第4章

类别:其他 作者:Johann Christoph Friedrich von字数:21268更新时间:19/01/03 14:38:45
Somepagesofletter-pressaretakenprintedononesideonly;andwaxed,torenderthemmoretransparent;thelettersarethencutoutandsorted。 Tocomposeanewpagelinesareruledonasheetofwhitepaper,andthewordsareformedbyfixingtheseperatelettersintheirproperorder。 Thepagebeingready,anegativephotographisproducedfromit,fromwhichtherequisitenumberofpositivephotogeniccopiesmaybeobtained。 Anothermethod,whichrequirestheuseofthecamera,consistsinemployinglargeletterspaintedonrectangularpiecesofwood,coloredwhite。Thesearearrangedinlinesonatabletorboard,byslippingthemintogrooveswhichkeepthemsteadyandupright,thusformingapageonanenlargedscale。 Itisnowplacedbeforeacamera,andareducedimageofitoftherequiredsizeisthrownuponthesensitivepaper。 Theadjustmentsmustbekeptinvariable,sothattheconsecutivepagesmaynotvaryfromoneanotherinthesizeofthetype。 Mr。Talbothaspatentedhisprocess,butwhatbenefitheexpectstoderivefromit,Iamatalosstodetermine。 EnlargedcopiesofcalotypeorDaguerreotypeportraitsmaybeobtainedbythrowingmagnifiedimagesofthem,bymeansoflenses,uponcalotypepaper。 THECHRYSOTYPE。 AmodificationofMr。Talbot’sprocess,towhichthenameofChrysotypewasgivenbyitsdiscoverer,SirJohnHerschel,wascommunicatedinJune1843totheRoyalSociety,bythatdistinguishedphilosopher。 Thismodificationwouldappeartounitethesimplicityofphotographywithallthedistintnessandclearnessofcalotype。 Thispreparationisasfollows。 Thepaperistobewashedinasolutionofammonio-citrateofiron; itmustthenbedried,andsubsequentlybrushedoverwithasolutionoftheferro-sesquicyanuretofpotassium。Thispaper,whendriedinaperfectlydarkroom,isreadyforuseinthesamemannerasifotherwiseprepared,theimagebeingsubsequentlybroughtoutbyanyneutralsolutionofgold。 Suchwasthefirstdeclarationofhisdiscovery,buthehassincefoundthataneutralsolutionofsilverisequallyusefulinbringingoutthepicture。 Photographicpicturestakenonthispaperaredistinguishedbyaclearnessofoutlineforeigntoallothermethods。 CHAP。X。 CYANOTYPE——ENERGIATYPE——CHROMATYPE——ANTHOTYPE——AMPHITYPE AND\"CRAYONDAGUERREOTYPE。\" Theseveralprocessesenumeratedattheheadofthischapter,arealldiscoveriesofEnglishphilosophers,withtheexceptionofthethirdandlastnamed。AnthotypewasfirstattemptedbyM。PontonaFrenchsavan,althoughitwasreservedtoMr。Hunttobringtheprocesstoitspresentstate。 The\"CrayonDaguerreotype\"isanimprovementmadebyJ。AWhipple,Esq。,ofBostonI。CYANOTYPE; Socalledfromthecircumstanceofcyanogeninitscombinationswithironperformingaleadingpartintheprocess。 ItwasdiscoveredbySirJohnHerschel。Theprocessisasimpleone,andtheresultingpicturesareblue。 Brushthepaperoverwithasolutionoftheammonio-citrateofiron。 Thissolutionshouldbesufficientlystrongtoresemblesherrywineincolor。 Exposethepaperintheusualway,andpassoveritverysparinglyandevenlyawashofthecommonyellowferro-cyanateofpotass。 Assoonastheliquidisapplied,thenegativepicturevanishes,andisreplacedbyapositiveone,ofavioletbluecolor,onagreenishyellowground,whichatacertaintimepossessesahighdegreeofsharpness,andsingularbeautyoftint。 AcuriousprocesswasdiscoveredbySirJohnHerschel,bywhichdormantpicturesareproducedcapableofdevelopementbythebreath,orbykeepinginamoistatmosphere。 Itisasfollows。 Ifnitrateofsilver,specificgravity1。200beaddedtoferro-tartaricacid,specificgravity1。023,aprecipitatefalls,whichisinagreatmeasureredissolvedbyagentleheat,leavingablacksediment,which,beingclearedbysubsidence,aliquidofapaleyellowcolorisobtained,inwhichthefurtheradditionofthenitratecausesnoturbidness。 Whenthetotalquantityofthenitratedsolutionaddedamountstoabouthalfthebulkoftheferro-tartaricacid,itisenough。 Theliquidsoprepareddoesnotalterifkeptinthedark。 Spreadonpaper,andexposedwettothesunshine(partlyshaded) forafewseconds,noimpressionseemstobemade,butbydegrees,althoughwithdrawnfromtheactionoflight,itdevelopesitselfspontaneously,andatlengthbecomesveryintense。 Butifthepaperbethoroughlydriedinthedark,(inwhichstateitisofaverypalegreenishyellowcolor,) itpossessesthesingularpropertyofreceivingadormantorinvisiblepicture,toproducewhichfromthirtytosixtyseconds’ exposuretosunshineisrequisite。Itshouldnotbeexposedtoolong,asnotonlyistheultimateeffectlessstriking,butapicturebeginstobevisiblyproduced,whichdarkensspontaneouslyafteritiswithdrawn。Butiftheexposurebediscontinuedbeforethiseffectcomeson,aninvisibleimpressionistheresult,todevelopewhichallthatisnecessaryistobreatheuponit,whenitimmediatelyappears,andveryspeedilyacquiresanextraordinaryintensityandsharpness,asifbymagic。 Insteadofthebreath,itmaybesubjecttotheregularactionofaqueousvapor,bylayingitinablottingpaperbook,ofwhichsomeoftheouterleavesonbothsideshavebeendampened,orbyholdingoverwarmwater。 II。ENERGIATYPE。 UnderthistitleaprocesshasbeenbroughtforwardbyMr。Hunt。 Itconsistsoftheapplicationofasolutionofsuccinicacidtopaper,whichissubsequentlywashedoverwithnitrateofsilver。 Theimageisthentobetakeneitherinthecameraorotherwise,asrequired,andisbroughtoutbytheapplicationofthesulphateofironinsolution。Althoughthisprocesshasnotcomeintogeneraluse,itsexactdescriptionmaybeinterestingtothegeneralreader,andwethereforesubjoinit。 Thesolutionwithwhichthepaperisfirstwashedistobepreparedasfollows:succinicacid,twodrachms;commonsalt,fivegrains; mucilageofgumarabic,halfafluiddrachm;distilledwater,onefluiddrachmandahalf。Whenthepaperisnearlydry,itistobebrushedoverwithasolutionofnitrateofsilver,containingadrachmofthesalt,toanounceofdistilledwater。 Itisnowreadyforexposureinthecamera。Tobringoutthedormantpictureitisnecessarytowashitwithamixtureofadrachmofconcentratedsolutionofthegreensulphateofironandtwodrachmsandahalfofmucilageofgumarabic。 Subsequently,however,ithasbeenfoundthatthesulphateofironproducesuponallthesaltsofsilvereffectsquiteasbeautifulasinthesuccinate。Ontheiodide,bromide,acetate,andbenzoate,theeffectsarefarmorepleasingandstriking。Whenpicturesareproduced,orthedormantcameraimagebroughtout,bytheagencyofsulphateofiron,itisremarkablehowrapidlytheeffecttakesplace。 Engravingscanbethuscopiedalmostinstantaneously,andcameraviewsobtainedinoneortwominutesonalmostanypreparationofsilver。 Thecommonsulphateofcoppersolutionhasthesameproperty。 III。CHROMATYPE。 Manyeffortshavebeenmadetorenderchromaticacidanactiveagentintheproductionofphotographs。M。Pontonusedapapersaturatedwithbichromateofpotash,andthiswasoneoftheearliestphotogenicprocesses。 M。Becquerelimproveduponthisprocessbysizingthepaperwithstarchprevioustotheapplicationofthebichromateofpotashsolution,whichenabledhimtoconvertthenegativepictureintoapositiveone,bytheuseofasolutionofiodine,whichcombinedwiththatportionofthestarchonwhichthelighthadnotacted。Butbyneitheroftheseprocessescouldclearanddistinctpicturesbeformed。 Mr。Hunthas,however,discoveredaprocesswhichissoexceedinglysimple,andtheresultingpicturesofsopleasingacharacter,that,althoughitisnotsufficientlysensitiveforuseinthecamera,itwillbefoundofthegreatestvalueforcopyingbotanicalspecimens,engravings,orthelike。 Thepapertobepreparediswashedoverwithasolutionofsulphateofcopper——aboutonedrachmtoanounceofwater——andpartiallydried; itisthenwashedwithamoderatelystrongsolutionofbichromateofpotash,anddriedatalittledistancefromthefire。 Paperthuspreparedmaybekeptanylengthoftime,inaportfolio,andarealwaysreadyforuse。 Whenexposedtothesunshineforatime,varyingwiththeintensityofthelight,fromfivetofifteenortwentyminutes,theresultisgenerallyanegativepicture。 Itisnowtobewashedoverwithasolutionofnitrateofsilver,whichimmediatelyproducesaverybeautifuldeeporangepictureuponalightdimcolored,orsometimesperfectlywhiteground。 Thispicturemustbequicklyfixed,bybeingwashedinpurewater,anddried。Withregardtothestrengthofthesolutions,itisaremarkablefact,that,ifsaturatedsolutionsbeemployed,anegativepictureisfirstproduced,butifthesolutionsbethreeorfourtimestheirbulkofwater,thefirstactionofthesun’sraysdarkensthepicture,andthenaverybleachingeffectfollows,givinganexceedinglyfaintpositivepicture,whichisbroughtoutwithgreatdelicacybythesilversolution。 Itisnecessarythatpurewatershouldbeusedforthefixing,asthepresenceofanymuriatedamagesthepicture,andherearisesanotherpleasingvariationoftheChromatype。 Ifthepositivepicturebeplacedinaveryweaksolutionofcommonsalttheimageslowlyfadesout,leavingafaintnegativeoutline。Ifitnowberemovedfromthesalinesolution,dried,andagainexposedtosunshine,apositivepictureofalilaccolorwillbeproducedbyafewminutesexposure。 Severalotherofthechromatesmaybeusedinthisprocess,butnoneissosuccessfulasthechromateofcopper。 IV。ANTHOTYPE。 Theexpressedjuice,alcholic,orwateryinfusionofflowers,orvegetablesubstances,maybemadethemediaofphotogenicaction。 ThisfactwasfirstdiscoveredbySirJohnHerschel。 Wehavealreadygivenafewexamplesofthisinthethirdchapter。 Certainprecautionsarenecessaryinextractingthecoloringmatterofflowers。Thepetalsoffreshflowersarecarefullyselected,andcrushedtoapulpinamarblemortar,eitheraloneorwiththeadditionofalittlealcohol,andthejuiceexpressedbysqueezingthepulpinacleanlinenorcottoncloth。 Itisthentobespreaduponpaperwithaflatbrush,anddriedintheairwithoutartificialheat。Ifalcoholbenotadded,theapplicationonpapermustbeperformedimmediately,astheair(eveninafewminutes),irrecoverablychangesordestroystheircolor。 Ifalcoholbepresentthischangeismuchretarded,andinsomecasesisentirelyprevented。 Mostflowersgiveouttheircoloringmattertoalcoholorwater。 Some,however,refusetodoso,andrequiretheadditionofalkalies,othersofacid,&c。Alcoholhas,however,beenfoundtoenfeeble,andinmanycasestodischargealtogetherthesecolors;buttheyare,inmostcases,restoredupondrying,whenspreadoverpaper。 Paperstingedwithvetegablecolorsmustalwaysbekeptinthedark,andperfectlydry。 Thecolorofaflowerisbynomeansalways,orusually,thatwhichitsexpressedjuiceimpartstowhitepaper。 SirJohnHerschelattributesthesechangestotheescapeofcarbonicacidinsomecases;toachemicalalteration,dependingupontheabsorptionofoxygen,inothers;andagaininothers,especiallywheretheexpressedjuicecoagulatesonstanding,toalossofvitality,ordisorganizationofthemolecules。 Tosecureanevenessoftintonpaper,thefollowingmanipulationisrecommended:——Thepapershouldbemoistenedonthebackbyspongingandblottingoff。Itshouldthenbepinnedonaboard,themoistsidedownwards,sothattwoofitsedges(supposetheright-handandlowerones)shallprojectalittlebeyondthoseoftheboard。Theboardthenbeinginclinedtwentyorthirtydegreestothehorizon,thealcoholictincture(mixedwithaverylittlewater,ifthepetalsthemselvesbenotveryjuicy)istobeappliedwithabrushinstrokesfromlefttoright,takingcarenottogoovertheedgeswhichrestontheboard;buttopassclearlyoverthosethatproject; andobservingalsotocarrythetintfrombelowupwardsbyquicksweepingstrokes,leavingnodryspacesbetweenthem,butkeepingupacontinuityofwetspaces。Whenalliswet,crossthembyanothersetofstrokesfromabovedownwards,somanagingthebrushastoleavenofloatingliquidonthepaper。 Itmustthenbedriedasquicklyaspossibleoverastove,orinawarmcurrentofair,avoiding,however,suchheatasmayinjurethetint。 Inadditiontotheflowersalreadymentionedinmythirdchapter,thefollowingareamongthoseexperimenteduponandfoundtogivetolerablegoodphotographicsensitives。Icanonlyenumeratethem,referringthestudent,foranyfurtherinformationhemaydesireonthesubject,toMr。Hunt’swork;althoughwhatIhavesaidaboveissufficientforallpracticalpurposes;andanyone,withtheambition,canreadilyexperimentuponthem,withoutfurtherresearch,onanyotherflowerhemaychoose。 ViolaOdorata——orsweetsentedviolet,yieldstoalcoholarichbluecolor,whichitimpartsinhighperfectiontopaperSenecioSplendens——ordoublepurplegroundsel,yieldsabeautifulcolortopaper。 Theleavesofthelaurel,commoncabbage,andthegrasses,arefoundsufficientlysenstive。 CommonMerrigoldyieldsaninvaluablefaecula,whichappearsidenticalwiththatproducedbytheWall-flower,andCochorusjaponicamentionedbefore,andisverysensitive,butphotographsprocureduponitcannotbepreserved,thecolorissofugitive。 FromanexaminationoftheresearchesofSirJohnHerschelonthecoloringmatterofplants,itwillbeseenthattheactionofthesun’sraysistodestroythecolor,effectingasortofchromaticanalysis,inwhichtwodistinctelementsofcolorareseparated,bydestroyingtheoneandleavingtheotheroutstanding。 Theactionisconfinedwithinthevisiblespectrum,andthusabroaddistinctionisexhibitedbetweentheactionofthesun’sraysonvegetablejuicesandonargentinecompounds,thelatterbeingmostsensiblyaffectedbytheinvisibleraysbeyondtheviolet。 Itmayalsobeobserved,thattherayseffectiveindestroyingagiventint,areinagreatmanycases,thosewhoseunionproducesacolorcomplementarytothetintdestroyed,or,atleast,onebelongingtothatclassofcolorstowhichsuchcomplementarytintmaybepreferred。 Forinstance,yellowstendingtowardsorangearedestroyedwithmoreenergybythebluerays;bluesbythered,orangeandyellowrays; purplesandpinksbyyellowandgreenrays。 V。AMPHITYPE。 ThisprocessisadiscoveryofSirJohnHerschelandreceivesitsnamefromthefactthatbothnegativeandpositivephotographscanbeproducedbyoneprocess。Thepositivepicturesobtainedbyithaveaperfectresemblancetoimpressionsofengravingswithcommonprinter’sink。 Theprocess,althoughnotyetfullycarriedout,promisestobeofvastutility。 Paperproperforproducinganamphitypepicturemaybepreparedeitherwiththeferro-tartrateortheferro-citrateoftheprotoxide,ortheperoxideofmercury,oroftheprotoxideoflead,byusingcreamsofthesesalts,orbysuccessiveapplicationsofthenitratesoftherespectiveoxides,singlyorinmixture,tothepaper,alternatingwithsolutionsoftheammonia-tartrateortheammonia-citrateofiron,thelattersolutionbeinglastapplied,andinmoreorlessexcess。Ipurposelyavoidstatingproportions,asIhavenotyetbeenabletofixuponanywhichcertainlysucceed。 Papersopreparedanddriedtakesanegativepicture,inatimevaryingfromhalfanhourtofiveorsixhours,accordingtotheintensityofthelight;andtheimpressionproducedvariesinapparentforcefromafaintandhardlyperceptiblepicturetooneofthehighestconceivablefulnessandrichnessbothoftintanddetail,thecolorbeinginthiscaseasuperbvelvetybrown。 Thisextremerichnessofeffectisnotproducedunlessleadbepresent,eitherintheingredientsused,orinthepaperitself。 Itisnot,asIoriginallysupposed,duetothepresenceoffreetartaricacid。Thepicturesinthisstatearenotpermanent。 Theyfadeinthedark,thoughwithverydifferentdegreesofrapidity,some(especiallyiffreetartaricorcitricacidbepresent)inafewdays,whileothersremainforweeksunimpaired,andrequirewholeyearsfortheirtotalobliteration。 Butthoughentirelyfadedoutinappearance,thepictureisonlyrendereddormant,andmayberestored,changingitscharacterfromnegativetopositive,anditscolorsfrombrowntoblack,(intheshadows),bythefollowingprocess:——Abathbeingpreparedbypouringasmallquantityofsolutionofpernitrateofmercuryintoalargequantityofwater,andlettingthesubnitratedprecipitatessubside,thepicturemaybeimmersedinit,(carefullyandrepeatedlyclearingoffallairbubbles,) andallowedtoremaintillthepicture(ifanywherevisible,) isentirelydestroyed;oriffaded,tillitisjudgedsufficientfrompreviousexperience;atermwhichisoftenmarkedbytheappearanceofafeeblepositivepicture,ofabrightyellowhue,onthepaleyellowgroundofthepaper。Alongtime(severalweeks) isoftenrequiredforthis,butheatacceleratestheaction,anditisoftencompletedinafewhours。Inthisstatethepictureistobeverythoroughlyrinsedandsoakedinpurewarmwater,andthendried。Itisthentobewellironedwithasmoothiron,heatedsoasbarelynottoinjurethepaper,placingit,forgreatersecurityagainstscorching,betweencleansmoothpaper。 Ifthentheprocesshavebeensuccessful,aperfectlyblackpositivepictureisatoncedeveloped。Atfirstitmostcommonlyhappensthatthewholepictureissootyordingytosuchadegreethatitiscondemnedasspoiled,butonkeepingitbetweentheleavesofabook,especiallyinamoistatmosphere,byextremelyslowdegreesthisdinginessdisappears,andthepicturedisengagesitselfwithcontinuallyincreasingsharpnessandclearness,andacquirestheexacteffectofacopper-plateengravingonapapermoreorlesstintedwithapaleyellow。 Ioughttoobserve,thatthebestandmostuniformspecimenswhichI haveprocuredhavebeenonpaperpreviouslywashedwithcertainpreparationsofuricacid,whichisaveryremarkableandpowerfulphotographicelement。Theintensityoftheoriginalnegativepictureisnocriterionofwhatmaybeexpectedinthepositive。 Itisfromtheproductionbyoneandthesameactionoflight,ofeitherapositiveornegativepictureaccordingtothesubsequentmanipulations,thatIhavedesignatedtheprocess,thusgenerallysketchedout,bythetermAmphitype,——anamesuggestedbyMr。Talbot,towhomIcommunicatedthissingularresult; andtothisprocessorclassofprocesses(whichIcannotdoubtwhenpursuedwillleadtosomeverybeautifulresults,) Iproposetorestrictthenameinquestion,thoughitappliesevenmoreappropriatelytothefollowingexceedinglycuriousandremarkableone,inwhichsilverisconcerned: AtthelastmeetingIannouncedamodeofproducing,bymeansofasolutionofsilver,inconjunctionwithferro-tartaricacid,adormantpicturebroughtintoaforciblenegativeimpressionbythebreathormoistair。(SeeCyanotype。)Thesolutionthendescribed,andwhichhadatthattimebeenpreparedsomeweeks,Imayhereincidentallyremark,hasretaineditslimpidityandphotogenicproperties,quiteunimpairedduringthewholeyearsinceelapsed,andisnowassensitiveasever,—— apropertyofnosmallvalue。Now,whenapicture(forexampleanimpressionfromanengraving)istakenonpaperwashedwiththissolution,itshowsnosignofapictureonitsback,whetherthatonitsfaceisdevelopedornot;butif,whiletheactinicinfluenceisstillfreshupontheface,(i。e。,assoonasitisremovedfromthelight),thebackbeexposedforaveryfewsecondstothesunshine,andthenremovedtoagloomyplace,apositivepicture,theexactcomplementofthenegativeoneontheotherside,thoughwantingofcourseinsharpnessifthepaperbethick,slowlyandgraduallymakesitsappearancethere,andinhalfanhouroranhouracquiresaconsiderableintensity。 Ioughttomentionthatthe\"ferro-tartaricacid\" inquestionispreparedbyprecipitatingtheferro-tartrateofammonia(ammonia-tartrateofiron)byacetateoflead,anddecomposingtheprecipitatebydilutesulphuricacid。 WhenleadisusedinthepreparationofAmphitypepaper,thepartsuponwhichthelighthasactedarefoundtobeinaveryhighdegreerenderedwaterproof。——SirJ。Herschel。 Thisprocessisanewinventionofourcountryman,J。A。Whipple,Esq。,ofBoston,andhasbeenpatentedbyM。A。Root,Esq。,ofPhiladelphia。 Itwillbeseen,however,fromthepreviouspagesofmyworkthatMr。Rootismistakeninregardtohisbeingthefirstimprovementpatentedinthiscountry,althonghitisunquestionablythefirstbyanAmerican。 OfthisimprovementMr。Rootsays: VI。\"CRAYONDAGUERREOTYPE。\" \"Theimprovementtowhichyoureferisdenominated\"TheCrayonDaguerreotype。\"ThisinventionmadebyMr。J。A。Whipple,istheonlyimprovementinDaguerreotyping,Ibelieve,forwhichLettersPatentfortheUnitedStateswereeverissued。 Thepicturesproducedbythisprocess——whichisofthesimplestdescriptionimaginable——havetheappearanceandeffectofveryfine\"CrayonDrawings,\"fromwhichtheimprovementtakesitsname。 Someofourmostdistinguishedartistshavegivenittheirunqualifiedadmiration。Amongthem,ourMezzotintoEngravers,especiallyJohnSartain,Esq。,who,fromhisrichembellishmentstomostoftheleadingMagazinesandAnnualsofthecountry,aswellasfromthecelebrityofthesuperbMagazinewhichbearshisname,issowellknownandsowellqualifiedtojudgeofitsmerits。Asanauxiliarytotheartist,infurnishingheadstotheMagazines,orotherworks,itisinvaluable; thegreatobjectwhichitaccomplishesbeingtogiveafinereffectandmoredistinctexpressiontoallthefeatures—— thewholepoweroftheinstrumentbeingdirectedto,andconfinedtothehead。\" \"Thelatehouratwhichthissubjecthasbeenbroughttoournoticepreventssofulladescriptionaswewouldotherwisehavebeengladtofurnish。TheNewEnglandStateshavebeendisposedof; negotiationsforanyoftheotherscanbemadethroughM。A。Root,140Chestnutstreet,Philadelphia。\" \"Aseriesofbeautifulportraitsareaboutbeingpreparedbythe\"CraytonProcess\"fortheexpresspurposeofbeingplacedontheexhibitionatthe\"ArtUnion,\"whenamateurs,artists,andthepublicgenerallywillhaveanopportunityofwitnessingitseffect。 Weareespeciallygratifiedwiththisstrikingimprovement,fromtheadvantageswhichitpromisestotheDaguerreanart。\" \"Itisadmirablydesignedtoexciteanewinterestonthesubjectthroughthecommunity,andinthisway——andfromitstendencytorendertheartmoregenerallyuseful,andtoelevateanddistinguishit—— tomakeittoallamatterofmoregeneralimportance。\" \"Yoursrespectfully,\"M。A。ROOT。\" Inoursecondedition,wehope——withMr。Root’spermission—— tolaythewholeprocessbeforethepublic,althoughourartistsmustbearinmindthatMr。Root’spatentsecurestohimtheexclusiverightofitsapplication。 CHAP。XI。 ONTHEPROBABILITYOFPRODUCINGCOLOREDPICTURESBYTHESOLARRADIATIONS—— PHOTOGRAPHICDEVIATIONS——LUNARPICTURES——DRUMMONDLIGHT。 HavingbeforenoticedthefactthatsomeadvanceshadbeenmadetowardstakingDaguerreotypesincolor,bymeansofsolarrays,andexpressedthehopethatthedaywasnotfardistantwhenthismightbeaccomplished,IheresubjoinMr。Hunt’sremarksonthissubject。 Mr。Biot,in1840,speakingofMr。FoxTalbot’sbeautifulcalotypepictures,considersasanillusion\"thehopetoreconcile,notonlytheintensitybutthetintsofthechemicalimpressionsproducedbyradiations,withthecolorsoftheobjectfromwhichtheseradiationsemanated。\" Itistruethatthreeyearshavepassedaway,andwehavenotyetproducedcoloredimages;yetIamnotinclinedtoconsiderthehopeasentirelyillusive。 Itmustberememberedthatthecolorofbodiesdependsentirelyuponthearrangementoftheirmolecules。 Wehavenumerousverybeautifulexperimentsinproofofthis。 Thebi-niodideofmercuryisafinescarletwhenprecipitated。 Ifthisprecipitateisheatedbetweenplatesofglass,itisconvertedintocrystalsofafinesulphuryellow,whichremainofthatcolorifundisturbed,butwhichbecomesveryspeedilyscarletiftouchedwithanypointedinstrument。 ThisverycuriousopticalphenomenahasbeeninvestigatedbyMr。TalbotandbyMr。Warrington。Perfectlydrysulphateofcopperiswhite;theslightestmoistureturnsitblue。 Muriateofcobaltisofapalepinkcolor;averyslightheat,byremovingalittlemoisture,changesittoagreen。 Theseareafewinstancesselectedfrommanywhichmightbegiven。 Ifwereceiveaprismaticspectrumonsomepapers,wehaveevidencethatthemolecularorchemicaldisturbancebearssomerelationtothecolorofeachray,or,inotherwords,thatcoloredlightsomodifiestheactionofENERGIA thattheimpressionitmakesisinproportiontothecolorofthelightitaccompanies,andhencethereresultsamoleculararrangementcapableofreflectingcolorsdifferently。 Someinstanceshavebeengiveninwhichtheraysimpressedcorrespondwiththecolorsoftheluminousraysinaveryremarkablemanner。*Oneofthemostdecidedcasesisthatofthepaperpreparedwiththefluorideofsodaandnitrateofsilver。 SirJohnHerschelwas,however,thefirsttoobtainanygoodspecimensofphotographicallyimpressedprismaticcolorations。 *SeeMr。Hunt’s\"ResearchesonLight。\" ItwasnoticedbyDaguerrethataredhousegaveareddishimageonhisiodizedsilverplateinthecameraobscura; andMr。Talbotobserved,veryearlyinhisresearches,thattheredofacoloredprintwascopiedofaredcolor,onpaperspreadwiththechlorideofsilver。** **In1842,IhadshownmeapictureofahouseintheBowery,whichhadbeenrepairedafewdaysprevious,andinthewallaredbrickleft。ThisbrickwasbroughtoutontheDaguerreotypeplateofpreciselythesamecolorasthebrickitself。 Thesameartistalsoexhibitedtome,thefulllengthportraitofagentlemanwhowereapairofpantaloonshavingabluestripedfigure。 Thisbluestripewasfullybroughtout,ofthesamecolor,inthepicture。——AMER。ED。 \"In1840IcommunicatedtoSirJohnHerschelsomeverycuriousresultsobtainedbytheuseofcoloredmedia,whichhedidmethehonorofpublishinginoneofhismemoirsonthesubjectfromwhichIagaincopyit。\" \"Apaperpreparedwithmuriateofbarytesandnitrateofsilver,allowedtodarkenwhilstwetinthesunshinetoachocolatecolor,wasplacedunderaframecontainingared,ayellow,agreen,andablueglass。 Afteraweek’sexposuretodiffusedlight,itbecameredundertheredglass,adirtyyellowundertheyellowglass,adarkgreenunderthegreen,andalightoliveundertheblue。 \"Theabovepaperwashedwithasolutionofsaltofiodine,isverysensitivetolight,andgivesabeautifulpicture。 Apicturethustakenwasplacedbeneaththeaboveglasses,andanotherbeneathfourflatbottlescontainingcoloredfluids。 Inafewdays,undertheredglassandfluid,thepicturebecameadarkblue,undertheyellowalightblue,underthegreenitremainedunchanged,whilstundertheblueitbecamearosered,whichinaboutthreeweekschangedintogreen。 Manyotherexperimentsofasimilarnaturehavebeentriedsincethattimewithlikeresults。 \"Inthesummerof1843,whenengagedinsomeexperimentsonpaperspreparedaccordingtotheprinciplesofMr。Talbot’scalotype,Ihadplacedinacameraobscuraapaperpreparedwiththebromideofsilverandgallicacid。 Thecameraembracedapictureofaclearbluesky,stucco-frontedhouses,andagreenfield。Thepaperwasunavoidablyexposedforalongerperiodthanwasintended——aboutfifteenminutes,——averybeautifulpicturewasimpressed,which,whenheldbetweentheeyeandthelight,exhibitedacuriousorderofcolors。Theskywasofacrimsonhue,thehousesofaslatyblue,andthegreenfieldsofabrickredtint。 Surelytheseresultsappeartoencouragethehope,thatwemayeventuallyarriveataprocessbywhichexternalnaturemaybemadetoimpressitsimagesonpreparedsurfaces,inallthebeautyoftheirnativecoloration。\" PHOTOGRAPHICDEVIATIONS。 Beforetakingleaveofthesubjectofphotogenicdrawing,Imustmentiononeortwofacts,whichmaybeofessentialservicetooperators。 IthasbeenobservedbyDaguerre,andothers,inEurope,andprobablybysomeofourownartists,thatthesuntwohoursafterithaspassedthemeridian,ismuchlesseffectiveinthephotographicprocess,thanitistwohoursprevioustoitshavingreachedthatpoint。 Thismaydependuponanabsorptivepoweroftheair,whichmayreasonablybesupposedtobemorechargedwithvaportwohoursbeforenoon。 Thefuseofthehygrometermaypossiblyestablishthetruthorfalsityofthissupposition。Thefact,however,ofabetterresultbeingproducedbeforenoonbeingestablished,personswishingtheirportraitstaken,willseetheadvantageofobtaininganearlysitting,iftheywishgoodpictures。 Ontheotherhand,ifthesuppositionabovementionedprovetrue,atooearlysittingmustbeavoided。 Ifwetakeaconsiderablethicknessofadensepurplefluid,as,forinstance,asolutionoftheammonia-sulphateofcopper,weshallfindthatthequantityoflightisconsiderablydiminished,atleastfour-fifthsoftheluminousraysbeingabsorbed,whilethechemicalrayspermeateitwiththegreatestfacility,andsensitivepreparationsareaffectedbyitsinfluence,notwithstandingthedeficiencyoflight,nearlyaspowerfullyasifexposedtotheundecomposedsunbeams。 Itwasfirstimaginedthat\"underthebrilliantsunandclearskiesofthesouth,photographicpictureswouldbeproducedwithmuchgreaterquicknessthantheycouldbeintheatmosphereofParis。 Itisfound,however,thatamuchlongertimeisrequired。 EvenintheclearandbeautifullightofthehigherAlps,ithasbeenprovedthattheproductionofthephotographicpicturerequiresmanyminutesmore,evenwiththemostsensitivepreparations,thanitdoesinLondon。 IthasalsobeenfoundthatunderthebrilliantlightofMexico,twentyminutes,andhalfanhour,arerequiredtoproduceeffectswhichinEnglandwouldoccupybutaminute;andtravellersengagedincopyingtheantiquitiesofYucatanhaveonseveraloccasionsabandonedtheuseofthephotographiccamera,andtakentotheirsketchbooks。 Dr。Draper*hasobservedasimilardifferencebetweenthechemicalactionoflightinNewYorkandVirginia。ThiscanbeonlyexplainedbythesuppositionthattheintensityofthelightandheatoftheseclimesinterfereswiththeactionoftheENERGICraysonthosesensitivepreparationswhichareemployed。 *Iwouldheretakeoccasiontoremarkthatourcountryman,Dr。Draper,isveryfrequentlyquotedbyMr,Huutinhis\"Researches。\" LUNARPICTURES——DRUMMONDLIGHT。 TheRomanAstronomersstatethattheyhaveprocuredDaguerreotypeimpressionsoftheNebulaoftheswordofOrion。 SignorRondinihasasecretmethodofreceivingphotographicimagesonlithographicstone;onsuchapreparedstonetheyhavesucceededinimpressinganimageoftheNebulaanditsstars;\"andfromthatstonetheyhavebeenenabledtotakeimpressionsonpaper,unlimitedinnumber,ofsingularbeauty,andofperfectprecision。\" Experimentshave,however,provedthat\"noheatingpowerexistsinthemoon’srays,andthatlunarlightwillnotactchemicallyupontheiduretofsilver。\" Itwasatonetimesupposedthatterrestrialorartificiallightpossessednochemicalrays,butthisisincorrect——Mr。Brandediscoveredthatalthoughtheconcentratedlightofthemoon,orthelightevenofolefiantgas,howeverintense,hadnoeffectonchlorideofsilver,oronamixtureofchlorideandhydrogen,yetthelightemittedbyelecterizedcharcoalblackensthesalt。 AttheRoyalPolytechnicInstitutionpictureshavebeentakenbymeansofsensitivepaperacteduponbytheDrummondLight; butitmustofcoursebedistinctlyunderstood,thattheyareinferiortothosetakenbythelightofthesun,ordiffuseddaylight。 Ifouroperatorscouldmanagetoproducegoodpicturesinthiswaytheywouldputmoneyintheirpockets,asmanywhocannotfindtimeduringthedaywouldresorttotheirroomsatnight。 Ithrowoutthehintinhopessomeonewillmaketheexperiment。 Ihavelearned,sincetheabovewaswritten,thatanoperatorinBostonsucceededashorttimesinceinprocuringverygoodpicturesbytheaidoftheDrummondLight;butthattheintensityofthelightfallingdirectlyuponthesitter’sfacecausedgreatdifficulty,andheabandonedit。 Thismay,probably,beremediedbyinterposingascreenofverythintissuepapertingedslightlyofabluishcolor。 CHAP。XII。 ONCOLORINGDAGUERREOTYPES。 Nearly,ifnotquiteallthevariouscolorsusedinpaintingmaybemadefromthefiveprimitivecolors,black,white,blue,redandyellow,butfortheDaguerreanartistitwouldbethebestpolicytoobtainsuchasarerequiredbytheirartalreadyprepared。Inamajorityofcases,thefollowingwillbefoundsufficient,viz。 Carmine。 PrussianBlue。 White。 ChromeYellow,Gamboge,YellowOchre;orallthree。* *Gambogeisbestfordrapery;Ochrefortheface。 LightRed。 Indigo。 BurntSienna。 Bistre,orBurntUmber。 If,incoloringanypartofalady’sorgentleman’sapparel,itisfoundnecessarytoproduceothertintsandshades,thefollowingcombinationsmaybeused: Orange——Mixyellowwithred,makingitdarkerorlighterbyusingmoreorlessred。 Purple——ThisismadewithPrussianblue,orindigoandred。 CarmineandPrussianblueproducingtherichestcolor,whichmaybedeepenedintheshadowsbyaslightadditionofindigoorbrown。 Greens——Prussianblueandgambogemakesaveryfinegreen,whichmaybevariedtosuitthetasteofthesitteroroperator,bylargerportionsofeither,orbyaddingwhite,burntsienna,indigo,andred,asthecasemayrequire。 Thesecombinations,underdifferentmodifications,givealmostendlessvarietiesofgreen。 Brown——Maybemadeofdifferentshadesofumber,carmineandlamp-black。 Neutraltint——Iscomposedofindigoandlamp-black。 Crimson——Mixcarmineandwhite,deepeningtheshadedpartsofthepicturewithadditionalcarmine。 FleshColor——Thebestrepresentativeoffleshcolorislightred,brightenedinthemoreglowingorwarmerparts,withcarmine,softenedoffinthelighterportionswithwhite,andshadedwithpurpleandburntsienna。 LeadColor——Mixindigoandwhiteinproportionstosuit。 Scarlet——Carmineandlightred。 ForJewelrycupsofgoldandsilverpreparationsaccompanyeachboxforDaguerreotypists,ormaybeprocuredseparately。 ThemethodoflayingcolorsonDaguerreotypesisoneofconsiderabledifficulty,inasmuchastheyareusedintheformofperfectlydryimpalpablepowder。Theauthorofthislittleworkisnowexperimenting,inorder,ifpossible,todiscoversomemoreeasy,artisticandunexceptionablemethod。 Ifsuccessful,theresultwillbepublishedinafutureedition。 TherulesweshallgiveforcoloringDaguerreotypesdepends,andarefounded,uponthoseobservedinminiaturepainting,andareintendedmoreashintstoDaguerreanartists,inhopesofleadingthemtoattemptimprovements,thanasinstructionswhollytobeobserved。 Thewriterisconfidentthatsomecompoundoringredientmayyetbediscoveredwhich,whenmixedwiththecolors,willgiveamoredelicate,pleasing,andnaturalappearancetothepicturethanisderivedfromthepresentmodeoflayingthemon,whichinhisestimationismorelikeplasteringthancoloring。 INCOLORINGDAGUERREOTYPES,theprincipalshadesoftheheadaretobemadewithbistre,mixedwithburntsienna,touchingsomeplaceswithamixtureofcarmineandindigo。 Thefleshtintsareproducedbytheuseoflightred,deepenedtowardstheshadedpartswithyellowochre,blueandcarminemixedwithindigo,whilethewarmer,ormorehighlycoloredpartshaveaslightexcessofcarmineorlake。 Colortheshadesaboutthemouthandneckwithyellowochre,blue,andaverylittlecarmine,heighteningthecolorofthelipswithcarmineandlightred,lettingthelightredpredominateontheupper,andthecarmineonthelowerlip; theshadesinthecornerofthemouthbeingtouchedslightlywithburntsienna,mixedwithcarmine。 Incoloringtheeyes,theartistwillofcoursebeguidedbynature,observingaverydelicatetouchinlayingonthecolors,soastopreserveasmuchtransparencyaspossible。Aslighttouchofblue—— ultramarinewouldbebestifitwouldadheretotheDaguerreotypeplate—— inthewhitesoftheeyeneartheiris,willproduceagoodeffect。 Incoloringtheheadsofmenitwillbenecessarytousethedarkertintswithmorefreedom,accordingtothecomplexionofthesitter。 Forwomen,thewarmertintsshouldpredominate,andinordertogivethattransparencysouniversalwiththesoftersex—— andwhichgivessomuchlovelinessandbeautytotheface—— alittlewhitemaybejudiciouslyintermingledwiththeredtintsaboutthelighterportionsoftheface。 Intakingapictureofaladywithlightorauburnhair,bytheDaguerreanprocess,muchofthebeautyofthefaceisdestroyed,onaccountoftheimperfectmannerinwhichlightconveystheimageoflightobjectstothespectrumofthecamera。 Thismaybeobviatedinsomemeasurebypropercoloring。 Todothis,touchtheshadedpartswithburntsiennaandbistre,fillingupthelighterportionswithyellowochre,delicatetouchesofburntsienna,andinthosepartswhichnaturallyhaveabluishtint,addverydelicatetouchesofpurple—— sodelicateinfactashardlytobeperceived。Therootsofthehairattheforeheadshouldalsobetouchedwithblue,andtheeyebrowsnearthetemplesmadeofapinkishtint。 Thechinofawomanisnearlyofthesamecolorasthecheeksinthemostglowingparts。Inmenitisstronger,andofabluishtint,inordertoproducetheeffectgivenbythebeard。 Inportraitsofwomen——themiddletintsonthesideofthelight,whichareperceivedonthebosomandarms,aremadeofaslightmixtureofochre,blueandlake,(orcarmine),towhichadd,ontheshadedsides,ochre,bistreandpurple,thelatterinthedarkerparts。 Thetintsofthehandsshouldbethesameastheotherpartsoftheflesh,theendsofthefingersbeingalittlepinkishandthenailsofaviolethue。 Ifanyportionofthefleshypartsisshadedbyportionsofthedress,orbythepositionofthehand,thisshadeshouldbecoloredwithumbermixedwithpurple。 TOCOLORTHEDRAPERY。——VioletVelvet——UsepurplemadeofPrussianblueandcarmine,touchinguptheshadedpartswithindigoblue。 GreenVelvet——MixPrussianblueandred-orpiment,shadewithpurple,andtouchupthelightswithalittlewhite。 RedVelvet——Mixaverylittlebrownwithcarmine,shadingwithpurple,markingthelightsinthestrongestpartswithpurecarmine,andtouchthemostbrilliantslightlywithwhite。 WhiteFeathers——Maybeimprovedbydelicatelytouchingtheshadedpartswithalittlebluemixedwithwhite。 Whitemuslin,linen,lace,satin,silk,etc。,mayalsobecoloredinthesameway,beingcarefulnottolaythecolorontooheavily。 FURS——RedFursmaybeimitatedbyusinglightredandalittlemasticot,shadedwithumber。GrayFurs——blackandwhitemixedandshadedwithbistre。 Sable——whiteshadedlightlywithyellowochre。 Thesefewdirectionsarequitesufficientfortheart,anditisquiteunnecessaryformetopursuethesubjectfurther。 Iwould,however,remarkthattheDaguerreotypistswouldfinditgreatlytotheiradvantagetovisitthestudiesofourbestartists,ourpublicgalleriesofpaintings,andstatuary,andwhereverelsetheycanobtainasightoffinepaintings,andstudythevariousstylesofcoloring,atitudes,foldsofdraperyandotherpointsoftheart。 IncoloringDaguerreotypes,artistswillfindthemagnifyingglassofmuchadvantageindetectinganyimperfectionsintheplateorintheimage,whichmayberemediedbythebrush。 Inselectingbrusheschoosethosemostsusceptibleofafinepoint,whichmaybeescertainedbywettingthembetweenthelips,orinaglassofwater。 CHAP。XIII。 THEPHOTOGRAPHOMETER。 Thelastnumber(forMarch,1849)ofthe\"LondonArt-Journal,givesthefollowingdescriptionofarecentimprovementinPhotographicManipulation,andasIamdesirousoffurnishingeverythingnewintheart,Istopthepresstoaddit,entire,tomywork。 \"Sincethephotographicpowerofthesolarraysbearsnodirectrelationtotheirluminousinfluence,itbecomesaquestionofconsiderableimportancetothosewhopracticethebeautifulartofphotography,tohavethemeansofreadilymeasuringtheeverchangingactivityofthisforce。Severalplansmoreorlesssuccessful,havebeendevisedbySirJohnHerschel,Messrs。Jordan,ShawandHunt。 Theinstrument,however,whichisnowbroughtforwardbyMr。Claudet,whoiswellknownasoneofourmostsuccessfulDaguerreotypists,appearsadmirablysuitedtoallthosepurposeswhichthepracticalmanrequires。Thegreatdifficultywhichcontinuallyannoysthephotographicamateurandartist,isthedeterminationofthesensibilityofeachtabletemployed,relativelytotheamountofradiation,luminousandchemical,withwhichheisworking。 WiththephotographometerofMr。Claudetthisiseasilyascertained。 Thefollowingwoodcutsandconcisedescriptionwillsufficientlyindicatethisusefulandsimpleapparatus。 [hipho_30。gif] \"Foraninstrumentofthiskinditisimportantinthefirstplacetohaveamotionalwaysuniform,withoutcomplicatedorexpensivemechanism。Thisisobtainedbymeansfoundedupontheprincipleofthefallofbodiesslidingdownaninclinedplane。 Thesensitivesurfaceisexposedtothelightbytherapidanduniformpassageofametalplate,A,B,(Fig。31,)havingopeningsofdifferentlength,whichfollowageometricprogression。 Itisevidentthattheexposuretolightwillbethesameforeachexperiment,becausetheplatefurnishedwiththeproportionalopeningsfallsalwayswiththesamerapidity,theheightofthefallbeingconstant,andtheangleoftheinclinedplanethesame。 Eachopeningofthismoveableplateallowsthelighttopassduringthesamespaceoftime,andtheeffectuponthesensitivesurfaceindicatesexactlytheintensityofthechemicalrays。 Therapidityofthefallmaybeaugmentedordiminishedbyalteringtheinclinationoftheplanebymeansofagraduatedarc,C,D,(Fig。30,)furnishedwithascrew,E,bywhichitmaybefixedatanyangle。Thesameresultmaybeobtainedbymodifyingtheheightofthefallortheweightofthemoveableplate。 Thephotogenicsurface,whether[hipho_31。gif] itbetheDaguerreotypeplate,theTalbotypepaper,oranyotherpreparationsensitivetolight,isplacednearthebottomoftheinclinedplane,F。Itiscoveredbyathinplateofmetal,piercedwithcircularholes,whichcorrespondtotheopeningsofthemoveableplateatthemomentofthepassageofthelatter,duringwhichthesensitivesurfacereceivesthelightwhereverthecircularholesleaveitexposed。 \"Thepartoftheapparatuswhichcontainsthesensitivesurfaceisanindependentframe,anditslidesfromadarkboxintoanopeningonthesideoftheinclinedplane。 \"Acoveringofblackclothimpermeabletolightis,attachedtothesidesofthemoveableplate,envelopingthewholeinclinedplane,rollingfreelyovertworollers,R,R,placedtheoneattheupperandtheotheratthelowerpartoftheinclinedplane。 Thisclothpreventsthelightstrikingthesensitivesurfacebeforeandafterthepassageofthemoveableplate。 \"Itwillbeseenthatthisapparatusenablestheexperimentalisttoascertainwithgreatprecisiontheexactlengthoftimewhichisrequiredtoproduceagivenamountofactinicchangeuponanysensitivephotographicsurface,whetheronmetalorpaper。 Althoughatpresentsomecalculationisnecessarytodeterminethedifferencebetweenthetimewhichisnecessaryforexposureindirectradiation,andtotheactionofthesecondaryradiationsofthecameraobscura;thisis,however,averysimplematter,anditappearstousexceedinglyeasytoadaptaninstrumentofthisdescriptiontothecameraitself。 \"BythisinstrumentMr。Claudethasalreadydeterminedmanyveryimportantpoints。Amongothers,hehasprovedthatonthemostsensitiveDaguerreotypeplateanexposureof。0001 partofasecondissufficienttoproduceadecidedeffect。 \"Regardingphotographyasanauxiliaryaidtotheartistofnomeanvalue,wearepleasedtorecordadescriptionofaninstrumentwhich,withoutbeingcomplicated,promisestobeexceedinglyuseful。Inthisopinionwearenotsingular; atarecentmeetingofthePhotographicClub,towhichthisinstrumentwasexhibited,itwaswithmuchrealsatisfactionthatwelearnedthatseveralofourmosteminentartistswerenoweagerandmostsuccessfulstudentsinPhotography。 Thebeautifulproductionsofthemoreprominentmembersofthisclubexcitedtheadmirationofall,particularlythecopiesofarchitecturalbeauties,andsmallbitsoflandscape,byMessrs。 CundellandOwen。Wethinkthatnowtheartistseestheadvantagehemayderivefromtheaidofscience,thatbothwillgainbytheunion。\" Ihopetheabovedescriptionwillinduceourtownsman,Mr。Roach,tosuccessfullyproduceaninstrumentthatwillmeetthewantsofourartistsinthatpartoftheDaguerreanprocessreferredto。 FINIS。 INDEX。 AcceleratingLiquids。65 Amphitype。116 Anthotype。113 Apparatus。Daguerreotype。43 Calotype97 Photogenic87 ApplicationofPhotogenicDrawing。95 ApplyingtheSensitive。64 BringingoutthePicture。71 BromineBox。51 Chlorideof68 Roach’sTrippleCompoundof67 water。65 BromideofIodine。67 ofLime。68 Paper。91 ofsilver。35 Brushes。88 BuffSticks。60 Calotypeprocess。97 paper。ExposureinCameraof100 Pictures。Bringingoutib。 Fixing101 Camera。Descriptionofthe43 Stand。49 Woodbridge’sib。 Calotype。50 Voigtlander45 ChlorideofBromine。68 ofGold。36 tomakeasolutionof75 ofIodine。66 ofSilver。31 Chromatype。112 Chrysotype。106 CleaningandPolishingtheplate。61 CoatingBoxes。51 ColorBoxes。53 ColoredDaguerreotypesonCopper。77 ColoringthePicture。76 Daguerreotypes。129 ConcaveMirrors。19 ConvexMirrors19 CorchorusJaponica。37 CrayonDaguerreotypes。120 Cyanotype109 DaguerreotypeApparatus。43 Process。61 Plates。62 Daguerreotypes。Crayon77 onpaper81 Dedication。iiiDefinitionsoftermsusedinoptics,15 Differentmethodsofpreparingphotogenicpaper。89 DirectionsforuseofGalvanicBattery。58 Distilledwater88 Drummondlight。128 DrySensitive。68 Dryingapparatus。72 Effectsoflightonbodies25 Energiatype111 EtchingDaguerreotypes。83 Fifthoperation。Fixingthepicture。61 Firstoperation。Cleaningtheplate61 Fluoricacid。69 Fourthoperation-Bringingoutthepicture。71 Funnels。53 GalvanicBattery。57 Solutionforuseof58 Gildingstand。53 thepicture。74 Gold。Chlorideof36 Tomakesolutionof75 Hyposulphite;orSaltof74 Preparationof。36 Gurney’sSensitive。67 HeadRests。57 HintsandSuggestions。39 HistoryofPhotography。3 HungarianLiquid。69 Hygrometers。55 HyposulphiteofGold。74 ofSoda。28 InstantaneouspicturesbymeansofGalvanism。77 Introduction。iIodine,Dry64 Chlorideof66 Bromideof67 Box。51 Iodideofsilver。32 loduretofsilver。33 IodizethePlate。To64 IodizedPaperforCalotypes。Toprepare98 TopreparefortheCameraib。 Lamps,Spirit53 Light。Theoryon14 Motionof16 Reflectionof17 Refractionof20 onbodies。Effectsof25 Prismaticanalysisof22 Lime,Bromideof68 LunarPictures。127 Mead’sAccelerator。68 MercuryBath50 NitrateofSilver。89 OxideofSilver。29 OncoloringDaguerreotypes129 OntheprobabilityofProducingcoloredPhotographs。123 Paper。blotting;orbibulous,88 Daguerreotypes。81 preparationof89 suitableforPhotographs。87 PhotogenicdrawingonibPhotographicprinciple,the22 Photographicprocessonpaper。92 drawing。Applicationof95 Tofixthe93 deviations。126 Photographometer,The135 PlateSupport。59 Blocks。50 Vice。51 Poppy,TheRed37 Porcelaindishes。59 PositiveCalotype104 Preface。vPreparationofIodizedPaper。98 ofGold。36 PrismaticSpectrum。22 AnalysisofLight。ibReflectionofLight。17 RefractionofLight。20 Roach’sTrippleCompoundofBromine。67 SandClock。70 Sealingpaper。Tomake77 Secondoperation。94 Sensitive。ibSilver。Bromideof35 Clorideof31 Iodideof32 Ioduretof33 Nitrateof89 Oxideof28 SolutionofChlorideof59 Sixthoperation。74 SodaHyposulphiteof72 SolarandStellarLight。21 Stillforpurifyingwater,54 SubmittingthePlatetotheactionofLight69 SynopsisofMr。Hunt’sTreatiseonLight,29 TalbotypeCamera。50 TheoryonLight。14 Thirdoperation。69 WallFlower。37