,photographic ,reproduction ,processes ,a ,practical ,treatise ( ! ,photo-,impressions ,)\t ,silv] ,salts ,by ,p4,c4 ,du*o*ois ,new ,york ,! ,scovill ,adams ,company #dbc ,broome ,/reet4 #ahia ,,cont5ts ,,introduction4 ,,! ,,designs4 ,,! ,,cyanotype ,,or ,,blue ,,process4 ,,! ,,cyan(]4 7,pellet's ,process47 ,,! ,,black ,,or ,,ink ,,process4 7,f]ro-tannate ,process47 ,,! ,,cuprotype4 7,burnett's ,process47 ,,! ,,anil9e ,,process4 ,,! ,,primul9e ,,or ,,diazotype ,,process4 ,,trac+ ,,process ,,on ,,metal4 ,,graphotypy4 ,,! ,,uranotype4 ,,! ,,plat9otype4 ,,artigues' ,,process ,,! ,,c>bon ,,process4 ,,app5dix4 ,,illu/rations ,a ,t\rnette ,*>don's me?od ( coat+ ,,prep>]',s ,,note ,please rememb] t ?is book 0 publi%$ ov] a c5tury ago1 long be=e today's *emical safety /&>ds4 ,please get exp]t advice be=e attempt+ to p]=m any ( ! proc$ures describ$ 9 ?is book4 ,,au?ors ,,quot$ ,artigues4 ,bevan1 ,e4,j4 ,b+ham ,borl9etto ,brasseur1 ,*s4 ,buckle4 ,burnett1 ,c4 ,j4 ,*>don ,*eysson ,colas4 ,coop]1 ,h4 ,cross1 ,c4 ,f4 ,de la ,blan*re1 ,h4 ,de ,/4 ,flor5t ,drap]1 ,dr4 ,john ,ducos du ,hauron ,dum\l91 ,e4 ,endemann1,h4 ,fis*1 ,a4 ,godefroy4 ,gre51 ,a4 ,g4 ,graubassi ,h>man1 ,alfr$4 ,h]s*el1 ,sir ,john4 ,h\doy ,hbl1 ,b>on4 ,hunt1 ,rob]t ,liesegang1 ,dr4 ,l4 ,loeffl]1 ,j4 ,monckhov51 ,dr ,von4 ,nipce1 de ,/4 ,victor ,ob]nett]1 ,j4 ,b4 ,pellet4 ,p]soz4 ,phipson1 ,dr4 ,pizzighelli1 ,capta9 ,j4 ,poitev91 ,a4 ,roy1 ,paul ,sella1 ,v4 ,j4 ,smee1 ,pr(essor ,/ephan[ski1 ,k>l4 ,swan1 ,j4 ,w4 ,willis1 ,william ,wo?ly1 ,j4 ,x4 ,,introduction4 ,! photographic processes ) ! salts ( iron are all d]iv$ f ! rese>*es ( ,sir ,john ,h]s*el4 ,! inve/igations ( t great philosoph] are s valuable1 s full ( in/ructions t we are l$ to repr9t !m1 toge!r ) ^? ( ,mr4 ,c4 ,j4 ,burnett1 on ! salts ( uranium1 etc41 z an ,introduction4 ,x w be se5 t ! process by :i* blue pr9ts are to-day obta9$ is exactly t ,sir ,john ,h]s*el devis$ 9 #ahdj4 8,x is no long] an insulat$ & anomal\s affection ( c]ta9 salts ( silv] or gold1 b "o :i*1 d\btless1 9 a great] or less degree1 p]vades all nature1 & connects itself intimately ) ! me*anism by :i* *emical comb9ation & decomposition is op]at$4 ,! g5]al in/ability ( organic comb9ations might lead u to expect ! occurr5ce ( num]\s & rem>kable cases ( ?is affection among bodies ( t class1 b among metallic & o!r elem5ts inorganically arrang$1 in/ances en\gh h already appe>$1 & m are daily pres5t+ !mselves1 to ju/ify its ext5sion to all cases 9 :i* *emical elem5ts may be suppos$ comb9$ ) a c]ta9 degree ( laxity1 & s to speak 9 a tott]+ equilibrium4 ,!re c be no d\bt t ! process1 9 a great majority1 if n 9 all cases1 :i* h be5 notic$ among inorganic sub/ances1 is a deoxidiz+ "o1 s f> z ! m refrangible rays are conc]n$4 ,x is obvi\sly s 9 ! cases ( gold & silv]4 ,9 ! case ( ! bi*romate ( pota% x is mo/ probable t an atom ( oxyg5 is p>t$ )1 & s ( _m o!rs4 ,a beautiful example ( su* deoxidiz+ action on a non-arg5t9e comp\nd has lately occurr$ to me 9 ! exam9ation ( t int]e/+ salt1 ! f]rosesquicyanuret ( potassium describ$ by ,mr4 ,smee 9 ! ,philosophical ,magaz9e1 ,no4 #aji1 ,septemb]1 #ahdj1 & he has %[n h[ to manufacture 9 abundance & purity1 by voltaic action on ! common or yell[ f]rocyanuret4 ,9 ?is process nasc5t oxyg5 is absorb$1 hydrog5 giv5 (f1 & ! *>act]s ( ! result+ comp\nd 9 respect ( ! oxides ( iron1 =m+ z x does ,prussian blue ) proto salts1 indicate an excess ( electro-negative en]gy1 a disposition to "p ) oxyg51 or :i* is ! same ?+1 to absorb hydrog5 79 ! pres5ce ( moi/ure71 & !reby to return to its pri/9e /ate1 "u circum/ances ( mod]ate solicitation1 su* z ! aff9ity ( protoxide ( iron 7= in/ance7 = an additional dose ( oxyg51 etc40 8,pap] simply wa%$ ) a solution ( ?is salt is highly s5sitive to ! action ( ! light4 ,prussian blue is deposit$ 7! base be+ necess>ily suppli$ by ! de/ruction ( "o portion ( ! acid1 & ! acid by ! de/ruction ( ano!r74 ,aft] half an h\r or an h\r's exposure to sun%9e1 a v beautiful negative photograph is ! result1 to fix :i*1 all t is necess>y is to soak x 9 wat] 9 :i* a little sulphate ( soda is dissolv$4 ,:ile dry ! impression is ( a dove color or lav5d] blue1 :i* has a curi\s & /rik+ effect on ! gre5i% yell[ gr\nd ( ! pap] produc$ by ! sal9e solution4 ,aft] wa%+ ! gr\nd color disappe>s & ! photograph becomes bright blue on a :ite gr\nd4 ,if too long expos$1 x gets #8ov]-sunn$1' & ! t9t has a br[ni% or yell[i% t5d5cy1 :i*1 h[ev]1 is remov$ 9 fix+2 b no increase ( int5sity beyond a c]ta9 po9t is obta9$ by ! cont9uance ( exposure40 8,if pap] be wa%$ ) a solution ( ammonio-citrate ( iron & dri$ & !n a wa% pass$ ov] x ( ! yell[ f]ro-cyanuret ( potassium1 !re is no imm$iate =mation ( true ,prussian blue1 b ! pap] rapidly acquires a violet-purple color1 :i* deep5s aft] a few m9utes1 z x dries1 to almo/ absolute blackness4 ,9 ?is /ate x is a positive photographic pap] ( high s5sibility1 & gives pictures ( great dep? & %>pness1 b ) ?is peculi>ity1 t !y d>k5 aga9 spontane\sly on exposure to ! air 9 d>kness1 & are soon oblit]at$4 ,! pap]1 h[ev]1 rema9s susceptible to light1 & capable ( receiv+ o!r pictures1 :i* 9 _! turn fade1 )\t any possibility 7s f> z ,i c see7 ( arre/+ !m1 :i* is to be regrett$1 z !y are v beautiful1 & ! pap] ( su* easy prep>ation4 ,if wa%$ ) ammonia or its c>bonate1 !y are = a few mom5ts entirely oblit]at$1 b pres5tly reappe> ) rev]s$ lights & %ades4 ,9 ?is /ate !y are fix$1 & ! ammonia1 ) all t x w dissolve1 be+ remov$ by wa%+ 9 wat]1 _! color becomes a pure ,prussian blue1 :i* deep5s mu* by keep+4 ,if ! solution be mix$ !re results a v d>k violet-color$ ink1 :i* may be kept un9jur$ 9 an opaque bottle1 & w readily furni% by a s+le wa% at a mom5t's notice ! positive pap] 9 "q1 :i* is mo/ s5sitive :5 wet40 8,x seems at fir/ sight natural to ref] ^! curi\s & complex *anges to ! in/ability ( ! cyanic comp\nds2 & t ?is op9ion is to a c]ta9 ext5t correct is prov$ by ! photographic impressions obta9$ on pap]s to :i* no iron has be5 add$ beyond :at exi/s 9 ! f]rocyanic salts !mselves4 ,nev]!less1 ! foll[+ exp]im5ts abundantly prove t 9 sev]al ( ! *anges above describ$1 ! imm$iate action ( ! sol> rays is n ex]t$ on ^! salts1 b on ! iron conta9$ 9 ! f]rug9\s solution add$ to !m1 :i* x deoxidizes or o!rwise alt]s1 !reby pres5t+ x to ! f]rocyanic salts 9 su* a =m z to precipitate ! acids 9 comb9ation ) ! p]oxide1 or protoxide ( iron1 z ! case may be4 ,to make ?is evid5t1 all t is necess>y is simply to leave out ! f]rocyanate 9 ! prep>ation ( ! pap]1 :i* ?us becomes r$uc$ to a simple wa%+ ov] ) ! ammonio-citric solution4 ,pap] s wa%$ is ( a bright yell[ color1 & is app>5tly little1 b 9 reality highly s5sitive to photographic action4 ,expos$ to /rong sun%9e1 = "s "t inde$1 its bright yell[ t9t is dull$ into an o*rey hue1 or ev5 to gray1 b ! *ange altoge!r am\nts to a mod]ate p]c5tage ( ! total light reflect$1 & 9 %ort exposures is su* z w\ld easily escape notice4 ,nev]!less1 if a slip ( ?is pap] be held = only f\r or five seconds 9 ! sun 7! effect ( :i* is q imp]ceptible to ! eye71 & :5 )drawn into ! %ade be wa%$ ov] ) ! f]rosesquicyanate ( pota%1 a consid]able deposit ( ,prussian blue takes place on ! sunn$ "p1 & none :atev] on ! re/2 s t on wa%+ ! :ole ) wat]1 a pretty /rong blue impression is left1 demon/rat+ ! r$uction ( iron 9 t portion ( ! pap] to ! /ate ( protoxide4 ,! effect 9 "q is n1 x %\ld be obs]v$1 peculi> to ammonio-nitrate ( iron40 8,! ammonio & potasso-t>trate fully possess & ! p]*loride exactly neutraliz$ p>takes ( ! same prop]ty2 b ! exp]im5t is f> m neatly made & succe$s bett] ) ! o!r salts40 8,! v>ieties ( cyanotype processes seem to be innum]able1 b t :i* ,i %all n[ describe des]ves p>ticul> notice n only = its pre-em95t beauty :ile 9 progress1 b z illu/rat+ ! peculi> p[] ( ! ammoniacal & o!r p>salts ( iron above-m5tion$ to receive a lat5t picture susceptible ( developm5t by a great v>iety ( /imuli4 ,?is process consi/s 9 simply pass+ ov] ! ammonio-citrat$ pap] on :i* su* a lat5t picture has be5 impress$1 v sp>+ly & ev5ly1 a wa% ( ! solution ( ! common yell[ f]rocyanate 7prussiate7 ( pota%4 ,! lat5t picture1 if n s fa9t z to be q invisible 7& = ?is purpose x %\ld n be s71 is negative4 ,z soon z ! liquid is appli$1 :i* _c be 9 too ?9 a film1 ! negative picture vani%es1 & by v sl[ degrees is replac$ by a positive "o ( a violet blue color on a gre5i% yell[ gr\nd1 :i* at a c]ta9 mom5t possesses a high degree ( %>pness & s+ul> beauty & delicacy ( t9t4 ,if at ?is in/ant x be ?r[n into wat]1 x passes imm$iately to a ,prussian blue1 los+1 at ! same "t1 h[ev]1 mu* ( its %>pness1 & sometimes inde$ becom+ q blotty & confus$40 8,to prev5t ?is confusion gum arabic may be add$ to ! prussiat$ solution1 by :i* x is h9d]$ f spread+ unmanageably )9 ! pores ( ! pap]1 & ! precipitat$ ,prussian blue all[$ "t to agglom]ate & fix itself on ! fib]s4 ,by ! use ( ?is +r$i5t also1 a mu* ?9n] & m equal film may be spread ov] ! surface1 & :5 p]fectly dry1 if n suffici5tly develop$1 ! application may be repeat$4 ,by op]at+ ?us ,i h occasionally 7?\gh r>ely7 succe$$ 9 produc+ pictures ( great beauty & ri*ness ( effect1 :i* !y reta9 7if n ?r[n 9 wat]7 betwe5 ! leaves ( a portfolio1 & h a c]ta9 degree ( fixity--fad+ 9 /rong light & recov]+ _! tone 9 ! d>k4 99 99 990 8,if pap] be wa%$ ) a mixture ( ! solutions ( ammonio-citrate ( iron & f]rosesquicyanate 7r$ prussiate7 ( pota%1 s z to conta9 ! two salts 9 ab\t equal proportions1 & be+ !n impress$ ) a picture1 be ?r[n into wat] & dri$1 a negative blue picture w be produc$4 ,?is picture ,i h f\nd to be susceptible ( a v curi\s trans=mation4 ,to effect ?is x mu/ be wa%$ ) a solution ( protonitrate ( m]cury1 :i* 9 a little "t entirely dis*>ges x4 ,! nitrate be+ ?or\ghly wa%$ out & ! picture dri$1 a smoo? iron is pass$ ov] x1 some:at hott] ?an is us$ = iron+ l951 b n suffici5tly s to scor* or injure ! pap]4 ,! oblit]at$ picture imm$iately reappe>s1 n blue1 b br[n4 ,if kept = "s weeks 9 ?is /ate betwe5 ! leaves ( a portfolio1 9 complete d>kness1 x fades1 & at l5g? almo/ disappe>s4 ,b :at is v s+ul>1 a fre% application ( heat revives & re/ores x to its full int5sity40 8,?is curi\s trans=mation is in/ructive 9 ano!r way4 ,x is n op]at$ by light1 at lea/ n by light alone4 ,a c]ta9 temp]ature mu/ be atta9$1 & t temp]ature suffices 9 complete d>kness4 ,nev]!less1 ,i f9d t on expos+ to a v conc5trat$ spectrum 7collect$ by a l5s ( %ort focus7 a slip ( pap] prep>$ z above 7t is to say1 by wa%+ ) ! mix$ solutions1 exposure to sun%9e1 wa%+ & dis*>g+ ! uni=m blue color s induc$1 z 9 ! la/ article71 its :it5ess is *ang$ to a br[n ov] ! :ole region ( ! r$ & orange rays1 b n beyond ! lum9\s spectrum4 ,?ree conclusions seem unavoidable3 fir/--t x is ! heat ( ^! rays1 n _! light1 :i* op]ates ! *ange2 second--t ?is heat possesses a peculi> *emical quality :i* is n possess$ by ! purely calorific rays outside ( ! visible spectrum1 ?\gh f> m int5se2 & ?ird--t ! heat radiat$ f obscurely hot iron ab\nds especially 9 rays analog\s to ^? ( ! region ( ! spectrum above indicat$40 ,sir ,john ,h]s*el !n proce$s to %[ t :atev] be ! /ate ( ! iron 9 ! d\ble salts 9 "q1 its r$uction by blue light to ! /ate ( protoxide is indicat$ by _m o!r ag5ts4 8,?us1 = example10 says ,rob]t ,hunt1 8if a slip ( pap] prep>$ ) ! ammonio-citrate ( iron be expos$ p>tially to sun%9e1 & !n wa%$ ) ! bi*romate ( pota%1 ! bi*romate is deoxidiz$ & precipitat$ ^u ! sunn$ portion1 j z x w\ld be if directly expos$ to ! sun's rays40 8,i h prov$ ?is fact ) a great numb] ( prep>ations ( cobalt1 nickel1 bismu?1 plat9um & o!r salts :i* h be5 ?\ght hi!rto to be ins5sitive to ! sol> ag5cy2 b if !y are p>tially sunn$ & !n wa%$ ) nitrate ( silv] & put aside 9 ! d>k1 ! metallic silv] is sl[ly r$uc$ ^u ! sunn$ portion4 ,9 _m in/ances days 7 requir$ to produce ! visible picture2 & 9 "o case pap] be+ wa%$ 9 ! d>k ) neutral *loride ( plat9um 0 sunn$ & !n wa%$ 9 ! d>k ) nitrate ( silv]2 x 0 "s weeks be=e ! image made its appe>ance1 b x 0 ev5tually p]fectly develop$1 &1 :5 q s1 rema9$ p]man5tly impress$ ^u ! pap]40 ,! foll[+ process1 discov]$ at ! same "t z ! cyanotype1 & t]m$ *rysotype1 is ?us describ$ by ,sir ,john ,h]s*el3 8,9 ord] to asc]ta9 :e!r any portion ( ! iron 9 ! d\ble ammoniacal salt employ$ has really und]gone deoxidation1 ,i _h rec\rse to a solution ( gold1 exactly neutraliz$ by c>bonate ( soda4 ,! proto-salts ( iron1 z is well kn[n to *emi/s1 precipitate gold 9 ! metallic /ate4 ,! effect prov$ exce$+ly /rik+1 &1 z ! exp]im5t w probably be repeat$ by o!rs1 ,i %all "h describe x ab initio4 ,pap] is to be wa%$ ) a mod]ately conc5trat$ solution ( ammonio-citrate ( iron & dri$4 ,! /r5g? ( solution %\ld be su* z to dry into a good yell[ color1 n at all br[n4 ,9 ?is /ate x is ready to receive a photographic image1 :i* may be impress$ on x ei!r f nature 9 ! cam]a obscura1 or f an engrav+ on a frame 9 sun%9e4 ,! image s impress$ is1 h[ev]1 v fa9t1 & sometimes h>dly p]ceptible4 ,! mom5t x is remov$ f ! frame or cam]a1 x mu/ be wa%$ ov] ) a neutral solution ( *loride ( gold ( su* /r5g? z to h ab\t ! color ( a %]ry w9e4 ,in/antly ! picture appe>s1 n1 inde$1 at once ( its full int5sity1 b d>k5+ ) great rapidity up to a c]ta9 po9t1 dep5d+ on ! /r5g? ( ! solutions us$1 etc4 ,at ?is po9t no?+ c surpass ! %>pness & p]fection ( detail ( ! result+ photograph4 ,to arre/ ?is process & to fix ! picture 7s f> at lea/ z ! fur!r ag5cy ( light is conc]n$71 x is to be ?r[n into wat] v slightly acidulat$ ) sulphuric acid1 & well soak$1 dri$1 wa%$ ) hydrobromate ( pota%1 r9s$ & dri$ aga94 99 99 990 8,9 po9t ( direct s5sibility1 ! *rysotype pap] is c]ta9ly inf]ior to ! calotype2 b x is "o ( ! mo/ rem>kable peculi>ities ( gold z a photographic +r$i5t1 t extremely feeble impressions once made by light g on aft]w>ds1 d>k5+ spontane\sly & v sl[ly1 app>5tly )\t limit s long z ! lea/ ve/ige ( unr$uc$ *loride ( gold rema9s 9 ! pap]4 ,to illu/rate ?is curi\s & 7s f> z applications g7 highly important prop]ty1 ,i %all m5tion incid5tally ! results ( "s exp]im5ts made dur+ ! late f9e wea!r on ! habitudes ( gold 9 pres5ce ( oxalic acid4 ,x is well kn[n to *emi/s t ?is acid1 heat$ ) solutions ( gold1 precipitates ! metal 9 its metallic /ate2 x is ^u ?is prop]ty t ,b]zelius has f\nd$ 8 det]m9ation ( ! atomic weight ( gold4 ,light1 z well z heat1 also op]ates ?is precipitation2 b to r5d] x effectual1 sev]al conditions are necess>y3--,fir/--! solution ( gold %\ld be neutral1 or at mo/ v slightly acid2 secondly--! oxalic acid mu/ be add$ 9 ! =m ( a neutral oxalate2 & ?irdly--x mu/ be pres5t 9 a c]ta9 consid]able quantity1 :i* quantity mu/ be great] ! great] ! am\nt ( free acid pres5t 9 ! *loride4 ,"u ?is condition1 ! gold is precipitat$ by light z a black p[d] if ! liquid be 9 any bulk2 & if m]ely wa%$ ov] pap]1 a /a9 is produc$1 :i*1 h[ev] feeble at fir/1 "u a c]ta9 dosage ( ! *loride1 oxalate & free acid1 goes on increas+ f day to day & f week to week1 :5 laid by 9 ! d>k & especially 9 a damp atmosph]e1 till x acquires almo/ ! black ( ink2 ! unsunn$ portion ( ! pap] rema9+ unaffect$1 or s slightly z to r5d] x almo/ c]ta9 t :at little action ( ! k9d exi/s is due to ! effect ( casual disp]s$ light incid5t 9 ! prep>ation ( ! pap]4 ,i h be=e me a specim5 ( pap] s treat$ 9 :i* ! effect ( ?irty seconds' exposure to sun%9e 0 q invisible at fir/1 & :i* is n[ ( s int5se a purple z may be well call$ black1 :ile ! unsunn$ portion has acquir$ comp>atively b a slight br[n4 ,& 7:at is n a little rem>kable1 & indicates t 9 ! "t ( exposure m5tion$ ! maximum ( effect 0 atta9$7 o!r portions ( ! same pap] expos$ 9 graduat$ progression = long] times1 viz41 "o m9ute1 two m9utes1 & ?ree m9utes1 are n 9 ! lea/ p]ceptible degree d>k] ?an ! portion on :i* ! light has act$ dur+ ?irty seconds only40 8,if pap] prep>$ z above recomm5d$ = ! *rysotype1 ei!r ) ! ammonio-citrate or ammonio-t>trate ( iron1 & impress$1 z 9 t process1 ) a lat5t picture1 be wa%$ ) nitrate ( silv] in/ead ( a solution ( gold1 a v %>p & beautiful picture is develop$ ( great int5sity4 ,its disclosure is n in/antane\s2 a few mom5ts elapse )\t app>5t effect2 ! d>k %ades are !n fir/ t\*$ 91 & by degrees ! details appe>1 b mu* m sl[ly ?an 9 ! case ( gold4 ,9 two or ?ree m9utes1 h[ev]1 ! maximum ( di/9ctness w n fail to be obta9$4 ,! picture may be fix$ by ! hyposulphite ( soda1 :i* alone1 ,i believe1 c be fully dep5d$ on = fix+ arg5tic photographs40 8,! be/ process = fix+ ! photographs prep>$ ) gold is z foll[s3 ,z soon z ! picture is satisfactorily br\ght out by ! aurif]\s liquid1 x is to be r9s$ 9 spr+ wat]1 :i* mu/ be ?ree times r5ew$1 lett+ x rema9 9 ! ?ird wat] five or t5 m9utes4 ,x is !n to be blott$ (f & dri$1 aft] :i* x is to be wa%$ on bo? sides ) a some:at weak solution ( hydriodate ( pota%4 ,if !re be any free *loride ( gold pres5t 9 ! pores ( ! pap] x w be discolor$1 ! lights pass+ to a ruddy br[n2 b !y spe$ily :it5 aga9 spontane\sly1 or at all ev5ts on ?r[+ x 7aft] ly+ a m9ute or two7 into fre% wat]1 9 :i*1 be+ aga9 r9s$ & dri$1 x is n[ p]fectly fix$40 ,z ! *rysotype w be no m ref]r$ to1 we %all /ate1 fir/1 t ! image c be develop$ ) a pla9 solution ( silv] nitrate or "o acidifi$ ) citric or any o!r organic acid1 :i* g5]ally gives a br[n impression t c be ton$ ) an acid or alkal9e gold ba?1 ! color v>y+ ) ! solution employ$2 & secondly1 t ! process may be employ$ to obta9 outl9es ( any picture on pap] or canvas to be color$ 9 oil-pa9ts4 ,! impression develop$ ) gold t]*loride is pale blue1 q p]man5t1 & does n at all int]f]e ) ! "w ( ! arti/4 ,! canvas %\ld fir/ be wa%$ ) a mixture ( alcohol & aque\s ammonia1 !n dri$ & rubb$ ) pumice /one p[d] to give a too?4 ,! modus op]&i sugge/s itself4 ,! rese>*es ( ,mr4 ,c4 ,j4 ,burnett on ! application ( uranium salts & o!r comp\nds to photography are record$ 9 ! ,photographic ,notes ( ,?s4 ,sutton = #aheg4 ,we give 9 ! foll[+ l9es ! mo/ int]e/+ p>ts ( ! two pap]s ( ,mr4 ,burnett3 99 99 99 8,! next class ( processes are dep5d5t on ! s5sitiv5ess to light ( ! salts ( uranic oxide or sesquioxide ( uranium1 ,u#b,o#c40 8,9 ! fir/ process1 ! pap] be+ *>g$ ) ! uranic salt & expos$ to ! sol> influ5ce "u ! negative to be copi$1 is wa%$ ) a solution ( ! f]ridcyanide or r$ prussiate ( pota%4 ,! #8,h>ve/ ,sc5e' 9 ! exhibition1 be+ f an album5 negative l5t me by ,mr4 ,ross1 ! well-kn[n ,ed9burgh photograph]1 is an example1 ! salt ( ! sesquioxide ( uranium be+ 9 ?is case ! hydr(luate1 & ! "t ( exposure f ! /r5g? ( ! album5 negative fully an h\r ( good sun%9e4 ,i h us$ = ! solution ( ! uranic oxide = ?is process a v>iety ( acids ) v simil> results2 ! s5sitiv5ess ( ! prep>$ pap] to light v>y+ mu*1 h[ev]4 ,= in/ance1 a collodion negative ) ! hydr(luate pap] produc+ a v good pr9t 9 half an h\r ( un/eady sun1 :ile ) a pap] prep>$ ) ! t>t>ic acid solution ( ! oxide1 x gave an equally good impression 9 less ?an five m9utes ( ! same int]mitt+ sun%9e1 indicat+ ?us a diff]5ce ( s5sitiv5ess ( six to "o 9 favor ( ! t>trate40 8,! rationale ( ?is process is ! r$uction ( ! sesqui-oxide ( uranium1 ,u#b,o#c1 on ^? p>ts ( ! pap] expos$ to ! sol> influ5ce1 to a l[] /ate ( oxidation1 ! photo-oxide ,,uo1 ! salts ( :i* h ! prop]ty ( =m+ ) soluble alkal9e f]ridcyanides a ri* *ocolate-br[n precipitate1 :ile ! salts ( ! sesquioxide are de/itute ( ?is reaction4 ,h5ce ! br[n deposit on ! p>ts ( ! picture on :i* ! sun has be5 all[$ to act :5 ! develop+ solution is appli$1 & ! abs5ce ( any su* appe>ance on ^? p>ts :i* h be5 protect$ f its influ5ce40 8,z to ! manipulatory details ( ?is process1 ! pap] is float$ on ! solution 9 a d>k room & hung up to dry1 & !n pres]v$ f light 9 a portfolio4 ,if c>efully seclud$ f light x appe>s to keep well4 ,aft] exposure = ! prop] "t "u ?is negative1 !re is 9 "s cases sc>cely any visible impression2 :ile 9 o!r cases1 p>ticul>ly :5 us+ ! t>t>ic solution1 ,i h f\nd ! impression v di/+ui%able1 ( a br[ni% or blacki% %ade1 al?\gh /ill q fa9t4 ,! developm5t is be/ conduct$ by float+ x1 any?+ l rubb+ ! picture be+ v objectionable40 8,:5 ! picture has fully come out1 :i* is g5]ally f ?ree to t5 m9utes at ! v mo/1 x is remov$ f ! develop+ ba?1 plac$ 9 cold wat] & wa%$ v g5tly = a few m9utes1 ! wat] be+ frequ5tly *ang$ till x ceases to acquire a yell[ t+e f ! dissolv$ r$ prussiate4 ,! picture is !n dra9$ f ! wat]1 press$ betwe5 folds ( blott+ pap]1 dri$ 7,i dry 9 ! d>k71 & ! process is complete4 99 99 99 ,i may /ate1 z "o recomm5dation ( ?is process to ladies & o!r lov]s ( clean h&s1 t any br[n /a9s left by x on ! f+]s or else:]e are at once removable by a little weak ammonia or soap & wat]4 99 99 99 ,i w\ld p>ticul>ly sugge/1 z des]v+ ( notice1 ! developm5t ( ! salts ( sesquioxide ( uranium1 & /ill m iron1 by ! metals & metallic-cyanic alkal9e salts1 z also by ! mellonides & nitro-prussides1 & ! latt] also by itself & z develop$ by _m metallic salts40 8,i h s9ce _h ! opportunity ( try+ ! nitro-prusside ( sodium1 :i*1 by itself1 gives a blue & :ite picture1 9 color l t obta9$ f ! r$ prussiate ( pota%40 8,:5 mix$ ) a solution ( ammonio-nitrate ( copp]1 previ\s to its application to ! pap]1 ! color obta9$ is pale purpli% p9k or pea*-blossom color4 ,by mix+ x 9 ! same way ) ammonio-oxalate ( sesquioxide ( iron1 we get a dull gre5 picture1 *angeable ?r\gh int]m$iate /ages into br[n by alkal9e c>bonates1 & t into a dirty black by gallic acid4 ,x may be well to "k t ! blue ( ! picture giv5 by ! r$ prussiate 9 ! process ( ,sir ,john ,h]s*el may be consid]ably modifi$ or entirely *ang$ to ano!r color1 9 _m ways1 )\t int]f]+ ) ! purity ( ! :ite gr\nd1 by /eep+ ! picture1 aft] ! undecompos$ r$ prussiate has be5 wa%$ out1 9 solution ( salts ( v>i\s metals1 copp]1 uranium or cobalt1 = in/ance1 & t ! colors s produc$ may be modifi$ z desir$1 accord+ to ! /age at :i* ! action is /opp$40 8,!re rema9s b "o class ( uranic photographs to be describ$1 namely1 t obta9$ :5 we develop ) a salt ( silv] or gold 7or plat9um874 ,?is class may be made to pr9t mu* m rapidly ?an our ord9>y silv] pr9t+ process1 approa*+ sometimes m ne>ly to ! calotype developm5t 9 ?is respect4 ,we get ! m9ute/ details ) great fidelity1 & ! picture is effectually fix$ by a simple fre% hyposulphite solution1 ) a good color 9 _m cases1 or by ammonia1 :i* w be consid]$ an advantage by ^? :o hold ! hyposulphite an enemy to durability4 ,diff]5t %ades ( color are produc$ accord+ to diff]5t solv5t acids & diff]5t details4 ,i h got a good black p]fectly l t ( an engrav+1 by ! nitrate ( uranic oxide1 develop$ by ammonio-nitrate ( silv] 7or pla9 nitrate7 & fix$ by pla9 hyposulphite )\t any color+ ba?4 99 99 99 ,i h tri$ ! hyposulphite ( gold on "s ( ! silv]-develop$ pr9ts prep>$ ) ! hydr(luate ( ! uranic oxide & fix$ ) ammonia1 :i* _h an exce$+ly unpleasant raw-r$ color1 a v agreeable gray 0 at once obta9$4 ,i h succe$$ 9 gett+ v beautiful impressions by developm5t ( ! uranic pap] by *loride ( gold alone40 ,9 ano!r communication to ! ,photographic ,notes1 m int]e/+ p]haps ?an ! =ego+1 ,mr4 ,burnett says3 8,! cle>e/ & brighte/ ( my results h be5 obta9$ by ! action ( gallic acid1 tann91 or especially a mixture ( tann9 & c>bonate ( ammonia1 pota% or soda1 on ! blue pictures obta9$ by ! sol>ization ( pap] prep>$ ) f]ridcyanide ( potassium1 f]rocyanide or f]ridcyanide ( ammonium4 99 99 99 ,i h also exp]im5t$ ) ! bi*romate & iron1 ) gallic1 tann9 & o!r develop]2 b ,i mu/ confess to n hav+ be51 9 ?is p>ticul> way1 s successful z ,mr4 ,sella appe>s to h be5 9 ! pres]vation ( ! :ites1 ow+ possibly to my n hav+ tak5 ! tr\ble to wa% out suffici5tly ! iron be=e ton+407#a7 8,i h exp]im5t$ mo/ ext5sively 9 _m ways ) ! *romates & bi*romates1 & h succe$$ 9 v>i\s ways 9 gett+ v good results4 ,a v capital process = _m purposes is to float or /eep y\r pap] 9 a mix$ solution ( bi*romate ( pota% & sulphate ( copp]4 ,z = ,e4 ,hunt's *romotype process10 7#b7 ,i h mix$ gelat9e1 or occasionally grape sug>1 or bo?1 ) ! solution1 b in/ead ( develop+ x by a silv] solution1 z 9 ! *romotype1 wa% out ! salts unact$ on by light1 & develop by float+ on a solution ( f]rocyanide ( potassium4 ,! color ( ! r$ copp] salt :i* n[ =ms ! picture may be modifi$ or *ang$ 9 _m ways1 viz41 by soak+ ! picture1 aft] ! f]rocyanide ( potassium has be5 wa%$ out ( ! lights1 9 a solution ( sulphate ( iron 7or ! iron salt may1 b n s advantage\sly1 h be5 appli$ to ! picture be=e ! application ( ! f]rocyanide74 ,solutions ( *loride ( t91 gallic & tannic acids1 alone or ) alkalies or alkal9e c>bonates1 may also be employ$ to modify or *ange ! color4 ,in/ead ( develop+ by f]rocyanide y may develop by ! cobalt or *romo-cyanog5 salts1 or by an alkal9e mellonide ars5ite1 etc4 ,sulphuret$ hydrog51 or a sulphide1 w give a br[n1 or black tone1 :i* may be protect$ aga9/ oxyg5 & dampness by a res9\s v>ni%4 8,( all ! simple pictures obta9able ) bi*romat$ pap]s1 )\t complications or o!r ton+s1 ^? obta9able by ! comb9ation ( a salt 7say ! sulphate7 ( manganese1 ) ! bi*romate 9 ! pap] prep>ation1 are ab\t ! be/2 ^! pictures be+1 h[ev]1 capable ( be+ ton$ & modifi$ 9 _m diff]5t ways if desir$4 ,?is may be accompli%$ by ! use ( ton+ ba?s ( f]ridcyanide or f]rocyanide1 or o!r metal cyanog5 salts1 etc41 or by ei!r mix+ ! salts ( o!r metals1 z copp] or iron1 ) ! cyanic ton+ ba?s1 or us+ !m 9 ! orig9al solution1 or by soak+ ! pap] 9 !m1 z 9 ,sella's process1 previ\sly to ! application ( ! metal cyanic1 mellonic or o!r ton+ ba?s4 ,alkalies & alkal9e c>bonates may also be us$ to remove ! *romic acid1 & leave a subsalt1 or ! v /able oxide or c>bonate ( manganese1 :i* may be p]oxidiz$ by ! use ( *loride ( lime1 p]oxide ( hydrog51 or ozone40 8,9 all ! processes ) metallic salts1 alone ) bi*romates1 ! use ( siz$ or unsiz$ pap] along ) gelat9e1 etc41 has "s advantages4 ,i h got good results by su* processes on album5 pap]1 ! album5 t5d+ to prev5t meal9ess 9 ! pr9t2 also on pap] soak$ 9 gelat9e be=e ! application ( ! bi*romic solution4 99 99 99 ,!re is great int]e/ connect$ ) ! action ( all su* pap]s1 along ) ! tann9 & vegetable color+ matt]s4 ,i h long be5 ( op9ion t by ! /eep+ ( pap]s or textile fabrics1 conta9+ ! salts n only ( iron1 z recomm5d$ by ,mr4 ,sella1 b ( t91 copp]1 bismu?1 lead1 etc41 9 solutions ( co*9eal1 r$ cabbage1 beetroot1 grass or ! mo/ ord9>y foliage1 etc41 t ! mo/ useful results might be obta9$2 ?\gh = c]ta9 p]man5ce ,i am n sure b t "s ( ! o!r processes :i* ,i h briefly run ov] ) ! cyanog5 acid salts or metallic acid salts1 z precipitators1 may be m to be dep5d$ ^u4 ,! processes ) precipitat$ oxides1 su* z ! "o ) manganese & simil> ones1 ) o!r metals :i* ,i h describ$1 ,i also consid] z des]v+ ( m att5tion ?an almo/ any processes :i* h be5 /at$1 on ! score ( probable p]man5ce2 b p]haps ! be/ process = black1 or g5]ally useful neutral t9t1 )\t silv]1 t has yet be5 (f]$ to ! public1 ,i believe to be ! process allud$ to ) ! bi*romate ( pota% & sulphate ( copp]1 ton$ by an iron salt4 99 99 99 ,?is process1 ! cuprotype 7z also ! uranotype & manganotype7 is applicable p]fectly to films ( album5 or gelat9e on glass or porcela91 textile fabrics1 p>*m5t1 pap]1 tiles & _m o!r sub/ances besides pap]40 ,,! ,,designs4 ,,h[ ,,to ,,make ,a ,,negative ,,draw+ ,! draw+ pap] = designs to be reproduc$ by ! cyantotype & ! o!r processes describ$ 9 ?is book %\ld be ( a f9e texture1 free f opacities & v :ite2 &1 z ! design mu/ s]ve z a cli* x is a s9e qua non t x be drawn ) a v black ink & ) well-f$ l9es1 especially ^? :i* are v f9e4 ,to obta9 a complete opacity1 &1 at ! same "t1 to keep ! ink q fluid1 :i* gives great facility to ! design]1 "o adds "s gamboge 7or burnt si5na7 to ! ,india ink4 ,! ink ( ,b\rgeois1 :i* is comp\nd$ ) yell[ & c be dilut$ z easily z ,india ink1 is excell5t1 s is also ! ,am]ican ink ( ,higg9s47#c7 ,z mu* z possible x is desirable to replace ! color$ l9es indicat+ ! con/ructions1 ! axis1 projections1 etc41 by diff]5tly punctuat$ l9es made ) ,india ink4 ,h[ev]1 if ! use ( colors be obligatory on ! orig9al design1 "o %\ld trace ! r$ l9es ) v ?ick v]milion or si5na1 ! yell[ l9es ) gamboge1 & ! blue & gre5 l9es ) a ?ick mixture ( ,prussian blue & *rome yell[ 9 diff]5t proportions4 ,"o mu/ ab/a9 f apply+ wa%es ( any t9ts on ! orig9al4 ,if necess>y !y %\ld be bru%$ ov] :5 ! reproductions are made2 moreov] !y c be (t5 replac$ by cross-l9es m or less op51 & ! %ad[+ repres5t$ by ?ick] b n clos] l9es4 ,trac+ pap] is recomm5d$ in/ead ( l951 :i* latt]1 on acc\nt ( its ?ickness & granulation1 gives less satisfactory results 9 reg>d to ! transp>5cy ( ! gr\nd & ! cont9uity ( ! l9es4 ,to reproduce a design on ord9>y pap]--n too ?ick--or an engrav+1 etc41 ! pap] is r5d]$ transp>5t by rubb+ ov] on ! back ( ! orig9al a solution ( #c p>ts 9 volume ( ca/or oil 9 #aj p>ts ( alcohol1 by means ( a small sponge4 ,:5 ! pap] is q transp>5t1 ! oil 9 excess is remov$ by pressure betwe5 %eets ( blott+ pap]1 & ! pap] dri$ be=e ! fire or spontane\sly4 ,! design s treat$ is n 9 ! lea/ injur$1 = x assumes its primitive condition by dissolv+ ! oil f ! pap] by imm]sion into /rong alcohol1 :i* x is necess>y to r5ew once or twice1 !n r9s+ 9 alcoholiz$ wat] if ! draw+ be 9 ,india ink1 or simply 9 wat] 9 ! case ( an engrav+1 & f9ally dry+ betwe5 %eets ( blott+ pap]4 ,in/ead ( an alcoholic solution ( ca/or oil1 vasel9e c be employ$4 ,! pap] is m transp>5t4 ,! me?od by :i* are made negative draw+s1 t is1 ^? :i* c be us$ z negative cli*s to reproduce ! design 9 black l9es on a :ite gr\nd1 is ?us describ$ by ,mr4 ,*eysson1 wlio orig9at$ x1 9 a manual publi%$ by ! ,dep>tm5t ( ,public ,works ( ,france1 f :i* we h borr[$ mo/ ( ! above in/ructions = ! draw+ ( designs suitable = ! photo-reproduction processes37#d7 8,"o c avoid ! necessity ( mak+ a negative f ! orig9al draw+ by trans=m+ ! draw+ itself into a negative40 8,to t effect x suffices to draw ) li?ographic ink1 !n to cov] ! pap] ) anil9e br[n1 &1 aft] dry+1 to wa% x ) turp5t9e oil :i* dissolves ! li?ographic ink )\t alt]+ ! anil9e4 ,! l9es appe> !n :ite on a br[n gr\nd imp]vi\s to light 7t is1 non-act9ic74 ,! design is ?us trans=m$ into a negative1 & c yield positive impressions ) pap] s5sitiz$ ) silv] salts1 ! f]riprussiate or ! bi*romate ( pota%4 ,! li?ographic ink %\ld be v black & ! l9es well f$40 8,:5 ! draw+ is f9i%$ x is plac$ on a bo>d l9$ ) %eets ( blott+ pap]1 !n "o spreads all ov] x ! anil9e br[n ) a bru%1 &1 la/ly1 aft] dry+1 ! pap] is c>efully rubb$ ) a bung ( cotton or a rag imbu$ ) turp5t9e until ! l9es ( ! design are dissolv$40 ,9 our practice we h (t5 tak5 a negative cli* f draw+s made 9 ! ord9>y mann]1 )\t ! aid ( ! cam]a obscura 7:i* w\ld h be5 too exp5sive = draw+s ( a c]ta9 size71 by simply pr9t+ a pro( by contact on pla9 or album5iz$ silv]$ pap]1 & fix+1 )\t ton+1 9 a new solution ( sodium ?iosulphate1 !n wa%+ z usual4 ,! pro(s ?us obta9$ f designs drawn ) an opaque ink1 :i* all[s a long insulation &1 !re=e1 yields an int5se r$uction1 are ( a deep brick-r$ color1 q non-act9ic1 & give v good positives by ! ,artigues process4 ,n4,b4--,pap] 9 dry+ nev] assumes its orig9al %ape2 x is1 !re=e1 necess>y to make ! figures on ! reproductions f plans :5 !y are n on ! orig9als4 ,,*oice ,,( ,,pap]4 ,,siz+4 ,9 all ! photographic processes by precipitation ( metallic oxides ! quality ( ! pap] has a great influ5ce on ! results4 ,:5 ! pap] is n well siz$ & n well cal5d]$1 ! s5sitiz+ solution is absorb$1 in/ead ( simply impregnat+ ! surface ( ! pap]1 & n only ! image is sunk 9 & its %>pness impair$1 b good :ites c nev] be obta9$1 especially if ! image %\ld be ton$1 ow+ to ! impossibility ( elim9at+ ! metallic salts n act$ on1 t is1 n r$uc$ by ! action ( light :i* ! fib]s ( ! pap] me*anically reta94 ,! 8endless0 rolls ( pap]1 #ed3 in*es wide--or 8blue pr9t pap]10 z x is sometimes t]m$--( ,blan*et frres et ,klb]1 ( ,rives1 bett] kn[n z 8,rives' pap]01 t ( ,johannot1 ( ,annonay 7,france71 & ! ,/e9ba* 7,saxe7 pap] are recomm5d$4 ,= small pr9ts f negatives 9 half tone ! positive pap]1 #ahbb in*es1 ( ,rives or ,saxe1 %\ld be pref]r$ to ! heavy k9d4 ,x is advisable to size x1 s t ! impressions be entirely =m$ on ! surface ( ! pap]4 ,moreov]1 an additional siz+ is always advantage\s1 :atev] be ! photographic process employ$1 to prev5t ! imbibition ( ! s5sitiz+ comp\nd & to obta9 m brilliant & vigor\s images1 = ! iron1 *romium1 uranium & o!r metallic soluble salts require ! pres5ce ( an organic matt] 7alcohol1 e!r1 gum arabic1 glucose1 case9e1 etc47 to be r$uc$ by ! ag5cy ( light2 & z a consequ5ce1 ! great]1 )9 c]ta9 limits1 ( c\rse1 ! am\nt ( organic matt]s1 & ! m ?or\ghly !y are mix$ ) ! salts1 ! m s5sitive ! prep>ation & ! bett] ! results4 ,arr[root is ! be/ siz+ = our purposes4 ,gelat9e may be employ$1 album5 also1 b ! coat+ %\ld be insolubiz$ :5 appli$ on ! pap] & dry4 ,siz+ ) ,arr[root4--,9 a porcela9 di% diffuse #d p>ts ( p[d]$ arr[root & "o "p ( liquid glucose 9 #bjj p>ts ( di/ill$ or ra9 wat] & dissolve by heat ov] an alcohol lamp1 /irr+ all ! :ile4 ,let ! solution boil = an in/ant1 & :5 ! pa/e is homog5e\s let x cool d[n & !n remove ! sk9 =m$ on its surface & /ra9 x ?r\gh a f9e canvas4 ,n[ provide ) ?ree small sponges free f gritty matt]s & clean$ 9 wat]1 & nail by ! f\r corn]s1 "o ov] ! o!r1 felt size upp]mo/1 z _m %eets ( pap] z y wi% to size on a bo>d some:at small] ?an ! pap]4 ,?is done1 ) "o ( ! sponges take a small quantity ( ! arr[root &1 bru%+ x l5g?-way & cross-way1 spread ! pa/e into an ev5 lay]1 !n1 by rubb+ v lightly ) ! second sponge1 efface ! /riae & smoo? ! coat+ z well z possible4 ,! ?ird sponge s]ves to remove ! excess ( pa/e :5 too mu* is at fir/ spread on4 ,f six to sev5 %eets ( pap]1 #ahbb1 c be siz$ ) ! quantity ( arr[root pa/e above giv54 ,ano!r1 b n q s effective a mann] ( siz+ al?\gh suffici5t = ! cyanotype1 is ! foll[+1 employ$ by ,mr4 ,pizzighelli = ! pap] us$ 9 ! plat9otypic process3 ,t5 p>ts ( arr[root are p[d]$ 9 a mort> ) a little wat] & !n mix$ by small quantities to #hjj p>ts ( boil+ wat]4 ,aft] a few m9utes #bjj p>ts ( alcohol are add$ & ! mixture filt]$4 ,! pap] is imm]s$ = two or ?ree m9utes 9 ! w>m solution & hung up to dry4 ,siz+1 ) ,gelat9e4--,dissolve at a temp]ature ( ab\t #adj deg4 ,fahr4 7#fj deg4 ,c47 #aj p>ts ( good gelat9e 9 #hjj p>ts ( wat]1 !n add #bjj p>ts ( alcohol & #c p>ts ( alum dissolv$ 9 a little wat]4 ,filt] & prep>e ! pap] by imm]sion z above direct$4 ,! gelat9iz$ pap] :5 dry %\ld be prep>$ a second "t & dri$ by hang+ x up 9 ! opposite direction 9 ord] to obta9 an ev5 coat+4 ,,! ,,cyanotype ,,or ,,blue ,,process4 ,?is process gives :ite impressions on a blue gr\nd ) diapositives or draw+s on transp>5t or semi-transp>5t mat]ials1 & blue impressions on a :ite gr\nd f negatives4 ,x is commonly kn[n "u ! names ( 8blue pr9t process10 8negative f]rotype process0 & 8f]ro-prussiate process40 ,! process is inde$ exce$+ly simple4 ,a %eet ( pap]1 impregnat$ or s5sitiz$1 z x is t]m$1 ) a solution ( f]ric citrate & f]ricyanate is impress$ "u a cli*17#e7 !n imm]s$ 9 pure wat]1 :]eby ! image is develop$ & at ! same "t fix$4 ,x is on acc\nt ( ! great advantages (f]$ by its simplicity t ?is process is g5]ally pref]r$ by civil eng9e]s & ar*itects = ! reproduction ( _! plans4 ,! s5sitiz+ solution is prep>$ 9 mix+ by equal volumes ! two solutions foll[+3 ,a4 ,iron1 ammonio #bj p>ts citrate ,wat] #ajj p>ts ,b4 ,potassium #ae p>ts f]ricyanate 7r$ prussiate7 ,wat] #ajj p>ts ,al?\gh ! mixture keeps pretty well = a c]ta9 p]iod 9 ! d>k1 x is be/ to prep>e only ! quantity want$ = actual use47#f7 ,! pap] is pref]ably s5sitiz$ 9 op]at+ z foll[s3 ,take hold ( ! pap] by ! two opposite corn]s & fold x into a loop1 lay x on ! iron solution1 ! c5t] ( ! %eet fir/ plac$ 9 contact ) ! liquid1 & !n gradually spread x by l[]+ ! corn]s ) a little pressure4 ,no solution %\ld run ov] on ! back ( ! pap]2 x w\ld be a cause ( /a94 ,?is done1 & )\t all[+ ! liquid to p5etrate 9 ! pap]1 imm$iately take hold ( ! two corn]s ne> ! body & )draw ! pap] by dragg+ x ov] on a glass rod = ?is purpose fix$ on ! edge ( ! tray4 ,n[ p9 up ! pap] to dry1 :i* %\ld be done rapidly1 & s5sitize a second "t 9 proce$+ 9 ! same mann]4 ,if ?is second s5sitiz+ be f\nd objectionable1 let float ! pap] = no m ?an t5 seconds2 ( c\rse ?is me?od ( s5sitiz+ is n applicable to prep>e l>g] %eets ( pap]4 ,9 ?is case ! pap] is p9n$ by ! f\r corn]s on a draw+ bo>d or any o!r support1 l9$ ) blott+ pap] & quickly bru%$ ov] ) a sponge sp>+ly imbu$ ) ! s5sitiz+ mixture1 s z to wet ! pap] ) a v small excess ( liquid4 ,! rationale ( ?is mann] ( s5sitiz+ is to impregnate only ! v surface ( ! pap] ) ! f]ric salts1 & !reby to obta9 an int5se blue ) v good :ites1 :i* latt] x w\ld be impossible ( obta9+ %\ld ! s5sitiz+ solution be all[$ to rea* 9 ! fib]s ( ! pap]1 =1 9 ?is condition1 x is impossible1 ow+ to ! exig5cies ( ! process1 to wa% out ?or\ghly ! iron salts to prev5t ! *emical *anges :i* cause ! :ites to be t9t$ blue4 ,x is = ?is reason t bett] results are also obta9$ ) well siz$ pap]s4 ,! s5sitiz+ %\ld be done by a v diffus$ daylight1 & ! dry+1 ( c\rse1 9 a d>k room4 ,:5 s5sitiz$ ! pap] is yell[i% gre54 ,x %\ld be well dri$ = keep+1 & roll$ or wrapp$ 9 orange or br[n pap] & pres]v$ f ! action ( dampness & ( ! air4 ,x does n keep well1 h[ev]1 no m ?an two or ?ree mon?s1 p]haps1 9 good condition2 b ! soon] x is employ$ ! f9] ! pro(s1 ! bett] ! :ites & m rapidly is ! pap] impress$4 ,!re is 9 ! m>ket a pap] :i* keeps = a long "t4 ,x is prep>$ by add+ a small quantity ( gum arabic or ( dextr9e to ! s5sitiz+ solution4 ,good = ! reproduction ( l9e "w1 x does n give v satisfactory results = pictures 9 half tones4 ,! foll[+ comp\nd gives a pap] mu* m s5sitive1 b n keep+ s long1 ?an t prep>$ accord+ to ! =mula previ\sly giv53 ,t>t>ic acid #be p>ts ,f]ric *loride1 solution #hj p>ts 79 volume7 at #de deg4 ,baum ,wat] #ajj p>ts ,:5 ! acid is dissolv$1 add gradually conc5trat$ aque\s ammonia1 j en\gh to neutralize ! solution--#agj volumes1 ab\t4 ,! *emical *ange consi/s 9 ! =mation ( f]ric t>trate4 ,let cool ! solution1 !n1 aft] add+ ! foll[+1 keep x 9 ! d>k3 ,potassium f]ricyanate #ba p>ts ,wat] #ajj p>ts ,ano!r & v s5sitive prep>ation is ! foll[+3 ,a4 ,iron p]*loride1 #dj p>ts cry/ ,oxalic acid #aj p>ts ,wat] #ajj p>ts ,b4 ,potassium #bj p>ts f]ricyanate ,wat] #ajj p>ts ,mix ,pr9t+4--,! process we describe yields negative impressions1 t is a positive image f a negative cli*1 & a negative image f a positive cli*1 exactly z ! silv] pr9t+-out process ord9>ily employ$ 9 photography4 ,consequ5tly1 = ! production ( non-rev]s$ pro(s f plans1 etc41 ! orig9al draw+ %\ld be plac$ face d[nw>ds on ! glass plate ( ! pr9t+ frame1 &1 ^u ! back1 ! s5sitive pap] is laid & press$ into p]fect contact by means ( a pad1 felt or ?ick clo?4 ,! pr9t+ frame is t us$ by photograph]s4 ,! lid is divid$1 accord+ to ! side1 9 two1 ?ree & ev5 f\r sections1 held by h+es & fa/5$ = pr9t+ by z _m cross-b>s1 9 ord] t by op5+ "o section1 f "t to "t1 ! op]ator c foll[ ! progressive *anges result+ f ! action ( light on ! iron salts4 ,to pr9t1 ! frame %\ld be plac$ 9 ! light 9 su* a mann] z ! lum9\s rays fall p]p5dicul>ly ^u ! draw+ or cli*4 ,! reason ( ?is is obvi\s1 s9ce ! s5sitive pap] is n 9 direct contact ) ! design1 b sep>at$ by ! mat]ial ^u :i* x is drawn4 ,dur+ ! insolation--^: "t dep5ds necess>ily f ! m or less transp>5cy ( ! cli*1 &1 also1 f ! int5sity ( ! light7#g7--! pap] assumes fir/ a violet t9t1 :i* gradually int5sifies to a d>k %ade2 !n ?is t9t fades1 becomes br[ni%1 !n pale lilac1 :ile ! p>ts "u ! l9es--t is1 ! design--^u :i* ! light has1 !re=e1 no action1 are visible by keep+ ! orig9al yell[-gre5 t9t ( ! prep>$ pap]4 ,x is :5 ! lilac color is produc$ t ! exposure is suffici5t4 ,to asc]ta9 :5 ! exposure is correct1 a few black l9es c be trac$ on "o ( ! edges ( ! m>g9 ( ! design1 & /rips ( ! s5sitive pap] plac$ ^u !m to s]ve z te/s 9 op]at+1 z x w be expla9$ 9 ! description ( ! ,cyan(] process4 ,:5 "o ( !m is tak5 out & %[1 by be+ wa%$ 9 wat]1 a cle> :ite l9e on a deep blue gr\nd1 ! exposure is at an end4 ,"o und]/&s t ! blue color ( ! gr\nd is m or less int5se accord+ to "t ( insolation1 = ! *emical actions betwe5 ! r$uc$ & ! non-r$uc$ iron salts is s mu* m complete z ! salts act$ on are m or less deoxidiz$1 t is1 r$uc$ to f]r\s salts2 & t to obta9 ! maximum ( effect1 :i*1 !re=e1 dep5ds on ! all[able "t ( exposure1 ! draw+ ink %\ld be opaque & non-act9ic z f> z possible1 because :51 on te/+1 ! l9es are t9t$ ! exposure %\ld be discont9u$4 ,h[ev]1 a slight coloration ( ! l9es is n v objectionable1 = x disappe>s by a long] wa%+ aft] ! developm5t4 ,! image is develop$ & fix$ by wa%+ 9 wat] two or ?ree times r5ew$4 ,! wat] mu/ be free f calc>e\s salts2 ^! salts conv]t+ ! iron into c>bonates :i* imp>t an o*rey t+e to ! pro(4 ,ra9 wat]--any wat] 9 :i* no precipitate is ?r[n d[n by ! addition ( a few drops ( a weak solution ( silv] nitrate--may be us$ ) safety4 ,dur+ ! developm5t ! gr\nd takes a blue color :i* rapidly int5sifies1 :ile ! iron comp\nd1 n act$ on & imp>t+ a yell[ gre5 t9t to ! design1 is wa%$ out f ! :ite pap]4 ,if ! pr9t has n be5 suffici5tly expos$ ! gr\nd rema9s pale blue1 m or less2 ! reason has be5 expla9$4 ,9 ?is case ! developm5t %\ld be done quickly1 z ! blue is always dis*>g$ by wa%+4 ,on ! o!r h&1 :5ev] ! :ites are t9t$ by excess ( exposure1 !y c be cle>$ p>tly or entirely by a prolong$ imm]sion 9 wat]1 b ! gr\nd is also to "s ext5t light5$4 ,:5 ! pro( is well develop$ & fix$1 t is1 :5 ! soluble iron salts are elim9at$1 ! blue color c be bright5$ by add+ to ! la/ b "o wa%+ wat] a small quantity ( citric acid1 or ( potassium bisulphate1 or a little ( a solution ( hypo*lorite ( lime 7blea*+ p[d]74 ,! action ( light 9 ?is1 z well z 9 ! o!r photographic processes ) metallic salts describ$ 9 ?is "w1 is "o ( deoxidation1 z %[n by ,h]s*el4 ,! *emical *anges :i* produce ! blue precipitate is q complicat$4 ,x is evid5t t bo? ! f]ric citrate & ! f]ric cyanate are p>tly r$uc$ to f]r\s salts "u ! lum9\s influ5ce1 & react 9 pres5ce ( wat] ) ! unr$uc$ "p ( ea* ( ^! comp\nds1 ! f]ric citrate ) ! f]r\s cyanate =m+ ,prussian blue 7f]ric-f]rocyanate71 & ! f]ric cyanate ) ! f]r\s citrate giv+ rise to ,turnbull's blue 7f]r\s f]ricyanate74 ,! blue ( ! pr9t is consequ5tly a mixture 9 a c]ta9 proportion ( ! two comp\nds2 & z ! color ( ,prussian blue is q diff]5t f t ( ,turnbull's1 x foll[s t by v>y+ 9 a c]ta9 measure ! p]c5tage ( ! two f]ric salts =m+ ! s5sitiz+ solution1 ! color ( ! blue may be v>i$ !reby4 ,h5ce ! diff]5ce 9 ! =mulas giv5 by diff]5t au?ors47#h7 ,! blue color ( ! image c be *ang$ into black or d>k gre54 ,b to t purpose ! pap] %\ld be1 al?\gh n exactly necess>y1 well siz$ z be=e direct$1 & s5sitiz$ ) extra c>e to prev5t ! imbibition ( ! iron solution into ! pap]4 ,aft] exposure ! pro( %\ld necess>ily be ?or\ghly wa%$ to elim9ate ! soluble iron salts1 !n imm]s$ = a mom5t 9 wat] acidifi$ ) nitric acid1 #a3ajj1 & ?is done & )\t wa%+ treat$ by a solution ( aque\s ammonia at #b p] #ajj ( wat]4 ,9 ?is ! blue color disappe>s1 be+ *ang$ into a r$ br[ni% t9t1 :i* indicates t ! ,turnbull's & ,prussian blues are trans=m$1 ! =m] into f]roso-f]ric hydrate1 ) =mation ( f]rocyanate1 & ! latt] into f]ric hydrate4 ,x is by ! action ( tann9 7gallotannic acid7 on ! f]ric oxides ?us =m$ t ! black is produc$1 & by t ( cate*u-tannic acid conta9$ 9 ! extract ( cate*u t "o obta9s a d>k gre51 almo/ black color4 ,to obta9 ! black tone x suffices to imm]se ! pro( on its removal f ! ammoniacal 9 a solution ( tann9 at #e p] #ajj ( wat]1 & :5 ton$1 to wa% x 9 a few *anges ( wat]4 ,! process to turn ! blue color into a gre5 0 devis$ by ,mr4 ,paul ,roy4 ,x is z foll[s3 ,dissolve #g p>ts ( borax 9 #ajj p>ts ( wat]1 & acidify ! solution ) sulphuric acid add$ drop by drop until ! litmus pap] becomes r$2 !n1 9 ! same mann]1 neutralize ) aque\s ammonia n 9 excess1 b j en\gh to %[ an alkal9e reaction2 ?is done dissolve #a "p ( p[d]$ cate*u & filt]4 ,9 ?is ! pro( is imm]s$ aft] developm5t until ! desir$ effect is atta9$4 ,wa%1 etc4 ,to cle> ! l9es1 or to make additions1 or to write on ! blue m>g9 ( ! pro( a solution ( potassium oxalate is employ$4 ,x dissolves ! blue )\t leav+ sc>cely any trace ( x4 ,! solution c be prep>$ by mix+ ! two solutions ^: =mula is giv5 bel[37#i7 ,a4 ,oxalic acid #aj p>ts ,wat] #ajj p>ts ,b4 ,cau/ic potassa #ab p>ts ,wat] #ajj p>ts ,! blue pr9ts are p]man5t4 ,:5 dry+ !y d>k5 a little f oxidation2 expos$ to sun%9e = "s h\rs1 !y blea* consid]ably2 b 9 ! %ade ! fad$ pictures progressively absorb oxyg5 f ! air & assume _! orig9al int5sity & color 9 a p]iod s mu* ! long] z ! insulation has be5 m prolong$2 x may take weeks if ! picture 7 mu* blea*$4 ,,! ,,cyan(]4 7,,pellet',s ,,process47 ,?is process gives blue impressions on a :ite gr\nd f positive cli*s1 & :ite impressions on a blue gr\nd f negative cli*s4 ,x is t]m$ 8positive f]rotype process40 ,! cyan(] is an application ( "o ( ! num]\s & useful inv5tions = :i* photography is indebt$ to ,a4 ,poitev94 ,9 #ahfc he discov]$ t c]ta9 organic sub/ances 7 r5d]$ insoluble by f]ric *loride1 & t !y aga9 became soluble2 :5 "u ! influ5ce ( light ! f]ric *loride has be5 r$uc$ to a f]r\s salt4 ,?is curi\s ph5om5on is ! base ( ! process n[ to be describ$4 ,z usual ! process has be5 modifi$ by comp\nd+ ! s5sitive solution 9 v>i\s ways & by m9or details 9 ! mann] op]at+4 ,b al?\gh ^! modifications h r5d]$ ! process easi] to "w )1 !re is n a great diff]5ce 9 ! results obta9$4 ,we give two =mulas4 ,aside f ! addition ( gum arabic1 :i* 0 sugge/$ by ,mr4 ,pellet1 & :i* con/itutes ! capital improvem5t ( ! process1 ! =mula is sub/antially t devis$ by ,mr4 ,poitev94 ,prep>e ?ree solutions z foll[s3 ,a4 ,gum arabic1 be/ #ej p>ts quality ,wat] #agj p>ts ,b4 ,t>t>ic acid #ab p>ts ,wat] #hj p>ts ,c4 ,f]ric *loride #ce p>ts 9 volume solution at #de deg4 ,baum ,mix gradually ,b to ,c1 !n ,c1 by small quantities1 9 agitat+ briskly4 ,x is important to prep>e ! solution z direct$1 = by add+ ! f]ric *loride be=e t>t>ic acid1 ! gum arabic w\ld be at once coagulat$4 ,:5 ! f]ric *loride is mix$1 ! solution at fir/ ?ick5s1 b becomes suffici5tly fluid = use 9 a c]ta9 p]iod4 ,x does n keep1 & %\ld be employ$ ! day x is made if possible4 ,! pap]1 :i* %\ld be well siz$ & cal5d]$1 & :i*1 :5 n giv+ good results by too mu* absorb+ ! s5sitive solution1 mu/ be />*$ z be=e direct$1 is coat$ ei!r by bru%+ or by float+4 ,by ! fir/ me?od a roll ( pap] five y>ds long c be prep>$ )\t great tr\ble1 & give1 p]haps1 bett] results ?an if prep>$ by float+2 b ! latt] me?od is by f> ! ! mo/ conv5i5t3 "o does n g5]ally prep>e by bru%+ %eets ( pap] l>g] ?an ab\t #cjdj in*es4 ,= bru%+1 ! pap] is p9n$ on a bo>d1 !n1 ) a l>ge badg] bru% dipp$ 9 ! s5sitive solution1 ! latt] is appli$ z ev5ly z possible2 aft] :i*1 by lightly pass+ ! bru% ov]1 ! /riae are remov$1 ! coat+ well equaliz$1 & ! pap] hung up to dry4 ,! coat+ %\ld n be v ?91 &1 above all1 n too ?ick1 = !n x w\ld require an unusually long exposure to all[ ! light act+ ?r\gh ! :ole ?ickness ( ! film1 :i* is a s9e qua non to obta9 a cle> gr\nd1 i4e41 n /a9$ blue4 ,to prep>e by float+1 p\r ! solution 9 a %all[ tray1 :i* ne$s n to be m ?an #bjcd in*es1 #cj in*es be+ ! wid? ( ! draw+ pap] usually employ$2 !n roll ! pap] & place x on ! solution4 ,n[1 tak+ hold ( x by two corn]s1 draw x out sl[ly3 ! pap] w unroll by itself4 ,?is op]ation c be done by diffus$ daylight1 b1 ( c\rse1 ! pap] %\ld be dri$ 9 a d>k room4 ,x dries rapidly4 ,endless rolls are prep>$ by ma*9]y4 ,to expose1 ! draw+ is plac$ 9 ! pr9t+ frame1 face d[nw>ds1 & ! s5sitive pap] laid ov] x4 ,! :ole is !n press$ into contact by int]pos+ a cu%ion betwe5 ! lid ( ! frame & ! pap]1 & expos$ s t ! rays ( light fall p]p5dicul>ly ^u x4 ,! cyan(] prep>ation is q s5sitive4 ,f half a m9ute to two m9utes exposure1 accord+ to ! int5sity ( ! light & ! ?ickness ( ! coat+1 is suffici5t 9 sun%9e to reproduce a draw+ made on ! ord9>y trac+ pap]4 ,9 ! %ade1 by a cle> sky1 ! exposure is ab\t five times long]1 & v>ies f half an h\r to an h\r & m 9 cl\dy wea!r1 b !n ! design is seldom p]fectly %>p4 ,! progresses ( ! impression is foll[$ by op5+ "o side ( ! pr9t+ frame & exam9+ ! pro(4 ,! exposure is suffici5t :5 ! pap] is t+$ br[n on ! p>ts correspond+ to ! gr\nd ( ! design4 ,! image appe>s !n negative1 t is1 yell[i% on a t+$ gr\nd4 ,ano!r & m safe me?od ( asc]ta9+ ! correct "t ( exposure1 :i* c be employ$ concurr5tly ) ! o!r1 is to place a few /rips ( ! same %eet ( s5sitive pap] betwe5 ! m>g9 ( ! design1 ^u :i* a few l9es h be5 trac$1 & ! pap]1 &1 )\t op5+ ! frame1 to draw "o ( !m1 f "t to "t1 & dip x 9 ! develop+ solution4 ,if ! :ole /rip be t9t$ blue1 ! pro( is n suffici5tly expos$2 b if ! l9es soon appe> ) an int5se coloration on ! yell[i% gr\nd ( ! pap]1 & ! latt] d n turn blue 9 a m9ute1 at ! mo/1 ! exposure is "r4 ,by excess1 ! l9es are ) difficulty develop$ or brok54 ,= develop+1 we provide ) ?ree wood5 trays l9$ ) lead or gutta-p]*a1 or1 m economically1 coat$ ) yell[ wax4 ,! wax is melt$1 !n appli$ v hot1 &1 :5 x is solidifi$ & q cold1 ! coat+ is equaliz$ ) a hot iron1 :]eby ! cracks produc$ by ! contraction ( ! wax :5 cool+ are fill$ up4 ,"o ( ^! trays %\ld conta9 a lay]1 ab\t ?ree-qu>t]s ( an in* ?ick1 ( an almo/ saturat$ solution ( potassium f]rocyanate 7! develop]72 ! next be fill$ ) wat]1 & ! ?ird ) wat] acidifi$ by sulphuric acid 9 ! proportion ( ?ree p] c5t4 9 volumes4 ,all ?is be+ ready1 ! m>g9 ( ! pro( is turn$ upw>ds--s z to =m a disk ( :i* ! outside is ! impress$ surface--9 ord] t ! f]rocyanate solution does n f9d its way on ! back ( ! pro(1 :i* w\ld produce /a9s4 ,n[ ! pro( is laid1 ! l[] edge fir/1 on ! develop]1 & gradually l[]$ ^u x1 :51 tak+ imm$iately hold ( x by ! two corn]s ne>e/ to ! body1 x is lift$ out & held upright to all[ "o foll[+ ! developm5t ( ! image2 &1 pres5tly1 if any air-bubbles are se5 on ! pro(1 !y %\ld at once be t\*$ up ) a bru% wett$ ) ! f]rocyanate solution2 ! reason expla9s itself4 ,! image appe>s at once4 ,z soon z ! f9e l9es are well def9$1 ! blue int5se1 &1 especially1 :5 ! gr\nd has a t5d5cy to be t+$ blue1 ! pro( is plac$ 9 ! tray fill$ ) wat] & 9 ?is turn$ ov] two or ?ree times1 :5 x is imm]s$ 9 ! dilut$ sulphuric acid4 ,9 ?is ba? ! pr9t acquires a deep blue coloration1 consi/+ ( ,prussian blue1 & ! gr\nd becomes t9t$ ) a blue precipitate )\t adh]5ce1 :i* is easily wa%$ (f by ?r[+ ! liquid on ! pro( ) a wood5 spatula1 or1 bett]1 by rubb+ ) a rag ti$ to a /ick4 ,:5 ! gr\nd is cle>$1 & aft] ?ree or f\r m9utes imm]sion to dissolve ! iron salts act$ on1 ! pro( is r9s$ 9 wat] sev]al times r5ew$ to free x f acid1 & hung to dry4 ,!re are two causes ( failures 9 ?is process1 viz41 ov] & "u-exposure4 ,9 ! =m] case ! f9e l9es are brok5 or wa%$ out 9 cle>+ ! pro( 7:i* may also arise f ! draw+ made ) an ink n opaque en\gh72 9 ! latt] ! gr\nd is m or less /a9$4 ,! blue /a9s1 ! l9es = corrections1 etc41 are eras$ ) ! ! potassic oxalate 7blue salv+1 z x is t]m$7 ^: =mula has be5 giv54 ,! additions1 corrections & writ+ are made ) a ,prussian blue ink prep>$ by mix+ ! two foll[+ solutions3 ,a4 ,f]ric *loride1 #d p>ts dry ,wat] #cej p>ts ,b4 ,potassium #ae p>ts f]rocyanate ,wat] #bej p>ts ,! precipitate be+ collect$ on a filt] & wa%$ until ! wat] comm5ces to be t+$ blue1 is dissolv$ to ! prop] consi/5cy 9 ab\t #djj p>ts ( wat]4 ,?is ink does n corrode /eel p5s4 ,x has be5 /at$ t ! cyan(] process keeps = ye>s if pres]v$ f ! comb9$ action ( dampness & ! air4 ,! writ] f\nd 9 8 practice t ! f]ric salts 9 pres5ce ( ! organic matt]s 7! sizes7 acts z does potassium bi*romate & r5d]s1 9 a c]ta9 p]iod1 ! cyan(] film insoluble ev5 aft] a prolong$ insulation4 ,pap] fre%ly prep>$ is always m s5sitive & gives bett] :ites & g5]ally f9] results47#aj7 ,! pr9ts c be ton$ black 9 op]at+ z 9 ! cyonotype1 b ! results are seldom good4 ,capta9 ,pizzighelli's =mula is z foll[s3 ,prep>e ,a4 ,gum arabic #ae p>ts ,wat] #ajj p>ts ,b4 ,ammonia f]ric #de p>ts citrate ,wat] #ajj p>ts ,c4 ,f]ric *loride #de p>ts ,wat] #ajj p>ts ,= s5sitiz+ mix 9 ord]3 ,solution ,a #ajj p>ts ,solution ,b #dj p>ts ,solution ,c #bj p>ts ,! mixture v mu* ?ick5s at fir/1 b becomes suffici5tly fluid = use 9 a few h\rs4 ,x keeps well = two or ?ree days4 ,leav+ out ,b & replac+ x by ra9 wat]1 ?is makes also a good solution = ! cyanotype4 ,,! ,,black ,,or ,,ink ,,process4 7,,f]ro-,,tannate ,,process47 ,?is process gives black positive impressions on :ite gr\nd f positive cli*s1 & negative impressions f negative cli*s4 ,x has be5 attribut$ to ,mr4 ,colas1 b 9 reality x 0 inv5t$ by ,mr4 ,poitev91 :o describes x z foll[s 9 8 communication ( ,may1 #ahfj1 to ! ,socit ,francaise de ,photographie3 8,i make a solution conta9+--0 ,iron p]*loride1 cry/ #aj p>ts ,t>t>ic acid #c p>ts ,wat] #ajj p>ts 8,i apply ! pap] on ?is mixture & let x dry spontane\sly 9 ! d>k1 & at ! mom5t ( us+ x ,i completely desiccate x at a g5tle heat4 ,?us prep>$ ! pap] is ( a deep yell[ color4 ,light decolors x rapidly1 & t5 or twelve m9utes' exposure ?r\gh a positive cli* suffices to well impress x1 t is1 to r$uce 9 ! :ites ! iron p]*loride to ! /ate ( proto*loride40 8,to pr9t1 "o is guid$ by ! decoloration ( ! pap]1 & ev5 = m facility ,i add to ! solution ( iron p]*loride & t>t>ic acid a small quantity ( a solution ( potassium sulphocyanide = ! purpose ( obta9+ a r$ t9t1 :i* is m visible & disappe>s also "u ! influ5ce ( light 9 proportion to ! decomposition ( ! p]*loride4 ,"o obta9s !n aft] exposure a r$ design on ! :ite gr\nd ( ! pap]4 ,?is r$ color is n p]man5t4 ,x ev5 disappe>s by keep+ ! pro( 9 ! d>k40 8,to develop & !n to fix ! design ?us obta9$ ,i wa% rapidly ! pap] 9 ord9>y wat]1 or bett]1 9 wat] hold+ *alk 9 susp5sion4 ,! r$ coloration disappe>s1 a "p ( ! iron p]*loride is wa%$ out1 & 9 ! p>ts :i* h n be5 act$ on by light ! p]*loride is trans=m$ into sesquioxide4 ,i replace !n ! wat] by solution ( gallic acid or ( tann9 & ! image progressively appe>s 9 ink-black4 ,:5 ,i judge ! image to be suffici5tly int5se ,i wa% ! pro( 9 ra9 wat]1 9 pref]5ce to ord9>y wat]1 :i* might cause ! gallic acid & tann9 to turn br[n4 ,i sponge betwe5 %eets ( blott+ pap] & let ! pro( dry spontane\sly40 8,if 9 place ( gallic acid ,i use a dilut$ solution ( potassium f]ricyanide 7r$ prussiate ( pota%71 ,prussian blue is =m$ 9 ! p>ts act$ on by light4 ,! prep>ation is ev5 s5sitive en\gh to p]mit "o to obta9 an impression 9 ! cam]a obscura 9 develop+ by ! f]ricyanide40 8,z to ! pro(s 9 gallate 7or tannate7 ( iron1 !y c be trans=m$ into ,prussian blue 9 a solution ( potassium f]rocyanide 7yell[ prussiate ( pota%7 slightly acidifi$ by sulphuric acid40 ,! pap] mo/ suitable = ?is process is t :i* has be5 previ\sly well siz$ ) />*1 z expla9$ 9 a special p>agraph ( ?is pamphlet4 ,pap] prep>$ ) a film ( coagulat$ album5 gives also good results4 ,x may be prep>$ by bru%+ z well z by float+1 b 9 ei!r case ! pap] %\ld be wett$ on ! surface only & dri$ rapidly at a temp]ature ( ab\t #aae deg4 ,fahr4 7#df deg4 ,c47 & kept 9 a dry place4 ,x does n keep = m ?an f t5 to fifte5 days1 ow+ to ! hygroscopicity ( ! iron comp\nd4 ,mr4 ,colas1 :o prep>es ! pap] = ! ,p>isian m>ket1 ,i ?9k1 /ates t he avoids its det]ioration by keep+ x wrapp$ 9 blott+ pap]1 betwe5 two %eets ( ,india rubb]1 to exclude air & dampness4 ,silv]$ album5 & pla9 pap]1 well desiccat$1 c\ld be kept 9 t way = a c]ta9 p]iod1 especially if ! blott+ pap] is impregnat$ ) sodium bic>bonate & well dri$4 ,mr4 ,a4 ,fis* advises to disc>d ! prelim9>y wa%+ & to develop j on ! removal ( ! pro(s f ! pr9t+ frame4 ,9 op]at+ 9 ?is mann] ! developm5t is be/ made by float+1 tak+ c>e t ! solution does n run (f ! back ( ! pro(4 ,! develop] may consi/ ( a dilute solution ( nutgalls or ( ,tann9 or gallic acid #d p>ts ,oxalic acid #j4ae p>ts ,wat] #a1jjj p>ts ,aft] develop+ ! pro( %\ld be wa%$ rapidly--"u a jet ( wat]1 if possible--= 7 ! iron salt & ! reag5t n soon remov$1 or any rema9 9 ! pap]1 ! gr\nd w\ld be t9t$ violet4 ,& :atev] be ! c>e tak51 x v seldom occurs t ! :ites are pure :5 ! pro( is dry4 ,?is = half-tone pictures has n a great importance1 b = ! reproductions ( plans x is sometimes objectionable4 ,9 fact x mu/ be ackn[l$g$ t none ( ! processes n[ at our disposal--if we except ! s-call$ ,artigues process describ$ fur!r on--gives an entirely satisfactory result4 ,a simple & exp$iti\s process1 yield+ int5se black impressions on a :ite gr\nd1 is yet to be f\nd = ! reproduction ( plans1 maps1 etc41 )\t resort+ to a negative cli* or draw+4 ,,! ,,cuprotype4 7,,burnett',s ,,process47 ,?is process gives positive impressions f negative cli*s4 ,uranic nitrate #aj p>ts ,cupric nitrate #b p>ts ,wat] #ajj p>ts ,float = a m9ute /rong1 well-siz$ pap] on ?is solution & let x dry spontane\sly 9 ! d>k4 ,expose until ! image is visible1 !n develop by float+ on a solution ( potassium f]ricyanide at #e p] #ajj ( wat]--! image appe>s at once ) a ri* br[n color4 ,:5 develop$1 wa% x 9 sev]al *anges ( wat] until ! unalt]$ salts are elim9at$4 ,! pro( is !n fix$1 &1 if too int5se1 c be r$uc$ 9 wat] slightly acidifi$ ) hydro*loric acid4 ,a f9e black image is obta9$ by ton+ 9 a solution ( plat9ic *loride at #a p] #ajj ( wat]4 ,! *emical actions giv+ rise to ! =mation ( ! metallic f]rocyanide1 ( :i* ! image consi/s1 are q complicat$4 ,"u ! lum9\s ag5cy ! uranic nitrate is fir/ r$uc$1 !n ! uran\s oxide acts on ! cupric nitrate1 =m+ cupric oxide1 :i* is f9ally r$uc$ to ! metallic /ate4 ,?is metal n[ conv]ts ! f]ricyanate 9 ! f]ro comp\nd1 :i*1 by ano!r action1 =ms bo? cupric & uranic f]rocyanate4 ,! foll[+ uranium process gives black impressions3 ,9 a saturat$ solution ( t>t>ic acid dissolve fre%ly precipitat$ f]ric oxide1 & keep ! solution--f]ric t>trate--9 ! d>k4 ,to prep>e ! s5sitiz+ solution1 dissolve #bj p>ts ( uranic nitrate & f #a to #c p>ts ( t>t>ic acid 9 #ajj p>ts ( wat]1 & add a small quantity ( f]ric t>trate1 ! proportion v>y+ ) ! t9t desir$3 an excess gives a blue black4 ,) ?is solution bru% ! pap] ov]1 &1 :5 dry1 expose "u ! negative cli*1 !n develop ) a solution ( potassium f]ricyanate at #d p] #ajj ( wat]4 ,to fix1 x suffices to wa% 9 wat]1 r5ew$ ?ree or f\r times4 ,z po9t$ out by ,mr4 ,b4 ,j4 ,burnett 7see ,introduction71 _m photographic processes c be devis$ by bas+ !m ^u ! v>i\s *emical *anges1 ( :i* uran\s oxide1 r$uc$ by light f ! uranic nitrate or sulphate1 is susceptible by means ( metallic or organic reag5ts4 ,9 ! ,app5dix "s ( ! mo/ important processes1 ) or )\t silv] salts z reag5ts1 w be describ$4 ,,! ,,anil9e ,,process4 ,! anil9e process 0 publi%$ 9 #ahfe1 by ,mr4 ,willis1 ! inv5tor ( ! plat9otype47#aa7 ,x is bas$ on ! oxidation ( anil9e by *romic acid1 ?us3 ,a %eet ( pap] bru%$ ) a solution ( potassium bi*romate & sulphuric acid1 dri$1 & aft] insolation "u a cli* expos$ to ! fumes ( anil9e :i*1 9 react+ ) ! *romic comp\nd n r$uc$ by light1 =ms a blue-black image4 ,! process gives1 consequ5tly1 a positive impression f a positive cli*4 ,!re are v>i\s me?ods ( op]at+2 we w briefly describe !m4 ,,s5sitis+ ,,solution4 #a4 ,potassium #f p>ts bi*romate ,sulphuric acid #f p>ts ,magnesium *loride #aj p>ts ,wat] #aej p>ts ,willis recomm5d$ #aj p>ts ( solid phosphoric acid in/ead ( sulphuric acid2 ! latt] =ms a prep>ation ab\t twice m rapidly r$uc$4 #b4 ,potassium #aj p>ts bi*romate ,mangan\s sulphate #d p>ts ,potassium #bj p>ts bisulphate ,wat] #cjj p>ts #c4 ,ammonium #e p>ts bi*romate ,ammonium *loride #e p>ts ,cupric sulphate #a "p ,sulphuric acid #h p>ts ,wat] #aej p>ts ,good well-siz$ pap] %\ld be employ$4 ,rives is too t5d] & absorbs too mu*4 ,/e9ba* is bett]4 ,= small sizes1 :atev] be ! pap] select$1 x is well to size x ) />* &1 if possible1 to cal5d] x on a hot /eel plate1 or1 9 lieu1 to iron x4 ,?is is n1 h[ev]1 a s9e qua non4 ,! pap] is s5sitiz$ by bru%+ or by float+4 ,to s5sitize by float+1 x %\ld be left b = a few seconds on ! solution & remov$ by dragg+ x on a glass rod 9 ord] to remove ! sup]flu\s liquid4 ,only ! surface ( ! pap] %\ld be impregnat$1 o!rwise ! :ites w\ld be m or less t9t$ & ! image imb$d$ n z %>p4 ,s5sitiz$1 ! pap] mu/ be dri$ z rapidly z possible4 ,x does n keep1 & %\ld be employ$ ! day x is prep>$ or ! day aft]1 keep+ x well wrapp$ 9 pap]4 ,z said above1 x is expos$ "u a positive cli*1 plans1 designs1 etc41 drawn on trac+ pap] or l954 ,! m transp>5t ! mat]ial1 ! m rapid ! *emical *anges4 ,dur+ ! insolation--& x is v %ort--! *romic comp\nd is r$uc$1 ! p>ts correspond+ to ! gr\nd1 t is1 ! transp>5t p>ts ( ! cli*1 are discolor$1 :ile ^? "u ! design rema9 unalt]$2 ! image be+1 !re=e1 fa9tly visible1 & be+ =m$ ( ! *romic mixture1 x is develop$ by ! fumes ( anil9e 9 a blue black tone4 ,!re=e1 if ! pap] be n suffici5tly expos$1 ! gr\nd is color$ l ! image1 al?\gh n z deeply1 s9ce ! dye =m$ is proportionate to ! m or less quantity ( unr$uc$ comp\nd1 & if expos$ too long ! image is imp]fectly develop$ or n at all by excess4 ,! discoloration ( ! gr\nd1 :i* turns to a gre5i% hue1 easily indicates :5 ! exposure is suffici5t4 ,b1 to asc]ta9 x1 ! beg9n] %\ld use te/s z 9 ! cyan(] process4 ,mr4 ,endemann regulates ! "t ( exposure by p>tly cov]+ a /rip ( ! s5sitive pap] ) a piece ( ! trac+ mat]ial ^u :i* ! design is made1 & expos+ ! :ole until ! cov]$ "p ( ! pap] assumes ! same %ade z ! "p directly expos$ to light4 ,to develop ! pr9t is plac$ 9 ! bottom ( a tray1 :i* is !n cov]$ ) a lid ^u :i* is p9n$ blott+ pap] well imbu$ ) an anil9e & b5z9e mixture1 or ! rev]se2 t is1 expos+ ! pr9t fa/5$ to ! lid & plac+ ! anil9e on ! bottom ( ! tray4 ,! tray %\ld be h]metically clos$2 t is a condition to obta9 a f9e & equal coloration4 ,= ?is purpose ! lid %\ld be well l9$ ) %eets ( blott+ pap] & a weight plac$ ov] x dur+ ! op]ation4 ,l>ge pr9ts are necess>ily develop$ 9 a fumigat+ box made ad hoc4 ,! anil9e solution consi/s ( ,anil9e 7comm]cial = #h p>ts r$7 ,b5z9e1 rectifi$ #ajj p>ts ,9 place ( b5z9e1 e!r ,u4,s4,p41 sp4 grav4 #j4hcg1 may be us$4 ,:5 ! pro( is n ov]-expos$ ! developm5t comm5ces 9 a few m9utes4 ,! image fir/ takes a dirty black olive color :i* turns blue 9 wat]1 !n ! tone d>k5s to a d>k-br[ni% t9t4 ,! "t ( exposure to ! anil9e fumes dep5ds on ! "t ( insolation2 if %ort1 ! gr\nd is soon t9t$1 & consequ5tly ! developm5t %\ld !n be /opp$2 if ov]-expos$1 ! developm5t proce$s sl[ly4 ,! d>ke/ tone is obta9$ by a r full exposure :i* admits a long fumigation4 ,sometimes ! image takes a gre5 color2 x suffices !n to wa% ! pro( 9 wat] r5d]$ alkal9e by a few drops ( aque\s ammonia to obta9 ! normal color4 ,to some:at improve ! tone ( ! image &1 if objectionable1 to remove ! *romic oxide :i* t+es ! gr\nd gre5i%1 ! pro( %\ld be imm]s$ 9 a dilute solution ( sulphuric acid #a3ajj1 !n wa%$ twice1 & f9ally pass$ 9 ammoniacal wat] #a3ajj4 ,mr4 ,h]mann ,endemann has publi%$1 9 #ahff1 ! foll[+ process 9 ! ,j\rnal ( ! ,am]ican ,*emical ,society1 pp4 #ahi et seq43 ,! pap]1 :i* mu/ be well siz$ ) glue1 #a3ej1 is s5sitiz$ ) ! foll[+ solution & expos$ :5 dry1 b /ill slightly damp3 ,a4 ,potassium #a ounce or #dhj bic>bonate p>ts ,salt #a ounce or #dhj p>ts ,sodium vanadate #b_/c gra9 or #j4ff "p ,wat] #bj ounces or #i1fjj p>ts ,b4 ,sulphuric acid #b ounces or #ifj p>ts ,wat] #aj ounces or #d1hjj p>ts ,:5 cold mix to ,a4 8,f ! composition ( ! solution10 says ,mr4 ,endemann1 8x is evid5t t x mu/ be /rongly acid2 b :5 ?is solution is expos$ to light1 9 ! pres5ce ( ! organic sub/ances ( ! pap]1 ! acidity ( ! solution disappe>s1 we obta9 potassium & sodium sulphates1 basic *romium sulphate1 salt & vanadic acid4 ,:ile1 !re=e1 ! un*ang$ p>ts ( ! pap] rema9 acid1 ! *ang$ p>ts acquire a neutral reaction1 & :ile ! fir/ w readily assimilate bases1 ! second w n4 ,expos$ 9 an atmosph]e lad5 ) wat] & anil9e1 ! anil9e w be absorb$ 9 ^? p>ts :]e ! solution rema9s acid & 9 proportion to ! rema9+ acidity40 ,to develop ! image ! pap] is spread ov] ! op5+ ( a frame tightly plac$ on a pan1 9 ! bottom ( :i* is heat$ a solution ( anil9e 9 wat]1 #a3ej1 until ! image appe>s br[n1 & = fur!r developm5t 9 a box lad5 ) /eam wat]1 :i*1 accord+ to ,mr4 ,endemann1 requires two h\rs to obta9 a deep black coloration4 ,to remove ! *romium comp\nd ! picture is imm]s$ 9 a solution ( aque\s ammonia1 #a3f1 !n wa%$ & dri$4 ,a few ye>s ago ! anil9e process 0 improv$ by develop+ ! image ) ! anil9e-b5z9e mixture vaporiz$ by /eam 9 a box made specially = t purpose1 :]eby a reproduction c be obta9$ 9 less ?an t5 m9utes4 ,9 ! photographic dep>tm5t ( ,messrs ,p\lson ,eg]'s ,hecia ,ar*itectural & ,ornam5tal ,iron ,works1 :i* is direct$ by ,*>les ,bilordeaux1 ?is process is work$ 9 ! foll[+ mann]3 ,! develop+ is made ( %eet iron ) a door slid+ up & d[n1 x be+ balanc$ by a c\nt]poise1 & provid$ ) a *imney4 ,9 ! box is a gutt]1 ext5d+ ! :ole l5g? ( ! bottom1 cov]$ ) musl9 & connect$ to a /eam pipe2 !re is also a coil simil>ly connect$4 ,aft] ! insolation1 :i* requires ab\t "o m9ute 9 sun%9e1 ! pr9t is susp5d$ 9 ! box1 ! musl9 bru%$ ov] ) ! solution ( anil9e1 & live /eam all[$ to pass ?r\gh ! gutt] = only two m9utes1 :]eby ! anil9e be+ vaporiz$ acts on ! *romic salt & develops ! image2 !n ! /eam is all[$ 9 ! coil1 &1 9 f ?ree to f\r m9utes1 ! pap] is dry & ! picture f9i%$4 ,! image /&s on a slightly gre5i% gr\nd1 :i* is n objectionable = ! purpose ! reproductions are made4 ,! s5sitiz+ solution is simil> to t publi%$ by ,mr4 ,endemann1 viz43 ,potassium bi*romate #dfj grams ,sodium *loride #dfj grams ,ammonium vanadate #j4ge gram ,sulphuric acid #a lit] ,wat] #ac lit]s ,,! ,,primul9e ,,or ,,diazotype ,,process4 ,primul9e1 discov]$ 9 #ahhg by ,mr4 ,a4 ,g4 ,gre51 an ,engli% *emi/1 is a dye ( a primrose color1 possess+ a great aff9ity = cotton fib]s1 to :i* x is readily fix$ by simply imm]s+ ! mat]ial = a few mom5ts 9 a hot solution ( ! dye4 ,if ! mat]ial s dy$ be plac$ 9 an acidifi$ solution ( nitr\s oxide1 ! primul9e is diazotiz$1 =m+ a d]ivative comp\nd ( a deep] color1 :i* fades 9 ! light1 & :i* 9 pres5ce ( am9es & ph5ols gives rise to a v>iety ( dyes ^: color dep5ds on ! reag5t employ$1 :ile1 :5 act$ on by light1 ! result+ comp\nd is entirely depriv$ ( ?is prop]ty4 ,9 o!r words1 ! diazotiz$ primul9e acts z a mordant only :5 n alt]$ by ! lum9\s action4 ,! *emical *ange light effects 9 ! diazotiz$ primul9e is n well kn[n4 ,x is pretty c]ta91 h[ev]1 t nitrog5 is set free1 = if gelat9e imbu$ ) primul9e be imm]s$ 9 wat] aft] insulation1 nitrog5 is set free & c be collect$ z usual 9 a tub fill$ ) wat] & inv]t$ on ! sub/ance4 ,by itself diazotiz$ primul9e is sl[ly influ5c$ by light1 b quickly act$ on 9 pres5ce ( organic sub/ances4 ,x is m s5sitive :5 appli$ on cotton or pap] ?an on wool1 silk1 l951 & su* organic comp\nds z gelat9e1 album51 case9e1 />*1 etc4 ,its s5sitiv5ess is ab\t "o-t5? less ) gelat9e ?an ) cotton4 ,! s5sitiv5ess ( diazotiz$ primul9e to light1 :5 unit$ to organic sub/ances & ! diff]5t colors :i* c be obta9$ ) ! unalt]$ comp\nd1 h giv5 rise to an int]e/+ pr9t+ me?od1 ! inv5tion ( ,messrs4 ,a4 ,g4 ,gre51 ,c4 ,f4 ,cross1 & ,e4 ,j4 ,bevan1 :i* yields positive impressions f positive cli*s4 ,! manipulations ( ! process are simple3 ,9 a c]ta9 quantity ( ra9 wat]1 kept at ne>ly ! boil+ temp]ature by an alcohol lamp plac$ "u ! vessel1 dissolve p] c5t4 #b p>ts ( comm]cial primul9e1 & 9 ?is imm]se1 by means ( a glass rod1 "s pieces ( calico--free f dress+--turn+ !m ov] sev]al times dur+ ! imm]sion4 ,:5 ! fib]s are well imbu$1 :i* requires f f\r to five m9utes1 remove ! calico ) ! glass rod & r9se x ?or\ghly 9 wat]4 ,?is done1 wr+ out ! sup]flu\s liquid z mu* z possible1 &1 f9ally1 imm]se ea* piece sep>ately 9 a solution ( ,sodium nitrite1 #g p>ts comm]cial ,hydro*loric acid1 #af p>ts comm]cial ,wat] #ajj p>ts ,aft] turn+ ! pieces ( calico two or ?ree times ov]1 !y are r9s$ to elim9ate ! acid1 !n dra9$ & plac$ betwe5 %eets ( blott+ pap] to dry4 ,all ?is1 except ! impregnation ) primul9e1 %\ld be done 9 ! d>k room4 ,z said above1 primul9e is trans=m$ by nitr\s oxide into a diazotiz$ comp\nd1 & consequ5tly ! mat]ial is n[ susceptible ( be+ act$ on by light4 ,x does n keep1 & %\ld be expos$1 etc41 soon aft] its prep>ation4 ,pap] is impregnat$ ) primul9e ei!r by float+ or bru%+4 ,! be/ results are obta9$ ) pap] previ\sly siz$ ) arr[root or gelat9e 9 ord] to keep ! image entirely on ! surface ( ! pap]4 ,l951 silk & wool are treat$ z calico4 ,! cli*s %\ld be positive to obta9 positive expressions & some:at m opaque ?an ^? employ$ 9 ! processes be=e describ$1 else vigor & int5sity c\ld n be obta9$4 ,"h we mu/ /ate t ! primul9e process seems to be bett] adapt$ = ! reproductions ( draw+s1 su* z made = ! black process1 & ( opaque photo-cli*s 9 l9es1 or :ite & black1 ?an = pr9t+ 9 half tone4 ,:5 ! mat]ial to pr9t ^u is ?ick & :olly impregnat$ ) diazotiz$ primul9e1 x is advisable1 s9ce ! insulation c\ld n be prolong$ to effect ! *ange ?r\gh1 to expose ! back ( ! mat]ial = a c]ta9 b %ort p]iod 9 ord] to cle> x4 ,?is is especially advantage\s :5 ! cli* is n ( good int5sity4 ,dur+ ! exposure1 :i* v>ies f #cj seconds to #aj m9utes & m by a dull light1 ! progresses ( ! lum9\s action is se5 by ! blea*+ ( ! mat]ial :i* assumes a d+y coloration4 ,b 9 ord] to asc]ta9 :5 ! decomposition is complete on ! gr\nd ( ! image1 x is well to use te/s z 9 ! cyan(] process1 dipp+ "o ( !m 9 ! develop] f "t to "t4 ,! develop]s are comp\nd$ z foll[s3 ,,= ,,r$4 ,beta-naph?ol #d p>ts ,cau/ic potassa #f p>ts ,wat] #ejj p>ts ,rub ! alkali & ! naph?ol ) a little wat] 9 a mort> & add ! rema9d] ( ! wat]4 ,,= ,,orange4 ,resorc9 #c p>ts ,wat] #ejj p>ts ,:5 dissolv$ add ,cau/ic potassa #e p>ts ,,= ,,yell[4 ,c>bolic acid1 cry/ #e p>ts ,wat] #ejj p>ts ,,= ,,purple4 ,naph?ylam9e #f p>ts ,hydro*loric acid1 9 #f p>ts volume ,mix 9 a mort>1 !n add ,wat] #ejj p>ts ,,= ,,black4 ,eikonog51 :ite cry/als #f p>ts ,wat] #ejj p>ts ,pulv]ize ! eikonog51 add ! wat] &1 at ! same "t1 ! mat]ial on its removal f ! pr9t+ frame1 & keep 9 motion until ! developm5t is effect$4 ,,= ,,br[n4 ,pyrogallol #e p>ts ,wat] #ejj p>ts ,aft] ! developm5t1 :i* requires b a few mom5ts1 x suffices to wa% ! mat]ial to fix ! image by elim9at+ ! soluble comp\nds4 ,h[ev]1 = purple ! mat]ial %\ld be pass$ 9 a dilute solution ( t>t>ic acid & n wa%$ aft]w>ds2 x %\ld rema9 acid4 ,:5 x is desirable to obta9 an impression 9 sev]al colors1 ! v>i\s develop]s are ?ick5$ ) />*1 !n locally appli$ ) a bru% on ! image1 :i* is always visible aft] exposure4 ,= pr9t+ on wood1 glass & porcela91 see fur!r on4 ,,pr9t+ ,,on ,,wood1 ,,canvas1 ,,opal1 ,,& ,,transp>5cies ,pr9t+ on ,wood4--,to pr9t on a wood block a design to be engrav$ on ! same pres5ts c]ta9 difficulties4 ,9 ! fir/ place1 ! s5sitiz+ solution mu/ n be absorb$ by ! wood1 b rema9 :olly on its surface2 !n ! photo film1 al?\gh ?ick en\gh to produce an image suffici5tly int5se to be di/9ctly visible 9 all its details1 %\ld n scale or clip away "u ! grav]1 & n int]f]e 9 any way ) ! "w ( ! arti/2 ! lea/ t\* ( ! grav] mu/ rea* ! wood & make its impression4 ,la/ly1 ! design %\ld be p]man5t4 ,^! difficulties w be avoid$ by adh]+ to ! in/ructions giv5 9 ! l9es foll[+4 ,! solution to r5d] imp]vi\s ! surface ( ! wood consi/s ( ,common gelat9e #e p>ts ,gum arabic #c p>ts ,ca/ile soap #c p>ts ,wat] #ajj p>ts ,dissolve by heat on a wat] ba?4 ,to apply x1 ! wood is rubb$ ) f9e s&pap]1 !n heat$ ov] a _s lamp to ab\t #hf deg4 ,fahr4 7#cj deg4 ,c47 & ^u x is p\r$ 9 excess ! liquefi$ & q w>m solution1 :i* mu/ be all[$ to p5etrate 9 ! pores ( ! wood by lett+ x gelat9ize1 :5 x is wip$ (f clean4 ,no?+ mu/ rema9 on ! surface ( ! wood4 ,?is done1 & :ile /ill damp1 ! prep>ation is r5d]$ insoluble by p\r+ ov] a solution ( alum at #e p] #ajj ( wat]4 ,! object ( ?is prelim9>y op]ation is to r5d] ! wood imp]vi\s1 & !re=e to prev5t ! s5sitiz+ solution to p5etrate its texture4 ,! wood is !n heat$ aga9 & its surface :it5$ ) a little silv] :ite or sulphate ( b>ium1 diffus$ 9 a small quantity ( ! foll[+ w>m solution3 ,gelat9e #a p>ts ,alum #j4a "p ,wat] #ajj p>ts ,:ile wet1 ?is is smoo!d ) a jewel]'s bru%1 tak+ c>e to leave on ! wood1 a v ?9 lay] ( ! mixture1 only suffici5t to obta9 a :ite surface :i*1 by contra/+ ) color ( ! wood assi/s ! engrav] 9 8 "w4 ,! wood %\ld n[ be all[$ to dry ?or\ghly1 :5 x is coat$ ) a tepid solution ( ,is+lass #c p>ts ,wat] #ajj p>ts & dri$4 ,n[ ! s5sitiz+ process diff]s accord+ z :e!r ! cli* is positive or negative4 ,9 ! =m] case ! prep>ation is s5sitiz$ ) ! solution employ$ 9 ! black process1 proce$+ aft]w>ds z usual2 9 ! latt]1 t is1 :5 ! cli* is negative1 ! be/ process is ! cuprotype47#ab7 ,= pr9t+1 special frames are employ$ to p]mit "o to exam9e ! progress ( ! impression f "t to "t )\t ! possibility ( ei!r ! wood block or ! cli* mov+4 ,^! frames op5 9 two4 ,! upp] frame is provid$ ) screws on ! f\r sides to hold firmly ! block :5 x is plac$ into contact ) ! cli* by means ( ! screws fix$ on ! cross b>s4 ,z to ! cli*1 if x is made on a glass plate1 x is secur$ on ! ?ick glass plate ( ! l[] frame by two wood5 b>s aga9/ x pu%$ by screws4 ,:5 ! block is ready = pr9t+1 ! prep>$ side is usually concave4 ,x is /raight5$ by slightly wett+ ! back & re/+ x on "o end1 prep>$ side aga9/ ! wall4 ,pr9t+ on ,canvas4--,! canvas %\ld be fir/ bru%$ ) a solution ( aque\s ammonia 9 alcohol1 #a3c1 to remove greas9ess until ! ?read j comm5ces to %[1 !n1 :5 r9s$ & dry1 rubb$ ) f9e s& to give a too?1 du/$1 wa%$ ) a sponge & !n coat$ ) ! foll[+ solution1 proce$+ aft]w>ds z 9 ! cuprotype process3 ,is+lass #h p>ts ,uranic nitrate #e p>ts ,copp] nitrate #b p>ts ,wat] #bjj p>ts ,pr9t+ on ,opal1 ,celluloid1 etc41 is q simple2 x suffices to coat ! mat]ial ) ! foll[+ gelat9e solution1 &1 :5 ! film is dry1 to proce$ 9 op]at+ by any "o ( ! processes be=e describ$4 ,! s5sitiz+ comp\nd may be incorporat$ to ! gelat9e solution1 b we pref] n to d x & to s5sitize ! plates z !y are want$ = use4 ,a4 ,gelat9e #d p>ts ,wat] #gj p>ts 9 volume ,dissolve & mix little by little 9 ord]3 ,b4 ,*rome alum #j4be p>ts ,wat]1 hot #bj p>ts ,c4 ,alcohol #aj p>ts ,:5 coat$ place ! plates on a level /& until ! gelat9e is set1 & let !m dry on a rack4 ,transp>5cies4--,prep>e ! plate z direct$ above ) ,a4 ,gelat9e #f p>ts ,wat] #gj p>ts ,b4 ,*rome alum #j4c "p ,wat]1 hot #bj p>ts ,c4 ,alcohol #aj p>ts ,s5sitize ) ! uranic-copp] solution employ$ 9 ! cuprotype4 ,by ?is process transp>5cies ( a ri* br[n1 n act9ic1 color are obta9$4 ,consequ5tly !y c be us$ to reproduce negatives by ! same process4 ,= lant]n slides !y may be ton$ black by plat9ic *loride4 ,to /rip (f ! picture1 apply1 fir/1 on ! glass plate a sub/ratum ( ,india rubb]1 #b to #ajj ( b5zole1 coat ) pla9 collodion1 imm]se ! plate 9 wat] z soon z ! film is set1 & :5 greas9ess has disappe>$ p\r on ! gelat9e solution & proce$4 ,= tranf]r+ on any mat]ial1 a %eet ( pap] is imm]s$ 9 a solution ( ,india rubb] cem5t 9 #bj p>ts ( b5zole1 dri$1 coat$ ) ! gelat9e solution1 s5sitiz$1 etc41 by op]at+ 9 ! ord9>y mann]4 ,aft] developm5t1 ! pro(1 be+ dry1 is bru%$ ov] ) alum$ gelat9e mod]ately w>m1 dri$1 imm]s$ 9 tepid wat] until ! gelat9e is s(t5$ & tacky1 :5 x is plac$ on ! mat]ial & squeez$ into contact4 ,?is done1 ! transf] %\ld be all[$ to dry ?or\ghly4 ,n[1 by imbu+ ! pro( ) b5zole to dissolve ! ,india rubb]1 ! pap] is easily /ripp$ (f1 leav+ beh9d ! picture adh]+ to ! mat]ial4 ,,trac+ ,,process ,,on ,,metal4 ,we call ! att5tion ( metal engrav]s to ?is process4 ,x is well kn[n t wood engrav]s h _! orig9al designs photograph$ on ! block 9 ord] to save consid]able "t by n mak+ ! draw+ !mselves2 moreov] ! co/ is nom9al1 s to say1 & ! copy m true & p]fect ?an x c be done by h&4 ,:y %\ld n ! copp] engrav] & ! aqua=ti/ avail !mselves ( ! same advantages8 ,a few d x secretly1 no d\bt1 b ! g5]ality n kn[+ ! process1 or1 if s1 n hav+ tri$ x1 ?9k x is n possible or t x may spoil _! plates4 ,?is is an error4 ,x c be done & v easily by adh]+ to ! foll[+ in/ructions3 ,dissolve #b p>ts ( ammonium bi*romate 9 #ajj p>ts ( wat]1 & 9 ?is let soak = an h\r or s #aj p>ts ( ,coignet's be/ gelat9e1 !n dissolve on a wat] ba?1 filt] ?r\gh flannel1 & ! solution is ready = use4 ,be=e be+ coat$1 ! plate %\ld necess>ily be clean$ free f oxidation & greasy matt]s4 ,?is is done by imm]s+ ! plate = a few mom5ts 9 a w>m solution ( common pota%1 !n r9s+ & rubb+ x ) *alk moi/5$ ) a little wat]1 :5 aft] r9s+ aga9 & dra9+ ! plate %\ld be imm$iately prep>$4 ,to spread ! gelat9e solution 9 an ev5 & ?9 lay]1 a t\rnette is employ$4 ,! mo/ simple consi/s ( a r\nd wood5 /ick ( :i* ! upp] "p is c>v$ 9 ! =m ( a cup ) an edge1 or rim1 ab\t "o qu>t] ( an in* broad4 ,on ?is rim is melt$ "s gutta-p]*a1 ^u :i* ! plate is press$ into contact & adh]s q firmly :5 ! gutta-p]*a is solidifi$4 ,! /ick is p]=at$ at ! l[] end & revolves on an iron pivot fix$ at ! bottom ( ! support1 be+ held 9 ! op5+ on ! plat=m ( ! same1 z %[n 9 ! diagram on ! foll[+ page4 ,! plate be+ fa/5$ to ! t\rnette1 ! w>m gelat9e solution is fl[$ ov] x & spread to ! edges by means ( a glass rod or a piece ( c>dbo>d1 avoid+ air bubbles4 ,?is done ! t\rnette is set into motion1 & :5 ! film is equaliz$1 :i* is done 9 a mom5t1 ! plate is deta*$1 plac$ on a level$ /& & sl[ly dri$ ) ! _s lamp4 ,a ,t\rnette ,by a good light ! exposure on ! %ade does n exce$ tw5ty m9utes ) a pretty int5se transp>5cy1 & %\ld be regulat$ ) a photomet]4 ,:5 ! insulation is suffici5t1 ! image is slightly visible1 & %\ld be s4 ,! plate is !n bord]$ ) bank+ wax & bitt5-9 ) a solution ( f]ric *loride at #de deg4 ,baum1 or-- ,f]ric *loride1 cry/al #bj p>ts ,hydro*loric acid #a "p ,wat] #ajj p>ts ,! p>ts ( ! gelat9e film ! mo/ act$ on are imp]meable1 s to say1 & consequ5tly d n all[ ! et*+ fluid to p5etrate to ! copp]2 :ile ^? ! lea/ impress$ are p]meat$ accord+ z to _! degree ( insolation1 ,!re=e1 :5 ! f]ric *loride solution is p\r$ ^u ! film & c>efelly bru%$ ov] ) a s(t bru%1 9 a few mom5ts ! image progressively appe>s1 ! deep blacks fir/1 !n ! half t9ts1 & la/ly ! mo/ delicate details1 ! :ole requir+ b a few m9utes4 ,x is n[ t ! et*+ action %\ld be /opp$ by wa%+ "u ! tap4 ,h[ev]1 %\ld by excess ( exposure1 or any o!r cause1 ! details n appe> )9 five or six m9utes1 ! f]ric *loride %\ld nev]!less be wa%$ (f1 = !n x may f9d its way "u ! film & ! plate w\ld be spoil$4 ,aft] wa%+ ! gelat9e is dissolv$ 9 a solution ( pota%1 etc41 :5 ! image w\ld be f\nd slightly engrav$4 ,%\ld ! image be 9 half-t9ts1 x w\ld be advisable to apply a gra9 ( ros9 on ! gelat9e film j be=e et*+4 ,to engrave on /eel ! op]ations are ! same1 b on its removal f ! pr9t+ frame ! plate %\ld be soak$ ) wat] r5ew$ sev]al times until ! bi*romate is wa%$ (f4 ,! film is !n dri$ spontane\sly & aft]w>ds fl[$ = ab\t two m9utes ) ! ,solution ,a1 !n1 ?is be+ ?r[n away1 ) ! ,solution ,b1 :i* is all[$ to act = a simil> p]iod4 ,a4 ,nitric acid1 pure #abj p>ts ,silv] nitrate #f p>ts ,alcohol1 #ie deg #ej p>ts ,wat] #ge p>ts ,b4 ,nitric acid1 pure #e p>ts ,alcohol1 #ie deg #dj p>ts ,wat] #fj p>ts ,,graphotypy4 ,?is process consi/s 9 conv]t+ a cli* 9 half tones into "o 9 l9es1 :i* c be directly pr9t$ on pap]1 or impress$1 by means ( an ink transf] made z expla9$ be=e1 on a /one1 or on a z9c or copp] plate = et*+ 9 relief1 or 9 intaglio1 accord+ z ! cli* is negative or positive4 ,a cli* on gelat9e1 b pref]ably on a collodion film1 is v>ni%$ ) a solution ( yell[ wax & bitum5 9 b5zole & turp5t9e-oil3 ,bitum5 ( ,judaea #h p>ts ,yell[ wax #b p>ts ,b5zole #dj p>ts ,turp5t9e oil #fj p>ts 7filt]7 !n et*$ z done to engrave 9 ! aqua=tis mann]1 ! corrections be+ made by apply+ ) a bru% "s ( ! above v>ni% on ! defective p>ts1 :i* are work$ ov] :5 ! v>ni% is dry4 ,! tools are simply ne$les ( v>i\s ?ickness gr\nd 9 %>p squ>e & r\nd po9ts ( diff]5t sizes4 ,:5 ! et*+ is f9i%$1 ! p>ts :i* %\ld =m ! gr\nd1 or :ite p>ts ( ! design1 be+ cov]$ ) ! bitum5 v>ni% is non-act9ic1 or1 9 o!r words1 does n admit ! light act+ on ! s5sitive plate prep>ation employ$ to reproduce ! design1 except by an exposure a good deal long] ?an t necess>y to r$uce ! metallic salts4 ,! engrav] w see at once t1 al?\gh x greatly simplifies ! copy+ "w &1 consequ5tly1 saves mu* "t1 ?is process does n1 h[ev]1 b9d him to any rules & leaves him p]fectly free to foll[ its inspirations & make su* alt]ations z he ?9ks prop] to produce arti/ic effects2 9 a ^w1 ! reproduction w no m be a picture tak5 by a me*anical process1 s to say1 b an orig9al draw+ reflect+ 8 tal5t & *>act]i/ic mann]4 ,a simil> process mu* employ$ by photo engrav]s1 & pres5t+ ! same advantages1 is to conv]t an ord9>y photograph on pap]--or a blue pr9t1 z devis$ by ! writ]--into a design 9 l9es by draw+ ) ,india ink1 or ! special ink ( ,higg9s1 &1 ?is done1 to wa% (f ! photographic image1 ! design be+ aft]w>ds reproduc$ by ! ord9>y processes z a negative or a positive cli*4 ,:5 ! photograph is a silv] pr9t especially made = ! purpose 9 "q &1 consequ5tly n ton$1 b simply fix$ 9 a new ?iosulphate 7hyposulphite7 ba?1 & well wa%$--x is blea*$ by fl[+ ov] a solution (-- ,bi*loride ( m]cury #e p>ts ,alcohol #dj p>ts7#ac7 ,wat] #ajj p>ts ,if ! photograph has be5 ton$1 i4e41 color$ by a deposit ( gold1 or if x 0 fix$ 9 a ?iosulphate ba? 9 :i* ton$ pr9ts h be5 fix$1 !n ! image is dissolv$ by treatm5t 9 a solution ( potassium cyanide 9 alcoholiz$ wat]4 ,:5 a blue photograph is r$uc$1 x is advisable be=e draw+ ^u x to fir/ r$uce its int5sity by a prolong$ imm]sion into wat]4 ,pale blue is a v act9ic color :i* is n reproduc$ 9 photography1 except by ! or?o-*romatic process1 or if x does1 ! impression be+ v weak1 is n objectionable4 ,:5 ! image has n be5 suffici5tly or n at all blea*$1 ! blue is dissolv$ by an alcoholiz$ solution ( ! blue solv+4 ,,! ,,uranotype4 ,?is process1 devis$ by ,j4 ,wo?ly1 9 #ahfd1 did n receive f ! photograph]s ! att5tion x m]its1 z x is always ! case :5 a process is pat5t$1 & c be replac$ by ano!r equally practical :i* is n4 ,x gives pictures ( a v good tone1 :i* are q p]man5t2 we h "s made 9 #ahff1 :i* are suff]$ no *ange :atev]1 !y seem to h be5 pr9t$ f ye/]day4 ,! fir/ process giv5 by ,wo?ly does n appe> to be complete4 ,x has be5 well describ$ by ,h4 ,coop] & a g5tleman :o signs by ! initial lett] ,x4 ,! process publi%$ 9 #ahfe by ,wo?ly is z foll[s3 ,a %eet ( pap] is siz$ by bru%+ ) a pa/e made ( #bd p>ts ( arr[root 9 #ejj p>ts ( wat]1 to :i* are add$ a few drops ( a solution ( citric or t>t>ic acid1 !n coat$ ) a collodion consi/+ ( #ajj cubic c5timet]s ( pla9 collodion1 a few drops ( oil ( turp5t9e & #cj cubic c5timet]s ( ! foll[+ s5sitiz+ solution3 ,nitrate ( uranium #cj to #ij p>ts ,*loride ( plat9um #b p>ts ,alcohol #ahj p>ts ,! "t ( exposure is ab\t t requir$ = pap] prep>$ ) silv] *loride4 ,! image is blui%-black b weak4 ,aft] wa%+ ! pr9t is imm]s$ 9 a solution conta9+ #j4e p>ts ( *loride ( gold = #b1jjj p>ts ( di/ill$ wat]1 & !n fix$ 9 a ba? ( sulphocyanate ( potassium1 :i* tones ! image blue-black4 ,x may happ5 t ! pro( is slightly t9t$ r$4 ,?is arises f a small quantity ( lime 9 ! pap] :i* =ms uranate ( calcium4 ,to prev5t ! pro(s turn+ yell[1 x %\ld be wa%$ 9 an exce$+ly weak solution ( acetic acid4 ,if1 aft] exposure1 ! pr9t is imm]s$1 )\t x be+ wa%$1 9 ! gold ba?1 ! image becomes rose-r$1 b ! :ites rema9 pure4 ,! effect is peculi>4 ,h4 ,,coop]',s ,,process 7#ahfe74 ,,prep>ation ,,( ,,! ,,pap] ,/4 ,v9c5t arr[root #bjj gra9s ,boil+ wat] #aj ounces ,cru% ! arr[root to f9e p[d]1 !n rub x to a pa/e ) a little wat]1 & let an assi/ant p\r a few drams ( boil+ wat] :ile y keep /irr+ all ! "t2 f9ally1 let him add ! re/ ( ! boil+ wat]1 ! op]ator /ill cont9u+ ! /irr+4 ,! pa/e is all[$ to cool1 & w be ?ick] :5 cold ?an :5 hot4 ,remove ! upp] portion entirely :5 q cold1 o!rwise1 if any left1 x w give rise to /reaks4 ,! au?or insi/s ^u ! necessity ( all ^! c>es4 ,two %eets ( pap] are n[ plac$ side by side on a flat bo>d1 !n ! surface ( ! fir/ is cov]$ ) ! pa/e by means ( a sponge1 proce$+1 be=e y leave x1 all ov] ! %eet 9 a horizontal direction2 ! second %eet is cov]$ 9 a l mann]4 ,by ! "t ! second %eet is pa/$1 ! fir/ "o w be p>tially dry4 ,! sponge is n[ drawn ov] ea* %eet1 9 succession1 9 a p]p5dicul> direction 9 ord] to efface ! /reaks f ! fir/ spong+4 ,if ! pa/e drags 9 a slimy mann]1 x is too /rong1 & a fre% arr[root mu/ be prep>$1 because dilution only ends 9 failure4 ,:y dry1 ! pap] is roll$ "u mod]ate pressure1 & :5 x lies smoo?ly ! maximum pressure may be appli$4 ,,pla9 ,,collodion4 ,alcohol #ab ounces ,e!r #d ounces ,pyroxyl9e #hj gra9s ,,s5sitive ,,collodion4 ,pla9 collodion #a ounce ,nitrate ( uranium1 pure #cj gra9s ,nitrate or silv] #e gra9s ,add ! uranium fir/1 & z soon z x has dissolv$ all t x c1 add a gra9 or two ( soda1 & :5 settl$ p\r (f ! sup]natant collodion & add ! silv]47#ad7 ,to coat ! pap] ) collodion1 use a bo>d ) a h&le b5ea?1 su* z is us$ by pla/]]s4 ,on ?is place a %eet ( pap]1 ! edges be+ turn$ up ab\t ! sixte5? ( an in*2 ?is enables ! :ole ( ! %eet to be cov]$ )\t spill+ ! collodion or all[+ x to run on ! back ( ! pap]4 ,!re is a m>k$ diff]5ce 9 ! appe>ance ( ! pr9ts :5 !y leave ! pressure frame4 ,"s samples ( collodion cause ! picture to pr9t ( a beautiful gre51 o!rs ( a ri* br[n1 & "s ( a yell[ or orange t9t4 ,! la/ take ! longe/ ( all to tone1 & difficultly assume ! t9t ( well ton$ silv] pr9ts17#ae7 ^? pr9t+ to gre5 or br[n tone v rapidly4 ,aft] pr9t+ ! pictures are plac$ 9 dilut$ sulphuric acid1 #a to #cj ( wat]1 until ! high lights are p]fectly cle> & :ite2 ?is takes f t5 to fifte5 m9utes4 ,aft] wa%+ well "u a /ream ( wat]1 !y are plac$ 9 ! ton+ & fix+ ba?4 ,,ton+ ,,& ,,fix+ ,,ba?4 ,sulphocyanide ( ammonium #a ounce ,wat] #ab ounces ,*loride ( gold #a to #c gra9s ,aft] remov+ f ?is ba?1 ! pr9ts are imm]s$ = a few mom5ts 9 wat]1 & !n rapidly wa%$4 ,,=mula ,,= ,,prep>+ ,,! ,,pyroxyl9e ,nitric acid1 sp4 gr4 #a4cj #ab fluid ounces ,sulphuric acid1 sp4 gr4 #cf fluid ounces #a4hde ,wat] #h fluid ounces ,temp]ature #acj degrees ,fahr4 ,"t ( imm]sion #ae m9utes4 ,x',s ,,process 7#ahfe74 7,secrets ( ! ,uranotype7 ,prep>ation ( ! ,uranium ,comp\nd4--,precipitate ! nitrate ( uranium f its solution by conc5trat$ liquid ammonia4 ,let settle ! precipitate1 decant1 & wa% 9 sev]al *anges ( wat]4 ,dissolve x by heat 9 pure nitric acid1 tak+ c>e n to add an excess ( acid4 ,! ammonio-nitrate ( uranium salt is !n cry/alliz$ & dri$4 ,mix a solution ( #f drams ( ?is salt1 dissolv$ 9 #c drams ( wat]1 to a solution ( #ae gra9s ( silv] 9 #cj m9ims ( wat]1 & cry/allize4 ,?is salt is call$ ammonio-nitrate ( uranium & silv]4 ,,s5sitiz+ ,,solution4 ,ammonio nitrate salt #c drams ,alcohol #h drams ,di/ill$ wat] #ae drops ,nitric acid1 pure #a drop ,pla9 ,collodion4--,dissolve 9 a small quantity ( e!r #a dram ( ,canada balsam & #a dram ( ca/or oil1 filt] & let evaporate ! solution to ! consi/5cy ( oil4 ,( ?is1 add #aj m9ims to a collodion made ( ,alcohol #aj ounces ,e!r #bj ounces ,pyroxyl9e #bbj gra9s ,,s5sitive ,,collodion ,pla9 collodion #ab drams ,s5sitiz+ solution #f drams ,nitric acid #b or m drops ,keep ?is collodion 9 ! d>k1 z x is q s5sitive4 ,,prep>ation ,,( ,,! ,,pap] ,arr[root1 pulv]iz$ #a ounce ,wat] #cb ounces ,solution ( acetate ( #aj drops lead ,heat to #ajj deg4 ,fahr4 & !n add f\r ounces ( album54 ,! pap] is float$ on ?is solution = five m9utes & hung up to dry4 ,! siz+ may also be appli$ ) a sponge 9 ! mann] (t5 describ$4 ,! pro(s %\ld be slightly ov]-pr9t$ &1 be=e ton+ & fix+1 plac$ = ab\t t5 m9utes 9 ! foll[+ solution3 ,di/ill$ wat] #dj ounces ,acetic acid #a ounce ,hydro*loric acid #a ounce ,aft] wa%+ 9 sev]al *anges ( wat]1 ! pro(s may be ton$ 9 any ton+ ba?1 & !n fix$ ) sulphocyanide ( potassium1 wa%+ aft]w>ds 9 ! usual mann]4 ,,! ,,plat9otype4 ,?is process1 discov]$ by ,william ,willis17#af7 yields v f9e impressions :i* :olly consi/s ( plat9um & are1 !re=e1 *emically p]man5t4 ,x has be5 describ$ !oretically & practically by ,pizzighelli & ,kbl 9 a pap] = :i* ! ,vi5na ,photographic ,society has aw>d$ ! ,voightl&] prize47#ag7 ,! foll[+ is an abridgm5t ( ?is important process1 z describ$ by ! au?ors3 ,! pap]1 cal5d]$ or n17#ah7 is siz$ ) gelat9e or arr[root4 ,! color ( ! pro( ) ! latt] size is br[ni% black1 & blui% black ) ! =m]4 ,to prep>e ! gelat9e solution #aj p>ts ( gelat9e are soak$ 9 #hjj p>ts ( wat] & !n dissolv$ at a temp]ature ( #fj deg4 ,c4 7#adj deg4 ,fahr471 :5 #bjj p>ts ( alcohol & #c p>ts ( alum are add$ & ! solution filt]$4 ,to prep>e ! arr[root solution #aj p>ts ( ! sub/ance are p[d]$ 9 a mort> ) a little wat] & mix$ to #hjj p>ts ( boil+ wat]1 add$ gradually 9 /irr+4 ,aft] boil+ = a few m9utes #bjj p>ts ( alcohol are add$ & ! mixture filt]$4 ,^! solutions are employ$ w>m4 ,! pap] is imm]s$ = two or ?ree m9utes & hung up to dry 9 a heat$ room1 !n imm]s$ a second "t & dri$ by hang+ x up 9 ! opposite direction1 9 ord] to obta9 an ev5 coat+4 ,! potassic plat9ic *loride is an article ( comm]ce4 ,x %\ld be soluble )\t residue 9 #f p>ts ( wat] & )\t acid reaction4 ,9 ?is proportion x con/itutes ! normal /ock solution employ$ 9 ! v>i\s =mulas4 ,! /&>d f]ric oxalate solution is also f\nd 9 comm]ce4 ,treat$ by potassium f]ricyanate x %\ld n be color$ blue1 nor become turpid :5 dilut$ ) "o-t5? "p ( wat] & boil$4 ,! =m] reaction indicates t x conta9s no f]r\s salt1 & ! latt] no basic oxalate4 ,! au?ors give ! foll[+ in/ructions = prep>+ ! f]ric oxalate solution1 to :i* !y atta* mu* importance3 ,five hundr$ p>ts ( f]ric *loride are dissolv$ 9 #e1jjj p>ts ( wat] & heat$ to boil+1 :5 a solution ( soda is add$ until ! liquid becomes alkal9e47#ai7 ,ab\t #bej p>ts ( cau/ic soda are g5]ally employ$ = ?is purpose4 ,! precipitate--f]ric oxide--is n[ wa%$ 9 w>m wat] until ! la/ wa%+ wat] is q neutral to te/ pap]1 !n dra9$ & mix$ ) #bjj p>ts ( pure cry/alliz$ oxalic acid4 ,! mixture is !n all[$ to /& 9 ! d>k = sev]al days at a temp]ature n exce$+ #cj deg4 ,c4 7#hf deg4 ,fahr47 ,at fir/ ! solution f gre5 turns to a yell[ gre51 & f9ally becomes almo/ br[n4 ,at ?is mom5t ! excess ( f]ric oxide is filt]$ out & ! liquor submitt$ to a quantitative analysis1 ! result ( :i* leads to asc]ta9 ! quantity ( f]ric oxalate 9 #ajj p>ts ( ! solution & ! excess ( oxalic acid4 ,! solution %\ld !n be dilut$ ) di/ill$ wat]1 su* z x conta9s #bj p>ts ( f]ric oxalate p] #ajj p>ts ( wat]1 & oxalic acid mu/ be add$ 9 ! proportion ( f #f to #h p] #ajj ( ! f]ric oxalate1 tak+ into acc\nt ! quantity ( acid ! solution already conta9s4 ,! solution %\ld be kept 9 ! d>k4 ,x is alt]$ by light47#bj7 ,,iron ,,*lorate ,,solution ,f]ric oxalate solution #ajj p>ts ,potassium *lorate #j4d p>ts ,?is solution is employ$ to obta9 m contra/s4 ,,prep>ation ,,( ,,! ,,s5sitiz+ ,,solution ,plat9um solution #ab p>ts ,f]ric oxalate solution #aa p>ts ,di/ill$ wat] #b p>ts ,?is solution gives v s(t tones ) int5se black4 ,to obta9 m brilliancy we use ! foll[+ proportions3 ,plat9um solution #ab p>ts ,f]ric oxalate solution #i p>ts ,*lorate ( iron solution #c p>ts ,di/ill$ wat] #b p>ts ,to obta9 results comp>able to ^? :i* ! silv] pr9t+ out process gives1 ! foll[+ mixture is employ$3 ,plat9um solution #ab p>ts ,f]ric oxalate solution #h p>ts ,*lorate ( iron solution #d p>ts ,di/ill$ wat] #h p>ts ,= v weak negatives1 reproductions ( draw+s1 etc41 we use-- ,plat9um solution #ab p>ts ,*lorate ( iron #aa p>ts ,di/ill$ wat] #b p>ts7#ba7 ,to obta9 pro(s n completely black1 z1 = example1 reproductions ( lead draw+s1 ! solution may be dilut$ ) half or ! :ole volume ( di/ill$ wat]4 ,b if ! solution be appli$ on little absorb5t surfaces or on pap] /rongly siz$ x is n advisable to dilute x4 ,prep>ation1 ( ! ,pap]4--,! pap] %\ld be kept slightly moi/ 9 ord] t x does n too completely absorb ! s5sitiz+ solution4 ,!re=e1 :5 ! atmosph]e is v dry1 x is well to keep ! pap] 9 a damp place1 9 ! cell> = example4 ,be=e s5sitiz+1 :i* %\ld be done by a v diffus$ light1 a quantity ( ! solution proportionate to ! surface to be s5sitiz$ 7ab\t #ae c4c41 = a :ole %eet ( ,rives' or ,saxe pap]7 mu/ be measur$1 & spread ) a l>ge bru%7#bb7 on ! pap] fix$ ) draw+ p9s on a bo>d cov]$ ) a %eet ( blott+ pap]4 ,:5 well impregnat$1 ! pap] is hung up to dry 9 ! d>k room1 & z soon z ! app>5t dampness ( ! surface has disappe>$1 x %\ld be dri$ imm$iately at a temp]ature ( #cj--dj deg4 ,c4 7#hf--aja deg4 ,fahr74 ,if ! pap] be dri$ too rapidly ! s5sitive comp\nd rema9s on its surface1 & 9 develop+ ! image does n come out well4 ,if1 on ! o!r h&1 ! dry+ is too sl[1 ! solution p5etrates too mu* 9 ! pap] & ! image is want+ ( vigor & does n appe> v %>p4 ,"o _c dep>t f ?is rule t ! desiccation f ! mom5t ! solution has be5 appli$ until ! pap] is dry %\ld la/ no m ?an f twelve to fifte5 m9utes4 ,! s5sitiz$ pap] is hygroscopic & mu/ be pres]v$ 9 a calcium box4 ,x is a conditio s9e qua non t ! pap] mu/ be q dry be=e1 dur+1 & aft] pr9t+1 to obta9 good results4 ,dampness is ! greate/ enemy 9 ?is process4 ,= pr9t+ a pad ( ,india rubb] %\ld be plac$ ov] ! plat9um pap] to prev5t x f attract+ ! atmosph]ic moi/ure1 & 9 damp wea!r x is ev5 advisable to cov] x ) sev]al %eets ( blott+ pap] previ\sly heat$ be=e ! fire4 ,! plat9um pap] is at lea/ ?ree times m s5sitive ?an ! silv] pap] us$ 9 ! pr9t+-out process1 "u ! r$uctive action ( light ! yell[ color ( ! prep>$ pap] turns br[n & !n becomes ( a light] color1 ne>ly orange1 s t ! d>k] p>ts ( ! image (t5 appe>s m lum9\s ?an ! d>k half t9ts4 ,no rule c be giv5 to regulate ! insolation1 b aft] a few trials x is easy to judge :5 x is "r by obs]v+ ! progress ( ! r$uction & ! color ( ! image4 ,! orange color indicates ! complete r$uction ( ! f]ric oxalate4 ,:5 ! details 9 ! lights are fa9tly visible1 ! exposure is g5]ally "r4 ,! develop] consi/s ( an almo/ saturat$ solution ( potassium oxalate acidifi$ by oxalic acid1 & = use heat$ to #hj--he deg4 #j4 7#agf--ahd deg4 ,fahr4717#bc7 9 an agate glaz$ iron tray plac$ ^u a wat] ba? at ! above temp]ature4 ,by simply draw+ ! pro( ov] x1 ! image is at once develop$47#bd7 ,:5 ! pro( is ?\ght to be ov]-expos$1 ! oxalate solution c be employ$ at a l[] temp]ature4 ,if1 on ! contr>y1 x is "u-expos$1 ! solution may be heat$ ev5 to ! boil+ po9t4 ,! develop] c be us$ ov] & ov] aga94 ,x %\ld always h an acid reaction4 ,accord+ to ,mr4 ,borl9etto a sepia tone is obta9$ by us+ ! foll[+ cold develop]3 ,saturat$ solution ( #abj p>ts potassium oxalate ,saturat$ solution ( #ac p>ts copp] *loride ,oxalic acid #a4e "p ,aft] develop+ ! pro(s are imm$iately imm]s$ = fix+ 9 a solution ( hydro*loric acid1 #a to #hj ( wat]1 r5ew$ s long z ! pap] is t+$ yell[ 7ab\t ?ree times71 leav+ ! pro(s t5 m9utes 9 ea* solution4 ,la/ly1 !y are wa%$ to remove ! acid4 ,! plat9otype has be5 /ill improv$ by ,capta9 ,pizzighelli1 :o devis$ ! foll[+ me?ods ( op]at+ by :i* ! impressions are obta9$ by ! cont9u\s action ( light1 t is1 )\t developm5t1 ?us r5d]+ ! plat9otype j z simple z ! ord9>y pr9t+-out silv] process4 ,9 ^! new processes to ! s5sitiz+ solution is add$ ! alkal9e oxalate1 :i* effects ! r$uction ( ! plat9\s salt dur+ ! exposure to light4 ,consequ5tly ! prep>$ pap] is insolat$ until ! image appe>s z x %\ld be1 or--:i* is exce$+ly useful 9 cl\dy wea!r--until x is entirely visible b /ill defici5t 9 delicate half tones1 = 9 ! d>k ! action proce$s & ! image develop+ itself w be f\nd f9i%$ 9 a p]iod :i* may ext5d to a few h\rs4 ,b x c be1 h[ev]1 develop$ 9 a few seconds by imm]sion 9 a cold or slightly w>m solution ( sodium c>bonate1 #a3be ( wat]4 ,! image is fix$ z direct$ 9 ! =ego+ process4 ,! pap]1 prep>$ exactly z 9 ! =m] process & kept 9 ! calcium box until want$ = use1 %\ld n be employ$ q dry1 b all[$ to absorb a little moi/ure by hang+ x 9 ! d>k room4 ,h5ce1 ! ,india rubb] & o!r protect+ pads c be disp5s$ )4 ,!y are ev5 objectionable1 = dampness is absolutely necess>y to promote ! *emical *anges by :i* ! image is develop$4 ,a4 ,,ammonio-,,f]ric ,,oxalate ,,solution ,f]ric oxalate solution #ajj p>ts ,neutral ammonium oxalate #ah to #bj p>ts ,b4 ,,sodio-,,f]ric ,,oxalate ,,solution ,f]ric oxalate solution #ajj p>ts ,neutral sodium oxalate #ae to #ah p>ts ,to prep>e ^! two solutions ! ammonium or sodium oxalate is dissolv$ by small quantities at a "t1 & :5 ! em]ald color due to ! =mation ( ! d\ble oxalate comm5ces to d>k51 ! saturation be+ !n complete1 no m ( ei!r salt %\ld be add$4 ,! solution is n[ well %ak5 ) #c p>ts ( glyc]9e1 all[$ to settle & filt]$4 ,any "o ( ! d\ble oxalates c be us$4 ,! ammonium t5ds to produce s(t] pictures & blui% tones4 ,to obta9 m contra/s a little potassium *lorate may be add$4 ,c4 ,,iron ,,*lorate ,,solution ,solution ,b #ajj p>ts ,potassium *lorate #j4d "p ,d4 ,,m]curic ,,solution4 ,m]curic *loride #bj p>ts solution at #e3ajj ,sodium oxalate solution #dj p>ts at #c3ajj ,glyc]9e #b p>ts ,,s5sitiz+ ,,solutions4 ,,= ,,black ,,tones4 ,plat9ite solution1 #a3f #e p>ts ,solution ,b #f p>ts ,solution ,c #b p>ts ,,= ,,sepia ,,tones4 ,plat9ite solution1 #a3f #e p>ts ,solution ,c #d p>ts ,solution ,d #d p>ts ,int]m$iate tones are obta9$ by dim9i%+ ! dose ( ,c & replac+ x by an equal volume ( ,b4 ,= ?is process ! pap] %\ld be siz$ ) ,arr[root #b p>ts ,sodium oxalate at #c3ajj #ajj p>ts ,to disp5se ) ?is prelim9>y siz+ ,capta9 ,pizzighelli adds gum arabic to ! plat9ite solution1 :]eby ! siz+ & s5sitiz+ are done 9 "o op]ation4 ,! gum arabic solutions are prep>$ z foll[s3 ,e4 ,gum arabic 9 #dj p>ts p[d] ,sodium f]ric #dj p>ts oxalate solution1 ,b ,sodium oxalate #ajj p>ts solution at #c3ajj ,glyc]9e #c p>ts ,place ! glyc]9e & ! gum arabic 9 a mort>1 !n1 /irr+ ) ! pe/le1 dissolve by add+1 little by little1 ! mixture1 heat$ to #dj--de deg4 ,c4 7#ajd--aac deg4 ,fahr471 ( ! solution ( sodium f]ric oxalate & sodium oxalate4 ,let /& = ab\t two h\rs & gr9d aga9 to dissolve entirely ! gum arabic4 ,filt] ?r\gh musl94 ,f4 ,m]curic *loride #bj p>ts solution1 #e3ajj ,sodium oxalate solution1 #dj p>ts #c3ajj ,gum arabic 9 p[d] #bd p>ts ,glyc]9e #b p>ts ,dissolve z said above4 ,,s5sitiz+ ,,solutions4 ,,= ,,black ,,tones4 ,plat9ite solution1 #a3f #e p>ts ,solution ,e #f p>ts ,solution ,c #b p>ts ,,= ,,sepia ,,tones4 ,plat9ite solution1 #a3f #e p>ts ,solution ,c #d p>ts ,solution ,f #d p>ts ,mix j be=e use4 ,! solutions d n keep4 ,! pap] prep>$ by ei!r "o ( ^! two processes c be expos$ z 9 ! old process1 & ! image develop$ by! hot oxalate solution4 ,! prep>ation ( wood1 canvas1 etc41 = ! plat9otype pr9t+ ne$ n to be describ$2 x sugge/s itself4 ,,causes ,,( ,,failures4 ,! images are veil$4 ,?is defect may result f v>i\s causes1 viz43 #a/4 ,! /ock f]ric oxalate solution is impair$ by a p>tial r$uction ( ! f]ric salt into f]r\s oxalate4 ,! solution %\ld be pres]v$ 9 an orange color$ vial1 & kept 9 ! closet ( ! d>k room4 ,x %\ld be te/$ f "t to "t = ! f]r\s salt ) a solution ( potassium f]ricyanate4 ,if x does n conta9 any f]r\s oxalate x c be us$ by add+ to x a little ( ! iron *lorate solution4 #b;d4 ,! pap] has be5 expos$ to light dur+ ! s5sitiz+ or ! subsequ5t op]ations4 ,"o %\ld be> 9 m9d t ! plat9um pap] is twice m s5sitive ?an silv]$ pap]4 #c;d4 ,! s5sitiz$ pap] has be5 dri$ at a temp]ature above #dj deg4 ,c4 7#ajd4 deg4 ,fahr47 #d?4 ,ov]-exposure4 ,! pro(s are n %>p4 #a/4 ,! s5sitive pap] has absorb$ moi/ure4 #b;d4 ,x is too old4 ,! pap] _c be kept good = ov] six weeks1 unless special c>e be tak54 ,accord+ to ,mr4 ,bory1 ! s5sitive pap] alt]$ by keep+ is re/or$ to its orig9al good quality by simply bru%+ x ov] ) a solution ( #j4je p>ts ( potassium *loride or ! same quantity ( potassium *lorate 9 #ajj p>ts ( di/ill$ wat]1 or a mixture ( ^! two solutions1 or "o ( iron *lorate4 ,by treat+ ! insolat$ pap] ) ^! solutions1 ! image is de/roy$1 & ! pap] c be us$ aga94 ,"o op]ates z = s5sitiz+1 tak+ c>e to desiccate ! pap]1 z x has be5 direct$4 ,! pro(s are brilliant dur+ ! developm5t1 b become dull 9 dry+4 ,! pap] n well siz$4 ,x has be5 dri$ too sl[ly4 ,rememb] t x %\ld be q desiccat$ )9 fifte5 m9utes4 ,! pap] is m or less yell[4 #a/4 ,! pap] t9t$ ) ultram>9e4 #b;d4 ,! s5sitiz+ solution or ! develop] are n suffici5tly acid4 #c;d4 ,! wa%+ 7fix+7 9 ! solution ( hydro*loric acid 0 n suffici5t to elim9ate ! iron salts f ! pap]4 ,! pro(s h>%1 devoid ( half tones4 #a/4 ,! s5sitiz+ solution conta9s too mu* iron *lorate4 #b;d4 ,exposure too %ort4 ,! pap] is /a9$4 ,! bru% n kept clean :ile s5sitiz+4 ,black spots4 ,!y are g5]ally due to metallic du/ 9 ! pa/e ( ! pap]1 or f p>ticles ( undissolv$ salt 9 ! plat9ite solution4 ,,nb3 ,no good results c be expect$ unless ! pap] be kept absolutely dry be=e1 dur+ & aft] exposure1 :5 us+ ! =m] 7orig9al7 process4 ,impair$ s5sitiv5ess ( ! pap]1 want ( vigor1 t+$ :ites1 mudd9ess1 indicate dampness4 ,,artigues' ,,process ,! ,artigues process1 s call$1 is1 )\t any d\bt1 ! be/ to be employ$ = ! reproduction ( plans & draw+s 9 l9es4 ,x is simple1 exp$iti\s1 & yields black impressions on a v pure :ite gr\nd :i* are absolutely p]man5t4 ,& ?is is ( ! utmo/ importance :5 ! copies are to be us$ = milit>y purpose1 or kept 9 ar*ives1 su* z ^? ( ! ,pat5t ,(fice1 = example4 ,%\ld x n require ! use ( negative cli*s1 x w\ld c]ta9ly sup]s$e any ( ! processes previ\sly describ$2 moreov]1 z x w be se51 x c be employ$ = _m o!r purposes ?an t ( obta9+ duplicates f orig9al draw+s4 ,! objection is n ev5 v great inde$1 = ! design c be1 )\t great tr\ble1 trans=m$ into a negative by ! anil9e me?od describ$ 9 ! beg9n+ ( ?is "w4 ,! ,artigues process is an adaptation = ! purposes 9 "q ( ! c>bon process inv5t$ by ,poitev94 ,we %all describe x 9 ext5so4 ,! pap] c be prep>$ ) any "o ( ! foll[+ solutions3 #a/4 ,dissolve #b p>ts ( ammonium bi*romate & #e p>ts ( be/ gum arabic 9 #ae p>ts ( wat] & neutralize ) a few drops ( conc5trat$ aque\s ammonia2 !n add #ajj p>ts 9 volume ( :ites ( egg & a c]ta9 quantity ( ?ick ,india ink1 &1 ?is done1 beat ! :ole to a ?ick fro?4 ,9 t5 or twelve h\rs ! album5 w be deposit$ & ready = use4 ,! quantity ( ,india ink add$ to ! album5 %\ld be su* z ! pap] be black :5 coat$1 b1 h[ev]1 suffici5tly transp>5t = "o to see ! %ad[ ( objects plac$ on ! back ( x1 & ! coat+ %\ld n be ?ick4 ,?is is important 9 ord] to all[ ! light act+ ?r\gh ! :ole ?ickness ( ! prep>ation :5 ! pap] is insolat$ "u ! cli*1 =1 if ! film be too opaque or too ?ick 7by addition ( too mu* gum arabic71 x w\ld be only impress$ on its surface1 & ! image dissolv$ dur+ ! developm5t4 ,! cause ( ?is failure mu/ be expla9$4 ,"u ! action ( light ! bi*romate employ$ to s5sitize ! album5 is r$uc$ into *romic oxide :i* r5d] insoluble ?is organic sub/ance--or any o!r1 su* z case9e1 gelat9e1 gum arabic1 etc42 !re=e :5ev] ! film is n act$ on 9 its :ole ?ickness1 ! subjac5t "p be+ /ill soluble1 is necess>y wa%$ (f & ) x ! sup]ficial impress$ "p1 t is1 ! image4 #b;d4 ,take #aj p>ts ( lamp black & "w x up 9 a mort> to ! consi/5cy ( a ?9 pa/e by gradually p\r+ a little ( a solution ( f #f to #h p>ts ( gum arabic & #a "p ( liquid glucose 9 #ajj p>ts ( wat]1 add+ aft]w>ds ! rema9d]1 into :i* #b p>ts ( ammonium bi*romate h be5 dissolv$1 & filt] ?r\gh flannel4 ,) ?is1 coat ! pap] by bru%+ s z to =m a ?9 & uni=m film1 & p9 x up to dry 9 ! d>k4 ,^! solutions keep well = a c]ta9 p]iod4 ,we h kept ! album51 :i* we pref] to use1 = two mon?s 9 good condition2 b ! s5sitive pap] does n = m ?an ?ree or f\r days 9 tak+ ! usual c>e4 ,x is m practical--& ?is is recomm5d$--to leave out ! bi*romate f ! prep>ations1 & to coat ! pap]1 9 quantity1 be=eh&1 & = use to s5sitize x ) a solution ( potassium bi*romate at #c p] c5t4 ( wat] appli$ on ! v]so ) a ,buckle bru%47#be7 ,! bi*romate solution %\ld be all[$ to imbue ! pap] = ab\t "o m9ute1 & hav+ bru%$ x once m1 ! pap] is p9n$ up to dry 9 ! d>k room4 ,x c also be s5sitiz$ f ! back by float+1 if ?is mann] is f\nd m conv5i5t4 ,:5 dry ! pap] is impress$ "u a negative cli* ( good int5sity until ! design1 well def9$ 9 all its details1 is visible on ! back ( ! pap]1 :i* requires an insolation ( ab\t two m9utes 9 cle> sun%9e1 & f eight to t5 times long] 9 ! %ade4 ,9 cl\dy wea!r ! exposure to light is necess>ily v long4 ,z expla9$ be=e1 ! lum9\s action1 by r$uc+ ! *romic salt 9 pres5ce ( c]ta9 organic sub/ances1 causes ! latt] to become insoluble2 consequ5tly if1 on its removal f ! pr9t+ frame1 ! pro( be soak$ 9 cold wat]1 =1 say1 t5 m9utes1 &1 plac+ x on a glass plate or a smoo? bo>d1 g5tly rubb$ ) a bru% or a s(t rag1 ! p>ts ( ! album5 or gum arabic prep>ation n act$ on w dissolve1 leav+ beh9d ! black image /&+ out on ! :ite gr\nd ( ! pap]4 ,?is done1 & :5 ! unr$uc$ bi*romate is wa%$ out 9 two *anges ( wat]1 ! op]ation is at an end4 ,z to ! !ory ( ?is & simil> processes1 ! insolubilization ( ! bi*romate organic sub/ance act$ on by light 0 =m]ly attribut$ to ! oxidation ( ! sub/ance by ! oxyg5 evolv$ dur+ ! r$uction ( ! *romic salt into *romic oxide2 b f ! fact t oxidation g5]ally t5ds to de/roy organic matt]s1 or to increase _! solubility1 x is m probable t x results f ! =mation ( a peculi> comp\nd ( ! sub/ance ) *romic oxide 7,j4 ,w4 ,swan72 moreov]1 gelat9e imbu$ ) an alkal9e bi*romate1 !n imm]s$ fir/ 9 a solution ( f]r\s sulphate & aft]w>ds 9 hot wat]1 is insolubiliz$ ) =mation ( *romium trioxide1 ,cr#b,o#g,k#b,,s#d;,fe ,,s#d,k#b;,c#b,o#d;,fe,c#b,o#c 7,monckhov574 ,a simil> b inv]se action occurs1 z %[n by ,poitev91 :5 gelat9e r5d]$ insoluble by f]ric *loride becomes soluble by ! trans=mation1 "u ! influ5ce ( light1 ( ! f]ric salt into "o at ! m9imum4 ,! writ] has improv$ ! above process by simplify+ ! modus op]&i z foll[s3 ,in/ead ( comp\nd+ ! prep>ation ) gum arabic & ! color+ matt]1 ! album5 is simply cl>ifi$ by beat+ ! :ites ( eggs to a fro?1 etc41 & ! pap] is coat$ by float+ = "o m9ute1 !n hung up to dry 9 a place free f du/4 ,if ! read] has any objection = album5iz+ 8 own pap]1 he c use ! album5 pap] f\nd 9 ! m>ket = ! pr9t+-out silv] process g5]ally employ$ by photograph]s4 ,! pap] is s5sitiz$ f ! back ) ! potassium bi*romate ba? by float+ or by bru%+4 ,:5 dry1 x is expos$ z usual1 b = a %ort] p]iod ?an :5 ! prep>ation conta9s ! ,india ink or o!r color+ matt]s :i* imp$e ! action ( light4 ,! progress ( ! impression is foll[$ by view+1 f "t to "t1 ! album5iz$ side ( ! pap]4 ,:5 ! design is visible1 well def9$ & br[ni%1 ! pro(1 be+ remov$ f ! pr9t+ frame1 is rubb$ ) v f9ely p[d]$1 or1 bett]1 levigat$ graphite1 &1 ?is done1 imm]s$ 9 cold wat] = f fifte5 to tw5ty m9utes1 :5 by g5tly rubb+ x "u a jet ( wat] ) a s(t rag1 or ) a sponge imbu$ ) wat]1 ! album5 is wa%$ (f f ! p>ts n act$ on1 leav+ ! design on a p]fectly :ite gr\nd4 ,if in/ead ( graphite1 or any dry color insoluble 9 wat]1 li?ographic ink1 mu* ?9n$ ) turp5t9e oil1 be appli$ on ! pr9t 9 a light coat+ :i* p]mits "o to see ! design "u x1 & if1 !n1 ! pr9t be soak$ 9 wat] & aft]w>ds develop$ z j direct$1 an image 9 greasy ink is obta9$4 ,&1 fur!rmore1 by replac+ ! pr9t+ by transf] ink1 "o readily obta9s a transf] ready = ! /one or a z9c plate to be et*$ 9 ! ord9>y mann]4 ,z usual !re are two causes ( failures 9 ^! processes1 viz41 "u & ov]-exposures4 ,9 ! =m] case ! image is p>tly wa%$ (f2 9 ! latt] ! gr\nd _c be cle>$4 ,! reasons are obvi\s4 ,mr4 de ,sa9t ,flor5t gives ! foll[+ processes37#bf7 ,a %eet ( album5iz$ or gelat9iz$ pap] is s5sitiz$ f ! v]so on a solution ( potassium bi*romate1 dri$ 9 ! d>k & expos$ "u a positive cli*4 ,aft] insolation1 ! pro( is wa%$ 9 wat]1 to :i* are add$ few drops ( ammonia1 !n ink$ all ov] ) an ink consi/+ ( #ajj p>ts ( liquid ,india ink1 #g p>ts ( sulphuric acid & #c p>ts ( cau/ic potassa1 & dri$ 9 a horizontal position4 ,:5 q dry1 ! pro( is plac$ 9 wat]1 & aft] an imm]sion ( ab\t t5 m9utes1 rubb$ ) a s(t bru%3 ! image little by little appe>s1 & if ! "t ( exposure be "r1 x is soon entirely cle>$1 &1 !n1 if n en\gh vigor\s1 x may be ink$ aga94 ,! gloss ( ! image is remov$ by means ( a solution ( cau/ic potassa at #aj p] #ajj1 & ! pro( f9ally wa%$ ) c>e4 ,if 9 lieu ( album5 pap]1 "o employs pap] prep>$ ) a ?9 coat+ ( gelat9e1 & dissolves ! n act$ on gelat9e 9 w>m wat]1 a v f9e positive image is obta9$ by means ( acidifi$ inks :i* w fix !mselves on ! b>e pap]4 ,positive impressions f positive cli*s c also be obta9$ 9 op]at+ 9 ! foll[+ mann]3 ,on its removal f ! pr9t+ frame ! pro( is wa%$1 spong$ betwe5 %eets ( blott+ pap]1 !n cov]$ ) n acidifi$ ,india ink mix$ ) potassium bi*romate1 &1 :5 dry1 expos$ f ! v]so to ! action ( light4 ,?is done ! image is cle>$ ) a some:at h>d bru%4 ,,! ,,c>bon ,,process4 ,! c>bon tissue is seldom prep>$ by photograph]s4 ,h[ev]1 = ! sake ( complet5ess1 we %all give ! =mula ( ! mixtures mo/ g5]ally employ$1 & describe ! mann] ( coat+ ! pap] on a small scale4 ,prep>ation ( ! ,tissue4--,! gelat9e g5]ally recomm5d$ to comp\nd ! mixture is ! ,nelson's autotype gelat9e4 ,coignet's gold label gelat9e1 mix$ ) a m soluble product1 su* z ,cox's gelat9e1 = example1 gives also excell5t results4 ,gelat9e #aaj p>ts ,sug> #be p>ts ,soap1 dry #ab p>ts ,wat] #cej p>ts ,! color+ sub/ances consi/ (3 ,,= ,,engrav+ ,,black4 ,lamp-black #bj p>ts ,crimson lake #b p>ts ,indigo #a "p ,,= ,,w>m ,,black4 ,lamp-black #c p>ts ,crimson lake #c p>ts ,burnt amb] #b p>ts ,indigo #a "p ,,= ,,sepia ,lamp-black #b p>ts ,sepia ( ,cologne #ah p>ts ,,= ,,photographic ,,r$ ,,br[n4 ,india ink #c p>ts ,crimson lake #d p>ts ,van ,dyck br[n #d p>ts ,= blue1 ,turnbull's blue is employ$2 = yell[1 light *rome yell[2 = r$1 c>m9e dissolv$ 9 aque\s ammonia1 evaporat+1 !n add+ wat]1 etc4 7,see fur!r on47 ,to prep>e ! mixture1 dissolve ! sug> & soap 9 ! cold wat]1 add ! gelat9e1 let x soak = an h\r1 !n dissolve x 9 a wat] ba? & mix by small quantity ! colors f9ely gr\nd toge!r & wett$ to ! consi/5cy ( a pa/e4 ,aft] filt]+ ?r\gh flannel ! mixture is ready = use4 ,= coat+1 ! me?od devis$ by ,mr4 ,alf4 ,h>man has be5 f\nd excell5t 9 ! h&s ( ! writ]1 n only = ! purpose 9 "q1 b also = coat+ pap] ) gelat9\s or visc\s 7gum arabic7 prep>ations4 8,take two t9 di%es1 su* z us$ = ! developm5t ( ! c>bon pr9ts2 arrange "o on y\r b5* tilt$ to an angle2 ! l[] angle is int5d$ to receive ! w>m wat] = keep+ ! gelat9e mixture to a prop] temp]ature4 ,into ?is angle ( ! tray arrange ano!r tray some:at small]1 & keep x f t\*+ ! bottom ( ! out] "o by ! ins]tion ( any small article t w sugge/ itself4 ,into ! inn] tray ! gelat9e mixture is to be p\r$40 8,! actual mak+ ( ! tissue c n[ be proce$$ )1 & is s simple & c]ta9 z n to be believ$ until put to ! te/4 ,pur*ase a roll ( pap]-hang]'s l9+ pap] ( good quality1 cut x into wid?s ( ab\t "o & a half in* less ?an ! wid? ( y\r inn] tray1 & 9 l5g? (1 say1 ?irty in*es4 ,= ! success ( ! op]ation x is necess>y t ! pap] be roll$ up ! n>r[ way4 ,n[ hav+ j suffici5t wat] at a temp]ature ( #ajj deg4 ,fahr4 7#ch deg4 ,c47 into ! out] tray1 p\r ! gelat9e mixture into ! inn] "o1 & take "o ( ! l5g?s ( roll$ pap]1 &1 hold+ x by bo? ends1 g5tly l[] x on ! surface ( ! gelat9e2 !n at once sl[ly raise ! end ( ! pap]1 :i* w unroll itself & become beautifully coat$ 9 f> less "t ?an x takes to describe4 ,tw5ty %eets may be coat$ 9 a qu>t] ( an h\r1 & be equal 9 all respects to t made by ! mo/ exp5sive ma*9e40 ,9 ! description ( ?is me?od ( coat+1 ,mr4 ,h>man does n expla9 h[ ! gelat9e %\ld be all[$ to set be=e hang+ up ! pap] to dry1 :i* is1 h[ev]1 obvi\sly important4 ,x is z foll[s3 ,place on ! tray a smoo? bo>d a little l>g] ?an ! %eet ( pap]1 leav+ a small space at ! end fur!/ f ! body1 & sl[ly1 )\t a /op1 draw (f ! pap]1 prep>$ side upp]mo/1 on ! bo>d ^u :i* x %\ld rema9 until ! gelat9e is set4 ,if ! pap] curls up1 wet ! back a little ) a sponge be=e coat+4 ,! foll[+ coat+ me?od1 due to ,mr4 ,*>don1 is excell5t = %eets ( pap] ( ! ord9>y photographic size1 #ahbb in*es4 ,on a glass plate plac$ on a level$ /&1 is laid a %eet ( pap] previ\sly wett$1 :i* is !n flatt5$ into contact ) an ,india rubb] squeegee1 tak+ c>e to remove ! air bubbles int]pos$4 ,! quantity ( gelat9e necess>y to coat ! pap] is regulat$ by means ( a glass rod held by an iron la?1 :i* s]ves to h&le x2 at ea* end ( ! rod is ins]t$ a piece ( an ,india rubb] tube ^: ?ickness regulates t ( ! gelat9e lay]4 ,! mixture is p\r$ f a small teapot1 at ! op5+ ( :i* has be5 adapt$ a b5t glass tube ab\t ?ree-sixte5?s ( an in* 9 diamet]1 betwe5 ! rod & ! la?1 s t by a simultane\s motion1 "o c equalize ! gelat9e z x is p\r$ on4 ,:5 ! gelat9e is set ! pap] is hung up to dry4 ,9 dry+1 ! gelat9e contracts1 &1 necess>ily1 causes a de=mation ( ! tissue1 :i* curls up at ! edges & loses its planimetry4 ,to prev5t ?is1 :ile ! gelat9e is almo/ dry1 ! tissue is plac$ "u pressure until q desiccat$4 ,dum\l9 advises to apply on ! film1 :ile /ill s(t & tacky1 a wood5 frame1 :i*1 by adh]+ to x4 keeps ! tissue p]fectly plane z x dries4 ,*>don's me?od ( coat+ ,s5sitiz+4--,! tissue is s5sitiz$ 9 a ba? ( potassium bi*romate4 ,! degree ( conc5tration ( ! ba?1 :i* v>ies f #b to #e p] c5t4 ( wat]1 is important4 ,! tissue s5sitiz$ 9 a weak ba? is less rapidly act$ on by light & yields m contra/s ?an :5 imbu$ 9 a conc5trat$ "o4 ,! =m] %\ld consequ5tly be employ$ = pr9t+ weak negatives1 & ! latt] = ^? :i* are int5se4 ,a ba? comp\nd$ ) #cj p>ts ( potassium bi*romate1 #a1jjj p>ts ( wat] & #b p>ts ( aque\s ammonia1 is us$ = pr9t+ negatives ( ! ord9>y int5sity1 ! tissue be+1 !n practically ( ! same s5sitiv5ess1 a silv]$ pap] insolat$ to obta9 a pr9t n ov]-expos$4 ,= int5se negatives ! ammonia %\ld be disc>d$ & replac$ by ! same quantity ( *romic acid4 ,! "t ( imm]sion has also a c]ta9 influ5ce on ! results4 ,! less ! tissue is all[$ to absorb ! solution ! less s5sitive x is1 b also ! m ! t5d5cy ( ! half t9ts to be wa%$ (f dur+ ! developm5t4 ,g5]ally ! tissue %\ld rema9 imm]s$ until x lies flat & ! edges j comm5ce to curl up1 unless :ite & black impressions are desir$1 b ev5 !n x is pref]able to op]ate z said above1 us+ a ba? at #b p] c5t4 ,= use ! bi*romate ba? %\ld be cool$ d[n to #ae deg4 ,c4 7#ei deg4 ,fahr471 & mu* l[] 9 summ]1 say #aj deg4 ,c4 7#ej deg4 ,fahr471 & kept at ab\t ?is temp]ature by plac+ pieces ( ice ar\nd ! tray4 ,at #bj deg4 ,c4 7#fh deg4 ,fahr47 ! pr9ts are m or less granulat$2 above ?is ! gelat9e is s(t5$ & ! reticulation great]2 at #be deg4 ,c4 7#ge deg4 ,fahr47 x may dissolve4 ,! addition ( alcohol to ! bi*romate ba?--sometimes recomm5d$ to h>d5 ! film & all[ x to /& a high] temp]ature1 & to ha/5 ! desiccation ( ! tissue--is objectionable1 = ! spirits t5d to r$uce ! bi*romate1 :i* is trans=m$ into ! gre5 salt1 &1 !re=e1 a p>tial or complete insolubilization ( ! gelat9e is ! result4 ,aque\s ammonia add$ to ! s5sitiz+ solution has = its object to p]mit "o to keep ! s5sitive tissue = a some:at long] p]iod1 b x r5d]s x less s5sitive4 ,if en\gh be add$ to turn ! solution yell[ weak pr9ts are obta9$4 ,! bi*romate ba? %\ld be r5ew$ (t54 ,x does n keep ow+ to ! pres5ce ( gelat9e & o!r organic matt]s :i* x dissolves & :i* cause ! r$uction ( ! *romic salt ev5 9 ! d>k4 ,! tissue prep>$ 9 su* a ba? is n v s5sitive & ! image develops ) difficulty1 & ev5 _c be develop$ at all4 ,z said above1 ! tissue is well s5sitiz$ :5 its edges comm5ce to curl up4 ,x is !n remov$ f ! ba? by draw+ x on a glass rod fix$ at ! end ( ! tray1 & plac$1 prep>$ side d[n1 on a slightly wax$ glass plate1 rubb+ x ) an ,india rubb] squeegee to remove ! sup]fl\s liquid1 :5 x is hung up to dry4 ,:ile wet ! bi*romat$ tissue is ins5sitive2 ! s5sitiz+ c !re=e be made by daylight1 b ! dry+ %\ld ( c\rse be done 9 ! d>k room1 t is 9 a room light$ by a c&le or ! sunlight filt]$ ?r\gh a deep orange w9d[ glass4 ,caution4--,! soluble bi*romates are v poison\s4 ,by absorption !y produce sk9 diseases n )\t dang] & v difficult to cure4 ,h5ce :5 h&l+ ! wet tissue ! f+]s %\ld be protect$ by ,india rubb] tips1 & any yell[1 /a9s on ! h&s %\ld be rubb$ ) a dilute solution ( aque\s ammonia1 & ! h&s well r9s$ 9 wat]4 ,dry+4--,:5 ! tissue dries rapidly x adh]es well on ! support ^u :i* x is appli$ = develop+ & yields brilliant images :i* are easily cle>$4 ,on ! o!r h&1 7 x all[$ to dry sl[ly ! adh]5ce w\ld n be s complete1 ! image dull & develop+ ) difficulty4 ,!y may ev5 refuse to develop at all f ! insolubilization ( ! gelat9e4 ,9 w9t] & 9 ! cool days ( spr+ & autumn1 ! gelat9e dries quick en\gh 9 ! air1 b :5 ! wea!r is w>m & damp1 ! gelat9e1 dry+ v sl[ly1 may be s s(t5$ z to run (f1 or to produce an entirely objectionable reticulation1 or ! defects above m5tion$4 ,?is may be avoid$ by dry+ x p9n$ up 9 a box1 or a closet1 ov] quick-lime4 ,:5 dry1 ! tissue is g5]ally wr9kl$1 brittle1 breaks easily 9 h&l+ & _c be laid flat on ! cli*2 b by hold+ x ov] a bas9 ( boil+ wat]1 ! /eam 9 a few mom5ts r5d]+ x suffici5tly pliable to lay x flat betwe5 glass plates1 :]e x %\ld be kept "u pressure until want$ = use4 ,! writ] always dries ! tissue 9 ! foll[+ mann]1 :i* he devis$ ab\t sixte5 ye>s ago47#bg7 ,& n only ! lea/ trace ( reticulation is avoid$1 b ! tissue1 dry+ q flat1 lies 9 p]fect contact ) ! negative1 :i* is q important to obta9 pro(s exactly %>p all ov]4 ,a clean glass plate is rubb$ ) talc1 or1 :i* ! writ] pref]s1 fl[$ ) a solution (7#bh7 ,yell[ wax1 pure #a "p ,b5z9e1 pure #ajj p>ts !n /rongly heat$1 all[$ to cool & rubb$ clean 7app>5tly7 ) a piece ( flannel4 ,aft] once m repeat+ ?is op]ation ! plate is coat$ ) ! foll[+ pla9 collodion37#bi7 ,e!r1 conc4 #bej p>ts1 9 volume ,alcohol1 #ie deg #bej p>ts1 9 volume ,pyroxyl9e #c p>ts ,:5 ! film is set1 ! plate is imm]s$ 9 filt]$ wat] until greas9ess has disappe>$1 :5 on its removal f ! bi*romate ba? ! tissue is laid1 )\t dra9+1 ^u x & press$ into contact ) ! squeegee to remove ! excess ( liquid &1 ) x1 ! air bubbles int]posit$4 ,! tissue is !n all[$ to dry 9 ! air on ! collodioniz$ plate 9 ! cold season1 or1 :5 ! wea!r is w>m & damp1 9 a box 9 ! bottom ( :i* is plac$ a quantity ( quicklime 9 e>!n di%es4 ,:5 dry1 ! plates are plac$ "o ^u ano!r1 wrapp$ 9 pap] & kept 9 a dry place4 ,:5 want$ = use ! tissue is /ripp$ (f & w be f\nd q flat ) a beautiful surface to pr9t ^u4 ,"o %\ld avoid to keep ! s5sitiz$ tissue 9 a moi/ & w>m atmosph]e1 = 9 less ?an t5 h\rs x becomes insoluble ev5 9 complete d>kness4 ,x %\ld nei!r be kept 9 ! air contam9at$ ) gase\s r$uctive matt]s1 su* z ! products ( ! combu/ion ( coal gas & petroleum1 sulphydric or sulphur\s emanations f any s\rce1 ! fumes ( turp5t9e oil1 etc41 :i*1 by r$uc+ ! *romic salt1 cause ! insolubilization ( gelat9e1 prev5t ! pr9t to adh]e on ! support or ! cle>+ ( ! image1 :i* may ev5 refuse to develop4 ,! s5sitive tissue keeps well = ?ree or f\r weeks 9 cool & dry wea!r1 & no m ?an eight or t5 days 9 summ] unless well desiccat$ & kept 9 a pres]vative box4 ,if kept too long ! image _c be develop$4 ,! ,photomet]4--,! "t ( exposure is regulat$ by means ( a photomet]4 ,( all ! photomet]s :i* h be5 devis$ = t purpose we d n "k any "o m practical ?an t sugge/$ 9 #ahgf by ,mr4 ,j4 ,loeffl]1 ( ,/at5 ,isl&4 ,x is made z foll[s3 ,on a /rip ( a ?9 glass plate1 #fb in*es1 make f\r or five negatives1 #aa in*1 expos+ ea* "o exactly = ! same p]iod & develop+ 9 ! usual mann]1 b )\t any int5sification :atev]4 ,x is ev5 advisable to r$uce ! int5sity if !y 7 opaque4 ,fix1 etc41 & apply a good h>d v>ni%4 ,n[ cov] ! back ( ^! negatives ) /rips ( vegetable pap] or transp>5t celluloid1 or1 bett]1 ( ?9 %eets ( mica1 9 su* a mann] z !re be "o ?ickness on ! second negative1 two on ! ?ird1 ?ree on ! f\r?1 etc41 leav+ ! fir/ "o uncov]$4 ,!n place on ! :ole a glass plate ( ! same size z ! fir/ & bord] l a passe-p>t\t4 ,! ,negatives4--,= ! c>bon process ! negatives %\ld be int5s] ?an ^? int5d$ = pr9t+ out on silv] pap]4 ,h[ev]1 good pro(s may be obta9$ f any negatives1 s to say1 by v>y+ ! /r5g? ( ! bi*romate solution1 z1 also1 by us+ ! tissue fre%ly s5sitiz$ = weak negatives1 9 ord] to obta9 vigor1 & = /rong negatives1 ! tissue two or ?ree days aft] its prep>ation1 :5 x yields bett] half tones4 ,pr9t+ dodges are also resort$ to4 ,t ! mo/ commonly employ$ consi/s to v>ni% ! back ( ! negatives ) a matt v>ni%1 or to /ret* on ! same a %eet ( m9]al pap] ^u :i* ! ret\*es are made by rubb+ graphite1 *rome yell[1 p9k or blue colors to /r5g!n ! %ad[s or ! :ites1 z ! case requires4 ,z a rule1 x is advantage\s to cov] ! pr9t+ frame ) tissue pap]1 :atev] be ! quality ( ! negatives4 ,! negatives %\ld be bord]$ ) deep yell[ or orange-r$ pap] to =m :at is t]m$ a 8safe edge0 ^u :i* %\ld re/ ! tissue 9 ord] to prev5t ! m>g9 f be+ insolubiliz$ by ! r$uctive action ( light4 ,if ?is precaution 7 neglect$ x w\ld be impossible to /rip (f ! pap] )\t te>+ ! pro( :5 ! tissue is appli$ on ! support ^u :i* ! image is to be develop$4 ,be=e expos+ x is advisable to asc]ta9 :at ! pr9t+ qualities ( ! negative are by mak+ on silv]$ pap] a pro( ( x--n ov]-pr9t$--& ano!r ( ! photomet]1 bo? be+ expos$ at ! same "t & = ! same p]iod4 ,?is done1 comp>e ! pro( f ! negative cli* ) ^? ( ! photomet]1 & m>k ! negative ) ! numb] ( t ( ! photomet] to :i* x corresponds1 /at+ ! %ade ( ! pro( next to x2 = example3 ,no4 #b2 ,no4 #c fa9t1 or comm5ces to appe>1 etc4 ,?is ,no4 #b & ! obs]vation w indicate ! int5sity ( ! negative & s]ve z a guide = pr9t+ on ! tissue1 s9ce1 z be=e expla9$1 ! silv] pap] is practically ( ! same s5sitiv5ess z ! tissue prep>$ = negatives ( ! ord9>y int5sity4 ,exposure4--,to pr9t1 ! tissue is laid ov] ! negative1 tak+ c>e t x cov]s ! safe edge1 & a /rip ( silv]$ pap] plac$ 9 ! photomet]1 !n bo? ! pr9t+ frame & ! photomet] are expos$ to light side by side4 ,unless ! negative be weak1 :5 m vigor is obta9$ by expos+ 9 sun%9e1 ! pr9t+ %\ld be done 9 ! %ade4 ,x is a well-kn[n fact t ! "p ( ! bi*romat$ film correspond+ to ! half tones 9 ! lights are n suffici5tly impress$ 9 comp>ison to ! blacks :ile impress$ 9 direct sun's light 9 ?is z well z 9 ! collotype1 photogravure & o!r processes ) ! *romic salts1 because ! lum9\s action ?r\gh ! b>e glass1 or ne>ly s1 :i* 9 ! negative repres5t ! %ad[s & half blacks1 is m en]getic 9 proportion ?an ?r\gh ! o!r p>ts1 f :i* x results t ^! p>ts be+ mo/ act$ on are made deeply insoluble ?r\gh ! ?ickness ( ! film1 & !n require to be cle>$ by a treatm5t ) wat] at a high] temp]ature ?an ! p>ts repres5t+ ! half t9ts 9 ! lights ( ! picture1 :i* are b sup]ficially & slightly insoluble1 c /&4 ,f "t to "t dur+ ! exposure ! pr9t 9 ! photomet] is exam9$1 & :5 a c]ta9 picture is pr9t$ to a c]ta9 %ade1 or :5 ! "o next by comm5ces to appe> or is fa9tly pr9t$1 etc41 ! exposure ( ! tissue is suffici5t4 ,?is1 z ! read] has already inf]r$1 is a matt] ( exp]i5ce1 ! guide be+ ! k ( ! int5sity negative te/$ z above expla9$4 ,developm5t4--,! c>bon pr9ts are develop$ ei!r on a %eet ( pap] ^u :i* x %\ld rema9 7s+le or simple transf]71 or on a provisory support to be aft]w>ds transf]r$ on pap] or any o!r mat]ial 7d\ble transf]74 ,simple ,transf]4--,?is process is q simple3 ,! impress$ tissue & a %eet ( pap] coat$ ) alum$ 7insoluble7 gelat9e are imm]s$ face to face 9 cold wat]1 & :5 ! tissue is s(t5$ bo? are remov$1 "o sup]pos$ on ! o!r1 & ! :ole1 be+ plac$ on a glass plate & cov]$ ) a ?9 oil clo?1 is firmly press$ into contact ) ! squeegee4 ,! rationale ( apply+ "u wat] ! tissue on ! gelat9iz$ pap] is to avoid ! int]position ( air bubbles4 ,to op]ate by simple transf] ! tissue %\ld be impress$ "u a rev]s$ negative4 ,! reason is obvi\s4 ,d\ble ,transf]4--,by ?is me?od ! c>bon pr9ts are g5]ally develop$ on porcela9 or opal plates1 :i* m easily ?an glass plates p]mit "o to foll[ ! progress ( ! developm5t & to ret\* ! imp]fections be=e transf]r+ ! picture on pap]4 ,9 ord] t ! image does n adh]e on ! provisory support a little ( ! foll[+ mixture is spread ov] ! plate1 :i* is !n pretty /rongly heat$1 &1 :5 x has cool$ d[n1 poli%$ lightly ) a piece ( :ite flannel to obta9 a v ?9 & ev5 lay] free f /ri4 ,if ! plate has n be5 us$ be=e = ! purpose 9 "q1 x %\ld be wax$ a second "t 9 ! same mann]3 ,yell[ wax #d p>ts ,ros9 #a "p ,turp5t9e or b5z9e #bej p>ts ,! plates c be develop$ on ! plates s wax$1 b = 8full gloss10 t is1 = enamel$ pictures1 a film ( collodion is appli$ on ! plates1 :i* !n1 in/ead ( be+ wax$1 %\ld to be simply fl[$ ) a solution ( ,india rubb] #a to #ajj ( b5zole3 ,e!r #bej p>ts ,alcohol #bej p>ts ,ca/or oil #a "p ,pyroxyl9e #e to #f p>ts ,:5 ! plate is coat$ & ! collodion film set1 x is imm]s$ 9 wat] until greas9ess has disappe>$ & want$ = use4 ,!n ! tissue1 previ\sly soak$ 9 wat]1 is appli$ ^u x 7tak+ c>e to avoid air bubbles7 & squeez$1 lightly at fir/1 ) "s =ce aft]w>ds1 to insure a p]fect contact4 ,z9c plates are also employ$ z provisory supports in/ead ( glass1 opal or porcela9 plates4 ,! modus op]&i is exactly ! same47#cj7 ,! plates %\ld be well plan$1 free f scrat*es1 etc41 & well poli%$ to obta9 glossy pictures )\t "o hav+ rec\rse to a film ( collodion4 ,= matt pictures1 i4e41 )\t gloss :atev]1 ! plate %\ld be f9ely granulat$1 & :5 wax+ a v light pressure %\ld be ex]t$ to remove ! excess ( wax1 else x might be q impossible to /rip (f ! picture 9 transf]r+ on pap]4 ,= d\ble transf] on biscuits1 objects 9 alaba/]1 porcela91 wood1 any ev5 or curv$ rigid mat]ials1 flexible supports are employ$ to develop ! pictures4 ,^! supports are prep>$ by fa/5+ album5 pap] on a bo>d & ev5ly bru%+ ov] ! foll[+ hot comp\nd1 filt]$ ?r\gh flannel1 :i*1 :5 dry1 is poli%$ ) a clo?3 ,/e>9e #ae p>ts ,ros9 #c p>ts ,alcohol #ajj p>ts ,! flexible supports %\ld be wax$1 !n collodioniz$ = full gloss1 z ! glass1 porcela9 & metallic plates4 ,ano!r me?od :i* ! writ] recomm5ds is ! foll[+1 due to ,mr4 ,swan3 ,imm]se a %eet ( pap] 9 a solution ( ,india rubb]1 #d3ajj ( b5zole1 & let dry1 :i* requires a few m9utes4 ,?is is ! flexible support4 ,!n aft] exposure1 bru% ov] ! ,india rubb] solution on ! c>bon tissue1 apply ^u x ! support :5 ! b5zole is evaporat$1 & pass ! :ole "u a roll+ press to secure adhesion1 !n develop4 ,to transf]1 soak ! pro( 9 tepid wat]1 apply x on ! mat]ial prep>$1 z x w be expla9$ fur!r on1 & :5 dry1 imbue ! support f ! back ) b5zole1 to s(t5 ! ,india rubb]1 & /rip4 ,to disp5se ) a roll+ press1 ! pro( may be develop$ on lacqu]$ vegetable pap] prep>$ by imm]sion 9 a solution ( #aj p>ts ( r$ %ellac 9 #ajj p>ts ( alcohol4 ,aft] develop+ ! pro( is coat$ ) alum$ gelat9e1 & :5 dry transf]r$ z usual4 ,to /rip (f x suffices to imbue ! pap] ) alcohol 9 ord] to dissolve ! %ellac4 ,:5 ! picture mu/ be transf]r$ on small spaces or on small objects ! mo/ simple me?od--! mo/ effective1 p]haps--is ! foll[+1 devis$ "s ye>s ago by ! writ] & n[ employ$ = ! ornam5ts ( 8articles de ,p>is30 ,prep>e ! provisory support z usual1 b ) a ?ick] film ( collodion2 !n1 aft] develop+ & color+1 if necess>y1 ! picture is coat$ ) gelat9e1 to :i* may be add$ "s z9c :ite or o!r color$ sub/ance to =m a gr\nd4 ,?is dry1 /rip (f1 imm]se ! pellicle 9 wat] to s(t5 ! gelat9e & transf] on ! mat]ial collodion side up4 ,! pro(s %\ld be develop$ )9 ?ree or f\r h\rs aft] insolation1 = ! lum9ons action cont9ues pretty actively 9 ! d>k1 & ?is = a long "t2 ?us3 a pro( rightly expos$ 9 ! morn+ behaves z "o ov]-expos$ if develop$ 9 ! ev5+1 & aft] a c]ta9 p]iod ei!r c n be develop$ or refuses to adh]e on ! support4 ,h[ev]1 ! pro(s c be kept = ?ree weeks1 may be m1 be=e developm5t1 if ! soluble bi*romate be wa%$ (f1 ! tissue spong$ & dri$ rapidly 9 ! w>m season4 ,?is capital improvem5t is due to ,mr4 ,*>les ,brasseur4 ,x has be5 said t be=e be+ appli$ on ! support ! pro( %\ld be imm]s$ 9 wat] to s(t5 ! tissue4 ,! "t :i* x %\ld be all[$ to absorb wat] has an importance :i* mu/ n be neglect$4 ,if x d n rema9 long en\gh to be soak$ ?r\gh1 small invisible air bubbles are =m$ on its surface1 & int]pos+ !mselves betwe5 ! image & ! support1 =m m9ute1 brilliant1 silv]-l spots on ! f9i%$ picture2 &1 if ! temp]ature ( ! wat] is above #bj deg4 ,c4 7#fh deg4 ,fahr471 ! image w be m or less reticulat$4 ,! temp]ature dep5ds a good deal ( ! s(tness ( ! gelat9e2 #ae deg4 ,c4 7#ei deg4 ,fahr47 is safe1 except1 h[ev]1 :5 ! !rmomet] is 9 ! ?irtie?s 7#ij? ,fahr471 :5 ! wat] %\ld be cool$ d[n a few degrees l[]1 b n at ! melt+ ice temp]ature1 = !n ! pro( w\ld n adh]e well4 ,z a rule1 ! tissue %\ld rema9 9 ! cold wat] until x becomes flat & %[s a t5d5cy to curl up4 ,x is at ?is v mom5t t x %\ld be squeez$ on ! support4 ,! pro(s %\ld n be develop$ imm$iately aft] transf]r+4 ,! adh]5ce is great] & ! pictures f9] & devoid ( defects :5 ! developm5t is made half an h\r1 & ev5 an h\r1 aft]4 ,if develop$ too soon ! picture w be p>tly1 & ev5 entirely1 wa%$ (f4 ,h5ce1 a numb] ( transf]s c be prep>$ be=eh&1 plac+ !m1 face to face "o ^u ano!r1 9 ord] t ! tissue does n dry1 :i* is q ess5tial4 ,to develop1 ! plate1 ) ! tissue adh]+ to x1 is plac$ 9 wat] heat$ to #cj deg4 ,c4 7#hj deg4 ,fahr471 :]e x is left rock+ ! tray occasionally until ! pap] rises up by itself at ! corn]s1 :5 tak+ hold ( x by "o corn]1 x is /ripp$ (f1 leav+ beh9d ! image buri$ 9 soluble gelat9e4 ,%\ld ! pap] (f] any resi/ance :atev]1 ! gelat9e %\ld be all[$ to become m soluble by increas+ ! temp]ature ( ! wat]1 or by a long] imm]sion4 ,!re is1 9 fact1 no objection to ?is4 ,! plate--& t is a good me?od--c be plac$ 9 an upright position 9 a t9 box1 made ad hoc1 & left !re9 9 w>m wat] until ! pap] deta*es itself & ! image is p>tly develop$ & ! bi*romate wa%$ (f4 ,?is done1 ! plate is held 9 an incl9$ position on a tray fill$ ) wat] at #ce deg4 ,c4 7#ie deg4 ,fahr471 :i* is da%$ ) a wood5 spoon on ! image to cle> x f ! non-act$-on gelat9e4 ,pres5tly "o c judge :e!r ! exposure is "r4 ,if x is too %ort1 ! half t9ts 9 ! %ad[s are wa%$ (f1 unless ! negative be too int5se1 :5 a simil> effect also occurs 9 ! :ites4 ,if x is too long1 ei!r ! image is ) difficulty cle>$ or rema9s undevelop$4 ,9 ! latt] case1 x is recomm5d$ by "s op]ators to increase ! temp]ature ( ! develop+ wat] to ne> ! boil+ po9t1 &1 = local cle>+1 to p\r x on4 ,?is we f9d objectionable1 = ! half t9ts are easily wa%$ (f4 ,a bett] process1 :5 ! picture c n be cle>$ by wat] at #ej deg4 7#abb deg4 ,fahr471 or !reab\t1 is to use a solution ( common salt at #e or #f p] c5t4 ( slightly w>m wat]47#ca7 ,x is ev5 pref]able to f9i% ! developm5t 9 a tepid solution ( potassium sulpho-cyanide1 #ab3ajj4 ,! dissolv+ action is long1 b n only1 z said above1 ! half t9ts are be/ pres]v$1 b bli/]+ & local wa%+-(f are avoid$4 ,aft] developm5t ! plate is r9s$ "u ! tap1 !n fl[$ two or ?ree times ) a solution ( *rome alum at #a p] c5t4 ( wat]1 !n wa%$1 & f9ally all[$ to dry spontane\sly4 ,x is objectionable to use a /rong solution ( alum1 & 9 x to imm]se ! plate = any l5g? ( "t2 ! gelat9e is consid]ably h>d5$--:i* is n necess>y--& m liable to crack by "t 9 be+ ?or\ghly desiccat$4 ,we disc>d ! common alum :i* we f\nd liable to produce a slight reticulation4 ,two defects are compla9$ ( by ! beg9n]s1 viz41 ! want ( adh]5ce ( ! deep blacks1 &1 especially1 ! isolat$ & f9e l9es :5 ! picture is a reproduction ( an engrav+1 a draw+1 etc41 & ! liability 9 half tone pictures ( ! delicate details be+ wa%$ out4 ,! fir/ defects are avoid$ by p\r+ a solution ( boric acid on ! transitory support be=e apply+ ! tissue & develop+ at a l[ temp]ature ) salt$ wat]4 ,! second f an imp]fect k ( ! prop]ties ( gelat9e act$ on by light 9 pres5ce ( a salt ( *romic acid4 ,"o %\ld be> 9 m9d t ! degree ( solubility ( gelat9e s act$ on1 z also its degree ( imp]meability--:i* is important 9 c]ta9 processes ( photogravure--is proportionate to ! degree ( insolation2 ?us1 :5 n impress$1 bi*romat$ gelat9e dissolves 9 wat] heat$ to ab\t f #be to #cj deg4 ,c4 7#gg to #hj deg4 ,fahr471 & :5 act$ on betwe5 #cj & #ajj deg4 ,c4 7#hf to #aab deg4 ,fahr471 accord+ z to ! degree ( insolation1 t is1 ( r$uction ( ! *romic salt1 ! latt] temp]ature be+ t ( insolubility ( ! p>ts ! mo/ act$ on4 ,! v delicate half t9ts d n1 g5]ally1 /& a temp]ature high] ?an #ce deg4 ,c4 7#ie deg4 ,fahr471 &1 !re=e1 z ! degree ( insolubility ( ! v>i\s p>ts _c be asc]ta9$1 a priori1 x is advisable dur+ ! developm5t to increase gradually ! temp]ature ( ! wat] f ?is degree1 & n to exce$ #de deg4 ,c4 7#aac deg4 ,fahr471 9 ord] to obta9 ! mo/ p]fect result f a negative ( good int5sity4 ,inde$1 by plac+ ! supports on a rack & imm]s+ ! :ole 9 wat] heat$ to #cj to #ce deg4 ,c4 7#hf to #ie deg4 ,fahr471 ! image w cle> up by itself to p]fection 9 a c]ta9 p]iod4 ,?is me?od is excell5t = pro(s 9 l9es4 ,^? f ! gra9$ negatives employ$ 9 photogravure are /ill m p]fectly develop$ 9 a tepid solution ( potassium sulphocyanate1 s9ce ! impressions :olly consi/ ( insoluble p>ts 7! l9es7 & gelat9e n act$ on4 ,ret\*+4--,! ret\*es are easily made4 ,!y %\ld be done be=e transf]r+ :5 work+ by ! d\ble transf] process4 ,! transp>5t spots1 & any p>ts :i* %\ld be alt]$1 are ret\*$ ) ! mat]ial ( ! tissue dissolv$ 9 w>m wat]2 ! :ites are cle>$ ) a scrap]2 & any p>ts :i* are n int5se en\gh1 or :i* %\ld be bl5d$ by ! addition ( half t9ts1 are work$ on ! pro(--to :i* a too? has be5 giv5 by rubb+ ) cuttle-fi% p[d]--by means ( a /ump & an appropriate color1 a mixture ( lamp-black & c>m9e1 = example1 9 v f9e p[d]4 ,! pro(s c also be color$ by *emical means 7see fur!r on71 or ) wat] colors employ$ ) a solution ( *rome alum1 #a to #bjj ( wat]1 or gilt1 silv]$ or bronz$ ) metallic p[d]s appli$ ) ! gild]'s size ?9n$ ) turp5t9e on ! pro( previ\sly coat$ ) a ?9 lay] ( alum$ gelat9e4 ,second ,transf]4--,to transf]1 a %eet ( enamel$ or simple transf] pap] is imm]s$ 9 tepid wat] until ! gelat9e is s(t5$ & feels slipp]y to ! f+]s4 ,! support is !n plac$ "u wat] at ord9>y temp]atures--n "u #af deg4 ,c4 7#fj deg4 ,f47--= two ?ree m9utes1 !n rubb$ ) a camel bru% to remove ! air bubbles1 :i* might be =m$ on ! surface ( ! image1 :51 )\t dra9+1 ! gelat9iz$ pap] is laid ^u x1 cov]$ ) ! ?9 oil clo?1 & press$ into contact ) ! squeegee1 comm5c+ 9 ! c5t] to ! sweep (f ! wat]1 !n repeat+ ! op]ation = ! o!r half1 z expla9$ to apply ! tissue on ! provisory support4 ,:5 ! :ole is q dry1 :i* requires ?ree or f\r h\rs1 ! edges are cut ) a p5knife & ! :ole /ripp$ (f4 ,x may happ5 t ! pro( is cov]$ ) m9ute1 silv]-l brilliant spots1 :i* are no?+ else ?an v small air bubbles int]posit$ betwe5 ! c>bon pro( & ! transf] pap]4 ,!y are caus$ by ! gelat9e pap] n hav+ be5 suffici5tly s(t5$ or n laid on ! pro( ) prop] c>e4 ,! defect may also arise f ! transf] pap] coat$ ) n suffici5tly ?ick gelat9e4 ,to transf] on any rigid mat]ial1 ! pro(s on flexible supports are coat$ by float+ on ! foll[+ gelat9e solution1 !n all[$ to dry1 &1 :5 want$ = use1 imm]s$ 9 tepid wat] to s(t5 ! gelat9e & secure adh]5ce3 ,gelat9e #ej p>ts ,wat] #djj p>ts ,solution ( *rome alum1 #f p>ts #d3ajj ,developm5t on ,absorb+ ,mat]ials4--,! developm5t ( c>bon pr9ts on absorb5t mat]ial--su* z canvas & palettes to be pa9t$ 9 oil1 etc4--_c be made 9 ! ord9>y mann] on acc\nt ( ! impossibility to elim9ate entirely ! *romic salt :i* t+es ! mat]ial yell[4 ,to turn ! difficulty1 x suffices to wa% (f 9 sev]al *anges ( cold wat] all ! unalt]$ bi*romate f ! pr9ts on _! removal f ! pr9t+ frame1 & to proce$ z usual1 or ! pr9ts c be all[$ to dry & transf]r$ at "s future "t4 ,canvas %\ld be prep>$ by bru%+ ) a solution ( aque\s ammonia 9 alcohol1 #e3bj1 to remove greas9ess until ! ?read is app>5t1 &1 :5 dry1 rubb$ ) s& to gra9 x--or to give a too?1 z x is t]m$--!n rubb$ dry ) a solution ( soluble glass1 #a to #aj ( be]47#cb7 ,palettes %\ld be r5d]$ imp]vi\s1 or ne>ly s1 by fl[+ ^u !m a solution ( alum$ gelat9e1 :i* is all[$ to p5etrate into ! pores ( ! wood & ! excess scrap$ (f :5 solidifi$1 :5 ! surface may be :it5$1 if necess>y1 z = pr9t+ on wood box1 q4v4 ,opals1 porcela91 or ivory %\ld be prep>$ ) ! foll[+ sub/ratum3 ,gelat9e #ej p>ts ,wat] #djj p>ts ,*rome alum1 #d3ajj #f p>ts ,v f9e c>bon pro(s hav+ ! appe>ance ( pictures on opal plates are made by transf]r+ 9 ! foll[+ mann]1 devis$ by ! au?or3 ,develop on ! gr\nd surface ( a glass or porcela9 plate1 well wax$1 to obta9 a matt picture1 or 9 ! ord9>y mann] = full gloss1 & :5 ! image is ret\*$ or color$1 apply a ?9 coat+ ( gelat9e1 let dry & coat ) ! foll[+ opaque collodion3 ,a4 ,e!r1 conc4 #ajj p>ts ,alcohol1 #ie deg #ij p>ts ,pyroxyl9e #g p>ts ,b4 ,:ite z9c 9 v #i p>ts f9e p[d] ,ca/or oil #c p>ts ,alcohol #aj p>ts ,gr9d 9 a mort>1 add+ ultram>9e blue & c>m9e1 or a little ( any suitable color+ matt]s1 & mix to ,a4 ,:5 ! collodion is dry1 :i* requires a few h\rs1 /rip ! :ole or back ) /rong :ite or color$ pap] be=e /ripp+4 ,a solution ( gelat9e ) glyc]9e1 :ite z9c1 etc41 may be sub/itut$ = collodion :5 ! pictures are employ$ z ornam5ts on wood1 etc4 ,c>bon pr9ts on celluloid are n[ made = simil> purposes4 ,,opal ,,gelat9e ,,solution ,gelat9e #aej p>ts ,glyc]9e #ae p>ts ,z9c1 :ite #dj p>ts ,wat] #fjj p>ts ,to :i* "s color+ matt]s may be add$ accord+ to ta/e4 ,gr9d ! :ite ) ! glyc]9e & a little wat]1 mix to ! gelat9e dissolv$ 9 ! rema9d] ( wat]1 & filt] ?r\gh canvas4 ,apply ! mixture mod]ately hot1 #cj deg4 ,c4 7#hf deg4 ,fahr47 ,transp>5cies4--,! transp>5cies are pr9t$ on a special tissue sold "u ! "n ( 8diapositive40 ,x diff]s f ! ord9>y tissue 9 ?is1 t ! mixture conta9s a great] quantity ( ! color matt]1 ,india ink1 :i* is gr\nd exce$+ly f9e4 ,! pro(s = transp>5cies %\ld be pr9t$ deep] ?an ^? to be se5 by reflection1 & develop$ on ?9 glass plates1 free f any defects1 & coat$ ) ei!r "o ( ! foll[+ sub/rata3 ,soluble glass #e p>ts ,:ite ( eggs #ae p>ts ,wat] #bj p>ts ,! :ole is beat5 up to a ?ick fro? & all[$ to subside1 :5 ! cle> liquid is decant$1 filt]$ ?r\gh flannel & ! glass plates coat$4 ,! sub/ratum %\ld be all[$ to dry = a few h\rs1 & r9s$ "u ! tap be=e use4 ,! o!r sub/ratum consi/s ( ,gelat9e #ce p>ts ,acetic acid1 ,no4 #h #bej p>ts ,alcohol1 #ie deg #ej p>ts ,wat] #gjj p>ts ,*rome alum1 #d3ajj #fj p>ts ,dissolve ! gelat9e 9 ! acid at a mod]ate heat1 add aft]w>ds ! alcohol & wat]1 & la/ly mix ! *rome alum by small quantities at a "t4 ,^! sub/rata are employ$ to avoid ! peel+ (f ( ! image4 ,to prev5t ! entire desiccation ( ! gelat9e1 :i* is ! cause ( ! defect above allud$ to1 x is advisable to add glyc]9e to ! wa%+ wat] aft] ! image is cle>$4 ,"s op]ators recomm5d a coat+ ( flexible collodion1 t is1 prep>$ ) ca/or oil1 = ! purpose 9 "q4 ,we d n ?9k t necess>y :5 ! transp>5cies are n expos$ to sun%9e4 ,if any?+ %\ld be appli$ we w\ld pref] ! encau/ic4 ,c>bon transp>5cies are invaluable = reproduc+ negatives 9 ! orig9al size by ! same 7c>bon7 process1 or = enl>g+ by ! collodion or gelat9e process4 ,= ^! purposes !y %\ld be made on ! special r$ tissue manufactur$ by ! ,autotype ,company1 ( ,london1 ,eng4 ,!y c1 h[ev]1 be made on ! ord9>y tissues4 ,:atev] be ! tissue employ$1 ! transp>5cies = ! reproduction ( negatives are seldom opaque en\gh1 & %\ld be int5sifi$4 ,?is is done by treat+ !m ) a v dilute solution ( sodium p]manganate1 :i* colors !m olive gre54 ,transp>5cies = lant]n slides1 etc41 are be/ color$ ) ! c\leurs l'album9e ( ,l4 ,encausse1 sold by ,j4 ,reygondaud1 ,p>is 7,france74 ,!y are transp>5t47#cc7 ,ton+ & ,int5sify+4--,! c>bon pro(s c be ton$ & at ! same "t int5sifi$ by reag5ts act+ ) *romic oxide4 ,! dyes or color+ matt]s precipitat$ are n opaque1 &1 z a consequ5ce1 n objectionable = transp>5cies4 ,! foll[+ processes are ! mo/ employ$3 ,prep>e ?ree solutions z foll[s3 ,a4 ,f]ric sulphate #e p>ts ,wat] #ajj p>ts ,b4 ,sodium c>bonate #b p>ts ,wat] #ajj p>ts ,c4 ,gallic acid #e p>ts ,wat] #ajj p>ts ,dissolve ! gallic acid 9 w>m wat]4 ,filt] ea* solution4 ,!y keep well4 ,to tone1 ! plate is imm]s$ =1 say1 t5 m9utes 9 ,a1 !n1 aft] r9s+ slightly1 x is plac$ 9 ,b = ! same p]iod1 r9s$ aga9 & fl[$ ) ,c until ! desir$ color is obta9$4 ,! tone is a spl5did purple black color4 ,if a solution ( pyrogallol be sub/itut$ to t ( gallic acid1 ! tone is gre51 & to a gre5 bord]+ to black :5 a solution ( cate*u is us$1 ! cate*u ex]t+ at ! same "t a tann+ action on ! gelat9e4 ,aft] ton+1 ! plate %\ld be ?or\ghly wa%$4 ,a simil> process consi/s to wet ! plate "u ! tap1 !n to fl[ ov] a mixture by ab\t equal volumes ( ,a4 ,f]r\s sulphate #e p>ts ,acetic acid1 ,no4 #h #e p>ts ,wat] #ajj p>ts1 filt] ,b4 ,gallic acid #e p>ts ,wat] #ajj p>ts ,:5 ton$1 ! plate is well wa%$1 !n fl[$ once ) ! alum solution & aga9 wa%$4 ,! tone by ?is process easily turns to an inky blue n v agreeable4 ,! action %\ld be /opp$ a little be=e ! desir$ color is obta9$4 ,x sometimes happ5s t ! image 9 dry+ int5sifies m !n necess>y4 ,x c be cle>$ ) a solution ( oxalic or citric acid4 ,a br[n sepia is obta9$ by ton+ fir/ ) potassium p]manganate1 #a p] c5t4 ( wat]1 !n1 aft] wa%+1 ) a solution ( pyrogallol4 ,if gallic acid be us$ in/ead ( pyrogallol1 ! tone is black4 ,by ?is process a great int5sity is obta9$4 ,a dilute solution ( ammonium sulphide c be employ$ z a cle>+ ag5t4 ,pyrogallol & silv] nitrate give a w>m black tone4 ,potassium bi*romate foll[$ by silv] nitrate =m a brick-r$ precipitate ( "s opacity47#cd7 ,*loride ( nickel & potassium f]rocyanate produce a f9e br[n4 ,lime wat] & aliz>9e dissolv$ 9 alcohol dye violet4 ,aliz>9e & ! cau/ic alkalies produce a v>iety ( t9ts1 f violet to purple1 accord+ to ! conc5tration ( ! solutions4 ,lead acetate & aliz>9e 9 ammoniacal solution dye purple4 ,potassium f]rocyanide & uranium nitrate produce a w>m sepia tone4 ,) *loride ( nickel ! tone is br[n4 ,ammoniacal solution ( corall9e dilut$ ) wat] gives c>m9e r$4 ,potassium bi*romate & extract ( indigo produce a f9e gre5i% tone suitable = l&scapes4 ,extract ( indigo colors blue7#ce7 ,"s ( ^! reactions c be appli$ to ! pr9t+ processes ) ! bi*romates1 etc4 ,! pap] %\ld be coat$ ) galat9e4 ,see ! ,app5dix4 ,o!r colorations c be obta9$ ) dyes 9 utiliz+ 7z %[n by ,p]soz7 *rom\s *romic oxide z a mordant3 aliz>9e1 ,brazil & yell[ wood 7morus t9ctoria71 ,fu/et 7rhus cot9us71 etc4 ,! ext5t ( ?is "w does n admit ( describ+ ! num]\s processes :i* c be employ$2 !y w sugge/ !mselves to ! *emi/4 ,! alkalies employ$ ) ! dyes %\ld be employ$ 9 dilut$ solutions1 z be+ liable to produce reticulation4 ,by apply+ ! color+ matt]s & ! mordants ?ick5$ ) a little />*1 ! image c be color$ ) diff]5t colors4 ,lant]n slides c be ?us color$ ) great ease4 ,,prep>ation ,,( ,,r$1 ,,yell[1 ,,or ,,blue ,,tissues4 ,r$ ,tissue4--,dissolve #aj grams ( c>m9e 9 #a lit] ( aque\s ammonia & evaporate4 ,:5 ! smell ( ! alkali has almo/ disappe>$1 add #a lit] ( ra9 wat]4 ,( ?is take #fe cubic c5timet]s1 add #ce c4c4m4 ( ra9 wat]1 & 9 ! solution let soak = an h\r #ae grams ( v soluble gelat9e1 add #a gram ( sug>1 & dissolve 9 a wat] ba?4 ,filt]1 & take ( ! mixture a suffici5t quantity 7#be c4c4m4 = a surface #ahbd c5timet]s7 to cov] a %eet ( pap] :i* has be5 previ\sly appli$ ^u a glass plate 9 ! foll[+ mann]3 ,9 a tray full ( hot wat]1 imm]se ! plate & ! pap]2 remove ! :ole 9 su* a mann] z ! pap] rema9s 9 contact ) ! plate2 rub out ! excess ( wat] ) a squeegee1 & fl[ ! gelat9e ov] ! pap] /ill damp4 ,let cool on a level$ /&1 & :5 ! gelat9e is solidifi$ to a consi/5t jelly1 remove ! pap] f ! plate & place x to dry 9 an ov5 heat$ at n ov] #bd or #be deg4 ,c4 ,x is desirable t 9 dry+ ! pap] does n curl up4 ,to t end1 apply ov] x1 be=e x be+ remov$ f ! plate a wood5 frame to :i* ! gelat9e1 /ill /icky1 w suffici5tly adh]e to hold ! tissue :5 x /ret*es 9 dry+4 ,yell[ ,tissue4--,pulv]ize to an impalpable p[d] #be grams ( light *rome yell[ 9 tablets 7wat] color71 & gradually add 9 /irr+ #a lit] ( ra9 wat]4 ,take #ajj c4c4m4 ( ?is & into x let soak = an h\r #ae grams ( ! same gelat9e us$ = ! r$ tissue1 add #a gram ( sug>1 !n proce$ z above4 ,blue ,tissue4--,9 a liquid consi/+ ( #he c4c4m4 ( ra9 wat] & f #ab to #ae c4c4m4 ( blue ink1 su* z sold by /ation]s1 let soak = an h\r #ae grams ( ! same gelat9e & #a gram ( sug>1 & proce$4 ,prep>ation ( ,transf] ,pap]4--,two k9ds ( transf] pap] are employ$--! enamel & pla9 transf] pap]4 ,to enamel ! pap]3 ,dissolve #ajj p>ts ( b>ium nitrate 9 #ejj p>ts ( wat]1 &1 on ! o!r h&1 #bjj p>ts ( sodium sulphate 9 ! same quantity ( wat]4 ,mix1 wa% well ! precipitate--b>ium sulphate--by decantation1 & :5 well dra9$1 mix to ! foll[+ solution3 ,gelat9e1 ,coignet's #cjj p>ts ,glyc]9e #hj p>ts ,ultram>9e blue #a "p ,crimson lake #j4a "p ,wat] #b1ejj p>ts ,let soak ! gelat9e =1 say1 "o h\r1 dissolve by heat1 !n add by small quantities1 /irr+ viol5tly1 #d p>ts ( *rome alum dissolv$ 9 #bej p>ts ( hot wat]4 ,filt] ?r\gh flannel & coat ! pap] z direct$ to prep>e ! tissue4 ,! mixture %\ld be employ$ imm$iately aft] add+ ! *rome alum4 ,! pla9 transf] pap] is prep>$ 9 ! same mann]1 leav+ out ! b>ium sulphate & ! color+ matt]s4 ,prep>ation ( ! ,silv] ,pap]4--,imm]se ! pap] = two m9utes 9 a solution (-- ,sodium *loride 7common #b p>ts salt1 dry7 ,lemon juice #a "p ,wat] #ajj p>ts 7filt]7 ,:5 dry & want$ = use1 s5sitize ! salt$ pap] by float+ = "o m9ute on-- ,silv] nitrate #h p>ts ,nitric acid #j4a "p ,wat] #ajj p>ts ,on its removal f ! silv] ba?1 sponge ! pap] betwe5 %eets ( blott+ pap] & hang x up to dry4 ,,encau/ic ,,= ,,s+le ,,transf] ,,pro(s4 ,:ite wax #be p>ts ,ma/ic #c p>ts ,turp5t9e #ajj p>ts ,dissolve by heat1 fir/ ! ma/ic1 !n ! wax1 & keep = use 9 a l>ge m\!d vial4 ,,matt ,,v>ni%4 ,s&>ac #f p>ts ,ma/ic #f p>ts ,lav5d] oil4 #j4e p>ts ,e!r #ajj p>ts ,:5 dissolv$1 add #cj p>ts ( b5z9e4 ,! opacity ( ! film v>ies ) ! quantity ( b5z9e add$2 by excess ! v>ni% dries transp>5t4 ,,wat] ,,colors ,,:i* ,,resi/ ,,! ,,action ,,( ,,light4 ,r$4 ,indian r$4 ,light r$4 ,orange4 ,m>s yell[4 ,blue4 ,cobalt blue4 ,fr5* blue4 ,smalt4 ,new blue4 ,br[n4 ,raw umb]4 ,burnt si5na4 ,gre5 ,t]re v]te4 ,yell[4 ,cadmium ,yell[ ,roman o*re4 yell[4 o*re4 ,,app5dix4 ,al?\gh we int5d$ to only describe ! pr9t+ processes )\t ! use ( silv] salts1 we ?\ght x w\ld be well to complete ?is "w by giv+ ! mo/ practical & int]e/+ processes ev] publi%$ to obta9 p]man5t photographs2 z !y may give rise 9 ! h& ( exp]im5t]s to useful applications4 ,f "t to "t processes are publi%$ "u 8que]0 names1 :i* are bas$ on ! well kn[n actions ( reag5ts on ! f]ric salts r$uc$ by light4 ,!y are d]iv$ f ^? describ$ 9 ! foll[+ pages4 ,we call specially ! att5tion ( ! read] to ! process ( ,poitev91 by :i* "o c exp]im5t ) e f]ric salts1 citrate1 lactate1 oxalate1 t>trate1 b5zoate1 etc41 by simply excit+ ) ! correspond+ acid4 ,obs]ve t to obta9 good results ! pap] %\ld be /rongly siz$2 x is a s9e qua non1 al?\gh n recomm5d$ by ,poitev94 ,c4,j4 ,,burnett',s ,,process7#aheg74 8,a capital process = _m purposes10 says ,mr4 ,burnett1 8is to float or /eep ! pap] 9 a mix$ solution ( bi*romate ( pota% & sulphate ( copp]1 z = ,hunt's *romotype process47#cf7 ,i h mix$ gelat9e1 or occasionally grape sug>1 or bo? ) ! solution27#cg7 b in/ead ( develop+ x ) nitrate ( silv]1 z 9 *romotype1 wa% out ! salt unalt]$ by light1 & develop by float+ on a solution ( f]rocyanate ( potassium4 ,! purple r$ color ( ! copp] salt :i* n[ =ms ! picture may be modifi$ or *ang$ 9 _m ways17#ch7 viz41 by soak+ ! picture1 aft] ! f]rocyanate ( potassium has be5 wa%$ out ( ! lights1 9 a solution ( sulphate ( iron4 ,solutions ( gallic acid1 tannic acid ) alkalies ( c>bonate1 may also be employ$ to modify or *ange ! color4 ,?is process has ! advantage t "o may regulate ! exact tone 7black or useful neutral t9t7 to ! greate/ nicety by ! "t we all[ ! pr9t to rema9 9 ! iron ton+ ba?40 ,,godefroy',s ,,process 7#aheh74 ,float ! pap] ^u ! foll[+ solution = ?ree m9utes & hang x up to dry3 ,uranium nitrate #cj to #fj p>ts ,silv] nitrate #h p>ts ,wat] #ajj p>ts 7#ci7 ,! s5sitiv5ess increases 9 proportion to ! quantity ( uranium nitrate4 ,) ! above =mula ! pap] c be expos$ 9 ! cam]a1 or1 = pr9t+1 "u a negative cli*4 ,9 pr9t+ an exposure ( five seconds 9 diffus$ light gives an image p]fectly visible1 & a grayi% black tone2 t5 seconds gives a vigor\s image almo/ ( a black color2 9 f fifte5 to tw5ty seconds ! image is v /rong1 ) ! color ( an engrav+4 ,9 sun%9e ! action is necess>ily mu* m rapid4 ,! impression is develop$ by imm]sion 9 ,f]r\s sulphate #h p>ts ,t>t>ic acid #d p>ts ,sulphuric acid #a "p ,wat] #ajj p>ts ,! image is rapidly develop$4 ,x is fix$ by wa%+ 9 wat]4 ,,de ,,la ,,blan*]e',s ,,process 7#aheh74 ,uranium nitrate #be p>ts ,di/ill$ wat] #ajj p>ts ,filt] ! solution & keep x 9 ! d>k4 ,! pap] %\ld be siz$ ) a gelat9e solution at #e p] #ajj ( wat]1 &1 :5 dry1 kept 9 ! d>k47#dj7 ,x is s5sitiz$ by float+ five m9utes4 ,! exposure "u a negative v>ies f fifte5 to tw5ty m9utes 9 ! %ade1 & f "o to ?ree m9utes1 at ! mo/1 9 sun%9e4 ,z a rule1 x is advisable to some:at und]expose 9 ord] t ! developm5t be regul>1 progressive1 "u control4 ,! image is develop$ by float+1 or imm]sion 9 ,silv] nitrate #b p>ts ,di/ill$ wat] #ajj p>ts ,nitrate acid1 ,c4,p4 a trace ,:5 ! image is int5se en\gh x is wa%$ 9 sev]al *anges ( wat]1 !n ton$ 9 a solution ( gold at #a p] #a1jjj ( wat] acidifi$ ) traces ( hydro*loride acid47#da7 ,! foll[+ ba? develops sl[ly1 & gives v ri* purple tones )\t ton+3 ,nitrate ( silv] #c p>ts ,nitrate ( uranium #a "p ,nitrate ( cadmium #a "p ,alcohol #aj p>ts ,wat] #ajj p>ts ,nitric acid traces ,! develop+ solutions %\ld be z little acid z possible1 b n neutral1 = !n ! pro(s w\ld be veil$ & grayi%4 ,! image c also be develop$ 9 a solution ( gold1 or 9 a v weak solution ( m]curic *loride at #a p] #aj1jjj4 ,! pro( mu/ be extremely well pr9t$ & left = f two to five m9utes 9 ! m]curic solution4 ,if ! "t ( exposure is "r1 ! image w *ange b little 9 ! solution1 & w take1 :5 treat$ ) silv] nitrate1 ! mo/ spl5did tones4 ,! pro(s %\ld be c>efully wa%$ :5 f9i%$4 ,if !y 7 develop$ ) silv]1 !y mu/ be imm]s$ 9 dilut$ aque\s ammonia1 :i* w p]fectly cle> ! :ites4 ,if develop$ ) *loride ( gold1 ! wat] %\ld be heat$ to #fj to #hj deg4 ,c4 7#adj to #agf deg4 ,fahr47 ,,h\doy',s ,,process 7#aheh47 ,! pap] is float$ ^u a lukew>m solution ( gelat9e at #e3ajj1 & :5 dry1 on a ba? ( uranium at #aj or #ae p] #ajj ( wat]4 ,aft] exposure to ! sun ! image is develop$ ) a solution ( silv] nitrate acidifi$ ) acetic acid4 ,! exposure v>ies1 accord+ to ! nature ( ! negative1 f "o to t5 m9utes2 x mu/ be long en\gh = ! image be+ develop$ 9 f ?irty to =ty seconds4 ,x is !n remov$ f ! silv] ba? & plac$ 9 ! foll[+3 ,f]r\s sulphate #c to #h p>ts ,acetic acid #b p>ts ,wat] #ajj p>ts ,9 ?is ba? ! image takes a great vigor & appe>s entirely on ! surface ( ! pap]4 ,:5 ! pro( has be5 too long expos$ x %\ld be wa%$ slightly be=e plac+ x 9 ! iron ba?4 ,develop$1 ! image is1 g5]ally1 ( a sepia tone1 :i* c be turn$ to black by a solution ( *loride ( gold1 #a3a1jjj1 wa%+ aft]w>ds z usual4 ,,ni,,pce ,,de ,,/4 ,,victor',s ,,process 7#ahei74 ,r$ ,pr9ts4 ,float ! pap] = fifte5 or tw5ty seconds on a #bj p] c5t4 solution ( nitrate ( uranium & dry be=e ! fire 9 ! d>k room4 ,?is pap] c be prep>$ _m days be=e use4 ,expose 9 sun%9e f eight to t5 m9utes1 accord+ to ! int5sity ( ! light & ! quality ( ! negative1 !n wa% 9 mod]ately w>m wat] 7#ej to #fj deg4 ,c47 = a few seconds4 ,?is done1 imm]se 9 a solution ( r$ prussiate ( pota% at #b p] c5t4 ( wat]2 9 a few mom5ts ! pro( w become ( a f9e blood-r$ color1 l 8sangu9e40 ,wa%1 etc4 ,gre5 ,pr9ts4 ,make a r$ pr9t z above describ$1 imm]se x = a few m9utes 9 a solution ( nitrate ( cobalt & dry x )\t wa%+4 ,fix !n 9 a solution ( sulphate ( iron at #bj p] c5t4 ( wat] & #d ( sulphuric acid4 ,wa% & dry be=e ! fire4 ,violet ,pr9ts4 ,prep>e ! pap] 9 ! uranium ba?1 expose1 wa% & develop 9 a solution ( *loride ( gold1 #a3bjj1 until ! pro( has assum$ a f9e violet color4 ,wa% 9 sev]al *anges ( wat]4 ,blue ,pr9ts4 ,s5sitize ! pap] ) a r$ prussiate ( pota% solution at #bj p] #ajj4 ,let dry1 expose until ! pro( is slightly blue2 imm]se x = five or t5 seconds 9 a saturat$ solution ( bi*loride ( m]cury1 wa% only once & imm]se 9 a solution ( oxalic acid--saturat$ :5 cold--heat$ to ab\t #ee deg4 ,c4 ,wa% 9 ?ree or f\r wat]s & let dry spontane\sly4 ,black ,pr9ts4 ,float ! pap] on a mixture by equal volumes ( a solution ( iron p]*loride & ano!r ( uranium nitrate1 ea* at #aj p] #ajj ( wat]4 ,expose & develop on a saturat$ solution ( gallic acid4 ,,dr4 ,t4,l4 ,,phipson',s ,,process 7#ahfa74 ,take a solution ( p]*loride ( iron &1 hav+ precipitat$ ! p]oxide ) ammonia1 collect ! precipitate on a filt] & wa% x ) boil+ wat]4 ,add ! precipitate 9 excess to a w>m solution ( oxalic acid4 ,a beautiful em]ald gre5 solution is obta9$1 :i* mu/ be a little conc5trat$ by evaporation & !n set aside 9 a d>k room = use4 ,! pap] is float$ = t5 787 m9utes ^u ! gre5 solution ( f]ric oxalate1 to :i* has be5 add$ a little oxalate ( ammonia & hung up to dry 9 ! d>k4 ,expose "u a negative = f t5 to tw5ty m9utes1 accord+ to ! wea!r1 & wa% well ! pap] ) ra9 wat]4 ,spr+ wat] w n d on acc\nt ( ! lime x may conta91 :i* w =m oxalate ( lime 9 ! pap] 7insoluble74 ,:5 all ! non-decompos$ oxalate is wa%$ f ! pro(1 a feeble image ( oxalate ( protoxide ( iron1 sc>cely visible1 is left on ! pap]4 ,to develop x & to obta9 ! vigor1 ! tone & color ( silv] pr9ts proce$ z foll[s3 ,plunge ! pro( = a little :ile 9 a 7weak7 solution ( p]manganate ( potassium to :i* a few drops ( ammonia h be5 add$2 9 ! ba? ! image becomes br[n & di/9ctly visible4 ,x is !n )drawn & imm]s$ 9 a solution ( pyrogallic acid = half an h\r1 aft] :i* x is wa%$ & dri$4 ,! image ?us obta9$ c h>dly be di/+ui%$ f silv] pr9ts2 ! tone is s(t1 brilliant & p]man5t4 ,?is process is q orig9al & int]e/+4 ,! !ory is z foll[s3 ,"u ! action ( light ! f]ric oxalate is r$uc$ 9 ! f]r\s salt1 insoluble1 :i*1 aft] ! pr9t has be5 cle>$ f ! f]ric oxalate1 is oxidiz$ & r$uc$ into f]ric oxide by ! alkaliz$ p]manganate1 ! latt] !n =m+ color$ comp\nds ) reag5ts4 ,x has be5 lately publi%$ 9 ,engl& "u ! "n ( 8kallitype10 a new process--or old1 ad libitum--:i* consi/s 9 develop+ ! image 9 f]r\s oxalate by a peculi> silv] comp\nd ^: =mula is giv5 bel[4 ,! pap] is prep>$ by bru%+ ) a /rong solution ( neutral f]ric oxalate dri$ rapidly--:i* is a s9e qua non :5 us+ deliquesc5t salts2 & aft] exposure ! image is develop$1 etc4 ,silv] nitrate #ej gra9s ,sodium citrate #hjj gra9s ,potassium bi*romate #a to #b gra9s ,wat] #aj ounces 8,dissolve ! silv] nitrate 9 #a ounce ( wat]1 ! citrate & bi*romate 9 ! rema9d] & mix4 ,! precipitate--silv] citrate & *romate--is !n dissolv$ by add+ #a dram ( ammonia 4#hhj1 & aft] #ce drops ( /rong nitric acid has be5 add$ ! solution is ready = use40 ,?is process rem9ds u t ( ,rob]t ,hunt 7#ahdb71 & t ( m rec5t date 7#ahfc71 ( ,borl9etto1 :o develop$ ! image 9 black ) a silv] nitrate alcoholic solution1 #a3ejj1 & aft] wa%+ ! picture 9 a solution ( citric acid1 #a3aj1 fix$ x by aque\s ammonia4 ,b1 al?\gh t is n absolutely necess>y1 we w\ld advise "o work+ ?is1 or simil> processes 9 :i* a silv] salt is employ$ = develop+1 to fix ! image1 aft] treatm5t ) citric acid to cle> ! pro(s f iron salts1 9 a solution ( ammonium sulphocyanate--:i* has n ! injuri\s effect ( sodium ?iosulphate 7hyposulphite7--9 ord] to prev5t ! pap] to be t+$ by ! r$uction ( ! silv] nitrate :i* is me*anically reta9$ 9 its fib]4 ,! solution ( ammonium sulphocyanate %\ld be comp\nd$ ) auric *loride to tone ! picture at ! same "t x is fix$2 ?us3 ,ammonium sulphocyanate #ce p>ts ,gold t]*loride #j4ae "p ,wat] #cej p>ts ,! solution c be us$ ov] aga94 ,9 ! processes devis$ by ,dr4 ,phipson1 ,monckhov5 & o!r au?orities1 ! d\ble ammonio-f]ric oxalate is rightly recomm5d$ in/ead ( ! simple oxalate4 ,n only is ! prep>ation m s5sitive to ! lum9\s action1 b bett] half tones are obta9$4 ,z usual1 x is advantage\s to size ! pap] ) />*4 ,! ammonio-f]ric oxalate is prep>$ by precipitat+ f]ric *loride or sulphate by aque\s ammonia1 !n wa%+ ! precipitate collect$ on a filt] until ! wa%+ wat] be neutral or does n evolve ! smell ( ammonia4 ,! precipitate is !n plac$ 9 an evaporat+ di%1 & by small quantity is add$ a hot solution ( ammonium oxalate until x is ne>ly 7n entirely7 dissolv$1 :5 ! solution is set aside = a few h\rs1 !n filt]$ & evaporat$ to cry/allization4 ,= use1 ! cry/als ( ammonio-f]ric oxalate are dissolv$ 9 ! proportion ( #a = #e ( di/ill$ wat]4 ,! solution z well z ! cry/als %\ld be kept 9 ! d>k4 ,if "o object to ! tr\ble ( cry/alliz+1 ! solution c be prep>$ by dissolv+ ! f]ric oxide 9 a hot solution ( #cj p>ts ( ammonium oxalate & #be p>ts ( oxalic acid 9 #ahj p>ts ( wat] obs]v+ t ! oxide mu/ be 9 excess47#db7 ,! foll[+ s5sitiz+ solution gives also excell5t results3 ,ammonio-f]ric oxalate #aj p>ts ,ammonio-f]ric lactate #d p>ts ,wat] #ajj p>ts ,aft] exposure1 :i* v>ies f five to t5 m9utes1 accord+ to ! int5sity ( ! light & ! pr9t+ quality ( ! negatives1 ! picture appe>s negative f =mation ( f]r\s oxalate4 ,x may be develop$ 9 a great _m ways3 by a solution ( silv] nitrate at #b or #c p] c5t4 ( wat] acidifi$ slightly by an organic acid--citric acid1 = example--or a dilut$ solution ( ammonio-nitrate ( silv]1 :i* mo/ likely con/itutes ! be/ develop]2 ! image is black & consi/s ( metallic silv] & f]ric oxide1 ) =mation ( silv] oxalate1 :i* dissolve 9 ! ammonia4 ,if ! pr9t be treat$ by a weak solution ( aque\s ammonia1 ! image turns gre51 !n br[n1 & if1 be=e ! latt] coloration is obta9$1 gallic acid or pyrogallol be add$1 ! image becomes blui%-black or br[n-black4 ,9 ! same circum/ances tann9 7gallo-tann97 produces a blue-black image2 cate*u-tann97#dc7 & qu9o-tann9 give gre51 etc4 ,employ$ z a develop]1 potassium f]ricyanate develops an image 9 prussian blue1 & auric *loride "o 9 ! *>act]i/ic violet metallic gold4 ,to fix ! images obta9$ by ! latt] reactions1 x suffices to wa% !m 9 a few *anges ( wat]1 &1 if develop$ ) silv]1 !y c be ton$ by any ( ! alkal9e solutions ( auric *loride us$ 9 ! pr9t+ out silv] process1 etc4 ,! photographs obta9$ by all ^! processes are p]man5t4 ,,dr4 ,j4,b4 ,,ob]nett]',s ,,process 7#ahfc74 ,copp] *loride #ajj p>ts ,f]ric *loride1 sol4 sp4 #ac p>ts gr4 #a4e ,hydro*loric acid1 conc4 #ab p>ts ,c4 ,p4 ,wat] #a1jjj p>ts ,float ! pap] on ?is solution = ab\t two m9utes & hang x up to dry4 ,! keep+ quality ( ! prep>$ pap] is rem>kable2 x has be5 kept = two ye>s )\t app>5t *ange2 its s5sitiv5ess is at lea/ "o-?ird great] ?an t ( silv] album5 pap]4 ,unless develop$ )9 an h\r or two1 ! vigor ( ! pro( is mu* impair$2 aft] tw5ty-f\r h\rs a pr9t c be tak5 ov] on ! same4 ,:5 expos$1 only a fa9t image is visible4 ,x %\ld be fix$ 9 ! foll[+ solution3 ,potassium sulphocyanate #ab p>ts ,sulphuric acid1 conc4 #a "p ,s5sitiz+ solution #aj to #ab p>ts ,wat] #a1jjj p>ts ,a pr9t is float$ on ?is solution1 face d[nw>d1 = ?ree or f\r m9utes1 tak+ c>e to agitate ! liquid z little z possible2 ! pr9t is aft]w>ds imm]s$ & ano!r "o float$ 9 its place1 ?us proce$+ until all ! pr9ts are imm]s$ or ! solution c hold no m4 ,a fre% solution is !n add$ to /r5g!n x3 ! old] ! solution ! m rapidly & bett] x works4 ,9 ?is develop] copp] cyanide is precipitat$ on ! p>ts act$ on by light1 & ?is exactly 9 ! proportion to ! lum9\s action4 ,! "t ( imm]sion dep5ds on ! me?od select$ to f9i% ! pro(s2 x its f five m9utes to half an h\r4 ,if ! pro( is imm]s$ =1 say1 tw5ty-f\r h\rs1 ! image comes out 9 a relief :i* may br+ ! %ad[s to two l9es 9 dep?4 ,:5 well develop$ & ?or\ghly wa%$1 ! pro( c be dri$ & ! subsequ5t op]ations made at any conv5i5t "t4 ,v>i\s processes may be employ$ to give to ^! pro(s ! tone requir$2 ?us3 ! pr9ts well wa%$ are plac$ 9 a solution ( f]ricyanate ( potassium at #f to #ab p] #ajj ( wat]1 :]e !y take a r$ color increas+ 9 int5sity4 ,if left ov] night ! color becomes a spl5did velvet deep r$ ) p]fect cle> :ites4 ,to obta9 ! color ( silv] photographs "o h\r's imm]sion is suffici5t4 ,aft] ?is op]ation ! pro(s are wa%$ until ! wat] is no m t+$ yell[4 ,by imm]sion 9 ,f]r\s sulphate #ajj p>ts ,iron sesqui*loride #dj p>ts ,hydro*loric acid #hj p>ts ,wat] #bjj to #cjj p>ts ! pro(s und]go ! foll[+ gradation ( colors3 r$1 r$di% violet1 blue-violet1 black & gre5i% black4 ,z soon z ! desir$ color is obta9$1 ! pro(s are wa%$ 9 acidifi$ wat] & dri$4 ,! mo/ beautiful purple violet is obta9$ by leav+ ! pro(s 9 ! iron solution until gre5-black1 & !n wa%+ = a mom5t 9 a dilute solution ( sub-acetate ( lead4 ,a br[n-black may be produc$ by treatm5t1 aft] wa%+1 ) an ammoniacal solution ( hyp]manganate ( pota%4 ,a weak solution ( nitrate ( silv] also yields v f9e pictures1 b ! exposure %\ld be v %ort1 & ! pro(s mu/ be fix$ 9 wat] conta9+ a small quantity ( oxalate ( ammonia4 ,9 ord] to imp>t to ! pro(s ! gloss ( silv] photographs1 !y %\ld be album5iz$ 9 ! ord9>y mann]1 & ! album5 insolubiliz$ by well kn[n means4 ,! *emical actions 9 ?is process ,i expla9 9 ! foll[+ mann]3 ,on ! pap] !re are ,fe#b;,cl#c & ,cu,cl1 ! latt] 9 excess4 ,by ! action ( light1 & accord+ to ! transp>5cy ( ! negative1 ,fe#b;,cl#c is r$uc$ to ,fe,cl1 :ile ,cu,cl suff]s no alt]ation4 ,if ! pap] be imm$iately plac$ 9 an absolutely dry room aft] exposure1 ! picture rema9s un*ang$4 ,9 a moi/ atmosph]e ,fe,cl attracts moi/ure &1 ) a "p ( ,cu,cl1 is s decompos$ t ,fe#b;,cl#c is =m$ toge!r ) ,cu#b;,cl4 ,aft] ?is action has comm5c$1 if ! pro( be n imm$iately imm]s$ 9 a solution ( sulphocyanate ( potassium1 ,cu#b;,cl passes ov] to a high] comb9ation ( *lor9e1 & ! pap] is aga9 fit to be impress$ anew by ! action ( light4 ,z long z ,fe,cl or ev5 ,cu#b;,cl is pres5t1 if ! pr9t is imm]s$ 9 ! sulphocyanate solution1 sulphocyanate ( copp] is imm$iately =m$ on ! r$uc$ p>ts1 :ile on ! o!rs ! sulphocyanide ( copp]1 =m$ & dissolv$ by ! sulphocyanide ( potassium 9 excess1 becomes decom pos$ ) wat] 9 soluble sulphocyanide ( copp] & deposit$ z su* on ! p>ts already cov]$ ) ! salt4 ,frequ5tly ! pr9ts appe> yell[ f =mation ( ! d\ble sulphocyanide ( copp]1 b ! color disappe>s by wa%+ 9 wat]4 ,r$ coloration is due to decomposition into f]rocyanide ( copp]4 ,l4 ,,liesegang',s ,,process 7#ahfe74 ,p\r ammonia into a nitrate ( uranium solution1 wa% ! precipitate ( uranate ( ammonia 9 di/ill$ wat]1 !n dissolve 9 citric acid4 ,mix ?is solution ( citrate ( uranium & a little ( a solution ( *loride ( gold ) a pa/e prep>$ by dissolv+ tapioca 9 hot wat]4 ,! quantity ( *loride ( gold mu/ be small & ! heat n too great1 o!rwise ! gold w\ld be r$uc$4 ,spread ! mixture ) a sponge on ! pap]1 :i* takes a brilliant yell[ color1 & expose :5 q dry2 ! pro(s h ! delicacy & vigor ( album5 pr9ts4 ,! pro(s come f ! frame ) a blui%-black color2 !y %\ld n be ton$1 b m]ely fix$ by wa%+ until ! yell[ color ( ! pap] has disappe>$4 ,! color ( ! picture c be *ang$ to a purple by a solution ( *loride ( t94 ,,gu>bassi',s ,,process 7#ahfg74 ,! pap] is float$ 9 ! d>k = f\r or five m9utes on a saturat$ solution ( bi*romate ( pota%4 ,:5 dry1 x is pr9t$ a little long] ?an = silv] pr9ts & aft]w>ds float$1 face upw>ds1 on a wat] ba? until all ! unalt]$ bi*romate is dissolv$4 ,x is !n imm]s$ 9 ! foll[+ solution1 :i* improve by use & tones ! pictures to a r$di% color3 ,saturat$ solution #d p>ts nitrate ( m]cury1 z free f acid z possible ,saturat$ solution #a "p bi*romate ( pota% ,di/ill$ wat] #bh p>ts ,?is solution %\ld be prep>$1 filt]$ & all[$ to /& = "s "t be=e use4 ,! pr9t is left 9 ! ba? until x has assum$ an int5se r$ color1 ! :ites rema9+ p]fectly pure4 ,x is !n wa%$ & put 9 ano!r ba? to obta9 a br[ni% t9t4 ,?is ba? is ?us compos$3 ,conc4 aque\s ammonia #b p>ts ,di/ill$ wat] #ajj p>ts ,! pr9t mu/ be imm]s$ at once1 & :51 9 a %ort "t1 x has assum$ ! prop] color1 x %\ld be wa%$ imm$iately4 ,! picture is ton$ 9 a v dilut$ solution ( *loride ( gold1 #a3g1jjj1 9 :i* ! color passes f a light br[n to a deep black or a violet black tone1 :5 x is wa%$ 9 two *anges ( wat]4 ,a4 ,,poitev9',s ,,process 7#ahgj74 8,i use a pap] prep>$ ) iron sesquioxide r5d]$ s5sitive to light by t>t>ic or1 bett]1 citric acid 9 conc5trat$ solution4 ,?is pap]1 aft] desiccation & exposure to light1 possesses ! prop]ty ( r$uc+ ! solution ( silv] nitrate & t ( *loride ( gold1 & ( turn+ blue ) a solution ( potassium f]ncyanate 9 ! p>ts :]e light has r$uc$ ! iron sesqui*loride into ! oxide at ! m9imum40 8,to coat ! pap] ) an equal lay] ( iron sesqnioxide1 ,i bru% x ) a tuft ( f9e l95 dipp$ 9 a solution ( iron p]*loride at #aj or #ab p] c5t4 ( wat]1 & dry ! %eets 9 ! d>k4 ,i imm]se aft]w>ds ^! %eets1 "o aft] ! o!r1 9 a tray conta9+ aque\s ammonia1 9 su* a mann] z to well wet ea* %eet successively4 ,a suffici5t numb] ( %eets be+ imm]s$1 ,i p\r (f ! ammonia 9 a vial1 &1 9 ! tray1 ,i wa% !m sev]al times1 & remove !m "o by "o to hang !m up to dry1 ev5 9 full light1 ! iron sesquioxide n be+ s5sitive to light40 8,! pap] c be prep>$ 9 quantities be=eh&4 ,to use x ,i apply ^u ea* %eet a solution ( citric acid at #cj or #ce p] c5t4 ( wat]7#dd7--:i* may be done by daylight--& let !m dry 9 ! d>k40 8,expos$ "u a negative ( ! ord9>y int5sity1 ! pap] is impress$ 9 sun%9e 9 a few m9utes2 9 ! %ade x requires ab\t ! same "t z *loride ( silv] pap]40 8,aft] exposure ! image is n visible1 & )\t be+ oblig$ to %elt] x f light1 ,i imm]se ! pr9t 9 a solution conta9+ ab\t #a p] c5t4 ( silv] nitrate4 ,?is solution c be us$ ov] & ov] aga91 by add+ to x a little ( ! silv] salt4 ,x does n become turpid by use2 x simply turns slightly gre5 f =mation ( iron nitrate4 ,! image appe>s soon & rapidly becomes vigor\s2 9 half an h\r x w be completely develop$4 ,:5 ! exposure is suffici5t ! color is deep sepia1 b n s int5se if ! quantity ( citric acid is feeble4 ,no fix+ is necess>y2 x suffices to wa% 9 sev]al *anges ( wat]s40 8,! image c be ton$ ) great facility by a weak solution ( gold or ( plat9um *loride1 or1 bett]1 by a mixture ( ^! two salts4 ,if ! impress$ pap] be treat$ by a v dilut$ solution ( potassium f]rocyanate1 "o obta9s v pretty blue pro(s40 8,a weak solution ( gold *loride develops a violet image4 ,a solution ( plat9um *loride has no effect40 8,all ! v>i\s phases ( ?is pr9t+ me?od c be foll[$ 9 full 7diffus$7 light2 !re is only ! desiccation ( ! pap] :5 s5sitiz$ ) citric acid1 :i* requires to be done 9 ! d>k40