,transcrib]'s ,note ,italic text is enclos$ 9 und]scores2 subscripts are enclos$ 9 curly brackets4 ,additional notes w be f\nd ne> ! end ( ?is ebook4 ,,! ,,manufacture ,,( ,,e>? ,,col\rs ,,! ,,manufacture ,,( ,,e>? ,,col\rs ,,by ,,dr4 ,,josef ,,b]s* ,,translat$ ,,f ,,! ,,?ird ,,g]man ,,edition 7,,z ,,revis$ ,,by ,,pr(4 ,,dr4 ,,wilhelm ,,b]s*7 ,,by ,,*>les ,,salt] ,,) ,,?irty-,,"o ,,illu/rations ,,london ,,scott1 ,,gre5wood ,,son #h ,,broadway1 ,,ludgate1 ,e4,c4#d #aiba ,! sole rights ( translation 9 ,engli% rema9 ) ,scott1 ,gre5wood ,son4 ,,pr9t$ ,,9 ,,great ,,brita9 ,,by ,,ri*>d ,,clay ,,sons1 ,,limit$1 ,,p>is ,,g>d51 ,,/am=d ,,/41 ,s4,e4 #a1 ,,& ,,bungay1 ,,suffolk4 ,,preface ,orig9ally issu$ z a volume ( ! s]ies on pigm5ts & col\r+ matt]s by ! pres5t au?or's fa!r1 ! necessity = a new edition af=d$ a welcome opportunity ( revis+ 8,e>? ,col\rs40 ,al?\gh1 9 ! nature ( ?+s1 little progress has be5 made 9 ?is subject itself1 !re 0 a good deal to add 9 connection ) ! me*anical appliances = treat+ ! col\r e>?s & manufactur+ !m into pigm5ts4 ,9 o!r respects1 too1 ! "w has be5 c>efully gone ?r\gh & br\ght up to date1 ) new & additional illu/rations4 ,! au?or desires to express 8 ?anks to ! v>i\s firms :o h af=d$ him assi/ance 9 8 task by furni%+ illu/rations & descriptions ( new ma*9]y1 toge!r ) o!r in=mation4 ,x is hop$ t ?is ?ird edition w meet ! approval ( ^? int]e/$ 9 ! subject2 & ! au?or w be glad to receive supplem5t>y in=mation to r5d] ! "w m complete 9 ! ev5t ( a future edition be+ f\nd advisable4 ,,pr(4 ,,dr4 ,,wilhelm ,,b]s*4 #aiah4 ,,cont5ts ,,*apt] ,i ,,page ,,introductory #a ,,*apt] ,,ii ,,! ,,raw ,,mat]ials ,,= ,,e>? ,,col\rs #h 7,a7 ,:ite ,raw ,mat]ials & ,pigm5t>y ,e>?s #aa ,lime/one 7,calcite1 ,lime/one1 ,*alk7 #aa ,gypsum 7,alaba/]7 #ah ,b>ytes1 or ,heavy ,sp> #ai ,talc1 ,soap/one1 ,/eatite #bj ,clay #ba 7,b7 ,yell[ ,e>?s #bc ,br[n ,iron/one #bc ,o*re #be ,yell[ ,e>? #bf ,t]ra di ,si5a #bg 7,c7 ,! ,r$ ,e>?s #bg ,r$ ,iron/one #bh ,bole #ca ,alum ,sludge #cb ,m9e ,sludge #cb 7,d7 ,blue ,e>?s #cc ,azurite1 or ,ultram>9e #cc ,vivianite #cc 7,e7 ,gre5 ,e>? ,pigm5ts #cd ,gre5 ,e>? #cd ,mala*ite #ce 7,f7 ,br[n ,e>? ,pigm5ts #cf ,umb] #cf ,asphaltum #cg 7,g7 ,black ,e>? #ch ,black ,s*i/ #ch ,graphite #ch ,,*apt] ,,iii ,,! ,,prep>ation ,,( ,,! ,,col\r ,,e>?s #dj ,cru%+ ,ma*9]y #dc ,cru%+ & ,sift+ #gg ,calc9+ #ha ,mix+ & ,improv+ #ha ,m\ld+ #he ,,*apt] ,,iv ,,:ite ,,e>? ,,col\rs #hg ,cau/ic ,lime #hg ,pe>l ,:ite #id ,vi5na ,:ite #ie ,*alk #ih ,precipitat$ ,*alk #ajg ,calc>e\s ,m>l #aaj ,gypsum #aaa ,kaol91 ,pipeclay #aab ,b>ytes1 or ,heavy ,sp> #aai ,c>bonate ( ,magnesia #abc ,talc #abd ,/eatite or ,soap/one #abe ,,*apt] ,v ,,yell[ ,,e>? ,,col\rs #abg ,! ,o*res #abh ,calc9+ 7,burn+7 ,o*re #acb ,o*res f ,v>i\s ,deposits #acf ,artificial ,o*res #ach ,o*res z ,by-products #adf ,,*apt] ,,vi ,,r$ ,,e>? ,,col\rs #aea ,bole #aeb ,native ,f]ric ,oxide z a ,pigm5t #aed ,iron ,glance #aed ,hematite #aee ,raddle #aee ,burnt ,f]ric ,oxide & ,o*res #aeh 7a7 ,burn+ 9 ! ,muffle #aeh 7b7 ,caput ,mortuum1 ,colco?> #afj 7c7 ,calc9+ ,f]ric ,oxide #afa ,f]ric ,oxide ,pigm5ts f ,alum ,sludge #afd ,,*apt] ,,vii ,,br[n ,,e>? ,,col\rs #afh ,t]ra di ,si5a #afh ,true ,umb] #agj ,cologne ,e>? 7,cologne ,umb]7 #agc ,asphaltum ,br[n 7,bitum57 #agd ,,*apt] ,,viii ,,gre5 ,,e>? ,,col\rs #agf ,gre5 ,e>?1 or ,celadon ,gre5 #agf ,artificial ,gre5 ,e>? 7,gre5 ,o*re7 #ahj ,mala*ite ,gre5 #aha ,,*apt] ,,ix ,,blue ,,e>? ,,col\rs #ahc ,mala*ite ,blue 7,lazulite7 #ahc ,vivianite or ,blue ,o*re #ahd ,,*apt] ,x ,,black ,,e>? ,,col\rs #ahe ,graphite #ahe ,black ,*alk #aid ,,*apt] ,,xi ,,! ,,comm]cial ,,nom5clature ,,( ,,! ,,e>? ,,col\rs #aig ,:ite ,e>? ,col\rs #aih ,yell[ ,e>? ,col\rs #bjj ,r$ ,e>? ,col\rs #bjj ,br[n ,e>? ,col\rs #bjj ,gre5 ,e>? ,col\rs #bja ,blue ,e>? ,col\rs #bjb ,grey ,e>? ,col\rs #bjb ,black ,e>? ,col\rs #bjb ,,index #bjc ,,e>? ,,col\rs ,,*apt] ,i ,,introductory ,bo? f ! *emical & practical /&po9t x is necess>y to divide pigm5ts into cle>ly def9$ gr\ps1 ! foll[+ classification be+ adopt$ on ! basis & natural hi/ory ( ! sub/ances conc]n$3-- 7#a7 ,pigm5ts occurr+ native 9 a f9i%$ condition1 & only requir+ me*anical prep>ation to fit !m = use z pa9t]s' col\rs4 7#b7 ,pigm5ts :i* are n ready =m$ 9 ,nature1 b conta9 "s metallic comp\nd z pigm5t>y mat]ial1 :i* requires c]ta9 *emical treatm5t = its full developm5t4 7#c7 ,pigm5ts :i*1 9 contra/ to ^! two gr\ps1 conta9 only organic1 & no inorganic1 con/itu5ts4 ,?is la/ class comprises all ! natural vegetable pigm5ts1 toge!r ) ! l>ge gr\p ( col\rs obta9$ artificially f t> products1 fre% gr\ps ( :i* are be+ cont9ually introduc$4 ,n[adays1 !re is no long] any /rict l9e ( dem>cation betwe5 ! natural & artificial organic col\r+ matt]s1 x be+ possible to produce ev5 ^? ( ! vegetable s]ies1 su* z madd] & indigo1 by artificial means4 ,:il/ ?is gr\p ( col\rs exhibits ! greate/ v>iety1 & is con/antly be+ enri*$ & increas$ by ! progress ( col\r *emi/ry1 ! case is diff]5t ) ! fir/ gr\p1 ! natural e>? pigm5ts4 ,"h we h *iefly to d ) ! prep>ation ( mat]ials occurr+ 9 ,nature1 or ) br++ ab\t c]ta9 *emical results1 s t1 consequ5tly1 ! range ( v>iety is f> m re/rict$1 & !re is little or no possibility ( increas+ ! numb] ( ^! col\rs by ! manufacture ( really new products4 ,! e>? col\rs nev]!less h a high te*nical & economic importance1 on acc\nt ( _! extremely valuable prop]ties1 c\pl$1 = ! mo/ "p1 ) l[ co/4 ,if ! t]m 8e>? col\rs0 7 /rictly adh]$ to1 ! pres5t "w w\ld h to be conf9$ to a description ( ! physical & *emical prop]ties ( ! v>i\s pigm5ts1 & ( ! v>i\s means by :i* !y c be br\ght into suitable condition = use 9 pa9ts4 ,h[ev]1 ( late1 ! t]m has f\nd wid] application ?an =m]ly1 s9ce x has be5 f\nd practicable to modify 7%ade7 c]ta9 ( ! e>? col\rs by simple op]ations1 & ?us consid]ably increase ! range ( tones ( ! sub/ances kn[n z e>? col\rs4 ,! progress ( *emical indu/ry has also l>gely increas$ ! numb] ( ! s-call$ e>? col\rs1 c]ta9 me?ods ( *emical treatm5t hav+ enabl$ sub/ances t are ( little use = o!r purposes1 to be employ$1 9 l>ge quantities1 z pigm5ts4 ,! application ( ^!--usually *eap--by-products is /ill fur!r facilitat$ by ! fact t !y c be trans=m$1 by a simple *emical treatm5t1 into pigm5ts :i* are di/+ui%$ by _! beauty ( col\r & at ! same "t possess ! great advantages ( durability & *eapness4 ,z an example ( ?is1 m5tion may be made ( iron oxide1 :i* occurs 9 ,nature 9 ! =m ( v>i\s m9]als :i* c be made into pigm5ts by me*anical treatm5t4 ,9 _m cases1 ?is treatm5t has already be5 c>ri$ out by ,nature1 & deposits ( iron oxide are f\nd 9 :i* ! mat]ial has only to be incorporat$ ) a vehicle to make x fit = imm$iate use z a pa9t]s' col\r4 ,moreov]1 ! same oxide is obta9$1 9 l>ge quantities1 z a by-product ( ! treatm5t ( o!r m9]als4 ,f ! po9t ( view ( *emical composition1 ?is by-product is ( v l[ value1 by reason ( ! l>ge supplies ( native oxide available4 ,by means ( a v simple *emical treatm5t1 h[ev]1 ?is by-product oxide c be consid]ably improv$ 9 comm]cial value1 be+1 9 _m cases1 conv]tible1 by m]ely heat+ x to c]ta9 temp]atures1 into a v>iety ( col\rs :i* sell at remun]ative prices4 ,consequ5tly1 9 view ( ! pres5t condition ( ! *emical indu/ry1 ! t]m 8e>? col\rs0 c be enl>g$ to include a numb] ( wa/e products :i* fet* good prices z col\rs1 ?\gh o!rwise practically valueless 9 !mselves4 ,! numb] ( e>? pigm5ts is v l>ge1 & comprises repres5tatives ( all ! pr9cipal col\rs4 ,= pa9t+ purposes1 few pigm5ts beyond ! e>? col\rs 7 kn[n to ! anci5ts2 & mo/ ( ! col\rs 9 ! pa9t+s :i* h come d[n to u f antiquity are pure e>? pigm5ts1 ?us af=d+ pro( ( _! great durability1 hav+ reta9$ _! fre%ness unimpair$ = hundr$s--& "s = ?\s&s--( ye>s4 ,! e>? col\rs might be divid$ into su* z occur ready-=m$ 9 ,nature1 & require only me*anical prep>ation1 & :i* ei!r require special treatm5t 7e4 g4 calc9+71 or are artificial products 7l ! iron oxide m5tion$ above74 ,s9ce1 h[ev]1 su* a classification w\ld n advantage our k ( ! nature ( ?is class ( col\rs1 x appe>s useless & sup]flu\s1 & we w !re=e simply conf9e ourselves to arrang+ ! e>? pigm5ts accord+ to _! col\r--:ite1 yell[1 r$1 etc4 ,adopt+ ?is classification1 ! foll[+ m9]als & *emical products may be consid]$ z e>? col\rs3-- ,:ite4--,^! include ! v>ieties ( calcium c>bonate1 su* z *alk1 m>ble1 precipitat$ *alk1 calcium phosphate1 calcium sulphate 79 ! =m ( gypsum1 alaba/]1 muriacite & ! precipitat$ gypsum produc$ z a by-product 9 _m *emical works71 heavy sp>1 ! diff]5t v>ieties ( clay1 & magnesia4 ,yell[4--,?is gr\p comprises f]ric hydroxide 7hydrat$ oxide ( iron7 9 ! =m ( ! v>i\s m9]als kn[n z o*re2 all ! prep>ations *iefly compos$ ( ?is hydroxide1 & all ^? prep>$ by artificial means4 ,a v important memb] ( ?is gr\p is orpim5t2 ! o!r ars5ical comp\nds frequ5tly met ) native1 be+ h[ev]1 on acc\nt ( _! poison\s prop]ties1 no long] us$ z pigm5ts4 ,r$4--,*ief among ! r$ e>? col\rs are ^? consi/+ ( f]ric oxide 7iron oxide71 "u v>i\s names4 ,! only o!r memb] ( ! gr\p is ! f> r>] v]milion4 ,blue4--,! blue e>? col\rs are few 9 numb] & ( no p>ticul> beauty2 b !y are ( importance on acc\nt ( _! *eapness & because all ! artificial blue pigm5ts are r exp5sive4 ,two products 9 p>ticul> m]it att5tion 9 ?is connection1 namely1 ultram>9e1 & ! m9]al kn[n z blue o*re or blue iron/one4 ,! latt]1 z a matt] ( fact1 _c be us$ = any?+ else ?an a pa9t]s' col\r1 & c be obta9$ at a l[ price2 :]eas ultram>9e also =ms a valuable raw mat]ial = ! recov]y ( copp]1 & is !re=e de>]4 ,gre54--,?is gr\p1 aga91 conta9s only two memb]s1 viz4 mala*ite gre5 7*rysocolla71 & ! gre5 e>?s 7seladonite71 kn[n z ,v]ona1 etc41 gre54 ,^! occur fairly (t5 9 ,nature1 & ! gre5 e>?s 9 p>ticul> f9d a wide indu/rial application by reason ( _! l[ price4 ,mala*ite gre5 is v simil>1 9 *emical con/itution1 to ultram>9e2 & bo? =m s\rces ( copp] & are consequ5tly exp5sive4 ,x %\ld be m5tion$ t bo? ultram>9e & mala*ite gre5 c only be pr(itably made into pigm5ts :]e ! m9]als c be obta9$ *eaply1 s9ce bo? ( !m c be manufactur$ :]e artificial pigm5ts are produc$1 & are put on ! m>ket "u ! same names z ! native articles4 ,! v l[ price ( ! gre5 e>?s makes !m highly popul> z col\r+ matt]s 9 c]ta9 bran*es ( indu/ry1 & !y are v l>gely us$ by wall-pap] manufactur]s4 ,br[n4--,?is is a l>ge gr\p1 & ! pigm5ts compos+ x are specially di/+ui%$ = _! beauty & dep? ( col\r1 on :i* acc\nt !y are us$ 9 ! f9e/ pa9t+s4 ,"h1 aga91 x is f]ric oxide1 9 comb9ation ) wat]--& !re=e f]ric hydroxide--t furni%es a l>ge numb] ( ! memb]s ( ! gr\p4 ,l ! r5[n$ ,si5a e>?1 ! arti/s' col\rs kn[n z ,v&yck br[n1 bole1 ,lemnos e>?1 umb]1 etc41 ma9ly consi/ ( m or less pure f]ric hydroxide4 ,^! m9]als are1 moreov]1 specially important to ! col\r manufactur]1 inasmu* z mo/ ( !m enable a l>ge numb] ( diff]5t %ades to be obta9$ by a simple me?od ( treatm5t consi/+ m]ely ( ! application ( heat 9 a suitable mann]2 & ^! col\rs are among ! mo/ excell5t we possess1 by reason ( _! beauty & p]man5ce4 ,among/ ?is s]ies mu/ also be class$ native manganese br[n1 :i* *iefly consi/s ( a mixture ( manganese oxide & ! hydrat$ p]oxide ( ! same metal4 ,black4--,!re is really only "o memb] ( ?is class1 :i*1 h[ev]1 is frequ5tly us$1 viz4 t =m ( c>bon occurr+ z hexagonal cry/als & kn[n z graphite4 ,ano!r natural black natural product1 occasionally us$ z a pa9t]s' col\r is ! s-call$ black *alk4 ,h[ev]1 s9ce black pigm5ts c be produc$ v *eaply by artificial means1 ! natural col\rs f9d only a limit$ application2 & only 9 "o in/ance is graphite us$ alone1 viz4 = mak+ blacklead p5cils4 ,z already m5tion$1 c]ta9 *emical indu/ries furni% by-products :i* are ( v little value 9 !mselves1 & _m ( !m1 inde$1 may be class$ z wor?less1 s9ce *emical manufactur]s naturally endeav\r to get ev]y?+ possible out ( _! mat]ials 9 ! c\rse ( manufacture4 ,"s ( ^! by-products1 h[ev]1 c advantage\sly be us$ z pigm5ts1 a good example ( ?is be+ af=d$ by ! iron oxide =m$ z a by-product 9 ! manufacture ( fum+ sulphuric acid 7,nordhaus5 oil ( vitriol71 by ! old process1 f gre5 vitriol 7f]r\s sulphate74 ,9 itself1 ?is oxide is practically valueless1 b1 by v simple treatm5t1 x c be conv]t$ into v valuable pigm5ts :i* h a m>ket value f> 9 excess ( ! orig9al mat]ial4 ,al?\gh x has hi!rto be5 ! cu/om to conf9e ! t]m e>? col\rs to su* z occur ready-=m$ 9 ,nature & only require simple me*anical treatm5t to make !m ready = imm$iate use z pigm5ts1 ! au?or is nev]!less ( op9ion t a book deal+ exhau/ively ) e>? col\rs %\ld also make "s m5tion ( all ! m9]al col\r+ matt]s :i* c be easily made into pigm5ts by simple processes1 su* z calc9ation or br++ into association ) o!r sub/ances4 ,9 accordance ) ?is view1 ! pres5t "w w describe all ! pigm5ts t are obta9able 9 ?is mann]4 ,mo/ ( ! e>? col\rs consi/ ( decomposition products ( c]ta9 m9]als2 & ?is applies p>ticul>ly to su* ( !m z conta9 iron oxide4 ,accord+ z ! decomposition ( ! orig9al m9]al has be5 m or less ext5sive1 ! natural product exhibits diff]5t prop]ties2 & ! manufactur] mu/ consequ5tly endeav\r to treat !m 9 su* a mann] z to ensure t ! pigm5t obta9$ w be z uni=m z possible 9 %ade & p]man5ce4 ,9 ord] to accompli% ?is x is ess5tial to h an accurate k ( ! orig9 ( ! raw mat]ial "u treatm5t1 & ( its *emical & physical prop]ties4 ,9 view ( ?is1 ! au?or consid]s x necess>y to deal m fully ) ! pigm5t>y e>?s =m+ ! raw mat]ials ( ! e>? col\rs1 be=e pass+ on to ! prep>ation ( ! col\rs !mselves4 ,,*apt] ,,ii ,,! ,,raw ,,mat]ials ,,= ,,e>? ,,col\rs ,! m9]als con/itut+ ! raw mat]ials = ! prep>ation ( ! e>? col\rs occur "u v div]g5t conditions 9 ,nature4 ,"s ( !m1 su* z *alk1 =m imm5se deposits1 ev5 :ole m\nta9s1 :il/ 9 o!r cases1 e4 g4 ! blue f]rug9\s e>?s1 ! occurr5ce is connect$ ) c]ta9 local conditions1 & _m are f\nd only 9 isolat$ deposits1 z pockets or b$s4 ,?is la/ is ! case1 = in/ance1 ) ! h&some br[n iron pigm5ts2 & inde$ ! names by :i* !y are kn[n indicate t !y are only f\nd 9 well-def9$ localities1 or t !y are met ) ( special quality !re4 ,! br[n e>? col\r kn[n to all pa9t]s z ,t]ra di ,si5a1 is f\nd at _m o!r places z well z ne> ,si5a1 b ! product f t city acquir$ a=etime a special reputation = beauty1 & !re=e all simil> e>?s1 provid$ !y are equal to t f ,si5a1 also be> ! same "n 9 comm]ce4 ,a numb] ( raw mat]ials = ! prep>ation ( e>? col\rs are f\nd1 x is true1 9 _m deposits1 b _! utilisation dep5ds1 9 turn1 on local conditions4 ,= example1 _m copp] m9es conta91 9 addition to ! o!r cuprif]\s m9]als1 ^? us$1 9 ! p[d]$ /ate1 z ultram>9e or ultram>9e gre51 & n infrequ5tly lumps ( m9]al are f\nd conta9+ bo? blue & gre5 toge!r4 ,h[ev]1 x is only :5 ^! m9]als occur 9 suffici5t quantity to make ! necess>y sort+ pr(itable t _! manufacture into pigm5ts c be reg>d$ z practicable4 ,be=e comm5c+ to "w a deposit x is ess5tial to make sure :e!r ! raw mat]ial1 or pigm5t>y e>?1 is actually suitable = ! manufacture ( e>? col\r4 ,ev5 ! g5]al "* ( ! mat]ial is important1 ^? ( s(t1 e>?y consi/5cy be+ mu* easi] to treat1 & ! co/ ( prep>ation small]1 ?an if ! raw mat]ial be h>d1 t\gh & cry/all9e4 ,! ext5t & ?ickness ( ! deposit1 & ! ease ) :i* x c be work$1 also play an important1 & ev5 decisive "p1 s9ce1 o!r conditions be+ equal1 x w n pay to erect a col\r works unless ! raw mat]ial is available 9 suffici5t quantity & is *eap4 ,g5]ally1 ! deposit is n homog5e\s ?r\gh\t1 ! m9]al be+ pur] 9 "s places & m contam9at$ ) gangue 9 o!rs4 ,! p]c5tage ( moi/ure also v>ies1 & 9 %ort1 a numb] ( circum/ances mu/ be tak5 into consid]ation 9 =m+ a conclusion z to :e!r a deposit is workable or n4 ,9 ord] to arrive at a reliable op9ion on all ^! conditions1 sampl+ is indisp5sable4 ,if ! samples are ( uni=m "*1 !y c be mix$ toge!r to make an av]age sample4 ,b if !y diff] consid]ably 9 appe>ance1 g5]al "*1 proportion ( gangue1 etc41 x is pref]able to exam9e !m sep>ately1 m especially :5 ! area :i* ea* repres5ts is l>ge4 ,! exam9ation %\ld ext5d1 on ! "o h&1 to ! natural p]c5tage ( moi/ure1 &1 on ! o!r1 to ! purity ( ! mat]ial4 ,! wat] cont5t is det]m9$ by ?or\ghly dry+ a weigh$ sample1 be>+1 h[ev]1 9 m9d ! fact t pigm5t>y e>?s ( a clayey nature v>y 9 wat] cont5t accord+ to ! "t ( ye>1 besides *ang+ 9 accordance ) ! wea!r :5 ! won mat]ial is /or$ 9 ! op54 ,! purity c only be asc]ta9$ by an exam9ation 9 :i* a sample ( ! s(t1 clayey mat]ial is cru%$ & pass$ ?r\gh a n>r[-me% gauze sieve1 ! am\nt ( ! co>se p>ticles--s&1 small /ones1 etc4--rema9+ on ! sieve be+ det]m9$4 ,a m accurate me?od1 ( c\rse1 is to sep>ate ! true pigm5t>y e>? f ! gangue by levigation4 ,= ?is purpose1 a weigh$ quantity ( ! cru%$1 air-dry sample is plac$ 9 a relatively n>r[ glass vessel & ?or\ghly mix$ ) wat]1 ! turbid sup]natant liquid be+ p\r$ (f aft] a %ort int]val4 ,! residue is repeat$ly treat$ 9 ! same way1 until no m f9e p>ticles rema9 9 susp5sion1 ! residue !n consi/+ ( impurities1 or gangue4 ,( c\rse1 ! wa%+s c be collect$1 ! susp5d$ matt] all[$ to settle1 & f9ally weigh$ 9 an air-dry condition4 ,by ?is means an approximate idea ( ! yield ( e>? col\r c be obta9$ at ! same "t4 ,raw mat]ials :i* are n amorph\s1 s(t & clayey mu/ fir/ be cru%$1 an op]ation facilitat$ by heat+ to r$ness & qu5*+ 9 cold wat]4 ,(t5times ! heat+ causes a *ange ( col\r & improves ! cov]+ p[]--a po9t to :i* ref]5ce w be made lat] on4 ,9 ! foll[+ description ( ! v>i\s raw mat]ials1 ! *emical composition ( ! pure m9]als w be giv51 toge!r ) an enum]ation ( ! mo/ common impurities4 7,a7 ,,:ite ,,raw ,,mat]ials ,,& ,,pigm5t>y ,,e>?s ,lime/one 7,calcite1 ,lime/one1 ,*alk7 ,! numb] ( mat]ials furni%+ :ite e>? col\rs is comp>atively l>ge1 & ^! col\rs are p>ticul>ly important1 because1 n only are !y ext5sively us$ by !mselves1 b !y also s]ve z adjuncts to o!r col\rs & = ! production ( special %ades4 ,! *ief raw mat]ial = ! prep>ation ( :ite e>? col\rs is ! m9]al calcite 9 its num]\s modifications4 ,calcite1 or calc sp>1 occurs v frequ5tly 9 ,nature1 & is "o ( ! mo/ highly div]sifi$ m9]als kn[n4 ,9 its pure/ /ate x appe>s z 8d\ble sp>0 7calcite71 9 ! =m ( wat]-:ite cry/als1 :i* are v rem>kable = c]ta9 optical prop]ties4 ,:ite m>ble is also a v pure v>iety ( calcite1 9 :i* ! individual cry/als are v small4 ,! v>i\s col\r$ m>bles owe _! appe>ance to c]ta9 admixtures ( extrane\s sub/ances1 *iefly metallic oxides4 ,no %>p l9e ( dem>cation sep>ates m>ble f ord9>y lime/one1 ! diff]5ce betwe5 !m really consi/+ only 9 ! degree ( f95ess ( gra92 & all lime/ones :i* gr9d & poli% well may be class$ z m>ble4 ,z is ! case ) m>ble1 !re are also lime/ones ( v>i\s col\rs1 grey be+1 h[ev]1 ! mo/ common4 ,?is grey lime/one =ms huge m\nta9 masses :i*1 9 ,europe1 foll[ = example1 ! ,alp9e *a9 on its nor!rn & s\!rn edges4 ,a few o!r examples ( calcite may be m5tion$ :i* occur 9 c]ta9 localities &1 9 "p1 are /ill 9 c\rse ( =mation4 ,to ^! belong ! /alactites & /alagmites1 :i* sometimes consi/ ( extremely pure calcite4 ,!y are =m$ by ! action ( wat]1 conta9+ c>bonic acid 9 solution1 :i* trickles ?r\gh cracks & cavities 9 lime/one rock & dissolves out calcium c>bonate f ! adjac5t /one4 ,on prolong$ exposure to ! air su* wat] gives (f its free c>bonic acid aga92 & z ! calcium c>bonate is insoluble 9 pure wat]1 x sep>ates out 9 cry/all9e =m4 ,! masses =m$ 9 ?is way usually resemble icicles 9 %ape1 & ! f9e/ examples are to be f\nd 9 ! well-kn[n /alactite grottoes at ,kra91 :il/ ! grotto at ,adelsb]g is r5[n$ = its beautiful /alactites4 ,occasionally1 /alactites h an opaque yell[ or br[ni% t+e1 :i* !y owe to ! pres5ce ( iron oxide4 ,a =mation simil> 9 its orig9 to /alactites is ! s-call$ calc s9t] & calc>e\s tuff4 ,! =m] (t5 occurs 9 cavities z irregul> masses :i*1 9 "s places1 enclose l>ge quantities ( fossil animal bones1 9 :i* case !y =m 8bone breccia0 7crag breccia74 ,calc>e\s tuff is deposit$ f num]\s spr+s1 occasionally 9 v l>ge quantities1 envelop+ plants & sometimes =m+ ?ick deposits 9 :i* ! /ructure ( ! plants c be cle>ly recognis$4 ,9 "s places a m or less pure :ite1 extremely friable v>iety ( calcite is met ) "u ! "n 8m\nta9 milk0 or 8m\nta9 *alk0 7e>?y calcite71 :i* seems to be a decomposition product1 & consi/s ( a mixture ( arragonite & *alk4 ,arragonite--:i* w be ref]r$ to lat]--is completely id5tical1 *emically1 ) calcite--bo? be+ compos$ ( calcium c>bonate--! sole diff]5ce be+ _! cry/all9e =m4 ,! mo/ important = ! col\r-mak]1 h[ev]1 is ! v>iety kn[n z *alk4 ,?is is really a fossil product1 i4 e4 x consi/s ( ! microscopic %ells ( m>9e animals unit$ into solid masses4 ,despite ! smallness ( ^! animals1 _! epo* la/$ long en\gh = _! %ells to =m entire m\nta9s :i* are enc\nt]$ all ov] ! _w4 ,a l>ge "p ( ! coa/ ( ,engl&1 ! isl& ( ,rg51 & _m o!r localities1 consi/ entirely ( *alk4 ,9 _m cases1 *alk is f\nd int]sp]s$ ) nodul> masses ( fl9t1 & 9 "s places x also conta9s great quantities ( ! rema9s ( o!r m>9e animals1 su* z sea ur*9s1 ! sp9es ( :i* occur 9 su* numb]s 9 c]ta9 k9ds ( *alk z to unfit !m entirely = use z a pigm5t4 ,! =ego+ v>ieties ( calc sp> are ! mo/ important1 & also occur 9 l>ge quantities2 b1 to complete ! tale1 x is necess>y to m5tion also a few o!rs :i*1 h[ev]1 are only f\nd 9 small am\nts4 ,to ^! belong1 = example1 an?racolite1 a lime/one /a9$ q black by coal2 ! ooli?ic lime/ones or roe /ones1 :i* are compos$ ( granules resembl+ fi% roe2 mus*elkalk1 :i* is also ( fossil "* & is almo/ entirely compos$ ( mussel %ells cem5t$ toge!r ) lime2 ! m>ls1 :i* consi/ ( calc sp> mix$ ) v>y+ quantities ( clay & consequ5tly (t5 be> a great resemblance to loam 9 _! prop]ties4 ,a few ( ^! v>ieties f9d ext5sive employm5t = c]ta9 purposes1 "s m>ls = in/ance be+ us$ = mak+ hydraulic lime1 :il/ all modifications ( calc sp> t are suffici5tly pure c be burn$ = quick lime4 ,x has already be5 /at$ t ! m9]al arragonite is id5tical1 *emically1 ) calc sp>1 s9ce bo? consi/ ( calcium c>bonate1 b diff] 9 _! cry/all9e habit4 ,?us1 :]eas ! cry/als ( calc sp> belong to ! rhomboh$ral or hexagonal sy/em1 ^? ( arragonite are always rhombic4 ,?is occurr5ce ( "o & ! same sub/ance 9 two diff]5t cry/all9e =ms is kn[n z dimorphism1 & calcium c>bonate is !re=e dimorph\s4 ,:e!r calcium c>bonate assumes ! =m ( calcite or arragonite dep5ds entirely on physical causes4 ,:5 ! deposition ( ! c>bonate takes place f a cold solution ! %ape ( ! cry/als is always "o belong+ to ! hexagonal or rhomboh$ral sy/em2 b :5 x is f hot solution1 rhombic cry/als are inv>iably =m$1 calc sp> result+ 9 ! =m] case & arragonite 9 ! latt]4 ,^! diff]5t me?ods ( =mation :i* c be c>ri$ out 9 ! laboratory by produc+ ! requisite conditions1 occur on ! l>ge scale 9 _m p>ts ( ! _w4 ,:]ev] a hot spr+ comes to ! surface1 conta9+ consid]able am\nts ( lime 9 solution1 ?is sep>ates out 9 ! =m ( arragonite1 :i* receiv$ its "n f ! circum/ance t specially h&some cry/als ( ?is m9]al are f\nd 9 ,arragon4 ,"o ( ! be/-kn[n places :]e ! =mation ( arragonite c be obs]v$ at ! pres5t "t is ,c>lsbad 9 ,bohemia4 ,! hot spr+s !re deposit a v l>ge am\nt ( lime1 :i* is /a9$ m or less yell[ or r$ by ! pres5ce ( v>y+ quantities ( iron oxide1 &1 "u ! "n ( 8sprudel/e90 is us$ = produc+ v>i\s works ( art4 ,:5 ! hot spr+s br+ up p>ticles ( s&1 ! lime sub/ance incru/s ^! s& gra9s1 =m+ globul> masses resembl+ peas1 & consequ5tly nam$ pisolite4 ,9 *emical composition1 calcite & arragonite consi/ ( a comb9ation ( calcium oxide 7lime7 & c>bonic acid1 ! =mula be+ express$ by ,ca,c,o#c4 ,calcium c>bonate is insoluble 9 pure wat]1 b dissolves some:at freely 9 wat] *>g$ ) free c>bonic acid4 ,x is assum$ t a comp\nd is =m$1 :i* is kn[n z calcium bi- 7or acid7 c>bonate1 is v un/able & c only exi/ 9 a /ate ( solution4 ,:5 a solution ( calcium bic>bonate--:i* c be prep>$ by pass+ c>bonic acid gas ?r\gh wat] conta9+ f9ely divid$ calcium c>bonate 9 susp5sion--is expos$ = "s "t to ! air1 x soon becomes cl\dy1 & a deposit ( calcium c>bonate settles d[n at ! bottom ( ! vessel1 because1 9 ! air ! dissolv$ calcium bic>bonate is decompos$ into free c>bonic acid gas & calcium c>bonate1 :i* latt]1 z has be5 m5tion$1 is q insoluble 9 wat]4 ,x has already be5 /at$ t ?is ph5om5on goes on 9 ,nature 9 ! =mation ( /alactites1 lime s9t] & calc>e\s tuff4 ,calcium c>bonate is readily soluble 9 acids1 ! conta9$ c>bonic acid be+ lib]at$ 7z c>bon dioxide7 ) eff]vesc5ce4 ,:5 su* acids are employ$ = solution z =m readily soluble salts ) lime1 su* z hydro*loric1 nitric1 acetic1 etc4 acids1 a p]fectly cle> solution is obta9$2 b if sulphuric acid is us$1 a :ite pulpy mass is =m$1 consi/+ ( calcium sulphate1 or gypsum1 :i*1 ow+ to its l[ solubility1 sep>ates out z small cry/als4 ,any s&y residue left :5 calcium c>bonate is dissolv$1 mo/ly consi/s ( qu>tz s&4 ,9 dissolv+ d>k-col\r$ lime/ones1 grey1 or ev5 black1 flakes are left1 :i* consi/ ( organic mat]ial v high 9 c>bon4 ,on lime/one be+ subject$ to fairly /rong calc9ation1 all ! c>bonic acid is expell$1 leav+ beh9d ! s-call$ quick or burnt lime1 :i* is1 *emically1 calcium oxide3-- ,ca,c,o#c ,ca,o ,,co#b ,calcium c>bonate ,quick lime ,c>bon dioxide ,if burnt lime be left expos$ to ! air = "s "t1 x aga9 gradually absorbs c>bon dioxide & is reconv]t$ into calcium c>bonate4 ,:5 burnt lime is spr9kl$ ) wat] x takes up ! latt] avidly1 becom+ v hot & f9ally crumbl+ d[n to a v friable :ite p[d]1 consi/+ ( slak$ or hydrat$ lime 7calcium hydroxide1 ,ca7,,oh7#b74 ,! consid]able rise ( temp]ature 9 qu5*+ ! lime is due to ! *emical comb9ation ( ! calcium oxide & wat]4 ,bo? quick & slak$ lime dissolve to a c]ta9 ext5t 9 wat]1 & imp>t /rongly alkal9e prop]ties !reto1 lime be+ "o ( ! /ronge/ ( bases4 ,on exposure to ! air1 ! solution ( quick lime 9 wat] 7lime-wat]7 quickly =ms an opalesc5t sup]ficial film ( calcium c>bonate1 & 9 a %ort "t no m lime is pres5t 9 solution1 ! :ole hav+ be5 trans=m$ into calcium c>bonate1 :i* settles d[n to ! bottom ( ! vessel z a v f9e p[d]4 ,lime/one t consi/s entirely ( calcium oxide & c>bon dioxide is ( r>e occurr5ce 9 ,nature1 =eign sub/ances be+ ne>ly always pres5t4 ,s9ce ! nature ( ^! admixtures is ( ! greate/ importance to ! col\r-mak]1 ow+ to ! consid]able influ5ce !y ex]t on ! suitability ( ! m9]als = 8 purposes1 x is necess>y t ^! extrane\s sub/ances occurr+ 9 lime/one %\ld be m closely describ$4 ,ne>ly all v>ieties ( lime/one conta9 c]ta9 proportions ( f]r\s & f]ric oxides4 ,! pres5ce ( f]r\s oxide1 :5 ! relative am\nt is b small1 _c be detect$ by m]e inspection2 & ev5 _m lime/ones conta9+ really appreciable quantities ( f]r\s oxide are pure :ite 9 col\r s long z !y are 9 l>ge lumps4 ,if1 h[ev]1 su* a lime/one be r$uc$ to p[d] & expos$ to ! air = a %ort "t1 x gradually assumes a yell[ t+e1 ! dep? ( :i* increases ) ! l5g? ( exposure4 ,! cause ( ?is *ange is due to ! fact t f]r\s oxide has a great aff9ity = oxyg51 by absorb+ :i* x *anges into f]ric oxide4 7,f]r\s oxide consi/s ( ,fe,o1 f]ric oxide ( ,fe#b,o#c47 ,f]r\s oxide & its comp\nds are ( a pale gre5 col\r :i* is n v noticeable1 :]eas f]ric oxide has a v p[]ful yell[ col\r1 & consequ5tly ! lime/one1 :5 its sup]ficial area has be5 greatly increas$ by r$uction to p[d]1 assumes ! yell[ t+e due to f]ric oxide4 ,a lime/one exhibit+ ?is prop]ty c evid5tly n be us$ = mak+ :ite e>? col\rs1 b is1 at be/1 only suitable = mix+ ) o!r col\rs4 ,occasionally1 lime/one conta9s v>y+ quantities ( magnesia1 & :5 ?is oxide is pres5t 9 l>ge am\nt1 *anges into ano!r m9]al kn[n z dolomite4 ,9 _m places ?is dolomite =ms l>ge masses ( rock1 :i*1 h[ev]1 is n employ$ = mak+ col\rs1 ow+ to ! yell[ %ade imp>t$ by ! fairly l>ge am\nt ( f]ric oxide pres5t4 ,gypsum 7,alaba/]7 ,?is m9]al occurs native 9 _m places1 & is frequ5tly work$ = a numb] ( purposes4 ,gypsum occurs 9 ,nature 9 a great v>iety ( =ms4 ,! pure/ k9d is met ) ei!r z wat]-cle> cry/als1 :i* cleave readily 9 two directions1 or z transp>5t tabul> masses 7sel5ite7 :i* also cleave easily4 ,micro-cry/all9e f9e-gra9$ gypsum is milk-:ite 9 col\r1 highly transluc5t & is l>gely us$1 "u ! "n ( alaba/]1 9 sculpture4 ,ow+ to its l[ h>dness1 alaba/] c be readily cut ) a knife1 & on ?is acc\nt is frequ5tly %ap$ by plan+ or la!-turn+4 ,gypsum is g5]ally met ) 9 d5se masses1 :i* may be ( any col\r1 grey1 blue & r$di% %ades be+ ! mo/ common1 :il/ pure :ite is r>]4 ,! d>k-col\r$ v>ieties c only be us$ = manurial purposes2 b ! :ite f9ds a tw(old application z a pigm5t1 &1 9 ! calc9$ /ate1 = mak+ pla/] ca/s4 ,9 po9t ( *emical composition1 gypsum consi/s ( sulphate ( lime1 or calcium sulphate 7,ca,s,o#d #b;,h#b,o74 ,x is soluble 9 wat]1 b only 9 su* small quantity t ov] #djj p>ts ( ! latt] are ne$$ to dissolve "o "p ( gypsum4 ,on be+ heat$ to betwe5 #abj & #acj ,c41 gypsum p>ts ) its two molecules ( comb9$ wat] & becomes anhydr\s calcium sulphate or burnt gypsum4 ,:5 ?is latt] is /irr$ ) wat] to a pulp1 x takes up ! wat] aga91 ) consid]able evolution ( heat1 swell+ up consid]ably & sett+ quickly to a solid mass4 ,! numb] ( sub/ances exhibit+ ?is prop]ty be+ small1 burnt gypsum is v frequ5tly us$ = mak+ ca/s ( /atu>y1 & = /ucco "w 9 build+4 ,f9ely gr\nd :ite gypsum c also be us$ z a pigm5t1 b is inf]ior to calcium c>bonate 9 cov]+ p[]1 & is !re=e seldom employ$ = ?is purpose1 ?\gh frequ5tly add$ to o!r col\rs4 ,! m9]al kn[n z muriacite or anhydrite consi/s ( anhydr\s calcium sulphate2 & is !re=e simil> 9 composition to burnt gypsum2 b x lacks ! prop]ty ( comb9+ ) wat] :5 br\ght into contact !re)4 ,b>ytes1 or ,heavy ,sp> ,! m9]al kn[n z heavy sp> occurs 9 v l>ge quantities & 9 num]\s localities4 ,x =ms rhombic cry/als1 :i* are v (t5 extremely well develop$ & =m flat plates ( consid]able size4 ,a rem>kable peculi>ity ( ?is m9]al is its high specific gravity1 :i* is due to ! b>ium cont5t4 ,x is f\nd native 9 all col\rs1 :ite be+ ! mo/ common4 ,*emically1 heavy sp> is b>ium sulphate1 ,ba,s,o#d4 ,x c be us$ z a pigm5t p] se1 b only :5 prep>$ artificially1 ! trade "n = ! product be+ p]man5t :ite1 or blanc fixe4 ,p[d]$ native heavy sp>1 ev5 :5 gr\nd ev] s f9e1 has n en\gh cov]+ p[]1 ?is prop]ty be+ peculi> to ! artificial product4 ,:5 x is desir$ to mix o!r pigm5ts ) a :ite sub/ance1 to light5 ! %ade1 p]man5t :ite c be specially recomm5d$1 s9ce x is q ins5sitive to atmosph]ic influ5ces & has no *emical action on ! col\r1 s t x c be us$ ) ev5 ! mo/ delicate col\rs )\t risk4 ,9 ?is way1 n only c ! col\rs be consid]ably *eap5$1 b ov]-d>k col\rs c be %ad$ to ! desir$ ext5t4 ,ano!r advantage ( su* mixtures is t a small] quantity ( oil or v>ni% is requir$1 b>ytes only ne$+ ab\t #h ( its own weight ( vehicle to =m a workable mixture1 :il/ o!r pigm5ts take five times z mu*1 or ev5 m4 ,9 _m cases ! l[ cov]+ p[] ( b>ytes enables l>ge quantities to be add$1 & ?is reacts fav\rably on ! consumption ( v>ni%4 ,ano!r b>ium m9]al is )]ite1 or b>ium c>bonate4 ,?is is n us$ direct z a pigm5t1 b--9 contra/ to heavy sp>--is readily soluble 9 hydro*loric acid1 & !re=e s]ves z raw mat]ial = ! prep>ation ( artificial b>ytes & o!r b>ium comp\nds1 ! fir/-nam$ be+ obta9$ by treat+ a solution ( b>ium *loride ) sulphuric acid1 insoluble b>ium sulphate be+ precipitat$4 ,talc1 ,soap/one1 ,/eatite ,talc occurs 9 ,nature ei!r z a pure :ite mass1 ( greasy lu/re1 or occasionally z yell[1 gre5 or grey masses1 all di/+ui%$ by a peculi> greasy appe>ance & a soapy feel4 ,?is appe>ance is common to all ! m9]als ( ! /eatite gr\p1 & is ! cause ( _! g5]ic "n1 soap/one4 ,al?\gh ! /eatites h a v l[ degree ( h>dness--mo/ ( !m c be scrat*$ by ! f+]-nail--"s difficulty is enc\nt]$ 9 r$uc+ !m to f9e p[d]4 ,calc9ation usually increases ! h>dness consid]ably1 s t1 9 "s cases1 ! calc9$ m9]al gives (f sp>ks :5 /ruck ) a /eel in/rum5t4 ,soap/one is compos$ ( magnesium silicates1 conta9+ v>y+ proportions ( magnesia & silica1 toge!r ) a small quantity ( wat]1 app>5tly 9 a /ate ( *emical comb9ation1 a v high temp]ature1 approa*+ :ite heat1 be+ requir$ to effect its complete expulsion1 ! residue !n atta9+ ! a=esaid high degree ( h>dness4 ,! composition ( talc c be express$ by ! symbol ,h#b,mg#b7,si,o#c7d1 correspond+ to #fceb ( silica1 #cagb ( magnesia1 & #dgf ( wat]4 ,9 "s v>ieties ( talc1 a portion 7#a-e7 ( ! magnesia is replac$ by f]r\s oxide4 ,talc is q unaffect$ by ! action ( dilute acids1 boil+ conc5trat$ sulphuric acid be+ requir$ to decompose x1 ) sep>ation ( silica4 ,ow+ to its l[ specific gravity & *emical indiff]5ce1 talc is suitable = light5+ ! %ade ( c]ta9 lake pigm5ts4 ,x c also be us$ z a pigm5t by itself1 & also z a gloss on wall-pap]1 = mix+ ) pap] pulp1 & = v>i\s o!r purposes4 ,clay ,! m9]al kn[n z clay is1 9 all cases1 a product ( ! decomposition ( o!r m9]als1 ma9ly felsp>4 ,?is sub/ance is a d\ble silicate ( alum9a & pota%1 ,k#b,o4,al#b,o#c47,si,o#b7f4 ,pure kaol9 is ,al#b,o#c7,si,o#b7b #b;,h#b,o1 or #dfej silica1 #cief alum9a1 #aci wat]4 ,clay may be suppos$ to h be5 =m$ by ! conv]sion ( felsp>1 "u ! action ( air & wat]1 into silicate ( alum9a1 ! silicate ( pota% be+ dissolv$ out4 ,be+ insoluble1 ! silicate ( alum9a w\ld be transport$ by ! wat]1 9 a v f9e /ate ( division1 & f9ally deposit$ z a s$im5t1 :i* 9 c\rse ( "t became a solid mass4 ,?is1 :5 aga9 br\ght into contact ) wat]1 =ms a v pla/ic pulp :i*1 :5 dri$ & bak$1 =ms a solid mass1 brick1 :i* is no long] affect$ by wat]4 ,p]fectly pure clay =ms a :ite mass1 :i*1 "u ! "n ( ,*9a clay or kaol91 is us$ = mak+ porcela91 & is only occasionally met ) 9 l>ge quantities4 ,pure kaol9 is *>act]is$ by its great *emical indiff]5ce1 be+ decompos$ only by /rong alkalis & sulphuric acid4 ,at ! high temp]ature ( ! pott]y kiln1 kaol9 s9t]s to a v compact mass1 b _c be fus$1 except :5 small quantities are subject$ to ! int5se heat ( ! oxyhydrog5 flame1 :]eupon x fuses to a col\rless glass ( great h>dness4 ,9 an impure /ate1 silicate ( alum9a occurs frequ5tly 9 ,nature1 & !n =ms ! m9]als kn[n "u ! g5]ic names ( clay1 loam1 m>l1 etc4 ,^! impure clays conta9 v>y+ proportions ( extrane\s m9]als :i* produce *anges 9 ! physical & *emical prop]ties4 ,!y are grey1 blue or yell[ 9 col\r1 ! grey & blue v>ieties mo/ly conta9+ appreciable quantities ( f]r\s oxide1 :il/ ! yell[ k9ds conta9 f]ric oxide4 ,:5 fir$1 all ( !m become yell[ or r$1 ! f]r\s oxide be+ trans=m$ into f]ric oxide by ! heat4 ,"s fairly :ite clays are high 9 lime1 :i* makes !m fusible at high temp]atures4 ,9 "s v impure k9ds1 ev5 ! comp>atively l[ heat ( ! brick-kiln is suffici5t to cause p>tial fusion4 ,= col\r-mak+1 ! :ite clays1 especially kaol9 & pipeclay1 =m a highly important mat]ial1 be+ procurable at v l[ prices & fairly easy to prep>e4 ,! :ite clays are ei!r us$ z pigm5ts by !mselves1 or = mix+ ) o!r col\rs ( l[ specific gravity4 7,b7 ,,yell[ ,,e>?s ,! numb] ( yell[ e>?s is l>ge1 b mo/ ( !m exhibit a c]ta9 simil>ity 9 *emical composition1 ! pigm5t>y pr9ciple 9 ! majority be+ ei!r f]ric oxide or f]ric hydroxide4 ,! =m] is yell[1 ! latt] br[n1 & ! col\r ( ! m9]als resembles t ( ! prepond]at+ iron comp\nd4 ,br[n ,iron/one ,! m9]al kn[n z br[n iron/one consi/s ( f]ric hydroxide1 & usually =ms compact masses1 no decid$ cry/als hav+1 s f>1 be5 obs]v$4 ,! lumps h an irregul> or e>?y fracture1 a h>dness ( #e-ee1 & a sp4 gr4 betwe5 #cdj & #cie4 ,! col\r ranges1 9 ! diff]5t v>ieties1 f yell[i% 7ru/y7 br[n1 ?r\gh c9namon to blacki%-br[n4 ,! *emical composition ( ! pure lumps may be express$ by ! symbol #b;,fe#b,o#c #c;,h#b,o2 b a little manganese oxide & silica is g5]ally pres5t ev5 9 ! pure k9ds4 ,! *ief v>ieties ( ?is m9]al are3-- 7a7 ,fibr\s br[n iron ore1 or br[n hematite1 mo/ly =m+ r5i=m or /alactitic masses4 7b7 ,compact br[n iron/one1 usually 9 d5se masses1 & n infrequ5tly also appe>+ 9 pseudo-morphs ( o!r m9]als4 7c7 ,o*re\s br[n iron/one4 ,?is v>iety is ! mo/ important to ! col\r-mak]1 = ^: purposes x is pref]ably us$4 ,x ne>ly always =ms v loose1 e>?y masses1 yell[ or br[n 9 col\r4 7d7 ,clay iron/one4 ,?is consi/s ( a mixture ( ! above-m5tion$ v>ieties ) v>iable proportions ( o!r m9]als1 clay be+ ! mo/ common +r$i5t4 ,nodul> iron ore1 olitic1 bog & silice\s ore belong to ?is class1 z also ! m9ette ores t are f\nd 9 great abundance 9 ,alsace-,lorra9e1 ,belgium & ,luxemburg1 & are class$ ) ! olitic br[n iron/ones4 ,9 mo/ cases1 ! v>ieties enum]at$ are f\nd toge!r1 & are us$ = ! production ( iron4 ,! o*re con/itut+ ! mo/ int]e/+ memb] to ! col\r-mak] (t5 occurs z deposits emb$d$ 9 d5se masses ( br[n iron/one1 ?\gh 9 _m places x is f\nd by itself4 ,,*emical ,,composition ,,( ,,v>i\s ,,br[n ,,iron/ones ,! foll[+ analyses ( br[n iron/one f diff]5t deposits w give an idea ( ! composition ( ^! m9]als4 ,ord9>y ,br[n ,iron/one ---------------------------------------- ----------------------- #a4 #b4 #c4 #d4 #e4 #f4 #g4 #h4 #i4 #aj4 ---------------------------------------- ----------------------- ,f]ric oxide #gfgfgcgeggedghejghdbdhbe -- -- -- -- ,manganese oxide #afefajej #bgj #aie #acjbdgc -- -- -- -- ,iron -- -- -- -- -- -- #cci #cghhedhjeejd ,manganese -- -- -- -- -- -- #jae #jag #jeg #jbj ,alum9a -- -- -- -- #aac #bccajjc #jhh #aae #bej ,lime #jfj #bge #jdh #ejh #cee #bhe #jda #jcb #jej #jcd ,magnesia #fdd -- #abe #dej #jah #jij #jfg -- #jjb #jch ,silica -- -- #cee #jhe #edhaacebhbiccch #jjb #jch ,,s#c -- -- -- -- -- #jji -- -- -- -- ,p#b,o#e -- -- -- -- #jji #jjh -- -- -- -- ,sulphur -- -- -- -- -- -- #jcc #jjf #jjd,trace ,phosphorus -- -- -- -- -- -- #jjd #jef #jjb #jjf ,loss on inc9]ation #efeadjjadea #iab #iaj #ihj #ihh #gggajeeajga ---------------------------------------- ----------------------- ,deposits3 7#a7 ,hamm2 7#b7 ,s*malkald52 7#c7 ,htt5b]g 7,c>yn?ia72 7#d7 ,/yria2 7#e7 & 7#i7 ,bilbao2 7#f7 ,alg]ia2 7#g7 ,s*welm 7,we/phalia72 7#h7 ,elb+]ode 7,h>z72 7#aj7 ,p5nsylvania4 ,argillace\s ,br[n ,iron/one ---------------------------------------- ----------------------- a4 b4 c4 d4 e4 f4 g4 h4 i4 k4 ---------------------------------------- ----------------------- ,f]ric oxide #hjgfaid #eeciffccegcbebejciejgefg -- -- ,iron -- -- -- -- -- -- -- -- #djijbafi ,manganese oxide -- #hb -- #fdb -- #edi #fab #jgb -- -- ,manganese -- -- -- -- -- -- -- -- -- -- ,z9c oxide #jib #af -- -- #jdg -- -- -- -- -- ,alum9a #bcfaaj #abhj #ggd #afh #ebc #ihi #caj #die #chh ,lime -- #bf ,trace #jda #jac #ccfbjcd #eja #eeibabe ,magnesia -- #jb -- #jcg -- #jcf -- -- #jdi #jcj ,silica #deh #dhfabbgcabigcjfd #hfd #ebb #hgjaffcadga ,p#b,o#e -- -- -- -- #jcb #chf #bai #cfh -- -- ,phosphorus -- -- -- #jjb -- -- -- -- #aac #jdh ,,s#c -- -- -- #jjc,trace -- -- -- -- -- ,sulphur -- -- -- -- -- -- -- -- #jaj #jje ,loss on inc9]ation#abga #ia #hejaaggabgjbjeebegd -- #afjdbhgj ---------------------------------------- ----------------------- 7a7 ,olitic 7pea7 ore f ,elligs]brick 7,brunswick72 7b7 f ,durla* 7,bad572 7c7 & 7d7 ,ore f ,essl+52 7e7 ,olitic ore f ,sipt+5 7,bad572 7f7 f ,ad5/$t1 nr4 ,pirna 7argillace\s72 7g7 ,ibid4 7calc>e\s72 7h7 ,m9ette f ,es*2 7i7 ,r$ m9ette f ,dolvaux2 7k7 ,br[n m9ette f ,r$ange4 ,limonite 7,bog ,iron ,ore7 ---------------------------------------- ------ #a4 #b4 #c4 #d4 #e4 #f4 ---------------------------------------- ------ ,f]ric oxide #fajjfgdffefffgeigjjefbbj ,manganese oxide #gjj #cai #chg #ade #agh #gfj ,p#b,o#e #bjj #jfg #aac #jah #jcd #afj ,,s#c -- #cjg,trace #jba,trace,trace ,silica #fjj #gjj #gae #ghi #hjcaffj ,alum9a -- -- #eji #dah #aej #bbj ,lime -- #jij #jhb #jdg #bca #afj ,magnesia -- -- #jae #jbc #jab #cgc ,wat] & organic acids #aijjagjj #fbbaghaaehgaiij ---------------------------------------- ------ 7#a7 ,limonite f ,lausitz2 7#b7 ,limonite f ,au]1 nr4 ,morizburg2 7#c to #f7 ,sw$i% limonite4 ,o*re ,o*re1 or yell[ ,t]ra di ,si5a1 =ms e>?y-look+ masses1 fawn1 r$di%-yell[ to br[ni%-r$ 9 col\r4 ,:il/ n infrequ5t 9 ,nature1 o*re is only f\nd 9 small quantities1 z pockets1 & n z ext5sive deposits4 ,! discov]y ( a b$ ( good col\r$ o*re is1 h[ev]1 always a v valuable f9d1 bright natural o*res be+ some:at r>e1 & mo/ k9ds requir+ special prep>ation be=e !y c be us$ z pa9t]s' col\rs4 ,ow+ to ! comp>ative sc>city ( good col\r$ o*res1 !y are (t5 call$ aft] ! place ( orig91 su* z ,?ur+ian1 ,italian 7,si5a71 ,engli%1 etc41 o*re4 ,9 ne>ly e case1 o*re is a decomposition product ( v>i\s f]rug9\s m9]als1 :i* has be5 transport$ by wat]1 (t5 9 admixture ) o!r m9]als1 & f9ally deposit$ 9 ! places :]e x is n[ f\nd4 ,mo/ o*res consi/ ( v>y+ mixtures ( clay1 f]ric hydroxide & lime2 &1 z a rule1 ! high] ! proportion ( f]ric hydroxide1 ! deep] ! col\r4 ,?us1 = example1 ! f]ric hydroxide may am\nt1 9 ! d>k grades1 to #be ( ! entire mass1 :il/ 9 ! light] k9ds x may be z l[ z #c4 ,x is v r>e t o*re is put on ! m>ket 9 its native condition1 be+ mo/ly subject$ to *emical treatm5t enabl+ a def9ite %ade ( col\r to be obta9$4 ,?is w be gone into m fully lat]4 ,yell[ ,e>? ,yell[ e>? is f\nd 9 _m places z compact masses1 & less frequ5tly z s*i/\s deposits4 ,x has a f9e e>?y fracture1 & is mo/ly devoid ( lu/re1 except = a fa9t %imm] on ! surface ( fracture2 slightly greasy feel2 & a t5d5cy to crumble1 9 wat]1 to a non-pla/ic p[d]4 ,x conta9s silica1 f]ric oxide & wat] 9 v>y+ proportions1 & ! yell[ e>?s f diff]5t deposits always v>y slightly 9 p]c5tage composition4 ,^! diff]5ces are cle>ly %[n 9 ! foll[+ analyses ( two v>ieties f ! vic9ity ( ,amb]g 7,bav>ia73-- ,i4 ,,ii4 ,silica #ccbc #ceaj ,alum9a #adba #addj ,magnesia #ach -- ,f]ric oxide #cggf #cfhj ,wat] #acbd #acfj ,:5 heat$1 ! col\r *anges gradually to r$1 & ! e>? becomes extremely h>d4 ,!re are sev]al recognis$ comm]cial grades1 ! price ( :i* v>ies ma9ly 9 accordance ) ! col\r & f95ess4 ,! ,amb]g v>iety is specially e/eem$1 ! ,hung>ian & ,moravian k9ds be+ less valuable4 ,! col\r n be+ p>ticul>ly good1 ?is e>? is nev] us$ = f9e "w1 b is l>gely employ$ z a yell[ wa% = h\ses & z ord9>y di/emp]4 ,x may also be us$ z an oil pa9t4 ,r$ ,o*re is a less important1 *eap v>iety ( o*re1 *iefly us$ 9 *eap pa9ts & = l[-pric$ wall-pap]s4 ,x occurs 9 ! deposits z clayey masses4 ,t]ra di ,si5a ,t]ra di ,si5a is a v pure =m ( f]ric hydroxide4 ,:5 gr\nd1 ! light to d>k br[n lumps furni% a pale to d>k yell[ p[d]1 :i* c be trans=m$ into a numb] ( gradations by burn+4 ,9 spite ( its h&some col\r1 ?is pigm5t is defici5t 9 cov]+ p[]1 9 addition to :i* x d>k5s :5 mix$ ) v>ni%1 & dries sl[ly4 7,c7 ,,! ,,r$ ,,e>?s ,ap>t f ! small quantities ( native v]milion h&some en\gh = direct use z pa9t]s' col\rs :5 r$uc$ to p[d]1 ! r$ e>?s1 ) practically no exception1 consi/ ( f]rug9\s m9]als1 & x is only )9 a rec5t p]iod t r$ pa9t]s' col\rs h be5 prep>$ f c]ta9 *emical wa/e products f manufactur+ processes4 ,9 all cases1 h[ev]1 comp\nds ( iron & oxyg5 con/itute ! bulk ( ! r$ e>?s4 ,9 addition to f]ric oxide1 :i* is ! *ief mat]ial us$ = mak+ ! important r$ col\rs1 are comp\nds ( f]ric oxide & wat]1 i4 e4 f]ric hydroxides4 ,! f]ric oxide pigm5ts are among ! mo/ important 9 ! entire s]ies ( e>? col\rs1 be+ on ! "o h& v *eap1 & on ! o!r s h&some 9 col\r t f]ric oxide c be us$ = ! f9e/ pa9t+s4 ,f]ric oxide c also be %ad$ v ext5sively by a fairly simple treatm5t1 s z to furni% a :ole range ( v h&some %ades4 ,9 nature1 f]ric oxide occurs 9 num]\s v>ieties ( "o & ! same m9]al1 r$ iron ore1 :i* is also kn[n z hematite1 blood /one1 raddle1 etc4 ,r$ ,iron/one ,r$ hematite occurs native z rhomboh$ral cry/als1 :i* mo/ly consi/ solely ( f]ric oxide1 & may be consid]$ z pure oxide = ! purposes ( ! col\r-mak]4 ,! diff]5ce betwe5 ! sev]al v>ieties is due1 n to any *emical v>iation1 b entirely to *anges 9 physical /ructure4 ,! v>ieties ) a radial1 fibr\s /ructure are kn[n z r$ hematite1 ! col\r ( :i* ranges f blood r$ to d>k br[n & is frequ5tly accompani$ by metallic lu/re4 ,! scaly modification ( ?is m9]al =ms micace\s iron ore1 & is usually a deep iron black4 ,9 ! neighb\rhood ( volcanoes x is frequ5tly f\nd z p>ticul>ly h&some cry/als4 ,iron cream 7fro/y hematite7 is ! "n giv5 to a beautiful *]ry r$ v>iety1 :i* easily rubs (f1 has a greasy feel & is compos$ ( extremely f9e scales4 ,! s-call$ raddle occurs 9 ,nature z a readily pulv]ul5t e>?y mass ( f]ric oxide contam9at$ m or less ) extrane\s sub/ances4 ,on acc\nt ( its abundance & l[ m>ket price1 x is l>gely us$ 9 pa9t+4 ,al?\gh mix$ ) num]\s =eign sub/ances1 c]ta9 clay iron/ones1 olitic iron/ones & silice\s iron/ones may be reg>d$ z f]ric oxide 9 ! s5se und]/ood by ! col\r-mak]1 all ^! m9]als hav+ a deep r$ to deep br[n col\r & be+ capable ( f9d+ advantage\s employm5t z pigm5ts4 ,f]ric oxide is di/+ui%$ by two prop]ties :i* r5d] x specially valuable to ! col\r-mak]4 ,:5 comb9$ ) wat]1 its col\r is no long] r$1 b a h&some br[n2 &1 on ! o!r h&1 :5 heat$1 ! col\r passes ?r\gh br[n into a p]man5t d>k violet4 ,by suitable treatm5t ( su* m9]als z consi/ ma9ly ( f]ric hydroxide1 mixtures c be obta9$ :i* conta9 ! oxide & hydroxide 9 v>iable proportions & give a :ole range ( %ades betwe5 br[n & r$4 ,! prep>ation ( ^! col\rs is easy :5 v pure r$ iron/one is available4 ,! some:at exp5sive pigm5t1 ,indian r$1 is--:5 pure--really no?+ b a v pure f]ric oxide ( ,indian orig94 ,f]ric oxide1 h[ev]1 (t5 conta9s impurities :i* consid]ably influ5ce ! col\r ( ! product4 ,ow+ to ! fact t l>ge quantities ( f]ric oxide are =m$ z by-products 9 c]ta9 *emical processes :i* are c>ri$ out on a v ext5sive scale1 ?is oxide1 :i* is v pure1 c be advantage\sly us$ = mak+ iron pigm5ts1 especially z its application = o!r purposes is v re/rict$1 & x c !re=e be _h at a v l[ price4 ,! foll[+ analyses %[ ! composition ( a numb] ( r$ iron/ones1 ,nos4 #a1 #b & #c be+ hematite f ,from5t1 or ,wetzl>1 ,no4 #d f ,wetzl>1 ,nos4 #e & #f hematite f ,:itehav51 ,no4 #g f ,?ur+ia1 ,no4 #h f ,bohemia1 ,no4 #i f ,spa91 ,no4 #aj f ,n4 ,am]ica1 & ,no4 #aa f ,engl&4 ---------------------------------------- ------------------------- ,f]ric ,manganese ,alum9a1 ,no4 oxide4 oxide4 ,silica4 ,p#b,o#e4 lime & ,wat]4 magnesia4 ---------------------------------------- ------------------------- #a #idjj ,trace #bjj -- ,trace #bjj #b #hjie -- #afgd #jea #jig #jhc #c #gcgg -- #bcaf #jde #ada #aba #d #ibde -- #efc #jai #jfe #ajh #e #ifbg -- #dbj -- #jei #ddj #f #fcje #ebi #bbgf -- #jdi #ddj #g #hejj #afja #ccjd #jdeg #hgie #jfcc ---------------------------------------- ------------------------- ---------------------------------------- ---------------------- ,man- ,alu- ,mag- ,phos- ,loss on ,no4,iron4 ganese4m9a4,lime4nesia4,silica4,sulphur4 phorus4calc9a- tion4 ---------------------------------------- ---------------------- #h #ccfd #jaj #geh #haj #jhb #aghj ,trace #jai #ihb #i #cach #jai #jjfbiie #jce #jhg -- #jji #bcfh #aj #fbed #aic #aga -- #jej #chj #jjb #jjd #bbc #aa #fbia ,trace #aci #jgj #jdb #ehi #jje #jaa -- ---------------------------------------- ---------------------- ,!re are c]ta9 o!r m9]als closely alli$1 bo? *emically & m9]alogically1 to r$ iron/one1 namely1 ! br[n hematites or iron/ones us$ 9 ! manufacture ( iron4 ,br[n hematite consi/s ( f]ric hydroxide1 ,fe#b,o#c;,h#b,o1 & occurs 9 a v>iety ( =ms 9 ,nature1 ! mo/ frequ5t be+ pea 7olitic7 ore1 :i* owes its "n to ! sph]ical %ape ( ! gra9s4 ,"s br[n hematites are decomposition products ( o!r m9]als1 & conta9 sulphur & phosphorus 9 addition to f]ric hydroxide4 ,l ! pure hydroxide1 !y are br[n 9 col\r1 b diff] !refrom consid]ably 9 _! *emical behavi\r :5 heat$4 ,?is is p>ticul>ly ! case ) ! s-call$ bog ore1 :i* is mo/ly f\nd1 z spongy yell[-br[n to black masses1 9 swamps1 & owes its orig9 to ! decomposition ( v>i\s f]rug9\s m9]als4 ,x v>ies greatly 9 *emical composition & occasionally conta9s up to ab\t #ej ( s&4 ,! am\nt ( f]ric oxide 9 bog ore v>ies betwe5 #bj & #fj1 & x also conta9s #g-cj ( wat]1 up to #d ( ,p#b,o#e1 small quantities ( f]r\s oxide & manganese hydroxide1 toge!r )1 9 mo/ cases1 me*anically admix$ organic residues4 ,! phosphorus cont5t makes bog iron a v inf]ior mat]ial = smelt+1 ! result+ iron be+ ( l[ quality4 ,nev]!less1 x c sometimes be advantage\sly us$ 9 mak+ e>? col\rs1 ?\gh ! products _c lay mu* claim to beauty ( col\r4 ,bole ,! native e>? pigm5ts kn[n by ?is "n =m masses ( ! col\r ( lea!r to d>k br[n1 ) a con*oidal fracture & an e>?y appe>ance4 ,bole *iefly consi/s ( iron silicate comb9$ ) wat]1 "s v>ieties conta9+ small quantities ( alum9a4 ,! composition fluctuates v consid]ably1 mo/ v>ieties conta9+ #da-db ( silica1 #bj-be ( alum9a1 & #bd-be ( wat]1 ! rema9d] consi/+ ( f]ric oxide4 ,"s k9ds1 su* z ,oravicza & ,s9ope bole1 conta9 only #ca-cb ( silica & #ag-ba ( wat]4 ,bole is us$ z a pa9t = walls1 clapbo>ds1 etc41 & is only m5tion$ "h because ( its relation%ip to ! f]ric oxide pigm5ts4 ,alum ,sludge ,l>ge quantities ( cl>ification sludge are produc$1 9 alum works1 z ! s$im5t f ! r$ liquors4 ,?is sludge consi/s ma9ly ( f]ric oxide1 ) small quantities ( o!r oxides & sulphuric acid 7basic f]ric sulphate71 & w\ld be an entirely wor?less by-product except = ! fact t x c be manufactur$ into pigm5ts1 "s ( !m ( great beauty4 ,all alum mak]s %\ld treat ?is residue & conv]t x into pigm5ts1 :i* !y c\ld put on ! m>ket at a l[ rate1 ! co/ ( prep>ation be+ small4 ,s9ce ! mat]ial is *iefly compos$ ( f]ric oxide1 ! result+ col\rs are v simil> to ^? obta9$ f iron ores2 & all %ades1 f yell[-br[n1 ?r\gh r$1 to ! d>ke/ br[n1 are repres5t$4 ,m9e ,sludge ,! wat] frequ5tly pres5t 9 iron m9es sometimes conta9s l>ge quantities ( s$im5t1 :i* consi/ ma9ly ( iron o*re & c be advantage\sly work$ up into pigm5ts4 ,!re is sc>cely any ne$ to m5tion t all sub/ances conta9+ f]ric oxide c be us$ = mak+ any ( ! pigm5ts obta9able f ! oxide itself1 ! only diff]5ce betwe5 ! v>i\s raw mat]ials be+ _! degree ( purity1 s t x is n always s easy to obta9 a c]ta9 desir$ %ade f a giv5 mat]ial 9 su* beauty z is furni%$ by ano!r mat]ial1 ! small quantities ( impurities associat$ ) ! f]ric oxide hav+1 9 _m in/ances1 an important influ5ce on ! col\r4 7,d7 ,,blue ,,e>?s ,only two m9]als are kn[n :i* are capable ( direct use z blue pigm5ts1 viz4 vivianite 7native ,prussian blue7 & copp] c>bonate 7azurite1 ultram>9e71 & z nei!r ( !m is p>ticul>ly h&some1 !y are only us$ = unimportant "w4 ,lapis lazuli is no long] employ$4 ,azurite1 or ,ultram>9e ,?is m9]al1 :i* is ( frequ5t occurr5ce ) mala*ite & o!r cuprif]\s m9]als1 =ms small cry/als ( a beautiful deep azure blue consi/+ ( cupric oxide 9 comb9ation ) c>bon dioxide & wat]1 express$ by ! =mula #b;,cu,c,o#c1 ,cu7,,oh7#b1 or ,cu#c7,,oh7#b7;,,co#c7b1 & conta9+ #fiai ( cupric oxide1 #beeh ( ,,co#b & #ebc ( wat]4 ,! col\r ( ! p[d]$ m9]al is mu* pal] ?an t ( ! cry/als4 ,! pigm5t1 :i* is us$ = *eap pa9ts1 is n p>ticul>ly /able1 & loses mu* ( its beauty :5 appli$ to pla/]4 ,vivianite ,?is m9]al occurs 9 _m places z cry/all9e masses1 b also =ms e>?y deposits1 "s ( :i*1 especially 9 c]ta9 bogs1 atta9 consid]able ?ickness4 ,! col\r is betwe5 indigo & blacki% blue2 & ! fre%ly won m9]al (t5 has an unsightly :iti% appe>ance1 :i*1 h[ev]1 soon *anges into ! pure blue4 ,! cause ( ?is peculi>ity is due to ! fact t vivianite orig9ally consi/$ ( hydrat$ f]r\s phosphate1 :i* is :ite1 ?is comp\nd be+ trans=m$1 "u ! influ5ce ( ! air1 into ! blue f]ric phosphate4 ,vivianite conta9s f]ric oxide1 phosphoric acid & wat]1 b 9 v>iable proportions4 ,! orig9al composition1 express$ by ,fe#b7,,po#d7b #h;,h#b,o#b1 corresponds to #dcjc ( f]r\s oxide1 #bhbi ( ,p#b,o#e & #bhfh ( wat]2 b1 9 ! air1 "p ( ! f]r\s phosphate is oxidis$ to basic f]ric phosphate1 s t ! cont5t ( f]r\s oxide may range f #ige to #dbga1 & t ( f]ric oxide betwe5 #aab & #chbj4 ,vivianite is also sold z blue o*re1 & is n[ seldom us$ z a pa9t]s' col\r1 ow+ to ! introduction ( a l>ge numb] ( artificially prep>$ blues1 :i* are sup]ior to vivianite 9 col\r & are *eaply made4 ,h[ev]1 x c /ill f9d application 9 localities :]e x is obta9able 9 quantity4 7,e7 ,,gre5 ,,e>? ,,pigm5ts ,! gre5 e>? pigm5ts comprise gre5 e>? 7,v]ona gre57 & mala*ite4 ,l ! blue e>?s1 !y _c lay any p>ticul> claim to beauty1 b !y are v *eap1 & consequ5tly are l>gely us$ :]e l[ price is ! *ief consid]ation4 ,gre5 ,e>? ,9 ,nature1 gre5 occurs z an entirely non-cry/all9e e>?y mass1 :i* is probably a decomposition product ( augite4 ,x has a close1 e>?y fracture1 a col\r betwe5 seladon & olive gre51 & a slightly greasy appe>ance4 ,9 po9t ( *emical composition x consi/s ( silica1 alum9a1 magnesia1 sodium1 potassium1 f]r\s oxide & wat]1 ! usual repres5tative =mula be+ ,,ros#a,o#b ,h#b,o1 9 :i* ,,ro symbolises a metallic oxide4 ,! col\r is due to f]r\s oxide2 & if left expos$ to ! air = a long "t1 or subject$ to p[]ful calc9ation1 ! great aff9ity ( f]r\s oxide = oxyg5 causes ! col\r to turn r$ & r$-br[n4 ,gre5 e>? is f\nd 9 _m localities1 e4 g4 ,bohemia1 ,hung>y1 ! ,tyrol & ,cyprus1 ! f9e/1 h[ev]1 occurr+ ne> ,v]ona1 on :i* acc\nt x is kn[n z ,v]onese e>?4 ,mala*ite ,! comm]cial pigm5t consi/s ( p[d]$ mala*ite1 a m9]al :i* usually occurs 9 compact masses ( a h&some em]ald gre5 col\r1 ?\gh isolat$ lumps exhibit consid]able v>iation 9 %ade1 "s ( !m be+ d>k gre5 & o!rs v pale4 ,9 *emical composition1 mala*ite is closely alli$ to azurite1 consi/+ ( cupric oxide1 c>bon dioxide & wat]1 & ! diff]5ce is entirely "o ( p]c5tage proportions4 ,! =mula is ,cu,co#c1 ,cu7,,oh7#b1 or ,cu#b7,,oh7#b;,,co#c1 correspond+ to #gaij ( cupric oxide1 #aiid ( c>bon dioxide & #haf ( wat]4 ,p[d]$ mala*ite 7ev5 ! d>k gre5 v>ieties7 is always r light 9 col\r1 & = ?is reason is n mu* us$4 ,fur!rmore1 ! m9]al is r h>d 7#ce71 & is consequ5tly difficult to gr9d2 9 addition to :i* ! m9]al is fairly exp5sive1 on acc\nt ( its employm5t z a s\rce ( copp]1 p>ticul>ly f9e pieces be+ also us$ z ornam5ts or = mak+ works ( art4 ,moreov]1 l all copp] comp\nds1 x is v s5sitive to ! action ( sulphurett$ hydrog51 & liable to discoloration 9 c\rse ( "t4 7,f7 ,,br[n ,,e>? ,,pigm5ts ,num]\s m9]als are adapt$ = ! manufacture ( br[n pigm5ts4 ,on ! basis ( *emical composition1 !y may be class$ 9 two gr\ps2 ^? consi/+ ( f]ric hydroxide1 & ^? 9 :i* ! br[n col\r is due to organic sub/ances4 ,! fir/ gr\p comprises ! m9]als :i* h already be5 m5tion$ 9 connection ) ! r$ e>? pigm5ts1 bole & br[n o*re 7umb]71 ,t]ra di ,si5a1 ,cologne e>? & a numb] ( o!r e>?s ri* 9 f]ric hydroxide belong+ to ?is category4 ,! second1 or organic gr\p1 includes comp\nds t are v ri* 9 c>bon & are !re=e ( a v d>k col\r1 ! %ades rang+ f light br[n to black1 e4 g4 ! true umb]s & asphaltum4 ,umb] ,z already m5tion$1 ! t]m 8umb]0 0 =m]ly appli$ to br[n v>ieties ( o*re1 :]eas at pres5t x is ext5d$ to c]ta9 masses ( br[n-coal "*1 (t5 int]sp]s$ ) iron o*re & sometimes conta9+ manganese4 ,umb] g5]ally consi/s ( fairly d5se1 e>?y masses1 :i* are dri$ & gr\nd--aft] cru%+ & levigation1 if necess>y4 ,valuable v>ieties are ,cappagh br[n & ,cal$onian br[n1 bo? ) a r$di% t+e4 ,x is ?us evid5t t 8umb]0 n[ implies two diff]5t k9ds ( mat]ials1 organic masses & iron-manganese comp\nds1 :i* c also be us$ z oil pa9ts4 ,^! umb]s c also be ext5sively %ad$ by burn+1 ! f9al col\r be+ p>ticul>ly influ5c$ by ! am\nt ( manganese comp\nds pres5t4 ,! c>bonace\s umb]s 7,cassel br[n1 ,c>bon br[n7 are combu/ible1 & mo/ly leave beh9d a m]ely small residue ( a%4 ,an important prop]ty ( ^! umb]s is _! p>tial solubility 9 alkalis1 a peculi>ity :i* is utilis$ = ! prep>ation ( br[n wood /a9s4 ,asphaltum ,asphaltum =ms v friable d>k br[n to black masses1 :i*1 9 contact ) a light1 easily ignite & burn ) a bright1 b v smoky1 flame1 dis5gag+ a peculi>1 8bitum9\s0 smell1 & leav+ only a v small quantity ( a%4 ,ext5sive deposits ( asphaltum are f\nd at ! ,dead ,sea1 ! ,pit* ,lake on ! isl& ( ,tr9idad1 9 ,dalmatia1 & _m o!r places1 :]e1 h[ev]1 x is 9 an impure condition & frequ5tly conta9s l>ge quantities ( s&4 ,9 _m localities ! rock is impregnat$ ) asphaltum1 :i* makes x d>k br[n to black 9 col\r & gives rise to a bitum9\s od\r :5 rubb$4 ,peat b$s sometimes conta9 pockets ( a mass ) a h&some br[n col\r & consi/+ ( a mixture ( humic acids & o!r organic sub/ances :i* may be rank$ ) ! hum9 bodies t are always =m$ :5 organic matt] decomposes 9 pres5ce ( an insuffici5t supply ( oxyg54 ,^! bodies are d>k col\r$1 mo/ly deep br[n1 ri* 9 c>bon1 &1 to "s ext5t1 simil> to br[n coal or peat 9 *emical composition4 ,_! high c>bon cont5t r5d]s ^! sub/ances v in]t t[>ds *emical reag5ts1 & !re=e p>ticul>ly adapt$ = ! prep>ation ( pa9t]s' col\rs4 ,g5u9e ,v&yke br[n1 :i* is ! h&some/ br[n kn[n1 is an e>? ri* 9 hum9 comp\nds2 & ,cassel br[n also belongs to ?is gr\p4 7,g7 ,,black ,,e>? ,! col\r ( ^! e>?s is entirely due to c>bon1 & pure c>bon1 a c]ta9 =m ( :i* occurs native1 is itself us$ z a pigm5t4 ,actually1 !re are only two m9]als t require to be m5tion$ 9 ?is connection3 black s*i/ & graphite4 ,black ,s*i/ ,9 mo/ cases ?is is a clay %ale1 s ri* 9 c>bon z to appe> deep black4 ,9 comm]ce1 ?is m9]al is also errone\sly call$ 8black *alk02 b at pres5t x is seldom us$ z a pigm5t or draw+-mat]ial1 black *alks be+ produc$ f> m *eaply ?an ! exp5se ( prep>+ ! natural article4 ,grey clay %ales are us$ = mak+ grey e>? pigm5ts 7/one grey1 & m9]al grey74 ,graphite ,?is m9]al is f\nd1 9 a v pure /ate1 9 _m localities1 celebrat$ deposits occurr+ 9 ,engl&1 ,sib]ia1 ,bohemia & ,bav>ia1 :il/ ,nor? ,am]ican graphite has lately come into prom95ce4 ,graphite is a modification ( pure c>bon1 & is met ) 9 ! =m ( hexagonal 7rhomboh$ral7 cry/als1 usually occurr+ z hexagonal plates ) a lu/r\s1 iron-black col\r4 ,x rubs (f easily1 & readily burns away1 leav+ a v small am\nt ( a%1 :5 subject$ to a v high temp]ature 9 pres5ce ( air4 ,! pr9cipal uses ( graphite are z an anticorrosive pa9t = iron1 & = mak+ lead p5cils4 ,z already m5tion$1 ! t]m 8e>? col\rs0 has be5 consid]ably broad5$ ( late4 ,:]eas1 =m]ly1 x 0 re/rict$ to col\rs prep>$ exclusively f m9]als by a simple treatm5t1 limit$ to cru%+1 levigation or calc9ation1 x n[ includes ! pigm5ts obta9able f l>ge by-products ( c]ta9 *emical processes4 ,?is latt] class is especially important z af=d+ an opportunity ( utilis+ products =m]ly consid]$ wor?less & ^: removal (t5 entail$ heavy exp5se4 ,by draw+ on ^! mat]ials ! indu/ry ( ! e>? col\rs has greatly enl>g$ its scope4 ,at pres5t1 _m col\rs ( ?is k9d are on ! m>ket1 & x is to ! int]e/ ( _m manufactur]s to endeav\r to utilise c]ta9 wa/e products 9 ! same direction4 ,! advantage ( su* a c\rse h>dly ne$s emphasis+2 b1 to give only a s+le example1 x may be m5tion$ t ! manufacture ( fum+ sulphuric acid f gre5 vitriol1 by ! old process1 produces residues :i* 7 =m]ly look$ ^u z q wor?less1 & sold at v l[ prices1 b are n[ work$ up1 9 a numb] ( factories1 into v h&some & durable pigm5ts4 ,,*apt] ,,iii ,,! ,,prep>ation ,,( ,,! ,,col\r ,,e>?s ,! prep>ation ( ! raw mat]ials = ! purpose ( mak+ e>? col\rs is a v important matt]1 because _m m9]als or pigm5t>y e>?s m]ely require me*anical treatm5t to r5d] !m at once fit = use4 ,! me*anical prep>ation diff]s consid]ably1 9 accordance ) ! raw mat]ial "u treatm5t1 sub/ances t are f\nd native 9 a f9ely p[d]$ condition only ne$+1 = ! mo/ "p1 to be levigat$4 ,x r>ely happ5s1 h[ev]1 t ! raw mat]ial occurs 9 condition = use direct1 an example ( ?is k9d be+ af=d$ by ! f9e/ clays or o*res4 ,:il/ ^! are f\nd 9 a /ate ( extremely f9e p[d]1 !y ne>ly always conta9 c]ta9 quantities ( s&y +r$i5ts or ev5 l>ge lumps ( =eign m9]als1 & !re=e require levigat+4 ,sometimes !y ne$ cru%+ z well1 ! small p>ticles coh]+ s /rongly t m]e treatm5t ) wat] 7levigation7 is unable to sep>ate !m4 ,me*anical =ce is !re=e necess>y1 a passage ?r\gh groov$ roll]s be+ g5]ally suffici5t to cru% ! lumps2 b 9 "s cases /amps h to be us$4 ,:5 solid mat]ials h to be treat$1 me*anical appliances mu/ always be us$1 _! selection dep5d+ on ! mat]ials 9 "q4 ,?us1 gypsum1 = example1 c be cru%$ ) ord9>y rolls or mill /ones1 its degree ( h>dness be+ s v l[ 7#b7 t x c be scrat*$ ) ! f+]-nail4 ,if1 h[ev]1 ! mat]ial to be r$uc$ is lime/one1 :i* belongs to ! ?ird degree ( ! scale ( h>dness 7c only be scrat*$ ) an iron nail71 or heavy sp> 7h>dness #c-ce71 v p[]ful /amps or edge-runn]s mu/ be employ$ to break x d[n into small lumps1 :i* c !n be fur!r r$uc$1 )\t any special difficulty1 9 an ord9>y mill4 ,x is ?us evid5t t a great v>iety ( me*anical appliances are us$ 9 ! manufacture ( e>? col\rs4 ,be=e go+ into _! con/ruction x is necess>y to po9t out t1 :atev] ! me*anical treatm5t employ$1 a consid]able exp5diture ( me*anical =ce is entail$2 & m p[] is ne$$ :5 mixtures h to be prep>$4 ,x is !re=e ess5tial1 9 plann+ a factory = mak+ e>? col\rs on a l>ge scale1 to make provision = ample motive p[]4 ,?is p[] may be suppli$ by a /eam eng9e2 b x mu/ n be =gott5 t ! prime co/ & runn+ exp5ses ( su* an eng9e are consid]able1 & =m an important item 9 view ( ! l[ value ( mo/ e>? col\rs4 ,consequ5tly1 x is highly important to be able to g5]ate motive p[] z *eaply z possible4 ,n[1 ! *eape/ & mo/ uni=m s\rce ( p[] is wat]2 & !re=e1 :]ev] ! conditions all[ ( ! erection ( ! col\r works ne> a /ream or riv]1 :i* c supply ! p[] to run ! v>i\s ma*9]y1 ! mo/ fav\rable circum/ances w h be5 secur$1 ! p[] be+ obta9$ at m9imum co/1 :il/ ! upkeep ( ! motor _c be v great4 ,if !re is suffici5t head = ! wat] to be run ?r\gh a tr\gh ov] ! top ( ! levigation tanks1 ! conditions w be ideally fav\rable4 ,w9d p[] co/s no?+1 once ! motor has be5 in/all$2 b un=tunately1 "o is dep5d5t on ! wea!r1 & sometimes !re is n en\gh w9d1 = days toge!r1 to drive ! sails at all1 & !re=e all ! op]ations h to be /opp$1 includ+ levigation1 ! wat] = :i* has to be rais$ by a w9dmill pump4 ,9 di/ricts :]e ! w9t]s are sev]e1 wat] p[] may also fail & "w h to be /opp$2 & consequ5tly1 ev5 :5 wat] p[] is ! prime s\rce ( en]gy1 a /eam eng9e mu/ be in/all$ z a /&-by1 be+1 ( c\rse1 only us$ :5 ! ma9 s\rce ( p[] gives out or proves insuffici5t4 ,! ma*9es employ$ = prep>+ ! raw mat]ials 9 ! manufacture ( e>? col\rs may be divid$ into ! foll[+ gr\ps3-- ,ma*9es op]at+ entirely by pressure3 cru%]s2 ma*9es act+ by impact3 /amps2 ^? act+ by impact & pressure3 v]tical mills 7edge-runn]s71 ball mills1 c5trifugal mills2 &1 f9ally1 ma*9es ) a frictional action3 gr9d+ mills4 ,!n !re are ! levigat+ ma*9es1 :i* d n r$uce ! mat]ial b sep>ate ! co>s] p>ticles f ! f9]4 ,! con/ruction ( ! =ego+ ma*9es is a matt] = ! ma*9]y manufactur] r ?an ! mak] ( e>? col\rs2 b z ! bus9ess ( ! latt] is dep5d5t on !m1 a %ort description is consid]$ necess>y4 ,! selection dep5ds1 on ! "o h&1 on ! nature ( ! mat]ials to be treat$1 &1 on ! o!r1 on ! size ( ! works1 s9ce a manufactur] :o has to deal ) l>ge quantities ( a giv5 raw mat]ial w require diff]5t ma*9es f ^? us$ on a small scale4 ,! sole purpose ( ! foll[+ description is to indicate to ! col\r mak] ! way 9 :i* ! r$uction ( ! raw mat]ial c be accompli%$4 ,,cru%+ ,,ma*9]y ,cru%]s & ,break]s4--,cru%]s usually consi/ ( groov$ iron roll]s revolv+ on horizontal axes4 ,"o ( ! roll]s is fix$1 ! o!r be+ adju/able by screws1 9 ord] t lumps ( diff]5t sizes may be treat$ 9 "o & ! same ma*9e1 :i* may be employ$ ei!r to turn out a r\ghly cru%$ product1 or to r$uce x to a c]ta9 degree ( f95ess4 ,if sev]al pairs ( cru%+ roll]s be m\nt$ 9 s]ies1 & ea* set a little clos] ?an its pr$ecessor1 ! mat]ial c be r$uc$ progressively f l>ge lumps to a fairly f9e p[d]4 ,ea* pair ( roll]s is ge>$ toge!r by p9ions1 & is turn$ 9 su* a way z to draw ! mat]ial 9 betwe54 ,if ! ge> p9ions h ! same numb] ( tee?1 ! two roll]s w revolve at ! same spe$ & w !n m]ely cru% ! mat]ial into lumps ( a size dep5d+ on ! di/ance at :i* ! roll]s are set ap>t4 ,nev]!less1 by simply alt]+ ! ge> ratio ( ! p9ions1 ! cru%+ action ( ! roll]s c be supplem5t$ by a gr9d+ action1 a mu* f9] p[d] be+ !n obta9able ?an o!rwise1 ! "o roll] runn+ at a high] spe$ ?an ! o!r4 ,^! cru%]s diff] 9 /r5g? ( con/ruction1 v /rongly built ma*9es be+ requir$ = deal+ ) l>ge lumps ( h>d mat]ial1 :]eas sub/ances ( l[ cru%+ /r5g?1 su* z clay or o!r e>?y mat]ials1 c be treat$ 9 mu* light] ma*9es4 ,9 any case1 h[ev]1 x is advisable to h ! ma*9e /rong] ?an is absolutely necess>y = ! "w 9 view2 =1 al?\gh ! prime co/ is ?us increas$1 ! outlay on repairs w be r$uc$1 & ! ma*9es c1 if necess>y1 be us$ on h>d] mat]ial z well4 ,! framework support+ ! roll]s %\ld always consi/ ( a /rong iron ca/+2 & ! ma*9e %\ld be set up z close z possible to ! eng9e or motor1 to m9imise ! loss ( p[] 9 transmission ?r\gh long %aft+1 etc4 ,illu/ration3 ,,fig4 #a4 ,fig4 #a repres5ts a break] 7made by ! ,badis*e ,mas*95fabrik1 ,durla*71 suitable = ! r\gh cru%+ ( clayey mat]ials suppli$ 9 l>ge lumps4 ,x c1 h[ev]1 also cru% %ale1 lime1 *alk1 z well z h>d1 /icky masses :i* w\ld clog up a /one-break]4 ,! mat]ial f$ into ?is break] is gripp$ at once by ! p[]ful project+ tee?1 :i* are connect$ toge!r by %>p-edg$ ridges1 & is cru%$ 9 su* a way t x c be easily r$uc$ /ill fur!r by a succe$+ pair ( smoo? roll]s4 ,illu/ration3 ,,fig4 #b4 ,! granulator 7,fig4 #b71 made by ! same firm1 is an example ( a ma*9e = cru%+ h>d] mat]ials4 ,x is simil> 9 con/ruction to a /one-break]1 b diff]s 9 ! movem5t ( ! jaws1 & comb9es ! prop]ties ( break] & gr9d]1 inasmu* z x te>s ! mat]ial z well z cru%es x4 ,! figure %[s ! ma*9e adapt$ = direct electric drive4 ,if necess>y1 ^! granulators c be fitt$ ) classify+ jig scre5s4 ,/amps4--,/amps or /amp+-mills h be5 us$ f prehi/oric times1 & 7 probably employ$ = r$uc+ h>d mat]ials long be=e ! introduction ( gr9d+-mills4 ,! und]ly+ pr9ciple ( ! /amp+-mill is v simple4 ,! mat]ial to be r$uc$ is plac$ 9 a tr\gh or mort>1 & ! ram or head1 :i* is ( consid]able weight1 is rais$ by a me*anical device & !n all[$ to fall freely1 f a c]ta9 height1 on to ! mat]ial und]nea?1 :i* x cru%es4 ,! heavi] ! head & ! great] ! height ( fall1 ! great] ! effect produc$4 ,z a rule1 a l>ge numb] ( /amps are m\nt$ toge!r1 & 9 su* a way t half ( !m are be+ lift$ :ile ! o!r half are fall+4 ,ei!r a sep>ate mort> or tr\gh is arrang$ "u ea* /amp1 or else ! :ole drop into a common tr\gh *>g$ ) ! mat]ial "u treatm5t4 ,sometimes a lat]al movem5t is imp>t$ to ! mat]ial 9 ! tr\gh1 s z to br+ x "u ! action ( all ! /amps 9 succession4 ,al?\gh ! con/ruction ( /amp+-mills 9 g5]al appe>s simple1 v>i\s modifications are employ$ = diff]5t purposes4 ,z a rule1 a s+le passage ?r\gh a /amp+-mill is n suffici5t to r$uce ! mat]ial completely to ! desir$ f95ess1 ! fir/ product always conta9+ l>ge & co>se fragm5ts ( v>i\s sizes1 z well z f9e p[d]4 ,if ! latt] 7 left 9 ) ! l>g] pieces = ! second /amp+ x w\ld imp$e ! "w1 & ! /amp+-mill %\ld !re=e be provid$ ) means = classify+ ! mat]ial dis*>g$ f ! tr\gh1 to sep>ate ! f9e f ! co>se & grade ! latt] into sizes4 ,?is is usually effect$ by means ( a grad+-scre54 ,/amp+-mills are *iefly us$ = r$uc+ brittle mat]ials4 ,a numb] ( /amps arrang$ 9 a r[ are alt]nately lift$1 by means ( cams m\nt$ on a common %aft1 & !n let fall on to ! mat]ial ly+ on a solid plate1 or else on a grat+ ?r\gh :i* ! cru%+s fall4 ,fig4 #c is a /amp+-mill con/ruct$ by ,h4 ,f4 ,/ollb]g1 ,(f5ba*4 ,illu/ration3 ,,fig4 #c4 ,^! mills are v /rongly built1 z indep5d5t units1 ! frame be+ ( ca/-iron & ! rams ( be/ wr\ght-iron ) int]*angeable *ill-ca/ heads4 ,9 "s mills ! /amps are rotat$ dur+ ! up-/roke1 9 ord] to equalise ! we> on ! heads1 & also to economise p[]4 ,! grat+ or tr\gh hold+ ! mat]ial is p]=at$ ) holes1 ! diamet] ( :i* v>ies ) ! mat]ial "u treatm5t & ! desir$ degree ( f95ess 9 ! product4 ,to increase ! effici5cy ( ! mill1 ! grat+ or tr\gh is adapt$ to move :ile ! mill is runn+1 9 ord] to clean itself automatically4 ,^! mills are made 9 diff]5t sizes1 ) #b1 #d1 #f1 or #h heads4 ,edge-runn]s4--,?is type ( cru%] is highly suitable = r$uc+ e>? col\rs 9 l>ge works4 ,! special feature ( ! type is t bo? /ones are m\nt$ v]tically & turn on a common %aft 9 ! same way t a c>t :eel does on its axle4 ,^! runn]s are p>ticul>ly useful = r$uc+ clay1 *alk & o!r e>? col\rs1 :i* h to be dealt ) 9 l>ge quantities4 ,!y w also cru% fairly l>ge lumps1 & !y c !re=e be us$ = ! fur!r r$uction ( mat]ials r\ghly cru%$ 9 a break]1 etc4 ,! mat]ial may be treat$ 9 ei!r ! wet or dry /ate1 only slight alt]ation be+ ne$$ to *ange f "o me?od to ! o!r4 ,!re are num]\s diff]5t patt]ns ( edge-runn]1 b all ( !m c be divid$ into two gr\ps1 viz43 mills ) /ation>y tr\ghs1 :il/ ! %aft c>ry+ ! runn]s rotates2 & ^? 9 :i* ! tr\gh revolves1 & ! /ones m]ely turn on ! /ation>y horizontal %aft4 ,illu/ration3 ,,fig4 #d4 ,comp>ison ( ! effici5cy ( ! two types has %[n t ! revolv+-tr\gh type is ! bett]1 giv+ a l>g] output p] unit "t ) a r$uc$ consumption ( p[]4 ,figs4 #d & #e %[ a v]tical section & plan respectively ( ?is type ( edge-runn]4 ,! tr\gh ,g is turn$ by means ( a too!d cr[n ge>+ ) ! bevel p9ion ,o m\nt$ on an ov]head %aft ,c driv5 by a belt pulley ,n4 ,illu/ration3 ,,fig4 #e4 ,! be>+s ( ! v]tical %aft ,j ( ! tr\gh are situat$ at ,l & ,m4 ,! runn]s ,h are loosely m\nt$ on ! fix$ horizontal %aft ,e & revolve 9 consequ5ce ( ! friction betwe5 !m & ! mat]ial 9 ! tr\gh4 ,z ! latt] revolves1 ! mat]ial is cont9u\sly pu%$ aside by ! runn]s1 & is aga9 br\ght "u !m by ! action ( scrap]s4 ,! great advantages af=d$ by edge-runn]s1 9 consequ5ce ( _! simplicity1 easy managem5t & l[ we> 9 comp>ison ) o!r gr9d+ appliances1 h l$ to _! re9troduction on a l>ge scale4 ,x %\ld1 h[ev]1 be borne 9 m9d t ! edge-runn] mill mu/ be ( a patt]n suitable to ! mat]ials x w h to treat4 ,! me?od ( drive usually dep5ds on local conditions4 ,! revolv+-tr\gh type is *iefly useful = mix+1 on acc\nt ( ! ease ) :i* ! mat]ials c be *>g$4 ,! capacity ( edge-runn] mills dep5ds on ! nature ( ! mat]ial1 ! diamet] & weight ( ! runn]s1 ! spe$ at :i* !y are run1 & also on ! rate at :i* ! r$uc$ mat]ial is dis*>g$ 9 ord] to give place to fre% portions ( ! *>ge4 ,?is is effect$ by means ( two sets ( scrap]s1 ! individual memb]s ( :i* c be adju/$ 9 any direction4 ,_! pl\gh+ action also greatly assi/s ! mix+ effect4 ,illu/ration3 ,,fig4 #f4 ,fig4 #f illu/rates an edge-runn] mill ) revolv+ tr\gh & ov]head drive2 & ,fig4 #g "o ) /ation>y tr\gh & bottom drive2 bo? made by ! ,badis*e ,mas*95fabrik1 ,durla*4 ,! runn]s are ( grey ca/-iron1 *ill-ca/+s or ca/-/eel be+ us$ = cru%+ h>d mat]ials4 ,! tr\gh 9 all cases is l9$ ) deta*able *ill-ca/ plates4 ,special att5tion is be/[$ on ! lubrication ( all ! mov+ p>ts1 & all ! lubricators are easily accessible4 ,illu/ration3 ,,fig4 #g4 ,! ma9 %afts ( ! fix$-tr\gh ma*9es h =g$ cranks1 & ! metal crank be>+s are provid$ ) du/ caps4 ,all ! %aft j\rnals run 9 deta*able metal bu%es4 ,a special advantage atta*+ to ?is type is ! automatic scre5+ device & ! return+ ( ! scre5 residue4 ,9 "s cases1 complicat$ appliances are employ$ to return ! co>se residue f ! scre51 bucket elevators1 worm conveyors1 etc41 all entail+ increas$ motive p[]1 n inconsid]able we>1 & a high] prime co/2 b 9 ?is in/ance ! object is a*iev$1 )\t extra p[] or we>1 by v simple means4 ,! du/-pro( %ell enclos+ ! runn]s & scre5 is provid$ ) l>ge doors & *>g+ hopp]s4 ,! motive p[] requir$ to drive edge-runn] mills dep5ds on ! dim5sions ( ! mill & on ! class ( mat]ial to be treat$2 ! l>g] ! mill & ! co>s] ! mat]ial1 ! m p[] ne$$ to drive x4 ,?is type is ! m suitable = raw mat]ials t are ( an e>?y "*1 s t all t is necess>y is to de/roy ! cohesion ( ! p>ticles1 z is ! case1 = example1 ) clay & all e>?y m9]als4 ,illu/ration3 ,,fig4 #h4 ,! wet me?od ( cru%+ ) edge runn]s is p>ticul>ly suitable z a prelim9>y to levigation4 ,a ma*9e arrang$ = ?is purpose is %[n 9 ,fig4 #h4 ,x consi/s ( two sets ( edge runn]s1 "o ) fix$1 & ! o!r ) revolv+ tr\gh4 ,! mat]ial is introduc$ by h&1 or by suitable *>g+ me*anism1 into ! upp]1 fix$-tr\gh ma*9e1 :]e x is cont9u\sly spr9kl$ ) wat] & knead$ by ! "o runn]1 & is pass$ !nce to ! second roll] :i* =ces x ?r\gh ! slott$ b$ into ! b$ ( ! l[] set4 ,! slott$ b$s ( ! upp] & l[] set are (fset2 & ! *ief function ( ! l[] set1 ) rotat+ b$1 is to secure intimate admixture ( ! mat]ial :i*1 9 mo/ cases1 is already suffici5tly r$uc$4 ,illu/ration3 ,,fig4 #i4 ,ball ,mills4--,ball mills are g5]ally us$ = cru%+ dry mat]ials to f9e p[d]4 ,! mill %[n 9 ,fig4 #i is a typical =m ( gr9d+ drum enclos$ 9 a du/-pro( cas+1 ! latt] be+ provid$1 at ! top1 ) an op5+ connect$ to ! du/ exhau/ pipe4 ,! dis*>ge outlet at ! bottom c be clos$ by a slide4 ,illu/ration3 ,,fig4 #aj4 ,! drum is provid$ ) two /rong lat]al %ields or *eeks 7,fig4 #aj71 "o ( :i* c>ries ! int]*angeable cross-arm & ! *>g+ hopp]4 ,bo? *eeks are l9$ ) deta*able *ill-ca/ plates1 to take up ! we>4 ,! b$ is =m$ ( heavy /eel b>s 7:i* c be turn$ r\nd71 betwe5 :i* are arrang$ adju/able slits = ! dis*>ge ( ! r$uc$ mat]ial4 ,gu>d sieves are m\nt$ all r\nd1 & close to1 ! b$1 & int]*angeable f9e scre5s surr\nd ^! 9 turn4 ,! me% ( ! f9e scre5s det]m9es ! f95ess ( ! product1 & ! residue falls d[n on to a plate :i* returns x to ! int]ior ( ! drum4 ,! r$uction ( ! *>ge is effect$ by a numb] ( v h>d1 =g$ /eel balls ( v>i\s sizes4 ,! mill mu/ be run 9 ! direction m>k$ by ! arr[ on ! out] %ell1 s t ! residue on ! scre5s c be return$ to ! drum by ! plate provid$ = t purpose2 & ! prescrib$ work+ spe$ mu/ be ma9ta9$4 ,! mill mu/ n be ov]load$4 ,! impact ( ! balls %\ld be mild1 b di/9ctly audible4 ,ov]load+ r$uces ! output4 ,idle runn+ causes ! mo/ we>1 s9ce ! balls !n roll directly on ! b$1 :i*1 ( c\rse1 %\ld be prev5t$ z f> z possible4 ,! fe$ is cont9u\s2 &1 ( c\rse1 only dry mat]ial %\ld be introduc$4 ,:5 ! balls h lo/ size & weight ?r\gh we>1 !y mu/ be replac$ by a fre% set4 ,pulv]is]s4--,pulv]is]s are ! be/ =m ( cru%] = t\gh & n ov]-h>d mat]ials4 ,!y are simple & /rong 9 con/ruction1 ( high capacity ) comp>atively small consumption ( p[]1 & furni% a good1 uni=m product1 ! size ( :i* ranges f f9e p[d] to co>se granules1 accord+ to ! scre5s us$ & ! class ( mat]ial treat$4 ,illu/ration3 ,,fig4 #aa4 ,! cru%+ is effect$ by a cross-arm beat]1 compos$ ( f\r to six radial /eel arms on a divid$1 ca/-/eel hub1 key$ on to ! horizontal %aft4 ,! arms are h>d5$1 & are adju/ably & deta*ably m\nt$ on ! hub4 ,! beat+ action ( ! arms1 :i* run at high spe$1 =ces ! mat]ial aga9/ ! /udd$ surface ( ! h>d5$ *eeks ( ! ma*9e & also aga9/ ! h>d5$ squ>e /eel b>s =m+ ! p]iph]y1 ! repeat$ impact ( ! mat]ial on itself1 z well z aga9/ ! arms & b>s1 progressively r$uc+ x until small en\gh to fall ?r\gh ! scre5 on ! "u half ( ! cas+1 into a clos$ receptacle bel[4 ,! scre5 me% v>ies accord+ to ! degree ( f95ess requir$4 ,! p]iph]al b>s are m\nt$ 9 a v simple mann]1 & 9 su* a way t :5 "o edge ( ! b>s is worn1 a qu>t] turn br+s a fre%1 %>p edge into op]ation1 s t all f\r edges ( ea* b> c be utilis$4 ,to prev5t ! escape ( du/1 ! ma*9e is provid$ ) an air-circulation *amb]1 :i* ma9ta9s ! fl[ ( air 9 cont9u\s circulation1 ! result+ /rong draught also draw+ ! f9e mat]ial ?r\gh ! scre5 & keep+ ! me%es op54 ,by ?is means ! capacity ( ! pulv]is] is consid]ably increas$4 ,! int]*ange ( ! cru%+ organs & scre5s1 & also ! clean+ ( ! ma*9e1 c be effect$ )\t difficulty or loss ( "t4 ,! *>ge is introduc$ ?r\gh a fe$ hopp] at ! side1 & may v>y1 accord+ to ! size ( ! ma*9e1 f nut size to lumps twice z l>ge z a man's fi/4 ,if necess>y1 suitable me*anical fe$ devices c be appli$4 ,illu/ration3 ,,fig4 #ab4 ,dis9tegrators 7,figs4 #ab & #ac74--,?is type ( ma*9e is us$ = r$uc+ m$ium-h>d or s(t mat]ials1 especially :]e x is desir$ to obta9 a comp>atively l>ge output ( a gritty product4 ,9 ! patt]ns %[n1 ! ma9 %aft is ( /eel1 ) du/- & dirt-pro( r$-brass be>+s ) pad or r+ lubrication4 ,! sp9dle case draws out to facilitate clean+4 ,me*anical fe$+ atta*m5ts c be provid$4 ,accord+ to local conditions1 ! dis9tegrator c be m\nt$ ei!r on a brick f\ndation1 ) lat]al dis*>ge outlet into a /orage b91 or on a rais$ grat+ ( iron joi/s4 ,if ! product is to be convey$ to a di/ance1 x is advisable to h a hopp]-%ap$ collector lead+ directly to a worm conveyor or bucket elevator4 ,illu/ration3 ,,fig4 #ac4 ,! arrangem5t %[n 9 ,fig4 #ac1 9 :i* ! dis9tegrator is m\nt$ on a du/-pro( ca/-iron collector1 has be5 f\nd v suitable = col\r works ( v>i\s k9ds 7anil9e1 lead1 m9]al & o!r col\rs71 p>ticul>ly on acc\nt ( ! suppression ( du/2 :il/ ! automatic *>g+ worm greatly increases ! capacity z comp>$ ) *>g+ by h&4 ,,levigation ,! effect ( levigation is bas$ on ! circum/ance t bodies ( great] d5sity ?an wat] rema9 long] 9 susp5sion 9 t m$ium 9 proportion z ! f95ess ( _! p>ticles increases4 ,?is treatm5t consequ5tly enables ! f9] portions ( a sub/ance to be me*anically sep>at$ f ! co>s]4 ,levigation is ext5sively practis$ 9 col\r works because x furni%es p[d] ( f9] gra9 ?an c be obta9$ by ev5 ! mo/ c>eful gr9d+4 ,! appliances us$ = levigation may be ( a v simple "*1 consi/+ only ( sev]al tubs or tanks1 m\nt$ 9 su* a way t ! liquid conta9$ 9 "o c be run (f into ! "o next bel[4 ,) ?is primitive plant1 ! mat]ial to be levigat$ is /irr$ up 9 ! wat] 9 ! upp]mo/ tub & left to settle until ! co>se/ p>ticles may be assum$ to h settl$ d[n1 :]eupon ! turbid wat] is drawn (f into ano!r tub1 9 :i* x is left to settle completely4 ,:5 ! cle> liquid has be5 c>efully drawn (f1 a f9e sludge is left 9 ! bottom ( ! tub1 consi/+ ( ! f9e p>ticles ( mat]ial mix$ ) wat]4 ,:5 a p>ticul>ly f9e p[d] is requir$1 a s+le levigation does n always suffice1 b ! liquid 9 ! second tub mu/ be left to settle = a %ort "t only1 & !n run into a ?ird = complete subsid5ce4 ,illu/ration3 ,,fig4 #ad4 ,a well-design$ levigator = treat+ l>ge quantities ( p[d] is illu/rat$ 9 ,fig4 #ad4 ,a /irr] ,r1 driv5 by cone ge>+1 is arrang$ 9 a wood5 or /one vat ,g4 ,! levigat+ wat] ent]s close to ! bottom ( ! vat1 ?r\gh ! pipe ,w4 ,:5 ,g is half full ( wat]1 ! /irr] is set runn+1 & ! sub/ance to be levigat$ is add$4 ,aft] a :ile1 ! wat] lad5 ) ! levigat$ p[d] beg9s to run (f at ,a into ! long n>r[ tr\gh ,t#a provid$1 at ! opposite end f ,a1 ) a numb] ( p]=ations ?r\gh :i* ! wat] runs into ! tr\gh ,t#b4 ,f ?is x escapes ?r\gh ! p]=ations into ! tr\gh ,t#c & !nce successively into ,t#d & ,t#e1 f9ally dis*>g+ into ! l>ge tank ,s4 ,! co>se/ & heavie/ ( ! wat]-borne p>ticles deposit 9 ! tr\gh ,t#a f9] p>ticles settl+ d[n 9 ,t#b1 & s on 9 succession1 until ! wat] rea*+ ! tank ,s conta9s only ! v f9e/ ( all 9 susp5sion1 ^! tak+ a long "t to settle d[n to ! bottom4 ,! deposit 9 ! upp] tr\ghs c be return$ to ! vat1 :il/ t 9 ! l[] ones w be f9e en\gh to dry z x is4 ,! residue 9 ! vat is dis*>g$ ?r\gh ,z :5 ! op]ation is f9i%$4 ,x w be evid5t t ! f95ess ( ! product dep5ds on ! numb] & l5g? ( ! tr\ghs ,t1 ! l>g] ^! factors ! m delicate w be ! p>ticles rema9+ 9 prolong$ susp5sion 9 ! liquid4 ,_m e>? col\rs require no treatm5t beyond levigation to fit !m = use 9 pa9ts4 ,?is is ! case )1 e4 g41 ! :ite clays2 & c]ta9 grades ( f]ric oxide1 :i* occur native 9 ! /ate ( f9e p[d]1 may also be includ$ 9 ?is category4 ,9 _m cases1 h[ev]1 if l>ge quantities ( a f9ely pulv]ul5t m9]al be /irr$ up ) wat] & left to /&1 ! deposit$ solid matt] =ms su* a highly coh]5t mass t x c only be di/ribut$ 9 wat] ) difficulty1 ! f9e p>ticles adh]+ s firmly toge!r t x is h>dly possible to /ir !m up aga9 completely 9 ! liquid by means ( a paddle4 ,nev]!less1 ?is c be easily effect$ by us+ a special appliance ( ! k9d employ$ by />* manufactur]s = a simil> purpose1 viz4 ! levigation ( />*4 ,?is app>atus is design$ 9 su* a way t ! pulpy *>ge ( mat]ial is gradually & completely dissem9at$ 9 ! introduc$ liquid4 ,illu/ration3 ,,fig4 #ae4 ,fig4 #ae %[s a device ( ?is k9d1 consi/+ ( a circul> vessel provid$ ) a /ep be>+ = a v]tical %aft driv5 by cone p9ions4 ,! l[] "p ( ! %aft is provid$ ) a ?read1 on :i* a nut is adapt$ to travel up & d[n4 ,by means ( rods1 ?is nut is connect$ to a wood5 cross-b> provid$ ) /iff bri/les on its l[] face4 ,a horizontal h&le is atta*$ to ! nut4 ,! wat] is admitt$ ?r\gh ! pipe on ! "r4 ,9 work+ ! app>atus1 ! %aft is rotat$ & ! h&le held firmly1 ?us caus+ ! nut & atta*$ cross-b> to rise to ! limit ( its travel4 ,! levigat+ liquid1 mix$ ) ! mat]ial "u treatm5t1 is !n admitt$1 until ! vessel is full1 & :5 ! solids h completely subsid$1 ! cle> liquid is drawn (f1 & ! op]ation is repeat$ until a ?ick lay] ( s$im5t has accumulat$ on ! bottom ( ! vessel4 ,to levigate ?is1 ! cross-arm c>ry+ ! bri/les is l[]$ until x j t\*es ! surface ( ! deposit1 & a cont9u\s /ream ( wat] is admitt$ ?r\gh ! pipe at ! side4 ,! bri/les gradually dissem9ate ! upp] lay]s ( ! s$im5t 9 ! wat]1 :i* becomes turbid & is !n drawn (f into ano!r vessel1 cem5t-l9$ pits be+ us$ 9 ! case ( l>ge quantities4 ,:5 ! bru%es no long] enc\nt] any ( ! sludge1 ! cross-arm is l[]$ suffici5tly to /ir up ano!r lay]2 & 9 ?is way1 l>ge quantities ( solid matt] c be di/ribut$ 9 wat]4 ,if ! cross-arm is rotat$ at l[ en\gh spe$1 ! co>s] p>ticles ( mat]ial keep on settl+ d[n aga91 & ! collect+ vessels w receive only ! f9e/ p>ticles4 ,9 addition to ! me*anical sep>ation ( co>se & f9e p>ticles1 levigation accompli%es ano!r purpose1 namely t ! prolong$ contact ( ! treat$ mat]ial ) wat] dissolves out any admix$ soluble con/itu5ts :i* might affect ! quality ( ! col\r1 ! latt] be+ left 9 a purifi$ condition4 ,= successful levigation x is ess5tial t ! *>ge %\ld be 9 a suffici5tly f9e condition at ! outset4 ,clayey raw mat]ials require no prelim9>y treatm5t o!r1 p]haps1 ?an pass+ !m ?r\gh a dis9tegrator1 :]eas h>d1 cry/all9e sub/ances mu/ fir/ be gr\nd 9 a wet mill1 su* z an edge-runn] mill ) /ation>y b$1 into :i* ! mat]ials are f$ ) an admixture ( wat]1 provision be+ made = keep+ ! *>ge "u ! runn]s all ! "t4 ,! cru%$ mat]ial is scre5$ previ\s to levigation4 ,9 ! levigation process a few vessels ( l>ge size are pref]able to a numb] ( small ones4 ,! nature ( ! mat]ial w det]m9e :e!r any /irr]s are requir$ or n1 ^! be+ unnecess>y 9 ! case ( ! pigm5t>y e>?s1 :i* naturally rema9 a long "t 9 susp5sion & !re=e d n require /irr+ up4 ,! pulpy levigat$ mat]ial is tak5 out ( ! tubs1 etc41 dra9$ 7if necess>y7 & dri$4 ,! dra9+ may be effect$ 9 bags1 or--9 l>ge plants--filt] presses or hydro-extractors4 ,9 ^! latt] in/ances1 pumps w be provid$ = fe$+ ! sludge direct to ! presses1 & conveyors = deliv]+ ! press$ mat]ial to ! dry+-plant4 ,,dra9+ ,,& ,,dry+ ,! levigat$ col\r e>?s =m a /iff pulp conta9+ a l>ge quantity ( wat]1 :i* c be elim9at$ 9 v>i\s ways4 ,usually1 ! mass is dri$ by spread+ x out ?9ly on bo>ds & leav+ x expos$ to ! air until x has become solid2 or else x is only left long en\gh to acquire ! consi/5ce ( a ?ick pa/e1 :i* is !n %ap$ into cones or blocks1 :i* are all[$ to dry completely 9 an airy place4 ,if ! col\rs are to be sold 9 ! =m ( p[d]1 ! dri$ lumps are cru%$4 ,to accel]ate dry+1 ! pulp may be put ?r\gh a hydro-extractor1 or dri$ 9 hot-air /oves or rooms4 ,z1 h[ev]1 ?is la/ me?od entails special appliances & also exp5diture1 ?is accel]ation is only resort$ to :5 r5d]$ necess>y by special conditions4 ,! ,hydro-extractor4--,:5 a sub/ance is set 9 rapid rotation1 x t5ds to fly away f ! c5tre at :i* ! rotational =ce is appli$4 ,! c5trifugal =ce ?us com+ into action increases ) ! velocity ( rotation & ) ! di/ance ( ! sub/ance f ! axis ( rotation4 ,! c5trifugal hydro-extractor consi/s1 !re=e1 ( a vessel 9 rapid rotation2 & if a liquid be introduc$ into su* vessel1 x is project$ ) consid]able =ce aga9/ ! p]iph]al walls4 ,if ! p]iph]al surface be p]=at$1 ! liquid portion ( a *>ge consi/+ ( liquid & solid matt]s w be eject$ ?r\gh ! p]=ations1 :ile ! solid matt] rema9s inside4 ,z a rule1 a few m9utes' treatm5t 9 a hydro-extractor is suffici5t to sep>ate ! wat] f a ?9 pulp s completely t ! solid residue is 9 an almo/ completely dry /ate4 ,a hydro-extractor :i*1 ?\gh ( an old patt]n1 is well adapt$ = ! purposes ( ! col\r-mak]1 is %[n 9 ,fig4 #af4 ,illu/ration3 ,,fig4 #af4 ,! drum ,a1 :i* revolves easily on a v]tical axis1 is ( metal1 & is provid$ ) a l>ge numb] ( f9e p]=ations on its p]iph]al surface4 ,x c be rotat$ at high spe$ by means ( ! crank f & p9ions d1 e1 or by ! fa/-&-loose pulley a b connect$ ) a s\rce ( p[]4 ,to prev5t any ( ! *>ge f be+ project$ ov] ! rim ( ! drum1 ! upp] edge is turn$ ov] s z to leave only a comp>atively small op5+ at ! top4 ,! l[] end ( ! drum %aft c>ries a /rong /eel sp9dle1 :i* mu/ be c>efully ma*9$ & enable ! drum to revolve z easily z possible4 ,?is is ess5tial1 because ev5 small ma*9es require a comp>atively l>ge am\nt ( motive p[]--:i* is n surpris+ 9 view ( ! high spe$ at :i* ! drum has to revolve 9 ord] to p]=m its functions4 ,! drum is enclos$ 9 a cas+ ( some:at l>g] diamet]1 :i* may be ( any conv5i5t mat]ial4 ,! bottom ( ! cas+ is pref]ably tap]$ slightly d[nw>d1 & is cov]$1 at its l[e/ "p--bel[ ! be>+ ( ! drum--) a sieve communicat+ ) a pipe ?r\gh :i* ! eject$ liquid is dra9$ (f4 ,:5 a liquid1 conta9+ solid matt]1 is f$ into ! drum1 :i* is already runn+ at high spe$1 ! liquid is ?r[n1 by ! c5trifugal =ce1 aga9/ ! p]iph]al surface ( ! drum & escapes ?r\gh ! p]=ations1 leav+ ! solid matt] beh9d4 ,:]e l>ge cry/als are 9 "q1 z = in/ance 9 sug> factories1 ! c5trifugal ma*9e c be employ$ )\t any additional precautions1 ! liquid be+ expell$ & ! cry/als be+ practically dri$ by keep+ ! ma*9e runn+ a %ort "t long]4 ,9 ! case ( ! pulp obta9$ by levigat+ col\rs1 h[ev]1 ?is proc$ure w\ld result 9 failure1 because ! f9e solid p>ticles w\ld be eject$ along ) ! liquid & ! drum w\ld be left q empty4 ,9 ?is case x is !re=e necess>y to provide means = reta9+ ! solid matt] 9 ! drum1 & all[ only ! wat] to escape1 ) :i* object ! drum is l9$ ) a bag ( closely wov5 fabric1 op5 at ! top & fitt+ snugly aga9/ ! inn] surface ( ! drum4 ,:5 ! drum is fir/ />t$1 ! eject$ liquid is milky1 no fabric be+ suffici5tly close to reta9 all ! extremely f9e solid p>ticles pres5t4 ,9 a v %ort "t1 h[ev]1 ! liquid w beg9 to run away p]fectly cle>1 ?is occurr+ z soon z ! pores 9 ! fabric h become s f> ob/ruct$ by ! project$ solids z to all[ wat] alone to pass ?r\gh4 ,! milky wat] is !n return$ to ! fe$ tank & run sl[ly into ! ma*9e4 ,! wat] is v quickly expell$1 & ! col\r rema9s 9 ! drum z a /iff pa/e1 ( suffici5t consi/5ce to be m\ld$ into lumps ( any desir$ %ape4 ,! use ( ! hydro-extractor may be p>ticul>ly recomm5d$ :5 ample motive p[] is available & accel]at$ dra9+ is desirable4 ,illu/ration3 ,,fig4 #ag4 ,fig4 #ag illu/rates a mod]n type ( hydro-extractor ) bottom dis*>ge & susp5d$ drum1 ! %aft ( :i* is c\pl$ directly to an electro-motor4 ,filt]-presses4--,:]eas ! hydro-extractor is only us$ 9 p>ticul> cases = ! purpose ( ! e>?-col\r manufactur]1 ! filt]-press enjoys m ext5sive application4 ,e filt]-press is compos$ ( a numb] ( closely fitt+ press frames1 held toge!r by ! pressure ( a screw4 ,^! frames1 :5 assembl$1 =m *amb]s provid$ ) inlet & outlet op5+s4 ,suitably %ap$ & /it*$ filt]-clo?s are secur$ inside ! *amb]s1 & ! sludge to be filt]$ is run into ! press f a high-level tank4 ,! wat] passes ?r\gh ! filt]-clo?s & runs (f1 :il/ ! col\r e>? gradually fills ! *amb]s4 ,:5 dra9+ is complet$1 ! press is tak5 ap>t & empti$4 ,9 ?is way ! e>?s are obta9$ 9 ! =m ( m or less dry cakes1 :i* are !n put ?r\gh fur!r treatm5t or dri$4 ,illu/ration3 ,,fig4 #ah4 ,fig4 #ah %[s a ,dehne filt]-press suitable = ! e>?-col\r manufactur]4 ,wood int]nal fitt+s are (t5 us$1 because wood does n affect ! %ade ( ! col\rs2 b1 :]ev] ! nature ( ! mat]ials admits1 iron presses are to be pref]r$ on acc\nt ( _! great] durability & ! c]ta9ty ( ! jo9ts cont9u+ tight4 ,! f9] ! gra9 ( ! levigat$ col\r1 ! m difficult ! expulsion ( ! wat]2 b z a rule1 a pressure ( #aae-aie in*es1 wat]-gauge1 w be suffici5t4 ,if ! sludge be run into ! press f a tank at suffici5t height1 two *>ges c be work$ 9 a day1 b ! cakes w n be z firm z butt] ( m$ium h>dness4 ,x is bett] to pump ! *>ge into ! press by means ( a special diaphragm pump4 ,! dra9age is !n incomp>ably quick]1 ! cakes w be =m$ 9 ab\t an h\r & w also be dri]4 ,a good deal1 h[ev]1 dep5ds1 naturally1 on ! nature ( ! e>? col\r4 ,if ! col\r conta9s acid1 alkali or salts1 ! filt]-clo?s c be wa%$ by flu%+ ! press ) wat] "u pressure4 ,! clo?s are made ( specially f9e cotton fabric4 ,! press-runn+s1 :i* are nev] q cle>1 are collect$ 9 a cl>ify+ tank1 :]e !y are treat$ ) lime & kies]ite1 :]eby gypsum is =m$1 & ! mass is put ?r\gh a filt]-press1 :i* reta9s ! solids & leaves ! efflu5t cle>4 ,illu/ration3 ,,fig4 #ai4 ,filt]-clo?s :i* h become *ok$ by use are spread on a table & scrubb$ ) wat]1 or else wa%$ 9 a special ma*9e 7,fig4 #ai71 consi/+ ( a rot>y drum1 ) belt drive1 ! rotation circulat+ ! wat] 9 ! int]ior tr\gh & enabl+ x to extract ! dirt f ! clo?s4 ,! fl[ & dis*>ge ( ! wat] are controll$ by valves1 & ! wat] may be w>m$ by admitt+ /eam into ! ma*9e4 ,! size ( ! wa%] dep5ds on t ( ! filt]-clo?s4 ,f ! press1 ! cakes ( col\r are convey$ to ! dry+-plant1 usually by ! aid ( automatic ma*9]y4 ,dry+ ,appliances4--,! /iff pa/e or cakes f ! hydro-extractor or filt]-press c be %ap$1 b require to be dri$ be=e !y are put on ! m>ket4 ,dry+ is a we>isome op]ation1 ! f9ely divid$ mat]ial tak+ a v long "t to dry completely1 ev5 dur+ ! summ] mon?s1 :il/ 9 w9t] x is almo/ impossible to get c]ta9 col\rs--su* z f]ric oxide col\rs & levigat$ clay--q dry 9 ! air1 ! inside ( ! lumps rema9+ s(t & pa/y aft] ly+ = mon?s4 ,! only way 9 :i* ?is tr\blesome delay 9 ! completion ( ! op]ation c be ov]come is by artificial dry+2 b z ! employm5t ( artificial heat entails exp5se1 x is necess>y to c>ry on ! process ) ! smalle/ possible outlay1 9 view ( ! l[ comm]cial value ( mo/ e>? col\rs4 ,long exp]i5ce has conv9c$ ! au?or t ! arrangem5t ( ! dry+-rooms 9 _m col\r works is bas$ on entirely wrong pr9ciples1 & t a great portion ( ! heat furni%$ by ! fuel is wa/$4 ,= ?is reason ! description ( a prop]ly arrang$ dry+-room w be welcom$ by a numb] ( read]s4 ,x is a well-kn[n fact t hot air is light] ?an cold4 ,consequ5tly1 :5 a room is artificially heat$1 ! highe/ temp]ature w be f\nd j "u ! ro( or ceil+1 & articles plac$ 9 t "p ( a heat$ room w dry mu* fa/] ?an ^? ne> ! floor4 ,if ! dry+-room is heat$ by an ord9>y /ove1 articles plac$ on a fairly l[ level w only dry v sl[ly1 because ! hot air fl[+ f ! /ove t5ds to asc5d4 ,9 ord]1 !re=e1 to utilise ! entire space ( ! dry+-room1 x is necess>y to place ! heat+ app>atus 9 su* a position t ! :ole ( ! room w be w>m$ z uni=mly z possible4 ,! /ove %\ld !re=e be situat$ 9 a *amb] und]nea? ! dry+-room prop]4 ,illu/ration3 ,,fig4 #bj4 ,because air t is already saturat$ ) moi/ure _c take up any fur!r quantity1 c>e mu/ be tak5 to remove ! damp air cont9u\sly f ! dry+-room1 & to replace x by dry air4 ,?is may be effect$ by suitably design$ v5tilation1 on ! l9es %[n 9 ,fig4 #bj1 :i* repres5ts a dry+-room arrang$ 9 su* a way z to provide = all ! above-m5tion$ cont+5cies1 & ensure cont9u\s dry+4 ,! heat+ app>atus is locat$ 9 ! cell>1 & consi/s pref]ably ( a sl[-combu/ion /ove compris+ a ca/-iron cyl9d]1 ) an air inlet ,a 7) slid+ regulator ,t71 = ! air ( combu/ion1 & a %oot ,f at ! top1 ?r\gh :i* ! /ove is f$ ) fuel--pref]ably coke1 on acc\nt ( its great heat+ p[]4 ,! /ove is surr\nd$ by an iron or brick %ell ,m1 hav+ two flues ,r & ,r#a lead+ to ! *amb]s ,i & ,,ii1 :]e !y t]m9ate 9 regi/] c[ls ,k1 :i* c be adju/$1 by turn+ ! h&les h1 s t :5 ! slots o 9 ,k co9cide ) correspond+ slots 9 ! end ( ! pipe1 ! maximum am\nt ( hot air f ! /ove is deliv]$ into ! dry+-*amb]s2 &1 by suitably adju/+ ! c[ls & ! draught ?r\gh ! fire-door ,t1 x is possible to regulate ! temp]ature ( ! *amb]s to )9 "o degree ( ! !rmomet] scale4 ,:5 only "o ( ! dry+-*amb]s is requir$ to be heat$1 ! regi/] 9 ! o!r is clos$1 & ! :ole ( ! hot air is deliv]$ to ! fir/ "o4 ,) ?is arrangem5t none ( ! heat is wa/$1 & ! cont5ts ( "o *amb] c be dri$ :ile ^? ( ! o!r are be+ remov$ & replac$4 ,! moi/ure-lad5 air f ! dry+-*amb]s c be l$ direct into ! /ove *imney4 ,:5 coke is us$1 ! flue gases consi/ almo/ entirely ( c>bon dioxide4 ,if ! v5t pipes are l$ f ! top ( ! dry+-*amb]s into ! *imney1 ! hot gases asc5d+ ! latt] induce a /rong draught 9 ! *amb]s & c>ry (f ! moi/ air into ! op54 ,^! pipes1 also1 are fitt$ ) regi/]s1 :i*1 :5 suitably adju/$1 assi/ 9 ! ma9t5ance ( a uni=m dry+ temp]ature4 ,! col\rs to be dri$ are spread on trays laid on suitable racks 9 ! dry+-*amb]s2 &1 by c>efully plann+ out ! available space1 a v l>ge quantity ( col\r c be quickly & completely dri$ 9 a comp>atively small plant4 ,! co/ ( ! fuel is s small z to be m ?an c\nt]balanc$ by ! sav+ ( "t4 ,! heat+ arrangem5ts 9 dry+-rooms are capable ( improvem5t 9 _m respects1 especially :]e /eam is at disposal2 & 9 su* cases1 x is bett] to sub/itute /eam heat+ = a fire4 ,x w !n be necess>y to put 9 a good fan1 or o!r device1 to ensure ! removal ( ! moi/ air4 ,an excessive room temp]ature--above1 say1 #ej ,c4 7#abb ,f47--is n only sup]flu\s1 b 9 _m cases injuri\s1 because1 ap>t f ! fact t "s col\rs *ange 9 %ade :5 ov]-w>m$1 an unduly high temp]ature causes ! surface lay]s to dry v quickly & =m a cru/ :i* prev5ts ! escape ( wat] vap\r f ! int]ior ( ! mat]ial4 ,ano!r =m ( dry+-plant = e>? col\rs is ! dry+-floor1 a l>ge room ) a ramm$ concrete or /one floor1 int]sect$ ) brick flues 7ab\t "o foot squ>e71 cov]$ ) iron or concrete slabs & convey+ hot flue gases f a furnace4 ,^! floors are p>ticul>ly suitable :]e !re is a possibility ( utilis+ an exi/+ supply ( hot flue gases4 ,dry+-tunnels are specially adapt$ :]e l>ge am\nts ( mat]ial h to be dri$4 ,! tunnels are built ( brick & provid$ ) a rail track on :i* ! trucks c>ry+ a s]ies ( trays lad5 ) col\r are run4 ,z ! trucks move sl[ly =w>d1 !y are met by a curr5t ( hot air :i* dries ! *>ge4 ,! tunnel is kept fill$ ) lad5 trucks1 ea* fre% "o introduc$ pu%+ a f9i%$ "o out at ! fur!r end4 ,9 _m cases1 dry+ tr\ghs are also useful4 ,^! are long1 semicircul>1 jacket$ tr\ghs ( boil] plate1 hot air or /eam be+ pass$ ?r\gh ! jacket space4 ,a worm conveyor keeps ! cont5ts mov$ =w>d1 turn$ ov] & mix$ to facilitate dry+4 ,m5tion may f9ally be made ( vacuum dry+-cupbo>ds1 :i* are heat$1 air-tight *amb]s1 = ! mat]ial1 9 :i* ! air is p>tially exhau/$1 ?us increas+ ! rate ( evaporation ( ! wat] & caus+ ! mat]ials to dry quickly at a mu* l[] temp]ature ?an o!rwise4 ,,cru%+ ,,& ,,sift+ ,! di/ribut+ & cov]+ p[] ( ! e>? col\rs dep5ds--ap>t f _! special prop]ties--on ! f95ess ( _! p>ticles4 ,= ?is reason1 all ! means adopt$ = ! purpose ( pulv]isation are ( p>ticul> int]e/4 ,! mo/ important cru%+ & p[d]+ devices h already be5 describ$1 & may be ref]r$ to1 all t ne$s m5tion 9 addition be+ ! fact t /one mills also are us$ = f9e gr9d+4 ,! gr\nd products1 h[ev]1 are n entirely homog5e\s1 always conta9+1 9 addition to ! v f9e/ p>ticles1 ^? ( a co>s] nature :i* mu/ be remov$ by sift+4 ,sift+ ma*9es are ess5tially sieves ?r\gh :i* ! col\r is pass$4 ,! sieves are made ( wire gauze or bolt+-clo?1 /ret*$ on prismatic frames :i* are rotat$ 7c5trifugal sieves71 or sup]pos$ on ! flat & reciprocat$4 ,9 c5trifugal sieves1 ! mat]ial is project$ aga9/ ! sieve1 & ! :ole app>atus is 9 a /ate ( vibration1 or else beat]s are provid$ to keep ! f9e orifices 9 ! sieve f *ok+ up4 ,n[adays !re are num]\s types ( sift+ devices1 none ( :i*1 h[ev]1 c be consid]$ z ! be/ = all purposes1 s9ce ea* type ( e>? col\r behaves diff]5tly & requires special treatm5t4 ,! proportion ( moi/ure 9 ! mat]ial1 also1 has an important influ5ce on ! me?od ( treatm5t requir$4 ,illu/ration3 ,,fig4 #ba4 ,a typical flat sift+-ma*9e1 ) ecc5tric jig motion1 is illu/rat$ 9 ,fig4 #ba4 ,! ma*9e is f$ ?r\gh a hopp] provid$ ) fe$ roll]s1 ! rate ( fe$ be+ adju/able4 ,! scre5$ product is dis*>g$ ?r\gh a %oot at "o side ( ! ma*9e1 & ! residue at ! opposite side1 into boxes1 etc41 plac$ und]nea?4 ,= mat]ials t give (f a l>ge am\nt ( du/1 ! ma*9e c be enclos$ 9 a du/-pro( cas+1 9 :i* ev5t ! product & residue are deliv]$ into draw]s4 ,! ma*9e is easily clean$ & ! sieves quickly *ang$1 & is well adapt$ = deal+ ) a succession ( diff]5t mat]ials4 ,! hopp] c be fitt$ ) a pair ( adju/able cru%+ roll]s4 ,illu/ration3 ,,fig4 #bb4 ,fig4 #bb is a drum sift]1 :i* is f$ by means ( a hopp] & worm2 & ! drum c be cov]$ ) wire or silk gauze4 ,! sift$ product falls into a worm conveyor 9 ! bottom ( ! cas+ & is dis*>g$ at ! side4 ,?is may be replac$ by a s]ies ( m\?s = dis*>g+ direct into bags1 or ! ma*9e c be adapt$ to deliv] into an elevator1 worm conveyor or o!r means ( transport to a di/ance4 ,! scre5+s are dis*>g$ ?r\gh a %oot at ! back ( ! ma*9e1 & c be h&l$ 9 v>i\s ways4 ,a beat] is provid$ to cle> ! drum & increase ! output4 ,illu/ration3 ,,fig4 #bc4 ,fig4 #bc illu/rates a c5trifugal sift+-ma*9e = produc+ v f9e p[d] 9 l>ge quantities )\t any escape ( du/4 ,x conta9s a scre5+ drum1 ! frames ( :i* are deta*able & facilitate *ang+ ! sieves4 ,a beat] revolv+ inside ! drum projects ! p[d] aga9/ ! sieves1 su* portions z pass ?r\gh be+ tak5 up & dis*>g$ by a worm conveyor2 ?is1 h[ev]1 c be replac$ by a bagg+ device1 etc4 ,,calc9+ ,col\r e>?s are sometimes calc9$ at a high temp]ature 9 ord] to modify _! /ructure & %ade1 ! op]ation be+ accompani$1 9 "s cases1 by ! de/ruction ( organic admixtures & ! expulsion ( volatile con/itu5ts4 ,an important feature ( calc9+ is t x improves ! cov]+ p[] ( _m col\rs1 especially heavy sp> & c]ta9 f]ric oxide pigm5ts4 ,?is alt]ation is probably due to ! heat caus+ ! f9e/ p>ticles to coh]e1 & also to ! expulsion ( *emically-comb9$ wat]1 etc4 ,! *ange ( %ade1 :i* is (t5 dep5d5t on ! degree & duration ( ! heat+1 is probably also connect$ ) cohesion2 b 9 _m in/ances x is attributable to *emical modifications produc$ by ! treatm5t2 f]ric hydroxide1 = example1 los+ its wat] ( hydration :5 heat$ & becom+ trans=m$ into f]ric oxide4 ,! details ( ! calc9ation process v>y ) ! nature ( ! mat]ial1 & w !re=e be describ$1 toge!r ) ! appliances us$1 :5 we deal ) ! col\rs :i* require to be put ?r\gh ?is treatm5t4 ,,mix+ ,,& ,,improv+ ,x is v important t ! mak] ( e>? col\rs %\ld always be able to turn out 8 products uni=m 9 %ade1 & s9ce ! raw mat]ials are liable to v>y 9 "*1 & ! composition ( ! e>?s f "o & ! same deposit is n inv>iable1 ! desir$ %ade has to be obta9$ by mix+4 ,= ?is purpose1 /&>d samples mu/ be prep>$1 = comp>ison 9 mat*+4 ,illu/ration3 ,,fig4 #bd4 ,mix+ is a highly important op]ation1 on ! prop] p]=mance ( :i* (t5times dep5ds ! sale ( c]ta9 col\rs & ! reputation ( ! mak]4 ,x may be effect$ 9 v>i\s ways1 su* z %ovell+ ! +r$i5ts toge!r or by comb9+ ! "w ) gr9d+ 9 edge-runn] mills1 ball mills1 etc4 ,ano!r me?od is ! mix+ b>rel %[n 9 ,fig4 #bd1 a /rong cask m\nt$ on an axial %aft driv5 by a motor1 etc4 ,! b>rel is fill$ ab\t two-?irds full ( ! mat]ials to be mix$1 &1 aft] clos+ ! fe$ door1 is sl[ly rotat$1 s9ce1 if run at excessive spe$1 ! cont5ts are m]ely project$ aga9/ ! sides ( ! b>rel by c5trifugal =ce1 & x c !n be turn$ = h\rs )\t result4 ,! mix+ effect c be consid]ably increas$ by m\nt+ ! b>rel s t ! %aft is (fset f ! longitud9al axis ( ! b>rel by an angle ( ab\t #cj1 ! cont5ts be+ !n mov$ f side to side at ea* revolution & ?us m intimately int]mix$ by ! tw(old motion4 ,illu/ration3 ,,fig4 #be4 ,9 addition to su* home-made appliances1 !re are mix+-ma*9es ( ! type illu/rat$ 9 ,fig4 #be1 ! body ( :i* is fitt$ ) a di/ribut+ worm at ! top1 & a pair ( roll]s at ! bottom4 ,bel[ ! roll]s1 :i* are cov]$ by plates t c be adju/$ at a conv5i5t angle1 is a worm conveyor deliv]+ into an elevator1 outside ! ma*9e cas+1 :i* connects ! two worms4 ,"o or m dis*>g+-doors1 accord+ to ! size ( ! ma*9e1 are provid$ "u ! worm conveyor at ! end next ! elevator4 ,! fe$ hopp] c be arrang$ on ! elevator or on top ( ! ma*9e1 accord+ to local conditions4 ,9 work+ ?is ma*9e1 ! elevator & di/ribut+ worm are />t$ & ! full *>ge is f$ into ! hopp]4 ,:5 x has all pass$ ?r\gh ! di/ributor & is lodg$ on ! slop+ plates & bottom roll]s1 ! latt] & ! worm conveyor are set 9 motion1 ! mat]ial be+ !n c>ri$ ?r\gh by ! rotation ( ! roll]s & dropp+ on to ! conveyor1 :i* deliv]s x to ! elevator1 to be return$ to ! di/ributor4 ,9 ?is way ! *>ge is kept 9 cont9u\s circulation1 & ! f9ely divid$ p>ticles are repeat$ly int]m+l$1 a uni=m mixture be+ obta9$4 ,! effect is height5$ by ! gr9d+ action ( ! roll]s z ! mat]ial passes betwe5 !m4 ,! s]ial ord] ( ! v>i\s +r$i5ts1 _! physical condition 7granul> or p[d]71 & _! d5sity1 are all immat]ial1 ! mix+ be+ effect$ s intimately t :51 = example1 a col\r is %ad$ ) anil9e dyes1 ! +r$i5ts are s completely bl5d$ 9 less ?an an h\r t ev5 ! smalle/ sample !n tak5 w p]fectly repres5t ! bulk4 ,^! ma*9es are made 9 v>i\s sizes1 are entirely automatic1 bo? 9 *>g+1 dis*>g+ & mix+1 & are q du/-pro(1 ! consumption ( p[] be+ also small4 ,if necess>y1 !y c be comb9$ ) a cru%] or sift] fe$+ direct into ! hopp]4 ,a simple means ( asc]ta9+ :e!r ! mix+ is complet$1 & "o t c also be employ$ = judg+ ! "* ( gr\nd mat]ials1 consi/s 9 plac+ a sample ( ! product on a %eet ( :ite pap] & spread+ x out1 "u g5tle pressure1 ) a /eel or horn spatula4 ,no irregul>ities1 /reaks1 spots or granules %\ld !n be disc]nible ei!r by ! unaid$ eye or "u a magnifi]4 ,improv+1 :i* consi/s 9 /a9+ e>? col\rs ) o!r 7usually organic7 col\r+ ag5ts1 to improve ! %ade1 is an op]ation :i* is g5]ally resort$ to only 9 case ( ne$1 because x means extra exp5se1 & is ( no value unless light-pro( col\rs are us$4 ,no p]man5t effect c be obta9$ by m]ely mix+-9 coal-t> dyes at r&om4 ,9 addition to c]ta9 organic dye/uffs1 artificially prep>$ m9]al col\rs & col\r lakes--artificial prep>ations ( an organic dye/uff ) an inorganic sub/ratum--are also us$ = improv+4 ,ano!r way ( improv+ e>? col\rs is by precipitat+ c]ta9 coal-t> dyes on !m1 9 pres5ce ( a fix+ ag5t4 ,( c\rse ! dyes us$ mu/ n only be fa/ to light1 b also in]t t[>ds ! sub/ratum & to any o!r +r$i5t1 su* z lime1 t is subsequ5tly add$ to ! e>? col\rs4 ,! foll[+ dye/uffs 7,h*/7 are suitable = direct precipitation on silice\s col\rs 7gre5 e>?s1 clay1 o*res1 etc474 ,auram9e1 conc4 ,o1 ,i1 ,,ii2 new phosph9e extra2 *rysoid9e ,a cry/41 ,b cry/41 ,c extra2 ,vesuv9e 7all m>ks72 ca*\ br[n ,d1 ,g2 d>k br[n ,m1 ,,mb2 safran9e ,g1 ,,gs conc41 ,b conc42 rhodam9e ,o extra1 ,b1 ,b extra2 fu*s9e 7all m>ks72 fu*s9e acetate2 c]ise ,g1 ,r2 gr5ad9e ,o1 ,r1 ,,rr2 m>oon ,o extra2 new fu*s9e ,o1 ,p2 me?yl5e violet 7all m>ks72 peacock blue ,p2 ,victoria blue ,b1 ,r2 ?ion9e blue ,,g2 me?yl5e blue 7all m>ks72 mala*ite gre5 7all m>ks72 brilliant gre5 7all m>ks72 coal black ,o1 ,i1 ,,ii4 ,,m\ld+ ,! col\r pulp c be made into tablets by m\ld+ x 9 dry boxes divid$ into a numb] ( comp>tm5ts4 ,! col\r %r9ks 9 dry+1 & ! tablets w !n easily fall out ( ! m\lds4 ,cones are obta9$ by plac+ ! pulp 9 a box1 ! bottom ( :i* is p]=at$ ) num]\s holes ( uni=m size1 ! box be+ !n tapp$ aga9/ ! surface ( a /one table4 ,at ea* /roke1 a c]ta9 am\nt ( col\r is =c$1 9 ! %ape ( small cones1 ?r\gh ! p]=ations1 on to a %eet ( pap] und]nea?4 ,! cones are !n dri$4 ,"s col\rs are m\ld$ into blocks by =c+ ! p>tly dri$ pa/e into suitable m\lds--pref]ably ( metal1 s t !y may be engrav$ ) ! mak]'s "n1 or o!r impr9t--& left to dry sl[ly & )\t crack+4 ,! cakes may be prev5t$ f crumbl+ by incorporat+ a small quantity ( adhesive1 su* z a weak solution ( dextr91 ) ! wat] 9 :i* ! col\r is susp5d$4 ,,*apt] ,,iv ,,:ite ,,e>? ,,col\rs ,! :ite e>? col\rs are important = ! purposes ( ! col\r-mak]1 because n only are !y us$ by !mselves z pa9ts1 b also s]ve 9 ! production ( light %ades ( o!r col\rs4 ,! :ite col\rs conta9+ clay or lime are ! mo/ abundant & important ( all1 & w !re=e be describ$ fir/4 ,! lime col\rs comprise cau/ic lime1 c>bonate ( lime 7*alk or p[d]$ lime/one71 gypsum & bone a%4 ,,cau/ic ,,lime ,?\gh ?is product is n us$ direct z a pa9t]s' col\r1 x is employ$ 9 ! prep>ation ( comp\nds t are s us$4 ,x is made on a l>ge scale = ! prep>ation ( mort>1 & !re is !re=e no ne$ = ! col\r-mak] to manufacture x himself1 s9ce x c always be b\ght f a lime-burn]4 ,x mu/ be borne 9 m9d1 h[ev]1 t lime = ! col\r-mak]'s purposes mu/ possess c]ta9 prop]ties1 fail+ :i* x is ( no use to him4 ,:at ^! prop]ties are & h[ ! product is made w n[ be briefly describ$4 ,:5 c>bonate ( lime1 i4 e4 native lime/one1 is expos$ to /rong heat x p>ts ) c>bon dioxide & is trans=m$ into burnt or cau/ic lime4 ,ca,c,o#c ,ca,o ,,co#b ,c>bonate ( lime4 ,cau/ic lime4 ,c>bon dioxide4 ,! lime/one is burn$ ei!r 9 kilns ( v simple con/ruction1 or else 9 m complicat$ furnaces 9 :i* a cont9u\s process is ma9ta9$4 ,! ord9>y limekiln1 :i* c be f\nd 9 _m p>ts ( ! c\ntry1 consi/s m]ely ( f\r walls1 ) a door 9 ! front "o = ! introduction ( ! fuel4 ,kilns ( ?is k9d are usually set up 9 ! vic9ity ( ! lime/one deposits1 & are ab&on$ :5 !y get worn out4 ,! lime/one is brok5 to lumps ( fairly ev5 size1 ab\t z l>ge z a man's head1 & ^! are pil$ up 9 a dom$ heap 9 ! kiln1 suffici5t space be+ left betwe5 ! lumps = ! passage ( ! flame4 ,a fire is !n light$ "u ! pile1 p9e wood be+ mo/ly us$ = ?is purpose on acc\nt ( its high cont5t ( res91 :i* gives a v /rong flame4 ,! fire is kept up until ! top ( ! pile has become :ite hot1 & only a blue1 smokeless flame is visible4 ,! appe>ance ( ?is d5otes t ! burn+ is end$1 ! fire be+ !n all[$ to die out & ! lumps left until cool en\gh to be tak5 out ( ! kiln4 ,?is op]ation is p]=m$ ) great c>e1 p>ticul> importance be+ atta*$ to pres]v+ ! lumps z intact z possible & prev5t+ ! =mation ( du/1 :i* is ( little value4 ,! lime made 9 ?is way is end[$ ) prop]ties t r5d] x valuable = ! purposes ( ! col\r-manufactur]2 b1 on ! o!r h&1 possesses c]ta9 disadvantages4 ,ow+ to ! use ( wood z fuel1 ! cau/ic lime obta9$ 9 ?is way is usually a v pure :ite1 because ! burn+ is cont9u$ until ! :ole mass is gl[+ & ! firewood has be5 completely consum$4 ,if ?is is n ! case1 ! burnt lime is greyi% 9 col\r1 f ! f9ely divid$ p>ticles ( c>bon1 :i*1 ( c\rse1 spoils ! lime = col\r-mak+4 ,! defects exi/+ 9 lime burn$ 9 ! above type ( kiln orig9ate 9 ! irregul> "* ( ! product4 ,x w be evid5t t ! lime/one lumps t are ne>e/ ! fire w be f> m /rongly heat$ ?an ^? 9 ! upp] "p ( ! dome2 & :5 calc9$ lime is kept inc&esc5t = a long "t1 x becomes s compact 9 texture t x qu5*es ) great difficulty :5 br\ght 9 contact ) wat]4 ,?is condition is kn[n z 8dead burnt10 & su* lime is ( little value4 ,! lumps at ! top ( ! pile are lea/ expos$ to ! heat1 & v (t5 /ill conta9 c>bonate1 z is %[n by ! eff]vesc5ce produc$ on treatm5t ) an acid4 ,su* lime is imp]fectly burnt1 & ! lumps frequ5tly /ill exhibit ! cry/all9e /ructure ( lime/one :5 brok54 ,!y qu5* rapidly1 b :5 mix$ ) a little extra wat]1 ! mass is no long] ( ! butt]y consi/5cy typical ( cau/ic lime1 b conta9s gritty portions consi/+ ( unalt]$ lime/one4 ,ow+ to ! defects ( dead burn+ on ! "o h& & insuffici5t calc9+ on ! o!r1 col\r-mak]s n[ pref] lime t has be5 burn$ 9 cont9u\s kilns1 because1 :5 prop]ly made1 su* lime is v uni=m 9 "*1 & is also *eap] ?an t burn$ ) su* an exp5sive fuel z wood4 ,9 consequ5ce ( ! great] capacity ( ! cont9u\s kiln1 & ! m uni=m "* ( ! product1 ! old-fa%ion$ kilns are m & m fall+ into disuse4 ,! arrangem5t ( ! cont9u\s kiln is v simple4 ,! kiln consi/s ( a fairly high %aft1 op5 at ! top1 & provid$ at ! bottom ) a small hole = ! removal ( ! burnt lime4 ,a coal fire is light$1 & z soon z ! kiln is heat$ up1 alt]nate lay]s ( lime/one & suffici5t coal = burn+ x are introduc$4 ,! burnt lime s9ks to ! bottom ( ! %aft & is pull$ out1 ) iron hooks1 f "t to "t4 ,giv5 ! "r proportions ( coal & lime/one1 ! lime made 9 ^! kilns is burnt to j ! "r degree1 & is excell5t = build]s' use4 ,9 _m cases1 h[ev]1 x is less valuable to ! col\r-mak]1 & 9 "s q useless4 ,= example1 :5 ! coal is n completely consum$1 c>bon1 ev5 ?\gh only a v small quantity1 is deposit$ on ! lime1 & ! burnt lime1 in/ead ( be+ a brilliant :ite1 z x %\ld be1 is grey2 & col\r made !refrom is also greyi% :ite & w spoil ! %ade ( o!r col\rs ) :i* x is mix$4 ,! *emical composition ( ! orig9al lime/one also has an influ5ce on ! "* ( ! burnt lime4 ,lime/one consi/+ entirely ( c>bon dioxide & lime is s r>e t suffici5t is nev] available = mak+ burnt lime on a l>ge scale4 ,ev5 ! pure/ lime/one f\nd native 9 l>ge quantities--namely m>ble--is n pure c>bonate ( lime1 b conta9s a c]ta9 proportion ( extrane\s sub/ances4 ,at ! same "t x is too exp5sive to use = te*nical purposes4 ,! ord9>y impurities pres5t 9 lime/one are f]r\s oxide1 f]ric oxide1 magnesia & organic matt]4 ,! pres5ce ( f]r\s oxide c usually be detect$ by ! gre5i% t+e ( ! raw lime/one1 & ! r$di% ca/ ( ! burnt product4 ,f]ric oxide is reveal$ by its r$di% col\r1 9 bo? ! lime/one & burnt lime4 ,magnesia1 :i* is pres5t1 = example1 9 dolomitic lime/one1 _c be detect$ by ! col\r1 ei!r be=e or aft] burn+1 ?is oxide be+ itself p]fectly :ite2 b its pres5ce is a drawback because if 9 l>ge quantity x makes ! lime v difficult to qu5*1 & su* lime is nev] ( a fatty "*4 ,organic matt] betrays itself by ! col\r1 ! lime be+ d>k t9t$1 v>y+ f grey to black4 ,black lime/ones usually conta9 c>bon 9 an extremely f9e /ate ( division1 & are q useless to ! col\r-mak] ow+ to ! impossibility ( completely burn+ (f ?is conta9$ c>bon1 :i* always imp>ts a greyi% t+e to ! burnt lime4 ,! behavi\r ( lime/ones 9 ?is respect v>ies1 h[ev]1 consid]ably1 & c only be asc]ta9$ ) c]ta9ty by a trial burn+4 ,_m t are r d>k 9 col\r w1 nev]!less1 burn p]fectly :ite1 :]eas o!rs1 mu* light] 9 %ade1 always give a product t is n q pure 9 tone4 ,?is div]g5t behavi\r seems to h "s connection ) ! *emical composition ( ! organic matt] 9 "q4 ,if x consi/s ( coal1 or sub/ances analog\s !reto1 no really pure :ite lime c be obta9$ f a light grey lime/one1 x be+ impossible to burn (f ! f9ely divid$ c>bon completely4 ,9 addition to mak+ a trial burn+ ) a fairly l>ge sample ( mat]ial1 ! behavi\r ( a lime/one t[>ds hydro*loric acid w af=d "s in=mation z to ! nature ( ! grey col\r+ matt]4 ,if ! lime/one dissolves completely :5 suffus$ ) ! acid1 ! indications are fav\rable = its usefulness to ! col\r-mak]4 ,if1 on ! contr>y1 a black residue is left1 ! coloration is due to f9ely divid$ c>bon1 & !re is !n little prospect ( ! mat]ial furni%+ a suitable product4 ,9 any ev5t1 a trial burn+ is ! mo/ reliable guide4 ,9 addition to c>bon1 ! pres5ce ( any l>ge proportion ( f]ric or f]r\s oxide is objectionable1 s9ce1 9 ei!r case1 ! product w be t+$ r$ ) f]ric oxide1 into :i* ! f]r\s oxide is trans=m$ at calc9ation temp]ature4 ,9 addition to comp>+ ! col\r ( ! product ) a /&>d sample1 ! suitability ( a burnt lime = col\r-mak+ c be te/$ by qu5*+4 ,if a lump ab\t ! size ( ! fi/ be plac$ 9 a l>ge porcela9 bas9 & suffus$ ) a small quantity ( wat]1 pref]ably p\r$ 9 a ?9 /ream1 ! lime1 if prop]ly burn$1 w cont9ue to absorb ! wat] = a consid]able "t1 l a sponge1 & w v soon give evid5ce ( a brisk reaction by increas+ 9 bulk & g5]at+ su* an am\nt ( heat z to cause ! imm$iate evaporation ( a few drops ( wat] all[$ to fall on ! surface ( ! mass4 ,f9ally1 ! entire lump w crumble d[n to a v delicate1 volum9\s p[d]1 consi/+ ( slak$ lime 7calcium hydroxide74 ,?is *emical reaction is express$ by ! equation3-- ,ca,o ,h#b,o ,ca7,,oh7#b ,lime ,wat] ,calcium hydroxide4 ,:5 ! am\nt ( wat] add$ to burnt lime is no m ?an suffici5t to effect its trans=mation into hydroxide1 ?is latt]1 z already /at$1 =ms a delicate :ite p[d]4 ,! addition ( m wat] results 9 ! =mation ( a homog5e\s pulp1 ( a peculi> fatty "*4 ,s9ce ?is fatty appe>ance is only possess$ by pure lime1 x is a crit]ion ( high quality 9 burnt lime1 & contra/s /rongly ) t ( ! less valu$ poor 7or lean7 lime4 ,calcium hydroxide acts z an extremely p[]ful base1 & !re=e mu/ n be mix$ ) col\rs t are s5sitive to ! action ( /rong bases4 ,z a matt] ( fact1 its direct use 9 pa9t+ is v small4 ,( c\rse1 a ?9 milk ( lime is us$ = :itewa%+ walls1 etc42 & if any col\r+ +r$i5ts are add$ !y mu/ be su*--e4 g4 o*res--z are n affect$ by ! lime4 ,nev]!less1 quick & slak$ lime are v important 9 col\r-mak+1 z =m+ ! orig9at+ mat]ial = ! prep>ation ( a numb] ( col\rs4 ,:5 slak$ lime is mix$ ) suffici5t wat] to =m a /iff pulp1 & is left expos$ to ! air = "s "t1 a *ange w be obs]v$ to take place1 ! mass solidify+ gradually 7comm5c+ on ! outside7 & f9ally crumbl+ to a s(t :ite p[d]4 ,?is *ange is due to *emical action1 ! lime hav+ a great aff9ity = c>bon dioxide1 :i* x readily takes up f ! atmosph]e--a fact :i* expla9s ! solidification m5tion$4 ,x w\ld be errone\s to assume t ! lime is aga9 completely conv]t$ into calcium c>bonate 9 ?is way2 =1 ?\gh su* conv]sion does ultimately take place1 x requires a v long "t = completion4 ,! result+ comp\nd is1 actually1 a d\ble comp\nd ( calcium oxide & c>bonate4 ,al?\gh ?is comp\nd has fairly /rong basic prop]ties1 !y are1 nev]!less1 f> weak] ?an ^? ( cau/ic lime1 be+ p>tly neutralis$ by ! c>bon dioxide absorb$4 ,if ! sup]ficial area ( ! slak$ lime be increas$ by spread+ x out ?9ly1 s z to (f] great] opportunity = ! action ( c>bon dioxide1 ! =mation ( ! d\ble comp\nd 9 "q w be greatly accel]at$4 ,?is d\ble comp\nd is prep>$ artificially 9 special works1 & ! result+ col\rs are put on ! m>ket "u v>i\s names4 ,!y1 too1 mu/ n be mix$ ) col\rs t are s5sitive to alkali1 & on ?is acc\nt !y _c be us$ 9 f9e pa9ts4 ,if appli$ z a :ite prim+ to ! walls ( rooms1 c>e mu/ be tak5 to cov] ! coat+ ) "s sub/ance t w protect ! topp+ col\r f ! action ( ! lime4 ,= ?is purpose1 pa9t]s use a wa% ( milk1 soap & wat]1 etc4 ,an important prop]ty ( lime is its behavi\r t[>ds case91 ! sub/ance =m+ ! curd ( milk4 ,) ?is body x comb9es to =m a mass :i* sets h>d & is highly resi/ant1 viz4 calcium caseate1 & is =m$ :5 limewa% is /irr$ up ) milk or fre%ly precipitat$ case94 ,wea!rpro( di/emp]s = outside use are prep>$ 9 ?is mann]4 ,,pe>l ,,:ite ,! prep>ation frequ5tly met ) 9 comm]ce "u ?is "n is no?+ m ?an a burnt lime ( great purity4 ,x is prep>$ 9 ! coa/al di/ricts by burn+ oy/] %ells1 ! result+ burnt lime be+ easily trans=m$ into a f9e p[d]1 ! pure :ite col\r ( :i* is due to ! abs5ce ( iron4 ,x is us$ 9 ! same way z pure burnt lime1 & is ma9ly ( int]e/ 9 seaside t[ns :]e oy/] %ells are (t5 accumulat$4 ,x may be po9t$ out t ! "n pe>l :ite is (t5 appli$ also to pure :ite grades ( :ite lead4 ,,vi5na ,,:ite ,?is col\r is prep>$ f any k9d ( burnt lime t is suffici5tly pure2 t is1 free f f]ric oxide4 ,! me?od ( prep>ation is simple1 requir+ no special app>atus1 & c !re=e be c>ri$ out :]ev] suitable lime is available4 ,op]ations are comm5c$ by c>efully slak+ well-burnt lime ) wat]1 a suffici5t excess ( :i* is add$ to produce a fairly ?ick pulp4 ,to accel]ate ! absorption ( c>bon dioxide1 ! mass is expos$ to ! air 9 ?9 lay]s1 by spread+ x out on bo>ds1 s z to pres5t a l>ge surface to ! air4 ,z soon z ! pulpy "* has disappe>$1 ! mass is deta*$ f ! bo>ds1 & is press$ & knead$1 ) wood5 paddles1 into prismatic cakes :i* are left expos$ to ! air--be+1 ( c\rse1 protect$ f ! wet--until ! absorption ( c>bon dioxide is complete--a condition t c be recognis$ by ! e>?y "* ( ! product4 ,! cakes are !n dri$1 an op]ation entail+ great c>e1 s9ce lightness is a sign ( good quality1 :]eas a damp product is v heavy4 ,9 =m+ ! cakes !y mu/ n be t\*$ by ! b>e h&s1 because ! lime is s cau/ic t x w\ld soon de/roy ! sk94 ,! =ego+ me?od ( manufacture is capable ( _m improvem5ts1 :i* c be introduc$ )\t add+ mu* to ! co/ ( production4 ,if ! lime is =m$ into l>ge blocks1 x w evid5tly take a long "t = ! mass to acquire1 all ?r\gh1 ! e>?y "* indicat+ comb9ation ) c>bon dioxide4 ,?is drawback c be easily rem$i$ by =m+ ! mass into small cakes1 :i* w become ripe1 ow+ to _! l>g] surface1 mu* soon] ?an ! bigg] blocks4 ,a v good plan to adopt 9 m\ld+ is to =m ! burnt lime into a /iff pa/e ) wat]1 pref]ably by add+ en\gh wat] to make a visc\s mass1 & leav+ ?is 9 a lime-pit = sev]al weeks1 ! prolong$ /orage enabl+ ! lime to acquire ! already m5tion$ fatty "*1 & at ! same "t to become highly pla/ic4 ,lime treat$ 9 ?is way c be =c$ ?r\gh a nozzle1 =m+ a cyl9drical rope1 :i* c be cut by a knife into conv5i5t l5g?s & left on bo>ds = a few days until !y h become firm en\gh to /& up )\t break+4 ,cyl9d]s made 9 ?is mann]1 ) a l5g? ( ab\t f\r in*es & a diamet] ( two in*es1 w absorb c>bon dioxide v quickly4 ,! absorption c be /ill fur!r accel]at$ by sett+ up ! cyl9d]s 9 an atmosph]e highly *>g$ ) ! gas1 = in/ance 9 ! vic9ity ( a manure pit1 z !y w !n avidly take up ! c>bon dioxide abundantly lib]at$ f ! rott+ manure4 ,simil> accel]ation w take place if ! bo>ds c>ry+ ! cyl9d]s are plac$ 9 a /able1 or 9 a room :]e wa% = mak+ spirits is f]m5t+1 because l>ge quantities ( c>bon dioxide are lib]at$ 9 bo? places4 ,work+ ! cau/ic mass by h& is accompani$ by s _m inconv5i5ces t x seems highly desirable to employ "s me*anical m\ld+ device :i* w r5d] contact ) ! wet lime entirely sup]flu\s4 ,x may be po9t$ out t su* a device c also be advantage\sly us$ = m\ld+ all e>? col\rs 9 pa/e or pulp =m1 & 9 p>ticul> = %ap+ f]ric oxide col\rs into rods or small cyl9d]s4 ,illu/ration3 ,,fig4 #bf4 ,su* a ma*9e 7,fig4 #bf7 is compos$ ( a rectangul> box ) semi-cyl9drical bottom1 a deta*able %aft c>ry+ a %eet-metal worm be+ arrang$ 9 ! box s t ! worm is 9 contact ) ! r\nd$ bottom & is cont9u$ into ! cyl9drical ext5sion ( ! box4 ,?is ext5sion t]m9ates 9 a holl[ cone1 to ! m\? ( :i* nozzles ( v>y+ ap]ture 7squ>e1 rectangul> or r\nd7 c be atta*$4 ,a knife1 op]at$ by h& or me*anical means1 enables ! extrud$ s(t mass to be cut into conv5i5t l5g?s1 :i* drop on to a s]ies ( easy runn+ roll]s 9 front ( ! nozzle1 & are !reby deliv]$ to an endless-belt conveyor f :i* !y c be transf]r$ to ! dry+-bo>ds4 ,:5 ! box has be5 *>g$ ) ! lime pulp & ! worm is rotat$1 ! latt] =ces ! s(t mass into ! cone & extrudes x ?r\gh ! nozzle1 s t1 z long z !re is any mat]ial 9 ! box1 x is dis*>g$ z a cont9u\s rope1 ( squ>e1 rectangul> or cyl9drical section1 on to ! guide-roll]s1 :]e x c be cut (f into l5g?s by ! knife4 ,a fundam5tal condition = ! prep>ation ( a good ,vi5na :ite is ! employm5t ( pure raw mat]ial1 :i* mu/ be free f f]ric oxide or e>?y impurities1 & fully burn$4 ,an excell5t mat]ial = ?is purpose is calc9$ mussel %ells1 :i* furni% a loose1 & at ! same "t v pure1 lime1 & are v l>gely us$ = lime-burn+ 9 places su* z ,holl&1 :]e !y are available 9 l>ge quantities4 ,vi5na :ite is n mu* us$ z a pa9t col\r1 ow+ to its p[]ful alkal9e prop]ties :i* h a de/ructive effect on _m col\rs4 ,x is1 h[ev]1 l>gely employ$ z a poli%+ ag5t1 = :i* purpose x is p[d]$ & is put on ! m>ket--mo/ly 9 bottles--z ,vi5na lime4 ,its v h&some :ite col\r & l[ price r5d] x p>ticul>ly suitable = co>se pa9t+1 = example z a prime coat+ = pa9t$ int]ior walls4 ,to gu>d aga9/ ! dang] ( ! pa9t$ decoration be+ de/roy$ by ! alkal9e nature ( ! :ite1 x is advisable to coat ! dri$ gr\nd ) alum solution1 ! alum9a ( :i* comb9es ) ! lime to =m an insoluble comp\nd to :i* organic col\rs adh]e well4 ,! sulphuric acid also ent]s into comb9ation ) ! lime1 ! result+ gypsum hav+ no effect on ! pa9ts subsequ5tly appli$4 ,,*alk ,! "n *alk is us$ = a numb] ( comm]cial sub/ances :i* diff] consid]ably 9 bo? ! m9]alogical & *emical s5se4 ,fr5* *alk1 = in/ance1 is a m9]al belong+ to ! /eatite gr\p &1 ap>t f its "n1 has no?+ 9 common ) true *alk1 except ! :ite col\r1 & ev5 ?is diff]s altoge!r f t ( *alk prop]ly s call$4 ,x is !re=e necess>y1 9 ! int]e/s ( prop] nom5clature1 to diff]5tiate ! v>i\s k9ds ( *alk1 comm5c+ ) ! m9]al kn[n by t "n to ! *emi/ & m9]alogi/4 ,9 *emical composition1 true *alk is calcium c>bonate1 b ( a fossil "*1 = if *alk du/ be exam9$ "u a high-p[] microscope1 x w be se5 to consi/ ( ! %ells ( m9ute animals1 & is !re=e to be reg>d$ z fossil4 ,! organic matt] ( ! animals has long disappe>$1 leav+ ! inorganic mat]ial1 a v pure calcium c>bonate1 beh9d4 ,illu/ration3 ,,fig4 #bg4 ,su* progress has be5 made t ! zoological /atus ( ! animals :i* inhabit$ ! %ells--_m ?\s&s ( :i* are pres5t 9 a lump ( *alk--has be5 id5tifi$2 & x is kn[n t ^! animals 7 ( m>9e type4 ,fig4 #bg %[s ! appe>ance ( ! animal rema9s 9 ,meudon *alk :5 highly magnifi$1 ! upp] half be+ view$ by transmitt$ light & ! l[] by reflect$ light4 ,not)/&+ ! extremely m9ute dim5sions ( ! *alk animalcul1 _! rema9s =m rocks ( great ?ickness 9 all p>ts ( ! _w4 ,9 ,europe we f9d1 = example1 ext5sive *alk =mations 9 ,engl&1 ^: ,lat9 "n ,albion 0 be/[$ on acc\nt ( ! :ite *alk cliffs occupy+ long /ret*es ( ! coa/4 ,! hills ( ,*ampagne consi/ almo/ entirely ( *alk2 & ,rg51 toge!r ) _m o!r isl&s1 is ne>ly all *alk cliffs4 ,x is only 9 v r>e cases1 h[ev]1 t *alk occurs 9 suffici5t purity to be imm$iately suitable = use z a pigm5t or writ+-mat]ial4 ,= ! mo/ "p x conta9s o!r m9]als1 or l>ge fossils1 f :i* x has to be sep>at$ by me*anical treatm5t4 ,nodul> fl9ts are (t5 met ) 9 *alk1 & _m deposits conta9 su* l>ge numb]s ( ! petrifi$ %ells ( ! sea ur*9 t ! *alk really _c be us$ z a pigm5t at all1 by reason ( ! high co/ ( purification4 ,! only places :]e *alk c be advantage\sly work$ = ! prep>ation ( pigm5t is :]e ! m9]al is 9 a high /ate ( purity1 & also conta9s only v few s&y p>ticles4 ,su* *alk deposits are work$ on a m9+ scale1 &1 z a rule1 9 ! /ate 9 :i* ! *alk comes f ! qu>ry2 x is 9 ! =m ( a s(t mass1 easily scrat*$ ) ! f+]-nail & ( fairly high d5sity1 ow+ to ! consid]able quantity ( wat] ) :i* x is ord9>ily impregnat$4 ,9 ord] to conv]t ?is crude *alk into a product t c be us$ z a pigm5t1 x is fir/ left to dry until ! lumps c be easily brok51 & !n cru%$ into small pieces1 f :i* all ! extrane\s m9]als1 :i* occur z l>ge lumps1 are sort$ out & remov$4 ,?is pick+ process is important1 especially :5 ! *alk conta9s fl9ts1 because ^! latt] are v h>d & w\ld injure ! mill/ones 9 ! subsequ5t gr9d+4 ,! lumps ( *alk are r$uc$ by me*anical means1 su* z a /amp-mill1 or1 m frequ5tly1 9 a mill ( ! same type z = gr9d+ fl\r1 s9ce x is impossible to get ! lumps s dry z to produce ! degree ( brittl5ess necess>y = a ?or\gh r$uction 9 a /amp-mill4 ,! mill/ones are enclos$ 9 a wood5 cas+1 & ! *alk is gr\nd 9 admixture ) wat]1 ! gr\nd mass escap+1 ?r\gh an op5+ 9 ! cas+1 z a ?ick pulp :i* is /or$ = a consid]able "t 9 l>ge tanks4 ,exp]i5ce has %[n t ?is me?od ( prolong$ /orage 9 contact ) wat] greatly improves ! col\r4 ,! only explanation ( ?is fact is t ! *alk /ill conta9s a v small am\nt ( organic matt]1 :i* gradually decomposes 9 pres5ce ( wat]4 ,! evid5ce 9 fav\r ( ?is is ! peculi> smell giv5 (f dur+ /orage4 ,ev5 ) ! mo/ c>eful gr9d+1 *alk _c be trans=m$ into su* a f9e p[d] t is directly fit = all purposes2 & ! only way to obta9 ! requisite f95ess is by levigation4 ,ow+ to ! l>ge quantities t are usually h&l$ 9 ?is process1 ! milky liquid com+ f ! mill is mo/ly run into l>ge brick tanks1 :]e x is left to settle until all ! *alk has deposit$ & ! sup]natant wat] is p]fectly cle>4 ,tapp+-(f be+ usually impracticable1 ! wat] is g5]ally drawn (f by c>eful syphon+1 s z n to di/urb ! f9e sludge at ! bottom ( ! tank4 ,! deposit 9 ! settl+-tanks is %ovell$ into wood5 boxes1 p]=at$ at ! sides to enable ! wat] to dra9 away1 ! *alk be+ prev5t$ f escap+ by l9+ ! boxes ) l95 clo?s4 ,! pulp soon loses its liquid "* & %r9ks consid]ably1 ! boxes be+ !n fill$ up ) m sludge1 & s on until ! cont5ts h ceas$ to %r9k4 ,:5 ! mass is s f> dry t x w no long] run :5 lift$1 ! boxes are cov]$ ) bo>ds & inv]t$1 dis*>g+ ! cont5ts on to ! bo>ds1 on :i* ! mass is left to become q dry4 ,filt]-presses are also us$4 ,l>ge prismatic masses ( *alk nev] dry s uni=mly z to prev5t ! =mation ( cracks1 & if ! *alk is to be sold 9 ?is =m ! cracks are pla/]$ up ) ?ick pulp2 ?is op]ation1 h[ev]1 be+ sup]flu\s :5 ! *alk is to be sold z p[d]4 ,9 ord] to obta9 a m compact product & accel]ate ! dry+ ( ! m\ld$ lumps1 "s mak]s use presses1 9 :i* ! fairly dry *alk is subject$ to progressive heavy pressure4 ,ow+ to ! f95ess ( ! compon5t p>ticles ( *alk1 !y adh]e s firmly toge!r1 )\t any b9d1 t a fair am\nt ( =ce is necess>y to break d[n a piece ( p]fectly dry levigat$ *alk4 ,sometimes1 h[ev]1 *alk exhibits ! unpleasant prop]ty ( los+ its cohesion almo/ completely :5 dry1 & 9 su* cases x c only be %ap$ into prisms ) great tr\ble4 ,?is peculi>ity is specially acc5tuat$ :5 ! *alk conta9s magnesia2 & 9 ord] to m\ld *alk ( ?is k9d into blocks1 a b9d+ ag5t1 su* z ord9>y glue1 mu/ be add$ to ! wat] us$ 9 gr9d+1 c>e be+ tak5 n to use too mu*1 or ! *alk w become too h>d1 :5 dry1 = c]ta9 purposes1 e4 g4 z draw+ or writ+ *alk4 ,= "s purposes1 *alk is sold 9 p[d] =m1 & v high purity is n !n ess5tial1 an admixture ( magnesia or clay be+ h>mless4 ,gild]s1 = in/ance1 use l>ge quantities ( *alk = prim+ picture frames1 & /ir ! *alk up ) a c]ta9 am\nt ( b9d 7mo/ly size71 to give ! p>ticles ! desir$ cohesion4 ,! *ief requirem5t exact$ ( a good quality *alk is a h&some :ite col\r2 & ?is dep5ds entirely on ! quality ( ! raw mat]ial1 n on ! me?od ( prep>ation4 ,x is kn[n t a sub/ance q devoid ( col\r w furni% a p]fectly :ite p[d]1 because ! col\rless p>ticles reflect ! light 9 all directions )\t break+ x up into its con/itu5t yell[1 r$ & blue rays4 ,*alk1 too1 is 9 reality a col\rless sub/ance1 & reflects light ) great] uni=mity 9 proportion z ! f95ess ( ! p>ticles increases4 ,consequ5tly1 :5 "o has a *alk t is n p]fectly :ite1 x c1 nev]!less1 be made to furni% a v h&some product by be/[+ great c>e on gr9d+ & levigation4 ,prop]ly prep>$ *alk %\ld be z f9e z ! f9e/ fl\r4 ,:5 ! col\r ( ! be/ grades ( *alk are comp>$ ) :at may be t]m$ pure :ite--su* z t ( :ite lead1 z9c :ite1 p]man5t :ite--a skill$ eye w always detect a greyi% or yell[i% t+e 9 ! =m]1 ev5 if obta9$ f ! :ite/ ,c>r>a m>ble4 ,! grey t+e is due to ! pres5ce ( organic matt]1 :i* _c be elim9at$ by any kn[n means1 b :i* c be %[n to exi/ by ! fact t :5 su* *alk is heat$ to inc&esc5ce 9 ! air = a %ort "t1 ! result+ burnt lime is pure :ite1 ! organic matt] hav+ be5 burn$ (f4 ,a yell[ t+e is caus$ by m9ute traces ( f]ric oxide1 :i*--z also f]r\s oxide--almo/ inv>iably accompanies calcium c>bonate2 & lime/one free f det]m9able quantities ( ^! oxides is ( r>e occurr5ce4 ,f]r\s oxide does n reveal its pres5ce 9 lime/one unless 9 l>ge proportion1 its pale gre5 col\r be+ ( l[ t9ctorial p[]1 :]eas f]ric oxide1 :i* is a v /rong col\r+ ag5t1 c be m readily detect$4 ,to ^? :o are engag$ 9 ! manufacture ( :ite e>? col\rs1 h[ev]1 x is q immat]ial :e!r a lime/one or *alk conta9s f]r\s oxide1 because t oxide quickly *anges into f]ric oxide 9 ! f9ely divid$ product1 & a *alk :i* 0 orig9ally pure :ite w become decid$ly yell[ 9 a %ort "t4 ,=tunately1 su* a yell[-t+$ product c be r5d]$ p]fectly :ite by simple means & at small co/1 all t is necess>y be+ to add a suitable quantity ( a blue col\r+ matt]4 ,:5 ?is has be5 done1 ! *alk w seem pure :ite to ev5 ! mo/ skill$ eye4 ,?is result ( add+ a blue pigm5t is bas$ on ! well-kn[n physical fact t c]ta9 k9ds ( col\r$ light produce :ite light :5 comb9$1 ! col\rs t give ?is effect be+ t]m$ 8complem5t>y40 ,a pure blue is complem5t>y to a yell[ ) a r$di% ca/--e4 g4 f]ric oxide--& !re=e a *alk t is t+$ yell[ by a small quantity ( f]ric oxide c be *ang$ into a seem+ly pure :ite sub/ance by ! addition ( a blue pigm5t4 ,! only pigm5ts ( use 9 ?is connection to ! col\r-mak] are su* z h v int5sive col\r+ p[] & at ! same "t are l[ en\gh 9 price4 ,su* sub/ances are ultram>9e1 smalt & coal-t> dyes4 ,smalt is ! be/ because its col\r is unalt]able4 ,9 po9t ( *emical composition1 ?is sub/ance is a v h>d glass col\r$ blue by cobalt\s oxide4 ,= improv+ ! col\r ( *alk or any o!r :ite1 ! smalt mu/ be 9 an extreme /ate ( f9e division1 & levigat$ to an impalpable p[d]4 ,ultram>9e c be us$ = ! same purpose1 b is n s p]man5t4 ,to asc]ta9 ! correct proportion ( blue pigm5t1 x is advisable to make a sy/ematic exp]im5t1 :i* is easily p]=m$4 ,exactly #ij p>ts ( ! *alk 9 "q are triturat$ ) #aj p>ts ( blue pigm5t 9 a mort> until ! entire mass has become a p]fectly uni=m pale blue p[d]1 :i* conta9s #aj ( ! blue +r$i5t4 ,sev]al samples1 ea* repres5t+ "o hundr$ p>ts ( ! :ite pigm5t to be correct$ are c>efully weigh$ out1 #a "p ( ! blue p[d] be+ add$ to ! fir/ sample1 #b p>ts to ! second1 #c to ! ?ird1 & s on1 & ! mixtures are comp>$ ) a /&>d :ite sub/ance1 su* z be/ :ite lead or z9c :ite1 to see :i* mo/ ne>ly approa*es ! /&>d col\r4 ,x is !n easy to calculate h[ mu* ( ! blue requires to be add$ to #ajj or #ajjj lb4 ( ! mat]ial to be correct$4 ,! correction c be effect$ 9 sev]al ways2 = in/ance1 by gr9d+ ! blue pigm5t directly ) ! bulk1 by add+ x at ! levigation /age1 or mix+ x ) ! dry1 f9i%$ product4 ,! fir/ two me?ods are att5d$ ) c]ta9 drawbacks :i* r5d] x difficult to obta9 a p]fectly uni=m product1 ow+ to ! specific gravity ( ! blue pigm5ts be+ high] ?an t ( ! :ites4 ,consequ5tly1 :5 ! two are mix$ 9 pres5ce ( wat]--z is always ! case 9 gr9d+ & levigation--! heavi] blue pigm5t settles d[n m quickly1 & sev]al /rata c be cle>ly di/+ui%$ 9 ! s$im5t4 ,! upp] lay]s w /ill h a decid$ yell[ t+e--! proportion ( blue be+ too small = prop] correction--:il/ ! next 9 ord] w be pure :ite--accurately correct$--& ^? at ! v bottom w be decid$ly blue1 because !y conta9 ! l>ge/ proportion ( ! blue sub/ance4 ,! mo/ satisfactory results are obta9$ by dry mix+2 & ?is c be successfully practis$ :5 ! col\r-mak] has a *eap s\rce ( p[] 7su* z wat] p[]7 available4 ,:]e1 h[ev]1 co/ly p[] plant has to be provid$1 only ! f9e/ grades ( :ite pigm5ts c be improv$ 9 ?is way1 ! exp5se ( lab\r be+ too high = *eap mat]ials4 ,z a pigm5t1 *alk possesses _m valuable prop]ties4 ,! organic /ructure ( *alk gives x high cov]+ p[] z a wa%1 a ?9 lay] appli$ to a surface suffic+ to mask ! col\r ( ! und]ly+ gr\nd completely4 ,! lime 9 *alk be+ comb9$ ) c>bonic acid1 its basic prop]ties are s ext5sively weak5$ t *alk c be mix$ ) ev5 ! mo/ delicate col\rs )\t fe> ( _! %ade be+ affect$4 ,a coat+ ( pure *alk pa9t on any surface w nev] *ange col\r 9 ! air2 & on ?is acc\nt1 *alk is ext5sively us$ bo? z an indoor wa% & by wall-pap] manufactur]s4 ,,precipitat$ ,,*alk ,_m *emical processes furni% soluble salts ( lime t con/itute a by-product ( little value4 ,^! salts1 h[ev]1 c be advantage\sly utilis$ = ! prep>ation ( an artificial *alk :i* is pref]able to ! native article 9 _m respects4 ,= in/ance1 :]e l>ge quantities ( calcium *loride solution are available1 & soda c be pur*as$ at a suffici5tly *eap rate1 !y c be conv]t$ into artificial *alk1 because ^! two sub/ances react on ea* o!r1 =m+1 on ! "o h&1 calcium c>bonate1 :i* is precipitat$ z a v delicate1 insoluble p[d]1 & on ! o!r1 sodium *loride1 or common salt1 :i* rema9s 9 solution1 accord+ to ! equation3-- ,ca,cl#b ,na#b;,,co#c ,ca,c,o#c ,na,cl4 ,if1 h[ev]1 ^! solutions 7 mix$ toge!r 9 a crude /ate1 ! result+ product w\ld be ( only l[ value z a pigm5t1 be+ ( a yell[ t+e & nev] pure :ite4 ,?is is due to ! fact t ! impure lime salts1 be+ wa/e products f *emical works1 frequ5tly conta9 fairly l>ge am\nts ( f]ric oxide1 & ! soda also is (t5 s high 9 t impurity t ! col\r ( ! precipitat$ *alk is consid]ably impair$4 ,=tunately1 !re is no difficulty 9 elim9at+ ?is f]ric oxide by *emical means1 & obta9+ a product ( sup]ior col\r to ! be/ native *alk4 ,?is is effect$ by treat+ ! p]fectly neutral lime-salt solution ) calcium c>bonate1 :i* causes ! precipitation ( ! iron1 a correspond+ am\nt ( lime pass+ into solution4 ,9 ord] to elim9ate ! f]ric oxide f ! lime-salt solution s completely t n ev5 ! mo/ delicate *emical te/ kn[n w be able to reveal any trace rema9+1 ! solution is plac$ 9 a vat & /irr$ up ) f9ely p[d]$ *alk4 ,if ! solution conta9s any free acid1 eff]vesc5ce1 due to ! lib]ation ( c>bon dioxide1 w take place2 & 9 su* ev5t ! addition ( *alk is cont9u$ until ! free acid is all neutralis$1 & ! add$ *alk s9ks to ! bottom undissolv$4 ,! *alk %\ld be 9 slight excess1 s t a decid$ s$im5t is visible at ! bottom ( ! liquid :5 at re/4 ,?is deposit is /irr$ up aga9 at int]vals ) ! liquid = sev]al days4 ,:5 f]ric oxide is pres5t1 ! col\r ( ! deposit w gradually *ange to a yell[i% br[n1 ?r\gh ! precipitation ( f]ric hydroxide by ! *alk2 & 9 ?is way ! f9al traces ( iron c be remov$4 ,! liquid is !n c>efully drawn (f1 )\t di/urb+ ! s$im5t1 & ! soda solution is run 9 s long z a precipitate ( calcium c>bonate cont9ues to =m4 ,! completion ( ! reaction c be asc]ta9$ by p\r+ a small quantity ( ! liquid into a tall1 n>r[ glass1 leav+ x to cl>ify1 add+ a little m soda solution & obs]v+ :e!r any fur!r precipitate is produc$4 ,on ! o!r h&1 x may be t an excess ( soda has already be5 add$ 9 ! precipitat+ tank2 & ?is c be det]m9$ by te/+ a sample ) turm]ic pap]--blott+-pap] soak$ 9 a solution ( ! col\r+-matt] ( turm]ic root--:i* is turn$ br[n by alkal9e reag5ts4 ,ev5 9 v dilute solution1 soda w give ?is col\r *ange1 & ! te/ is !re=e v accurate4 ,! complete precipitation ( ! lime 9 ! solution c be asc]ta9$ by pass+ a small quantity ?r\gh blott+-pap] & treat+ x ) a little acid potassium oxalate solution1 :i*1 if lime be pres5t1 w at once produce a /rong cry/all9e precipitate ( calcium oxalate1 :i* is only v sp>+ly soluble 9 wat]4 ,if ! oxalate gives m]ely a slight turbidity1 ! residual am\nt ( lime is s small t ! process may be reg>d$ z complete4 ,s9ce c>bonate ( soda is usually mu* de>] ?an ! lime-salt liquor1 x is pref]able to leave a small quantity ( ! lime unprecipitat$4 ,giv5 suffici5t c>e 9 effect+ ! precipitation1 & especially :5 fairly /rong solutions are us$1 a brilliant :ite precipitate ( calcium c>bonate is obta9$1 :i* is 9 su* a f9ely divid$ /ate t ! m9ute con/itu5t cry/als c only be detect$ "u a high magnify+ p[]4 ,?is precipitat$ *alk be+ already 9 an extremely f9e condition ne$s no fur!r prep>ation1 &1 :5 wa%$1 is ready = imm$iate use1 =m+ a h&some pigm5t ) excell5t cov]+ p[]4 ,:5 precipitation is end$1 ! deposit is all[$ to settle d[n1 & ! cle> sup]natant liquid is c>efully drawn (f s z n to di/urb ! delicate s$im5t1 :i* is !n /irr$ up ?or\ghly ) clean wat]1 left to subside1 wa%$ aga91 & !n spread out to dry on clo?s :i* are susp5d$ by ! f\r sides4 ,! surplus wat] dra9s away & ! residue gradually assumes ! consi/5cy ( pa/e1 9 :i* condition x c easily be m\ld$ to any desir$ %ape4 ,if left long en\gh to dry completely1 x =ms a v delicate p[d]1 furni%+ a pigm5t ( excell5t quality4 ,if ?is precipitat$ *alk be m\ld$ into prisms = sale1 ! blocks are laid on "o ( _! broad sides until firm en\gh to turn ov] on to "o ( ! n>r[ faces1 slabs ( gypsum be+ us$ z ! support+ mat]ial1 9 ord] to ensure uni=m dry+4 ,! gypsum absorbs wat] ) avidity & ?us dries ! prisms ev5ly4 ,a defect ( ^! prisms is _! great fragility2 b _! /r5g? may be improv$ by mix+ a little v weak solution ( dextr9 to ! mass aft] ! la/ wa%+-wat] has be5 completely remov$4 ,9 dry+1 ! dextr9 b9ds ! mat]ial ( ! prisms suffici5tly to keep !m f break+ except "u ! influ5ce ( a fair degree ( =ce4 ,,calc>e\s ,,m>l ,z already m5tion$1 calcium c>bonate r>ely occurs 9 a p]fectly pure condition 9 ,nature2 & *alk1 also1 is frequ5tly contam9at$ by o!r m9]als4 ,a v>iety ( lime/one occurr+ z ext5sive deposits 9 _m places is t 9 :i* calcium c>bonate is associat$ ) clay4 ,sometimes ! clay pr$om9ates1 & ! m9]al is !n kn[n z m>l1 be+ really a clay contam9at$ ) *alk4 ,if1 on ! o!r h&1 ! *alk =ms ! *ief con/itu5t1 ! m9]al is t]m$ calc>e\s m>l4 ,calc>e\s m>ls are us$ 9 mu* ! same way z lime/one1 "s modification1 h[ev]1 be+ necessitat$ by ! pres5ce ( ! clay4 ,al?\gh lime/one conta9+ a c]ta9 am\nt ( clay c be burn$ 9 ! kiln1 x yields an inf]ior lime t is ( little use to ! build] ow+ to its l[ b9d+ p[]4 ,m>l ( a c]ta9 composition f9ds an important application 9 ! manufacture ( hydraulic lime or cem5t4 ,! only k9d ( m>l suitable = pigm5t is t conta9+ clay ) v little col\r2 & ?is is ( some:at r>e occurr5ce1 because mo/ m>ls conta9 suffici5t f]ric oxide to give !m a yell[ %ade4 ,m>l t is fairly free f f]ric oxide1 h[ev]1 c v well be us$ z pigm5t2 & _m :ite pigm5ts sold z 8*alk0 are really f9ely gr\nd m>l4 ,9 accordance ) ! g5]al practice1 9 ! col\r indu/ry1 ( giv+ col\rs a great v>iety ( names1 & suppress+ ! real names1 :i*1 s f> z ! artificially prep>$ col\rs are conc]n$1 %\ld be> "s ref]5ce to _! *emical composition1 num]\s :ite e>? col\rs be> fancy names1 ?\gh really consi/+ ( *alk1 lime 7g5]ally m>l71 or :ite clay4 ,9 ,france1 :]e bo? *alk & clay are ( frequ5t occurr5ce--! soil ( ,*ampagne1 = in/ance1 be+ all *alky--! manufacture ( ! :ite e>? col\rs is ext5sively practis$1 & a l>ge numb] are put on ! m>ket1 usually nam$ aft] ! place ( orig91 & consi/+ ( ei!r calcium c>bonate or m>l4 ,! trade names ( ! :ite e>? col\rs include ,cologne *alk1 ,bologna *alk1 ,brianon *alk1 ,*ampagne *alk1 ,blanc de ,b\gival1 ,blanc de ,meudon1 ,spani% :ite1 ,blanc d',orleans1 ,blanc de ,troyes1 etc4 ,all are ei!r m or less pure *alk1 m>l1 or a fairly :ite clay1 pipeclay--:i* is also us$ = mak+ clay pipes & = remov+ grease spots4 ,,gypsum ,! m9]al kn[n z gypsum1 or alaba/]1 consi/s ( calcium sulphate1 or sulphate ( lime1 its composition be+ express$ by ,ca,s,o#d #b;,h#b,o4 ,9 gypsum ! cry/all9e /ructure is j disc]nible1 :il/ o!r v>ieties1 su* z ! s-call$ 8m>9e glass10 occur 9 consid]able quantities z l>ge1 p]fectly transp>5t masses4 8,russian glass0 consi/s ( l>ge1 transp>5t lumps possess+ ! specific prop]ty ( gypsum1 viz4 t ( cleav+ 9 two directions1 9 a high degree4 ,alaba/] is compos$ ( f9ely granul> masses1 :i* are ei!r q :ite1 or else yell[i%1 or trav]s$ by grey ve9s4 ,?is v>iety ( gypsum is v abundant 9 c5tral ,italy1 & ! be/ blocks are employ$ = ! production ( works ( art4 ,ord9>y gypsum1 :i* frequ5tly occurs 9 ! vic9ity ( dolomitic lime/ones1 is f\nd 9 a great v>iety ( col\rs1 blui%-grey1 yell[i% or r$di% t9ts be+ ! mo/ common4 ,pure :ite lumps1 :i* are pl5tiful 9 "s deposits1 c be us$ z :ite pigm5t1 ! me?od ( prep>ation be+ simple1 viz4 m]ely r$uc+ ! mass to p[d]4 ,?is is easily effect$1 ! specific h>dness ( gypsum be+ only #b2 & 9 _m cases x is s(t en\gh to scrat* ) ! f+]-nail4 ,if ! orig9al gypsum is :ite1 ! p[d] =ms a dazzl+ :ite fl\r :i*1 not)/&+1 is ( comp>atively little value z a pigm5t1 on acc\nt ( its l[ cov]+ p[]4 ,= ?is reason1 p[d]$ gypsum is *iefly us$ = mak+ pla/] ( ,p>is 7calc9$ gypsum7 = pla/] ca/s & /ucco4 ,gypsum may also be employ$ to advantage = light5+ v>i\s col\rs1 s9ce x is in]t t[>ds ev5 ! mo/ delicate4 ,,kaol91 ,,pipeclay ,l>ge areas ( ! e>?'s surface are cov]$ ) clay1 :i* (t5 atta9s a consid]able ?ickness4 ,nev]!less1 ! k9d ( clay t is suitable = use z pigm5t is comp>atively sc>ce4 ,! pr9cipal requirem5t = ?is purpose is a pure :ite col\r1 b by f> ! great majority ( clays are ei!r yell[ or ( a %ade betwe5 blue & grey 7= example ! clay ( ! ,vi5na bas974 ,! "* ( clay is j z v>i$ z its col\r4 ,9 "s places1 l>ge deposits ( extremely f9e clay are f\nd1 ! mat]ial1 :5 mix$ ) wat]1 =m+ a highly pla/ic mass :i*1 :5 dri$ & subject$ to slight pressure1 furni%es a v s(t p[d]4 ,on ! o!r h&1 "s clays are s int]sp]s$ ) l>ge quantities ( s&1 l>ge /ones & ! debris ( mussels1 t !y _c be us$ until !y h be5 put ?r\gh v c>eful me*anical treatm5t4 ,?is great div]g5ce 9 ! physical "* ( clays is due to _! me?od ( =mation4 ,clay orig9at$ 9 ! wea!r+ ( felsp>1 :i* *iefly consi/s ( a d\ble salt1 a comp\nd ( ! silicates ( alum9a & pota%4 ,"u ! influ5ce ( air & wat]1 ?is comp\nd is decompos$1 ! potassium silicate pass+ into solution1 :il/ ! alum9ium silicate1 be+ insoluble 9 wat]1 is c>ri$ away by t m$ium4 ,:5 ! wat] c no long] c>ry ! p>ticles ( alum9ium silicate 9 susp5sion--= example :5 x rea*es a sea or lake--! silicate settles d[n to ! bottom1 & a deposit ( clay is =m$4 ,if ! orig9al felsp> 0 v pure1 & 9 p>ticul> v l[ 9 iron1 ! result+ clay w be ( a h&some :ite col\r4 ,an example ( ?is is af=d$ by kaol91 or porcela9 e>?1 :i* is pref]ably us$ = mak+ *9a4 ,if1 h[ev]1 ! felsp> conta9$ a consid]able proportion ( f]ric oxide1 ! result+ clay is yell[2 & if /ones or mussel %ells became incorporat$ ) ! clay prior to deposition1 ^! bodies w be f\nd z inclusions 9 ! deposit1 & su* clay w require mu* tr\blesome prep>ation--gr9d+ & levigation--be=e x is fit = use4 ,= ! purposes ( ! col\r-mak]1 ! mo/ suitable clay is "o t is pure :ite1 free f inclusions1 & does n *ange col\r :5 expos$1 9 a f9ely divid$ /ate1 to ! action ( ! air4 ,_m clays t 7 orig9ally :ite gradually assume a yell[ t+e on prolong$ exposure to air & moi/ure1 because ! clay conta9$ f]r\s oxide1 :i* *anges1 9 ! air1 to ! /rong] pigm5t1 f]ric oxide4 ,_m k9ds ( clay m]ely require a simple levigation to fit !m = use z pigm5t4 ,! lumps ( fre%ly dug clay are plac$ 9 l>ge tanks1 etc41 fill$ ) wat] & /irr$ up cont9u\sly 9 ord] t1 in/ead ( =m+ a pla/ic mass :i* is v difficult to di/ribute 9 wat]1 ! p>ticles deta*$ f ! lumps may pass at once into susp5sion4 ,?is turbid wat] is !n transf]r$ to ano!r tank1 etc41 :]e ! m9ute p>ticles ( clay are all[$ to settle d[n1 & ! wat] becomes q cle>4 ,:]e ?is "w is c>ri$ on on a l>ge scale1 x is advisable to put ! fre%ly won clay into l>ge pits close to ! clay deposit1 & to leave x !re1 cov]$ ) wat]1 dur+ ! w9t] season4 ,! freez+ ( ! wat] breaks d[n ! l>g] lumps ( clay1 by ! result+ expansion1 & ?is facilitates ! subsequ5t levigation1 ! cohesion betwe5 ! p>ticles be+ de/roy$4 ,if ! clay conta9s l>g] proportions ( lime or magnesia1 a little exp]i5ce w enable _! pres5ce to be detect$ at once by ! way ! clay behaves on be+ plac$ 9 contact ) wat]4 ,pure clay quickly =ms a fatty & extremely pla/ic pa/e1 & /icks closely to ! tongue :5 appli$ 9 ! dry /ate4 ,on ! o!r h&1 clay conta9+ mu* lime or magnesia is f> less pla/ic :5 mix$ ) wat]1 & ! dry clay h>dly adh]es to ! tongue at all4 ,^! latt] clays are class$ z poor or lean1 9 contra/ to ! fat1 pla/ic k9ds4 ,= c]ta9 purposes = :i* clay is us$ z pigm5t1 ^! admixtures are n h>mful2 :]eas o!rs1 especially qu>tz s& & mica1 n infrequ5tly pres5t 9 :ite clays1 con/itute a s]i\s drawback4 ,z already m5tion$1 clay is =m$ by ! wea!r+ ( felsp>1 :i* is a con/itu5t ( granite & gneiss1 bo? rocks compos$ ( qu>tz1 mica & felsp>4 ,:5 ! clay has be5 d]iv$ f ! wea!r+ ( su* rocks1 x is easy to und]/& t x may conta9 admixtures ( qu>tz & mica1 :i* are frequ5tly visible to ! nak$ eye1 or at any rate "u ! microscope4 ,:]eas clay =ms a :ite1 amorph\s mass1 ! gra9s ( qu>tz s& are decid$ly cry/all9e1 transp>5t & ( vitre\s lu/re2 ! scales ( mica1 on ! o!r h&1 appe>+ z ?9 tabul> cry/als1 mo/ly ( a gre5 or br[n col\r & exhibit+1 :5 view$ at c]ta9 angles1 a brilliant metallic %e54 ,qu>tz s& c be elim9at$ f clay )\t any special difficulty1 qu>tz be+ ( high] specific gravity & !re=e settl+ d[n quickly1 leav+ ! delicate p>ticles ( clay 9 susp5sion 9 ! liquid4 ,! scales ( mica are h>d] to get rid (1 _! tabul> =m ret>d+ deposition f ! susp5d+ liquid2 & on ?is acc\nt1 sev]al wa%+s are (t5 requir$ to sep>ate !m completely4 ,9 all cases :]e clay is to be us$ z a :ite di/emp]1 ! pres5ce or abs5ce ( lime is immat]ial2 b :]e x is to be employ$ = remov+ grease1 lime is a drawback4 ,?is is also sometimes ! case :5 ! clay is want$ = ! purposes ( ! col\r manufactur]4 ,! au?or has f\nd1 by exp]i5ce1 t p]fectly pure1 :ite clay =ms a good pa9t1 9 a vehicle ( oil or v>ni%--a purpose to :i* x has1 s f>1 be5 seldom appli$1 if at all4 ,su* pa9t is ( good cov]+ p[]1 & possesses ! valuable prop]ty ( rema9+ q unaffect$ by atmosph]ic influ5ces4 ,if1 h[ev]1 ! clay conta9s ev5 b a small quantity ( lime1 x _c possibly be us$ z an oil or v>ni% pa9t1 = ?\gh ! fre%ly made pa9t has a v good appe>ance1 its "* soon *anges1 turn+ visc\s & suff]+ a consid]able dim9ution ( cov]+ p[]4 ,?9n+ ) turps or boil$ oil results 9 ! =mation ( small lumps1 s t x is q impossible to obta9 a uni=m coat+ on ev5 a small surface4 ,?is behavi\r is app>5tly due to ! pres5ce ( ! lime1 ! explanation be+ t ! fatty acids always pres5t 9 ! oils & v>ni%es us$ = ! pa9t comb9e ) ! lime to =m comp\nds :i*1 f ! /&po9t ( ! *emi/1 mu/ be reg>d$ z soaps4 ,! small lumps already m5tion$ really consi/ ( lime soap1 & ! =mation ( ^! col\rless comp\nds acc\nts = ! less5$ cov]+ p[]4 ,giv5 a f9e :ite clay1 o!rwise capable ( =m+ a valuable pigm5t1 x is sometimes possible1 by simple means1 to elim9ate accompany+ lime1 provid$ ! am\nt ( ! latt] is n too great1 & also provid$ t v *eap hydro*loric or acetic acid is available4 ,! acid ne$ n be pure1 & ! impure b v /rong pyroligne\s acid1 :i* is v *eap on acc\nt ( its empyreumatic smell1 may be us$4 ,to elim9ate lime f ! clay1 ! /ill moi/ levigat$ mass is introduc$1 9 small quantities1 into a vat conta9+ ! requisite quantity 7see lat]7 ( hydro*loric or acetic acid1 ! addition be+ cont9u$ until ! liquid gives only a fa9tly acid reaction ) blue litmus pap]4 ,:5 ! clay is run 91 eff]vesc5ce is produc$ by ! lib]ation ( ! c>bon dioxide displac$ by ! /rong] acid employ$4 ,! am\nt ( lime pres5t 9 a clay may be det]m9$ by v simple means4 ,a small sample ( ! clay is dri$ by artificial heat1 until ( con/ant weight1 & exactly #ajj p>ts by weight ( ! dry mass are plac$ 9 a glass & suffus$ ) hydro*loric acid1 suffici5t ( ! latt] be+ us$ to make ! liquid /ill /rongly acid aft] eff]vesc5ce has ceas$4 ,! cont5ts ( ! glass are transf]r$ to a filt]1 & wa%$ ) pure wat] s long z ! wa%+s cont9ue to r$d5 blue litmus pap]4 ,! residue is !n dri$ until ( con/ant weight1 & ! diff]5ce betwe5 ! initial & f9al weights w give ! p]c5tage ( sub/ances soluble 9 hydro*loric acid4 ,aft] p]=m+ ?is simple te/ on a clay1 x is easy to calculate ! quantity ( acid ne$$ to extract all ! soluble con/itu5ts f a giv5 weight ( ! mat]ial4 ,all t is necess>y is to measure ! volume ( acid requir$ to extract a small quantity ( ! clay completely4 ,?us1 if "o p9t ( ! acid at disposal is suffici5t to treat "o p\nd ( ! clay1 ! am\nt ne$$ = a giv5 quantity ( clay is a simple matt] ( calculation4 ,s9ce1 on acc\nt ( ! co/ ( pure hydro*loric acid1 crude acid w always be us$1 x w be necess>y to rememb] t ?is crude acid always conta9s f]ric oxide 9 solution--?is be+ ! cause ( its yell[ col\r4 ,if ! am\nt ( acid tak5 is b>ely suffici5t to comb9e ! :ole ( ! lime1 leav+ ! latt] slightly 9 excess1 ! f]ric oxide--:i* w\ld o!rwise t+e ! clay yell[--w be precipitat$4 ,if1 on ! o!r h&1 ! acid is 9 excess1 ! clay is obta9$ free f all con/itu5ts soluble 9 ! acid4 ,! purifi$ clay mu/ !n be fre$ f ! calcium *loride1 =m$ by dissolv+ ! lime1 by a ?or\gh wa%+1 s9ce ! clay w\ld o!rwise always rema9 moi/ on acc\nt ( ! hygroscopic prop]ties ( ! *loride 9 "q4 ,moreov]1 any small residuum ( free acid w\ld con/itute a drawback on ! clay be+ mix$ ) o!r col\rs4 ,calcium *loride is v soluble 9 wat]1 & !re=e c be completely remov$ f ! clay by wa%+4 ,! purifi$ clay is left to settle d[n z completely z possible1 & aft] draw+ ! liquid (f f ! s$im5t1 ! latt] is suffus$ ) pure wat] & left to settle once m4 ,z a rule1 two su* wa%+s w cleanse ! clay ( calcium *loride & free acid suffici5tly to r5d] ! product suitable = any purpose4 ,:5 l>ge quantities ( clay h to be treat$ 9 ?is mann]1 consid]able am\nts ( calcium *loride solution w be obta9$1 :i* c be advantage\sly utilis$ = ! production ( precipitat$ *alk1 all t is necess>y be+ to collect ! liquor 9 a l>ge tank & treat x ) a small quantity ( slak$ lime1 to trans=m ! surplus free acid into calcium *loride & precipitate ! f]ric oxide pres5t 9 solution4 ,at ! end ( a few days ! liquor 9 ! tank w consi/ ( a v pure solution ( calcium *loride :i* w furni% an excell5t precipitat$ *alk :5 treat$ 9 ! mann] already describ$ "u t head+4 ,,b>ytes1 ,,or ,,heavy ,,sp> ,?is m9]al--*emically1 b>ium sulphate1 ,ba,s,o#d--occurs native1 z ext5sive deposits1 9 _m places--,engl&1 ,bohemia1 ,saxony1 ,/yria1 etc4 ,x sometimes =ms h&some tabul> cry/als1 b m frequ5tly compact masses1 :i* may be pure :ite1 grey yell[1 etc41 9 col\r1 & are di/+ui%$ by high specific gravity 7usually #dc-dg71 to :i* ! m9]al owes its "n4 ,?is high d5sity also limits ! application ( ! m9]al1 & x _c be us$ z a pigm5t1 9 ! true s5se ( ! t]m1 be+ only suitable z an adjunct to artificially prep>$ col\rs4 ,! employm5t ( b>ytes 9 ! col\r indu/ry is (t5 reg>d$ z adult]ation1 :i*1 h[ev]1 x is n :5 ! case is consid]$ f ! "r po9t ( view4 ,= in/ance1 ! only prep>ation :i* c prop]ly be t]m$ :ite lead consi/s ( basic lead c>bonate4 ,?is1 :5 pure1 is a r exp5sive pigm5t1 :]eas1 = c]ta9 purposes1 ! consum] requires a product t c be obta9$ at a l[ price4 ,9 ord] to satisfy ?is dem&1 ! only c\rse op5 to ! col\r-mak] is to mix ! :ite lead ) a *eap :ite sub/ance1 :i* enables him to turn out diff]5t grades ( :ite lead1 :i*1 al?\gh l[ 9 price1 are f> inf]ior to ! pure article 9 cov]+ p[]4 ,pure :ite lead be+ itself a v heavy sub/ance1 ! only bodies suitable z adjuncts are su* z are also ( high specific gravity2 & ( all ! *eap pigm5ts kn[n1 heavy sp> is ! only "o end[$ ) ?is prop]ty4 ,consequ5tly1 ?is sub/ance is ext5sively us$ 9 mak+ ! *eap] grades ( :ite lead & ! pale k9ds ( *rome yell[4 ,! only cases 9 :i* ! addition ( heavy sp> to a col\r c be reg>d$ z an int5tional fraud on ! consum] is :5 he is sold1 z pure :ite lead1 *rome yell[1 etc41 a product really compos$ ( a mixture ( su* col\r & b>ytes4 ,moreov]1 ! pres5ce ( b>ytes 9 :ite lead c be easily detect$ by a simple exam9ation1 pure :ite lead readily dissolv+1 ) consid]able eff]vesc5ce1 9 /rong nitric or acetic acid1 :]eas b>ytes is insoluble 9 all acids1 & !re=e rema9s1 z a heavy :ite p[d]1 at ! bottom ( ! vessel4 ,9 ?is way bo? ! pres5ce & am\nt ( b>ytes conta9$ 9 a sample ( :ite lead or *rome yell[ c easily be asc]ta9$4 ,! prep>ation ( b>ytes = ! purposes ( ! col\r-mak] is entirely a me*anical op]ation4 ,! b>ytes1 :i* ?\gh fairly h>d is easily r$uc$1 is cru%$ ) /amps1 gr\nd 9 a mill & f9ally levigat$1 x be+ impossible to obta9 a suffici5tly f9e p[d] ev5 by repeat$ gr9d+4 ,native b>ytes mu/ n be conf\nd$ ) ! artificial b>ium sulphate sold z p]man5t :ite or blanc fixe1 :i* is an extremely f9ely divid$ b>ium sulphate obta9$ by precipitat+ a solution ( a b>ium salt ) sulphuric acid or a soluble sulphate1 & is a pa9t]s' col\r t is highly priz$ = c]ta9 purposes4 ,bo? ! native sulphate & ! artificial v>iety h ! prop]ty ( rema9+ completely unalt]$ by exposure to air1 & !y c !re=e be mix$ ) any k9d ( pigm5t )\t fe> ( ! col\r det]iorat+4 ,z a rule1 b>ytes is fir/ r\ghly cru%$ 9 edge-runn] mills or /amps1 & !n gr\nd to ! extreme degree ( f95ess obta9able 9 ord9>y mills4 ,ev5 ) ! greate/ c>e1 h[ev]1 x is impossible by ?is means to obta9 suffici5t f95ess ( division = mix+ ) f9e col\rs1 ! only way 9 :i* ?is c be accompli%$ be+ by levigation4 ,giv5 a fairly pure :ite b>ytes to beg9 )1 levigation furni%es a h&some :ite pigm5t t c be mix$ ) col\rs ( any k9d2 b :5 us$ by itself 9 association ) oil or v>ni%1 its cov]+ p[] is v l[ & ! col\r nev] p]fectly :ite4 ,native b>ytes is !re=e unsuitable1 z su*1 = pa9t4 ,v>ieties t are n pure :ite are sometimes correct$ ) ultram>9e1 add$ 9 ! gr9d+-mill4 ,if ! yell[ t+e is due to iron comp\nds1 ?is c (t5 be rem$i$ by treat+ ! f9ely gr\nd mat]ial ) hydro*loric acid1 :i* dissolves !m out1 ?is treatm5t be+ foll[$ by a ?or\gh wa%+ ) pure wat]4 ,z already m5tion$1 :ite lead is mo/ frequ5tly mix$ ) b>ytes1 ?is be+ usually add$ :5 ! :ite lead is be+ gr\nd1 by fe$+ ! two mat]ials to ! mill & gr9d+ !m toge!r4 ,! crud5ess ( me*anical me?ods ( r$uction is cle>ly exemplifi$ by comp>+ ! mo/ c>efully gr\nd & levigat$ b>ytes ) t obta9$ by artificial means4 ,! p]man5t :ite l>gely us$ 9 ! production ( wall-pap]1 & q unalt]able 9 air1 is1 *emically speak+1 id5tical ) native b>ytes1 viz4 b>ium sulphate4 ,! two also seem to be id5tical 9 cry/all9e habit1 z is usual 9 ! case ( "o & ! same m9]al1 :e!r native or prep>$ by artificial means4 ,artificial b>ytes is obta9$ by treat+ a soluble salt ( b>ium ) sulphuric acid1 or a solution ( sodium sulphate 7,glaub] salt71 s long z a precipitate cont9ues to =m4 ,?is precipitate is b>ium sulphate1 :i* subsides completely on acc\nt ( its extreme insolubility1 ?is be+ great] ?an t ( any o!r salt kn[n4 ,! rapid rate ( deposition results 9 ! =mation ( extremely small cry/als1 :i*1 be+ col\rless & reflect+ ! light completely1 appe> to be p]fectly :ite4 ,ev5 :5 p]man5t :ite is appli$ 9 v ?9 lay]s to any surface1 its cov]+ p[] is v consid]able1 by reason ( ! extremely f9e subdivision ( ! mat]ial4 ,?is behavi\r ( artificial b>ytes 9 comp>ison ) t ( ! natural product1 af=ds an important h9t 9 connection ) ! prep>ation ( e>? col\rs1 namely1 t 9 ord] to obta9 products ( specially good quality1 ! endeav\r %\ld be to r$uce ! raw mat]ials to ! f9e/ condition possible4 ,?is result is accompli%$ mo/ securely by be/[+ ! greate/ c>e on gr9d+ & levigation2 & x is !re=e highly important t ! manufactur] %\ld select1 f ! v>i\s app>atus us$ 9 r$uc+ ! mat]ials1 ^? t are be/ adapt$ = ! purpose4 ,,c>bonate ,,( ,,magnesia ,al?\gh c>bonate ( magnesia is seldom us$ alone z a pigm5t1 x c be advantage\sly employ$ z su* :5 circum/ances p]mit4 ,x is met ) n infrequ5tly1 9 ,nature1 9 a cry/all9e =m1 z magnesite or bitt] sp>1 ! latt] "n aris+ f ! fact t ! soluble salts ( magnesia h a bitt] ta/e4 ,/ill m frequ5tly1 magnesia occurs 9 association ) calcium c>bonate1 9 ! m9]al dolomite1 :i* conta9s up to #bj ( magnesia4 ,a less abundant native m9]al is hydromagnesite1 :i* consi/s ( basic magnesium hydroc>bonate4 ,hydromagnesite is a v light1 *alk-:ite mass1 ) a non-greasy feel1 :i*1 :5 r$uc$ to a s(t p[d]1 =ms an excell5t mat]ial = pa9t4 ,x is highly in]t1 9 a *emical s5se1 & c !re=e be mix$ ) ! mo/ delicate col\rs1 hav+ no o!r effect !reon ?an to r5d] !m light] 9 %ade4 ,?is product c also be prep>$ artificially1 by treat+ a dissolv$ magnesium salt ) a solution ( c>bonate ( soda1 ! result be+ ! =mation ( a pure :ite precipitate1 :i* is v brilliant :5 dry1 & is *>act]is$ by unusually l[ specific gravity4 ,9 "s places1 conditions are su* t ?is prep>ation c be made on a l>ge scale at v l[ co/4 ,= in/ance1 !re is a spr+ at ,bil91 9 ,bohemia1 ! wat] ( :i* conta9s l>ge quantities ( alkali c>bonates 9 solution2 :il/ 9 ! vic9ity ( ,saids*tz is a spr+ fairly ri* 9 magnesia salts4 ,! wat]s f ^! two spr+s are conc5trat$ by evaporation1 & mix$ 9 l>ge tanks2 & :5 a suffici5t deposit ( ! result+ basic c>bonate ( magnesia has accumulat$1 x is tak5 out ( ! tanks1 plac$ on l95 filt]s & wa%$ ) wat]4 ,! residue is dri$ sl[ly1 )\t ! employm5t ( a high temp]ature1 & !n =ms a :ite p[d]1 :i* is v light & c be us$ = a numb] ( purposes1 *iefly m$ic9al1 ?\gh x is also well adapt$ z a mat]ial = pa9t4 ,= ?is latt] purpose x is1 h[ev]1 f> too exp5sive2 b s9ce ! conditions obta9+ at ,bil9 are c]ta9 to occur else:]e1 we h includ$ c>bonate ( magnesia among ! e>? col\rs4 ,on acc\nt ( its specific lightness1 c>bonate ( magnesia is specially adapt$ = mak+ pale %ades ( c]ta9 delicate lake col\rs1 :i*1 if ton$ ) ev5 p]fectly pure *alk1 w\ld und]go alt]ation 9 c\rse ( "t4 ,c>m9e1 = in/ance1 c be grad$1 by ! addition ( c>bonate ( magnesia1 into e possible v>iety ( %ades betwe5 ! pure r$ ( c>m9e itself & ! pale/ p9k2 & ! result+ col\rs are q p]man5t :e!r mix$ ) gum solution or any o!r vehicle4 ,,talc ,al?\gh ?is m9]al is n us$ z a pigm5t by itself1 x mu/ be m5tion$ "h because x is n infrequ5tly employ$ = mix+ ) o!r col\rs1 & is also us$ 9 ! wall-pap] indu/ry4 ,x also s]ves to di/ribute c]ta9 pigm5ts 9 a /ate ( f9e division1 ! 8r\ge vgtal0 ( ! p]fum]1 = example1 usually consi/+ ( talc & a small quantity ( v f9e c>m9e4 ,9 comm]ce ! "n talc is sometimes appli$ to two sep>ate m9]als1 true talc & /eatite or soap/one4 ,! =m] is r>ely met ) native z well-def9$ cry/als1 mo/ly occurr+ z scaly masses 9 primitive rocks4 ,?9 pieces exhibit a c]ta9 degree ( flexibility4 ,! h>dness ( ?is m9]al is s small t x c be scrat*$ ) ! f+]-nail2 & its sp4 gr4 is #bi-bh4 ,talc is easily scrap$1 & ! p[d] rema9s /ick+ to ! knife1 a prop]ty :i* r5d]s ! sub/ance difficult to r$uce to p[d]1 because x balls toge!r & takes a v long "t to conv]t into a f9e fl\r4 ,! process is facilitat$ by calc9+ ! talc & qu5*+ x 9 cold wat]1 ?is treatm5t increas+ ! h>dness & at ! same "t mak+ x m brittle1 & ?us m easy to pulv]ise4 ,a *>act]i/ic feature ( all ! talc m9]als is _! peculi> greasy appe>ance & feel4 ,! col\r v>ies1 :ite pieces alone be+ ( any use to ! col\r manufactur]4 ,! yell[- or gre5-t+$ v>ieties owe _! %ade to ! pres5ce ( f]ric & f]r\s oxides4 ,9 *emical composition1 talc consi/s ( a comb9ation ( magnesium silicate ) hydrat$ silica1 ! suppos$ =mula be+3 #d,mg,o 4 ,si,o#b ,h#b,o 4 ,si,o#b1 & ! p]c5tage composition3 silica1 #fbf2 magnesia1 #cbi2 wat]1 #di4 ,,/eatite ,,or ,,soap/one ,/eatite s closely resembles talc 9 mo/ ( its prop]ties1 t ! two m9]als 7 long reg>d$ z id5tical4 ,:]eas1 h[ev]1 talc is sc>cely act$ ^u at all by ! /ronge/ acids1 /eatite is completely decompos$ by prolong$ boil+ !re)1 al?\gh bo? m9]als h exactly ! same composition4 ,z a pigm5t1 /eatite is f> m important ?an talc1 &1 z ,fr5* *alk1 is l>gely us$ = draw+ or writ+4 ,to prep>e x = ?is purpose pure :ite /eatite requires no prelim9>y treatm5t1 beyond cutt+ ! l>ge lumps up into quadrangul> prisms1 :i* are m\nt$ 9 wood1 l lead p5cil1 & us$ = writ+ on ! blackbo>d4 ,! p[d] produc$ 9 ! cutt+ process is made up into pa/el crayons4 ,) ?is object1 ! p[d] is mix$ ) a suffici5t quantity ( "s m9]al pigm5t to produce a mass ( ! desir$ %ade1 & is knead$ to a /iff pa/e ) wat] conta9+ an adhesive su* z gum1 glue or tragacan? mucilage4 ,! mass is %ap$ into prisms1 :i*1 :5 dry1 are cut into p5cils & m\nt$ 9 wood4 ,/eatite be+ l talc1 )\t action on ev5 ! mo/ delicate col\rs1 c be us$ z a dilu5t 9 ! prep>ation ( light %ades4 ,,*apt] ,v ,,yell[ ,,e>? ,,col\rs ,all ! yell[ e>? col\rs1 )\t exception1 h f]ric oxide z _! col\r+ pr9ciple1 ! diff]5ces 9 %ade be+ entirely due to ! v>y+ proportion 9 :i* t oxide is pres5t4 ,! v>i\s names "u :i* !y are kn[n date back to a p]iod :5 ! *emical nature ( ^! col\rs 0 /ill unkn[n1 & h be5 mo/ly d]iv$ f ! locality ( orig94 ,! yell[ e>?s c !re=e be divid$ into two gr\ps1 accord+ to _! *emical "*4 ,! fir/ gr\p1 9 :i* ! f]ric oxide is pres5t z hydroxide1 comprises all ! o*res1 ,si5a e>?1 & a numb] ( o!rs :i* are obta9$ f native o*re by special treatm5t4 ,9 ! col\rs ( ! second gr\p1 f]ric oxide is /ill ! col\r+ pr9ciple1 b is comb9$ ) o!r sub/ances 9 place ( wat]4 ,x is1 z a matt] ( fact1 incorrect to rank ! o*res 9 g5]al z yell[ e>?s1 because !y c be made to yield ne>ly e v>iety ( col\r f ! pale/ yell[ to ! deepe/ r$1 br[n & violet4 ,^! col\rs m]it ! p>ticul> att5tion ( ! col\r-mak] & ! pa9t]1 be+ di/+ui%$ by v l[ co/ ( production1 unusual p]man5ce & beauty ( tone4 ,9 ! int]e/s ( t highly important matt] to ! arti/1 namely ! production ( col\rs ( unlimit$ p]man5ce1 x is desirable t col\r manufactur]s %\ld be/[ great] c>e on ! manufacture ( ^! col\rs ?an has hi!rto be5 ! case4 ,an extremely fav\rable po9t ab\t ne>ly all ^! pigm5ts is t !y c be v *eaply prep>$ by artificial means1 s t ! manufactur] is 9 a position to turn out a l>ge numb] ( ! h&some/ & mo/ durable col\rs ) a small am\nt ( exp5se & lab\r4 ,,! ,,o*res ,o*res are f\nd 9 _m localities1 mo/ frequ5tly 9 /ratifi$ rock & rubble4 ,! deposits are r>ely ext5sive1 mo/ly occurr+ 9 pockets or b$s4 ,:]ev] f\nd1 o*re may be t]m$ a second>y product1 t is to say1 "o t has be5 =m$ ?r\gh ! de/ruction ( o!r m9]als4 ,! analysis ( o*res f diff]5t deposits %[s great div]g5ce 9 composition2 & "s consi/ almo/ entirely ( pure f]ric hydroxide1 t has already und]gone natural levigation & c be us$ z a pigm5t z soon z dug4 ,su* a =m is1 h[ev]1 r>e1 & mo/ o*res are int]mix$ ) small] or l>g] am\nts ( extrane\s m9]als1 ! contam9ation be+ sometimes s great z to preclude ! use ( ! o*re z pigm5t by reason ( ! high outlay requir$ = extract+ ! col\r+ con/itu5ts4 ,occasionally1 ! f]ric hydroxide is associat$ ) a c]ta9 proportion ( clay1 & z ?is increases1 ! o*re passes ov] into f]rug9\s clay4 ,?is class c also be us$ z pigm5t1 9 c]ta9 circum/ances1 t is to say :5 x is suffici5tly ri* 9 f]ric oxide to furni% a deep r$ mass on calc9ation4 ,:51 h[ev]1 ! proportion ( f]ric oxide is l[1 its pigm5t>y p[] is no long] suffici5t1 & ! clay has n ! requisite beauty ( col\r4 ,! ord9>y e>? us$ = mak+ tiles is an example ( ?is class1 its col\r 9 ! raw /ate be+ an ugly br[ni%-yell[1 b turn+ a dull 8brick0 r$ :5 fir$4 ,9 "s deposits ! f]ric oxide is accompani$ by lime4 ,unless ! latt] exce$s a c]ta9 proportion1 su* o*res1 too1 are suitable z pigm5ts1 ! lime be+ easily remov$ by simple levigation2 b :5 ! am\nt ( lime is high1 x is difficult to obta9 c]ta9 highly col\r$ %ades ( o*re f su* mat]ial4 ,^! %ades entail ! calc9ation ( ! o*re1 & ! temp]ature requir$ is (t5times insuffici5t to trans=m ! lime into ! cau/ic /ate4 ,moreov]1 ! pres5ce ( cau/ic lime w\ld be a drawback 9 "s cases1 x be+ !n impossible to mix ! o*re ) o!r col\rs )\t endang]+ ! %ade ?r\gh ! action ( ! lime on ^! latt]4 ,! foll[+ analyses w %[ ! p]c5tage composition ( o*res f v>i\s deposits3 ,o*re f-- ---------------------------------------- ------ ,comoal ,vi]z54 ,/4 ,georges4 7,savoy74 ---------------------------------------- ------ ,f]ric oxide #ai #bce #be ,lime #b -- -- ,alum9a #bj #fie #gj ,magnesia #a #fie #gj ,silica #dd #fie #gj ,wat] #g #g #e ---------------------------------------- ------ ,9 ! majority ( cases ! m9]alogical *>act]i/ics ( an o*re enable conclusions to be =m$ z to its suitability z pigm5t4 ,good o*re is m or less yell[ to d>k br[n 9 col\r1 & c easily be cru%$ betwe5 ! f+]s to a s(t1 f9e p[d] :i* feels l p[d]$ /eatite & does n produce a s5sation ( gritt9ess1 ?is latt] indicat+ ! pres5ce ( f9e gra9s ( s& 9 ! f]ric oxide4 ,! behavi\r ( ! o*re 9 pres5ce ( wat] is specially important4 ,if x adh]es firmly to ! tongue1 & =ms a fairly pla/ic pa/e :5 mix$ ) a little wat]1 ! m9]al conta9s a l>ge p]c5tage ( f]ric oxide1 & z a rule w yield o*re ( good col\r4 ,9 g5]al x may be said t ! value ( an o*re v>ies directly ) its cont5t ( f]ric hydroxide or oxide1 because :5 ?is is l>ge ! o*re w furni% a wide range ( col\rs "u suitable treatm5t4 ,a simple te/ = quality consi/s 9 weigh+ out an exact small quantity 7#aj grms471 & heat+ x to a temp]ature n exce$+ #aaj ,c41 until ! weight rema9s con/ant4 ,a simple calculation !n gives ! am\nt ( uncomb9$ wat] 9 ! sample4 ,s9ce ! proportion ( su* wat] v>ies 9 diff]5t p>ts ( "o & ! same deposit1 ! te/ mu/ be repeat$1 9 ord] to obta9 accurate results1 on samples tak5 f diff]5t po9ts1 or1 pref]ably1 on a prop]ly prep>$ av]age sample4 ,ev5 dry+ *anges ! col\r ( o*re consid]ably4 ,to asc]ta9 ! behavi\r ( an o*re on calc9ation1 a l>ge sample is dri$ at #aaj ,c4 until ! weight is con/ant1 & divid$ up into a numb] ( small samples weigh+1 say1 #aj grms4 ea*4 ,! samples are !n heat$ to diff]5t temp]atures1 "o to ! melt+-po9t ( lead1 ano!r to t ( z9c1 & s on4 ,! high] ! temp]ature employ$1 ! m w ! col\r ( ! o*re approximate to r$2 & specim5s v ri* 9 f]ric oxide w give bright r$ col\rs4 ,beyond ?is range1 a fur!r increase 9 temp]ature w give violet %ades1 v>y+ ) ! temp]ature & ! duration ( heat+4 ,aft] ?is prelim9>y te/1 x is desirable to make ano!r on a l>g] scale1 ) quantities up to ab\t #a lb4 ,= ?is te/1 ! diff]5t k9ds ( o*re frequ5tly f\nd 9 ! same deposit %\ld be mix$ toge!r1 9 ord] to obta9 an idea ( :at ! mean product1 obta9$ 9 work+ on ! l>ge scale1 w be l4 ,on ! :ole1 ! results ( ?is second te/ w be ! same z 9 ! fir/ s]ies1 ! only object ( ! second te/ be+ to ga9 in=mation :i* may be p>ticul>ly valuable 9 practical "w4 ,! bottles 9 :i* ! calc9$ samples are /or$ %\ld be m>k$ ) ! temp]ature & l5g? ( heat+1 s t1 :5 x is subsequ5tly desir$ to obta9 an o*re correspond+ to a p>ticul> sample1 all t is necess>y w be to heat x to ! same degree f ! same l5g? ( "t4 ,! p]=mance ( ?is simple te/ w be ( great assi/ance 9 /&>dis+ ! "w ) a m9imum loss ( "t4 ,:5 x is desir$ to asc]ta9 ! composition ( an o*re sup]ficially its behavi\r t[>ds hydro*loric acid may be not$4 ,a weigh$ quantity ( ! fre%ly dug 7undri$7 o*re is treat$ ) pure acid1 free f iron1 :i* w dissolve out ! f]ric oxide & lime1 leav+ clay & qu>tz s& beh9d4 ,! pres5ce ( lime is indicat$ by eff]vesc5ce on contact ) ! acid2 & if !re is no eff]vesc5ce1 lime is abs5t4 ,at ! end ( sev]al h\rs ! acid is c>efully decant$ f ! undissolv$ residue :i* is !n /irr$ up ) wat]1 left to subside1 & weigh$ :5 dry4 ,?is me?od w give ! am\nt ( sub/ances1 o!r ?an f]ric oxide & lime1 9 ! sample4 ,^! sub/ances usually consi/ ( clay or s&4 ,= a quantitative det]m9ation1 a small quantity--usually #a grm4--is weigh$ out1 treat$ ) a correspond+ am\nt ( hydro*loric acid1 & ! solution filt]$ into a glass4 ,! residue on ! filt] is wa%$ ) di/ill$ wat]1 ! wa%+s be+ unit$ to ! acid solution4 ,?is solution is treat$ ) ammonia s long z a precipitate ( f]ric hydroxide cont9ues to =m1 ?is be+ collect$ on a t>$ filt] & dri$ at #aaj ,c4 ,! precipitate may be reg>d$ z pure f]ric hydroxide1 & its weight w indicate ! proportion ( hydroxide 9 ! o*re ) suffici5t accuracy = te*nical purposes4 ,9 reality1 h[ev]1 x is n pure f]ric hydroxide1 b conta9s 9 addition all ! oxides t are precipitable by ammonia1 lime be+ always c>ri$ d[n z well4 ,x is !re=e desirable to dissolve ! precipitate ) a little hydro*loric acid1 & reprecipitate ) ammonia4 ,,calc9+ 7,,burn+7 ,,o*re ,9 _m places o*re is only put ?r\gh a v simple me*anical prep>ation be=e be+ sold = pigm5t1 namely left to dry 9 ! air s t mo/ ( ! uncomb9$ wat] evaporates4 ,no matt] h[ ?is dry+ process is protract$1 h[ev]1 x is impossible to get rid ( all ! wat] 9 ?is way1 a c]ta9 proportion be+ reta9$ by ! hygroscopic action ( ! f]ric hydroxide1 & to expel ?is ! mass mu/ be heat$ to above #ajj ,c4 ,dry+ is usually succe$$ by pulv]is+ & sift+ ! loose e>?y mass1 :i* is !n ready = sale4 ,:5 ! o*re conta9s s& or /ones1 ?is treatm5t is n suffici5t1 & levigation is necess>y4 ,no p>ticul> tr\ble is involv$1 ! m9]al be+ fairly heavy z ! result ( its cont5t ( f]ric hydroxide4 ,a simple me?od ( treatm5t suffices to improve ! value ( ! o*re consid]ably1 & enables a grade t is n p>ticul>ly bright-col\r$ 9 its natural condition to be conv]t$ into products ( v h&some tone & v>i\s %ades4 ,?is treatm5t consi/s 9 heat+ ! raw o*re to a def9ite temp]ature1 dur+ :i* process ! col\r *anges progressively1 & any desir$ tone c be obta9$ by sudd5ly cool+ ! hot mass4 ,! reason = ?is ph5om5on is t ! high] ! temp]ature1 ! l>g] ! am\nt ( wat] driv5 (f f ! f]ric hydroxide1 until f9ally1 :5 a v high temp]ature has be5 rea*$1 ! :ole ( ! wat] is expell$1 & ! f]ric hydroxide is trans=m$ into f]ric oxide4 ,! hydroxide is br[n1 :]eas ! oxide1 provid$ ! temp]ature has n be5 rais$ too high1 exhibits ! *>act]i/ic col\r kn[n z 8iron r$40 ,consequ5tly1 ! col\r ( mod]ately calc9$ o*re ranges ?r\gh a :ole scale f br[n to r$2 & ! high] ! temp]ature employ$1 ! r$d] ! tone4 ,if ! heat+ be protract$ aft] all ! hydroxide has become oxide1 ! latt] und]goes molecul> *ange1 increas+ consid]ably 9 d5sity & alt]+ 9 col\r2 & aft] v prolong$ heat+1 ! col\r f9ally becomes violet4 ,! calc9ation1 or burn+1 ( o*re is ord9>ily p]=m$ 9 a v crude mann]4 ,! m9]al is cru%$ to ! size ( peas1 & spread out on an iron plate :i* is made r$-hot4 ,z soon z ! o*re has rea*$ ! desir$ %ade ( col\r1 x is dropp$ into a tub ( wat] & !n cru%$ to p[d]4 ,! calc9ation requires great exp]i5ce on ! "p ( ! op]ator1 because s long z ! product is hot1 x has q a diff]5t col\r f t assum$ on complete cool+4 ,s9ce only comp>atively small quantities ( o*re c be treat$ 9 ?is way1 & ! op]ation unnecess>ily increases ! co/ ( ! product1 ow+ to ! l>ge consumption ( fuel1 x is highly desirable to employ a simple calc9+ app>atus capable ( treat+ l>ge quantities4 ,su* an app>atus may consi/ ( an iron drum1 m\nt$ ) a g5tle slope inside a furnace1 f :i* x projects at bo? ends4 ,a %aft c>ry+ a %eet metal worm is rotat$ inside ! drum2 & ! :ole app>atus is v simil> to an ,ar*im$ean screw4 ,:5 ! iron drum is rais$ to a /rong r$ heat1 & small quantities ( o*re are f$ cont9u\sly into ! upp] end ( ! drum1 ! rotation ( ! worm w pu% ! mat]ial =w>d1 & contact ) ! gl[+ sides ( ! drum w produce ! necess>y calc9ation1 ! degree ( :i* c be modifi$ by alt]+ ! spe$ at :i* ! worm is turn$4 ,! calc9$ product is dis*>g$ at ! l[] end ( ! drum1 ei!r into a vessel ( wat]1 or1 if only mod]ate heat+ has be5 appli$1 direct into a collector4 ,illu/ration3 ,,fig4 #bh4 ,fig4 #bh repres5ts an app>atus design$ by ,halliday = ! dry di/illation ( wood wa/e2 b1 ) slight /ructural modifications1 x c also be us$ = calc9+ o*re4 ,! mat]ial to be heat$ is introduc$1 9 small pieces1 into ! fe$ hopp] ,b1 & is c>ri$ d[nw>d1 by ! worm ,c1 into ! r$-hot drum ,a1 ?r\gh :i* x is propell$ by ! worm ,d until x drops out1 at ,f1 into ! tank ,g4 ,! l5g? ( "t ! mat]ial is subject$ to calc9ation dep5ds on ! spe$ at :i* ! worm ,d is run4 ,! pipe ,e c>ries (f ! wat] vap\r expell$ f ! *>ge4 ,9 ord] to obta9 a uni=m product :5 o*re is calc9$ 9 an app>atus con/ruct$ on ?is pr9ciple1 x is necess>y t ! mat]ial introduc$ %\ld be fairly regul> 9 size1 a condition :i* is easily fulfill$ by squeez+ ! fre%ly dug o*re betwe5 flut$ roll]s1 & !n pass+ x ov] a s]ies ( scre5s1 ea* grade be+ !n calc9$ sep>ately4 ,moreov]1 ! app>atus is only suitable = calc9+ at m$ium temp]atures2 & :5 highly calc9$ products are 9 "q1 ! op]ation is be/ p]=m$ 9 fire-clay cyl9d]s1 or 9 ?ick ca/-iron drums1 simil> to gas retorts1 built into a furnace4 ,o!r devices = calc9+ o*re w be describ$ lat]4 ,,o*res ,,f ,,v>i\s ,,deposits ,z previ\sly /at$1 o*res are frequ5tly met ) 9 ,nature1 bo? 9 ! imm$iate vic9ity ( iron ore1 & also at consid]able di/ances f su* deposits4 ,9 ! latt] case1 ! o*re mu/ be assum$ to be ! decomposition products ( f]rug9\s m9]als & to h be5 c>ri$ (f by wat] until ! latt] became /agnant & all[$ ! o*re to settle d[n4 ,9 _! me?od ( deposition ^! o*res are !re=e analog\s to clay1 & !y1 too1 (t5 conta9 l>ge quantities ( extrane\s m9]als1 :i* h giv5 rise to ! div]sifi$ sub/ances gr\p$ "u ! "n ( o*re4 ,al?\gh o*res are s widespread 9 ,nature1 only c]ta9 k9ds1 f\nd 9 c]ta9 localities1 h acquir$ a high reputation4 ,= ! mo/ "p1 ^! o*res are su* z h already be5 prep>$ 9 a high degree1 by ,nature1 = ! purpose = :i* !y are employ$4 ,?us1 we f9d t all ! o*res :i* h acquir$ a high repute among pa9t]s = p>ticul> beauty ( tone & p]man5ce1 are di/+ui%$ by two prop]ties3 a high cont5t ( f]ric hydroxide & great purity4 ,! =m] ( ^! prop]ties imp>ts brightness ( col\r2 & su* products w furni%1 on calc9ation1 a wide range ( col\r %ades4 ,:51 z is ! case ) ! f9] qualities ( o*re1 ! m9]al conta9s only a v small proportion ( impurities1 !re is no difficulty 9 br++ x1 by simple gr9d+ or levigation1 into a condition 9 :i* x is at once fit = use z a pigm5t4 ,! ,italian o*res h1 = long ages1 enjoy$ a high reputation = _! beauty ( col\r & p]man5ce4 ,?is category includes1 = example1 ! r5[n$ ,si5a e>?1 ,roman e>?1 ,italian umb]1 & o!r o*re col\rs4 ,?is high r5[n is probably due less to ! inh]5t prop]ties ( ! m9]al ?an to ! circum/ance t ! art ( pa9t+ atta9$ a high /ate ( developm5t at an e>ly p]iod1 & t ! arti/s paid special att5tion to ! use ( bright & p]man5t col\rs = _! "w4 ,al?\gh1 at pres5t1 _m deposits ( o*re are kn[n t are q able to compete1 on ! score ( beauty1 ) ! be/ ,italian products1 ! good "n ( ^! latt] has nev]!less be5 ma9ta9$4 ,x is true t ! "n ( ,italian o*re is (t5 m]ely borr[$1 = application to a product orig9at+ 9 "s o!r c\ntry1 v>ieties ( t]ra di ,si5a1 = in/ance1 be+ put on ! m>ket t h actually be5 d]iv$ f deposits 9 ,g]many4 ,z a result ( ?is cu/om1 c]ta9 names1 su* z t]ra di ,si5a1 umbra di ,roma1 h become g5]ic t]ms1 & _! use d5otes1 n an int5tion to sugge/ t ! e>? col\rs 9 "q really come f ,si5a or ! vic9ity ( ,rome1 b t ! prop]ties ( ! article are equal to ^? ( ! old-e/abli%$ col\rs ( ,si5a or ,rome4 ,x w\ld occupy too mu* space to g into an exhau/ive description ( all ! native v>ieties ( o*re1 & w\ld inevitably lead to a good deal ( repetition4 ,x w !re=e be suffici5t1 = our purpose1 to deal ) only a few ( !m4 ,! be/-kn[n o*res are ^? ( ,rome & ,si5a1 ! latt] be+ frequ5tly call$1 9 comm]ce1 by its ,italian "n1 t]ra di ,si5a4 ,roman o*re =ms yell[i%-br[n masses1 ( fairly f9e texture & compos$ ( f]ric hydroxide & clay4 ,!y are put on ! m>ket bo? 9 ! raw & calc9$ /ate4 ,on calc9ation1 ! col\r soon *anges to r$1 & if c>efully p]=m$1 ! result+ col\rs h a v w>m1 fi]y tone4 ,closely approa*+ ,roman e>? is ! ,engli% o*re1 :i* is work$ m p>ticul>ly 9 ,surrey1 & is n infrequ5tly sold z ,roman4 ,9 _m deposits ?is ,engli% o*re occurs 9 su* a high /ate ( purity t ! be/ pieces are pick$ out & sold )\t be+ ev5 cru%$ or gr\nd4 ,! pieces ( l[] quality are v c>efully gr\nd & levigat$1 = ! purpose ( be+ calc9$ = ! production ( diff]5t %ades1 & !n furni% highly priz$ col\rs4 ,9 po9t ( *emical composition1 ! o*re family also includes t]ra di ,si5a1 bole1 umb] & ,cassel br[n4 ,^! m9]als1 h[ev]1 are n yell[ l o*re1 b br[n1 & w !re=e be dealt ) along ) ! br[n e>? col\rs4 ,,artificial ,,o*res ,products v simil>1 bo? 9 *emical composition & col\r1 to ! native o*res c also be v simply & *eaply made by artificial means4 ,_! prep>ation may be p>ticul>ly recomm5d$ to col\r-mak]s :o desire to turn out a wid] range ( iron pigm5ts1 b are n 9 a position to obta9 natural o*res at a l[ price4 ,9 ! manufacture ( artificial o*re1 an endeav\r is made to imitate ! natural processes :i* h l$ to ! =mation ( o*re1 &1 ( c\rse1 to avoid any?+ likely to h9d] ! production ( a suitable col\r e>?1 = example ! pres5ce ( s& or a consid]able admixture ( extrane\s m9]als4 ,z already m5tion$1 ! *ief impurities 9 natural o*res are clay & s&1 bo? ( :i* c be easily exclud$ dur+ ! manufacture ( artificial o*re1 or _! am\nt controll$ 9 su* a mann] t pal] or d>k] products c be obta9$ at w1 & ! tone v>i$1 9 any desir$ mann]1 by calc9ation1 z 9 ! case ( ! native article4 ,! raw mat]ial = artificial o*re is always a f]r\s salt1 :i* c be pur*as$ 9 l>ge quantities & at v l[ prices1 namely gre5 vitriol1 :i*1 9 ! pure /ate1 consi/s ( f]r\s sulphate1 ,fe,s,o#d #g;,h#b,o4 ,?is sub/ance =ms sea-gre5 cry/als1 :i* are readily soluble 9 wat] & imp>t an objectionable inky flav\r !reto4 ,on exposure to ! air1 gre5 vitriol turns an ugly br[n col\r1 & is no long] completely soluble 9 wat]1 pass+ gradually into ! condition ( basic f]r\s sulphate4 ,?is is because f]r\s oxide is a highly un/able sub/ance1 :i* attracts oxidation & *anges into f]ric oxide4 ,?is latt]1 h[ev]1 requires = ! production ( soluble salts a l>g] quantity ( acids ?an does f]r\s oxide1 & !re=e ! oxidation ( f]r\s sulphate 9 ! air leads only to ! =mation ( salts t are imp]fectly saturat$ ) acid1 namely basic salts4 ,:5 a solution ( gre5 vitriol is left expos$ to ! air1 basic f]ric sulphate is also =m$1 :i* settles d[n to ! bottom ( ! vessel z a ru/y p[d]4 ,if1 h[ev]1 a correspond+ quantity ( sulphuric acid be add$ to ! solution at ! outset1 ! result+ f]ric sulphate rema9s 9 solution4 ,on treat+ ! gre5 vitriol solution ) "o ( cau/ic pota%1 cau/ic soda or quick lime1 ! f]r\s oxide is ?r[n d[n z ! correspond+ hydroxide1 =m+ a volum9\s greyi%-gre5 precipitate4 ,?is hydroxide /ill possesses a great aff9ity = oxyg51 & :5 ! precipitate is br\ght into contact ) air1 its col\r rapidly *anges to a ru/y r$1 ?r\gh ! trans=mation ( ! f]r\s hydroxide into f]ric oxide4 ,! f]r\s hydroxide c also be precipitat$ by alkali c>bonates1 ! deposits behav+ 9 exactly ! same mann] z t ?r[n d[n by ! cau/ic alkalis4 ,v>i\s me?ods c be adopt$ 9 ! prep>ation ( artificial o*re1 ! selection dep5d+ on ! prop]ties desir$ 9 ! f9i%$ product4 ,to obta9 an o*re ) p>ticul>ly good cov]+ p[]1 ! me?od mu/ be diff]5t f t employ$ to furni% a *eap product1 9 :i* l[ price is m important ?an cov]+ p[]4 ,9 ! =m] case1 ! f]r\s hydroxide is mix$ ) sub/ances :i*1 9 !mselves1 possess fairly high cov]+ p[]1 su* z *alk or :ite clay2 9 ! second1 gypsum1 :i* is ( l[ cov]+ p[]1 is us$4 ,! prep>ation ( ! *eape/ k9ds ( artificial o*re w be describ$ fir/1 foll[$ by t ( ! high] grades :i* belong to ! mo/ valu$ arti/s' col\rs4 ,= *eap artificial o*res1 ! f]r\s hydroxide is ?r[n d[n by cau/ic lime f a solution ( gre5 vitriol4 ,accord+ z a light] or d>k] %ade is requir$1 two to ?ree p>ts ( f]r\s sulphate are dissolv$ 9 wat]1 c>e be+ tak5 to select cry/als ( a pure gre5 col\r1 s9ce ^? t h a ru/y look are only imp]fectly soluble1 because !y conta9 basic f]ric sulphate4 ,! solution w always be cl\dy1 ow+ to ! p>tial precipitation ( ! hydroxide by ! lime 9 ! wat]2 b ?is is immat]ial4 ,= ! precipitation1 a milk ( lime is prep>$ by slak+ "o to two p>ts ( quicklime 7accord+ to ! quantity ( f]r\s sulphate to be treat$7 9 wat]1 & /irr+ ?is up 9 en\gh wat] to make a ?9 milk4 ,c>e mu/ be tak5 to exclude any l>ge p>ticles ( lime1 s9ce ^! w\ld f9d _! way into ! f9i%$ product & make ! col\r unev54 ,on ?is acc\nt1 ! milk ( lime %\ld be c>efully /ra9$ ?r\gh a loosely wov5 clo? or f9e sieve1 into ! precipitation vessel4 ,! f]r\s sulphate solution is !n p\r$ 91 ! mixture be+ kept /irr$1 & an ugly1 grey-gre5 precipitate is produc$1 consi/+ ( a mixture ( f]r\s hydroxide & calcium sulphate1 ! reaction be+ expla9$ by ! equation3-- ,fe,s,o#d ,ca7,,oh7#b ,fe7,,oh7#b ,ca,s,o#d4 ,! l>g] ! am\nt ( f]r\s sulphate solution add$ to ! milk ( lime1 ! d>k] ! result+ o*re4 ,z soon z all ! f]r\s sulphate is 91 ! /irr+ is susp5d$1 & ! liquid is left until q cle>4 ,! wat] is drawn (f ?r\gh tapholes 9 ! side ( ! vessel1 c>e be+ tak5 n to di/urb ! f9e precipitate1 & fre% wat] is add$1 9 :i* ! deposit is /irr$ up & aga9 left to settle d[n4 ,?is op]ation1 :i* is once or twice repeat$1 is to wa% ! precipitate4 ,:5 ?is object has be5 suffici5tly accompli%$1 ! mass is %ovell$ out ( ! vessel & spread ?9ly on bo>ds1 :]e x is left until ! desir$ %ade ( col\r has be5 atta9$1 ! col\r *ang+ quickly on exposure to air1 ow+ to ! oxidation ( ! f]r\s hydroxide into f]ric hydroxide4 ,to asc]ta9 :e!r oxidation is complete1 a l>ge lump ( ! mass is brok5 across2 & if x is ( a uni=m yell[-br[n col\r ?r\gh\t1 )\t be+ d>k] on ! outside ?an 9 ! middle1 all ! f]r\s hydroxide w h be5 trans=m$ into ! f]ric /ate4 ,! product c n[ be dri$ at once1 & :5 gr\nd w be ready = sale4 ,to obta9 diff]5t v>ieties f ! product1 x is c>efully heat$ 79 a f9ely p[d]$ condition7 9 %all[ pans2 b ! op]ation ne$s caution1 or ! wat] 9 ! gypsum pres5t w be expell$1 giv+ rise to drawbacks t are manife/$ :5 ! col\r is us$4 ,= in/ance1 9 mix+ su* a col\r ) wat]1 ! gypsum w\ld aga9 absorb wat] & cause ! :ole mass to set z a useless solid lump4 ,s9ce gypsum p>ts ) its wat] at a comp>atively l[ temp]ature1 x is bett] n to heat ^! *eap o*res at all1 b to obta9 ! v>i\s %ades by modify+ ! proportion ( f]r\s sulphate employ$4 ,ano!r defect ( ! o*res prep>$ by ?is me?od resides 9 ! excess ( lime pres5t1 x be+ impracticable to measure out ! quantity ( lime us$ ) su* accuracy t only j en\gh is tak5 to precipitate ! f]r\s hydroxide1 !re be+ always a slight excess4 ,?is lime is trans=m$ into calcium c>bonate on ! mass be+ expos$ to ! air1 j z 9 ! prep>ation ( ,vi5na :ite2 b z ! saturation ) c>bon dioxide takes a consid]able "t1 "s ( ! lime rema9s 9 ! cau/ic /ate & is liable to affect o!r col\rs t may be mix$ ) ! o*re4 ,an artificial o*re unit+ 9 itself all ! qualities ( ! natural product1 & also capable ( be+ %ad$ by burn+1 c be prep>$ 9 ! foll[+ mann]4 ,an accurately weigh$ quantity ( pure cry/allis$ f]r\s sulphate is dissolv$ 9 a def9ite am\nt ( wat]1 & ! solution is treat$ ) successive small portions ( crude nitric acid1 until all ! f]r\s oxide has be5 *ang$ into ! f]ric /ate4 ,! *ange c be detect$ by a v decisive te/4 ,if a liquid conta9+ f]ric oxide 9 solution is br\ght into contact ) a solution ( r$ prussiate ( pota% 7potassium f]ricyanide71 no precipitate is =m$ 9 ! abs5ce ( f]r\s oxide1 b only a br[n coloration2 :]eas1 if f]r\s oxide is pres5t1 a beautiful blue precipitate is =m$ at once1 ! col\r ( :i* is s int5se t v small quantities ( f]r\s oxide c be detect$ by ?is means4 ,= ! purpose n[ "u consid]ation1 ! pres5ce ( small am\nts ( f]r\s oxide 9 ! solution is immat]ial1 because !y are soon *ang$ into f]ric oxide on exposure to ! air4 ,x might1 !re=e1 be ask$1 :y take ! tr\ble to oxidise ! f]r\s oxide by means ( an ag5t involv+ exp5se1 :i* c\ld be sav$ by all[+ ! oxidation to take place 9 ! air8 ,! advantage1 h[ev]1 ( ! direct employm5t ( a solution ( f]ric oxide is t x gives at once a col\r t c be dri$ /raight away2 :il/ at ! same "t ! col\r und]goes no *ange 9 dry+1 :]eas x does :5 f]r\s oxide solution is us$4 ,! me?od ( produc+ o*res f ?is f]ric solution v>ies accord+ z ! product is to be us$ )\t any fur!r treatm5t ?an dry+1 or is to be modifi$ by fir+4 ,9 ! =m] ev5t1 cau/ic lime is aga9 us$ z ! precipitant1 b 9 only j suffici5t quantity to ?r[ d[n all ! f]ric oxide 9 ! solution4 ,?is am\nt c be calculat$ exactly1 #cfhd p>ts by weight ( pure burnt lime be+ requir$ = e #ajj p>ts ( pure f]r\s sulphate tak54 ,! actual quantity1 :e!r l>g] or small]1 w dep5d on ! relative purity ( ! sulphate & lime2 & ?is c readily be asc]ta9$ by a simple trial4 ,! lime is us$ 9 ! =m ( milk ( lime1 z already describ$4 ,if lime alone is employ$1 ! precipitate w consi/ ( pure f]ric hydroxide & ! calcium sulphate ?r[n d[n at ! same "t4 ,! result+ col\r1 :5 dri$1 w be an int5sely br[n mass1 :i* c be us$ 9 place ( ! v d>k natural o*res4 ,9 ord] to obviate entirely ! disadvantages result+ f ! pres5ce ( a l>ge am\nt ( cau/ic lime 9 ! precipitate1 f9e levigat$ *alk or :ite clay is add$ 9 ! prep>ation ( ! light] %ades ( o*re1 ! addition be+ made z soon z ! two +r$i5ts h be5 br\ght into contact2 & ! mixture is ?or\ghly /irr$1 to ensure uni=m admixture ) ! f]ric hydroxide4 ,! col\r ( ! settl$ deposit w be light] or d>k] 9 proportion to ! am\nt ( *alk or clay employ$2 & 9 ?is way ! :ole range ( %ades f pale yell[ to bright br[n c be obta9$ )\t ! application ( heat4 ,o*re t has be5 made ) *alk is unsuitable = ton+ by heat1 because ?is treatm5t w\ld cau/icise ! lime1 & ! o*re c\ld n be mix$ ) o!r col\rs1 s9ce ^! w\ld be affect$ by t sub/ance4 ,on ! o!r h&1 :5 :ite clay is us$ 9 prep>+ ! o*re1 ! latt] c be m easily ton$ by fir+1 provid$ c>e be ex]cis$ 9 ! process4 ,! o*re mu/ be dri$ completely 9 ! air1 & ei!r spread out 9 ?9 lay]s on iron plates1 = ! burn+ process1 or else put into a drum1 ( ! k9d already describ$1 9 :i* ! mass is mov$ onw>d by a worm4 ,! clay rema9s unalt]$ 9 fir+1 b ! gypsum p>ts ) its wat] ( cry/allisation4 ,9 ord] to re/ore ! latt]1 ! o*re issu+ f ! drum is dis*>g$ direct into a vessel ( wat]1 9 :i* x c be kept 9 con/ant motion by a /irr]4 ,! wat] is soon w>m$ by ! heat ( ! mass1 & absorption by ! gypsum proce$s at a rapid rate4 ,:5 ! :ole *>ge has be5 fir$ & collect$ 9 ! vessel ( wat]1 ! /irr] is /opp$ & ! precipitate dri$1 be+ !n ready = use4 ,9 c]ta9 circum/ances1 o*re c be made by o!r me?ods4 ,9 l>ge t[ns1 ammonium salts are sometimes obta9able at a mod]ate price1 be+ manufactur$ 9 l>ge quantities z a by-product 9 gasworks4 ,= our purpose1 crude gas liquor might be us$1 s9ce x conta9s ammonia = ! precipitation ( ! f]ric hydroxide4 ,9 mo/ cases1 h[ev]1 ?is gas liquor conta9s only v small quantities ( ammonia1 &1 !re=e1 9 a works ( any size1 v l>ge vessels w\ld be ne$$ = ! production ( a comp>atively small quantity ( o*re4 ,on ?is acc\nt1 pref]5ce is giv5 to crude c>bonate ( ammonia1 :i* is also obta9able at l[ prices4 ,on br++ a solution ( ?is salt into contact ) "o ( f]ric oxide1 f]ric hydroxide is precipitat$1 & ! sulphate ( ammonia result+ f ! reaction rema9s 9 solution4 ,by /irr+ :ite clay into ! liquid at ! same "t1 ! o*re c be correspond+ly light5$ 9 %ade4 ,! precipitates obta9$ 9 ?is way c be dri$ at once1 & conv]t$ into any %ade obta9able ) natural o*re1 f br[n to r$1 by /rong fir+4 ,! sulphate ( ammonia /ill rema9+ 9 ! air-dri$ product is completely volatilis$ by ! heat1 & ! result+ o*res are ev5 sup]ior to ! natural v>ieties 9 beauty & p]man5ce4 ,,o*res ,,z ,,by-,,products ,9 ! manufacture ( c]ta9 *emicals1 sub/ances ( div]g5t composition are obta9$ :i* are sold "u ! "n ( o*re & are us$ z pa9t]s' col\rs4 ,:]eas o*re1 prop]ly s-call$1 consi/s ( ei!r f]ric hydroxide or f]ric oxide 9 association ) clay1 lime1 etc41 ! products n[ "u consid]ation are basic f]ric salts compos$ ( v>y+ quantities ( f]ric oxide 9 comb9ation ) c]ta9 proportions ( sulphuric acid4 ,^! o*res are obta9$ z by-products 9 ! manufacture ( gre5 vitriol f pyrites1 & 9 alum manufacture2 &1 accord+ to _! orig91 !y are class$ z vitriol o*re1 s-call$ alum sludge1 & pit o*re4 ,all ! basic f]ric sulphates ( :i* !y are compos$ =m fairly l>ge cry/als1 &1 !re=e1 9 mo/ cases1 ! cov]+ p[] is small4 ,on ?is acc\nt ! products are ( l[ grade & are put on ! m>ket at l[ prices1 = :i* reason !y are l>gely us$ 9 mak+ *eap pa9ts4 ,vitriol ,o*re4--,comm]cial gre5 vitriol is1 = ! mo/ "p1 manufactur$ f native sulphides ( iron4 ,:5 _m ( ^! sulphides are pil$ 9 heaps & left to ! action ( ! air1 oxyg5 is gradually absorb$ & gre5 vitriol is =m$ :i* is dissolv$ out by ra9 & is collect$ 9 l>ge cl>ify+ tanks4 ,9 ! case ( pyrites1 h[ev]1 ! m9]al mu/ fir/ be roa/$ 9 a curr5t ( air1 s9ce o!rwise its conv]sion into gre5 vitriol w\ld only proce$ 9 a v sluggi% mann]4 ,9 any ev5t1 ! aque\s solution ( f]r\s sulphate has to be conc5trat$1 by evaporation1 to ! po9t at :i* ! gre5 vitriol cry/allises out4 ,bo? 9 ! cl>ify+-tanks &--/ill m s--9 ! evaporat+-pans1 a ru/y-look+ s$im5t =ms at ! bottom1 consi/+ ( basic f]ric sulphate4 ,?is orig9ates 9 ! p>tial oxidation ( ! f]r\s oxide 7fir/ =m$7 :ile ! pyrites is expos$ to ! air1 & s9ce ! quantity ( sulphuric acid pres5t is insuffici5t to saturate all ! f]ric oxide1 basic salts are produc$4 ,! yell[-br[n sludge deposit$ 9 ! pans dur+ ! conc5tration ( crude gre5 vitriol liquor1 con/itutes ! product t]m$ vitriol o*re1 :i* conta9s v>y+ am\nts ( f]ric oxide1 sulphuric acid & wat]1 accord+ to ! quantity ( f]ric oxide result+ f ! oxidation ( ! pyrites & ! "* ( ! latt]1 e4 g43-- ,f]ric oxide #fe-gj ,sulphuric acid #ad-af ,wat] #ac-af ,al?\gh ! col\r ( ^! o*res is n p>ticul>ly h&some1 !y c be trans=m$1 by fir+1 into col\rs ( fairly good quality4 ,z ?is subject w be m ?or\ghly gone into :5 deal+ ) ! prep>ation ( ! r$ iron pigm5ts1 ! applicability ( ^! o*res w only be casually ref]r$ to "h4 ,dur+ ! burn+ process1 ^! o*res1 ( c\rse1 "p ) ! :ole ( _! conta9$ wat]2 & by protract$1 high calc9ation1 ! :ole ( ! sulphuric acid c also be expell$1 s t f9ally no?+ b pure f]ric oxide is left4 ,alum ,sludge4--,solutions ( crude alum always conta9 a c]ta9 am\nt ( f]ric oxide :i* settles d[n at ! bottom ( ! pans dur+ conc5tration4 ,?is sludge1 too1 consi/s ( basic f]ric sulphate1 b is inf]ior 9 cov]+ p[] to vitriol o*re1 ! cry/als be+ ( co>s] gra94 ,on ! o!r h&1 ! o*re\s s$im5t f ! alum conc5trat+-pans has ! valuable prop]ty ( be+ readily trans=mable into r$-br[n to pure r$ tones by burn+4 ,= ?is reason1 p>ticul> att5tion has be5 devot$ to ?is sludge 9 a numb] ( alum works4 ,s9ce ! products are only ( value :5 burn$1 & ! %ades !reby obta9$ are always r$1 !y w be dealt ) m fully along ) ! r$ e>? col\rs4 ,pit ,o*re4--,spr+s conta9+ small quantities ( f]r\s sulphate & o!r salts are met ) 9 _m iron m9es1 b1 9 mo/ cases1 ! am\nts are too small = _! recov]y by artificial conc5tration to be contemplat$4 ,if1 h[ev]1 ! conditions all[ ( ! spr+s be+ easily div]t$1 !y may (t5 be utilis$ = ! prep>ation ( l[-grade o*re4 ,! *emical composition ( ^! pit o*res v>ies consid]ably1 & dep5ds on ! geological "* ( ! locality4 ,wat] c only dissolve su* m9]als z occur 9 ! =m ( fairly readily soluble comp\nds2 & = ?is reason pit wat]s are always solutions ( ! metals :i* are f\nd 9 ! m9e4 ,! v>iety ( comp\nds t may be pres5t 9 an o*re c be se5 f ! subjo9$ analyses ( o*res deposit$ f pit wat]s at ,rammelsb]g4 ,z else:]e1 two di/9ct classes ( o*re are met )1 hav+ a con*oid & an e>?y fracture respectively4 ,! latt] usually conta9 r m f]ric oxide1 &1 9 p>ticul>1 a high] cont5t ( =eign sub/ances1 ! mo/ important ( :i* is qu>tz s&4 ,9 ! ,table1 ! o*res ) con*oid fracture are m>k$ ,a1 & ^? ) an e>?y fracture1 ,b4 ,a4 ,b4 ,f]ric oxide #fhge #fche ,z9c oxide #abi #abc ,copp] oxide #jej #jhh ,sulphuric acid #ihj #acei ,wat] #aeeb #ahde ,clay & ,qu>tz #dad #bjj ,! prep>ation ( ! o*re is a simple matt]1 consi/+ 9 collect+ ! mass & sort+ out ! loose1 e>?y portions ( a pure yell[ col\r f ! d5s] & d>k] p>ts4 ,! =m] are dealt ) sep>ately1 usually by a simple process ( levigation1 = ! sole purpose ( gett+ rid ( ! e>?y matt]1 qu>tz s& 9 p>ticul>4 ,! d5s] v>ieties require mu* m "w1 b yield a f> sup]ior product1 :i*1 by suitable treatm5t1 c be conv]t$ into ! f9e/ grades ( o*re4 ,! fir/ op]ation consi/s 9 a v c>eful cru%+1 & z ! pieces are (t5 v h>d1 !y are treat$ 9 ord9>y or /amp-mills1 edge-runn]s be+ also employ$ ) advantage4 ,! product r$uc$ by any ( ^! means is pass$ ?r\gh a numb] ( sieves1 to sep>ate ! f9e p>ticles f ! co>se2 & ! f9e/ du/ is burnt4 ,?is la/ treatm5t causes a consid]able loss 9 weight1 bo? ! accompany+ wat] & mo/ ( ! sulphuric acid be+ volatilis$4 ,h[ev]1 s9ce1 z already /at$1 all v>ieties ( o*re c be obta9$1 ! process is consequ5tly v remun]ative not)/&+ ! loss 9 weight x involves4 ,yell[ ,e>?4--,f ! p>ticul>s giv5 9 ! g5]al description ( ! e>? col\rs1 yell[ e>? may also be reg>d$1 to "s ext5t1 z an o*re1 b "o conta9+ a l>ge proportion ( =eign sub/ances4 ,x might1 h[ev]1 be m accurately t]m$ a clay contam9at$ ) a consid]able am\nt ( qu>tz s& & a c]ta9 proportion ( f]ric oxide4 ,! me?od ( prep>ation is on ! same l9es z = o*re1 b burn+ is nev] practis$1 nor is ! treatm5t s c>eful z = ! bett] grades ( o*re1 ! l[ price ( ! col\r mak+ ?is unremun]ative4 ,,*apt] ,,vi ,,r$ ,,e>? ,,col\rs ,! numb] ( m9]als t c be directly us$ z r$ e>? pigm5ts is comp>atively small1 & by f> ! great] proportion consi/ ( f]rug9\s col\rs1 a few ( :i* are obta9$ by ! me*anical treatm5t ( native iron ores or clays col\r$ r$ by f]ric oxide1 ! majority1 h[ev]1 be+ =m$ by burn+ c]ta9 mat]ials ( ano!r col\r4 ,to ^! belong ne>ly all ! mat]ials m5tion$ 9 connection ) ! o*res & ! br[n iron col\rs1 toge!r ) a few by-products ( ! *emical indu/ry4 ,9 addition to ! =ego+1 :i* h f]ric oxide = _! pigm5t>y pr9ciple1 is ! native m]cury sulphide1 occurr+1 z sc>let1 cry/all9e masses1 "u ! "n ( c9nab> 7v]milion74 ,! only reason = includ+ natural v]milion ) ! e>? col\rs is to make ! li/ complete1 ! l>ge/ proportion ( ?is pigm5t be+ prep>$ by artificial me?ods4 ,! product sold z 8,*9ese0 v]milion may1 9 =m] times1 h really be5 introduc$ f ,*9a into ,europe1 & prep>$ !re by gr9d+ & levigat+ ! be/-col\r$ lumps ( ! natural c9nab>2 b1 at ! pres5t "t1 all ! v]milion made--9 ,europe at lea/--is f sulphur & m]cury1 by artificial processes1 & ! "n ,*9ese v]milion is m]ely reta9$ to designate a p>ticul>ly f9e grade4 ,on ! basis ( occurr5ce & *emical prop]ties1 ! r$ e>?s c be classifi$ into sev]al gr\ps4 ,! fir/ comprises natural products requir+ only me*anical prep>ation1 su* z ! m9]als kn[n z hematite1 micace\s iron ore1 ,elbaite1 etc41 & ! special modification ( r$ iron/one t]m$ raddle4 ,all ^! m9]als consi/ almo/ entirely ( f]ric oxide 9 a pure /ate4 ,! m9]al1 bole 7r$ *alk1 t]ra sigillata1 ,lemnos e>?71 is *emically alli$ to ! o*res1 be+1 l !m1 compos$ ( alum9a1 frequ5tly accompani$ by lime & small quantities ( magnesia1 b diff]+ 9 t f]ric oxide is always pres5t 9 bole1 :]eas ! o*res always conta9 f]ric hydroxide4 ,! second gr\p consi/s ( ! artificial r$s obta9$ by burn+ or calc9+ raw mat]ials1 ^: f]ric hydroxide is m or less trans=m$ by heat into f]ric oxide1 su* z vitriol o*re1 pit o*re & alum sludge4 ,( late ye>s ! artificial e>? col\rs h atta9$ a high degree ( importance4 ,!y are obta9$ 9 l>ge quantities 9 ! manufacture ( sulphuric acid f gre5 vitriol4 ,=m]ly1 x is true1 !y 7 also us$ z pigm5ts "u ! "n ( caput mortuum or colco?>1 b 7 n held 9 mu* e/eem2 & x is only )9 rec5t times t x has be5 discov]$ t ^! inf]ior by-products c be conv]t$ into v h&some & brilliant col\rs1 :i* n[ =m important articles ( comm]ce4 ,,bole ,bole1 ,lemnos e>?1 t]ra sigillata1 etc41 is1 = ! mo/ "p1 a product ( ! decomposition ( highly f]rug9\s m9]als1 & occurs1 9 ! =m ( lumps1 hav+ a con*oidal fracture1 9 pockets or detritus4 ,! lumps h a sp4 gr4 ( #bb-be1 are ,isabella br[n to d>k br[n 9 col\r1 & give a slightly greasy-look+ /reak4 ,!re are two di/9ct v>ieties ( bole3 ! "o adh]+ firmly to ! tongue1 :il/ ! o!r lacks ?is prop]ty &1 :5 plac$ 9 wat]1 crumbles d[n to p[d] 9 emitt+ a peculi> noise4 ,! composition ( ! boles v>ies1 b all ( !m may be reg>d$ z alum9o f]ric silicates comb9$ ) wat]4 ,mo/ ( ! specim5s exam9$ f diff]5t deposits conta9 #bd-be ( wat]1 #da-db ( silica1 & #bj-be ( alum9a1 ! rema9d] consi/+ ( f]ric oxide ) small traces ( manganese oxide4 ,"s v>ieties1 h[ev]1 are exceptional & conta9 only #cj-ca ( silica & #ag-ba ( wat]1 e4 g4 ^? f ,orawitza & ,s9ope4 ,lemnos e>?1 ! true t]ra sigillata1 is mo/ly silica 7#ff7 ) #h ( wat]1 & conta9s a small] p]c5tage ( f]ric oxide ?an ! o!rs4 ,x is also ( a di/9ct col\r1 light] ?an ! true boles & hav+ a greyi% or yell[i% t+e4 ,! behavi\r ( ! diff]5t k9ds on burn+ is j z div]se z _! *emical composition4 ,:il/ "s k9ds are infusible at ev5 ! highe/ temp]atures1 & m]ely *ange into h>d1 r$ masses2 o!rs1 aga91 fuse at a mod]ate heat4 ,?is diff]5ce is due to *emical composition1 ^? high 9 silica be+ g5]ally less refractory ?an ^? 9 :i* alum9a prepond]ates4 ,9 ord] to r5d] ! boles suitable = pa9t+1 !y are put ?r\gh a some:at diff]5t treatm5t ?an ! o!r e>? col\rs4 ,! fre%ly dug mat]ial is fir/ sort$1 ! uni=mly col\r$ lumps ( f9e texture be+ set ap>t & suffus$ ) wat]1 ) :i* !y =m a pa/y mass ( l[ pla/icity1 :i* is knead$ by h& to make x homog5e\s1 & is !n /irr$ up ) m wat]4 ,:5 ! lumps h di/ribut$ 9 ! wat]1 ! latt] is drawn (f into a second tub1 & ! residue is /irr$ up ) fre% wat]1 ! treatm5t be+ repeat$ until ! efflu5t no long] %[s any signs ( col\r4 ,! liquid 9 :i* ! f9ely divid$ bole is susp5d$ is left to settle1 & ! bole subsides z a f9e p[d]1 :i* is dri$ to ! condition ( pa/e1 press$ into m\lds & dri$ completely4 ,ow+ to its l[ cont5t ( f]ric oxide1 ! col\r ( bole is n p>ticul>ly bright1 b is v p]man5t--a prop]ty equally %>$ by all ! o!r f]ric oxide pigm5ts4 ,,native ,,f]ric ,,oxide ,,z ,a ,,pigm5t ,9 nature1 f]ric oxide =ms ext5sive deposits1 :i*1 by reason ( ! light r$ col\r *>act]i/ic ( c]ta9 v>ieties ( f]ric oxide1 are l>gely employ$ 9 pa9t+4 ,^! col\rs may be class$ among ! olde/ kn[n to mank9d1 f]ric oxide pigm5ts hav+ be5 us$ frequ5tly 9 ! mo/ anci5t pa9t+s4 ,! mo/ important v>ieties ( f]ric oxide = our purpose are3 iron glance1 ) its modifications1 micace\s iron ore & fro?y hematite2 r$ hematite1 & raddle4 ,,iron ,,glance ,?is sub/ance =ms h&some black cry/als ( v high lu/re1 :i*1 :5 small & scaly1 con/itute micace\s iron ore4 ,bo?1 :5 rubb$ d[n1 furni% a d>k r$ p[d] ( no p>ticul> beauty4 ,micace\s iron ore =ms ! transition /age into fro?y hematite1 or iron cream1 ! sole diff]5ce be+ t ! cry/als ( ! latt] are mu* small]1 & ! scales f9]1 ! iron-black col\r pass+ gradually into *]ry r$4 ,at ! same "t1 ! lu/re1 ?\gh /ill high1 loses mo/ ( ! metallic %e5 exhibit$ by micace\s iron ore4 ,,hematite ,! v>iety kn[n z hematite or blood/one1 sometimes occurr+ z %9y nodules1 is di/+ui%$ by its h&some r$ col\r4 ,"s ( ! lumps are compos$ ( long1 ?9 cry/als gr\p$ ab\t a common c5tre s z to =m a globul> mass4 ,despite its bright col\r1 ! h>dness ( hematite 7betwe5 #c & #e7 prev5ts x f be+ us$ z a pigm5t1 ! value ( ! product n be+ comm5surate ) ! co/ ( r$uction4 ,,raddle ,!re are num]\s deposits ( r$ iron/one1 9 ! /ate ( f9e e>?1 :]e ! op]ations ( gr9d+ & levigation h1 to a consid]able degree1 already be5 c>ri$ out by ,nature4 ,^! deposits =m ! m9]al :i*1 "u ! "n ( raddle1 is (t5 us$ z a pigm5t = ord9>y pa9ts4 ,x may be consid]$ to h orig9at$ 9 ! trans=mation ( r$ iron/one1 by ! natural =ces t c ev]y:]e be se5 dis9tegrat+ rocks1 namely wat] & fro/1 into a f9e p[d]1 :i* has be5 transport$1 (t5 ov] long di/ances1 by wat]1 & has f9ally settl$ d[n4 ,9 places :]e ! process has be5 c>ri$ out 9 ?is mann]1 ! raddle w be 9 a condition1 z reg>ds f95ess ( division & beauty ( col\r1 t leaves no?+ to be desir$1 & ! mat]ial itself is ready = use z a v valuable pigm5t4 ,l>ge deposits ( ?is k9d1 h[ev]1 are ( r>e occurr5ce2 b !re are pl5ty 9 :i* ! f]ric oxide is associat$ ) v>y+ quantities ( clay1 s&1 & sometimes lime4 ,! conditions "h are on all f\rs ) ^? ( clay1 :i*1 too1 has be5 =m$ 9 a simil> way4 ,pure clay1 ! s-call$ kaol91 is a highly valuable mat]ial1 :]eas ord9>y loam--highly contam9at$ clay--is only ( l[ value4 ,9 judg+ ! quality ( raddle z a pigm5t1 ! pres5ce ( impurities is ( less acc\nt ?an _! nature2 & 9 "s cases a v highly contam9at$ raddle may be wor? f> m1 z a pigm5t1 ?an "o conta9+ only v small admixtures ( extrane\s sub/ances4 ,z /at$ above1 ! ord9>y impurities 9 raddle are clay1 lime & qu>tz s&4 ,an admixture ( clay1 ev5 if fairly l>ge1 is no great drawback1 s9ce ! mat]ial c be us$ 9 its natural /ate1 & also be ton$ by burn+4 ,lime is less fav\rable1 = ?\gh a calc>e\s raddle c be us$ z x is1 ! lime p>ts ) its c>bon dioxide on calc9ation1 becom+ *ang$ into cau/ic lime & imp>t+ to ! product qualities :i* preclude its employm5t = a numb] ( purposes1 especially = mix+ ) delicate organic col\rs4 ,! pres5ce ( qu>tz s& is immat]ial :5 ! raddle is to be burn$1 inasmu* z s& is unalt]$ by calc9ation4 ,b x con/itutes a drawback because x makes ! f9e raddle gritty & unsuitable = f9e pa9t "w4 ,! only way to elim9ate ?is impurity is by levigation--an exp5sive op]ation :i* %\ld1 z f> z possible1 be avoid$ = ^! native f]ric oxides1 because !y mu/ be sold v *eaply1 & h to compete ) ! l>ge quantities ( oxide obta9$ z a by-product ( ! *emical indu/ry4 ,! suitability ( a giv5 specim5 ( raddle = use z a pigm5t may be easily asc]ta9$ by weigh+ out exactly #ajj grams & heat+ to ab\t #abj ,c4 ,! loss ( weight w give ! am\nt ( wat] 9 me*anical ret5tion4 ,! residue is suffus$ ) /rong v9eg>1 & left = sev]al days1 be+ /irr$ at frequ5t int]vals4 ,! c>bonates ( lime & magnesia pres5t w dissolve 9 ! acid1 ! f]ric oxide rema9+ unt\*$4 ,! liquid is decant$1 & ! residue wa%$ sev]al times ) wat] & dri$1 ! dim9ution 9 weight be+ a measure ( ! c>bonates 9 ! sample4 ,if ! v9eg> has turn$ a yell[ col\r1 ! pres5ce ( f]ric hydroxide 9 ! m9]al is indicat$1 ?is hydroxide be+ readily soluble 9 acetic acid4 ,if ! residue feels gritty1 x conta9s qu>tz s&1 ! am\nt ( :i* c be f\nd ) suffici5t accuracy by levigat+ ! mass & weigh+ ! s&y residue aft] dry+4 ,deposits occur1 9 _m places1 ( a m9]al simil> to raddle1 b =m$ "u peculi> conditions4 ,?us1 !re are f\nd1 9 ! vic9ity ( br[n-coal deposits t are ri* 9 pyrites1 e>?y masses :i* are occasionally ( a h&some r$ col\r & consi/ ( a v>iety ( m9]als admix$ ) a consid]able proportion ( f]ric oxide4 ,^! masses probably orig9at$ 9 fires 9 ! coal seams1 :]eby ! pyrites became trans=m$ into f]ric oxide & basic f]ric sulphate2 & :]e ! deposits are ( suffici5t size1 !y may be advantage\sly utilis$ 9 ! production ( *eap r$s4 ,9 mo/ cases1 h[ev]1 ! m9]als mu/ be levigat$1 ow+ to ! frequ5cy ) :i* !y conta9 l>ge proportions ( extrane\s m9]als 9 a gritty condition4 ,,burnt ,,f]ric ,,oxide ,,& ,,o*res ,x has already be5 /at$1 9 deal+ ) ! yell[ o*res1 t ^! col\rs c be ton$ by burn+1 "p ( ! f]ric hydroxide los+ its wat] & *ang+ into r$ f]ric oxide4 ,! m sev]e ! burn+1 ! l>g] ! am\nt ( f]ric oxide =m$ & ! ne>] ! col\r ( ! product approximates to r$4 ,accord+1 h[ev]1 z ! orig9al o*re 0 yell[ or br[n1 ! tone ( ! burnt col\r w lie betwe5 orange & br[ni% r$4 ,if ! heat+ be pu%$ s f> z to trans=m all ! f]ric hydroxide into oxide1 ! r$ w come m & m into prom95ce 9 proportion to ! am\nt ( hydroxide 9 ! orig9al mat]ial4 ,if ! product consi/s entirely ( f]ric oxide1 z is ! case ) t obta9$1 z a by-product1 9 ! manufacture ( ,engli% sulphuric acid1 a pure r$ f]ric oxide 7caput mortuum1 colco?>1 ,engli% r$1 etc47 w be obta9$4 ,if ! heat+ be increas$ above a c]ta9 po9t1 ! pure f]ric oxide w *ange col\r1 assum+ a br[n to violet tone accord+ to ! temp]ature employ$4 7a7 ,burn+ 9 ! ,muffle ,s9ce1 z a rule1 ! quantity ( mat]ial treat$ 9 ! prep>ation ( ^! br[n1 violet to black f]ric oxide pigm5ts = ! purposes ( ! pa9t] on porcela9 is n l>ge1 ! same k9d ( muffle furnace 7,fig4 #bi7 z s]ves = mak+ enamels c be us$4 ,! fire-clay muffle ,m is ins]t$ 9 a rev]b]atory furnace ,o1 ) a good draught1 & is rais$ to a :ite heat4 ,! f9ely p[d]$ mat]ial to be burn$ is spread out ev5ly on plates ( %eet-iron or fire-clay1 & introduc$ into ! :ite-hot muffle1 :]e x is left = a p]iod correspond+ to ! col\r desir$4 ,to save "t1 ! plates may be pre-heat$ 9 a second muffle arrang$ above ! fir/4 ,illu/ration3 ,,fig4 #bi4 ,by ?is means a l>ge range ( tones c be obta9$ f "o & ! same mat]ial1 by heat+ x to diff]5t temp]atures2 & ! col\rs s produc$ are di/+ui%$1 n only by _! w>m? ( tone1 b also by v high /ability4 ,9 fact1 !y may be reg>d$ z p]man5t1 because v /rongly calc9$ f]ric oxide only passes v sl[ly into solution ev5 "u prolong$ boil+ 9 ! /ronge/ acids4 ,ow+ to ?is excell5t prop]ty1 :i* is equall$ by v few o!r pigm5ts1 & ! l[ co/ ( prep>ation1 ^! col\rs des]ve ! mo/ c>eful consid]ation by all manufactur]s :o are 9 a position to obta9 suitable mat]ial 9 suffici5t quantities4 7b7 ,caput ,mortuum1 ,colco?> ,previ\s to ! ,engli% me?od ( mak+ sulphuric acid by ! oxidation ( sulphur dioxide ) nitric acid1 ?is acid 0 manufactur$ by heat+ dehydrat$ f]r\s sulphate 7gre5 vitriol72 & ev5 n[1 fum+ sulphuric acid--oil ( vitriol1 or ,nordhaus5 sulphuric acid--is l>gely obta9$ by ! same process4 ,:5 anhydr\s f]r\s sulphate1 ,fe,s,o#d1 is expos$ to a v high temp]ature--/rong :ite heat--x is decompos$ into sulphur trioxide1 ,,s#c1 sulphur dioxide1 ,,s#b1 & a residue1 ma9ly compos$ ( f]ric oxide & a little basic f]ric sulphate1 :i* rema9s beh9d 9 ! heat+-pan4 ,9 fact1 ev5 at ! highe/ possible temp]atures obta9able 9 ! furnaces us$ = ! di/illation ( ! gre5 vitriol1 x is impossible to recov] ! :ole ( ! sulphuric acid1 a small portion be+ t5aci\sly reta9$ by ! iron4 ,?is r$ residue is sold "u v>i\s names--colco?>1 caput mortuum1 ,engli% r$1 ,indian r$1 etc4--& is us$ z a l[-grade pigm5t1 & also z a poli%+ ag5t4 ,! "n caput mortuum is a survival f ! "t ( ! al*emi/s1 & 0 probably appli$ to indicate a dead-burn$ product1 f :i* all ! active +r$i5ts _h be5 remov$4 ,al?\gh1 9 =m] ages1 ?is sub/ance 0 held 9 l[ e/imation z a pigm5t1 attempts h be5 made 9 rec5t times to conv]t x1 by suitable treatm5t1 into a m valuable product2 & ^! attempts h be5 cr[n$ ) success1 af=d+ ano!r in/ance ( h[ a high comm]cial value c be imp>t$ to a wa/e product by prop] manipulation4 7c7 ,calc9+ ,f]ric ,oxide ,9 ord] to obta9 a s]ies ( tones ( colco?>1 x is subject$ to repeat$ calc9ation1 b n by itself1 s9ce x w\ld require an extremely l>ge quantity ( fuel to effect any *ange ( tone 9 view ( ! v high temp]ature ! mat]ial has already be5 expos$ to 9 ! sulphuric acid plant4 ,if1 h[ev]1 salt be add$1 !n a v>iety ( tones c be obta9$ )\t rec\rse to any p>ticul>ly high temp]ature4 ,x is frequ5tly /at$ t ! only effect ( ! pres5ce ( salt is to keep ! calc9+ temp]ature uni=m1 inasmu* z ! salt volatilises at a /rong r$ heat1 & :5 t temp]ature is rea*$1 ! :ole mass _c get any hott] until ! :ole ( ! salt has pass$ (f1 all ! heat appli$ be+ consum$ 9 trans=m+ ! salt into ! /ate ( vap\r4 ,z a rule1 h[ev]1 ! am\nt ( salt add$ does n exce$ #f ( ! weight ( ! *>ge to be calc9$2 & ?is quantity does n seem to be suffici5t to keep ! temp]ature at a uni=m level ?r\gh ! sev]al h\rs requir$ = ! calc9+ process4 ,! au?or is !re=e ( op9ion t ! salt also has a *emical action on ! mat]ial dur+ ! calc9ation4 ,z already m5tion$1 colco?> is by no means pure f]ric oxide1 b always conta9s basic f]ric sulphate4 ,n[1 x is feasible t "s reaction may take place betwe5 ! basic sulphate & ! sodium *loride at calc9ation temp]ature1 ) ! =mation ( cau/ic soda1 :i*1 be+ a f> m p[]ful base ?an f]ric oxide1 deprives ! latt] ( sulphuric acid1 sodium sulphate be+ =m$4 ,! *lor9e ( ! salt comb9es ) ! iron to =m f]ric *loride1 :i* volatilises at a gl[+ heat4 ,accord+ to ?is hypo!sis1 !re=e1 ! addition ( common salt 9 ! calc9ation ( colco?> is less = ! purpose ( ma9ta9+ a uni=m temp]ature )9 c]ta9 limits ?an = decompos+ ! basic f]ric sulphate pres5t & induc+ ! =mation ( a product consi/+ entirely ( pure f]ric oxide4 ,! v>i\s tones obta9$ are due to ! v>y+ l5g? ( exposure to ! heat4 ,! foll[+ me?od is pursu$ 9 ! conv]sion ( colco?> into iron pigm5ts on a manufactur+ scale4 ,! crude colco?> f ! sulphuric acid plant is gr\nd1 z f9ely z possible1 9 ord9>y mills1 & ! result+ s(t p[d] is intimately mix$ ) salt1 #b1 #d or #f be+ ! usual proportions add$4 ,! calc9ation is ord9>ily cont9u$ = six h\rs 9 ! case ( ! mixture conta9+ ! l>ge/ am\nt ( salt2 b only two h\rs1 or ev5 "o1 = ! o!r mixtures4 ,! op]ation is c>ri$ on 9 e>!nw>e pipes1 a l>ge numb] ( :i* 7up to sixty7 are built into a furnace4 ,! latt] is fir$ v c>efully1 ! temp]ature be+ rais$ only v gradually1 s9ce exp]i5ce has %[n t mu* bett] col\r$ products are obta9$ 9 ?is way ?an by rais+ ! mass quickly to a high temp]ature4 ,:5 inc&esc5t f]ric oxide is all[$ to cool d[n ) unre/rict$ access ( air1 ! col\r is n ne>ly s bright z :5 air is exclud$ dur+ ! cool+4 ,s9ce air has no action on f]ric oxide1 ?is rem>kable ph5om5on _c be due to ! pres5ce ( ! air1 b probably to ! influ5ce ex]t$ by ! rapid *ange ( temp]ature on ! arrangem5t ( ! f9e/ p>ticles ( ! oxide4 ,nev]!less1 "s manufactur]s hold t rapid cool+1 ) re/rict$ access ( air1 improves ! col\r4 ,to exclude air f ! f]ric oxide dur+ calc9ation1 ! op5 ends ( ! pipes are flang$ & cov]$ ) close-fitt+ plates1 :i* are lut$ ) clay4 ,! expansion ( ! int]nal air z x gr[s hot w\ld bur/ ! pipes unless a means ( escape 7 provid$1 :i* consi/s 9 leav+ small v5t holes 9 ! cov] plates4 ,z previ\sly m5tion$1 calc9$ f]ric oxide is v in]t1 *emically1 s t1 :5 ! calc9ation has be5 /rong1 prolong$ boil+ ) ! mo/ p[]ful acids is ne$$ to br+ ! oxide into solution4 ,if ! heat+ has be5 cont9u$ up to ! /ronge/ :ite heat1 & ! f]ric oxide ma9ta9$ 9 t condition = sev]al h\rs1 ev5 hot sulphuric acid w h only a slight effect on ! oxide1 & ! only way to make x m readily soluble is by fusion ) potassium bisulphate4 ,n[ indiff]5ce to *emical action is j ! prop]ty requir$ ( a pigm5t = f9e "w2 & 9 ?is respect1 ! f]ric oxide col\rs are sup]ior to all o!rs4 ,! gradations ( tone t c be obta9$ f f]ric oxide by v>y+ ! calc9ation are v num]\s1 compris+ all betwe5 iron r$1 r$-br[n & pure violet4 ,! au?or has tri$ heat+ f]ric oxide = a consid]able "t at a v high temp]ature1 equival5t to ! /ronge/ :ite heat1 & obta9$ a product :i* 0 no long] pure violet1 b _h a decid$ly blacki% col\r4 ,p]haps1 by greatly prolong+ ! heat+1 x might be possible to get a pure black2 b1 ev5 if ?is 7 s1 ! matt] w\ld be ( no special int]e/1 because black pigm5ts = pa9ts c be prep>$ 9 a mu* *eap] mann]4 ,all t w\ld be accompli%$ w\ld be ! pro( t f]ric oxide actually und]goes an ext5sive molecul> modification :5 heat$4 ,,f]ric ,,oxide ,,pigm5ts ,,f ,,alum ,,sludge ,alum is manufactur$ f alum %ale & alum e>?1 ! =m] be+ a c>bonace\s clay %ale int]sp]s$ ) pyrites1 & ! latt] a clay *>g$ ) pyrites & bitum54 ,! raw mat]ials are left 9 heaps = sev]al ye>s1 ! pyrites be+ !reby oxidis$ ) =mation ( free sulphuric acid & f]r\s sulphate4 ,?is free acid reacts fur!r on ! clay1 :i* x trans=ms into sulphate ( alum9a2 & by lea*+ ! heaps ) wat]1 a solution is obta9$ :i* conta9s ! sulphate ( alum9a & ! f]r\s sulphate4 ,on ! liquor be+ conc5trat$1 a basic f]ric sulphate is deposit$1 :i* is work$ up into r$ pigm5t4 ,= ?is purpose x is fir/ levigat$ 9 a special mann]1 ! sludge f ! pans be+ plac$ 9 a l>ge vat1 suffus$ ) wat]1 & kept 9 sl[ circulation by /irr]s1 :i* di/ribute ! p>ticles 9 ! wat]1 =m+ a turbid liquid4 ,?is liquid is conduct$ into a g5tly slop+ %ute1 ! sides ( :i* are p]=at$ ) op5+s at c]ta9 int]vals1 to all[ "p ( ! liquid to run (f into l>ge collect+ vessels und]nea?4 ,! heavie/ ( ! susp5d$ p>ticles settle d[n fir/ & are flu%$ out by ! wat] escap+ ?r\gh ! fir/ op5+4 ,! f9] ! p>ticles1 ! long] !y rema9 9 susp5sion1 s t ! liquid escap+ ?r\gh ! la/ holes c>ries (f only a v f9e p[d]4 ,! liquid collect$ 9 ! diff]5t vessels is all[$ to subside & is !n drawn (f f ! firm deposit4 ,! op]ation is repeat$ ) fre% quantities ( sludge until suffici5t sludge has be5 collect$ = fur!r treatm5t4 ,! collect+ vessel fur!/ away f ! intake ( ! %ute conta9s ! f9e/ levigat$ mat]ial1 & ?is is us$ = mak+ ! be/ o*res4 ,! levigat$ mass is dri$ 9 a v simple mann]1 be+ usually spread out on bo>ds1 :i* are expos$ to ! air 9 op5 %$s1 cov]$ ) a ro( to keep out ! ra94 ,"h ! sludge is left until x =ms a pa/y or e>?y mass1 & is !n calc9$4 ,! be/ calc9+ furnace is ( ! type us$ = colco?>2 b ! pipes mu/ be connect$ to an exhau/ pipe = c>ry+ (f ! vap\rs dis5gag$ dur+ calc9ation4 ,illu/ration3 ,,fig4 #cj4 ,h[ev]1 s9ce alum manufactur]s d n usually g 9 = mak+ ! highe/-grade pigm5ts1 simpl] calc9+ furnaces are us$1 consi/+ ( rev]b]atory furnaces 9 :i* ! heat+-gases are all[$ to act directly on ! mat]ials ( ! *>ge4 ,a front elevation & section ( su* a furnace are %[n 9 ,figs4 #cj & #ca4 ,! furnace is con/ruct$ ) sev]al ar*es1 "o above ano!r1 m>k$ c1 k1 d4 ,! *>ge is introduc$ ?r\gh ! op5+s b & b'4 ,! furnace *amb] is at a1 & ! a%pit at g4 ,! gases ( combu/ion fl[ ov] ! *>ge on ! he>?s ( ! sev]al ar*es & escape1 at ! top1 into ! /ack1 along ) ! acid vap\rs lib]at$ f ! gl[+ mass4 ,illu/ration3 ,,fig4 #ca4 ,! fur!r ! hot gases get away f ! fire1 ! cool] !y become1 & !re=e ! less /rongly heat$ ! *>ge on ! upp] he>?s4 ,consequ5tly1 ! result+ product 7f]ric oxide7 f ! diff]5t /ages ( ! furnace diff]s 9 col\r2 & a numb] ( gradations c be obta9$ by bl5d+4 ,! f]ric oxide pigm5ts prep>$ 9 ?is way are n pure oxide1 b also conta9 small quantities ( sulphuric acid & metallic oxides :i* 7 pres5t 9 ! orig9al crude sludge4 ,h[ev]1 by reason ( ! simple process ( prep>ation employ$1 ^! pigm5ts are usually sold at l[] prices ?an ^? f colco?>2 & = less f9e "w !y are excell5t4 ,,*apt] ,,vii ,,br[n ,,e>? ,,col\rs ,9 po9t ( *emical composition1 ! majority ( ! br[n e>? col\rs are closely alli$ to ! r$s1 bo? k9ds conta9+ f]ric oxide4 ,! ma9 diff]5ce consi/s 9 t1 9 ! br[n e>?s1 ! f]ric oxide is comb9$ ) wat] to =m f]ric hydroxide4 ,_m ( ! br[n e>? col\rs1 h[ev]1 are ( entirely diff]5t *emical composition1 & ei!r consi/ ma9ly ( organic matt] d]iv$ f ! decomposition ( plants--& !re=e v simil> to br[n-coal or peat--or else conta9 v>y+ quantities ( inorganic sub/ances mix$ ) ^! d>k-col\r$ organic decomposition products4 ,! br[n e>? col\rs =m a highly important gr\p1 "s ( ! memb]s ( :i* are us$ 9 ! f9e/ pa9t+s1 &1 = c]ta9 purposes1 _c be replac$ by o!r pigm5ts4 ,^? conta9+ f]ric hydroxide are f\nd--?\gh n v frequ5tly--9 natural deposits1 ! mo/ celebrat$ be+ ! t]ra di ,si5a1 occurr+ 9 ! vic9ity ( t city4 ,,t]ra ,,di ,,si5a ,?is highly r5[n$ pigm5t>y e>? is f\nd 9 deposits1 &1 9 ! crude /ate1 =ms d>k br[n masses :i* are devoid ( lu/re1 crumble readily betwe5 ! f+]s1 h a smoo? con*oidal fracture & absorb wat] ) avidity1 9 consequ5ce ( :i* prop]ty !y adh]e to ! tongue4 ,_! *ief *emical con/itu5t is f]ric hydroxide1 ) :i*1 h[ev]1 v>iable quantities ( s&1 clay & f]ric oxide are admix$4 ,^! admixtures cause a consid]able div]g5ce 9 ! col\r ( ! e>?1 rang+ f pure br[n to r$di%-br[n1 &1 9 ! case ( v impure lumps1 to an unsightly yell[-br[n4 ,m9]alogically1 t]ra di ,si5a is (t5 reg>d$ z a di/9ct species :i*1 accord+ to ! results ( analysis1 mu/ be consid]$1 n z f]ric hydroxide1 b z f]ric silicate comb9$ ) wat]4 ,sometimes1 a portion ( ! f]ric oxide is replac$ by alum9a1 s t ! p]c5tage composition ( ! m9]al becomes approximately3 f]ric oxide1 #ff2 silica1 #aa2 alum9a1 #aj2 & wat]1 #ac4 ,! h>dness ( ?is m9]al is #be1 & ! sp4 gr4 #cdf4 ,! me?od ( =mation ( t]ra di ,si5a 0 probably on ! same l9es z t already describ$ 9 ! case ( o*re1 namely by ! break+ d[n ( m9]als--9 ?is case br[n iron/one--& natural levigation1 ! p[d] be+ deposit$ 9 places :]e ! wat] conta9+ ! f]ric hydroxide 9 susp5sion came to re/ & all[$ ! solid p>ticles to settle d[n4 ,! be/ lumps ( t]ra di ,si5a 9 po9t ( purity & col\r c be us$ z pigm5ts )\t any prep>ation2 b 9 mo/ cases ! e>? is lightly calc9$1 9 ord] to improve ! col\r4 ,?is treatm5t enables a :ole s]ies ( tones1 f pure br[n to ! brighte/ r$1 to be obta9$4 ,! /rong] ! heat+1 ! m wat] expell$ f ! hydroxide1 & consequ5tly ! clos] ! approximation ( ! col\r to t ( f]ric oxide4 ,! pigm5ts met ) 9 comm]ce z t]ra di ,si5a c also be prep>$ artificially1 by mak+ f]ric hydroxide & heat+ ?is1 :5 dri$1 until ! requisite tone is atta9$4 ,= ?is purpose1 f]r\s oxide is precipitat$ f gre5 vitriol & expos$ to ! air1 "u :i* conditions x is rapidly trans=m$ into f]ric oxide1 & ! greyi%-gre5 col\r ( ! mass *anges to br[n4 ,light] tones c be obta9$ by ! addition ( in]t :ite sub/ances2 &1 9 o!r respects1 ! me?od ( prep>ation is ! same z t ( artificial o*re4 ,^! pigm5ts are sold "u v>i\s names1 ! d>k %ades1 betwe5 pure br[n & r$ br[n1 be+ usually call$ t]ra di ,si5a or mahogany br[n1 :il/ ! pal] sorts are sold z sat9ob]--m correctly sat9 o*re1 gold5 o*re1 etc4 ,o!r pigm5ts1 *emically alli$ to ! f]ric oxide or o*re pigm5ts1 are sometimes f\nd on ! m>ket "u v>i\s & entirely arbitr>y names4 ,x may be po9t$ out t ! greate/ confusion exi/s 9 ! nom5clature ( pigm5ts1 to su* an ext5t t1 9 _m cases1 nei!r ! *emi/ nor ! manufactur] kn[s precisely :at pigm5t is impli$ by a giv5 "n4 ,! confusion is /ill fur!r increas$ by ! use ( names tak5 f diff]5t languages4 ,,true ,,umb] ,umb]1 prop]ly s call$--also kn[n z ,turki%1 ,cyprian or ,sicilian umb]1 f ! c\ntry ( orig9--d]ives its "n1 accord+ to "s au?orities1 f ! prov9ce ( ,umbria 7,italy71 :]e a br[n e>? is f\nd1 ?\gh o!rs ascribe x to ! ,lat9 8umbra0 7%ade7 because ( ! pigm5t be+ us$ = pa9t+ %ad[s4 ,true umb] is an e>?y mass ( f9e texture & liv]-br[n col\r1 m]g+ into *e/nut 9 "s ( ! lumps4 ,*emically1 x consi/s ( a d\ble silicate ( iron & manganese comb9$ ) wat]1 a portion ( ^! metals be+ usually replac$ by alum9a4 ,! great] h>dness 7#ae7 & high] specific gravity 7#bb7 ( true umb] 9 comp>ison ) ,cologne e>? 7:i* is q arbitr>ily t]m$ 8umb]071 =m a ready means ( diff]5tiation betwe5 ! two4 ,accord+ to ,viktor ,m]z1 ! umb] f\nd 9 ,cyprus consi/s (3 f]ric oxide1 #eb2 manganese oxide1 #ade2 & alum9a1 #c2 & is1 possibly1 m]ely a mixture ( clay ) hydroxide ( iron or manganese4 ,an umb] exam9$ by ,klapro? conta9$ #ac ( silica1 #e ( alum9a1 #dh ( f]ric oxide1 #bj ( manganese oxide & #ad ( wat]4 ,! tone ( umb] c be modifi$1 9 ! direction ( r$1 by calc9ation1 b ?is process is seldom employ$1 ! d>k br[n %ade ( ?is col\r be+ ! "o mo/ appreciat$4 ,9 "s p>ts ( nor!rn ,g]many1 ,?ur+ia 9 p>ticul>1 ! iron m9es conta9 small] or l>g] pockets ( f]ric hydroxide1 ( a f9e e>?y texture1 f :i* umb] is prep>$1 by levigation & calc9ation4 ,! product is sold "u v>i\s names3 *e/nut br[n1 wood br[n1 mahogany br[n1 bi/re flea br[n1 roe br[n1 accord+ to ! %ade ( ! calc9$ pigm5t4 ,a m9]al 78sid]osilicate10 accord+ to ,von ,walt]haus57 compos$ ( f]ric silicate1 & approximat+ 9 ?is respect to t]ra di ,si5a1 is f\nd 9 ! neighb\rhood ( ,pass>o 7,sicily7 9 deposits ( tuff4 ,x =ms masses :i* are transp>5t at ! edges & are usually liv]-br[n to *e/nut 9 col\r4 ,! h>dness ( ! m9]al is #be1 ! sp4 gr4 #bgac1 & ! av]age *emical composition3 silica1 #cd2 f]ric oxide1 #dhe2 alum9a1 #ge2 & wat]1 #aj4 ,! =ego+ are only a few examples ( br[n or r$-br[n e>? col\rs4 ,9 all ^! m9]als ! pigm5t>y pr9ciple is iron1 9 comb9ation ei!r ) oxyg5 alone 7f]ric oxide71 ) oxyg5 & wat] 7f]ric hydroxide71 or silica comp\nds 7f]ric silicate71 & always associat$ ) c]ta9 quantities ( o!r metallic oxides1 especially alum9a & manganese oxide4 ,al?\gh b few ( ^! m9]als h ga9$ any special reputation z pigm5ts1 !re is no d\bt t simil> m9]als1 :i* are c]ta9 to occur 9 or ne> _m deposits ( iron ores1 c\ld equally well be us$ = t purpose4 ,!re is no ne$ to emphasise t ! discov]y ( su* a m9]al w\ld be a v valuable f9d1 & t ! products obta9able !refrom c\ld be utilis$ to great advantage4 ,! te/+ ( a m9]al = its suitability z pigm5t is a v simple matt]1 all t is requir$ be+ to subject a small quantity to ! same treatm5t t is appli$ to ! e>? col\rs on a l>ge scale4 ,= ?is purpose a few p\nds ( ! m9]al are levigat$1 & ! residue is dri$4 ,to asc]ta9 ! tones obta9able by calc9ation1 small samples--( ab\t #ajj grms4--are plac$ 9 crucibles1 & gradually heat$ 9 a furnace4 ,:5 ! masses h atta9$ a suffici5t temp]ature1 ! samples are tak5 out ( ! furnace1 at int]vals ( t5 m9utes1 & left to cool4 ,x w !n n be difficult to decide :e!r ! m9]al is at all suitable = ! purposes ( ! col\r-mak]2 & if s1 ^! te/s af=d at once an indication ( ! temp]ature & "t ! m9]al mu/ be heat$ 9 ord] to obta9 pigm5ts ( def9ite tones4 ,,cologne ,,e>? 7,,cologne ,,umb]7 ,! application ( ! t]m 8umb]0 to ?is e>? c only h be5 bas$ on a c]ta9 simil>ity 9 col\r to true umb]4 ,9 *emical composition1 h[ev]1 ! two are q diff]5t1 ,cologne e>? really consi/+ ( a mixture ( humic sub/ances4 ,x is well kn[n t ! rott$ wood f\nd 9 ! int]ior ( decay+ trees is (t5 a h&some br[n col\r2 & all woody matt]1 aft] ly+ a v long "t1 f9ally acquires ?is col\r1 ow+ to ! trans=mation ( ! wood into d>k-col\r$ comp\nds ri*] 9 c>bon4 ,?is effect c be se5 on ! l>ge scale1 9 ,nature1 9 ! case ( coal1 br[n coal & peat4 ,n[ ,cologne e>? consi/s ( a br[n-coal m\ld1 d>k br[n 9 col\r1 ( e>?y "* & ( su* l[ cohesive p[] t x crumbles ) ease4 ,ow+ to ?is "*1 ,cologne e>? c be easily ignit$ by ! flame ( a c&le1 & !n burns ) a /rong1 smoky flame1 leav+ v little a% & dissem9at+ ! peculi> bitum9\s smell giv5 (f :5 br[n coal is burn$4 ,! geological *>act]i/ics ( ,cologne e>? enable "o to conclude t1 :]e simil> conditions prevail1 mat]ials ( analog\s nature may be discov]$4 ,?is e>? is f\nd emb$d$ 9 a deposit ( br[n coal1 9 :i* x =ms pockets1 & occasionally l>ge bodies4 ,n[1 br[n-coal deposits ( enorm\s ext5t occur 9 v _m localities1 z = in/ance 9 ,upp] ,au/ria & 9 ,bohemia2 & _m ( ^! m9es are sure to conta9 pockets ( br[n-coal m\ld1 :i* h p]haps be5 ov]look$1 b might v well be utilis$ 9 ! prep>ation ( col\rs ( v simil> "* to ,cologne e>?4 ,! prep>ation ( ?is mat]ial is v simple4 ,! e>? com+ f ! deposits is put ?r\gh a simple levigation treatm5t :i* leaves1 z residue1 lumps ( semi-decompos$ wood1 m9]al admixtures1 s&1 etc4 ,! levigat$ e>? is sold 9 ! =m ( cubes4 ,cologne e>? comes into ! m>ket "u v>i\s o!r names1 su* z3 umb]1 ,cassel br[n1 ,spani% br[n1 etc4 ,! fi]y br[n :i* 0 s greatly pref]r$ by ! fam\s pa9t] ,van ,dyck1 & nam$ ,v&yke br[n aft] him1 0 ( v simil> composition to ,cologne e>?1 & is said to h be5 obta9$ f a deep br[n peat e>?4 ,! ,v&yke br[n ( ! pres5t day1 h[ev]1 is almo/ inv>iably a f]ric oxide pigm5t1 ton$ to ! prop] %ade by suitable calc9ation4 ,,asphaltum ,,br[n 7,,bitum57 ,z a natural product1 :i* c be us$ z a pa9t]s' col\r )\t any special prep>ation1 asphaltum 7bi/re1 bitum57 may also be class$ among ! e>? col\rs4 ,*emically1 x is compos$ ( hydroc>bons ( v>i\s k9ds1 & is ?us simil> to t>2 9 fact1 asphaltum may also be reg>d$ z a natural t> result+ f ! decomposition ( v>i\s organic sub/ances4 ,_m deposits ( ?is m9]al are kn[n1 & two ( !m are p>ticul>ly celebrat$3 ^? ( ! ,dead ,sea1 9 ,syria1 & ! ,lake ( ,asphalt1 9 ,tr9idad4 ,bo? deposits consi/ ( crat]s fill$ ) wat] on :i* ! asphaltum floats 9 l>ge cakes4 ,sev]al k9ds ( asphaltum are met ) 9 comm]ce1 rang+ 9 col\r f br[n to black4 ,! prep>ation ( ! mat]ial z a pigm5t is conf9$ to gr9d+ ! mass1 :i* is always ( a l[ degree ( h>dness4 ,be+ readily soluble 9 oil ( turp5t9e & !n furni%+ ! mo/ beautiful br[n tones :5 laid on ?9ly1 ! pigm5t is usually sold 9 ?is condition1 al?\gh x is also gr\nd 9 oil = ! same purpose4 ,f9ally1 x may be m5tion$ t v>i\s useless mat]ials c be trans=m$1 by suitable treatm5t1 into br[n pigm5ts closely resembl+ ,cologne e>? & applicable to ! same uses4 ,su* pigm5ts c be prep>$ f br[n-coal slack 7f inf]ior br[n coal7 or bitum9is$ wood--a v>iety ( br[n coal look+ l *>r$ wood--by treat+ ^! mat]ials ) a lye made f wood a%es & lime1 & wa%+ & dry+ ! residue4 ,,*apt] ,,viii ,,gre5 ,,e>? ,,col\rs ,al?\gh ! numb] ( gre5-col\r$ m9]als is l>ge1 b few ( !m are suitable = pa9t]s' col\rs1 because !y occur s r>ely 9 ,nature t _! employm5t = ?is purpose is out ( ! "q1 m especially s9ce a v l>ge numb] ( gre5 pigm5ts c be obta9$ by artificial means4 ,! mo/ important ( ! e>? col\rs 9 ?is category are ,celadon gre51 or gre5 e>?1 & mala*ite gre5--! latt]1 h[ev]1 less s1 because ! sub/ance ( :i* x is compos$ c be prep>$ artificially4 ,,gre5 ,,e>?1 ,,or ,,celadon ,,gre5 ,?is m9]al is ( a peculi> gre5 col\r1 & ! "n 8,celadon gre50 has be5 univ]sally adopt$ 9 ! nom5clature ( col\r %ades4 ,gre5 e>? occurs native 9 _m places1 be+ ! decomposition product ( an ext5sively di/ribut$ m9]al1 augite1 cry/als ( :i* are f\nd 9 _m ( ! deposits4 ,! gre5 e>? ( ,monte ,valdo1 on ,lake ,g>da 7,upp] ,italy7 has be5 us$ = a v long "t z a pigm5t4 ,x is *iefly prep>$ 9 ,v]ona = di/ribution 9 comm]ce1 & f ?is circum/ance has acquir$ ! "n 8,v]ona gre510 or 8,v]ona e>?40 ,! e>? is also f\nd 9 ,cyprus & ,bohemia1 :]e x frequ5tly occurs z ! decomposition product ( basaltic tuff4 ,h[ev]1 :e!r obta9$ f ,monte ,valdo or else:]e1 ! product is always plac$ on ! m>ket z ,v]ona e>?4 ,native gre5 e>? is always t\gh1 mo/ly occurr+ 9 amygdal\s lumps1 b occasionally 9 ! cry/all9e =m ( augite4 ,x has a f9e-gra9$ fracture1 a h>dness betwe5 #a & #b1 & a sp4 gr4 betwe5 #bh & #bi4 ,! col\r is n always q uni=m1 pure lumps hav+ ! *>act]i/ic ,celadon gre5 appe>ance1 :il/ impure lumps are olive gre5 to blacki% gre54 ,9 *emical composition x is *iefly f]r\s silicate1 & ?is comp\nd mu/ be reg>d$ z ! actual pigm5t>y pr9ciple ( gre5 e>?4 ,9 addition1 x conta9s v>y+ quantities ( o!r comp\nds :i* influ5ce ! dep? ( %ade ( ! product4 ,v]ona e>? *iefly consi/s ( f]r\s oxide 9 comb9ation ) silica2 alum9a1 magnesia1 pota%1 soda & wat] be+ also pres5t4 ,analysis %[s x to conta93 f]r\s oxide1 #ba2 silica1 #ea2 magnesia1 #f2 pota%1 #f2 soda1 #b2 & wat]1 #g4 ,! gre5 e>?s f ,gs51 ,ats*au & ,mnnelsdorf1 ne> ,kaad5 7,bohemia7 & ! ,giant's ,causeway 7,irel&7 h ! foll[+ composition3 ----------------------------------- ,kaad54 ,giant's ,causeway4 ----------------------------------- ,silica #da #efd ,alum9a #c #ba ,f]r\s oxide #bc #ea ,f]ric oxide -- #ada ,lime #h -- ,magnesia #b #ei ,pota% #c #hh ,c>bon dioxide #ai -- ,wat] -- #fh ----------------------------------- ,on acc\nt ( ! l>ge quantity ( me*anically associat$ wat]1 fre%ly dug gre5 e>? is greasy 9 "*1 l wet clay4 ,9 p>tial dry+1 mo/ ( ?is wat] evaporates1 ! mass becom+ e>?y & adh]5t to ! tongue4 ,sometimes ! col\r is an ugly br[ni%-gre51 ow+ to ! pres5ce ( a consid]able am\nt ( f]ric oxide =m$ z ! result ( *anges set up by expos+ ! m9]al to ! air4 ,f]r\s oxide is a v un/able comp\nd1 hav+ an en]getic t5d5cy to comb9e ) m oxyg5 & ?us und]go trans=mation into f]ric oxide2 s t :5 gre5 e>? is left 9 ! air = a long "t1 a consid]able proportion ( its f]r\s oxide is oxidis$ to f]ric oxide1 ! mass !reby assum+ ! br[n tone 9 "q4 ,su* an unsightly product c1 h[ev]1 be conv]t$1 by simple treatm5t1 into "o ( v bright & h&some appe>ance2 & x is ?is possibility t fir/ enabl$ gre5 e>? to atta9 importance z a pa9t]s' col\r4 ,=m]ly x 0 only us$ z a mat]ial = common "w1 be+ add$ to :itewa% or employ$ = indoor pa9ts4 ,:5 ! crude gre5 e>? is treat$ ) v dilut$ hydro*loric acid1 ! comp\nd ( f]r\s oxide & silica is left intact1 b mo/ ( ! extrane\s admixtures are remov$4 ,f]ric oxide1 9 p>ticul>1 passes into solution1 & ! calcium c>bonate l>gely pres5t 9 "s k9ds ( gre5 e>? is also dissolv$4 ,aft] prolong$ contact ) ! crude e>?1 ! acid liquor takes on a br[ni% coloration f ! dissolv$ f]ric oxide4 ,s9ce ! pres5ce ( iron salts has no influ5ce on ! purification ( ! gre5 e>?1 ! mo/ impure1 highly f]rug9\s hydro*loric acid c be us$1 & ! liquor c aft]w>ds be employ$ 9 ! prep>ation ( artificial o*re by leav+ x 9 prolong$ contact ) any /rongly f]rug9\s m9]al1 su* z br[n iron/one1 :i* neutralises ! surplus acid4 ,?is liquor is !n precipitat$ by lime1 alkali1 etc41 ! result+ deposit consi/+ ma9ly ( f]ric hydroxide1 ! fur!r treatm5t ( :i* is conduct$ exactly z describ$ 9 deal+ ) ! prep>ation ( artificial o*re4 ,! treatm5t ( ! crude e>? is be/ c>ri$ on 9 ! same vessels z are to be us$ 9 ! subsequ5t levigation process4 ,aft] ! acid liquor has be5 drawn (f1 ! e>? is br\ght into contact ) wat]1 /irr$ up well1 & ! wat] run (f1 by op5+ tapholes 9 ! side ( ! vessel1 into settl+-tanks1 :]e x is left until all ! susp5d$ matt] has completely subsid$4 ,! col\r ( gre5 e>? c also be ton$ by ! addition ( yell[ o*re1 ?us produc+ a range ( gre5s ) a yell[i% t+e4 ,^! light] %ades1 h[ev]1 are seldom met ) 9 comm]ce1 ! trade judg+ ! quality ( gre5 e>? m p>ticul>ly on ! dep? ( col\r4 ,gre5 e>? is a valuable pigm5t = all k9ds ( pa9t+1 on acc\nt ( its extreme p]man5ce4 ,x may be appli$ directly ov] lime )\t suff]+ any *ange1 :]eas mo/ ( ! *eap gre5 col\rs are de/roy$ 9 l circum/ances4 ,?is behavi\r r5d]s gre5 e>? specially valuable 9 fresco "w1 al?\gh x is also l>gely us$ z an oil col\r4 ,augite is ( frequ5t occurr5ce 9 volcanic di/ricts2 & 9 su* localities1 deposits ( gre5 e>? are c]ta9 to be f\nd4 ,! te/ = ! suitability ( a gre5 e>? consi/s ma9ly 9 treatm5t ) dilute hydro*loric acid4 ,if ! m9]al assumes a h&some gre5 tone1 x w g5]ally =m a useful pigm5t4 ,! te/ may be supplem5t$ by apply+ ! col\r to a fre% coat+ ( :itewa%1 "u :i* conditions x %\ld rema9 unalt]$4 ,,artificial ,,gre5 ,,e>? 7,,gre5 ,,o*re7 ,a product sometimes put on ! m>ket z gre5 e>? or gre5 o*re has no?+ beyond its "n 9 common ) gre5 e>? prop]ly s call$1 except a c]ta9 simil>ity 9 col\r4 ,?is pigm5t is prep>$ by mix+ yell[ o*re to a ?9 pulp ) wat] & add+ ab\t #b 7( ! weight ( o*re7 ( hydro*loric acid4 ,aft] a few days1 a solution ( #b p>ts ( yell[ prussiate ( pota% is add$1 & if ! liquor /ill gives a precipitate :5 te/$ ) f]r\s sulphate1 ?is la/-nam$ salt is add$ s long z su* a precipitate cont9ues to =m4 ,! deposit is wa%$1 & dri$ 9 ! ord9>y way4 ,:5 ! "r proportions h be5 tak51 a pigm5t is obta9$ t co9cides fairly 9 po9t ( tone ) true ,v]ona e>?4 ,x is1 h[ev]1 inf]ior 9 po9t ( p]man5ce1 ! ,b]l9 blue pres5t be+ some:at un/able & decompos+ v quickly :5 br\ght into contact ) lime4 ,! reaction tak+ place 9 ! production ( s-call$ 8artificial ,celadon gre50 is t ! hydro*loric acid us$ dissolves f]ric oxide f ! o*re1 ! addition ( ! yell[ prussiate ( pota% !n =m+ a blue precipitate ( ,b]l9 7,p>is7 blue :i*1 9 conjunction ) ! yell[ ( ! o*re1 gives a gre5-col\r$ mixture4 ,,mala*ite ,,gre5 ,al?\gh ! pigm5t sold "u ?is "n is ne>ly always an artificial product1 x _c be omitt$ f a "w deal+ ) ! e>? col\rs1 because1 9 =m] times1 x 0 prep>$ exclusively f ! m9]al mala*ite4 ,ow+ to ! fact t artificial mala*ite gre5 is "o ( ! *eape/ ( col\rs1 ! tr\blesome "w involv$ 9 ! me*anical prep>ation ( ! native pigm5t has be5 almo/ entirely ab&on$1 & ! mala*ite itself is n[ utilis$ to great] advantage z a s\rce ( copp]4 ,mala*ite gre5 7or m\nta9 gre57 is f\nd 9 ne>ly e case :]e copp] ores exi/1 & is /ill--?\gh v r>ely inde$--prep>$1 9 a few places1 f ! m9]al1 ! d>k-col\r$ lumps be+ pick$ out because ! light]-col\r$ ones w\ld furni% mu* too pale a col\r4 ,! treatm5t ( mala*ite = ! prep>ation ( pigm5t pres5ts c]ta9 difficulties ow+ to ! comp>ative h>dness 7#ce-d7 ( ! m9]al1 :i* is also r heavy 7sp4 gr4 #cf-dj74 ,on ! l>ge scale1 ! select$ m9]al is fir/ put ?r\gh a /amp+-mill1 & !n gr\nd1 v h>d /ones be+ requir$ = ?is purpose4 ,! f9e product f ?is 7usually wet7 process is levigat$ & dri$4 ,! pit wat] ( "s copp] m9es conta9s c]ta9 quantities ( blue vitriol 7copp] sulphate7 9 solution2 & su* pit wat] is g5]ally treat$ = ! recov]y ( a v pure =m ( copp]1 ! s-call$ cem5tation copp]4 ,! liquor might also be work$ up into mala*ite gre51 by collect+ x 9 l>ge tanks & precipitat+ ! dissolv$ copp] oxide ) milk ( lime1 ! blui%-gre5 deposit sep>at+ 9 association ) gypsum be+ trans=m$ into a light mala*ite gre5 by wa%+ & dry+4 ,a d>k] gre51 free f gypsum1 c\ld be prep>$ by us+ a solution ( c>bonate ( soda z precipitant4 ,nei!r ! native nor ! artificial mala*ite gre5 is p>ticul>ly h&some 9 col\r2 & bo? possess1 9 addition1 ! unpleasant prop]ty ( gradually go+ (f col\r 9 ! air1 all ! copp] comp\nds be+ q z s5sitive to sulphurett$ hydrog5 z ^? ( lead1 & f9ally turn+ q black "u ! influ5ce ( t gas4 ,,*apt] ,,ix ,,blue ,,e>? ,,col\rs ,only ?ree m9]als are kn[n to be suitable z pigm5ts2 & inde$1 at pres5t1 only two1 ! ?ird1 lapis lazuli1 be+ n[ ( m]ely hi/orical int]e/4 ,n[adays1 no "o w\ld ?9k ( us+ ?is r>e & exp5sive m9]al z a pigm5t1 s9ce ultram>9e1 :i* has ! same pigm5t>y prop]ties1 is extremely *eap1 :]eas ! pigm5t f lapis lazuli 0 wor? its weight 9 gold4 ,! only two blue e>? col\rs ( any int]e/ at pres5t are mala*ite 7copp]7 blue1 & ! blue iron e>? ,vivianite2 & ev5 ^!1 ?\gh by no means r>e1 are little us$1 s9ce artificial blues are n[ made :i* are f> sup]ior 9 beauty & c be obta9$ s *eaply t ! natural pigm5ts are put out ( competition4 ,,mala*ite ,,blue 7,,lazulite7 ,lazulite & mala*ite 7m\nta9 blue7 are ( frequ5t occurr5ce 9 copp] m9es1 & ! =m] is di/+ui%$ by its beautiful azure blue col\r1 :i*1 h[ev]1 suff]s consid]ably :5 ! cry/als are r$uc$ to p[d]4 ,bo? m9]als are v simil> 9 *emical composition1 & consi/ ( cupric c>bonate4 ,! =mula ( mala*ite is #b;,cu,o,c,o#b ,h#b,o1 t ( lazulite be+ #c;,cu,o7,,co#b7b ,h#b,o1 s t ! only diff]5ce betwe5 !m is t ( ! relative proportions ( ! sub/ances 9 comb9ation4 ,lazulite is also r h>d 7#ce-dj71 b ow+ to ! small size & brittle "* ( ! cry/als x is n v difficult to pulv]ise4 ,9 ! air1 mala*ite blue behaves 9 mu* ! same way z mala*ite gre51 turn+ black 9 pres5ce ( sulphurett$ hydrog54 ,mala*ite blue is *iefly us$ = indoor "w1 & also z a wat] col\r2 b x is always r pale & dull4 ,,vivianite ,?is m9]al--also t]m$ blue o*re--is a trans=mation product ( v>i\s iron ores1 & occurs native z fairly ext5sive deposits 9 "s places1 especially 9 peat bogs4 ,x =ms ill-def9$ cry/als1 :i* are ( a l[ degree ( h>dness 7#bj7 & v>y 9 specific gravity betwe5 #bf & #bg4 ,! col\r ( ! fre%ly won m9]al is :iti% or pale blue1 b soon *anges to a d>k blue 9 ! air1 ow+ to ! oxidation ( ! f]r\s phosphate1 orig9ally pres5t1 into f]ric phosphate4 ,vivianite c be trans=m$ into a pigm5t by a simple process ( cru%+ & levigation2 b ! product is nev] v h&some1 &1 at be/1 is only suitable = q common pa9t "w1 ?\gh *>act]is$ by consid]able /ability4 ,,*apt] ,x ,,black ,,e>? ,,col\rs ,only two m9]als are kn[n t c be us$ z black e>? col\rs1 namely black *alk or %ale black1 & blacklead or graphite4 ,:]eas ! =m] ( ^! is ( m]ely subord9ate importance1 mo/ ( ! black *alks be+ prep>$ artificially1 graphite is all ! m s because x is employ$1 n only z ! sole mat]ial = lead p5cils1 b also = mak+ graphite crucibles1 z blacklead /ove poli%1 z a lubricant1 etc4 ,"o ( its num]\s applications is 9 connection ) ! electro deposition ( metals1 its high electrical conductivity caus+ x to be us$ = coat+ ! int]ior ( ! m\lds 9 :i* ?is deposition is effect$4 ,,graphite ,graphite1 also kn[n z plumbago or blacklead1 consi/s ( c>bon4 ,x is usually spok5 ( z pure c>bon1 b f a v l>ge numb] ( c>efully conduct$ analyses1 x w\ld appe> t native graphite is nev] q pure1 ev5 ! f9e/ grades ( ! m9]al conta9+ #ifh ( c>bon at ! mo/4 ,! accompany+ sub/ances--:i* 9 "s cases =m ne>ly #ej ( ! :ole--are ( div]g5t composition & consi/ ( iron1 silica1 lime1 magnesia & alkalis4 ,ev5 ! combu/ible con/itu5t ( graphite is n pure c>bon1 b always conta9s a c]ta9--?\gh small--proportion ( volatile sub/ances4 ,^! slight traces ( volatile matt] are ( consid]able importance 9 connection ) ! hypo!sis on ! orig9 ( ! m9]al4 ,contr>y to ! old idea1 x is n[ almo/ univ]sally consid]$ t1 in/ead ( be+ ( volcanic orig91 graphite consi/s ( ! rema9s ( long-dead organisms1 & 9 ?is respect is closely relat$ to coal4 ,?is hypo!sis1 h[ev]1 fails to expla9 "o po9t1 namely ! cry/all9e nature ( graphite2 = ev5 an?racites1 :i* =m ! olde/ coals kn[n to h _h _! orig9 9 ! decomposition ( organic sub/ances1 d n reveal ! fa9te/ traces ( cry/all9e /ructure4 ,! uphold]s ( ! !ory t graphite 0 =m$ by ! action ( plutonic =ces adduce1 9 support1 ! fact t graphite c actually be produc$1 9 c]ta9 *emical processes1 at high temp]ature4 ,molt5 ca/-iron 9 cool+ causes ! sep>ation ( c>bon 9 ! =m ( graphite2 & ! same sub/ance is also =m$1 9 l>ge quantities1 9 gas retorts1 ?r\gh ! decomposition ( c]ta9 c>bonace\s comp\nds :5 br\ght into contact ) ! gl[+ walls ( ! retorts4 ,rec5t inve/igations1 h[ev]1 h %[n t ! temp]ature necess>y = ! trans=mation ( non-cry/all9e c>bon into cry/all9e graphite is by no means s high z 0 =m]ly suppos$2 & x is n[ kn[n t ! *ange takes place at z l[ z r$ heat4 ,possibly ! two !ories c\ld be reconcil$ by ! assumption ( a v old coal--su* z is f\nd1 = in/ance1 z an?racite 9 _m p>ts ( ! _w--be+ s /rongly heat$1 by plutonic action1 z to *ange into graphite4 ,native graphite cry/allises 9 ! =m ( hexagons1 mo/ly tabul>2 b really well-develop$ cry/als are ( extremely r>e occurr5ce1 & by f> ! greate/ quantities ( ?is m9]al are f\nd 9 ! condition ( d5se lumps1 9 :i* only ! cry/all9e /ructure1 & n any decid$ cry/als1 c be disc]n$4 ,! h>dness ( ! m9]al fluctuates )9 fairly wide limits1 rang+ f #je to #aj4 ,! sp4 gr4 av]ages #ahjah-ahdd1 b1 9 ! case ( impure lumps may increase to #ai-bb4 ,! foll[+ analyses w give "s idea ( ! consid]able div]g5ce exi/+ betwe5 graphites f diff]5t deposits3-- ,,sib]ian ,,graphite #a #b ,c>bon #idbh #djee ,a% #egb #efef ,wat] -- #bhj ,,portuguese ,,graphite ,c>bon #dbfi ,wat] 7*emically comb9$7 #cif ,a% #ecce ,,bohemian ,,graphite #a #b ,c>bon #faja #fijd ,alum9a #ghj #fhf ,silica #agcd #adah ,magnesia #ajc #jec ,lime #bef #jhj ,f]ric oxide #eed #djj ,pota% #jhg #jia ,wat] & volatiles #cbd #bhi ,sulphur #jea #jfb ,,graphites ,,f ,,upp] ,,/yria #a #b #c ,c>bon #hejj #hgaf #hbba ,a% #adhi #abff #agib #d #e #f ,c>bon #hbdj #haaj #eeej ,silica #abch #aafa #bajj ,alum9a #cij #efj #adef ,f]ric oxide #jec ,manganese protop]oxide #jfb #bjj #dhd ,lime #jjb #bjj #dhd ,alkalis ,trace ,trace #jfb ,sulphur -- -- #jcj ,loss on inc9]ation -- -- #bdc ,( ^! ,/yrian specim5s1 ,nos4 #a-d are crude k9ds1 ( sp4 gr4 #baddc2 ,no4 #e 0 levigat$ 9 ! laboratory1 & ,no4 #f 0 levigat$ f an inf]ior quality at ! m9e4 ,accord+ to ! "* ( ! cry/all9e /ructure1 ! col\r ( graphite v>ies1 b is mo/ly deep black4 ,v pure specim5s1 su* z ! beautiful graphite blocks 7f ! r5[n$ ,alib]t graphite m9es 9 ,sib]ia7 :i*1 z a rule1 are only to be se5 9 exhibitions & m9]alogical collections1 h ! appe>ance ( unpoli%$ /eel or :ite pig iron 7spiegeleis574 ,! mo/ important prop]ty ( native graphite is its l[ h>dness & cohesion1 9 consequ5ce ( :i* x leaves a /reak :5 drawn ov] ! surface ( pap]4 ,graphite seems to be ( frequ5t occurr5ce all ov] ! _w1 ?\gh only few deposits are kn[n :i* yield a product t is suitable = all ! purposes to :i* graphite is appli$4 ,9 ,european c\ntries1 ,au/ria is p>ticul>ly ri* 9 graphite2 & v l>ge deposits ( ?is m9]al are f\nd 9 ,bohemia4 ,consid]able deposits also occur 9 ,bav>ia1 :]e !y h long be5 work$4 ,engli% graphite is celebrat$ = its excell5t quality4 ,all ^! ,european deposits1 h[ev]1 are surpass$1 bo? 9 ext5t & 9 ! quality ( _! products1 by ^? discov]$ 9 ,sib]ia1 ! l>ge/ be+ t produc+ ! a=esaid ,alib]t graphite & situat$1 ne> ! ,*9ese fronti]1 9 ea/]n ,sib]ia4 ,at "o "t1 ,am]ica import$ all h] blacklead p5cils f ,europe1 hav+1 at t p]iod1 no kn[n graphite deposits furni%+ a suitable product4 ,at pres5t1 h[ev]1 deposits ( ?is k9d h be5 f\nd 9 ,cali=nia1 & !re c be little d\bt b t _m o!rs ( ?is valuable m9]al rema9 to be discov]$ 9 t enorm\s cont95t1 ! geological inve/igation ( :i* is /ill f> f be+ complete4 ,! graphite ( "s deposits is s highly contam9at$ by extrane\s m9]als t x _c be utilis$1 s9ce ! co/ ( purification w\ld exce$ ! value ( ! product4 ,on ! o!r h&1 ! pur] k9ds1 :5 suitably ref9$1 yield a graphite t is fully adapt$ to all requirem5ts4 ,! ref9+ process may be ei!r *emical or me*anical1 ! *oice ( me?ods dep5d+ entirely on ! "* ( ! associat$ m9]als4 ,if ^! ma9ly consi/ ( co>se1 /ony fragm5ts1 pref]5ce %\ld be giv5 to me*anical treatm5t2 b if !y are ( su* a "* t !y _c be elim9at$ 9 ?is way1 *emical me?ods mu/ be employ$4 ,sometimes ! two sy/ems are comb9$1 by fir/ subject+ ! graphite to a r\gh me*anical purification1 & !n complet+ ! op]ation ) *emical reag5ts4 ,! me*anical treatm5t consi/s 9 fir/ remov+ z _m ( ! impurities z possible by h&-pick+1 & gr9d+ ! rema9d] 9 edge-runn] mills1 along ) wat]4 ,! turbid liquid1 conta9+ ! p[d]$ graphite & extrane\s m9]als 9 susp5sion1 is l$ ?r\gh long laund]s1 ! sides ( :i* are not*$ at int]vals to all[ ! wat] to ov]fl[ into l>ge pits4 ,! graphite settl+ 9 ! fir/ ( ^! pits conta9s num]\s p>ticles ( ! heavy associat$ m9]als2 b t rema9+ susp5d$ 9 ! wat] & c>ri$ on to ! fur!r pits con/itutes ! bulk4 ,! wat] is left to cl>ify completely 9 ! pits1 & is !n drawn (f1 ! pa/y residue be+ %ap$ into prisms1 :i* are compress$ "u heavy pressure1 to increase _! d5sity1 :5 p>tially dry4 ,al?\gh levigation w remove mo/ ( ! accompany+ extrane\s m9]als1 x _c elim9ate ! a% con/itu5ts ( ! graphite4 ,exp]im5ts made 9 ?is direction h demon/rat$ t ! a% cont5t ( ! levigat$ graphite is exactly ! same z t ( ! crude mat]ial4 ,:il/ ^! a% con/itu5ts d n affect ! quality ( graphite = c]ta9 ( its uses1 !y nev]!less impair its beautiful black col\r to a consid]able degree4 ,! *emical treatm5t necess>y to elim9ate ^! con/itu5ts is att5d$ ) _m difficulties1 ! *ief ( :i* resides 9 ! fact t ! f]ric oxide pres5t is 9 a =m t is n readily accessible to ! action ( *emicals4 ,= ?is reason1 attempts to purify graphite ) crude hydro*loric acid are h>dly likely to prove successful1 s9ce bo? ! f]ric oxide & ! accompany+ silicates ob/9ately resi/ ! action ( ?is acid4 ,9 ord] to obta9 graphite ( a high /ate ( purity1 ! attempt mu/ be made to br+ ?is f]ric oxide & ! silicates into a soluble condition4 ,?is c be accompli%$ 9 v>i\s ways1 & ! *oice ( ! me?od w dep5d on ! purpose = :i* ! graphite is int5d$4 ,= example1 ! op]ations may ei!r be conf9$ to purification1 or else include ! atta9m5t ( a maximum condition ( subdivision4 ,:5 foliace\s graphite has to be treat$--& ?is k9d ( graphite _c1 9 its orig9al condition1 be us$ = mak+ lead p5cils--x is pref]able to employ a me?od :i* w produce bo? ! above results4 ,! purification may consi/ 9 cru%+ ! graphite to p[d]1 & fus+ ?is ) a mixture ( sulphur & c>bonate ( soda1 :]eby ! silicates pres5t are conv]t$ into soluble comp\nds1 & ! f]ric oxide into f]ric sulphide4 ,on extract+ ! melt ) wat]1 a portion ( ! conta9$ salts pass into solution & is c>ri$ (f4 ,! residue is !n treat$ ) dilute hydro*loric acid1 :i* dissolves out ! f]ric sulphide1 ) lib]ation ( sulphurett$ hydrog51 & leaves ! graphite 9 a v pure condition aft] wa%+4 ,9 ord] to r5d] foliace\s graphite suitable = lead p5cils1 a diff]5t me?od is pursu$1 b %\ld only be employ$ 9 special circum/ances1 on acc\nt ( ! exp5se entail$4 ,accord+ to ! process recomm5d$ by ,brodie1 ! graphite1 gr\nd to co>se p[d]1 is mix$ ) ab\t "o-f\rte5? ( its own weight ( *lorate ( pota%1 ?is mixture be+ heat$1 ) two p>ts by weight ( sulphuric to ea* "p ( graphite1 9 a wat] ba? s long z fumes ( hypo*lor\s acid cont9ue to be dis5gag$4 ,! heat+ mu/ be p]=m$ 9 /onew>e or porcela9 vessels1 ^? made ( any o!r mat]ials be+ /rongly corrod$ by ! *lor9e comp\nds =m$4 ,:5 ! evolution ( fumes ceases1 ! mass is all[$ to cool1 & is c>efully wa%$ ) a l>ge volume ( wat]1 ! residue be+ !n dri$ & heat$ to r$ness4 ,dur+ ?is calc9ation ! graphite und]goes a peculi> *ange1 increas+ consid]ably 9 bulk & =m+ an exce$+ly s(t p[d] :i*1 aft] ano!r wa%+1 consi/s almo/ entirely ( *emically pure c>bon4 ,graphite purifi$ 9 ?is way c be us$ = any purpose = :i* ?is mat]ial is employ$1 & may be made into ! f9e/ lead p5cils4 ,h[ev]1 z already m5tion$1 ?is process is usually too exp5sive = g5]al application4 ,! use ( graphite = writ+ is m anci5t ?an is usually suppos$1 hav+ be5 t5tatively employ$ betwe5 #aedj & #aefj4 ,x 0 dur+ ?is p]iod t ! graphite m9es 9 ,cumb]l& 7 discov]$2 & ! extremely pure graphite f\nd !re soon began to be us$ z a writ+ mat]ial4 ,up to ! close ( ! eighte5? c5tury1 lead p5cils 7 made by select+ pure lumps ( graphite & saw+ !m into ?9 rods1 :i* 7 !n encas$ 9 wood5 /icks4 ,ap>t f _! high price1 ^! p5cils exhibit$ v>i\s defects1 "o ( ! *ief be+ t a /ick ( su* p5cil 0 seldom ( uni=m h>dness ?r\gh\t its l5g?1 mo/ ( !m be+ s s(t 9 p>ts z to make a deep black1 sme>y m>k1 :il/ o!r p>ts w\ld h>dly give any m>k at all4 ,! defects inh]5t 9 native graphite are completely remov$ by ! me?od n[ g5]ally employ$ 9 mak+ lead p5cils2 & on ?is acc\nt ! old process ( saw+ ! lumps has be5 ab&on$4 ,graphite ) a f9e e>?y texture alone is suitable = lead p5cils1 scaly v>ieties be+ useless = ?is purpose1 unless specially prep>$1 s9ce !y w n give a solid black /reak4 ,by means ( ! ,brodie process1 h[ev]1 ev5 ! mo/ highly cry/all9e k9ds c be r5d]$ suitable = ?is purpose4 ,sib]ian graphite is di/+ui%$ by extremely high cov]+ p[]1 & is specially pref]r$ = ! manufacture ( p5cils4 ,excell5t v>ieties = ?is purpose are also f\nd 9 _m p>ts ( ,europe2 & inde$1 a l>ge proportion ( all ! lead p5cils us$ ?r\gh\t ! _w are made f ,bohemian1 ,/yrian & ,bav>ian graphite4 ,at pres5t1 all p5cils are made f gr\nd graphite1 ! extremely f9ely gr\nd & levigat$ mat]ial be+ knead$ into a pa/e ) clay4 ,?is op]ation fulfils a tw(old purpose1 ! pla/icity ( ! clay increas+ ! cohesion ( ! individual p>ticles ( graphite1 :il/ ! am\nt ( clay us$ det]m9es ! h>dness ( ! p5cil4 ,! l>g] ! proportion ( clay1 ! h>d] ! p5cil :5 bak$1 & !re=e ! pal] ! m>k ! p5cil w make on pap]4 ,9 ! p5cil factories1 ! clay is incorporat$ 9 special ma*9es2 & ! op]ation requires extreme c>e1 s9ce only a p]fectly uni=m mixture w give a composition ( regul> "* 9 all cases4 ,! intimately mix$ mat]ial is =m$ into ?9 rods1 :i* are dri$ & !n bak$1 ! heat driv+ out ! wat] 9 ! clay & trans=m+ x into a solid mass4 ,an addition to ?is ma9 application ( graphite1 ! m9]al is also us$ = mak+ crucibles1 *iefly = melt+ ! noble metals4 ,crucibles ( ?is k9d are l>gely manufactur$ ne> ,passau1 ,bav>ia1 & simil> crucibles are made 9 ,engl& f ,ceylon graphite4 ,ano!r important use = graphite is z a coat+ = iron articles to protect !m f ru/4 ,= ?is purpose1 h[ev]1 only ! inf]ior k9ds are employ$2 & ^! c also be made up into excell5t cem5ts capable1 9 p>ticul>1 ( (f]+ consid]able resi/ance to ! action ( heat & *emicals4 ,to complete ! tale ( ! applications ( graphite1 its employm5t z a lubricat+ ag5t = ma*9]y1 especially = r$uc+ friction 9 ma*9es made ( wood1 may be m5tion$4 ,latt]ly also1 ! f9e/ levigat$ graphite has come into use1 9 admixture ) solid fats or m9]al oils1 = lubricat+ l>ge eng9es1 = :i* purpose x is excell5tly adapt$4 ,,black ,,*alk ,black *alk1 slate black1 ,spani% *alk1 crayon1 etc41 is n a *alk at all1 9 ! m9]alogical s5se1 b consi/s ( clay %ale ( v>y+ col\r4 ,"s k9ds ( ?is %ale are pure black1 almo/ velvet black1 & ^! are consid]$ ! be/4 ,o!rs h a m greyi% or blui% t+e & are ( l[ value z pigm5ts4 ,! pur] ! black1 ! f9] ! gra9 ( ! mat]ial1 & !re=e ! great] its value to ! col\r-mak]4 ,! v>iety obta9$ f ,spa9 is g5]ally admitt$ to be ! be/1 & = ?is reason ! "n ( ,spani% *alk has be5 appli$ to all simil> m9]als4 ,9 all cases ! black col\r ( ,spani% *alk is due to c>bon2 b ! p>ticul> modification ( c>bon pres5t has n yet be5 accurately id5tifi$4 ,accord+ to "s1 x is *iefly graphite1 :]eas o!rs ascribe ! col\r to amorph\s c>bon4 ,app>5tly1 ! mat]ial f\nd 9 diff]5t deposits conta9s ei!r "o or ! o!r ( ^! modifications ( c>bon4 ,deposits ( black *alk are fairly pl5tiful1 b 9 _m ( !m ! mat]ial is s contam9at$ ) extrane\s m9]als t a some:at tr\blesome me?od ( prep>ation is ne$$ to fit !m = ! purpose ( ! draughtsman4 ,) ?is object1 ! native product mu/ be gr\nd extremely f9e1 & ! p[d] levigat$2 & ow+ to ! exp5se ( ^! processes1 !y are n[ seldom us$1 x be+ possible to obta9 a good black *alk f> m *eaply ?an by levigat+ ! natural mat]ial4 ,?is artificial black *alk is prep>$ by mix+ ord9>y :ite *alk1 or :ite clay1 ) a black col\r+ matt]1 %ap+ ! mass into prisms1 & saw+ ^! into suitable pieces :5 dry4 ,! :ite pigm5t may ei!r be mix$ ) "s v deep black sub/ance1 su* z lampblack1 or /a9$ ) an organic dye/uff1 :i* is1 9 reality1 n black1 b ei!r v d>k blue or gre54 ,! usual col\r+ matt] us$ ) :ite *alk is lampblack1 mix$ to a uni=m pa/e ) ?9 glue1 a suitable am\nt ( clay or *alk be+ incorporat$ ) ! mass4 ,! production ( a p]fectly homog5e\s mixture entails subject+ ! pa/e to a some:at protract$ me*anical treatm5t4 ,:5 ! mass has become p]fectly uni=m ?r\gh\t1 x is %ap$ into prisms1 :i* are expos$ to ! air to dry & are !n cut up ) a saw4 ,in/ead ( prisms1 ! mass c be %ap$ into ?9 /icks1 :i* dry m quickly4 ,a v h&some black *alk c be made1 ) comp>atively little tr\ble1 by treat+ *alk ) a suitable quantity ( logwood decoction previ\sly mix$ ) suffici5t gre5 vitriol solution to r5d] ! liquid a deep black4 ,?is liquid is add$ to ! dry *alk1 intimately mix$ !re)1 & ! pa/y mass %ap$ into /icks4 ,! col\r+ ag5t may be replac$ by a solution ( logwood extract black5$ by ! addition ( a small quantity ( *romate ( pota%2 or black dye/uffs may be us$4 ,,*apt] ,,xi ,,! ,,comm]cial ,,nom5clature ,,( ,,! ,,e>? ,,col\rs ,m5tion has already be5 made ( ! great confusion prevail+ 9 ! nom5clature ( pigm5ts1 & t _m ( ^! are put on ! m>ket "u a v>iety ( names tak5 f diff]5t languages4 ,al?\gh ! numb] ( ! e>? col\rs is f> small] ?an t ( ! artificial col\r+ matt]s1 ! nom5clature is 9 a no less confus$ condition4 ,mo/ frequ5tly1 e>? col\rs are nam$ aft] ! localities :]e !y are ei!r discov]$ or prep>$1 9 comb9ation ) ! ^w indicat+ ! col\r ( ! product--= example3 ,cologne :ite1 ,vi5na :ite--or ! t]m 8e>?0 7,v]ona e>?1 ,v]onese gre51 etc474 ,:il/ ^! names give1 to "s ext5t1 an indication ( ! nature ( ! pigm5t1 o!rs h no ref]5ce to x at all2 su* z colco?>1 bole1 umb]1 etc4 ,f9ally1 a numb] ( o!r names 9 use are calculat$ to produce ! impression t ! e>? col\rs 9 "q are ( an entirely diff]5t nature to _! real "o4 ,z an example1 we may cite ! "n 8,fr5* *alk10 :i* is n a *alk at all1 b consi/s ( ! m9]al talc4 ,black *alk1 aga91 is n *alk 7calcium c>bonate71 b a black %ale2 & graphite is (t5 t]m$ blacklead1 al?\gh x conta9s no lead at all1 & ! "n is m]ely a survival f ! "t :5 p5cils ( metallic lead 7 us$ = draw+4 ,9 ord] to br+ "s k9d ( ord] into ! v>i\s names :i* are appli$ to ! e>? col\rs1 a li/ ( ^? 9 curr5t use is app5d$4 ,_m ( ^! names1 x may be /at$1 h be5 select$ 9 a purely arbitr>y mann]1 "s manufactur]s1 = in/ance1 sell+ ord9>y *alk "u a v>iety ( =eign names1 = ! purpose ( !reby obta9+ high] prices4 ,^! borr[$ names w\ld seem to be sup]flu\s1 to say ! lea/4 ,pure & prop]ly levigat$ *alk is ! same article ev]y:]e1 :e!r prep>$ f ,engli%1 ,fr5* or ,g]man lime/one2 & 9 all cases ! simple "n1 8*alk10 ) an explanatory 8s+le10 8d\ble10 or 8triple0 levigat$1 %\ld be q suffici5t4 ,9 ! case ( e>? col\rs t are really obta9$ ( special quality 9 c]ta9 localities1 su* z t]ra di ,si5a1 gre5 e>? f ,v]ona1 or ! l1 ! correspond+ "n might be reta9$1 ev5 if ! pigm5t did n orig9ate f ! locality 9 "q1 z a g5]ic t]m = a pigm5t possess+ c]ta9 prop]ties & ( a c]ta9 composition4 ,9 ! foll[+ classification1 ! names ( ! e>? col\rs are giv5 9 accordance ) _! col\r & *emical composition4 ,,:ite ,,e>? ,,col\rs ,c>bonate ( ,lime3 ,*alk2 levigat$ *alk2 ,vi5na :ite2 ,spani% :ite2 m>ble :ite2 arti/s' :ite2 ,b\gival :ite2 ,*ampagne *alk2 ,p>is *alk2 ,cologne *alk2 ,m\nta9 *alk2 craie2 blanc m9ral2 ,blanc de ,*ampagne2 ,blanc de ,meudon2 ,blanc de ,b\gival2 ,blanc de ,troyes2 ,blanc d',orleans2 ,blanc de ,r\52 ,blanc de ,brianon4 ,basic ,c>bonate ( ,lime3 ,vi5na :ite2 ,vi5na lime2 pe>l :ite2 :it+2 ,blanc de *aux2 ,blanc de ,vi5ne4 ,note4--,! calc>e\s m>ls1 consi/+ ( c>bonate ( lime & clay1 are also frequ5tly sold "u ! above names1 ! same be+ ! case ) gypsum4 ,silicate ( ,alum9a3 ,:ite e>?2 pipeclay2 ,dut* :ite2 ,cologne e>?2 t]re d',argile2 ,argile blanc2 ,t]re blan*e4 ,silicate ( ,magnesia 7m9]alogically1 talc & soap/one73 ,talc2 ,v5etian e>?2 ,fr5* *alk2 ,v5etian :ite2 glossy :ite2 fea!r :ite2 %ale :ite2 face-p[d] :ite2 ,blanc de ,v5ise2 ,blanc d',espagne2 ,blanc de f>d4 ,note4--,f9e grades ( :ite lead are also sold z ,v5etian :ite1 ,spani% :ite & %ale :ite2 b c easily be recognis$ by _! weight4 ,! t]m 8prep>$0 :ite1 frequ5tly appli$ to e>? col\rs 9 ! trade1 usually indicates t ! mat]ial 9 "q has be5 ei!r levigat$1 gr\nd or burnt--9 %ort1 put ?r\gh "s k9d ( prep>atory treatm5t--& is !re=e 9 frequ5t use = all ! col\rs4 ,b>ium sulphate3 ,heavy sp>2 b>ytes2 heavy e>?2 m9]al :ite4 ,precipitat$ col\rs3 ,p]man5t :ite2 blanc fixe4 ,,yell[ ,,e>? ,,col\rs ,f]ric hydroxide1 ) admixtures ( f]ric oxide1 clay1 lime1 f]ric silicate1 basic f]ric sulphate1 etc4 ,o*re2 iron o*re2 gold5 o*re2 sat9 o*re 7sat9ob]72 pit o*re2 vitriol o*re2 ,m>s yell[2 ,*9ese yell[2 ,imp]ial yell[2 p]man5t yell[2 t]ra di ,si5a2 umb]2 ,italian e>?2 ,roman e>?2 bronze o*re2 oxide yell[1 etc4 ,yell[ o*re2 ,jaune de ,m>s2 ,t]re d',italie4 ,f]ric ,silicate3 ,yell[ e>?2 ,argile jaune2 yell[ wa%4 ,,r$ ,,e>? ,,col\rs ,f]ric oxide 7) alum9a & silica74 ,bolus2 bole2 ,t]ra sigillata2 ,lemnos e>?2 r$ *alk2 raddle2 ,/riegau e>?4 ,f]ric oxide3 ,colco?>2 ,engli% r$2 angel r$2 ,pompeii r$2 ,p]sian r$2 ,indian r$2 ,b]l9 r$2 ,naples r$2 ,nuremb]g r$2 crocus2 *emical r$2 ,crocus ,m>tis iron saffron2 caput mortuum2 raddle2 r\ge de f]2 ,r\ge de ,p]se2 ,r\ge des ,indes2 ,r\ge de ,m>s2 ,r\ge d',anglet]re4 ,,br[n ,,e>? ,,col\rs ,f]ric oxide3 ,f]ric hydroxide2 ,f]ric silicate 7conf4 ,yell[ ,e>? ,col\rs1 :i* are (t5 sold "u ! same names z ! br[ns4 ,! pal] k9ds are usually call$ 8pale0 or 8gold510 su* z pale o*re1 gold5 o*re1 etc474 ,t]ra di ,si5a2 burnt ,si5a2 sat9ob]2 mahogany br[n2 ,v&yke br[n4 ,f]ric silicate1 ,clay3 ,umb]2 umb] br[n2 ,roman e>?2 ,roman umb]2 ,turki% br[n2 ,sicilian br[n2 ,cyprus e>?2 *e/nut br[n2 burnt umb]2 ombre2 ,t]re d'ombre2 ,ombre brule4 ,organic decomposition products3 ,cologne umb]2 ,cologne e>?2 ,cassel br[n2 ,spani% br[n2 mahogany br[n2 ,v&yke br[n2 br[n c>m9e2 ,t]re brun de ,cologne2 ,brun de ,cologne2 ,brun d',espagne2 ,ombre de ,cologne2 ,brun de ,cassel2 ,t]re d',ombre2 ,cologne br[n4 ,asphaltum 7m9]al ros973 ,asphaltum br[n2 bi/re2 e>? br[n2 bitum52 pit* br[n2 ,asphalte2 ,brun de bitume2 ,bitume4 ,,gre5 ,,e>? ,,col\rs ,f]r\s oxide ) silica1 alum9a1 lime1 etc43 ,gre5 e>?2 ,v]ona gre52 ,celadon gre52 ,v]ona e>?2 ,italian gre52 /one gre52 ,bohemian e>?2 ,cyprus e>?2 ,tyrol gre52 p]man5t gre52 gre5 o*re2 ,t]re v]te2 ,t]re de ,vrone2 ,v]t d',italie4 ,cupric c>bonate3 ,mala*ite gre52 m\nta9 gre52 ,hung>ian gre52 copp] gre52 m9]al gre52 ,tyrolese gre52 %ale gre52 ,v]t de montagne2 ,v]t d',hongrie4 ,,blue ,,e>? ,,col\rs ,cupric c>bonate3 ,mala*ite blue2 m\nta9 blue2 lazulite blue2 azure blue2 m9]al blue2 copp] blue2 ,hamburg blue2 ,engli% blue2 ,c5dres bleues2 ,bleu d'azure2 ,bleu de cuivre2 ,v]t-de-gris bleu2 blue v]dit]4 ,,grey ,,e>? ,,col\rs ,grey clay %ale3 ,m9]al grey2 silv] grey2 /one grey2 slate grey4 ,,black ,,e>? ,,col\rs ,c>bon3 ,graphite2 blacklead2 plumbago2 iron black4 ,clay %ale3 ,black *alk2 slate black2 ,spani% black2 ,spani% *alk2 oil black2 ,s*i/e noir2 ,noir d',espagne4 ,,index ,alaba/]4 ,see ,gypsum4 ,alum9a1 silicate (1 #ba1 #bb ,alum9ium-potassium silicate1 #ba ,alum sludge1 #cb ----1 artificial o*re f1 #adh ----1 f]ric oxide pigm5ts f1 #afd-afg ,ammonium salts1 artificial o*re f1 #ade1 #adf ,anhydrite1 #ai ,an?racolite1 #ac ,arragonite1 #ac ,asphaltum1 #cg1 #ch4 ,see also ,bitum54 ----1 br[n1 #agd1 #age ,augite1 #agi ,azurite1 #cc ,ball ,mills1 #ee-ef ,b>ium c>bonate1 #bj ---- sulphate4 ,see ,b>ytes4 ,b>ytes1 #ai1 #bj1 #aai-abb ----1 artificial1 #acc ----1 correct+ col\r (1 #aba ----1 detect+1 9 :ite lead1 #abj ----1 l[ cov]+ p[] (1 #aba ,black *alk1 #ch ---- e>? col\rs1 #ahe-aif ---- ----1 trade names (1 #bjb ---- e>?s1 #f1 #ch-ci ---- s*i/1 #ch ,bitum51 #agd1 #age ,blanc fixe1 #ai ,blue e>? col\rs1 #ahc-ahd ---- ----1 trade names (1 #bjb ---- e>?s1 #d1 #cc-cf ,bole1 #ca1 #cb1 #aeb-aed ,bone breccia1 #ac ,br[n coal1 pigm5ts f1 #age ---- e>? col\rs1 #afh-age ---- ----1 trade names (1 #bjj ---- e>?s1 #e1 #cf-ch ,calc>e\s m>l1 #aaj1 #aaa ---- tuff1 #ab ,calc9+1 #ha ---- ,f]ric oxide1 #afa-afd ---- furnaces4 ,see ,furnaces4 ---- lime1 #hh-ij ---- o*re1 #acb-acf ,calcite1 #aa1 #ab1 #ad1 #ae ,calcium c>bonate1 #ab1 #ad1 #ae1 #af ---- ----1 action ( acids on1 #ae ---- hydroxide1 #af ---- sulphate4 ,see ,gypsum4 ,calc s9t]1 #ab ---- sp>4 ,see ,calcite4 ,cal$onian br[n1 #cf ,cappagh br[n1 #cf ,caput mortuum4 ,see ,colco?>4 ,c>bon br[n1 #cg ---- 9 lime/one1 #af ,cassel br[n1 #cg1 #ch1 #agd ,celadon gre54 ,see ,gre5 e>?4 ,*alk1 #ac ----1 black1 #aid-aif ----1 col\r (1 #ajc ----1 correct+ col\r (1 #ajd1 #aje1 #ajf ----1 cov]+ p[] (1 #ajf ----1 gr9d+1 #aja ----1 impurities 91 #ajc1 #ajd ----1 precipitat$1 #ajg-aji ----1 prep>ation & prop]ties (1 #ih-ajf ,classification ( e>? col\rs1 #d-h ,clay1 #ba-bc ,clay1 =mation (1 #aac ----1 impurities 91 #aad-aai ---- 9 o*re1 #abh ----1 levigat+1 #aad-aag ,colco?>1 #afj1 #afa1 #afb ,cologne e>?1 #agc1 #agd ,comm]cial nom5clature ( e>? col\rs1 #aig-bjb ,cru%]s & ,break]s1 #dc-de ,cru%+1 #gg-hj ---- ma*9]y1 #dc-fj ,dis9tegrators1 #eh-fj ,di/emp]1 wea!rpro(1 #id ,dolomite1 #ah ,dra9+ & ,dry+1 #ff-gg ,dry+ appliances1 #gc-gg ,dye/uffs = improv+ e>? col\rs1 #he ,edge runn]s1 #dh-ee ,engli% r$1 #afj ,f]ric hydroxide 9 o*re1 #abh-acb ---- oxide1 artificial o*re f1 #adc-add ---- ---- z by-product1 #cj ---- ----1 burnt1 #aeh-afd ---- ----1 calc9+1 #afa-afd ---- ---- 9 lime1 detection (1 #ia ---- ----1 native1 z pigm5t1 #aed ---- ---- pigm5ts f alum sludge1 #afd-afg ---- ----1 range ( col\rs1 #bi ---- ---- %ad+1 #bh ---- ----1 violet %ades f1 #afd ,f]r\s sulphate1 artificial o*re f1 #aci-adc1 #adf-adh ,filt]-clo?s1 clean+1 #gb ,filt]-presses1 #gj-gc ,furnaces1 calc9+1 #aeh1 #afb1 #afc1 #aff ,granulator1 #dc ,graphite1 #ch1 #ci1 #ahe-aid ---- z a lubricant1 #aid ---- z anticorrosive1 #aid ,graphite 9 ! manufacture ( lead p5cils1 #aia-aic ---- = crucibles1 #aic ----1 ref9+1 #ahi-aib ,gre5 e>?1 #agf-ahj ---- ----1 artificial1 #ahj ---- ----1 improv+1 #agh ---- ---- col\rs1 #agf-ahd ---- ----1 trade names (1 #bja ---- e>?s1 #e ,grey e>? col\rs1 trade names (1 #bjb ,grey e>?s1 #ch ,gypsum1 #ah1 #ai1 #aaa1 #aab ,heavy sp>4 ,see ,b>ytes4 ,hematite1 #aee ----1 br[n1 #bc1 #cj1 #ca ----1 r$1 #bh1 #cj ,hydro-extractor1 #ff-gj ,improv+ e>? col\rs1 #hd1 #he ,indian r$1 #bi1 #afj ,iron cream1 #bi ---- glance1 #aed ---- 9 lime/one1 #ag ---- ore1 bog1 #be1 #ca ---- ----1 micace\s1 #bh ,iron/one1 br[n1 #bc1 #bd1 #be ----1 clay1 #bd ----1 r$1 #bh-cj ,kaol91 #ba1 #bb1 #aab-aai ,lazulite1 #ahc ,lemnos e>?4 ,see ,bole4 ,levigation1 #fj-fe ,lime1 absorption ( c>bon dioxide by1 #ic ----1 action (1 on case91 #id ----1 ----1 on col\rs1 #ic1 #ih ----1 calc9+1 #hh-ij ----1 cau/ic1 prep>ation (1 #hg-id ----1 d\ble comp\nd ( oxide & c>bonate1 #ic ---- f mussel %ells1 #ih ----1 impurities 91 #ia1 #ib ---- 9 clay1 #bb ---- ----1 elim9at+1 #aag-aai ---- 9 o*re1 #abi ,lime 9 ! prep>ation ( artificial o*re1 #adj-add ----1 m\ld+1 #if-ih ----1 quick1 #af ----1 slak$1 #af ,lime/one1 #aa-ah ----1 suitability (1 = col\r-mak+1 #ib ,limonite1 #be ,magnesia1 c>bonate (1 #abc1 #abd ---- 9 lime1 #ia ---- 9 lime/one1 #ag ,magnesium silicate1 #ba ,mala*ite1 #ce ---- blue1 #ahc ,m>ble1 #aa1 #ad1 #ae ,m9]als1 te/+ = suitability z pigm5ts1 #agb ,m9e sludge1 #cb ,mix+ e>? col\rs1 #ha-hd ,m\ld+1 #he1 #hf ,m\nta9 *alk1 #ab ---- milk1 #ab ,muffle1 burn+ o*re 9 !1 #aeh-afj ,muriacite1 #ai ,mus*elkalk1 #ac ,o*re1 #bd1 #be1 #bf ----1 blue4 ,see ,vivianite4 ----1 calc9+1 #acb-acf ----1 ,engli%1 #ach ----1 gre51 #ahj ----1 pit1 #adh-aej ----1 ,roman1 #acg1 #ach ----1 ,si5a1 #acg1 #ach ----1 te/+1 #acj-acb ----1 ton+ ) *alk1 #add ----1 ton+ ) clay1 #add ----1 vitriol1 #adf-adh ,o*res1 #abh-aej ----1 artificial1 #ach-adf ---- z by-products1 #adf-aej ----1 burnt1 #aeh-afd ---- f v>i\s deposits1 #acf-ach ----1 ,italian1 #acg1 #ach ,ooli?ic lime/one1 #ac ,organic matt] 9 lime1 #ia ,pa/el crayons1 #abf ,pe>l :ite1 #id ,p]man5t :ite1 #ai1 #abb ,pipeclay4 ,see ,kaol94 ,prep>ation ( col\r e>?s1 #dj-hf ,pulv]is]s1 #ef-eh ,raddle1 #bi1 #aee-aeh ----1 impurities 91 #aef ----1 te/+1 #aeg ,raw mat]ials = e>? col\rs1 #h-ci ,r$ e>? col\rs1 #aea-afg ---- ----1 trade names (1 #bjj ,r$ e>?s1 #d1 #bg-cc ,sampl+ raw e>?s1 #i ,sel5ite1 #ah ,%ad+ pigm5ts ) p]man5t :ite1 #ai ,si5a1 ,t]ra di1 #be1 #bf1 #bg1 #afh-agj ----1 ----4 ,see also ,italian o*re4 ,sid]osilicate1 #aga ,sift+1 #gg-hj ,soap/one1 #bj1 #ba4 ,see also ,/eatite4 ,spani% br[n1 #agd ,sprudel/e91 #ae ,/eatite1 #bj1 #ba1 #abe1 #abf ,/amps1 #de-dh ,talc1 #bj1 #ba1 #abd1 #abe ,t]ra sigillata4 ,see ,bole4 ,te/+ purity ( raw e>?s1 #aj ,trade names ( e>? col\rs1 #aig-bjb ,ultram>9e1 #cc ,umb]1 #cf1 #agj-agd ----1 ,cologne1 #agc1 #agd ----1 true1 #agj-agc ,v&yke ,br[n1 #ch1 #agd ,v]milion1 #aea ,v]ona e>?4 ,see ,gre5 e>?4 ,vi5na :ite1 #ie-ih ,vivianite1 #cc1 #cd1 #ahd ,:ite e>? col\rs1 #hg-abf ,:ite e>?1 trade names (1 #aaa1 #aih1 #aii ,:ite e>?s1 #d ,:ite raw mat]ials & pigm5t>y e>?s1 #aa-bc ,)]ite1 #bj ,work+ e>? col\r deposits1 #i ,yell[ e>? col\rs1 #abg-aej ---- ----1 trade names (1 #ajj ,yell[ e>?1 #aej ,yell[ e>?s1 #d1 #bc-bg ,,pr9t$ ,,9 ,,great ,,brita9 ,,by ,,ri*>d ,,clay ,,sons1 ,,limit$1 ,,p>is ,,g>d51 ,,/am=d ,,/41 ,s4,e41 ,,& ,,bungay1 ,,suffolk4 ,! ,manufacture ( ,pa9t ,,! ,,practical ,,h&book ,,= ,,pa9t ,,manufactur]s1 ,,m]*ants ,,& ,,pa9t]s ,,by ,j4 ,,cruick%ank ,,smi?1 ,b4,sc4 ,second ,edition--,revis$ & ,enl>g$ ,,demy #h,,vo4 #gc ,,illu/rations4 #cjj ,,pages ,,cont5ts ,,*ap4 ,,"p ,i ,i4--,,scope ,,( ,,subject ,,& ,,def9ition ,,( ,,t]ms4 ,,ii4--,,/or+ ,,& ,,h&l+ ,,raw ,,mat]ial4 ,,iii4--,,te/+ ,,& ,,valuation ,,( ,,raw ,,mat]ial4 ,,"p ,,ii ,,iv4--,,plant ,,& ,,ma*9]y4 ,,"p ,,iii ,v4--,,! ,,gr9d+ ,,( ,,:ite ,,pigm5ts4 ,,vi4--,,! ,,gr9d+ ,,( ,,e>? ,,pigm5ts4 ,,vii4--,,! ,,oxide ,,( ,,iron ,,pigm5ts4 ,,viii4--,,! ,,gr9d+ ,,( ,,black ,,pa9ts4 ,,ix4--,,! ,,gr9d+ ,,( ,,*emical ,,col\rs4 ,x4--,,! ,,gr9d+ ,,( ,,pigm5ts ,,9 ,,wat]4 ,,xi4--,,! ,,gr9d+ ,,( ,,col\rs ,,9 ,,turp5t9e1 ,,gold ,,size1 ,,& ,,special ,,m$iums4 ,,"p ,,iv ,,xii4--,,mix$ ,,or ,,prep>$ ,,pa9ts4 ,,xiii4--,,enamels ,,& ,,enamel ,,pa9ts4 ,,"p ,v ,,xiv4--,,mod]n ,,conditions ,,:i* ,,affect ,,! ,,selection ,,& ,,application ,,( ,,pa9t4 ,,xv4--,,! ,,design+1 ,,te/+ ,,& ,,mat*+ ,,( ,,pa9ts4 ,,xvi4--,,co/ ,,*>ges--,,co/ ,,( ,,h&l+--,,c>riage ,,& ,,deliv]y ,,( ,,goods--,,co/ ,,( ,,mat]ials--,,ma*9]y ,,z ,,affect+ ,,manufactur+ ,,co/--,,electricity ,,z ,,motive ,,p[]--,,manufactur+ ,,onco/--,,prices--,,! ,,future ,,( ,,! ,,indu/ry4 ,price #abs4 #f;d4 net 7,po/ ,free1 #acs4 #c;d4 ,home & ,abroad74 ,,publi%$ ,,by ,,scott1 ,,gre5wood ,,son1 #h ,broadway1 ,ludgate1 ,london1 ,e4,c4 #d ,! ,*emi/ry ( ,pigm5ts ,,by ,,erne/ ,j4 ,,p>ry1 ,b4,sc41 7,,lond471 ,f4,i4,c41 ,f4,c4,s4 ,,& ,,john ,h4 ,,co/e1 ,f4,i4,c41 ,f4,c4,s4 ,demy #hvo4 #e ,illu/rations4 #bhj ,pages ,,cont5ts ,*apt] ,i4--,introductory ,light--,:ite ,light--,! ,spectrum--,! ,invisible ,spectrum--,normal ,spectrum--,simple ,nature ( ,pure ,spectral ,col\r--,! ,recomposition ( ,:ite ,light--,prim>y & ,complem5t>y ,col\rs--,col\r$ ,bodies--,absorption ,spectra4 ,*apt] ,,ii4--,! ,application ( ,pigm5ts ,uses ( ,pigm5ts3 ,arti/ic1 ,decorative1 ,protective--,me?ods ( ,application ( ,pigm5ts3 ,pa/els & ,crayons1 ,wat] ,col\r1 ,temp]a ,pa9t+1 ,fresco1 ,encau/ic ,pa9t+1 ,oil-,col\r ,pa9t+1 ,c]amic ,art1 ,enamel1 ,/a9$ & ,pa9t$ ,glass1 ,mosaic4 ,*apt] ,,iii4--,inorganic ,pigm5ts ,:ite ,lead--,z9c ,:ite--,enamel ,:ite--,:it5+--,r$ ,lead--,li?>ge--,v]milion--,royal ,sc>let--,! ,*romium ,gre5s--,*romates ( ,lead1 ,z9c1 ,silv] & ,m]cury--,brunswick ,gre5--,! ,o*res--,indian ,r$--,v5etian ,r$--,si5nas & ,umb]s--,light ,r$--,cappagh ,br[n--,r$ ,oxides--,m>s ,col\rs--,t]re ,v]te--,prussian ,br[n--,cobalt ,col\rs--,cruleum--,smalt--,copp] ,pigm5ts--,mala*ite--,brem5 ,gre5--,s*eele's ,gre5--,em]ald ,gre5--,v]digris--,brunswick ,gre5--,non-ars5ical ,gre5s--,copp] ,blues--,ultram>9e--,c>bon ,pigm5ts--,ivory ,black--,lamp ,black--,bi/re--,naples ,yell[--,ars5ic ,sulphides3 ,orpim5t1 ,realg>--,cadmium ,yell[--,v&yck ,br[n4 ,*apt] ,,iv4--,organic ,pigm5ts ,prussian ,blue--,natural ,lakes--,co*9eal--,c>m9e--,crimson--,lac ,dye--,sc>let--,madd]--,aliz>9--,campea* y--,qu]citron--,rhamnus--,brazil ,wood--,alkanet--,santal ,wood--,ar*il--,coal-t> ,lakes--,r$ ,lakes--,aliz>9 ,comp\nds--,orange & ,yell[ ,lakes--,gre5 & ,blue ,lakes--,indigo--,dragon's ,blood--,gamboge--,sepia--,indian ,yell[1 ,puree--,bitum51 ,asphaltum1 ,mummy--,index4 ,price #abs4 #f;d4 net 7,po/ ,free1 #acs4 #c;d4 ,home & ,abroad74 ,,publi%$ ,,by ,,scott1 ,,gre5wood ,,son1 #h ,broadway1 ,ludgate1 ,london1 ,e4,c4 #d ,transcrib]'s ,notes ,m9or use ( boldface 9 ! adv]tisem5ts is n %[n 9 ! ,pla9 ,text v]sion ( ?is book4 ,punctuation1 hyph5ation1 & spell+ 7 made consi/5t :5 a pr$om9ant pref]5ce 0 f\nd 9 ! orig9al book2 o!rwise !y 7 n *ang$4 ,simple typographical errors 7 correct$2 unbalanc$ quotation m>ks 7 rem$i$ :5 ! *ange 0 obvi\s1 & o!rwise left unbalanc$4 ,illu/rations 9 ?is e,book h be5 position$ betwe5 p>agraphs & outside quotations4 ,! index 0 n *eck$ = prop] alphabetization or correct page ref]5ces4