第4章

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