,,syn!tic ,,tann9s ,,_! ,,syn!sis1 ,,indu/rial ,,production ,,& ,,application by ,georg ,crass]1 ,dr4 ,phil41 ,+4 ,lectur] 9 ,tann+ ,*emi/ry at ! ,g]man ,te*nical ,college1 ,brunn ,,au?or',s ,,preface ,:il/ ! syn!sis ( ! natural tann9s has be5 successfully outl9$ by ,emil ,fis*]1 x has be5 left to ! ,*emical ,indu/ry1 notably ! ,badis*e ,anil9 und ,soda-fabrik 9 ,ludwig%af5-on-!-,rh9e1 to discov] ! means ( mak+ possible ! production ( ! syn!tic tann9s4 ,! sci5tific results ( ,fis*]'s rese>*es are to-day common k1 & ^!1 toge!r ) que/ions aris+ !refrom1 w only be lightly t\*$ ^u 9 ! book h]e) pres5t$4 ,ev5 an attempt at enum]at+ ! pres5t syn!tic tann9s has s f> n be5 publi%$1 & ,i h !re=e avail$ myself ( ! opportunity ( mak+ a brief summ>y ( !m4 ,my "w at ! ,b4,a4,s4,f4 deep5$ my insight 9 ?is new field2 ample opportunity ( apply+ ^! syn!tic products 9 practice 0 giv5 me :51 z a result ( ! w>1 ,i 0 appo9t$ te*nical consultant to ! ,au/rian ,hide & ,lea!r ,commission1 & 9 ?is capacity 0 call$ ^u to act z g5]al advis] to ! trade4 ,! ultimate object ( my sci5tific rese>*es 0 !n to inve/igate ! *emi/ry ( ?is p>ticul> field1 & ?is has l$ me to pres5t a picture1 complete z f> z x goes1 ( ?is bran* ( *emical te*nology4 ,! int5tion ( ! pres5t volume is to communicate to ! read] :at has s f> be5 sci5tifically evolv$ & practically appli$ 9 ?is field4 ,fir/ ( all1 h[ev]1 x may illu/rate ! extreme importance & ! univ]sal applicability ( ! syn!tic tann9s 9 ! mak+ ( lea!r4 ,! mod]n lea!r indu/ry _c1 to-day1 be )\t ^! important products1 b also 9 ^? tann]ies1 :]e ! syn!tic tann9s h n s f> be5 reg>d$ z indisp5sable1 _! use is /rongly recomm5d$4 ,j z 9 ! case ( ! coal-t> dyes1 ! syn!tic tann9s w make u indep5d5t ( =eign supplies1 & ?us keep )9 our own bord]s ! va/ sum ( money requir$ 9 =m] days = ! pur*ase ( =eign tann+ mat]ials4 ,may ?is book prove ! means ( provid+ an inc5tive = a /ill wid] application ( ! syn!tic tann9s4 ,,grass]4 ,,graz1 ,augu/ #aibj4 ,,translator',s ,,preface ,doctor ,grass] h>dly ne$s an introduction to ! lea!r trade ( ?is c\ntry 9 its sci5tific aspect1 b if "o be s\ght =1 none c\ld s]ve ! purpose bett] ?an a translation ( ! book h]e) pres5t$ to ! ,briti%-speak+ public4 ,view$ ) curiosity f _! />t1 ! syn!tic tann9s ne$$--l _m o!r important discov]ies--an extreme em]g5cy = ! purpose ( %[+ _! value4 ,! ,great ,w> provid$ ! opportunity ( :i* *emical indu/ry 0 to avail itself1 & to-day we d n only see syn!tic tann9s plac$ ^u ! m>ket z a v]itable triumph ( *emical te*nology & a cr$itable triumph ( manufactur+ *emi/ry2 we also see _! imm5sely practical qualities e/abli%$ z a fact1 &1 z ! au?or aptly rem>ks1 no mod]n tann] c to-day dissociate himself f ! use ( syn!tic tann9s = ! production ( lea!r 9 ! true s5se ( ?is ^w4 ,!re is no bran* ( lea!r-mak+ :]e syn!tic tann9s _c help & improve processes already e/abli%$4 ,! imm5se numb] ( sub/ances pat5t$ by ,g]man manufactur+ *emi/s = ! purpose ( produc+ syn!tic tann+ mat]ials is almo/ /agg]+4 ,9 view ( ?is fact x is d\bly pleas+ to see t ,briti% *emi/s h f\nd new ways1 & are able to produce equally good & m v>i$ syn!tic tann9s ?an has hi!rto be5 deem$ possible4 ,! orig9ator ( ^! products & 8 acolytes mu/ at lea/ %>e ! cr$it ) ^? :o1 9 spite ( ! limitations necess>ily set by ! =m]1 h be5 able to f9d new & bett] ways4 ,9 8 book ,dr4 ,grass] gives a %ort review ( ! necess>y =]unn] ( any "w ^u syn!tic tann9s3 ! inve/igations & syn!ses ( ! natural tann9s4 ,x is c]ta9ly to be hop$ t we may soon see su* works z ^? ( ,fis*]'s & ,freud5b]g's1 rec5tly publi%$1 translat$ into ,engli%4 ,= ! guidance ( ! read] x may be not$ t a %ort acc\nt ( ! works ( ^! au?ors may be f\nd 9 ! ,j\rnal ( ! ,society ( ,lea!r ,trades' ,*emi/s1 vol4 v4 7,may issue72 9 addition to ?is "s ( ! matt] conta9$ 9 ! *apt] on syn!sis ( tann+ matt]s appe>$ 9 ! ,janu>y #aiba issue ( ! ,j\rnal ( ! ,am]ican ,lea!r ,*emi/s' ,association4 ,9 addition to ^! two sections1 ! la/ "p ( ?is book deals ) ! practical applications ( syn!tic tann9s1 & x is hop$ t ! tann] w f9d mu* valuable in=mation 9 ^! pages4 ,! ma9 outl9es ( ! syn!sis ( tann+ matt]s %\ld prove ( great value to ! *emi/ engag$ 9 ?is bran* ( *emical te*nology4 ,! translator takes great pleasure 9 ! ackn[l$g+ ! valuable assi/ance r5d]$ him by ,mr4 ,rob9 ,bruce ,croad1 ,a4,r4,t4,c41 ,f4,i4,c41 & by ,mr4 ,ar?ur ,h>vey4 ,f4 ,g4 ,a4 ,,enna ,,cont5ts ,introduction3 ,classification ( ,syn!tic ,tann9s ,,"p ,i ,,section ,i ,! ,syn!sis ( ,vegetable ,tann9s #a4 ,tann9 #b4 ,digallic ,acid #c4 ,ellagic ,acid #d4 ,depsides ,c>bome?oxylation ( ,hydroxyb5zoic ,acids ,*lorides ( ,c>bome?oxyhydroxyb5zoic ,acids ,prep>ation ( ,didepsides ,prep>ation ( ,tridepsides ,prep>ation ( ,tetradepsides ,tannoid ,sub/ances ( ! ,tann9 ,type ,*>t %[+ ! ,decomposition ( ,products ( ,tann9 ,,section ,,ii ,syn!sis ( ,tann+ ,matt]s #a4 ,aromatic ,sulphonic ,acids #b4 ,cond5sation ( ,ph5ols ,cond5sation ( ,hydroxyb5z5e ,cond5sation ( ,dihydroxyb5z5e ,trihydroxy b5z5e ,polyhydroxyb5z5es ,qu9one ,ph5olic ,e!rs ,nitro ,bodies ,am9o ,bodies ,aromatic ,alcohols ,aromatic ,acids #c4 ,cond5sation ( ,naph?al5e ,d]ivatives #d4 ,cond5sation ( ! ,an?rac5e ,gr\p #e4 ,di- & ,triph5ylme?ane ,gr\ps #f4 ,summ>y ,table ,,section ,,iii ,tann+ ,effects ( ,mixtures & ,natural ,products #a4 ,mixture ( ,ph5olsulphonic ,acid & ,=maldehyde #b4 ,mixture ( ,ph5olsulphonic ,acid & ,natural ,tann9s #c4 ,tann+ ,effects ( ,diff]5t ,natural ,sub/ances ,,section ,,iv ,me?ods ( ,exam9+ ,tann+ ,matt]s ,,"p ,,ii ,syn!tic ,tann9s3 ,_! ,indu/rial ,production & ,application ,a4 ,cond5sation ( ,free ,ph5olsulphonic ,acid ,b4 ,cond5sation ( ,p>tly ,neutralis$ ,ph5olsulphonic ,acid ,c4 ,cond5sation ( ,completely ,neutralis$ ,ph5olsulphonic ,acid ,d4 ,cond5sation ( ,cresolsulphonic ,acid ,e4 ,relative ,behavi\r ( an ,alkal9e ,solution ( ,bakelite & ,natural ,tann9s ,f4 ,dicresylme?an$isulphonic ,acid 7,n]adol ,d7 #a4 ,n]adol ,d ,reactions #b4 ,electro-,*emical ,behavi\r ( ,n]adol ,d #c4 ,! ,influ5ce ( ,salts & ,acid ,cont5ts on ! ,tann+ ,effect ( ,n]adol ,d #d4 ,phlobaph5e ,solubilis+ ,action ( ,n]adols #e4 ,effect ( ,n]adol ,d on ,pelt #f4 ,reactions ( ,n]adol ,d ) ,iron & ,alkalies #g4 ,reag5ts suitable = ,demon/rat+ ! ,v>i\s ,/ages ( ,n]adol ,d ,tannage #h4 ,comb9ation ,tannages ) ,n]adol ,d 7#a7 ,*rome ,n]adol ,d ,liquors 7#b7 ,alum9um ,salts & ,n]adol 7#c7 ,fat ,n]adol ,d ,tannage #i4 ,analysis ( ,lea!r conta9+ ,n]adol ,d #aj4 ,prop]ties ( ,lea!r ,tann$ ) ,n]adol ,d #aa4 ,n]adol ,d1 ,free f ,sulphuric ,acid #ab4 ,neutral ,n]adol ,g4 ,diff]5t ,me?ods ( ,cond5sation z ,appli$ to ,ph5olsulphonic ,acid #a4 ,cond5sation ,induc$ by ,heat #b4 ,cond5sation ) ,sulphur ,*loride #c4 ,cond5sation ) ,phosphorus ,comp\nds #d4 ,cond5sation ) ,aldehydes #e4 ,cond5sation ) ,glyc]ol ,,regi/] ,,( ,,au?ors ,,index ,,introduction ,,classification ,,( ,,syn!tic ,,tann9s ,9 lay+ d[n a def9ition ( ,syn!tic ,tann9s1 x is fir/ ( all necess>y to cle>ly def9e ! conception ( tann94 ,prim>ily1 tann9s may be consid]$ ^? sub/ances ( vegetable orig9 :i* may be f\nd1 z wat]-soluble bodies1 9 _m plants1 exhibit+ c]ta9 *emical behavi\r1 possess+ a/r+5t prop]ties & be+ capable ( conv]t+ animal hide into lea!r4 ,?is latt] prop]ty ( ! tann9s1 t ( conv]t+ ! easily decomposable prote9 ( animal hide into a p]man5tly cons]v$ sub/ance & imp>t+ to ?is well-def9$ & te*nically valuable prop]ties1 has become ! crit]ion ( ! practical consid]ation ( a tann94 ,x appe>s t diff]5t sub/ances c]ta9ly %[ ! *emical reactions peculi> to ! tann9s1 & to a c]ta9 ext5t also exhibit a/r+5t "* )\t1 h[ev]1 possess+ ! important prop]ty peculi> to ! tann9s ( conv]t+ hide into lea!r4 ,su* sub/ances1 9 our pres5t-day t]m9ology1 are t]m$ pseudo-tann9s 7e4g41 ! tann9 conta9$ 9 c(fee-beans74 ,decomposition products ( ! natural tann9s1 to :i* belong1 = in/ance1 gallic acid & ! dihydroxyb5z5es1 exhibit ! well-kn[n reactions ( ! tann9s 7coloration ) iron salts71 b !y _c be reg>d$ z tann9s f ei!r a te*nical or a physiological /&po9t4 ,z reg>ds _! *emical con/itution1 ! natural 7true7 tann9s probably belong to diff]5t gr\ps ( organic comp\nds1 & ) our pres5t-day scant k ( _! *emi/ry1 x is impossible to classify !m4 ,"o is1 h[ev]1 ju/ifi$ 9 assum+ t bo? ! natural tann9s & ! relat$ humic acids are e/]-d]ivatives ( hydroxyb5zoic acids4 ,footnote3 ,e4 ,fis*]1 ,b]41 #aiac1 #df1 #cbec4 ,! production ( syn!tic tann9s employs two q di/9ct me?ods2 "o is to syn!sise ! mo/ simple tann91 viz41 ! tannic acid conta9$ 9 galls 7tann971 or to build up sub/ances simil> 9 "* to ! tann9s1 f hydroxyb5zoic acids4 ,! o!r1 entirely new way1 is to produce *emical sub/ances1 :i* c]ta9ly h no?+ 9 common ) ! con/itution ( ! natural tann9s1 b :i* behave l true tann9s 9 contact ) animal pelt1 & 9 addition1 s9ce !y c be manufactur$ on a comm]cial scale1 are ( practical value4 ,ow+ to ! fact t1 until rec5tly1 ! con/itution ( tann9 has rema9$ unkn[n1 x is easy to compreh5d t ! ef=ts to syn!sise ! latt] sub/ance1 or comp\nds simil> to x1 h be5 ma9ly attempt$ on simil> l9es4 ,! olde/ inve/igation 9 ?is direction dates f ,h4 ,s*iff1,footnote3 ,liebig's ,ann41 #ahgc1 #dc1 #agj4 :o prep>$ sub/ances simil> to tann9 by dehydrat+ hydroxyb5zoic acids4 ,by all[+ phosphorus oxy*loride to int]act ) ph5olsulphonic acid1 he obta9$ a well-def9$ sub/ance possess+ tann+ prop]ties1 :i* he consid]$ an e/]ifi$ ph5olsulphonic acid anhydride1 ! composition ( :i* he det]m9$ z ,,ho4,c#f;,h#d4,,s#b4,o4,c#f;,h#d;,,hso# c4 ,x is1 h[ev]1 probable t ?is sub/ance is n homog5e\s1 b consi/s ( a mixture ( high] cond5sation products4 ,klepl ,footnote3 ,j\r4 pr4 ,*em41 #ahhc1 #bh1 #bjh4 obta9$--by simply heat+ p-hydroxyb5zoic acid--a s-call$ di- & tridepside1 b ?is simple me?od is n applicable to _m o!r hydroxyb5zoic acids1 s9ce ^! are decompos$ by ! high temp]ature requir$ to induce reaction4 ,among/ o!r attempts to produce cond5sation products ) *>act]i/ics simil> to ^? possess$ by ! tann9s1 ^? by ,g]h>dt ,footnote3 ,liebig's ,ann1 #ahec1 #hg1 #aei4 & ,loewe ,footnote3 ,jahre%4 f4 ,*em41 #ahfh1 #eei4 mu/ be especially not$2 !y treat$ gallic acid ) phosphorus oxy*loride or ars5ic acid1 & !reby obta9$ amorph\s comp\nds1 exhibit+ ! reactions *>act]i/ic ( tann+ sub/ances4 ,e4 ,fis*] & ,freud5b]g1 ,footnote3 ,liebig's ,ann41 #cgb1 #de4 by treat+ p-hydroxyb5zoic acid 9 ! same way1 succe$$ 9 obta9+ a didepside1 & dur+ ! la/ ye>s practically only ^! two inve/igators h demon/rat$ ! syn!ses ( ^! depsides & produc$ high-molecul> polydepsides4 ,at ! same "t rese>*es 7 in/itut$ ) ! object ( det]m9+ ! con/itution ( tann91 & ,e4 ,fis*] succe$$ 9 demon/rat+ its probable composition z be+ t ( a glucoside conta9+ #e molecules ( digallic acid p] #a molecule ( glucose4 ,?is la/-nam$ class ( syn!tic tann9s--:i* may be prop]ly t]m$ tann+ matt]s 9 contradi/9ction to ! true tann9s--exhibit v di/9ct tann+ "* :5 br\ght 9 contact ) animal hide1 b f ! po9t ( view ( *emical con/itution h no?+ 9 common ) ! natural tann9s4 ,n only are !y ( int]e/ to ! indu/ry f a practical po9t ( view2 !y h also be5 exam9$ v closely f a *emical /&po9t4 ,x is1 h[ev]1 necess>y to diff]5tiate ) great exactitude betwe5 ! conception ( true tann+ effect & pickl+ effect :5 consid]+ ! action ( *emical sub/ances on pelt 7i4e41 animal hide1 treat$ ) lime1 depilat$1 & ! surplus fle% remov$74 ,:]eas any true tannage is *>act]is$ by ! complete p5etration ( ! sub/ance & its subsequ5t fixation by ! pelt 9 su* a way t a ?or\gh soak+ & wa%+ w n br+ ab\t a reconv]sion 7( ! lea!r7 to ! pelt /ate2 pickl+1 on ! o!r h&1 is only *>act]is$ by ! p5etration ( ! sub/ance 9 ! pelt & fixation to su* an ext5t t a subsequ5t wa%+ ( ! pickl$ pelt w br+ back ! latt] to a /ate closely approximat+ t ( a true pelt4 ,simple z su* a diff]5tiation appe>s1 !re are /ill a numb] ( cases occupy+ a position betwe5 ! two ref]r$ to1 & :i* we may t]m pseudo-tannage4 ,an example ( ! latt] is =maldehyde tannage2 =maldehyde has = a long "t be5 employ$ 9 hi/ological "w = ! purpose ( h>d5+ animal hide1 by :i* x is readily absorb$ f solution :]eby x h>d5s ! hide )\t1 h[ev]1 swell+ x4 ,a hide :i* has ?us be5 treat$ ) =maldehyde absorbs ! natural tann9s ) great] ease2 ?is1 on ! "o h&1 argues ! probability ( =maldehyde act+ z a pickl+ ag5t2 on ! o!r h&1 x is also "o ( its *>act]i/ics t x w ei!r 9 neutral acid1 ,footnote3 ,r4 ,combret1 ,g]4 ,pat1 #aab1 #ahc4 or1 /ill bett]1 9 alkal9e ,footnote3 ,j4 ,pullman1 ,g]4 ,pat1 #aaa1djh2 ,griffi?1 ,lea4 ,tr4 ,rev41 #aijh4 solution1 conv]t pelt into lea!r4 ,9 a =maldehyde-tann$ lea!r1 h[ev]1 no trace ( tann9 c be detect$2 & ! yield 7( lea!r1 bas$ on ! pelt employ$71 :i*1 f a practical /&po9t1 is s important1 is s v l[ t x is h>dly possible to speak ( x z a tann9 9 ! ord9>y s5se ( ! ^w4 ,=maldehyde mu/1 !re=e1 be t]m$ a pseudo-tann94 ,! tann+ effect ( =maldehyde is1 accord+ to ,?uau1 ,footnote3 ,collegium1 #aiji1 #cfc1 #baa4 increas$ by ^? salts :i* br+ ab\t colloidal polym]isation ( ! =maldehyde1 ! resultant comp\nds be+ absorb$ by ! hide fibre4 ,fahrion consid]s ?is to be a true tannage1 & is support$ by ,ni]5/e9 ,footnote3 ,ibid41 #aije1 #aeg1 #aei43-- ,r4,,nh#b ,r4,,nh- ,o4,c4,h4 ,,*#b ,h#b,o ,r4,,nh#b ,r4,,nh- 7,hide47 ,h 7,lea!r47 ,a peculi> comb9ation betwe5 true tannage & pickl+ is to be f\nd 9 ! taw+ process 7tannage ) pota%1 alum1 & salt71 :]eby1 fir/ly1 ! salt & ! acid "* ( ! alum produce a pickl+ effect1 & secondly1 ! alum at ! same "t is hydrolys$1 & its dissociation compon5ts p>tly adsorb$ by ! hide1 !reby effect+ true tannage4 ,?is d\ble effect is /ill m pron\nc$ 9 ! syn!tic tann9s :i* conta9 colloidal bodies ( pron\nc$ tann+ int5sity on ! "o h&1 inorganic & organic salts on ! o!r1 :i* !n act z describ$ above4 ,_! real mode ( action c only be expla9$ ) ! aid ( exp]im5tal data4 ,! foll[+ *apt]s w deal ) ! diff]5t behavi\r ( ! v>i\s gr\ps ( syn!tic tann9s4 ,,"p ,i ,,section ,i ,,! ,,syn!sis ,,( ,,vegetable ,,tann9s #a4 ,,tann9 ,! fir/ inve/igations ( gall-tann9 date f ! ye> #aggj1 at :i* "t1 h[ev]1 no exact diff]5tiation betwe5 tann9 & gallic acid 0 made4 ,! fir/ /ep 9 ?is direction 0 made :5 ,s*eele1,footnote3 ,grell's ,*em4 ,ann41 #aghg1 #c1 ,i4 9 #aghg1 discov]$ gallic acid 9 f]m5t$ gall extract1 & 9 ! same ye> ,kunzemull] ,footnote3,ibid41 #aghg1c1dac4 sep>at$ gallic acid 7or pyrogallol7 z a cry/all9e body f oak galls4 ,dize ,footnote3 ,j\r4 ,*im4 et ,phys41 #agia1 #cii4 cont9u$ ! inve/igations1 :i* 7 br\ght to a conclusion ) ,deyeux' "w ,footnote3 ,ann4 ,*im41 #agic1 #ag1 ,i42 bo? recognis$ t ! sub/ance isolat$ 0 n a s+le sub/ance1 b 0 a mixture ( gallic acid1 a gre5 col\r+ matt]1 a ros9 7tann9871 & extrane\s matt]4 ,pr\/ ,footnote3 ,ibid41 #agii1 #be1 #bbe4 0 ! fir/ to diff]5tiate ! cry/all9e gallic acid f ! amorph\s1 a/r+5t sub/ance1 :i* latt] he nam$ ,tann94 ,among/ ! num]\s subsequ5t inve/igations ( tann9 mu/ be especially not$ ! "o by ,b]zelius ,footnote3 ,pogg1,ann41 #ahbg1 #aj1 #beg41 :o purifi$ ! pota% salt & decompos$ ?is ) sulphuric acid4 ,pel\ze ,footnote3 ,liebig's ,ann41 #ahdc1 #dg1 #ceh41 lat] on1 obs]v$ ! =mation ( ! cry/all9e gallic acid f tann91 :5 ! latt] is boil$ ) sulphuric acid2 ?is _h already be5 obs]v$ by ,j4 ,liebig4,footnote3 ,ibid4#ahdc1 #ci1 #ajj4 ,bo? _h notic$ ! abs5ce ( nitrog54 ,9 addition to ! me?ods ( prep>ation ( tann9 !n 9 vogue neutral solv5ts 7 ma9ly employ$ by subsequ5t inve/igators2 ,pel\ze ,footnote3 ,j\r4 ,prakt4 ,*em41 #ahcd1 #b1 #cja1 & #cbh4 treat$ p[d]$ galls ) e!r conta9+ alcohol & wat]1 & consid]$ ! upp] lay] to be a solution ( gallic acid & impurities1 ! bottom lay] to conta9 ! pure tann94 ,! ,,empirical ,,=mula ( tann9 has also be5 ! subject ( mu* speculation by ! diff]5t inve/igators1 ! difficulty "h be+ t ( obta9+ a pure specim5 ( ! sub/ance free f sug>s1 & :i* c\ld be submitt$ to elem5t>y analysis4 ,:]eas ^! e>ly purifi$ sub/ances 7 ?\ght to correspond to ! =mula ( digallic acid 7galloylgallic acid71 ,c#ad;,h#aj,o#i1 ,fis*] & ,freud5b]g ,footnote3 ,b]41 #aiab1 #iae & #bgji4 7 able to %[1 ) approximate c]ta9ty1 t ! con/itution ( tann9 is t ( a p5tadigalloyl glucose4 ,e>ly attempts at hydrolys+ tann9 gave v>y+ results1 "s inve/igators claim+ ! pres5ce1 & o!rs ! abs5ce ( sug>s4 ,"h1 aga91 ,e4 ,fis*] & ,freud5b]g ,footnote3 ,ibid4 7 able to conclusively prove t on hydrolys+ tann9 ) dilute acids1 #g4i p] c5t4 glucose is dissociat$1 & t h5ce glucose =ms "p ( ! tann9 molecule4 ,fis*] & ,freud5b]g also det]m9$ ! optical activity ( pure tann9 9 wat]3 ,greek3 a,d 0 f\nd to lie betwe5 #eh & #gj4 ,graham f\nd ,footnote3 ,phil4 ,transact41 #ahfa1 #ahc4 t ! tann9 molecule is ( consid]able size1 s9ce its diffusion velocity is #bjj times less ?an t ( common salt4 ,pat]n ,footnote3 ,zeits4 phys4 ,*em41 #ahij1 iv4 #deg4 0 ! fir/ to det]m9e ! molecul> weight ( tann91 employ+ ,ra\lt's me?od2 he f\nd t tann9 9 aque\s solution behaves l a colloid & t h5ce ,ra\lt's me?od is n applicable4 ,:51 on ! o!r h&1 he dissolv$ tann9 9 acetic acid1 results concordant ) ! =mula ( ,c#ad;,h#aj,o#i1 correspond+ to a molecul> weight ( #cbb1 7 obta9$4 ,sabanajew ,footnote3 ,ibid41 #ahij1 v4 #aib4 lat] det]m9$ ! molecul> weight ( tann9 9 aque\s solution z #aajd1 9 acetic acid solution z #aaac-acbb1 ,krafft ,footnote3 ,b]41 #ahii1 #cb1 #afac4 z #aehg-afbf 9 aque\s solution4 ,wald5 ,footnote3 ,ibid41 #ahih1 #cafg4 det]m9$ ! molecul> weight ( tann9-s*u*>dt z #acej-aefj1 tann9-m]ck z #gec-gfc1 digallic acid z #cjg-caf 7calculat$ #cbb74 ,fei/ ,footnote3 ,*em4 ,ztg41 #aijh1 #iah4 det]m9$ ! molecul> weight ( tann9 z #fae & "o ( 8 own prep>ation z #gdf1 ,turki% tann9 z #eba & ,*9ese tann9 z #hii4 ,9 ?is connection x %\ld be not$ t ! calculat$ molecul> weight ( p5tagalloyl glucose1 :i* 9 ,e4 ,fis*]'s op9ion =ms a sub/antial "p ( ! tann9 molecule1 is #idj1 b ,fis*] also ?9ks t ?is comp\nd possesses a mu* high] molecul> weight4 ,,/ructure ,,( ,,tann9--,! olde/ /ructural =mula ( tann9 is ,s*iff's digallic acid =mula3--,footnote #a3 ,b]41 #ahga1 #d1 #bca4 ---------,,co4,o4---------- ,,oh ,,ho ,,oh ,,hooc ,,oh ,v ,v ,,oh ,a drawback to ! acceptance ( ?is =mula is ! abs5ce ( an asymmetrical ,c-atom2 ! =mula1 !re=e1 does n expla9 ! optical activity exhibit$ by tann94 ,s*iff attempt$ to ov]come ?is difficulty by adopt+ a diagonal /ructural =mula1 b ev5 :5 adopt+ ,clauss' diagonal =mula = b5z5e ! optical activity ( a numb] ( o!r comp\nds dep5ds ^u ! exi/5ce ( ! asymmetrical ,c-atom4 ,big9elli ,footnote #b3 ,gazz *im4 ,ital41 #aiji1 #ci1 #bfh4 also oppos$ ! digallic acid =mula1 & support$ 8 view by ref]r+ to ! ars5ic comp\nds obta9$ by him on heat+ ars5ic acid & gallic acid1 in/ead ( obta9+ digallic acid4 ,wald51 ,footnote #c3 ,b]41 #ahih1 #ca1 #cafh4 on ! o!r h&1 f\nd1 on analys+ ! digallic acid ?us prep>$1 only slight traces ( ars5ic &1 by ! elem5t>y analysis1 obta9$ figures closely correspond+ to ^? ( digallic acid4 ,bott+] ,footnote #d3 ,ibid41 #ahhd1 #ag1 #adgf4 prep>$ ! s-call$ ,greek3 b-digallic acid by heat+ e?yl gallate ) pyroracemic acid & sulphuric acid & propos$ ! s-call$ ketone-tann9 =mula3-- ,,ho,,oh ,,oh ,,ho--------,,co--------,,oh ,,cooh ,,oh ,s*iff complet$ ?is =mula by a diagonal1 s z to expla9 ! optical activity obs]v$-- ,,ho ,,oh ,,oh ,,ho--------,,co--------,,oh ,,cooh ,,oh ,diagonal bond betwe5 ,,ho & ,,cooh on left4 ,! ketone =mula 0 corroborat$ by ,ni]5/e91 ,footnote3 ,b]4 #aije1 #ch1 #cfda4 :o di/ill$ tann9 ) z9c du/ & obta9$ diph5ylme?ane 7smell ( b5z5e7 & a cry/all9e product1 ,m4,p4 #g,o-#ga ,c4 7,m4,p4 ( diph5yl #ga ,c474 ,knig & ,ko/anecki ,footnote3 ,ibid41 #aijf1 #ci1 #djbg4 s\ght to f9d ! con/itution ( ! tann9s 9 ! leuco-comp\nds ( ! oxyketones1 to :i* cate*9 belongs4 ,ni]5/e9 7see above71 h[ev]1 emphasises t ! high molecul> weight & ! optical activity speak aga9/ ! digallic acid =mula1 b 9 fav\r ( ?is are ! foll[+ po9ts3 7#a7 ! decomposition ( tann9 ) ! =mation ( gallic acid2 7#b7 ! decomposition ( me?ylotann9 ) ! =mation ( di- & trime?yl e/]s ( gallic acid2 & 7#c7 ! production ( diph5ylme?ane on di/illation ) z9c du/4 ,! latt] reaction especially illu/rates ! analog\s =mation ( fluor5e f comp\nds ( ! type-- --,,co4,o ,v ,v ,ni]5/e9 gave ! "n ,tannophor to ! "m-sub/ance ( tann91 ph5ylb5zoate1 ,c#f;,h#e-;,,coo-,c#f;,h#e4 ,dekk] ,footnote3 ,de ,looi/(f51 vol4 ii1 p4 #cj 7#aijh74 01 h[ev]1 unable to detect diph5ylme?ane on di/ill+ ) z9c du/1 & did1 !re=e1 n accept ,ni]5/e9's views4 ,9 propos+ ! =mula-- ,o ,,ho ,c ,o ,,oh ,c_/ ,,oh ,,ho ,v _/ ,,oh ,,oh ,,oh ,dekk] ,footnote3 ,b]41 #aijf1 #cd1 #bdig4 0 enabl$ to acc\nt = mo/ ( ! details 9 ! behavi\r ( tann91 viz43 7#a7 ! empirical con/itution1 ,c#ad;,h#aj,o#i2 7#b7 ! almo/ complete hydrolysis into gallic acid 7! dott$ l9e indicates ! decomposition ( ! molecule into #b molecules gallic acid by tak+ up wat]72 7#c7 ! =mation ( diph5ylme?ane z a result ( di/illation ) z9c du/2 & 7#d7 ! electrical non-conductivity4 ,s9ce tann9 on acetylat+ yields a consid]able am\nt ( triacetylgallic acid1 x %\ld1 accord+ to ,dekk]1 conta9 at lea/ six acetylisable hydroxyls4 ,ni]5/e9 ,footnote3 ,*em4 ,ztg41 #aijf1 #ca1 #hhj4 object$ to ?is =mula on acc\nt ( its conta9+ sev5 hydroxyl gr\ps1 :]eas ,dekk] f\nd six1 ,ni]5/e9 five1 & ,h]zig /ill few] hydroxyl gr\ps4 ,! =mula w\ld also fav\r ! conception ( t9ctorial prop]ties :i* c\ld h>dly be ascrib$ to tann94 ,lloyd ,footnote3 ,*emical ,news1 #aijh1 #ig1 #acc4 propos$ a v intricate =mula conta9+ ?ree digallic acid gr\ps jo9$ into "o six-r+ sy/em1 :i* w\ld !n expla9 ! optical activity2 x w\ld1 on ! o!r h&1 also require an inactive cis-=m4 ,ilj9 ,footnote3 ,j\r4 ( ! ,russian phys4 *em4 ,soc41 #aijh1 #ci1 #dgj4 prep>$ two ph5ylhydraz9e d]ivatives ( tann9 7,c#gd ,h#eh ,n#h ,o#cj & ,c#ih ,h#hb ,n#ad ,o#if7 & propos$ ! =mula1 ,c#eh ,h#dj ,o#cc1 ! con/itution ( :i* w\ld be-- ,r#a ,r#a ,c--,o--,o--,c ,r#b ,r#b ,o ,r#a ,r#a ,c--,o--,o--,c ,r#b ,r#b :]e ,r#a ,,co ,c#f ,h#b 7,,oh7#c & ,r#b ,c#f ,h#b 7,,oh7#b ,ni]5/e9 ,footnote3 ,b]41 #aije1 #ch1 #chda2 #aijg1 #dj1 #iag2 #aijh1 #da1 #gg & #cjae2 #aiji1 #db1 #aabb & #ceeb2 ,*em4 ,ztg41 #aijg1 #ca1 #gb2 #aiji1 #cd1 #ae4 consid]s tann9 to be a mixture ( digallic acid & leucotann91 ! latt] possess+ ! =mula-- -------,,*4,,oh--,o---- ,,oh ,,ho ,v ,,oh ,,hooc ,v ,,oh ,,oh ,! optical activity ( tann9 is express$ 9 ?is =mula & its probability is corroborat$ by ,ni]5/e91 :o 0 able to resolve ! acetylat$ tann9 by fractional precipitation into p5tacetyl tann9 7,m4,p4 #bjc-bjh ,c47 & p5tacetyl leucotann9 7,m4,p4 #aff ,c474 ,by oxidation1 ! =m] is conv]t$ into ellagic acid1 & on hydrolysis ) dilute sulphuric acid readily yield$ gallic acid4 ,hydrolysis ( ! p5tacetyl leucotann91 h[ev]1 yield$ gallic aldehyde1 & oxidation yield$ purpurotann9 7a naph?al5e d]ivative7 9 addition to ellagic acid4 ,ni]5/e9 ,footnote3 ,b]41 #aiaj1 #dc1 #fbh4 also succe$$ 9 conv]t+ tann9 into c>boe?oxytann91 ! latt] on saponification yield+ cry/all9e1 inactive digallic acid4 ,on acetylat+ p5tacetyl leucotann9 ) acetyl *loride a hexacetyl d]ivative 7,m4,p4 #aei ,c47 is obta9$1 ! /ry*n9e salt ( :i* is resolv$ into bo? ( ! active compon5ts4 ,?is proves ! pres5ce ( digallic acid & leucotann9 9 tann9 lev4 pur4 ,s*]+ inve/igat$ by ,ni]5/e94 ,! latt] au?or ,footnote3 ,liebig's ,ann41 #aiab1 #chf1 #cah2 #chh1 #bbc4 lat] consid]$ tann9 to be polydigalloylleucodigallic acid anhydride & ! simple/ tann9 to be a digalloylleucodigallic acid anhydride4 ,?is view1 h[ev]1 w\ld n /& subsequ5t criticisms1 be+ 9 disagreem5t ) ! e>li] obs]vations ( molecul> weight & acidic prop]ties ( tann94 ,mann+ ,footnote3 ,ibid41 #aiab1 #cd1 #iah4 believ$ to h isolat$ a p5te?yle/] ( ! p5tagalloyl glucoside f tann91 b ?is 0 %[n to be ! e?yl e/] ( gallic acid4 ,fei/ ,footnote3 ,b]41 #aiab1 #de1 #adic4 _h arriv$ at ! conclusion t tann9 0 a glucose comp\nd1 & ma9ta9$ t tann9 f ,turki% galls 0 a comp\nd ( glucogallic acid comb9$ z an e/] ) #b molecules gallic acid4 ,b ,fis*] & ,/rauss ,footnote3 ,ibid41 #aiab1 #de1 #cggc4 syn!tically prep>$ a glucoside ( gallic acid exhibit+ diff]5ces f ,fei/'s prep>ation :i* 7 s great t ! latt] no long] c\ld be consid]$ a s+le glucoside ( gallic acid4 ,fis*] & ,freud5b]g ,footnote3 ,ibid41 #aiab1 #de1 #bgag2 #aiac1 #df1 #aabg4 subsequ5tly elaborat$ a me?od ( purify+ tann91 & on inve/igat+ ! purifi$ sub/ance1 arriv$ at ! conclusion t no o!r hydroxyb5zoic acid ?an gallic acid 0 pres5t 9 tann94 ,on repeat+ ,/reck]'s hydrolysis !y obta9$ #g-h p] c5t1 sug>1 & h5ce conclud$ t #a molecule ( glucose 0 comb9$ ) ab\t #aj molecules ( gallic acid4 ,ow+ to ! difficulty ( isolat+ ! int]m$i>y hydrolysis products1 & ! subsequ5t impossibility ( draw+ any conclusions z to ! con/itution ( tann91 ! latt] inve/igators decid$ to adopt ! me?ods (f]$ by syn!sis4 ,_! basic idea 0 ! abs5ce ( c>boxylic gr\ps 9 tann91 & t h5ce ! total gallic acid mu/ be pres5t 9 e/] =m4 ,^! conditions are fulfill$ if "o views tann9 z be+ an e/] comp\nd ( #a molecule ( glucose & #e molecules ( digallic acid1 ( simil> con/ruction z1 = example1 p5tacetyl glucose4 ,fis*] & ,freud5b]g succe$$ 9 prep>+ ! =m] by %ak+ a mixture ( f9ely p[d]$ glucose1 *lor(orm1 & qu9ol9e ) an excess ( tric>bome?oxygalloyl *loride = tw5ty-f\r h\rs & precipitat+ ! result+ product ) me?yl alcohol2 suitably purifi$1 a light amorph\s col\rless sub/ance 0 obta9$ :i* prov$ to be p5ta-7tric>bome?oxygalloyl7 glucose4 ,c>eful saponification ) excess alkali 9 acetone-aque\s solution at room temp]ature yield$ a tann9 v closely resembl+ tann91 id5tifi$ z p5tagalloyl glucose4 ,x is d\btful1 h[ev]1 :e!r ?is sub/ance is homog5e\s1 & x is probably a mixture ( two /]eoisom]s4 ,fis*] & ,freud5b]g1 !re=e1 fur!r conclud$ t tann9 is ma9ly an e/] comp\nd ( glucose & #e molecules m-digallic acid4 ,elucidation on ?is po9t (f]$ itself advantage\sly 9 ,h]zwig's me?ylotann91 ,footnote3 ,b]41 #aije1 #ch1 #ihi4 :i* is obta9$ by ! int]action ( diazome?ane & tann94 ,! fir/ /ep 0 !n to prep>e p5tame?yl-m-digallic acid ,,*#c4,o ,,cooh ,,*#c4,o--,,co4,o-- ,,*#c4,o ,,*#c4,o ,o4,,*#c f trime?ylgalloyl *loride & ! m-p-dime?yl e!r ( gallic acid2 ! *loride ( ?is sub/ance1 c\pl$ ) ,greek3 a- & ,greek3 b-glucose1 yields-- ,,*4,,or ,,*4,,or ,h,o4,,*#c ,r,,co,o4,,*#c ,o ,,*4,,or ,h ,o ,h,o4,,*#c ,,* ,,co,o4,,*#c ,h ,o4,,*#c ,,*4,,or ,,*#b4,,or ,illu/ration3 ,p5ta-7p5tame?yl-m-digalloyl7-glucose4 ,! ,greek3 a- & ,greek3 b-d]ivatives ?us obta9$ diff] 9 _! behavi\r t[>ds pol>is$ light1 & are1 aga91 probably mixtures ( two /]eoisom]s1 i4e41 mixtures ( d]ivatives ( ,greek3 a- & ,greek3 b-glucose4 ,comp>$ to me?ylotann91 ^! prep>ations exhibit v close resemblance to ! =m]1 f :i* x may be conclud$ t !y are closely relat$ to ?is sub/ance1 & probably possess ! same or a v simil> /ructure2 ! result ( ! above exp]im5ts has1 !re=e1 br\ght u at lea/ 9 close proximity to ! /ructure ( tann94 ,x mu/1 h[ev]1 be borne 9 m9d t ! analysis & hydrolysis ( tann9 does n af=d an explanation ( ! "q z to :e!r tann9 is a comp\nd ( glucose & #aj1 #i1 or #aa molecules ( gallic acid2 x is also possible1 ?\gh n probable1 t tann9 w\ld conta9 a polysac*>ide in/ead ( glucose itself4 ,simil>ly to sug>1 ! true glucosides c be c\pl$ ) hydroxyb5zoic acids1 :i* is prov$ by ! prep>ation ( tetra-galloyl-,greek3 a-me?yl glucoside2 ?is sub/ance1 also1 exhibits tannoid "*4 #b4 ,,digallic ,,acid ,:]eas1 until rec5tly1 tann9 _h be5 consid]$ to be gallic acid anhydride1 or digallic acid1 clos] inve/igations h reveal$ t nei!r is tann9 digallic acid nor is ! syn!tically prep>$ digallic acid id5tical ) tann94 ,s*iff ,footnote3 ,b]41 #ahga1 #bca & #ifg4 prep>$ digallic acid by ! int]action ( phosphorus oxy*loride & gallic acid1 & believ$ ! product obta9$ to be id5tical ) tann92 to ?is latt] he fir/ ascrib$ an e!r =mula 7,i471 lat] an e/] =mula 7,,ii47-- 7,,oh7#b 7,,oh7#b ,c#f;,h#b---j---;,c#f;,h#b ,,cooh ,,cooh 7,i47 7,,oh7#b ,c#f;,h#b7,,oh7#c--;,c--,o4,c#f;,h#b ,o ,,cooh 7,,ii47 ,froda ,footnote3 ,gasz4 *im41 #ahgh1 #i4 held t ,s*iff's cond5sation product conta9$ phosphorus or ars5ic acid & ascrib$ its tann+ prop]ties to ! latt]2 accord+ to ?is inve/igator1 digallic acid1 :5 completely fre$ f ars5ic acid1 does n react ) gelat9e or qu99e4 ,big9elli ,footnote3 ,ibid41 #aiji1 #ci1 ii4 #bfh & #bhc4 did n consid] ! action ( ars5ic acid t ( a cataly/1 b held t x ent]$ into reaction2 accord+ to 8 inve/igations products conta9+ ars5ic 7,c#g;,h#g,o#h;,z & ,c#ad;,h#aa,o#ab;,z7 are obta9$ :5 gallic acid is heat$ ) ars5ic acid4 ,9 8 prep>ation ( digallic acid1 ,ilj9 ,footnote3 ,j\r4 f4 prakt4 ,*em41 #aiaa1 #hb1 #dea4 c\ld only obta9 gallic acid1 & ! e?yl e!r ( gallic acid %[+ no *>act]i/ics ( ! tann9s2 :51 h[ev]1 he heat$ gallic acid ) ars5ic p5toxide1 he obta9$ bodies exhibit+ ! reactions giv5 by tann9s4 ,bott+] ,foonote3 ,b]41 #ahhd1 #aejc4 made ! fir/ attempt at syn!sis+ tann92 he heat$ gallic acid or its e?yl e/] ) glyoxylic acid or pyroracemic acid1 & obta9$ a sub/ance ( ! composition ,c#ad;,h#aj,o#i4b;,h#b,o1 :i* c]ta9ly %[$ "s ( ! *>act]i/ics exhibit$ by tann91 b :i* by no means 0 id5tical ) ! latt]4 ,bott+]'s prep>ation is probably id5tical ) ,greek3 b-digallic acid1 "o ( two dibasic isom]s hav+ ! composition-- ,c#f;,h#b7,,oh7#b;,,cooh ,c#f;,h7,,oh7#c;,,cooh ! o!r possible isom] hav+ ! composition ,c#f;,h7,,oh7#c;,,cooh ,,co ,c#f;,h#b7,,oh7#c ,fis*] ,footnote3 ,b]41 #aijh1 #da1 #bhge4 obta9$ a digallic acid 7,m4,p4 #bge-bhj ,c7 by c\pl+ tric>bome?oxygalloyl *loride ) dic>bome?oxygallic acid4 ,ni]5/e9 ,footnote3 ,ibid41 #aiaj1 #dc1 #fbh4 obta9$1 f ! c>be?oxy comp\nd ( tann91 a cry/all9e1 optically active digallic acid1 ,m4,p4 #bfh-bgj ,c4 ,! p5tacetate ( ?is sub/ance1 obta9$ by r$uction & acetylisation1 yield$ hexacetylleucotann94 ,a p5tame?yldigallic acid me?yl e/] ( ! composition 77,o4,,*#c7c7;,c#f;,h#b----;,,coo-----,c #f;,h#b77,,o*#c7b7;,,coo4,,*#c 0 obta9$ by ,mau?n] ,footnote3 ,j\r4 f4 prakt4 ,*em41 #aiaa1 #hd1 #adj4 f ! *loride ( trime?ylgallic acid & ! me?yl e/] ( ! acid f ! glucoside ( syr+92 on saponification ) cau/ic pota% ! =m] comp\nd yield$ trime?ylgallic acid & syr+ic acid4 ,fis*] ,footnote3 ,b]41 #aiac1 #df1 #aaaf4 syn!sis$ ! s-call$ m-digallic acid by c\pl+ tric>bome?oxygalloyl *loride ) c>bonylgallic acid & subsequ5t splitt+ (f ( ,,co#b4 ,! m-digallic acid appe>s z r ?ick1 col\rless1 microscopic ne$les conta9+ ab\t #af p] c5t4 wat] ( cry/allisation1 ,m4,p4 #bga ,c4 ,!y are slightly soluble 9 cold1 soluble 9 hot wat]1 & v soluble 9 me?yl & e?yl alcohols4 ,_! aque\s solution gives d>k blue coloration ) f]ric *loride1 & precipitates gelat9e & qu99e4 ,fis*] & 8 /ud5ts ,footnote #e3 ,ibid41 #aiab1 #de1 #iae1 #bgji2 #aiac1 #df1 #aaaf4 prep>$ q a numb] ( digallic acid d]ivatives1 among/ :i* are ! foll[+3-- ,p5tame?yl-m-digallic acid me?yl e/]1 ,c#bj;,h#bb,o#i4 ,p5tacetyl-m-digallic acid1 ,c#bd;,h#bj,o#ad4 ,p5tame?yl-m-digallic acid1 ,c#ai;,h#bj,o#i4 ,p5tame?yl-m-digalloyl *loride1 ,c#ai;,h#ai,o#h;,cl4 ,p5tame?yl-p-digallic acid1 ,c#ai;,h#bj,o#i4 ,p5tame?yl-p-digallic acid me?yl e/]1 ,c#bj;,h#bb,o#i4 ,hydrolysis ( digallic acid yields gallic acid2 oxidation1 on ! o!r h&1 ellagic acid & luteic acid 7,luteo ,sure71 :i* c be sep>at$ by %ak+ ) pyrid9e4 ,! r$uction ( digallic acid yields1 by diff]5t me?ods1 ! same r$uction comp\nd1 ,footnote3 ,ni]5/e91 ,abd]hald5's ,h&b4 d4 bio*em4 ,arbeitsm41 vi4 #aed4 viz41 ! racemic leucodigallic acid1 :i* diff]s f digallic acid by be+ devoid ( any tannoid prop]ties2 ! latt] di/9ction may be ascrib$ to ! trans=mation ( ! tannophor gr\p--,,co4,o--1 to ! tannoid-inactive gr\p ,,*7,,oh7--,o--4 ,! successful resolv+ ( racemic leucodigallic acid into bo? ( its optically active compon5ts c only be br\ght ab\t ?r\gh ! d- or l-hexac>be?oxyleucodigallic acid on introduc+ ! latt] into a #a p] c5t4 pyrid9e solution & heat+ to #de-ej ,c41 :]eby ! d- or l-acid is =m$ accompani$ by a /rong evolution ( c>bon dioxide4 ,hydrolysis ( leucogallic acid yields gallic acid & gallic aldehyde2 oxidation by means ( hydrog5 p]oxide yields ellagic acid & luteic acid1 & oxidation ) potassium p]sulphate & sulphuric acid1 9 acetic acid solution1 yields purpurotann9 7see bel[7 ,footnote3 ,liebig's ,ann41 #aiab1 #chf1 #cah44 ,ano!r di/9ct diff]5ce betwe5 digallic acid & leucodigallic acid is ! fact t ! =maldehyde cond5sation product ( ! =m] resembles gallic acid1 :]eas t ( ! latt] resembles tann92 x is !re=e probable t ! leucodigallic acid "p ( ! tann9 molecule imp>ts ?is *>act]i/ic prop]ty to tann94 ---,,co4,o--- ,,ho ,v ,,oh ,,cooh ,v ,,oh ,,oh ,,oh ,illu/ration3 ,digallic ,acid becomes444 ---,,co4,o--- ,,oh ,,ho ,v ,,oh ,,cooh ,v ,,oh ,,oh ,,oh ,illu/ration3 ,luteic ,acid becomes444 ---,,co4,o--- ,,oh ,,ho ,v --,o4,,co-- ,v ,,oh ,,oh ,,oh ,illu/ration3 ,ellagic ,acid becomes444 ,,cooh ,,cooh ,,ho ,v ---,o--- ,v ,,oh ,,oh ,,oh ,illu/ration3 ,purpuro ,tann94 #c4 ,ellagic ,acid ,ellagic acid 0 discov]$ 9 #ahca by ,braconnot1 :o nam$ x acide ellagique4 ,its pres5ce 9 ! vegetable k+dom 0 n q compreh5d$ = "s "t1 & ,ni]5/e9 ,footnote3 ,*em4 ,ztg41 #aiji1 #hg4 0 ! fir/ to prep>e ?is sub/ance f alg>obilla1 dividivi1 oak b>k1 pomegranate1 myrabol>ms1 & valonea4 ,! acid is obta9$ by precipitat+ x ) wat] f a hot alcoholic extraction ( ! plants ref]r$ to1 & recry/allis+ ! precipitate f hot alcohol4 ,ano!r me?od ( prep>ation consi/s 9 boil+ ! dis9tegrat$ plants ) dilute hydro*loric acid1 wa%+ ! residue1 & extract+ ) hot alcohol1 f :i* ! acid w !n cry/allise4 ,accord+ to ,l[e1 ,footnote3 ,zeits4 f4 analyt4 ,*em41 #ahge1 #ce4 x may be obta9$ f dividivi1 an aque\s extract ( :i* is heat$ to #aaj ,c4 9 a tube clos$ at bo? ends1 :5 cry/all9e ellagic acid is deposit$4 ,he9emann ,footnote3 ,g]4 ,pat41 #acg1jcc & #acg1icd4 obta9$ ellagic acid by simply boil+ repeat$ly aque\s tann9 solutions4 ,l[e ,footnote3 ,j\r4 f4 prakt4 ,*em41 #ahfh1 #ajc1 #dfd4 fir/ syn!sis$ ellagic acid by heat+ gallic acid ) ars5ic acid or silv] oxide4 ,h]zig ,footnote3 ,monat%efte fur ,*emie1 #aijh1 #bi1 #bfc4 /ates t ellagic acid is deposit$ :5 air is conduct$ ?r\gh a mixture ( ! e?yl or me?yl e/] ( gallic acid & ammonia4 ,p]k9 ,footnote3 ,proc4 ,*em4 ,soc41 #aije1 #ba1 #bab4 obta9$ a sub/ance v simil> to ellagic acid by electrolysis ( gallic acid 9 sulphuric acid solution2 on oxidis+ gallic acid 9 conc5trat$ sulphuric acid solution1 ,p]k9 & ,ni]5/e9 ,footnote3 ,ibid41 #aije1 #ba1 #ahe4 obta9$ flavellagic acid4 ,ellagic acid is also obta9$ by heat+ luteic acid 9 a #aj p] c5t4 soda solution4 ,ellagic acid ?us prep>$ cry/allises ) #b molecules ( wat] z yell[ micro-cry/all9e rhombic prisms or prismatic ne$les4 ,! cry/als lose ?is wat] :5 heat$ to #ajj ,c41 & x is possible t x is wat] ( con/itution1 9 :i* case ! sub/ance w\ld be hexoxydiph5ylc>boxylic acid1 & ! sub/ance left aft] dry+ at #ajj ,c41 ! dilactone4,footnote3 ,ar*4 d4 ,ph>m41 #aijg1 #bdd1 #ege4 ,ellagic acid is slightly soluble 9 wat]1 alcohol1 & e!r1 b is easily soluble 9 cau/ic pota%4 ,) conc5trat$ nitric acid ! product assumes a r$ col\r1 :i* appe>s to be due to ! pres5ce ( impurities2 ellagic acid is comm]cially kn[n z aliz>9 yell[4 ,! con/itution ( ellagic acid 0 unc]ta9 = a long "t1 & diff]5t /ructural =mulae 7 propos$ :i* m or less correspond$ to its prop]ties4 ,! mo/ satisfactory /ructural =mula 0 propos$ by ,graebe--,footnote3 ,*em4 ,ztg41 #aijc1 #abi4 ---,,co4,o--- -------- ,,oh ,,ho ,v --,o4,,co-- ,v ,,oh ,,oh ,?is w\ld repres5t a tetroxydiph5ylme?ylolide4 ,! probability ( ! correctness ( ?is =mula is support$ by ! possibility ( ! foll[+ d]ivatives3 monome?ylellagic acid1 ,c'#ad;,h'#f,o'#g7,o4,,*'#c72 dime?ylellagic acid1 ,c'#ad;,h'#d,o'#f7,o4,,*'#c7'b2 tetrame?ylellagic acid1 ,c'#ad;,h'#b,o'#d7,o4,,*'#c7'd2 ph5ylhydraz9ellagic acid1 ,c'#ad;,h'#f,o'#h4,n'#b;,h'#c;,c'#f;,h'# e4 ,by ! electrolytic r$uction ( ellagic acid1 hexoxydiph5yl1 7,,oh7'#c;,c'#f;,h'#b-;,c'#f;,h'#b7,,oh7 '#c1 is obta9$2 ! ord9>y me?ods ( r$uction yield leucoellagic acid1 ,c'#ad;,h'#aj,o'#h1 :i* cry/allises 9 small %>p ne$les1 melt+ ) decomposition at #bid-bie ,c4 ,leucoellagic acid is soluble 9 e?yl & me?yl alcohols1 & 9 glacial acetic acid1 insoluble 9 *lor(orm1 b5z5e1 tolu5e1 c>bon tetra*loride1 & petrol e!r2 x gives a blui%-gre5 col\r ) f]ric *loride :i* quickly turns black4 ,leucoellagic acid is soluble 9 alkalies1 ! solution assum+ a deep-r$ coloration2 x r$uces silv] nitrate 9 ! cold1 b is n adsorb$ by mordant$ cotton clo?1 9 :i* respect x diff]s f ellagic acid4,footnote3 ,liebig's ,ann41 #aiab1 #cid1 #bdi4 ,,ellagitannic ,,acid1 ,c'#bf;,h'#bh',o'#aj-c;,h'#b,o1 is closely relat$ to ellagic acid2 ! =m] consi/s ( fa9tly yell[ ne$les1 ,m4,p4 #cbi-ccf;,c4 ,x is soluble 9 wat]1 precipitates gelat9e1 & is adsorb$ by hide p[d]4 ,x occurs ) gallic acid1 tann91 & ellagic acid 9 dividivi1 myrabolams1 alg>obilla1 & *e/nut wood extracts4 ,o!r bodies ( ?is class include3-- ,,metellagic ,,acid1 ,cl#d;,h#f,o#e1 d]iv$ f me?oxyb5zoic acid1 & recry/allis$ f acetic acid1 =ms small cry/all9e ne$les1 ,m4,p4 #bgc-bgf ,c41 & yields fluor5e on di/illation ) z9c du/4 ----,,co4,o---- ---------- ,v ---,o4,,co--- ,v ,,oh ,,flavellagic ,,acid1 ,c#ad;,h#f,o#i1 is obta9$ by ! oxidation ( gallic acid ) conc5trat$ sulphuric acid & potassium p]sulphate4 ,x cry/allises f pyrid9e 9 prismatic ne$les melt+ above #cfj ,c4 ,di/illation ) z9c du/ yields fluor5e 7see above7-- ----,,co4,o---- ---------- ,,oh ,,ho ,v ---,o4,,co--- ,v ,,oh ,,oh ,,oh ,by heat+ ellagic acid = ?ree-qu>t]s ( an h\r at #ahe ,c4 ) conc5trat$ sulphuric acid1 c]uleo-ellagic acid 7dioxyellagic acid71 ,c#ad;,h#f,o#aj1 is =m$ z yell[i% ne$les1 ,m4,p4 #cfj ,c41 :i* are b little soluble 9 ! usual solv5ts4 ,! acid is slightly soluble 9 /rong cau/ic soda solution1 ! col\r ( ! solution1 on dilut+1 *ang+ to gre5 & blue4 ,,luteic ,,acid 7,luteo ,saure1 p5toxybiph5ylme?ylolide c>boxylic acid71,c#ad;,h#h,o#i1 occurs1 9 addition to ellagic acid1 9 myrabolams-- ,footnote3 ,b]41 #aiji1 #db1 #cec4 ----,,co4,o---- ---------- ,,oh ,,ho ,v ,,oh ,,hooc ,v ,,oh ,,oh ,,oh ,x is obta9$ by extract+ myrabolams = "o h\r & a half1 "u reflux cond5s]1 ) pyrid9e1 filt]+ & add+ twice ! volume ( wat] to ! filtrate & boil+ till complete solution is obta9$4 ,aft] ab\t ?irty h\rs a r$di% p[d] deposits1 f :i* ellagic acid may be extract$ ) pyrid9e2 ! "m-liquor on be+ conc5trat$ yields luteic acid4 ,x is also obta9$ by oxidis+ tann9 ) hydrog5 p]oxide1 ! o!r oxidation product be+ ellagic acid1 & ! two may !n be sep>at$ z indicat$ above4 ,luteic acid =ms r$di% ne$les :i* are decompos$1 ) evolution ( gas1 at #cch-cda ,c4 ,heat$ ) #aj p] c5t4 cau/ic soda solution x yields ellagic acid4 ,9 pyrid9e solution ! c>boxyl gr\p maybe elim9at$ by hydrog5 iodide1 :]eby p5toxybiph5ylme?ylolide is =m$ z long silky ne$les1 :i* d n melt bel[ #cjj ,c4 ,! same sub/ance may also be obta9$ :5 ellagic acid is boil$ ) conc5trat$ cau/ic pota% solution4 ,:5 luteic acid is treat$ ) diazome?ane1 x yields ! me?yl e/] ( p5tame?oxybiph5ylme?ylolidc>boxylic acid4 #d4 ,,depsides ,! mo/ common decomposition products ( ! natural tannoids are hydroxyb5zoic acids1 notably gallic & proto-cate*uic acids2 fur!rmore1 o!r aromatic & aliphatic hydroxy comp\nds frequ5tly occur4 ,s f>1 h[ev]1 attempts at expla9+ ! con/itution ( ! complex decomposition products obta9$ by hydrolys+ high molecul> tannoids h n be5 successful4 ,on ! o!r h&1 ! con/itution ( ! simpl] natural tannoids is kn[n to a great] or less ext5t2 ( ^!1 lecanoric acid 7,lecanorsure7 is ! be/ kn[n1 be+ an e/] anhydride ( orsellic acid 7a dihydroxytoluylic acid74 ,x comb9es ) ery?rite1 =m+ ano!r tannoid1 ery?r9e4 ,! fact t hydroxyb5zoic acids are con/antly enc\nt]$ toge!r ) ! products obta9$ on hydrolysis ( ! tann9s1 seems to po9t t[>d ! conclusion t anhydrides ( hydroxyb5zoic acids are frequ5t con/itu5ts ( ! natural tannoid molecules4 ,! assumption t1 = in/ance1 9 tann9 at lea/ "p ( ! gallic acid radicals are comb9$ ) "o ano!r is highly probable1 & is support$ by ! =mation ( tri- & dime?ylgallic acid f me?ylotann91 ,footnote3 ,h]zig1 ,monat%efte f4 ,*emie1 #aiji1 #cj1 #cdc4 & by ! =mation ( ellagic acid :5 tann9 is oxidis$4 ,footnote3 ,ni]5/e91 ,b]41 #aijh1 #da1 #cjae4 ,fur!r pro( is br\ght =w>d by ! exi/5ce ( ! p5tacetyl-tann91 ,footnote3 ,s*iff1 ,ann4 d4 ,*em41 #ahgc1 #agj1 #gc4 & by ! results ( hydrolysis :i* has yield$ up to #ajd p] c5t4 anhydr\s gallic acid fiom tann9 ,footnote3 ,sisley1 ,bull4 ,soc4 ,*im4 #aiji1 #e1 #gbg4 ,( ! ?ree classes ( isom]ic anhydrides :i* c be =m$ f hydroxyb5zoic acids1 ! *emi/ry ( ! natural tann9s is only conc]n$ ) ! class compris+ ! e/] anhydrides4 ,if ! c>boxyl ( ! fir/ molecule comb9es ) a hydroxyl ( ! second molecule 7e/] =mation71 !n a sub/ance possess+ "* simil> to t ( a hydroxyb5zoic acid is =m$1 :i* is capable ( comb9+ up ) a fur!r molecule 9 ! same way4 ,x is natural to assume t ?is e/] =m is mu* m preval5t 9 ,nature ?an a comb9ation ( two c>boxyls by ! elim9ation ( wat]4 ,f ! po9t ( view ( ! *emi/ry ( ! tann9s1 !re=e1 ! />t+-po9t w\ld naturally be t ( syn!sis+ ! e/] anhydrides ( hydroxyb5zoic acids4 ,among/ ! small numb] ( syn!tically prep>$ e/] anhydrides ( hydroxyb5zoic acids1 a few occur exhibit+ ! prop]ties ( ! natural tannoids4 ,9 ord] to simplify ! t]m9ology ( ^! sub/ances1 ,fis*] ,footnote3 ,liebig's ,ann41 #aiaj1 #cgb1 #ce4 propos$ ! "n ,depsides f ,greek3 depheiv to tan4 ,9 analogy ) peptides & sac*>ides1 ! names di-1 tri-1 & polydepsides ( hydroxyb5zoic acids w\ld be suitable = ^! sub/ances4 ,! pr9ciples und]ly+ ! syn!sis ( depsides are ! foll[+3--,if ! *lorides ( c>bome?oxy 7or c>be?oxy7 hydroxyb5zoic acids are c\pl$ ) ! sodium salts ( hydroxyb5zoic acids1 e/]s are =m$1 e4g41 ,,*#c;,,co ,o4,o4,c#f;,h#d4;,,co4,cl ,na,o4,c#f;,h#d4;,,coo4,na ,na,cl ,,*#c4;,,coo4,o4,c#f;,h#d4;,,co4,o4,c#f; ,h#d4;,,coo4,na ,on g5tly saponify+ ! e/]s1 ^! are conv]t$ into ! correspond+ hydroxy d]ivatives-- ,,oh4,c#f;,h#d4;,,co4,o4,c#f;,h#d4;,,coo h ,accord+ to ,fis*] & ,freud5b]g1 ,footnote3 ,liebig's ,ann41 #aiji1 #cgb1 #cb4 ?is me?od possesses ! foll[+ advantages3-- #a4 ,! syn!sis takes place at l[ temp]atures1 s t any intramolecul> re>rangem5ts are improbable4 #b4 ,! composition ( ! sub/ances is controll$ by ! int]m$i>y comp\nds1 ! c>boalkyloxy d]ivatives4 #c4 ,! syn!sis p]mits ( m def9ite evid5ce z reg>ds ! /ructure ( ! result+ comp\nds4 #d4 ,! sub/ances obta9$ are easily purifi$4 ,depsides produc$ 9 ?is mann] are by no means new1 & 7 obta9$ by ,klepl by simply heat+ p-hydroxy-b5zoic acid 7cf4 ,introduction1 p4 #d74 ,?is simple proc$ure1 h[ev]1 is n applicable to mo/ o!r hydroxyb5zoic acids :i* are decompos$ at ! high temp]ature necess>y to induce reaction4 ,l[e & ,s*iff 7loc4 cit47 h obta9$ products simil> to tann9s1 ! latt] inve/igator by remov+ ! elem5ts ( wat] f gallic acid1 protocate*uic acid1 salicylic acid1 m-hydroxyb5zoic acid1 cresot9ic acid1 phloret9ic acid1 & pyrogallolc>boxylic acid4 ,^! depsides1 h[ev]1 are amorph\s sub/ances1 & x is h5ce difficult to sub/antiate _! homog5eity4 ,c>bome?oxylation ( ,hydroxyb5zoic ,acids ,among/ o!r comp\nds *lorphydroxyb5zoic acid is us$ 9 ! prep>ation ( ! mat]ials employ$ 9 ! syn!sis ( depsides2 ! free ph5olic gr\p1 h[ev]1 ex]ts a di/urb+ influ5ce :5 aromatic acids are act$ ^u by phosphorus *loride1 & ano!r gr\p1 :i* c subsequ5tly be easily remov$1 mu/ !re=e be introduc$ to cov] ! di/urb+ influ5ce ref]r$ to4 ,= ?is purpose1 ,fis*] ,footnote3 ,b]41 #aijh1 #da1 #bhfj4 *ose ! c>bome?oxy gr\p1 & ?is inve/igator succe$$1 by ! action ( *loroc>bonic alkyl e/] & alkali ^u hydroxyb5zoic acid 9 cold aque\s solution1 9 obta9+ sub/ances ) ! prop]ties requir$4 ,footnote3 ,b]41 #aijh1 #da1 #bhge4 ,9 su* sub/ances 7e4g41 salicylic acid7 :]e ! hydroxyl occupies ! or?o-position to ! c>boxyl1 complete c>bome?oxylation does n take place1 :]eas ! m- or p- positions (f] no h9drance4 ,9 ! case ( ! o-position1 h[ev]1 ! action ( *loroc>bonic alkyl e/] is successfully assi/$ by ! pres5ce ( dime?ylanil9e 9 an in]t solv5t1 e4g41 b5z5e4,footnote3 ,u4,s4 ,pat1 #a1fci1agd1 #ab1 xii41 #ahii4 ,! difficulty enc\nt]$ by ! o-position is elim9at$ :5 ! c>boxyl is n directly l9k$ to ! b5z5e nucleus1 e4g41 o-cum>ic acid4 ,_m hydroxyb5zoic acids require an excess ( *loroc>bonic me?yl e/]1 :i* !n also1 to "s ext5t1 attacks ! c>boxyl gr\p2 b on dissolv+ ! product 9 acetone & treat+ x ) bic>bonate ! c>boxyl gr\p z su* is aga9 re/or$ )\t splitt+ (f ! c>bome?oxy gr\p4,footnote3 ,b]41 #aiac1 #df1 #bdjj4 ,9 ?is way all hydroxyb5zoic acids may be c>bome?oxylat$4 ,footnote3 ,ibid41 #aijh1 #da1 #bhgg1 #bhha1 #bhhb2 #aiji1 #db1 #bbf1 #bah1 #bbc1 #bbe2 ,liebig's ,ann41 #aiab1 #cia1 #ceg1 #cff2 ,b]41 #aiac1 #df1 #aade1 #bcij1 #bdjj4 ,! c>bome?oxy gr\p is easily remov$ by excess ( aque\s alkali 9 ! cold1 & is also p>tially remov$ :5 insuffici5t alkali is pres5t2 ! latt] fact is ( importance 9 ! syn!sis ( didepsides4 ,*lorides ( ,c>bome?oxyhydroxyb5zoic ,acids ,! *lorides ( ^! comp\nds are obta9$ :5 phosphorus p5ta*loride is all[$ to act ^u ! acids1 & are z a rule cry/all9e4 ,= ! purpose ( syn!sis !y may be employ$ z foll[s3 #a4 ,!y readily =m e/]s ) alcohols1 :i* on subsequ5t saponification ) alkali are conv]t$ into ! e/]s ( ! free hydroxyb5zoic acids4 #b4 ,! *lorides int]act en]getically ) e/]s ( am9o-acids1 & may be c\pl$ ) am9o-acids 9 aque\s alkal9e solution4 ,on subsequ5tly remov+ ! c>bo-me?oxy gr\p d]ivatives ( hydroxyb5zoic acids are obta9$1 e4g41 ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,cl #b,,nh#b;,,*#b4;,,co4,c#b;,h#e ,,nh#b4;,,*#b4;,,co#b4;,c#b;,h#e ,h,cl ,,*#c4;,,co#b4,o4,c#f;,h#d ,,co4,,nh4,,*#b;,,co#b;,c#b;,h#e4 ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,,nh4,, *#b4;,,co#b4;,c#b;,h#e #c,na,o,h ,na#b;,,co#c ,c#b;,h#e,,oh ,,*#c,,oh ,,ho4,c#f;,h#d4;,,co4,,nh4,,*#b4;,c,o,o, na4 #c4 ,9 ! pres5ce ( ,al,cl#c ! *lorides easily comb9e ) b5z5e1 & on remov+ ! c>bome?oxy gr\p unsymmetrical hydroxy d]ivatives ( b5zoph5one are =m$3-- ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,cl ,c#f;,h#f ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,c#f;,h #e ,h,cl ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,c#f;,h #e #c,na,o,h ,na,o4,c#f;,h#d4;,,co4,c#f;,h#e ,na#c;,,co#c ,,*#c,,oh ,h#b,o #d4 ,! *lorides may be c\pl$ ) free hydroxyb5zoic acids1 & on remov+ ! c>bome?oxy gr\p didepsides are obta9$4 ,repetition ( ^! op]ations yields tri- & tetradepsides4 ,prep>ation ( ,didepsides ,a simple application ( ^! syn!ses is (f]$ by p-hydroxyb5zoic acid4 ,:5 ! *loride ( its c>bome?oxy d]ivative is all[$ to int]act ) p-hydroxyb5zoic acid 9 aque\s alkal9e solution1 9 ! cold1 ! alkali salt ( c>bome?oxy-p-hydroxyb5zoic acid is =m$3--,footnote #a3 ,b]41 #aiji1 #db1 #baf4 ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co4,cl ,na,o4,c#f;,h#d4;,c,o,o,na ,,*#c4;,,co#b4,o4,c#f;,h#d4;,,co#b4;,c#f ;,h#d4;,,co#b4,na ,na,cl4 ,be+ sp>+ly soluble1 ! salt 9 ?is case is readily deposit$ z cry/als1 b is readily conv]t$ into ! free acid by hydro*loric acid4 ,9 mo/ o!r cases1 h[ev]1 ! alkali salts are easily soluble & ! aque\s solution is !n directly acidifi$ ) a m9]al acid4 ,! *lorides1 be+ = ! mo/ "p solids1 ! mode ( proc$ure is z foll[s3--! hydroxyb5zoic acid requir$ = c\pl+ is dissolv$ 9 normal or d\ble-normal alkali 7! volume calculat$ p] molecule acid71 a little acetone add$1 & ! mixture well cool$2 a fur!r molecule ( #b,n cau/ic soda & ! *loride 7,i molecule7 dissolv$ 9 dry acetone are add$ 9 small portions1 :il/ /irr+1 to ! mixture4 ,9 spite ( ! l[ temp]ature ! c\pl+ proce$s quickly & ! sp>+ly soluble product c 9 mo/ cases be precipitat$ f ! solution by acidify+ & dilut+ ) wat]4 ,9 case ( m easily soluble c\pl+ products ! acetone is driv5 (f "u r$uc$ pressure or ! liquid acidifi$ & dilut$1 & ! sub/ance extract$ ) e!r4 ,in/ead ( alkali1 dime?ylanil9e may be employ$1 ) ! exclusion ( wat] z a solv5t = ! purpose ( c\pl+4 ,ano!r suitable me?od ( obta9+ o-didepsides is t ( treat+ o-hydroxyb5zoic acids ) phosphorus tri*loride & dime?ylanil9e 7e4g41 syn!sis ( disalicylic acid1 ,boehr+] ,sons74,footnote3 ,g]4 ,pat41 #baa1djc4 ,! c>bome?oxy d]ivatives ( ! depsides are z a rule cry/all9e sub/ances ( di/9ct acidic "*1 & decompose alkal9e c>bonates4 ,! elim9ation ( ! c>bome?oxy gr\p may be br\ght ab\t by dilute alkal9e solutions 9 ! cold1 or by aque\s ammonia4 ,if ! depside =m$ is s /able z to resi/ ! action ( alkali = sev]al h\rs1 ! use ( ! latt] is v conv5i5t = ! purpose requir$4 ,! sub/ance is dissolv$ directly 9 suffici5t normal alkali to neutralise ! c>boxyl gr\p & a fur!r #b molecules ( cau/ic soda = ea* c>bome?oxy gr\p to be elim9at$ are add$4 ,! temp]ature %\ld be ab\t #bj ,c41 :5 ! reaction z a rule is complet$ aft] "o-half to ?ree-qu>t]s ( an h\r4 ,x is usual1 h[ev]1 to use an aque\s ammonia solution 9 consid]able excess1 :]eby ! temp]ature %\ld aga9 be ab\t #bj ,c41 & ! solution ( ammonia normal or half normal4 ,! didepsides s f> inve/igat$ are cry/all9e bodies1 sp>+ly soluble 9 cold wat]2 !y--z a rule--decompose :5 fus$1 possess acid reaction1 & are dissolv$ by bic>bonates4 ,on acc\nt ( ! pres5ce ( a free ph5olic gr\p !y give a coloration ) f]ric *loride2 if ! ph5olic gr\p occupies ! o-position to c>boxyl1 ! coloration ) f]ric *loride is r$ or blui%-violet ,excess ( dilute alkali resolv$ all didepsides into _! compon5ts at ord9>y temp]atures4 ,! didepsides ( gallic1 proto-cate*uic1 g5tis9ic1 & ,greek3 b-resorcylic acids precipitate gelat9e & qu99e acetate1 & 9 ?is respect approa* ! natural tann9s4 ,! foll[+ summ>y gives an acc\nt ( depsides :i* h be5 prep>$ syn!tically or :i* occur naturally3--,footnote #a3 ,b]41 #aijh1 #da1 #bhhh2 #aiji1 #db1 #bag2 #aiac1 #de1 #bgah2 #aiac1 #df1 #aacj1 #bcif1 #aada1 #aadc2 ,liebig's ,ann41 #chd1 #bcj1 #bcc1 #bch2 #cia1 #cef1 #cfb4 ,di-p-hydroxyb5zoic acid4 ,di-m-hydroxyb5zoic acid4 ,disalicylic acid4 ,diprotocate*uic acid4 ,dig5tis9ic acid4 ,di-,greek3 b-resorcylic acid4 p-,diorsellic acid4 o-,diorsellic acid4 m-,digallic acid4 ,disyr+ic acid4 ,di-o-cum>ic acid4 ,dif]ulic acid4 ,di-,greek3 b-hydroxynaph?oic acid4 p-,hydroxyb5zoyl-m-hydroxyb5zoic acid4 m-,hydroxyb5zoyl-p-hydroxyb5zoic acid4 ,salicyl-p-hydroxyb5zoic acid1 ,vanilloyl-p-hydroxyb5zoic acid4 ,f]uloyl-p-hydroxyb5zoic acid4 ,greek3 a-,hydroxynaph?oyl-p-hydroxyb5zoic acid4 ,orsell9oyl-p-hydroxyb5zoic acid4 ,protocate*uyl-p-hydroxyb5zoic acid4 ,galloyl-p-hydroxyb5zoic acid4 ,pyrogallolc>boy p-hydroxyb5zoic acid4 ,syr+oyl-p-hydroxyb5zoic acid4 p-,hydroxyb5zoyl-syr+ic acid4 ,p5tame?yl-m-digallic acid4 ,p5tame?yl-p-digallic acid4 ,vanilloyl vanill94 ,prep>ation ( ,tridepsides ,monohydroxyb5zoic acids all[ !oretically ( tri-depsides ( ! type ,,ho4,c#f;,h#d;,,coo4,c#f;,h#d4;,,coo4,c #f;,h#d4;,,cooh only2 if1 on ! o!r h&1 di- or trihydroxyb5zoic acids are dealt )1 two =mulae are possible1 viz43-- ,,ho4,c#f;,h#d4;,,coo ,c#f;,h#c4;,,cooh ,,ho4,c#f;,h#d4;,,coo ,( ! =m] type1 two comp\nds are kn[n1 i4e41 di-p-hydroxyb5zoyl-p-hydroxyb5zoic acid & vanilloyl-p-hydroxyb5zoyl-p-hydroxyb5zoi c acid-- ,,ho ,c#f;,h#c4;,,coo4,c#f;,h#d4;,,coo4,c#f;, h#d4;,,cooh ,,*#c,o ,! fir/ nam$ ( ^! two comp\nds 0 obta9$ by ,klepl1 9 addition to ! didepside1 by heat+ p-hydroxyb5zoic acid4 ,fis*] & ,freud5b]g obta9$ a beautifully cry/all9e =m 9 ! foll[+ way3 c>be?oxyhydroxy-b5zoyl *loride 0 c\pl$ ) p-hydroxyb5zoyl-p-hydroxyb5zoic acid 9 alkal9e solution1 ! comp\nd dissolv$ 9 a mixture ( pyrid9e & acetone1 & ammonia add$ = ! purpose ( remov+ ! c>be?oxy gr\p4 ,! tridepside 0 !n obta9$ z long ne$les by re-dissolv+ 9 acetone4 ,bo? tridepsides melt well above #bjj ,c41 are practically insoluble 9 wat]1 & are b sp>+ly soluble 9 practically all organic solv5ts4 ,9 alcoholic solution !y give col\r reaction ) f]ric *loride simil> to ^? giv5 by p-hydroxyb5zoic acids4 ,prep>ation ( ,tetradepsides ,footnote3 ,fis*] & ,freud5b]g1 ,liebig's ,ann41 #aiaj1 #cgb1 #cb4 ,"h1 aga91 two =ms are kn[n1 e4g41 tri-p-hydroxyb5zoyl-p-hydroxyb5zoic acid-- ,,ho4,c#e;,h#d4;,,coo4,c#f;,h#d4;,,coo4, c#f;,h#d;,,coo4,c#f;,h#d ,,cooh & vanilloyl-di-p-hydroxyb5zoyl-p-hydroxyb5 zoic acid-- ,,ho ,c#f;,h#c4;,,coo4,c#f;,h#d4;,,coo4,c#f;, h#d4;,,coo4,c#f;,h#d4;,,cooh ,,*#c,o ,! =m] has be5 prep>$ f c>be?oxyhydroxy-b5zoyl-p-hydroxyb5zoyl *loride & p-hydroxyb5zoyl-p-hydroxyb5zoic acid 9 alkal9e solution2 ! second tetradepside 0 prep>$ f c>bome?oxyvanilloyl-p-hydroxyb5zoyl *loride & p-hydroxyb5zoyl-p-hydroxy-b5zoic acid4 ,! prep>ation ( ^! comp\nds is r5d]$ difficult by ! slight solubility ( ! sub/ances & _! slight aff9ities = ent]+ into reaction4 ,bo? tetradepsides 7 obta9$ 9 cry/all9e =m1 & are b v little soluble 9 mo/ organic solv5ts4 ,!y decompose on be+ fus$4 ,tannoid ,sub/ances ( ! ,tann9 ,type ,! prep>ation ( p5tagalloyl glucose has prov$ ?is comp\nd to be ne>ly id5tical ) tann9 obta9$ f galls 7tann972 a few o!r natural tann9s belong to ?is type :i* ,fis*] t]ms acyl comp\nds ( sug> ) hydroxyb5zoic acids4 ,! me?od ( prep>ation employ$ 9 ! syn!sis ( p5tagalloyl glucose may be easily appli$ to o!r hydroxyb5zoic acids1 e4g4 p5tap-hydroxyb5zoyl glucose ,footnote3 ,fis*] & ,freud5b]g1 ,b]41 #aiab1 #de1 #icc4 0 prep>$ 9 ?is way4 ,simil> *>act]i/ics are exhibit$ by p5tasalicylo glucose4 ,m5tion mu/ also be made ( ! correspond+ d]ivative ( pyruvic acid & ! comp\nd ) pyrogallolc>boxylic acid1 p5ta-pyrogallolc>boylglucose4 ,footnote3 ,fis*] & ,rapoport1 ,b]41 #aiac1 #df1 #bcig4 ,! latt] is isom]ic ) p5tagalloyl glucose & possesses simil> prop]ties2 !re is1 h[ev]1 a va/ diff]5ce 9 ! solubility ( ! two4 ,:]eas ! galloyl comp\nd is easily soluble 9 cold wat]1 its isom] is h>dly soluble 9 hot1 & completely insoluble 9 cold wat]4 ,consid]+ ! v simil> /ructure ( ^! two tann9s1 su* diff]5ces appe> surpris+1 b an analogy may be readily f\nd 9 ! exi/5ce ( colloidal solutions ( tann9 & ! 7ne>ly7 id5tical p5tagalloyl glucose4 ,^! prop]ties cle>ly %[ h[ dep5d5t is ! colloidal /ate on small diff]5ces 9 ! /ructure ( two sub/ances4 ,on ! o!r h&1 ! =mation ( hydrosols is ( ! greate/ importance relatively to ! "p play$ by ^! sub/ances 9 ,nature z well z relat+ to _! *emical *>act]i/ics2 ?us x is extremely difficult to make a solution ( p5ta-pyrogallolc>boyl-glucose1 at ! same "t asc]ta9+ its a/r+5t ta/e & its prop]ty ( precipitat+ gelat9e4 ,! exp]i5ce ga9$ by ! me?yl glucosides makes x exce$+ly probable t ! simpl] polyhydric alcohols also are suitable sub/ances to employ 9 ^! syn!ses2 z a matt] ( fact1 glyc]ol has be5 cond5s$ ) gallic acid4 ,footnote3 ,fis*] & ,freud5b]g1 ,b]41 #aiab1 #de1 #ice4 ,"o ( ! *ief *>act]i/ics ( syn!tic tann9s is _! high molecul> weight2 = in/ance1 ! molecul> weight ( p5ta-tric>bome?oxygalloyl-glucose is #a1haj1 t ( p5ta-p5tame?yl-m-digalloyl-glucose #b1jea4 ,employ+ gallic acid d]ivatives1 especially ! trib5zoyl comp\nds1 c\pl$ ) glucose1 e4g41 mannite1 yield$ a neutral e/] ( molecul> weight #b1ifg4 ,! det]m9ation ( ! elem5t>y composition ( comp\nds ( high molecul> weight is greatly facilitat$ by employ+ _! halog5 d]ivatives2 s1 = in/ance1 is p iodoph5yl maltosazone v suitable4 ,c\pl+ ! latt] ) trib5zoylgalloyl *loride yield$ hepta-trib5zoyl-galloyl-p-iodoph5yl maltosazone1 ! /ructure ( :i* is repres5t$ by-- ,,*3,n#b;,h4,c#f;,h#d;,i ,c3,n#b;,h4,c#f;,h#d;,i ,,*4,o4,r ,r ,,co4,c#f;,h#b7,o4,,co4,c#f;,h#f7b ,,*4,o4,r ,,*4,o4,r ,r ,r ,r ,r ,o ,o ,o ,o ,,*#b4,o4,,*4,,*4,,*4,,*4,,*4,,*#b ---,o--- ,! molecul> weight ( ?is sub/ance is #d1jba1 & probably repres5ts ! highe/ molecul> organic body obta9$ 9 any *emical syn!sis4 ,f a physiological /&po9t ! recognition ( tann9s z e/]s ( glucose & hydroxyb5zoic acids1 possess+ *>act]i/ics simil> to ^? ( tann91 is ( great importance4 ,especially int]e/+ appe>s ! fact ( plants utilis+ sug>s = ! e/]ification ( acids1 j z glyc]ol or monohydric alcohols may be employ$ = ! same purpose4 ,free acids1 z a rule1 are only tol]at$ 9 c]ta9 p>ts ( ! organism1 ! latt] usually /riv+ to neutralise acidic gr\ps :i* may be br\ght ab\t by salt =mation2 =mation ( am9o comp\nds 7prote9s7 or e/]ification 7fats72 &1 la/ly1 e/]=mation by means ( sug>s4 ,:y ,nature %\ld always build up sub/ances ( v complex con/itution c only be expla9$ by bio*emical inve/igations1 b x may1 at any rate1 be assum$ t by ?is means any sub/ance poison\s to ! liv+ organism is r5d]$ inactive4 ,! function ( ! tann9s pres5t 9 plants may ?us be expla9$2 if1 = in/ance1 ph5ols are =m$ by ! oxidation ( correspond+ sug>s1 ,footnote3 ,mielke1 ,ueb] die ,/ellung d] ,g]b/(fe im ,/(fwe*sel d] ,pflanz5 7,hamburg1 #ahic74 ! poison\s "* ( ! =m] w\ld be less5$ by ! introduction ( ! c>bonic acid e/]s & subsequ5t c\pl+ ( ! sub/ances 7depside =mation74 ,! depsides ?us =m$ w\ld s]ve z vehicle ( ! sug>s & transport ! migrat+ tann9s1 ,footnote3 ,kraus1 ,grundl9i5 zu e9] ,physiologie d] ,g]b/(fe 7#ahhi74 &1 aft] subsequ5t deposition ( ! sug>s1 w\ld !n be elim9at$ f ! plant organism1 ei!r by oxidation into ellagic acid & phlobaph5es or by cond5sation ) ! =mation ( cork4 ,diagrammatically1 ! foll[+ w\ld repres5t ! physiology ( ! tann9s3--,footnote3 ,ni]5/e91 ,*emie d] ,g]b/(fe 7,/uttg>t1 #aiaj74 ,sug>--,ph5ol--,hydroxyb5zoic ,acid--,depside-- ,phlobaph5e --,migrat+ ,depside--,glucoside--,free ,depside---,ellagic ,acid ,cork4 ,illu/ration3 ,*>t ,%[+ ! ,decomposition ( ,products ( ,tann94 ,,section ,,ii ,,syn!sis ,,( ,,tann+ ,,matt]s #a4 ,,aromatic ,,sulphonic ,,acids ,9 organic *emi/ry di/9ction is made betwe5 sulphonic acids ( ! aliphatic & ! aromatic s]ies1 ! *>act]i/ic gr\p ( ^! acids be+ ! s-call$ sulphonic acid gr\p1 ,,hso#c4 ,:5 sulphides or m]captans 9 glacial acetic acid solution are heat$ ) p]manganate1 ! result+ sulphonic acid comp\nds exhibit great simil>ity to comp\nds conta9+ free c>boxyl gr\ps4 ,! sulphonic acid gr\p may also be directly introduc$ ei!r by conc5trat$1 or by fum+ sulphuric acid1 or by elim9ation ( halog5 by ! action ( sodium or silv] sulphite on ! halog5 d]ivatives ( ! aliphatic comp\nds4 ,saturat$ hydroc>bons d n react ) sulphur trioxide1 b unsaturat$ hydroc>bons are readily attack$ by ,,s#c4 ,simil>ly1 halog5at$ comp\nds & alcohols react ) conc5trat$ or fum+ sulphuric acid =m+ sulphonic & hydrosulphonic acids respectively4 ,! aromatic comp\nds =m1 z a rule1 sulphonic acids ) mu* great] facility4 ,b5z5e1 = in/ance1 is easily conv]t$ into ! m-disulphonic acid by g5tly heat+ ) fum+ sulphuric acid2 /rong] heat+ conv]ts ! m- into ! p-disulphonic acid1 & at #aij ,c4 ! trisulphonic acid is =m$4 ,tolu5e treat$ ) fum+ sulphuric acid fir/ yields o- & p-sulphonic acids1 f9ally o- & p-disulphonic acids1 e?ylb5z5e at ! boil+ po9t p-e?ylb5z5e-sulphonic acid4 ,( ! ?ree isom]ic xyl5es o- & m-xyl5e dissolve 9 conc5trat$1 p-xyl5e 9 fum+ sulphuric acid only4 ,! action ( sulphuric acid on naph?al5e is /rong] ev5 ?an on b5z5e4 ,equal p>ts ( naph?al5e & sulphuric acid heat$ to #ajj ,c4 yield #hj p] c5t4 ,greek3 a & #bj p] c5t4 ,greek3 b-monosulphonic acid4 ,at #afj-agj;,c4 #be p] c5t ,greek3 a- & #ge p] c5t4 ,greek3 b-sulphonic acid is =m$1 & at high] temp]atures ,greek3 b-monosulphonic acid only4 ,if1 on ! o!r h&1 #h p>ts ( naph?al5e are heat$ ) #c p>ts ( conc5trat$ sulphuric acid to #ahj ,c41 two diff]5t naph?yldisulphonic acids are obta9$4 ,complete solution ( ! sub/ance 9 sulphuric acid is1 g5]ally speak+1 a crit]ion ( complete sulphonation4 ,a completely sulphonat$ comp\nd %\ld rema9 cle> on dilution ) wat]1 or1 9 case precipitation occurs1 ! precipitate %\ld be completely soluble 9 alkali or ammonia4 ,x is necess>y to submit ! product to ?is te/1 s9ce _m organic sub/ances are soluble 9 conc5trat$ sulphuric acid )\t und]go+ any alt]ation 9 composition4 ,phosphorusp5toxide or potassium sulphate consid]ably increase ! sulphonat+ prop]ty exhibit$ by fum+ sulphuric acid4 ,! sep>ation ( ! sulphonic acids f sulphuric acid is effect$ by salt+ out ! =m] ) common salt1 or by remov+ ! sulphuric acid ) calcium1 b>ium1 or lead salts1 provid$ t ! sulphonic acid salts ( ^! metals are soluble 9 wat]4 ,! sulphonic acid1 9 its *emically pure /ate1 is be/ obta9$ f its cry/all9e b>ium salts1 :i* are decompos$ ) ! equival5t ( sulphuric acid2 ano!r way is to decompose ! calcium salts ( ! sulphonic acids ) oxalic acid4 ,! sulphonic acids are frequ5tly hygroscopic & are easily soluble 9 wat]2 ! majority ( _! b>ium & lead salts are also soluble 9 wat]4 ,! sulphonic acids are insoluble 9 e!r4 ,! halog5s d n easily react ) sulphonic acids1 b :5 !y d !y usually replace ! sulphonic acid gr\p4 ,9 ord] to prep>e ! halog5 sub/itution products1 !re=e1 use is made ( sulphonic *lorides4 ,! latt] are obta9$ by ! action ( *lorosulphonic acid on aromatic hydroc>bons2 a simpl] me?od1 h[ev]1 is to treat ! dry alkali sulphonates ) phosphorus p5ta*loride-- ,c#f;,h#e,,s#c,na ,p,cl#e ,c#f;,h#e,,s#b4;,cl ,na,cl ,p,o,cl#c ,d]ivatives ( sulphonic *lorides are sulphonamides1 :i* are easily prep>$ f ! =m] by gr9d+ ) ammonium c>bonate-- ,c#f;,h#e,,s#b4;,cl 7,,nh#d7b;,,co#c ,c#f;,h#e4,,s#b4,,nh#b ,,nh#d;,cl ,,co#b ,h#b,o ,sulphonic *lorides react ) alkal9e sulphides to =m ?iosulphonic acids-- ,c#f;,h#e,,s#b4;,cl ,k#b,s ,c#f;,h#e,,s#b4,,sk ,k,cl ,sulphonic *lorides1 dissolv$ 9 e!r1 yield sulph9ic acids on r$uction ) z9c du/ or metallic sodium-- ,c#f;,h#e,,s#b4;,cl ,h#b ,c#f;,h#e,,s#b4;,h ,h,cl ,9 ! sulphonic acid comp\nds x is assum$ t ! sulphur is hexaval5t1 & x is h5ce possible to consid] ! sulphones to be e/]s ( sulph9ic acid4 ,o ,r--,s,o --,h ,! sulphones are mo/ly solid bodies1 :i* s(t5 prior to melt+ :5 heat$4 ,!y are v /able t[>ds *emical reag5ts2 = in/ance1 saponification ( a mono-sulphone v r>ely yields sulph9ic acid4 ,if a hydroxyl is sub/itut$ = a hydrog5 atom 9 ! aromatic hydroc>bons1 ! action ( sulphuric acid is greatly facilitat$2 ?us1 by m]ely mix+ ph5ol ) sulphuric acid1 ! sulphonic acid is at once =m$1 :]eby1 9 ! cold1 o-ph5olsulphonic acid prevails :i* on heat+ = "s "t to #ajj-aaj ,c4 is completely conv]t$ into p-ph5olsulphonic acid4 ,9 ! abs5ce ( free sulphuric acid ! conv]sion ( o- into p-ph5olsulphonic acid is br\ght ab\t by heat+ ! aque\s solution4 ,ph5ol-#b1d-;disulphonic acid is prep>$ f o- or p-ph5olsulphonic acid1 :]eas ph5ol-#b1d1f-trisulphonic acid is prep>$ directly f ph5ol by heat+ ) conc5trat$ sulphuric acid 9 pres5ce ( phosphorus p5toxide4 ,ph5olsulphonic acids are also obta9$ by fus+ b5z5$isulphonic acid ) alkali4 ,cresol is n s easily sulphonat$ z is ph5ol2 o-cresol :5 heat$ eight to t5 h\rs at #ij ,c4 ) "o & "o-half times its weight ( conc5trat$ sulphuric acid1 yields o-cresol-p-sulphonic acid4 ,! ph5olsulphonic acids are /rong1 r /able acids2 _! alcoholic hydroxyl-hydrog5 atom may1 simil>ly to t ( ! ph5ols1 be sub/itut$ by a metal or an alkyl radical4 ,f ,greek3 a- & ,greek3 b-naph?ol a numb] ( sulphonic acids may easily be prep>$2 viz41 mono-1 di-1 & trisulphonic acids4 ,ne>ly all ^! acids are important z basic mat]ials 9 ! dye/uff indu/ry1 especially #b1f-;,greek3 b-naph?olmonosulphonic acid 7,s-acid71 #b1c1f-;,greek3 b-naph?oldisulphonic acid 7,r-acid7 & #b1f1h-;,greek3 b-naph?oldisulphonic acid 7,g-acid74 #b4 ,cond5sation ( ,ph5ols ,ph5olsulphonic acids exhibit pron\nc$ t5d5cies to cond5sation1 = :i* purpose ,a4 v4 ,baey] 7#ahgb7 employ$ aldehydes4 ,! reaction is r viol5t1 & yields1 9 addition to well-def9$ cry/all9e sub/ances1 amorph\s bodies resembl+ ros9s4 ,9 addition to =maldehyde1 p>a=maldehyde1 trioxyme?yl5e1 me?ylal1 hexame?yl5e-tetram9e1 & o!r sub/ances conta9+ a reactive me?yl5e gr\p1 z well z acetaldehyde1 b5zaldehyde & o!r aldehydes may be employ$ to induce reaction4 ,a numb] ( ^! cond5sation products are d]ivatives ( diph5ylam9e or hydroxyb5zyl alcohols4 ,:5 ! latt] are heat$1 ei!r by !mselves or 9 pres5ce ( acids1 anhydrides & polym]isation products are =m$ produc+ h>d1 brittle1 fusible sub/ances1 insoluble 9 wat] b fairly soluble 9 organic solv5ts4 ,! same sub/ances are =m$ :5 ph5ols are cond5s$ ) =maldehyde1 especially 9 ! pres5ce ( acid contact sub/ances & excess ( ph5ol by suffici5tly long heat+ at c]ta9 temp]atures4 ,! sub/ances ref]r$ to are t]m$ ,novolak3 simil> to ^! are ! s-call$ ,resols1 insoluble & non-fusible sub/ances1 v resi/ant to *emical & physical action4 ,ano!r memb] ( ! s]ies is ! s-call$ ,bakelite or ,resitol1 :i* does n fuse b s(t5s :5 heat$ & swells 9 organic solv5ts4 ,! ultimate product ( ?is class ( sub/ances is ,resit :i* is obta9$ :5 conc5trat$ hydro*loric acid is all[$ to act ^u a mixture ( ph5ol & =maldehyde2 ! temp]ature rises spontane\sly1 & a h>d1 por\s1 insoluble mass ( great resi/ance is obta9$4 ,by heat+ resols1 resitols are =m$ :i*1 on fur!r heat+1 are f9ally conv]t$ into resits4 ,footnote3 ,b]41 #ahib1 #be1 #cbac4 ,( all ^! products1 bakelite 7resitol7 has f\nd ! greate/ indu/rial application2 9 its pure/ =m1 ?is sub/ance is a ne>ly col\rless or light yell[ body ( sp4 gr4 #a4be &1 be+ a poor conductor ( heat & electricity1 con/itutes an excell5t insulat+ mat]ial2 x is exce$+ly resi/ant t[>ds mo/ *emical reag5ts ev5 9 conc5trat$ =ms ( ! latt]4 ,its pron\nc$ refractivity1 & ! ease ) :i* x may be work$1 makes bakelite a fav\rite sub/itute = amb] 7,g]4 ,pat1 #bhf1 #efh74 ,simil>ly1 ! resols :i* c be easily m\ld$ are us$ ei!r z su* or mix$ ) s&1 pulv]is$ cork1 asbe/os or wood1 & ! m\ld$ sub/ances !n conv]t$ into ! m highly resi/ant bakelite by heat+4 ,! con/itution ( ^! bodies no d\bt dep5ds l>gely on _! me?od ( prep>ation2 ,baekel& ,footnote3 ,*em4 ,ztg41 #aiac1 #gc1 #gcc4 consid]s resit a polym]is$ hydroxyb5zylme?yl5e glycol anhydride2 ,ras*ig1 a diph5ylme?ane d]ivative 7e4g41 dihydroxydiph5ylme?ane alcohol72 ,wohl ,footnote3 ,b]41 #aiab1 #de1 #bjdf4 consid]s !m polym]isation products ( me?yl5e d]ivatives ( tautom]ic ph5ol4 ,,*,,* ,h#b;,c3,c ,,co ,,*,,* ,note3 ,l[] ,"r ,,* has d\ble bond to ,,co ,?is gr\p possesses ! *>act]i/ic prop]ty ( be+ capable ( conv]t+ animal hide into lea!r :5 suitably dissolv$4 ,! au?or has dissolv$ a numb] ( ^! wat]-insoluble cond5sation products 9 alkali & alcohol & 0 able to demon/rate _! tann+ effects on pelt2 bakelite is easily soluble 9 alkali2 a fa9tly alkal9e solution p>tially precipitates gelat9e1 & completely s :5 ! alkali is neutralis$4 ,?is latt] solution gives a dirty br[n precipitate ) iron salts4 ,^! cond5sation products ga9$ extraord9>y importance = ! tann+ trade :5 ,/iasny ,footnote3 ,g]4 ,pat1 #bfb1eeh2 ,au/r4 ,pat1 #eh1dje4 succe$$ 9 prep>+ !m 9 wat]-soluble =m :5 !y are enabl$ to directly ex]t _! tannoid prop]ties4 ,?is may be done by act+ ^u two molecules ( conc5trat$ ph5olsulphonic acid ) "o molecule ( =maldehyde1 ! temp]ature !reby n exce$+ #ce;,c4 ,by cond5sation1 h[ev]1 consid]able heat is lib]at$1 & h5ce ! rise 9 temp]ature c only be limit$ by add+ ! dilut$ =maldehyde drop by drop1 :il/ /irr+ & cool+1 to ! ph5olsulphonic acid4 ,! orig9al lett]s pat5t is word$ z foll[s3 #aj kilos ea* ( crude ph5ol & sulphuric acid 7#ff ,b47 are heat$ ) /irr+ = two h\rs at #aje-ajf;,c41 cool$ to ab\t #ce;,c41 & #dfc kilos #cj p] c5t4 =maldehyde add$ dur+ ?ree h\rs1 ! temp]ature !reby n exce$+ #ce;,c42 ! /irr+ is cont9u$ = a c\ple ( h\rs aft] ! f9al addition ( =maldehyde4 ,?is yields ab\t #bd kilos ( ! crude cond5sation product4 ,on a comm]cial scale1 h[ev]1 cresol 7cresylic acid7 is sub/itut$ = ph5ol4 ,!re are ?ree isom]s ( cresol1 viz41 o-1 m-1 & p-cresol1 & x 0 naturally ( int]e/ to inve/igate :e!r "o or ! o!r ( ! isom]s ex]t$ any p>ticul> influ5ce on ! prop]ties ( ! f9al product4 ,x 0 f\nd1 h[ev]1 t cond5sation products f ! ?ree isom]s 7 di/+ui%able f "o ano!r nei!r 9 physical nor 9 tannoid prop]ties4 ,x is h5ce possible to employ crude cresol1 :i* conta9s v>y+ quantities ( ! o-1 m-1 & p-comp\nds1 9 ! manufacture ( ^! tann+ matt]s4 ,footnote3 ,g5 ,pat1 #bia1deg4 ,! t> obta9$ f ! ,ro*l+ coal-gas g5]ator conta9s consid]able quantities ( ph5ols 7,b4,p4#bjj-bej;,c471 & ! au?or has protect$ ! use ( ^! = ! production ( syn!tic tann9s by ,g]4 ,pat1 #bfb1eeh4 ,a deep br[n visc\s mass is obta9$ :i*1 :5 p>tly neutralis$1 yields simil> results to ^? giv5 by ! product above ref]r$ to4 ,x may be anticipat$ t by analogy f ! *emical reactions tak+ place 9 ! cond5sation ( ph5ols on ! "o h& & cresolsulphonic acid on ! o!r1 t all o!r homologues ( ph5ol1 its polyval5t d]ivatives1 sub/itution products & acids1 w\ld yield simil> cond5sation products4 ,! p>ticul> position occupi$ by ! aromatic hydroxy comp\nds 9 ! *emi/ry ( sub/ance possess+ tannoid "* is n only evid5c$ by ! natural classification ( ! tann9s1 tann9 d]ivatives1 & decomposition products s f> isolat$ & inve/igat$1 b also by o!r *emical behavi\r %[n by ^! sub/ances4 ,meuni] & ,seyewetz ,footnote3,collegium1 #aijh1 #cae1 #aie41 = example1 7 able to %[ t ph5ol1 p-am9oph5ol1 *loroph5ol1 tr9itroph5ol1 cate*ol1 resorc9ol1 hydroqu9one1 mono*lorohydroqu9one1 orc9ol1 pyrogallol1 & gallotannic acid precipitate gelat9e f its aque\s solution1 t is1 to a c]ta9 ext5t possess tann+ prop]ties4 ,! au?or has ext5d$ ?is s]ies some:at & obta9$ ! foll[+ results3-- ,relative ,behavi\r ,t[>ds ,sub/ances ,gelat9e4 ,hide ,p[d]4 ,pelt4 ,tribromoph5ol ,slight ppte4 ,tans ,surface tannage ,footnote3 ,9 alcoholic solution o-,nitroph5ol ,no ppte4 ,br-o-,nitroph5ol ,slight ppte4 ,tribromopyrogallic ,ppte4 acid ,bromophlorogluc9ol ,no tannage ,gall(lav9e ,slight ppte4 ,bromosalicylic acid ,bromo-,greek3 b ,tans -naph?ol ,footnote3 ,9 alcoholic solution ,rosolic acid ,footnote3 ,9 alcoholic solution ,gallic acid ,no ppte4 ,no tannage ,no tannage ,by ! cond5sation ( _! sulphonic acids1 x may be demon/rat$ exp]im5tally h[ ! tannoid prop]ties ( ne>ly e memb] ( ! s]ies are int5sifi$4 ,inve/igattion 9 ?is direction1 h[ev]1 has n be5 sy/ematically und]tak51 = :i* reason ! au?or det]m9$ to exam9e ?is subject2 b ! enorm\s numb] ( samples requir$1 obta9able only ) great difficulty dur+ ! w>1 made x impossible to conclude completely ! rese>*es 9 ?is field4 ,:at little has s f> be5 done relatively to ?is subject %\ld1 :5 collect$1 indicate ! way to be pursu$ 9 ?is wide field ( inve/igation4 ,:at foll[s w h5ce comprise ! conv]sion ( a few ( ! mo/ important memb]s ( ?is s]ies ( sub/ances into _! me?yl5e-cond5sation products ) a brief discussion ( ! qualitative & tannoid reactions ( ! latt]4 ,! didepside ( ph5olsulphonic acid is obta9$ by cond5s+ c>bome?oxyph5olsulphonic *loride ) sodium ph5olsulphonate 9 ! pres5ce ( ! calculat$ am\nt ( cau/ic soda4 ,a product ( ! composition ,,*#c4j4;,,coo4,c#f;,h#d,,s#b4j4;,c#f;,h #d4,,s#c,na is fir/ obta9$1 :i* on saponification ) soda yields ! pure didepside-- ,,ho4,c#f;,h#d4,,s#b4;,c#f;,h#d4,,s#c4,n a ,by acidify+ ! conc5trat$ solution ! didepside is obta9$ z a :ite cry/all9e sub/ance2 a solution ( :i* precipitates gelat9e )\t1 h[ev]1 exhibit+ any tann+ effect ^u animal hide4 ,if1 on ! o!r h&1 ! above e/] is conv]t$ into ! *loride ,,*#c,o4,,coo4,c#d;,h#d,,s#b4,o4,c#f;,h# d4,,s#b;,cl by treatm5t ) ,p,cl#e1 & ! *loride ?us obta9$ fur!r cond5s$ ) sodium ph5olsulphonate1 saponifi$1 & ! solution acidifi$1 ! pure tridepside ,,ho4,c#f;,h#d4,,s#b4,o4,c#f;,h#d4,,s#b4 ,o4,c#f;,h#d4,,s#c,na is precipitat$ z :ite cry/all9e ne$les :i* n only precipitate gelat9e1 b are capable ( conv]t+ animal hide into lea!r4,footnote3 ,*em4 ,ztg41 #aiai1 #dc1 #cah4 ,( ! class ( hydroxy-cym5es ?ymol1 ,c#f;,h#c4;,,*#c4;,c#c;,h#g,,oh1 0 conv]t$ into ! wat]-soluble sulphonic acid by w>m+ ) conc5trat$ sulphuric acid at #ej ,c41 ! sulphonic acid be+ subsequ5tly easily cond5s$ ) =maldehyde by slightly heat+ ! mixture4 ,! cond5sation product ?us obta9$ is a visc\s br[n mass :i* is easily soluble 9 wat]1 precipitates gelat9e completely1 gives a blui%-black coloration ) iron salts1 & gives a precipitate ) anil9e hydro*loride4 ,to inve/igate its tannoid prop]ties1 ! mixture 0 br\ght to ! acidity #a gm #aj c4c4 ,n_/#aj ,na,o,h & a piece ( bat$ calf sk9 0 !n introduc$ into a solution measur+ ab\t #b ,b4 ,aft] eighte5 h\rs ! pelt 0 ne>ly tann$ ?r\gh1 & a fur!r tw5ty-f\r h\rs complet$ ! tann+ process1 aft] :i* a light fat-liquor 0 giv54 ,! dri$ lea!r 0 br[ni%-grey 9 col\r1 possess$ s(t & full feel & good t5sile /r5g?4 ,on acc\nt ( _! importance1 ! ?ree dihydroxyb5z5es 7 exam9$ ) a view to te/ _! suitability = conv]sion into tannoid sub/ances4 o-,dihydroxyb5z5e1 cate*ol1 yields a sulphonic acid easily soluble 9 wat]1 :i* on ! c>eful addition ( =maldehyde assumes a blue col\r4 ,! comp\nd ?us obta9$ may be heat$ to #ajj ,c41 )\t deposit+ insolubles4 ,a fur!r addition ( =maldehyde1 h[ev]1 results 9 ! =mation ( a consid]able quantity ( insolubles :il/ ! liquid assumes a br[n coloration4 ,if1 on ! o!r h&1 ! sulphonic acid is dilut$ ) twice its volume ( wat]1 =maldehyde add$ & ! mixture heat$ on ! wat] ba?1 ! liquid imm$iately turns br[n1 ! =maldehyde is completely fix$1 & a cond5sation product soluble 9 wat] results4 ,! latt] gives a br[ni%-black coloration ) f]ric *loride1 completely precipitates gelat9e1 b gives no opalesc5ce ) anil9e hydro*loride4 ,tann+ exp]im5ts ) ! p>tly neutralis$ 7#a gm4 #aj c4c4 ,n_/#aj ,na,o,h7 sub/ance result$ 9 bo? gra9 & fle% be+ tann$ ) a black col\r1 :]eas ! int]ior ( ! pelt 0 pickl$ 7:ite col\r74 ,aft] a fur!r =ty-eight h\rs1 h[ev]1 ! black col\r p5etrat$ ! pelt1 & tannage 0 complete4 ,! wa%$ & lightly fat-liquor$ lea!r 0 s(t1 ( full feel & good t5sile /r5g?1 & 0 greyi% col\r$ ?r\gh\t4 ,) reg>d to ! black col\r possess$ by lea!rs tann$ ) syn!tic tann9s ! foll[+ %\ld be not$4 ,:5 sulphonat+ & especially :5 cond5s+ sub/ances1 black dye/uffs or v f9ely divid$ c>bon 9 ! colloidal /ate are (t5 =m$4 ,su* a sub/ance does n deposit ! black p>ticles1 ev5 :5 filt]$ ?r\gh kaol91 & h5ce conv]t pelt into lea!r possess+ black col\r on ! surface4 ,! hide 9 ?is case acts z a p]fect filtration m$ium1 :]eby ! surface lay]s reta9+ ! col\r$ p>ticles assume _! col\r2 ?us only ! pure tann+ matt] ent]s into ! int]ior1 :i* !n1 accord+ to ! composition ( ! =m]1 imp>ts a col\r v>y+ f :ite to light br[n to ! inn] lay]s4 m-,dihydroxyb5z5e1 resorc9ol1 is also easily sulphonat$ by conc5trat$ sulphuric acid1 ! br[ni%-col\r$ sulphonic acid be+ easily soluble 9 wat]4 ,if ! sulphonic acid is dilut$ ) ?ree times its volume ( wat]1 cool$ d[n1 a few drops ( =maldehyde add$ & ! mixture heat$ on ! wat] ba? to completely fix ! =maldehyde1 & ?is process repeat$ till no m =maldehyde is tak5 up1 a br[n wat]-soluble cond5sation product results1 ! aque\s solution ( :i* precipitates gelat9e completely1 anil9e hydro*loride only p>tly & :i* gives a deep blue col\r ) f]ric *loride4 ,a piece ( calf sk9 imm]s$ 9 a solution ( ! p>tly neutralis$ 7z above7 product 0 tann$ ?r\gh 9 tw5ty-f\r h\rs2 :5 lightly fat-liquor$1 ! result+ lea!r possess$ a yell[i%-gre5 col\r & good t5sile /r5g?1 & 0 s(t & full4 p-,dihydroxyb5z5e1 hydroqu9one1 0 conv]t$ into ! wat]-soluble sulphonic acid by heat+ x ) conc5trat$ sulphuric acid at #ajj ,c42 ! sulphonic acid1 mix$ ) =maldehyde at ord9>y temp]ature1 imm$iately solidifies to a :ite mass1 :i* is soluble 9 wat] & :i* _h completely fix$ ! =maldehyde4 ,if1 h[ev]1 ?is mass is heat$ = "s "t to #ajj;,c1 x assumes a light br[n coloration & its solubility 9 wat] is dim9i%$4 ,a slight excess ( =maldehyde & ! application ( heat result 9 d>k violet insoluble cond5sation products4 ,! aque\s solution precipitates gelat9e1 gives a deep blue col\r ) f]ric *loride1 b gives no precipitate ) anil9e hydro*loride2 on ! o!r h&1 addition ( potassium nitrite produces ! yell[ col\r *>act]i/ic ( hydroqu9one4 ,! product effects a sl[] tannage 7sev5 days7 ?an ! =m] product1 :5 a br[n1 s(t1 b r empty lea!r ( good t5sile /r5g? is obta9$4 ,( ! trihydroxyb5z5es pyrogallol & phlorogluc9ol only 7 includ$ 9 ^! inve/igations4 ,:5 pyrogallol is sulphonat$ ) conc5trat$ sulphuric acid a violet-col\r$ sulphonic acid1 soluble 9 wat]1 is obta9$1 :i*1 :5 treat$ ) =maldehyde fir/ 9 ! cold & !n :5 heat$1 yields a solid deep r$-col\r$ mass1 :i* precipitates gelat9e b n anil9e hydro*loride1 & gives a blacki%-br[n col\r ) f]ric *loride4 ,! p>tly neutralis$ sub/ance 9 aque\s solution tans pelt 9 tw5ty-f\r h\rs ) black col\r on ! surface only1 ! int]m$i>y lay] be+ pickl$ 7:ite col\r7 only1 b ! black-col\r$ tann+ matt] ultimately p5etrates ! pelt1 :i* tann$ ?r\gh 9 sev5 days4 ,! resultant lea!r is col\r$ black ?r\gh\t1 is full1 s(t1 & possesses good t5sile /r5g?4 ,sulphonation ( phlorogluc9ol succe$s at high] temp]atures only1 ! sulphonic acid be+ a solid :i* is sc>cely soluble 9 wat]1 ! latt] !n assum+ a w9e-r$ col\r4 ,! cond5sation product--prep>$ z describ$ = resorc9ol1 b requir+ high] temp]ature--is a brick-r$ p[d]1 insoluble 9 wat]4 ,! same end-product also seems to be obta9$ by simply heat+ ! sulphonic acid at a high] temp]ature2 ?is also induces cond5sation ) ! =mation ( a r$di%-br[n mass insoluble 9 wat]4 ,x is1 ( c\rse1 impossible to attempt any tann+ exp]im5ts ) ?is product 9 aque\s solution2 attempts at dissolv+ ! cond5sation product 9 alcohol prov$ b>r5 ( result1 s9ce only traces ( impurities accompany+ ! sub/ance dissolv$1 imp>t+ a light r$di%-br[n col\r to ! solution4 ,9 highly conc5trat$ alcohol1 h[ev]1 ! cond5sation product is some:at soluble1 yield+ a r$di%-br[n solution4 ,a piece ( pelt introduc$ into ! alcoholic solution 0 surface tann$ only aft] =ty-eight h\rs1 leav+ ! rema9d] ( ! pelt pickl$2 ext5d+ ! exp]im5t ov] a fur!r f\r days produc$ no *ange 9 ! pelt4 ,! latt] 0 !re=e r9s$ ) wat]1 lightly fat-liquor$ & dri$1 :5 a s(t b empty lea!r ( grey col\r & good t5sile /r5g? 0 obta9$4 ,x appe>s1 !re=e1 to be a case ( pseudo-tannage1 :]e an inf9itesimal am\nt ( syn!tic tann9 produces a tann+ effect )\t1 h[ev]1 a true tannage be+ effect$4 ,! ,elb]feld] ,f>b5fabrik5 h protect$ ! use ( ! cond5sation products ( di- & polyhydroxyb5z5es by ,g]4 ,pat41 #bhb1cac2 ow+ to ! high co/ ( ! latt] sub/ances1 h[ev]1 x is d\btful :e!r syn!tic tann9s prep>$ f ^! mat]ials w\ld n be too exp5sive = any o!r ?an ph>maceutical purposes4 ,be=e leav+ ! ph5ols1 m5tion mu/ be made ( ! qu9ones1 ! use ( :i* = tann+ purposes 0 fir/ protect$ by ,g]4 ,pat41 #bjf1ieg 7#cj? ,april #aijg74 ,accord+ to ?is pat5t1 only #djj gm4 ( qu9one are requir$ = ! conv]sion into lea!r ( #djj kilos pelt1 drum tannage be+ pref]able4 ,dur+ ! process ! lea!r fir/ assumes a r$di% col\r1 *ang+ ?r\gh violet to br[n2 its resi/ance to wat]1 acids1 & alkalies is said to be consid]ably great] ?an t exhibit$ by all o!r k9ds ( lea!r4 ,! *emi/ry ( ! qu9one tannage has be5 inve/igat$1 & an explanation giv5 by ,?uau ,footnote3 ,collegium1 #aiji1 #cfc1 #baa4 assumes a reaction betwe5 ! qu9one & ! am9o gr\ps ( ! hide prote9 ) ! =mation ( hydroqu9one-- -,o ,,oh #b,r4,,nh#b #b;,c#h;,h#d ,c#f;,h#d ,c#f;,h#d7,o4,,nh4,r7#b -,o ,,oh 7,pelt47 7,lea!r47 ,fahrion has %[n t1 dur+ ! tann+ process1 ! qu9one loses its active oxyg51 & ?is c only be br\ght ab\t by ! am9o gr\p ( ! hide prote91 ! am9o gr\p only be+ capable ( effect+ r$uction ( ! qu9one4 ,an analogy is "h (f]$ by dianil9oqu9one4 ,a sp5t qu9one liquor conta9s consid]able am\nts ( hydroqu9one4 ,! tannage may also be effect$ by expos+ pelt saturat$ ) hydroqu9one to oxidation by ! air4 ,! pelt1 :i* is unalt]$ by ! hydroqu9one ba?1 on be+ remov$ f ! latt]1 & 9 ! pres5ce ( alkali1 assumes a r$ col\r at fir/1 :i* *anges into violet1 blue1 & f9ally br[n1 ! pelt be+ !reby conv]t$ into a qu9one-tann$ lea!r4 ,x may be not$ t qu9one only effects pseudo-tannage2 qu9one mix$ ) wat] deposits1 9 "t1 a black amorph\s sub/ance practically insoluble 9 wat]4 ,?is sub/ance is easily adsorb$ by hide p[d]1 b is n capable ( conv]t+ ! latt] into t insoluble =m into :i* x is conv]t$ by ! natural tann9s4 ,among/ polyhydric alcohols1 ! behavi\r ( ! me?yl e/] ( cate*ol1 guaiacol 0 inve/igat$4 ,! sulphonic acid 0 prep>$ by heat+ guaiacol ) conc5trat$ sulphuric acid1 ! result+ wat]-soluble product possess+ a light1 br[ni%-gre5 col\r4 ,on cond5s+ ! sulphonic acid ) =maldehyde1 ! same precautions 7 obs]v$ z 9 ! case ( resorc9ol1 b complete fixation ( ! =maldehyde c\ld only be obta9$ by f9ally heat+ ! product = a %ort "t ov] a free flame1 at ab\t #aje ,c4 ,cond5sation 0 indicat$ by ! br[ni% appe>ance ( ! liquid4 ,no insoluble products 7 =m$4 ,! cond5sation product easily dissolves 9 wat]1 ! solution assum+ a ri* br[n col\r & exhibit+ ! foll[+ reactions3 gelat9e is completely precipitat$1 anil9e hydro*loride produces opalesc5ce1 & f]ric *loride a deep br[n coloration4 ,tannage1 ) ! p>tly neutralis$ product1 0 rapid1 ! pelt be+ ne>ly tann$ ?r\gh 9 tw5ty-f\r h\rs1 except+ a small :ite /reak 9 ! middle2 aft] a fur!r tw5ty-f\r h\rs ?is /reak _h vani%$1 & ! completely tann$1 d>k grey-col\r$ lea!r1 aft] wa%+1 fat-liquor+1 & dry+1 0 s(t1 full1 & ( good t5sile /r5g?1 v simil> to ! lea!r yield$ by ! cate*ol-cond5sation product4 ,( ! nitro-comp\nds1 tr9itroph5ol1 ,c#f;,h#b7,,no#b7c,,oh 7picric acid71 0 inve/igat$4 ,if a conc5trat$ solution ( picric acid is br\ght into contact ) pelt x w p5etrate ! latt] completely 9 a few days2 x is1 h[ev]1 difficult to fat-liquor ! resultant lea!r1 s9ce ! fat is absorb$ only ) difficulty4 ,if a pelt treat$ 9 ?is way be dri$1 a s(t b r flat lea!r results1 ! col\r ( :i* easily rubs (f1 ! lea!r also ta/+ int5sely bitt]4 ,^! disagreeable qualities prev5t a g5]al use ( ?is mat]ial = tann+ purposes2 9 spite ( !m1 h[ev]1 picric acid1 9 admixture ) boracic acid1 salicylic acid1 & glyc]ol1 is us$ 9 ! production ( ! s-call$ transp>5t lea!r4 ,! latt] is v flexible & possesses great t5sile /r5g?1 b loses ! latt] quality :5 expos$ to heat1 &1 :5 /or$1 also loses its flexibility4 ,by simply wa%+ ) wat]1 ! lea!r is reconv]t$ into pelt4 ,:5 picric acid is treat$ ) hot sulphuric acid & =maldehyde gradually add$1 a d>k col\r$ wat]-soluble cond5sation product is =m$ :i* /rongly precipitates gelat9e4 ,expos$ to ! action ( brom9e1 ! cond5sation product yields a mass :i* is insoluble 9 wat]4 ,exp]i5ce has taught t ! am9o bodies--! basic ,n-d]ivatives ( ! ph5ols--d n yield sub/ances possess+ tannoid prop]ties on cond5sation4 ,on acc\nt ( _! importance1 h[ev]1 a few h be5 includ$ 9 ?is s]ies ( inve/igations4 ,am9ob5z5e1 ,c#f;,h#e,,nh#b1 anil9e1 treat$ ) sulphuric acid1 yields ! wat]-soluble anil9e sulphate1 :i*1 on cauti\s addition ( =maldehyde1 yields a r$di%-col\r$ gel1 insoluble 9 wat]1 9 addition to a small volume ( a r$di%-yell[ liquid4 ,! latt] precipitates gelat9e1 b is n capable ( conv]t+ pelt into lea!r4 ,! insoluble gel is likewise insoluble 9 alcohol1 s t tann+ exp]im5ts ) ?is sub/ance are exclud$4 ,dime?ylanil9e1 ,c#f;,h#e,n7,,*#c7b1 :5 treat$ ) sulphuric acid1 yields a product soluble 9 wat] :i* nei!r reacts ) nor fixes =maldehyde4 ,h5ce ! sub/ance does n precipitate gelat9e4 ,if1 on ! o!r h&1 nitrosodime?ylanil9e1 ,,no ,c#f;,h#d 7,,*#c7b is sulphonat$1 & ! wat]-soluble sulphonation product heat$ ) =maldehyde = "s "t1 ! product rema9s soluble 9 wat] & precipitates gelat9e4 ,no tann+ effect c\ld1 h[ev]1 be detect$4 ,arylsulpham9o>ylsulphonic acids & arylsulphoxy>ylsulphonic acids precipitate gelat9e b are devoid ( tannoid "*4 ,! latt] is acquir$ by comp\nds belong+ to ?is class conta9+ two or m sulpham9o gr\ps1 or :5 !y1 9 addition to "o sulpham9o gr\p1 conta9 a sulphoxy gr\p & ano!r sulphonic gr\p4 ,accord+ to ,g]4 ,pat41 #big1ahg 7,society oc ,*emical ,indu/ry1 ,basle71 su* comp\nds are obta9$ :51 = in/ance1 sodium sulphanilide 9 alkal9e solution acts ^u nitrotolu5esulpho*loride1 & ! result+ nitrotolu5esulpham9o comp\nd is subsequ5tly r$uc$ ) acetic acid & iron4 ,! result+ am9otolu5esulpham9ob5z5esulphonic acid is f9ally treat$ ) p-tolu5esulphonic *loride till ! latt] disappe>s4 ,a comp\nd ( ! composition -----,,nh-----,,s#b----- ---,,nh--- ,v ,v ,v ,,s#b,na ,,*#b is !reby obta9$1 :i*1 :5 acidifi$1 is readily capable ( be+ us$ = tann+ purposes4 ,! int]m$i>y product ( ! am9otolu5esulpham9ob5z5esulphonic acid obta9$ by ?is process may aga9 be employ$ = ! purpose ( react+ ) "o-half molecule soda & #a molecule nitrotolu5esulphonic *loride4 ,! foll[+ comp\nd is obta9$-- ---,,nh---,,s#b--- ---,,nh---,,s#b--- ,,*#c v v ---,,nh---,,s#b--- v v ,,s#c,na ,,*#c ,,*#c ,if p-tolu5esulpham9ob5z5esulphonic *loride is cond5s$ ) sodium sulphanilide1 a comp\nd1 ---,,s#b---,,nh--- ,na,s,o#c v v ---,,s#b---,,nh--- v ,,s#c,na is obta9$ :i*1 :5 acidifi$1 exhibits tannoid prop]ties4 ,on cond5s+ sodium ph5olsulphonate ) nitrotolu5esulphonic *loride1 r$uc+ ! cond5sation product & cond5s+ ! latt] ) p-tolu5esulphonic *loride1 a comp\nd simil> to ! above is obta9$-- ---,o---,,s#b--- ,,*#c v v ---,,nh---,,s#b--- v ,na,s,o#c ,,*#c ,aga91 a simil> product is obta9$ :5 p-tolu5esulpham9ob5z5esulphonic *loride or its homologues or isom]s are cond5s$ ) sodium-o-cresylsulphonate-- ---,,s#b---,,nh--- ,,s#c,na ,,*#c v v ---,,s#b---,o--- v ,,*#c ,! *loride ( ?is comp\nd may aga9 be cond5s$1 = in/ance1 ) sodium am9otolu5esulpham9ob5z5e-sulphonate1 & yields ! comp\nd-- ---,,nh---,,s#b--- ---,,nh---,,s#b--- v v ---,,nh---,,s#b--- v v ,,* ,na,s,o#c ,,*#c ,! ?ree latt] comp\nds1 :5 dissolv$ 9 wat] & ! solution acidifi$1 ex]t tann+ action4 ,x is also possible to employ mixtures ( arylsulpham9ob5zylsulphonic acids 9 acidifi$ aque\s solution = tann+ purposes4 ,accord+ to ,g]4 ,pat41 #big1ahh1 su* mixtures are obta9$ by nitrat+ b5zyl*loride & heat+ ) an equimolecul> am\nt ( sodium sulphite2 ! sodium nitrob5zylsulphonate ?us obta9$ is r$uc$ to am9ob5zylsulphonic acid ) iron & acetic acid1 & f9ally cond5s$ ) ! calculat$ am\nt ( p-tolu5esulphonic *loride4 ,a mixture o- & p-tolu5esulpham9ob5zylsulphonic acid ,footnote #a3 ,cf4 also ,g]4 ,pat1 #cai1gac & #cbj1fac4 ?us results4 ,among/ aromatic alcohols ! dihydric alcohols %[ *>act]i/ic behavi\r2 ! latt] comb9e ) sulphonic acids ) ! elim9ation ( wat]1 cond5sation tak+ place )\t =maldehyde1 & ! result+ products be+ soluble 9 wat] & possess+ tannoid prop]ties4 ,footnote #b3 ,g]4 ,pat41 #cjj1efg1 ( #bj? ,septemb] #aiag4 ,9 addition to ph5olic mono- & disulphonic acids 7& high] sulphonation comp\nds71 ! homologues1 cresols1 xyl5ols1 & naph?ols ent] into reaction4 ,! two compon5ts cond5se ) great ease1 lib]at+ heat2 dilute solutions 7( ! compon5ts7 are heat$ to ab\t #ajj ,c41 ! process be+ complete 9 a few m9utes4 ,! products obta9$ are exce$+ly pure & are easily cry/allisable4 ,employ+ #a1 respectively #b1 molecules ( sulphonic acid1 ! reactions take place accord+ to3-- ,,oh ,,*#b4,,oh ,,oh ,,oh ,c#f;,h#d ,,ho4,c#f;,h#c ,h#b,o ,c#f;,h#c-;,,*#b-;,c#f;,h#c ,,hso#c ,,*#b4,,oh ,,hso#c ,,*#b4,,oh ,,oh ,,oh ,,*#b4,,oh ,,*#b4;,c#f;,h#c ,c#f;,h#d ,,ho4,c#f;,h#c #b7;,h#b,o7 ,,ho4,c#f;,h#c ,,hso#c ,,hso#c ,,*#b4,,oh ,,oh ,,*#b4;,c#f;,h#c ,,hso#c ,,oh ,,*#b4,,oh ,,oh ,,oh ,c#f;,h#c4;,,*#c ,,ho4,c#f;,h#c ,h#b,o ,c#f;,h#b4;,,*#c4;,,*#b4;,c#f;,h#c ,,hso#c ,,*#b4,,oh ,,hso#c ,,*#b4,,oh ,,oh ,,oh ,,*#b4,,oh ,,*#b4;,c#f;,h#b4;,,*#c ,c#f;,h#c4;,,*#c ,,ho4,c#f;,h#c #b7;,h#b,o7 ,,ho4,c#f;,h#c ,,hso#c ,,hso#c ,,*#b4,,oh ,,oh ,,*#b4;,c#f;,h#b4;,,*#c ,,hso#c ,,oh ,,*#b4,,oh ,,oh ,,oh 7,c#aj7;,h#f ,,ho4,c#f;,h#c ,h#b,o 7,c#aj7;,h#e4;,,*#b4;,c#f;,h#c ,,hso#c ,,*#b4,,oh ,,hso#c ,,*#b4,,oh ,,oh ,,oh ,,*#b4,,oh ,,*#b47;,c#aj7;,h#e 7,c#aj7;,h#f ,,ho4,c#f;,h#c #b7;,h#b,o7 ,,ho4,c#f;,h#c ,,hso#c ,,hso#c ,,*#b4,,oh ,,oh ,,*#b47;,c#aj7;,h#e ,,hso#c ,! cond5sation products above enum]at$ 7 te/$ ) reg>d to _! tann+ p[]1 bo? non-neutralis$ & p>tly neutralis$ 7#a3aj1 #a3bj1 & #a3cj c4c4 ,n_/#aj ,na,o,h7 samples be+ exam9$4 ,9 all cases rapid tannage 0 obs]v$ yield+ firm & s(t lea!rs ( light br[n col\r & v>y+ degrees ( swoll5ness4 ,relatively to _! reactions1 all ! products /rongly precipitate gelat9e1 :]eas only ! cond5sation products ( ph5ol1 cresol1 & xyl5ol d]ivatives give a *>act]i/ic coloration ) iron salts4 ,! tann9 cont5ts ( ! non-neutralis$ cond5sation products lie betwe5 #gb-hj p] c5t4--figures :i* cle>ly indicate ! purity & effici5cy ( ^! sub/ances4 ,notable among/ aromatic acids is salicylic acid1 ,c#f;,h#d4,,oh4,,cooh1 :i* at high] temp]atures is easily sulphonat$ ) conc5trat$ sulphuric acid2 ! sulphonation product repres5ts a :ite solid1 :i* easily dissolves 9 wat] =m+ a cle> liquid4 ,! sulphonic acid1 :5 mix$ ) ab\t "o-?ird ( its weight ( wat] & heat$ to ab\t #abj ,c41 is easily cond5s$ ) =maldehyde4 ,t[>ds ! end ( ! reaction1 consid]able fro?+ sets 91 b 9 spite ( ! high temp]ature requir$ by ?is reaction no insoluble bakelites are =m$4 ,a r$di%-br[n fluid is obta9$ easily soluble 9 wat]1 to :i* x imp>ts a br[n col\r4 ,an aque\s solution ( ! product completely precipitates gelat9e1 gives a /rong opalesc5ce ) anil9e hydro*loride & a deep violet coloration ) f]ric *loride4 ,neutralis$ z usual1 ! product1 9 a #c ,b solution1 conv]ts pelt )9 ?ree days into a :ite1 full lea!r ( good t5sile /r5g?4 ,?is process has be5 pat5t$ by ! ,deuts*-,koloniale ,g]b und ,f>b/(f ,gesells*aft 7,g]man-,colonial ,tann+ & ,col\r ,extracts ,ltd47 9 ,k>lsruhe1 ! lett]s pat5t also includ+ ! r+ homologues ( salicylic acid4 ,simil> results are obta9$ :5 cresot9ic acid 7hydroxy-toluic acid71 ,,oh4,c#f;,h#c4;,,*#c4;,,cooh1 is employ$ z base4 ,if ! ph5yl e/] ( salicylic acid1 ,salol1 ,,ho4,c#f;,h#d4;,,co4,o4,c#f;,h#e is sulphonat$1 a product is obta9$ :i* is easily soluble 9 wat]1 b :i* is id5tifi$ z a mixture ( ! sulphonation products ( salicylic acid & ph5ol1 ! salol be+ dissociat$ on sulphonation4 ,! temp]ature mu/ n exce$ #hj ,c4 by cond5sation ) =maldehyde1 or insoluble bakelite w be =m$ f ! ph5ol2 ! aldehyde mu/ also be add$ gradually4 ,an aque\s solution ( ! p>tly neutralis$ cond5sation product has a pron\nc$ tann+ effect on pelt1 & conv]ts ! latt] into lea!r 9 "o to two days2 ! lea!r be+ v simil> to t produc$ by ! salicylic acid cond5sation product4 ,! qualitative reactions ( ! product 9 aque\s solution are ! same z ^? giv5 by ! salicylic acid cond5sation product4 ,salicylic acid may1 h[ev]1 also be cond5s$ ) =maldehyde )\t fir/ be+ sulphonat$2 9 ?is case1 a little hydro*loric acid %\ld be pres5t4 ,a product slightly soluble 9 wat] is obta9$1 :i* may be look$ ^u z be+ me?yl5$isalicylic acid4 ,9 alkal9e solution x is easily soluble1 ,footnote #a3 ,its solubility 9 alcohol & alkalies r5d]s ?is product an effective & *eap sub/itute = %ellac4--,transl4 ! liquid possess+ an int5sely bitt] ta/e4 ,! sodium salt gives a deep violet coloration ) f]ric *loride1 a slight precipitate ) gelat9e1 & slight opalesc5ce ) anil9e hydro*loride4 ,9 contact ) pelt1 h[ev]1 x exhibits no tann+ effect1 b :5 dissolv$ 9 alcohol1 a pickl+ effect may be obs]v$4 ,footnote #b3 ,a simil> reaction is obs]vable 9 ! case ( ! sodium salts ( ,,me?yl5$isalicylic acid brommat$ or iodis$1 :i* =m a cle> solution v>y+ f r$ to r$di%-br[n4 ,! attempt at prep>+ a cond5sation product f sodium-m-hydroxyb5zoate by means ( =maldehyde & bisulphite is wor?y ( att5tion4 ,a d>k br[n1 visc\s liquid is obta9$ :i* is p]fectly soluble 9 wat]1 & ! aque\s solution ( :i* gives opalesc5ce ) gelat9e1 a precipitate ) anil9e hydro*loride1 & a blui%-black coloration ) f]ric *loride4 ,its behavi\r t[>ds pelt is v simil> to t ( ph5olsulphonic acid1 & x yields a simil> lea!r4 ,a v simil> cond5sation product 0 obta9$ by cond5s+ sodium-p-hydroxyb5zoate ) =maldehyde & subsequ5t sulphonation ) sulphuric acid4 ,f a practical /&po9t1 h[ev]1 ^! sub/ances _c be employ$1 s9ce _! tann+ action is only effective 9 acid solutions ( su* conc5tration ( acid z w\ld gelat9ise ! pelt4#c ,if1 on ! o!r h&1 non-cond5s$ me?ane d]ivatives ( ph5ol1 e4g41 hydroxyph5ylme?anesulphonic acid1 are p>tly neutralis$ & a solution ( ! product ?us obta9$ us$ = tann+ exp]im5ts1 no tann+ action is obs]vable4 ,! acidifi$ solution does n precipitate gelat9e1 & gives a d>k br[n coloration only ) f]ric *loride4 ,,gallic ,,acid1 ,c#f;,h#b7,,oh7#c;,,cooh1 :5 heat$ ) sulphuric acid1 is easily conv]t$ into ! insoluble rufigallic acid1 :i* is also insoluble 9 alcohol4 ,if1 h[ev]1 gallic acid is heat$ ) an excess ( sulphuric acid1 ! product cool$ & treat$ ) =maldehyde1 a deep br[n cond5sation product is obta9$ :i* is soluble 9 alcohol1 & 9 ?is /ate is capable ( conv]t+ pelt into a sub/ance simil> to lea!r :i*1 ?\gh r h>d1 possesses good t5sile /r5g?4 ,?is wat]-insoluble cond5sation product is also soluble 9 alkalies1 ! solution exhibit+ prop]ties simil> to t describ$ above4 ,gallic acid1 !re=e1 is n a suitable base = ! production ( syn!tic tann9s soluble 9 wat]4 ,ph?alic acid also is difficult to sulphonate3 ! sulphonat$ comp\nd treat$ ) =maldehyde gives only wat]-insoluble cond5sation products4 #c4 ,cond5sation ,( ,naph?al5e ,d]ivatives ,! simple/ me?od ( cond5s+ ,greek3 b-naph?al5e-sulphonic acid is to heat x at #ace ,c4 at a pressure ( #bj mm4 = sev]al h\rs4,footnote3 ,au/r4 ,pat41 #fa1jfa1 ( #aj? ,septemb] #aiac4 ,! result+ product is a *eesy mass :i* reacts /rongly acid4 ,by r$uc+ ! acidity ( ! sub/ance to #a gm4 #aj c4c4 ,n_/#a,o ,na,o,h1 a grey1 *eesy mass results1 :i* easily dissolves 9 wat]1 ! solution be+ col\r$ a light yell[-br[n & precipitat+ gelat9e anil9e hydro*loride2 no coloration1 h[ev]1 appe>s on add+ f]ric *loride4 ,! cond5sation ( ,greek3 b-naph?al5esulphonic acid1 h[ev]1 proce$s ) mu* great] en]gy 9 ! pres5ce ( =maldehyde4 ,9 practice1 = in/ance1 #aj kilos ( naph?al5e is heat$ ) ! same weight ( conc5trat$ sulphuric acid 7#ff ,b71 :5 ! mixture is conv]t$ into ,greek3 b-naph?al5esulphonic acid by heat+ = sev]al h\rs at #aej-afj ,c2 ! sulphonation complet$1 ! sulphonic acid is cool$ to ab\t #he ,c41 & #d kilos ( =maldehyde 7#cj p] c5t1 by weight7 sl[ly add$2 f9ally1 ! product is /irr$ at ! temp]ature m5tion$ till all =maldehyde has comb9$4,footnote3 ,au/r4 ,pat41 #fi1aid1 ( #be? ,june #aiae2 ,g]4 ,pat1 #bij1ife4 ,tann+ exp]im5ts ) ?is product yield$1 9 a %ort "t1 a ne>ly :ite col\r$ lea!r 7see lat]74 ,9 addition to =maldehyde1 !re are o!r sub/ances :i* induce cond5sation ( naph?al5esulphonic acid2 if1 = in/ance1 sulphur *loride is all[$ to act ^u ,greek3 b-naph?al5esulphonic acid1 a light br[n solid ( pron\nc$ acidic "* is obta9$2 if ! latt] is p>tly neutralis$ ) cau/ic soda1 a greyi%-br[n solid results1 :i* dissolves 9 wat] ) a light br[n col\r1 ! solution precipitat+ gelat9e & anil9e hydro*loride1 b giv+ no coloration ) f]ric *loride4,footnote3 ,au/r4 ,pat41 #if1aid4 ,tann+ exp]im5ts ) ?is product 9 aque\s solution gave a light br[n1 r s(t lea!r1 & ?is1 9 addition to ! qualitative reactions ( ! sub/ance1 prove t ?is me?od ( cond5sation h>dly alt]s ! "* ( ! product f a tann+ po9t ( view4 ,! br[n coloration imp>t$ to ! lea!r tann$ ) ?is cond5sation product owes its exi/5ce to col\r$ int]m$i>y products4 ,attempts at cond5s+ *loronaph?al5esulphonic acid & nitronaph?al5esulphonic acid result$ 9 soluble cond5sation products :i* gave "s ( ! reactions giv5 by ! tann9s 7precipitation ( gelat9e & anil9e hydro*loride71 b :i* 7 incapable ( tann+ pelt1 a light tannage be+ effect$ on ! surface only4 ,greek3 a-,naph?ol dissolv$ 9 hot conc5trat$ sulphuric acid & heat$ = "s "t on ! wat] ba?1 yields ! light br[n1 wat]-soluble ,greek3 a-naph?olsulphonic acid4 ,a dilute solution ( ! latt]1 :5 treat$ ) =maldehyde 9 ! cold1 und]goes no *ange2 on heat+ ! mixture on ! wat] ba? a br[n precipitate is ?r[n d[n4 ,if gelat9e solution is add$ to ! opaque liquid1 a yell[ floccul5t precipitate sep>ates4 ,if cau/ic soda is add$ to ! opaque liquid conta9+ ! cond5sation product describ$ above1 a cle> solution results f :i* no deposit sep>ates on ! addition ( acetic acid4 ,gelat9e is precipitat$ by ?is solution4 ,! conc5trat$ hot a-naph?olsulphonic acid1 ^u addition ( suffici5t =maldehyde1 eff]vesces /rongly & yields a d>k br[n cond5sation product insoluble 9 wat]1 b soluble 9 cau/ic soda4 ,if acetic acid is add$ 9 excess to ! alkal9e solution1 ! resultant solution /rongly precipitates gelat9e4 ,a susp5sion 9 wat] ( ! insoluble cond5sation product does n precipitate gelat9e4 b-,naph?ol1 dissolv$ 9 hot conc5trat$ sulphuric acid & heat$ = "s "t1 yields ! light br[n1 visc\s b-naph?olsulphonic acid4 ,a dilute solution ( ! latt]1 mix$ ) =maldehyde1 rema9s cle>2 :5 heat$ on ! wat] ba?1 h[ev]1 x assumes a d>k1 r$di%-yell[ col\r1 & rema9s soluble 9 wat] & precipitates gelat9e /rongly4 ,?is cond5sation product1 on add+ excess ( cau/ic soda1 assumes a deep blue coloration1 ! alkal9e solution giv+ no precipitate ) gelat9e2 on add+ acetic acid ! solution turns br[n1 rema9s cle>1 & n[ precipitates gelat9e4 ,! conc5trat$ b-naph?olsulphonic acid heat$ ) =maldehyde on ! wat] ba? yields z cond5sation product a d>k1 r$di%-yell[ mass1 soluble 9 wat]1 :i* precipitates gelat9e4 ,a dilute solution1 :5 all[$ to act ^u pelt1 gave 9 a few days a light br[n lea!r1 ! prop]ties ( :i* are v simil> to ^? possess$ by vegetable tann$ lea!rs4 ,! use ( naph?olsulphonic & am9onaph?olsulphonic acids = ! manufacture ( syn!tic tann9s is protect$ by ,g]4 ,pats41 #bic1fdj1 #bic1fic1 #bic1jdb1 & #cjc1fdj4 ,footnote3 ,cf4 ,au/r4 ,pat41 #gj1afb4 ,x is a rem>kable fact t non-cond5s$ me?ane d]ivatives ( naph?ol1 e4g41 b-naph?ol-a-me?anesulphonic acid1 dissolv$ 9 wat] & p>tly neutralis$1 are devoid ( tann+ "* :5 all[$ to act ^u pelt4 ,nei!r does ?is sub/ance precipitate gelat9e1 b x does give a deep blue coloration ) f]ric *loride4 ,! cond5sation product ( b-naph?ol above ref]r$ to precipitates gelat9e & anil9e hydro*loride & gives a br[n coloration ) f]ric *loride4 ,?ionaph?olsulphonic acid1 :5 act$ ^u by =maldehyde1 yields a cond5sation product ( ! foll[+ con/itution3-- ,,hso#d ,,% ,,% ,,hso#d ,,*#b v v v v ,?is is a light yell[ p[d] :i*1 dissolv$ 9 wat]1 yields an opaque solution2 ! latt] only exhibits any tann+ prop]ties :5 x is n neutralis$ & ev5 slightly acidifi$ & !n precipitates gelat9e1 anil9e hydro*loride & b>ium *loride2 dissolv$ 9 alkali1 x =ms a cle>1 yell[ solution devoid ( tannoid prop]ties4 ,lea!r tann$ ) ! acidifi$ solution is v simil> to ^? tann$ ) ! ph5olsulphonic acid cond5sation products2 its col\r1 h[ev]1 is m pron\nc$ly yell[4 b-,naph?ol cond5s$ ) hydro*loric acid & =maldehyde yields a me?yl5$9aph?ol1 :i* is insoluble 9 wat]2 ! sodium salt1 h[ev]1 easily dissolves4 ,! same cond5sation1 h[ev]1 takes place 9 alkal9e solution ) direct =mation ( ! sodium salt4 ,! cond5sation product gives a slight precipitate ) gelat9e1 & a blui%-grey precipitate ) f]ric *loride2 acids re-precipitate ! insoluble me?yl5e comp\nd4 ,t[>ds pelt x exhibits tann+ prop]ties1 :]eby ! insoluble product ref]r$ to above is deposit$1 & s(t1 full1 & :ite lea!r is obta9$1 possess+1 h[ev]1 b little t5sile /r5g?4 #d4 ,cond5sation ( ! ,an?rac5e ,gr\p ,an?rac5e heat$ ) excess sulphuric acid yields ! wat]-soluble an?rac5esulphonic acid2 ! latt]1 :5 heat$ ) =maldehyde1 yields wat]-soluble1 r$di%-br[n cond5sation products1 :i* rema9 soluble on prolong$ heat+ ) =maldehyde4 ,! aque\s solution ( ! cond5sation product %[s no p>ticul> reactions2 x gives a floccul5t precipitate ) gelat9e & a gre5 precipitate ) copp] sulphate1 soluble ) blue col\r 9 excess ( ! reag5t4 ,! p>tly neutralis$ solution tans pelt--to :i* x imp>ts a br[n col\r--9 eight days1 b on ! surface only2 ! inn] lay]s are m]ely pseudo-tann$ 7:ite col\r74 ,:5 dri$1 pelt ?us treat$ yields a full & s(t lea!r ) br[n gra9 & fle% possess+ b little t5sile /r5g?4 ,h5ce1 ?is cond5sation product ex]ts a pickl+ r ?an a tann+ effect4 ,an?raqu9one heat$ ) sulphuric acid & treat$ ) =maldehyde 9 ! usual mann]1 yields a sub/ance :i*1 :5 mix$ ) wat]1 =ms an opaque1 milky solution4 ,?is is n alt]$ by excess ( cau/ic soda4 ,! aque\s solution precipitates gelat9e & anil9e hydro*loride2 all o!r tann9 reag5ts give no reaction4 ,! p>tly neutralis$ solution ( ! cond5sation product ex]ts1 9 ! ma91 a pickl+ action on pelt2 only ! surface ( :i* is tann$1 ) br[n col\r1 ! rema9d] be+ m]ely pickl$ 7:ite col\r74 ,dur+ tannage1 bakelite is =m$ 9 ! liquid1 & practically all solubles orig9ally pres5t are deposit$4 ,! tannage complet$1 a light br[n1 fairly s(t & full lea!r1 possess+ little t5sile /r5g?1 results2 ?is lea!r c be wa%$ only ) great difficulty & approa*es m ! "* ( a pickl$ pelt4 #a-;,hydroxyan?raqu9one1 #a1e-;di*loroan?raqu9one1 l1#e-;diam9oan?raqu9one1 #a-me?ylam9oan?raqu9one1 #a-;b5zoylam9o1 #f-;*loran?raqu9one1 #a-m-toluidoan?raqu9one1 :5 treat$ ) sulphuric acid & =maldehyde1 all yield cond5sation products :i* are b little soluble 9 wat]1 & :i* d n at all precipitate gelat9e4 ,tann+ exp]im5ts ) ^! cond5sation products 9 alcoholic solution yield$ empty lea!rs ( pron\nc$ pickle "*4 ,if1 h[ev]1 #a-me?ylam9o-#d-;broman?raqu9one is cond5s$ ) sulphuric acid & =maldehyde1 a cond5sation product is obta9$ :i* is b slightly soluble 9 wat]1 b :i* precipitates gelat9e4 ,:5 ph5an?requ9one is heat$ ) excess ( sulphuric acid = "s "t1 a wat]-soluble1 r$di%-yell[ col\r$ cond5sation product results4 ,! latt]1 :5 treat$ ) =maldehyde 9 ! cold & !n f9ally heat$1 gradually fixes ! =maldehyde & =ms a sub/ance soluble 9 wat]4 ,if ! heat+1 h[ev]1 is prolong$1 insoluble bakelites are =m$1 :i* are nei!r soluble 9 alkali nor 9 alcohol4 ,an aque\s solution ( ^! cond5sation products gives no reactions ) ! usual tann9 reag5ts1 ?\gh x completely precipitates gelat9e4 ,:5 act+ ^u pelt1 ! p>tly neutralis$ dilute solution ( ! cond5sation product pickles ! =m]1 & aft] a few days ! pelt is conv]t$ into a light br[n1 full1 & r s(t lea!r possess+ good t5sile /r5g?4 ,:5 ! cond5sation product is act$ ^u by brom9e 9 hot aque\s solution1 an additive comp\nd is =m$ & ! result+ product is soluble 9 wat]4 ,! aque\s solution ( ! brom9at$ product gives no special reactions ) ! usual tann9 reag5ts1 b precipitates gelat9e completely4 ,its tann+ action ^u pelt is mu* sl[] ?an t ( ! orig9al cond5sation product2 ! surface ( ! pelt only is tann$ ) br[n col\r1 ! inn] pelt be+ only pickl$ 7light br[n col\r74 ,:5 dri$1 a h>d & empty lea!r ( good t5sile /r5g? is obta9$1 possess+ ma9ly ! prop]ties ( a pickl$ pelt4 ,,co ,,oh ,,qu9iz>5e1 1 treat$ ) sulphuric acid v v v ,,co ,,oh & =maldehyde1 yields a cond5sation product :i* is b little soluble 9 wat] & :i* does n precipitate gelat9e4 ,,qu9ol9e1 :5 sulphonat$ & cond5s$ ) =maldehyde1 yields a d>k col\r$ cond5sation product1 completely soluble 9 wat]2 ! solution does n precipitate gelat9e4 ,,oxyqu9ol9e exhibits simil> behavi\r4 ,on ! o!r h&1 ! use ( ret5e 7me?ylisopropylph5an?r5e71 ,,*#c ,,*3,,* ,c#c;,h#g v v = ! production ( syn!tic tann9s1 is protect$ by ,g]4 ,pat41 #bij1ife ,footnote #a3 ,cf ,au/r4 ,pat41 #fi1aid #e4 ,di- & ,triph5ylme?ane ,gr\ps ,if ,,diph5ylme?ane1 7,c#f;,h#e7b;,,*#b1 is heat$ ) excess sulphuric acid1 a d>k blue mass1 easily soluble 9 wat]1 is obta9$4 ,! product g5tly heat$ ) =maldehyde yields a br[n1 wat]-soluble cond5sation product2 once cond5sation is complete1 ! product w /& /rong] heat4 ,if1 on ! o!r h&1 m =maldehyde is add$1 br[n1 wat]-insoluble bakelites are =m$4 ,! wat]-soluble cond5sation product precipitates gelat9e1 b n anil9e hydro*loride4 ,dissolv$ 9 wat]1 x possesses tannoid prop]ties3 ! pelt is1 h[ev]1 tann$ on ! surface only1 ! int]m$i>y lay]s be+ m]ely pickl$2 aft] f\r days 9 ! solution1 ! pelt aft] dry+ 0 f\nd to be conv]t$ into a greyi%-br[n1 badly col\r$ lea!r1 :i* 0 empty1 h>d1 & possess$ b little t5sile /r5g?4 ,,c>bazole 7dib5zopyrrole71 v v v ,n#c on ! o!r h&1 0 f\nd a suitable base = ! comm]cial production ( syn!tic tann9s2 its use is protect$ by ,g]4 ,pat1 #bij1ife4 ,,triph5ylme?ane1 7,c#f;,h#e7c;,,*1 heat$ ) excess sulphuric acid1 yields a ne>ly black mass :i*1 :5 cond5s$ ) =maldehyde 9 ! cold1 & subsequ5tly heat$1 yields a mass :i* is soluble 9 wat]4 ,) gelat9e & anil9e hydro*loride x exhibits reactions simil> to ^? giv5 by ! diph5ylme?ane cond5sation products2 its tann+ prop]ties also are simil> to ^? ( ! latt]4 ,! resultant lea!r is black1 b is s(t & full & possesses good t5sile /r5g?4 ,baey]'s obs]vation1 ,footnote3 ,b]41 #ahgb1 #e1 #bhj1 #ajif4 t pyrogallol on cond5sation ) =maldehyde yields an amorph\s body soluble 9 wat]1 :i* precipitates gelat9e & is v simil> to tann91 0 confirm$ by ,c>o ,footnote3 ,ibid41 #ahib1 #be1 #idg4 & ,kahl4 ,footnote3 ,ibid41 #ahih1 #ca1 #aad4 ,^! inve/igators f\nd t by ! cond5sation ( ph5ols & hydroxyb5zoic acids ) =maldehyde1 diph5ylme?ane d]ivatives 7 =m$2 pyrogallol yields hexahydroxydiph5ylme?ane-- ,c#f;,h#b7,,oh7#c ,,*#b ,c#f;,h#b7,,oh7#c ,ni]5/e9 ,footnote3 ,collegium1 #aije1 #bba4 repeat$ ^! exp]im5ts1 & f\nd t 9 addition to ! insoluble diph5ylme?anes1 wat]-soluble bodies 7 =m$1 :i* latt] precipitate gelat9e4 ,! cond5sation product yield$ by gallic acid 0 id5tifi$ z hexahydroxyaur9ec>boxylic acid-- ,c#f;,h7,,oh7#c;,,cooh ,c-,c#f;,h7,,oh7#c;,,cooh ,c#f;,h7,,oh7#b;,,cooh ,o :i* is =m$ 9 addition to hexahydroxydiph5ylme?ane-dic>boxylic acid-- ,c#f;,h7,,oh7#c;,,cooh ,,*#b ,c#f;,h7,,oh7#c;,,cooh ,baey]'s exp]im5t ) pyrogallol probaly also yields1 accord+ to ,ni]5/e91 ano!r comp\nd ( ! foll[+ con/itution-- ,c#f;,h#b7,,oh7#c ,c-,c#f;,h#b7,,oh7#c ,c#f;,h#b7,,oh7#b ,o ,ni]5/e9 consid]s ^! bodies confirmation ( 8 hypo!sis ( ! exi/5ce ( a tannophor1--,,co--1 9 ! tann9s4 ,?is supposition 0 adopt$ by ,/iasny ,footnote3 ,g]b]1 #aije1 #bcc4 & ,kaus*ke ,footnote3 ,collegium1 #aijf1 #cfb4 & ! latt] po9ts out t ^! easily soluable sub/ances exhibit tann+ prop]ties4 ,ni]5/e9 ,footnote3 ,ibid41 #aijf #dbd4 0 fur!r able to %[ t by all processes ( cond5sation betwe5 ph5ols 7or hydroxyb5zoic acids7 & =maldehyde1 comp\nds ( ! "* ( hydroxyaur9e 7or hydroxyaur9ec>boxylic acid7 7 =m$ 9 addition to ! insoluble hydroxydiph5ylme?anes 7or hydroxydiph5ylme?anec>boxylic acids71 ! =m] possess+ ! *>act]i/ic tannophor gr\p & h5ce precipitat+ gelat9e1 i4e41 ex]t+ tann+ action4 ,if ! =mation ( lea!r is view$ 9 ! light ( ,s*iff's base1 ,footnote3 ,ibid41 #aije1 #aei4 "o may consid] ! con/itution ( a hexahydroxyaur9ec>boxylic acid lea!r z foll[s3-- ,c#f;,h#b7,,oh7#c4;,,cooh ,c-,c#f;,h#b7,,oh7#c4;,,cooh ,c#f;,h#b7,,oh7#b4;,,cooh ,r-,n ,9 ! prep>ation ( ^! & simil> cond5sation products1 ,ni]5/e9 & ,web/] ,footnote3 ,b]41 #aijh1 #da1 #hj4 obs]v$ a peculi> /]ic effect ( ! c>boxyl gr\p4 ,ea* #b4e gm4 ( ! ph5ol or ! acid 9 "q 7 dissolv$ 9 #cj c4c4 ( wat]1 ! solution br\ght to boil & #e c4c4 =maldehyde 7#bj p] c5t47 & #b4e c4c4 hydro*loric acid add$ drop by drop2 ! precipitate =m$ 0 filt]$ (f aft] tw5ty-f\r h\rs1 dri$ at #aaj ,c4 to con/ant weight1 extract$ 79 a ,goo* crucible7 freely ) wat]1 & ! residue aga9 dri$ at #aaj ,c4 till con/ant4 ,! foll[+ values 7 obta9$3-- ,total ,insol4 ,aq4 ,sol4 ,aq4 ,oxy- ,precipitate ,diph5ylme?ane aur9ec>boxylic 9 ,grammes4 ,d]ivatives ,acid4 ,p] ,c5t4 ,p] ,c5t4 ,phlorogluc9ol #b4djjb #ajj 444 ,hydroqu9one #b4cgaf #ajj 444 #b4jedb #ajj 444 ,pyrogallol #b4eaej #ajj 444 #b4gidj #ajj 444 ,pyrocate*ol #b4ihje #ajj 444 #b4iegd #ajj 444 ,resorc9ol #b4iied #ajj 444 #b4igbe #ajj 444 ,gallic acid #b4jgjf #gh4hd #ba4af #a4bbdj #hc4ah #af4hb #a4adje #ei4id #da4jf ,greek3 b-,resorcylic acid #b4ajdj #ea4jh #dh4ib #b4bjjh #dg4ab #eb4hh ,protocate*uic acid 444 444 444 444 444 444 ,vanillic acid 444 444 444 ,tann9 #b4jeii 444 ,ne>ly all sol4 ,digallic acid #b4ajdb #hj4af #ai4hd ,leucodigallic acid #b4jjda #a4id #ih4jf ,) ! introduction ( ! c>boxylic gr\p ! t5d5cy ( cond5sation to diph5ylme?ane d]ivatives is less5$2 by protocate*uic acid ! t5d5cy is nil4 ,ni]5/e9 consid]s ?is reaction analog\s to ! =mation ( cork1 to ! g5etic relation ( :i* ) ! diph5ylme?ane =mation ,drabble & ,ni]5/e9 h ref]r$ 9 an e>li] publication4 ,footnote3 ,bio*emical ,j\r441 #aijg1 #b1 #if4 ,x is h5ce possible t ! plants may employ =maldehyde z a me?ylation m$ium1 & produce ^! insoluble cond5sation products = ! purpose ( ridd+ !mselves ( ! poison\s ph5ols & aromatic hydroxy acids 7& tann9s71 9 addition to oxidis+ processes :]eby phlobaph5es1 ellagic acid1 etc41 are =m$4 ,! reaction betwe5 ph5ols & aldehydes has be5 fur!r /udi$ by ,mi*ael1 ,footnote3 ,am]4,j\r41 #e1 #cch2 #i1 #acj4 :o prep>$ a cond5sation product f ph5ol & resorc9ol ) b5zaldehyde1 & ,russan[1 ,footnote3 ,b]4#i #ahhi1 #bb1 #aidd4 :o also employ$ b5zaldehyde & ph5ol4 ,lipp ,footnote3 ,diss41 ,b]n41 #aije4 inve/igat$ ! action ( b5zaldehyde & pip]onal on ph5ols1 anisoles1 cresols1 cresylic e!r1 resorc9ol1 & ! e!r ( ! latt] & ph5ol1 & %[$ t :5 free ph5ols are cond5s$ ) b5zaldehyde ! hydroxyls occupy ! same position z by ! int]action betwe5 b5zaldehyde & ! correspond+ ph5olic e!rs4 ,! result+ dihydroxytriph5ylme?ane d]ivatives =m beautiful cry/als1 :i* on oxidation are conv]t$ into b5zaur9es1 ! con/itution ( ! latt] probably be+-- ,o ,,oh v v v ,c ,c#f;,h#e ,9 alkalies1 ! hydroxylat$ triph5ylme?anes dissolve )\t imp>t+ any col\r to ! solution2 by conc5trat$ sulphuric acid !y are tak5 up ) int5se coloration4 ,if ! hydroxyls occupy ! or?o-position to me?yl1 !y may =m xan!nes by splitt+ (f wat]-- ,o ,,*#c v v v ,,*#c ,,* ,c#f;,h#e ,9 ! b5z5e s]ies ?is reaction is difficult to e/abli%1 & has to be induc$ by di/ill+ ! p>ticul> dihydroxy-diph5ylme?ane at ord9>y pressure4 ,9 ! naph?al5e s]ies1 on ! o!r h&1 ! r+ closes up by1 = in/ance1 ! cond5sation ( ,greek3 b-naph?ol ) b5zaldehyde or p>aldehyde1 & yields ! foll[+ comp\nds3-- ,c#aj;,h#f ,c#aj;,h#f ,c#f;,h#e-;,,* ,o ,,*#c-;,,* ,o ,c#aj;,h#f ,c#aj;,h#f ,^! xan!nes are :ite1 silk-glossy ne$les1 :i* are soluble 9 wat] & 9 alkalies4 ,9 conc5trat$ sulphuric acid1 !y are tak5 up ) beautiful fluoresc5ce4 #f4 ,summ>y ,f ! qualitative reactions ( ! diff]5t cond5sation products describ$ x may be se5 t _! tannoid prop]ties are n dep5d5t on :e!r !y precipitate gelat9e or are adsorb$ by hide p[d] or n4 ,hydroxynaph?ylme?anesulphonic acid1 = in/ance1 precipitates gelat9e b does conv]t pelt into lea!r2 on ! o!r h&1 sodium dicresylme?anesulphonate does n precipitate gelat9e1 & nei!r does x tan pelt2 nev]!less x is adsorb$ by hide p[d] z tann+ matt]4 ,! au?or discov]$ t o-nitroph5ol does n precipitate gelat9e1 b has "s tann+ action on bo? hide p[d] & pelt4 ,relatively to ! possibilities ( =m+ cond5sation products possess+ tannoid prop]ties1 ! foll[+ may be /at$3-- ,all mono- & polyhydric ph5ols may be conv]t$ into true tann+ matt]s by ei!r cond5s+ !m z su*1 or aft] _! conv]sion into ! correspond+ sulphonic acids1 by sub/ances capable ( elim9at+ ! elem5ts ( wat]4 ,x makes no diff]5ce to ! f9al product :e!r ! cond5sation is ! fir/ /ep foll[$ by sulphonation & consequ5t solubilisation ( ! int]m$i>y insoluble product1 or :e!r1 vice v]sa1 ! sulphonic acid is subject$ to cond5sation4 ,alkal9e solution ( ph5ols may also be cond5s$1 ! reaction products1 :5 cond5s$1 con/itut+ tann+ matt]s soluble 9 wat]4 ,among ! sub/itution products ( ! ph5ols1 ! ?io-1 *loro-1 bromo-1 nitro-1 & am9oph5ols z a rule yield tann+ matt]s simil> 9 "*4 ,! qu9ones are z su*--i4e41 )\t be+ cond5s$--sub/ances possess+ tannoid prop]ties4 ,! aromatic dihydric alcohols are easily cond5s$ ) ! diff]5t sulphonic acids & yield valuable tann+ matt]s4 ,( aromatic acids all ^? :i* yield wat]-soluble sulphonation products seem suitable = ! indu/rial production ( tann+ matt]s4 ,if ! acids !mselves d n yield wat]-soluble sulphonation products1 ! alkali salts ( ! latt] may be cond5s$ ) =maldehyde1 & ! result+ products !n con/itute tann+ matt]s provid$ _! solutions c be neutralis$ or fa9tly acidifi$ )\t ! solute be+ ?r[n out ( solution 9 insoluble =m4 ,! diph5yl d]ivatives ( ! above gr\ps (t5 possess tannoid prop]ties4 ,! same holds good ( ^? comp\nds ) cond5s$ nuclei 7naph?al5e1 an?rac5e1 etc471 & all _! d]ivatives :i* satisfy ! above conditions4 ,! *oice ( cond5s+ ag5t is1 z a rule1 ( little significance4 ,elim9ation ( ! elem5ts ( wat] by ! m]e application ( heat succe$s 9 few cases only1 s9ce ! high temp]ature requir$ to induce reaction 9 _m cases causes decomposition ( ! sub/ances4 ,?is difficulty is ov]come by heat+ 9 vacuo4 ,cond5sation ) =maldehyde always succe$s1 ) acetaldehyde & b5zaldehyde only p>tly4 ,! action on hide p[d]1 pelt1 & gelat9e by ^! *>act]i/ic sub/ances is tabulat$ bel[3-- ,relative ,behavi\r t[>ds ,sub/ance4 ,gelat9e4 ,hide ,p[d] ,pelt ,=maldehyde 444 444 ,tann+ ,ph5ol ,ppte4 444 444 ,*loroph5ol 444 444 ,surface ,tribromoph5ol ,slight ppte ,tann+ tann+ o ,nitroph5ol ,no ppte ,bromonitroph5ol ,slight ppte ,tr9itroph5ol ,ppte ,tann+ ,bromotr9itroph5ol ,slight ppte p ,am9oph5ol ,ppte 444 444 m ,dihydroxyb5z5e 444 444 ,orc9ol 444 444 p ,dihydroxyb5z5e ,tann+ ,tann+ ,mono*loro p dihydroxyb5z5e 444 444 o ,dihydroxyb5z5e 444 444 ,pyrogallic acid 444 444 ,surface ,tribromopyrogallic acid ,tann+ ,tann+ ,gallic acid ,no ppte ,n tann+ ,n tann+ ,bromophlorogluc9ol ,ppte ,tann+ ,gallotannic acid ,tann+ ,gall(lav9e ,slight ppte ,n tann+ ,qu9one ,tann+ ,bromosalicylic acid ,n tann+ ,d9aph?ylme?an$isulphonic acid ,ppte ,tann+ ,diph5ylme?an$isulphonic acid ,dicresylme?an$isulphonic acid ,sodium dicresylme?an$isulphonate acid ,no ppte ,n tann+ ,dixylylme?an$isulphonic acid ,ppte ,tann+ ,naph?oldisulphonic acid ,n tann+ ,n tann+ ,me?yl5$9aph?ol ,tann+ ,tann+ ,hydroxyph5ylme?anesulphonic acid ,n tann+ ,hydroxynaph?ylme?anesulphonic ,slight ppte acid ,diam9onaph?ylme?an$isulphonic ,ppte ,tann+ ,n tann+ acid ,dihydroxynaph?ylme?an$isulphonic acid ,di*loronaph?ylme?an$isulphonic acid ,surface tann+ ,d9itronaph?ylme?an$isulphonic acid ,di?ionaph?ylme?an$isulphonic acid ,tann+ ,bromo ,greek3 b naph?ol #a ,slight ppte ,rosolic acid #a ,ppte ,footnote #a3 ,9 alcoholic solution4 ,,section ,,iii ,,tann+ ,,effects ,,( ,,mixtures ,,& ,,natural ,,products #a4 ,mixture ( ,ph5olsulphonic ,acid & ,=maldehyde ,! mo/ important inv5tion relatively to ! se>* = new tann+ mat]ials 0 t ( ,we9s*5k1,footnote3 ,g]4 ,pat41 #ahd1ddi4 :o fir/ %[$ t pelt may be conv]t$ into lea!r by ! action ^u x ( mixtures ( naph?ols & =maldehyde4 ,?is process consi/s ( two /eps3 ! pelt is fir/ imm]s$ 9 a #j4be-j4ej p] c5t1 =maldehyde solution1 & secondly 9 an aque\s solution ( -,greek3 a or -,greek3 b naph?ol2 ?is ord] may be rev]s$4 ,if1 on ! o!r h&1 a pa/y mixture is made ( =maldehyde & naph?ol1 & ?is is all[$ to act ^u ! pelt1 ! latt] is rapidly conv]t$ into lea!r1 b ! mixture mu/ be adm9i/]$ v gradually or o!rwise ! insoluble me?yl5$9aph?ol is =m$ outside ! pelt & h9d]s any tann+ effect4 ,lea!r obta9$ ?r\gh ! action ( ,greek3 a-naph?ol is1 :5 fre%ly tann$1 pure :ite & suffici5tly s(t & firm1 b quickly assumes a br[n col\r on /or+2 if1 h[ev]1 ,greek3 b-naph?ol is employ$1 a cream-col\r$ lea!r results1 ! col\r ( :i* turns only slightly m yell[i% ev5 :5 expos$ to ! direct rays ( ! sun4 ,a simil> process has rec5tly 7#be1 xii41 #aiae7 be5 protect$ by ,g]4 ,pat1 #cje1eaf1 grant$ to ! ,deuts*-,koloniale ,g]b--und ,f>b/(if ,gesells*aft1 9 ,k>lsruhe4 ,accord+ to ?is pat5t1 pelt is treat$ 9 sep>ate solutions1 "o ( :i* is =maldehyde1 ! o!r be+ t ( su* aromatic comp\nds or _! salts :i* yield wat]-soluble cond5sation products ) =maldehyde2 = example1 pelt is imm]s$ 9 #b-e p] c5t1 solution ( =maldehyde = a few days1 & is subsequ5tly treat$ ) #a-b p] c5t neutral or fa9tly acidifi$ solutions ( ,greek3 a-naph?ylam9e hydro*loride1 resorc9ol or sodium ph5ate or cresylate1 = sev]al days4 ,! resultant lea!r is claim$ to be s(t & full & to possess good t5sile /r5g?4 ,! tann+ prop]ties ( mixtures ( ph5olsulphonic acid & =maldehyde h be5 exam9$ by ! au?or ) ! foll[+ results3-- ,i4 ,,ii4 ,,iii4 ,grammes =maldehyde #aj #bj #dj ph5olsulphonic acid #bj #ej #ajj cau/ic soda 7sol1 #dj p] c5t47 #aj #bj #dj wat] #ejj #ejj #ejj ,! above solutions 7 made up & all[$ to act ^u pelt pieces weigh+ #ae gm42 :]eas ,solution ,i4 rema9$ cle> ?r\gh\t ! exp]im5t1 ,solution ,,ii4 became some:at cl\d$1 & ,solution ,,iii4 assum$ a milky appe>ance4 ,! pelts 7 tann$ ?r\gh 9 sev5 days & yield$ lea!rs :i*1 aft] dry+ & f9i%+1 possess$ yell[ col\r1 long fibre1 & good t5sile /r5g?1 b a r empty feel4 ,to prev5t sep>ation ( insoluble matt] dur+ tannage1 ano!r exp]im5t 0 c>ri$ out1 9 :i* ! pelts 7 fir/ submitt$ to ! action ( =maldehyde 7#aj1 #bj1 & #dj gm4 9 #ejj c4c4 wat]7 = ?ree days1 be+ subsequ5tly remov$ to fre% solutions ( p>tly neutralis$ ph5olsulphonic acid 7cf4 above74 ,simil> results 7 obta9$1 b ! lea!r felt ev5 m empty ?an ^? obta9$ by ! =m] exp]im5t4 ,attempts at conv]t+ pelt into lea!r by fir/ imm]s+ ! pelt 9 a p>tly neutralis$ solution ( ph5olsulphonic acid1 & subsequ5tly transf]r+ x to fre% solutions ( =maldehyde1 gave m]ely negative results2 ! ph5olsulphonic acid effect$ pickl+ action ^u ! pelt1 b 0 subsequ5tly quickly replac$ by ! =maldehyde1 be=e ! latt] _h p5etrat$ ! pelt 9 suffici5t quantity to induce cond5sation1 !reby ex]t+ tann+ action4 ,to expla9 ! tann+ effects ( ^! mixtures1 ! au?or analys$ ! lea!rs result+ f ! effects ( ! latt]1 & 0 able to %[1 t 9 ^! cases also1 cond5sation ( ph5olsulphonic acid & =maldehyde takes place inside ! pelt1 s9ce on ! "o h& ! analyses left no d\bt b t true tannage _h be5 effect$1 & on ! o!r h& an ammoniacal extract ( ! lea!rs gave ! typical reaction = cond5sation products ( ph5olsulphonic acid1 ) anil9e hydro*loride4 ,footnote3 ,collegium #aiac1 #eaf1 #adb4 ,! lea!r analyses gave ! foll[+ figures3-- ,moi/ure - - - #ah4cj p] c5t4 ,fats - - - - #j4dg ,a% - - - - #j4ih ,lea!r ,tann9 - - - #bf4cg sub/ance ,hide sub/ance - - #ec4hh ,a *>act]i/ic feature is ! l[ value ( tann91 :i* is consid]ably high] ,footnote3 ,ibid41 #aiac1 #eba1 #dgh4 :]e cond5sation products ( ph5olsulphonic acids are us$ z tann+ ag5ts2 ! action effect$ by ! sep>ate con/itu5ts1 !re=e1 is m t ( pickl+4 #b4 ,mixture ( ,ph5olsulphonic ,acid & ,natural ,tann9s ,a piece ( pelt 0 imm]s$ 9 a half-neutralis$ solution1 measur+ #f ,b41 ( ph5olsulphonic acid1 & left sixte5 h\rs 9 ! solution1 :i* completely p5etrat$ ! pelt dur+ ?is "t2 x 0 !n transf]r$ to a #ab ,b4 solution ( a mixture ( quebra*o & *e/nut1 :i* 9 two days conv]t$ ! pelt into a light col\r$ lea!r possess+ good t5sile /r5g?4 ,by us+ a ba? compos$ ( half-neutralis$ ph5olsulphonic acid & quebra*o extract 9 #g ,b4 solution1 ano!r piece ( pelt 0 completely tann$ 9 two days4 ,! same result 0 obta9$ by fir/ half neutralis+ ! ph5olsulphonic acid & !n add+ sulphit$ quebra*o extract till a #e ,b4 solution 0 obta9$4 ,a piece ( pelt receiv$ a #b ,b4 liquor compos$ ( #c p>ts ( ph5olsulphonic acid & #a "p ( =maldehyde = sixte5 h\rs1 & 0 !n completely p5etrat$2 x 0 subsequ5tly transf]r$ to a #aj ,b4 liquor compos$ ( *e/nut & quebra*o1 be+ completely tann$ 9 two days4 ,! same result 0 obta9$ on add+ suffici5t sodium sulphate to ! above mixture ( ph5olsulphonic acid & =maldehyde to raise ! d5sity f #b-c ,b4 ,sixty grammes ( ph5olsulphonic acid 7 p>tly neutralis$ ) #ajj c4c4 ( a #aj p] c5t solution ( cau/ic soda1 & #aj c4c4 =maldehyde add$ to #djj c4c4 ( ! mixture 7#b ,b473 a piece ( pelt 0 completely p5etrat$ by ! solution 9 sixte5 h\rs1 & 0 subsequ5tly tann$ 9 two days1 us+ an extract ( #aj ,b4 ,simil>ly1 by treat+ a pelt ) #djj c4c4 ( a half-neutralis$ solution ( ph5olsulphonic acid 7#c ,b47 plus #h c4c4 =maldehyde1 & add+ aft] eighte5 h\rs sulphit$ quebra*o extract to ! same ba?1 /r5g!n+ ! latt] to #f ,b41 ! pelt 0 conv]t$ into lea!r 9 two days2 9 ?is case1 h[ev]1 mu* ( ! tann9 0 precipitat$ by ! =maldehyde pres5t 9 ! solution4 ,if1 on ! o!r h&1 a mixture ( #hj gm4 dilute ph5olsulphonic acid 7#a3a aq7 & #ad gm4 ( =maldehyde 7 cool$ = sev]al h\rs & subsequ5tly /r5g!n$ ) sulphit$ quebra*o extract to #g ,b41 no tann9 0 precipitat$ 9 ! liquor1 & a piece ( pelt imm]s$ 9 ! latt] 0 completely tann$ 9 sixte5 h\rs4 ,to prev5t ! precipitation ( tann9 caus$ by ! =maldehyde1 sulphite cellulose extract 7wood pulp7 0 sub/itut$ = sulphit$ quebra*o extract1 & ! foll[+ exp]im5ts c>ri$ out3-- ,to #bjj c4c4 ( a #f ,b4 sulphite cellulose extract plus #bjj c4c4 ( half-neutralis$ ph5olsulphonic acid solution 0 add$ #ae c4c4 =maldehyde1 & ?is solution tann$ pelt 9 f\r days2 ! resultant lea!r 0 light br[n1 firm1 & possess$ good t5sile /r5g? & long fibre4 ,ano!r piece ( pelt 0 imm]s$ 9 a solution ( #djj c4c4 ph5olsulphonic acid ( #c;,b4 plus #ae c4c4 =maldehyde = eighte5 h\rs1 & 0 !n tann$ 9 a #f ,b4 solution ( sulphite cellulose extract4 ,! resultant lea!r 0 extremely light col\r$1 & possess$ qualities simil> to ^? describ$ 9 ! =m] exp]im5t4 ,f9ally1 pelt 0 imm]s$ 9 a #f ,b4 solution compos$ ( #adj gm4 ( a #ae ,b4 sulphite cellulose extract1 #aj gm4 ( =maldehyde1 #djj gm4 wat]1 #ae gm4 ph5olsulphonic acid1 & #cj gm4 ( a #aj p] c5t cau/ic soda solution1 & 0 tann$ 9 f\r days4 ,?is lea!r also 0 col\r$ light br[n1 ( good t5sile /r5g?1 & r firm4 ,^! exp]im5ts prove t :5 pelt is treat$ ) =maldehyde1 ph5olsulphonic acid1 & vegetable tann9s1 ! two =m] compon5ts effect1 m or less1 actual tannage2 x is admitt$ly a matt] ( "s difficulty to e/abli% :e!r ! effect is "o ( pickl+ or pseudo-tannage1 or :e!r ! tannage may be consid]$ a true "o4 ,! f9al effect1 h[ev]1 is ne>ly always t ( a true tannage1 i4e41 by v>y+ ! composition ( ! tann+ solutions lea!r is obta9$ ) prop]ties id5tical ) ^? tann$ ) true tann9s ( vegetable orig94 ,! only difficulty enc\nt]$ 9 ^! comb9ations is ! prop]ty ( =maldehyde1 ( precipitat+ ! natural tann9s1 & x is h5ce ess5tial1 = practical purposes1 to s arrange ! comb9ation t _! value is n r$uc$ by ! prop]ty ref]r$ to4 ,! fact t n only comp\nds already exi/+ may conv]t pelt into lea!r1 b t a simil> effect is obta9$ inside ! pelt1 by _! compon5ts1 is inde$ ( !oretical int]e/4 #c4 ,tann+ ,effects ( ,diff]5t ,natural ,sub/ances ,9 addition to ! vegetable tann9s1 ,nature has also provid$ o!r sub/ances ( vegetable orig91 :i*1 admitt$ly1 d n effect tannage 9 _! orig9al /ate1 b :i* may1 by suitable treatm5t1 acquire ?is prop]ty4 ,! olde/ in=mation on ?is po9t is suppli$ by ,res*1 ,footnote3 ,s*]]'s ,j\r41 #ahja1 #f1 #die4 :o c>ri$ out tann+ exp]im5ts1 us+ ?ree p>ts ( peat & "o "p ( oak b>k4 ,by ! action ( nitric acid on sub/ances ( vegetable & animal orig91 ,hat*ett1 ,footnote3 ,gehl5's ,j\r41 #ahje1 #a1 #ede4 ,*evreul1 ,footnote3 ,ann4 ,*im41 #ahaj1 #gc1 #cf4 & ,vogel ,footnote3 ,j\r4 ,*em4 ,phys41 #ahab1 #f1 #aja4 claim to h obta9$ tann+ mat]ials1 :il/ lat]1 ,buff ,footnote3 ,ibid41 #ahbg1 #ea1 #ch4 obta9$ a mat]ial suitable = tann+ purposes f indigo4 ,by subsequ5t treatm5t ) lime & soot1 or t>1 ,a%more ,footnote3 ,d+i]'s ,j\r41 #ahcc1 #dh1 #fg4 claims to h conv]t$ pelt into lea!r4 ,by treat+ peat ) nitric acid1 ,j5n+s ,footnote3 ,jahresb]4 d4 ,*em41 #aheh1 #fff4 & ,payne ,footnote3 ,*em4 ,c5tralbl41 #aijh1 ii4 #eed2 ,g]4 ,pat41 #bjj1 #eci4 h produc$ artificial tann+ mat]ials4 ,skey ,footnote3 ,*em4 ,news1 #ahff1 #bjf2 ,zeits4 f4 ,*em41 #ahff1 #gec4 obta9$ a d>k br[n extract1 soluble 9 wat] & precipitat+ gelat9e1 by treat+ bitum9\s coal or lignite ) nitric acid2 by extract+ coal ) alkalies1 ,re9s* ,footnote3 ,ph>m4 ,c5tralh41 #ahhg1 #ada4 isolat$ a sub/ance 7pyr(usc9e7 :i*1 :5 p>tly neutralis$ ) c>bon dioxide1 0 capable ( conv]t+ pelt into lea!r4 ,9 addition to ^! tann+ mat]ials ! recov]y ( a sub/ance possess+ tann+ prop]ties f ! s-call$ acid ros9s has be5 made ! subject ( a pat5t2 ,footnote3 ,g]4 ,pat41 #cf1jai4 ?is ros9 is =m$ :5 crude oil is treat$ ) conc5trat$ sulphuric acid 9 ! oil ref9]ies4 ,! greasy sub/ance is p>tly neutralis$ ) alkali & is claim$ to produce a v spr+y lea!r4 ,! wa/e liquors obta9$ 9 ! manufacture ( cellulose1 ! s-call$ sulphite & sodium cellulose wa/e1 h1 h[ev]1 be5 ! subject ( num]\s inve/igations1 & sev]al hundr$ publications h appe>$ & a great numb] ( pat5ts ,footnote3 ,lit]atur beri,sulfitablauge #aiaj-ac4 7,repr9t f ,woche,wochenbl,papie,papierfabrikation7 tak5 out1 ! fir/ "o be+ t ( ,mits*]li* ,footnote3 ,jahresb]4 d4 ,*em41 #ahic1 #hij2 ,g]4 ,pat41 #gb1afa4 & ,hnig ,footnote3 ,*em4 ,c5tralbl41 #aijb1 ii4 #agd2 ,g]4 ,pat41 #acb1bbd4 ,! wa/e liquors conta9 l>ge quantities ( acids & lime1 & 9 ord] to utilise ! liquors = tann+ purposes1 ! excessive sulphuric & sulphur\s acids z well z ! lime mu/ be remov$4 ,! active tann9 is no d\bt ! lign9sulphonic acid1 & ^? cellulose extracts conta9+ ! l>ge/ am\nts ( free lign9sulphonic acid may also be consid]$ ! mo/ effici5t4 ,accord+ to ! au?or1,footnote3 ,te*nikum1 #aiab1 #bj1 #aef4 su* sulphitecellulose extracts precipitate gelat9e1 anil9e hydro*loride1 ammoniacal z9c acetate1 & basic coal-t> dyes1 & give a gre5i%-black coloration ) f]ric *loride4 ,^! reactions indicate ! pres5ce ( tann+ matt]s 9 cellulose extracts4 ,! (ficial %ake me?od ( analysis gives ! foll[+ results3--,footnote3 ,ibid4 ,tann+ matt]s #bc4j p] c5t4 ,non-tann9s #cj4c ,insoluble matt]s #j4g ,wat] #df4j --------------- #ajj4j p] c5t4 ,a% #d4c ,sulphur\s acid #j4f ,_m o!r sub/ances h be5 us$ = tann+ exp]im5ts1 a numb] ( !m precipitat+ gelat9e4 ,za*>ias ,footnote3 ,zeits4 f4 ,ang4 ,*em41 #aijg1 #afde4 obta9$ lea!r by ! action ( _m coal-t> dyes on pelt1 simil>ly ,h]zog & ,adl]1 by us+ ,prussian blue1 ,neufu*s91 pat5t blue ,v1 cry/al violet1 & colloidal gold4 ,mo/ inorganic sub/ances possess tann+ prop]ties :5 9 ! colloidal /ate1 e4g41 sulphur1 halog5s1 *romium salts1 iron salts1 silv] oxide1 & ! salts ( m]cury1 copp]1 bismu?1 z9c1 lead1 plat9um1 cesium1 vanadium1 & ! r>e e>?s 7salts ( c]ium1 lan?anum1 didymium1 neodymium1 ?orium1 & z]conium74 ,= practical purposes1 h[ev]1 only sulphur1 *rome1 & alum salts are us$1 ! latt] two be+ ( ! greate/ importance4 ,,section ,,iv ,,me?ods ,,( ,,exam9+ ,,tann+ ,,matt]s ,:]eas ! evaluation ( vegetable tann+ matt]s necessitates det]m9ations ( _! practical applicability 9 addition to qualitative & quantitative analyses1 ! latt] two det]m9ations are ( practically no value :5 deal+ ) syn!tic tann9s4 ,! way 9 :i* tann+ matt]s obta9$ by *emical means ex]t _! action1 9 addition to ! int5sity ) :i* !y conv]t pelt into lea!r1 is ! only crit]ion ( _! quality = practical 7tann+7 purposes2 bo? may be demon/rat$ by exp]im5tal te/s4 ,:5 deal+ ) ! natural tann+ mat]ials x is desirable to "k _! cont5ts ( actual tann+ matt]1 f :i* _! special qualities z tann+ ag5ts may be d$uc$4 ,:]e ! vegetable tann+ mat]ials h already be5 conv]t$ into extracts1 x is ess5tial to e/abli% ! id5tity ( ! orig9al mat]ial us$ by ! qualitative reactions ( ! extract 9 addition to ! quantitative e/imation ( actual tann9 cont5ts4 ,x is frequ5tly necess>y to exam9e :e!r ! extract 9 "q has be5 actually prep>$ f ! mat]ial giv+ ! extract its "n1 or :e!r ! extract has suff]$ ! addition ( o!r extracts ( tann+ mat]ials ( b l[ quality4 ,su* det]m9ations may be und]tak5 by microscopical obs]vations & by means ( qualitative & quantitative reactions2 = ?is purpose _m col\r reactions & precipitation me?ods are available 9 addition to ! det]m9ation ( ! molybd5um figure 7,lauffmann71,footnote3 ,collegium1 #aiac1 #aj4 ! alcohol & e?yl acetate figures & microscopical exam9ation 7,grass]74,footnote3 ,ibid41 #aiaa1 #cdi4 ,( o!r adult]ants t5d+ to r$uce ! quality ( extracts may be m5tion$ sug>s1 m9]al salts1 & coal-t> dyes2 ,footnote3 ,grass]1 ,collegium1 #aiaj1 #cgi4 = ! det]m9ation ( ^!1 ! special lit]ature %\ld be consult$4 ,footnote3 ,grass]1 ,h&bu* f4 g]b]ei*em4 ,laboratori5 7,leipzig1 #aiad72 ,proct]-,paessl]1 ,g]b]ei*em4 ,unt]su*ung5 7,b]l91 #aija74 ,two me?ods are devis$ = ! purpose ( quantitatively det]m9+ ! tann9 cont5ts1 bo? ( :i* employ hide p[d]1 & :i* are kn[n z ! %ake me?od & ! filt] bell me?od respectively3 ! =m] is adopt$ z ! (ficial me?od ( ! ,int]national ,association ( ,lea!r ,trades' ,*emi/s 7,i4,a4,l4,t4,c474 ,footnote3 ,& also by ! ,society ( ,lea!r ,trades' ,*emi/s4-,transl4 ,! orig9al me?od1 ,footnote3 ,lea!r ,manufactur]1 #ahid1 ,no4 #i ,j4,s4,c4,i41#ahid1 #did4 work$ out 9 ! laboratory ( ! ,york%ire ,college 7n[ ! ,univ]sity ( ,le$s71 ess5tially consi/s 9 introduc+ #f-i gm4 ( hide p[d] 9 a %ak]1 wa%+ x at lea/ twice ) di/ill$ wat] & c>efully squeez+ out ! p[d] 9 a l95 clo? betwe5 ea* wa%+4 #ajj c4c4 ( ! solution to be exam9$1 :i* may n conta9 m ?an #a p] c5t1 total solids1 are introduc$ into ! %ak+ bottle :i* is !n weigh$4 ,ab\t "o-?ird ( ! wa%$ hide p[d] is !n add$1 & ! bottle %ak5 t5 to fifte5 m9utes2 ano!r ?ird is !n add$ &1 aft] %ak+1 ! ?ird portion4 ,! bottle plus cont5ts is n[ weigh$1 & ! am\nt ( hide p[d] introduc$ asc]ta9$ by diff]5ce ( ! two weigh+s4 ,! liquid is !n filt]$ ?r\gh filt] pap]1 #ej c4c4 ( ! cle> filtrate evaporat$ 9 a bas91 dri$ & weigh$4 ,! residue 9 ! orig9al solution is !n obta9$ by multiply+ ! =m] by #ajj 7plus weight ( wat] add$ ) hide p[d]71 & divid+ by #ajj4 ,?is me?od 0 closely inve/igat$ by a l>ge numb] ( lea!r trades' *emi/s1 0 consid]ably improv$1 & 9 its f9al =m pres5t$ a me?od ( ! highe/ degree ( accuracy2 ! me?od 0 !re=e adopt$ z ,! ,(ficial ,me?od ( ,tann+ ,analysis by ! ,i4,a4,l4,t4,c41 :i* body1 at ! same "t1 gave precise in/ructions z to ! details ( ! me?od4 ,! late/ in/ructions1 :i* are repr9t$ bel[1 p]mit ( any me?od ( analysis :i* obs]ves ! foll[+ conditions3-- #a4 ,! solution = analysis mu/ conta9 betwe5 #c4e & #d4e gm4 ( tann+ matt] p] litre1 & solid mat]ials mu/ be extract$ s t ! great] "p ( ! tann9 is remov$ at a temp]ature n exce$+ #ej ,c4 #b4 ,! total solubles mu/ be det]m9$ by ! evaporation ( a measur$ quantity ( ! solution previ\sly filt]$ till optically cle>1 bo? by reflect$ & transmitt$ light4 ,?is is obta9$ :5 a bright object su* z an electric light filam5t is di/9ctly visible ?r\gh at lea/ #e cm ?ickness1 & a lay] ( #a cm4 deep 9 a beak] plac$ on a black glass or black glaz$ pap] appe>s d>k & free f opalesc5ce :5 view$ f above4 ,any necess>y mode ( filtration may be employ$1 b if su* filtration causes appreciable loss :5 appli$ to a cle> solution1 a correction mu/ be det]m9$ & appli$ z describ$ 9 p>agraph #f4 ,filtration %all take place betwe5 ! temp]atures ( #ae ,c4 & #bj ,c4 ,evaporation to dryness %all take place betwe5 #ih4e ,c4 & #ajj ,c4 9 %all[1 flat-bottom$ bas9s1 :i* %all aft]w>ds be dri$ until con/ant at ! same temp]ature1 & cool$ be=e weigh+ = n less ?an tw5ty m9utes 9 air-tight desiccators ov] dry calcium *loride4 #c4 ,! total solids mu/ be det]m9$ by dry+ a weigh$ portion ( ! mat]ial1 or a measur$ portion ( its uni=m turbid solution1 at a temp]ature betwe5 #ih4e ,c4 & #ajj ,c4 9 %all[1 flat-bottom$ bas9s1 :i* %all aft]w>ds be dri$ until con/ant weight at ! same temp]ature1 & cool$ be=e weigh+ = n less ?an tw5ty m9utes 9 air-tight desiccators ov] dry calcium *loride4 ,moi/ure is ! diff]5ce betwe5 #ajj & ! p]c5tage ( total solids1 & insoluble ! diff]5ce betwe5 total solids & total solubles4 #d4 ,non-,tann9s4--,! solution mu/ be detannis$ by %ak+ ) *rom$ hide p[d] till no turbidity or opalesc5ce c be produc$ 9 ! cle> solution by salt-gelat9e solution4 ,! *rom$ p[d] mu/ be add$ 9 "o quantity equal to #f4j-f4e gm4 ( dry hide p[d] p] #ajj c4c4 ( ! tann+ solution1 & mu/ conta9 n less ?an #j4b p] c5t4 & n m ?an #a p] c5t4 ( *romium calculat$ on ! dry weight1 & mu/ be s wa%$ t 9 a blank exp]im5t ) di/ill$ wat]1 n m ?an #e mg4 ( solid residue %all be left on evaporation ( #ajj c4c4 ,all wat] conta9$ 9 ! p[d] %\ld be det]m9$ & all[$ = z wat] ( dilution4 #e4 ,prep>ation ( ,infusion4--,su* a quantity ( mat]ial %all be employ$ z to give a solution conta9+ z ne>ly z possible #d gm4 ( tann+ matt] p] litre1 & n less ?an #c4e or m ?an #d4e gm4 ,liquid extracts %all be weigh$ 9 a bas9 or beak] & wa%$ ) boil+ wat] into a litre flask1 fill$ up to ! m>k ) boil+ wat]1 & well mix$ & rapidly cool$ to a temp]ature ( #ag4e ,c41 aft] :i* x %all be accurately made up to ! m>k1 aga9 well mix$1 & filtration at once proce$$ )4 ,sumac & myrabolam extracts %\ld be dissolv$ at a l[] temp]ature4 ,solid extracts %all be dissolv$ by /irr+ 9 a beak] ) successive quantities ( boil+ wat]1 ! dissolv$ portions be+ p\r$ into a litre flask1 & ! undissolv$ be+ all[$ to settle & treat$ ) fur!r portions ( boil+ wat]4 ,aft] ! :ole ( ! soluble matt] is dissolv$1 ! solution is treat$ simil>ly to t ( a liquid extract4 ,solid tann+ mat]ials1 previ\sly gr\nd till !y w pass ?r\gh a sieve ( sixte5 me%es p] squ>e c5timetre1 are extract$ 9 ,ko*'s or ,proct]'s extractor ) #ejj c4c4 ( wat] at a temp]ature n exce$+ #ej ,c42 ! extraction is !n cont9u$ ) boil+ wat] till ! filtrate am\nts to #a litre4 ,x is desirable to all[ ! mat]ial to soak = "s h\rs be=e comm5c+ ! p]colation1 :i* %\ld occupy n less ?an ?ree h\rs1 s z to extract ! maximum ( tann94 ,any rema9+ solubles 9 ! mat]ial mu/ be neglect$ or report$ sep>ately z difficultly soluble sub/ances4 ,! volume ( liquid 9 ! flask mu/1 aft] cool+1 be accurately made up to #a litre4 #f4 ,filtration4--,! infusion %all be filt]$ till optically cle> 7vide #b74 ,no correction = absorption is ne$$ = ! ,b]kefeld c&le1 or = ,s4 & ,s4 #eij pap] ,footnote3 ,s*lei*] & ,s*ll1 ,dr5 7,rhe9l&71 ,g]many4 if a suffici5t quantity 7#bej-cjj c4c47 is reject$ be=e measur+ ! quantity = evaporation1 & ! solution may be pass$ ?r\gh repeat$ly to obta9 a cle> filtrate4 ,if o!r me?ods ( filtration are employ$1 ! av]age correction necess>y mu/ be det]m9$ 9 ! foll[+ mann]3--,ab\t #ejj c4c4 ( ! same or a simil> tann+ solution is filt]$ p]fectly cle>1 & aft] ?or\gh mix+ #ej c4c4 is evaporat$ to det]m9e ,total ,soluble ,a4 ,a fur!r portion is n[ filt]$ 9 ! exact me?od = :i* ! correction is requir$ 7"t ( contact & volume reject$ be+ kept z con/ant z possible71 & #ej c4c4 is evaporat$ to det]m9e ,total ,soluble ,b4 ,! diff]5ce betwe5 ,a & ,b is ! correction s\ght1 :i* mu/ be add$ to ! weight ( ! total solubles f\nd 9 analysis4 ,an alt]native me?od ( det]m9+ correction1 :i* is equally accurate & (t5 m conv5i5t1 is to filt] a portion ( ! tann+ solution ?r\gh ! ,b]kefeld c&le till optically cle>1 :i* c be g5]ally accompli%$ by reject+ #cjj or #djj c4c41 & return+ ! rema9+ filtrate repeat$ly2 & at ! same "t to evaporate #ej c4c4 ( ! cle> filtrate obta9$ by ! me?od = :i* correction is requir$1 :5 ! diff]5ce betwe5 ! residues w be ! correction s\ght4 ,an av]age correction mu/ be obta9$ f at lea/ five det]m9ations4 ,x w be f\nd t ?is is approximately con/ant = all mat]ials1 & am\nts 9 ! case ( ,s4 & ,s4 #fje1 #aej c4c4 be+ reject$1 to ab\t #j4jje gm41 & :]e #b gm4 ( kaol9 are employ$ 9 addition to #j4jjge gm4 ,! kaol9 mu/ be previ\sly wa%$ ) #ge c4c4 ( ! same liquor1 :i* is all[$ to /& fifte5 m9utes & !n p\r$ (f4 ,pap] #fje has a special absorption = a yell[ col\r+ matt] (t5 conta9$ 9 sulphit$ extracts4 #g4 ,hide p[d] %all be ( a woolly texture1 ?or\ghly delim$1 pref]ably ) hydro*loric acid4 ,x %all n require m ?an #e c4c4 or less ?an #b4e c4c4 ( dec9ormal ,na,o,h or ,,koh to produce a p]man5t p9k col\r ) ph5olph?ale9 on #f4e gm4 ( ! dry p[d] susp5d$ 9 wat]4 ,if ! acidity does n fall )9 ^! limits x mu/ be correct$ by soak+ ! p[d] be=e *rom+ = tw5ty m9utes 9 t5 to twelve times its weight ( wat]1 to :i* ! requisite calculat$ quantity ( /&>d alkali or acid has be5 add$4 ,! hide p[d] mu/ n swell 9 *rom+ to su* an ext5t z to r5d] difficult ! necess>y squeez+ to #gj-ge p] c5t4 ( wat]1 & mu/ be suffici5tly free f soluble organic matt] to r5d] x possible 9 ! ord9>y wa%+ to r$uce ! total solubles 9 a blank exp]im5t ) di/ill$ wat] bel[ #j4jje gm p] #ajj c4c4 ,! p[d]1 :5 s5t out f ! mak]1 %all n conta9 m ?an #ab p] c5t4 ( moi/ure1 & %all be s5t out 9 air-tight t9s4 ,! detannisation %all be c>ri$ out 9 ! foll[+ mann]3-- ,! moi/ure 9 ! air-dri$ p[d] is det]m9$1 & ! quantity equal to #f4e gm4 actual dry p[d] is calculat$1 :i* w be practically con/ant if ! p[d] be kept 9 an air-tight vessel4 ,any multiple ( ?is quantity is tak5 accord+ to ! numb] ( analyses to be made1 & wet back ) approximately t5 times its weight ( di/ill$ wat]4 ,two grammes p] #ajj ( dry p[d] ( cry/allis$ *romic *loride1 ,cr,cl#c4f;aq41 is n[ dissolv$ 9 wat] & made basic ) #j4f gm4 ( ,na#b;,,co#c by ! gradual addition ( #aa4be c4c4 ( normal ,na#b;,,co#c1 ?us mak+ ! salt correspond to ! =mula ,cr#b;,cl#c7,,oh7#c4 ,9 laboratories :]e analyses are cont9ually be+ made1 x is m conv5i5t to employ a #aj p] c5t /ock solution1 made by dissolv+ #ajj gm4 ( ,cr#b;,cl#f4f;aq4 9 a little di/ill$ wat] 9 a litre flask & v sl[ly add+ a solution conta9+ #cj gm4 ( anhydr\s sodium c>bonate1 ) con/ant /irr+1 f9ally mak+ up to ! m>k ) di/ill$ wat] & well mix+4 ,( ?is solution #bj c4c4 p] #ajj gm41 or #a4c c4c4 p] #f4e gm4 ( dry p[d]1 %\ld be us$4 ,?is solution is add$ to ! p[d]1 & ! :ole *urn$ = "o h\r4 ,at ! end ( ! "o h\r ! p[d] is squeez$ 9 l95 to free x z f> z possible f ! residual liquor1 & wa%$ & squeez$ repeat$ly ) di/ill$ wat]1 until1 on add+ to #ej c4c4 ( ! filtrate "o drop ( #aj p] c5t4 ,k#b;,cr,o#d & f\r drops ( dec9ormal silv] nitrate1 a brick-r$ col\r appe>s4 ,f\r or five squeez+s are usually suffici5t4 ,su* a filtrate _c conta9 m ?an #j4jja gm4 ( ,na,cl 9 #ej c4c4 ,! p[d] is !n squeez$ to conta9 #gj-ge p] c5t1 ( wat]1 & ! :ole weigh$4 ,! quantity ,q conta9+ #f4e gm4 dry hide is ?us f\nd1 weigh$ out1 & add$ imm$iately to #ajj c4c4 ( ! unfilt]$ tann9 infusion along ) 7#bf4e-,q7 ( di/ill$ wat]4 ,! :ole is cork$ up & agitat$ = fifte5 m9utes 9 a rotat+ bottle at n less ?an #fj revs4 p] m9ute4 ,x is !n squeez$ ?r\gh l951 ! fitrate /irr$ & filt]$ ?r\gh a fold$ filt] ( suffici5t size to hold ! entire filtrate1 return+ till cle>4 ,sixty c4c4 ( ! filtrate is !n evaporat$ & calculat$ z #ej c4c41 or ! residue ( #ej c4c4 multipli$ by #f_/e4 ,! non-tann9 filtrate mu/ give no turbidity ) a drop ( a solution ( #a p] c5t1 gelat9e & #aj p] c5t1 common salt4 ,footnote3 ,x is conv5i5t = te*nical purposes to employ ! comm]cially obta9able *rom$ hide p[d] z prep>$1 = in/ance1 by ! ,g]man ,exp]im5tal ,/ation at ,freib]g1 ,saxony4 ,"o gramme ( kaol91 fre$ f all soluble matt]1 may be add$ to ! filtrate1 or x may be us$ by mix+ x ) ! hide p[d] 9 ! %ak+ bottle4 ,! analysis ( us$ liquors & sp5t tans %all be made by ! same me?ods z are employ$ = fre% tann+ mat]ials2 ! liquors be+ dilut$1 are conc5trat$ by boil+ 9 vacuo1 or 9 a vessel s clos$ z to re/rict access ( air1 until ! tann+ matt] is if possible betwe5 #c4e & #d4e gm4 p] litre1 b 9 no case beyond a conc5tration ( #aj gm4 p] litre ( total solids1 & ! weight ( hide p[d] us$ %all n be v>i$ f #f4e gm4 ,! results %all be report$ z %[n by ! direct e/imation1 b x is desirable t 9 addition ef=ts %all be made1 by det]m9ation ( acids 9 ! orig9al solution & 9 ! non-tann9 residue1 to asc]ta9 ! am\nt ( lactic & o!r non-volatile acids absorb$ by ! hide p[d]1 & h5ce return$ z tann+ matt]s4 ,9 ! case ( tann+ mat]ials x mu/ be cle>ly /at$ 9 ! report :e!r ! calculation is on ! sample ) moi/ure z receiv$1 or ^u "s arbitr>ily assum$ p]c5tage ( wat]2 & 9 t ( liquors :e!r ! p]c5tage giv5 ref]s to weight or to grammes p] #ajj c4c41 & 9 bo? cases ! specific gravity %all be report$4 ,all analyses report$ mu/ be ! av]age result ( duplicate det]m9ations1 :i* mu/ agree 9 ! case ( liquid extracts )9 #j4f p] c5t1 & ( solid extracts )9 #a4e p] c5t1 or ! analysis %all be repeat$ until su* agreem5t is obta9$4 ,all reports %all be m>k$3 ,analys$ 9 accordance ) ! rules ( ! ,s4,l4,t4,c4 7,i4,a4,l4,t4,c47--:5 ! analyses h be5 c>ri$ out accord+ to ! me?od describ$ above4 ,z has be5 repeat$ly emphasis$ 9 ?is treatise1 ! syn!tic tann9s =m a special class ( sub/ances1 & ! results obta9$ by ei!r ( ! two hide-p[d] me?ods d n give figures :i* are always comp>able to ^? ( ! natural tann9s4 ,an example ( ! inapplicability ( ! me?ods :]e syn!tic tann9s are conc]n$ is illu/rat$ by ! behavi\r t[>ds hide p[d] ( !m :5 p>tly neutralis$ to v>y+ degrees3 comm]cial ,n]adol ,d ( acidity #a gm4 #aj c4c4 ,n_/#aj ,na,o,h conta9s #cc p] c5t4 tann+ matt]s1 completely neutralis$ ,n]adol ,d1 :i* ex]ts no true tann+ action on pelt1 /ill conta9s #bj p] c5t tann+ matt] :5 analys$ accord+ to ! ,(ficial ,me?od2 a diff]5ce h5ce exi/s reg>d+ ! adsorption by hide p[d] ( a tann9 & ! adsorption ( ! latt] by hide4 ,z1 h[ev]1 we are unable to make a di/9ction betwe5 ^! two diff]5t prop]ties by us+ hide p[d] only1 we are also unable to draw ! factor into acc\nt4 ,ano!r s\rce ( error is ! swell+ influ5ce on hide p[d] by acids2 = in/ance1 an acid extract ( vegetable tann9s w\ld %[ high] tann9 cont5ts 9 ! analysis ?an w\ld ! same extract :5 less acid4 ,! free sulphonic acid1 h[ev]1 is ! active pr9ciple 9 syn!tic tann9s1 & s9ce ! latt] always conta9 o!r acids 7( organic & inorganic orig97 devoid ( tannoid "*1 a s\rce ( error is ?us introduc$1 :i* we _c elim9ate by ! pres5t me?od ( analysis4 ,( o!r me?ods ( e/imat+ ! quality ( a tann+ mat]ial or tann+ extract ! det]m9ation ( solubility1 a%1 col\r1 & weight-giv+ prop]ties 9 addition to ! firmness imp>t$ to ! lea!r by ! p>ticul> mat]ial are ( importance4 ,z reg>ds ! syn!tic tann9s !y are z a rule v soluble & x w g5]ally be f\nd suffici5t to subject !m to ! ord9>y qualitative exam9ation4 ,! a% det]m9ation 9 syn!tic tann9s1 on ! o!r h&1 is n ( su* value z 9 ! case ( natural tann+ extracts4 ,f _! composition we "k t syn!tic tann9s conta9 consid]able quantities ( m9]al salts1 ! pres5ce ( "s ( :i* on ! "o h& emphasises _! pickl+ effect1 & t on ! o!r h& ! prop]ty ( dissolv+ phlobaph5es exhibit$ by ! syn!tic tann9s is closely connect$ ) _! salt cont5ts4 ,a col\r det]m9ation ( syn!tic tann9s is n ( mu* importance1 s9ce syn!tic tann9s ne>ly always imp>t a :ite or light br[n col\r to ! hide4 ,9 ^? cases only :]e col\r$ decomposition products appe> z a result ( int]m$i>y reactions1 may ! =m] imp>t greyi% or dirty colorations ( little beauty to ! hide4 ,?is is easily asc]ta9$ by lightly tann+ a pelt4 ,! det]m9ation ( ! weight & solidity-giv+ prop]ties is important bo? = lea!rs tann$ ) vegetable tann+ extracts & = ^? treat$ ) syn!tic tann9s1 b ! results obta9$ :5 us+ animalis$ cotton are n directly conv]tible into figures requir$ = practical purposes4 ,comp>ative figures are bett] obta9$ by actually tann+ pieces ( pelt on z practical a scale z is possible1 & te/+ ! weights & t5sile /r5g?s ( ! pieces z aga9/ ^? ( ! orig9al pelts1 :]eby 9 ! =m] case ! yield 7pelt -- lea!r7 is obta9$4 ,its capability z a tann+ ag5t may be asc]ta9$ by submitt+ ! syn!tic tann9 to an actual te/ tannage4 ,! latt] is c>ri$ out by introduc+ ! dilute extract into op5 glass j>s1 hold+ ab\t #djj c4c4 at a wid? ( ab\t #h cm4 ,footnote3 ,accumulator j>s are excell5t = ! purpose4--,transl4 ,! conc5tration ( ! solution is *os5 accord+ to acidity & salt cont5ts ( ! syn!tic tann91 ! mo/ suitable be+ #a4e-b4e ,b4 ,a piece ( bat$ pelt is susp5d$ 9 ! liquor 9 su* a way t ! pelt is completely surr\nd$ by liquor1 )\t1 h[ev]1 be+ creas$ or t\*+ ! bottom4 ,if ! pelt 7 creas$ dur+ tannage1 ! wr9kles w\ld become fix$ & w\ld %[ 9 ! f9i%$ lea!r4 ,?us an unfair judgm5t ( ! extract w\ld be deliv]$1 s9ce simil> results are produc$ by liquors :i* are ei!r too conc5trat$ or are n prop]ly compos$1 & naturally ?is prop]ty ( an extract w\ld be greatly to its disadvantage4 ,! v>i\s /ages ( tannage may be judg$ f v>i\s /&po9ts :5 exam9+ ! pelt z tannage proce$s4 ,on ! "o h&1 ! surface ( ! b slightly por\s pelt is alt]$ s z to pres5t a m por\s appe>ance1 :i* is n[ r5d]$ m capable ( absorb+ liquids4 ,on ! o!r h&1 a simil> alt]ation takes place )9 ! pelt1 to ! ext5t to :i* ! tann+ matt] has p5etrat$ x4 ,h[ f> ! p5etration has proce$$ is easily det]m9$ by utilis+ ! diff]5t adsorption ( coal-t> dyes by untann$ & tann$ pelt 7see p4 #aba74 ,an indicator = ^? syn!tic tann9s1 :i* are d]iv$ f ! ph5ols1 is f]ric *loride1 :i* only col\rs ^? p>ts ( ! pelt :i* h be5 p5etrat$ by ! syn!tic tann9s2 cle>] & bett] results are1 h[ev]1 obta9$ :5 ! dye/uffs ref]r$ to above are employ$4 ,z soon z ! tann+ matt] has completely p5etrat$ ! pelt1 ! total "t ( tannage is not$1 & ! velocity ) :i* ! tann+ matt] conv]ts ! pelt into lea!r at t p>ticul> conc5tration is ?us obta9$4 ,! tannage complet$1 ! lea!r mu/ be well wa%$ 9 runn+ wat] to remove excess ( syn!tic tann9 & !n dri$4 ,on exam9+ ! dry lea!rs1 ! col\r may !n be obs]v$1 & a cut w give an idea ( ! t5sile /r5g? & ! l5g? ( fibre ( ! lea!r4 ,! t5sile /r5g? is1 h[ev]1 n ( mu* value 9 su* a b>ely tann$ lea!r & _c be comp>$ ) t obta9$ 9 lea!rs tann$ on a practical scale4 ,! l5g? ( fibre is1 h[ev]1 ( "s importance1 s9ce a special feature ( f9i%$ lea!rs tann$ ) syn!tic tann9s is ! beautifully long fibre--a prop]ty :i* manife/s itself :5 ! lea!r is torn & 9 :i* an expression ( ! quality ( ! syn!tic tann9 may be f\nd4 ,simil>ly1 tann+ exp]im5ts comb9+ syn!tic & natural tann9s may be c>ri$ out1 ! mo/ int]e/+ features ( ^! be+ ! diff]5t proportions 9 :i* ! two products are mix$4 ,su* exp]im5ts may be done1 = in/ance1 by prep>+ #b ,b4 solutions ( ea* extract & !n mix+ !m 9 proportions (1 say1 #aj3ij1 #bj3hj1 #cj3gj1 etc4 ,"h x is aga9 possible to inf] ! tann+ int5sity ( ! syn!tic tann9 f ! conc5tration & ! "t us$ = tannage4 ,a fur!r det]m9ation ( ! quality ( a syn!tic tann9 is ! capability ( ! latt] ( dissolv+ or precipitat+ ! natural tann9s4 ,z is well kn[n1 syn!tic tann9s frequ5tly possess ! practically important prop]ty ( r5d]+ natural tann9s easily soluble 9 wat]4 ,9 "s cases1 h[ev]1 syn!tic tann9s appe> to solubilise natural tann9s 9 conc5trat$ solutions2 :51 h[ev]1 ! latt] are dilut$1 ! natural tann9 is precipitat$ ) v>y+ complet5ess1 ! reason ( :i* is (t5 ! pres5ce ( excessive acid or ! pres5ce ( su* salts z h no phlobaph5e-solubilis+ prop]ties4 ,= practical purposes ?is det]m9ation may be c>ri$ out by mix+1 9 diff]5t proportions1 conc5trat$ tann9 solutions & ! syn!tic tann92 heat+ ! mixture on ! wat] ba? = a %ort "t1 cool+ & f9ally dilut+ #aj1 #bj1 & #cj gm4 ( ! mixture to #ajj c4c41 :i* are !n left 9 measur+ cyl9d]s = twelve to tw5ty-f\r h\rs2 ! am\nt deposit$ w !n be an indication ( ! solubilis+ or precipitat+ effect exhibit$ by ! syn!tic tann94 ,o!r prop]ties ( ! syn!tic tann9s connect$ ) _! practical application w be discuss$ 9 ,"p ,,ii4 ( ?is treatise4 ,,"p ,,ii ,,syn!tic ,,tann9s3 ,,_! ,,indu/rial ,,production ,,& ,,application ,) reg>d to _! indu/rial production1 b few syn!tic tann9s are1 to-day1 ( practical & comm]cial int]e/4 ,9 addition to simplicity 9 ! me?od ( manufacture a c]ta9 degree ( purity ( ! raw mat]ials con/itutes ! crit]ion ( _! suitability4 ,! me?ods ( manufacture1 ( :i* ne>ly all are ! prop]ty ( ! ,b4,a4,s4,f41 h be5 s work$ out t ! production ( syn!tic tann9s pres5ts no difficulties on a practical scale4 ,cresols1 naph?al5es1 & high] hydroc>bons are us$ z />t+ mat]ials 9 ! production ( syn!tic tann9s2 ! =m] sub/ances or _! oxidation products are sulphonat$ by means ( conc5trat$ sulphuric acid1 & ! tann+ matt] produc$ by cond5s+ ! sulphonic acids ) =maldehyde4 ,! crude syn!tic tann9 ?us obta9$ has yet to be dilut$ & p>tly neutralis$ be=e x c be appli$ 9 practice1 & ?is is c>ri$ out by mix+ ! crude product ) /rong cau/ic lye4 ,by ^! means ! high acidity is r$uc$ to a suitable degree le>n$ f exp]i5ce on ! "o h&2 on ! o!r h&1 ! salts ( ! sulphonic acids =m valuable compon5ts ( ! comm]cial syn!tic tann9s4 ,! fir/ product plac$ on ! m>ket 0 nam$ ,n]adol ,d2 ?is repres5ts ! cond5sation product ( cresolsulphonic acid4 ,! second syn!tic tann9 0 ,n]adol ,n1 :i* repres5ts ! cond5sation product ( naph?al5esulphonic acid2 :5 dilut$ & neutralis$ to ! same ext5t z is done 9 ! case ( ,n]adol ,d1 ! product is nam$ ,n]adol ,n ,d4 ,! late/ syn!tic tann9 has be5 call$ ,ordoval ,g1 ! />t+ mat]ial ( :i* is a /ill high] hydroc>bon4 ,! tannoid-*emical prop]ties ( ^! syn!tic tann9s h be5 exhau/ively det]m9$ by ! au?or1 :o employ$ ,n]adol ,d1 :i* is mo/ suitable = su* a purpose1 & ! inve/igations relat+ to x w n[ be treat$ fully 9 ! foll[+ *apt]s4 ,! two o!r syn!tic tann9s exhibit v simil> prop]ties1 b _! few *>act]i/ics %all be %ortly dealt )4 ,! cond5sation product obta9$ by ! me?od describ$ on p4 #ee =ms a visc\s1 d>k col\r$ mass1 ! analysis ( :i* by ! %ake me?od gives ! foll[+ figures3- ,tann+ matt]s #fb4f p] c5t4 ,non tann9s #f4d ,insolubles #j4j ,wat] #ca4j --------------- #ajj4j p] c5t4 ,acidity3 #a gm4 #dj c4c4 ,n_/#aj ,na,o,h4 ,accord+ to its *emical con/itution1 ?is product may be consid]$ to be d9aph?ylme?an$isulphonic acid4 ,samples ( ?is crude1 /rongly acid mat]ial 7 p>tly neutralis$1 & ! foll[+ figures obta9$ on analysis3-- ,acidity4 ,tann+ ,soluble ,wat]4 ,matt]s4 ,non-tans4 ,p] ,c5t4 ,p] ,c5t4 ,p] ,c5t4 #a gm4 #ce c4c4 ,n_/#aj ,na,o,h #fa4h #g4j #ca4b #a #cj #eh4i #g4a #cd4j #a #be #ej4a #g4i #db4j #a #bj #db4b #h4i #dh4i #a #ae #cg4d #aj4d #eb4b #a #aj #ca4f #ac4f #ed4h #a #e #bf4c #af4f #eg4a ,exp]im5tal tann+ te/s :i* 7 c>ri$ out ) ! v>i\s p>tly neutralis$ samples yield$ lea!rs :i*1 on an av]age1 7 ne>ly :ite1 b :i* 9 comp>ison ) a lea!r tann$ ) ,n]adol ,d appe>$ r m greyi% & 7 mu* h>d]4 ,a solution ( ! half-neutralis$ sub/ance 7#a;gm4 #bj c4c4 ,n_/#aj ,na,o,h7 gives ! foll[+ reactions3--- ,gelat9e--,precipitate1 p>tly soluble 9 excess tann9 solution4 ,f]ric *loride-----,no coloration4 ,b>ium *loride-----,precipitate1 insoluble ,,hno#c4 ,brom9e wat]-----,no reaction4 ,silv] nitrate-----,no reaction4 ,anil9e hydro*loride----,precipitate1 dissolves :5 solution is heat$4 ,?is cond5sation product is v soluble 9 wat]1 b insoluble 9 mo/ solv5ts1 except+ me?yl & e?yl alcohols4 ,! above reactions %[ ! simil>ity ( ?is d9aph?yl d]ivative to ! dicresyl d]ivative1 & ! abs5ce 9 ! =m] ( *>act]i/ic reactions ) iron salts is ma9ly acc\nt$ = by its lack ( ph5olic gr\ps4 ,! abs5ce ( ?is reaction does n1 ( c\rse1 influ5ce ! tannoid "* ( d9aph?ylme?an$isulphonic acid 9 ! lea/1 & is ( no importance 9 practice1 s9ce ! v>i\s /ages ( tannage may be demon/rat$ by means ( a solution ( indigot9e4 ,f a te*nical po9t ( view ! abs5ce ( ?is reaction is advantage\s to ?is ext5t1 t x elim9ates ! exce$+ly great c>e to avoid ! contact ( tan liquors & tann$ pelt ) iron p>ticles :i* has to be obs]v$ :5 tann9s ( ph5olic "* are employ$4 ,9 a *emical & te*nological evaluation ( ?is tann+ matt]1 all ^? details apply :i* w be describ$ :5 discuss+ ,n]adol ,d4 ,! mo/ important advantage possess$ by ?is tann+ matt]1 f a comm]cial po9t ( view1 is ! l[] price :i* x owes to ! great] ease ) :i* naph?al5e may be obta9$4 ,by treat+ ! non-cond5s$ crude product ) b>ium *loride1 a product completely devoid ( sulphuric acid is easily obta9$2 ! cont5ts ( sulphuric acid calculat$ z ,ba,s,o#d is ab\t #i4e p] c5t4 ,?is value is high] ?an t f\nd by ,n]adol ,d1 & may be expla9$ by ! fact t a slight excess ( sulphuric acid is necess>y = ! prep>ation ( ,greek3 b-naph?al5esulphonic acid4 ,comp>ative tann+ te/s us+ products conta9+ sulphuric acid & products free f sulphuric acid 7neutralis$ to ! same degree ( acidity7 yield$ lea!rs :i* 7 v simil>2 ! liquor conta9+ no sulphates yield$ slightly s(t] lea!r ?an t obta9$ f a liquor conta9+ sulphates4 ,an exp]im5t 0 also c>ri$ out1 us+ a liquor conta9+ ! tann9 completely neutralis$ ) cau/ic soda & subsequ5tly acidifi$ ) acetic acid till ! acidity ( #a gm4 #aj c4c ,n_/#aj ,na,o,h2 "h1 aga91 no ess5tial diff]5ce c\ld be detect$ 9 ! lea!r z comp>$ ) t f a liquor conta9+ sulphates4 ,"o ( ! mo/ /rik+ prop]ties ( ?is tann+ matt] is its solubilis+ effect on natural tann9s & ! phlobaph5es2 ?is prop]ty may ma9ly be comp>$ to ! simil> "o ( o!r cond5s$ sulphonic acids 9 _! behavi\r t[>ds natural tann9s4 ,if1 !re=e1 natural tann9s are mix$ ) ?is product & ! solution us$ = tann+ purposes1 ! resultant lea!r w possess a d>k col\r ow+ to ! pres5ce ( solubilis$ phlobaph5es2 if1 on ! o!r h&1 a d>k col\r$ lea!r1 :i* has be5 tann$ ) natural tann9s1 is wa%$ ov] ) a #e ,b solution ( ?is syn!tic tann91 or imm]s$ = "s "t 9 ! solution1 ! lea!r assumes a light] col\r ow+ to ! phlobaph5es be+ dissolv$ & remov$ f ! lea!r by ! syn!tic tann94 ,! pres5ce ( ,n]adol ,,nd 9 lea!rs is detect$ by me?ods to be describ$ "u ,n]adol ,d 7cf4 p4 #ajh74 ,! oxyazo reaction only succe$s :5 ! solution has be5 boil$ ) a few drops ( hypo*lorite solution1 quickly cool$ & excess ( ammonia add$4 ,:5 apply+ ! indoph5ol reaction1 ! solution mu/ be treat$ z foll[s3 #c-d drops ( hypo*lorite solution is add$1 & ! solution heat$ = a %ort "t2 or #e-f drops hypo*lorite solution may be add$1 & ! solution left = "s "t1 9 :i* case ! heat+ may be omitt$4 ,! solution is !n made di/9ctly ammoniacal1 #a-b drops ( dime?yl-p-ph5yl5$iam9e solution & a lay] ( alcohol p\r$ on ! top4 ,9 mo/ cases a blue coloration w appe>2 ! addition ( #a-b drops ( potassium f]ricyanide solution ) =mation ( a blue coloration indicates ! pres5ce ( ,n]adol ,,nd )\t fail4 ,! fact t a product possess+ tann+ prop]ties may be obta9$ by cond5s+ ,greek3 b-naph?al5esulphonic acid makes x int]e/+ to inve/igate ! behavi\r ( a non-cond5s$ ,greek3 b-naph?al5esulphonic acid t[>ds pelt4 ,! foll[+ solutions 7 all[$ to act ^u pelt = twelve days3-- 7#a7 ,conc5trat$ solution ( ,greek3 a-naph?al5esulphonic acid 7#aj ,b74 7#b7 ,greek3 b- 7#f ,be47 7#c7 #b1g- 7#ah ,b474 ,solution #a swells ! pelt to a consid]able ext5t )\t1 h[ev]1 solubilis+ x4 ,solution #b produces a simil> effect4 ,solution #c dissolves ! pelt appreciably on ! fir/ day2 aft] six days1 solubilisation is complete4 ,! reason ( ?is diff]5t behavi\r ( ! mono- & disulphonic acids is ma9ly to be s\ght 9 _! diff]5ce ( solubility2 ! monosulphonic acids are n v soluble1 & are only capable ( giv+ solutions measur+ #aj & #f ,b1 respectively1 :]eas ! disulphonic acid yields an #ah ,b solution1 9 addition to :i* ! mu* high] acidity ( ! latt] quickly gelat9ises ! pelt4 ,z reg>ds ! capability ( ! naph?al5esulphonic acids ( dissolv+ phlobaph5es1 ! foll[+ results 7 obta9$3--solid ,arg5t9e quebra*o extract 0 mix$ )-- #e p]c5t1 ,greek3 a-naph?al5esulphonic acid3 opaque sol41 l>ge quantity ( insolubles4 #aj less] #bj no insolubles4 #cj #e ,greek3 b-naph?al5esulphonic acid3 opaque sol41 less] quantity ( insolubles4 #aj #bj cle> solution1 no insolubles #cj #e #b1g-naph?al5$isulphonic acid3 opaque sol41 l>ge quantity ( insolubles4 #aj #b1g z above4 #bj #b1g slightly opaque1 "s insolubles4 #cj #b1g ne>ly cle> solution1 no insolubles4 ,x is h5ce cle> t ! ,greek3 b-sulphonic acid possesses phlobaph5e-solubilis+ qualities great] ?an ^? ( ! ,greek3 a-sulphonic acid or ! disulphonic acid2 ! ,greek3 b-sulphonic acid 0 !re=e made ! subject ( ,g]4 ,pat41 #aha1bhh 7#h? ,febru>y #aiag74 ,! syn!tic tann91 ,ordoval ,g1 is ! =maldehyde cond5sation product ( high] hydroc>bons 7ma9ly ret5es71 & is a p>tly neutralis$ product conta9+ no sulphuric acid4 ,! au?or's analysis gave ! foll[+ figures3-- ,tann+ matt]s #aj4g p] c5t4 ,soluble non-tann9s #af4d ,insolubles #j4j ,wat] #gc4j ,acidity3 #a gm4 #d c4c4 ,n_/#aj ,na,o,h4 ,d5sity3 #bc ,be4 ,ordoval ,g is completely soluble 9 wat] & glacial acetic acid4 ,only its organic con/itu5ts are soluble 9 alcohol1 e?yl acetate1 & acetone1 :]eby a d>k col\r$ cry/all9e mass sep>ates4 ,ordoval ,g is insoluble 9 b5z5e4 ,! aque\s solution ( ,ordoval ,g gives ! foll[+ reactions3-- ,gelat9e ,mod]ate floccul5t precipitate4 ,f]ric *loride ,d>ki% coloration4 ,potassium di*romate ,no reaction4 ,anil9e hydro*loride ,d>k br[n precipitate4 ,=maldehyde hydro*loric acid ,no precipitate4 ,brom9e wat] ,no reaction4 ,z9c acetate ,v slight opalesc5ce4 ,b>ium *loride ,slight opalesc5ce4 ,its capability ( solubilis+ & consequ5t sav+ ( natural tann9s is %[n by ! fact t #ajj kilos ( vegetable tann+ mat]ial may be sub/itut$ by #dj kilos ( ,ordoval ,g & ! mat]ial 9 "q 9 ord] to obta9 ! entire tann+ int5sity ( ! latt]4 ,9 "o respect--t ( its salts--,ordoval ,g diff]s f ! ,n]adols2 :]eas ! *romium & alum9ium salts ( ! latt] possess no su* tannoid prop]ties z w make ! resultant lea!r exhibit any ( ! *>act]i/ics ( ei!r tannage1 x is possible to c>ry out comb9$ tannage ) a mixture ( ,ordoval ,g & metallic salts4 ,tann+ exp]im5ts c>ri$ out ) ! *romium1 iron1 alum9ium1 & calcium salts ( ,ordoval ,g yield$ lea!rs :i* possess$ proportionate *>act]i/ics ( ei!r k9d ( tannage to ! ext5t to :i* ei!r mat]ial 0 pres5t4 ,?is comb9ation tannage seems to be assur$ ( a great future2 especially may a comb9ation tannage ( iron salts & ,ordoval ,g ev5tually entirely replace *rome tannage4 ,! detection ( ,ordoval ,g 9 lea!r is c>ri$ out z foll[s3 #aj gm4 ( lea!r are boil$ ) #aej c4c4 ( acetic acid1 a solution ( #be gm4 ( ,cr,o#h 9 #be c4c4 ( a #ej p] c5t1 solution ( acetic acid gradually add$1 & ! mixture boil$ = ?ree h\rs1 till ! lea!r is decompos$ & ! solution has assum$ a br[n in/ead ( ! orig9al light yell[ col\r4 ,! solution is !n evaporat$1 ! residue dissolv$ 9 #fjj c4c4 hot wat]1 & ! *romium precipitat$ ) a #dj ,b4 solution ( cau/ic soda4 ,! solution is filt]$ & cool$1 & a little hydrosulphite is add$ to #bj c4c4 ( ! cold alkal9e filtrate2 9 ! pres5ce ( ,ordoval ,g1 a r$ col\r w appe> 7oxan?ranolsulphonic acid74 ,brief m5tion mu/ be made ( ! s-call$ ,cor9al ,footnote3 ,swiss ,pat1 #gh1bhb1 #gh1gig1 #gi1ci4 a syn!tic tann9 plac$ ^u ! m>ket by ,*em4 ,fabrik ,worms ,a4-,g41 9 ,worms-on-!-,rh9e4 ,x is a visc\s1 br[n fluid1 conta9+ ! alum9ium salts ( ! tannoid acids4 ,! latt] are =maldehyde-cond5sation products ( sulphonat$ t> oils1 or ! hydroxylat$ d]ivatives ( ! latt]4 ,! d5sity be+ #cc ,b1 x conta9s #bh4a p] c5t4 tann+ matt]s1 #ac p] c5t4 soluble non-tann9s1 & #aj4h p] c5t4 inorganic matt] 7#c4b p] c5t4 ,al#b,o#c & #g4f p] c5t4 ,na#b,,s#d4 ,a simil> product1 conta9+ *rome salts z base1 is ! s-call$ ,,esco-,,extract1 ,footnote3 ,s*orlemm]1 ,collegium1 #aiag1 #abd manufactur$ by ! ,*em4 ,fabrik ,juck] ,co4 9 ,halt+5 7,bad574 ,?is product is a d>k1 r$di%-br[n fluid1 possess+ acid reaction1 :i* /rongly precipitates gelat9e4 ,analys$ by ! filt] me?od x conta9s #ab-ae p] c5t4 tann+ matt]s1 #ag-bj p] c5t4 soluble non-tann9s1 & #ah p] c5t4 a%1 ( :i* #c p] c5t4 is ,cr#b,o#c4 ,?is syn!tic tann9 may be employ$ alone or 9 conjunction ) o!r tann9s1 & yields a lea!r simil> to t obta9$ by *rome tannage4 ,a4 ,cond5sation ( ,free ,ph5olsulphonic ,acid ,9 practice1 ! results ( cond5s+ ph5olsulphonic acid ) =maldehyde are manifold1 accord+ to :e!r ^! mat]ials are us$ 9 _! conc5trat$ or dilute /ate2 :e!r !y int]act 9 ! cold or :5 heat$2 or :e!r _! int]action is gradual or rapid4 #a4 ,if a mod]ately dilute solution ( ph5olsulphonic acid 7#a3a7 is mix$ ) "o-six? ( its volume ( a dilute =maldehyde solution 7#a "p #cj p] c5t4 ,,h*o solution plus #c p>ts ( wat]7 9 ! cold1 ) cont9u\s /irr+1 ! solution rema9s cle> & assumes a br[n col\r4 ,:5 left sev]al h\rs1 a light1 :ite floccul5t precipitate deposits1 :i* increases 9 quantity on dilut+ ) wat]4 ,! solution precipitates gelat9e2 ! floccul5t precipitate is easily soluble 9 hot cau/ic soda solution1 &1 :5 subsequ5tly neutralis$ ) acetic acid1 precipitates gelat9e4 ,if equal p>ts ( dilute ph5olsulphonic acid & dilute =maldehyde 7conc5trations z above7 are gradually mix$ 9 ! cold1 :il/ /irr+1 ! mixture soon becomes opalesc5t1 & a floccul5t deposit sep>ates aft] eighte5 to tw5ty-f\r h\rs4 ,^! exp]im5ts c>ri$ out on ! wat] ba? imm$iately yield opalesc5t liquids1 f :i* an insoluble1 br[n1 gluey1 & v /icky mass sep>ates aft] tw5ty-f\r h\rs2 ! latt] is sp>+ly soluble 9 alkalies1 p>tly s 9 organic solv5ts4 #b4 ,if a mod]ately dilute solution ( ph5olsulphonic acid 7#a3a7 is gradually mix$ ) "o-six? ( its volume ( a conc5trat$ 7#cj p] c5t47 =maldehyde solution 9 ! cold1 :il/ /irr+1 slight opalesc5ce imm$iately results1 & a floccul5t deposit sep>ates aft] ab\t tw5ty m9utes1 :i* gradually increases 9 quantity dur+ ! next few h\rs4 ,if ! volume ( =maldehyde is increas$ to ! same z t ( ph5olsulphonic acid solution1 ! floccul5t deposit imm$iately sep>ates1 & aft] tw5ty-f\r h\rs a br[n1 gluey1 & v /icky mass--( ! same solubility z t describ$ 9 ! previ\s exp]im5t--is to be f\nd at ! bottom ( ! vessel us$4 ,x %\ld be not$ t 9 bo? ^! exp]im5ts ) conc5trat$ =maldehyde solution a slight increase 9 temp]ature occurs concurr5tly ) ! process ( cond5sation4 ,if ! exp]im5ts are c>ri$ out on ! wat] ba?1 a gelat9\s mass is in/antly =m$1 :i* assumes ! col\rs ( grey1 dirty light violet & d>k violet1 9 ! ord] nam$1 & :i*1 :il/ left sev]al h\rs--or :5 heat$ on ! wat] ba?--is sudd5ly conv]t$ into ! insoluble1 br[n1 gluey mass above ref]r$ to4 #c4 ,if1 = ! purpose ( cond5sation1 ph5olsulphonic acid to :i* #aj p] c5t1 ( wat] has be5 add$1 is employ$1 ! reaction proce$s v quickly & en]getically4 ,if "o-six? ( its volume ( =maldehyde 7#a3c ( ! #cj p] c5t4 solution7 is add$ drop by drop to a cold solution ( ph5olsulphonic acid1 a r$di%1 milky solution results1 :i* assumes a slightly light] col\r on addition ( m =maldehyde & deposits an insoluble floccul5t precipitate4 ,if ! solution is kept bel[ #de ,c41 by artificial cool+1 ! light col\r is ma9ta9$1 b a gelat9\s precipitate is soon =m$1 ! viscosity ( :i* increases on /irr+1 & f9ally is conv]t$ into an insoluble1 t\gh1 gummy mass4 ,if1 on ! o!r h&1 ! mass is heat$ at ! beg9n+ ( ! reaction1 or if ! am\nt ( =maldehyde is increas$ & ! mass cool$ dur+ reaction1 eff]vesc5ce occurs1 & a *eesy1 dirty-col\r$ mass results1 :i*1 on cool+1 rapidly becomes solid & yields a v firm1 ela/ic1 rubb]y mass1 :i* is absolutely insoluble 9 wat]4 #d4 ,! cond5sation proce$s exce$+ly viol5tly :5 conc5trat$ ph5olsulphonic acid is act$ ^u by "o-six? ( its volume ( =maldehyde4 ,if ! latt] is fir/ly add$ drop by drop to ! ph5olsulphonic acid1 a gel imm$iately results1 ! temp]ature ( :i* quickly increases on fur!r addition ( =maldehyde & sudd5ly boils ov]1 yield+ a reaction product :i*1 :5 cool$1 =ms a dirty violet1 firm1 ela/ic1 & rubb]y mass1 insoluble 9 alkalies & h>dly affect$ by organic solv5ts4 ,f9ally1 if ! am\nts ( conc5trat$ ph5olsulphonic acid & =maldehyde /at$ above are mix$1 /rong eff]vesc5ce occurs & heat is evolv$1 & a dirty blacki%-violet mass is in/antly =m$ :i*1 on cool+1 yields a r brittle1 h>d product insoluble 9 wat]4 #e4 ,totally diff]5t end-products are1 h[ev]1 obta9$ :5 ! addition ( =maldehyde 7#cj p] c5t47 9 ! proportion ( "o-six? ( ! volume ( dilute ph5olsulphonic acid 7#a plus #i aq47 to ! latt] is ext5d$ ov] sev]al h\rs4 ,9 ?is case a slightly opalesc5t liquid is obta9$ :i*1 :5 left twelve h\rs1 is trans=m$ into a br[n mass soluble 9 wat]1 :i* /rongly precipitates gelat9e & possesses tann+ prop]ties4 ,h5ce direct tannoid sub/ances are obta9$ by ?is me?od ( cond5sation4 ,:]eas no direct tann+ exp]im5t c be c>ri$ out ) ! insoluble compact mass obta9$ 9 ! prep>ations describ$ above on acc\nt ( _! absolute insolubility1 x is /ill possible to c>ry out tann+ exp]im5ts ) opalesc5t colloidal solutions 9 ! foll[+ ways3-- 7a7 ,if a bat$ pelt is imm]s$ 9 a liquid conta9+ a cond5sation product obta9$ by gradually mix+ a mod]ately dilute solution ( ph5olsulphonic acid & a dilute solution ( =maldehyde1 ! pelt is rapidly tann$ on ! surface4 ,complete p5etration ( ! sub/ance does n occur ev5 aft] sev]al days1 s9ce ! /rong acidity ( ! solution causes a /rong swell+ ( ! pelt4 7b7 ,if a pelt is %ak5 = six h\rs 9 a %ak+ app>atus conta9+ ! liquid m5tion$ "u 7a71 tannage aga9 only takes place on ! surface1 p5etration be+ imp$$ by ! /rong swell+ effect ( ! liquid4 ,repetition ( ! latt] two exp]im5ts1 ) ! addition ( #ae p] c5t1 common salt1 increases ! tann+ effect to "s ext5t2 ! pelt1 h[ev]1 is n tann$ ?r\gh1 b ! non-tann$ lay]s may be cle>ly se5 to be pickl$4 ,! tann+ effects describ$ above are only exhibit$ :5 ! colloidal tan-liquor is pres5t 9 great excess ov] ! pelt1 s9ce ! =m] obvi\sly only conta9s small am\nts ( tann+ matt]1 & ev5 ! pres5ce ( common salt does n br+ ab\t complete tannage ( ! pelt4 ,9 ord] to prove ! pres5ce ( tann+ matt]s 9 ! liquid describ$ above1 sev]al fre%ly prep>$ samples ( ! latt] 7 analys$ by ! %ake me?od ( analysis )\t be+ fir/ filt]$ & ! foll[+ figures obta9$3-- #a4 #b4 #c4 #d4 ,p] ,c5t4 ,p] ,c5t4 ,p] ,c5t4 ,p] ,c5t4 ,tann+ matt]s #f4d #g4g #h4b #i4a ,soluble non-tann9s #ae4b #ag4d #ad4e #aa4h ,^! cond5sation products susp5d$ 9 wat] all precipitate gelat9e /rongly & leave beh9d a p]fectly cle> liquid4 ,9 all cases1 an int5se blue col\r 0 obta9$ on add+ f]ric *loride1 a slight precipitate only 0 obta9$ ) anil9e hydro*loride1 & brom9e 0 rapidly absorb$ ) ! sep>ation ( an insoluble :ite deposit4 ,! cond5sation products obta9$ by ! int]action ( dilute solutions ( ph5olsulphonic acid & =maldehyde at mod]ately high temp]ature1 :i* =m slimy masses & are insoluble 9 wat]1 are soluble 9 alcohol4 ,an alcoholic solution ( su* a product 0 us$ 9 a tann+ exp]im5t1 & a piece ( pelt imm]s$ 9 ! solution 0 tann$ ?r\gh 9 a few days2 ! resultant lea!r be+ r firm1 spr+y1 & slightly h>d1 & ! col\r 0 a light br[ni%-grey4 ,all ^? cond5sation products :i* are easily or p>tly soluble 9 alcohol dissolve 9 cau/ic soda1 sodium c>bonate1 9 "s cases also 9 borax & sodium sulphite4 ,!y are r5d]$ soluble ) great] ease :5 ! fre%ly prep>$ solution is heat$ on ! wat] ba? ) ! alkali2 ! alkal9e solution1 neutralis$ z f> z is possible ) acetic acid1 yields light br[n col\r$ solutions1 ! tann+ effects ( :i* h prov$ v satisfactory4 ,lea!rs tann$ 9 su* solutions1 h[ev]1 are r empty & h>d1 possess b little resili5ce & an unev51 dirty greyi%-br[n col\r4 ,a sample ( su* a product1 z ne>ly z possible neutralis$ ) acetic acid1 conta9$ #ad4h p] c5t4 tann+ matt]s1 by ! %ake me?od ( analysis4 ,b4 ,cond5sation ( ,p>tly ,neutralis$ ,ph5olsulphonic ,acid ,attempts 7 made at cond5s+ p>tly neutralis$ ph5olsulphonic acid2 ! latt] 0 obta9$ by mix+ equal quantities ( ph5olsulphonic acid & sodium ph5olsulphonate 7prep>$ by exactly neutralis+ ph5olsulphonic acid ) a conc5trat$ solution ( cau/ic soda74 ,! consequ5t dilution & decrease 9 acidity1 h[ev]1 consid]ably dim9i%$ ! velocity ( ! reaction4 ,h5ce1 if ! half-neutralis$ ,solution ,a#a 7cf4 p4 #ih7 is dilut$ ) wat]1 tak+ equal volumes1 & "o-six? ( ! volume ( dilute =maldehyde 7#a3c7 gradually add$ 9 ! cold1 cond5sation is n induc$4 ,:5 heat$ sev]al h\rs an opalesc5t liquid results f :i*1 h[ev]1 no floccul5t deposits sep>ate :5 left = "s "t4 ,us+ a conc5trat$ solution ( =maldehyde 7,exp]im5t ,a#b1 p4 #ih7 9 ! cold produces no reaction1 b aft] heat+ = a "t an opalesc5t liquid is obta9$4 ,bo? liquids give only slight precipitates ) gelat9e4 ,excess =maldehyde does n influ5ce ! reaction4 ,a repetition ( ,exp]im5t ,a#c 7cf4 p4 #ii71 us+ ! above half-neutralis$ ph5olsulphonic acid1 simil>ly requir$ heat to induce cond5sation1 :5 a milky liquid ( light r$di% col\r result$4 ,:]eas ! addition ( =maldehyde to non-neutralis$ conc5trat$ ph5olsulphonic acid caus$ viol5t reaction1 ?is proce$$ v sl[ly 9 ! case ( half-neutralis$ ph5olsulphonic acid1 result+ 9 ! =mation ( a semi-solid mass1 :i* on heat+ became m visc\s1 & f9ally1 :5 left tw5ty-f\r h\rs1 became a solid1 compact1 insoluble mass possess+ a dirty light violet col\r4 ,tann+ exp]im5ts ) ^! opalesc5t solutions prov$ !m to ex]t a rapid p5etration on ! surface1 complete tannage1 h[ev]1 tak+ place aft] eight days only1 :5 a flat1 greyi%-col\r$ & r h>d lea!r result$4 ,c4 ,cond5sation ( ,completely ,neutralis$ ,ph5olsulphonic ,acid ,if conc5trat$ ph5olsulphonic acid is gradually neutralis$ ) conc5trat$ cau/ic soda solution till ! =m] is fa9tly alkal9e1 ! sodium salt ?us obta9$ is n s easily cond5s$ ) =maldehyde z is ! case ) ! free acid4 #a4 ,if =maldehyde is gradually add$ to ! neutralis$ ph5olsulphonic acid 9 ! cold1 opalesc5ce imm$iately results2 on addition ( wat]1 ! liquid assumes a milky appe>ance4 ,on add+ gelat9e to ?is liquid1 a slimy precipitate is ?r[n d[n1 leav+ a slightly opalesc5t liquid4 #b4 ,if =maldehyde is add$ to neutralis$ ph5olsulphonic acid :il/ x is heat$ on ! wat] ba?1 a slimy mass in/antly sep>ates1 :i* on cool+ solidifies & =ms a greyi%-blue brittle mass1 insoluble 9 wat] & b sp>+ly soluble 9 alcohol2 ! alcoholic solution is capable ( conv]t+ pelt into lea!r4 ,! filtrate f ! solidifi$ mass /rongly precipitates gelat9e1 :]eas ! insoluble cond5sation product is soluble 9 cau/ic soda2 ?is alkal9e solution also precipitates gelat9e & ! addition ( acetic acid trans=ms ! mixture into ! gel /ate4 ,if ! insoluble cond5sation product is dissolv$ 9 w>m conc5trat$ sulphuric acid1 ! solution rema9s cle> ^u ! addition ( wat]1 b does n precipitate gelat9e4 ,if1 f9ally1 ?is solution is neutralis$ ) cau/ic soda1 ! solution rema9s cle> & precipitates gelat9e /rongly4 ,d4 ,cond5sation ( ,cresolsulphonic ,acid ,exp]im5ts 7 c>ri$ out ) ! object ( cond5s+ o-1 m-1 & p-cresolsulphonic acids ) =maldehyde 9 v>i\s ways2 no ess5tial diff]5ces c\ld be detect$ z reg>ds ! mode ( reaction or ! prop]ties ( ! int]m$i>y & end-products z comp>$ to ^? ( ph5olsulphonic acid4 ,simil>ly1 cond5sation ( diff]5t samples ( crude cresol conta9+ v>y+ quantities ( o-1 m-1 & p-cresol did n yield end-products suffici5tly diff]5t to ju/ify describ+ !m 9 detail4 ,e4 ,relative ,behavi\r ( an ,alkal9e ,solution ( ,bakelite & ,natural ,tann9s ,ph5olsulphonic acid 0 cond5s$ ) a little =maldehyde1 & ! r$di% pa/y cond5sation product dissolv$ 9 cau/ic soda4 ,?is alkal9e solution ( bakelite 0 exactly neutralis$ ) acetic acid & mix$ ) /rong solutions ( an untreat$ quebra*o extract4 ,x 0 obs]v$ t ! solubility ( ! quebra*o extract 0 n increas$ by ?is treatm5t1 b ! fa9tly acidic "* ( ! natural tann9 caus$ ! bakelite to be ?r[n d[n z an insoluble precipitate4 ,crude ph5olsulphonic acid1 :5 add$ to a solution ( ! quebra*o extract ref]r$ to1 does n increase ! solubility ( ! latt]1 :i* ev5 deposits consid]able am\nts ( insoluble tann9 p>ticles4 ,q diff]5t prop]ties are exhibit$ by sodium ph5olsulphonate1 :i* completely conv]ts quebra*o tann9 into a wat]-soluble sub/ance1 ! aque\s solution ( :i* deposits no insolubles4 ,! p>tly neutralis$ cond5sation product ( ph5olsulphonic acid & =maldehyde exhibits simil> prop]ties ,footnote3 ,grass]1 ,collegium1 #aiac1 #eba1 #dgh4 7see lat]74 ,f4 ,dicresylme?an$isulphonic ,acid 7,n]adol ,d7 ,footnote3 ,g]1 ,pat41 #bia1 #deg2 ,au/r4 ,pat41 #fa1 #jeg4 ,n]adol ,d is a visc\s liquid1 measur+ ab\t #cc ,b41 :i* is simil> to extracts ( natural tann9s4 ,"o ( its *>act]i/ics is its ph5olic od\r2 x is completely soluble 9 wat]1 =m+ a cle>1 semi-colloidal solution1 b is insoluble 9 all organic solv5ts ) ! exception ( alcohol1 glacial acetic acid & e?yl acetate1 :i* dissolve all b its inorganic con/itu5ts4 ,! latt] owe _! pres5ce to ! neutralisation ( ! crude ,n]adol ) cau/ic soda1 & are compos$ ( sodium salts ( ! sulphonic acid 9 addition to ,glaub] salts4 ,! aque\s solution ( ,n]adol ,d %[s prop]ties simil> to ^? exhibit$ by solutions ( natural tann9s & reacts z foll[s3--,footnote3 ,grass]1 ,collegium1 #aiac1 #ebj1 #dac4 ,me?yl orange ,acid reaction4 ,b>ium *loride ,:ite precipitate1 insoluble 9 ,,hno#c4 ,f]ric *loride ,deep blue coloration4 ,silv] nitrate ,slight opalesc5ce4 ,brom9e wat] ,no precipitate4 ,=maldehyde hydro*loric acid ,no precipitate4 ,gelat9e ,complete precipitation4 ,anil9e hydro*loride ,/rong precipitate4 ,! reactions ) f]ric *loride & gelat9e %\ld be especially not$1 s9ce !y are analog\s to ^? giv5 by natural tann9s4 ,on ! o!r h&1 ! reactions ) ,ba,cl#b1 brom9e wat] & =maldehyde hydro*loric ,footnote3 ,/iasny c>ries out ! reaction ) =maldehyde-hydro*loric acid z foll[s3--#ej c4c4 ( ! tann9 solution1 plus #e c4c4 conc5trat$ hydro*loric acid & #aj c4c4 =maldehyde 7#dj p] c5t47 are heat$ "u reflux cond5s] = t5 m9utes2 mo/ natural tann9s are completely precipitat$ 7,collegium1 #aijf1 #dce2 #aijg1 #eb et #ahh74 acid prove ! diff]5t *emical composition ( ,n]adol ,d z comp>$ to t ( ! natural tann9s4 ,! fact t a positive reaction is giv5 ) anil9e hydro*loride ,footnote3 ,?is reaction is c>ri$ out z foll[s3--#e c4c4 ( ! tann9 solution to be exam9$ 7ab\t #d gm4 tann+ matt] p] litre7 are %ak5 viol5tly 9 a te/ tube ) #j4e c4c4 anil9e & #b c4c4 conc5trat$ ,h,cl add$4 ,all natural tann9s are unaffect$ by ?is treatm5t1 lign9sulphonic & o!r sulphonic acids cause opalesc5ce4 ,note4--,employ+ =mic acid 9 lieu ( hydro*loric acid 7,kn[les7 r5d]s ! reaction no m reliable4--,transl4 is v puzzl+2 none ( ! natural tann9s are precipitat$ by ?is reag5t1 b only sulphite cellulose on acc\nt ( its cont5t ( lign9sulphonic acid4 ,"o is ju/ifi$ 9 assum+ t !re is at lea/ "s connection betwe5 ! con/itution ( lign9sulphonic acid & t ( dicresylme?an$isulphonic acid4 ,/iasny ,footnote3 ,collegium1 #aiac1 #eaf1 #adb4 recomm5ds ! foll[+ reaction = ! detection ( & diff]5tiation betwe5 ,n]adol ,d & wood pulp extract3--#aj c4c4 ( a #e p] c5t4 solution ( ! extract to be analys$ are viol5tly %ak5 ) #a-b drops ( a #a p] c5t4 alum solution & ab\t #e gm4 ( ammonium acetate4 ,if only ,n]adol ,d is pres5t no precipitate sep>ates ev5 aft] tw5ty-f\r h\rs1 b if wood pulp be pres5t1 a precipitate is ?r[n d[n 9 a quantity correspond+ to ! am\nt ( wood pulp pres5t4 ,! (ficial analysis gives ! foll[+ figures3 ,footnote3 ,grass]1 loc4 cit4 ,tann+ matt]s #cb4e p] c5t4 ,soluble non-tann9s #cc4j ,insolubles #j4j ,wat] #cd4e ------------- #ajj4j p] c5t4 ,a% #ag4j ,acidity3 #a gm4 #aj c4c4 ,n_/#aj ,na,o,h4 ,d5sity3 #cc ,b4 ,a comp>ison ( its quantitative analysis to t ( a natural tann+ extract is illu/rat$ by ! foll[+ figures ( a *e/nut & a quebra*o extract ( same d5sity 7#bf ,b73-- ,*e/nut ,quebra*o ,p] ,c5t4 ,p] ,c5t4 ,tann+ matt]s #cb4j #cd4j ,soluble non-tann9s #ab4j #h4j ,insolubles #a4e #b4j ,wat] #ed4e #ef4j ----- ----- #ajj4j #ajj4j ,a% #j4d #b4j ,?is comp>ison %[s t extracts ( natural tann9s fir/ly conta9 c]ta9 am\nts ( insolubles1 :]eas ,n]adol is completely soluble 9 wat]1 =m+ a cle> solution2 secondly1 natural tann+ extracts conta9 small] quantities ( soluble non-tann9s1 consi/+ ( col\r+ matt] & sug>s1 9 addition to small quantities ( m9]al matt]s 7a%74 ,n]adol ,d conta9s consid]able am\nts ( soluble non-tann9s1 d]iv$ f salts ( sulphonic & sulphuric acids1 aga9 (f]+ a satisfactory explanation ( ! high a%4 ,if1 !re=e1 a mixture ( ,n]adol ,d & a natural tann+ extract 0 submitt$ to a quantitative analysis1 ! high] non-tann9s & ! high a% w\ld indicate ! pres5ce ( ,n]adol ,d1 provid$ t wood pulp or a highly sulphit$ extract 7 n compon5ts ( ! mixture4 ,! *emical reactions tak+ place 9 ! prep>ation ( ,n]adol ,d may be express$ ?us3- ,,oh ,,oh ,,oh ,,oh ,h ,h,o,h ,h ,h ,h,,*#b;,h ,h ,h#b,o ,,*#b ,h v ,,*#c ,,*#c v ,h v ,,*#c ,,*#c v ,h ,,hso#c ,,hso#c ,,hso#c ,,hso#c #a4 ,n]adol ,d ,reactions #a4 ,! quantitative det]m9ation ( ph5ols introduc$ by ,bad]1 ,footnote3 ,bull4 soc4 sci5t41 ,buc>exi1 #ahii1 #h1 #ea4 :i* consi/s 9 precipitat+ !m z oxyazo comp\nds1 has be5 modifi$ by ,appelius & ,s*midt ,foot,note3 ,collegium1 #aiad1 #eig4 = ! purpose ( detect+ ,n]adol ,d3--,to #ej c4c4 ( ! tann9 solution 7analytical /r5g?7 #ae c4c4 ( diazo solution are add$1 ! mixture filt]$1 if necess>y1 & ! filtrate made alkal9e ) cau/ic soda2 9 ! pres5ce ( ,n]adol ,d 9 suffici5t quantity1 a blood-r$ coloration results4 ,if b little ,n]adol ,d be pres5t1 ! proc$ure is alt]$ z foll[s3--,! tann9 solution1 to :i* ! diazo solution has be5 add$1 is filt]$1 & ! filtrate p\r$ on a piece ( filt] pap] :i* is !n dri$2 a solution ( cau/ic soda is spott$ on ! pap]1 :51 if ,n]adol ,d be pres5t1 a r$-edg$ spot w appe>4 ,accord+ to ,ts*ir* & ,edn]1 ,footnote3 ,ar*iv4 d4 ,ph>m41 #aijg1 #aej4 ! diazo solution is prep>$ z foll[s3--#e gm4p-nitranil9e are introduc$ into a #ejj c4c4 measur+ flask1 #be c4c4 ( wat] & #f c4c4 conc5trat$ sulphuric acid add$1 ! mixture %ak5 & a solution ( #c gm4 ( sodium nitrite 9 #be c4c4 ( wat] plus #ajj c4c4 ( wat] add$1 & ! :ole !n fill$ up to #ejj c4c4 ,! solution %\ld be /ock$ 9 ! d>k4 #b4 ,a less s5sitive reaction = ,n]adol & wood pulp extract con/itutes t ( ,appelius & ,s*midt employ+ c9*on9e1 ,footnote3 ,collegium #aiad1 #eig4 :ile ! pres5ce ( ! sub/ances 9 "q yields *>act]i/ic precipitates4 #c4 ,seel & ,s&] ,footnote3 ,zeits4 f4 ang4 ,*em41 #aiaf1 #ccc4 recomm5d ! foll[+ me?od ( detect+ ,n]adol ,d3-- 7a7 ,oxyazo ,reaction4--,ab\t #e c4c4 ( ! tann9 solution are r5d]$ alkal9e ) cau/ic soda2 aft] cool+ ) ice1 ab\t half ! volume ( alcohol is add$4 #c-d drops ( diazo solution are !n add$4 ,frequ5tly1 ?is results 9 ! solution assum+ a blue coloration4 ,if n1 ! solution is acidifi$ ) hydro*loric acid1 e!r add$1 & ! mixture well %ak54 ,! wat] is n[ sep>at$ f ! mixture1 fre% wat] add$1 toge!r ) "s cau/ic soda solution1 :51 if ,n]adol ,d be pres5t1 ! salt ( ! col\r acid =m$ dissolves 9 ! wat] ) a beautiful gre5 or blui%-gre5 col\r4 ,at ! place ( contact ( ! wat] & ! e!r a blui%-gre5 r+ appe>s4 ,! diazo solution is prep>$ by dissolv+ p-am9oph5ol or its hydro*loric 9 a little dilute hydro*loric acid1 cool+ 9 ice & c>efully diazotis+ 9 ! cold till a slight excess ( nitr\s acid is pres5t4 ,x is ess5tial t ?is solution %\ld be te/$ be=e use1 & ?is is c>ri$ out by c\pl+ x ) an alkal9e ph5ol solution2 if a d>k blue oxyazo col\r is =m$1 ! solution may be us$4 ,x mu/ be kept cool by surr\nd+ x ) ice4 7b7 ,indoph5ol ,reaction4--,to #e c4c4 ( ! solution to be te/$1 a drop ( a solution ( dime?yl-p-ph5yl5$iam9e is add$1 ! solution r5d]$ alkal9e ) cau/ic soda & #a-b drops ( a #e p] c5t4 solution ( potassium f]ricyanide add$4 ,if ,n]adol ,d be pres5t1 a blue col\r appe>s1 ei!r imm$iately or aft] "s "t4 ,! reaction is r5d]$ m s5sitive if alcohol is c>efully p\r$ on ! solution aft] x has be5 r5d]$ alkal9e1 & potassium f]ricyanide is !n add$4 ,at ! place ( contact a blue lay] is =m$1 :i* ultimately diffuses into ! alcohol4 ,accord+ to ,lauffmann ,footnote3 ,collegium1 #aiag1 #bcc4 ! pres5ce ( natural tann9s z well z t ( wood pulp dim9i%es ! s5sitiv5ess ( ! reactions describ$ above2 ,footnote3 ,zeits4 f4 ang4 ,*em41 #aiaf1 #ccc4 ?is inve/igator recomm5ds a modification ( ^! reactions4 #b4 ,electro-,*emical ,behavi\r ( ,n]adol ,d ,! au?or's inve/igations ( ! electro-osmosis ( an aque\s solution ( ,n]adol ,d ,footnote3 ,collegium1 #aibj1 #eig1 #bd4 prov$ t dicresylme?an$isulphonic acid exhibits anodic migration2 h5ce ?is product possesses negative *>ge & acidic "*4 ,! impurities accompany+ ! syn!tic tann91 i4e41 salts1 free sulphuric acid1 & "s ph5ols1 migrat$ anodic & ca?odic respectively1 accord+ to _! *>ges4 ,a ,n]adol ,d purifi$ by electro-osmosis f9ally yield$ a pure solution ( dicresylme?an$isulphonic acid1 :i* precipitat$ gelat9e & exhibit$ pron\nc$ tann+ effects1 b gave a gre5i%-black coloration ) iron salts4 ,?is conclusively proves t ! blue coloration giv5 by ,n]adol ,d ) iron salts is no *>act]i/ic feature ( ! pure syn!tic tann91 b is caus$ by ! ph5olic impurities accompany+ ! latt]4 ,especially ! fir/ /age ( ! electro-osmosis produces a ca?odic migration ( ! ph5ols1 :i* may !n be detect$ at a ca?ode by means ( ! iron & brom9e reactions4 ,x is *>act]i/ic ( a dicresylme?an$isulphonic acid purifi$ by electro-osmosis t x does n precipitate anil9e hydro*loride4 ,x appe>s1 !re=e1 t ?is reaction--:i* is *>act]i/ic ( mo/ syn!tic tann9s--is aga9 caus$ by ! pres5ce ( impurities4 #c4 ,! ,influ5ce ( ,salts & ,acid ,cont5ts on ! ,tann+ ,effect ( ,n]adol ,d ,*emical analysis ( crude ,n]adol reveal$ a natural dicresylme?an$isulphonic acid 7! tann+ ag5t7 cont5ts ( ab\t #fh p] c5t1 :i* agrees fairly well ) ! calculat$ am\nt4 ,l o!r /rong & weak acids ?is sulphonic acid ex]cises a /rongly swell+ influ5ce on pelt4 ,:]eas ! effect ( acid pres5t 9 solutions ( ,n]adol ,d ( m$ium conc5tration & its tann+ effect bo? influ5ce ! pelt & are fairly well balanc$1 ?is is n ! case z reg>ds highly conc5trat$ & v dilute solutions4 ,if1 = in/ance1 a v dilute solution ( crude ,n]adol 7ab\t #j4be ,b47 is us$1 ! tann+ effect ( ?is solution is exce$+ly small & does n %[ itself till aft] sev]al h\rs4 ,! relatively high dissociation ( ! acids at ?is high degree ( dilution causes an extremely rapid & /rong swell+ ( ! pelt1 :i* has !re=e absorb$ its maximum am\nt ( wat] 7maximum swell+7 be=e ! tann+ effect ( ! sulphonic acid comes into play & by fix+ ! surface ( ! pelt is enabl$ to prev5t ! excessive swell+ effect ( ! acids4 ,! addition ( neutral salts to ! tan liquor dim9i%es ! effect ( ! acids on pelt 7dehydrates ! pelt7 & prev5ts draw+ ( ! gra94 ,if1 = in/ance1 common salt be add$ to a solution ( crude ,n]adol1 ! orig9al quantity ( sulphonic acid pres5t w\ld rema9 con/ant1 b ! pres5ce ( salt w\ld dim9i% ! degree ( dissociation & consequ5tly ! swell+4 ,?is effect is /ill m pron\nc$ :5 ! absolute am\nt ( free sulphonic acid is dim9i%$4 ,h5ce1 if crude ,n]adol is treat$ ) increas+ am\nts ( cau/ic soda1 a s]ies ( products conta9+ increas+ quantities ( salt & decreas+ conc5trations ( sulphonic acid is obta9$4 ,! acidity ( ! ,n]adols may be det]m9$ by titration ) ,n_/#aj cau/ic soda2 ?is proc$ure h5ce e/abli%es a means ( det]m9+ ! 7unkn[n7 acidities :i* may be express$ 9 t]ms ( c4c4 ,n_/#aj ,na,o,h4 ,! acidity ( crude ,n]adol 0 f\nd to be-- #a gm4 #ej c4c4 ,n_/#aj ,na,o,h i4e41 #a gm4 ( crude ,n]adol requires #ej c4c4 ,n_/#aj ,na,o,h = complete neutralisation2 ! decrease 9 acidity causes a decrease 9 cont5ts ( tann+ matt]s & ! quantities ( salts increase4 ,! foll[+ table gives ! figures obta9$ by diff]5tly neutralis$ n]adols3-- ,acidity4 ,tann+ ,matt]s4 ,na#b,,s#d4 ,p] ,c5t4 ,p] ,c5t4 #a gm4 #ej c4c4 #fh 444 #a gm4 #dj c4c4 #ei #d #a gm4 #cj c4c4 #ej #h #a gm4 #bj c4c4 #da #ab #a gm4 #aj c4c4 #cc #ag #a gm4 #e c4c4 #bh #bj #a gm4 #j c4c4 #bj 444 ,tann+ exp]im5ts ) ^! diff]5t n]adols 7employ+ solutions ( #a ,b4 /r5g?7 demon/rat$ t n]adols ( acidity #ej1 #dj1 & #cj ex]t$ /rong swell+ & gave comp>atively h>d lea!rs2 n]adols ( acidity #bj1 #aj1 & #e ex]t no swell+1 yield quick tannage & s(t lea!r4 ,! swell+ 7h>d5+7 effect ( ! acid & ! dehydrat+ 7s(t5+7 effect ( ! salts 9 ?is case1 !re=e1 are well balanc$1 & ?is fact af=ds an explanation ( ! rapid *ange f h>d5+ to s(t5+ effects exhibit$ by p>tly neutralis$ ,n]adol :]e less acid & a great] quantity ( salts respectively are pres5t4 ,x may f9ally be not$ t ! acidity ( ,n]adol ,d1 #a gm4 #aj c4c4 ,n_/#aj ,na,o,h1 has be5 f\nd to be ! mo/ suitable "o = practical purposes4 ,! au?or has1 h[ev]1 successfully employ$ "s n]adols ( consid]ably high] acidities4 ,! acidity above m5tion$ is possess$ by a ,n]adol ,d conta9+ #ag p] c5t4 a% & #cj p] c5t4 sodium sulphonates & ,glaub]'s salts cry/als respectively4 ,?is l>ge quantity ( salts pres5t on ! "o h& effects ! rapid pickle & tann+ effect exhibit$ by ,n]adol ,d1 on ! o!r h& x also effects ! s(tness 9 ! lea!r result+ f its use ei!r alone or 9 admixture ) natural tann9s4 #d4 ,phlobaph5e ,solubilis+ ,action ( ,n]adols ,a special feature ( ,n]adol ,d is its prop]ty ( solubilis+ phlobaph5es1 :i* may be ascrib$ to its cont5ts ( sulphonic acids or _! salts4 ,9 ord] to demon/rate :e!r ! sulphonic acids & _! salts are capable ( solubilis+ ! insoluble or sp>+ly soluble anhydrides ( ! tann9s 7! phlobaph5es7 be=e & aft] cond5sation1 ! foll[+ exp]im5ts 7 c>ri$ out3-- ,crude ,arg5t9e solid quebra*o extract 0 conv]t$ into a highly visc\s liquid by treat+ x = sev]al h\rs ) wat] at #ajj ,c41 & ! anhydrides r5d]$ insoluble by dilut+ ! liquid ) a l>ge volume ( cold wat]4 ,! precipitate =m$1 consi/+ ( quebra*o phlobaph5es1 0 sep>at$ f ! liquid by decantation1 & purifi$ by wa%+ x sev]al times ) wat]4 ,ea* #aj gm4 ( ?is moi/ pa/e 7 treat$ 9 ! cold ) 7a7 free ph5olsulphonic acid2 7b7 sodium ph5olsulphonate2 7c7 crude ,n]adol & 7d7 ,n]adol ,d1 #bj c4c4 ( wat] at #de ,c4 add$1 & ! mixture all[$ to cool sl[ly2 ! foll[+ solutions result$3-- 7a7 ,opalesc5t solution1 mu* deposit1 7b7 ,cle> solution1 no deposit4 7c7 ,ne>ly cle> solution1 v little deposit4 7d7 ,cle> solution1 no deposit4 ,?is cle>ly proves t free & cond5s$ ph5olsulphonic acids z su* are n capable ( completely solubilis+ phlobaph5es1 :]eas ! sodium salts ( free & cond5s$ ph5olsulphonic acids possess ?is prop]ty4 ,! salt cont5ts ( ,n]adol ,d1 !re=e1 con/itute an advantage 9 ?is respect1 t n only may ,n]adol ,d be mix$ ) solutions ( any natural tann9 )\t insolubles be+ !reby deposit$1 b x may also be add$ 9 l>ge quantities to a tann9 solution ) ! result t ! sp>+ly soluble & :olly insoluble con/itu5ts 7phlobaph5es7 are completely br\ght into solution4 ,! practical importance ( ! solubilis+ effect ( ,n]adol ,d relat+ to solid ,arg5t9e quebra*o extract is demon/rat$ 9 ! foll[+ s]ies ( inve/igations c>ri$ out by ! au?or3-- ,footnote3 ,collegium1 #aiac1 #dgh2 ,au/r4 ,pat41 #fh1 #gif4 ,solid ,n]adol ,matt]s ,tann+ ,abs4 ,increase ,arg5t9e ,d4 ,calc4 ( ,mixture ,increase p] ,quebra*o ,f\nd4 9 ,tann+ #ajj gms4 ,extract4 ,matt]s4 ,extract4 ,gm4 ,gm4 ,p] ,c5t4 ,p] ,c5t4 #ajj #j #ff4j #ff4j 444 444 #j #ajj #cb4e #cb4e 444 444 #ij #aj #fb4g #fd4g #b4j #b4b #hj #bj #ef4a #eh4g #b4f #c4c #fj #dj #eb4f #ef4i #d4c #g4a #ej #ej #di4c #ee4b #e4i #aa4h #cj #gj #db4f #dg4c #d4g #ae4f #bj #hj #ci4b #db4c #c4a #ae4e ,! maximum solubilis+ effect is exhibit$ 9 ! mixture ( #gj p>ts ( ,n]adol & #cj p>ts ( quebra*o1 ) an additional p]c5tage ( tann+ matt]s 9 ! mixture ( #ae4f p] c5t4--a figure :i* is v ne>ly id5tical ) t ( ! insolubles pres5t 9 ! orig9al ,arg5t9e quebra*o extract4 ,! phlobaph5e-solubilis+ prop]ty ( ,n]adol ,d is closely connect$ ) ! influ5ce ( ! latt] on ! col\r ( lea!rs tann$ ) natural tann9s4 ,if1 on ! "o h&1 a pelt is tann$ ) natural 7i4e41 non-treat$7 quebra*o extract1 a r light col\r$ lea!r results1 ! fle%y col\r ( :i* is *>act]i/ic ( quebra*o4 ,! d>k col\r$ phlobaph5es pres5t1 on acc\nt ( _! insolubility1 w h no influ5ce on ! col\r ( ! lea!r4 ,if1 n[1 ! quebra*o extract be treat$ ) sulphite & bisulphite 9 ! usual way1 ! phlobaph5es are solubilis$1 b ! r$uc+ effect ( ! bisulphite t5ds to bright5 ! col\r ( ! o!rwise d>k col\r$ phlobaph5es z well z t ( ! soluble tann9s1 & a r$di%-yell[ col\r$ extract results1 imp>t+ its own col\r to ! pelt4 ,:51 on ! o!r h&1 ! quebra*o extract is solubilis$ by means ( ,n]adol ,d1 ! phlobaph5es are br\ght into solution )\t r$uction tak+ place1 & a d>k br[ni%-r$ extract results1 :i* imp>ts a simil> col\r to ! f9i%$ lea!r4 ,?is d>k5+ effect ( ,n]adol ,d is mo/ conspicu\s 9 ! case ( mangrove1 maletto1 & *e/nut1 b is abs5t 9 ! case ( alg>obilla1 dividivi1 gambir1 sumac1 & valonea4 ,! v>y+ phlobaph5e cont5ts ( ! tann9s easily af=d an explanation ( ! diff]5t prop]ties above allud$ to3 ! mangrove phlobaph5es are d>k col\r$ bodies1 ^? ( mimosa1 maletto1 & *e/nut are ( light] col\r1 & ! la/-nam$ tann+ mat]ials enum]at$ above are ei!r devoid ( phlobaph5es or possess !m only z v light col\r$ bodies4 ,alg>obilla1 sumac1 gambir1 dividivi1 & valonea1 on ! o!r h&1 are associat$ ) l>ge am\nts ( sp>+ly soluble ellagic acid1 kn[n z bloom or mud :i* imp>ts a light col\r to ! f9i%$ lea!r1 & conv5i5tly cov]s ! d>k col\r imp>t$ to ! lea!r by o!r tann+ mat]ials2 = ?is reason ! =m] are (t5 us$ 9 ! lay-aways or 9 ! f9i%+ processes4 ,simil> effects to ^? ( ,n]adol ,d are exhibit$ by o!r salts ( sulphonic acids1 e4g41 sodium b5zylsulphanilate 7,solv5ol ,b4,a4,s4,f41 or solution salt 7,solutionsalz7 ,hoe*/72 ! au?or prep>$ mixtures ( su* salts & untreat$ quebra*o extract 9 ord] to det]m9e _! solubilis+ effects1 & arriv$ at ! foll[+ results3-- #cj p>ts ,solv5ol plus #gj p>ts quebra*o extract3 cle> solution1 no deposit4 #be p>ts ,solv5ol plus #be p>ts quebra*o extract3 cle> solution1 v little deposit #bj p>ts ,solv5ol plus #hj p>ts quebra*o extract3 ne>ly cle> solution1 v little deposit4 #ae p>ts ,solv5ol plus #he p>ts quebra*o extract3 slightly opaque solution "s deposit4 ,lea!rs tann$ ) ^! mixtures 7 m or less d>k col\r$ accord+ to ! am\nts us$ ( solv5ol & ! consequ5t solubilisation ( ! phlobaph5es4 ,a simil> effect1 ?\gh ( opposite nature f a tann+ /&po9t1 is exhibit$ by sulphonates on c]ta9 colloidal d>k col\r$ sub/ances4 ,a ph5olsulphonic acid1 :i* _h be5 ov]heat$ dur+ sulphonation & subsequ5tly cond5s$ 7crude ,n]adol71 imp>t$ a conspicu\s greyi%-br[n col\r to ! lea!r2 samples ( ?is crude product 7 !n p>tly neutralis$ ) v>y+ am\nts ( alkali1 & ^! samples 7conta9+ increas+ quantities ( salts7 te/$ = tann9 & col\r effects4 ,x 0 f\nd t ! m highly neutralis$ samples imp>t$ a d>k] col\r to ! solutions1 b ^! d>k products did n deposit ! d>k impurities on ! pelt4 ,"o may !re=e assume t tannoid sub/ances are colloidally susp5d$1 & :5 conv]t$ into true solutions are incapable ( be+ fix$ 9 insoluble =m by ! pelt4 ,j z1 by add+ ,n]adol ,d to a tann+ extract1 ! phlobaph5es are solubilis$ & a d>k col\r$ extract results1 x is also possible to remove ! me*anically deposit$ phlobaph5es & oxidis$ tann9s f ! f9i%$ lea!r1 &1 z a consequ5ce1 light5 ! col\r ( ! lea!r4 ,= practical purposes1 blea*+ ) ,n]adol ,d is c>ri$ out by bru%+ ov] ! d>kly col\r$ lea!r ) a #b-c ,b4 solution ( ,n]adol ,d1 & !n r9s+ well ) wat]1 9 ord] to remove ! solubilis$ tann94 ,a light] col\r may also be obta9$ by imm]s+ ! lea!r 9 a liquor ( ! /r5g? m5tion$ above = sev]al h\rs1 & !n r9s+ ) wat]1 b by ?is proc$ure n only ! surface tann9 is remov$1 b also tann9 f ! lea!r sub/ance itself2 ?is me?od is !re=e n suitable = heavy lea!rs :i* are sold by weight4 ,! advantage ( employ+ ,n]adol ,d z a blea* 9 ?is way is to be f\nd 9 ! fact t1 on ! "o h&1 ! blea*+ sulphonic acid attacks ! lea!r to a mu* slight] ext5t ?an is ! case ) inorganic acids usually employ$ = ?is purpose2 on ! o!r h&1 ! me?od ( bru%+ ! sulphonic acid on ! lea!r only introduces small am\nts ( sulphonic acid 9 ! lea!r1 ?us less5+ ! h>mful effects ( acids ^u lea!r4 ,fur!rmore1 ! common me?ods ( us+ alkalies z tann9-solubilis+ ag5ts ) ! consequ5t runn+ (f & wa/e ( alkal9e tan liquors are "h sub/itut$ by a me?od leav+ liquors ri* 9 tann9 & ,n]adol1 & :i* may be us$ 9 ! ord9>y proc$ure ( tannage4 ,s9ce ,n]adol ,d conta9s neutral sodium sulphate 7ab\t #c p] c5t471 & ! latt]1 by precipitat+ col\r+ matt]s pres5t 9 tan liquors1 may slightly blea* ^!1 x 0 ( int]e/ to det]m9e :e!r ! sodium sulphate plays any "p 9 ! blea*+ effect$ by ,n]adol4 ,mixtures ( *e/nut & quebra*o extracts 7 prep>$1 to :i* 7 add$3-- 7#a7 #e p] c5t4 ,n]adol ,d4 7#b7 #e p] c5t4 ,n]adol ,d4 free f ,na#b,,s#d4 7#c7 #ae ,p] c5t4 sodium sulphate 7correspond+ to above ,n]adol ,d74 ,^! mixtures 7 all[$ to act ^u pelt alongside ( comp>ison te/s us+ quebra*o & *e/nut extracts only1 ! /r5g? ( ! liquors 9 all cases be+ #a4e ,b2 ! pelt 0 left 9 ! solution till tann$ ?r\gh4 ,! foll[+ results 7 obta9$3-- 7#a7 ,quebra*o tann$ lea!r 0 d>k]2 no diff]5ce 9 col\r by *e/nut extract4 7#b7 ,simil> to 7,i74 7#c7 ,same col\r z giv5 by ! orig9al extracts4 ,?is exp]im5t demon/rates t abs5ce ( sodium sulphate 9 ! mixture is )\t influ5ce on ! col\r ( ! result+ lea!r1 & t an addition ( sodium sulphate to natural extracts does n affect ! col\r imp>t$ by !m to pelt #e4 ,effect ( ,n]adol ,d on ,pelt ,be+ a sulphonic acid d]ivative1 ! *emical con/itution ( ,n]adol is obvi\sly consid]ably diff]5t f t ( ! natural tann9s1 & ! "q has be5 ask$3 ,w ,n]adol ,d1 9 its conc5trat$ =m1 attack ! hide sub/ance8,footnote #a3 ,collegium1 #aiac1 #eba1 #dhg4 ,be>+ 9 m9d t conc5trat$ extracts ( vegetable tann9s 9 "s circum/ances effect a dead tannage 7cf4 case-h>d5+7 & h5ce r$uce _! practical value1 & t = ?is reason x is impossible to all[ ei!r conc5trat$ extracts or conc5trat$ ,n]adol ,d to act ^u pelt1 ! au?or /ill decid$ to c>ry out "s exp]im5ts 9 ?is direction4 ,conc5trat$ ,n]adol ,d 7#cc ,b47 & /rong aque\s solutions ( ?is mat]ial 9 /r5g?s (-- #cj #be #bj #ae #aj #e #c #a ,b4 7 !re=e all[$ to rema9 9 contact ) pelt = a p]iod ( t5 days1 :5 ! pelts 7 tak5 out & wa%$ 9 runn+ wat] = tw5ty-f\r h\rs1 & !n dri$4 ,! resultant lea!rs possess$ ! foll[+ prop]ties3-- #cc ,b4 solution3 completely gelat9is$4,footnote #b #cj ,footnote #b #be two-?irds gelat9is$2 surface tann$4 #bj "o ?ird gelat9is$2 surface dead tann$4 #ae pelt 0 glassy ?r\gh\t4 #aj r cracky lea!r1 b well tann$4 #e normal tannage4 #c #a ,footnote #b3 ,impossible to subject ! pieces to a prop] wa%+ out4 ,! int]iors ( ! lea!rs obta9$ f ! #be & #bj ,b4 solutions 7 completely gelat9is$2 ?is may be acc\nt$ = by assum+ t ! surface 0 dead tann$1 & t h5ce ! free dissociat$ sulphonic acid diffus$ into ! lea!r1 t[>ds :i* x exhibit$ hydrolys+ r ?an a tannoid effect ) ! consequ5t result describ$ above4 ,above #aj ,b4 ! effect is m t ( an acid ) conc5trations bel[ #aj ,b4--! only ones ( te*nical importance--h[ev]1 no ill-effects may be obs]v$4 ,= tann+ purposes1 ,n]adol ,d solutions ( #b ,b4 are q satisfactory1 & x has be5 f\nd ,footnote #a3 ,te*nikum1 #aiac1 #hj1 #cbd4 t solutions ( ?is /r5g? d n dissolve out any prote9 ( ! hide4 ,footnote #b3 ,! translator _c agree ) ! au?or on ?is po9t4 ,he has1 = in/ance1 f\nd t solutions ( analytical /r5g? dissolve consid]able am\nts ( hide sub/ance1 & 8 practical exp]i5ce confirms results arriv$ at 9 ! laboratory4 ,a purely ,n]adol ,d tann$ lea!r may be produc$ by imm]s+ a bat$ pelt1 free f lime1 9 a #b ,b4 ,n]adol ,d liquor = ab\t f\r days2 ! resultant lea!r be+ ne>ly :ite & o!rwise v simil> to a lea!r tann$ ) vegetable tann+ mat]ials4 ,! ma9 application ( ,n]adol ,d is 9 admixture ) vegetable tann+ mat]ials2 especially 9 ! e>ly /ages ( tannage is ?is sub/ance ( value1 s9ce by its use n only a light col\r$ lea!r surface is obta9$1 b its pres5ce prev5ts a subsequ5t dead tannage :5 /rong vegetable tan liquors are appli$1 & x also imp>ts /r5g? to ! gra9 lay]4 ,x is ?us possible to %ort5 ! "t consum$ by ! tann+ process by employ+ ,n]adol ,d 9 ! mann] describ$4 ,a fur!r explanation z to :y ! tann+ process is consid]ably ha/5$ by us+ ,n]adol ,d1 ei!r alone or 9 conjunction ) natural tann9s1 is af=d$ by ! fact t ?\gh ,n]adol ,d quickly p5etrates ! gra91 x is b loosely fix$ by ! latt]1 i4e41 x is n deposit$ to su* an ext5t t x w\ld prev5t p5etration ( ! vegetable tann9s4 ,9 ! case ( a mixture ( ,n]adol ,d & vegetable tann9s1 ! =m] quickly diffuses into ! pelt & fixes ! fibres1 ?us facilitat+ p5etration ( ! vegetable tann9s4 ,?is assumption is ju/ifi$ 9 view ( ! spe$ ) :i* ,n]adol ,d completely p5etrates & tans ! pelt1 s9ce ,n]adol ,d conta9+ acids & salts exhibits effects simil> to ^? ( a pickle4 #f4 ,reactions ( ,n]adol ,d ) ,iron & ,alkalies ,a special *>act]i/ic ( ,n]adol ,d tannage is ! s5sitiv5ess ( ! latt] to ! action ( iron & alkalies4 ,! active pr9ciple ( ,n]adol ,d be+ free dicresylme?an$isul-phonic acid1 :i* is easily neutralis$ by lime1 ammonia1 & am9o-acids & h5ce r5d]$ inactive = tann+ purposes1 x is ess5tial t ! pelt prior to tannage ) ,n]adol ,d %\ld be completely delim$1 bat$1 & fre$ f all con/itu5ts possess+ alkal9e reaction4 ,x is1 h[ev]1 possible to reg5]ate ,n]adol ,d liquors contam9at$ ) alkali or p>tly neutralis$ by ! addition ( small quantities ( organic 7=mic1 acetic1 lactic1 & butyric7 or inorganic 7hydro*loric or sulphuric7 acids1i4e41 ! dicresyl-me?an$isulphonic acid is aga9 p>tly lib]at$1 & ?is proc$ure is always pref]r$ :]e ! tann+ process does n all[ ( a complete delim+ ( ! pelt prior to introduc+ ! latt] into a ,n]adol ,d liquor4 ,if1 on ! o!r h&1 su* liquors are kept prop]ly1 & ! addition ( acid ref]r$ to kept up1 !y w rema9 active = weeks & ne$ only /r5g!n+ up ) ! requisite quantity ( ,n]adol prior to introduc+ fre% pack4 ,! s5sitiv5ess to alkalies ( ,n]adol ,d is consid]ably great] ?an 9 ! case ( natural tann9s1 & x appe>s t a vegetable tan liquor neutralis$ ) lime w n ev5 surface-tan :5 act+ ^u pelt & w nei!r imp>t a d>k col\r to ! lea!r nor remove f x any appreciable am\nt ( prote94 ,simil>ly1 a ,n]adol ,d liquor neutralis$ ) lime ex]ts no tann+ action1 b 9 contradi/9ction to ! vegetable tan liquor simil>ly treat$1 w imp>t a blue or blacki%-blue col\r to ! pelt1 f :i* x removes l>g] quantities ( prote94 ,! au?or exam9$ two su* liquors relat+ to _! cont5ts ( tann+ matt]s & prote9 & obta9$ ! foll[+ results3-- ,reaction4 ,b>k4 ,tans4 ,non-,tans ,insol4 ,prote9s ,p] ,p] ,p] ,p] ,c5t4 ,c5t4 ,c5t4 ,c5t4 ,vegetable ,slightly #ab #j #b4ic #j4ce #j4ja tan alkal9e liquor ,n]adol #aj #j #d4dc #j4ag #j4ag ,^! figures d n only %[ ! high] prote9 cont5ts ( ! ,n]adol ,d liquor1 b d also %[ high] cont5ts 9 soluble non-tann9s1 :i* consi/ ma9ly ( lime 7#b4ab p] c5t47 & sodium salts 7#a4h p] c5t471 ?us e/abli%+ ! fact ( ! s5sitiv5ess ( ,n]adol ,d to alkalies 9 addition to its lime-solubilis+ effects4 ,! s5sitiv5ess t[>ds alkalies is also noticeable on a l>ge scale :]e ! tanpits h be5 built ( cem5t2 ?\gh ! pelt may be q free f lime1 ! ,n]adol ,d is quickly neutralis$ by ! cem5t1 ) results simil> to ^? enum]at$ above4 ,! blue col\r$ soluble comp\nd ( ,n]adol ,d & iron salts1 to :i* frequ5t ref]5ce has be5 made1 is v important f a practical /&po9t4 ,:]eas ! cate*ol tann9s 7i4e41 fir1 gambir1 hemlock1 cut*1 mangrove1 & quebra*o7 are col\r$ black1 ^? ( ! pyrogallol class 7i4e41 alg>obilla1 dividivi1 valonea1 gallotannic acid1 myrabolams1 & sumac7 blui%-black1 & ! mix$ tann9s 7i4e41 canaigre1 oak1 & mimosa b>k7 blui%-purple by iron alum1 ,n]adol ,d is col\r$ a pure blue4 ,h[ s5sitive ?is reaction is1 ! foll[+ comp>ative analyses illu/rate3 to ea* litre ( tan liquor conta9+ #d gm4 tann+ matt] prep>$ f 7a7 quebra*o extract & 7b7 ,n]adol ,d1 #aj c4c4 ( a #aj p] c5t4 iron alum solution 7 add$1 ! solutions heat$ to #ajj ,c41 cool$ & filt]$1 & ! col\r ( ! filtrates & ! weight ( ! precipitates det]m9$3-- 7a7 ,quebra*o solution3 light r$di%-br[n filtrate1 #c4bb gm4 precipitate4 7b7 ,n]adol solution3 deep blue filtrate1 #j4jb gm4 precipitate4 ,h5ce1 on add+ a soluble iron salt to a solution ( a natural tann91 mo/ ( ! tann+ matt] is precipitat$2 ! col\r ( ! filtrate1 h[ev]1 is mu* ! same z t ( ! orig9al solution4 ,a ,n]adol ,d liquor simil>ly treat$ gives no precipitate1 b is col\r$ blue ?r\gh\t4 ,! filtrates f ! above solutions 7 all[$ to act ^u pelt1 & ! foll[+ obs]vations 7 made3-- 7a7 ,! light r$di%-br[n filtrate f ! quebra*o liquor exhibit$ no well-def9$ tann+ effect on pelt1 to :i* x imp>t$ a light br[n col\r4 7b7 ,on ! o!r h&1 ! deep blue filtrate f ! ,n]adol ,d liquor exhibit$ well-def9$ tann+ effects1 & imp>t$ a deep blue col\r to ! pelt4 ,= practical purposes1 ! s5sitiv5ess ( ,n]adol ,d to iron is n only rem>kable because any contact ) iron p>ticles w col\r ! liquor 7& h5ce ! pelt7 blue1 b also because ! slight am\nt ( iron always pres5t 9 cem5t r5d]s ! use ( cem5t pits prohibitive :]e ,n]adol ,d liquors are us$4 ,?is int5se blue coloration might h made possible a colorimetric e/imation ( ,n]adol ,d4 ,! au?or has inve/igat$ ?is possibility1 us+ diff]5t conc5trations ( ,n]adol ,d liquors to :i* a solution ( iron ammonium alum 0 add$1 & f\nd t :51 at c]ta9 conc5trations1 ! maximum blue col\r _h be5 obta9$1 x 0 /ill possible to increase ! quantity ( ,n]adol )\t ! int5sity ( ! col\r be+ affect$4 ,addition ( a little alkali t5ds at fir/ to d>k5 ! blue col\r1 m alkali *anges ! blue col\r to br[n & yell[1 successive additions ( a weak organic acid 7e4g41 acetic acid7 rapidly light5 ! blue col\r4 ,s9ce indu/rially us$ ,n]adol ,d liquors always conta9 v>y+ quantities ( acid & may be neutral or ev5 slightly alkal9e1 x mu/ be consid]$ impossible to make any use ( su* a colorimetric e/imation = practical purposes4 #g4 ,reag5ts ,suitable = ,demon/rat+ ! ,v>i\s ,/ages ( ,n]adol ,d ,tannage ,! ext5t to :i* tannage ) ,n]adol ,d proce$s on ! surface & )9 ! pelt may be judg$ f ! feel ( ! sk91 b su* a me?od is totally unsuit$ to any b a practical tann]4 ,a suitable & reliable reag5t is indigot9e 7,b4,a4,s4,f471 :i* cle>ly di/+ui%es tann$ & untann$ lay]s ( ! pelt4 ,if1 = in/ance1 a #a-b p] c5t1 solution ( indigot9e is br\ght into contact ) a fre% cut on a pelt1 & ! latt] subsequ5tly wa%$ ) w>m wat]1 ! indigot9e is only reta9$ by ! untann$ p>ts2 a lea!r tann$ ) ,n]adol ,d is !re=e only col\r$ by indigot9e to ! ext5t to :i* x has comb9$ ) ! ,n]adol4 ,footnote3 ,accord+ to ,seel & ,s&] 7,zeits4 f4 ang4 ,*em41 #aiaf1 #ccc71 basic dye/uffs are also v suitable = demon/rat+ tann$ p>ts ( ! pelt4 ,ano!r reag5t is con/itut$ by iron ammonium sulphate2 ! ext5t ( ! p5etration ( ,n]adol ,d1 :i* gives an int5se blue coloration ) iron salts1 into ! lea!r may be det]m9$ by wa%+ ! pelt treat$ ) ,n]adol ,d1 mak+ a cut1 aga9 wa%+ & treat+ ! cut ) a few drops ( a weak solution ( iron ammonium sulphate4 ,^? p>ts ( ! pelt :i* h be5 conv]t$ into lea!r !n appe> deep blue2 on ! o!r h&1 ^? :i* h be5 9 contact ) ,n]adol ,d1 b h n yet be5 conv]t$ into lea!r1 are light blue4 ,^? p>ts :i* h n yet be5 9 contact ) ,n]adol ,d appe> pure :ite2 ! results ( ?is reaction are !re=e opposite to ^? obta9$ by ! use ( indigot9e4 #h4 ,comb9ation ,tannages ) ,n]adol ,d ,:]eas mixtures ( ,n]adol ,d & vegetable tann9s imp>t prop]ties to ! lea!r consi/5t ) ! proportions 9 :i* ^! mat]ials are pres5t1 x is n possible to comb9e ,n]adol ,d ) m9]al tann+ ag5ts or fats 7e4g41 fi% oils1 etc47 9 su* a way t a lea!r *>act]is$ by ! prop]ties ( ei!r mat]ial is obta9$4 ,exp]im5ts 7 c>ri$ out us+ 7#a7 *rome salts plus ,n]adol ,d2 7#b7 alum9ium salts plus ,n]adol ,d2 & 7#c7 oils plus ,n]adol ,d1 & ! foll[+ conclusions 7 arriv$ at3-- #a4 ,,*rome-,,n]adol ,d liquors1 conta9+ comp>atively l>g] am\nts ( ,n]adol ,d1 act too rapidly on ! pelt & draw ! gra92 small] am\nts ( ,n]adol ,d seem )\t influ5ce on ! f9i%$ lea!r1 :i* possesses pron\nc$ *>act]i/ics ( *rome lea!r4 ,ano!r disagreeable factor is ! foll[+3 ! *rome salts mu/ possess a c]ta9 degree ( basicity 9 ord] to produce good lea!r2 ! ,n]adol ,d mu/1 on ! o!r h&1 possess a c]ta9 acidity to produce ! optimum results1 & x is h5ce impossible to balance practically ! basicity ( ! *rome salts & ! acidity ( ! ,n]adol 9 ord] to ju/ify ! pres5ce ( bo?4 ,if "o ( ! two is us$ sep>ately be=e ! o!r1 a lea!r always results possess+ ! *>act]i/ics ( ! mat]ial fir/ employ$1 provid$ ! "t ( action has be5 suffici5tly ext5d$4 ,if insuffici5t "t has be5 all[$1 ! *>act]i/ics imp>t$ by ! ma9 tann+ ag5t are n alt]$4 #b4 ,,alum9ium ,,salts ,,& ,,n]adol require practically ! same basicity & acidity respectively1 & :5 comb9$ always yield a lea!r possess+ ma9ly ! prop]ties ( "o ( ! compon5ts4 ,9 addition to ?is fact1 lea!rs tann$ ) alum9ium salts possess great s(tness & /ret*1 ^? tann$ ) ,n]adol ,d great] firmness & less /ret*1 & ^! oppos+ qualities completely comp5sate "o ano!r & r5d] nil ! value ( su* mixtures4 ,9 addition to ?is1 ! pres5ce ( alum9ium salts produces no bett] fixation on ! lea!r fibre ( basic coal-t> dyes1 s t 9 ?is respect also a comb9ation ( alum9ium salts & ,n]adol ,d is ( no value4 #c4 ,,fat ,,n]adol ,d ,,tannage3 ,j z alum9ium salts imp>t special *>act]i/ics to lea!r1 ?is prop]ty is exhibit$ by fatty matt]s1 especially s z reg>ds /ret*9ess & s(tness4 ,bo? ( ! latt] are n app>5t to ! same ext5t 9 an oil tannage into :i* ,n]adol ,d & oil ent] z con/itu5ts4 ,x is1 h[ev]1 n exclud$ t1 9 view ( ! fact t ! comb9ation ( oils & ,n]adol ,d appe> to produce ! mo/ promis+ results ( ! ?ree f a te*nical po9t ( view1 su* comb9ation w\ld yield products possess+ less /ret* & great] s(tness :i*1 by occupy+ an int]m$i>y position1 might possess c]ta9 advantages & be useful = c]ta9 te*nical purposes4 #i4 ,analysis ( ,lea!r ,conta9+ ,n]adol ,d ,*emical exam9ation ( lea!rs tann$ ) ,n]adol ,d or ) mixtures ( natural tann9s & ,n]adol ,d (t5 involve a det]m9ation ( ! mat]ials employ$ 9 tannage4 ,9 mo/ lea!rs exclusively tann$ ) vegetable tann+ mat]ials1 x is usually possible to det]m9e at lea/ ! nature ( ! ma9 tann+ ag5t1 :]eas ! attempts at det]m9+ ^? tann9s :i* are only pres5t 9 m9or quantities r>ely succe$4 ,s9ce ,n]adol ,d usually is employ$ 9 comp>atively small quantities1 x has be5 imp]ative to f9d a me?od :i* also p]mits ( ! detection ( small] quantities ( ,n]adol ,d4 ,provid$ ! pres5ce ( n less ?an #e p] c5t4 7on ! weight ( ! lea!r7 ( ,n]adol ,d1 ! foll[+ me?od yields reliable results3--#bj-cj gm4 ( ! lea!r are gr\nd or slic$ z f9ely z possible & ! p[d] 7or ! slices7 treat$ 9 ! cold ) a suffici5t volume ( dilute ammonia solution 7#e c4c4 ammonia plus #ie c4c4 ( wat]7 = eight to twelve h\rs4 ,! object ( ?is is to dissolve ! tann9s1 b no prote9 %\ld g into solution4 ,! solution is filt]$ & ! filtrate evaporat$ on ! wat] ba? till x occupies a volume ( ab\t #cj c4c4 ,a few c4c4 ( anil9e hydro*loride are n[ cauti\sly add$1 :5 x %\ld be c>efully not$ if a precipitate is ?r[n d[n :i* might be ei!r completely or only p>tly soluble 9 excess ( anil9e hydro*loride4 ,a precipitate is always ?r[n d[n :5 ,n]adol ,d or wood pulp is pres5t2 only ! ,n]adol ,d precipitate is soluble 9 excess ( anil9e hydro*loride4 ,p>tial solubility ( ! precipitate !re=e indicates ! pres5ce ( bo? wood pulp & ,n]adol ,d4 ,! quantitative det]m9ation ( sulphuric acid--! detection & e/imation ( :i* 9 lea!r is important--is consid]ably influ5c$ by ! pres5ce ( ,n]adol ,d4 ,practically all me?ods 9 vogue deal+ ) its det]m9ation 7 bas$ on ! e/imation ( ! sulphur introduc$ into lea!r by sulphuric acid4 ,! pres5ce ( ,n]adol ,d1 ! ma9 con/itu5t ( :i* is dicresylme?an$isulphonic acid1 r5d]s x impossible by su* me?ods to det]m9e :e!r ! comb9$ sulphur owes its orig9 to sulphuric or sulphonic acid4 ,x rema9s yet to be det]m9$ :e!r ! sulphonic acid influ5ces ! lea!r sub/ance to ! ext5t t sulphuric acid does2 x mu/1 h[ev]1 be borne 9 m9d t ,n]adol ,d 9 addition to free sulphonic acid also conta9s sulphonates & sulphates1 :i* may ent] into ! lea!r & ?us increase ! sulphur cont5ts ( ! latt]4 ,a me?od mu/ h5ce be devis$ :i* e/imates ! free acid only & provides ! means ( di/+ui%+ ?is f all o!r acids ( organic & inorganic acids4 ,paessl]1 ,footnote3 ,collegium1 #aiad1 #ebg1 #abf2 #eca1 #eji2 #ecb1 #efg4 by extract+ ! lea!r & dialys+ ! filtrate1 has effect$ a sep>ation ( ! acids & ! tann+ & col\r+ matt]s & quantitatively e/imat$ ! sulphuric acid 9 ! dialysate4 ,imm]heis] ,footnote #a3;,collegium1 #aiah1 #ehb1 #bic4 devis$ a me?od1 bas$ ^u ! prop]ty ( sulphuric acid ( comb9+ ) e!r1 = ! purpose ( det]m9+ free sulphuric acid 9 lea!rs3--#aj gm4 ( ! lea!r1 cut into small pieces1 are extract$ ?ree times ) #bjj c4c4 di/ill$ wat] at room temp]ature1 ! "t ( ea* extraction be+ t5 to twelve h\rs1 & ! comb9$ extracts evaporat$ to dryness on ! wat] ba?1 #e gm4 ( qu>t s& be+ add$4 ,! dry residue is n[ p[d]$1 introduc$ into an ,erl5mey] flask provid$ ) a glass /opp]1 & #bjj c4c4 ( anhydr\s e!r ,footnote #b3 ,to be te/$ = wat] by %ak+ ) anhydr\s copp] sulphate4 add$4 ,aft] ab\t two h\rs1 dur+ :i* ! flask is occasionally %ak51 ! e!r is p\r$ ?r\gh a filt]1 ! residue wa%$ ) a little e!r1 & ! op]ation repeat$ twice ) ea* #dj c4c4 anhydr\s e!r1 us+ ! same filt]4 ,to ! comb9$ e!r extracts 7ab\t #bjj c4c47 ,h,cl & ,greek3 ba,cl#b are add$1 ! e!r di/ill$ (f & ! residue evaporat$ on ! wat] ba?1 9 ord] to decompose ! e!r-sulphuric acid comp\nd4 #ej c4c1 ( hot wat] acidifi$ ) ,h,cl are n[ add$1 ! precipitate all[$ to settle1 filt]$1 wa%$1 dri$1 & weigh$4 ,! sulphuric acid ?us e/imat$ 0 pres5t 9 ! lea!r z free sulphuric acid4 ,t pres5t z sulphates soluble 9 wat] is e/imat$ 9 ! residue on ! filt]3 ! residue is extract$ ) hot wat]1 ! s& filt]$ (f1 ! filtrate acidifi$ ) ,h,cl1 boil$ = "o qu>t] h\r & filt]$ if necess>y4 ,! cle> filtrate1 :i* may be col\r$1 is br\ght to boil & ,greek3 ba,cl#b is add$4 ,! b>ium sulphate indicates ! sulphuric acid pres5t 9 ! lea!r z wat]-soluble sulphates4 ,:e!r ! latt] be sulphates or bisulphates may be indicat$ by ! aque\s extract ( ! above residue1 s9ce neutral reaction w\ld indicate ! abs5ce ( bisulphates1 acid reaction _! pres5ce 9 addition to possible normal sulphates2 ! quantitative e/imation ( ! metals w\ld decide ?is po9t def9itely4 #aj4 ,prop]ties ( ,lea!rs ,tann$ ) ,n]adol ,d ,:]eas ! col\r ( lea!rs tann$ ) ,n]adol ,d only is ne>ly a pure :ite1 ^? tann$ ) mixtures ( ,n]adol ,d & vegetable tann+ mat]ials are m or less light col\r$ accord+ to ! quantity ( ,n]adol ,d pres5t1 z has be5 expla9$ :5 discuss+ ! phlobaph5e-solubilis+ action ( ,n]adol ,d4 ,9 any case1 all lea!rs tann$ ) ,n]adol ,d possess fibre ( rem>kable l5g?1 :i* expla9s _! increas$ t5sile /r5g? & ela/icity4 ,! t5sile /r5g? ( a lea!r tann$ ) a mixture ( ,n]adol ,d & vegetable tann9s 0 #c4g p] c5t1 z comp>$ to #c p] c5t :5 no ,n]adol 0 us$2 ! ext5sion 0 #ef p] c5t1 :5 tann+ ) ,n]adol ,d z aga9/ #cf p] c5t1 )\t ! latt]4 ,! s5sitiv5ess to light ( lea!rs tann$ ) ,n]adol ,d may be m5tion$4 ,expos$ to direct sunlight1 ! surface ( ! lea!r assumes a yell[i% col\r aft] two days' exposure1 & assumes a pure yell[ col\r aft] a fur!r ?ree days4 ,a fur!r fifte5 days' exposure only d>k5s ! lea!r slightly1 ! f9al col\r be+ v little diff]5t f ! "o obta9+ aft] five days' exposure4 ,9 pass+1 x may be rem>k$ t ?is yell[ col\r is obs]v$ on ! surface only1 ! gra9 o!rwise possess+ t pure :ite col\r *>act]i/ic ( ,n]adol ,d tann$ lea!r4 ,fur!r1 x may be not$ t lea!rs tann$--) ,n]adol ,d fix basic coal-t> dyes excell5tly1 :]eas acid & sub/antive dye/uffs are fix$ ) o!r ?an _! natural %ades4 ,! au?or has analys$ a lea!r exclusively tann$ ) ,n]adol ,d1 & has obta9$ ! foll[+ results3--,footnote3 ,collegium1 #aiac1 #eba1 #dgh4 ,moi/ure - - - - - #ae4ec p] c5t4 ,a% - - - - - - #j4ic p] c5t4 ,fats- - - - - - #a4bf p] c5t4 ,extrane\s matt]s - - - #j4jj p] c5t4 ,lea!r ,sub/ance ,tann+ matt]s- #cf4ib p] c5t4 ,lea!r ,sub/ance ,hide sub/ance - #de4cf p] c5t4 --------------- #ajj4jj p] c5t4 ,footnote3 ,sp4 gr41 #j4fdb4 ,f ^! figures1 ^? ( degree ( tannage & yield 7pelt--lea!r7 are calculat$ z #ha4d & #bbj respectively4 ,^! figures correspond closely to ^? obta9$ by ! analysis ( lea!rs tann$ ) vegetable tann+ mat]ials1 & ?is proves ! simil>ity betwe5 ! ,n]adol ,d tannage & a vegetable tannage 9 _! *emical aspects4 #aa4 ,n]adol ,d ,free ,f ,sulphuric ,acid ,9 ord] to prep>e ph5ol & cresulphonic acids1 su* quantities ( te*nical sulphuric acid are us$ z d n all[ ( ! assumption ( complete utilisation ( ! sulphuric acid2 h5ce x 0 ( !oretical int]e/ to remove ev5tual traces ( free sulphuric acid f ! product4 ,= ?is purpose1 ! au?or dilut$ crude ,n]adol to #bj ,b4 & gradually add$ small quantities ( milk ( lime2 ! precipitates 7 fre$ f ! liquid by suction & wa%+1 & a ,n]adol free f sulphuric acid result$1 :i* 0 !n br\ght to ! acidity ( ,n]adol ,d ) ! calculat$ am\nt ( alkali4 ,f ! calcium sulphate precipitate1 ! am\nt ( sulphuric acid orig9ally pres5t 0 calculat$1 & 0 f\nd to be only #d p] c5t4 ,! acid-free sample ( ,n]adol 0 te/$ ) reg>d to its suitability z a tann+ ag5t2 lea!r tann$ ) ?is sample diff]$ f "o tann$ ) an untreat$ sample 7,n]adol ,d7 by be+ h>d] & possess+ a pron\nc$ly greyi% col\r4 ,?is diff]5ce1 h[ev]1 may n be due to ! abs5ce ( sulphuric acid b to ! pres5ce ( ! slightly soluble calcium sulphate 9 ! sample treat$ ) milk ( lime4 ,to prove ?is po9t1 ano!r way ( prep>+ ,n]adol ,d free f sulphuric acid 0 look$ out =4 ,sodium acetate 0 add$ to a solution ( crude ,n]adol until ! latt] 0 no long] acid to congo-r$2 at ?is po9t no free sulphuric acid c be pres5t 9 ! solution4 ,! product1 p>tly neutralis$ till ! acidity ( ,n]adol ,d 0 rea*$ 7"p ( ! acidity !n be+ due to lib]at$ acetic acid71 yield$ a lea!r :i* nei!r 9 col\r nor 9 feel diff]$ f ! usual ,n]adol ,d tann$ lea!r4 ,?is proves t ! grey col\r & ! h>dness ( ! lea!r describ$ 9 ! =m] exp]im5t is due to ! pres5ce ( calcium sulphate4 ,if ! crude ,n]adol treat$ ) sodium acetate is n p>tly neutralis$1 ! analysis gives ! foll[+ figures3-- ,tann+ matt]s #fg4c p] c5t4 ,soluble non-tann9s #h4f ,insolubles #j4j ,wat] #bd4a --------- #ajj4j p] c5t4 ,acidity3 #a gm4 #df c4c4 ,n_/#aj ,na,o,h4 ,comp>$ to ! analysis ( crude ,n]adol conta9+ sulphuric acid1 ! figures %[ t1 on ! "o h&1 ! pres5ce ( ! comp>atively small quantity ( sodium acetate b slightly influ5ces ! cont5ts ( non-tann9s & wat]1 b1 on ! o!r h&1 r$uces ! cont5ts ( tann9s & also ! acidity4 ,! tann+ int5sity ( ?is product1 h[ev]1 is consid]ably increas$1 & us+ a #a ,b4 solution a lea!r is obta9$ 9 a v %ort "t v simil> to t yield$ by ord9>y ,n]adol ,d1 b consid]ably h>d]2 ! latt] prop]ty is due to high] acidity & almo/ complete abs5ce ( salts 9 ! product treat$ ) sodium acetate4 ,! au?or f9ally attempt$ to p>tly neutralise crude ,n]adol ) v>i\s hydroxides & c>ri$ out tann+ te/s ) samples conta9+ ! diff]5t metals4 ,h>dly any diff]5ce 9 ! f9i%$ lea!rs c\ld be obs]v$ z reg>ds col\r or quality2 ! tannage c\ld by no means be describ$ z t ( a comb9ation ( ,n]adol ,d & ! respective metals4 #ab4 ,neutral ,n]adol ,crude ,n]adol1 completely neutralis$ ) cau/ic soda1 yields a product ( ! foll[+ composition3-- ,tann+ matt]s #ai4h p] c5t4 ,soluble non-tann9s #cg4i ,insolubles #j4j ,wat] #db4c ------------ #ajj4j p] c5t4 ,! qualitative reactions ( ?is product diff] f ^? ( non-neutralis$ ,n]adol to ! ext5t t gelat9e is n precipitat$ & iron salts are n col\r$ blue1 b dirty br[n1 by ! aque\s solution ( ?is product4 ,! completely neutralis$ product1 dilut$ to v>i\s conc5trations 7( #a1 #b1 #c1 & #e ,b47 & te/$ z to tann+ prop]ties1 reveal$ ! surpris+ fact t ! pelts 7 n ev5 surface tann$1 & 7 col\r$ ev5ly blue ?r\gh\t by indigot9e4 ,x might h be5 anticipat$ t sodium dicresylme?an$isulphonate w\ld be z devoid ( tann+ p[]s z is a neutralis$ vegetable tann91 b x is difficult to expla9 ! fact ( ! sodium salt be+ adsorb$ by hide p[d] z tann+ matt]s 9 ! ,(ficial ,me?od ( ,analysis4 ,br\ght to a logical conclusion1 ! figure #ai4h p] c5t1 %\ld be d$uct$ f #cb4e p] c5t1 obta9$ 9 ! analysis ( a p>tly neutralis$ ,n]adol ,d1 :i* comp>atively l>ge quantities ( ! sodium sulphonate also adsorb$ by hide p[d]1 leav+ ! tann+ matt]s ( ,n]adol ,d at #ac4e p] c5t4 ,?is dim9i%$ figure1 h[ev]1 does 9 no way r$uce ! value z a tann+ ag5t ( ,n]adol ,d2 x m]ely %[s h[ inadequate is ! hide p[d] me?od ( analysis :5 appli$ to sub/ances ( ! composition ( ,n]adol ,d4 ,?is is fur!r confirm$ by ! ,loew5?al p]manganate me?od1 :i* yields ! foll[+ figures3-- ,tann+ matt]s #g4b p] c5t4 ,soluble non-tann9s #ei4a ,footnote3 ,collegium1 #aiac1 #eba1dhg4 ,if1 on ! o!r h&1 completely neutralis$ ,n]adol is acidifi$ ) an organic acid1 su* z acetic acid1 till ! acidity1 7#a gm4 #aj c4c4 ,n_/#aj ,na,o,h7 is rea*$1 ! result+ product is 9 all respects simil> to ,n]adol ,d & yields a correspond+ lea!r4 ,x is p]missible to assume t ! irregul>ity exhibit$ by ,n]adol ,d z reg>ds ! analytical e/imation ( its tann9 cont5ts is connect$ ) ! l[ molecul> weight ( ! tann+ pr9ciple4 ,:]eas all tann9s s f> isolat$ f ! natural tann+ mat]ials possess r high molecul> weights1 t ( ,n]adol ,d deviates consid]ably f ?is rule1 z is %[n by ! foll[+ table3-- ,n]adol ,d tann9 ,cl#e;,h#af,s#b,o#h #ceh ,mangrove ,c#bd;,h#dj,o#bl #fgj ,oak b>k ,c#bh;,h#bh,o#bc #hdj ,myrabolam ,c#ed;,h#dh,o#ce #abef ,dividivi ,c#ed;,h#df,o#ce #abgj ,malletto 7,c#dl,h#ej,o#bj7b #agbd ,?is l[ molecul> weight may ma9ly acc\nt = ! figures obta9$ by ! incorrect oxymetric e/imation ) p]manganate2 ! app>5t tannoid prop]ty ( ! tannoid-inactive neutral salt ( dicresylme?an$isulphonic acid may be expla9$ by assum+ t ?\gh x is1 probably1 9 ! colloidal /ate1 & z su* adsorb$ by hide p[d]1 x is /ill devoid ( a/r+5t prop]ties4 ,g4 ,diff]5t ,me?ods ( ,cond5sation z ,appli$ to ,ph5olsulphonic ,acid ,9 addition to =maldehyde1 _m o!r sub/ances may1 !oretically1 induce cond5sation ( ph5olsulphonic acid2 cond5sation takes place ei!r ) ! elim9ation ( wat] or1 9 addition to ?is1 ) ! introduction ( me?ane gr\p4 ,s f>1 ! foll[+ cond5s+ ag5ts h be5 inve/igat$3-- 7#a7 ,heat+ 9 vacuo4 7#b7 ,sulphur *loride4 7#c7 ,phosphorus comp\nds4 7#d7 ,aldehydes4 7#e7 ,glyc]ol4 #a4 ,cond5sation ,induc$ by ,heat ,if ph5olsulphonic acid is heat$ 9 vacuo at #acj ,c4 = tw5ty h\rs1 cond5sation takes place ,footnote3 ,au/r4 ,pat41 #fd1dgi4 )\t ! addition ( any cond5s+ ag5t1 & an anhydride ( ! ,o v v ,,hso#c ,,hso#c composition is =m$4 ,?is product is a visc\s liquid1 possess+ a v corrosive action4 ,add$ to a solution ( gelat9e1 a light1 f9e floccul5t precipitate is ?r[n d[n4 ,analys$ by ! %ake me?od ( analysis1 ! tann9 cont5t ( ! product equals ab\t #df p] c5t4 ,its /rongly acidic & h5ce swell+ "* does n express qualities consi/5t ) ! conception ( suitability = tann+ purposes3 a sample ( ! product 0 !re=e p>tly neutralis$ to ! acidity ( ,n]adol ,d1 :5 ! %ake me?od ( analysis yield$ ! foll[+ figures3-- ,tann+ matt]s #ba4e p] c5t4 ,soluble non-tann9s #dh4c ,wat] #cj4b -------------- #ajj4j p] c5t4 ,?is p>tly neutralis$ sulphonic acid repres5ts a :ite1 pa/y mass1 :i* is n p>ticul>ly easily soluble 9 wat]1 yield+ a solution ( milky appe>ance4 ,treat$ ) ! usual tann9 reag5ts1 x exhibits ! foll[+ *>act]i/ics3-- ,gelat9e ,light ,floccul5t precipitate4 ,brom9e wat] ,compete fixation4 ,f]ric *loride ,*]ry-r$ coloration4 ,lead acetate ,v slight ,p]cipitate1 insoluble ,,hno#c4 ,anil9e hydro*londe ,slight p]cipitate4 ,solutions ( ?is product 9 conc5trations f #a-h ,b4 ex]t$ no tann+ action :atev]1 :]eas m conc5trat$ solutions 7#ae ,b47 conv]t$ pelt 9 eight days into a lea!r v simil> to a ,n]adol ,d lea!r 9 col\r & feel1 b consid]ably h>d]4 ,9 ord] to det]m9e its phlobaph5e-solubilis+ effects1 samples( ! product 7 mix$ ) conc5trat$ quebra*o extract 9 ! proportions #e1aj1 #bj1 & #cj p] c5t4 on ! weight ( extract1 & ! foll[+ obs]vations made3--#e & #aj p] c5t4 7 )\t effect1 #bj & #cj p] c5t4 %[$ "s solubilis+ t5d5cy1 b on dilut+ ! mixture ) wat] ! quebra*o 0 completely ?r[n out ( solution4 ,app>5tly ?is anhydride is1 9 ?is respect also1 q diff]5t f ! p>tly neutralis$ diph5ylme?an$isulphonic acid4 #b4 ,cond5sation ) ,sulphur ,*loride ,:5 sulphur *loride is all[$ to act ^u ph5olsulphonic acid :il/ heat is appli$1 a yell[i%-grey mass results1 :i* dissolves 9 wat]1 =m+ a r$di%-yell[ solution4 ,neutralis$ to acidity #aj1 x exhibits ! foll[+ reactions3-- ,gelat9e----------------,precipitate4 ,f]ric *loride---------,deep blue coloration4 ,lead acetate------------,:ite precipitate1 insoluble ,,hno#c4 ,anil9e hydro*loride---,precipitate4 ,brom9e wat]-----------,no reaction4 ,! p>tly neutralis$ #b ,b4 solution ( ?is product yield$ a r$di%-grey col\r$ lea!r1 ! qualities ( :i* 7 v simil> to t yield$ by ,n]adol ,d4 #c4 ,cond5sation ) ,phosphorus ,comp\nds ,s*iff's well-kn[n syn!sis1 ,footnote3 ,liebig's ,ann41 #agh1 #agc4 9 :i* phosphorus oxy*loride int]acts ) ph5olsulphonic acid1 yields a product :i* exhibits "s tann9 reactions1 b :i*1 :5 act+ on pelt1 conv]ts ! latt] into a lea!r :i*1 :5 dri$1 is v cracky4 ,if1 on ! o!r h&1 cresolsulphonic acid is cond5s$ ) phosphorus oxy*loride by heat+ ! two toge!r1 products em95tly suitable = tann+ purposes result4 ,^! products are non-cry/all9e bodies easily soluble 9 wat]1 & are col\r$ blui%-violet by f]ric *loride & precipitate gelat9e4 ,solutions ( ! free acids & acidifi$ solutions ( ! salts conv]t pelt into firm & :ite lea!rs possess+ great s(tness & pliability4,footnote3 ,au/r4 ,pat1 #ff1hie4 #d4 ,cond5sation ) ,aldehydes ,by treat+ ph5olsulphonic acid ) acetaldehyde 9 ! usual way1 a visc\s br[n mass is obta9$1 :i* is v soluble 9 wat]1 ! solution be+ ( a br[n col\r4 ,:5 br\ght to acidity #aj1 ! foll[+ reactions are exhibit$ by ! product3-- ,gelat9e - - - ,precipitate4 ,f]ric *loride - - ,deep blue coloration4 ,aque\s ammonia - - ,*]ry-r$ coloration4 ,lead acetate - - - ,yell[i% precipitate1 insoluble ,,hno#c4 ,anil9e hydro*loride - - ,yell[ precipitate1 soluble excess anil9e4 ,brom9e wat]- - - ,no reaction4 ,tann+ exp]im5ts ) ?is sub/ance yield$1 ev5 aft] ext5d$ tannage1 an und]tann$ lea!r1 ! surfaces be+ col\r$ br[n1 ! inn] lay]s1 h[ev]1 :ite4 ,fur!r neutralisation r$uces ! tann+ int5sity ( ! product2 ! addition ( sodium sulphate to ! orig9al p>tly neutralis$ product ha/5$ tannage1 ! lea!r1 h[ev]1 possess+ d>k col\r & be+ und]tann$4 ,! foll[+ con/itution may be ascrib$ to ?is product3-- ,,oh ,,oh ---,,*#b---;,,*#b--- v v ,,hso#c ,,hso#c ,if b5zaldehyde is us$ 9 lieu ( acetaldehyde = cond5s+ ph5olsulphonic acid1 a wat]-soluble product results1 exhibit+ reactions simil> to ^? ( ! acetaldehyde-cond5sation product4 ,! =m] product is m suitable z a tann+ ag5t & yields a r$di%-br[n r firm & h>d lea!r2 x possesses ! con/itution-- ,h ,,oh ,,oh ,c v v ,,hso#c v ,,hso#c ,= ! purpose ( cond5s+ ph5ol ) =maldehyde1 x is n ess5tial to fir/ conv]t ! ph5ol into ! wat]-soluble ph5olsulphonic acid1 s9ce x is possible to conv]t ! cond5sation products ( ph5ol & its d]ivatives1 :i* are soluble 9 alkali1 into wat]-soluble =m by ei!r heat+ ! cond5sation products ) conc5trat$ solutions ( =maldehyde & neutral sulphites1 or by dissolv+ ! cond5sation products 9 alkali & induc+ reaction by means ( =maldehyde bisulphite4 ,footnote3 ,collegium1 #aiac1 #eah1 #cbd4 ,highly conc5trat$ solutions result1 :i* may be conc5trat$ ei!r z su* or aft] ! alkali pres5t has be5 neutralis$4 ,! sulphur\s acid =m$ prev5ts oxidation ( ! product on evaporation4 ,a special advantage ( ?is me?od ( prep>ation is ! fact t sulphuric acid1 :i* is b difficultly remov$ f ! end-product1 is n employ$ at all4 ,! product ?us obta9$ is a yell[i%-:ite crumbly mass1 :i* is v soluble 9 wat]1 =m+ a cle> solution4 ,! latt] exhibits ! foll[+ reactions3-- ,gelat9e---------------,precipitate4 ,f]ric *loride--------,deep blue coloration4 ,aque\s ammonia--------,*]ry-r$ coloration4 ,lead acetate-----------,:ite precipitate1 insoluble 9 ,,hno#c4 ,anil9e hydro*loride--,precipitate4 ,brom9e wat]----------,no reaction4 ,! product br\ght to acidity #aj1 yield$ on analysis ! foll[+ figures3-- ,tann+ matt]s------------------ #be4b p] c5t4 ,soluble non-tann9s-------------- #ef4c ,insolubles----------------------- #j4j ,wat]---------------------------- #ah4c ------------- #ajj4j p] c5t4 ,tann+ exp]im5ts ) ?is sub/ance yield$ :ite & s(t lea!rs1 :i* 7 indi/+ui%able f ^? tann$ ) ,n]adol ,d4 ,a *>act]i/ic feature ( ?is syn!tic tann9 is its behavi\r 9 conc5trat$ =m t[>ds pelt1 :i* is n attack$ by x1 b is readily tann$ ev5 at su* high conc5trations4 ,an explanation ( ?is is to be f\nd 9 ! l>ge quantity ( salts pres5t 9 ! product4 ,a disadvantage ( ?is syn!tic tann9 is its complete incapability ( dissolv+ phlobaph5es1 :i* is ev5 s f> ext5d$ z to precipitate o!rwise easily soluble tann9s :5 add+ x to solutions ( ! latt] 9 comp>atively l>ge proportions2 "h1 aga91 ! salts are responsible = ?is behavi\r1 _! l>ge quantities effect+ a salt+ out ( ! natural tann9s4 ,! class ( aldehyde cond5sations also comprises t ( induc+ cond5sation by means ( sug>s2 if ph5olsulphonic acid is heat$ ) glucose1 a r$di%-br[n liquid results1 :i* is soluble 9 wat]4 ,! solution exhibits reactions simil> to ^? ( ,n]adol ,d4 ,x is1 h[ev]1 n possible1 by ?is me?od ( cond5sation1 to prep>e z highly conc5trat$ products z is possible 9 ! case ( ,n]adol ,d1 s9ce employ+ sug>s z cond5sation ag5ts means lib]ation ( a l>ge volume ( wat]4 ,analysis ( ?is product1 us+ ! %ake me?od1 gives a tann9 cont5t ( #af4b p] c5t2 tann+ exp]im5ts demon/rat$ t ! "t ( tannage1 us+ a #b ,b4 solution1 0 ! same z t requir$ by ,n]adol ,d1 & yield$ a lea!r1 ! surface ( :i* 0 r$di%-grey1 ! inn] lay]s be+ :ite1 b :i* is o!rwise v simil> to ,n]adol ,d tann$ lea!r4 ,footnote3 ,au/r4 ,pat1 #fi1cge1 #fi1cgf1 #fi1cgg4 ,relatively to its capability ( solubilis+ phlobaph5es1 ?is product exhibits simil> prop]ties to t obta9$ by m]ely heat+ ph5olsulphonic acid1 to a slight ext5t only solubilis+ quebra*o extract1 :i*1 on dilut+ ! mixture1 is completely ?r[n out ( solution4 #e4 ,cond5sation ) ,glyc]ol ,ph5olsulphonic acid1 :5 heat$ ) glyc]ol1 und]goes ! process ( cond5sation1 & =ms a br[n fluid1 :i*1 :5 br\ght to acidity #aj1 exhibits ! foll[+ reactions3-- ,gelat9e-----------------,precipitate4 ,f]ric *loride----------,br[n-black coloration4 ,lead acetate-------------,:ite precipitate1 insoluble 9 ,,hno#c4 ,anil9e hydro*loride----,slight precipitate4 ,tann+ exp]im5ts ) ?is p>tly neutralis$ product result$ 9 a v gradual conv]sion ( ! pelt into a gre5i%-grey col\r$ lea!r2 ! col\r1 h[ev]1 does n p5etrate ! pelt & is h5ce caus$ by colloidally susp5d$ impurities4 ,if ! solution is filt]$ ?r\gh a filt] c&le1 a some:at cle>] solution results1 b ! latt] also tans v sl[ly & yields a br[n col\r$ lea!r4 ,analysis ( ! p>tly neutralis$ product reveals a tann9 cont5t ( #ag4f p] c5t4 ,a #b ,b4 solution ( ! non-neutralis$ product %[$ a rapid tann+ effect at fir/1 :5 br\ght into contact ) pelt1 on :i* x _h a /rong swell+ effect1 & to :i* x imp>t$ a gre5i% col\r2 ! tann+ effect1 h[ev]1 sl[$ d[n consid]ably1 aft] a few days1 & ! solution p5etrat$ ! pelt only v gradually2 ?is is probably due to ! pres5ce ( l>ge quantities ( colloidally susp5d$ impurities1 :i*1 :5 ! sub/ance is p>tly neutralis$ ) ! =mation ( salts ( ! sulphonic acids1 are br\ght into true solution & h5ce p5etrate ! pelt ) great] rapidity4 ,,index ,,( ,,au?ors ,adl] ,appelius ,a%more ,bad] ,badis*e ,anil9 u47,g]man abbreviation = und7 ,soda-,fabrik ,baekel& ,baey] ,b]zelius ,big9elli ,boehr+] ,sons ,bott+] ,braconnot ,buff ,c>o ,*em4 ,fabrik ,juck] ,co4 ,*evreul ,dekk] ,deuts*-,koloniale ,g]b u4 ,f>b/(f ,gesells*aft ,deyeux ,diz ,drabble ,edn] ,elb]feld] ,f>b5fabrik5 ,fahrion ,fei/ ,fis*]1 ,e4 ,freud5b]g ,froda ,g]h>dt ,gesells*aft f47,g]man abbreviation = fr7 ,*em4 ,indu/rie1 ,basle ,graebe ,graham ,grass] ,hat*ett ,he9emann ,h]zig ,h]zog ,hnig ,ilj9 ,imm]heis] ,j5n+s ,kahl ,kaus*ke ,klepl ,knig ,ko/anecki ,krafft ,krauss ,kunzemll] ,lauffmann ,liebig ,lipp ,lloyd ,lwe ,mann+ ,mau?n] ,meuni] ,mi*ael ,mielke ,mits*]li* ,ni]5/e9 ,paessl] ,pat]n ,payne ,pel\ze ,p]k9 ,pr\/ ,rapoport ,ras*ig ,re9s* ,res* ,russan[ ,sabanajew ,s&] ,s*eele ,s*iff ,s*midt ,s*orlemm] ,seel ,seyewetz ,sisley ,skey ,/iasny ,/rauss ,?uau ,ts*ir* ,vogel ,wald5 ,web/] ,we9s*5k ,wohl ,za*>ias ,a ,alcohol figure ,alg>obilla ,aliz>9 ,aliz>9 yell[1 9 pa/e ,alkalies1 reaction (1 to ,n]adol ,d ,alum-n]adol tannage ,alum tannage ,am9ob5z5e ,am9oph5ol1 p- ,anil9e dyes ,an?rac5e ,an?raqu9one ,arylsulpham9o>ylsulphonic acids ,arylsulphoxy>ylsulpho acids ,b ,bakelite ,bakelite solution ,b5zoylam9o #f-;*loran?raqu9one ,b5zylsulphanilate sodium ,bismu? salts ,blea*+ me?od = lea!r ) ,n]adol ,d ,bloom ,bromo-,greek3 b-naph?ol ,bromonitroph5ol ,bromophlorogluc9ol ,bromosalicylic acid ,bromotr9itroph5ol ,c ,c>bazole ,c>bome?oxyhydroxyb5zoic acid1 ,c>bome?oxyhydroxyb5zoic acid *loride1 ,cate*9e ,cate*ol ,c]ium salts ,c]uleoellagic acid ,cesium salts ,*e/nut wood extract ,*loronaph?al5esulphonic acid ,*loroph5ol ,*rome-,n]adol ,d tannage ,*rome salts ,*rome tannage ,coal1 bitum9\s ,c(fee tann9 ,comb9ation tannage ) ,ordoval ,comb9ation tannage ) ,n]adol ,d ,cond5sation by heat ,cond5sation me?ods ,cond5sation ) aldehydes ,cond5sation ) glyc]ol ,cond5sation ) phosphorus comp\nds ,cond5sation ) sulphur *loride ,copp] salts ,cor9al ,cresol ,cresol-p-sulphonic acid1 o- ,cresolsulphonic acid ,cresot9ic acid ,d ,depsides ,detannisation ) hide p[d] ,diam9oan?raqu9one ,diam9onaph?ylme?an$isulphonic acid ,dianil9oqu9one ,dib5zopyrrol ,di-,greek3 b-oxynaph?oic ,di-,greek3 b-resorcylic acid ,di*loran?raqu9one ,di*loronaph?ylme?an$isulphonic acid ,dicresylme?an$isulphonic acid ,dicresylme?an$isulphonic acid purifi$ electro-osmotically ,dicresylme?ane sulphonate sodium ,didepsides ,didymium salts ,dif]ulic acid ,digallic acid ,digallic acid1 ,greek3 b- ,digallic acid1 inactive ,digallic acid1 m- ,digalloylleucodigallic acid anhydride ,dig5tis9ic acid ,dihydric alcohols1 aromatic ,dihydroxyb5z5e1 m- ,dihydroxyb5z5e1 o- ,dihydroxyb5z5e1 p- ,dihydroxyb5z5es ,dime?ylanil9e ,dime?ylellagic acid ,di-m-oxyb5zoic acid ,d9aph?ylme?an$isulphonic acid ,d9itronaph?ylme?an$isulphonic acid ,di-o-cum>ic acid ,diorsellic acid1 o- ,diorsellic acid1 p- ,dioxyellagic acid ,dioxynaph?ylme?an$isulphonic acid ,dioxytoluic acid ,diph5ylme?ane ,diph5ylme?an$isulphonic acid ,di-p-hydroxyb5zoic acid ,diprotocate*uic acid ,disalicylic acid ,disyr+ic acid ,di?ionaph?ylme?an$isulphonic acid ,dividivi ,dividivi tann9 ,dixylylme?an$isulphonic acid ,e ,electro-*emical behavi\r ( ,n]adol ,d ,electro-osmosis ( ,n]adol ,d ,ellagic acid ,ellagitannic acid ,empirical =mula ( tann9 ,ery?r9e ,esco-extract ,e/] =mula ( tann9 ,e?yl acetate figure ,f ,fat-,n]adol ,d tannage ,f]uloyl-p-oxyb5zoic acid ,flavellagic acid ,fluor5e ,=maldehyde ,=maldehyde tannage ,g ,g-acid ,gallate e?yl ,gallic acid ,gall(lav9e ,galloyl-p-hydroxyb5zoic acid ,galls1 oak ,gall tann9 ,g5]ator t> ,guaiacol ,h ,halog5s ,hepta-trib5zoyl-galloyl-p-iodoph5ylmalt osazone ,hexahydroxyaur9ec>boxylic acid ,hexoxyan?raqu9one ,hexoxydiph5yl ,hexoxydiph5yldic>boxylic acid ,hexoxydiph5ylme?an$ic>boxylic acid ,humic acid ,hydrolysis ( tann9s ,hydroqu9one ,hydroxyb5zoate sodium1 m- ,hydroxyb5zoate sodium1 p- ,hydroxyb5zoic acid1 p- ,hydroxyb5zoic acid ,hydroxy-cym5es ,i ,indoph5ol reaction ,iron1 reaction (1 to ,n]adol ,d ,iron salts ,k ,ketone =mula ( tann9 ,l ,lan?anum salts ,lead salts ,lea!r analysis 9 pres5ce ( ,n]adol ,d ,lecanoric acid ,leucodigallic acid ,leucoellagic acid ,leucotann9 ,lignite ,luteic acid ,m ,malletto tann9 ,mangrove tann9 ,melangallic acid ,m]cury salts ,metellagic acid ,me?ylam9o-#d-;broman?raqu9one ,me?yl5$9aph?ol ,me?yl5$isalicylic acid ,me?yl5$isalicylic acid1 brom9at$ ,me?yl5$isalicylic acid1 iodis$ ,me?ylisopropylph5an?r5e ,me?ylotann9 ,molybd5um figure ,mono*loro-p-dihydroxyb5z5e ,mud ,myrabolams ,myrabolams1 tann9 ,n ,naph?al5esulphonic acid1 ,greek3 b- ,naph?ol1 ,greek3 a- ,naph?ol1 ,greek3 b- ,naph?ol-,greek3 a-me?anesulphonic acid ,naph?oldisulphonic acid ,naph?olmonosulphonic acid ,naph?olsulphonic acid1 ,greek3 a- ,naph?olsulphonic acid1 ,greek3 b- ,neodymium salts ,n]adol ,d ,n]adol ,d tann9 ,n]adol ,n ,n]adol ,,nd ,n]adol ,,nd1 neutral ,nitronaph?al5esulphonic acid ,nitroph5ol1 o- ,nitrosodime?ylanil9e ,non-tann9s ,novolak ,o ,oak b>k ,oak b>k tann9 ,(ficial me?od ( tann9 analysis ,orc9ol ,ordoval ,g ,orsellic acid ,orsell9oyl-p-oxyb5zoic acid ,oxyan?raqu9one ,oxyazo reaction ,oxyb5zoyl-m-hydroxyb5zoic acid ,oxyb5zoyl-p-hydroxyb5zoic acid1 m- ,oxyb5zoylsyr+ic acid ,oxynaph?oyl-p-hydroxyb5zoic acid1 a- ,oxynaph?ylme?anesulphonic acid ,oxyph5ylme?anesulphonic acid ,oxyqu9ol9e ,p ,,pat5ts-- ,au/rian #eh1dje2 #fa1jeg2 #fa1jfa2 #fd1dgi2 #ff1hie2 #fh1gif2 #fi1aid2 #fi1cge2 #fi1cgf2 #fi1cgg2 #gj1afb ,g]man #gb1afa2 #aaa1djh2 #aab1ahc2 #acb1bbd2 #aha1bhh2 #ahd1ddi2 #bjj1eci2 #bjf1ieg2 #baa1djc2 #bfb1eeh2 #bhb1cac2 #bhf1efh2 #bij1ife2 #bia1deg2 #bic1jdb2 #bic1fdj2 #bic1fic2 #big1ahg2 #big1ahh2 #cjj1efg2 #cjc1fdj2 #cje1eaf2 #cai1gac2 #cbj1fac ,swiss #gh1bhb2 #gh1gig2 #gi1aci ,u4,s4,a4 #a1fci1agd ,peat ,pelts ,pelts1 action on1 ( ,n]adol ,d ,p5ta-p-hydroxyb5zoyl glucose1 ,p5ta-p-me?yl-m-digalloyl-glucose ,p5ta-pyrogalloylc>boyl-glucose ,p5tacetylleucotann9 ,p5tacetyl-m-digallic acid ,p5tacetyl tann9 ,p5tadigalloylglucose ,p5tagalloylglucose ,p5tagalloylglucoside ,p5tame?yldigallic acid1 me?yl e/] ,p5tame?yl-m-digalloyl *loride1 ,p5tame?yl-m-digallic acid ,p5tame?yl-m-digallic acid me?yl e/] ,p5tame?yl-p-digallic acid ,p5tame?yl-p-digallic acid me?yl e/] ,p5tame?oxybiph5ylme?ylolide c>boxylic acid me?yl e/] ,p5toxybiph5ylme?ylolide ,p5toxybiph5ylme?ylolide c>boxylic acid ,ph5an?raqu9one ,ph5olsulphonate sodium ,ph5olsulphonic acid ,ph5olsulphonic acid anhydride ,ph5ol1 tautom]ic ,ph5ylc>boxylic acid ,ph5ylhydraz9e d]ivatives ( tann9 ,ph5ylhydraz9e ellagic acid ,phlobaph5e ,phlobaph5e-solubilis+ action ( n]adols ,phlorogluc9ol ,ph?alic acid ,pickl+ ,picric acid ,plat9um salts ,polydepsides ,polydigalloylleucodigallic acid anhydride ,polyhydroxyb5z5es ,pomegranate ,prep>ation ( tann9 infusion ,prop]ties ( lea!r tann$ ) ,n]adol ,protocate*uic acid ,protocate*uyl-p-hydroxybemoic acid ,pseudo-tannage ,purpuro tann9 ,pyrogallol ,pyrogallic acid ,pyrogalloylc>boyl-p-oxyb5zoic acid ,pyruvic acid ,q ,qu9az>5e ,qu9ol9e ,qu9one ,r ,r-acid ,reaction1 ,proct]-,hir/ ,reag5ts = ,n]adol ,d tannage ,resites ,resitol ,resols ,resorc9ol ,resorcylic acid1 ,greek3 b- ,ret5e ,ros9s1 acid ,rosolic acid ,rufigallic acid ,s ,s-acid ,salicylic acid ,salicylic acid ph5yl e/] ,salicyl-p-hydroxyb5zoic acid ,salol ,silv] oxide ,solution salt ,solv5ol ,/ructure ( tann9 ,sulph9ic acid ,sulphite cellulose extract ,sulphite lye ,sulphonamide ,sulphonic acids1 aromatic ,sulphonic *loride ,sulphur ,sulphur tannage ,sulphuric acid-free ,n]adol ,d ,sulphuric acid 9 lea!r ,syr+oyl-p-hydroxyb5zoic acid ,t ,tann9 ,tann9 action1 real ,tann9 analysis ,tann+ matt]s ,tann9 molecule ,tann91 pure ,tannophor ,te/ tannage ,tetradepsides ,tetragalloyl-,greek3 a-me?ylglucoside ,tetrame?ylellagic acid ,tetroxydiph5yldime?ylolide ,?ionaph?olsulphonic acid ,?iosulphonic acid ,?orium salts ,?ymol ,toluidoan?raqu9one1 l-m- ,total solids ,total solubles ,tribromoph5ol ,tribromopyrogallic acid ,tric>bome?oxygalloyl *loride ,tridepside ,trihydroxyb5z5es ,tr9itroph5ol ,triph5ylme?ane ,v ,valonea ,vanadium salts ,vanillic acid ,vanilloyl-di-p-oxyb5zoyl-p-hydroxyb5zoi c acid ,vanilloyl-p-hydroxyb5zoic acid ,vanilloyl vanill9 ,x ,xan!nes ,z ,z9c salts ,zirconium salts