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