,! lim$ pelts are fir/ bat$ lightly at ab\t #hj ,f4 = two days1 scudd$ & dr5*$4 ,!y are sometimes pu]$1 b m (t5 m]ely delim$ ) organic acids4 ,9 ?is la/ case !y are fir/ paddl$ 9 w>m wat] to remove excess ( lime1 & a mixture ( organic acids is v sl[ly add$ at def9ite int]vals4 ,:5 ne>ly free f cau/ic alkali ! sk9s are remov$ & dr5*$ ov]night4 ,!re are two types ( tannage4 ,! ,we/ ( ,engl& tannage is simil> to ^? not$ = sealsk9s :5 oak b>k & suma* are employ$ 7,section ,,iii474 ,!re is also ! t5d5cy to paddle m & h&le less1 & to use ! /rong] tann+ mat]ials su* z myrabs1 gambi] & o!r extracts4 ,aft] ab\t #ab h\rs' tannage 9 paddles !y are col\r$ ?r\gh1 & are !n degreas$ by hydraulic pressure4 ,! sk9s are pil$ 9 ! press ) lay]s ( sawdu/ or bran betwe5 !m1 & ! pressure appli$ v sl[ly4 ,mu* grease runs out1 = ! natural %eepsk9 conta9s up to #ae p] c5t4 ( oil & fat4 ,degreas+ may be po/pon$ till tannage is complete1 & ! grease c !n be extract$ by solv5ts 7b5z5e1 acetone1 etc474 ,degreas+ aft] "p tannage is usually consid]$ pref]able1 & ! sk9s may be tann$ out 9 pit or paddle 9 ab\t a week4 ,! ,scot* tannage is ) l>* b>k f ,p9us l>ix1 :i* conta9s up to #ac p] c5t4 ( a r mell[ cate*ol tan4 ,?is mat]ial has also "s sug>s & yields s\r & plump+ liquors4 ,! basils are paddl$ 9 weak liquors 7#h-aa7 = ab\t #b days1 & :5 /ruck ?r\gh are degreas$ by hydraulic pressure4 ,!y are !n soak$ back & tann$ out 9 /rong] liquors 7#aa-bj71 :i* takes up to "o week4 ,!y are !n dri$ out & sort$ 9 ! cru/4 ,! f9i%+ dep5ds ( c\rse ^u ! purpose 9 view4 ,if = l9+s !y are soak$1 %av$1 suma*$1 /ruck out well1 nail$ on bo>ds & dri$ "r out4 ,!y are next /a9$ ) a solution ( />*1 milk & r$ dye/uff4 ,aft] dry+ !y are glaz$ by ma*9e & s(t5$ ) a h& bo>d4 ,= fancy slipp]s ! cru/ sk9s are />*$ & /a9$ directly1 !n /ak$ 7see ,"p ,,iii41 ,section ,,ii471 fluff$1 season$ & glaz$4 ,if int5d$ = legg+s & gait]s a fle% f9i% is giv54 ,! sk9s are soak$1 /ret*$1 %av$ & suma*$4 ,!y are !n r9s$1 dra9$1 samm$ & /a9$4 ,a br[n /a9 mix$ ) l9se$ jelly is usual4 ,?is is spread ev5ly ov] ! fle% & glass$ 94 ,! sk9s are dri$ out1 re/a9$ if necess>y1 & /ak$ to raise a nap4 ,basils = gait]s are dy$ 9 paddle & fluff$ ov] ! em]y :eel4 ,skiv]s are split 9 ! lim$ /ate & sometimes imm$iately degreas$4 ,!y are next pu]$ at #he ,f4 = ab\t #c h\rs 9 a paddle1 & scudd$4 ,!y are dr5*$ at a l[ temp]ature 7#fh-gj ,f471 b (t5 #b or #c days4 ,!y are aga9 scudd$ & !n r9s$ & s5t to tan4 ,! skiv]s are tann$ 9 a few days by suma* liquors work+ ! goods up f mell[ to fre% z usual4 ,! liquors are w>m$4 ,c>e mu/ be tak5 t ! goods d n te>4 ,a great v>iety ( f9i% is possible1 b ! pa/e gra9 skiv] = fancy goods & ! pla9 f9i% = hat lea!rs are suffici5tly typical4 ,= pa/e gra9s !y are soak$ & cle>$ = dye+ by imm]sion 9 v weak sulphuric acid1 excess ( :i* is c>efully wa%$ out ) wat]4 ,paddle-dye+ foll[s1 & is pref]r$ to drum dye+ z ! sk9s are s liable to te>4 ,aft] be+ /ruck out !y are pa/$1 by spread+ on to ! fle% a glue jelly1 us+ fir/ ! h&1 !n a /iff bru% & f9ally a clo?4 ,! goods are !n dri$ out4 ,!y are !n season$1 p>tly dri$ & pr9t$ cross-gra94 ,!y are next gra9$ two ways lightly2 %ank to %ank1 & across1 lightly too?-roll$ & glaz$4 ,!y are regra9$ two ways z be=e1 dri$ out1 & f9ally s(t5$ ) a gra9+ bo>d4 ,!y are sometimes siz$ on ! gra9 to fix ! patt]n & give a gloss4 ,= hat lea!rs ! sk9s are fir/ soak$1 suma*$ & /ruck out4 ,if = :ite or cream f9i%es !y are n[ lead-blea*$4 ,?is consi/s ( pigm5t dye+ ) lead sulphate4 ,!y are imm]s$ alt]nately 9 lead acetate & 9 sulphuric acid solutions until precipitation is suffici5t4 ,!y are !n dy$ to %ade4 ,if = br[ns x is common to mordant ) titanium & use basic dye/uffs1 paddl+ aft]w>ds 9 suma* to fix ! dye4 ,aft] dye+ ! goods are /ruck out aga91 />*$1 & dri$ out on bo>ds4 ,!y are aga9 />*$ & roll$ to give ! pla9 f9i%4 ,roans are n split4 ,!y are degreas$1 pu]$1 scudd$ & dr5*$ ov]night at #ie ,f4 ,!y are tann$ ) suma* usually 9 pits1 & take r long] ?an usual to tan4 ,!y are f9i%$ 9 mu* ! same /yle z goatsk9s = morocco lea!r1 b z ! %eepsk9 has little natural gra9 x ne$s emboss+ or pr9t+ accord+ to ! type requir$4 ,if = h>d gra9s1 ! sk9s are soak$1 suma*$1 season$1 dri$1 glaz$ & damp$ back = pr9t+4 ,?is is done by ! h>d gra9 roll]1 & ! goods are dri$ out to fix ! patt]n4 ,!y are damp$ back1 samm$1 & gra9$ 9 f\r directions 7cp4 ,section ,,ii471 dri$ out & bo>d$ to s(t54 ,if = /raight gra9s !y are pr9t$ ) a /raight-gra9 roll]1 or gra9$ neck to butt4 ,aft] too? roll+ !y are bo>d$1 dri$ & glaz$4 ,!y are s(t5$ d[n & air$ (f 9 a cool /ore4 ,roll] lea!r is a special class ( %eepsk9 lea!r :i* is us$ to cov] ! roll]s us$ 9 cotton sp9n+4 ,! ess5tial requirem5ts are t a smoo? pla9 f9i% %\ld be giv51 & ! lea!r mu/ n /ret* or be greasy4 ,= ?is purpose small %eepsk9s ) a f9e small gra9 are *os51 su* z ^? obta9$ f ! ,wel% m\nta9 %eep4 ,! pelts are ma*9e fle%$1 %ort hair$ & (t5 pu]$1 b ! delim+ is also br\ght ab\t by organic acids also4 ,! pelts are dr5*$ 9 pits fitt$ ) paddles1 :i* are us$ to /ir up ! infusion occasionally4 ,a ?or\gh scudd+ is giv54 ,= ! smoo?-gra9 f9i% x is necess>y to tan 9 weak liquors1 & to give pl5ty ( "t s z to ensure complete p5etration4 ,an oak-b>k tannage is pref]r$1 b a little extract is usual to assi/4 ,! goods are col\r$ ?r\gh 9 paddle1 l basils1 & are !n degreas$ by hydraulic pressure4 ,?is %\ld be z complete z possible1 & a little heat is us$ to assi/ ! escape ( grease4 ,! press$ sk9s1 moreov]1 mu/ be q fre$ f creases1 & ?is is atta9$ fir/ by paddl+ 9 w>m wat] to remove sawdu/1 & !n by drumm+ 9 fairly hot wat]1 9 :i* !y are left ov]night4 ,! sk9s are tann$ out 9 susp5d]s1 tak+ ab\t #c weeks4 ,! cru/ sk9s ne$ c>eful sort+1 & are soak$ & h& %av$4 ,!y are suma*$ 9 drum1 r9s$1 /ruck out1 samm$ & set4 ,! /rik+ & sett+ %\ld be ?or\gh1 9 ord] to get rid ( /ret*4 ,!y are next fill$ by coat+ ) l9se$ jelly or simil> mat]ial1 & dri$ out on bo>ds 9 a ?or\ghly /ret*$ condition4 ,!y are !n trimm$1 season$ & roll$ ) a /eel roll]4 ,!y are !n /ak$ or p]*$1 fluff$1 reseason$1 dri$ & glaz$4 ,!y are c>efully %ort-hair$1 glaz$ aga9 & f9ally iron$4 ,e4,i4 %eepsk9s are import$ 9 a tann$ condition4 ,^! are soak$ back & ! turw> b>k tannage /ripp$ z f> z possible by drumm+ ) soda = #bj-cj m9utes at #ie ,f42 aft] wa%+ !y are s\r$ 9 weak 7#a_/b p] c5t47 sulphuric acid solution1 & retann$ ) suma* pa/e = an h\r1 drumm+ at #ajj ,f4 ,!y may !n be f9i%$ = basils1 moroccos or roll] lea!r z describ$ above1 b are (t5 f9i%$ z imitation glac kid4 ,9 ?is case !y are drum dy$1 lightly fat-liquor$ 7see ,"p ,,iii41 ,section ,,iv471 /ruck out & dri$4 ,!y are /ak$ by ma*9e1 fluff$1 season$ & glaz$4 ,!y may be re-/ak$ & reglaz$ if desir$4 ,,ref]5ces4 ,a4 ,seym\r ,jones1 ,! ,%eep & its ,sk94 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #cj1 #he1 #ajg1 #bjh1 #cdi-ced1 #che4 ,,section ,v4--,,calfsk9s ,calfsk9s are ! raw mat]ial = _m classes ( lea!r4 ,! t]m itself is r broad4 ,a calfsk9 may be obta9$ f a v "y animal & weigh only a v few p\nds1 or x may be any?+ j %ort ( a kip4 ,goat1 seal1 & %eep sk9s are obta9$ f adult animals1 b calfsk9s f ! "y ( a l>ge animal4 ,?us !re are _m grades ( quality1 accord+ to age1 & ! mat]ial mu/ be *os5 ) reg>d to ! purpose 9 view4 ,"s ( ^! purposes h already be5 discuss$4 ,heavy calf is treat$ mu* l kip z a curri$ lea!r = upp] "w4 ,ev5 light] sk9s are giv5 ! wax$ calf & sat9 calf f9i%es1 & make upp] lea!r ( excell5t quality4 ,to produce su* lea!rs ! treatm5t is mu* ! same z describ$ 9 ,"p ,i41 ,section ,,viii4 ,calfsk9s 7 also us$ = v light upp] "w1 9 :i* !y 7 n s heavily greas$ 9 f9i%+1 b r dy$ & f9i%$ z a light lea!r4 ,9 ?is direction1 h[ev]1 ! vegetable tannage has be5 almo/ completely sup]s$$ by ! m9]al tannages1 fir/ by calf kid1 an alum$ lea!r 7,"p ,,iv41 ,section ,i471 & aft]w>ds by ! n[ popul> *rome tannage ( box calf1 will[ calf1 glac calf1 dull calf1 etc4 7,"p ,,iii41 ,section ,,iii474 ,9 ?is section1 !re=e1 we h only to consid] calfsk9s z us$ to make a vegetable-tann$ light lea!r1 su* z may be employ$ 9 bookb9d+ & 9 ! manufacture ( fancy goods4 ,= ^! purposes ! sk9s receive a mell[ lim+ ( #b-a_/b - #c weeks4 ,no sulphide ne$ be employ$1 z ! goods are soon fit to unhair4 ,9 su* a mell[ lim+ x is important t ! bact]ial activity is n too prom95t1 & h5ce x becomes advantage\s to "w ! lim+ sy/ematically 9 ! =m ( a r\nd ( pits4 ,to avoid ov]-plump+ 9 ! newe/ limes "s old liquor is us$ 9 mak+ up a new pit1 & its bact]ial activity is r$uc$ by add+ x to ! new cau/ic lime :il/ slak+4 ,?us = a pack ( #bjj-bej sk9s1 #ad-af /one ( lime may be slak$ ) ab\t #cj gallons ( old lime1 & ! pit fill$ up ) wat]4 ,if x be necess>y to %ort5 ! process & to use sulphide1 ?is %\ld be add$ only to ! tail liquors ( ! r\nd1 & ) x %\ld be add$1 if possible1 "s calcium *loride to r$uce ! h>%ness ( ! soda4 ,! sk9s %\ld be pu]$ ?or\ghly to obta9 ! necess>y s(tness1 bate-%av$ if desirable1 & dr5*$ ) #h p] c5t4 ( bran ov]night4 ,9 tann+ = fancy "w & = d>k col\rs1 ! goods are col\r$ (f & ev5ly /ruck ?r\gh ) suma* liquors1 & !n tann$ fur!r ) liquors made f oak b>k1 myrabolans or *e/nut extract4 ,! me?ods are v closely simil> to ^? us$ = goatsk9s & sealsk9s 7,"p ,,ii41 ,sections ,,ii4 & ,,iii471 & ne$ n be describ$ 9 fur!r detail4 ,! tannage is f9i%$ (f 9 suma*4 ,= bookb9d+ "w1 h[ev]1 a pure suma* tannage is giv51 us+ liquor slightly w>m 7#gj ,f474 ,paddle tannages are common1 b = bookb9d+ ! bag or bottle tannage is (t5 pref]r$4 ,! sk9s are sewn toge!r 9 pairs1 gra9 outw>ds1 & ne>ly fill$ ) w>m suma* infusion1 j z describ$ = goatsk9s4 ,!y are !n h&l$ 9 old suma* liquors = ab\t #c days1 & pil$ to dra9 & press4 ,at ?is /age ! bag is cut op51 ! goods work$ on ! fle%1 & ! tannage is complet$ ) sep>at$ sk9s 9 new] suma* liquors1 h&l+ at lea/ once a day = #d-e days1 z necess>y4 ,9 f9i%+ !re is ! usual v>iety1 b a pla9 ungra9$ f9i% is mo/ typical1 z ! smoo? & f9e gra9 ( ! "y animal l5ds itself to ?is type ( f9i% bett] ?an ! sk9s ( goat & seal1 & gives a bett] quality lea!r ?an ^? f ! %eep4 ,! cru/ sk9s are wet back ) wat] at ab\t #aaj ,f41 &1 if necess>y1 samm$ & %av$4 ,suma*+ foll[s1 ! op]ation be+ c>ri$ out 9 a drum = #a-b h\rs4 ,! sk9s are !n well /ruck out4 ,/rik+ & sett+ %\ld always be ?or\gh = a pla9 f9i%1 & ?is case =ms no exception4 ,dye+ foll[s next1 ! paddle be+ (t5 pref]r$ to ! drum1 :i* is liable to "w up a gra94 ,! dy$ sk9s are plac$ 9 cold wat] = a :ile & aga9 well /ruck out4 ,!y are (t5 nail$ on bo>ds to samm1 & are !n set out1 lightly oil$ ) l9se$ oil & dri$ out 9 a cool %$4 ,season+ foll[s1 ) milk & wat] only4 ,! op]ation may be done ) ei!r bru% or sponge1 aft] :i* ! goods are pil$ gra9 to gra9 & fle% to fle% to regulate4 ,!y may be next p]*$ to s(t5 & fluff$ if desir$4 ,aft] top season+ ) milk1 wat] & album9 ! sk9s are hung up = a :ile1 pil$ to regulate & bru%$1 fir/ lightly & !n m vigor\sly4 ,!y may be !n oil$ v lightly & dri$ out 9 a cool /ove to ensure a s(t lea!r4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #ee1 #hd1 #aje1 #bja1 #bjg1 #cjc4 ,,section ,,vi4--,,japann$ ,,& ,,enamell$ ,,lea!rs ,! lea!rs :i* receive a japann$ or enamell$ f9i% are usually vegetable tannages1 & s may be discuss$ at ?is /age4 ,!y are popul>ly kn[n z pat5t lea!r1 b = no obvi\s reason4 ,! *ief object is to obta9 a lea!r ) an exce$+ly bright & p]man5t gloss or poli%1 & ?is is atta9$ by coat+ ! lea!r sev]al times ) suitable v>ni%es4 ,! great difficulties are to prev5t ! v>ni% crack+ :5 ! lea!r is b5t or 9 use1 & to prev5t x peel+ (f f ! lea!r4 ,almo/ all classes ( vegetable tannage are japann$ & enamell$4 ,hides are split & enamell$ = c>riage1 motor c> & uphol/]y lea!rs1 & enamell$ calf1 seal & %eep sk9s are us$ = boot upp]s1 toe caps1 dress %oes1 slipp]s1 ladies' & *ildr5's belts1 hat lea!rs1 & s on4 ,broadly speak+1 a japann$ lea!r is a smoo? f9i% & is usually black1 :il/ an enamell$ lea!r is a gra9 f9i% ) a gra9 patt]n work$ up1 & m (t5 9 col\rs4 ,h5ce japann$ lea!rs are (t5 made f fle% splits or lea!rs ) a damag$ gra94 ,x is 9 any case advantage\s to buff ! gra9 lightly1 = ?is p]mits ! v>ni%es to s9k r deep] & get a firm] grip1 & avoids ! too sudd5 transition f phase to phase :i* is "o cause ( /ripp+ or peel+4 ,_m fle% splits1 h[ev]1 are pr9t$ or emboss$ to give an artificial gra9 & are !n enamell$1 :i* t5ds to fix ! emboss$ patt]n4 ,almo/ any me?od ( prep>+ dress+ hides = upp] or bag "w w yield a suitable lea!r = enamell+ & japann+ 7see ,"p ,i41 ,section ,,viii42 & ,section ,,ix474 ,if any?+ ! lim+ %\ld be some:at long] & mell[] 9 ord] to elim9ate grease1 z ! natural grease ( ! hide causes ! /ripp+ ( "s v>ni%es4 ,9 f9i%+ x is important to obta9 ev5 sub/ance1 or ! v>ni% is liable to crack4 ,hides are soak$ & samm$ 91 & (t5 split4 ,sometimes !y are split twice1 giv+ gra91 middle & fle%1 ! two =m] be+ enamell$ & ! la/ japann$4 ,o!r goods are %av$ v smoo?4 ,! goods %\ld be next ?or\ghly sc\r$ & /on$ to get z mu* /ret* z possible remov$4 ,!y are (t5 suma*$1 wa%$ 9 w>m wat]1 slick$ out aga9 & samm$4 ,!y are !n lightly buff$ on ! gra91 & aft] oil+ lightly are ?or\ghly set out & dri$4 ,emboss+ or pr9t+ = enamels is done be=e ! goods are q dry4 ,consid]able diff]5ce ( op9ion obta9s z to ! be/ oil to use 9 ! above oil+4 ,l9se$ oil is widely pref]r$ z be+ mo/ likely to agree ) v>ni%es made f l9se$ oil4 ,"s manufactur]s ( japans d n dislike ! use ( m9]al oil1 b /rongly object to cod oil1 tall[ or o!r /uff+ greases z t5d+ to cause ! v>ni% to /rip or peel4 ,o!r manufactur]s1 on ! o!r h&1 w n h lea!r ) m9]al oil 9 x1 & indicate t no?+ b cod oil %\ld be us$4 ,9 all probability ^! v>i\s pref]5ces are det]m9$ by ! nature ( ! v>ni%1 :i* diff]s widely 9 v>i\s p>ts ( ! globe4 ,9 ?is c\ntry ! v>ni%es are made l>gely f l9se$ oil by boil+ x ) dri]s4 ,?is oil conta9s mu* triglyc]ide ( an unsaturat$ relative ( /e>ic acid4 ,! d\ble bonds are v susceptible to oxidation ) ! production ( res9\s bodies ( unkn[n con/itution4 ,?is ph5om5on is kn[n z dry+ ! oil1 & has be5 ext5sively us$ 9 ! manufacture ( l9oleums4 ,! dri]s are ei!r oxidiz+ ag5ts or oxyg5 c>ri]s1 su* z li?>ge1 ,prussian blue1 raw umb]1 manganese dioxide1 manganese borate1 & res9ate4 ,prussian blue is mo/ pref]r$ = ,briti% japans1 z x always mat]ially assi/s ! atta9m5t ( ! desir$ black col\r4 ,! exact details ( ! boil+1 & ! manufacture ( ! v>ni%es is /ill l>gely ! trade secret ( ! ma/] japann]s1 & diff]s inde$ = ! v>i\s /ages ( japann+4 ,! v>ni% = ! e>li] coats is boil$ long]1 & ! dry+ c>ri$ fur!r1 ?an 9 ! case ( ! lat] coats4 ,?is is p>tly to obta9 a product ( su* /iffness t x w n p5etrate ! lea!r4 ,! dri]s & ! pigm5ts %\ld be f9ely p[d]$ & ?or\ghly mix$ 94 ,! boil+ takes sev]al days :5 at a l[ temp]ature1 b if done 9 #bd h\rs ! temp]ature may be up to #egj ,f4 ,9 ! lat] coats dri]s are (t5 n us$1 & ! product is (t5 mix$ ) copal v>ni%1 pyroxyl9 v>ni%1 etc41 :i* greatly help 9 obta9+ smoo?ness & gloss4 ,turp5t9e1 petroleum _s & o!r solv5ts are also us$ to ?9 ! v>ni%es4 ,be=e boil+1 ! oil is (t5 purifi$ by a prelim9>y heat+ ) nitric acid1 rose _s & o!r oxidiz+ ag5ts1 :i* precipitate impurities & !reby assi/ 9 obta9+ a bright gloss4 ,be=e ! application ( ! v>ni%es1 ! lea!r is fir/ dri$ ?or\ghly 9 a /ret*$ condition4 ,?is is accompli%$ by nail+ d[n on bo>ds :i* fit l movable %elves into a /ove1 a clos$ *amb] heat$ by /eam pipes4 ,! temp]ature ( ! /ove v>ies widely 9 diff]5t factories1 f #adj-bjj ,f41 accord+ to ! nature ( ! v>ni%es4 ,! fir/ coat ( w>m & r /iff japan is laid ov] ! hot lea!r 9 a w>m room1 be+ spread ov] fir/ by h&1 !n by a s]rat$ slick]1 & !n aga9 smoo!d by h&4 ,! goods are !n put into ! /ove = sev]al h\rs to dry4 ,:5 dry ! surface is pumic$ & bru%$ & a second coat appli$ 9 a simil> mann]1 b ) increas$ c>e4 ,?is is repeat$ ) f9] japans until ! desir$ result is obta9$4 ,bru%es are us$ to apply ! lat] coats4 ,up to sev5 coats may be appli$ = ! production ( a smoo? japan--?ree coats ( gr\nd japan1 two coats ( ?9n] japan1 & two coats ( f9i%+ v>ni%4 ,aft] ! /ov+ is complete1 ! product is giv5 a few days "u ord9>y atmosph]ic conditions to p]mit ! reabsorption ( moi/ure to ! usual ext5t4 ,enamell$ lea!rs are !n gra9$ to develop ! patt]n4 ,,ref]5ce4 ,b5nett1 ,manufacture ( ,lea!r1 p4 #chj4 ,,"p ,,iii4--,,*rome ,,lea!r ,,section ,i4--,,! ,,nature ,,( ,,*rome ,,lea!rs ,9 ^! days ! manufacture ( *rome lea!r has atta9$ a position h>dly less 9 importance ?an t occupi$ by ! anci5t me?od ( tann+ by means ( ! vegetable tann+ mat]ials1 & l>ge quantities ( hides & sk9s are n[ *rome tann$ aft] prep>atory processes analog\s to ^? describ$ 9 connection ) vegetable tannages 7,"p ,,ii41 ,section ,,ii42 & ,"p ,,ii41 ,section ,i474 ,*rome lea!rs are made by tann+ pelts ) ! salts ( *romium1 & are typical ( :at are kn[n z m9]al tannages1 9 :i* inorganic salts are ! tann+ ag5ts4 ,tannage ) alum & salt 7see ,"p ,,iv41 ,section ,i47 is "o ( ! e>lie/ m9]al tannages1 b is n[ ( relatively m9or importance4 ,*rome tann+ 0 fir/ inve/igat$ by ,knapp 7#aheh71 :o exp]im5t$ ) *romic *loride made basic by add+ alkali1 b 8 conclusions 7 unfav\rable to ! process4 ,a pat5t 0 tak5 out lat] by ,cavall9 9 :i* sk9s 7 to be tann$ by treat+ ) potassium di*romate & !n ) f]r\s sulphate :i* r$uc$ ! =m] to *romic salts1 be+ itself conv]t$ into f]ric salt4 ,! product1 :i* 0 a comb9ation ( iron-*rome tannage1 did n yield a satisfactory comm]cial lea!r4 ,ano!r pat5t1 tak5 out 9 #ahgi by ,he9z]l+1 specifi$ ! use ( potassium di*romate & alum4 ,?is 9 effect 0 a comb9ation *rome-alum9a tannage4 ,! alum _h its own tann+ action & ! di*romate 0 r$uc$ to *romic salts by ! organic matt] ( ! sk9 itself & by ! greases employ$ 9 dress+4 ,! process1 h[ev]1 0 n a comm]cial success4 ,9 #ahha pat5ts 7 obta9$ by ,eitn]1 an ,au/rian1 ^: process 0 a comb9ation *rome & fat tannage4 ,! *rome 0 employ$ z basic *romium sulphate made by add+ common soda to a solution ( *rome alum until a salt correspond+ to ! =mula ,cr7,,oh7,,s#d 0 obta9$4 ,su* a solution is n[ kn[n to be p]fectly satisfactory1 b at fir/ x prov$ difficult to devise satisfactory f9i%+ processes1 & to supplem5t ! *rome tannage ) ! fat tannage4 ,! fir/ und\bt$ comm]cial success 9 *rome tann+ 0 obta9$ by ! process ( ,augu/as ,s*ultz1 ^: pat5t 0 ! n[ widely kn[n two-ba? process1 9 :i* ! sk9s are treat$ successively ) a *romic acid solution & ) an acidifi$ solution ( hypo 7sodium ?iosulphate74 ,! fir/ ba? 0 made up comm]cially ( potassium di*romate & hydro*loric acid1 s t1 /rictly speak+1 x conta9$ potassium *loride also4 ,! second ba? conta9$1 9 effect1 sulphur\s acid1 :i* r$uc$ ! *romic acid 9 ! sk9 fibres to ! tann+ *rome salts4 ,free sulphur is also =m$ 9 ?is ba? & 9 ! sk91 & contributes to ! *>act]i/ic product obta9$ by ?is process ( tann+4 ,_m m9or deviations f ! orig9al process ( ,s*ultz h be5 introduc$1 b ! ma9 features h be5 un*ang$1 & ?is me?od ( tann+ is widely employ$ at ! pres5t "t = bo? light & heavy *rome lea!r4 ,9 #ahic tann+ by basic *romic salts 0 reviv$ & ! use ( ! basic *loride 0 pat5t$ by ,m>t9 ,d5nis1 :o (f]$ su* a tann+ solution = sale4 ,! validity ( ! pat5t has always be5 d\btful on acc\nt ( ! previ\s "w ( ,knapp & o!rs1 b ! process itself 0 comm]cially satisfactory1 & ! _m v>iants ( ?is & ( ! basic sulphate tannages are n[ g5]ally kn[n z ! "o-ba? process 9 contradi/9ction to ! v>iants ( ! ,s*ultz process1 & are widely us$ = all classes ( *rome lea!r4 ,a "o-ba? process :i* des]ves special m5tion 0 publi%$ 9 #ahig by ,pr(4 ,h4 ,r4 ,proct]4 ,9 ?is ! tann+ liquor 0 made by r$uc+ potassium di*romate 9 ! pres5ce ( a limit$ am\nt ( hydro*loric or sulphuric acid by add+ glucose4 ,al?\gh a basic *rome salt is ! *ief tann+ ag5t ?us produc$1 !re is little d\bt t ! organic oxidation products play an ess5tial "p 9 produc+ ! fullness & mell[ness ( ! lea!r ?us tann$1 b _! nature & mode ( action has n yet be5 fully made cle> ?\gh lyotrope influ5ce is probable4 ,m rec5tly ,bald]/on has sugge/$ ! suitability ( sulphur\s acid z r$uc+ ag5t4 ,a /ream ( sulphur dioxide gas is pass$ ?r\gh a solution ( sodium di*romate until r$uction is complete4 ,! result+ *rome liquor has be5 fav\rably report$ ^u by "s *rome tann]s4 ,bisulphite ( soda has also (t5 be5 us$ z ! r$uc+ ag5t4 ,o!r organic sub/ances are also (t5 us$1 in/ead ( glucose1 to r$uce ! di*romate4 ,!ory ( ,*rome ,tannage4--,z to ! !ory ( *rome tann+ !re is /ill consid]able diff]5ce ( op9ion & mu* room = exp]im5t4 ,"s lea!r *emi/s reg>d ! tannage z diff]+ ess5tially f ! vegetable tannages4 ,mr4 ,j4 ,a4 ,wilson has ev5 sugge/$ t ! proteid molecule is 9 "t p>tly hydrolyz$ ) ! =mation ( a *romic salt ) ! acid gr\ps4 ,! au?or1 h[ev]1 /rongly fav\rs ! view t 9 *rome tann+ *anges take place :i* are closely analog\s to ^? :i* occur 9 vegetable tannage1 ! diff]5ces be+ ma9ly ( degree4 ,?us ! hide gel is imm]s$ into a lyophile sol--! *rome liquor--& !re foll[s lyotrope influ5ce1 adsorption1 gelation ( ! tann+ sol1 z well z diffusion into ! gel1 & f9ally also1 probably1 precipitation ( ! tann+ sol at ?is int]face4 ,9 *rome tannage ! lyotrope influ5ce is mu* m prom95t ?an 9 vegetable tannage1 b ! effect is 9 ! same s5se1 viz41 to r$uce ! imbibition ( ! hide gel4 ,?us ! potassium sulphate 9 a *rome alum liquor has its own specific action ( ?is k9d & contributes to ! lea!r =mation4 ,unhydrolyz$ *romium sulphate & ! sodium sulphate =m$ 9 mak+ basic act also 9 ! same s5se4 ,! tann+ sol is probably *romium hydrate1 =m$ by ! hydrolysis ( *romium sulphate3 x is a lyophile or emulsoid sol & is 9 consequ5ce v /rongly adsorb$ by ! hide gel4 ,?is adsorption1 involv+ a conc5tration ( lyophile sol1 is ! fir/ /age 9 gelation1 :i* occupies a relatively m prom95t place 9 *rome ?an 9 vegetable tannage4 ,"s diffusion into ! gel also occurs1 & bo? ! gelation & diffusion ( ! sol are affect$ by lyotrope influ5ce1 b to a great] ext5t ?an 9 ! vegetable tannage4 ,?us f> ! analogy is almo/ complete4 ,!re rema9s ! "q ( ! precipitation ( ! tann+ colloid at ! int]face4 ,?is is a po9t :i* has n yet be5 ?or\ghly inve/igat$1 & :i* (f]s consid]able difficulty to a cle> und]/&+1 b ! matt] may be probably summ>iz$ ?us3 ! adsorb$ *romium hydrate is precipitat$ at ! int]face ( gel & sol to "s ext5t1 *iefly ?r\gh ! neutralization ( its *>ge by ! oppositely *>g$ ions ( ! electrolytes pres5t1 b possibly also--9 ! la/ /ages ( manufacture by ! mutual precipitation ( oppositely *>g$ gel & sol4 ,to illu/rate ! matt]1 ! case ( a basic *rome alum liquor w be consid]$4 ,! *romium hydrate sol is prim>ily a positive sol1 j l f]ric & alum9ium hydrate sols3 i4e4 9 wat] !y are some:at exceptional 9 t !y adsorb ,h r ?an ,,oh-4 ,to cause precipitation !re=e x is necess>y to make ! sol less positive & m negative4 ,! positive *>ge ( ! sol1 h[ev]1 is great] ?an 9 wat]1 because ( ! free acid =m$ 9 ! hydrolysis1 :i* results 9 ! adsorption ( m hydrions by ! sol4 ,h5ce to ensure precipitation /eps mu/ be tak5 to r$uce ! adsorption ( hydrions by ! *romium hydrate sol4 ,9 practice su* /eps are tak51 & to su* an ext5t t !re c be little d\bt t ! *rome sol is n f> f its isoelectric po9t4 ,among/ ^! /eps are 7#a7 mak+ ! liquor basic1 i4e4 add+ alkali to neutralize mu* ( ! free acid1 :i* involves a consid]able r$uction 9 ! /abiliz+ effect ( ! hydrions2 7#b7 ! adsorption ( hydrions by ! hide gel :5 fir/ imm]s$ 9 approximately neutral condition2 7#c7 ! op]ation ( ! val5cy rule t ! pr$om9ant ionic effect 9 dis*>g+ is due to ! multival5t anions4 ,9 ?is case ! dival5t ,,s#d-- ions assi/ mat]ially 9 dis*>g+ ! positive *>ge on ! *rome sol2 7#d7 ! f9al process ( neutralization 9 :i* /ill m alkali is add$4 ,! op]ation ( ! val5cy rule is ! mo/ complex ( ^! factors1 = !re is also to be consid]$ ! /abiliz+ effect ( ! kations1 especially ( ! trival5t kation ,cr f ! unhydrolyz$ *romium sulphate4 ,x is q possible also t 9 ! la/ /ages ( *rome tann+ !re are zones ( non-precipitation due to ! total effect ( multival5t ions1 & x is q conceivable t ! *rome sol may *ange its sign1 i4e4 become a negative sol & ?us give also a mutual precipitation ) ! hide-gel4 ,?is is p>ticul>ly probable :]e a local excess ( alkali occurs 9 neutralization4 ,h[ev] t may be1 x is probable t mo/ ( ! tannage is accompli%$ by *romium hydrate 9 acid solution1 & x is !re=e legitimate to conclude t adsorption & gelation h a relatively great] "p 9 *rome tannage4 ,! op]ation ( ! val5cy rule makes x easy to und]/& :y basic *lorides d n tan s well z sulphates2 ! precipitat+ anion is only monoval5t 7,cl-7 & *romic *loride conta9s no sub/ance analog\s to ! potassium sulphate ( *rome alum & h5ce conta9s a less conc5tration ( ! precipitat+ anion4 ,h5ce also ! /abiliz+ influ5ce ( common salt add$ to a basic alum liquor1 ! effect be+ to replace p>tially ! dival5t ,,s#d-- by ! monoval5t ,cl-4 ,lyotrope influ5ce1 h[ev]1 may be "h at "w4 ,x is possible to make out a r weak case t ! tann+ sol is n *romium hydrate at all1 b a basic salt ( *rome also 9 colloidal solution1 & to cont5d t ?is salt1 l mo/ sub/ances1 =ms a negative sol1 b 9 practice n negative en\gh1 h5ce ! desirability ( alkali1 dival5t anions1 etc4 ,f ?is po9t ( view ! analogy ) vegetable tannage becomes m complete & ! /abiliz+ effect ( ! soda salts ( organic acids becomes easy to und]/&4 ,x is highly probable t ! electrical prop]ties ( ! *rome sol ne$ clos] inve/igation on acc\nt ( ! complexity due to ! prom95t effect ( multival5t ions4 ,x is desirable to be> 9 m9d ! rem>kable ph5om5on obs]v$ by ,burton 7,phil4 ,mag41 #aije1 vi1 #ab1 #dgb71 :o add$ v>i\s conc5trations ( alum9ium sulphate to a silv] sol 7negative74 ,he obs]v$ 7#a7 a zone ( non-precipitation due to protection2 7#b7 a zone ( precipitation due to ! trival5t kation2 7#c7 a second zone ( non-precipitation due to protection aft] ! sol has pass$ ?r\gh ! isoelectric po9t & become a positive sol2 7#d7 a second zone ( precipitation due to ! precipitat+ effect ( ! anion on ! n[ positive sol4 ,x seems to ! writ] t simil> ph5om5a may possibly occur 9 *rome tann+1 = :atev] ! sol actually is1 x is n f> f ! isoelectric po9t4 ,a few obs]vations on ! vegetable-*rome comb9ation tannages w n be out ( place at ?is /age4 ,wilson ref]s to ! well-kn[n practical fact t *rome lea!r c take up ab\t z mu* vegetable tan z if x 7 un*rom$ pelt1 & consid]s ?is evid5ce t ! two tannages are ( fundam5tally diff]5t nature4 ,9 m9]al-tann$ lea!rs ! metal is comb9$ ) c>boxyl gr\ps1 :ile 9 vegetable-tann$ lea!r ! tann9 is comb9$ ) ! am9o gr\ps4 ,?is /rongly sugge/s ! possibility t ! two me?ods ( tann+ are to "s ext5t indep5d5t ( "o ano!r1 & t a piece ( lea!r tann$ by "o me?od may rema9 z capable ( be+ tann$ by ! o!r me?od z ?\gh x 7 /ill raw pelt 7,collegium 7,london71 #aiag1 #aaj-aaa74 ,to ! writ]1 h[ev]1 x seems t ! facts are evid5ce = ! contr>y proposition1 t ! tannages are fundam5tally ( ! same nature4 ,on ! adsorption !ory1 "o w\ld expect *rome lea!r to adsorb z mu* tan z pelt2 ! readily adsorbable tan is ! same1 & ! *rome lea!r is an adsorb5t ( v mu* ! same ord] ( specific surface z pelt4 ,! adsorption !ory w\ld f9d x difficult to acc\nt = *rome lea!r n adsorb+ z mu* tan z pelt4 ,x is q conceivable t a *rome lea!r c\ld adsorb m tan ?an pelt1 ow+ to ! m complete isolation ( ! fibrils by ! *rome tannage & to _! be+ coat$ ov] by a m adsorb5t gel4 ,adsorption is (t5 delib]ately increas$ by a prep>atory adsorption4 ,?us suma*-tann$ goatsk9s are wet back f ! cru/ & retann$ 9 suma* be=e dye+1 to coat ! fibres ) a fre% & m adsorb5t gel & s ensure ! ev5 & ?or\gh adsorption ( ! dye/uff4 ,mordant+ fabrics has a simil> object1--! adsorption ( colloidog5ic sub/ances :i* give rise to an adsorb5t gel on ! fibre4 ,unless vegetable-tann$ lea!r is s mu* load$ ) tan t its specific surface is effectively r$uc$1 "o w\ld simil>ly expect t vegetable-tann$ lea!r w\ld adsorb ! *rome sol4 ,?is1 ( c\rse1 is exactly ! case ( semi-*rome lea!r4 ,if1 on ! *emical comb9ation !ory1 ! vegetable tan comb9es ) ! am9o gr\ps & ! *rome ) c>boxyl gr\ps1 x is natural to inquire :i* gr\ps ! dye/uffs comb9e )4 ,z ei!r tannage does n int]f]e ) ! adsorption ( dye1 are we to conclude simil>ly t tann+ & dye+ are fundam5tally diff]5t processes8 ,^? :o fav\r ?is *emical comb9ation !ory1 & :o (f] equations = ! =mation ( vegetable & ( *rome lea!r1 %\ld likewise sugge/ an equation = ! =mation ( lea!r f pelt by ! action ( dye/uffs--a practical ?\gh h>dly an economic process4 ,! rem>ks made e>li] 9 ?is volume 7,"p ,i41 ,section ,,iii47 z to ! occurr5ce ( :at h be5 call$ irrev]sible *anges subsequ5t to ! mutual precipitation ( oppositely *>g$ gel & sol1 are equally applicable to ! *rome tannages4 ,*rome tannage 0 once ?\ght to embrace su* irrev]sible *anges1 b ! process c n[ be rev]s$ ) ease4 ,! rev]sibility ( ! *rome tannage is an easi] proposition ?an t ( vegetable tannage1 p>tly because ! lea!r is comp>atively mu* less tann$1 & p>tly because ! acidity or alkal9ity ( ! /ripp+ ag5t may be adju/$1 z desir$1 )\t ! oxidation tr\ble4 ,9 approa*+ ?is "q f ! !oretical side "o mu/ consid] ma9ly :e!r to solate ! tann+ ag5t to a positive or to a negative sol4 ,our imp]fect k ( ! electrical =ces 9 op]ation 9 ! *rome tannage is ?us a s]i\s drawback1 b ! evid5ce on ! :ole po9ts to ! precipitation be+ effect$ by a negative sol ne> its isoelectric po9t b 9 fa9tly acid solution4 ,h5ce1 we %\ld !oretically expect t rev]sion %\ld take place into a negative sol 9 ne>ly neutral or ev5 fa9tly alkal9e solution4 ,?us1 suitable /ripp+ ag5ts = *rome lea!r w\ld be ! alkali salts ( organic acids 7especially if multival5t74 ,n[1 ,proct] & ,wilson h rec5tly accompli%$ ?is /ripp+ ( *rome lea!r by ! use ( su* salts4 ,!y approa*$ ! "q f an empirical & practical po9t ( view & f\nd t ,ro*elle salt1 sodium citrate1 & sodium lactate w\ld /rip ! *rome tannage ) ease4 ,?is important & v cr$itable a*ievem5t w h great practical & comm]cial importance4 ,proct] & ,wilson h delib]ately & c>efully refra9$ f (f]+ an exact explanation ( ?is rev]sible action1 b po9t out t all _! /ripp+ ag5ts are salts ( hydroxy-acids1 & /rongly insi/ t ^! =m soluble complexes ) ! *rome4 ,:il/ n d5y+ ?is 9 ! lea/1 ! pres5t au?or w\ld po9t out t accord+ to ! views advanc$ 9 ?is book1 ! salts ( organic acids :i* d n conta9 hydroxyl gr\ps %\ld1 :5 comb9$ ) a monacid base1 also /rip ! *rome tannage4 ,?is he has f\nd to be ! case4 ,?us ! *rome tannage is rev]sible 9 solutions ( ammonium or potassium oxalate & ( ammonium acetate4 ,) ^! salts ! full effect ( multival5t anions is n atta9$1 s t some:at /rong solutions are necess>y4 ,a #aj p] c5t4 solution ( ammonium acetate %[s "s /ripp+ effect aft] a few days1 b a #dj p] c5t4 solution aft] a few h\rs4 ,saturat$ ammonium oxalate is only a #d4b p] c5t4 solution1 b %[s a /ripp+ effect 9 #b-c days4 ,potassium oxalate 7#cc p] c5t47 %[s di/9ct /ripp+ 9 #bd h\rs4 ,potassium acetate & sodium acetate %[ only slight action1 because ! solution is too alkal9e1 b /rip if acetic acid be add$ until litmus is j r$d5$4 ,x is notewor?y f a !oretical po9t ( view t a #dj p] c5t4 solution ( ammonium acetate is di/9ctly acid1 & inde$ smells ( acetic acid4 ,!re c be little d\bt t su* /ripp+ actions are also connect$ ) ! solubility ( ! /ripp+ ag5t 9 ! gel1 = ! liquid mu/ pass ?r\gh ! walls ( ! gel to dilute ! liquid 9 ! int]ior4 ,?is view fits 9 ) ! facts t hydroxy acids & ammonium salts are p>ticul>ly effici5t1 = ! t5d5cy ( *rome to =m ammonia-complexes z well z hydroxy complexes is well kn[n4 ,f ?is po9t ( view we %\ld n expect a /ripp+ action f a salt su* z disodium phosphate1 :i* w\ld =m an insoluble sub/ance4 ,actually sodium phosphate does n /rip1 & inde$ r$uces ! /ripp+ p[] ( ammonium acetate4 ,simil>ly1 we might expect "s /ripp+ action by ammonia & ammonium *loride1 ) ! =mation ( *rome ammonia complexes4 ,?is actually occurs1 a p9k solution be+ obta9$4 ,sodium sulphite does n /rip1 possibly p>tly on acc\nt ( its too great alkal9ity1 b is int]e/+ !oretically to obs]ve t sodium sulphite z well z ,ro*elle salt w /rip salt /a9s 7see ,yocum's pat5t1 ,collegium 7,london71 #aiag1 #f2 also ,proct] & ,wilson1 loc4 cit474 ,?is po9ts to ! =mation ( a negative sol1 & sugge/s _m o!r sub/ances = remov+ salt /a9s4 ,special ,qualities ( ,*rome ,lea!r4--,a few words on ! special peculi>ities ( ! lea!r =m$ by *rom+ w n be out ( place at ?is /age4 ,"o ( ! greate/ disadvantages ( ! *rome tannage has be5 ! abs5ce ( :at is kn[n z ! cru/ or r\gh lea!r /age4 ,9 *rome tann+1 ! f9i%+ op]ations h _h to foll[ on imm$iately aft] ! tannage4 ,*rome lea!r1 aft] tann+1 may be dri$ out l o!r lea!rs1 b if ?or\ghly dri$1 or if kept 9 a dri$ condition = any "t1 x w n wet back aga9 ) wat]4 ,v>i\s sugge/ions h be5 made to ov]come ?is difficulty b none yet h f\nd mu* fav\r 9 practice4 ,! discov]y ( ! rev]sibility ( ! tannage1 h[ev]1 ought to solve ?is difficulty1 & ! au?or w\ld sugge/ t any ( ! sub/ances us$ = de*rom+ might also be suitable = wett+ 9 *rome lea!r :i* has be5 well dri$ out4 ,a piece ( *rome lea!r1 dri$ out well aft] neutraliz+1 & kept 9 a w>m place = f\r ye>s1 wett$ back easily 9 ammonium acetate1 9 ! au?or's laboratory4 ,ano!r peculi>ity ( ! *rome tannage is t any defects 9 ! raw mat]ial always seem m obvi\s 9 *rome ?an 9 vegetable lea!r4 ,?is (t5 necessitates ! use ( a bett] quality hide or sk94 ,weak gra9 or loose gra9 becomes v obvi\s4 ,! pres5ce ( %ort hair :i* bo? unhair+ & scudd+ h fail$ to remove also is usually m evid5t4 ,a m s]i\s disadvantage ( *rome lea!r is its t5d5cy to /ret*4 ,9 ! case ( belt+ lea!r ?is feature is an obvi\s nuisance1 & has inevitably l$ manufactur]s to use p[]ful /ret*+ ma*9es ^u ! goods be=e !y are m>ket$4 ,9 *rome sole lea!r also !re is a t5d5cy to spread & ?r[ ! boot out ( %ape4 ,fur!r disadvantages arise f ! fact t ! *rome tannage is an empty tannage4 ,comp>$ ) ! vegetable tannage1 v little ( ! tann+ ag5t is adsorb$4 ,h5ce !re is little matt] ( any k9d betwe5 ! hide fibres isolat$ dur+ tannage4 ,! inevitable effect ( ?is is t ! lea!r has n ! same solidity & firmness1 & ne$s fill+ out ) o!r mat]ials4 ,a comm]cial consequ5ce is also t x is impossible to obta9 ! same yield ( lea!r f any giv5 quantity ( raw mat]ial4 ,9 trade p>lance *rome tannage does n give good weight4 ,ano!r consequ5ce is t 7ev5 :5 well fill$ ) greases 9 f9i%+7 *rome lea!r t5ds to be woolly on ! fle% side or at cut edges4 ,on ! o!r h&1 *rome tann+ has v _m advantages ov] ! old] process4 ,! mo/ obvi\s ( ^! is ! great sav+ 9 "t4 ,_m *rome tannages involve only a day or two1 & none m ?an a week or two4 ,a *rome lea!r factory !re=e ne$s less capital on acc\nt ( ! quick] turnov]4 ,if1 moreov]1 ! m>ket be unfav\rable1 a *rome tann] c /op or r$uce 8 output 9 a v %ort "t1 :]eas a vegetable tann] is committ$ to _m weeks' supply ( ! goods he is manufactur+4 ,ano!r notable advantage ( *rome lea!r is its durability4 ,9 ! f9i%+ processes m grease is usually employ$ ?an 9 vegetable tannage1 & ?is has a pres]vative effect ^u lea!rs :i* (t5 get wet4 ,*rome sole lea!r & hydraulic lea!rs are cases 9 po9t4 ,*rome lea!r w also /& *anges ( temp]ature & friction mu* bett] ?an vegetable tannages4 ,! light *rome tannage results1 fur!r1 9 yield+ a lea!r :i* has great t5sile /r5g?1 & x is n surpris+ to f9d t *rome h>ness & *rome pick+ b&s are highly ?\ght (4 ,! empty nature ( ! tannage necessitates ! use ( /uff+ greases1 b su* l>ge proportions ( ^! may be us$ t *rome tannage becomes obvi\sly suitable if "o wi%es to produce a wat]pro( lea!r4 ,h5ce ! popul>ity ( *rome tannage = wat]pro( sol+ & hydraulic lea!rs4 ,! advantages ( ! *rome process are v real1 & v obvi\sly su* z w appeal to manufactur]s4 ,*rome lea!rs h n[ be5 = "s "t 9 ! =efront z f> z boot-upp]s are conc]n$1 especially = ! be/ quality goods1 9 :i* ! popul> box-calf & glac kid are s l>gely employ$4 ,!re seems little d\bt t ?is w cont9ue to be ! case4 ,x is an un=tunate fact t 9 ?is important bran* ( tann+1 ,briti% manufactur]s h n q ris5 to ! occasion4 ,_! products h 9 ! pa/ be5 fac$ ) v s]i\s competition f ,cont95tal & ,am]ican manufactur]s ( *rome upp]s1 & !re c be no d\bt t ^! competitors produc$ a bett] article1 & produc$ x m economically4 ,! disorganization ( ! ,cont95tal factories ow+ to ! w> %\ld give ,briti% manufactur]s a valuable opportunity ( putt+ su* bus9esses on a bett] basis4 ,= sole lea!r also ! *rome tannage makes con/ant headway1 & ! relative proportion ( x becomes gradually great]4 ,a great impetus to *rome sole lea!r has be5 giv5 by ! w> conditions ( ,brita94 ,ow+ to ! subm>9e campaigns ( ,g]many ! tonnage "q became all-important1 & ! bulky imports ( vegetable tann+ mat]ials became a s]i\s item4 ,briti% tann]s 7 !re=e enc\rag$ to make m *rome sole & less vegetable sole4 ,! urg5t ne$ ( lea!r = our armies also assi/$ 9 ! same s5se4 ,! production ( *rome sole progress$ !re=e enorm\sly dur+ #aiag & #aiah1 & al?\gh "s reaction w d\btless occur1 !re seems little d\bt t *rome sole lea!r has tak5 a def9ite & p]man5t leap =w>d4 ,once ! g5]al public fully appreciate its qualities ( wat]pro(ness & durability its future w be assur$4 ,on ! :ole ! position & prospects ( *rome tann+ are good4 ,! *rome tannages are mak+ headway 9 all directions1 & und\bt$ly ?reat5 ! exi/5ce ( _m ( ! old] processes ( vegetable tann+4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #aih-bbj4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #baj1 #cee4 ,b5nett1 ,j4,s4,l4,t4,c41 #aiag1 #agf4 ,/iasny1 ,collegium1 #aijh1 #aag4 ,,section ,,ii4--,,g5]al ,,me?ods ,,( ,,*rome ,,lea!r ,,manufacture ,x has be5 previ\sly po9t$ out t ! *rome tannage is an empty "o2 ! prim>y pr9ciple 9 ! wet "w ( goods = *rome lea!r is to avoid any?+ :i* w make ?is feature m obvi\s4 ,9 ! vegetable tannages relatively l>g] am\nts ( ! tann+ ag5ts are us$1 & ^! fill ! int]fibrill> spaces2 inde$1 z we h se5 7,"p ,i41 ,sections ,,iii41 ,v4 & ,,vi471 ef=t is made to increase ^! spaces & to fill !m to _! maximum capacity1 ?us yield+ a lea!r ( :i* #ej p] c5t4 is ! tann+ ag5t4 ,9 *rome tann+1 h[ev]1 ! tann+ ag5t may only be approximately #e p] c5t4 ( ! f9i%$ lea!r1 s t any tr\ble tak5 to split ! hide fibres or to dissolve hide sub/ance is usually n only sup]flu\s1 b also calculat$ to enhance ! empt9ess4 ,! gov]n+ pr9ciple ( all ! prep>atory processes = *rome tannage is !re=e ! cons]vation ( hide sub/ance1 & ?is pr9ciple det]m9es ! modifications ( ! processes ( soak+1 lim+1 & delim+1 :i* are 9 vogue4 ,n[1 9 mo/ ( ^! processes !re is usually "s loss ( hide sub/ance1 & x is ! p>ticul> problem ( *rome tann+ to r$uce ?is loss to a m9imum 9 ea* /age4 ,:e!r ! loss ( hide sub/ance be due to alkal9e or f]m5tive hydrolysis1 or to solation ( ! hide gel1 ! effect is increas$ by swell+1 & 9 ! wet-"w = *rome1 !re=e1 any v>iations 9 ! degree ( swell+ are objectionable4 ,! prep>atory processes %\ld be c>ri$ out ) z little *ange z possible 9 ! volume & ela/icity ( ! pelt4 ,:e!r also ! loss ( hide be due to hydrolysis or solation1 x is increas$ by "t1 h5ce %ort processes are 7o!r ?+s be+ equal7 mu* to be pref]r$4 ,f]m5tive hydrolysis is m9imiz$ by cleanl9ess1 alkal9e hydrolysis by avoid+ /rongly alkal9e liquors1 & solation ( collag5 is r$uc$ by bo?1 & also by avoid+1 z f> z possible1 ! pres5ce ( calcium & ammonium salts4 ,soak+ %\ld be quick & clean4 ,! use ( ! paddle or drum gives ! greate/ effici5cy & also assi/s 9 procur+ ! s(tness s ess5tial to ! bulk ( *rome lea!rs4 ,lim+ *rome lea!r satisfactorily is almo/ an impossible ideal4 ,e conceivable arrangem5t has "s objection to x4 ,! "t ( ! process may be %ort5$ ei!r by ! use ( sulphide or by ! use ( mell[ or old limes4 ,to %ort5 "t by ! use ( sodium sulphide un=tunately involves ! employm5t ( m alkali ?an is desirable1 ) a consequ5t plump+ effect & t5d5cy to h>%ness4 ,if suffici5t sulphide be us$ to make ! lim+ v %ort1 !n ! grease is n kill$ 7saponifi$ or emulsifi$74 ,if ! h>%ness & alkal9ity be remov$ by us+ also an excess ( calcium *loride1 !n ! lyotrope influ5ce ( ?is sub/ance enhances ! solation ( ! hide gel4 ,on ! o!r h& ! use ( old lime liquors avoids ! plump+ effect1 b increases consid]ably ! bact]ial activity1 & ! bact]ial enzymes produce bo? hydrolysis & solation ( ! pelt4 ,9 practice :at is g5]ally done is to %ort5 "t by bo? me?ods & s to admit bo? disadvantages to a limit$ ext5t4 ,?is is !oretically m s\nd ?an w\ld appe>1 = 9 mell[ limes sulphide has less plump+ p[] b is j z /rong a depilatant2 :il/1 on ! o!r h&1 a mell[ lim+ %ort5$ by sulphide is less objectionable z !re is "s evid5ce t bact]ial activity is relatively less 9 ! fir/ few days4 ,h5ce a mell[ sulphide lim+ ( #g-aj days is v common 9 practice1 b sometimes a #c-d days' process ) m sulphide is also f\nd satisfactory4 ,x w\ld seem probable t ! real solution ( ! problem w\ld be f\nd by a diff]5t process altoge!r4 ,9 ?is connection x is int]e/+ to note t a ,cont95tal proposal to unhair by enzyme action only has be5 f\nd mo/ practicable ) goods = *rome1 &1 9 ! au?or's op9ion1 "s developm5t on ^! l9es1 9 :i* a lipolytic enzyme is us$ 9 addition to a proteolytic1 might solve ! difficulty1 & give a rapid depilation :i* disp5ses ) lim+1 plump+ & delim+ ) ! consequ5t loss ( valuable hide sub/ance4 ,9 ! usual %ort1 mell[1 sulphide lim+ x is cle> t !re is n mu* advantage 9 a r\nd or set ( pits4 ,h5ce ! "o-pit sy/em is popul> on acc\nt ( ! less lab\r involv$4 ,! above rem>ks are less applicable 9 ! case ( *rome sole lea!r4 ,9 ?is case weight is a great consid]ation & plump+ is necess>y4 ,9 su* lea!r ! *rome tannage is supplem5t$ by ! use ( waxes1 :i* fill up ! spaces betwe5 ! fibres & give solidity & wat]pro(ness to ! f9i%$ article4 ,) ?is lea!r an ord9>y sole lea!r lim+ 9 %>p liquors is n unsuitable1 h&l+ ! goods f mell[ to fre%1 b !re is1 on ! :ole1 a t5d5cy to %ort5 ! process to ab\t a week by us+ m sulphide4 ,processes = delim+ pelt = *rome lea!r %\ld also be *os5 by our guid+ pr9ciple ( hide sub/ance cons]vation4 ,"h aga9 %ort processes involv+ little *ange 9 swell+ %\ld be pref]r$4 ,n[1 ! ord9>y bat+ & pu]+ processes give 7#a7 neutralization ( lime by organic acids comb9$ ) weak bases2 7#b7 ! solation ( "s hide sub/ance2 & 7#c7 a pull+ d[n effect on ! swoll5 pelt4 ,n[1 neutralization is q sup]flu\s1 z ! acids ( ! *rome liquor 7"o-ba? or two-ba?7 c q well accompli% ?is2 ! solv5t effect is undesirable altoge!r2 & ! pull+ d[n effect is also unnecess>y if ! goods are n plump$ up4 ,) any me?od ( lim+1 h[ev]1 "s plump+ is obta9$1 & ?is creates a problem ( practical importance4 ,9 ! huge quantities ( pelt :i* g = *rome upp] lea!rs1 a prim>y consid]ation is ! s(t1 k9d1 or mell[ feel ( ! gra9 9 ! f9i%$ lea!r4 ,?is is obta9$ only by tann+ ! pelt :5 ! gra9 at lea/ is 9 a ?or\ghly deplump$ & inela/ic condition4 ,x is ess5tial to delime n only s t ! alkal9e plump+ effect is completely remov$1 b also s t no acid plump+ effect succe$s x4 ,! practical problem is to decide :e!r1 9 any p>ticul> in/ance1 dung pu]s & bates are necess>y to obta9 ?is result4 ,bat+ is cle>ly n v desirable1 on acc\nt ( ! l5g? ( ! process1 dur+ :i* hide sub/ance w\ld be lo/ unnecess>ily1 & also because !re w usually be a slight alkal9e swell+4 ,pu]+ ) dog-dung infusions is pref]able2 x is n su* a long process1 ! liquor is j acid to ph5olph?ale91 & ! action is m int5se1 & by pu]+ = a %ort "t only ! loss ( hide may be conf9$ to ! gra9 & fle% only1 :il/ ! desir$ inela/icity ( gra9-pelt is soon obta9$4 ,_m l>ge firms h admitt$ly f\nd !mselves unable to disp5se ) pu]+1 b o!rs h succe$$ 9 sub/itut+ = x ! use ( non-swell+ delim+ & lyotrope ag5ts l ammonium *loride & boric acid4 ,9 all cases x is futile to delime or pu] ! gra9 & !n all[ ! goods to /& until ! c5tre lime has diffus$ outw>ds4 ,! goods mu/ pass into ! *rome liquors :5 9 ! correct condition4 ,= heavy *rome lea!r a surface delim+ ) boric acid is all t is necess>y4 ,ev5 t is sup]flu\s :5 ! goods are to be pickl$ be=e tann+4 ,types ( ,two-ba? ,*rome ,tannage4--,al?\gh ! orig9al process ( ! ,s*ultz pat5t is q a practicable "o1 _m modifications h be5 introduc$4 ,^! modifications h be5 made to suit ! class ( goods "u treatm5t1 to suit ! p>ticul> mode ( application :i* is available or suitable1 & to effect economies ( *rome & o!r mat]ial1 & ( "t1 & also to comb9e ) ! tannage a pickl+ effect or a p>tial alum tannage4 ,o!r modifications arise f ! precise acid1 neutral1 or alkal9e condition ( ! pelt1 be+ = example obvi\sly necess>y :5 pickl$ /ock replace neutral pelts4 ,! _m two-ba? processes :i* h be5 f\nd useful h be5 classifi$ previ\sly by ! au?or#f into ?ree types3 7#a7 ,! ,s*ultz type1 9 :i* su* quantities ( di*romate & acid are us$ t !re is no excess ( free acid 7o!r ?an *romic71 b an excess ( unalt]$ di*romate2 7#b7 ! ,acid type1 9 :i* ! *romic acid is completely free & ! liquor conta9s also "s excess ( m9]al acid also2 & 7#c7 ! ,neutral type1 9 :i* nei!r ( ^! ma9 con/itu5ts is 9 excess1 j suffici5t m9]al acid hav+ be5 us$ to lib]ate all ! *romic acid f ! di*romate4 ,footnote #f3 ,types ( ,two-ba? ,*rome ,tannage1 ,lea!r1 #aiji1 #bbg-bei4 ,n[3-- ,k#b;,cr#b,o#g #b;,h,cl #b,k,cl #b;,cr,o#c ,h#b,o #bjd #gc ,tak+ ! comm]cial hydro*loric acid z a #cj p] c5t4 solution1 #gc p>ts w be obta9$ 9 ab\t #bej p>ts ( comm]cial acid4 ,h5ce #bid p>ts di*romate ne$ #bej p>ts comm]cial hydro*loric acid = ! above reaction2#g 9 o!r words1 #e p] c5t4 di*romate ne$s #d-a_/d p] c5t4 comm]cial acid4 ,simil>ly #f p] c5t4 & #d p] c5t4 ( di*romate ne$ #e4a p] c5t4 & #c4d p] c5t4 respectively ( comm]cial acid4 ,if !re=e su* quantities be us$ we h ! s-call$ ,neutral type ( *rom+ ba?4 ,if less quantities ( acid be us$ we h ! ,s*ultz type1 & if great] quantities ( acid be us$ we h ! ,acid type4 ,! orig9al ,s*ultz pat5t us$ #e p] c5t4 di*romate & #b-a_/b p] c5t4 hydro*loric acid1 & well exemplifies its type1 = !re is mu* undecompos$ di*romate4 ,! composition ( "s *rom+ ba?s 9 common use on a practical scale are giv5 bel[ "u ! head+ ( _! type3-- ---------------------------------------- ----------------- ,type4 ,di*romate4 ,hydro*loric ,salt4 ,alum9ium ,acid4 ,sulphate4 ---------------------------------------- ----------------- #e #b-a_/b -- -- #e #b-a_/b -- #c ,s*ultz #e #b-a_/b #e -- #e #b-a_/b #aj -- #f #c -- -- ---------------------------------------- ----------------- #d #d -- -- #d #d #e -- #e #e #e #c ,acid #e #e #aj -- #f #f #ae -- #c #c #ae #d #b #d #aj -- #d #ae #bd -- ---------------------------------------- ----------------- #e #d-a_/d #e -- #e #d -- #b-a_/b ,neutral ,*romic acid #e -- #e -- #f -- #h -- #d -- #aj -- ---------------------------------------- ----------------- ,footnote #g3 ,comm]cial acids ( c\rse v>y 9 /r5g?1 & ! am\nt ne$$ v>ies accord+ly4 ,all ! figures are p]c5tages ( ! weight ( pelt4 ,z ,k#b;,cr#b,o#g has a molecul> weight ( #bid1 & ,na#b;,cr#b,o#gb;,h#b,o a molecul> weight ( #bih1 9 practice !y may be consid]$ z int]*angeable1 weight = weight4 ,! sodium salt is *eap] & m (t5 us$4 ,! correspond+ am\nt ( *romic acid1 #b;,cr,o#c1 has an equival5t weight ( #bjj1 h5ce any weight ( di*romate may 9 practice be sub/itut$ by two-?irds ! weight ( comm]cial *romic acid4 ,equival5t weights ( comm]cial sulphuric acid are sometimes us$ 9 place ( hydro*loric4 ,! quantity dep5ds ^u ! /r5g? ( ! sulphuric acid us$4 ,alum9ium sulphate1 ,al#b7,,s#d7cah;,h#b,o 7mol4 wt4 #fff71 may be replac$ by ord9>y pota% alum1 ,k#b,,s#d;,al#b7,,s#d7cbd;,h#b,o 7mol4 wt4 #idh74 ,9 practice #g p>ts ( ! =m] & #aj p>ts ( ! latt] may be consid]$ equival5t4 ,x %\ld be rememb]$ t bo? ^! salts are hydrolyz$ 9 solution1 & !re=e increase slightly ! am\nt ( free acid pres5t4 ,_! pres5ce decreases ! am\nt ( *rome tak5 up1 & z little or no alum9a is f\nd 9 ! lea!r1 !re is usually small advantage 9 _! employm5t4 ,! use ( salt is common b (t5 unnecess>y4 ,x is consid]$ desirable 9 ba?s ( ! acid type to prev5t swell+ by ! excess ( acid1 & 9 ba?s made up f comm]cial *romic acid to replace correspond+ly t normally =m$ f ! reaction ( di*romate & acid4 ,x is us$ also 9 all ba?s :i* are int5d$ to treat pickl$ goods4 ,l all electrolytes its pres5ce decreases ! adsorption ( *romic acid4 ,all ^! conceivable modifications w make good lea!r1 & ! *oice ( a process (t5 dep5ds l>gely ^u m>ket prices4 ,on ! :ole ! t5d5cy is to pref] ! neutral or acid type1 on acc\nt ( ! great] ease & complet5ess ) :i* ! ba? may be exhau/$4 ,pickl$ /ock may be depickl$ be=e tann+1 by a ba? ( salt1 mix$ ) borax1 :it5+1 or basic alum solutions4 ,x may also be plac$ direct 9 ! *rom+ ba?1 b ! am\nt ( acid ?us add$ ) ! goods mu/ be det]m9$ & all[$ = :5 mak+ up ! ba?4 ,no all[ance is usually necess>y1 h[ev]1 if ! pickle consi/ only ( alum & salt4 ,! *rom+ op]ation is c>ri$ out usually 9 drums or paddles4 ,drums are pref]able because m conc5trat$ ba?s may be us$2 ^! solutions p5etrate quick] & are easi] to exhau/ economically4 ,!y are also pref]able = hides & heavy sk9s4 ,paddles are pref]able :]e gra9 is important1 & = light sk9s 9 :i* little "t is ne$$4 ,small v>iations 9 ! ratio ( *rome to pelt1 or 9 conc5tration ( liquor1 h little influ5ce ^u ! result+ lea!r4 ,! analytical inve/igation & control ( *rom+ ba?s is usually simple4 ,a suitable volume ( liquor is titrat$ ) ,n_/#aj ?iosulphate aft] acidify+ ) hydro*loric acid & add+ potassium iodide4 ,! op]ation %\ld be conduct$ 9 a /opp]$ bottle1 & ! liquor all[$ to /& = #aj-ae m9utes aft] add+ ! iodide & be=e titrat+4 ,a little fre% />* infusion %\ld be add$ t[>ds ! end ( ! reaction4 ,ea* c4c4 ,n_/#aj ?iosulphate corresponds to #j4jjcc gram ,cr,o#c or #j4jjdi gram ,k#b;,cr#b,o#g4 ,! same volume ( liquor %\ld also be titrat$ ) ,n_/#aj cau/ic soda & ph5olph?ale94 ,potassium *romate is neutral to ?is indicator1 i4e4 *romic acid acts z a dibasic acid4 ,any excess ( hydro*loric acid is also titrat$4 ,m indicator %\ld be add$ t[>ds ! end ( ! titration1 z x is (t5 oxidiz$4 ,ea* c4c4 ,n_/#aj soda corresponds to #j4jje gram ,cr,o#c1 #j4ja gram half-b\nd ,cr,o#c 7i4e4 pres5t z di*romate71 #j4jadg gram ,k#b;,cr#b,o#g1 or #j4jjcfe gram ,h,cl4 ,if a c4c4 ,n_/#aj ?iosulphate & b c4c4 ,n_/#aj soda be ne$$ ! type ( *rom+ ba? may be se5 at a glance-- ---------------------------------------- ----------------------- ,if ,! type is ,! ba? conta9s ---------------------------------------- ----------------------- b is great] ?an #a_/c;a ,s*ultz potassium di*romate b is less ?an #b_/c;a & *romic acid b is great] ?an #b_/c;a ,acid *romic acid & free hydro*loric acid b equals #a_/c;a ,neutral *romic acid only ---------------------------------------- ----------------------- ,if #aj c4c4 *rome liquor require a & b c4c4 ( ?iosulphate & soda respectively-- ,i4 #aj c4c4 ( a ,s*ultz ba? conta9 7b - #a_/c;a7 #j4ja gram ,cr,o#c & 7a#j4jjcc7 - 7b - #a_/c;a7 #j4ja #a4dg grams ,k#b;,cr#b,o#g ,,ii4 #aj c4c4 ( an acid ba? conta9 7a#j4jjcc7 grams ,cr,o#c & 7b - #b_/c;a7 #j4jjcfe grams ,h,cl ,,iii4 #aj c4c4 ( a neutral ba? 7a#j4jjcc7 grams ,cr,o#c or 7b#j4jje7 grams _/ ,! second ba? ( ! two-ba? *rome tannage consi/s ( a solution ( sodium ?iosulphate acidifi$ ) hydro*loric acid4 ,! reactions 9 ?is ba? are some:at complicat$1 sev]al occurr+ simultane\sly4 ,broadly speak+1 ! f9al result is due to 7#a7 ! r$uction ( ! *romic acid to a *romic salt by ! sulphur\s acid2 7#b7 ! =mation ( a basic *romic salt ow+ to ! excess ( ?iosulphate2 7#c7 ! reaction ( ! add$ acid & ?iosulphate to give free sulphur1 :i* is deposit$ 9 & on ! lea!r4 ,! relative int5sity ( ^! effects is v>iable1 accord+ to ! conditions ( op]ation1 e4g4 ! am\nts ( *emicals us$1 _! conc5tration1 ! nature & condition ( ! goods1 ! "t ( application1 ! mann] ( application1 etc4 ,9 practice ! mo/ fav\rable conditions are usually discov]$ empirically1 b1 broadly speak+1 ! goods are usually add$ soon aft] ! ?iosulphate & acid are well mix$4 ,!re is "s evid5ce t ! r$uction is 9 /eps1 int]m$iate products su* z sodium tetra?ionate & *romium dioxide are kn[n to be =m$4 ,! goods *ange f yell[ to d>k br[n1 !n to gre51 & f9ally to ! famili> blue4 ,! sulphur makes ! f9al col\r a light] blue ?an 9 ! case ( a "o-ba? tannage1 h5ce ! two-ba? process is (t5 pref]r$ = col\rs4 ,on acc\nt ( ! empirical "* ( ?is hypo ba?1 x is impossible to fix any exact relation betwe5 ! quantities ( mat]ial us$ 9 ! *rom+ ba?1 & ! quantities ( hypo & acid us$ 9 ! r$uc+ ba?4 ,! foll[+ rules1 !re=e1 mu/ be und]/ood z r\gh approximations = practical use1 & ?\gh !y h be5 empirically discov]$ _! !oretical significance is (t5 fairly obvi\s4 #a4 ,! am\nt ( hypo necess>y is almo/ directly proportional to ! am\nt ( di*romate us$4 ,9 *rom+ ) ba?s ( ! acid or neutral type1 ! p]c5tage ( hypo %\ld be ab\t ?ree times ! p]c5tage ( di*romate us$4 ,?us #d p] c5t4 di*romate ne$s #ab p] c5t4 hypo2 & #f p] c5t4 di*romate ne$s #ah p] c5t4 hypo on ! pelt weight4 ,9 ba?s ( ! ,s*ultz type a less proportion ( hypo may suffice1 b ! #aj p] c5t4 hypo = #e p] c5t4 di*romate1 recomm5d$ by ! ,s*ultz pat5t1 is g5]ally consid]$ r insuffici5t4 #b4 ,! proportion ( hypo is increas$ some:at = ! heavi] classes ( goods1 & may ev5 rea* #bj p] c5t4 ( ! pelt weight4 #c4 ,an increase 9 ! proportion ( hypo is usual ) an increase 9 ! am\nt ( free acid 9 an acid *rom+ ba?4 #d4 ,! p]c5tage ( hydro*loric acid 9 ! r$uc+ ba? is r\ghly half t ( ! hypo1 b is ! mo/ v>iable factor4 ,! quantity v>ies ) ! rate & mode ( addition1 ! class ( goods "u treatm5t1 & ! composition ( ! *rom+ ba?4 #e4 ,9 ba?s ( ! ,s*ultz & neutral type x is bett] to add "s acid to ! hypo ba? be=e add+ ! goods1 b ?is is less ess5tial = goods f an acid *rom+ ba?4 #f4 ,9 ! case ( goods f acid *rom+ ba?s1 ! am\nt ( acid us$ 9 ! r$uc+ ba? is an inv]se function ( ! excess ( acid 9 ! fir/ ba?1 e4g4 take ! foll[+ two processes3-- ---------------------------------------- --------------------------- ,*rom+ ba?4 ,hypo ba?4 ---------------------------------------- ------------------------- ,di*romate4 ,hydro*loric acid4 ,hypo4 ,hydro*loric acid4 ---------------------------------------- ------------------------- #d #d #ab #e #d #ae #ae #a ---------------------------------------- ------------------------- #g4 ,!re %\ld be "s excess ( hypo at ! end ( ! process4 ,?is acts z a feeble alkali1 & comm5ces ! neutralization4 ,! process c be c>ri$ out 9 paddles or 9 drums z pref]r$1 = reasons simil> to ^? applicable 9 ! case ( ! fir/ ba?4 ,on ! :ole1 h[ev]1 drums are less popul> = ! second ba?1 = ! dilute solutions ( ! paddle effect "s economy ( sulphur\s acid1 :i* is apt to escape into ! air4 ,a prelim9>y hypo dip is sometimes us$ to prev5t ! ble$+ ( ! *romic acid4 ,! use ( _m o!r r$uc+ ag5ts has be5 sugge/$ z sub/itutes = hypo4 ,sulphides1 sulphurett$ hydrog51 polysulphides1 sulphites1 bisulphites1 hydrog5 p]oxide1 nitr\s acid1 lactic acid1 etc41 h be5 us$1 b none are s easy to manipulate z ?iosulphate4 ,types ( ,"o-ba? ,*rome ,tannage4--,! "o-ba? process is simpl] ?an ! two-ba? process inasmu* z only "o k9d ( liquor is involv$1 viz4 "o 9 :i* ! *romium is 9 ! *romic /ate4 ,h5ce ! v>iants ( ! "o-ba? process consi/ ma9ly ( v>iations 9 ! composition ( ?is liquor4 ,! *ief po9t ( v>iation is 9 ! read9ess ) :i* *romium hydrate is adsorb$4 ,?is is det]m9$ by ! ext5t to :i* ! *romic salt is hydrolyz$ to =m ! tann+ sol & free acid1 & by ! conc5tration & nature ( ?is free acid z well z ( o!r sub/ances4 ,x is difficult un=tunately to express ^! factors 9 t]ms :i* are comp>able "u g5]al conditions4 ,*romic salts are usually hydrolyz$ to "s ext5t1 b ?is ext5t is v diff]5t ev5 9 wat]1 accord+ to ! nature ( ! acid radical4 ,! degree ( hydrolysis is also l>gely affect$ by ! ext5t to :i* ! solution has be5 made basic by ! addition ( alkalies4 ,by ! neutralization ( ! free acid 9 ?is way !re is fur!r hydrolysis1 ! ext5t ( :i* is aga9 influ5c$ by ! nature ( ! acid radical involv$ & o!r dissolv$ sub/ances1 especially ( organic matt]s4 ,aga91 ! hydrolysis is l>gely affect$ by ! conc5tration ( ! solution ev5 :5 ! proportions ( ! +r$i5ts are con/ant1 & ?is is practically important on acc\nt ( ! necessity = exhau/+ ! *rome liquors economically4 ,nor is ! matt] entirely "o ( degree ( hydrolysis1 = 7z we h not$ 9 ! prec$+ section7 ! electrical condition ( ! *rom+ sol is ( great importance ow+ to ! op]ation ( ! val5cy rule & ! possibility ( zones ( non-precipitation4 ,! alkal9e1 neutral or acid condition ( ! goods :5 fir/ introduc$ has also its influ5ce on all ^! po9ts4 ,x w be readily und]/ood1 !re=e1 t !re is "s difficulty 9 express+ ! tann+ p[] ( a *rome liquor4 ,z ne> z c be yet said ?is is det]m9$ by 7#a7 ! conc5tration ( ! actual tann+ sol1 & 7#b7 its ne>ness to ! isoelectric po9t4 ,n[1 ^! po9ts are n readily det]m9$ by analytical me?ods1 & ! be/ t c yet be done is to det]m9e ! conditions :i* h l>ge influ5ce ^u ^! po9ts4 ,?us ! degree to :i* ! liquor is made basic by add+ alkali is kn[n1 & c be express$ 9 =mul by assum+ t ! acid neutraliz$ by ?is alkali is replac$ 9 ! *rome salt by hydroxy gr\ps4 ,*romic *loride1 ,cr#b;,cl#f1 ) ! addition ( soda to correspond to half ! acid =m$ ^u complete hydrolysis1 w\ld be consid]$ !n to be a solution ( ! salt1 ,cr#b7,,oh7#c;,cl#c4 ,?is has giv5 rise to ! conception ( ! basicity ( a *rome liquor1 :i* may be express$ 9 _m ways1 ! mo/ common ( :i* 9 practice is ! numb] ( grams ,,s#d /ill comb9$ ) #eb grams ,cr4 ,?us ! salt correspond+ to ! composition ,cr7,,oh7,,s#d is said to h a basicity ( #if4 ,! practical importance ( su* det]m9ations ( basicity has be5 mu* exagg]at$1 = !y are b a r\gh guide to ! degree ( hydrolysis ( ! *rome & to ! ext5t to :i* ! sol is positive4 ,?us if ! *rome salt be actually a sulphate1 a liquor ( basicity #if has ab\t ! same practical value z a *loride liquor ( basicity #gb1 & 9 ea* case ! figures are ( little significance if _m organic sub/ances be pres5t4 ,if1 h[ev]1 z is usual 9 practice1 !re be approximately ! same acid radicals ?r\gh\t ! tannage & ab\t ! same relative proportion ( organic matt]s or ( inorganic salts1 !n ^! det]m9ations h "s practical value = comp>ative purposes4 ,! det]m9ation is itself simple3 a portion ( liquor is titrat$ direct ) cau/ic soda4 ,! titration is at boil+-po9t1 & is cont9u$ until a p]man5t p9k is obta9$ ) ph5olph?ale94 ,! am\nt ( ,,s#d correspond+ to ! soda requir$ is !n relative to ! am\nt ( ,cr 9 ! same volume ( liquor4 ,a *romium e/imation is !re=e also necess>y & is mo/ readily done by evaporat+ a portion ( liquor to dryness1 ignit+ ! residue & oxidiz+ ! *rome to *romate by heat+ 9 a muffle furnace ) magnesia & sodium c>bonate 9 equal p>ts1 or fus+ 9 a bl[pipe ) sodium & potassium c>bonates 9 equal p>ts4 ,! oxidiz$ residue is dissolv$ 9 hydro*loric acid & titrat$ ) ?iosulphate z describ$ = ! two-ba? process4 ,ano!r attempt to det]m9e ! practical value ( a *rome liquor is ! empirical te/ sugge/$ by ,mc,candlish1 9 :i* #aj c4c4 ( ! liquor is titrat$ ) /&>d alkali until ! precipitation po9t is rea*$ & a turbidity appe>s4 ,! figure ?us indicates approximately ! degree ( ne>ness to ! precipitation po9t & ! am\nt ( free acid 9 ! liquor4 ,! au?or has f\nd ?is a useful te/ tak5 9 conjunction ) ! basicity det]m9ation4 ,x is be/ express$ 9 ! same units1 e4g4 grams ,,s#d p] #eb grams ,cr4 ,ano!r me?od is ! det]m9ation ( ! hydrion conc5tration ( ! liquor4 ,?is has useful possibilities = rese>* "w1 b is usually too labori\s = rapid comm]cial control4 ,! results1 moreov]1 are n less empirical1 = ! hydrion conc5tration ( ! liquor indicates b imp]fectly ! electrical condition ( ! p>ticles ( ! tann+ sol4 ,9 classify+ "o-ba? liquors into types1 x is be/ to take toge!r ^? 9 :i* ! usual basicity & acidity det]m9ations h at any rate approximate comp>ative value1 & ?is is det]m9$ 9 ! ma9 by ! me?od by :i* ! liquor is manufactur$4 ,broadly speak+1 !re are ?ree types ( *rome liquor3 7#a7 ^? made f *romic salts by add+ suitable am\nts ( alkali2 7#b7 ^? made f sodium di*romate by r$uction ) organic matt]2 & 7#c7 ^? made f sodium di*romate by r$uction ) sulphur\s acid or its salts4 ,( ! fir/ type ! mo/ common is t 9 :i* *rome alum 7a bye-product ( ! dye+ indu/ry7 is ! />t+-po9t4 ,to a solution ( ?is a solution ( wa%+ soda is gradually add$1 ) con/ant /irr+1 until ! salt correspond+ ) ! =mula ,cr7,,oh7,,s#d is obta9$4 ,n[3-- ,k#b,,s#d;,cr#b7,,s#d7cbd;,h#b,o ,na#b,,s#d _/ #iih ,na#b;,,co#caj;,h#b,o _/ #bhf #b;,cr7,,oh7,,s#d ,k#b,,s#d ,,co#b #cc;,h#b,o ,h5ce1 9 practice1 = e t5 p>ts ( *rome alum #b4hf p>ts ( soda cry/als 7or #a4jf p>ts anhydr\s soda7 are us$4 ,a conv5i5t /ock solution is ( #aj p] c5t4 /r5g?4 ,?us #aj lbs4 ( *rome alum is dissolv$1 made basic1 & made up to #aj gallons4 ,to dissolve ! alum a me*anical /irr] is necess>y1 = ! wat] mu/ n be m ?an w>m4 ,! disadvantage ( ?is liquor is ! limit$ solubility ( *rome alum & ! ne$ = its solution 9 ! cold4 ,liquors may be also made by dissolv+ *romium hydrate 9 hydro*loric acid1 & mak+ basic to correspond to ! =mula ,cr#b7,,oh7#c;,cl#c4 ,_m prep>ations are on ! m>ket conta9+ bo? *lorides & sulphates ) appropriate basicity4 ,*rome alum liquors h be5 less (t5 us$ 9 ,brita9 ( rec5t ye>s ow+ to ! high price ( *rome alum1 caus$ 9 "p by ! pres5ce 9 ! salt ( potassium1 all ! salts ( :i* h be5 sc>ce & de> "u w> conditions4 ,( ! second type ,proct]'s glucose liquor is a good example4 ,use #e lbs4 sulphuric acid1 #f lbs4 sodium di*romate1 & #g lbs4 ( glucose1 or quantities 9 simil> proportion4 ,! di*romate is fir/ dissolv$1 & ! acid add$ gradually4 ,! glucose is !n add$ cauti\sly on acc\nt ( ! brisk eff]vesc5ce ( c>bon dioxide4 ,a glucose ( good quality is necess>y1 & ! proportion to be us$ is n q def9ite1 = suffici5t only is ne$$ to effect ! r$uction1 & ?is am\nt is influ5c$ by ! rate ( addition & temp]ature ( ! mixture4 ,! r$uction %\ld be c>eful & regul>1 or ! oxidation products w be irregul> & h a v>y+ effect ^u ! tann+4 ,molasses c be sub/itut$ = glucose1 9 am\nts v>y+ ) its /r5g?4 ,( ! ?ird type ! mo/ common is t 9 :i* ! di*romate is r$uc$ by sulphuric acid & sodium bisulphite4 ,solid bisulphite may be us$1 b x is usually de>1 & solutions are m commonly employ$4 ,into ?is type fall also ! liquors =m$ by pass+ sulphur dioxide gas into di*romate solution4 ,/ock liquors ( ?is type h ! advantage t /rong solutions may be made 7up to #ah p] c5t4 ,cr#b,o#c72 !y h ! disadvantage t !y are liable to conta9 excess ( free sulphur\s acid4 ,! me?od ( application ( *rome liquors is usually by paddl+ or drumm+ ! goods 9 solutions ( appropriate /r5g?--broadly speak+1 paddles us$ = light] goods & pla9 f9i%es1 & sl[ly revolv+ drums = heavi] hides & gra9$ f9i%es4 ,heavy *rome lea!r is (t5 tann$ 9 pits by susp5sion j z 9 vegetable tann+4 ,9 su* in/ances rock]s may be usefully employ$4 ,9 any case1 ! goods are successively br\ght into contact ) liquors ( increas+ /r5g?1 z 9 vegetable tannage1 & ! liquors are ?us mo/ conv5i5tly exhau/$ economically4 ,! gre5 goods ?us receive fir/ ne>ly sp5t liquor & f9i% out ( fre% /rong liquor4 ,! goods may be1 ( c\rse1 h&l$ f drum to drum1 or f pit to pit1 b ! mod]n t5d5cy is to save lab\r by mov+ ! liquors in/ead4 ,?us 9 drum tann+ ! liquor is run out & pump$ into ! next drum4 ,9 pits air ejectors h prov$ suitable1 n only z lift pumps1 b also z agitators ( ! liquor 9 :i* goods are susp5d$4 ,! press sy/em is also us$4 ,f9i%+ ,op]ations4--,9 ne>ly all cases ! *rome lea!r has to be neutraliz$ aft] tann+4 ,?is consi/s 9 remov+ ! acid rev]sibly adsorb$4 ,?is removal is necess>y to ! f9i%+ processes1 z well z to br+ ! tann+ sol into condition = m p]man5t tannage4 ,neutralization gets rid ( soluble *rome salts z well z free m9]al acid1 & is ! f9al /age 9 r5d]+ ! tann+ sol less positive1 & p]haps ev5 negative4 ,x is br\ght ab\t by ! use ( weak alkalies1 ( :i* borax is ! easie/ & safe/1 b n ! *eape/4 ,sodium silicate1 phosphate1 c>bonate1 & bic>bonate h be5 also us$1 & a mixture ( soda & an ammonium salt has be5 sugge/$ by ,/iasny4 ,:it5+ has also be5 tri$1 b is v sl[-act+4 ,consid]able economy 9 alkali may be effect$ by a ?or\gh wa%+ ( ! lea!r be=e us+ ! alkali4 ,if ! wat] be h>d1 s mu* ! bett]1 & if w>m wat] be available ! process is ha/5$4 ,= mo/ lea!rs x is necess>y to remove excess ( alkali j z mu* z excess ( acid1 s t a ?or\gh wa%+ 9 wat] g5]ally foll[s ! treatm5t ) alkali4 ,any?+ f #a_/d to #c p] c5t4 borax 7or its equival5t7 on ! pelt weight may be us$1 &1 g5]ally speak+1 x is bett] to use solutions z dilute z practicable 9 ord] to avoid local ov]-neutralization & t5d] lea!r4 ,fat liquor+ is a process :i* is v l>gely typical ( *rome lea!r manufacture2 x consi/s 9 drumm+ ! goods ) an oil emulsion1 ! grease ( :i* is entirely tak5 up by ! lea!r4 ,x ?us /rongly resembles drum /uff+ 7,"p ,i41 ,section ,,iv47 9 me?od1 b ! fat liquor is su* t x mixes easily ) wat]1 & usually conta9s soap 9 ord] to assi/ 9 ?is s5se1 & may sometimes inde$ consi/ ( soap only4 ,m9]al oil is also us$ frequ5tly 9 fat liquors4 ,! object ( fat liquor+ is to give s(tness1 pliability1 or wat]pro(ness1 & to fe$ ! empty *rome tannage4 ,x is also us$ z a prep>ation = m complete impregnation ( grease1 e4g4 z 9 /uff+ *rome h>ness1 & 9 dipp+ *rome sole lea!r4 ,fat liquors are usually made by dissolv+ ! soap 9 boil+ wat] & gradually add+ ! oil ) con/ant agitation4 ,p]fect emulsification is ess5tial1 & ?is is assi/$ by ! use ( case91 album51 gelat9e1 />*1 egg yolk 9 addition to soap & oil4 ,soda & borax also assi/1 & degras & sod oil are also useful & are admissible :]e ! lea!r is to receive a dull f9i%4 ,! op]ation ( fat liquor+ is greatly assi/$ by heat1 & temp]atures ( ab\t #aaj to #acj ,f4 are usual4 ,*rome lea!r may be dy$ be=e or aft] fat liquor+3 if be=e1 ! fat liquor sometimes t5ds to alt] ! %ade2 if aft]1 ! dye+ t5ds to be unev54 ,logwood extract & iron salts are l>gely us$ = blacks4 ,x is common to mordant *rome lea!r ) vegetable tann+ be=e dye+4 ,suma* & gambi] are (t5 us$ = ?is purpose1 & ! usual fix+ ag5ts 7t>t> emetic1 titanium salts1 etc47 may also be us$4 ,( ! me*anical f9i%+ op]ations /ak+ is ! mo/ *>act]i/ic4 ,x is n[ done entirely by ma*9es1 & ! prim>y purpose is to s(t5 ! lea!r1 :i* o!rwise dries out 9 a non-pliant & /iff condition4 ,9 ! /ak+ ma*9e1 ! blade is fix$ betwe5 two roll]s1 :i* are h[ev] on ! o!r side ( ! lea!r4 ,! lea!r is held by ! op]ator1 & ! ma*9e head pulls a fold ( ! lea!r ov] ! blade4 ,season+ & glaz+ are also common = _m *rome lea!rs4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #aih-bbj4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #baj1 #cab1 #cee1 #cge4 ,b5nett1 ,types ( ,two-ba? ,*rome ,tannage1 ,lea!r1 #aiji1 ,aug4 & ,sept4 ,,section ,,iii4--,,*rome ,,calf ,! tannage ( calfsk9s by ! *rome processes = ! manufacture ( upp] lea!rs is "o ( ! mo/ ext5sive bran*es ( lea!r manufacture4 ,! des]v$ly popul> box calf is typical ( ^! lea!rs1 & ! obs]vations ( ?is section are prim>ily applicable to x4 ,a *rome-tann$ calf sk91 fat liquor$ & black$1 provides z suitable an upp] lea!r z c\ld be desir$ = ord9>y boots4 ,x is at once supple & durable4 ,x is also suffici5tly wat]pro(1 b c be giv5 a bright glaz$ f9i%4 ,9 reg>d to ! wet "w = *rome calf1 ! g5]al pr9ciples & me?ods discuss$ 9 ! previ\s section are mu* to ! po9t4 ,x is ess5tial to avoid undue plump+ & ! loss ( hide sub/ance4 ,! sk9s %\ld be wa%$ clean z soon z possible4 ,?ree fre% wat]s are desirable1 ! goods rema9+ only a %ort "t 9 ea*4 ,salt$ sk9s ne$ m "t1 b ! liquors mu/ be kept sweet4 ,drumm+ ! sk9s 9 runn+ wat] is v suitable = ! fir/ & la/ /ages ( soak+4 ,! lim+ %\ld be %ort b n %>p1 i4e4 mell[ sulphide limes are suitable1 depilation be+ c>ri$ out aft] ab\t #g days4 ,! "o-pit sy/em is usual1 b two liquors may be giv51 ! gre5 goods be+ fir/ ins]t$ into a us$ liquor1 & aft] h&l+ re9s]t$ into ! same pit ) a new lime liquor made up ) lime1 sulphide & a proportion ( ! old liquor4 ,scudd+ %\ld be c>efully done1 z hair on ! f9i%$ lea!r is v objectionable4 ,9 delim+ x is ess5tial to h ! gra9 ( ! sk9s ?or\ghly relax$ & pull$ d[n4 ,! f9i%$ box calf %\ld h a *>act]i/ic s(t & silky feel1 & ?is is only atta9$ by procur+ ! inela/ic pelt4 ,x is n surpris+ t a light pu]+ is a popul> me?od = atta9+ ?is1 b !re is also a t5d5cy to use artificial bates su* z are made f ammonium *loride & pancreat91 toge!r ) organic acids1 or non-swell+ acids l boric acid4 ,dr5*+ is also common aft] a prelim9>y delim+ ) acid4 ,! sk9s may be half or two-?irds delim$ ) lactic acid1 r9s$ & dr5*$ ov] night at #he ,f4 ) #f p] c5t4 bran on ! pelt weight4 ,less acid may be also us$1 9 tepid wat]1 & ! dr5* made up ) #aj p] c5t4 bran & a little pea meal4 ,x is v common to pickle ! sk9s 9 #e p] c5t4 alum & #e to #aj p] c5t4 salt be=e tann+4 ,?is is (t5 ( d\btful advantage1 b sometimes prev5ts drawn gra9 :5 ! goods are mov$ rapidly into /rong *rome liquors4 ,?is pickl+ is said to give fullness to ! lea!r4 ,! tannage ( box calf is usually by ! "o-ba? process1 ?\gh ! two-ba? process gives q z good a result & is sometimes us$4 ,aga91 drum tannages are ! mo/ popul> on acc\nt ( _! spe$ & ! economy ( *rome4 ,! practical problem is to use up all ! *rome1 & to tan quickly )\t draw+ ! goods4 ,x is1 9 any case1 usual to comm5ce ! tannage 9 a us$ & ne>ly sp5t liquor & f9i% 9 a fre% liquor4 ,! mo/ appropriate way dep5ds l>gely ^u local conv5i5ce1 ! numb] ( drums available1 supply ( lab\r1 etc4 ,9 a "o-drum sy/em ! goods may be />t$ 9 an old liquor1 :i* is run (f :5 exhau/$ by ! gre5 goods4 ,fre% /ock solution is !n add$ at int]vals ( an h\r or two & ! drumm+ cont9u$ till tannage is complete1 :i* is usually 9 less ?an #bd h\rs4 ,! rema9+ liquor is us$ to comm5ce ! tannage ( ! next pack4 ,9 ano!r sy/em ! op]ation is simil> except t ! liquors are weak]1 & ! goods are !n remov$ & f9i%$ 9 ano!r drum4 ,a ?ree-liquor sy/em1 h[ev]1 is (t5 comb9$ ) a "o-drum me?od2 ! goods are ?us n h&l$4 ,! liquors are run (f & pump$ to o!r drums1 ! once-us$ liquor to a drum conta9+ goods already treat$ ) a twice-us$ liquor2 ! twice-us$ liquor to a drum conta9+ gre5 goods1 & ! ?rice-us$ liquor pump$ to ! dra94 ,9 any ( ^! me?ods ! *rome alum liquor is suitable1 us+ #aj p] c5t4 alum & #c p] c5t4 soda on ! pelt weight4 ,! glucose liquor has also prov$ v suitable = *rome calf1 & ! liquors made ) sulphur\s acid or its salts h increas+ popul>ity on acc\nt ( l[] co/s4 ,_m tann]s use b\ght liquors--*rome extracts :i* are suppos$ to be specially devis$ to suit ! tannage ( *rome calf4 ,:5 ?or\ghly tann$ ?r\gh1 z c be readily judg$ f a sectional cut ( ! lea!r1 & also by ! /r5g? ( ! liquor rema9+1 ! goods are hors$ 9 pelt ov]night1 & are !n ready = f9i%+4 ,9 f9i%+ box calf ! neutralization %\ld be ?or\gh1 or ! acid may cause tr\ble 9 dye+ & fat liquor+4 ,imp]fect removal ( excess *rome salts may cause ! =mation ( *rome soaps :i* are v difficult to remove2 ! goods %\ld !re=e be well wa%$4 ,!re are two g5]al types ( treatm5t be=e black+4 ,9 "o1 ! sk9s are fir/ well wa%$ ) wat] at #aaj ,f41 neutraliz$ ) ab\t #c p] c5t4 borax1 & well wa%$ aga94 ,/rik+ foll[s & is usually v ?or\gh1 p>tly because x assi/s 9 produc+ ev5ly ! *>act]i/ic box gra91 & p>tly because ! f9i%$ lea!r is sold by ! squ>e foot4 ,ma*9e /rik+ is n[ almo/ univ]sal1 & may be done sev]al times at diff]5t /ages 9 ! dry+4 ,:5 half dry 7samm$7 ! sk9s are %av$ by ma*9e &1 at ?is /age usually1 weigh$4 ,dye+ & fat liquor+ !n foll[s4 ,9 ! o!r type1 ! goods are m]ely wa%$1 & !n /ruck out1 samm$1 %av$ & weigh$4 ,! sk9s are !n neutraliz$1 wa%$ & imm$iately dy$ & fat liquor$4 ,! advantages ( ?is latt] c\rse are t ! goods rema9 9 ! drum = ! la/ f\r processes1 :i* is economical ( lab\r1 & also t by neutraliz+ imm$iately be=e dye+ & fat liquor+ !re is less dang] ( a fur!r diffusion ( acid4 ,9 dye+ logwood extract is l>gely us$1 occasionally a little fu/ic is us$ also1 & by us+ a /rik] ( iron & copp] sulphates a good black is obta9$4 ,logwood is (t5 us$ also 9 conjunction ) coal-t> dye/uffs4 ,! goods are fir/ w>m$ 9 ! drum up to #adj ,f41 & ! dye/uff solution gradually run into ! drum :il/ x is revolv+4 ,up to #c_/d h\r may be necess>y to exhau/ ! ba?1 ! goods be+ con/antly drumm$4 ,! fat liquor is !n run 9 simil>ly1 & ! drumm+ cont9u$ until ! grease is all absorb$ by ! lea!r1 :i* may take ano!r h\r4 ,! sk9s are hors$ till next day1 dur+ :i* "t ! grease p5etrates m completely4 ,! sk9s are n[ dri$ out1 sometimes by susp5d+ f ! h9d %anks & sometimes by nail+ on bo>ds or wood5 frames4 ,!y are damp$ back = /ak+ by leav+ = #a-a_/b to #b days 9 moi/ sawdu/4 ,aft] /ak+ !y are dri$ /ra9$ 9 a /ove at ab\t #aje ,f4 ,9 f9i%+ (f1 ! gra9 is cle>$ by spong+ ) #aj p] c5t4 lactic acid1 & season$ ) a mixture ( milk1 blood & black dye/uff4 ,:5 dry on ! surface ! sk9s are glaz$ by ma*9e1 & gra9$ two ways--neck to butt & belly to belly4 ,!y are usually reseason$1 dri$ out1 reglaz$1 regra9$1 lightly oil$ ) m9]al oil1 & f9ally trimm$4 ,^! v>i\s op]ations are fairly typical1 b !re is obvi\sly ample scope = div]g5ce4 ,?us "o may fat liquor be=e dye+1 & ! sk9s may be /ak$ be=e dry+ out1 & may be re-/ak$ aft] glaz+4 ,mu* s-call$ box calf is n made f calf sk9s4 ,a v close approximation1 h[ev]1 is obta9$ f r old] animals1 & box-kip is l>gely manufactur$ by simil> me?ods4 ,light hides are also widely us$1 be+ simil>ly treat$ except t !y are split & also cut into two along ! sp9e4 ,! f9i%$ article is sold z box-sides4 ,to yield ! *>act]i/ic gra9 patt]n1 ! goods are frequ5tly pr9t$ & emboss$4 ,ev5 ! fle% splits are sometimes made into box calf imitations1 "s fill+ mat]ial be+ us$ & an artificial gra9 patt]n emboss$4 ,will[ calf typifies ! *rome calf :i* is f9i%$ 9 col\rs4 ,! soak+1 lim+ & delim+ processes are ! same z = box calf4 ,! tannage1 h[ev]1 is g5]ally by ! two-ba? process on acc\nt ( ! light] col\r !reby obta9$4 ,?is col\r is l>gely due to ! deposition ( sulphur 9 & on ! lea!r 9 ! second ba?4 ,9 "o tann+ process ! sk9s are fir/ pickl$ 9 #b p] c5t4 hydro*loric acid & #aj p] c5t4 salt4 ,!y are !n drumm$ 9 solution conta9+ #b p] c5t4 di*romate 7/r5g? #a 9 #fj7 = ab\t half an h\r4 ,a solution conta9+ #d p] c5t4 di*romate1 #c-a_/b p] c5t4 hydro*loric acid1 & #e p] c5t4 salt is gradually add$1 & ! sk9s drumm$ until well /ruck ?r\gh4 ,!y are !n hors$ ov]night & /ruck out & pass$ ?r\gh a hypo dip1--a #b p] c5t4 solution ( ?iosulphate1--& !n into ! r$uc+ ba?1 :i* conta9s #aj p] c5t4 ( ?iosulphate1 to :i* #e p] c5t4 hydro*loric acid is add$4 ,ano!r process employs paddles in/ead ( drums4 ,! *rom+ liquor is made up ) #d-a_/b p] c5t4 *romic acid & #aj p] c5t4 salt4 ,! ba? is exhau/$ by comm5c+ ! tannage ( a succe$+ pack4 ,! sk9s are r$uc$ z 9 ! la/ process4 ,9 ano!r process ! acid type ( *rom+ ba? is us$4 ,! sk9s are paddl$ ) a solution conta9+ #e p] c5t4 di*romate1 #e p] c5t4 hydro*loric acid1 #b p] c5t4 alum9ium sulphate1 & #aj p] c5t4 salt4 ,9 ! r$uc+ ba? #ad p] c5t4 hypo & #d p] c5t4 hydro*loric acid are us$4 ,9 yet ano!r process ! sk9s are pickl$ fir/ 9 #e p] c5t4 alum9ium sulphate1 #g-a_/b p] c5t4 salt1 & #c p] c5t4 sulphuric acid1 & are !n dri$ out & sort$4 ,! tannage prop] is 9 ! drum1 us+ #f p] c5t4 di*romate1 #e p] c5t4 hydro*loric acid1 & #e p] c5t4 salt4 ,9 ! r$uc+ drum #ae p] c5t4 hypo is us$ & #d-a_/b p] c5t4 hydro*loric acid4 ,:i*ev] process ( tann+ has be5 us$1 ! sk9s are neutraliz$ & wa%$ ?or\ghly1 z = box calf1 samm$ & %av$4 ,9 dye+1 ! sk9s are fir/ mordant$ ) a filt]$ infusion ( leaf suma*1 us$ at #aaj ,f4 = half an h\r4 ,z fix+ ag5t1 #d oz4 t>t> emetic p] doz5 sk9s is !n add$ & ! drumm+ cont9u$ = half an h\r4 ,! goods are wa%$1 /ruck out & drum dy$ at #adj ,f4 ) basic col\rs1 & imm$iately fat liquor$4 ,9 ! fat liquors olive oil & ca/or oil1 ) ! correspond+ soaps1 h be5 popul>1 b sub/itutes are n[ us$ on economical gr\nds4 ,! sk9s are next hors$ a :ile1 well /ruck out aga9 & dri$ /ra9$4 ,!y are n[ f9i%$ (f z = box calf1 except t x is usual to gra9 only "o way--neck to butt--& ! season %\ld consi/ ( milk1 wat] & album9 only1 ?\gh sometimes o!r mucilag5\s matt]s are add$4 ,z ) box calf1 ! f9i%+ may be v>i$ 9 _m ways4 ,! sk9s may be dy$ ) acid col\rs aft] fat liquor+4 ,= pale %ades direct dyes are us$ )\t a mordant4 ,= d>k] %ades ( br[n & r$1 ! dyewoods are us$ bo? z mordants & gr\nd col\rs1 & titanium salts are useful z fix+ ag5ts4 ,bo? ! box & will[ f9i% are l>gely a matt] ( public ta/e1 & ! fa%ion v>ies f "t to "t on su* po9ts z to :e!r ! gra9 %\ld be "o way or two ways1 & :e!r x %\ld be fa9t or bold4 ,!re are also o!r common f9i%es besides ! typical box gra94 ,glac calf is made mu* 9 ! same way z box calf1 b !re is no gra9+ at all4 ,! goods are usually season$ & glaz$ ?ree times4 ,small sk9s are pref]r$ = ?is f9i%4 ,dull calf is also a pla9 f9i%4 ,! lea!r conta9s m grease1 & ! fat liquor is made up ) great] proportions ( degras4 ,! goods are n season$ or glaz$1 b iron$1 siz$ ) gum1 oil1 soap & logwood1 & aft] bru%+ are dri$ & roll$4 ,9 bo? ^! pla9 f9i%es a "o-ba? paddle or pit tannage is common1 9 ord] to ensure ! smoo? f9i%4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #aih4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #ee1 #hd1 #aje1 #bbg1 #cfj-cfc1 #cge4 ,b5nett1 ,!ory & ,practice 9 ,wetwork ( ,*rome ,calf1 ,%oe & ,lea!r ,report]1 ,sept41 #aiji4 ,,section ,,iv4--,,*rome ,,goat ,,& ,,%eep ,imm5se quantities ( goat & %eep sk9s are *rome tann$ = upp] lea!rs4 ,mo/ ( !m are manufactur$ into ! well-kn[n & popul> ,glac kid1 to ! manufacture ( :i* ?is section is *iefly devot$4 ,to be q /rict1 glac kid %\ld be made f kid sk9s1 b actually comp>atively few ( su* sk9s are us$1 !y be+ res]v$ r = glove lea!rs4 ,! popul> upp] lea!r is made f goatsk9s4 ,*rome goat is des]v$ly popul>2 x is an ideal upp] lea!r = %oes & light boots4 ,z comp>$ ) *rome calf 7?ickness & o!r factors be+ equal71 x is n only s(t] & m pliant1 b also m durable4 ,x is usually1 h[ev]1 n q s ?ick1 & p]haps !re=e n q s w>m & wat]pro(4 ,! popul>ity ( glac is probably enhanc$ by ! bright] & m glassy f9i% ?an is usual ) box4 ,z ! supply ( goatsk9s is un=tunately too limit$1 an ev5 m widely us$ glac upp] lea!r is made f %eepsk9s1 & (t5 sold z glac kid4 ,f :at has be5 previ\sly said z to ! quality ( goat & %eepsk9 lea!rs 7,"p ,,ii41 ,sections ,,ii4 & ,,iv471 x w be readily und]/ood t glac %eep is by no means s good a lea!r z glac goat4 ,x is p]haps z s(t1 b is m spongy & loose textur$1 & is nei!r s wat]pro( nor s durable z *rome goat4 ,! ubiquit\s %eep1 h[ev]1 provides an imm5se supply ( raw mat]ial1 & ! result+ lea!r1 :i* %\ld /rictly be reg>d$ z a glac kid imitation1 f9ds a ready sale4 ,:5 well f9i%$ x is inde$ a good imitation 9 respect ( appe>ance1 & ?is fact1 toge!r ) its comp>atively l[ co/1 causes x to meet an und\bt$ public ne$4 ,! production ( glac goat w fir/ be consid]$4 ,! soak+ process is q simil> to t be=e describ$ = ! production ( goatsk9 moroccos 7q4v47 & ne$ n be "h repeat$4 ,! lim+ is simil> 9 _m respects also1 b f :at 0 said 9 ,section ,,ii4 ab\t ! undesirability ( excessive plump+ ( pelt = *rome lea!r1 x w be cle> t cau/ic soda %\ld be omitt$ f ! limes4 ,! lim+ %\ld also be %ort] = glac ?an = moroccos1 & ?is is atta9$ bo? by us+ a great] proportion ( sulphide & by us+ mell[] lime liquors1 pref]ably ! latt]1 z s(t pelts are bett] ensur$4 ,calcium *loride has sometimes be5 add$ to ! limes3 ?is reacts ) ! soda f ! sulphide1 yield+ salt & probably precipitat+ lime1 & has its own lyotrope influ5ce1 ?us r$uc+ ! plump+ effect possibly 9 two ways4 ,to obta9 ei!r effect x is necess>y to use consid]able am\nts ( calcium *loride4 ,z goatsk9s are s tight fibr$1 a long] lim+ & a great] loss ( collag5 is p]missible ?an ) mo/ pelts = *rome4 ,! delim+ op]ations %\ld be exce$+ly ?or\gh 9 ord] to obta9 ! desir$ s(tness & ! smoo? gra94 ,pu]+ is l>gely us$ to ! full ext5t1 i4e4 ! goods are ?or\ghly pull$ d[n at #he-ij ,f41 & are c>efully delim$ 9 ! pu] liquor4 ,aft] pu]+ x is common to give a l[ temp]ature dr5* 7#fj-fe ,f471 :i* ( c\rse acts sl[ly ov] a day or two4 ,! sk9s mu/ be well scudd$ aft] pu]+ or aft] dr5*+2 sometimes aft] bo?4 ,! dr5*+ is (t5 sub/itut$ = purely delim+ processes1 ( :i* may be m5tion$ ! use ( boric acid & also ! use ( w>m solutions ( ! comm]cial organic acids 7lactic1 =mic1 acetic1 butyric1 etc471 toge!r ) calcium *loride4 ,9 place ( ! *loride1 a salt ( ! acid may be employ$1 & ! delim+ ba? may be reg5]at$ by oxalic acid & us$ repeat$ly4 ,sometimes pu]+ is omitt$ & ! desir$ result obta9$ by wa%+ 9 w>m wat]1 ne>ly delim+ ) w>m solutions ( organic acid1 wa%+ aga9 & dr5*+4 ,sk9s are also wa%$ (t5 aft] dr5*+4 ,9 tann+ *rome goat = glac ! two-ba? process is mo/ly pref]r$4 ,?is is p>tly because ! sulphur deposit$ 9 ! r$uc+ ba? assi/s mat]ially 9 produc+ ! mell[ness & fullness :i* are s ess5tial1 & p>tly because a l>ge proportion ( sk9s are f9i%$ 9 col\rs4 ,! two-ba? process also l5ds itself to a paddle tannage1 :i* is necess>y = ! smoo? gra9 f9i%4 ,"o or two illu/rative processes may be giv54 ,"o process pres5ts _m po9ts ( resemblance to ! fir/ process sugge/$ = will[ calf 9 ,section ,,iii4 7q4v474 ,! sk9s are fir/ pickl$ 9 a paddle ) #b p] c5t4 hydro*loric acid & #aj p] c5t4 salt1 & !n pass into ! *rom+ paddle1 :i* conta9s at fir/ only #b p] c5t4 di*romate4 ,subsequ5tly #d p] c5t4 di*romate1 #c-a_/b p] c5t4 hydro*loric acid1 & #e p] c5t4 salt are add$ to ! paddle liquor1 & ! sk9s paddl$ until well /ruck ?r\gh4 ,aft] be+ hors$ ov]night ! sk9s are /ruck out by ma*9e1 pass$ ?r\gh a hypo dip if desir$1 & r$uc$ ) #ab p] c5t4 ( ?iosulphate & ab\t #e p] c5t4 ( acid4 ,! sk9s may be left ov]night 9 ! hypo paddle1 & ! excess ( ?iosulphate1 :i* is a feeble alkali1 comm5ces ! neutralization4 ,9 ano!r process ! *rom+ ba? is made up ( #e-a_/b p] c5t4 *romic acid & #f-a_/b p] c5t4 ( salt1 & to ?is paddle liquor #b or #c p] c5t4 ( alum9ium sulphate may be add$ if desir$4 ,! r$uction is ) #ad p] c5t4 hypo & #g p] c5t4 hydro*loric acid4 ,a little ( ! acid is add$ to ! r$uc+ ba?2 :5 ! liquor turns milky1 ! sk9s are rapidly ins]t$1 & ! re/ ( ! acid gradually add$4 ,9 ! f9i%+ processes ! me*anical op]ation ( /rik+ is v prom95t1 on acc\nt ( ! necessity ( obta9+ area & smoo? gra94 ,! sk9 ( goats has r a t5d5cy to bold gra91 & ?is enhances ! ne$ ( /rik+4 ,mo/ manufactur]s lay great /ress ^u ?or\gh neutralization & wa%+4 ,an important po9t also is t ! /ak+ %\ld be c>ri$ out at ! prop] condition ( dryness4 ,if ei!r too damp or too dry1 ! requisite mell[ feel is n obta9$4 ,!re is1 ( c\rse1 ample scope = v>iation & +5uity1 & ! foll[+ processes = blacks & col\rs mu/ be tak5 z broadly typical4 ,! sk9s f ! r$uc+ ba? are fir/ ma*9e-/ruck1 & !n imm$iately neutraliz$ ) "o p] c5t4 borax until ?is is ?or\ghly us$ up1 & ! sk9s are !n paddl$ = _m h\rs 9 runn+ wat]4 ,!y are aga9 /ruck out & lightly %av$1 possibly aft] a little dry+4 ,!re is a t5d5cy to save "t by us+ a /rong] borax solution1 & by us+ w>m or tepid wat]1 & "s factories save borax by wa%+ well fir/ 9 w>m wat]4 ,if = blacks a common plan is to dye gra9 & fle% a violet-blue & !n black ! gra9 only ) logwood & iron4 ,! sk9s are drum dy$ blue ) a coal-t> dye/uff1 drumm+ half an h\r 9 ! solution at #aaj ,f41 & aga9 /ruck out4 ,!y are !n pair$ or pleat$1 & rapidly pass$ successively ?r\gh ?ree vats conta9+ respectively cold weak ammonia1 a logwood & fu/ic infusion at #abj ,f41 & a solution ( f]r\s sulphate conta9+ a little copp] sulphate4 ,! sk9s mu/ be imm$iately wa%$ well to remove excess ( iron4 ,in/ead ( ?is process ! sk9s may be pass$ ?r\gh vats conta9+ coal-t> blacks4 ,in/ead ( blue back+ ! sk9s may be drum-dy$ black on fle% & gra9 ) ei!r coal-t> blacks or ) logwood & iron4 ,9 ! latt] case ! sk9s mu/ be drumm$ 9 wat] = an h\r to remove excess ( iron4 ,h[ev] dy$1 ! sk9s are (t5 /ruck out aga9 aft] dye+1 & samm$ slightly = fat liquor+4 ,neatsfoot oil is a popul> +r$i5t ( ! fat liquor4 ,! sk9s are drumm$ dry = a few m9utes 9 a hot drum1 & ! fat liquor add$ at #acj ,f41 & ! drumm+ cont9u$ aft] ! grease has be5 tak5 up 9 ord] t x may be ?or\ghly di/ribut$4 ,! sk9s are /ruck out aga91 rapidly dri$ out1 & wet back = /ak+ 9 damp sawdu/4 ,! /ak+ %\ld be ?or\gh1 &1 if necess>y1 repeat$ :5 ! goods are r dri]4 ,9 f9i%+ (f ! sk9s may be fluff$ if desir$1 & are !n cle>$ by spong+ ) #aj p] c5t4 lactic or acetic acid4 ,!y are !n season$ & glaz$ aft] "s dry+4 ,?is is repeat$ until ! requir$ gloss has be5 obta9$4 ,!y are f9ally oil$ lightly ) a mixture ( l9se$ & m9]al oils4 ,on f9i%+ dull kid a heavi] fat liquor is giv51 9 :i* degras is us$1 & ! sk9s are n season$ & glaz$1 b are iron$ & oil$4 ,9 f9i%+ = col\r$ glac1 ! sk9s are mordant$ be=e dye+ by ! use ( dyewood extracts1 antimony & titanium salts be+ us$ z fix+ ag5ts4 ,! fat liquor %\ld conta9 less soap & m egg yolk1 & = fancy %ades ev5 egg yolk only is sometimes us$4 ,! production ( *rome glac %eep foll[s ! same g5]al l9es z glac goat4 ,!re is less difficulty 9 obta9+ smoo? gra91 s t /rik+ is p]haps less prom95t1 & drum tannages are pref]r$1 :e!r "o ba? or two ba?4 ,! sk9s are receiv$ aft] fellmong]+ 7see ,"p ,,ii41 ,section ,,iv47 & ne$ ?or\gh pu]+ to remove scud1 & may be !n r9s$ ?r\gh boric acid4 ,pickl+ is v common ) ^! goods4 ,9 ! pickl$ /ate !y are (t5 sort$ out be=e tann+4 ,! pickl+ is usually a "o-ba? process 9 :i* vitriol & salt or else alum & salt are us$1 b sometimes all ?ree sub/ances4 ,! sk9s may inde$ be receiv$ 9 a pickl$ /ate4 ,!y may be depickl$ by paddl+ ) salt & borax1 bic>bonate1 or basic alum solution4 ,!y may also be tann$ )\t depickl+ if ! composition ( ! pickle be all[$ = 9 ! fir/ *rom+ liquor4 ,a commonly us$ pickle consi/s ( #c p] c5t4 alum9ium sulphate & #i p] c5t4 salt4 ,if ^! goods are to be dri$ out1 fl\r also may be us$ ) ! pickle1 :i* ?us becomes practically a light prelim9>y alum tannage 7see ,"p ,,iv41 ,section ,i474 ,a commonly us$ acid pickle is ( #e p] c5t4 comm]cial sulphuric acid & #be p] c5t4 salt4 ,! delim$ or depickl$ /ock may be tann$ z n[ describ$4 ,! two-ba? process may be us$ ) drums4 ,! *rom+ ba? conta9s #e p] c5t4 di*romate1 #e p] c5t4 hydro*loric acid1 & #aj p] c5t4 salt4 ,aft] ! sk9s are ?or\ghly p5etrat$ !y are hors$ ov]night & r$uc$ ) #bj p] c5t4 ?iosulphate1 up to #g p] c5t4 ( hydro*loric acid be+ add$ aft] half an h\r 9 ?iosulphate only4 ,alum pickl$ or taw$ sk9s are wet back by drumm+ = ab\t an h\r 9 wat]1 & are !n tann$ by ! "o-ba? process 9 drums4 ,only a few h\rs are ne$$4 ,t[>ds ! end ( ! op]ation ab\t #a_/b p] c5t4 ( bic>bonate ( soda may be add$ to ! *rome liquor4 ,acid pickl$ sk9s may be wet back ) #aj p] c5t4 salt1 & depickl$ by add+ a basic alum solution & ! *rome tannage sup]impos$ aft] ab\t half an h\r )\t h&l+ ! goods4 ,! basic *rome alum liquor is suitable = ?is purpose4 ,9 f9i%+ glac %eep mu* ! same me?ods are us$ z 9 ! case ( glac goat4 ,%eepsk9s are p]haps m lightly fat liquor$1 be+ naturally s(t & por\s4 ,degreas+ is (t5 necess>y to obta9 an ev5 f9i%4 ,z %eep gives an empty pelt & *rome an empty tannage1 a slight retannage is (t5 giv5 9 gambi]1 especially = blacks1 9 :i* case ! sk9s are well mordant$4 ,?is retannage makes ! lea!r less /ret*y4 ,logwood & iron blacks are usual4 ,= col\rs1 fu/ic or suma* are ! usual mordants1 ) t>t> emetic to fix4 ,if = glove lea!rs1 sk9s pickl$ 9 alum & salt or taw$ %\ld be pref]r$1 & fl\r may be us$ 9 ! fat liquor4 ,%eepsk9 splits are sometimes giv5 a *rome tannage & f9i%$ z *rome *amois4 ,?is lea!r may be us$ = l9+s1 b n = poli%+ silv] on acc\nt ( ! sulphur orig9at+ f ! r$uction ba?4 ,! splits are pu]$ heavily1 & pickl$ 9 #f p] c5t4 vitriol & #bd p] c5t4 salt4 ,!y are paddl$ 9 ?is pickle liquor1 & #d p] c5t4 di*romate add$ 9 successive portions4 ,! fle%es are hors$ ov]night & r$uc$ 9 #ae p] c5t4 ?iosulphate1 to :i* a little hydro*loric acid is add$ if ne$$4 ,9 f9i%+ ! splits are wa%$ 9 w>m wat]1 neutraliz$ 9 weak soda1 & wa%$ aga94 ,!y are samm$ by ma*9e /rik+1 & fat liquor$1 us+ mu* soap4 ,!y are !n hors$1 /ruck & dri$ out4 ,!y are /ak$ sev]al times aft] damp+ back1 dry+ out aga9 betwe5 /ak+s4 ,!y are f9ally fluff$4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #aih4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #ee1 #hd1 #aje1 #bcj1 #cfd4 ,b5nett1 ,!ory & ,practice 9 ,wetwork ( ,*rome ,goat1 ,%oe & ,lea!r ,report]1 ,sept41 #aiaj ,,section ,v4--,,heavy ,,*rome ,,lea!rs ,! t]m heavy *rome lea!r is tak5 to include *rome sole lea!r1 *rome /rap & h>ness butts1 wat]pro( *rome upp] lea!rs1 motor butts & pick+ b& butts4 ,^! w be discuss$ 9 turn4 ,*rome sole lea!r1 z /at$ 9 ,section ,i41 has made headway 9 ,brita9 dur+ ! ,european ,w>1 ! ,army au?orities hav+ recogniz$ its great advantages 9 durability & wat]pro(ness4 ,at ! "t ( writ+1 h[ev]1 its manufacture has receiv$ a set back1 & _m factories are r$uc+ _! output4 ,! prim>y cause ( ?is is t ! ,army pur*ases h l>gely ceas$1 :il/ ! g5]al public h n yet be5 educat$ to its value4 ,m5 :o take *rome upp]s = grant$ talk ( *rome sole z a lea!r sub/itute ) an implication t x is ( inf]ior value4 ,x mu/ be recogniz$1 too1 t !re is "s int]e/$ opposition to its developm5t4 ,cobbl]s & bootmak]s compla9 t x ru9s _! tools1 be+ s h>d to cut4 ,n[1 x is manife/ly impossible = x to be s(t to cut & h>d to we> out2 ! compla9t is !re=e an excell5t te/imonial4 ,!re is also a /upid fe> t an article :i* la/s twice z long w r$uce repairs & retail sales by #ej p] c5t4 ,ev5 ! manufactur] has sometimes a suspicion t a dem& r$uc$ 9 proportion to durability w n be balanc$ by an ext5d$ export trade4 ,^! po9ts ( view w become m9or consid]ations :5 ! public realize its relative economy1 & :5 ! community z a :ole grasp t a durable article is a natural asset4 ,mean:ile cr$it is due to ^? firms :o p]sev]e 9 _! pione]+ "w ( educat+ ! public4 ,! manufacture ( *rome sole lea!r pres5ts _m analogies ) ! vegetable tannages4 ,! soak+ & lim+ %\ld be ab\t id5tical1 b ! hides = *rome are g5]ally giv5 m sulphide & ! depilation is r$uc$ to ab\t a week4 ,! me?ods us$ = delim+ diff] widely 9 diff]5t factories4 ,"s delime completely ) m9]al acids1 "s ev5 pickle 9 acid & salt1 :il/ o!rs m]ely delime ! gra9 ) boric acid4 ,! la/ is really q suffici5t4 ,aga91 9 tann+ "o f9ds simil> div]g5ces ( me?od4 ,drum tann+ is practis$1 b tannage 9 pits by susp5sion is m usual1 ?\gh1 z ?is la/ involves m dilute liquors1 x involves also great] "t to tan4 ,9 drum tannages a few days only are suffici5t4 ,9 pit tann+ at lea/ a week is giv51 b sometimes up to a mon?1 accord+ to ! /r5g? ( ! f9al liquor & ! rate ( progress ( ! goods into /rong] liquors4 ,liquors conta9+ ov] #a p] c5t4 ( *romium may easily be sp5t out s z to conta9 only #j4ja p] c5t4 ,lab\r & "t are sav$ 9 pit tann+ by ! use ( rock]s4 ,! press sy/em ( avoid+ h&l+1 h[ev]1 s complicates ! analytical control t its advantage is d\btful1 a bett] way be+ to %ift ! liquors by an air ejector1 :i* may also be us$ z an agitator ( ! liquor & ?us aboli% ! ne$ = rock]s 7,=s>e pat5t74 ,*rome butts are tann$ out 9 susp5sion4 ,no floats or lay]s are us$4 ,! neutralization ne$ n be s ?or\gh z = light *rome upp]s1 z dye+ is n practis$ & tr\ble does n arise ) emulsions made f sulphonat$ oils4 ,?or\gh wa%+ is advisable1 & ! butts are usually !n cut into b5ds & may be oil$ be=e dry+ if desir$4 ,! b5ds are dri$ /ra9$1 to obta9 flatness & smoo? gra91 = no ma*9es1 su* z /rik]s & roll]s1 are usually employ$4 ,x is necess>y to dry v ?or\ghly1 = ! b5ds are wat]pro($ by dipp+ ! dry lea!r into molt5 waxes4 ,! mo/ commonly us$ wax & ! *eape/ is p>aff9 wax ) a m4p4 ( ab\t #abg ,f4 ,x is r a brittle wax1 h[ev]1 & z ! f9i%$ lea!r consi/s ( up to "o-?ird ( ! wax1 x is bett] to use at lea/ "s proportion ( h>d fat1 ,japan wax or c]es9 wax1 to obta9 a /uff+ mat]ial ) less cry/all9e texture4 ,! use ( #aj-cj p] c5t4 ros9 9 ! /uff+ grease is also usual4 ,?is prev5ts ! lea!r f be+ s slipp]y :5 9 we>4 ,! /uff+ %\ld take place at temp]atures f #aej-aie ,f41 accord+ to ! melt+-po9t ( ! grease employ$4 ,! b5ds are tak5 out & laid 9 pile to cool & set 9 a flat condition1 & are !n f9i%$4 ,! *rome tannage ( butts = /rapp+ & h>ness backs1 & = motor butts & pick+ b&s may be simil> to t = *rome sole1 b drum tannages are m common & ! two-ba? process is (t5 us$4 ,9 ! latt] case ! acid *rom+ ba? is pref]r$1 us+ #f p] c5t4 ( di*romate & ( acid1 ) up to #ae p] c5t4 ( salt1 & r$uc+ ) #ae p] c5t4 ?iosulphate & acid z ne$$4 ,?is process assi/s 9 ! production ( ! light col\r :i* is pref]r$ 9 ! case ( "s ( ^! lea!rs4 ,/rap butts aft] tann+ are v ?or\ghly wa%$ ) cold wat] 9 pits1 & repeat$ly /ruck out by ma*9e betwe5 ! wa%+s4 ,!y are !n oil$ ) heavy m9]al oil1 & /ret*$ by p[]ful ma*9es4 ,!y are dri$ & curri$ dur+ ! /ret*+4 ,degras1 wool fat & vasel9e are greases us$1 & ! dry+ & /ret*+ f9i%$ (f at #abj ,f4 ,!y are !n fluff$ on ! fle%1 ,fr5*-*alk$ & heavily roll$4 ,h>ness backs are neutraliz$1 ma*9e samm$1 & lightly fat liquor$ ) #d-a_/b p] c5t4 soap4 ,!y are !n /ruck & oil$ ) heavy m9]al oil & dri$ = /uff+4 ,h& /uff+1 drum /uff+1 & burn+ 9 are all us$ 7see ,"p ,i41 ,section ,,iv474 ,/e>91 p>aff9 wax1 c]es9 wax1 wool fat1 sod oil & m9]al oil are ! greases employ$4 ,! butts are black$ aft] /uff+ ) lamp black & oil1 glass$ well & buck-tall[$ on ! gra94 ,motor butts are fat liquor$ lightly1 us+ soap only4 ,!y h to be s(t5$1 !re=e1 dur+ ! dry+ by be+ me*anically work$4 ,a bo>d+ ma*9e is repeat$ly us$ dur+ ! dry+4 ,!y are f9i%$ (f ) ,fr5* *alk on fle% & gra94 ,pick+ b& butts are neutraliz$ by us+ w>m wat] & !n borax solution1 & are !n samm$ by ma*9e & v heavily fat liquor$ ) cod oil & tall[ & h>d soap1 to :i* degras may also be add$4 ,up to #bj p] c5t4 ( greases 7on ! pelt weight7 may be us$4 ,!y are well drumm$ 9 ?is1 /ruck out1 ,fr5* *alk$1 & dri$ out4 ,!y are s(t5$ f9ally by ma*9e4 ,wat]pro( *rome upp] lea!rs are manufactur$ usually f hides tann$ by ! two-ba? process1 :i* is said to give a mell[] lea!r4 ,! neutral type ( *rom+ ba? is common4 ,! butts are neutraliz$1 ma*9e samm$ & /ruck1 & !n fat liquor$ ) #b p] c5t4 ea* ( neatsfoot oil & s(t soap4 ,!y are !n samm$1 %av$ & black$ on ! gra9 ) logwood & iron1 & dri$ fur!r4 ,!y are /uff$ !n by bru%+ ) an abundant am\nt ( conc5trat$ fat liquor4 ,?is gives ! wat]pro(ness4 ,!y are /ak$ aft] dry+ fur!r1 & (t5 gra9$ ?ree ways4 ,a fur!r wat]pro( f9i% is giv5 consi/+ ( a fat liquor conta9+ beeswax4 ,!y are f9ally bru%$ & re-oil$ ) l9se$ oil1 to :i* "s m9]al oil may be add$4 ,?is lea!r is mu* ! mo/ durable type = a %oot+ boot1 or :]e wat]pro( upp]s are desirable4 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #aih4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bcd1 #cfh4 ,,"p ,,iv4--,,miscellane\s ,,tannages ,,section ,i4--,,alum ,,tannages ,! use ( alum = mak+ pelt into lea!r is sev]al c5turies old4 ,x 0 ! fir/ case ( :at are call$ m9]al tannages4 ,! tannage is closely analog\s 9 !ory to ! *rome tannages discuss$ 9 ,"p ,,iii41 & if soda be add$ to ord9>y pota% alum 9 solution1 a basic alum liquor is obta9$ :i* is q capable ( yield+ a satisfactory lea!r1 & :i* is ?us a /rict analogy ( ! basic *rome alum liquor describ$ 9 ,"p ,,iii41 ,section ,,ii4 ,! range ( basicity :i* is practicable is v limit$1 h[ev]1 & x is mu* m usual to use common salt ) ! alum in/ead ( soda4 ,! alum is1 ( c\rse1 hydrolyz$ & free sulphuric acid is quickly adsorb$1 :il/ ! colloidal solution ( alum9a is adsorb$ also b m sl[ly4 ,! adsorb$ acid t5ds to swell ! pelt & to cause x to take up ! alum9a less readily4 ,! function ( ! salt is to repress ! swell+ by a pickl+ action4 ,! actual result is ?us p>tly due to ! alum tannage & p>tly due to ! tempor>y tannage giv5 by ! pickle4 ,h5ce su* tannages are n firmly fix$1 nor is ! result wat]-resi/+1 = mu* ( ! tann+ mat]ial may be wa%$ out4 ,if1 h[ev]1 su* lea!rs be /or$ = a "t 9 a dry condition1 ! alum9a becomes mu* m firmly fix$1 ow+ probably to a fur!r dehydration ( ! alum9a gel deposit$ ^u ! fibres4 ,! tannage is ?us relatively m irrev]sible1 & su* /orage is practis$ 9 comm]ce = ?is purpose1 be+ kn[n z ! age+ ( ! lea!r4 ,x w be und]/ood t x is possible to use too great a proportion ( salt1 ! hygroscopic nature ( :i* w\ld keep ! lea!r moi/ & ?us int]f]e ) a glossy f9i%4 ,ab\t "o-?ird ! weight ( ! alum us$ is usually suffici5t4 ,all t has be5 said 9 ,"p ,,iii4 z to ! empty nature ( ! *rome tannage is equally applicable to ! alum tannages4 ,x is z necess>y !re=e to employ fill+ ag5ts4 ,a fat liquor is q satisfactory = _m purposes1 b is too d>k col\r$ & greasy = glove lea!r4 ,egg yolk is ! fav\rite emulsion 9 ^! cases4 ,x conta9s ab\t #cj p] c5t4 ( an oil v simil> to ole9 & 9 v p]fect emulsion4 ,olive oil is also l>gely ole9 & is also us$1 be+ emulsifi$ by ! egg yolk & effectively r$uc+ ! proportion requir$ ( ?is exp5sive mat]ial4 ,fl\r is also us$ z a fill+ ag5t4 ,x acts also z a :it5+ ag5t & z an emulsifi]4 ,its use enables ! tann] to obta9 ! requir$ fullness )\t s mu* greas9ess4 ,?us s(tness & fullness may be obta9$1 & yet a glossy f9i% be possible4 ,x w be cle> t ! m fl\r is us$1 ! m oil may also be us$4 ,! mat]ials m5tion$1 viz4 alum1 salt1 fl\r1 egg yolk & olive oil1 are all mix$ toge!r into a pa/e ) "s am\nt ( wat]4 ,! goods are drumm$ 9 ?is pa/e & !n dri$ out4 ,?is op]ation is kn[n z taw+4 ,! goods are !n ag$ = sev]al weeks & f9i%$ z requir$4 ,! manufacture ( glove kid f lambsk9s & kid sk9s is ! mo/ typical example ( alum tannage4 ,lambsk9s are unwooll$ v usually by pa9t+ ! fle% ) a mixture ( lime & sodium sulphide4 ,!re mu/ n be too mu* ( ! latt] on acc\nt ( its t5d5cy to give h>%ness1 a fatal defect 9 glove kid4 ,! addition ( calcium *loride is desirable1 & ! sk9s1 :i* %\ld be pull$ z soon z possible1 %\ld be quickly plac$ 9 s(t wat] or weak lime4 ,= kidsk9s a set ( lime liquors may be us$1 & 9 pref]5ce to sodium sulphide r$ ars5ic is employ$4 ,ab\t "o p] c5t4 realg> on ! weight ( ! lime is us$1 b m (t5 l>g] quantities are pref]r$1 ev5 up to #f p] c5t4 ,! lim+ is ?us %ort5$ to #d or #e days4 ,fre% lime liquors are sometimes us$ )\t any sulphides4 ,ano!r me?od is to place ! sk9s 9 a pa/e ( lime to :i* realg> has be5 add$ 9 slak+4 ,9 any me?od x is necess>y to saponify or emulsify ! grease on ! gra91 or difficulties occur 9 dye+ & f9i%+4 ,sk9s :i* are to be taw$ = glove kid are bo? pu]$ & dr5*$4 ,!y are heavily pu]$ at #gj ,f4 = #c h\rs1 or ev5 long] = ! heavi] sk9s4 ,aft] scudd+ !y are dr5*$ ) #aj p] c5t4 bran & "s pea meal at #ie ,f4 = a few h\rs only4 ,9 prep>+ ! taw+ pa/e1 ! fl\r %\ld be mix$ ) tepid wat]2 ! egg yolk %\ld also be dilut$ ) tepid wat] slightly1 & /ra9$ if necess>y1 & !n add$ to ! fl\r4 ,! oil is !n c>efully mix$ 94 ,! alum & salt are dissolv$ sep>ately at #aaj ,f4 & add$ to ! fl\r & oil4 ,! taw+ pa/e %\ld be us$ at ab\t #aje ,f4 ,= e hundr$ m$ium-siz$ lambsk9s !re w be requir$3 #aj lbs4 fl\r 9 #b-a_/b gallons wat]1 #a qu>t pres]v$ egg yolk1 #c-c_/d lbs4 alum & #a-a_/d lbs4 salt4 ,! sk9s are drumm$ 9 ?is = an h\r or s & dri$ out on poles rapidly1 b n ) great heat4 ,?is is ess5tial to get /ret*4 ,!y are next wet back1 /ak$1 dri$ & /ak$ aga94 ,!y are !n ag$4 ,to wet back = dye+ & f9i%+ ! sk9s are drawn ?r\gh w>m wat] & !n drumm$ 9 wat] at #ie ,f4 = #ae m9utes to wet ev5ly & ?or\ghly4 ,?is liquor1 :i* conta9s mu* ( ! taw+ mat]ial1 is run (f & replac$ by ! dye solution1 e4g4 fu/ic or turm]ic1 ) :i* ! goods are drumm$ = half an h\r4 ,iron1 *rome or copp] salts may be us$ = sadd5+4 ,aft] ?is bottom col\r is obta9$1 a coal t> col\r is add$ = topp+ & ! drumm+ cont9u$ until ! requir$ %ade is obta9$4 ,! excess liquor is n[ run (f1 & ! mat]ials lo/ 9 soak+ are replac$ by drumm+ fur!r ) egg yolk & salt = #ae m9utes4 ,?is is kn[n z re-egg+4 ,blacks are obta9$ ) logwood & iron4 ,aft] re-egg+1 ! sk9s are dri$ out & /ak$4 ,!y are season$ ) a weak emulsion ( soap & oil1 dri$1 oil$ lightly ) l9se$ oil1 iron$1 re-oil$ & f9ally bru%$4 ,:ites are undy$1 & #aj lbs4 ,fr5* *alk p] #ajj sk9s is us$ 9 re-egg+4 ,calf kid is a once popul> b n[ obsolete upp] lea!r made by taw+ calfsk9s4 ,! sk9s 7 well plump$ 9 limes1 delim$ by wa%+ & dr5*+1 taw$ mu* z = glove kid1 split1 dri$ out rapidly1 /ak$ & ag$4 ,!y 7 f9i%$ dull & black ) soap & wax4 ,! v>i\s :ite lea!rs us$ = belts1 laces1 :ip la%es1 aprons1 cov]s = /opp]$ bottles1 etc41 are v usually made ) an alum tannage4 ,alum1 salt & fl\r only are us$4 ,:it5+ is also mix$ 9 & acts z neutraliz+ ag5t z well z pigm5t dye4 ,wool rugs are manufactur$ f suitable %eepsk9s by an alum tannage4 ,!y are fir/ well clean$1 us+ soap on wool & fle%4 ,!y are next degreas$ by pa9t+ ) full]'s e>? pa/e & dry+4 ,!y are taw$ by pa9t+ ! fle% ) a /rong solution ( alum & salt1 or ev5 by rubb+ on ! solid salts4 ,!y are dri$ out1 ag$ & sort$ = suitable col\rs4 ,! dye+ is r difficult1 z _m artificial dye/uffs are ( no use4 ,x is usual to blea* ! sk9s fir/ 9 a weak solution ( blea*+ p[d]1 & aft]w>ds to dye ) infusions ( ! dyewoods1 e4g4 logwood1 fu/ic1 s&alwood1 t]ra japonica1 qu]citron b>k1 turm]ic1 indigo1 etc4 ,vat dye+ is usual4 ,aft] dye+1 retann+ ) alum & salt is necess>y1 on acc\nt ( ! loss ( ^! 9 blea*+ & dye+4 ,rugs are usually f9i%$ black1 :ite1 grey1 br[n1 walnut1 crimson1 blue or gre54 ,,ref]5ces4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 pp4 #ahd1 #bcf4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bci1 #cga4 ,,section ,,ii4--,,fat ,,tannages ,= ! manufacture ( a p]man5t lea!r ! ess5tial requirem5ts are t ! fibres ( ! hide or sk9s gel %\ld be dri$ 9 a sep>ate condition1 & t !y %\ld be coat$ by "s wat]pro( or insoluble mat]ial4 ,_m sub/ances fulfil ! fir/ b n ! second ( ^! conditions4 ,= example1 ! dehydration only may be accompli%$ m or less by salt 7z 9 cur+ hides71 /ill bett] by salt if a little m9]al acid be us$ 7z 9 pickl+71 & by o!r salts su* z potassium c>bonate & ammonium sulphate1 & dehydrat+ ag5ts su* z alcohol4 ,su* tempor>y lea!rs1 h[ev]1 are n wat]-resi/+1 z ! second requirem5t has n be5 fulfill$1 viz4 ! coat+ ( ! fibres ) "s m or less wat]pro( mat]ial4 ,?us if pelts dehydrat$ ) alcohol be treat$ ) an alcoholic solution ( /e>ic acid1 ! second condition is fulfill$ & a p]man5t lea!r is obta9$4 ,n[1 _m tann+ ag5ts accompli% ^! two requirem5ts only imp]fectly4 ,z we h not$ 9 ! prec$+ section1 ! alum-tann$ lea!rs are n v wat] resi/+1 & mu* ( ! tannage w wa% out4 ,lea!rs made by ! vegetable tannages usually conta9 "s excess ( vegetable tann+ matt]s :i* are soluble 9 & remov$ by wat]1 ?\gh mu* tann9 c no long] be ?us remov$1 ow+ to ! mutual precipitation ( ! oppositely *>g$ tann9 sol & hide gel4 ,! necessity = fulfill+ ! second requirem5t m5tion$ is "o reason = ! practice ( foll[+ ^! tannages by applications ( oil1 fat or ( bo?4 ,9 ?is way ! isolat$ fibres are n only dri$ sep>ately1 b are coat$ ) a typical wat]-resi/+ mat]ial4 ,9 ! fat tannages an attempt is made to fulfil ?is second requirem5t )\t ! use ( any specific tann+ ag5t = produc+ ! fir/ requirem5ts2 i4e4 an attempt is made to dry ! fibres sep>ately 9 an untann$ condition1 & to coat !m simultane\sly ) fat s t a p]man5t lea!r is obta9$4 ,x is only possible to d ?is1 if ! pelt is con/antly dur+ dry+ subject$ to me*anical work+1 e4g4 by twi/+1 fold+1 b5d+1 drumm+1 /ak+1 etc4 ,! result+ lea!r is (t5 call$ ra:ide lea!r1 & pres5ts a real advantage ov] o!r lea!rs 9 its great t5sile /r5g?4 ,:]e t\ghness is an ess5tial quality1 !re is mu* to be said = ! fat tannages4 ,x is also possible1 ( c\rse1 to effect compromises betwe5 ord9>y tannages & ! /raight fat tannages2 ?us pick+ b& butts1 :i* mu/ be t\gh1 are (t5 v lightly tann$ ) oak b>k or *rome1 & !n giv5 :at is practically a heavy fat tannage4 ,9 ! mo/ typical ( fat tannages1 moreov]1 x is (t5 common to col\r ! goods by a brief imm]sion 9 a weak vegetable tan liquor4 ,fur!r1 ! employm5t ( fats 9 ! curry+ ( dress+ lea!r is 9 effect a fat tannage sup]impos$ ^u ! vegetable tannage4 7,see ,comb9ation ,tannages1 ,section ,,vi47 ,! fat tannage is und\bt$ly "o ( ! e>lie/ me?ods = mak+ lea!r4 ,prehi/oric man discov]$ t ! sk9s ( animals kill$ 9 hunt+ c\ld1 by alt]nately rubb+ ) fats & !n dry+ slightly1 be ev5tually conv]t$ into a useful lea!r1 :]eas )\t ! fat x 0 /iff & horny4 ,ev5 yet simil> me?ods are 9 use1 ?ongs ( raw hide be+ cont9ually twi/$ dur+ dry+1 ) int]mitt5t application ( fats4 ,9 ! mod]n fat tannages drums are us$ to give ! necess>y me*anical work+ to ! goods4 ,! raw hide lea!r produc$ 9 ! ,u4,s4,a4 is made by drumm+ ! ne>ly delim$ goods ) tall[ & neatsfoot oil4 ,9 ?is c\ntry ! fat tannages h be5 typifi$ by ! ,cr[n & ,helvetia lea!rs4 ,! hides are ?or\ghly lim$ 9 mell[ limes1 & aft] ! beam "w are delim$ by dr5*+1 scudd$1 & sometimes fle%$ aga91 & !n col\r$ (f 9 tan liquor4 ,aft] p>tial dry+1 !y are drumm$ w>m = "s h\rs to ensure isolation ( ! fibres4 ,aft] fur!r dry+ !y are coat$ ) ! tann+ pa/e1 :i* consi/s ess5tially ( s(t fats & fl\r to produce p>tial emulsification4 ,equal p>ts ( s(t fats & ( fl\r may be us$1 to :i* may be add$ small] proportions ( degras1 cod oil1 mutton tall[1 salt1 toge!r ) ab\t #be p] c5t4 wat]4 ,! goods are coat$ ) ?is mixture1 drumm$1 & dri$ fur!r1 & ?is r\t9e repeat$ z (t5 z necess>y to fill ! int]/ices ?or\ghly ) fat4 ,! temp]ature 9 ! drum may rea* #ie ,f4 ,9 f9i%+ an attempt is made to /uff fur!r ) grease4 ,! goods are ?or\ghly set out1 dri$ a little1 & coat$ aga91 fle% & gra91 ) a mixture ( tall[1 cod oil1 glyc]9e & degras1 & dri$ fur!r4 ,! excess grease is slick$ (f & ! goods aga9 set out & gra9$4 ,!y are !n dri$ out4 ,,ref]5ces4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bde1 #bdf & #cgf4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #cgh4 ,,section ,,iii4--,,oil ,,tannages ,!re are v obvi\s analogies betwe5 ! fat tannages discuss$ 9 ,section ,,ii4 & ! oil tannages n[ to be dealt )1 b !re is nev]!less a di/9ct dep>ture 9 pr9ciple involv$4 ,9 ! oil tannages ! me*anical treatm5t is g5]ally m vigor\s1 & ! dry+ process is conduct$ at a mu* high] temp]ature1 ) ! result t !re is a vigor\s oxidation ( ! oil4 ,?is results 9 ! =mation ( insoluble oxidation products :i* coat ! fibre & play an ess5tial "p 9 ! production ( a p]man5t lea!r4 ,pung5t vap\rs are evolv$ 9 ! dry+ op]ations1 among/ :i* is acrole9 & probably also o!r aldehydes1 & x is ?\ght by ,proct] t ^! aldehydes also are ess5tial tann+ ag5ts & typical ( ! process 7cf4 ,section ,,iv474 ,fahrion consid]s t ! tann+ action is due solely to unsaturat$ fatty acids ) m ?an "o d\ble l9kage4 ,g>elli & ,apo/olo1 h[ev]1 believe t ! tannage is due to a coat+ ( fatty acid :e!r saturat$ or n4 ,^! obs]v]s made lea!r ) /e>ic & palmatic acids 9 colloidal aque\s solution4 ,! manufacture ( *amois lea!r f ! fle% splits ( %eepsk9s comprises ! l>ge/ & mo/ typical bran* ( ! oil tannages4 ,! %eep pelts are split 9 ! lim$ /ate1 & ! fle%es are giv5 ano!r %>p lim+ :i* may la/ up to a =tnight4 ,!y are next friz$1 i4e4 scrap$ ov] ! beam ) a %>p two-h&l$ knife1 to remove r\ghness & loose fat4 ,! goods are next ?or\ghly wa%$ 9 runn+ wat] & dr5*$4 ,a paddle dr5* is (t5 pref]r$1 & if n us$ ! h&l+ %\ld be frequ5t4 ,paddl+ dr5*+ r$uces ! "t requir$ f ab\t #af h\rs to ab\t #f h\rs4 ,an h\r or m 9 a hydraulic press removes sup]flu\s liquor & "s m grease4 ,! fle%es are sep>at$1 cool$ & !n /ock$ = #cj m9utes to equalize ! moi/ure 9 !m4 ,aft] remov+ f ! /ocks !y are spr9kl$ on bo? sides ) cod oil & ?r[n back into ! /ocks = a few h\rs4 ,!y are !n dri$ cold = a day or two4 ,! /ocks us$ are simil> to ^? once popul> = s(t5+ dri$ hides dur+ soak+1 & consi/ ( two heavy hamm]s :i* fall alt]nately ^u ! goods :i* are conta9$ 9 a curv$ box bel[4 ,! result is a me*anical knead+ action4 ,! fle%es are aga9 spr9kl$ ) cod oil1 re/ock$ = a few h\rs & dri$ aga91 ?is "t at #ajj ,f4 ,!y are !n repeat$ly spr9kl$1 /ock$ & dri$1 ! la/ op]ation be+ conduct$ always at an increas+ temp]ature until f9ally ! f9al heat] is ev5 up to #afj ,f4 ,z ! op]ation proce$s x is advantage\s to hang ! splits also ne>] "o ano!r1 & 9 ! f9al heat] !y are q close4 ,! next /age is to pack ! goods quickly into suitable boxes & all[ !m to heat1 i4e4 to oxidize fur!r4 ,?is is a r critical /age 9 ! process1 & to prev5t ov]heat+ 7burns7 x is (t5 necess>y to op5 out & repack into ano!r box1 ) possibly "s little int]m$iate cool+4 ,!y are turn$ ov] ?us repeat$ly until ! oxidation is complete1 & !n spread out to cool4 ,! fle%es are n[ a d>k br[n col\r1 & are next treat$ to remove excess ( oxidiz$ oil products4 ,! goods are dipp$ ?r\gh wat] at #aaj ,f4 & !n subject$ to hydraulic pressure4 ,! grease & wat] :i* exude are all[$ to sep>ate by settl+1 & ! ?ick yell[ oil s obta9$1 kn[n z degras1 =ms a valuable mat]ial = lea!r dress+1 z x m readily emulsifies ) wat] ?an _m oils1 & imp>t ?is quality to o!r greases mix$ ) x4 ,a fur!r quantity ( a simil> oil is obta9$ by paddl+ ! goods ) a weak soda solution4 ,! liquor obta9$ is treat$ ) sulphuric acid to neutralize ! alkali1 & ! grease recov]$ is kn[n z sod oil4 ,! fle%es are n[ well wa%$ ) hot wat] 7#adj ,f471 fat liquor$ ) cod oil & s(t soap1 ma*9e samm$1 ei!r by a wr+] or a c5trifuge1 & !n dri$ out4 ,mu* *amois lea!r is also made 9 ,france by closely simil> me?ods4 ,! sk9s are usually oil$ on tables & fold$ up be=e /ock+4 ,o!r m>9e oils 7seal1 :ale1 etc47 replace cod oil4 ,g5]ally speak+ ! oxidation is m mod]ate1 & ! grease f ! hydraulic press 7moellon7 is mix$ ) o!r fi% oils to =m comm]cial degras4 ,an inf]ior quality ( degras is obta9$ by subsequ5t treatm5t ) soda4 ,! cru/ *amois obta9$ z above has only to be ?or\ghly /ak$ to s(t51 gr\nd$ & fluff$ to raise ! nap1 & !n trimm$1 & ! ord9>y wa%-lea!r is obta9$4 ,if int5d$ = glove lea!rs sup]ior sk9s are select$4 ,^! are fluff$ c>efully ^u em]y :eels1 us+ fir/ a co>se surface & ev5tually a f9e surface s t a f9e velvet effect is atta9$4 ,! sk9s are next blea*$4 ,9 ! sun blea* or grass blea* ! goods are soak$ 9 a #a-a_/b p] c5t4 s(t soap solution & expos$ to sunlight aft] be+ wrung4 ,!y are blea*$ 9 ab\t #c days 9 summ]1 b ne>ly a =tnight may be necess>y 9 w9t]4 ,9 ! p]manganate blea*1 :i* is less t$i\s1 ! sk9s are fir/ degreas$ by soak+ 9 a w>m #c_/d p] c5t4 solution ( soda cry/als & !n drumm+ = #cj m9utes 9 wat] at #ie ,f4 ,!y are !n paddl$ 9 a #a_/h p] c5t4 solution ( comm]cial p]manganate = an h\r at ! same temp]ature1 r9s$ ?r\gh wat]1 & ! br[n manganese dioxide is !n remov$ by paddl+ or drumm+ ! goods 9 a #c p] c5t4 solution ( sodium bisulphite to :i* hydro*loric acid is add$ z requir$4 ,! goods are well wa%$ 9 w>m wat]1 & are !n tuck$1 i4e4 plac$ 9 a vat ( boil+ wat] conta9+ a little s(t soap1 j = a few seconds4 ,! goods %r9k & curl up1 & !y are !n dri$ out at #abj-adj ,f4 to fix ! tuck4 ,!y are !n /ak$1 fluff$1 & dy$4 ,9 dye+ ) coal t> col\rs ! aliz>9 col\rs may be us$ aft] mordant+ ) *rome alum4 ,direct dyes1 natural dye/uffs & pigm5t dyes are also us$4 ,! goods are /ruck out aft] dye+1 lightly fat liquor$ ) comm]cial egg yolk1 dri$ out at #aaj to #abj ,f41 /ak$ & fluff$ on ! face side4 ,buff lea!r is a simil> lea!r made f hides4 ,!y are lim$ mell[ = a =tnight1 unhair$1 fle%$1 & !n lim$ aga9 = ano!r week 9 %>p limes4 ,! gra9 is !n split (f1 & ! goods r9s$ & scudd$1 slightly delim$ & hung up to dry4 ,!y are !n treat$ 9 mu* ! same way z fle%es = *amois1 b lime is (t5 add$ to ! cod oil us$ 9 /ock+4 ,buck lea!r is a simil> product obta9$ f de]sk9s1 b mu* mock buck is made f *eap] raw mat]ial4 ,,ref]5ces4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bdg-bej & #cgf-cgi4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #cgh4 ,,section ,,iv4--,,=maldehyde ,,tannage ,! use ( =mal9 = h>d5+ gelat9 has long be5 kn[n1 b x 0 left = ,payne & ,pullman to devise a comm]cial process = tann+ pelt into lea!r by means ( =maldehyde 7,h,,*o7 solutions4 ,_! process1 :i* 0 pat5t$1 specifi$ ! use ( alkalies 9 conjunction ) =maldehyde or o!r aldehydes4 ,! function ( ! alkalies is n v obvi\s1 = x has be5 %[n t =maldehyde w tan also 9 neutral & 9 acid solution4 ,! precise action ( ! aldehydes is also z yet some:at obscure1 b x is notewor?y t v small proportions ( =mal9 w give a complete tannage4 ,x is probable t ! action ( =maldehyde is n p]fectly analog\s ) t ( its homologues1 = x is a mo/ reactive sub/ance1 & w c]ta9ly ) proteids und]go reactions :i* are n analog\s to ^? ) o!r aldehydes4 ,! lea!r obta9$ by tann+ ) =mal9 is q :ite & resembles buff lea!r1 b has advantages ov] ! latt] 9 t no blea*+ is necess>y4 ,accord+ to ! pat5t specifications ! pelt %\ld be drumm$ 9 wat] & ! tann+ liquor--a solution ( =mal9 & sodium c>bonate--add$ gradually at #ae-m9ute int]vals4 ,up to #f h\rs = light sk9s1 & up to #dh h\rs = heavy hides1 are requir$ = complete tannage4 ,! temp]ature is rais$ dur+ ! process f #ajj to #aah ,f4 ,! tann+ liquor may be made f #af lbs4 ( comm]cial =mal9 7#cf p] c5t4 =maldehyde7 & #cb lbs4 soda 7#hj p] c5t4 ,na#b;,,co#c7 9 #aj-ae gallons ( wat]4 ,?is %\ld be add$1 "o gallon at a "t1 to #d cwt4 pelt 9 #ajj-abj gallons ( wat]4 ,aft] tannage is complete ! goods %\ld be paddl$ ) a #a-a_/b p] c5t4 solution ( ammonium sulphate to remove ! soda1 & n\ri%$ 9 a solution ( s(t soap & salt1 ab\t #b-a_/d p] c5t4 ( ea* on ! weight ( pelt4 ,! goods are !n dri$ out1 & may be f9i%$ l *amois1 buff1 & buck lea!rs 7,section ,,iii474 ,,ref]5ces4 ,payne & ,pullman1 ,engli% ,pat5t #ahih1 #bhgb4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bej & #cgi4 ,,section ,v4--,,syn!tic ,,tann+ ,,mat]ials ,9 spite ( mu* valuable "w on ! con/itution ( ! vegetable tann9s & ! comp\nds usually associat$ ) !m1 su* z t ( ,e4 ,fis*]1 ,k4 ,freud5b]g & _! collaborators on gallo-tannic acid1 & t ( ,a4 ,g4 ,p]k9 on ellagic acid & cate*91 we are /ill 9 ! d>k ) respect to ! con/itution ( ! tann9s :i* are ( comm]cial importance1 & any syn!tic production ( ^! mat]ials is ?us out ( ! "q z yet4 ,attempts1 h[ev]1 h be5 made to produce artificially sub/ances :i* possess simil> prop]ties to ! tann9s & :i* may be us$ = conv]t+ pelt into lea!r4 ,into ?is category fall "s ( ! e>li] attempts to syn!size gallo-tannic acid by heat+ gallic acid ) cond5s+ reag5ts4 ,! fir/ comm]cial success 9 ?is direction 0 atta9$ by ,/iasny1 :o produc$ cond5sation products ( ! ph5olsulphonic acids1 to :i* products he gave ! g5]al "n ( syntans 7syn!tic tann9s74 ,! ,badis*e ,co4 plac$ "o ( ^! products on ! m>ket z ,n]adol ,d1 & lat] took out subsidi>y pat5ts = ! manufacture ( simil> products by slightly diff]+ me?ods ( productions4 ,s9ce ! outbreak ( ! ,european ,w> su* pat5t rights h be5 susp5d$1 & sev]al ,briti% firms h be5 manufactur+ syn!tic tann+ mat]ials by simil> me?ods1 b d\btless ) developm5ts & improvem5ts ( _! own discov]y4 ,^! products 7e4g4 ,cresyntan1 ,maxyntan1 ,p>adol1 ,syntan1 etc47 are n[ 9 use 9 _m factories1 & assi/ r ?an sub/itute ! vegetable tann9s 9 produc+ lea!r ( ! desir$ col\r & quality4 ,^! syn!tic tann+ mat]ials resemble ! vegetable tann9s 9 ! foll[+ respects4 ,!y are organic acids conta9+ ph5olic gr\ps4 ,!y are semi-colloidal1 pass+ sl[ly ?r\gh semip]meable membranes4 ,!y precipitate gelat91 basic dye/uffs & lead acetate1 give a violet-blue col\r ) f]ric salts1 & conv]t hide into an und\bt$ lea!r4 ,!y diff] f ! vegetable tann9s 9 t !y conta9 sulphur & sulphonic acid gr\ps1 b !y agree 9 t bo? are aromatic d]ivatives4 ,9 ea* case ! tann+ effect is dim9i%$ by alkalies1 b ! syn!tic mat]ials are ! m s5sitive4 ,me?ods ( ,manufacture4--,!re are1 broadly speak+1 ?ree types ( me?od by :i* ^! cond5sation products are produc$1 viz41 cond5sation by =maldehyde1 cond5sation by phosphorus tri*loride or simil> reag5ts1 & cond5sation by heat alone4 ,illu/rative me?ods w n[ be giv54 ,cond5sation by =maldehyde 0 ! fir/ me?od us$4 ,! proc$ure is giv5 by ! ,au/rian pat5t #eh1dje4 ,a ph5ol1 e4g4 crude cresylic acid1 is heat$ ) ! equival5t am\nt ( sulphuric acid = a few h\rs to #ajj-baj ,c41 cool$1 & =maldehyde add$ sl[ly :il/ cool+ & /irr+1 9 ! proportion ( "o molecule ( =maldehyde to #b molecules ( ph5ol4 ,! free m9]al acid is neutraliz$1 & ! result+ product is ! syntan ,n]adol4 ,by ?is proc$ure only wat]-soluble products are obta9$1 b an alt]native process is to heat ! ph5ols 9 slightly acid solution1 & !n to r5d] soluble ! res9\s products obta9$ by treat+ ) sulphuric acid4 ,! proportion ( =maldehyde to ph5ol us$ l$ ,/easny to conclude t ! result+ products 7 diph5yl-me?ane d]ivatives :i* polym]ize to =m molecules ( consid]able size4 ,! =maldehyde supplies ! c>bon bridge4 ,?is view 0 criticiz$ by ,a4 ,g4 ,gre5 z too simple1 & he sugge/$ ! alt]native !ory t polym]ization does n take place at all1 b t m advanc$ or high] cond5sation products are =m$2 he ?\ght t o-hydroxy-b5zyl alcohols 7 fir/ produc$1 t ^! cond5s$ ) ano!r molecule1 & aft]w>ds ! process 0 repeat$4 ,! result 0 a col\rless dye/uff4 ,?is view receives "s support f ! o!r types ( me?od ( manufacture4 ,) ! use ( o!r cond5s+ reag5ts ! proc$ure may be z 9 ! process ( ! ,b4,a4,s4,f4 7,fr4 pat4 #dea1hge-f71 ?us3 #bbe p>ts ( o-cresol-sulphonic acid are heat$ to #fj ,c4 = #d h\rs ) #bfb4e p>ts ( phosphorus oxy*loride4 ,! excess ( oxy*loride is remov$ by di/illation "u r$uc$ pressure & ! residue wa%$ ) dilute hydro*loric acid4 ,cond5sation by heat alone is illu/rat$ by ! me?od giv5 9 ! same pat5ts1 ?us3 ph5ol-p-sulphonic acid is heat$ to #acj ,c4 = #bd h\rs "u a pressure ( #bj mm4 or 9 a curr5t ( dry air at atmosph]ic pressure4 ,! product may be us$ direct or may be purifi$ by dissolv+ 9 wat]1 neutraliz+ ) cau/ic soda1 filt]+ & evaporat+ to dryness4 ,a :ite p[d] is obta9$ :i* tans :5 its solution is acidifi$4 ,an alt]native is to mix ph5ol ) sulphuric acid & heat ! mixture to #adj ,c4 = #gb h\rs "u #bj mm4 pressure & purify z be=e4 ,me?ods ( ,use4--,! syn!tic tann+ mat]ials may be put to _m uses4 ,:5 well manufactur$ !y make practically a :ite lea!r1 & ?is fact makes a valuable op5+ = _! use 9 connection ) light lea!r tannages & ! dress+ ( rugs4 ,x is also claim$ t !y improve ! col\r usually obta9$ 9 ! ord9>y vegetable tannages4 ,if us$ 9 ! susp5d]s to ! ext5t ( #e-aj p] c5t4 !y are said to bright5 ! col\r ?r\gh\t ! tannage4 ,if us$ 9 blea*+ & f9i%+ !y are said to light5 ! col\r ( ! f9i%$ lea!r4 ,ab\t #e p] c5t4 on ! weight ( ! goods may be add$ to ! blea* or vat liquors2 !y may be also mix$ ) sumac dur+ f9i%+1 & 9 effect act z a sumac sub/itute2 solutions are also bru%$ ov] ! gra9 be=e oil+1 ) a view to obta9+ good col\r4 ,x is also claim$ t _! use prev5ts vegetable-tann$ lea!r f becom+ r$ "u ! action ( sunlight4 ,! syntans are also us$ to light5 ! col\r ( *rome lea!r1 ev5 ( *rome sole lea!r aft] x has be5 dipp$4 ,x is claim$ also t syntans produce a t\gh lea!r1 & if us$ = heavy lea!r 9 ! e>ly /ages !y give a t\gh gra9 & assi/ 9 avoid+ a cracky gra94 ,on ?is acc\nt !y are also recomm5d$ = retann+ ,e4,i4 tann$ kips4 ,:5 us$ 9 heavy lea!r susp5d]s !y are said to get rid ( lime bla/ 7,ca,c,o#c7 & to quick5 ! tannage1 i4e4 to enable ! same weight to be obta9$ 9 less "t4 ,proct] sugge/s t a tannage ( comm]cial value might be obta9$ by bl5d+ !m ) wood pulp extract4 ,if us$ alone = tann+ a s]ies ( pits conta9+ liquors ( #d to #cg ,bkr4 may be us$1 b drum tannages may be giv5 us+ liquors ( #ad-bi ,bkr41 ! goods be+ tann$ 9 #f-h h\rs4 ,ab\t #cj p] c5t4 ( syntans are said to be necess>y = complete tannage4 ,,ref]5ces4 ,e4 ,/iasny1 ,a ,new ,syn!tic ,tann91 ,collegium1 #aiac1 #adb-ade4 7,see also ,j4,s4,c4,i41 ,abs4 #aiac1 #ejj47 ,e4 ,/iasny1 ,syntans--,new ,artificial ,tann+ ,mat]ials1 ,j4,s4,c4,i41 #aiac1 #gge4 ,pat5ts3--,au/rian #eh1dje4 ,g]man #bfb1eeh1 ,sept4 #ab1 #aiaa4 ,fr5* #dea1hge1 ,dec4 #ac1 #aiab2 #dea1hgf1 ,dec4 #ac1 #aiab2 #dea1hgg1 ,dec4 #ac1 #aiab4 ,,section ,,vi4--,,comb9ation ,,tannages ,! =mation ( lea!r be+ due to ! adsorption ( colloidog5ic sub/ances at ! int]face ( ! tann+ liquor & ! hide gel1 !re is ! obvi\s possibility t sev]al su* sub/ances may be us$ simultane\sly1 & t ! result+ lea!r may be due to ! comb9$ effect ( ^! sub/ances4 ,inde$1 ! av]age vegetable tannage consi/s ( su* a comb9ation tannage1 ea* tann+ mat]ial contribut+ its own individual tann9 & *>act]i/ic a/r+5t non-tann9s4 ,!re is evid5tly also ! possibility t ! diff]5t types ( tannage discuss$ above might be us$ ei!r simultane\sly or successively1 & t a lea!r might be obta9$ :i* comb9es to "s ext5t ! qualities ( ea* ( ! types 9 comb9ation4 ,x is su* a case t is g5]ally call$ a comb9ation tannage4 ,!re are _m conceivable comb9ations1 & 9 ?is section w be *iefly discuss$ a few :i* h demon/rat$ "s comm]cial possibilities4 ,"s ( ^! h already receiv$ notice 9 ! prec$+ sections4 ,! manufacture ( curri$ dress+ lea!rs is a comb9ation ( vegetable & fat tannages4 ,! manufacture ( wat]pro( *rome upp]s illu/rates a comb9ation ( *rome & fat tannages4 ,! use ( syntans 9 conjunction ) vegetable tann+ mat]ials is also a comb9ation tannage4 ,! case ( *amois lea!r is possibly a comb9ation ( aldehyde tannage ) fatty acid tannage4 ,two-ba? *rome lea!r is a comb9ation ( *rome1 sulphur & fat tannage4 ,=maldehyde & vegetable tannage is also a kn[n possibility4 ,x is cle> t !re are possibilities ( endless complexity1 & t :at normally may appe> z a simple tannage is 9 reality a v complex comb9ation tannage4 ,f ?is /&po9t "o might in/ructively consid] ! successive adsorptions involv$ 9 a goatsk9 tann$ fir/ ) syntans1 !n ) oak b>k1 retann$ 9 sumac1 mordant$ ) *rome1 dy$ ) coal-t> dye/uffs & f9ally oil$ ) l9se$ oil4 ,x w be easily se5 t 9 a v /rict s5se ne>ly all tannages are comb9ations4 ,usually1 h[ev]1 ! t]m comb9ation tannage is conf9$ to ^? cases :]e ! ma9 tann+ ag5ts n only diff] 9 type1 b :]e none are 9 pr$om9ant quantity4 ,a typical case is t ( semi*rome lea!r1 9 :i* a vegetable tannage is succe$$ by a *rome tannage4 ,e4,i4 tann$ %eep & goat sk9s are r heavily /ripp$ ( _! vegetable tannage & heavy oil+1 by drumm+ ) w>m soda solutions1 & aft] wa%+ ) wat] are *rom$ ) ! "o-ba? process2 !y are neutraliz$1 dy$1 fat liquor$ & f9i%$ = glac upp] lea!r4 ,9 a precisely simil> way kips & split hides :i* h receiv$ vegetable tannage are /ripp$ & retann$ 9 *rome & f9i%$ z = box calf1 ( :i* !y are a good imitation4 ,su* vegetable-*rome comb9ation tannages possess _m ( ! prop]ties ( *rome lea!r4 ,to *rome ! pelt fir/ & aft]w>ds to subject x to vegetable tannage is also an obvi\s possibility1 b has n yet be5 made a comm]cial success 9 ?is c\ntry1 b has be5 increas+ly us$ 9 ! ,u4,s4,a4 dur+ ! ,w>4 ,ano!r typical case ( comb9ation tannage is ! dongola lea!r produc$ by ! use ( gambi] & ( alum & salt4 ,?is is a vegetable-alum comb9ation1 & yields a good quality lea!r = light upp]s1 gloves1 etc4 ,goatsk9s = glaz$ dongola are paddl$ tann$ 9 gambi] liquors1 & alum & salt are subsequ5tly add$4 ,!y are tann$ 9 #bd h\rs1 well wa%$1 & are fat liquor$ )\t age+4 ,! ,e4,i4 tann$ sk9s may also be /ripp$ ) soda1 & retann$ 9 alum & salt1 us+ fl\r also if desir$4 ,dull dongola are fir/ taw$ & !n retann$ 9 gambi] liquor4 ,sude & velvet calf are also taw$ & retann$ ) gambi]4 ,yet ano!r case ( comb9ation tannage is t ( %eepsk9s = glac upp]s1 :i* are fir/ taw$ ?or\ghly ) alum1 salt & fl\r & dri$ out = sort+1 & are !n retann$ 9 *rome by ! "o-ba? process1 & f9i%$ z usual4 ,closely relat$ to ?is is ! me?od ( pickl+ 9 alum & salt & !n *rome tann+4 ,ano!r case is ! comb9$ "o-ba?1 two-ba? me?od ( *rome tann+4 ,! goods are *rom$ by a "o-ba? liquor conta9+ di*romate 7say #b p] c5t471 & !n pass into a r$uc+ ba?4 ,!re is n mu* advantage 9 su* proc$ure1 h[ev]4 ,f a /rictly comm]cial po9t ( view ! dongola & semi*rome lea!rs h prov$ ! mo/ successful comb9ation tannages1 b !re seem to be possibilities 9 comb9ations ( ! vegetable tann9s ) syn!tic tann+ mat]ials4 ,_m o!r sub/ances are kn[n to tan1 e4g4 iron salts1 c]ium salts1 sulphur1 qu9ones1 fatty acids1 ! halog5s1 etc41 etc42 h5ce !re is always ! possibility t new useful comb9ation tannages may be discov]$4 ,,ref]5ces4 ,b5nett1 ,manufacture ( ,lea!r1 pp4 #bdc1 #cgd-e4 ,proct]1 ,pr9ciples ( ,lea!r ,manufacture1 p4 #bcf4 ,,section ,,vii4--,,! ,,evolution ,,( ,,! ,,lea!r ,,indu/ry ,! lea!r trades are among/ ! olde/ ( all indu/ries1 b _! evolution has be5 mu* m rapid dur+ ! la/ two or ?ree decades ?an at any o!r p]iod ( _! hi/ory4 ,! ,european ,w>1 moreov]1 has caus$ ! comm5cem5t ( ano!r p]iod ( rapid developm5t1 & x is ! aim ( ?is section to po9t out "s ( ! pr9cipal l9es ( *ange :i* h already become app>5t4 ,_m ( ^! l9es ( evolution 9 ! me?ods ( manufacture h be5 previ\sly discuss$ 9 _! appropriate sections4 ,!y may all be summ>iz$ z attempts at m economical production4 ,prom95t among/ !m is ! p]si/5t ef=t to atta9 quick] processes4 ,dur+ ! la/ tw5ty-five ye>s ! "t necess>y to produce ! heavy lea!rs has be5 r$uc$ f #ab mon?s to z _m weeks4 ,! t5d5cy is to r$uce ! "t fur!r /ill1 b ?is is ( c\rse increas+ly difficult to accompli%4 ,on ! o!r h&1 x is m urg5t to /rive 9 ?is direction ?an ev]1 because a ne$less week involves m capital ly+ idle ?an ev] be=e4 ,moreov]1 z mo/ lea!r factories are n[ l>ge works1 a sav+ ev5 ( #bd h\rs has become a s]i\s item 9 economic production4 ,h5ce 9 lim+1 bat+1 tann+1 dry+ & 9 w>eh\s+ !re are increas$ ef=ts to make a quick] turnov]4 ,a good illu/ration ( ?is spe$+ up 9 mod]n tann]ies is ! adoption by all l>ge factories ( mu* m rapid me?ods ( extract+ tann94 ,on ! old press-lea* sy/em liquors may be p]colat+ ?r\gh ! mat]ial = possibly a =tnight4 ,! extract manufactur] r$uces ?is op]ation to ab\t two days4 ,/eam g5]at$ f ! sp5t b>k is us$ to heat ! extract+ vats1 & to "w a vacuum pan or evaporator :]eby m wat] c be us$ & a m complete z well z a m rapid extraction obta9$4 ,! evaporator also makes easy ! prep>ation ( ! /rong liquors us$ 9 mod]n tann+4 ,h&-9-h& ) quick] production & manipulation are ! attempts to obta9 a l>g] turnov]4 ,x is realiz$ t ! big bus9ess atta9s *eap production4 ,ev5 be=e ! w> ! small] factories 7 disappe>+4 ,a small tann]y mu/ n[ ei!r ext5d or close d[n4 ,?is has be5 bett] realiz$ 9 ! heavy ?an 9 ! light lea!r trades4 ,9 ! sole lea!r tann]ies v (t5 _m ?\s& hides p] week are put into "w1 b 9 ! glac kid factories !re is no?+ yet to correspond to ! output ( ,am]ican glac factories1 :i* sometimes rea*es ?ree or f\r ?\s& doz5 a day4 ,ano!r v prom95t feature ( factory evolution is ! increas$ use ( lab\r-sav+ ma*9]y4 ,?is practice has be5 9 op]ation = a consid]able "t1 b ) m>k$ accel]ation dur+ ! la/ few ye>s ow+ to ! lab\r %ortage occasion$ by milit>y s]vice4 ,?is developm5t ( ma*9e "w has l>gely disp5s$ ) t lab\r :i* involv$ any skill or tra9+4 ,! j\rneyman curri] is n[ practically ext9ct4 ,9 ! beam h\se1 too1 fle%+1 unhair+ & scudd+ are rapidly becom+ ma*9e in/ead ( h& op]ations4 ,_m devices are n[ be+ adopt$ also :i* r$uce ! quantity ( unskill$ lab\r ne$$4 ,in/ead ( h&l+ ! goods f pit to pit1 mod]n tann]ies aim at mov+ ! liquors4 ,?us 9 ! ,=s>e & ,til/on sy/ems ( lim+1 hides are plac$ 9 a pit & lie undi/urb$ until ready = depilation1 ! soak liquors & lime liquors be+ suppli$ & run (f j z requir$1 :il/ ^! liquors are agitat$ z (t5 z desir$ by means ( a curr5t ( compress$ air4 ,?is agitation replaces ! h&l+ up & d[n once practis$4 ,9 ! tany>d prop] ! same t5d5cy is at "w1 rock]s are increas+ly pref]r$ to h&l]s1 & an inv]sion ( ! press lea* sy/em p]mits ! exhau/ion ( tan liquors by a gravity fl[1 & s avoids ! h&l+ =w>d f pit to pit4 ,!re is also a t5d5cy to in/all lifts1 ov]head runways1 trucks on l9es1 motor lorries1 etc41 to replace c>ry+1 b>r[+1 c>t+1 etc41 & s to arrange ! tann]y t ! m9imum transport is ne$$4 ,all ^! l9es ( evolution involve m int5sive production1 & necessitate mu* m c>eful sup]vision4 ,x is n surpris+1 !re=e1 t ! indu/ry n[ feels t sci5tific ov]sight & adm9i/ration are ess5tial4 ,a doz5 ye>s ago ! trade *emi/s 7 l>gely unqualifi$ m51 ^: "w lay solely 9 ! laboratory1 & consi/$ ma9ly 9 ! analysis ( mat]ials b\ght4 ,to-day all l>ge tann]ies h qualifi$ *emi/s1 & x is realiz$ t !y are ! practical tann]s4 ,_! function is s to control ! manufactur+ processes t all wa/e is avoid$1 & s to correlate & co-ord9ate ! manufactur+ results ) ! analytical & exp]im5tal records ( ! laboratory1 t con/ant improvem5ts are made 9 ! me?ods ( production4 ,! ext5d$ use ( ma*9]y1 & ! necessity = economy 9 coal & p[]1 give ! eng9e] also v l>ge scope = useful "w4 ,mod]n bus9ess conditions1 moreov]1 h made necess>y m skilful cl]ical "w & acc\ntancy 9 ! l>ge (fices ( a mod]n tann]y4 ,9 ! creation ( cordial relation%ips betwe5 capital & lab\r 9 ! lea!r trades1 !re has be5 un=tunately little progress4 ,! lea!r trade is n a sweat$ indu/ry4 ,its work]s h always enjoy$ reasonable h\rs ( "w4 ,9 mo/ factories an approximate #dh-;h\r work+ week 7involv+ no night "w7 has long be5 9 op]ation4 ,! indu/ry1 h[ev]1 is n "o 9 :i* high wages obta94 ,! av]age tann]y work] receives a wage :i* is nev] mu* above ! level ( subsi/5ce4 ,?is is mo/ly due to ! fact t he is usually a q unskill$ lab\r]1 & is !re=e on ! bottom rung ( ! lab\r ladd]4 ,9 addition to ?is ! "w itself is (t5 di/ress+ly monoton\s1 & makes little dem& ^u ! intellig5ce ( ! work]4 ,! trade consequ5tly (f]s little attraction to ! intellig5t lab\r]4 ,! old sy/em ( appr5tice%ip is n[ q obsolete1 p>tly ow+ to ! rapidity ( ! *anges 9 ! me?ods ( manufacture1 p>tly to ! specialization ( lab\r :i* results f ! developm5t ( l>ge factories1 & p>tly also1 because to und]/& mod]n tann+ involves a bett] g5]al education ?an mo/ workm5 receive4 ,x is inde$ frequ5tly difficult to f9d compet5t "u-=em5 = ! diff]5t dep>tm5ts ( ! mod]n lea!r factory4 ,until rec5tly lea!r work]s h be5 ei!r unorganiz$ or badly organiz$1 & _! views & compla9ts h be5 confus$ & sporadic1 b dur+ ! w> p]iod !re has be5 a v rapid ext5sion ( trade union movem5ts1 & consequ5tly a m articulate expression ( ! dem&s = democratization z well z a great] %>e 9 ! fruits ( ! indu/ry4 ,9 ! lea!r trades1 h[ev]1 ! gulf betwe5 ! unskill$ lab\r]s & ! weal?y employ]s is p]haps unusually wide1 & !re is little disposition on ! "p ( capital to recognize ! equity ( ei!r ( ! above dem&s ( lab\r4 ,g5]ally speak+1 ! lea!r trade firms are n public b private companies4 ,!re is absolutely no trace ( co-p>tn]%ip or pr(it-%>+ s*emes1 or ( co-op]ative production4 ,!re is little recognition t ! trades' prosp]ity %\ld be %>$ 9 any way by ! workpeople1 & /ill less recognition ( any "r to a voice 9 indu/rial conditions4 ,?is condition ( affairs has an om9\s reaction ^u ! attitude ( lab\r1 :i* believes t x is produc+ great weal? b n obta9+ mu* m ?an subsi/5ce4 ,x is n ! function ( ?is volume to pron\nce a v]dict ^u ! wages "q or ^u ! democratization ( ! lea!r trades1 b "o may be p]mitt$ e>ne/ly to hope t if su* be ! future l9es ( developm5t1 !re w be also1 z an absolutely ess5tial "p ( any su* s*emes1 a mu* high] /&>d ( education among/ ! work]s1 = ?is is ! only satisfactory gu>antee t ! voice ( lab\r 9 c\ncil w h any practical value1 or t high] wages w be at all wisely us$ by ! recipi5ts4 ,9 8 in/ructive & valuable volume on ,! ,evolution ( ,indu/ry1 ,pr(4 ,mac,gregor po9ts out t mod]n indu/ry has evolv$ ?ree out/&+ types1 viz4 ! ,co-op]ative ,movem5t1 ! ,tru/s1 & ! me?ods ( ,public ,trad+4 ,he also sugge/s t ^! types t5d to bl5d4 ,9 ! lea!r indu/ry co-op]ative & municipal production are unhe>d (1 b ! indu/ry has c]ta9ly develop$ along ! l9es ( ! l>ge tru/s4 ,l>ge bus9esses h replac$ small1 & lat] /ill h =m$ local f$]ations1 :i* 9 turn h comb9$ to =m ! ,unit$ ,tann]s' ,f$]ation4 ,w> conditions h c]ta9ly /imulat$ evolution t[>ds ! tru/ type4 ,! ,unit$ ,tann]s' ,f$]ation has become possess$ ( p[]s :i* 7 n orig9ally contemplat$1 su* z ! pur*ase & di/ribution to its memb]s ( hides1 b>k1 extract1 sulphide & o!r mat]ials4 ,h[ f> "s ( ^! arrangem5ts w be p]man5t is problematical1 b "o b5eficial result is t ! alli$ trades h c]ta9ly realiz$ m ?or\ghly _! unity ( int]e/s4 ,?is is %[n by ! mu* fre] collaboration ( ! tann]s1 & by ! enc\ragem5t n[ giv5 to simil> collaboration betwe5 _! *emi/s4 ,m evid5ce is f\nd 9 ! proposals = comb9$ rese>*4 ,!re is also consid]able reason to believe t !re is "s movem5t 9 ! direction ( p>tial ,/ate control4 ,!re is little d\bt t evolution along tru/ l9es w make ?is less difficult & possibly m desirable4 ,! c\ntry _c af=d ! spectacle ( a ,lea!r ,tru/ p]man5tly at w> ) a ,lab\r]s' ,union4 ,! public has realiz$ t ! well-be+ ( ! lea!r indu/ry is vital to ! national safety4 ,x has realiz$ t ! lea!r trades are great produc]s ( national weal?1 & t increas$ production ) ! developm5t ( ! export trade w mat]ially assi/ to re/ore ! c\ntry's f9ancial position4 ,x has realiz$ also its own "r to protection f bad lea!r & f exorbitant prices4 ,on all ^! gr\nds x is probable1 ?\gh !re may be "s reaction f ! pres5t position1 t ! ,/ate1 :i* has already got its f+]s 9 ! pie1 w refuse to draw !m out altoge!r4 ,! ,imp]ial aspect ( ! "q af=ds "s fur!r ju/ification = ?is attitude4 ,! lea!r trades op]ate v l>gely ^u import$ mat]ial1 & x is cle>ly desirable t !re %\ld be close co-op]ation betwe5 ! home indu/ry & ! colonial supplies ( mat]ial4 ,"h too ! w> has also giv5 a great /imulus 9 ?is direction4 ,indian myrabolans has long be5 a /aple tann+ mat]ial4 ,s\? ,african wattle b>k has dur+ ! la/ few ye>s replac$ almo/ completely1 & probably to a l>ge ext5t p]man5tly1 ,turki% valonia4 ,!re has also be5 great increase 9 ! imports ( ,indian kips & ( ,s\? ,african hides1 & x is n at all an impossible proposition to ma9ta9 a self-conta9$ ,imp]ial ,lea!r ,trade1 %\ld ?is be necess>y4 ,fr5* *e/nut extract1 & quebra*o extract1 h[ev]1 are mu* too valuable tann+ mat]ials to exclude = m]ely s5tim5tal reasons4 ,^! in/ances indicate possible advantages 9 ,imp]ial co-op]ation1 b also %[ ! ne$ = caution 9 ! elaboration ( su* s*emes4 ,al?\gh a p>tial1 & inde$ increas+1 measure ( ,/ate ,control is probable1 !re has be5 z yet no s]i\s proposal to nationalize ! lea!r indu/ry4 ,su* a proposition1 inde$1 is h>dly ripe ev5 = discussion4 ,until ! nationalization ( transport & ( m9es is a prov$ success1 & until ! m]ely di/ributive und]tak+s ( ! municipalities 7e4g4 ( coal & ( milk & o!r foods7 are pa/ ! exp]im5tal /age1 any proposition to nationalize ! lea!r trades seems premature4 ,x is notewor?y1 h[ev]1 t 9 ,que5sl&1 ,au/ralia1 ! ,gov]nm5t h ! "r to comm5ce & to adm9i/] ,/ate ,tann]ies4 ,any progress 9 ! direction ei!r ( democratization or ( nationalization1 has be5 c]ta9ly po/pon$ by ! sudd5 & unprec$5t$ trade slump :i* comm5c$ 9 ! e>li] "p ( #aibj4 ,?is depression1 9 spite ( heavy falls 9 ! prices ( raw mat]ials1 has made economic production a mu* m difficult problem4 ,x has und\bt$ly giv5 a fur!r /imulus to evolution t[>ds ! tru/ type1 & creat$ a fur!r t5d5cy t[>ds ! clos+ ( ! small] factories1 & ! employm5t ( lab\r-sav+ devices4 ,:5 ! g5]al fall 9 prices has made an appreciable fall 9 ! co/ ( liv+1 "s r$uction 9 ! lea!r work]s' wages1 toge!r ) m effici5t "w1 w also contribute to ! solution ( ! difficulty4 ,x is *iefly to be desir$1 h[ev]1 t ! export trade %\ld be re/or$4 ,! realization ( ?is hope dep5ds l>gely ^u ! e/abli%m5t ( peace & prosp]ity abroad1 & ! consequ5t /abilization ( ! v>i\s =eign ex*anges4 ,,"p ,v4--,,gelat9e ,,& ,,glue4 ,,section ,i4--,,prop]ties ,,( ,,gelat9e ,,& ,,glue ,_m ( ! *emical prop]ties ( gelat9e1 especially ^? :i* di/+ui% x f o!r prote9s1 h be5 describ$ 9 ! ,introduction to ?is volume1 & ne$ no fur!r comm5t4 ,9 ?is section its colloid nature & behavi\r w *iefly be consid]$1 = ^! po9ts h greate/ importance f ! /&po9t ( indu/rial *emi/ry4 ,x is hop$1 moreov]1 t ?is section w be ( int]e/ n only to ! *emi/ conc]n$ 9 ! manufacture ( gelat9e & glue1 b t x w be ( value also to ^? conc]n$ 9 lea!r manufacture4 ,! diff]5ce betwe5 ! collag5 :i* composes ! hide fibre & ! high-grade gelat9es is s small t = _m practical purposes x may be consid]$ negligible4 ,?us ! description ( ! behavi\r ( a gelat9e gel is v l>gely applicable to a hide gel also4 ,gelat9e has be5 cry/alliz$ by von ,weim>n by evaporat+ a dilute solution 9 aque\s alcohol :il/ 9 a desiccator conta9+ potassium c>bonate1 ! temp]ature be+ ma9ta9$ at #fj-gj ,c4 ,! c>bonate takes up wat] only1 & ! conc5tration ( ! alcohol !re=e sl[ly increases until ! gelat9e is no long] soluble4 ,gelat9e is usually f\nd & kn[n 9 ! colloid /ate1 h[ev]1 & its behavi\r 9 ?is /ate only is ( practical importance4 ,! fundam5tal idea ( mod]n colloid *emi/ry is t colloids are het]og5e\s sy/ems1 usually two-phas$1 9 :i* "o phase is liquid & ! o!r phase ei!r liquid or solid4 ,! latt] phase1 :i* is divid$ into small sep>ate volumes1 is kn[n z ! disp]se phase1 :il/ ! o!r is ! cont9u\s phase or disp]sion m$ium4 ,! disp]sity is ! degree to :i* ! r$uction ( ! dim5sions ( ! disp]se phase has be5 c>ri$1 & is be/ express$ num]ically 9 t]ms ( specific surface1 i4e4 surface area divid$ by volume1 b x is also (t5 express$ z ! ?ickness or diamet] ( a film or p>ticle4 ,:5 ! disp]sity is n high1 we h ord9>y susp5sions & emulsions1 :i* ) increas+ disp]sity m]ge into ! typical colloids4 ,by analogy1 colloids h be5 divid$ into susp5soids & emulsoids1 :5 ! disp]se phase is solid & liquid respectively4 ,! classification1 h[ev]1 has n be5 f\nd satisfactory1 = "s sy/ems 9 :i* ! disp]se phase is und\bt$ly liquid1 exhibit *>act]i/ic prop]ties ( susp5soids1 & vice v]s4 ,a m satisfactory division1 !re=e1 is f\nd 9 ! pres5ce or abs5ce ( aff9ity betwe5 ! two phases1 ! sy/ems be+ t]m$ lyophile & lyophobe respectively4 ,if wat] be ! cont9u\s phase ! t]ms hydrophile & hydrophobe are (t5 us$4 ,broadly speak+1 ! lyophile colloids correspond to ! emulsoids1 & ! lyophobe colloids to ! susp5soids4 ,gelat9e is a typical hydrophile colloid4 ,ano!r fundam5tal idea ( colloid *emi/ry is t ! great ext5sion ( surface involv$ 9 a high disp]sity causes ! surface en]gy to be no long] a negligible fraction ( ! total en]gy ( ! sy/em1 & t ! rec5t advances 9 k respect+ surface ph5om5a may be call$ 9 to assi/ 9 ! explanation ( ! special prop]ties ( ! colloid /ate4 ,p>ticles :i* exhibit ! ,br[nian movem5t1 ab\t #aj7-e7 cm4 diamet]1 d[n to ! limit ( microscopic visibility 7#aj7-c7 cm47 are t]m$ microns4 ,p>ticles less ?an ?is1 b j visible 9 ! ultra-microscope 7#eaj7-g7 cm47 are t]m$ submicrons4 ,p>ticles /ill less1 approximately #aj7-g7 cm41 h be5 %[n to exi/1 & are t]m$ amicrons4 ,! dim5sions ( molecules su* z may exi/ 9 true solutions are ( ! ord] ( #aj7-h7 cm4 ,a colloid sol may conta9 p>ticles ( v>i\s sizes4 ,?us a gelat9e sol 7l o!r lyophile sy/ems7 conta9s *iefly amicrons1 b submicrons are also obs]vable4 #a4 ,,! ,,cont9u\s ,,phase ,ow+ to ! contractile =ce ( surface t5sion1 x is conclud$ t ! surface lay] ( a liquid is "u v great pressure1 mu* great] ?an ! bulk ( ! liquid4 ,any ext5sion ( ! surface ( ! liquid naturally causes a correspond+ ext5sion ( ! proportion ( liquid :i* is ?us compress$4 ,if 9 a beak] ( wat] !re be plac$ a por\s sub/ance1 su* z animal *>coal1 !re is a great ext5sion ( ! surface ( ! wat]1 & a correspond+ increase 9 ! am\nt ( compress$ wat]4 ,if in/ead !re be sub/itut$ a l>ge numb] ( v small p>ticles ( a sub/ance1 a /ill fur!r increase 9 ! am\nt ( compress$ wat] is involv$4 ,z ! specific surface ( ! sub/ance ins]t$ is increas$1 & its am\nt1 ! proportion ( compress$ & d5s] wat] increases also1 until x is a practically appreciable p]c5tage ( ! total volume4 ,x is cle> also t ! ext5t ( ! zone ( compression w be det]m9$ also by ! nature ( ! sub/ance ) :i* ! wat] is 9 contact at its surface1 i4e4 by ! ext5t to :i* x is hydrophile1 & ?is inde$ may be ! m important factor4 ,n[ 9 a gelat9e sol we h ! necess>y conditions = a sy/em 9 :i* ! compress$ wat] be>s an unusually l>ge ratio to ! total1 ow+ to ! enorm\s surface develop$ by ! m9ute p>ticles ( ! disp]se phase 7amicrons7 & to ! unusually wide zone ( compression surr\nd+ ea* p>ticle caus$ by ! /rongly hydrophile nature ( gelat9e4 ,x %\ld be po9t$ out t ^! zones ( compression d n involve any abrupt transition f ! zone ( non-compression1 ! lay] ne>e/ ! p>ticle is "u ! greate/ pressure1 & ! conc5tric lay]s "u less & less pressures1 ! actual compression be+ ?us an inv]se function ( ! di/ance f ! p>ticle4 ,n[ if !re be a gradual increase 9 ! conc5tration ( ! sol1 ! "t w come :5 ^! zones ( compression beg9 to come 9 contact1 & ! sy/em w !n %[ a consid]ably increas$ viscosity4 ,) fur!r increase 9 conc5tration ! zones ( compression w ov]lap ?r\gh\t ! sy/em1 & :5 ! lay]s "u consid]able pressure are ?us cont9u\s1 ! :ole sy/em w acquire a rigidity mu* great] ?an wat] & approa*+ t ( a solid body4 ,?is is a gelat9e gel1 or jelly4 ,) increas+ conc5tration ! jelly becomes increas+ly rigid1 & if x be ev5tually dri$ out "u suitable conditions x =ms :at is practically solid body--gelat9e--:i*1 h[ev]1 /ill conta9s f #ab to #ah p] c5t4 ( wat]4 ,x w be cle> t1 9 ! case ( gelat9e jellies 7e4g4 ( #c-aj p] c5t4 /r5g?71 an increase 9 temp]ature w cause an increase 9 ! k9etic en]gy ( ! p>ticles & effectively r$uce ! zones ( compression4 ,inde$1 !y may be r$uc$ to su* an ext5t t !y are no long] 9 contact1 & ! rigidity due to ! cont9u\s contact ( ! lay]s ( great compression w !n disappe>2 z we say usually1 ! jelly melts4 ,on cool+1 ! decreas$ k9etic en]gy ( ! wat] molecules results 9 ! return ( ! /ate ( compression1 ) rapidly increas+ viscosity & ev5tual gelation2 z we say usually1 ! jelly sets4 ,nei!r ( ^! *anges takes place at a def9ite temp]ature 7l a melt+-po9t71 & 9 melt+ 7solation7 or 9 sett+ 7gelation7 ! temp]ature-viscosity curve is q cont9u\s4 ,by v>i\s arbitr>y devices1 h[ev]1 approximate melt+ & sett+ po9ts may approximately be det]m9$4 ,! results also v>y some:at ) ! conc5tration ( ! gel or sol4 ,gels betwe5 #e & #ae p] c5t4 /rong melt ab\t #bf-cj ,c4 & set at #ah-bf ,c4 ,on ?is view1 we mu/ reg>d a gelat9e gel z a cont9u\s network ( wat] "u great compression1 & 9 ?is network are zones ( /ill great] compression1 :i* surr\nd ! p>ticles ( ! disp]se phase--! gelat9e itself1 & zones ( less compression :i* 9 a weak gel1 at any rate1 h a compression equal to or mu* ! same z ! normal /ate ( compression 9 wat]4 ,"o consequ5ce ( ?is sy/em is1 t :5 a piece ( gelat9e swells1 !re is a consid]able enl>gem5t 9 ! zones ( compression2 9 o!r words1 "s1 at lea/1 ( ! imbib$ wat] is compress$4 ,n[ ! compression ( wat] means t "w is done1 & :5 gelat9e swells1 !re=e1 we expect--& actually f9d--t heat is lib]at$ 7#e4g cal p] g4 gel74 ,h5ce also by ! ,le ,*ateli] !orem1 we expect--& f9d--t gelat9e swells be/ 9 cold wat]4 ,fur!r1 ! compression ( wat] involves a decrease 9 volume1 & we !re=e expect--& actually f9d--t ! volume ( ! swoll5 jelly is appreciably less ?an ! volume ( gelat9e plus ! volume ( wat] imbib$4 ,ano!r consequ5ce ( su* a compress$ sy/em is t a gelat9e jelly1 ev5 9 wat]1 w h a surface t5sion t[>ds wat] j z ! wat] itself has su* a t5sion to ! wat] vap\r above ! liquid4 ,?is int]facial t5sion ( ! jelly w ( c\rse h a contractile effect1 & w t5d to resi/ swell+ & to limit x z f> z x possibly c4 ,?is =ce1 t5d+ to contract ! jelly & resi/ imbibition is !re=e "o ( ! ma9 influ5ces at "w 9 ! swell+ ( gelat9e1 & is "o ( ! two pr9cipal factors :i* det]m9e ! ext5t ( ! maximum swell+ :5 equilibrium is e/abli%$4 ,! =ce t5d+ to resi/ swell+ is1 9 ! ultimate1 j surface t5sion4 ,its actual magnitude dep5ds1 ( c\rse1 ma9ly ^u ! ext5t ( compression 9 ! disp]sion m$ium ( ! gel1 & w be a resultant :i* is a function ( ?is compression4 ,! magnitude w ?us v>y ) ! av]age compression 9 ! cont9u\s network ( compress$ wat]4 ,x w be obvi\s t z ! jelly swells ! p[] ( resi/+ ! swell+ w decrease1 & ! int]facial t5sion ) ! ext]nal wat] w t5d to disappe>4 ,if ! =ce t5d+ to swell 7 great en\gh ! swell+ w\ld cont9ue until ! zones ( compression 7 no long] 9 contact & ! gel w\ld become sol4 ,z sugge/$ above1 x is probable t ! ext5t ( ! zones ( compression is det]m9$ by ano!r factor 9 addition to ! great developm5t ( surface4 ,t factor is connect$ if n id5tical ) t p[] :i* makes ! sy/em lyophile1 & is evid5tly connect$ also ) ! solubility ( ! disp]se phase1 & may inde$ be electro*emical =ces t5d+ to =m a s]ies ( hydrates1 or at lea/ to cause an ori5tation or def9ite arrangem5ts ( ! wat] molecules 9 ! zone ( compression4 ,?is idea receives "s support f ! hydrate !ory ( solution1 & ! zones ( compression & ori5tation are ! colloid analogue ( ! hydrates suppos$ to exi/ 9 solutions ( electrolytes4 ,! ext5sion ( su* zones on cool+ are !n analog\s ) ! s]ies ( hydrates =m$1 = in/ance1 by manganese *loride ) #b1 #d1 #f1 #aa1 or #ab molecules ( wat] :5 cry/alliz$ at temp]atures ( #bj1 #ae1 -#ba1 -#cj1 & -#dh ,c4 respectively1 ! idea be+ t ! salts mo/ hydrat$ 9 solution cry/allize ) mo/ wat]4 ,z ! compression is ! result ( two factors1 "o ( :i* dep5ds ^u ! nature ( ! disp]se phase1 we expect--& f9d--9 o!r lyophile sy/ems a consid]able v>iation 9 _! p[] ( gelation4 ,"s inde$1 ?\gh v visc\s1 e4g4 egg album91 nev] q set l gelat9e1 & o!rs 7e4g4 ag>-ag>7 set to a /iff gel f a mu* weak] sol ?an gelat9e4 ,:5 ! zones ( compression are l>ge1 z 9 gelat9e1 ! magnitude ( ! compress+ =ce on ! out]mo/ "p ( ! zone is relatively small1 & x is n surpris+ t "t is necess>y = ! victory ( ?is =ce ov] ! k9etic en]gy ( ! wat] molecules4 ,h5ce we f9d a #e p] c5t4 jelly sets readily on cool+1 b its ela/icity increases /eadily = _m h\rs aft] x has set4 ,?is ph5om5on1 kn[n z hy/]esis1 we %\ld expect--& f9d--to be mu* m m>k$ 9 a case :]e ! zone ( compression is unusually l>ge 7e4g4 an ag> gel74 ,we %\ld also expect--& f9d--t hy/]esis is m m>k$ 9 a high-grade gelat9e ?an 9 a l[-grade gelat9e :]e bo? ev5tually =m gels ( equal ela/icity4 ,we %\ld expect too--& we f9d--t hy/]esis is m prom95t 9 weak gels ?an 9 /rong4 ,^! po9ts are ( obvi\s importance 9 te/+ gelat9e by its ela/icity1 e4g4 ! well-kn[n f+] te/4 ,!re are also o!r facts & consid]ations :i* h an important be>+ ^u ! po9t "u discussion4 ,x is necess>y ultimately to reg>d true solutions ( electrolytes & o!r bodies z het]og5e\s1 ?\gh p]haps ( a r diff]5t ord]4 ,f ?is po9t ( view molecules & ions exi/+ 9 an aque\s solution w pres5t a surface & h associat$ zones ( compression analog\s ) ^? sugge/$ = ! m9ute p>ticles ( gelat9e4 ,n[ rec5t inve/igations h %[n t ! ess5tial physical prop]ties ( wat] are affect$ by dissolv$ sub/ances 9 a def9ite mann] & to a fix$ ext5t1 & t ^! sub/ances exhibit a sequ5ce 9 ord] ( _! effect4 ,?is sequ5ce is also exhibit$ 9 ! ess5tial prop]ties ( wat] z solv5t & z disp]sion m$ium = colloid sols4 ,! sequ5ce is kn[n z ! lyotrope s]ies4 ,?us ! num]ical value ( ! compressibility ( aque\s solutions is r$uc$ bel[ t ( wat] by salts :i*1 ) ! same kation1 exhibit an effect 9 ! foll[+ ord]3-- ,,co#c ,,s#d ,cl ,br ,,no#c ,i ,?is same ord] is obs]v$1 9 ! effect on ! increas$ values = ! surface t5sion1 d5sity & viscosity ( ^! solutions4 ,on ! o!r h&1 ! kations h a simil> sequ5ce ( effects1 ,mg ,,nh#d ,li ,k ,na ,rb ,cs :i* appe>s :5 salts ( ! same anion are *os54 ,x is n surpris+ to f9d t ?is lyotrope s]ies exhibit an analog\s influ5ce on ! *emical reactions ( wat]1 e4g4 ! hydrolysis ( e/]s4 ,9 ! hydrolysis by acids ,,s#d ret>ds ! action1 ! o!r anions & ! kations accel]ate x1 9 ! lyotrope ord]4 ,9 ! hydrolysis by bases ! s]ies is rev]s$4 ,simil>ly ! lyotrope s]ies ex]t ! same ord] ( effect ^u ! inv]sion ( cane sug> & o!r reactions4 ,?is lyotrope influ5ce has also be5 %[n to ex]t consid]able effect 9 ! behavi\r ( lyophile sols4 ,) ! lyophobe sols ! addition ( =eign sub/ances app>5tly affects ! disp]se phase only1 b ) ! lyophile sols ! effect on ! cont9u\s phase is also important1 & may ov]%ad[ ! o!r4 ,n[1 9 gelat9e & 9 hide gels & tann+ sols we are deal+ ) lyophile sy/ems1 & !re are _m po9ts ( behavi\r 9 :i* lyotrope influ5ces become prom95t4 ,simil> effects are obs]v$ ^u o!r lyophile sols 7e4g4 album91 ag>-ag>1 etc47 :i* diff] widely 9 *emical nature4 ,?us ! salt+ out ( album9 7rev]sible precipitation7 is influ5c$ by sodium salts 9 lyotropic sequ5ce z foll[s4 ,! anions h9d] precipitation2 9 ord] ( precipitat+ p[] !y are3 citrate t>trate ,,s#d acetate ,cl ,,no#c ,cl,o#c ,i ,,cns ,! sulphates illu/rate ! kation effect1 :i* is indep5d5t & :i* fav\rs precipitation3 ,li ,k ,na ,,nh#d ,mg ,if ! exp]im5ts be c>ri$ out 9 fa9tly acid solution ?is ord] ( effect is exactly rev]s$1 iodide & ?iocyanate hav+ ! greate/ effect & citrates ! lea/4 ,! coagulation temp]ature ( album9 & ! coagulation by o!r organic sub/ances are simil>ly influ5c$ by ! lyotrope s]ies4 ,lyotrope influ5ce also ex]ts a p[]ful effect on ! behavi\r ( gelat9e sols & gels4 ,! gelation temp]ature is influ5c$ ?us3-- rais$ by ,,s#d citrate t>trate acetate l[]$ by ,cl ,cl,o#c ,,no#c ,br ,i ,! kation effect 7small7 is ,na ,k ,,nh#d ,mg ,o!r lyotrope sub/ances raise or l[] ! temp]ature ?us3-- glucose glyc]ol--7,h#b,o7--alcohol urea ,! effect on gelation is also illu/rat$ by ! *ange ( viscosity ( ! sol ) "t4 ,! same lyotrope ord] is f\nd4 ,9 ! salt+ out or precipitat+ ( gelat9e ) salts1 ! ord] ( anions is lyotrope3 ,,s#d citrate t>trate acetate ,cl ,also ! osmotic pressure ( gelat9e sols is m>k$ly l[]$ by neutral electrolytes 9 lyotrope sequ5ce3 ,cl ,,s#d ,,no#c ,br ,i ,,cns ,simil>ly lyotrope influ5ces are %[n 9 ! modulus ( ela/icity3 sub/ances :i* fav\r gelation increase ela/icity1 :il/ sub/ances :i* fav\r solation decrease ela/icity4 ,! ord] is aga9 lyotrope4 ,! p]meability ( ! gel is affect$ by lyotrope influ5ces2 alcohol & glyc]ol r$uce diffusion ?r\gh gelat9e 7or ag>72 & urea1 *loride & iodide increase x4 7,simil>ly ! diffusion ( sols ?r\gh semip]meable membranes is affect$ by lyotrope influ5ce47 ,! lyotrope s]ies also influ5ce ! optical activity ( gelat9e sols & ! d\ble refraction ( /ra9$ gels4 ,! swell+ ( gelat9e 7& o!r gels7 is v /rongly influ5c$ by ! lyotrope sub/ances & m]its m att5tion ?an x has receiv$4 ,h5ce ?is lyotrope influ5ce ex]ts a pr(\nd effect 9 ! manufacture ( gelat91 & p]haps ev5 great] 9 ! manufacture ( lea!r4 ,?is is only to be expect$4 ,if a gel comprise a cont9u\s network ( compress$ wat]1 z sugge/$ above1 ! pres5ce ( o!r sub/ances 9 ! gel :i* cause increases or decreases 9 ! compression mu/ modify accord+ly ! prop]ties :i* dep5d ^u ?is /ate ( compression1 su* z ! viscosity ( ! melt$ gel1 ! rate ( gelation1 ! ela/icity ( ! gel1 & ! rate & ext5t ( its imbibition4 ,?is inde$ we f9d to be ! case4 ,n[ ! sub/ances :i* affect ! compressibility1 surface t5sion1 etc41 ( wat] lea/1 i4e4 ! sub/ances produc+ little or no compression ( wat]1 are j ^? :i* r$uce ! compression ( wat] 9 a gelat9e jelly1 & cause a decreas$ viscosity1 ela/icity1 surface t5sion1 etc41 & :i* !re=e naturally all[ ! gel to swell m ?an 9 pure wat]4 ,conv]sely1 ! sub/ances :i* cause ! greate/ compression ( wat]1 ! greate/ increase 9 its surface t5sion & viscosity1 are also ! sub/ances :i* increase ! compression1 viscosity1 ela/icity1 & surface t5sion ( gels1 & :i* !re=e h9d] imbibition4 ,! effect on swell+ is z foll[s3-- ,sodium sulphate t>trate citrate acetate2 alcohol glucose cane sug>2 7wat]7 *lorides-potassium sodium ammonium2 sodium *lorate nitrate bromide iodide ?iocyanate urea4 ,z ! am\nt ( compression w dep5d ^u ! am\nt ( sub/ance1 we expect--& f9d--t ! effect is usually additive1 & t suitable mixtures ( sub/ances hav+ an effect 9 ! opposite s5se w produce no *ange4 ,! int]pretation ( lyotrope influ5ce is ( c\rse some:at speculative1 b consid]$ z a surface ph5om5on1 ! surface specific ( ! molecules & ions ( ! lyotrope sub/ance mu/ be "o ( ! factors involv$4 ,"o naturally also connects ! effect ) solubility & ! t5d5cy to =m hydrates 9 solution1 ! zones ( compression be+ zones ( ori5tation & ( electro*emical attraction4 ,! hydrate !ory ( solution aga9 af=ds an in/ructive comm5t>y4 ,! fact t1 broadly speak+1 ! polyval5t anions & ! monoval5t anions also gr\p !mselves toge!r1 sugge/s t electrical =ces are at "w1 & ! ord] ( effect ( monoval5t anions almo/ sugge/s t :at are call$ residual val5cies are 9 op]ation4 ,x is difficult to resi/ ! conclusion t 9 ! lyotrope influ5ce1 9 ! cry/alliz+ ( salts1 & 9 ! =mation ( a gel1 we h zones ( compression & ori5tation :i* are manife/ations ( ! same =ces--surface & electrical2 ! *ief diff]5ces 9 ! case ( gelat9e be+ t ! zones are l>g] & t ! electrical effect is p]haps ( less def9ite magnitude4 ,h[ev] ^! ?+s may be1 ! fact ( wat] compression det]m9es ! rigidity ( ! gel1 & ! *anges 9 ?is compression ( ! cont9u\s phase det]m9e ! surface t5sion resultant :i* h9d]s swell+1 & :i* is "o ( ! two ma9 factors fix+ bo? ! rate at :i* gelat9e swells 9 wat]1 & ! f9al volume atta9$ by ! gel4 ,be=e leav+ ?is po9t1 x is desirable to note ! effect on ! swell+ ( gelat9e ( ! extremes ( ?is lyotrope influ5ce4 ,sub/ances l iodides1 ?iocyanates & urea prev5t a gelat9e sol f sett+ to a gel at all1 & a piece ( gelat9e 9 su* solutions swells rapidly until x solates4 ,on ! o!r h&1 sulphates1 t>trates1 etc41 make a /iff] gel on acc\nt ( ! enhanc$ compression4 ,gelat9e 9 su* solutions may swell1 b at a mu* sl[] rate ?an 9 wat] & ) a decreas$ maximum ext5t4 ,a gelat9e gel may 9 su* solutions n only fail to swell at all1 b actually contract & 9 "s cases1 inde$1 be practically dehydrat$4 ,if a gel be 9 a v conc5trat$ solution ( su* a sub/ance1 x may be t ! lyotrope compression 9 ! ext]nal solution is great] ?an ! compression 9 ! disp]sion m$ium ( ! gel2 9 :i* case ! surface t5sion effect is rev]s$1 & ! ext]nal solution t5ds to increase 9 volume & ! gel to contract4 ,h5ce we f9d t ! saturat$ solutions ( su* sub/ances z ammonium sulphate & potassium c>bonate w dehydrate a gel almo/ completely1 & w also1 by a simil> action on pelt1 make a k9d ( :ite lea!r4 ,x is important to rememb] ?is contractile effect ( /rong solutions ( salts1 because x is v easy to confuse ?is effect ) a simil> result produc$ 9 ano!r mann]1 viz41 by a r$uction ( ! =ce t5d+ to swell4 #b4 ,,! ,,disp]se ,,phase ,a v important feature ( ! colloid /ate is t ! p>ticles ( ! disp]se phase appe> to possess an electric *>ge1 & if ?is *>ge be remov$ a colloid sol no long] rema9s su*1 b precipitates1 flocculates1 coagulates1 etc4 ,z to ! orig9 ( ?is *>ge sev]al !ories h be5 advanc$1 b ! mo/ g5]ally accept$ is t x is a result ( ! adsorption ( electrically *>g$ ions by ! p>ticles ( ! disp]se phase4 ,! enorm\s specific surface possess$ by ?is phase r5d]s x p>ticul>ly liable to su* adsorption4 ,?is view h>monizes well also ) ! g5]al behavi\r1 ( colloid sols & gels1 9 endosmosis1 kataphoresis1 precipitation1 etc4 ,accord+ to ?is po9t ( view ! p>ticles ( ! disp]se phase are surr\nd$ by a surface lay] 9 :i* ^! ions are 9 mu* great] conc5tration ?an 9 ! volume conc5tration ( ! disp]sion m$ium4 ,! hydrion & hydroxyl ion are p>ticul>ly liable to su* adsorption4 ,9 ! case ( a lyophile colloid1 l gelat9e1 ! *>ge may be ei!r positive or negative1 accord+ to ! nature ( ! pr$om9ant ions 9 ! disp]sion m$ium1 & ! am\nt ( adsorption is det]m9$ by ! conc5tration ( ^! ions 9 accordance ) ! adsorption law4 ,9 effect1 !re=e1 ! p>ticles ( ! disp]se phase ea* c>ry an electric *>ge ( ! same nature1 & z simil>ly *>g$ bodies repel "o ano!r1 ! p>ticles ( ! disp]se phase w t5d to sep>ate & to occupy a bigg] volume4 ,x is ! au?or's op9ion t ?is repulsion ( simil>ly *>g$ p>ticles is ! cause ( ! swell+ ( gelat9e4 ,! am\nt ( *>ge & =ce--t5d+ to swell--is due possibly to sev]al ionic adsorptions1 :i* may be consid]$ to op]ate indep5d5tly1 & ! p[] ( repulsion is det]m9$ by ! nett *>ge1 :i* 9 ! case ( a positive colloid is positive1 & 9 ! case ( a negative colloid is negative4 ,z ions possess diff]5t electric *>ges1 ! *>ge on ! disp]se phase is subject to ! val5cy rule4 ,n[ ! repulsive =ce betwe5 two simil> & simil>ly *>g$ bodies is proportional to ! am\nt ( *>ge & is inv]sely proportional to ! squ>e ( ! di/ance betwe5 !m4 ,! am\nt ( *>ge on a colloid p>ticle w be det]m9$ by ! disp]sity--be/ signifi$ by ! specific surface 7s7--& by ! op]ation ( ! adsorption law y mac7#a_/n7 ,! di/ance betwe5 ! p>ticles v>ies ) ! degree ( swell+1 & is det]m9$ by ! cube root ( ! volume ( ! gel 7v74 ,h5ce if ,f be ! =ce t5d+ to make ! gelat9e swell1 we may write ,f ,q_/7d#b7 7sy7_/v7#b_/c7 ,n[ ) all electrolytes1 ev5 ) wat]1 we h bo? positively & negatively *>g$ ions1 & y is consequ5tly det]m9$ by ! diff]5ce 9 ! am\nts adsorb$4 ,h5ce 9 ! case ( an electrolyte ) an equal numb] ( oppositely *>g$ ions y ma#a;c7#a_/n#a7 - ma#b;c7#a_/n#b71 :]e a#a1 a#b1 & n#a1 n#b1 are ! appropriate con/ants = ! p>ticul> ions conc]n$4 ,h5ce at con/ant temp]ature1 pressure1 etc41 we may write ,f sm7 a#a;c7#a_/n#a7 - a#b;c7#a_/n#b7 7 _/ v7#b_/c7 ,! =ce t5d+ to make a piece ( gelat9e swell is proportional to its mass1 :i* is p]haps fairly obvi\s4 ,! swell+ =ce is also an inv]se function ( ! volume ( ! gel1 & z swell+ proce$s !re=e ! =ce t5d+ to swell fur!r decreases4 ,! =ce t5d+ to swell is proportional to ! specific surface ( ! disp]se phase1 o!r factors be+ con/ant4 ,to illu/rate ?is "o has only to imag9e t "o p>ticle ( ! disp]se phase be split into two p>ticles ea* c>ry+ half ! orig9al *>ge4 ,x is cle> t a new repulsive =ce becomes op]ative1 :i* did n be=e influ5ce ! swell+1 & t ! di/ance betwe5 ! p>ticles is halv$4 ,9 ! swell+ ( gelat9e1 h[ev]1 we may consid] ! disp]sity con/ant = con/ant temp]ature1 & if we consid] unit mass we see t ! =ce caus+ swell+ dep5ds ^u ! op]ation ( ! adsorption law & ^u ! degree to :i* ! gel is already swoll54 ,9 ! swell+ ( 7say7 "o gram ( gelat9e to its maximum1 bo? ! contractile =ce ( surface t5sion & ! exp&+ =ce ( electrical repulsion are 9 op]ation4 ,at ! comm5cem5t ! latt] is mu* ! great] =ce--h5ce ! rapid imbibition4 ,bo? ^! =ces decrease 9 magnitude z ! swell+ proce$s1 b ! =ce t5d+ to swell decreases at a m rapid rate1 & ! "t comes :5 x has decreas$ to ! precise value ( ! =ce t5d+ to resi/ swell+4 ,at ?is po9t equilibrium is e/abli%$ & ! maximum swell+ atta9$4 ,obvi\sly ?is maximum w 9 _m cases be det]m9$ l>gely by ! value ( a#a;c7#a_/n#a7 - a#b;c7#a_/n#b74 ,?is factor1 !re=e1 dem&s p>ticul> consid]ation4 ,n[1 un=tunately1 ! adsorption law con/ants = ! diff]5t ions h n yet be5 num]ically det]m9$1 s t we are /ill some:at 9 ! d>k z to ! op]ation ( ionic adsorptions4 ,x is possible1 h[ev]1 to =m conclusions ( a qualitative or relative ord]1 & ^! are su* z to ?r[ mu* light ^u ! "q at issue4 ,9 ! fir/ place1 we "k t 9 g5]al ! v>i\s ions are n usually v widely diff]5t 9 ! ext5t to :i* !y are liable to be adsorb$4 ,if ?is 7 o!rwise1 ! val5cy rule w\ld h>dly op]ate s well 9 endosmosis1 kataphoresis1 & precipitation4 ,9 consequ5ce we mu/ expect ! diff]5ces betwe5 ! ions to appe> 9 small r ?an 9 l>ge conc5trations1 ! am\nts adsorb$ be+ "u ^? conditions m affect$ by *anges 9 ! volume conc5tration4 ,at ! l>g] conc5trations1 !re=e1 ! value ( a#a;c7#a_/n#a7 - a#b;c7#a_/n#b7 is small1 & ! =ce caus+ swell+ (t5 t5ds to z]o4 ,!re are1 h[ev]1 noticeable diff]5ces at l[] conc5trations4 ,?us we "k t if a sub/ance be prim>ily a positive colloid1 x w absorb kations m readily ?an anions4 ,z gelat9e falls into ?is class1 we may !re=e conclude t usually a#a a#b4 ,fur!r1 x (t5 happ5s t v adsorbable sub/ances are less affect$ by conc5tration *anges1 & 9 ! case "u consid]ation1 !re=e1 we %\ld expect t n#a n#b4 ,moreov]1 we "k t ! hydrion & hydroxyl ion are mu* m readily adsorb$ ?an o!r ions1 i4e4 h a l>ge value = a4 ,h5ce 9 ! case ( gelat9e we expect t a#a;c7#a_/n#a7 - a#b;c7#a_/n#b7 w h a comp>atively l>ge value :5 "o ( ! ions is ,h or ,,oh-4 ,also we "k t organic anions are usually mu* m /rongly adsorb$ ?an inorganic anions1 & h5ce t 9 su* cases a#a is m ne>ly approa*$ by ! value ( a#b4 ,x %\ld be emphasiz$ p]haps1 at ?is po9t1 t ^! v>i\s consid]ations are n bas$ ^u any facts relat+ to ! ph5om5a ( imbibition 9 gels1 or 9 gelat9e 9 p>ticul>1 b are bas$ ^u ! behavi\r ( colloids 9 endosmosis1 kataphoresis1 electrolytic precipitation1 adsorption1 etc4 ,illu/ration3 ,,fig4 #a4 ,n[ if we select a few simple figures :i* are 9 accord ) ! above consid]ations1 we c exam9e ! value ( ! factor a#a;c7#a_/n#a7 - a#b;c7#a_/n#b7 9 a purely illu/rative & typical way1 & at any rate =m "s idea z to ! mann] 9 :i* x is likely to v>y4 ,! figures might be3-- ,ion4 n4 a4 ---------------------------------------- --- ,hydrion or hydroxylion #bj #aj ,kation ( a metal #ae #g ,organic anion #aj #h ,inorganic anion #f #f ,= ! sake ( simplicity we c assume t ^! ions are all monoval5t4 ,! ions adsorb$ by unit mass w !n be #aj;c7#a_/bj71 etc4 ,if ^! hypo!tical adsorption iso!rms be plott$ z usual we get ! fairly typical curves %[n 9 ,fig4 #a4 ,n[ 9 practice !re are always two ( ^! ions1 ea* giv+ its own specific effect 9 opposite s5ses1 & ! diff]5ce 7 a#a;c7#a_/n#a7 - a#b;c7#a_/n#b7 7 repres5ts ! nett *>ge adsorb$4 ,h5ce we h ! foll[+ comb9ations3-- ,inorganic acid #aj;c7#a_/bj7 - #f;c7#a_/f7 ,organic acid #aj;c7#a_/bj7 - #h;c7#a_/aj7 ,alkali #aj;c7#a_/bj7 - #g;c7#a_/ae7 ,inorganic salt #g;c7#a_/ae7 - #f;c7#a_/f7 ,if we plot ^! values ( nett adsorption aga9/ ! conc5tration we obta9 ! curves %[n 9 ,fig4 #b4 ,illu/ration3 ,,fig4 #b4 ,on ! assumption t ! nett *>ge adsorb$ is ! dom9ant factor 9 det]m9+ ! maximum swell+ at equilibrium1 "o mu/ !re=e reg>d ! curves ( ,fig4 #b z repres5t+ ! *anges 9 volume ( ! swoll5 gel z ! conc5tration is increas$4 ,n[ 9 type ^! curves correspond to ^? obta9$ by exp]im5t f hydro*loric acid1 acetic acid1 cau/ic soda1 & common salt4 ,! maximum swell+ ) hydro*loric acid increases rapidly ) ! conc5tration at fir/ & !n rapidly decreases1 ?\gh n at su* a great rate4 ,! swell+ ) acetic acid increases less rapidly & to a less maximum1 b decreases m sl[ly4 ,) common salt !re is a slight swell+ foll[$ by contraction4 ,cau/ic soda gives a rapid increase 9 volume at fir/1 aft]w>ds mu* less s1 & f9ally yields an exce$+ly sl[ decrease4 ,! correspond5ce ( ^! facts ) ! type-curves inevitably sugge/s t ! ph5om5on ( swell+ might be acc\nt$ =1 9 "p at lea/1 along ^! l9es4 ,( c\rse x is n likely t ! simple figures select$ = ! illu/ration ( ! argum5t are ei!r relatively or absolutely correct4 ,?us we "k t ! adsorption curve = hydrions & hydroxylions are n likely to be q id5tical1 z assum$ above4 ,z gelat9 is prim>ily slightly positive1 x is probable t ! values ( a & ( n = hydrion adsorption w be relatively slightly great]4 ,! relative values suppos$1 h[ev]1 are ne> en\gh to illu/rate ! cont5tion t ! type ( ! maximum volume curve c be expla9$ on ?is assumption ( diff]5t adsorption iso!rms = ea* ( ! ions4 ,if ! rem>ks on ! compression ( ! cont9u\s phase be recall$1 x w be obvi\s t 9 ! pres5t p>agraphs we h be5 giv+ ! "q ( equilibrium-volume a r "o-sid$ consid]ation4 ,! volume ( ! gel :5 equilibrium is e/abli%$ may be det]m9$ 9 type by ! nett *>ge adsorb$ by ! disp]se phase1 b x w be modifi$ also by ! lyotrope influ5ce ( ! p>ticul> sub/ance on ! cont9u\s phase4 ,:5 gelat9e swells 9 solutions ! influ5ces on bo? phases are always 9 op]ation1 & ei!r ^u occasion may become pr$om9ant4 ,9 ! case ( neutral organic sub/ances1 su* z cane-sug>1 ! lyotrope influ5ce is ! det]m9+ factor4 ,9 ! case ( neutral salts ! pr$om9ant influ5ce is decid$ by ! place occupi$ by ! salts 9 ! lyotrope s]ies4 ,if at ei!r end ( ! s]ies ! lyotrope influ5ce is upp]mo/ & ! effect ( ionic adsorptions is practically swamp$4 ,?us sodium sulphate & sodium iodide h9d] & promote imbibition respectively z c\ld be expect$ f _! /rong lyotrope p[]4 ,on ! o!r h&1 9 ! case ( sodium *loride1 :i* has comp>atively feeble lyotrope influ5ce1 ! relatively diff]5t adsorptions ( its ions comes to ! =e4 ,) acids & alkalies ! relatively l>ge adsorption ( ! hydrion & hydroxylion causes ?is to be ! pr$om9ant influ5ce1 b we mu/ conc$e ! possibility t purely lyotrope influ5ces may be at "w 9 "s cases1 & especially at ! great] conc5trations4 ,inde$1 x is sometimes a difficult problem to decide :e!r an increase or decrease 9 swell+ is due to lyotrope or adsorptive influ5ce1 b1 broadly speak+1 we c expect /rong lyotrope effects at ei!r end ( ! s]ies & also at l>ge conc5trations1 & we c expect /rong adsorptive effects 9 dilute solutions1 9 ! middle ( ! lyotrope s]ies & 9 ! case ( alkalies & acids4 ,= mu* ( ! above explanation ( ! nature & behavi\r ( gelat9e1 ! au?or mu/ himself take responsibility1 & 9 ?is section he has freely quot$ f 8 own pap]s ^u ! subject 7see ,ref]5ces74 ,he claims t 8 view ( a gelat9e gel z involv+ a network ( compress$ wat]1 liable to modification by lyotrope influ5ce ^u ! cont9u\s phase & by ionic adsorptions ( ! disp]se phase1 is mo/ 9 h>mony ) ! rec5t advances 9 our k ( colloids2 t mu* ( ! !ory is a necess>y coroll>y ( ^? discov]ies2 & also t he has f\nd ?is view to be a s\nd guide 9 practice1 bo? 9 tann+ & 9 gelat9e manufacture4 ,_m o!r !ories h be5 advanc$1 b mo/ are g5]alizations ov] too limit$ a field1 & f exp]im5ts ) only a few sub/ances1 & %[ little or no correlation ) ! wid] facts ( colloid behavi\r4 ,t ( ,proct]1 = example1 disc>ds altoge!r ! idea ( a two-phas$ /ructure ( ! gel z an unprov$ & r gratuit\s assumption1 dismisses surface t5sion consid]ations z m complicat$ & less v]ifi$1 & adsorption z :olly empirical1 :il/ x ignores lyotrope influ5ce & ! analogy ) ag> gels completely4 ,proct]'s !ory applies ma9ly to ! swell+ ( gelat9e by acids1 :i* swell+ he consid]s to be due to ! osmotic pressure ( ! anion ( a highly ionizable salt =m$ by ! *emical comb9ation ( ! acid ) gelat9e4 ,on ?is assumption1 ma!matical consid]ations %[ t ! electric *>ge on ! gelat9e is giv5 by ! expression z sqrt7#d;ex e#b71 :]e z ! am\nt ( ion tak5 up1 x ! conc5tration ( ! surr\nd+ solution1 & e ! excess conc5tration ( diffusible ions 9 ! jelly4 ,! prop]ty ( gelat9e & glue :i* is *iefly us$ 9 classify+ !m into grades ( diff]5t comm]cial value1 is ! /r5g? ( ! jelly obta9$ z comp>$ ) any arbitr>y /&>d gelat9e4 ,an enorm\s numb] ( o!r physical te/s h be5 devis$1 b none are ne>ly s simple or s reliable4 ,gelat9e is un=tunately v liable to hydrolysis ev5 by wat]1 & long be=e any amido-acids1 etc41 h appe>$ !re is a *ange to a n greatly hydrolyz$ product 7sometimes call$ beta gelat9e7 :i* has lo/ ! p[] ( sett+ to an ela/ic gel4 ,x is ?us ! lyophile nature :i* has be5 alt]$1 & ! fall 9 ela/icity corresponds to ! fall 9 p[] ( compress+ wat]1 :i* is proportional to ! conc5tration ( alpha gelat9e4 ,n[ ! ela/icity ( a gelat9e gel v>ies z ! squ>e ( ! conc5tration4 ,h5ce if "o s arranges ! conc5trations ( /&>d & unkn[n samples t gels ( equal ela/icity are obta9$1 ! conc5tration ( alpha gelat9e is ! same 9 bo? gels1 & ! relative am\nts ( alpha gelat9e 9 ! orig9al samples are inv]sely proportional to ! weights us$ to give gels ( equal ela/icity4 ,! /r5g? ( a gelat9e or glue is !re=e usually /at$ z ! numb] ( grams ( a /&>d gelat9e :i* w yield a gel ) ela/icity equal to t f #ajj grams ( ! gelat9e or glue be+ te/$4 ,ela/icity is mat*$ by lightly press+ ) ! f+]-tips4 ,x is also possible to grade samples ( gelat9e & glue by ! e/imation ( peptones1 ^: am\nt indicates ! degree ( hydrolysis4 ,nitrog5 is e/imat$ by ,kjeldahl's me?od 9 ! sample & 9 ! precipitate obta9$ by saturat+ a solution ) z9c sulphate4 ,! diff]5ce is calculat$ z peptones by multiply+ by #e4cc4 ,trotman & ,hack=d say t ! results are 9 ! same sequ5ce z ^? ( ! f+] te/4 ,! me?od1 h[ev]1 is mu* m labori\s ?an ! f+] te/4 ,gelat9e is also grad$ accord+ to ! results ( blea*+ & cl>ify+1 b ) q arbitr>y /&>ds1 l>gely det]m9$ by ! fancy ( ! cu/om]4 ,*emical analyses1 involv+ e/imations ( a%1 lime1 fat1 acid1 wat]1 insoluble matt]1 & poison\s metals1 e4g4 ars5ic1 copp]1 z9c & lead1 are ( value = special cases accord+ to ! de/9y ( ! goods4 ,special physical te/s1 su* z break+ /ra9 & foam te/1 are also ( "s little value 9 special cases4 ,,ref]5ces4 ,! ,*emi/ry ( ,colloids1 ,w4 ,w4 ,taylor4 #aiae4 ,h&book ( ,colloid ,*emi/ry1 ,w4 ,o/wald4 #aiai4 ,*emi/ry ( ,colloids1 ,zsigmondy & ,spe>4 #aiah4 ,introduction to ! ,*emi/ry & ,physics ( ,colloids1 ,e4 ,hats*ek4 ,surface ,t5sion & ,surface ,en]gy1 ,will[s & ,hats*ek4 ,*emi/ry ( ,colloids1 ,v4 ,ps*l4 ,grundzge d4 ,disp]soid ,*emie1 von ,weim>n4 ,! ,lyotrope ,s]ies & ! ,!ory ( ,tann+1 ,b5nett1 ,j4,s4,l4,t4,c41 #aiag1 p4 #acj4 ,! ,swell+ ( ,gelat9e1 ,b5nett1 ,j4,s4,l4,t4,c1 #aiah1 p4 #dj4 ,! ,swell+ ( ,gelat9e1 ,proct]1 ,j4,c4,s4 ,trans41 #aiad1 #aje1 #cac2 & ,koll4 ,*em4 ,beihefts1 #aiaa1 #b1 #bcd4 ,! ,swell+ ( ,gelat9\s ,tissues1 ,proct]1 ,j4,s4,c4,i41 ,april #af1 #aiaf4 ,summ>y ( ,proct]'s ,views1 & ,bibliography1 ,collegium 7,london71 p4 #c1 #aiag4 ,lyotrope ,influ5ce & ,adsorption 9 ! !ory ( wet "w1 ,b5nett1 ,j4,s4,t4,c41 #aibj1 p4 #ge4 ,= ! f+] te/1 see-- ,glue & ,glue ,te/+1 ,rideal1 #bnd ed41 p4 #aeh4 ,lea!r ,trades' ,*emi/ry1 ,trotman1 p4 #bda4 ,,section ,,ii4--,,raw ,,mat]ials ,,& ,,prelim9>y ,,treatm5t ,! raw mat]ials = ! manufacture ( gelat9e & glue may be classifi$ accord+ to _! orig94 ,! prelim9>y treatm5t1 :i* comprises *iefly purify+ & cleans+ op]ations1 is v>i$ accord+ to type ( manufactur+ process = :i* x is a prep>ation4 ,9 ! case ( hide or sk9 gelat9e1 ! raw mat]ial is a bye-product ( ! lea!r indu/ry4 ,aft] ! hides or sk9s h pass$ ?r\gh ! prep>atory processes :i* conv]t !m into pelt 7see ,"p ,i41 ,section ,,ii471 !y are s trimm$ t all t is left w make a useful lea!r4 ,^! trimm+s or r\nd+s include e>s & noses1 ! udd]s ( c[s & heif]s1 & also include p>ts f ! butt1 belly & %anks :i* are collectively t]m$ pieces4 ,! op]ation ( fle%+ 7,"p ,i41 ,section ,,ii471 9 :i* fat & fle% are cut f t side ( ! hides & sk9s :i* 0 next ! fle%1 also involves cutt+ into ! collag5 to "s ext5t1 & ^! fle%+s comprise ano!r v l>ge class ( raw mat]ial4 ,! fle%+s obta9$ by h& lab\r conta9 di/9ctly m hide sub/ances ?an ^? obta9$ by ma*9e "w1 & _! comm]cial value to ! gelat9e manufactur] is ( c\rse proportionate to ! collag5 cont5t4 ,"s hides & sk9s are split 9 ! pelt 7,"p ,i41 ,section ,,ix42 ,"p ,,ii41 ,sections ,,ii41 ,,iii4 & ,,iv471 & ! fle% split1 ?\gh sometimes made into lea!r1 is also us$ 9 mak+ gelat9e1 a high quality be+ obta9$ f su* mat]ial4 ,m9or s\rces ( mat]ial are t5dons & c>tilages1 & also hides & sk9s :i* h be5 too mu* damag$ by p>tial putrefaction or by accid5ts to make s\nd lea!r4 ,( c\rse ! mat]ial f ! hides = heavy lea!rs =m ! great] bulk ( raw mat]ial = sk9 gelat9e :i* is ?us d]iv$ pr9cipally f ox hides b %eep & goat sk9 pieces h also an important place4 ,! sk9s ( o!r animals1 su* z dogs1 cats1 h>es & rabbits n usually made into lea!r c also be depilat$ & us$ = mak+ sk9 gelat9e & glue4 ,horse hide fle%+s & pieces are sometimes us$1 b are notori\s = ! poor quality ( _! product4 ,!y seem to conta9 less alpha gelat94 ,all ^! mat]ials are ( c\rse readily putrescible & mu/ be put into "w )\t mu* loss ( "t4 ,:5 x is impossible to convey !m f ! tann]y to ! gelat9e factory quickly en\gh1 e4g4 =eign mat]ial1 ! glue /ock is dri$ out completely & sold 9 t condition4 ,9 ! manufacture ( pick]s f lim$ pelt !re is "s sup]flu\s mat]ial1 & ?is is cut into %av+s & dri$4 ,?is pick] wa/e also =ms a useful s\rce ( raw mat]ial4 ,sk9 gelat9e mat]ial is n v /rong 9 gelat9e-sub/ance4 ,! fle%+s1 pieces1 etc41 conta9 mu* wat]1 ev5 up to #hj p] c5t4 ,?is1 h[ev]1 is v v>iable1 & only a practical te/ or a hide sub/ance det]m9ation c indicate ! comm]cial value ( any p>ticul> mat]ial4 ,?is value1 moreov]1 is det]m9$ n only by ! yield & quality ( ! gelat9e :i* c be obta9$1 b also by ! yield ( grease1 ! valuable bye-product4 ,! prelim9>y treatm5t ( mat]ial = sk9 gelat9e consi/s ess5tially ( lim+ & ( wa%+4 ,! object ( ea* process is to purify4 ,lim+ has mu* ! same action on hide pieces1 etc41 z on hides1 & inde$ ! lim+ treatm5t is some:at sup]flu\s on cutt+s f well-lim$ hides4 ,! mat]ial is plump$ up & ! p>tially hydrolyz$ products are tak5 into solution4 ,lime also acts z mild antiseptic1 /ops any putrefaction & lib]ates ammonia =m$ by f]m5tation 9 transit to ! factory4 ,:5 plump+ is p>ticul>ly want$ 7z 9 wett+ 9 dry /ock7 cau/ic soda is sometimes us$ z an assi/ant 7cf4 dri$ hides74 ,sodium sulphide has also be5 us$ = ?is purpose4 ,! lim+ is 9 brick pits1 an excess ( undissolv$ lime be+ always us$4 ,x is advantage\s frequ5tly to di/urb or agitate ! goods 9 ! lime pits4 ,up to t5 weeks lim+ has sometimes be5 giv51 b ab\t ?ree weeks is n[ g5]ally consid]$ suffici5t1 & ! t5d5cy is to %ort5 ! "t4 ,! lime & soda h also a det]g5t action on soil$ /ock1 & !y probably assi/ 9 hydrolyz+ ! pigm5ts ( ! hair roots & %ea?s4 ,!y also saponify & emulsify ! grease1 & x is obvi\s1 !re=e1 t lim+ c be c>ri$ too f>4 ,slak$ lime1 ( c\rse1 mu/ always be us$4 ,aft] lim+ ! soak$1 s(t5$ & plump$ /ock is wa%$ z ?or\ghly z possible4 ,to d ?is x is necess>y to supply repeat$ bat*es ( clean cold wat]4 ,"s manufactur]s1 h[ev]1 use ! w>m wat] f ! evaporators4 ,wood5 vats or brick pits ) arrangem5ts = agitation1 = dra9+ (f & = inspection1 are us$ = ?is purpose4 ,! agitation may be c>ri$ out by means ( revolv+ %afts or drums ) project+ curv$ spokes or vanes4 ,an ,am]ican pat5t 7,hoevel]'s glue /ock wa%]7 involves ! use ( a paddle :eel4 ,x is comb9$ ) a settl+ tank to ga!r p>ticles ( /ock4 ,9 ! wa%+ ! *alk1 excess lime1 dirt1 etc41 are quickly remov$ & a sl[ delim+ process is comm5c$4 ,! s$im5t f ! wa%]s & wa% wat]s has "s value 9 mak+ f]tiliz]s4 ,delim+ _c be c>ri$ on fur!r ?an c]ta9 limits by wat] alone4 ,h5ce acid is (t5 add$ to f9i% (f ! process4 ,hydro*loric acid has ! advantage ( =m+ soluble salts1 b if !y are n remov$ completely _! lyotrope influ5ce is to weak5 ! gelat9e4 ,sulphuric & sulphur\s acids are ev5 *eap]1 & ! lyotrope influ5ce ( _! salts is 9 ! opposite s5se4 ,! latt] also has ! advantage ( de/roy+ sulphides1 an important advantage = food gelat9es4 ,:atev] acid is us$1 h[ev]1 x is evid5t t an abundance ( pure cold wat] is ! fundam5tal requirem5t ( a pure product4 ,x is a s\nd maxim 9 gelat9e manufacture to avoid1 if at all possible1 ! addition ( any soluble sub/ance1 = x is always pres5t 9 a m conc5trat$ /ate 9 ! f9i%$ article4 ,?us if its solubility be ev5 mod]ate1 "o is likely to atta9 sup]saturation 9 ! cake & consequ5tly a dull product4 ,fur!r1 lyotrope influ5ces c nev] /r5g!n a gel v mu*1 b may & (t5 d weak5 x v consid]ably4 ,h5ce ! aim ( mo/ manufactur]s 9 ! prelim9>y treatm5t is s to delime t a ne>ly neutral & salt-free product is obta9$4 ,an exception is ! case ( sk9 gelat9e 9 :i* excess ( sulphur\s acid is us$4 ,?is process has = its object n only delim+ & purify+1 b also a blea*+ action4 ,9 ! case ( bone gelat9e1 ! raw mat]ial is su* t !re are mu* long] & m elaborate prep>atory processes4 ,?is arises f ! fact t ab\t half ! bones ( animals consi/s ( m9]al matt]1 *iefly calcium phosphate4 ,bones1 ( c\rse1 v>y 9 composition to "s ext5t1 & ^? f y\ng] animals conta9 di/9ctly less ( ! m9]al con/itu5ts4 ,approximately speak+1 bones h ! foll[+ av]age composition3-- ,gelat9\s matt] #ba-a_/b p] c5t4 ,fat #ab-a_/b ,calcium phosphate #dh ,calcium c>bonate #c ,alkali salts1 silica1 etc4 #b-a_/b ,wat] #ab-a_/b -------- #ajj ,x w be se51 !re=e1 t ! manufacture ( bone gelat9e & ( a comp>atively l>ge proportion ( phosphate involves ! recov]y & purification ( mu* fatty matt]4 ,! manufactur+ processes are naturally subject to consid]able v>iation4 ,"o respect 9 :i* !y diff] is ! /age 9 :i* grease is remov$4 ,sometimes ?is is simply done z ! ne$ & occasion arise1 & x is skimm$ out 9 ! acid or wat] extractions1 b x is n[ m usual to h a special degreas+ process4 ,!re are1 moreov]1 two q di/9ct types ( manufacture4 ,9 "o ( ^! 7! boil+ process7 ! r\t9e be>s "s resemblance to t = sk9 gelat9e4 ,9 ?is process ! bones are wa%$ & cleans$ & !n imm$iately subject$ to extraction ) wat]4 ,?is removes ! gelat9\s matt] & leaves ! phosphate & e>?y matt]s beh9d4 ,grease may be remov$ be=e ! wat] extraction1 b is also sometimes remov$ by skimm+ (f dur+ ! extraction1 z is usual 9 ! case ( sk9 gelat9e4 ,?is proc$ure is n[ n mu* fav\r$ unless only a l[-grade glue is requir$4 ,9 ! o!r type ( manufacture 7! acid process7 ! mat]ial is fir/ degreas$1 & !n ! m9]al matt] is extract$ or dissolv$ by acids1 leav+ ! gelat9\s matt] beh9d = subsequ5t ref9em5t & solution4 ,! acid process has long be5 pref]r$ = high-class bone gelat9e1 & h5ce ne$s fur!r discussion4 ,! degreas+ op]ation 0 once br\ght ab\t by /eam+ only1 b is n[ accompli%$ ) ! assi/ance ( fat solv5ts4 ,! object ( cleans+ is n only to remove dirt1 b also fle%y matt] :i* (t5 adh]es to ! bones4 ,?is may conta9 a little gelat9e1 b consi/s ma9ly ( o!r prote9s & insoluble fibre1 nei!r ( :i* are want$ 9 ! wat] extraction4 ,! mill consi/s ( a l>ge cyl9d] ( /\t wire gauze4 ,?is revolves r\nd ! axis ( ! cyl9d]1 & ! bones are f$ 9 at "o end by a hopp] & are dis*>g$ at ! o!r4 ,! revolution ( ! mill causes ! friction :i* poli%es (f ! fle%y matt]4 ,! dirt & fle% fall ?r\gh ! gauze & are s5t to ! f]tiliz] factory4 ,! poli%+s are sometimes fur!r sep>at$ by a simil> ma*9e4 ,raw bones may ?us yield ne>ly #fj p] c5t4 ( degreas$ bones1 & ab\t #ef p] c5t4 cleans$ bones ready = extraction1 & #c or #d p] c5t4 bone meal4 ,! next /age is ! extraction ( ! m9]al matt]s by acid1 = :i* purpose hydro*loric acid has prov$ v suitable1 z bo? phosphate & c>bonate ( lime are dissolv$ by x4 ,! usual c\nt]-curr5t sy/em ( extraction is us$ cp4 ,lea*+ & extract manufacture1 ,"p ,i41 ,section ,,iii41 p4 #ce4 ,! process is me?odical & regul>1 ! acid liquor pass+ successively ?r\gh a batt]y ( six vats 9 su* a mann] t ! liquor ri*e/ 9 lime salts comes into contact ) ! bones mo/ rec5tly *>g$2 ! fre% acid ?us acts ^u ! ne>ly extract$ bones4 ,! hydro*loric acid us$ is ( #h to #aj p] c5t4 /r5g? 7#e to #g ,b474 ,/rong] acid is apt to hydrolyze 7rot7 ! gelat9e1 :il/ weak] acid takes long] "t4 ,! process takes #h to #aj days1 ?\gh up to #ad days is sometimes giv51 &1 on ! o!r h&1 ! process has be5 occasionally r$uc$ to #d days4 ,! gelat9\s matt] undissolv$ has ! %ape ( ! orig9al bone1 b is mu* swoll54 ,:5 ! acid liquor is saturat$ ) lime salt1 ! liquor is drawn (f f bel[ ! vats & s5t to ! phosphate precipitation tanks4 ,! phosphate is usually precipitat$ by add+ j suffici5t milk ( lime to neutralize ! hydro*loric acid4 ,! precipitat$ phosphate is !n well wa%$ by decantation to remove calcium *loride4 ,x is !n dra9$1 & dri$ at a l[ temp]ature4 ,z a l>ge bulk ( phosphate is obta9$ x is (t5 filt]-press$ & dri$ quickly 9 long revolv+ *amb]s ?r\gh :i* a curr5t ( air is pass$4 ,! phosphate is sometimes also precipitat$ by ammonia4 ,x is !n m easily wa%$ & dri$1 & ! ammonium *loride is recov]$ & may be us$ to reg5]ate ammonia1 or be sold z a valuable bye-product4 ,sometimes ! acid liquor is n us$ = mak+ precipitat$ phosphate1 b is evaporat$ ) animal *>coal & silica & !n di/ill$ to make phosphorus4 ,! next /age is ! purification by wa%+ ( ! gelat9\s matt] :i* rema9s4 ,! vat is fill$ up ) pure cold wat] & ! mat]ial all[$ to /eep = six or sev5 h\rs4 ,! acid & salts rema9+ diffuse outw>ds into ! wat]4 ,?is is dra9$ (f & replac$ by fre% wat]1 & ! proc$ure repeat$ half a doz5 times or z (t5 z necess>y4 ,! end is said to be det]m9$ by ! abs5ce ( a precipitate on add+ silv] nitrate to ! wa% wat]1 or by ! abs5ce ( any action on blue litmus pap]4 ,x w be se51 h[ev]1 t !re are two actions involv$1 "o be+ ! removal ( calcium *loride & ! o!r ! removal ( excess acid4 ,! =m] is ! easi]1 & is almo/ necess>ily br\ght ab\t by ! latt]4 ,h5ce 9 "s factories ! neutralization is br\ght ab\t1 !re=e1 by ! addition ( a c]ta9 quantity ( soda1 or m usually by lime1 & ! mat]ial is sometimes submitt$ to a v]itable lim+ by :i* x rema9s 9 milk ( lime = ab\t ?ree weeks1 ! lime liquor be+ r5ew$ sev]al times4 ,! product is f9ally wa%$ aga9 to remove excess lime4 ,?is is c>ri$ out 9 a rotat+ vessel ?r\gh :i* passes a cont9u\s /ream ( wat]4 ,if a slightly acid gelat9e is requir$1 h[ev]1 ! lime & lim+ are bo? sup]flu\s1 & ! proc$ure is simply to wa% z ?or\ghly z possible & !n to imm]se ! mat]ial 9 a #a p] c5t4 sulphur\s acid solution = #c h\rs to blea*1 & !n to proce$ ) ! wat] extraction or solution ( ! gelat9e4 ,! hydro*loric acid us$ = ^! processes %\ld be z pure z possible1 & ! degreas+ z ?or\gh z possible1 =1 if n1 a gelat9e ) a bad od\r is liable to be obta9$4 ,in/ead ( us+ hydro*loric acid = ! solution ( m9]al matt]1 sulphur\s acid is sometimes employ$1 & has ! advantages t its blea*+ effect is !reby obta9$ ?r\gh\t ! process1 & t x is recov]able = subsequ5t use4 ,! ,b]gmann process1 mo/ g5]ally fav\r$1 is describ$ v concisely by ,rideal ?us3 ,a sulphur\s acid solution is made to circulate ov] ! bones 9 a s]ies ( clos$ tanks1 ! solution be+ cont9ually enri*$ ) sulphur\s acid f a cyl9d] ( ! liquefi$ gas4 ,! result+ liquor1 conta9+ an acid calcium phosphate & calcium bisulphite1 is heat$ by /eam 9 a lead5 dige/or1 :5 ! excess ( sulphur\s acid is lib]at$ & passes back to ! tanks1 :ile neutral calcium phosphate & sulphite are precipitat$4 ,! latt] is decompos$ by an equival5t ( hydro*loric acid1 sett+ free ! rema9+ sulphur\s acid1 :i* is return$ to ! tanks1 leav+ calcium *loride 9 solution1 & neutral calcium phosphate 9 susp5sion4 ,n m ?an #e p] c5t4 ( sulphur\s acid is said to be lo/ 9 ?is process1 & ! gelat9e is m ?or\ghly blea*$4 ,x is subsequ5tly well wa%$ be=e extraction4 ,recov]y & ,purification ( ,grease4--,! degreas+ op]ation1 :i* is appli$ usually to bones & to sk9 glue scut*1 0 once br\ght ab\t by /eam+ only1 b is n[ accompli%$ ) ! assi/ance ( fat solv5ts1 ?\gh 9 ! latt] case /eam+ toge!r ) me*anical c5trifugal =ce has prov$ suffici5tly successful4 ,on ! ,cont95t c>bon disulphide 0 once l>gely us$ z solv5t1 & 9 ?is c\ntry b5z5e has be5 employ$1 b _! l[ volatility & high inflammability1 z well z _! exp5se1 make bo? ^! sub/ances some:at unsuitable1 & x is n[ usual to make use ( petroleum oils1 :e!r ,scot*1 ,am]ican or ,russian4 ,a fraction :i* boils ab\t ! same temp]ature z wat] is usually employ$1 & all ( x mu/ be volatile "u #bhj ,f4 ,be=e ! actual grease extraction ! bones %\ld be sort$ ov] & unsuitable sub/ances 7horns1 gravel1 iron1 etc47 remov$4 ,!y are also usually put ?r\gh a mill & r\ghly cru%$ or brok54 ,! actual grease extraction plant consi/s ( l>ge copp] vessels :i* w ea* take #e tons ( bones4 ,^! extractors are arrang$ 9 sets s t ! degreas+ is proce$+ 9 "s :il/ ! o!rs are be+ empti$ & re*>g$4 ,! doors = *>g+ & empty+ mu/ be securely fa/5$4 ,:5 ! extractor is *>g$ ! solv5t is run 9 & heat$ by a /eam coil :i* ev5tually causes x to di/il4 ,aft] "s h\rs ! rema9d]1 :i* has dissolv$ mu* grease1 is run (f1 & a fre% lot ( solv5t is add$ & heat$ up4 ,aft] f\r su* extractions only ab\t #a_/d p] c5t4 ( grease rema9s 9 ! bones4 ,to remove ! rema9d] ( ! solv5t high-pressure /eam 7#hj lbs47 is bl[n ?r\gh ! bones4 ,! extractor is !n op5$ & ! degreas$ & some:at dri$ bones are me*anically convey$ to ! cleans+ mill4 ,! grease solutions obta9$ are subject$ aga9 to /eam ) a view to remov+ ! solv5t & obta9+ x = repeat$ use 9 ?is s5se4 ,! effici5t di/illation & recov]y ( ! solv5t is inde$ an ess5tial elem5t 9 ! success ( ! process4 ,! greases obta9$1 :e!r by ! use ( fat solv5ts or by skimm+ (f dur+ extraction1 or 9 any o!r way1 are mix$ toge!r z is appropriate to _! orig9 & purity1 & subject$ to fur!r purification1 ! object ( :i* is to remove gelat9\s & album9\s matt]s1 & to decompose lime or soda soaps4 ,! precise me?ods ( purification are1 ( c\rse1 dep5d5t ma9ly ^u ! impurities kn[n to be pres5t1 b ! readie/ me?od is to give ! grease fur!r /eam+ or boil+ ) wat]1 & s effect by wa%+ & by solv5t action ! elim9ation ( non-fatty matt]s4 ,9 _m cases x is f\nd advantage\s to employ m9]al acids or oxidiz+ ag5ts to assi/ ! process4 ,! process may be repeat$ z (t5 z is desir$4 ,! recov]$ & purifi$ greases are (t5 ( a high /&>d ( purity1 & ! be/ are q fit = edible purposes4 ,! l>ge ext5sion ( ! m>g>9e indu/ry 9 ?is c\ntry has inde$ caus$ a l>g] proportion ?an ev] ( ?is bye-product to be s us$4 ,9 "s cases x is f\nd comm]cially advantage\s to submit ! grease to action ( ! filt] press1 & s to sep>ate x into solid & liquid portions1 ! =m] conta9+ a mu* l>g] proportion ( /e>91 & ! latt] ( ole94 ,mu* ( ! grease f ! gelat9e trade is also f\nd suitable = soap manufacture1 & is !re=e a valuable s\rce ( glyc]9e4 ,o!r ,raw ,mat]ials4--,:il/ hide pieces & fle%+s1 & animal bones1 comprise ! pr9cipal raw mat]ial = ! manufacture ( gelat9e & glue1 !re are also m9or s\rces ( raw mat]ial :i*1 ?\gh (t5 n suitable = gelat9e manufacture1 w yield a satisfactory glue4 ,?us ! sk9s1 bladd]s & bones ( fi% =m ! s\rce ( fi% glue4 ,sole sk9s1 inde$1 :5 deodoriz$ by *lor9e & decoloriz$ by animal *>coal1 are made into gelat9e4 ,! bladd]s ( "s fi% 7e4g4 ! /urgeon7 are wa%$1 purifi$ & dri$ ) roll+ to make is+lass1 a =m ( natural gelat9e 9 :i* ! orig9al fibr\s /ructure is reta9$4 ,!re is a limit$ dem& = ?is mat]ial = cl>ify+ purposes by brew]s1 w9e m]*ants & cooks4 ,lea!r wa/e may sometimes be us$ to make a l[-grade glue4 ,vegetable-tann$ lea!r (f]s mu* difficulty unless v lightly & rec5tly tann$4 ,! tannage mu/ be /ripp$ by drumm+ ) weak alkalies1 e4g4 borax1 sodium sulphite1 or weak soda4 ,*rome lea!r may be /ripp$ easily & completely by ,ro*elle salt & o!r salts ( hydroxy acids 7,proct] & ,wilson71 & also by ammonia acetate1 oxalate & simil> salts 7,b5nett71 also by c]ta9 organic acids 7,lamb74 ,processes are pat5t$ by :i* *rome lea!r is dige/$ ) lime to make glue1 ! *romium hydrate be+ insolubiliz$4 ,visc\s & t5aci\s sub/ances are also obta9$ f "s vegetable matt]s & are call$ glue4 ,,ref]5ces4 ,glue & ,glue ,te/+1 ,s4 ,rideal1 ,d4,sc41 #bnd ed42 ,sk9 ,gelat9e & ,glue1 pp4 #be-dh2 ,bone ,gelat9e & ,glue1 pp4 #ei-ff4 ,gelat9e1 ,glue & _! ,alli$ ,products1 ,t4 ,lamb]t1 pp4 #aa-eb4 ,encyclop$ie *imique1 ,fremy1 tome x4 ,,section ,,iii4--,,extraction ,! t]m extraction is appli$ to t ess5tial process by :i* ! gelat9\s matt] f :atev] raw mat]ial is us$1 is actually dissolv$ 9 wat] & remov$ f ! re/ ( ! mat]ial4 ,extraction is (t5 t]m$ boil+ or cook+4 ,:e!r "o is treat+ hide fle%+s & pieces or :e!r "o is deal+ ) raw or acidulat$ bones1 ! g5]al pr9ciples ( extraction are mu* ! same1 & mo/ ( ?is section is equally applicable to any class ( mat]ial4 ,! *ief pr9ciple ( extraction is s to arrange ! process t bo? ! mat]ial & ! extract$ liquor are ma9ta9$ at high temp]atures = ! %orte/ possible "t4 ,z we h obs]v$1 gelat9e is readily hydrolyz$ by hot wat]1 & z hot wat] is ne$$ = its extraction or solution1 c>e mu/ be tak5 to remove ! solution z soon z possible f ! s\rce ( heat4 ,9 practice ?is c only be done some:at imp]fectly1 z x is necess>y to obta9 a gelat9e sol ( sev]al p] c5t4 /r5g? be=e remov+ x f ! extraction vessel4 ,! /rong] ?is sol is made be=e removal1 ! less ! "t1 tr\ble & exp5se is incurr$ 9 evaporation subsequ5tly1 b ! m is ! exposure to heat ) consequ5t weak5+ ( ! gelat9e4 ,h5ce 9 practice x is necess>y to compromise4 ,! matt] is complicat$ fur!r by ! necessity ( obta9+ a cle> sol1 = :i* x is desirable t ! sol obta9$ 9 extraction %\ld n be too conc5trat$1 z impurities settle & filt] mu* m readily f weak] & less visc\s sols4 ,x w be und]/ood1 !re=e1 t :atev] mat]ial is be+ extract$1 ! mo/ fav\r$ proc$ure is to extract 9 fractions4 ,! fir/ fraction1 :i* is lea/ expos$ to hydrolytic decomposition1 produces ! highe/ quality products1 & ! subsequ5t fractions 7ne>ly always two m1 & sometimes sev]al7 yield products :i* gradually become ( inf]ior quality ow+ to ! numb] ( times ! raw mat]ial has be5 re-heat$4 ,)9 limits1 ! precise temp]ature ( extraction does n h ! importance "o w\ld expect4 ,lamb]t sugge/s ! temp]ature ( #ahe ,f4 z suitable = bo? sk9 & bone gelat9e1 & mo/ manufactur]s w\ld1 on ! :ole1 endorse ?is4 ,if1 h[ev]1 a high] temp]ature be pref]r$1 ! hydrolytic action is increas$ 9 int5sity b decreas$ 9 its "t ( op]ation1 :il/ if a l[] temp]ature be adopt$ ! decomposition is ret>d$ 9 spe$1 b is increas$ 9 totality because ( ! long] "t ne$$ to obta9 a suitable /r5g? ( liquor4 ,?us1 ) c>e1 mu* ! same result is obta9$ by extraction at ne> boil+-po9t = a %ort "t z by extraction at #afj ,f4 = a long "t4 ,! high] temp]atures h ! def9ite advantage ( spe$1 :il/ ! l[] temp]atures h ! advantage t "o may *oose to be satisfi$ ) a weak] extract1 & s ga9 a little 9 ! /r5g? ( ! gel1 by ?r[+ m "w on ! evaporator4 ,"o o!r po9t %\ld1 h[ev]1 be borne 9 m9d 9 ?is connection1 viz4 t a gelat9e sol kept at temp]atures above #ahe ,f4 beg9s to det]iorate 9 col\r4 ,:il/1 !re=e1 mu* dep5ds ^u ! precise class ( mat]ial1 x is broadly true to say t ! high] temp]atures are advantage\s = glue1 :il/ ! l[] temp]atures are pref]able = ! highe/ quality gelat9e4 ,extraction 9 op5 vats is us$ bo? = sk9 & bone gelat9e4 ,x is usually pref]r$ :5 x is int5d$ to extract at ! l[] temp]atures1 & x is usually adopt$ also :5 ! mat]ial is su* t ! extraction is comp>atively rapid1 z = example 9 ! case ( sk9 gelat9e & bones by ! acid process4 ,! vats !mselves are (t5 con/ruct$ ( wood1 9 :i* case !y are heat$ by a copp] 7or brass7 /eam coil4 ,!y may be con/ruct$ also ( iron1 ca/ or wr\ght1 ! =m] be+ *eap]1 less liable to corrosion1 b m liable to fracture4 ,9 ! case ( iron vessels ! heat+ may also be done by a /eam coil b5ea? a false bottom1 b x is sometimes arrang$ t iron vats are heat$ by a /eam jacket1 & ev5 by a hot-wat] jacket4 ,heat+ 9 ei!r wood or iron vessels has be5 br\ght ab\t by direct application ( raw /eam1 b ! results are bo? unc]ta9 & unsatisfactory ow+ to local ov]heat+4 ,:atev] appliances are us$ agitation ( ! mat]ial or liquor is advantage\s4 ,extraction 9 clos$ vats is also us$4 ,?is is g5]ally associat$ ) extraction at high] temp]atures1 & m (t5 also ) ! manufacture ( glue ?an ( gelat9e4 ,x has be5 us$ on ! ,cont95t = sk9 glue1 & 9 ?is c\ntry = bone gelat9e & glue by ! boil+ process4 ,9 ?is sy/em ( work+ ! vessels are usually made ( #c_/h-;in* /eel plates1 & w take a *>ge ( #c to #e tons ( mat]ial4 ,x is claim$ = ! sy/em t !re is a less5$ /eam consumption z well z less] manipulation1 t /rong liquors are m easily & quickly obta9$1 & t ! mat]ial may be m ?or\ghly exhau/$4 ,extraction is sometimes made by /eam & wat] play+ alt]nately on ! mat]ial1 b _m manufactur]s pref] ! use ( direct /eam1 keep+ ! pressure at #ae lbs4 = ab\t #b h\rs4 ,! pressure is !n r$uc$ consid]ably & ! process f9i%$ (f by spray+ ! mat]ial ) wat]4 ,f su* a proc$ure a #bj p] c5t4 glue sol may be obta9$4 ,x is common to "w su* extractors 9 c\ples or 9 batt]ies ( f\r to six4 ,x w be readily und]/ood t ! process is suitable = mak+ bone glue :5 ! phosphate has n be5 dissolv$4 ,! high temp]ature is 9 ?is case almo/ necess>y to ensure ?or\gh extraction4 ,x w be equally cle> t ! process is n s suitable 9 ! manufacture ( a /rong gel4 ,z alt]natives to ! sy/ems ( fractional extraction1 sev]al processes h be5 devis$ 9 :i* ! extraction is cont9u\s4 ,among/ ^! is ! t[] sy/em1 9 :i* ! mat]ial is plac$ ^u a s]ies ( p]=at$ %elves arrang$ inside a /eam-tight cyl9d] or t[]4 ,wat] is admitt$ f ! top & trickles d[n ov] ! mat]ial :il/ /eam is admitt$ f ! bottom4 ,sup]heat$ /eam is sometimes us$4 ,! mat]ial may ?us be dige/$ ) a m9imum am\nt ( wat]1 & ! sol passes out ( ! app>atus & f ! action ( heat soon aft] x is =m$4 ,f bones ! sol obta9$ is ( good col\r1 b is some:at dull4 ,sev]al v>iants ( ?is process h be5 pat5t$4 ,ano!r cont9u\s sy/em ( extraction is t involv+ ! use ( ! ,ar*im$ean screw4 ,! mat]ial is f$ into "o end ( a cyl9d] c>ri$ along & dis*>g$ at ! o!r end by ! screw4 ,! cyl9d] is ( metal gauze & is /eam jacket$4 7,lehmann's pat5t1 #aiab47 ,cont9u\s sy/ems1 involv+ a batt]y ( dige/ors connect$ by pipes1 h also be5 devis$4 ,arrangem5ts are made ( c\rse = admitt+ wat] & /eam z requir$4 ,,ref]5ces4 ,glue & ,glue ,te/+1 by ,s4 ,rideal1 ,d4,sc41 #bnd ed41 pp4 #dg-ef & #fa4 ,gelat9e1 ,glue & _! ,alli$ ,products1 by ,t4 ,lamb]t1 pp4 #ba-bd1 #dj1 #db-dd1 #di & #ea4 ,encyclop$ie *imique1 ,fremy1 tome x41 p4 #hc4 ,,pat5ts4 ,edison3 ,u4,s4,a4 pat5t1 #aijb1 #gjcbjd4 ,b]tram3 ,engli% pat5t1 #ahib1 #iea4 ,dor5burg3 ,g]man pat5t1 #aiaa1 #bcifgf4 ,lehmann3 ,fr5* pat5t1 #aiab1 #ddaedh4 ,,section ,,iv4--,,cl>ification ,,& ,,decolorization ,aft] ! raw mat]ial has be5 appropriately prep>$ & an aque\s extract or gelat9e sol obta9$ !refrom1 !re are c]ta9 ref9em5ts necess>y be=e ! weak sol is evaporat$4 ,^! purify+ processes include 7#a7 cl>ification1 7#b7 decolorization1 & 7#c7 blea*+4 ,:il/ mo/ manufactur]s h m or less successfully solv$ ! problems involv$ 9 ^! processes1 ! practical me?ods t are 9 common use h be5 evolv$ & elaborat$ 9 a purely empirical way1 & ! und]ly+ pr9ciples h be5 v imp]fectly recogniz$1 & inde$ (t5 confus$ & misund]/ood4 ,h5ce x is ev5 yet n uncommon to f9d ^! t]ms r loosely us$1 & x is "o aim ( ?is section to def9e & di/+ui% ^! v>i\s op]ations 9 pr9ciple z well z 9 practice4 ,cl>ification consi/s ess5tially 9 ! removal ( susp5d$ matt]s1 ) ! consequ5t production ( a sol or gel :i* is bright1 cle>1 & app>5tly homog5e\s4 ,blea*+ consi/s ess5tially 9 de/roy+ ! col\r+ matt]s ( ! sol by *emical action1 su* z oxidation or r$uction4 ,decolorization involves ! removal r ?an ! de/ruction ( col\r+ matt]s1 & does n !re=e imply a *emical action 9 ! ord9>y s5se4 ,cl>ification may be n[ consid]$ m p>ticul>ly4 ,x is necess>y 9 ?is connection to consid] :at is meant by susp5d$ matt]4 ,! mod]n view is t ! diff]5ce betwe5 a true solution & a muddy liquor or an emulsion is "o *iefly ( degree4 ,if ! p>ticles ( matt] 9 susp5sion or emulsion 7! disp]se phase7 be r$uc$ 9 size !y ev5tually m]ge into colloidal sols :i* are sometimes analog\sly nam$ susp5soids & emulsoids1 if fur!r r$uc$ 9 size into susp5sides & emulsides1 & ) fur!r r$uction into true solutions4 ,on ?is view n only susp5sions & emulsions1 b also sols1 solutides & solutions are all het]og5e\s4 ,n[ 9 practice ! cl>ify+ ( a gelat9e sol involves only ! removal ( ! p>ticles :i* are evid5t to sight4 ,:at is ne$$ is t ! product %\ld make a sol or gel :i* to ! nak$ eye appe>s to be optically cle> bo? to reflect$ & to transmitt$ light4 ,if desir$1 ! limit c\ld be express$ 9 t]ms ( disp]sity or specific surface4 ,n[ x is a comp>atively easy matt] to remove ! co>s] sub/ances :i* (t5 pass into ! sol1 e4g4 undissolv$ portions ( raw mat]ial or ! insoluble portions1 su* z ! hair1 ! gra9 7hyal9e lay]71 & ! ela/ic fibres ( sk9 gelat9e mat]ial1 & ! fibres :i* ev5 rema9 9 extract+ acidulat$ bones4 ,a m difficult proposition is ! removal ( /ill f9] p>ticles :i* may be almo/ said to be 9 colloidal solution1 b :i* at any rate are s l>ge t !y cause a visible opalesc5ce or ev5 a turbidity ( ! gelat9e sol4 ,a m difficult task also is ! removal ( m9ute p>ticles ( grease1 :i* are an exce$+ly common cause ( turbidity & :i* are (t5 v effectively emulsifi$ 9 ! sol4 ,n[ at ?is /age x is necess>y to po9t out t besides ! diff]5ce 9 ! size ( ! p>ticles ( ! disp]se phase1 !re is ano!r important diff]5ce involv$1 viz4 t ! p>ticles ( a colloid sol c>ry an electric *>ge ow+ to ! adsorption ( electrically *>g$ ions ( ! electrolytes 7salts1 acids or alkalies7 pres5t4 ,if ?is *>ge be remov$ ! colloid is precipitat$ 7coagulat$1 flocculat$7 & is !n filt]$ (f ) comp>ative ease4 ,?is precipitation c be br\ght ab\t by a r$uction or elim9ation ( ! pot5tial diff]5ce betwe5 ! disp]se phase & ! cont9u\s phase4 ,! electric *>ge giv5 by ! adsorb$ ions may be r$uc$ by dilution1 = dilution causes a less5$ adsorption ( ! *>g+ ions4 ,h5ce ! well-kn[n practical fact t x is m satisfactory to filt] a dilute gelat9e sol4 ,fur!r1 ! electric *>ge may be r$uc$ also by caus+ ! adsorption ( an ion ( opposite *>ge4 ,?is is ! pr9ciple und]ly+ ! precipitation 7( any colloid7 by add+ electrolytes4 ,x is ess5tial "h to consid] :i* ions are mo/ likely to be adsorb$1 & also to be> 9 m9d :at *>ge !y c>ry4 ,n[ ! hydrion 7,h7 ( acids & ! hydroxyl ion 7,,oh-7 ( alkalies are mo/ /rongly adsorb$1 s t to precipitate a negative sol1 acid is v effective1 :il/ ) a positive sol an alkali is an appropriate precipitant4 ,fur!r1 x is kn[n t organic ions are usually m /rongly adsorb$1 h5ce :5 precipitat+ f an alkal9e sol 7negative sol71 "o %\ld pref]ably select an inorganic or m9]al acid r ?an an organic acid4 ,?us 9 cl>ify+ an alkal9e gelat9e sol1 hydro*loric or sulphuric acid is to be pref]r$ to acetic or lactic acid4 ,aga91 x is necess>y to rememb] t a dival5t ion c>ries twice ! *>ge ( a unival5t ion1 h5ce ! precipitat+ p[] ( an electrolyte dep5ds ^u ! val5cy ( ! ion ^: electric *>ge is opposite to t on ! sol 7,h>dy's val5cy rule74 ,?us a negative sol is mo/ easily precipitat$ by a monobasic acid4 ,?us hydro*loric acid is bett] ?an sulphuric1 on acc\nt ( ! /abiliz+ effect ( ! dival5t ,,s#d-- ion on a negative sol4 ,9 su* a sol1 also1 ! val5cy rule indicates t ! multival5t kations1 e4g4 iron1 ,fe2 *romium1 ,cr2 & alum9ium1 ,al1 %\ld h great precipitat+ & cl>ify+ effect4 ,?is ( c\rse is kn[n to be ! case1 alum9ium salts hav+ long be5 us$4 ,! rule indicates1 also1 t alum9ium *loride w\ld be bett] ?an ! sulphate or ?an pota% alum4 ,ano!r feature ( precipitation wor?y ( m5tion is ! ph5om5on ( acclimatization4 ,?is describes ! fact t :5 ! precipitat+ reag5t is add$ v sl[ly1 or a little at a "t1 a l>g] am\nt mu/ be us$1 & ! sl[] ! addition ! great] ! excess requir$4 ,h5ce 9 precipitat+ matt]s f an alkal9e gelat9e sol ! acid1 if practicable1 %\ld be add$ all at once4 ,9 any case x is cle> t "o %\ld aim at filt]+ a gelat9e sol :5 x is ne> ! iso-electric po9t1 :i* is /able en\gh = gelat9e itself1 b a po9t ( in/ability = _m undesir$ impurities4 ,yet ano!r ph5om5on ( colloid *emi/ry is conc]n$1 viz4 protection4 ,! p>ticles x is desir$ to precipitate n only adsorb ions ( electrolytes1 b also ! gelat9e sol itself1 & ! p>ticles1 ?us cov]$ by a lay] ( a /able emulsoid sol1 atta9 mu* ( ! /ability ( ?is gelat9e sol4 ,un=tunately = gelat9e manufactur]s1 gelat9e possesses v great p[]s z protective colloid1 & ?is no d\bt greatly enhances ! practical difficulty ( obta9+ a cle> & bright sol or gel4 ,"h aga9 dilution ( ! sol r$uces ! adsorption & correspond+ly r$uces1 to "s ext5t1 ! difficulty4 ,) reg>d to ! turbidity or opalesc5ce 9 a gelat9e sol due to m9ute globules ( grease1 ! case pres5ts "s analogy to ! co>s] colloid solutions1 b ! analogy has its limits1 = an emulsion ( grease is n an emulsoid sol4 ,d\btless ! grease globules exhibit adsorptive ph5om5a1 9 :i* case ! val5cy rule comes into =ce2 ! gelat9e1 also1 by l[]+ int]facial t5sion1 assi/s 9 protect+ ! emulsion2 b grease emulsions are c]ta9ly /abiliz$ 9 alkal9e m$ia 7h5ce ! det]g5t effect ( soap1 soda1 borax1 etc471 & x is und\bt$ly easi] to sep>ate ! emulsion by mak+ ! m$ium acid4 ,h5ce ! practical fact t an acid sol is m easily cl>ifi$ f grease ?an an alkal9e or ev5 ?an a neutral "o4 ,! next /age 9 cl>ification is ! sep>ation ( precipitat$ matt]s & ( ! coalesc$ p>ticles ( grease4 ,?is may be atta9$ by ! two processes usual 9 su* a problem ( *emical eng9e]+1 viz4 s$im5tation & filtration4 ,aft] precipitation1 !re=e1 ! sol %\ld be all[$ to /& = "s h\rs1 dur+ :i* "t ! precipitate n only flocculates b also settles to ! bottom1 & ! globules ( grease coalesce fur!r & rise to ! top1 f :i* !y may be skimm$ (f4 ,s$im5tation alone is bo? too sl[ & too incomplete to be suffici5t = prop] cl>ification1 & 9 ^! days x is always supplem5t$ by ! use ( ! filt]-press4 ,?is well-kn[n appliance c easily be adapt$ to ! local requirem5ts ( ! manufactur]4 ,z spe$ ( work+ is an ess5tial requirem5t x is necess>y to h a l>ge filt]+ surface1 & ?is may be done ei!r by increas+ ! numb] ( plates 9 ! press or by increas+ ! area ( ! plates us$4 ,! l>ge plates1 h[ev]1 are (t5 cumbr\s & inconv5i5t1 & if ( metal are v heavy4 ,! plates may be con/ruct$ ( well-season$ wood1 or 9 ! case ( alkal9e gelat9e & glues1 ev5 ( iron4 ,! framework is 9 any case usually iron4 ,acid gelat9es & glues may h wood5 plates1 b acid-pro( alloys are sometimes us$ to make !m4 ,:]e x is ess5tial to filt] quickly two presses may be arrang$ 9 p>allel1 ?us d\bl+ ! active filt]+ surface4 ,:5 x is ess5tial to obta9 ! highe/ possible cl>ity1 two presses may be work$ 9 s]ies1 :i*1 9 effect1 means t ! sol is filt]$ twice4 ,9 us+ ! filt] press = gelat9e & glue x is mo/ necess>y to obs]ve ! mo/ scrupul\s cleanl9ess1 & ! plates mu/ be frequ5tly wa%$ & /]iliz$4 ,rideal recomm5ds weak *lor9e wat] or blea*+ p[d] solution = ?is purpose4 ,! process ( decolorization1 by :i* col\r+ matt]s are remov$ )\t be+ *emically alt]$ or de/roy$1 usually prec$es or takes place concurr5tly ) ! filtration4 ,! und]ly+ pr9ciple ( ?is op]ation is adsorption4 ,! col\r+ matt]s are usually 9 colloidal solution & mo/ frequ5tly are emulsoids1 h5ce !y are sub/ances :i* are kn[n to be exce$+ly susceptible to positive adsorption4 ,x is probable1 also1 t 9 a gelat9e sol are p>ticles :i* cause turbidity1 ?\gh n col\r$1 & :i* are capable ( be+ adsorb$4 ,h5ce ! adsorption ( col\r+ matt]s n only makes ! sol m col\rless1 b 9 all probability makes x bright] & cle>]4 ,fur!r1 decolorization by adsorption probably also involves ! removal ( ! la/ traces ( emulsifi$ grease4 ,x w be cle>1 !re=e1 t 9 ! improvem5t 9 brightness & col\r ( a gelat9e sol1 adsorption fulfils a triple usefulness4 ,! ord9>y processes ( dye+ fabrics or lea!r are adsorption processes1 & ! decolorization ( gelat9e sols consi/s ess5tially ( ! same process1 except t ! conc5tration ( ! dye/uff is mu* less1 & ! liquor rema9+1 in/ead ( ! adsorb5t1 is ! prim>y consid]ation4 ,decolorization ( gelat9e sols may be effect$ by any sub/ance ) a l>ge specific surface4 ,inde$1 a great v>iety ( adsorb5ts are actually us$ 9 practice1 & ea* factory has its fav\rite mat]ial or mixture1 & its fav\rite mode1 place1 & "t ( application1 det]m9$ p>tly by ! nature ( ! adsorb5t & p>tly by ! precise =m ( app>atus us$4 ,among/ ! adsorb5ts :i* h receiv$ special fav\r are s&1 kieselguhr1 asbe/os1 animal *>coal1 wood pulp fibre1 album9 & alum9a4 ,s& is v effective1 b a comp>atively l>ge weight is ne$$1 & its cleans+ = repeat$ use is tr\blesome4 ,on ! o!r h&1 x may be completely r5ovat$ by ignition4 ,kieselguhr is a v p[]ful adsorb5t1 & only a little w d mu* good2 x is1 h[ev]1 h>dly suffici5t alone4 ,animal *>coal has great specific surface1 b its pores are v small = visc\s liquors1 & its use is less suitable 9 ! case ( gelat9e ?an 9 ! decolorization ( liquors :i* may be boil$4 ,wood pulp fibre is a v popul> decoloriz+ mat]ial1 n only 9 gelat9e b also 9 o!r trades4 ,its %ort1 woolly fibres give a cl>ify+ z well z a decoloriz+ effect4 ,x may ?us act z a me*anical filt] = susp5d$ matt] & grease1 z well z an adsorb5t = col\r+ matt]s pres5t z sols4 ,its two functions1 h[ev]1 are (t5 confus$4 ,x may be reg5]at$ = repeat$ use by c>eful wa%+1 & special pulp-wa%+ ma*9es are manufactur$ & sold = ! purpose4 ,det]g5ts are usually employ$ 9 ! wa% wat]s4 ,asbe/os is also a good adsorb5t1 & its long fibres make x mu* less liable to non-op]at+ *annels & bur/s4 ,x also has ! advantage t1 if desir$1 x may be reg5]at$ by ignition4 ,x =ms a v useful mixture ) pulp fibre4 ,all ! above decoloriz+ mat]ials are insoluble & hydrophobe1 & act 9 virtue ( _! f9ely divid$ conditions1 :i* causes !m to h a l>ge specific surface2 b !re is ano!r type or bran* ( sub/ances1 ^: effect is due to surface action ( r a diff]5t type4 ,^! are ! hydrophile gels4 ,9 a gelat9e sol ! colloid p>ticles h l>gely adsorb$ ! col\r+ matt]s :i* x is desir$ to remove4 ,?is adsorption1 :i* is aft] all only an equilibrium1 is r$uc$ by introduc+ ano!r v /rong adsorb5t4 ,?is latt]1 by adsorption f ! cont9u\s phase1 r$uces ! adsorption ( col\r+ matt]s by ! gelat9e p>ticles4 ,9 ! case "u discussion ano!r lyophile colloid is introduc$1 & aft] br++ ab\t su* an action is remov$ by appropriate means4 ,! use ( album9 has long be5 kn[n = su* a purpose1 its special advantage be+ t aft] its admixture & adsorptive action1 x may easily be remov$ by rais+ ! temp]ature above #gj ,c41 :5 coagulation takes place1 & by subsequ5t me*anical filtration4 ,! coagulat$ album9 takes d[n ! adsorb$ col\r+ matt]s4 ,album9 has be5 us$ 9 ?is way n only = gelat9e & glue liquors1 b also = tann+ extracts 7,"p ,i41 ,section ,,iii47 & o!r comm]cial prep>ations4 ,into ?is class ( decoloriz+ ag5ts fall ! insoluble inorganic gels :i* h be5 advocat$ by ,w4 ,gordon ,b5nett1 e4g4 alum9a cream4 ,fre%ly precipitat$ alum9a hydrate is a colloid gel ) v consid]able adsorptive p[]s4 ,x has also ! advantage t x is q insoluble1 easily remov$ 9 filtration1 & has a p[]ful adsorptive action ^u o!r objectionable impurities1 especially ! poison\s metals1 ars5ic1 copp]1 z9c & lead4 ,its use is an und\bt$ advantage :5 9 addition to ! o!r cl>ify+ ag5ts & adsorb5ts4 ,x is conceivable1 9 "s cases1 t :5 alum is employ$ z cl>ify+ ag5t 9 an alkal9e gelat9e liquor1 "s alum9a may be =m$1 & z su* contribute to ! total effect4 ,,section ,v4--,,blea*+ ,! adsorption law indicates t h[ev] mu* col\r+ matt] is remov$ f ! volume conc5tration 7cont9u\s phase7 !re mu/ always be "s left4 ,aft] all t ! decolorization processes c d1 !re /ill rema9s mu* col\r t c only be remov$ by a *emical action ( ! ord9>y s5se4 ,! am\nt ( col\r+ matt] ( ?is k9d is n l>ge1 b x is a deep r$-br[n1 & :5 ! gelat9e sol has be5 evaporat$ & dri$ out ! f9al product1 if untreat$1 possesses ?is typical col\r1 & is kn[n z glue4 ,if1 be=e gelation1 a *emical blea*+ action is appli$ to de/roy ?is pigm5t1 ! product may be !n dri$ out 9 a ne>ly col\rless condition & is kn[n z gelat9e4 ,gelat9e1 !re=e1 is simply blea*$ glue4 ,_m o!r def9itions h be5 giv51 & _m elaborate di/9ctions drawn1 b ! fact ( blea*+ is ! ess5tial diff]5ce4 ,9 ^! days :5 gelat9e is s valuable1 ! high]-grade products are ne>ly always blea*$1 & ! t]m glue is consequ5tly m (t5 appli$ to a l[]-grade product1 & is sometimes us$ 9 a s5se imply+ ?is fact4 ,if x be desir$ to manufacture gelat9e1 x is fairly obvi\s t ! task is light5$ by obs]v+ ! axiom t prev5tion is bett] ?an cure4 ,if /eps are tak5 to prev5t ! pres5ce or developm5t ( su* col\r+ matt]1 a great advantage is atta9$1 = n only is ! problem ( blea*+ easi]1 b also quick] & less exp5sive 9 *emicals4 ,! nature ( ! col\r+ matt]s is b imp]fectly inve/igat$1 b 9 ! case ( sk9 gelat9e ! pigm5t ( ! hair roots & epid]mis is d\btless "o factor4 ,a long lim+ is said to assi/ 9 its de/ruction1 possibly because ?is completes ! loos5+ ( epi!lial /ructures & possibly because ! alkali causes "s hydrolysis ( ! pigm5t4 ,9 bo? sk9 & bone gelat9e sols1 h[ev]1 !re is a consid]able t5d5cy to develop ! br[n col\r+ matt] typical ( glue4 ,?is t5d5cy is enhanc$ by an increase 9 temp]ature & also by ! pres5ce ( acid or alkali4 ,^! facts seem to indicate t its developm5t is associat$ ) a p>tial hydrolysis ( ! gelat9e 9 "s direction4 ,rideal says ?is col\r+ matt] is alli$ to c>amel4 ,9 h>mony ) ?is is ! exp]i5ce t its developm5t is greate/ 9 products :i* h be5 burnt1 i4e4 subject$ to unusually high temp]ature4 ,! practical maxims :i* arise f ^! consid]ations are fairly obvi\s & widely kn[n1 viz4 to conduct ! extraction & evaporation at z l[ a temp]ature z possible & 9 z neutral a condition z practicable4 ,! temp]ature is p>ticul>ly important dur+ evaporation 7see ,section ,,vi474 ,=tunately = manufactur]s ( gelat9e1 ! col\r+ matt] to be attack$ is v susceptible bo? to r$uction & to oxidation1 & bo? types ( blea* are widely us$ 9 practice4 ,x is some:at curi\s t ! same col\r+ matt] %\ld be de/ructible bo? by r$uction & by oxidation1 b !re is no d\bt t ea* type gives a p]fectly satisfactory blea*+ action & c result 9 a practically col\rless gelat9e4 ,on ! o!r h&1 ! r$uction is ! m un/able reaction1 = ! glue col\r sl[ly develops aga9 9 ! gelat9e on keep+ x1 ev5 9 a dri$ condition4 ,gelat9e blea*$ by oxidation1 h[ev]1 reta9s its col\r q well1 & ev5 t5ds to improve ) keep+4 ,x is q possible t q diff]5t reactions are involv$ 9 ! two processes1 b 9 ! light ( ! above facts x is some:at surpris+ to obs]ve ,rideal's /atem5t t r$uction foll[$ by oxidation has be5 successful 9 practice4 ,al?\gh !re is a wide *oice ( r$uc+ & ( oxidiz+ ag5ts1 ^? :i* are suitable = application to gelat9e cov] a v limit$ field4 ,?is limitation arises n s mu* f ! ineffectiv5ess ( ! blea*1 z f ! o!r effects ( ^! sub/ances ^u ! purity ( ! product & ^u ! ela/icity ( ! gel :i* x c yield4 ,especially important is ! lyotrope influ5ce ( ! blea*+ ag5t4 ,_m reactive sub/ances are rul$ out simply because !y ei!r insolubilize ! gelat9e or weak5 ! gel x makes4 ,o!rs are inadmissible on acc\nt ( _! poison\s nature4 ,x mu/ nev] be =gott5 t :atev] is us$ 9 blea*+ is1 l ! gelat9e itself1 mu* conc5trat$ dur+ evaporation & dry+4 ,its possible p]c5tage 9 ! f9i%$ product %\ld be consid]$1 & also ! possibility t 9 ^! f9i%+ op]ations :at is pres5t may n rema9 9 solution1 ow+ to sup]saturation4 ,blea*+ by ,r$uction4--,( all ! r$uc+ ag5ts sugge/$1 sulphur\s acid has prov$ to be mu* ! mo/ suitable & successful4 ,x has be5 us$ ) equal success bo? = bone & = sk9 gelat9e1 b on ! :ole has prov$ m suitable = ! =m]4 ,sulphur\s acid c fulfil 9 ?is in/ance a d\ble function1 viz4 t ( acid solv5t = ! bone phosphate1 & t ( blea*+ ag5t also4 ,z x p5etrates ! bone mat]ial1 dissolv+ ! phosphate1 x also ex]cises its blea*+ influ5ce on ! gelat9\s "p ( ! mat]ial4 ,*anges ( liquor t5d to complete bo? actions1 s t a c\nt]-curr5t sy/em is f\nd mo/ conv5i5t4 ,! acid process = ! manufacture ( bone gelat9e has be5 previ\sly describ$ 7,section ,,ii471 & ! use ( sulphur\s acid 9 ?is connection is typifi$ 9 ! ,b]gmann process4 ,9 ?is process blea*+ is 9 effect m]ely a cont9u$ treatm5t4 ,9 ! case ( sk9 gelat9e1 also1 sulphur\s acid may fulfil a d\ble function1 viz4 t ( delim+ ag5t z well z ( blea*+ ag5t4 ,9 su* in/ance x is necess>y to use excess ( blea*+ acid1 "s act+ z delim+ mat]ial & ! rema9d] z blea*+ ag5t4 ,z x is desirable to get rid ( ! lime & soda salts1 sev]al *anges ( liquor are giv5 to ! goods1 possibly ) int]m$iate wa%+4 ,"h aga9 approximation to a c\nt]-curr5t sy/em is ( advantage1 z ! employm5t ( us$ blea* liquors = delim+ purposes effects consid]able economy ( sulphur\s acid4 ,inde$1 !re ne$ be no wa/e acid at all4 ,:e!r ! mat]ial be = bone or sk9 gelat9e1 h[ev]1 x w be se5 t ! extraction is conduct$ 9 an acid condition & ! result+ sol is also acid4 ,mo/ usually ! decolorization & filtration processes are also conduct$ ) su* an acid sol4 ,f :at has be5 said 7,section ,,iv47 ( ! value ( dibasic inorganic acids z cl>ify+ ag5ts1 x w be und]/ood t ! pres5ce ( sulphur\s acid at ?is /age is ( great advantage 9 ! production ( a cle> & bright gelat9e4 ,inde$1 x is well kn[n 9 trade circles t sulphur\s acid gelat9es are usually ( exceptional cl>ity & brightness4 ,! disadvantage ( sulphur\s acid processes is also f\nd 9 ! same fact t bo? sol1 gel & cake are 9 an acid condition4 ,to complete ! blea* x is sometimes necess>y to add sulphur\s acid to ! sol aft] extraction1 or ev5 aft] evaporation1 b ?is is to be avoid$ if possible4 ,usually ! ideal attempt$ is t ! blea*+ action %\ld be z mu* z possible be=e extraction2 ! excess ( sulphur\s acid is !n wa%$ (f j be=e ! extraction1 z f> z practicable1 & ! re/ is boil$ (f dur+ extraction4 ,! ideal is practically nev] atta9$1 = ! acid is /rongly adsorb$1 & ! result is t ! f9i%$ article is always an acid gelat9e1 & sometimes inde$ v decid$ly su*4 ,! acid condition is objectionable 9 ! case ( "s =ms ( filt] press on acc\nt ( ! solv5t action on ! metals1 & is objectionable 9 evaporation = simil> reasons4 ,acid gelat9es are also objectionable = _m purposes = :i* gelat9e is usually sold1 & ?is limits ! comm]cial possibilities ( ! product ?us obta9$4 ,sulphur\s acid is itself1 ( c\rse1 a gas1 & :il/ ! gas itself has be5 us$ = treat+ ! mat]ial 7e4g4 bones71 x has be5 f\nd n only m conv5i5t b also m effective to use an aque\s solution4 ,?is is ma9ly because x is possible to atta9 a great] adsorption 9 a liquor4 ,un=tunately1 h[ev]1 sulphur\s acid is n a v soluble gas1 & al?\gh #h-aj p] c5t4 solutions may be1 ) great c>e1 obta9$1 !y are really sup]saturat$ & readily yield ! gas1 ev5 ) slight me*anical agitation4 ,solutions ev5 ( #b to #c p] c5t4 /r5g? are also liable to ?is1 & ! g5]al exp]i5ce is t #a to #b p] c5t4 solutions are mo/ economical & conv5i5t = practical purposes4 ,z ! freight on weak solutions is prohibitive1 ! manufactur] us+ sulphur\s acid is fac$ ) ! necessity ei!r ( pur*as+ cyl9d]s ( sulphur dioxide liquefi$ by pressure or mak+ ! gas & solution himself4 ,! =m] is ! mo/ conv5i5t c\rse :5 only small am\nts are requir$1 b ! latt] pref]able = a gelat9e factory ( any size4 ,sulphur\s acid is easily manufactur$ by burn+ sulphur & lead+ ! fumes by induc$ draught up a scrubb] d[n :i* wat] sl[ly trickles4 ,=c$ draught may also be us$1 z 9 ! ,sa*s5burg plant4 ,( ! o!r r$uc+ ag5ts :i* h be5 us$1 sodium hydrosulphite 7,na#b,,s#b7 des]ves m5tion4 ,x is a v p[]ful r$uc+ ag5t1 & has be5 f\nd mo/ useful :5 employ$ z an assi/ant to sulphur\s acid4 ,?is reag5t is usually add$ to ! sol1 aft] evaporation & be=e gelation4 ,x is sold z a :ite p[d]1 usually "u trade names4 ,sometimes a mixture ( bisulphite & p[d]$ z9c replaces x1 b ?is is objectionable = pure food gelat9es4 ,its use also involves an impurity 9 ! f9i%$ article1 & a great] am\nt ( inorganic a%4 ,blea*+ by ,oxidation4--,_m oxidiz+ ag5ts h be5 sugge/$ = blea*+ gelat9e1 b mo/ ( !m h "s practical disadvantage4 ,mo/ ( !m contradict ! maxim 7previ\sly not$7 t x is desirable to avoid add+ any soluble sub/ance1 z ?is involves a p]man5t impurity1 possibly conc5trat$ to sup]saturation 9 ! f9i%+ processes1 & possibly involv+ a disadvantage\s lyotrope influ5ce4 ,!re is ano!r objection to oxidiz+ ag5ts also2 :il/ _! blea*+ action on ! pigm5ts is und\bt$1 "s ( !m h also a special action ^u ! gelat9e itself :i* is 9 reality ak9 to tann+1 & may inde$ involve an insolubilization ( ! gelat9e4 ,?us1 *lor9e gas 7:i* ,meuni] pat5t$ = tann+7 has be5 us$ = blea*+ gelat9e1 b ! conditions ( success h n yet be5 ?or\ghly elucidat$1 & x is problematical inde$ :e!r ! process is consi/5t ) be/ results4 ,hypo*lorites & blea*+ p[d] h also a simil> action1 :i* has be5 utiliz$ ) "s success 9 practice4 ,rideal sugge/s t a suitable conc5tration = ^! reag5ts is #a3bjjj1 & emphasizes ! c>e necess>y4 ,an advantage ( all ^! *lor9ations is ! =mation ( ! /rongly antiseptic *loram9es1 :i* pres]ve ! gelat9e f putrefaction4 ,ozone has also be5 tri$ z an oxidation blea* = gelat9e1 b n successfully1 p>tly on acc\nt ( difficulties 9 controll+ ! quantity us$4 ,p]oxide ( soda has also be5 us$1 b x is n only alkal9e1 b liable to conta9 sodium hydrate & c>bonate z impurities1 & ?is involves neutralization ei!r be=e use or 9 ! gelat9e sol1 & ! consequ5t pres5ce ( sodium salts 9 ! f9i%$ article4 ,p]oxide ( calcium is op5 to ! same objections1 except t calcium is m easily remov$ f ! sol ?an sodium4 ,rideal's sugge/ion = remov+ ?is lime1 viz4 precipitation by a curr5t ( c>bonic acid1 m]its att5tion 9 ?is & 9 o!r directions also4 ,rideal also /ates t 9 ! case ( an acid bone gelat9e1 a good p]oxide ( lime is almo/ an ideal reag5t = blea*+1 inasmu* z ! lime c>ries d[n phosphate1 sev]al impurities & col\r+ matt]s4 ,x ?us acts z blea*1 z neutraliz+ ag5t1 & z precipitant1 & ! precipitate itself is a /rong adsorb5t4 ,on acc\nt ( its fre$om f bases1 & because its residue is simply wat]1 p]oxide ( hydrog5 has be5 f\nd ( great s]vice 9 practice1 & 9 mo/ factories x has %[n itself sup]ior n only to ! o!r p]oxides1 b also to all o!r oxidiz+ ag5ts4 ,its application is simple1 a conc5trat$ solution be+ add$ to ! gelat9e sol be=e or aft] evaporation4 ,x is ! mo/ fool-pro( ( all ! oxidiz+ ag5ts us$ 9 blea*+1 & x yields ! pure/ product4 ,its blea*+ action is p]fectly satisfactory1 b only 9 a non-acid sol4 ,hydrog5 p]oxide is mod]ately /able 9 acid solution1 & its blea*+ action is be/ 9 slightly alkal9e solution4 ,an acid sol blea*es too sl[ly1 or n at all2 an alkal9e sol induces evolution ( oxyg5 & consequ5t wa/e4 ,! great disadvantage ( p]oxide ( hydrog5 is its great exp5se1 :i* is enhanc$ by an increas+ dem& = x 9 o!r indu/ries4 ,a m9or disadvantage is its in/ability1 :i* leads to loss 9 transit & /orage4 ,x is sold usually 9 /r5g?s indicat$ by ! volume ( oxyg5 obta9$ f unit volume ( ! solution1 :5 treat$ ) p]manganate 9 a nitromet] 7e4g4 #ae vols4 p]oxide74 ,x is a =tunate feature ( bo? ! oxidiz+ & r$uc+ ag5ts usually employ$ 9 blea*+1 t !y h consid]able antiseptic p[]4 ,?is assi/s mat]ially 9 pres]v+ ! gelat9e f putrefaction dur+ ! critical p]iod betwe5 extraction & conc5tration4 ,,ref]5ces4 ,glue & ,glue ,te/+1 ,s4 ,rideal1 ,d4,sc41 #bnd ed41 pp4 #fa-ff1 #gh-hb4 ,gelat9e1 ,glue1 & ,alli$ ,products1 ,t4 ,lamb]t1 pp4 #bi1 #cj1 #di1 #ea4 ,*emical ,eng9e]+1 ,j4,r4 ,san4 ,in/41 ,no4 #b1 #aiaj4 ,s4 ,rideal4 ,on adsorption ph5om5a3 #a4 ,*emi/ry ( ,colloids1 ,dr4 ,w4 ,w4 ,taylor4 #b4 ,*emi/ry ( ,colloids1 ,v4 ,ps*l4 #c4 ,*emi/ry ( ,colloids1 ,zsigmondy & ,spe>4 #d4 ,*emi/ry & ,physics ( ,colloids1 ,e4 ,hals*ek4 #e4 ,surface ,t5sion & ,surface ,en]gy1 ,will[s & ,hats*ek4 ,,section ,,vi4--,,evaporation ,! evaporation ( ! weak gelat9e sols 7#c-i p] c5t47 obta9$ by ! processes describ$ 9 previ\s sections into sols ( su* conc5tration 7#bj-ee p] c5t47 t !y readily set to a /iff gel on cool+1 is n[ an ess5tial feature ( gelat9e manufacture1 & is "o ( ! mo/ important processes4 ,9 ! e>ly days ( ?is indu/ry1 manufactur]s aim$ at obta9+ a conc5trat$ sol1 z ?is sav$ "t 9 dry+1 & s r$uc$ ! possibilities ( putrefaction4 ,! adv5t ( evaporation has r$uc$ ^! possibilities to a m9imum1 & has also enorm\sly r$uc$ ! space requir$ & ! capital outlay ne$$ 9 ! dry+ %$s4 ,x has1 9 addition1 giv5 ! practical advantages involv$ 9 deal+ up to ! la/ m9ute ) a mu* less visc\s liquor4 ,z ! liquors extract$ are weak]1 ! extraction is m complete & ! decolorization m easily effect$4 ,! e>lie/ attempts at evaporation 7 n v successful1 p>tly on acc\nt ( ! prolong$ /ew+ :i* ru9$ ! sett+ p[]1 & p>tly because ( ! poor economy ( heat4 ,?us 9 ! op5 evaporators ! sol 0 ma9ta9$ at a high temp]ature = a long p]iod1 & ?is process only prov$ suitable = l[-grade products4 ,a great /ride =w>d 0 made by ,h[>d's inv5tion ( ! ,vacuum ,pan4 ,?is made x possible to und]take conc5tration at mu* l[] temp]atures1 a mo/ important improvem5t 9 ! case ( gelat9e & o!r organic matt]s easily damag$ by heat4 ,! process1 h[ev]1 0 /ill sl[1 & ! sol expos$ to heat = a long "t1 z mu/ be ! case :5 evaporation takes place 9 bulk4 ,^! disadvantages 7 /ill fatal to ! production ( ! highe/-grade gelat9e4 ,!re 7 also ! practical difficulties ( entra9m5t 7bl[+ ov]71 9 :i* p>ts ( ! sol 7 c>ri$ away by ! escap+ vap\r1 & also ( incru/ation :i* s rapidly r$uces ! heat+ effici5cy & evaporative capacity ( ! ma*9e4 ,! vacuum pan1 h[ev]1 pres5t$ two decid$ advantages--evaporation at a l[ temp]ature1 &1 z a coroll>y1 ! possibility ( utiliz+ exhau/ /eam to atta9 ?is temp]ature4 ,:il/ ! vacuum pan 0 a satisfactory ma*9e = _m bran*es ( *emical eng9e]+1 ! problem ( evaporation 0 /ill unsolv$ = gelat9e liquor because ( ! /ew+ involv$1 until ! adv5t ( ! film evaporator1 :i* dealt ) ! liquor n 9 bulk1 b 9 a cont9u\s /ream4 ,9 ?is way ! product 0 only expos$ to heat = a comp>atively %ort "t4 ,_m evaporators ( ?is type came into be+1 & rapid improvem5t 0 made 9 ! con/ructional details4 ,! film evaporators reta9$ usually ! advantage ( evaporation 9 vacuo1 s t x 0 n[ possible to evaporate gelat9e sols by exposure = a %ort "t to a comp>atively l[ temp]ature4 ,( ?is type ( evaporator1 ! ,lillie1 ,y>yan1 ,s*wag]1 ,claass51 ,gre9]1 ,blair ,campbell1 & ! ,ke/n] ma*9es are well-kn[n examples4 ,a fur!r advance 9 solv+ ?is problem 0 ! application ( ! pr9ciple ( multiple-effect evaporation4 ,! vap\r driv5 (f dur+ evaporation possesses ( c\rse _m heat units1 & is ( v consid]able volume4 ,9 multiple-effect evaporators ?is vap\r is us$ to "w a simil> evaporator1 & ! evaporat$ liquor passes imm$iately into :at is practically a second ma*9e1 & is fur!r evaporat$ by ! heat f ! vap\r j driv5 f x4 ,su* an arrangem5t w\ld be t]m$ a d\ble-effect evaporator4 ,! vap\r f ! second effect may ( c\rse be simil>ly us$ to op]ate a ?ird effect1 & ! vap\r f ?is to "w a f\r? effect1 & s on4 ,?us1 we may h triple effect1 quadruple effect1 etc41 ev5 up to octuple effect4 ,! great advantage ( multiple-effect evaporation is 9 ! sav+ ( co/ly /eam4 ,reavell gives ! foll[+ figures to illu/rate ! economy ?us obta9$3-- ,,wat] ,,evaporat$ ,,p] #ajj ,,units ,,/eam4 ---------------------------------------- ------- ,s+le4 ,d\ble4 ,triple4 ,quadruple4 ---------------------------------------- ------- #ie #aej #bbj #cjj ---------------------------------------- ------- ,!re is naturally a limit beyond :i* ! capital co/ ( ! ma*9e neutralizes ! advantage ( /eam economy1 & x is seldom t octuple effects are us$4 ,!re are probably m triple effects 9 use ?an any o!r ma*9e4 ,an ess5tial & important "p ( ! mod]n evaporator is ! cond5s]1 9 :i* ! vap\r f ! la/ effect is conduct$ into wat] 7jet cond5s]s7 or ov] cool$ surfaces 7surface cond5s]s71 ) a view to produc+ & ma9ta9+ ! vacuum4 ,a la/+ vacuum _c be ma9ta9$ )\t an air-pump1 z air is (t5 introduc$ 7#a7 ) ! /eam1 hav+ ent]$ ! boil] dissolv$ 9 ! fe$ wat]2 7#b7 by leakage f ! atmosph]e into ! cond5s] & ! connect$ vacu\s spaces2 & 7#c7 9 jet cond5s]s1 9 solution ) ! circulat+ cond5s] wat]4 ,t f ! fir/ two s\rces may be r$uc$1 b ! ?ird is beyond control3 h5ce if high vacua are necess>y1 surface cond5s]s are to be pref]r$4 ,dissolv$ air is usually #e-bj p] c5t4 ( ! wat] volume1 & is lea/ = sea-wat]4 ,x %\ld be not$ t wat] leav+ a surface cond5s] is 9 a v air-free /ate1 & !re=e p>ticul>ly suitable = boil] supply4 ,ap>t f ! capital co/ ( a cond5s] ! *ief co/ ( ma9ta9+ a vacuum is 9 pump+ ! circulat+ wat]1 ( :i* up to #gj lbs4 is usual p] lb4 ( /eam cond5s$4 ,if ,w weight ( /eam cond5s$ 7lbs4 p] h\r72 ,q weight ( cool+ wat] circulat$ 7lbs4 p] h\r7 ,ti inlet temp]ature 7 ,f47 ( cool+ wat]2 ,to outlet temp]ature 7 ,f47 ( cool+ wat]2 !n ,to ,ti #ajej7,w_/,q7 ,x w be und]/ood t = high vacua1 l[ temp]ature ( cool+ wat] 7,ti7 is m important ?an copi\s supply 7,q_/,w74 ,x is advantage\s1 h[ev]1 to *oose a site yield+ pl5ty ( cold wat]1 su* z a riv] or canal side4 ,o!rwise x is (t5 necess>y to use cool+ t[]s or spray nozzles4 ,! cool+ is by evaporation 7 #fj to #hj p] c5t4 ( ,w71 cold wat] replac+ t evaporat$1 & yield+ wat] #ge to #hj ,f4 ,if ,ti #hj ,f4 & ,q_/,w #gj1 a vacuum ( #bh4cd is possible1 b ! #j4cd %\ld be all[$ = ! p>tial pressure ( ! air1 det]m9$ exactly by ! air ent]+ & by ! displacem5t ( ! air-pump4 ,ano!r feature ( ! mod]n evaporator is ! heat] or calorifi]1 by :i* ! liquor to be evaporat$ is l$ 9 a cont9u\s rapid /ream ?r\gh heat$ tubes imm$iately prior to its entry into ! fir/ effect4 ,x is ! aim ( ! heat] to raise ! temp]ature ( ! liquor to ! temp]ature ( evaporation1 & s to avoid ?is be+ necess>y 9 ! fir/ effect4 ,! heat] ?us fur!r avoids /ew+1 ensures /eady runn+1 & effectively increases ! capacity ( a ma*9e4 ,x is notewor?y t sup]heat$ /eam is n desirable = work+ an evaporator4 ,! pr9ciple ( evaporation by /eam is n m]ely t ! temp]ature ( ! liquor is rais$ to boil+ po9t2 x is t 9 ! cond5sation ( ! heat+ /eam its lat5t heat is yield$ to ! liquor be+ evaporat$4 ,to evaporate quickly1 !re=e1 ! heat+ /eam mu/ cond5se rapidly4 ,h5ce1 z sup]heat$ /eam has a rate ( cond5sation #bj-cj times sl[] ?an saturat$ /eam1 ! latt] is mu* to be pref]r$4 ,a slight sup]heat+1 h[ev]1 may be ju/ifiable :]e ! /eam has any di/ance to travel be=e use4 ,x is ! fact t x is ! lat5t heat ( /eam :i* is ma9ly utiliz$ :i* gives /eam its great practical advantage ov] hot non-cond5sable gases4 ,/eam 9 cond5s+ yields an enorm\sly great] numb] ( heat units p] lb4 ?an hot wa/e gases4 ,/eam has also ! advantage ( m con/ant temp]ature4 ,! capacity & effici5cy ( an evaporator dep5ds ^u a good _m factors1 "s ( :i* are wor?y ( discussion at ?is po9t4 ,! transf]5ce ( heat & ! am\nt ( evaporation are directly proportional to ! mean temp]ature diff]5ce betwe5 ! heat+ /eam & ! liquor be+ evaporat$4 ,^! temp]atures1 h[ev]1 bo? v>y some:at1 ! /eam los+ "p ( its pressure & temp]ature z x passes along ! heat+ surface2 ! liquid g5]ally increases 9 temp]ature4 ,! mean diff]5ce 9 temp]ature1 moreov]1 is n ! ari?metic mean betwe5 ! smalle/ & l>ge/ temp]ature diff]5ces1 b is giv5 by ! foll[+ expressions1 :i* yield results n wide ap>t3-- ,if !taa temp]ature diff]5ce at comm5cem5t2 !tae end2 & !tam mean temp]ature diff]5ce2 !n !tam 7!taa - !tae7 _/ log7!taa _/ !tae7 or 7!taa - !tae7 _/ n7#a - n? root (7!tae _/ !taa77 ,?is mean temp]ature diff]5ce is 9 practice usually spok5 ( z ! temp]ature head or heat drop4 ,x w be cle> t ?is temp]ature head is increas$ by us+ /eam at high] pressure 7temp]ature71 & by evaporat+ "u r$uc$ pressure4 ,s9ce mo/ liquids h _! boil+ po9ts r$uc$ ab\t #dj ,c4 by op]at+ 9 vacuo1 ! advantage ( ! vacuum is app>5t4 ,x %\ld be rememb]$ t ! temp]ature head has n ! same value 9 any "p ( ! scale3 x has m value high] up ! scale1 because ! /eam is d5s] & m heat units come 9 contact ) a giv5 area 9 a giv5 "t4 ,x mu/ also be rememb]$ t :il/ ! pressure gauge is a mo/ useful indicator ( /eam temp]ature1 x is n necess>ily accurate4 ,! pressure 9 ! hot space is ! sum ( ! pressures ( air & /eam1 & s9ce ! temp]ature 7! important condition7 ( ! hot space dep5ds ^u ! pressure ( ! /eam1 & n on ! sum ( ! pressures1 ! temp]ature 9 a /eam space is always r l[] ?an w\ld be suppos$ f ! pressure indicat$ by ! gauge4 ,! transf]5ce ( heat is influ5c$ by ! velocity ( bo? ! heat+ fluid & ! fluid be+ heat$ ov] ! heat+ surface4 ,! m rapidly ea* fluid moves1 ! m rapid is ! transf]5ce ( heat1 because a great] numb] ( p>ticles ( bo? fluids are br\ght to ! heat+ surface 9 any giv5 "t4 ,?is is popul>ly kn[n z ! effect ( circulation1 & is illu/rat$ by ! advantage ( /irr+ a liquid be+ heat$ 9 bulk4 ,9 ! film evaporators ! circulation is ?r\gh tubes at high spe$ 7up to #b miles a m9ute71 & ! maximum effect 9 ?is s5se is ?us obta9$4 ,! increase 9 heat transf]5ce is n directly proportional to ! increase 9 velocity1 b 9 a l[] ratio1 sometimes approximately ! squ>e root ( ! velocity4 ,9 su* a case1 if ei!r velocity be quadrupl$1 ! heat transf]5ce is d\bl$4 ,o!r advantages ( high velocity are t ! heat+ /eam m readily sweeps away cond5s$ /eam f ! heat+ surface1 & ! high-spe$ film simil>ly sc\rs away incru/ations on ! int]ior ( ! tubes4 ,! transf]5ce ( heat is also proportional to ! conductivity ( ! metal =m+ ! heat+ surface4 ,= gelat9e liquors1 copp] tubes are almo/ inv>iably employ$1 ! advantage be+ great ev5 :5 price is tak5 into consid]ation4 ,! foll[+ conductivity coeffici5ts illu/rate ?is po9t 7calories p] h\r ?r\gh #a sq4 metre ( metal #a metre ?ick1 ) a temp]ature diff]5ce ( #a ,c473-- ,copp]444#ccj ,iron44444#ef ,/eel4444#bb-dj ,t9444444#ed ,z9c44444#aje ,lead44444#bh ,! coeffici5t ( heat transmission decreases ! m ) increas+ ?ickness ( wall1 ! worse conductor is ! metal4 ,= copp] tubes1 h[ev]1 ?is decrease is usually unimportant4 ,! transf]5ce ( heat is also mu* influ5c$ by ! viscosity ( ! liquor be+ evaporat$2 ! great] ! viscosity1 ! l[] ! coeffici5t ( heat transmission4 ,un=tunately = ?is process ( evaporation1 gelat9e sols are exce$+ly visc\s1 & ?us ! difficulty 9 obta9+ a conc5trat$ sol is ?us greatly enhanc$4 ,! transf]5ce ( heat is (t5 greatly h9d]$ by incru/ations ( ! tubes1 :i* incru/ations g5]ally conduct heat v badly4 ,?us ! relative heat conductivities ( copp] & *alk are z #ajjj3e4 ,! am\nt ( heat transf]r$ is ( c\rse det]m9$ also by ! area ( ! heat+ surface4 ,! am\nt ( evaporation ne$$ ?us det]m9es ! numb] ( tubes 7( /&>d size7 9 ! evaporator1 & ?us ! capacity ( ! ma*9e4 ,an evaporator %\ld h its heat+ surface area *os5 ) a view to ! duty requir$ ( x4 ,9 practice ! work+ ( an evaporator is (t5 n a v difficult matt]1 & l>ge numb]s ( ma*9es are op]at$ by unskill$ lab\r4 ,tr\bles g5]ally arise f incon/ant /eam pressure1 incru/ation1 leakages ( air1 :i* r$uce ! vacuum1 ! temp]ature head1 & h9d] heat transmission4 ,= ! evaporation ( gelat9e liquors ! ,y>yan1 ! ,ke/n]1 & ! ,blair-,campbell film evaporators are ! mo/ widely us$4 ,! velocity ( ! liquor ?r\gh "s ( ^! ma*9es is s great t occasionally no vacuum is us$4 ,! temp]ature obta9$ is high 7#bjj ,f471 b ! "t is v %ort1 if rapid cool+ ( ! evaporat$ liquor is arrang$4 ,,ref]5ces4 ,evaporat+1 ,cond5s+ & ,cool+ ,app>atus1 by ,e4 ,hausbr&4 ,scott1 ,gre5wood ,son 7#aiaf ,ed474 ,evaporation1 by ,e4 ,kappes*a>4 ,norman ,rodg] 7#aiad74 ,evaporation 9 ! ,*emical ,indu/ry1 by ,j4,a4 ,reavell1 ,m4,i4,me*4,e41 ,j4,s4,c4,i41 #aiah1 ,april #aa?4 ,glue & ,glue ,te/+1 ,s4 ,rideal1 ,d4,sc41 pp4 #ef-ei4 ,gelat9e1 ,glue1 & _! ,alli$ ,products1 ,t4 ,lamb]t1 pp4 #bf-bi4 ,notes on ,cond5s+ ,plant1 ,j4,m4 ,newton1 ,b4,sc41 ,j4 ,junior ,in/4 ,eng9e]s1 ,aug41 #aiab4 ,,section ,,vii4--,,cool+ ,,& ,,dry+ ,! conv]sion ( a gelat9e sol into cakes ( gelat9e has be5 mu* simplifi$ by ! adv5t ( ! evaporator4 ,be=e ?is ma*9e 0 us$ mu* tr\ble 0 exp]i5c$ ) putrefaction1 & 9 hot & ?und]y wea!r1 especially on ! ,cont95t1 x 0 (t5 necess>y to susp5d op]ations4 ,evaporation has1 h[ev]1 mat]ially contribut$ to ! possibility ( rapid & satisfactory cool+ & dry+4 ,f ! "t ! weak sol is decoloriz$ & blea*$1 ! f9i%+ processes consi/ ess5tially 9 ! removal ( wat]4 ,?is is n[ usually done p>tly by evaporation ( ! sol1 & p>tly by ! desiccation ( ! gel4 ,!re is an obvi\s ela/icity 9 me?od1 & factory practice does actually v>y consid]ably 9 ! relative proportions ( ^! two alt]natives4 ,"s factories evaporate to a #bj p] c5t4 sol1 approximately1 & rely ^u dry+ %$s & l(ts to complete ! desiccation3 o!r factories evaporate up to a #ee p] c5t4 gelat9e sol1 & s c manage ) less %$ room4 ,some?+ dep5ds ^u local conditions1 b ! ma9 issue is betwe5 ! co/ ( /eam 9 evaporation & ! co/ ( l& & build+s requir$ = %$s4 ,on ! :ole ! mod]n t5d5cy is to evaporate m1 = ?is c\rse has ! additional advantage ( spe$1 involv+ bo? a quick] turnov] & less liability ( putrefaction4 ,l[]-grade products ne$ relatively great] evaporation to =m a gel ( equal rigidity4 ,aft] evaporation & blea*+1 ! conc5trat$ sol is fir/ cool$ rapidly until x has set to a /iff gel1 !n cut up into cakes accord+ to ! size requir$1 ^! be+ dri$ out on network frames arrang$ 9 ti]s1 ?r\gh :i* a draught ( air is usually =c$ or induc$4 ,?is g5]al description is ( c\rse applicable to _m factories ) innum]able v>iations 9 detail1 mo/ ( :i* v>iations orig9ate 9 local conv5i5ce & are uness5tial p>ts ( ! manufacture4 ,an ess5tial pr9ciple is t ! cool+ or gelation %\ld be done rapidly1 n only to avoid putrefaction b also to avoid ! action ( heat on ! ela/icity ( ! gel4 ,a hot sol or gel is liable to hydrolysis & loss ( sett+ p[]1 & %\ld h its temp]ature quickly r$uc$1 b a w>m sol or gel 7say #ajj ,f47 is mo/ liable to putrefaction1 s t ! cool+ %\ld be cont9u$ quickly4 ,on ! o!r h&1 ! gel %\ld n be froz54 ,= cool+ purposes a copi\s supply ( cold wat] is mo/ usually employ$1 b "s factories h in/all$ refrig]ators4 ,^! plants op]ate by ! rapid evaporation ( liquefi$ gases su* z c>bon dioxide1 sulphur dioxide1 or ammonia1 s arrang$ z to cool a solution ( common salt1 :i* =ms ! circulat+ liquor & is return$ aft] use to ! refrig]ator4 ,:]e su* plants are us$1 x is natural t _! use %\ld be ext5d$ to ! dry+ %$s to cool ! air ent]+ 9 ! height ( summ]4 ,9 "s factories ! cool+ is atta9$ nei!r by cold wat] nor cool$ br9e1 b m]ely by cold air4 ,! k9d ( vessel 9 :i* gelation is induc$ v>ies widely 9 diff]5t factories4 ,= l[]-grade products metal boxes are us$1 heavily galvaniz$ iron be+ ! mo/ common mat]ial4 ,if ! liquor be muddy1 deep boxes are pref]r$1 b if cle>1 rapid cool+ is be/ atta9$ by hav+ !m long & %all[1 & s expos+ a relatively great] area to ! cool+ action4 ,9 ei!r case ! boxes may conta9 up to #a_/b cwt4 ( jelly4 ,lamb]t m5tions boxes #bd #f1 :i* are #e deep2 ,cavali] sugge/s rectangul> m\lds hold+ #cj litres4 ,9 place ( galvaniz$ %eet iron1 boxes ( %eet z9c or ( wood l9$ ) z9c are sometimes us$4 ,9 any case ! mo/ scrupul\s cleanl9ess %\ld be obs]v$ 9 all cool+-h\se "w1 & 9 "s factories ! mo/ elaborate precautions are tak5 = cleans+ vessels1 tools1 floors1 etc41 & ev5 = _! dis9fection & /]ilization4 ,iron1 t9n$ iron1 & copp] cool+ vessels are rul$ out on acc\nt ( _! t5d5cy to ru/ & t>ni%1 & ! la/ is unju/ifiably exp5sive4 ,_m ( ^! vessels are unsuitable = pure food gelat9es 9 :i* traces ( copp]1 z9c & ars5ic are held to be v objectionable4 ,= ! be/ gelat9es1 !re=e1 a v %all[ vessel 7#a_/d to #a_/b deep7 ) a %eet glass bottom is pref]r$1 & ! conc5trat$ sol is run on to ?is = gelation4 ,glue 7or gelat9e7 :i* has set 9 ?is way is sometimes call$ ca/ glue4 ,t :i* sets 9 metal boxes 9 blocks is t]m$ cut glue1 because ! blocks ( jelly ne$ subsequ5tly to be cut into slabs ( ! desir$ size & %ape4 ,jelly blocks may be cut by h& ) ! wire knife :i* yields a *>act]i/ic wavy appe>ance to ! f9i%$ product4 ,?is may also be done by ma*9]y1 ! block ( gel be+ plac$ on a s]ies ( correctly spac$ wires & =c$ ?r\gh ! network by hydraulic pressure4 ,a cutt+ ma*9e 7,s*neible7 has also be5 us$ to cut up blocks ( jelly into slices ( ! requir$ ?ickness1 b ^! ma*9es h n made great headway 9 ?is c\ntry4 ,x w be cle> t ca/ glue is cool$ m rapidly ?an glue 9 blocks2 x is !re=e n surpris+ to note ,lamb]t's /atem5t t ! =m] comprises ! l>g] proportion on ! m>ket4 ,! cut or ca/ cakes are next plac$ ^u network frames1 & a s]ies ( su* frames are plac$ on a bogey4 ,! bogey is run along tram l9es into ! dry+ tunnel1 ?r\gh :i* air is =c$ or induc$ by a fan4 ,_m su* bogeys are1 ( c\rse1 pass$ into ea* tunnel1 & z _m tunnels z requir$ may be con/ruct$4 ,c>e is necess>y to expose ! cakes ev5ly to ! action ( ! air4 ,x is mo/ly necess>y to w>m ! air at ! inlet by means ( /eam pipes & s increase its dry+ p[]4 ,?is is especially necess>y 9 w9t] or wet wea!r4 ,9 summ]1 h[ev]1 x is (t5 arrang$ t ! air is cool$ be=e ent]+ ! %$s4 ,?is is accompli%$ by pass+ ! air ?r\gh pipes f a refrig]ator4 ,:5 heat$ air is us$1 x is /at$ by ,lamb]t t ! maximum temp]ature %\ld be #be4e ,c4 7#gh ,f472 ,rideal consid]s #ba ,c4 7#gj ,f47 %\ld be ! maximum4 ,9 all cases ! dry+ p[] ( ! air is easily asc]ta9$ f a wet-&-dry bulb !rmomet]1 & ! am\nt ( air pass+ along ! %$ f a w9d gauge4 ,lamb]t /ates t dry+ normally occupies f\r to five days4 ,! f9al product is /ill a gel1 ( c\rse1 & conta9s f #aj to #ah p] c5t4 ( wat]4 ,x appe>s1 h[ev]1 v h>d & solid4 ,! dri$ cakes are remov$ f ! frames & transf]r$ to ! w>eh\se1 :]e !y are sort$ accord+ to quality & pack$ 9 bags or t9-l9$ boxes4 ,"s mat]ial is gr\nd to p[d]4 ,! network ( ! dry+ frames has be5 made f _m mat]ials4 ,cotton or /r+ nett+ is v common1 b is liable to sag & to get dirty4 ,x also has a %ort life4 ,ord9>y galvaniz$ iron soon loses its galvaniz+ cov]1 & ! iron !n is liable to ru/4 ,attempts h be5 made to use %eet z9c & o!r alloys1 :i* are cut or pun*$ into nets ) squ>e or diamond-%ap$ holes4 ,^! 7 f\nd to w>p & break4 ,rideal's conclusion1 :i* is confirm$ by ! g5]al exp]i5ce1 is t ! be/ mat]ial is a heavily galvaniz$ iron wire nett+4 ,he sugge/s t x %\ld h #ae to #be p] c5t4 ( its weight ( z9c1 & t x %\ld be /r5g!n$ by /iff] ribs arrang$ bo? longitud9ally & transv]sely4 ,_m attempts h be5 made1 & _m pat5ts tak5 out1 ) ! object ( mak+ ! cool+1 cutt+1 & dry+ processes z cont9u\s & z quick z possible1 & ) a view to sav+ lab\r1 :i* is r co/ly at ?is /age4 ,^! attempts1 h[ev]1 h only met ) indiff]5t success4 ,a common idea is t a cont9u\s supply %\ld fall ^u a revolv+ appliance1 & be in/antly congeal$ 9 a ?9 /ate1 :i* la/ l5ds itself to m rapid desiccation4 ,vacuum dry+ has also be5 attempt$4 ,,ref]5ces4 ,glue & ,glue ,te/+1 ,s4 ,rideal1 ,d4,sc41 pp4 #fh-gd4 ,glue1 ,gelat9e1 & ,alli$ ,products1 ,t4 ,lamb]t1 pp4 #cj-ce4 ,*em4 ,zeit41 #aiaa1 #he1 #ag 7,cavali]74 ,,pat5ts4 ,eng4 ,pat5t 7#ahid7 #aa1dbf 7,hewitt74 ,eng4 ,pat5t 7#ahih7 #b1djj 7,brau]74 ,fr4 ,pat5t 7#aiji7 #cih1eih 7,lehmann71 ,j4,s4,c4,i41 #aiji1 #hig4 ,u4,s4 ,pat5t 7#aiab7 #a1jdg1afe 7,am]ican ,glue ,co474 ,,section ,,viii4--,,uses ,,( ,,gelat9e ,,& ,,glue ,gelat9e & glue h bo? be5 put to an imm5se v>iety ( uses1 & ! li/ is con/antly ext5d+4 ,inde$1 no "o :o consid]s ! foll[+ acc\nt ( _! applications c d\bt t gelat9e & glue h become a necess>y "p ( our civilization4 ,gelat9e = edible purposes c]ta9ly =ms a v consid]able "p ( ! total us$1 & great pa9s are n[ tak5 to obta9 a pure product4 ,?us1 a gelat9e ) m ?an #a4d p>ts p] million ( ars5ic1 or m ?an #cj p>ts p] million ( copp]1 is n consid]$ good en\gh = pure food4 ,! food value ( gelat9e1 comp>$ ) o!r proteids1 is exce$+ly l[2 its use 9 ?is connection has no connection ) ! calories ( heat en]gy x w yield4 ,x is us$ almo/ entirely because ( its prop]ty ( =m+ a gel4 ,table jellies =m1 ( c\rse1 "o popul> use ( gelat91 b ! manufacture ( sweets makes also a great dem& ^u ! gelat9e trade4 ,cul9>y op]ations (t5 require a little gelat9e1 especially is x us$ 9 pies & s\ps4 ,an ext5sion ( ! same idea is f\nd 9 its employm5t = _m manufactur$ foods1 e4g4 t9n$ meats1 meat extracts1 & ! conc5trat$ foods4 ,! use ( gelat9e 9 connection ) ! fir/ ( ^! receiv$ a big impetus dur+ ! w> p]iod4 ,9 gelat9e = any ( ^! purposes1 ! pres5ce ( excess ( sulphur\s acid is objectionable1 z its ta/e is easily notic$4 ,gelat9e = m$ic9al purposes f9ds an ev]-gr[+ numb] ( applications4 ,gelat9e capsules = hold+ greasy liquids & solutions ( nause\s drugs are increas+ly popul>1 = ! dose may be swall[$ )\t unpleasantness4 ,9 mak+ ^! capsules "s sug> is also us$1 & ! f9i%$ article is (t5 protect$ f atmosph]ic moi/ure by treatm5t ) a weak solution ( alum4 ,9 a simil> way pills are (t5 coat$ ) a #cc p] c5t4 gelat9e sol4 ,su* pills are n only pleasant] to swall[1 b are less liable1 aft] be+ dri$1 to /ick toge!r 9 ! box4 ,alcohol solutions ( drugs 7or ess5ces1 p]fumes1 etc47 may be suitably /or$ 9 gelat9e in/ead ( metal tubes4 ,m$icat$ w9es are detannat$ by gelat9e be=e ! addition ( drugs :i* w\ld h be5 precipitat$ by ! tann94 ,! ,briti% ,ph>macopoeia specifies f\r k9ds ( ,lamell1 :i* are small discs ( gelat9 & glyc]91 ea* conta9+ a m9ute b def9ite dose ( "s p[]ful alkaloid4 ,glyc]9 jelly is a mixture ( gelat9 glyc]9 ) "s wat]4 ,x is us$ = *app$ & r\gh h&s2 ! mixture is also us$ = glyc]9 suppositories1 & = m\nt+ microscopic sections4 ,! mixture also =ms ! basis ( gelato-glyc]91 us$ 9 nasal b\gies1 & ( glyco-gelat9 = m$icat$ loz5ges4 ,gelat9e insolubilis$ by =mal9 7=mo-gelat97 has be5 us$ = mak+ tabloids1 w\nd dress+s1 & artificial silk4 ,gelat9e is 9 con/ant dem& = bact]iological "w1 = :i* purpose a high-grade product is desir$4 ,nutri5t m$ia = ! culture ( bact]ia are solidifi$ by #aj-ae p] c5t4 ( gelat91 & ! gr[? ( colonies ( bact]ia (t5 %[ typical =mations4 ,by inoculat+ into a melt$ & /]ile quantity & sett+ quickly 9 a flat di% aft] mix+1 ! numb] ( bact]ia 9 ! volume introduc$ c be judg$ f ! numb] ( colonies :i* develop4 ,bact]ia are also di/+ui%$ (t5 z liquefy+ or non-liquefy+ accord+ to _! type ( culture on nutri5t gelat9e m$ia4 ,gelat9e = su* "w %\ld be neutral & ( high cl>ity4 ,! gelat9e requir$ = photographic purposes is also a high-class product4 ,x %\ld be neutral1 col\rless1 & free f *lorides & o!r m9]al salts4 ,grease also is objectionable4 ,gelat9e is us$ 9 ! num]\s c>bon processes1 9 :i* ! pr9ciple is t gelat9e is made insoluble 9 wat] by ! action ( potassium di*romate "u ! action ( light4 ,x is us$ also 9 ,poiteo9 process = copy+ eng9e]+ draw+s1 :i* is bas$ ^u ! p[] ( a f]ric salt to r5d] gelat9e insoluble s long z x is n expos$ to ! act9ic rays4 ,gelat9e is us$ 9 ! manufacture ( ! cry/all9e glass us$ = decorative purposes4 ,advantage is tak5 ( ! imm5se contractile =ce x ex]ts on dry+4 ,:5 gr\nd glass is coat$ ) gelat9e1 & ! latt] dri$1 x te>s away ! surface ( ! glass itself1 & leaves peculi> f]n-l patt]ns4 ,inorganic salts dissolv$ 9 ! sol influ5ce ! nature ( ! patt]n obta9$4 ,gelat9e is us$ also v l>gely 9 ! textile trades1 = f9i%+ col\r$ y>ns & ?reads1 = siz+ wooll5 & wor/$ w>ps1 & = ?ick5+ ! dye/uffs us$ 9 pr9t+ fabrics4 ,x is also us$ = f9i%+ :ite /raw hats2 z a size 9 ! manufacture ( high-class pap]s1 & z a wax sub/itute = cov]+ corks & bottle necks4 ,glue is us$ in/ead ( gelat9e 9 all cases :]e col\r is n a matt] ( mu* mom5t4 ,! fact t x has n be5 blea*$ makes no diff]5ce to its suitability 9 su* a case1 & ! co/ is sub/antially r$uc$4 ,?us1 = d>k-col\r$ /raw hats1 textiles1 sweets1 pap]s1 & 9 all suitable woolwork1 glue is us$ 9 place ( ! m exp5sive article4 ,a v l>ge quantity ( glue is us$ 9 ! manufacture ( mat*es1 :]e x functions z ! mat]ial b9d+ ! head to ! /em4 ,a #ae-ej p] c5t4 sol is us$1 conta9+ nitrate or *lorate ( pota% z oxidiz+ ag5t4 ,! mixture is kept at #ch ,c4 & ! phosphorus cauti\sly add$1 & :5 ?is is emulsifi$1 ! friction +r$i5ts 7s&1 glass1 etc47 are also add$4 ,! glue acts also 9 prev5t+ premature oxidation4 ,glue is also us$ 9 mak+ ! mat*-boxes1 & simil>ly 9 mak+ s&1 em]y1 & glass pap]s & clo?s4 ,!re is a l>ge consumption ( glue by jo9]s1 c>p5t]s1 cab9et-mak]s1 & all k9ds ( woodwork & fancy "w4 ,x is us$ 9 ! manufacture ( furniture ( all k9ds1 ( pianos1 organs1 billi>d tables1 panels1 picture frames1 & ( toys & bru%es4 ,mix$ ) :ite lead1 *alk1 & sawdu/1 x =ms a composition us$ = mirror frames1 rosettes1 etc4 ,glue is us$ = v5e]+1 = mosaics1 plaques1 trays1 f+]plates1 lea!r wall cov]+s1 & = /a9+ floors4 ,!re is also a consid]able sale = glue 9 bookb9d+1 = :i* a sweet1 light-col\r$1 & /rong product is requir$4 ,x has be5 f\nd p>ticul>ly suitable = lea!r b9d+s :]e ! gra9 has be5 artificially pr9t$ or emboss$1 & 9 f9i%+ & gild+4 ,! compositions us$ = pr9t+ roll]s all conta9 gelat9e or glue toge!r ) sug> or glyc]9 & possibly oil & soap4 ,!y are (t5 h>d5$ ) =mal94 ,simil> mixtures are us$ = ! b$s ( hectographs4 ,glue 7toge!r ) wa/e lea!r7 is us$ 9 ! manufacture ( imitation lea!r & lea!r sub/itutes4 ,cotton & wool fibres are (t5 incorporat$1 & sometimes textile fabrics4 ,mu* glue is conv]t$ into size1 :i* is a weak gel us$ z a fill+ r ?an z an adhesive ag5t4 ,a l[-grade glue is (t5 !re=e pref]r$ = su* purposes1 z hav+ body r ?an /r5g?4 ,size is (t5 sold 9 cake1 b sometimes 9 ! =m ( ! gel itself1 9 :i* case x may nev] h be5 evaporat$4 ,inde$1 size is (t5 ov]boil$ glue1 made by crude & out-(-date me?ods4 ,x is l>gely us$ 9 ! pap] trade1 & = wallpap]s1 millbo>ds1 papi]-ma*e1 pap] & c>dbo>d boxes1 etc4 ,mix$ ) logwood & iron1 & possibly alum1 x =m$ ! blue size once l>gely us$ by bootmak]s z a f\ndation = black+1 & is simil>ly us$ 9 curry+4 ,size is also us$ 9 mak+ oil pa9ts & v>ni%es4 ,di/emp] is a size ) :i* is incorporat$ :it+ or gypsum & col\r$ pigm5ts4 ,9 all applications ( size1 x is common to use antiseptics4 ,salicylic acid has be5 widely us$ 9 ?is s5se4 ,l[-grade glue is us$ = ! manufacture ( *eap bru%es & = fly-pap]s4 ,innum]able pat5ts h be5 tak5 out & mixtures inv5t$ = ! production ( pla/ic mat]ials1 :i* frequ5tly involve gelat9e or glue4 ,?us1 gelat9e & glue are us$ 9 mak+ pla/] ca/s1 & = imitation ivory1 wood1 /one1 & rubb]4 ,_m ( ^! inv5tions h be5 inve/igat$ by ,rideal1 :o po9ts out ! features common to mo/ ( !m4 ,usually a visc\s sol is ?ick5$ by ! addition ( in]t fibres & p[d]s1 & ) ! object ( mak+ ! prep>ation m wat]pro( x is cu/om>y to incorporate oils1 fats1 waxes1 t>s1 & res9s be=e ! gel is set4 ,! surface is h>d5$ by tann+ ) =mal9 or tann9 solution1 f9ally pa9t$ or v>ni%$4 ,equally innum]able are ! inv5tions1 recipes1 & pat5ts = mak+ glues t %all rema9 liquid4 ,! conv5i5ce ( ?is ideal is obvi\s1 b _m ( ! sugge/ions are useless4 ,x is q easy to incorporate into a gel sub/ances :i* keep x liquid--any soluble sub/ances ) a lyotrope influ5ce ( ! iodide type w d ?is--b ^! also prev5t ! glue sett+ :5 us$4 ,ev5 9 small quantity !y w influ5ce ! t5acity ( ! jo9t4 ,o!r me?ods dep5d ^u a p>tial hydrolysis ( ! prote94 ,among/ ! mo/ successful ( ^! attempts are to dissolve #c p>ts ( glue ei!r 9 #ab-ae p>ts sac*>ate ( lime1 or 9 #i p>ts ( #cc p] c5t4 acetic acid4 ,_m special glues & cem5ts are made f comm]cial glue1 accord+ to ! purpose requir$4 ,m>9e glue conta9s no glue2 x is made f %ellac & rubb] mix$ ) b5z5e or naph?a4 ,its advantage is wat]pro(ness4 ,,ref]5ces4 ,glue & ,glue ,te/+1 ,s4 ,rideal1 ,d4,sc41 #bnd ed4 ,uses ( ,glue1 *ap4 iii4 p4 #hc4 ,uses ( ,gelat9e1 *ap4 iv4 p4 #ajj4 ,special ,glues1 p4 #ajh4 ,liquid ,glues1 p4 #aai4 ,gelat9e1 ,glue1 & _! ,alli$ ,products1 ,t4 ,lamb]t4 ,uses ( ,glue & ,gelat9e1 *ap4 ix4 p4 #hj4 ,liquid ,glues & ,cem5ts1 *ap4 viii4 p4 #fi4 ,,section ,,ix4--,,! ,,evolution ,,( ,,! ,,gelat9e ,,& ,,glue ,,indu/ry ,! manufacture ( gelat9e & alli$ products has receiv$ a great /imulus 9 ?is c\ntry f ! circum/ances aris+ f ! ,european ,w>4 ,! l>ge re/riction ( cont95tal--especially ,fr5* & ,belgian--supplies ( gelat9e1 l$ to great] dem&s = ! ,briti%-made product1 & result$ n m]ely 9 a p]iod ( great] prosp]ity1 b 9 a p]iod 9 :i* mu* great] ef=ts 7 made to supply a high-grade article 9 l>g] quantities4 ,mo/ manufactur]s /rove to make high-class gelat9e r ?an l[-grade glue1 great ext5sions 7 made1 & _m new bus9esses 7 e/abli%$4 ,! developm5t ( ! lea!r trades1 m p>ticul>ly 9 respect ( great] production1 caus$ a bigg] supply ( raw mat]ial = sk9 gelat9e1 & ! slaught] ( home animals = food caus$ a m pl5tiful supply ( bones4 ,at ! same "t x 0 realiz$ t great] production n only r$uc$ work+ co/s1 b also t a bigg] turnov] 9 any "o factory involv$ a proportionately less capital outlay4 ,^! facts t5d to c\nt]balance ! heavy freight on ! raw mat]ials4 ,production is ?us n only on a l>g] scale b m int5sive4 ,"o ( ! greate/ difficulties ( ?is indu/ry is to produce a regul> or /&>d article1 = ! raw mat]ial is s exce$+ly v>iable 9 quality2 t = sk9 gelat9e t5ds also to become less valuable4 ,9 su* a case1 z ,rideal has truly rem>k$1 to ensure t supplies to cu/om]s %all be always up to sample1 :i* is (t5 a matt] ( contract--exact & regul> work+1 /rict cleanl9ess1 obs]vance ( temp]atures & o!r physical data1 & sci5tific sup]vision1 are cle>ly necess>y4 ,rule ( ?umb is nev] q c]ta9 to produce ! same article twice4 ,9 pa/ ye>s ,briti% me?ods ( manufacture h be5 f> too empirical4 ,z 9 o!r indu/ries1 rule ( ?umb mu/ inevitably be replac$ by sci5tific pr9ciple4 ,! advances 9 colloid *emi/ry ( ?is la/ decade or s h1 9 ! au?or's op9ion1 suppli$ ! clue to ?is l9e ( developm5t4 ,9 ! prec$+ pages emphasis has be5 laid ^u ! importance ( ! adsorption law1 ! lyotrope s]ies1 & ! val5cy rule4 ,! manufactur] or sup]visor :o und]/&s & c apply ^! g5]alizations w f9d 8 task va/ly easi] & 8 factory m effici5t4 ,mu* rema9s to be le>nt1 h[ev]1 & ! indu/ry w\ld c]ta9ly b5efit by rese>* "w1 = :i* !re is a f]tile field4 ,!re is also consid]able room = improvem5t 9 ! me?ods ( *emical eng9e]+ usually employ$4 ,:il/ ! heat eng9e]s h c]ta9ly done mu* to solve ! "q ( evaporation & dry+1 !re is /ill great scope 9 ! m economical application ( heat 9 extraction1 & ! la/ ^w c h>dly h be5 said on ! problem ( cl>ification & decolorization4 ,!re is inde$ almo/ z mu* scope = rese>* by ! *emical eng9e] z by ! colloid *emi/4 ,! indu/ry also exhibits1 9 common ) ! lea!r & _m o!r trades1 ! same t5d5cy to save lab\r1 bo? by c>eful arrangem5t ( ! factory & by ! in/all+ ( me*anical lab\r-sav+ devices4 ,?us1 lifts1 runways1 hoi/s1 & trucks are increas+ly us$ to move ! solids1 & pipes & pumps to move ! liquors4 ,z ev]1 !re is scope = ! me*anical eng9e]4 ,if "s ( ^! problems are vigor\sly tackl$ dur+ ! pres5t recon/ruction p]iod1 !re is little d\bt t ! gelat9e & glue indu/ry w be 9 a mu* bett] position to cope ) all possible competition 9 ! future4 ,f :at has be5 said 9 ,section ,,viii4 z to ! wide uses ( gelat9e & glue1 x w be se5 t g5]al prosp]ity 9 trade is conducive to bett] trade conditions 9 ! gelat9e & glue indu/ry4 ,x is simil>ly true t a g5]al trade slump affects ! glue trade adv]sely4 ,! sev]e trade depression :i* comm5c$ 9 #aibj has _h ?is effect1 & has made economic production mu* m difficult z well z m ess5tial4 ,z (t5 is ! case1 ! l>g] factories & firms c bett] face ! difficulties1 & !re c be little d\bt t if ! depression be long cont9u$ !re w be a t5d5cy = ! small] factories to be clos$ d[n & = ! l>g] firms to unite4 ,z 9 ! lea!r trade1 bo? ! ,w> boom & ! ,peace slump h caus$ ! gelat9e & glue trade to develop along ! l9es ( ! great tru/s4 ,x may be reasonably expect$1 moreov]1 t ^! w be intimately connect$ ) ! lea!r tru/s4 ,?is fact1 toge!r ) ! heavy freight *>ges on ! raw mat]ial1 t5ds also to make ! sk9 glue factories gravitate t[>ds ! lea!r c5tres4 ,,"p ,,vi4--,,miscellane\s ,,prote9s ,,& ,,bye-,,products ,,section ,i4--,,bye-,,products ,,( ,,! ,,lea!r ,,trades ,9 ! lea!r trades by f> ! mo/ important & valuable bye-products are obta9$ f ! hides & sk9s !mselves1 & all ^! are obta9$ be=e ! tannage prop] is comm5c$4 ,! lea!r trades use only ! d]mis 7corium7 or true sk9 = ! manufacture ( lea!r1 & z we h not$ 7,"p ,i41 ,section ,,ii47 ?is prep>$ & purifi$ d]mis is call$ pelt4 ,! cutt+s & trimm+s f ! pelt =m ! mo/ valuable bye-product ( ! lea!r trades1 & are ! raw mat]ial ( ! gelat9e & glue indu/ries 7,"p ,v41 ,section ,,ii474 ,_m portions ( ! pelt1 inde$1 su* z e>s1 noses1 & c[s' udd]s1 are q useless = any o!r purposes4 ,o!r portions1 su* z *eeks1 faces1 & ev5 bellies1 may be made ei!r into glue or lea!r accord+ to ! /ate ( trade4 ,h>dly less important to ! same indu/ry are ! cutt+s ( adipose tissue remov$ 9 fle%+ ! hides & sk9s4 ,^!1 ?\gh yield+ less prote91 yield also1 h[ev]1 ! valuable animal greases 7,"p ,v41 ,section ,,ii474 ,to obta9 bo? ^! products 9 a pur] condition ! removal ( fle% aft] soak+1 b be=e lim+ 7,"p ,i41 ,section ,,ii471 has be5 fav\r$ by "s1 especially 9 ,am]ica4 ,among/ ! epi!lial /ructures ( ! hides & sk9s1 we h sev]al prote9 bye-products :i* h "s comm]cial value4 ,! horns ( cattle are n[ almo/ inv>iably remov$ be=e rea*+ ! lea!r manufactur]1 b h "s little value4 ,?is "p ( ! epid]mis is n solid k]at94 ,a pi? is easily remov$ aft] boil+ 9 wat]4 ,! out] p>ts1 too1 are (t5 co>se & some:at damag$1 b if remov$ by scrap+ reveal (t5 a r beautiful /ructure ( v>y+ col\r4 ,!re is "s op5+ = ?is product 9 ! manufacture ( small articles ( horn1 b mu* ( x1 toge!r ) ho(s1 is roa/$ & cru%$ = mak+ f]tiliz]s4 ,! hair ( cattle1 goat1 etc41 has also a comm]cial value4 ,?is is remov$ aft] lim+1 & ne$s subsequ5t purification 7,"p ,i41 ,section ,,ii474 ,! hair is well wa%$ ) wat]1 us+ ei!r repeat$ *anges or a cont9u\s supply1 ! op]ation be+ c>ri$ out 9 paddles or simil> ma*9es :i* /ir up ! hair 9 ! wat]4 ,:5 clean1 ! hair is transf]r$ to a c5trifugal ma*9e or sp9n]1 9 :i* mu* adh]+ wat] is remov$4 ,?is is a great assi/ance 9 dry+ out1 :i* is ! next & f9al op]ation4 ,9 dry+1 ! hair is laid ^u /eam-heat$ boxes or pipes1 & a curr5t ( w>m$ air pass$ ov] or ?r\gh x by means ( a fan4 ,x is bett] to h ! hair turn$ occasionally4 ,?is ensures quick] z well z m ev5 dry+4 ,! product is made up into l>ge bales & sold = ! manufacture ( felts1 mattresses1 etc4 ,:ite hair is usually kept sep>ate & comm&s a l>g] price4 ,! p[] consum$ 9 driv+ ! wa%+ ma*9]y1 ! c5trifuges & ! dry+ fan1 toge!r ) ! fuel requir$ = ! dry+ /eam1 & ! lab\r involv$ ?r\gh\t1 make x d\btful :e!r ?is bye-product is wor? ei!r ! capital outlay or ! work+ co/s necessitat$4 ,_m manufactur]s avoid ?is treatm5t altoge!r1 !re=e1 & ! wet lim$ hair is sold direct to ! f]tiliz] factory4 ,a less price is obta9$1 b mu* exp5se is sav$4 ,especially :5 ! animals h only _! %ort summ] coats1 ?is c\rse is pref]r$4 ,9 ! case ( ! wool f %eepsk9s ! product is mu* m valuable4 ,! wool1 inde$1 is (t5 ! prim>y consid]ation4 ,un=tunately ?is sometimes results 9 ! neglect ( ! pelt4 ,! removal ( wool f %eepsk9s =ms a special indu/ry kn[n z fellmong]+1 :i* has be5 previ\sly describ$ 7,"p ,,ii41 ,section ,,iv474 ,pa9s are tak5 to clean ! wool ev5 be=e removal f ! pelt1 by ! lib]al use ( wat] & ! burr+ ma*9e4 ,!re is mu* v>iation 9 quality1 & c>e is tak5 to keep ! v>i\s grades sep>ate1 ev5 dur+ ! pull+ op]ation4 ,f ! fellmong] ! wool passes to ! wool /apl]1 & =ms ! basis ( "o ( our mo/ important me*anical indu/ries1 ! manufacture ( wooll5 clo?s4 ,wool is also remov$ f %eep by ! p]iodic %e>+1 & 9 ?is case does n rea* ! fellmong] at all4 ,ap>t f ! raw mat]ial itself1 !re are few bye-products ( ! lea!r trades :i* are ( comm]cial importance4 ,! sludge f ! pits ( ! limey>d conta9s1 9 addition to mu* lime & *alk1 a c]ta9 proportion ( prote9 matt]4 ,?is is d]iv$ p>tly f ! blood & dung associat$ ) ! hide1 p>tly f ! solution ( ! corium hide sub/ance1 p>tly f ! solution ( ! s(t] k]at9s1 & p>tly also undissolv$ & loose hair4 ,?is bye-product is r difficult to deal )1 z x w n easily dry4 ,x is inde$ sometimes a problem to dispose ( x1 except 9 rural di/ricts1 :]e ! f>m]s appreciate its manurial value & w usually c>t x away = a nom9al fee4 ,:]e possible1 x is bett] to let x dra9 & settle on l&1 & pile x up 9 heaps to dry fur!r4 ,soak-pit sludge has a di/9ctly great] value z manure1 on acc\nt ( ! great] proportion ( dung prote9s4 ,z "s lime is (t5 us$ 9 ^! pits1 ! product is a really useful f]tiliz]4 ,! only o!r bye-product ( ! lea!r trades is wa/e lea!r itself4 ,= small pieces ( lea!r !re is always "s little op5+ 9 produc+ small articles1 su* z wa%]s = taps1 etc41 & !re is also ! possibility ( %r$d+ or pulp+ & mak+ an artificial lea!r4 ,! be/ lea!r sub/itutes1 inde$1 are made f wa/e lea!r4 ,nev]!less1 !re is always a c]ta9 am\nt ( wa/e lea!r :i* only f9ds an outlet 9 ! f]tiliz] factory4 ,su* mat]ial is usually /eam$ or roa/$ to make x brittle1 & !n cru%$ 9 a dis9tegrator4 ,x is !n mix$ 9 ) o!r mat]ials1 b is sometimes solubiliz$ by ! action ( sulphuric acid4 ,lea!r seldom conta9s less ?an #cj p] c5t4 prote94 ,,ref]5ces4 ,*emical ,f]tiliz]s & ,p>asiticides1 ,s4,h4 ,coll9s1 ,m4,s41 ,f4,i4,c4 7,companion volume 9 ?is s]ies on ,indu/rial ,*emi/ry47 ,wool ,wa/es1 ,"p ,,ii41 ,section ,v41 p4 #ge4 ,ho(s1 ,horns1 ,lea!r1 ,"p ,,iii41 ,section ,,ii41 p4 #aae4 ,gelat9e1 ,glue1 & ,alli$ ,products1 ,t4 ,lamb]t4 ,,section ,,ii4--,,bye-,,products ,,( ,,! ,,gelat9e ,,& ,,glue ,,trades ,f ! sk9 gelat9e & glue trades ! mo/ valuable bye-product is ! grease1 :i* is obta9$ f ! fle%+s ( ! adipose tissue4 ,^! fle%+s are !mselves a bye-product ( ! lea!r trades4 ,! recov]y & purification ( ?is grease has be5 dealt ) previ\sly 7,"p ,v41 ,section ,,ii474 ,9 ! sk9 glue trade ! only o!r bye-product is ! residue f ! extraction process 7,"p ,v41 ,section ,,iii474 ,?is residue is kn[n usually z glue scut*1 & is compos$ ( ! prote9s ( ! sk9 :i* are insoluble 9 hot wat]4 ,^! insoluble portions are obta9$ f all lay]s ( ! sk94 ,!re is mu* hair (t5 9 scut*1 ! hyal9e or glassy lay] 7gra971 & ! ela/ic fibres ( ! corium are also insoluble1 & a proportion is d]iv$ f ! fibres ( ! adipose tissue on ! fle% side4 ,all ^! portions are fairly ri* 9 nitrog51 & ! scut* has1 !re=e1 consid]able value to mak]s ( f]tiliz]s4 ,x is liable to conta9 also a p]c5tage ( grease1 :i* is usually remov$ by /eam+ "u hydraulic pressure4 ,?is process recov]s a valuable bye-product & increases ! manurial value ( ! scut*4 ,!re is always left 9 scut* "s ( ! gelat9\s sk9 sub/ance :i*1 /rictly speak+1 %\ld h be5 remov$ dur+ extraction4 ,!re is1 h[ev]1 a practical limit beyond :i* x does n pay to d ?is4 ,:5 ?is limit is rea*$ ! co/ ( /eam 9 extract+1 & also 9 evaporat+ & dry+1 toge!r ) ! loss ( "t & lab\r involv$ by occupation ( ! plant1 is great] ?an ! value ( ! possible product4 ,f ! bone-glue indu/ry1 ! grease is simil>ly a valuable bye-product1 b !re is also ano!r ( equal importance1 viz4 ! phosphate ( lime1 :i* comprises ab\t half ! raw mat]ial4 ,z previ\sly describ$ 9 ,"p ,,iv41 ,section ,,ii41 ?is is usually extract$ aft] ! grease1 by solution 9 weak hydro*loric acid4 ,! solution is neutraliz$ 9 lead-l9$ vats ) milk ( lime1 a precipitate ( di- & tri-calcium phosphates be+ obta9$4 ,calcium *loride is left 9 solution1 & ! precipitate %\ld be1 !re=e1 well wa%$ if x be desir$ to h dry phosphate4 ,! bone-glue indu/ry is1 g5]ally speak+1 mu* m intimately connect$ ) ! f]tiliz] trades ?an ! sk9-glue trades1 inde$ ! extraction ( ! bones = glue is n always advisable1 9 :i* case ! prote9 matt] z well z ! phosphatic matt] ( ! bones are employ$ = mak+ bone manures4 ,= details ( ?is indu/ry ! read] is ref]r$ to a companion volume 9 ?is s]ies on ,*emical ,f]tiliz]s4 ,,ref]5ces4 ,*emical ,f]tiliz]s & ,p>asiticides1 ,s4,h4 ,coll9s1 ,m4,sc4 ,bones1 ,"p ,,ii41 ,section ,v41 p4 #gb4 ,precipitat$ ,bone ,phosphate1 ,"p ,,iii41 ,section ,,iii41 p4 #aeg4 ,bone ,manures1 ,"p ,,iii41 ,section ,v41 p4 #agc4 ,gelat9e1 ,glue1 & ,alli$ ,products1 ,t4 ,lamb]t4 ,,section ,,iii4--,,food ,,prote9s ,al?\gh !re are ^? :o consid] t animal prote9s are bo? undesirable & unnecess>y z foods1 x is nev]!less true t man is almo/ univ]sally a c>nivor\s animal4 ,! animal _w provides mank9d ) "o ( its *ief s\rces ( food1 & especially ( prote9 foods4 ,prote9 foods are unque/ionably ess5tial1 & animal prote9 foods diff] *iefly f ^? ( vegetable orig9 9 ! fact t !y conta9 g5]ally mu* m prote94 ,( ! prote9s not$ 9 our ,introduction1 ! k]at9s h no value z foods2 ! gelat9s h "s value z cul9>y mat]ial1 b little actual food value2 :il/ ! album9s comprise practically all ! useful animal food prote9s4 ,:il/ ! actual fle% ( animals is ! pr9cipal s\rce ( food prote9s--bo? z to quantity & food value--o!r p>ts ( animals1 e4g4 kidneys1 liv]1 blood1 bra9s1 tongue1 are us$ & reli%$4 ,! mo/ important s\rces ( animal food prote9s are f fi%1 f[l1 %eep1 cattle1 & pigs1 ! meat f ^! be+ r\ghly 9 ! same sequ5ce z to dige/ibility4 ,!re are1 h[ev]1 _m o!r animals ( :i* ! fle% is q edible1 b mo/ ( ! above are specially f>m$ & propagat$ prim>ily = _! food value4 ,z ! animal food prote9s are exce$+ly putrescible1 !y are usually consum$ )9 a %ort "t ( ! animal be+ kill$4 ,x is p]haps natural1 !re=e1 t _m ef=ts h be5 made to discov] means ( pres]v+ su* foods4 ,^! ef=ts =m ! basis ( "s important indu/ries1 & ?\gh !y c h>dly be includ$ z *emical indu/ries1 x w n be out ( place 9 ?is volume to po9t out t ^! ef=ts pres5t analogies )1 z well z diff]5ces f ! me?ods us$ = pres]v+ hides & sk9s 7,"p ,i41 ,section ,i474 ,! cur+ ( hides & sk9s is a tempor>y pres]vation f putrefaction until ! opportunity is conv5i5t = ! p]man5t pres]vation 7i4e4 tannage74 ,! pres]vation ( meats is analog\s to cur+ inasmu* z m dra/ic treatm5t might inde$ make !m non-putrescible1 b w\ld also r5d] !m indige/ible & unsuitable = food4 ,?us dry+1 salt+1 dry+ & salt+1 pickl+ & freez+1 are j z suitable = pres]v+ food prote9s z = hide & sk9 prote9s4 ,h5ce we h dri$ meats1 salt bacon1 pickl$ beef1 froz5 mutton1 etc4 ,to a limit$ ext5t smok+ 7fi%1 bacon1 etc47 has be5 employ$ z a cure4 ,:5 x has be5 appli$ to sk9s x is usually comb9$ ) a fat tannage4 ,!re is1 h[ev]1 "o me?od ( pres]vation ( prote9s1 inapplicable to sk9s1 :i* has be5 em95tly successful & useful = food prote9s1 viz4 /]ilization by boil+4 ,! food has be5 plac$ 9 t9s1 h]metically seal$1 & ?or\ghly /]iliz$4 ,h5ce h appe>$ corn$ beef1 t9n$ tongue1 s>d9es1 etc41 :i* m]ely illu/rate ! imm5se possibilities involv$4 ,a notewor?y advantage ( ?is me?od ( pres]v+ animal food prote9s1 is t ! food is already cook$ & prep>$ = imm$iate consumption4 ,ano!r l9e ( ef=t is ! prep>ation ( conc5trat$ foods4 ,j z animal foods are on ! :ole m conc5trat$ 9 prote9 ?an vegetable foods1 s ^! prep>$ animal foods are m conc5trat$ ?an animal fle%1 & g5]ally also m soluble4 ,su* prep>ations ( animal prote9 are obvi\sly useful :5 !re is difficulty 9 swall[+ & :5 j\rneys are necess>y into regions ( poor food supply4 ,x is a little d\btful1 "o mu/ say1 :e!r ! conc5tration is z great 9 "s cases z is claim$4 ,yet ano!r indu/ry bas$ ^u ! animal prote9s is ! manufacture ( meat-extracts4 ,^! are n m]ely conc5trat$ extracts ( animal fle%1 b conta9 especially ! /imulative prop]ties ( animal food prote9s4 ,!re is n[ little d\bt ( ! value ( ^! prep>ations z /imulants1 & x is claim$ = !m t !y n only h food value1 b also t !y increase ! food value ( o!r foods us$ ) !m4 ,toge!r ) ^! products may be class$ all ! miscellane\s tonic foods1 9 :i* prote9s are bl5d$ ) c>bohydrates & (t5 also ) drugs4 ,^! aim at ! cure ( specific disord]s1 su* z n]v\s debility1 sleeplessness1 etc4 ,_! claims are (t5 extravagant4 ,among/ all ! multitude ( prep>$ foods1 !re des]ve p>ticul> m5tion ! p>tly pr$ige/$ foods4 ,9 cases :]e ! dige/ive functions are weak or disord]$ ^! products h be5 ( real s]vice4 ,"o ( ! mo/ useful & valuable ( animal food prote9s is obta9$ f h5 eggs4 ,! :ite ( eggs is almo/ pure album91 & !re is mu* prote9 9 ! yolk also4 ,eggs are n[ produc$ & import$ by ! million1 & =m a mo/ important item 9 ! c\ntry's diet>y1 ! prote9 be+ 9 a v easily dige/ible =m4 ,x is also necess>y to ref] to ! importance ( c[s' milk z a s\rce ( animal food prote94 ,! am\nt ( prote9 9 milk 7#d-e p] c5t47 is n l>ge1 b x is unit$ ) fats1 c>bohydrates1 salts1 & vitam9es 9 su* proportions1 t milk is ab\t ! only article :i* may reasonably pres5t a claim ( be+ a complete food4 ,milk1 moreov]1 =ms ! /aple diet ( infants & "y *ildr51 s t its prote9 is c]ta9ly ( great importance4 ,z an infant food1 c[s' milk is n altoge!r ideal4 ,ev5 :5 ! proportions ( fat1 c>bohydrate1 & prote9 h be5 adju/$ to resemble human milk1 !re rema9s ! difficulty t "s ( ! prote9s ( milk 7especially ! case97 are too indige/ible = "y infants4 ,?is difficulty has be5 only p>tly surm\nt$ by ^? indu/ries engag$ 9 manufactur+ infant foods4 ,"s claim to remove ! bulk ( ! case92 o!rs to h r5d]$ x dige/ible by treatm5t ) enzymes2 o!rs1 aga91 simply claim to supply conc5trat$ c[s' milk4 ,t9n$ milk1 g5]ally conc5trat$ to "s ext5t1 n[ =ms a useful addition to animal food products4 ,! case9 ( milk also f9ds "s outlet = indu/rial purposes4 ,:5 treat$ ) =maldehyde x yields an artificial horn mu* us$ = ! prep>ation ( imitation tortoise%ell4 ,skim milk is treat$ ) cau/ic soda or c>bonate ( soda1 ! case9 precipitat$ by acid1 press$1 impregnat$ ) =maldehyde1 & dri$4 ,! product is t]m$ galali?4 ,x c be di/+ui%$ f real tortoise%ell by ! action ( fum+ nitric acid 7see ,j4,c4,s4,i41 #aiji1 #aja74 ,! utilization ( ! blood ( animals1 :i* is v ri* 9 prote91 z a food/uff has long be5 kn[n1 b has met ) a good deal ( prejudice 9 ?is c\ntry4 ,?is prejudice has aris5 n m]ely f ! objection to blood z food1 b also f ! fact t su* foods h be5 p>ticul>ly liable to putrefaction & h5ce to cause poison+4 ,! %ortage ( all food/uffs occasion$ by ! ,european ,w> did mu* to ov]come ?is prejudice1 & !re 7 consid]able developm5ts 9 ! manufacture ( black pudd+ & simil> prep>ations ( animal blood4 ,! same circum/ances made x necess>y to consid] m s]i\sly ! possibilities ( o!r but*]s' (fal z human food1 & result$ 9 new prep>ations ( t9n$ animal prote9s be+ plac$ on ! food m>ket4 ,! au?or w\ld l to record 8 op9ion t by no means ! la/ ^w has be5 said on ! "q ( dry+ z a me?od = pres]v+ animal food prote9s4 ,!re is mu* to be said = ?is me?od on e gr\nd 9 !ory1 & x is evid5tly an increas+ success 9 practice4 ,dri$ milk has be5 foll[$ by dri$ eggs1 & 9 view ( ! success ( ! me?od :5 appli$ to fruits & vegetables1 !re seems a prospect ( bett] success 9 respect ( dri$ meats4 ,aft] all1 animal food prote9s are *iefly lyophile colloids1 & ?\gh desiccation pres5ts "s practical difficulties1 ! subsequ5t imbibition 7assi/$ p]haps by lyotrope influ5ces7 seems to be ! ideal me?od = re/or+ pres]v$ prote9 to its orig9al condition4 ,9 conclusion1 x w be int]e/+ to note 9 ! subjo9$ table1 ! relative importance ( ! diff]5t s\rces ( supply ( bo? animal & vegetable food prote94 ,! figures are tak5 f ! report ( a ,committee ( ! ,royal ,society4 ,!y %[ ! av]age quantities ( food mat]ials 7import$ & home produc$7 available = ! ,unit$ ,k+dom dur+ ! five ye>s #aiji-aiac inclusive1 toge!r ) ! am\nts ( prote91 fat1 & c>bohydrate pres5t & ! en]gy value4 ,?is in=mation =m$ ! basis ( ! ,committee's recomm5dations z to economy ( prote9 dur+ ! w> %ortage4 ,^! recomm5dations includ$ ! m economical production ( meat by slaught]+ cattle y\ng] & ! sav+ ( #ee1jjj metric tons ( prote9 annually by adopt+ *eese-mak+ z a g5]al practice 9 place ( butt]-mak+4 ,metric tons4 ,en]gy -------------------------------- value1 ,prote94 ,fat4 ,c>bo- millions ( hydrate calories4 ---------------------------------------- ---------------------------- ,c]eals #edi1jjj #fc1jjj #c1fbh1jjj #ag1gab1jjj ,meat #cef1jjj #gii1jjj -- #h1hij1jjj ,p\ltry1 eggs1 game1 #db1jjj #ca1jjj -- #dfa1jjj & rabbits ,fi% #ia1jjj #ag1jjj -- #eca1jjj ,dairy produce1 includ+ #aii1jjj #fhf1jjj #beh1jjj #h1bec1jjj l>d & m>g>9e ,fruit #i1jjj #ad1jjj #bbb1jjj #a1jgg1jjj ,vegetables #abj1jjj #aj1jjj #a1jca1jjj #d1hab1jjj ,sug>s 7includ+ cocoa1 #e1jjj #ah1jjj #a1egb1jjj #f1fcc1jjj etc47 ,o!r cottage & f>m produce #fg1jjj #ac1jjj #eea1jjj #b1fee1jjj ,,section ,,iv4--,,miscellane\s ,,animal ,,prote9s ,! excreta ( animals include animal prote9s ( great importance to agriculture & horticulture1 =m+ ! /aple supplies ( manure4 ,! manure ( animals %\ld conta9 n only ! solid wa/e mat]ial & undige/$ food1 b also ! ur9e1 :i* conta9s mu* nitrog51 & h5ce makes consid]able diff]5ce to ! value ( ! product z a f]tiliz]4 ,if ! animals are f$ on ri* foods1 ! manure obta9$ is correspond+ly ri*]1 especially 9 its prote9 cont5t4 ,! value ( dung manures dep5ds n m]ely ^u ! prote9 cont5t1 b also ^u its cont5t ( phosphate & pota%1 z well z o!r organic matt]4 ,! prote9 breaks d[n into simpl] nitrog5\s comp\nds1 & ev5tually1 ?r\gh ammonium c>bonate1 x becomes nitrate4 ,nitrog5\s manures d>k5 leaves & increase gr[? consid]ably4 ,dung manures are defici5t 9 phosphates & pota% & are ( value p>tly z nitrog5\s manures produc+ gr[?1 & p>tly z dress+s ( organic matt] = soil4 ,f bo? po9ts ( view x is desirable t ! manure %\ld be well decay$4 ,fre% dung manures are bo? wa/eful & injuri\s to soil1 except p]haps to v /iff clays4 ,!y are wa/eful inasmu* z mu* ammonia escapes1 & injuri\s inasmu* z !y cause ! d5itrification ( ! valuable nitrates already 9 ! soil4 ,:5 possible dung manures %\ld be kept "u cov]4 ,free exposure to air & ra9 w sometimes r$uce its value by "o half4 ,x %\ld be /or$ until sweet1 & until ! /raw has rott$ & become %ort4 ,?is takes usually sev]al mon?s4 ,a ton ( well-rott$ f>my>d manure conta9s v approximately #aj-ab lbs4 nitrog51 ab\t ! same am\nt ( pota%1 & ab\t half t quantity ( phosphates4 ,x is1 h[ev]1 v v>iable4 ,horse manure is r ri*] ?an c[ manure1 b m liable to loss on /orage4 ,pig manure is int]m$iate betwe5 !m4 ,%eep manure is di/9ctly ri*] 9 prote91 & has !re=e great] value z nitrog5\s f]tiliz]s4 ,p\ltry dropp+s are ri*] /ill1 p]haps p>tly because !y include ! ur9>y products4 ,:5 fre% !y conta9 #ah-be lbs4 nitrog51 #ab-bd lbs4 phosphate1 & #f-ab lbs4 pota% p] ton4 ,:5 dri$ !y h ab\t d\ble ! value4 ,pigeon manure is ev5 ri*]1 & ! pigeon l(t scrap+s h a manurial value ab\t d\ble t ( dry h5 manure1 & eight times t ( f>my>d manure4 ,guano is mu* decay$ dropp+s ( sea birds on ! tropical coa/s ( ,africa & ,am]ica4 ,! supplies are n[ q exhau/$1 & ! m>ket guanos are *iefly artificial f]tiliz]s4 99 99 99 99 99 ,!re is "o o!r animal prote9 :i* mu/ be ref]r$ to be=e ?is volume is conclud$1 viz4 silk4 ,?is is obta9$ f ! cocoon ( ! silkworm1 :i* is ! g5]al "n giv5 to ! l>v ( c]ta9 bombycid mo?s4 ,^! l>v fe$ on ! leaves ( ! mulb]ry1 & :5 ready to pupate produce a consid]able supply ( a s(t & delicate ?read :i* is w\nd r\nd ab\t ! l>va itself4 ,?is is ! raw silk1 & x is unw\nd f ! cocoon 9 a ma*9e call$ ! silk-reel1 & may !n be w\nd into a ?read4 ,two or m ?reads twi/$ toge!r =m ?r[n-silk4 ,silk ?reads are also wov5 into clo? ( *>act]i/ic texture & appe>ance4 ,?is prote9 ?us =ms ! raw mat]ial ( "o ( ! mo/ important textile indu/ries4 99 99 99 99 99 ,f ! fi% trade !re is mu* animal prote91 :i* is useless = food purposes & :i*1 to avoid nuisance1 x is necess>y to conv]t promptly 9 f]tiliz]s4 ,dur+ ! h]r+ season !re is ! disposal 9 ?is way ( ! heads1 tails1 & ! guts4 ,_m fi% are incid5tally caught :i*1 be+ valueless z food1 are yet useful z manure4 ,aft] ! extraction ( oil f fi% liv]s ! residue is suitable = a simil> purpose4 ,^! residues are /eam$1 dri$1 & gr\nd up1 =m+ fi% manure1 ri* 9 nitrog5 & (t5 also 9 phosphate4 ,,ref]5ces4 ,*emical ,f]tiliz]s & ,p>isiticides1 ,s4 ,h4 ,coll9s1 ,m4,sc4 ,organic ,nitrog5 ,f]tiliz]s1 ,"p ,,iii41 ,section ,,ii41 p4 #aje4 ,fi% ,manure1 p4 #aaj4 ,,index ,acclimatization 9 colloid sy/ems1 #bcf ,acid1 ellagic1 #bi gallic1 #bi sulphur\s1 #bbg1 #bdc ,acid process = bone gelat9e1 #bdc ,acids1 = delim+1 #bc = pickl+1 #aad 9 s\r liquors1 #bi1 #dd ,adsorption1 law (1 #dc me?ods ( cl>ification1 #bcd nature (1 #da ( ions by gelat9e1 #baa ,african hides1 #ae ,album9s1 #d1 #bdj1 #bgd1 #bgg ,alg>obilla1 #cb ,alum1 #bcf1 #bdj ,am]ican hides1 #ad ,animal excreta1 #bgi ,ars5ic sulphide1 #bj ,asiatic hides1 #ad ,a/r+5cy ( liquors1 #dd ,bact]ia 9 soaks1 #af limes1 #bj bates1 #bd tan liquors1 #bi ,bag lea!r1 #hf ,b&-knife splitt+1 #eb ,b>k1 hemlock1 #cd1 #dj mallet1 #cd mangrove1 #ce1 #da mimosa1 #cc oak1 #cd p9e1 #cd1 #da will[1 #cb ,basic dye/uffs1 #ig ,basils1 #aae ,bat+1 #bd1 #id ,belt+ lea!r1 #fe ,blair-,campbell evaporator1 #bdi ,blea*+ lea!r1 #fb glue1 #bda ,block ,gambi]1 #dj ,bloom1 #bi ,boil+ process = glue1 #bbc ,bone gelat9e1 #bbc manure1 #bgc meal1 #bbd ,bones1 #bbc ,bookb9d+ lea!r1 #ajd1 #ajf1 #aag1 #abj ,boric acid1 #bc ,bottle tannage1 #ajc ,box calf1 #aef ,bridle lea!r1 #ga ,briti% hides1 #h ,bru%+ lea!r1 #fc ,buck lea!r1 #aha ,buff lea!r1 #aha ,buff+1 #eb ,burn+ 91 #ed ,butt1 #bb ,bye-products ( ! gelat9e trade1 #bgb ( ! lea!r trades1 #bfh ,calcium sulphydrate1 #bb ,calf sk9s1 #gf1 #abj1 #aef ,case91 #bgf ,ca/ glue1 #beg ,cate*91 #cb ,cate*ol tans1 #cb ,cau/ic soda1 #ah1 #bj ,c5trifugal fan1 #ej ,*amois lea!r1 #aha ,*eeks1 #bfh ,*emi/ry ( colloids1 #bja ,*e/nut extract1 #cf ,*lor9e blea* = glue1 #bdf ,*rome calf1 #aef goat1 #afc hide1 #agj %eep1 #afc ,*rome tannage1 #abg-agd f9i%+ op]ations1 #aec g5]al me?ods1 #aci hi/ory (1 #abg "o ba?1 #adi special qualities (1 #acf !ory (1 #abi two-ba? process1 #adb ,cl>ification ( gelat9e1 #bcd ,coeffici5t ( conductivity1 #bec ,colloid *emi/ry1 #bja ,comb9ation tannages1 #aia ,conc5trat$ foods1 #bge ,cond5s] wat]1 #bea ,conductivity coeffici5t1 #bec ,cont95tal hides1 #ad ,cr[n lea!r1 #agh ,cube gambi]1 #dj ,cur+ hides1 dry+1 #ac dry-salt+1 #ac freez+1 #ac salt+1 #ab /]iliz+1 #ad ,curry+1 #di ,cut glue1 #beg ,decolorization ( glue1 #bch ,de]sk9s1 #ib1 #aha ,degreas+ bones1 #bbd1 #bbg lea!r1 #aae ,delim+1 #bc ,depilation1 #ai ,divi-divi1 #cb ,dongola lea!r1 #aia ,dr5*+1 #be1 #ie ,dress+ lea!r1 #bd1 #fe-ib ,drum /uff+1 #ec tann+1 #fc ,dry+ gelat9e & glue1 #bee hides1 #ac lea!r1 #ej ,dung bates1 #bd manures1 #bgi pu]s1 #id ,dye+ lea!r1 #if ,e>s1 #bbj1 #bfh ,eggs1 #bgf ,ela/ic fibres1 #f1 #bgb ,ellagic acid1 #bi ,enamell$ lea!r1 #abc ,enzymes1 #bd1 #be1 #id1 #ie ,erod91 #id ,evaporation1 #cg1 #bdh ,evaporators1 ,blair ,campbell1 #bdi ,ke/n]1 #bdi ,y>yan1 #bdi ,evolution ( gelat9e indu/ry1 #bfe ( lea!r indu/ry1 #aid ,extraction ( gelat9e & glue1 #bcj-bcc ( grease1 #aae1 #bbd1 #bbg ( phosphate1 #bbd ( tann91 #ce ,extracts ( meat1 #bge ( tann+ mat]ial1 #cg-da ,faces1 #bbj1 #bfh ,fan dry+ gelat9e1 #beg lea!r1 #ej ,fat liquor+1 #aed tannages1 #agh ,f$]ation ( ,tann]s1 #ajh ,fellmong]+1 #aac ,f]m5tation 9 bates & pu]s1 #bd1 #id 9 dr5*es1 #be 9 limes1 #bj1 #ba ,f]tiliz]s1 #bfi1 #bgi ,filt] press1 #bch ,f+] te/1 #bah ,f9i%+ *rome lea!r1 #aec heavy lea!r1 #di light lea!r1 #if ,fi% glue1 #bbh manure1 #bhj ,fle%+1 #bb ,flocculation1 #bcg ,food prote9s1 #bgd ,foods1 conc5trat$1 #bge dri$1 #bgg ,=maldehyde tannage1 #ahe ,fractional extraction ( glue1 #bcj ,galali?1 #bgg ,gallic acid1 #bi ,galls1 #cb ,gambi]1 #dj ,gelat9e1 blea*+1 #bda cl>ification (1 #bcd decolorization1 #bcd dry+ (1 #bee evaporation (1 #bdh extraction (1 #bcj prop]ties (1 #bjj raw mat]ial =1 #bbj uses (1 #bfj ,glac calf1 #aef goat & %eep1 #afc ,glaz+1 #ig1 #aee ,glove lea!r1 #agd ,glue 7see ,,gelat9e7 diff]5ce f gelat9e1 #bda ,goatsk9s1 #ii1 #afc ,gra9+1 #ig ,grease 9 bones & scut*1 #bbd1 #bbg 9 sk9s1 #aae ,guano1 #bgh ,hair1 removal (1 #bb ,h&l]s1 #dg ,h>d-gra9 morocco1 #aag ,h>ness lea!r1 #ga1 #agj ,heavy lea!r1 #g-ib *rome lea!r1 #agj ,helvetia lea!r1 #agi ,hemlock b>k1 #cd ,hides1 ,am]ican1 #ad ,african1 #ae ,asiatic1 #ad ,briti%1 #h ,cont95tal1 #ad dri$1 #ac dry-salt$1 #ac fre%1 #h froz51 #ac salt$1 #ab ,ho(s1 #bfh ,horns1 #bfh ,hyal9e lay]1 #bgb ,hydrophile colloids1 #bdj ,hydrophobe colloids1 #bdj ,hydrosulphite ( soda1 #bde ,hypo ba?1 #abh1 #adg ,imitation box calf1 #aei glac kid1 #afc ,imp]ial aspect ( lea!r trade1 #aih ,increase 9 /r5g? ( tan liquor1 #dd ,incru/ation1 #bed ,influ5ce ( ,lyotrope s]ies1 #bjf-bji ,int5sive production1 #aid1 #bfe ,int]fibrill> sub/ance1 #bd ,iron & logwood1 #ge1 #hc1 #aji ,jack+ lea!r1 #ea ,japann$ lea!r1 #abc ,jelly1 #bjc1 #beh ,k]at9s1 #d ( epid]mis1 #bgb ,ke/n] evaporator1 #bdi ,kid sk9s1 #afc1 #agd ,kips1 #h1 #gf1 #aei ,lactic acid1 #bc ,lambsk9s1 #aaj1 #afc1 #agd ,l>* b>k extract1 #da ,layaways1 #dg ,lay]1 hyal9e or glassy1 #bgb ,lay]s1 #dg ,lea*+1 #ce ,lea!r1 def9ition (1 #bg ,legg+ lea!r1 #gf ,levant gra91 #aji ,lime1 function (1 9 depilation1 #bj ,lim+ = *rome lea!r1 #abg glue pieces1 #bbj hides1 #ah lea!r1 #hc sk9s1 #ib ,liquor1 *rome #abg1 #abi1 #adc-aec lime1 #ah-bb tan1 #ce ,logwood1 #ge1 #hc1 #aji ,lyophile colloids1 #bja ,lyophobe colloids1 #bja ,lyotrope s]ies colloids1 #bjf-bji ,ma*9e fle%+1 #bc scudd+1 #bc %av+1 #eb1 #hb ,mallet b>k1 #cd ,mangrove b>k extract1 #da ,mean temp]ature diff]5ce1 #beb ,meat extracts1 #bge ,mell[ lime liquors1 #ah-ba tan liquors1 #dd ,memel butts1 #hc ,milk1 #bgf ,mimosa b>k1 #cc ,miscellane\s prote9s1 #bff1 #bgi tannages1 #agd ,mix$ tannage ( sole lea!r1 #ee ,mordants1 #if ,morocco lea!r1 calf1 #abj goat1 #ii seal1 #ajf %eep1 #aaj ,motor butts1 #agj ,multiple-effect evaporation1 #bdi ,myrabolans1 #cj ,nature ( *rome lea!r1 #abg ( lea!r1 #bg ,nett adsorption1 #bae ,neutralization1 #aec ,nitrog5 9 prote9s1 #a value ( manures1 #bhj ,noses1 #bfh ,oak b>k1 #cd ,oakwood extract1 #cg ,(fal = sole lea!r1 #fc ,oil tannage1 #aha ,"o-ba? *rome tannage1 #adi ,"o-pit sy/em ( lim+1 #ai ,op5-vat sy/em ( extraction1 #bca ,oxidation me?od ( blea*+1 #bde ,paddles = wa%+1 pu]+1 dye+1 & tann+1 #ag1 #id1 #if1 #ajc ,p>k]1 on valonia1 #ca ,pelt1 prep>ation (1 #af1 #ib1 #aci ,p]oxides = blea*+1 #bdf ,phlobaph5es1 #cc ,phosphate ( lime1 #bbc1 #bbe1 #bgc ,pick+ b& butts1 #ij ,pickl+ foods1 #bge sk9s1 #aad ,pigsk9s1 #ib ,p9e b>k1 #cd ,plump+1 #ai1 #dd ,precipitation1 #bcf ,pr$ige/$ foods1 #bgf ,prep>ation ( pelt1 #af1 #ib1 #aci ,press lea*1 #ce ,pr9ciples ( *rome tannage1 #aci cl>ification ( gelat9e1 #bcd lim+1 #ib vegetable tannage1 #da ,proct]1 def9ition ( lea!r1 #bg glucose *rome liquor1 #aeb on gelat9e swell+1 #bag on pickl+1 #aae ,prop]ties ( *rome lea!r1 #abg gelat9e & glue1 #bjj ,protective colloid1 #bcg ,prote9s1 classification1 #c composition (1 #a-c food1 #bgd miscellane\s1 #bff1 #bgi ( d]mis1 #bga ( epid]mis1 #bgb ,pu]+1 #id ,purification ( grease1 #bbg ,putrid soaks1 #ah ,pyrogallol tans1 #bh ,qualities ( *rome lea!r1 #abg gelat9e & glue1 #bjj ,quebra*o extract1 #ch ,qu]cus gilops1 #cj robur1 #cd ,quick processes ( evaporat+1 #bdh ( tann+1 etc41 #aid ,rabbit sk9s1 #bba ,raw mat]ial = gelat9e1 #bbj heavy lea!r1 #g light lea!r1 #ib ,r$s1 #cc ,r$uction blea*+ ( glue1 #bdc ,refrig]ator1 #beh ,roans1 #aag ,rock]s1 #df ,roll] lea!r1 #aah ,roll+ lea!r1 #ea ,r\nd ( pits1 #ai1 #df ,r\nd+ pelt1 #bb ,salt$ food prote9s1 #bge hides1 #ab ,samm+1 #ej ,sat9 lea!r1 #gf ,s*ultz *rome tannage1 #abh ,sc\r+1 #ea ,scudd+1 #bb ,scut*1 #bga ,sealsk9s1 #ajf ,season+1 #ig ,semi-*rome1 #aia ,%>p limes1 #ai ,%av+1 #ea ,%e>l+s1 #aad ,%$work on gelat9e1 #beg on lea!r1 #ej ,%eepsk9s1 #aaj1 #afc1 #agd1 #aha ,%ort processes1 #dg1 #aid ,silk1 #bhj ,sk9s1 #ib ,skiv]s1 #aaf ,sludge f lime pits1 #bgj ,smok$ foods1 #bge ,soak+ hides1 #af ,soda1 #ah1 #bj ,sodium sulphide1 #ah1 #bj ,sole lea!r1 #ee ,s\r tan liquors1 #dd ,split fle%es1 #gf1 #aha hides1 #hf ,splitt+1 #eb ,/ak+1 #aee ,/ocks1 #ah ,/on+1 #ea ,/ove dry+1 #aje1 #aji1 #abe ,/rap butts1 #fe ,/rik+ lea!r1 #ea ,/uff+ lea!r1 #di1 #ec ,sub/ance1 int]fibrill>1 #bd ,sulphide ( ars5ic1 #bj soda1 #ah1 #bj ,sulphur\s acid1 #bbg1 #bdc ,suma*1 #ca use 9 dye+1 #ajd1 #aag use 9 f9i%+1 #fb1 #hd use 9 tann+1 #ajb ,susp5d]s1 #df ,sweat+1 #aac ,swell+ ( gelat9e1 #bja-bbj ( pelt1 #ai ,syntans1 #ahh ,syn!tic tann+ mat]ials1 #ahg ,tannage1 alum1 #agd bag1 #ajc bottle1 #ajc *rome1 #abg1 #aci comb9ation1 #aia drum1 #dg fat1 #agh =mal91 #ahe oil1 #aha ) syn!tic mat]ials1 #ahg ( bag lea!r1 #hf ( bridle lea!r1 #ga ( belt+ lea!r1 #fe ( h>ness lea!r1 #ga ( bookb9d+ lea!r1 #ii1 #aaj1 #abj ( morocco lea!r1 #ii1 #ajf1 #aaj1 #abj ( pick+ b& lea!r1 #ij ( sole lea!r1 #ee ( upp] lea!r1 #gf ( roll] lea!r1 #aah ,tannage1 *rome1 ( calf1 #aef ( goat & %eep1 #afc ( hides1 #agj ,tannage1 vegetable1 heavy hides1 #ee-ij sk9s1 #ib-abc ,tann+1 !ory (1 #da *rome1 !ory (1 #abi ,tann9s1 cate*ol1 #cb classification (1 #bh prop]ties (1 #bg pyrogallol1 #bh ,?ree-paddle sy/em ( tann+ sk9s1 #ajc ,?ree-pit sy/em ( lim+1 #ai ,tissue1 adipose1 #bga ,two-ba? *rome tannage1 #adb ,udd]s1 #bbj ,unhair+1 #bb1 #bc ,upp] lea!r1 #gf1 #aae1 #abj1 #abc ,vacuum on cond5s]1 #bej pan1 #bdh ,val5cy rule1 #aca1 #bcf ,valonia1 #cj ,vatt+ sole lea!r1 #fb ,vegetable tannage1 #da ( hides1 #ee-ij sk9s1 #ib-abc tann+ mat]ials1 #bh ,velocity effect on heat transf]5ce1 #bec ,w>1 effect on me?ods1 #aid1 #bfe on supplies1 #aa-ac1 #cc1 #bgg ,w>ble fly1 #aj ,wa/e lea!r1 #bgj ,wattle or mimosa b>k1 #cc ,wax$ lea!rs1 #gf-hf ,wea!r dry+1 #di ,will[ b>k1 #cb calf1 #aef ,wood1 ,j4 ,t41 action ( pu]1 #id ,wool1 #aaj1 #bfi ,y>yan evaporator1 #bdi ,zones ( compress$ wat]1 #bjb-bje