american hand book of the daguerreotype-第5部分

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eloped。　　After　taking　the　number　ordered；　he　proceeded　to　repack　his　apparatus；　and　to　his　surprise；　when　he　took　up　the　bottle　he　carried　the　mercury　in；　he　found　it　still　filled；　and　none　in　the　bath；　except　only　such　particles　as　had　adhered　to　the　sides；　after　dusting　and　being　jolted　for　several　miles　over　the　rough　road。　From　this　it　will　be　seen　that　a　very　little　mercury　will　suffice　to　develop　fine　proofs。　　I　saw　some　of　the　impressions　referred　to　above；　and　they　were　certainly　well　developed；　and　very　superior　specimens　of　our　art。

Removing　the　Coating。After　the　impression　has　been　developed　over　the　mercurial　vapor；　the　next　step　is　to　remove　the　sensitive　coating。　For　this　purpose　the　following　solution　is　used：

Put　about　two　ounces　of　hyposulphite　of　soda　in　a　pint　of　water；　which　should　always　be　filtered　before　using。　A　convenient　way　of　doing　this　is　to　have　two　bottles；　and　a　large　funnel　with　a　sponge　pressed　into　the　neck　of　it；　or；　what　is　better；　some　filtering　paper　folded　in　it。　The　solution　in　one　bottle；　the　funnel　is　placed　in　the　other；　and　the　picture　held　over　it；　when　the　solution　is　poured　on　the　plate；　it　runs　from　it　into　the　filter；　and　is　always　ready　for　use。

It　is　best　that　the　washing　be　done　immediately　on　the　plate　coming　from　the　mercury　bath。　　If　allowed　to　stand　long　with　the　coating　on；　it　assumes　a　very　dark　tintas　the　operation　of　the　light　continues；　though　less　active　than　while　exposed　in　the　camera；　and　destroys　that　brightness　which　would　otherwise　have　been　obtained。　It　is　preferable　to　wash　and　gild　a　picture　without　it　first　being　dried；　yet　when　there　are　doubts　of　its　giving　satisfaction；　there　would　sometimes　be　a　saving　by　drying　and　getting　the　decision　of　the　subject　before　gilding；　as　this　last　injures　the　plate　for　another　impression。　　First；　light　your　spirit…lamp；　then　with　your　plyers　take　the　plate　by　the　lower　right…hand　corner；　holding　it　in　such　a　manner　that　the　plyers　will　form　in　a　line　with　the　upper　left…hand　corner；　pour　on；　slowly；　the　hyposulphite　solution；　slightly　agitating　the　plate；　until　all　the　coating　is　dissolved　off；　then　rinse　off　with　clean　water；　and　if　it　is　not　to　be　gilded；　dry　by　holding　the　plate　perpendicular　with　the　bottom　left…hand　corner　lowest；　and　applying　the　blaze　of　the　spirit…lamp　to　the　back；　at　the　same　time　blowing　gently　downward　on　the　face　of　the　plate。

The　hyposulphite　solution　should　be　often　filtered　through　a　sponge；　and　it　will　answer　for　a　great　number　of　washings。　　Yet　it　is　observed　that　the　mercury　collects　in　this　solution　in　small　globules；　these　often　come　in　contact　with　the　plate；　causing　white　spots；　which　spoil　the　impression。　They　should　be　guarded　against；　and　the　solution　renewed。　　Again；　in　order　to　prevent　streaks　or　scum　on　the　surface　of　the　plate；　it　is　necessary　that　the　coating　should　be　removed　with　a　good　degree　of　uniformity。　I　find　in　practice　that　the　hyposulphite　of　soda　in　our　market　varies　much　as　regards　strength；　and　consequently　the　rule　to　be　adopted　is　to　make　a　solution　of　sufficient　strength　to　remove　the　coating　in　about　ten　seconds。　I　am　aware　that　it　may　be　said　that　this　strong　solution　would　have　a　tendency　to　injure　the　impression　by　destroying　in　a　measure　the　sharpness　of　outline。　To　meet　this；　it　need　only　to　be　said　that　the　preventive　is；　to　not　let　the　solution　rest　on　the　surface　of　the　plate　for　a　longer　time　than　is　absolutely　necessary；　and　then　it　should　be　drenched　copiously　with　water；　hence　a　chemical　action　upon　the　image　is　prevented　and　the　general　operation　facilitated。　　This　plan　is　adopted　by　our　first　operators　with　the　greatest　success。

If　the　operator　should　allow　the　hyposulphite　solution　to　run　over　the　plate　unevenly；　it　is　quite　likely　that　white　or　blue　streaks　would　result。　　These　it　is　impossible　to　remove　without　injury　to　the　impression。　　Some；　in　order　to　prevent　this；　breathe　over　the　surface；　thus　moistening　it　and　putting　it　in　a　condition　to　receive　the　solution　with　greater　uniformity。　The　plate　should　be　well　washed　with　water　before　gilding。

Gilding；　or　Fixing　the　Image。The　next　process　to　be　given　is　that　for　fixing　the　image　on　the　plate。　　This　is　done　by　precipitating　a　thin　film　of　gold　over　the　surface　and　is　productive　of　the　most　brilliant　effect　when　prepared　immediately　after　the　plate　has　been　washed　with　water　after　the　application　of　the　hyposulphite　solution；　and　before　the　plate　has　been　allowed　to　dry。　When；　however；　the　plate　has　been　dried　and　allowed　to　stand　for　any　time；　before　gilding；　the　hyposulphite　wash　should　be　applied　as　at　first；　in　order　to　destroy　any　chemical　coating　that　may　have　been　formed　on　exposure　of　the　plate　to　the　air。　　For　gilding　the　larger　plates；　we　have　a　gilding　stand　so　constructed　that　the　plate　can　be　put　on　a　perfect　level。　In　practice；　I　prefer　holding　the　plate　with　nippers；　fastened　at　one　corner。　Hold　the　plate　in　the　same　manner　as　in　removing　the　coating；　pour　on　the　gilding；　newly　filtered；　until　the　surface　is　wholly　covered；　and　with　the　blaze　of　the　spirit　lamp；　at　least　three　inches　high；　apply　it　to　the　back　of　the　plate；　moving　it　about；　that　the　surface　may　be　heated　with　as　much　uniformity　as　possible。　　Continuing　this　operation；　the　surface　will　generally　become　covered　with　small　yellow　bubbles　which　soon　disappear；　leaving　the　image　clear　and　distinct。

It　is　advisable　to　make　use　of　a　lamp　having　a　sufficiently　strong　flame　to　produce　the　effect　in　a　few　minutes。　If　after　a　first　heating；　it　is　found　that　the　impression　can　admit　of　a　greater　degree　of　intensity；　it　might　be　heated　anew；　but　that　is　seldom　necessary；　and　often　by　trying　to　do　too；　well；　the　operator；　if　he　persists　in　heating　certain　parts　of　the　plate；　may　find　the　liquid　dry　up　just　above　the　flame；　and　inevitably　cause　a　stain*；　or　else　the　blacks　are　covered　with　a　film；　or　even　the　coating　of　gold　may　suddenly　exfoliate；　when　small　particles　are　detached　from　the　plate。　The　impression　is　then　entirely　spoiled；　but　the　plate　may　be　re…polished。

*　This　can　be　remedied；　however；　if　it　is　immediately　washed　over　with　the　same　solution　that　is　on　the　plate；　so　that　the　surface　shall　not　become　cool；　continue　for　a　short　time　to　apply　the　lamp　under；　and　agitate　the　plate　slightly；　and　it　will　soon　be　free　from　all　imperfections　and　give　a　fine　clear　tone。

It　is　not　unfrequent　that　the　surface　assumes　a　dark；　cloudy　appearance。　This　is　generally　the　best　sign　that　the　gilding　will　bring　out　the　impression　with　the　greatest　degree　of　distinctness。　Soon；　the　clouds　gradually　begin　to　disappear；　and；　〃like　a　thing　of　life〃　stands　forth　the　image；　clothed　with　all　the　brilliancy　and　clearness　that　the　combined　efforts　of　nature　and　art　can　produce。　When　in　the　operator's　judgment　the　operation　has　arrived　at　the　highest　state　of　perfection；　rinse　suddenly；　with　an　abundance　of　clean　water；　and　dry　as　before　described。

When　an　impression　is　dark；　the　gilding　process　may　be　longer　continued；　but　when　light；　it　should　be　gilded　quickly；　as　lengthening　the　time　tends　to　bleach　the　impression　and　make　it　too　white。　The　cause　of　this　appears　to　be；　that　with　a　moderate　heat　the　chlorine　is　merely　set　free　from　the　gold；　and　remaining　in　the　solution；　instead　of　being　driven　off；　with　its　powerful　bleaching；　properties；　it　immediately　acts　upon　the　shades　of　the　picture。　　A　dark　impression　can　thus；　by　a　low　heat；　long…continued；　be　made　quite　light。　To　procure　the　best　effect；　then；　heat　suddenly　with　a　large　blaze；　and　judging　it　to　be　at　the　maximum；　cool　as　suddenly　as　possible。

When　the　hyposulphite　of　gold　is　used　instead　of　the　chloride；　a　less　heat　should　be　employed。

Coloring　Daguerreotypes。Of　all　the　so…called　improvements　in　the　Daguerreotype；　the　coloring　is　the　least　worthy　of　notice。　Yet　the　operator　is　often；　in　fact　most　generally；　called　upon　to　hide　an　excellent　specimen　under　paint。　I　can　conceive　of　nothing　more　perfect　in　a　Daguerreotype　than　a　finely…developed　image；　with　clearness　of　lights　and　shadows；　possessing　the　lively　tone　resulting　from　good　gilding。　Such　pictures；　however；　are　not　always　had；　and　then　color　may　perform　the　part　of　hiding　the　imperfections。　We　present　the　following　method　as　given　in　Willat's　Manual：

〃Daguerreotype　portraits　are　now　commonly　met　with　beautifully　colored；　but　the　coloring　is　a　process　requiring　great　care　and　judgment；　and　many　good　pictures　are　spoiled　in　fruitless　experiments。　Several　different　methods　of　coloring　have　been　proposed。　The　simplest　mode　appears　to　be　that　of　using　dry　colors　prepared　in　the　following　manner：　　A　little　of　the　color　required；　very　finely　ground；　is　thrown　into　a　glass　containing　water；　in　which　a　few　grains　of　gum　arabic　have　been　dissolved。　After　standing　a　few　moments；　the　mixture　may　be　passed　through　bibulous　paper；　and　the　residue　perfectly　dried　for　use。　The　principal　colors　used　are　Carmine；　Chrome　Yellow；　Burnt　Sienna；　Ultramarine　and　White；　boxes　fitted　with　sets　of　colors　properly　prepared；　may　be　obtained　of　the　dealers；　and　include　Carmine；　White；　Lilac；　Sky　Blue；　Pink；　Yellow；　Flesh　color；　Orange；　Brown；　Purple；　Light　Green；　Dark　Green　and　Blue。　　With　a　few　colors；　however；　all　the　rest　may　be　made　thus：　　Orange；　by　Yellow　and　Red；　Purple；　with　Blue　and　Red；　Green；　Blue　and　Yellow；　Brown；　with　Umber；　Carmine　and　Lamp　Black；　Scarlet；　Carmine　and　Light　Red。　While　it　is　true　that　a　little　color　may　relieve　the　dark　metallic　look　of　some　Daguerreotypes；　it　must　not　be　concealed　that　the　covering　of　the　fine　delicate　outline　and　exquisite　gradations　of　tone　of　a　good　picture　with　such　a　coating；　is　barbarous　and　unartistic。

〃The　prevaling　taste　is；　however；　decidedly　for　colored　proofs；　and　the　following　directions　will　assist　the　amateur　in　ministering　to　this　perverted　taste；　should　he　be　so　inclined。　The　coloring　should　commence　with　the　face；　and　the　flesh　tint　must　be　stippled　on　（not　rubbed）　with　a　small　camel's…hair　brush；　beginning　from　the　centre　of　the　cheek；　taking　great　care　not　to　go　over　the　outline　of　the　face；　and　also　not　to　have　too　much　color　in　the　brush；　the　eyes　and　eyebrows　must　not　be　touched　with　color。　　After　the　flesh　color　is　applied；　take　a　piece　of　ve