Digitized by the Internet Archive in 2015 https://archive.org/details/handmaidtoarts01doss ■ 1 THE HANDMAID T O T H E Id A R VOL. THE FIRST. T E A C r. A perfe£i knowledge of the ma- teria pictoria; or,thenature, ufe, preparation, and compofition, of all the various fubftances em- ployed in PAINTING, as well ow- ders^ and imitations of them, as alfo of the fat oil, gold fi^es, and other neceffary compofitions ; — the art of japanning, as applicable not only to the former purpofes, but to coaches, fnufF- boxes, &c. in the manner lately introduced ; — and the method of staining different kinds OF substances, %jitb all the feveral colours* The whole being calculated, as well for conveying a more accuiate and extenfive knowledge of the matters treated of to profelTed artifts, as to initiate thole who are delirous to attempt thefe arts, into the method of preparing and uling all the colours, and other fubllances employed in painting in cil, miniature, crayons, cncaujhc, enamel, njarnijh, dijiemper, and frefco, z.s CxMoiw gilding, &c. 1 The Second Edition, with confiderable Additions and Improvements. LONDON: Printed for J* Nourse, Bookfeller in Ordinary to his MAJESTY, MDCGLXIV. //.... n^-\'>... r ^ J , ■ . ■ ■ '. ■ • ''i<' .V^‘- • >: - ■ , ■ ^ iVy THE J. PAUL GETTY MUSEUM LIBRARY TO THE SOCIETY FOR THE Encouragement of Arts, Ma- nufactures, and Commerce. Gentlemen, T he correfpondence betwixt tbe dcfign of this work, and the views of your inftitution, naturally points out to me, to whom it may be addreffed with the greateft propriety. The furnilliing means of eftablifla- ing and improving ufeful arts, efpe- cially thofe which relate to confi- derable manufactures, and the creat- ing incitements and motives to the exercife of thofe means, are to a coun- try that owes its riches, power, and even domeftic lecurity to commerce, ol the greateft concern and moment; A 2 and DEDICATION, and it is more peculiarly meritorious in thofe, who, in a private capacity, exert their utmofl endeavours on thcle accounts, as lucli purluits Teem to take up a very little fliare of the re- gard of the public here, at a time, when all the neighbouring govern- ments (and efepecially that of our rival France) make them a principal objedt of their . attention and care. To you, therelore, I dedicate this book, as it is not only - in your power, but intirely w’ithin the fphere of your profelled intentions, to en- force, in a m.ore extenfive and pub- licly beneficial w'ay, the pradtice of many particulars taught in it. I am. Gentlemen, Your mofi; obedient, and humble Servant, The AUTHOR T H E PREFACE. the national iwproveme7it of fill and tajle, in the execution of zvorks of de- fign, is a Tiiattcr of g7''cat importance to any country^ not only on account of the honour which is derived to civilised 77ations by excellmg in the polite erts^ but likewife of the commercial ad-> vantages refultwg from it^ will be allowed by all zvho have not very fmgtdar notions with refpehi to thefe ^natters; though^ in what degree fuch improvements are (ffentially interefing to us at prefent^ is fcarcely conceived by any^ but thofe who particularly concern thewfeives in fpe^ culations of this nature. 1 he frong dfpoftion 4 that prevails not only in the European countries^ but in the rcfpeEiive fettlcments of their people in Jifa and America for ifng thofe decorations and ornaments in drefs., as well as buildings equi- pages^i and furniture^ that employ the arts of dc-- fgn.^ gives at prefent the foundation to feveral of the mof confiderable branches of trade\ and this is daily increafng., with the luxury that ferns removing from the Fmft^ and fpreading itfelf over thefe Wefern countries and their colonies^ in fiLch manner^ as zvill probably foon render fame A 3 • articles VI PREFACE. articles of this kind equal in the return to the 7 nof faple and extenfive oj thofe of the foriner co7iimerce, As^ moreover^ fever al circumfances both of our ccconomical and political condition^ by enhancing to a very high degree the price of commo?i fiecejfaries^ and introducing ??iore ex^ pejifive modes of life^ are depriving us of the fbare vae had of the grojfer manufaElures that depend on labour^ it pectdiarly behoves us at pre^’ fent to exert ourfelves in cultivating thofe of a more refned nature^ where fill and tafe (in which we by no means fetm naturally wanfing) are required to give a higher value to the worky and to fand in the place of a higher proportion of manual operation. It miift be with regret^ therefore^ we fee the French have long got the fart of us in this very 7naterial purfiiit ; and that the encouragement given by their government^ together with the op-- port unities afforded by a weU-infiiuted academy y has diffufedfuch a judgment and tafe in defign, among all ciaffes of artifans^ as render France at this time the fource of nearly all invcjition of fafjionsy and neceffarily occofion an extreme great dem,and from her for all thofe articles y in the production of which fuch talents are excr^ cifed, ^ .The advantages which France has mw over tis in tJsefe concerns y are ?tot however fo well fe^ curcdy that we fjould defpair of being ablcy in timey to wref them cut of her hands. For where the mechanical party either as it depends on machines or matiual dexterity y is in quefiony P P. E F A C E. vii we have given on all occafions the proofs of fnpe-- rior abilities ; and whenever^ therefore^ the im- provement of fancy and propriety in the deftgning of models and patterns fsall he fo far advanced . hcre^ as to put us on a Irvel vAth her in tbofe points, vee fall foon become as formidable a rived to her, in what fbe now coiifders her pccuiium, as fee has in a parallel manner been before to us, in the woollen trader from our ad- vanced price of labour. The mcafures by which this very dcfrable end may be attained, confjl of three particulars ; the founding a well-regulated academy, where not only youth and novices may have an opportunity of being well initiated in the principles of defign; but where even artifs themfclves^ may have the means of induicement to further fudy, in order to the frongef exertion of their genius \ the creating fuch incitements, by pecuniary re- wards or honorary difindions, to excel in thefe arts, and more ifpecially in the appUcatmi of them to the perfe^ing tbofe manufaclures, to which they have any relation, as may f imulate the more indolent, and raife greater emulation among the forward, to apply their iitrnof powers to excel; — and the diffufng a more general arid accurate knowledge of thofe fecondary or aux- iliary arts that are rcqmfte to the praAtifing defign, or to the execution of works dependant on it. The firf of thefe means, viz, the erecting an academy of arts, we mi ft hope, will be fme- lime thought an objeSf worthy the notice and care of the government ; fince it is too apparent y A 4 from vili PREFACE. from the failure of the attempts already made^ that nothing eJfeBual 'with regard to it can re-- fult from the efforts of private perfons, 'The fecond might be procured by a right difpenfa- iion of the premiums of' the fociety injiitutcd for that purpofe. The laf are intended to be fuppUed by this work^ but 'with 'what title to fuccefs^ 1 7 nuf leave it to the judgment of the public to deter mine \ only I 'will take the liberty of f jewing fome'what more explicitly here^ in what particular manner it is propofed to cfeSl this end, • A difquifition on the Materia Pictoria makes the firf part\ 'where the natural hiflcry^ preparation^ and iife^ of not only the fubfances of 'which colours are formed^ but of all others rendered fubfervient in any way to the purpofes of paintings are diflinEily taught^ 'with the rnan^ ner of conipoftion^ and application of them^ as they depend either on mechanical or chymical operations. The principal view in this difqui-* fition is to enable thofe'^ who have already learnt to drawy to make thewfelves eaftly inofers of painting in any manner they may choofe ; by which afffance many perfons of genius^ wkoy from ignorance of the nature and ife of colours^ might be deterred from it., may be both induced and enabled to attempt painting fuccefsfully^ and hung thcfe talents info praEiicc., which would be otherwife lof to the public and themfelvcs. But it is not to thefe alone the view of ben eft is con- fncd. The frefcnt adulterate and imperfcEl prepay ation of (he colours., from the fordidncfs PREFACE. ix and Ignorance of the jews^ and other low people concerned in the preparatim of them^ is a difad-^ vantage of the highef moment to fuch as paint.^ even vDith the greatef f ili^ either in oil or vDatc7\ and for 'which they can fnd no appofte remedy •without fome aid of this kind', for^ as the preparation of colours is kept a fecret in the hands of thofe few who manufadhire them^ either here or abroad-^ and coifeqiiently is very little known to modern painters ; , and as a much greater foare of knovoledge m naticral kifory^ experi^ mental philofophy-i and chymijlry^ is required to the undaflanding the nature of the fimples^ and principles of the c67npoftion, in a fpecidative light, than is confifent with the fudy of other fiibje&s more immediately Jiecefjayy to an artijl^ there remains ?io means of furmounting this dif- fculty, but the being fupplied, by fome perfjn^ whefe application could be more properly ddre5led to the attainnmit of this fcience^ with fuch a fyfem of the theory and practice of every thing relating to the Materia Piftoria, as may enable them cither to prepare the colours themfelves-^ where 7iot to be otherwife obtained perfehl, or to judge critically with fome certainty of the good- nefs of fuch as they procure from others. This / have therefore attempted on their behalf and I hope not- in vain, as not only a general acquaintance with the fjraUice of the fever al branches of the chymiced art, but a very large experimental inquiry into the nature of thefe fulje&s ni particular, form my pretenfions to fome knowledge of them. As X PREFACE. As the depravity of the maniier of prepara^ tzon has alfo extended itfelf to the very primhig of cloths for grounds of paintmg^ ( a work trujl-^ ed too 7iegleclfully at prefent to the care of colour-f nien ) from whence great inconvenience to the painter^ and detriment to the piSlures^ are pro^ diiced^ I have fiihjoined a method^ by which thofe^ who are really in earnef about the merit of their pezformances^ may procure cloths to be made without either .f ijfening^ crackings or caufing (as it is called) the colours to fink in. And^ as this has an apparent utility with refpeB to painters in the cafe of new pictures^ fo the improvements offered in the methods of cleanings preferving^ and mending the old^ arc not lefs ohviouf y benefcial to others poffefed of the works of former rnafers. The art of cleaning pidurcs being indeed of the utmof confequence to the in-- tcref of tafhe, as no lover of the polite arts can refle^^ without the \utmofl regret^ on the vajl havock made in the works of all the great painters by erroneous and faulty management in this point. The explanation of the Jiaturc^ and manner of application of the colours.^ grounds.^ ^<^c, ufed m that method^ called painting in encaiftic^ is here frf introduced, into the work., in this fecond edition of it. Whatever has been hitherto brought before the public under this name.^ muf be confidered ra^^ ther as an effay towards a new manner of paint-, ing., than the completion of an art. When this work was firfi printed., Count Cay las was the foie perfon who had offered any thing of fuch a kind T R E F A C E. XI a kind to the ^uDorld ; and what he publijhed of his trials^ only feemed to prove the difficulty of bringing this method to any ufeful degree of perfeclion. Since that timCy many other per^ fons have made attempts in the fame way ; and Mr. Munt% has publijhed a treat if on the fubjecli in which y he pretetidsy to have made fuch imt)rovements on Count Cay las s tnethod^ as to have rendered this manner of painting of pradli cal importance. The concurrence of ethers with him in this opiniony and the atten* iion, which the public have given to this mat- tery have rendered fame notice of ity at prefenty proper in this work. 1 have therefore prejented a full, though concife account of whatever ma- terial has been advanced on this head, with fuch obfervationsy as well on the wholcy as fever al particularsy as occurred to my own judg- ment. ' A complete fyllcm of the theory and praBice'of enamel paintingy forms the next articky the value of which will be beji under flood by thofe for whofe ufe it is intended. For as this art is of late introdudiion among us, and the man- ner of conducting ity with refpecl to the pre- paration and compoJitio7i of the colour Sy fluxes y and grounds, has been carefully concealed in the places abroad where it has been longer efablif- edy a very fmall fare of knowledge in the prepa- ration of the colour Sy and yet lejs of that of the grounds and fluxeSy is the whole hitherto gained by the ar tiffs of this country. They are for the moft part obliged to etnploy a white enamel pre^ pared xli PREFACE. pared at Venice for their ground, to pick up the remains of a kind of glafs formerly made there for a flux, and to procure the colours^ cither in a more perfecl or faulty jlate as they can meet ^dcith them, except in the cafe of thofe who have recipes for fome kinds which they prepare ; but with that precarioiifnefs of the qualities,' that attends the blindly following recipes, without any compreheifion either of the generhl properties of the ingredients, or princi^ pies of the operations. From which circum^ flances, uncertainties in the fuccefs, and embar^ rafments in the work, are the frequent refult, as well from a want of underjlanding the nature of the fib fiances they ife, as the not being able to procure what is good of each kind, or fit for their particular purpoje, Fhe afjifling in the cultivation of the art of enamelling here was indeed one principal objeci of the defgn of this book, as fuch art is very materially iniere/Ung to us at prefent ; for it is become the bafis of a manufadlure, from which ■'we may' expect great advantages flnee we already fee it carried fuddenly to fuch a de- gree of perfcBion, with refpeB to the facility of working, as to raife a demand for the pro-- dace in foreign markets; notwith flan ding the long pra5Iicc and cheap living of the people of Geneva, who had been in pofjejpon of this branch of commerce, for a conjiderable time, gave them originally the great ejl advantages in it over us. This part of the work has been cenfured by feme, who have confuted the former edition, as zivinz o o Xlll PREFACE. grving errofieousy or infufficient injlrudlions ^vith rejpeci to the preparation oj fever al of the colours. But I am Jatisfed, that as to mcjl' of thofe ohjetlionsy the error , or defehily lay ra- ther in the manner of trial to put them in prahUcCy of t ho je who condemned them, than in the injiruclions themjelves. It is not indeed to be wondered at, that perjons who are wholly un- accuftomed to chymical procefj'esy fould mifcarry in the atteinpting fome of thefe^ which are of the niceji kindy and where the intention may he jrujirated by fo many 7ninute accidents ; and therefore not a juf conclufony to infer from ex periments fo madcy that the end propofed may not be ejfetled by the fame means more accurately applied. 'The procefs jor obtaining a crmfon colour from goldy is an infiancCy which verifies this in the jlrongefi degree. For though 7nany have attempted this matter without the defir ed fuccefs, yet I have unquefiionable evide7icey that others have obtained the endy even beyond their mojt f anguine expedlationsy .without the leafi aidy but what they have received from this work. The fame holds good of 7770ft of the other articles of iifiportance, refpeciing the art of enamellingy and 1 have therefore made very little change in this edition, except the adding fome new articles , as to this part oj the work. 1 he paint mg on glajs with vitreous colours, is fiot a matter oJ equal importance with enamel- ling but, as it IS conjidered as one of the arts of which the myfery is at prejent lojl to us, {though, on the contrary, bemg in fadi iiothiru^ more XIV P R E F. A C E. . more than painting with tranfparent enamel co- lours on glafs grounds by much the fame methods^ the modern i7nprovements made i7i the art of en- amelling have given us an eaual -Juperiority in this) I thought it a necefary part of the work ; and have accordingly entered on an explanation of the whole of it y availing myj elf ^ neverthelefs^ of' its afinity with enamel paintings fo as to refer for moji particulars to what was before laid down on that fcore^ and enlarge only on fame points in which a difference is found betwixt them. But 2 fatter myjt If that ^ not%vit hftanding the brevity of the manner^ any per [on mayy by a proper at- tention to what is delivered on this bead^ eafily make himfelf rnafer of every thing peculiar to painting on glafs. The gilding enamel and glafs by vitreous co- lours., and annealing, was a necefary appendage to the art of painting in enamel ; but there is yet another circumfiance which made the cor/irnu- nication of the bef methods of doing this of jo?ne confeqiience to the public. It is the great demand now Jubfifting for drinking glafes with gilt edges, which are mofly, at prefent, either imported from Germany, or fraudulently imirated here by ■ gilding with gu??i water or fizes that will not bear inoiflure ; though, were the means well un- der food, they might in large parcels, with very little more expence or trouble, be done in the genuine manner, I he method of taking off mezzotinto prints on glafs, which makes the next article, is not a matter of any great moment ; but^ as the prac- tifing XV. P R E E A C E. tifing it is very alluring, by the produBion of piBures even witkcut being able to draw, it may be an inducement to tome to apply themfelves to painting and the ftudy of dcfi^n ; fincethof will not long reft faUsfted with this manner of exer^ cifing their fancy ^ who have a genius for greater ■ things, T he art of wafting maps and other prints is however of more general ufe, and requires no apology for holding a place in the work, '1 he devices and mechanical means employed for the more eajily and accurately obtaining out- line ftzetches of dejigns after nature or works of art, which begin the fecond part, are of dhe greateji ajjftance ana jervice to all who paint or draw ; and though moji of them are known to artifls of larger experience, yet beginners are to learn them, and moft frequently want an adequate opportunity. On their account therefore they were necefary for the anfwering the full in-- tention of this book; and perhaps even jiich as are more verfed in thefe matters, may meet with fome thing not unacceptable to them in a colleBion of inventions of this nature, fo copious as that The methods of cafting in large, which fol- low m this part, will be much lefs extenftvely lifeful, as it is pratlifed only by few ; and the managing it in more dtfticuk cafes not eaftiy re- ducible to rule. But fome notice of them were wanting to render the fy ft em complete ; efpecialiy as they are conneBed fo as not to bear well a fe- par at ion from them with tkofe of cafting medals and XVI PREFACE. and other fmailer pieces^ and the manner of taking of mprejjions from various fubjeBs ; both which are articles of very general utility, "The difplaying the fever al methods of gildings which is done in the third party will be f ound a convenience to numbers y who would occafonally pradiife themy if they had the means in their power y and the application of the art of jap an- fling to fo many purpofeSy where a mixture of gilding is requiredy as the introdudlion (^’papier mac he has occajffoned lately y makes this commu- nication particularly feafonable at prefent, f he article of gilding leather y as pra5lifed for the rnanufadiure of hangingSy freensy &c^ is of very great importance. It is indeed only pradlifed by fome few, who carry on great con- cerns in it ; but 1 thought an explanation of the art merited a place herey as it may furnif the means of fuch trials to othersy as may lead to improvements. There is more reafon to hope this, as the method here defer ibed is that pradlifed in France at prefenty and differs in fome par- ticulars from the Englifh. The principal objetl is the compofition of the laquer or varnifhy which is every where concealed as a jecret by the manufadlurers. But the recipe here im- parted will produce fuchy as is at leaf equal tef the heft hitherto in ufe. Silvering and bronzing have alfo their utility ^ though in a lefs degree than gilding ; and there- fore properly claim to follow ity as they are in fa^ only dfferent applications of the fame means^ PREFACE. xvli The kfio'wledge of the ^nethods of japanning h at prcfait more 'iv anted than that of any other cf the Tuyferious arts ivhatever^ as it is now demanded to be praBfed on coaches and other vehicles in a very large and expenfvt way^ by thofe who till lately were utter f rangers to it. Information of this kind^ fuch as is intended to be conveyed in the fourth chapter of this partj is in a pccidiar manner requifiie to them., that they may the more eafly and readi y execute thofe defigns they have fleewn thewjelves capable of makin f ( when fuffcientiy paid t< afford the due application ) with a tafte and judgment., that proves them to be not greatly irferior to the French in this f pedes of perj ormaned though fo lately undertaken by them. Laquering had too great an afinlty with ja~^ panning not to be joined with it in this worky though it is of lefs confequence. Having, how-' ever., been carried by fame to much greater per-- fellion here than in any other country., even to the rivalling gilding 'in its ejfeli., the communis eating the bef cornpofition of laquer to number Sy who are either compelled to purchafe what they tfe cf particular perfons that have the Jecret cf preparing it, or to employ a very inferior kind of their own produBion, is not without fuch advantages as may make it to be properly con- fidercd as one means of improvement in the more elegant tnanufaBures. The means of faining paper, par chm.ent, woody ivory, bone, horn, and foncs of any kind, with ail the variety of colours, make the lajl contents VoL. I. a of xvill P R E F A C E. of this 'loork^ and wi:l^ I hope^ for piirpcfcs cf real ufe as 'll' el I as amifcment^ be found agreeable to many. Iheir greatefl relation to the at'ts cf defign lies^ however^ in the article cf faining f ones ^ from the frequent cccafons fatuariess and others 'who work in marble and alahcftr^ have to give artifcial colours to them, the method of doing which^ in a m^re perfeEl manver.^ is ne*‘ vcrthclefs known to very few at prcfent. Thefe are the particular topics cf" irfruhlion contained in the frf volume., by which this work is intended to promote the improvement cf the arts., and the more curious kinds of manufac^ tures; and excepting engraving., etching, and f craping rne%%otintos , they com prebend mofi fub- jecls that have any immediate relation to ibem\ though fame are touched upon in a more copious .f and others only in a brief mariner, accorciing to ike importance of the matter, or the room given for an advantageous enlargement on it. It may probably be imagined, that the ends propofed by this treatife may be anfwered by the ‘writings of others already publifsed, as there is 'more than one book in cur own language, which pretend to plans not greatly different from that on which it is formed, befides a multiplicity of others that prof e/s to teach partiezdar arts. But on a ' clofer exam nation, lam afraid it will by ?io means ‘be found that all the volumes 'which have been compiled on thefe heads taken together, and much lefs any fingle one cf the number, have effellually provided the inf or motion wanted, or even gone any covfdcrable lengths towards it. One could fcarcely PREFACE. xix fcarccly believe^ neverthelefs^ •without having pernfed them^ that almojl every book already voritten on thefe fubjeEis fo generally interejling JJjould be egrigioujly defedive in matter^ fonn^ and veracity^ and yet this is almojl equally the cafe of all where they are treated oj' in a more copious and entenfive maimer. But it will appedr kfs extraordinary when we Jlnd^ that the authors were for the mof part unacquainted^ in an ex-- pciBnental way^ with what they took upon them to teach ^ and not better qualfed with any fpecu- lative kno%vledge that could enable them to judge critically of what they procured on the authority cf others, They therefore either blindly copied after former writers^ or added' implicitly fuch additional articles^ as the reports of living perfons they inquired offurnifhed them with^ and were perhaps as often deceived by the dcfign as the ignorance cf tkofe from whom they j'ought injor^ motion^ being thenfelvei pqfbly not ahvays very Jolicitous fo much about the value^ as the quantity of what they colleBed, With refped to the preparation of painters colours^ Neri, in his treatife on glcfs^ feems to have laid the foundation for all the collediions of ' recipes of that kind publifoed here, probably from its becoming known by means of Merreds tratf lation to the writers,, whefe reading was not ' ext ei five enough to lead thpn to an acquaintance with Eire litis,, or the pajfages in Mathiohis, JVormius, Ccfalpinus,, and others who have cc^ caf orally touched on this head. a 2 Caneparius XX P R E F A C E. Canepariiis, i/i his hook De atramentlsj^ji^^ a more extcjifive view of the preparation and com-- pofition of pigments for paintings by adopting what Nerl had giveii^ ( though he has never qiiofe'd him by name ) and adding fever al more particulars omitted by him^ as likewife a varietv of other praBices relating to the arts^ but mixt with many erroneous ayid fafe accounts both cf the prccejfcs and the produce of them. Merret, an I.ngUjh phyfician^ tranfated Nerl into our language^ and gave notes upon him ; hut not havings as appears the leaf light to direB him in his opinions ^ but what he borrowed from other writers^ his obfervations neither illnf rated nor augmented^ in any material degree^ the co?y- tents of Neri*s book, Kunckel repuhlifoedfn the German language^ Ner?s work with Merref s notes^ and his own obfervations on both; and he alfo inferted.^ as well there as in bis other differtations on the art of making glafs, fever al procefes for the preparation of painters colour s., much better than thofe of Neri or the others before him^ as likewife many more ifefid recipes regarding the arts and myferious trades. 'But he feems to be the only writer^ who has treated, thefe fabjeBs in a more dijfufive manner^ that was' experimentally converfant with what he undertook to teach. After this^ Salmon, in his Potygraphices, took upon him to give inf ruB ions for the praBice of 'almof all the arts and myferious trades; and by the afifance of the former writer s.^ and private information^ got together a larger body cf mat- PREFACE. xxi ttr refpeSllng thefe fubje^s than any before him had done. His coUeclion ^oou/d indeed ha'iee had coujiderable merit at the time it was pubz liJJoedy if the '-calnablc parts had not been con^ founded with fucb a heap of abfurd fluff and jafiticsy as rendered every pafjage fufpiciouSy and dijpofed in a manner Jo void of all order and met body that ( an index being wanting likewfe,) it was impracticable, without turning over and carefully examining a great number of pages, to jind any article reauired', though fe- veral are repeated four or five times over in different places. But the difficulty of finding what was wanted, and uncertainty whether what might be found would prove a jiifi ac^ count of the matter, or feme extravagant Llun^ der or impofuion, d f courage d thoje who might have profited by many of hts recipes and infiriic^ tions, from feeking any afffiance from him in matters of a more nice or common nature,' This conduct in dige fling with Jo little care, and debajing with impertinences and falfijoods, the proper matter of that work, is however no great ground of wonder in the cafe of a writer, who, after he found this book met with a good reception from the public, was capable of conjpi- ring with bookfellers to blend^ a long dijcoiirfe oj' chiromantical Jignatures, or the means of telling fortunes by the lines of the hands, and a majs cf the moft ridiculous nonfenfe that has been written on the philofopher s Jlone, with the contents oj' a treatife profejfng to convey a practical knowledge of the ujeful arts, for the fake oJ enlarging the a 3 volume. xxii PREFACE. ^coliimey in order to raife the pricff under pre-* tence that vaiuable additions had been made to the ^u)ork. ^ T he laj} performance of this kind ivas pub--' liJJeed under the ajjiimihg title of the Sc'aool of Arts ; from which name one might have looped^ if not for a complete fyjiem ef knowledge of this kindy at leaf} for fomew hat better than the ear^ Her writers bad produced, efpecially as many amendment s of the former pradlice, as well as the introdudlion into ufe'of fever al iniportant, inventionsy had furnijhed much ampler matter ; but the author, inflead of f sunning their errors, or availing himfef of the advantages th^ prefent fate of things gave him over them, adopted with great augmentation all the defedls and faults .of thofe who had gone before him, and formed his work on a plan that deprived him of all opportunity of profiting of the greater adn vance towards perfeclion of the modern pradlicc', for, being a German, ( as 1 conjediure from his manner of changing the Englijh idiom ) he feems to have conceived, that nothing could be added to the labours of his countrymen', and has, therefore, with refpecl at leaf to thofe topics he has touched upon in common with this work, confined himfelf to tranfating and compiling from Kunckel, and other Germans, who being of cider date, could not fupply him with the im- ^provements and inventions of the prefent time. In conjequence of which condudi, obfolete and in- fuficient wethodi are taught, inf e ad of the mo^ dern and effedluah, and many of the rnof material articles F P. E F A C E. xxiU articles wholly omitted. In the injlance of gild- ingy all the vijiruvlions are conjined to metals i and zvttb regard even to therriy relate only to means now exploded ; and many important mat- ters jiridlly connecitd with his phiUy are not once mentioned in the booty while other s of muds Ufs conftquencey as the method of c hr yflalUz^ing Jilver under the rcjcmblance of a tree^ are re- peated four or five times over. Lite Salmout ■he gleaned aljo together all the extravagancies be could lay hold cfy in order to increafe the fize of the work to the bookfellers unreajonable Jiandard ; . and therefore inferted in his fir/i volurnty a nioji prepojierous and lying account of the breeding /ilk worms by putnfied veal, and producing firange ferpents by equivocal generation \ and in his fecond volume y a difer.- tation on the catchingy breedings feedingy and teaching nightingales y which takes up fxteen pages 'y with a multiplicity of other fuch wretch- ed ahfurdities tn both, as greatly dif grace thtt title oj Scliool of Arts, and conduce indeedy from their having been fo often admitted into tbemy to make works of this kind in general contemptible. But what is fill modi unhappy in the cafe of this author y he appears neither io have under jlood the language he tranfiated froiriy nor that he wri^te in. Whence the recipes and . cbfervations he has given are fo ill deliveredy by his mijiaking the fenfe of technical terms y and putting the name of one thing for another y with refped even to (ubftancesy aSy together with the alterations he has had the vanity to make a 4 in xxlv PREFACE. in them, from the ?nanner they were given by thoje he took them from, according to his own grojs mif conceptions, render them frequently un- intelligible, and not to. be depended upon in many injiances, "The pretenfons of the oflentatious works, the Cyclopedias, and Encyclopedias, and other fuch Didlionaries, have not been, however, much more ma ie goca than thofe of the School of Arts. For, indeed, it is jurpnftng how fbamejully filent thej'e hooks, which proje/s to comprehend every thing relating to fubjeth of this iitnde ore with rejpeti to mo ft of the efenttal articles', even thoje where the writings of others, had they been 'induflrioufly conjulted', would have furnifjecl what was required. Nor is the French uic^ tionary now publifoed, in the leaf an exception to this for, on examining it, in order to have informed myfelj of the methods prahlifed by the French, with rcjpetl to certain particulars in which they excel, I was JurpriJed to fnd, that, in fome cafes, every thing concerning them was entirely omitted, and i.n others, recipes, or other pa f ages, taken from fome of the old books with the moji injudicious choice, jupphed the place of the jujl account of the improved methods obtained from the ableji pradl it ioners of the fever al arts, which, in the propojals for this work, were promifed to have been given. There is, among many others, a glaring infance of this in the article Carmine; which pigment, being pre- pared at Paris in much greater perfedlion than pny other place at prefent, and of the greateji CQTl” XXV P R E F A C E. confeqiience in painting with water colours^ was well worth the attention of the compilers ojthis work Buty irijlead of any account of the mo* clem and (jfcacious prndlice of the preparation of carmine y which is not moreover a fecret m the hands -cj a Jingle perfon, but known to feve-^ ral who make it together with other colours ; all that is ihjerted on thii heady confjis oj three recipes taken from the old writers ; two oj which contain only directions for doing what will be barren of ' any ujtf u I product y and the other a> bad procefs taken from Kunckel for making lake of B raft I 'wood^ which is y never thelejsy prai/ed as the communication of an excellent method of making carmine, L was indeed difappointed in my expectations from that worky with relation to this important articley as it has never been in my power to df cover by experiment s, or procure by information, the knowledge of the means of preparing '"carmine oj equal goodnejs with that of the French, But 1 cboofe much rather to ac-- knowledge my ignorance in this point, thany like the preceding writersy to give methods which are injericr to thoje of the improved praBice, or to obtrude ahfurd and fruitlefs proceff'es on the public y in the place oj the proper and effec- tual, J am fenfiblcy I run fome hazard of a retali- at ion y in canvaffing thus freely the performances of others y Jince douhdefs my own is not exempt from errors and defeBs , ' But I thought it a neceffary vindication of theje kinds of writings, and of my own undertaking in particular, to Jhow that the ceiufe oj the difregard^ or even contempt y in which the great efi part of the books of this kind are held by the more juchciousy did not arife from the nature of the Jubjedly but the faulty manner of treating it, through the infuf^ ficiency and venahty of the authors. And with refpedi to my own mij carriages, I am fo little confcious of having occafioned them, either by neglect, or a mercenary condudl, that I am not in the leaf diffident of trujiing my work to the can- dour of the impartial, who will excufe fome mif takes and omifftons, which, in taking fo great a fcope offubjefi, it is aimofl impcfible to avoid, on the Jcore of fo many ifeful articles as will be found to be irijertcd ; for, with refpedl to the far greatef part, 1 can avouch them to be au- thentic and jif, either from ms own experi^ ments and obfervations, the information oj per- fons of undoubted veracity who have p radii fed them, or clear dedudlions from unquejlionable principle. . < Befdes the articles mentioned above, there is a mimber of others of confderable importance added in this edition, and many of thoje conr iaified in the firji are alfo illujirated, or altered, where late improvements, or more ext en jive in- formation have given occafon to it 7 he value of the work is therejore conjequently enhanced, ■as well as the volume enlarged*, but the editor, riotw 'itbjlanding the additional expence, has con- tinued the book at the original price, deviating from the praciice ofj'ormer pitblifbers of fuch ircatifes, who, when they have tnet with en- ' couragement PREFACE. xxvii couf'agement from the public^ hi the fale of one imprejfion^ have augmented the book with what^ ever matter they could fndy in order to have a pretence to advance its price. CON- CO CO C O N T E N. T' S. ■ P A . R T I. of the MATERIA PICTORIAy or, the nature, preparation, and ufe of all the various fubftances em- ployed in painting, i y C H A P, I. , ■ > ' O F the fubftances in general ufed In painting;—- ' p, i ; V C H A P. II, Of colours. E C T. I. Of colours in generaL 3 E C T. 'II. 0/ the ute7ifils,^ mfruments^ fiibfervient to the making and preparing colours^ / 13 SECT.* III. Of the general operations fubfervient to the making or preparing colours, 'X I %J SECT. IV. Of the nature and prepa- rations of particular colours, ' 43 CHAP. CONTENTS. CHAP. III. Of the vehicles, dryers, and other fubftances ufed in painting for the laying on ' and binding the colours. s S E C T. I. Of the vehicles^ dryers^ hi general. p. 144' SECT. II. Of oils in general. 150 SECT. III. Of particular oils. i<;'4 SECT. IV. Of particular dryers. 158 SECT. V. Of the fubfances ufed for rendering water a proper vehicle for colours. 165 SECT. IV. Of the fubfances ufed to render fpirit of wine a vehicle for colours. 1 69 CHAP. IV. Of the manner of compounding and mixing the colours, with their proper vehicles, for each kind of painting. SECT. I. Of the colours proper to he ufed with oils^ and the manner of com*> pounding and mixing them with the oils and dryers'. l yj SECT. II. Of the fever al methods of painting in water ^ as dfinguifhed by the colour s-i vehicles., and grounds y re- quired for different 'pur pofes. lyy SECT. III. Of the colours to be i fed in the PAINTING WITH WATER CO- LOURS, or in miniature^ with the manner ^ CONTENTS* manner of mixture^ or compofition of them^ with their proper vehicles, P» 1 7S SECT. IV* Of the colours ft to be ifed in difemper,^ or painting with fi%e^ and the manner of mixing and compoundmg them with the proper vehicles. 187 SECT. V. Of the colours proper to be ufed in jrefco paintings and the inixture of them with the water. 189 SECT. VI. Of the colours proper to be . , ifed in varnifD painting.^ and' the man- ner of mixing and compounding them withjhe proper vehicles. 19a CHAP. V. 'Of -the nature and preparation of paftils or crayons. 195 CHAP. VI. Of the grounds for the feveral kinds of painting. SECT. I. Of the grounds for oil paint- ing. 216 SECT. II. Of the grounds for painting in water colours ^ or primitive paintingi 220 ’ SECT. III. Of the grounds for painting in dfemper. . 222 SECT. IV. Of the grounds for painting in frefco. 223 SECT. V. Of the grounds for varniflo painting. 224 CHAP. C,0 N T E N T S. CHAP. VII. Of the methods of varnlfalng and preferv- ing pidlures and paintings. p. 224 CHAP. VIII. Of mending and cleaning pidures and paint- ings. S E C T. I. Of mending piEhires. 234 S E C T. II. Of cleaning p inures and paintings. .236 G H A P. IX. Of the nature, preparation, and ufe of the feveral fubftances employed in encaustic painting. SECT. I* Of the general nature of encaific painting. SECT’. II. Oj the grounds 'tfed tn en^ caufic painting. * — * ■ ■ - Of the colours to be ufed in encauftc painting. SECT. III. Of the manner of fixing the colours in the praBice of painting in encatific. SECT. IV. Of the inanner of painting %vitb crap ns in encaufic. 245 247 253 257 259 C H A CONTENTS. C H A P. X. ' ‘ Of the nature, preparation, and life, of the feveral fubftances employed in enamel painting. S E C T. I. Of the general nature^ of enamel p amt ing, p, 261 SECT. II. Of the apparatus^ orfet of iitenfls for the preparmg and laying on the grounds and colours in ejiamel painting, 266 SECT. III. q/- the general 7iature and, application of the fubfances tftd in amel paintings with their previous pre-^ paration, , 278 SECT. IV. Of the compounding andpre^ paring the fluxes for enamel painting, 322 'SECT. V. Of the compofition and pre-^ paration of white enamel for grounds ■ and other pur pofes, 33a SECT. VI, Of the compoftion of the colouring fubfances-^ together with the proper fluxes in order to the painting with all the variety of colours in enamel, 336 SECT. VII. Of the majiner of laying on and burning the ejiamel grounds, 335 SECT. VIII. Of the manner of laymg on and burning the e?iamel colours, , 361 CHAP. XI. Of the method of painting on glafs by burn- ing, or with tranfparent colours that vitrify. SECT. CONTENTS. SECT. T. Gf the general fiature of paint" ing on glafs with vitreous colours, p. 362 SEC'r. 11 . Of glajs as a ground for painting with vitreous colours^ or by burning. .365 SECT, III. Of the fluxes and colours to be tifed in painting on glajs by burning. 367 SECT. IV. Of the manner of laying the- colours on glafs g rounds.^ and burn- ing them. 371 • ^ CHAP. XII. Of gilding enamel and glafs by burning. 374 C H A P. XIII. Of the taking off mezzotinto prints on glafs, and painting upon them with oil, water, or varnifh colours. 375 CHAP. XIV. Of colouring or wafhing maps, prints, &c. 381 PART II. Of the feveral arts ufed in making outline fketches of defigns from nature, or de- pidled reprefentations; and of the means of taking calls and impreffions from figures, bulls, medals, leaves, &c. VoL. L b CHAP. CONTENTS, CHAP. I. Of the devices employed for the more eafily obtaining a juft outline in making defigns from nature, and the various methods of off-tracing, calking, and reducing pidures, prints, or drawings. ' p, 385 1 ■ C H A P. II. . Of the means of taking cafts and impreflions, from' figures, bufts, medals, leaves, &c. 404 PART III. Of gilding, filvering, bronzing, japanning, laquering, and the ftaining different kinds of fubftances, with all the variety of ' colours. C H A P. I. Of gilding. S E C T. I. Of gilding in general. 42 1 SECT. II. Of the injlruments that are common to the oil^ burnifh^ and japan^ ners gilding. ■ 424 • SECT. III. Of the manner f oil gild-- ing^ and the preparation of fat oil. 426 SECT. CONTENTS. SECT. IV, OJ burnijlo gildings with the' preparation of the proper ft%es^ p. 43 1 SECT. V. Of japanners gilding. 438 SECT. VI. Of gilding paper and veU lum^ or parchment. 444 SECT. VII. Of gilding leather. 453 SECT. VIII, Of gilding glafs without annealing or burning. 469 Of filvering, Of bronzing. CHAP. II. CHAP. III. 471 I 476 CHAP. IV. Of japanning. SECT. I. Of japanning in general. 479 SECT. II. Of jap an grounds. 483 SECT. III. Of painting japan work. 495 SECT. IV. Of varnijhing japan work. 496 SECT* V. Of gilding japan work. 501 CHAP. V. Of laquering. 502 f CHAP. CONTENTS. CHAP. VI. Of ftaining wood, — Ivory, bone, and horn,— paper, and parchment, — alabafter, marble, and other ftones, of various colours. S E C T. I. Of Jlalning wood, p. 508 SECT. II. Of Jlahiins: ivory ^ bone^ or horn, . 515 SECT. III. Of Jlaining paper ^ or parch- ment^ of various colours, ■ . 519 SECT. IV. Of faming alabafer^ marble -t and other f ones ^ of various colours, 521 ADVERTISEMENT. I F any VN^ord occur in the contents of the following pages, which may not be under- ftood by the reader, on confalting the index, a reference will be always found to fome place where it is fully explained; this work being intended, along with other purpofes, to an- fwer that of a gloffary to the technical words and expreffions, relating to the fiibjefts treated of, peculiar to' painters and other artifts. PART PART I. OF THE MATERIA PICTORIA: The nature, preparation, and ufeof all the various fubftances employed in painting. Of the fubftances in general ufed in painting. T H E principal kind of fubftances ufed in painting is the CO LOURS : by which is to be underftood, all the various bodies employed by painters, for pro- ducing the difference of hue or teint. But, as feveral of thefe are of a folid confiftence, and an earthy, or incohering texture, it was necef- fary, as well for the laying them on, and fpreading them properly, as for the binding and making them adhere to the grounds on which they are laid, that, in many cafes, fomewhat of a fluid nature fliould be added to give them an unduous confiftence while ufed, and proper degree of tenacity when again d O R, CHAP I. VOL. I. B 2 Of THE Substances To this end, many different kinds of bo- dies have been applied; from whence proper VEHICLES have been formed, which, at the fame time, anfwer the double purpofe of reducing the colours to a ftate fit for their being worked with the brufti or pencil, and of cementing them to each other and the ground they are laid upon; as alfo defending them from being eafily injured by accidents. The fubftances ufed in painting, may be therefore all confidered as of thefe two kinds; Colours and Vehicles. For, though there are feveral ufed occafionally, which are not imme- diately fubfervient to the principal intentions of vehicles ; yet, being employed to remedy the defects of thofe which are, they muft be deem- ed as fubordinate to them; and ought, con- fequently, to be claffed with fuch as compofe vehicles. The nature of thefe fecondary intentions I fhail, therefore, point out in its due place; and reduce the fubftances ferving to them to their proper clafles accordingly. As It ih necef- fary, in order to underftand critically and com- pletely the art of preparing and ufing the various articles of the materia piBoria-y to comprehend clearly the general intention in which each is ufed, as well as to know the particular purpofe to which it is applied. And, •for the fame reafon, as alfo for the fake of being intelligibly concife, I fhall treat of the whole under fuch methodical diftin£tions as refer to thefe intentions: adopting, heverthelefs, on 2 every USED IN Painting. 3 every occafion, the terms of art in common ufe; and explaining them, according to the meaning they bear, when applied with any propriety or precifion, by the particular rela- tion they have to thefe intentions. CHAP. II. Of Colours. SECT. I. Of colours in general. C OLOURS may be either PIGMENTS or FLUIDS, pigments^ is meant all fuch folid bodies as require to be mixed with fome fluid, as a vehicle, before they be em- ployed as paints (except in the cafe of crayons, where they are ufed dry). Thefe make the far greateft part of the whole: the fluid co- lours being only a fmall number of aqueous tlnftures, which come into the clafs of water colours; and afphaltum, a bituminous fubftance, which is fometimes employed in oil painting. Colours are diftinguifhed into feveral kinds, . according to the vehicles in which they are worked: as oil colours^ water colours^ enamel colours^ &c. The fame forts of pigments, be- ing however, as in many inftances, employed B 2 in 4 Of the Substances in more than one kind of painting, as vermw Hon and lake in feveral, and ultramarine in all, I fhall not diftribute them into claiTes, in that view, till I come to fpeak of their particular application; but treat at prefent of them pro- mifcuoufly in teaching their general nature and preparation; dividing them according to their affinity In colour only. As this method of arrangement vrill not only render each article more eafy to be found; but, at the fame time, exhibit, to the artift, together, the whole ftock of every kind from whence he muft take what he wants on each occafion: by which, he will be the more enabled to choofe what may beft fuit his particular purpofe. For the fame reafon, alfo, this method is certainly more ex- pedient than the difpofmg them in clalTes, ac- cording to their natural relation to each other, as earths, minerals, vegetables, &c. which would lead to the like kind of confufion and repeti- tion. The principal qualities In colours, confi- dered with regard to their perfedHon or faults nefs, are two; purity of colour^ and durable-- nefs. Purity of colour is, by the painters, called BRIGHTNESS \ and the defeft of it, FOULNESS^ or fometimes the BREAK’- ING THE COLOUR. Durablenefs is called STANDING; and the negation or want of it FLYING, or FLYING OFF. Thefe terms, for concifenefs, I fhall ufe in fpeaking of thefe qualities. Bright^ USED IN Painting. 5 Brightnefs and Jlanding well are the only pro- perties which are neceffary to the perfection of every kind of colours; and they equally re- late to all; but there are others which are elfential to many forts, with regard only to ' particular purpofes and ufes. Such of them, however, as do not fall within the general con- lideration of the nature of colours, will be treated of in thofe parts of the work where the particular ufes of colours come in queftion. The moft confiderable of the more general properties of colours, after purity and durable- nefs, or brightnefs^ and funding well^ are tran- fparency and opacity: for according to their condition, with refpeCt to thefe qualities, they are fitted to anfwer very different kinds of pur- pofes. Colours which become tranfparent in oil, fuch as lake, Pruffian blue, and brown pink, are frequently ufed without the admix- ture of white, or any other opake pigment. By which means, the teint of the ground on whkh they are laid retains, in fome degree, its force; and the real colour, produced in the painting, is the combined effeCl: of both. This is called GLAZING: and the pigments, in- dued with fuch property of becoming tranf- parent in oil, are called glaring colours. The fame holds good alfo of fuch colours as are tranfparent in water : only when they are there ufed in this manner, they are not called glaring but WASHING colours. When colours have no degree of fuch tranfparency in ^le vehicle in which they are ufed, as vermilion, B 3 King’s 6 Of the Substances King’s yellow, and feveral others, they are faid TO HAVE A BODY, and TO COVER. The property of glazing or wajlomg is of fo much importance, both in oil and water, that no other method can equally well produce the fame effed in many cafes, either with regard to the force, beauty, or foftnefs of the co- louring. It is therefore very effential to the perfedion of feveral kinds of pigments that they* fhould poffefs this property in a com- plete degree; but, in other inftances, the ufing colours with aftrong body is not lefs neceffary, cfpecially for the grounding or laying in, as it is called, of many objeds to be painted. There is another material quality in colours, that relates only to their ufe in oil, which is the drying well and (as it is called) not fattening. By FAl TENING is meant, a coagulation of the oil, that frequently happens on its commixture with feveral kinds of pigments, by the effed they have upon it; from whence, after fome time keeping, it is rendered of fo vifcidor glutinous a confiftence, as to be wholly Incapable of be- ing worked with either brufli or pencil. This quality, when found in them, deftroys almoft wholly the value of fuch pigments for the purpofes of the colourman. As they fell a great part of them ground with oil, and tied up in pieces of bladder, w^here they are kept till there is a demand for them ; which fre- quently does not happen foon; and, therefore, gives time for their fpoiling in confequence of this quality. But to painters, who mix the colours USED IN Painting 7 colours for themfelves, on their pallets, with the oil, this property is not an equal inconve- nience, when in a leffer degree. Only, in general, it mud be obferved, that colours, in proportion to their tendency to fatten, are flow in drying ; and when the oil once contradls this date, it will be a very long time before it Vvull become duly hard and firm in the paintings. There are two other qualities of colours in general that relate only to their teint or hue ; but which render them neverthelefs ht or impro- per, in a very material degree, for different pur- pofes. They are diflinguifhed by the nam.es of JVARMTH COOLNESS: terms which indeed are ufed very frequently by painters ; but, for the moft part, very indefinitely, and without any precife or clear meaning. What is meant, when properly ufed, by warmth, is that fiery effeft which a fmall admtion of yel- low gives to a true red; and that glowing ap- pearance which red imparts to either yellow or blue. By warmth-, therefore, in red, is to be underftoodj^a fmall inclination towards orange; by the fame term, applied to yellow, a like tendency by the admixture of red ; and, by the fame, again in the cafe of blue, muft be underftood its flightly verging on the purple. By coohiefs-^ is to be underftood, the oppofite to warmth. But this term is feldoin ufed, ex- cept in fpeaking of yellow and blue; and there it means either the negation of that which caufes warmth, or a tendency to green, in either colour, by a flight admixture of the other. B 4 The 8 Of the Substances The fenfe of the word warmthy when ap- plied to colouring or the combined appearance of various teints, muft not be confounded with that which it has when fpeaking of particular colours. For there It relates to the producing a ftrong effedl, by the difpofition or contrail of the colours, or the groflhefs of the teints; and not the qualities peculiar to, or inherent in the colours themfelves. The colours which may be ufed In all the feveral kinds of painting, except fome peculiar to enamd, are as follow: HED. BLVB. i Class I. fVcrmilion. Native cinnabar. Red lead. Scarlet Oker. Common Indian red. Spanifti brown. < ^ erra di Sienna burnt Scarlet or tending to the orange^ Carmine. Lake. Rofe pink. Red oker. ^Venetian red. 1 \Crimfony or tending T to the purple » Class II. ( Ultramarine. Ultramarine alhes. Pruflian blue. Vcrditer. ^ Cendre blue, or fanders blue. Indigo. Smalt. Bice. ^Litmus, orlacmus. till the whole contents become of a red colour; after which take the pipkin out of the fire; and, being ‘‘ cold, break it, and feparate the calcined vitriol from it. Take then of this calcined vitriol powdered two parts, of the fcoria or ‘‘ clinkers of a fmith’s forge, finely levigated — Sturbridge clay or Windfor loom dryed, and powdered, — and fine fand, each one part: mix them well together, and then temper them, with the blood of any beaft, till they become of the confiftence of mor- tar; a tw’^entieth part of the w^eight of the whole of fhort hair being beaten up wfith them.” The feveral furnaces neceflary for making the finer kinds of colours are ; thofe for fub- liming cinnabar for making vermilion ; — for fub- liming King^s yellow ; and for calcining blood for making Prufian blue^ oker^ idtr amarine^ &c. The FURNACE FOR VERMILION, as Well as the operation to be performed in it, are of the moft nice nature of any objects relating to the art of making colours : it is indeed fo difficult a thing to manage w^ell the manufaflure of ver- i6 Of THE Substances inillon, that it is given up in general in this country, even when the price of quickfilver would make it very profitable ; and the greatefl; part, if not the whole of the confumption, is fupplied from Holland: but if any will prepare well the apparatus as here directed, and execute properly the procefs given be- low, they need not doubt, with fome ex- perience, but to be able to carry on this ma- nufafture as well as the Dutch. The man- ner of conftruding the furnace may be as follows. The firft ftep muft be to procure the proper iron-work, which confifts of bars for bearing the fuel,- — a frame, the doors for lighting the fire, — a ftrong plate for fupporting the brick- work over them,-^ — an iron frame and ftoppef for feeding the fire, — and an iron ring for lay- ing over the top of the furnace, for the better hanging the bodies or fubliming veffels in it. The bars fhould be of hammered iron, eight in number, eight inches in length, a quarter of an inch in breadth, half an inch in depth, and fixed firmly by each end, at the diftance of a quarter and an half quarter of an inch from each other, into two ftrong crofs-bars ; which crofs-bars muft be fufEciently long to admit of their fufferingthe brick-work to have good hold of them; and muft be made flat at their ends, on that account. The frame and door muft be alfo of ham- mered iron. They may be of the length of the area or fire-place as formed by the bars ; but USED IN Painting. 17 but need not be more than four inches high. They {hould be of the ufual form of thofe made for the furnaces of coppers, but ftronger; and it is better to have the latch bigger than is common, and carried acrofs the whole door; which will give it ftrengthto refift the weight of the fuel, that otherwife, when the iron is foftened by violent heat, is apt to force the middle part outwards. The iron bar to lay acrofs the frame of the door may be three inches in breadth, and about three inches longer than the frame itfelf; it may be either of caft or hammered iron, as fhall be moft eafy to be procured. The frame and ftopper for feeding the fire fhould be alfo of hammered iron ; the frame may be four inches long, and three inches high. It may be formed of four plates of a moderate ftrength; of which thofe of the top and bottom muft Hope downwards towards the fire in a parallel; they muft alfo project beyond their joining with the fide plates, in order to their being fixed in the brick-work. The ftopper muft be formed of five plates, put together in fafhion of a box, (as in the doors of portable iron furnaces) and of fuch figure and proportion as to Aide into the hole formed by the frame, and fill it up exactly, fo as to render that part of the furnace intire, when it is not taken out occafionally to feed or ftir the fire. The hollow of this box or ftopper muft be turned towards the fire, and filled with fire- lute ; and a handle muft be fixed in the middle VoL. I G of l8 Or THE SUBS^TANCES of the outward part, for the more commodi- ous ufe of it when hot. The iron ring for hanging the bodies or fub- liming veifels in the fire mull be made of call iron. It fhould be of about four inches depth, and of a conic form, converging outwards. It fhould have an outward rim, or margin turn- ing off from the ring horizontally, in order to its lying on the brick-work of the furnace. The diameter of the ring mult be in propor- tion to the fize of thefublimers to be hung in it: it fhould be about two inches wider in the lower part than their diameters; and mufl diverge or inlarge itfelf upwards half an inch. The iron work being thus prepared, and a proper quantity of Windfor bricks, and the loom they are made of, or Sturbridge clay, as well as common bricks, and coal-afh, and common mortar, provided, the dimenfions of the furnace muft then be thus fettled. Take the diameter of the greatefl fublimer intended to be- worked in it, and add to it two inches to allow for the lute, if any fhould be ufed round it; then add twenty-two inches, and it will give the diameter of the whole area of the furnace. The dimenfions of the furnace being thus fettled, the ground plan muft be made in the following manner. A round of bricks muft be laid of the dia- meter of the area of the whole fabric as fettled above, and the bars muft be laid in the centre of USED IN Painting. 19 of It, In their proper pofitlon; and a line drawn clofe at the back of the furthermofl; crofs-bar, which miift begin a quarter of an inch beyond the infertion of the outermoft of the long bars on one fide, and extend to a quarter of an inch beyond the outermoft bar on the other fide. From the extremity of this line, two others muft be drawn, parallel to the fides of the outermoft bars, and extended to the circular line which marks the area of the whole fabric. The ground plan being fo marked, a cylinder of brick-work muft be ralfed in this circle, leaving a hollow fquare within the lines formed as above for the area of the fire-place and a£h- hole. This cylinder muft be carried up about eight inches, and may be built of common bricks and coal-afti mortar; but they muft be laid folid, that the whole mafs may not fbrink when fubjeded to a great heat. When this cylinder of brick-work is raifed, the bars of the fire-place muft be laid over the innermoft part of the vacuity left for the alh-hole ; and the door, with its frame, muft be allb placed in their proper pofition in the front of the bars, which will not be, in this manner of conftru£):ion, on a level with the exterior fur- face or front of the furnace, as in thofe of the common kind, but only half the length of the bars from the centre of the whole furnaces. The brick-work muft be then again carried up fix inches higher, in the fame manner as be- fore; only it muft be made to take proper hold both of the crofs-bars of the fire-grate and the C 2 frame 20 Of the Substances frame of the door; but in this part of the fabric the courfes next the fire fhould be of Windfor bricks, and laid in Windfor loom, or Sturbridge clay. The fabric being raifed to this height, the iron plate prepared for that purpofe muft be laid over the opening of the brick-work, from the top of the door-frame to the exterior fur- face of the fabric, that the brick-work may be carried inti rely round about, and the cylin- der of brick muft be again proceeded with as before; only it muft be now continued intirely round, forming only an area in the middle, which muft be made floping from that which is to hold the fuel, and muft inlarge itfelf in fuch manner that in raifing the furnace eight inches high the diameter of the cavity may be equal to the diameter of the fubliming vef- fel, with the addition of fix inches, to allow for the fpace in which the fire muft come round it on each fide. In the laft courfe of bricks which raife the fabric to this height, the hole muft be left for fixing the frame that is to form the opening’ for feeding the fire; which muft be accord- ingly placed in it in fuch manner that the Hope formed by the upper plates, which com- pose it, may incline towards the fire. The proper fituation for this hole is in the front of the furnace, over the opening leading to the door of the afti-hole. From this height the brick-work muft be carried up, forming a hollow cylinder for four USED IN Painting. 21 four inches more, when a courfe of bricks, of which the inner ends are cut floplng, mull be laid fo as to contradl the circk of brick-work to the diameter of the iron ring for fupporting the fublimer, which mull be then let into this opening left at the top of the furnace, and fixed with fire-lute; the bricks furrounding it being well pointed with the fame. This part of the furnace, from the fire-place to the top, fhould be intirely built of Windfor bricks, laid with Windfor loom or Sturbridge clay. In the laft courfe of bricks mull be left an opening of four inches length for venting the fmoke into the chimney; over which open- ing an iron plate mull be laid, and carefully pointed with fire-lute, that the air may have no accefs to fpoil the draught. The chimney may be about fixteen or eighteen feet high, and the hollow about fix inches fquare, or of an area equal to that, and need not be built of a greater thicknefs of bricks than is necelTary in order to its fupporting itfelf. The FURNACE FOR SUBLIMING KiNG’s YELLOW muft have a fand-pot, as the heat of the naked fire would be too great. This pot may be of a greater or lefs lize, accord- ing to the quantity of the King’s yellow pro- pofed to be made; but where there is no particular convenience in varying from it, the ordinary fize will be found moft commo- dious. The fand-pot being procured, as likewife the reft of the iron-work, according to the C 3 preced- 22 Of the Substances preceding direftions given for the furnace for vermilion, except the iron ring for the top fof the furnace, which in this cafe muft be changed for a flat rim of caft iron of four inches breadth, with a groove to receive the pot, and fupport It hanging in the furnace, the plan of the furnace mufl be made out in the following manner. The diameter of the pot being firfl taken, fix inches mufl be added to it, for the cavity to admit the 'fire to come round the pot, and the length of two bricks to allow for the thicknefs of the fides of the furnace : thefe being put together, give the diameter of the whole furnace. To find the due height, the depth of the pot muft be firft taken; to which muft be added ten inches for the diftance betwixt the pot and the bars ; eight inches for the diftance of the bars from the ground, with the height of a brick for a courfe that muft be carried round the edge of the pot ; which being all put together, give the height. The building may be then carried on, in the fame manner as was before advifed for the furnace for vermilion, till all be completed but the laft courfe; and the rim muft be then laid on the top of the brickwork, and well pointed wfith fire-lute : after which, when thefe parts of the furnace are fo dried as to hold well together, the pot fhould be let down into the furnace, where it will hang by its margin or turned edge, refting on the groove made for it in the iron rim : and. another courfe of bricks USED IN Painting 23 bricks muft then be ralfed, in a continued line with the fides of the fand-pot, that part of them which touches the pot being laid in fire-lute. The FURNACE FOR CALCI\’ING THE Prussian blue, okfr, ultramarine, &c. may be of that kind commonly called a wind-furnace; and may be conftrucfted in the following manner. Firft prepare a fet of bars, which may be a foot in length, and fix- teen in number, wfith a ftrong frame and door, of w^hich the breadth mufi; equal that of the bars, and the height be a foot; as alfo a plate, or two ftrong fiat bars, to fup- port the brickwork over the door-frame, and another to fupport the brickwork over the afh-hole. A foundation or pedeftal of bricks muft then be raifed, about three feet and a half high, and two feet four inches fquare ; which may be done with common bricks and mortar ; and need only, indeed, be four w^alls ; the hollow formed by which may be filled up with rubbifh, and floored over with bricks or tiles. On this pedeftal, raife three other w^alls ; one on each fide, and one at the furthermoft end, of the whole brick thicknefs, forming an area betwixt them, of the length of a foot, and of the breadth of ten inches ; of which area the front will necef- farily be open,* from the default of the fourth wall. Over this opening, in the front, lay the bars in the centre of the brick-work, and place along with them a plate that C 4 wtII 24 Of THE Substances will reach from their edge to the extremity of the furnace, to bear the brick- work which muft lie over that part of the hollow. Then carry up the fides as before, but with four w^alls in- ftead of three, to inclofe the area of the fire- place Intirely, taking care that the firft courfe have .good hold of the flat ends of the crofs- bars. This part muft rife eight inches above the bars, and then the door and frame muft be fixed, and the other fides carried up as before. When the building is carried to the height of the door and frame, the ftrong plate muft be laid to bear the brick-work over it; and the hollow muft then be made to converge, till it become fo narrow as to form a chim- ney, of which the area of the cavity may be fix inches fquare, or it may be turned into a funnel, or flew, to communicate with any other chimney, if fuch there be fufficiently near. But, as a wind-furnace demands a very confiderable draught, if ^the flew be made from it into the chimney of any other furnace, which may not happen to be at work when there is occafion to ufe this, care muft be taken to ftop the chimney of the other furnace, be- low the admiflion of this flew into it, to pre- vent a falfe draught, which would otherwife intirely deftroy its effects on the wind-furnace ; and for this end regifters fhould be always put to the flews, or chimneys below where the flews eater, of each furnace, whenever two USED IN Painting. 25 two or more vent themfelves into the fame common funnel. SuBLiMERS muft be of glafs, and may be generally had ready made of a proper figure at the glafs-houfes, where glaffes are blown for the common chymical purpofes. They mufl: be inquired for under the name of bodies^ or cucurbits, which name they bear when ap- plied to medicinal ufes. They fhould be chofen of a fpheroidal form; neither the conical lhape in which fome, nor the oval in which others are made, being fo commodious for fublirning colours as a .longifli fpheriod; but where they cannot be obtained of this figure, an oval may be difpenfed with. The magnitude of the fublimers muft be determined by the quantity of matter to be fublimed, and the dimenfions of the furnace; but thofe ufed in fand-pots fliould be always at leaft two inches lefs in the diameter than the pot in wTich they are to be placed ; and thofe ufed in the naked fire fhould never be more than four inches lefs in diameter than the iron ring of the furnace in which they are to be hung. Where Vermillion is made in great quan- tities, earthen fublimers are ufed ; but vx fliall fpeak of them in their proper place. A PEWTER BOILER is neceffary for boiling cochineal, brazil, or other woods, French ber- ries, &c. for making lake, brown pink, Pruflian blue, and many other pigments. It is requi- fite that this metal fhould be ufed for it, be- caufe 26 Of the Substances caufe iron and copper, as they will neceflarily be corroded in a greater or lefs degree by the faline fubftances reqiiifite to be ufed for making feveral forts, are extremely injurious to the co- lours, and fhould therefore never be fuffered to approach the finer kinds. The form of this boiler may be cylindrical, v/ith a bottom making a fedion of a fphere. Its dimenfions fhould be three feet in depth, and one diameter: but this may be varied, as the quantities of colours propofed to be made may vary the occafion. At the height of about two feet muft be joined to it a ftrong margin or rim, by which it may be hung in the fur- nace; and a little above, muft be two bow handles oppofite to each other, by which it may be lifted in and out of the furnace. The whole muft be wrought ftrong, as there will be frequent occafion to move it, when contain- ing a confiderable quantity of fluid. The furnace for this boiler muft be con- ftrudled in the following manner. A rim of iron, fuch as was before directed to be ufed for hanging the fand-pot, together with the other iron-work, muft be firft procured. The diameter of the boiler being taken, as alfo its depth below the rim by which it is to hang, the proceeding in the fabrication may be the fame as that of the furnace for the fand-pot, till the iron rim is to be fixed; when the courfe of bricks, which is raifed upon the rim in that kind of furnace, muft be in this wholly omitted. It is not improper, however, to allow two inches ' more USED IN Painting. . 27 more diftance in this furnace betwixt the boiler and the fire than was directed for the fand-pot, becaufe the boiler may otherwife be more liable to be melted on any negligent treatment. When the boiler is ufed, it is to be lifted into the.fur- nace, and hang by the rim, which muft reft in the groove made for that purpofe in the iron rim; and if it is to be emptied while the fur- nace is hot, it fhould always be lifted up with two or three gallons of fluid remaining in it; otherwife the bottom will be melted by the heat of the furnace : and, as the round figure of the bottom renders it not proper for ftanding of it- felf on the flat ground, a bafs-work haffock or cufliion fhould be made, finking in the mid- dle correfpondently to the form of the bottom of the boiler. A PEWTER BOWL, with a handle of proper length, fhould be had to the foregoing boiler, for lading out any matter boiled in it; as like- wife an inftrument of the fame metal, made like a poker, but with a flatter end, for ftirring about any folid matter that may be put along with fluids into the boiler. Retorts are ufeful for fome purpofes in the making colours ; and glafs receivers of various fizes for many. They may both be of the form in which they are ufually found ready made at the fhops and glafs-houfes ; but it is proper to have fome receivers very large, and with necks fo wide,' that the hand may be in- troduced into them to clean them thoroughly. A BAL^ 28 Of the Substances A B ALNEUM MARIJE^ or evaporating bath, is likewife neceflary. It maybe made by fitting a tin boiler, formed like the pewter one, to the above defcribed furnace ; but it need only be a foot in depth below the rim for hang- ing it in the furnace, and only one inch in height above. To this boiler, a pewter veffel for containing the matter to be evaporated muft be adapted. It muft be at leaft two inches lefs in diameter than the boiler, and muft have a rim like that of the boiler, by which it may reft on the edge of the boiler^ hanging in its cavity. Proper filters are extremely requifite for the preparation of many pigments. They idiouid be made of pewter, in the form of the common earthen cullenders, but with more, and larger holes ; and their fize fhould be fuch as admits of their interior furface being w^holly covered by a fheet of filtering paper, when laid into them. Their edge fhould be turned outwards, fo as to form a margin or rim, by vAIch tliey may hang on a proper frame over the tubs, or other veflels, which are to receive the liquid they filter ; and this frame may be only two narrow pieces of wood, of fufficient ftrength to bear the weight of the filter and its contents, fixed together by two other crofs pieces, at fuch diftance that the filter may juft pafs betwixt the four, and hang by the riin. For thefe filters muft be provided proper paper; as alfo linen cloths to lay over or under the paper occafionally. The kind USED IN Painting. 29 kind of paper fit for this purpofe is that called bloom or JUtering paper; but care mufi: be taken in the choice of it; for it is difficult to find, in common ftationers fhops, fuch as will even moderately well anfwer the end. For coarfe colours, fuch as rofe pink, flan- nel bags may be employed for expedition. They fhould be made in the form of pudding bags; and are called, when applied to the fame purpofe in medicine, Hippocrates’s fleeve. They fhould have proper frames for fixing them, which may be made of three flicks or wooden rods, fixed together at fuch a diftance that the bag, being hung upon them by three loops faftened to it, may have its mouth or opening fubtend to a due width for pouring in the matter to be filtered. Long boards muft be like wife provided for drying colours. They fliould be made of found wood, and very well plained; and it will be yet better, if the furface be made flill fmoother by varnifhing them with feed lac varnifh. Chalk-flones are alfo proper on fome occa- fions, for expedition, for the drying ultrama- rine, Pruffian blue, w^afhed okers, and feveral other kinds; but they muft never be ufed for lake, carmine, or any colours made of vegeta- ble matter ; for the alkaline quality of chalk may be very detrimental to fuch colours. Where Pruffian blue is made in very great quantities, there is a particular apparatus ufed for drying it; but we fihall fpeak of that in its proper place. ^ ” ' The 30 Of the Substances The levigatlon of colours, being of the moft general ufe of any operation, is likewlfe re- quired in many cafes to be moft perfe£Uy per- formed; and, therefore, proper inftruments fubfervient to it are extremely requifite. Hand- mills, and fdmetimes even horfe- mills, areufed for grofter forts of pigments, or where very large quantities are to be difpatched: but, as they are to be had of the proper workmen, duly conftrufted, it is needlefs to defcribe them here. In the cafe of vermilion, mills of different degrees of finenefs are requifite : and that through which it is laft paft ftiould be of fteel, and the moft clofely fet that can pof- fibly be wrought. But for this end, inftruc- tions here are unneceffary, as dependence muft be had on thofe who are the proper makers of fucli machines; and who will fucceed beft in follov>dng their own meth ds. The mullar and ftone are generally ufeful, and ‘fhould alone be depended on,, at leaft for completing the levigation after the grinding them in the mills, whenever the colours are of any great value or nice ufe. Bafons fhould likewife be provided for wafhing over the colours accord- ing to the manner below deferibed. SECT. USED IN Painting. 31 SECTION III. Of the general operatmts fuhfet^vmtt to the making or preparing colotcrs. T he operations fubfervlent to the making and preparing colours, are fiiblimation ^ — calcination, — -fohuion, precipitation, — -Jiltra-- tion, — and levigation. As the practice of moft of thefe operations is confined at prefent, in a great degree, to the purpofes of chymiftry, and therefore very little imderftood by any, except thofe who concern themfelves in that art, I fhall endeavour to ex- plain them, as far as they relate to the prepara- tion and treatment of colours. I fhall alfo' give fuch general directions for the performing them as may take away the neceffity of repeat- ing, on every occafion, thofe particulars which occur in almoft all the proceffes that partake of the fame nature ; but with refpeCt to fuch operations as are more commonly known and pradifed, I fliall only touch on them in a more general way, without entering into minuter confiderations regarding them. ' Of fM'^^eition. Sublimation* is the raifmg foUd bodies in fumes, by mmns of heat; which fumes are afterwards colle&ed by condenfation, either in the 32 Of the Substances the upper part of the fame veffel where they are or in others prope that purpofe. The end of fubllmatlon is, either to fepa- rate fubllaiices from each other, in order to the purification of one of them, or to mix them more perfeftly than can be effefled* 'without fubjedling them to fuch a degree of heat as will neceffarily render them volatile. The means are, to put the matter, whether fimple or compound, into a proper veffel or fublimer, and there give it a due heat, by placing it in a fand-pot, or the cavity of fome furnace where the naked fire is required; in doing which the followfing particulars are the moft material objeils of attention. The firft care muft be to provide glaffes of the kind above-mentioned, page 25, and of a due fize, which muft be regulated, as was be- fore mentioned, by the quantity of matter to be fublimed, and by the dimenfions of the fand-pot, or cavity of the furnace 'wdiere they are to be ufed. . The fublimer ufed for making King’s yellow, or for any other operation to be performed in a fand-pot, need no previous preparation. But thofe to be ufed for vermilion, which muft be placed in the naked fire, fhould be firft well coated with the fire-lute; and a rim of the fame matter muft be worked round the coat at about two-thirds of the height of the fublimer, to fupport it in the iron ring when let down into the cavity of the furnace. This coat of lute fliould rly adapted to it for USED IN Painting. 33 fhould be laid on of fuch thicknefs that it may be about half an inch thick when thoroughly dry, and if it be laid on at feveral diftances of time, fo that the firft covering of the glafs may be pretty dry before the fecond be put on, it will be the better; but great care fliould be taken that the whole be of fufficient drynefs before the fublimer be let down into the furnace, and that the rim of lute fit well the iron rim; for otherwife ill fuccefs will moft likely attend the procefs of the operation. In default of the fire-lute, the following may be fubftituted in its place for the coating fublimers, and is in- deed, on account of its cheapnefs, moft com- monly ufed, though greatly inferior to the other with refpeft to the fecurity of the glafles. Take of Windfor loom, or very good com- mon loom, fine fand, and dung of horfes ‘‘ which feed on hay, each equal parts ; tem- ‘‘ per them with water, or the blood of any beaft, and beat them well together.” To fix the fublimers in the fand-pots, an inch and half, or two inches of fand muft be firft put into the pot, on which the fublimer muft be gently fet ; the pot muft then be filled with fand up to the brim, and the matter to be fublimed muft be put into the fublimer through its neck or mouth, which muft be afterwards covered by a piece of tile, or flat glafs, laid loofely upon it. The fublimers ufed without a fand-pot muft be fixed in the cavity of the furnace, by let- ing them through the ring of iron on the top VoL. I. D of 34 Of the Substances of the furnace, till they hang by the rim of lute After which the joint, formed by the rim and ring, muft be made good by pointing with the fire-lute ; which muft, however, be of a dryifti confiftence, and ufed fparingly, left it moiften the lute of Which the rim is made, and caufing it to give way, occafion the fublimers’ flipping through into the fur- nace. The fublimers being fixed, the fire muft be lighted, but muft be kept in a moderate de- gree till the lute be thoroughly baked; when, being increafed. the matter will rife in fumes, and form itfelf in, a cake on the upper part of the glafs. This, may be urged forwards by faifing the fire as ftrongly as it will bear to be without forcing the fumes out of the mouth of the fublimer ; which, if it appear to happen, muft be remedied as quickly as poflTible by abating the heat. But proper care muft be taken that the mouth of the glafs or fublimer be not choaked up by the fubliming matter ; for which reafon, the tile, or piece of glafs which covers it, Ihould be lifted up at proper intervals, and an opening made, with the end of a tobacco-pipe, into the cavity of the fub- limer. On the negled: of this caution, the glafles are very liable to be burft by the rare- faction of the fumes, on the fire’s, burning briikly. When no more fumes arife, which may be known by the' abatement of the heat in the upper part of the fublimer, notwith- ftanding the fire be equally ftrong, the opera- tion USED IN Painting. 35 tion may be concluded to be completed, and the furnace being fuffered to cool, the fubli- mer muft be taken out and broken, and the cake of fubllmed matter in the upper part of the glafs collected, obferving carefully that it be kept free from the drofs or caput mortuum left in the bottom. Of calcination. Calc I NATION /j* the operating on fuhfancesy hy means of heat^ fo as to produce fome change either in their texture or colour. Calcination is fometimes performed by ex- pofing fubftances to the fire with as great ex- tent of furface as polTible ; as in the cafe of lead for converting it into the red lead or mi- nium^ and antimony to prepare it for its con- verfion into glafs. In other cafes it is per- formed by putting the fubftances into a cru- cible, or other fuch veflel, in a more collected body, and furrounding the veflel with fire; and there is a cafe indeed, viz. that of the mafticot, where bringing it near the fire will be fuificlent. The red lead," red oker, and antimony for making the glafs, being calcined in large quan- tities by thofe who make it their foie bufi- nefs, and have large furnaces like ovens con- ftrucfted for thefe particular purpofes, I fhall be lefs explicit with regard to them; as it will be fcarely worth while for any, but thofe who carry it on as a grofs manufadure, to'concern D 2 them- 36 Of THE Substances themfelves with them, unlefs as a fpeculative experiment. The calcination of other fubftances for the preparation of colours may be performed by putting the matter into a crucible, and placing it in a common fire; or, where greater heat or room is required, in the wind-furnace de- fcribed, p. 23, where the fire muft be raifed round it, and continued of fuch a degree, and for fuch a duration as the occafion may make neceflary. This may be underftood to be all that is re- quifite where calcination is ordered in the proceffes below given, without any particular diredtion for the manner of performing it; but where fuch dire£lion is needful, it will be found to be inferted as each occafion occurs. Of folutioTU By SOLUTION is rneant the reducing any folid body to a liquid fate by means of another^ into which ^ being piit^ it is melted or cofiverted itfelf alfo hito a fate of fuidity. This is performed by the fimply putting one body to the other and mixing them well together, except in fome cafes where heat is neceffary to expedite the effedt. When therefore bodies are ordered in the proceffes below given to be diffolved in others, it is only to be underftood that they are to be put together, and ftirred or fhaken at proper intervals, till the folid body be melted. But where USED IN Painting. 37 where that appears to proceed too flowly, the veffel muft be put into a proper heat to ac- celerate the operation, though this heat fhould be always underftood to be lefs than will make water boil, except where the contrary be ex- prefsly direded. Of precipitation. Precipitation is the refeparatlng a /olid body from any fluid one-^ in which it is diffolved or melted^ by the addition of a third body^ which is capable of producmg that effect. As for ex- ample, if feed-lac be diffolved in fpirit of wine, and water be added, the feed-lac will be precipi- tated, that is, feparated from the fpirit in which it was diffolved, and reduced to the ftate of an impalpable powder, which will fubfide to the bottom of the veflel containing the mixture. The means of precipitation are therefore equally fimple with thofe of folution, there being nothing more required, than to put the matter, which is to fuffer the precipitation, into a proper veffel, and to add that which is to caufe it; and when the effed is produced, to feparate the fluid from the folid body pre- cipitated, by pouring off what can be fo parted from it, and draining off the reft in a filter. Of filtration. Filtration, though a very fimple opera- tion, yet when it is required to be done through D 3 paper, 38 Of the Substances paper, and great quantities of fluid are to be filtered, demands fome nicety and judgment in the management of it ; otherwife accidents are very liable to happen, which retard greatly the work, and occafion frequently much delay and trouble, efpecially with thofe who are unpraftifed in it. The end of Alteration is of two kinds ; the one to free fluids from any folid bodies of a feculent nature with which they are mixed ; the other, to feparate any precipitated powder, or other folid body, from fuperfluous fluid. The means muft be varied accordingly. In the firft cafe, paper, if it be of a right kind, is fufficient ; in the other cafe, a coarfe linen cloth muft be put over the paper; otherwife, in taking the filtered matter out of it, parts of the paper will unavoidably mix themfelves with it, and irremediably foul it. Where filtering through paper is neceflary, the pewter cullenders, defcribed p. 28, will be found extremely commodious. But great care muft be taken to accommodate rightly the paper to the cullender, as well as to pour the matter very flowly into it at firft, till it be VvTell fettled ; for on negledl of this cau- tion the paper will be very apt to burft, and delay the operation, by fouling the veflels with the unfiltered matter. If, as frequently hap- pens, the paper which is procured prove of a bad texture, and want tenacity to bear the weight of the fluid poured into it; or when the fluid itfelf may be of a very relaxing nature. A USED IN Painting. 39 and weaken the paper, a coarfe linen cloth ihould be always ufed with the paper, what- ever the intention of the filtering may be. For, though the fluid will pafs fafter through paper alone, yet much time will be faved from adding the linen, by preventing the trou- blefome accidents that will elfe unavoidably occur. In filtering large quantities it will be fre- quently found, that, after the paper has been for fome time foaked in the wet, the operation will proceed very flowly: the Avelling of the fubftance of the paper, as well as the foulnefs of the fluid, diminifhing, and at lafl choaking up the percolating pores of the paper. When this is the cafe, the paper fhoiild be always changed as foon as it is perceived that the filter ceafes to run moderately ; for, otherwife, the operation becomes intolerably tedious. Where great quantities of more ordinary colours are made, fuch as rofe pink, the kind of Pruffian blue ufed for paper-hangings, or other fuch grofl'er kinds, the flannel bags men- tioned, p. 29, may be ufed; as the filtering fuch great quantities of fluid through paper would be an almofl: end.lefs labour. In doing this, nothing more is required than to hang the bags on the frames by their loops, and to * feed them with the matter to be filtered; only the firft quantity which runs through, being apt to be foul, muft be returned into the bag, till it be perceived that the fluid come , clean D4 Of 40 Of the Substances Of evaporation* VAPORATION, or the reducing moijl bodies dryjiefs by an artificial heat^ where it is not required to be in balneo marice^ may be perform- ed by boiling in any commodious veflel, till the matter be freed from all humidity ; the veffel being fed with a frefti fupply as the fluid ap- pears to be diminifhed. But in the cafe of ve- getable or animal fubftances, where they are to be evaporated to drynefs, or to a thick con- fillence, as in the artificial gall-ftones, lake, or brown pink, it ought to be performed in bal- neo marine. This is done by putting the veflel containing the matter into another filled with ‘ water, and kept of a boiling heat; for, by this means, the fubftances are prevented from burn- ing to the veflel as they grow dry, which would otherwife unavoidably happen. The evaporation in balneo maried may be commodioufly performed in the veflTels I have deferibed, p. 28, by fixing the tin boiler in the furnace, and hanging the pewter veffel in it by the rim; the remaining cavity of the tin boiler being filled with v/ater, and made to boil till the matter be brought to a proper dry- nefs or confiftence. This is all that is requi- fite where the quantity of matter remaining after the evaporation is large ; but, where it is fmall, it is better to ufe fome fmaller veffel ; as it would be fo diffufed on thefides and bottom of the pev7ter one as would render it difficult to USED IN Painting. 41 to be colleded. The beft. expedient for this is to ufe a China bafon of a proper fize, and to hang It by packthread to two fticks hiid a-crofs the edge of the boiler, and fixed at a proper diftance from each other, by two other fticks tied to them crofs-way ; by which little machine the bafon may be fufpended in the boiling water; and being fed with the fluid to be evaporated, as proper room appears in it for a frefh fupply, will perform the office ex- tremely well. But wffiere the quantity of fluid to be evaporated is great, though the remain- ing matter when dry be fmall, a previous eva- poration by the naked fire may be ufed till the quantity be properly reduced; taking care that the matter do not acquire fo thick a con- fiftence as may fubjed: it to burn to the fides or bottom of the boiler. Of levigation and w of ding over. Levigation of colours, where great quan- tities are in queftion, is performed in hand and horfe-mills; but this fails to produce fo per- fed an eflfed as the mullar and flone which is ufed in all other cafes ; the affiftance of a peftle and mortar being indeed taken in the cafe of glafs and hard bodies to prepare them for the mills or flone. The method of ufing thefe feveral kinds of inflruments, as well as the conftrudure of the inftruments themfelves, are fo well known that it is needlefs to dw*ell on any particulars regard- 42 Of the Substances regarding them. But the other method fub- fervi^nt to the intention of levigation (that is to fay, to the reducing pigments to a due de- gree of hnenefs as powders) called wajhing over^ being lefs generally underftood, and yet of the greateft utility for procuring many colours in the moft perfedl: ftate, 1 will explain fully the manner of performing it, which is as folio ;vs : ‘‘ The matter intended to be brought by ‘‘ this operation to an impalpable finenefs, miift be firft well levigated, or if it be a body of a chalky texture, as the okers bro- ‘‘ ken to a grofs powder by pounding, then ‘‘ let it be put into a deep bafon almoft full of very clean water, and there well llirred “ about. Having refted a fhort time, that the groffer parts may fink to the bottom, let the water, together with the finer parts yet fufpended in it, be poured off into another ‘‘ bafon of the fame kind, and fuffered to ftand ‘‘ at reft till the powder has totally fubfided ‘‘ and left the water clear. Let as much of this water as can without difturbing the fediment be then poured back into the firft bafon, and let the ftirring, decantation, &c. be repeated. as before, as often as fhall be found neceffary to feparate all the powder that is of fufficient finenefs. The remaining grofler part may be then again ground, and ‘‘ the fame treatment continued till the whole of the matter be obtained in that ftate. This operation is, however, in fome cafes to be USED IN Painting. 43 repeated feveral times before the colour can be rendered fo perfeclly fine as may be wiflied ; but when it is duly executed, pig- “ ments may be reduced to the moft impal- pable powders with great eafe, even though, like vermilion, they be of the moft obdurate ‘‘ texture, and the okers, or any fuch bodies ‘‘ of a chalky or clayey texture as grow foft ‘‘ in water, may be freed from fand, ftones, or other impurities, and rendered of the higheft degree of finenefs, even without any pre- vious grinding. Where great quantities of ‘‘ matter are. to be walked over, as in the cafe of okers, common Indian red, &c. tubs muft ‘‘ be had to fupply the place of bafons, and lading with a bowl-dilh muft be ufed in- ftead of decantation or pouring off.” Class I. Of red colours. N Oj' Vermilion, V ERMILION is a bright fcarlet pig- ment, formed of common fulphur and quickfilver, previoufly prepared by a chymi- cal procefs into a fubftance, called faclittGiis SECTION IV. nature and preparations of particular colours. cinnabar. 44 Of the Substances cinnabar. It is one of the moft ufeful colours- in every kind of painting, except enamel or on * glafs; as it is of moderate price, fpends to great advantage in any kind of work, and llands or holds its colour extremely well. It may be prepared in great perfeftion by the following procefs. “ Take of quickfilver eighteen pounds, of flowers of fulphur fix pounds: melt the ful- phur in an earthen pot, and pour in the quickfilver gradually, being alfo gently warmed, and fl;ir them well together with the fmall end of a tobacco-pipe. But if from the effervefcence, on adding the lat- “ ter quantities of the quickfillver, they take ‘‘ fire, extinguifh it by throwing a wet cloth (which fhould be had ready) over the vef- fel. When the mais is cold, powder it, fo that the feveral parts may be well mixed to- gether. But it is not neceflary to reduce it, ‘‘ by nicer levigation, to an impalpable ftate* Having then prepared an oblong glafs body, or fublimer, by coating it well with fire-lute over the whole furface of the glafs, and work- ing a proper rim of the fame round it, by which it may be hung in the furnace infuch a manner that one half of it may be expofed “ to the fire, fix it in a proper furnace ; and let the powdered mafs be put into it, fo as to nearly fill the part that is within the fur- nace, a piece of broken tile being laid over the mouth of the glafs. Sublime then the ‘‘ contents with as ftrong a heat as may be “ ufed US ED IN Painting. 45 ufed without blowing the fumes of the ver- milion out of the mouth of the fublimer. When the fublimation is over, which may ‘‘ be perceived by the abatement of the heat towards the top of the body, difcontlnue the fire; and, after the body is cold, take ‘‘ it out of the furnace and break it ; colled: “ then together all the parts of the fublimed ‘‘ cake, feparating carefully from them any ‘‘ drofs that may have been left at the bottom “ of the body, as alfo any lighter fubfiancc than may have formed in the neck, and ap- pears to be diflimilar to the reft. Lev ' gate ‘‘ the more perfed part; and, when reduced ‘‘ to a fine powder, it will be vermilion pro- ‘‘ per for ufe; but on the perfednefs of the “ levigation depends, in a great degree, the brightnefs and goodnefs of the vermilion. ‘‘ In order therefore to perform this, it is ne- ‘‘ ceflary that two or three mills of different ‘‘ clofenefs fhould be employed, and the laft fhould be of fteel, and fet as finely as poffible ‘‘ according to what has been before men- ‘‘ tioned in fpeaking of the apparatus for making vermilion, Sedion II.” Where great quantities of vermilion' are manufadured, it is a pradice, for the fake of cheapnefs, and to fave the labour of coating, with fo much care, glafs fublimers with lute,^. to have earthen ones made of the fame fort of clay as that employed for long necks. When this Is done, thefe fublimers fiiould be of a fpheroidal figure, and about an inch lefs in their 46 Of the Substances their leaft diameter than the ring of the fur- nace in which they are to be hun^; they muft alfo have a rim worked at about mo-thirds of this height, of the fame matter they are made of, by which they may hang in the iron ring, as the glafs fublimers, by means of the rim of lute. It is much tlie beft way, however, to give them a coat of good common loom, fand, and horfe dung. Indeed, except for the fake of curiofity, or where none that is genuine and good can be other wife procured, it is never vrorth while to go through the procefs for making vermilion where great quantities are not to be prepared ; for it is both trouble- forne, expenfive, and very precarious with re- gard to the fuccefs of the operation to make fmall quantities. The perfeftion of vermilion is to be of a very bright colour, and of a great degree of finenefs, and that is moft efteemed which moft inclines to a crimfon hue. Thefe appear- ances, befides the rendering it more advanta- geous for the purpofes to which it is employed in painting, are the readieft proofs of its being unfophifticate. Vermilion, when pure, will ftand very well, whatever vehicle it be ufed with, and may therefore be depended upon for carnations, or the niceft purpofes. It is very ufual, I might almoft fay general, for dealers to fophiflicate vermilion with red lead, which renders it very liable to change, and lofe its brightnefs, as the red lead is apt to turn USED IN Painting 47 turn black, whether ufed with oil or water. This adulteration, v/hen made in a greater degree, may be perceived by the difference in colour betwixt the fophifticated and pure. For the red lead being confiderably more of the orange hue than the vermilion, renders it lefs crimfon : but to deted: with certainty the fraud of mixing red lead with the vermilion, both with rcfped: to the general fad and the pro- portion, the following means may be ufed. ‘‘ Take a fmall, but known quantity of the vermilion fufpeded to be adulterated, and put it into a crucible, having firft mixed ‘‘ with it about the fame quantity, in bulk, of charcoal duff; put the crucible into a com- mon fire, having firft covered it with a leffer crucible inverted into it, and give a heat fufficient to fufe lead; when the crucible, being taken out of the fire, fhould be well fhaken, by ftriking it againft the ground. If the fufpeded adulteration has been prac- “ pradifed, the lead will be found reduced to its metalline ftate in the bottom of the crucible, and being weighed and compared with the quantity of cinnabar that was put into the crucible, the proportion of the adulteration may be thence certainly known; but if no lead be found in the crucible, it may be fafely inferred that no red lead had been commixt with the vermilion.’’ It is very neceffary that vermilion fhould be extremely well levigated, as it both contri- butes to its brightnefs and fpending further in the 48 Of THE Substances the work; and this can fcarcely be efFeftuated by mills without the lubfeqiient ufe of the mul- lar and ftone, though it has been ufual for preparers to pafs it off as it comes out of the mill; but whoever would have vermilion in perfeftion, efpecially for painting carnations or mixing with white, fliould improve its finenefs by v’ailiing over. Of native cinnaha7\ Native cinnabah is a pigment com- pounded of quickfilver and fulphur; and there- fore differs in nothing from vermilion but in the manner of its production, and the being fometimes of a more crimfon colour. Some perfons of intelligence have, however, doubted whether there be any native cinnabar fuffici- ently bright and clear for the ufes of painting, and confequently whether all that is brought hither from the Eaft, or fald to be fo, be not factitious ; there being none found in the European mines which can give reafon to think otherwife. Native cinnabar is found na- turally formed in the earth, though feldom, fet- ting afide the doubt here mentioned, fo pure as to be fit for the ufes of painting, at leaft with- out being purified by fublimation ; which ope- ration, being probably not well known to thofe who have any concern in the finding it, has not been hitherto praCtifed, as far as appears. On this account native cinnabar has as yet been fcarce and dear; a great part of what has been USED IN Painting. 49 been fold as fuch, having certainly been fadli- tious; but the crimfon colour of fome quan- tities, and the miftaken notion that it would ftand better than vermilion, becaufe it was a natural produdfion, have made it to be coveted by painters who are curious in colours. It is, however, never worth their while to be folici- tous about It, as it never excels the beft ver- milion in brightnefs, and as that may be like- wife rendered equally crimfon, if the proportion of fulphur be made only as one to fix or feven of the quickfilver. Moreover, if there really were any fuperiority, with regard toftanding of .the native cinnabar to the other, there never could be any certainty of having it genuine. When native cinnabar Is ufed as a colour, there is no other preparation neceffary than a careful levigation, which may be beft per- formed with water on the ftone; but whoever would have it in the moft perfedf ftate, muft fuperadd waihing over to the grinding. It has been ufual to wafti this colour, as well as ver- milion, in urine, juice of lemon, and other fluid fubftances; but there is not the leaft alteration to be made In it by any fuch means, if It be pure, for the reafon before given with refpedl to vermilion. Of red leady or minium^ Red lead Is lead calcined, till It acquire a proper degree of colour, by expofing it with a large fur face to the fire. VoL. i li The 50 Of THE Substances The bright orange colour of red lead might render it valuable in painting, if it would ftand with certainty in either oil or water ; but it is fo fubjedt to turn black when ufed with oil, and even fometimes when with water, that it is by no means fit to be trufted either alone or mixed with any other colours where the ftand- ing well is of confequence; except in hard varnilhes, indeed, which, locking up the pig- ments from the air and moifture, renders their colour durable in almoft all inftances. For this reafon red lead is feldom now employed in oil, nor very frequently in water, but for very grofs purpofes, or to make a ground for ver- milion, which being flightly fpread upon it> will go much farther than on any other ground. But even this is not advifeable where it is de- fired the colour fliould ftand for a long time. The goodnefs of red lead may be diftin-* guifhed by the brightnefs of its colour; for whatever it is adulterated with, will of courfe diminilh it; and it is on this account not fo liable to be fophifticated as white lead, ver- milion, and fome other pigments. The adulteration, hovrever, where any is fiifpedt- ed, may be eafily deteded by the following means. ‘‘ Put an ounce of what is fufpeded into a crucible, with an equal bulk of charcoal dull, mixing them well together. Place the crucible in a common fire' fufficiently hot to melt lead, covering it with another fmaller crucible inverted into it. Continue it USED IN Painting. ‘ 51 it in the fire for fome time, and then take “ it out, and ftrlke it againft the. ground. The red lead will then be reduced to its me- tallic ftate, and being poured out and freed from the charcoal duft, may be weighed when cold, and will fhew by its deficience the proportion of adulterating matter/^ Of fcarlet oker. Scarlet oker is the ochrous earth, or rather iron, which is the bafis of green vitriol, feparated from the acid of the vitriol by cal- cination. It is of a broken orange fcarlet co- lour ; but for its great certainty of {landing, in which it equals any of the native okers, and its extreme great llrength and warmth either as a ground or in the fhades of carnations, it is neverthelefs very valuable. It may be ufed as a colour in any kind of painting (but in enamel it turns to a tranfparent yellow like brown pink, if the flux be ftrong) and is eafily prepared in the following manner, ‘‘ Take of green vitriol or copperas any quantity, and being put into a crucible, of which it will fill two thirds; fet it on a common fire to boil (taking care that it do “ not boil over) till the matter be nearly dry, when it will be greatly diminifhed ‘‘ in quantity. Fill then the crucible to the “ fame height again, and repeat the boiling and replenifhing, till the crucible be filled E 2 ‘‘ with 52 Of the oTTbsta with dry matter. Take it then from this fire and put it into the wind-furnace; or, if the quantity be fmall, it may be continued in the fame fire, the coals being heaped up “ round it* Let the contents be calcined ‘‘ there till they become of a red colour when ‘‘ cold, which muft be examined by taking ‘‘ a little of the matter out of the middle, and ‘‘ fuffering it to cool; for fo long as it re- ‘‘ mains hot the red colour will not appear, “ though it be fufficiently calcined. When duly calcined, take the oker out of the cru- cible while hot, and put it into water, in which the parts of the broken crucible niay be foaked likewife, to obtain more eafily ‘‘ w’-hat fhall adhere to them, and ftir the ‘‘ oker well about in the water, that all the remaining vitriol may be melted out of it. Let it then fettle, and when the water ap- pears clear, pour it off and add a frefh quantity, taking out all the broken pieces of the crucible, and proceed as before, ‘‘ repeating feveral times this treatment with frefh quantities of water. Then purify the oker from any remaining foulnefs by wafh- over; and, having brought it to a proper ‘‘ ftate of drynefs, by draining off the fluid by a filter, in which the paper mufl be ‘5 covered with a linen cloth, lay it to dry on ‘‘ boards.’’ Common USED IN Painting. '53 Common Indian red. The common Indian red meant here is of an hue verging to the fcarlet; but the true Indian red (of which I fhall fpeak' below) is greatly inclining to the purple, among which colours it may be well claffed. This common kind has been introduced as a counterfeit or fubftitute for the_ real kind brought from the Eaft-Indies; and has, by its cheapnefs and fervlng equally well for common purpofes, prevented that from being brought over for a long time. So that the true teint of the original kind, being in fome meafure for- gotten, this has been gradually made to vary from it, till it is in fadl a quite different colour. But though the common Indian red will not an- fwer the ends of the true kind, it is yet a very ufeful colour for many other purpofes; and is, therefore, on account of its flanding, and w^arm, though not bright colour, much ufed as well in finer as coarfer paintings in oil. As it is made of the caput mortuum of vitriol after the diftillation of aqua forth and oil of - vitriol, it is afforded at a very moderate price, and may be thus managed. Take of the caput mortuum^ or oker left in the iron pots after the diftillation of aqua forth from nitre and vitriol, two parts, and of the' caput mortuum y or colcothary left in the long necks after the diftillation of oil of vitriol, one part; break the lumps found E j ‘‘ among 54 Of the Substances them, and put them In.to tubs with a good quantity of water, and having let them ftand for a day or two, frequently ftirring them well about, lade off as much water as can be got clear from them, and add a frefli quantity, repeating the fame treatment till all the falts be wafhed out, and the water come off nearly infipid. The red powder which remains muft then be wafhed over, and, being freed from the water, laid out to dry. ‘‘ When this Is defigned for nicer purpofes, ‘‘ it fhould be wafhed over again in bafons, the grofs manner of lading it out of one tub into another not fitting it always com- pletely to fuch ends.” As it is now difficult to procure the caput mortuum left after the diflillation of oil of vitriol from green vitriol, the oil of vitriol being now for the moft part made from fulphur, the refiduum of the diflillation of aqua forth when made with green vitriol may be ufed alone; but in this cafe the matter fhould be firft cal- cined in the wind-furnace, p. 23, to give it a more purplifh hue. Of Venetian red. Venetian red Is a native red oker, rather inclining to the fcarlet than the crimfon hue: it is not far different from the common Indian red, but fouler, and may therefore be eafily prepared from mixing common red oker with USED IN Painting. 55 the colcothar or caput mortumn taken out of the aqua forth pots, and waflied over. As it is generally ufed by houfe-painters in imitation of mahogany, it requires no other preparation than to be well ground with the oil with which it is ufed; but when, as is fometimes the cafe, it is ufed in miniature painting, it ihould be carefully wafhed over. Spanijh brown. Spanifh brown, or brown red, is a native earth found in the ftate, and of the colour in which it is ufed ; it is nearly of the fame co- lour with the Venetian red, but fouler. It was probably from its name brought originally from abroad, and was then moft likely of a finer kind ; but what is now ufed is the pro- duce of our own country, being dug up in fe- veral parts of England. It is ufed for grounds and primings for coarfe work by houfe-painters, and by colourmen in the preparation of the cloths for pictures and other coarfe work, but feldom in any more delicate paintings. It therefore needs no other prepara- tion than freeing it well from ftones and filth. Though if any, who may be defirous to ufe it for nicer purpofes, want to have it in a more perfect ftate, they may make it equal in finenel's and purity to any other pigments whatever, by waftiing over. And if they can render it ufeful to them with regard to the colour, they may depend on its ftanding equally with any E 4 ' other 56 Of the Substances other pigment whatever, being a native ochrous earth, of which kind none are ever known to fail, whether they be ufed of their natural teint, or changed by calcination. Of calcinedy or burnt terra di Sienna. The TERRA DI SIENNA is a native oker brought hither from Italy in a ftate in which it is naturally found. -It is yellow originally, (of its qualities in which ftate we fhall treat in its proper place below) but when mode- rately calcined it becomes an orange red, though not very bright. Being, however, femi-tranfparent in oil, it is of great ufe where a ftrong brown red fliade is wanted, as in the face in portrait painting, and on many othef occafions. The calcination may be performed by put- ing lumps of it, either in a crucible, or naked, in a common fire, and continuing it there till the colour be changed from yellow to red in the proportion wanted; after which it mufl: be well levigated and wafhed over. It is fcarcely ever ufed but in oil painting, having no advantage for other purpofes over pigments much more eafily obtained. Terra di Sienna admits of no adulteration, if it be had in the ftate in which it is naturally found, which is that of hard lumps. It may be diftinguifhed from other ochrous earths by its femi-tranfparency. With USED IN Painting. -57 ■ With refpedt to the goodnefs of terra di Sienna^ we have but one kind brought here, all difference therefore of one parcel from another muft lie in their being more or lels pure. Of carmine. Carmine is a bright crimfon colour, and IS formed of the tinging fubftance of cochineal brightened with aqua forth ^ by a procefs fimilar to that ufed for dying fcarlet in grain. It is of great advantage in painting as well in water as varnifh, both on account of its beauty and ftanding well; but it will not mix with oil fo as to have the due effect in that kind of painting. The preparation of this colour in perfedion is kept a fecret by thofe who prepare it. The greateft part of what is ufed here is brought from France; what is made in England not ftanding well in general, but being apt to turn purple on the addition of any kind of white, or even ^vith the fweat of the hands or face. Mr. Godfrey, the chymift, is neVerthelefs pof- feffed of a method of preparing it entirely free from this defed; and I have feen fome parcels made by him which were equal to the bell French I ever faw. The fuperiorlty of the French carmine, as well as of the fcarlet dye, has been attributed to fome qualities in' the air and water of France; but nothing is more abfurd |h^n this fuppofition, as the air has very little concern 58 Of the Substances concern in the produftion of carmine; and the qualities of the water, if different, might be artificially changed. But the difference itfelf betwixt the Englifh and French carmine, which does not lie in the beauty of the co- louiv but in its diirablenefs and fixt nature, clearly evinced a diverfity in the preparation; and Mr. Godfrey’s fuccefs leaves no room to doubt but that the carmine may be equally well made in this country, when we are llioroughly mafters of the art. The extenfion of this art would be a confiderable faviiig to the public, as at prefent we buy of France the far greateft part of what is confumed ; which' is more than can be eafily imagined, till v/e recollefl: how frequent the ufe of red is grown among the Englifh ladies; and that this is almoft the only fubftance ufed in this country as a red paint for living faces. The compilers of the new French Cyclo- pedia have given two or three old recipes for the preparation of this colour ; and afterwards recommended another, as preferable to them, taken from Kunckel; which, on examiflation, is only a procefs for making bad lake of fear- let rags. But rather than to infert fuch imper- fed inflrudions for the making an article of great confequence, as may delude thofe who are earneft in their purfuit of this art into a fruitlefs expence of time and money, or to reveal fome information wdiich I owe to the confidence of a friend, to his difadvantage, i choofe to befilentonthis particular, till I can obtain ^usED IN Painting 55’ obtain a fatigfaitory recipe by means whick leave me at liberty to publilh it without breach of honour. Of lake. Lake is a white earthy body, as cuttle- filh-bone, the bafis of allum or chalk, tinged with fome crimfon vegetable dye, fuch as is obtained from cochineal, or Brafil wood dif- folved or taken up by means of fome alkaline fait, and precipitated on the earth by the addi- tion of fome acid. Lake is ufed in all kinds of painting (except enamel) but particularly in oil, where it fup- plies the place of carmine, which does not at all agree with that vehicle. It is valuable both for its brightnefs and crimfon teint, which makes it ufeful for carnations to the por- trait painters; for fkies to the landlkip or fhip painters ; and for flowers to thofe who paint ftill life. Its tranfparency in oil renders it alfo of great fervice in glazing, as it is called, over vermilion ; and in painting fcarlet draperies, and the red parts of the lips; and its acquiring a dark hue by this tranfparency, when ufed without the addition of any opake pigment, gives it an unrivalled excellence in the fhades of red draperies or other limilar cafes. Not- withflanding thefe meritorious qualities, lake is not at prefent univerfaliy approved ; nor without reafon ; for there is a defect which makes it to be frequently rejedted where its ufe caa 6o Of THE Substances can be avoided. This defedt is the uncertainty of" its ftanding, when prepared in that manner which moft conduces to its perfedtion in other refpedls. For though fome parcels will hold their colour entirely well, yet others prepared in the I'arne manner, as far as art can aflure it, will Hy in a degree that makes the ufe of it deftrudtive to any painting; and if this defediibe effedlually remedied, as it may be by fecuring the tinging particles by gums from all attacks of the air, yet that is generally at the expence of the brightnefs and tranfparency.; the earth, which is the bafis of the pigment, being locked up by the gums, and rendered incapable of being combined intimately with, or imbibing the oil. Befides the perfedlions of lake, which it may have in common with other colours, there is yet another that relates only to itfelf. This is the inclining to the fcarlet hue, which makes it more valuable for alnioft all the purpofes which it is applied to, and where this quality joined to the others happens to be found in it, there isfcarcely any limits to be fet to its value with eminent painters of any kind, as was fliewn in the in« ttance of a parcel made by an unknown perfon, fuppofed to be a member of the Royal Society, and vended by one Stocks, then a colourman in Newgate-Street, which was afterwards fold by fome of thofe who purchafed it of him at two guineas an ounce. Lake was moft probably made from the colour found in the grains of the ftlck-lac, from whence it feems to have taken it^ name. But USED IN Painting. 6i But it may be made from a great variety of fubftances which afford a crimfon tinge, though at prefent it is feldom prepared from any other than cochineal, fcarlet rags, and Brafil wood. The beft of what is commonly fold is made from the colour extra(fled from fcarlet rags, and depofited on the cuttle-bone, which may be done in the following manner. ‘‘ Take a pound of the beft pearl-aflies, ‘‘ and, having diflblved them in two quarts of water, purify them by filtering through paper; add then to this folution two more quarts of water, and having put in a pound ‘‘ of fcarlet fhreds procured of the taylors, ‘‘ (for they muft be entirely clean) boil them in the pewter boiler, defcribed p. 25, till the ‘‘ .fhreds appear to have wholly loft their fcav- let colour. Take them out of the folution and prefs them well, dipping them after in water and prefling them again, that all the fluid they had imbibed may^be got from them, in order to be put back to the reft. Take then another pound of the fcarlet fhreds, and repeat the like treatment of them in the fame folution, as alfo a third and fourth pound. While this is doing, dilfolvea pound and half of cuitle-fifli-bone in a pound of ftrong aqm forth m. aglafs receiver; add- ing more of the bone, if it appear to pro- duce any ebullition in the aqua forth^ and having ftrained off this folution through flan- nel, pour it into the other by degrees, ob- ferving whether it produce any effervefcence ‘‘ on €2 Of the Substances on putting in the laft quantity ; which if it do in any great degree, more of the cuttle- fifh-bone muft be diflblved in aqua for thy and the folution very gradually added till no ebullition apear to be raifed by it in the mixture. If this be properly managed, the fluid will foon become clear and colourlefs, and the tinging particles extrafted from the fhreds, together with the cuttle-fifh-bone, will fubfide to the bottom and form a crlm- fom fediment, which is the lake. The wa- ter muft then be poured off ; and two gal- ‘‘ Ions of hard fpring water muft be put to the lake, and well ftirred about to mix them. This being likewife poured off, ** after the lake has again fettled to the bottom, muft be replaced by another two “ gallons; and the fame method muft be re- peatedfour or five times; but if hard water ‘‘ cannot be procured, or the lake appear too purple, half an ounce of allum fhould be ‘‘ added to each quantity of water before it be ufed. When the lake is thus fufficiently freed from the falts, it muft have the water drained from it in a filter covered with a linen cloth, which has been fo worn as to have no knap or down remaining on its fur- face. After the lake has been drained to a proper drynefs, it muft be dropped on clean boards, by means of a proper funnel, through which the drops being fuffered to pafs, and reft on the board at proper dift- ances, they will become fmall cones or pyra- mids ; USED IN Painting. 63 mids; in which form the lake muft be ‘‘ fuffered to dry, and the preparation is then completed.’’ If the lake thus prepared be of a deeper colour than be defired, the proportion of fcarlet flireds may be diminilhed; or, if it be wanted yet deeper, they may be in- creafed. This lake, when the procefs fucceeds well, will be very bright, and will Hand equally to any whatever; but it is not fo tranfparent and fit for glazing as that where earth of allum Is the bafis. Lake may be prepared from cochineal in the following manner. “ Take two ounces of cochineal, and boil it gently in a quart of clean water. Filter the folutlon through paper, and then add to it two ounces of pearl-afhes diflblved in half a pint of warm w’^ater, and then filtered alfo through paper. Make then a folution of cuttle-fifh-bone, as in the above procefs ; and to a pint of it add two ounces of allum diffolved in half a pint of water. Put this mixture gradually to that of the cochineal “ and pearl-afhes, as long as any ebullition “ appear to arife ; and proceed as to the reft according to the diredions of the above pro- cefs.” This lake will be very fine, if luckily ma- naged, and will ftand extremely well ; it will alfo be very fcarlet if the cochineal and an- nato be good. Prr- (?4 Of THE Substances Freparation of beautiful lake from Brazil wood. ‘‘ Take of Brazil wood (not coloured in the grinding by the addition of pearl-afhes) three pounds, and boil It an hour in a fo- lution of three pounds of common fait and “ three gallons of water, and then filter the “ fluid through paper while hot; prepare then a folution of five pounds of allum in three gallons of water, which add to the filtered folution of common fait tinged with the colour. Make alfo a folution of three pounds of the befl pearl-afhes in a gallon and a half of water, and purify it by filter- ing ; put this to the other gradually, till the ‘‘ whole of the colour appear to be preclpitat- ed^ and leave the fluid clear and colourlefs; but if any appearance of purple be feen, add a frefh quantity of the folution of allum by degrees, till a fcarlet hue be produced. ‘‘ The proportion of allum mull, however, in ‘‘ this cafe be nicely adjufted; for a fmall excefs wilheaufe part of the tinging matter to be diflblved again,, which will appear by the fluid’s being coloured; and in fuch cafe, a balance mull again be made by the addition of a fmall quantity of the folu- tion of pearl-afhes. When the fluid is thus rendered clear of colour, and the fedi- ment, being fubfided, appears of a crim- “ fon teint tending to fcarlet, the direilions ‘‘ in USED IN Painting. 65 in the firft procefs muftbe followed in every point.” This lake cannot be confided in for either painting in oil or water ; but in varnifli, or for any other purpofe, where it is defended from air, it is fuperior to airy other whatever, on account of its great briglitnefs and tranf- parency. It may be rendered fafe, however, with re- fped: to {landing, if half a pound of feed-lac be added to the folution of pearl-afhes, and dilTolved in it before its purification by the fil- ter ; but, in this cafe, two pounds of the wood, and a proportionable quantity of the common fait and water, muft be ufed in the coloured folution. This will produce a lake that will Hand well in either oil or water, and will fometimes be extremely beautiful, but it is not fo tranfparent in oil as without the feed- lac. The lake with Brazil wood may be made alfo with the addition of half an ounce of annatto to each pound of' the wood, which will render it much more fcarlet where it is fo wanted. But the annatto muft be diflblved in the folution of pearl-afhes ; and not in that of the common fait along with wood. The goodnefs of lake cannot be pofitively known but by the actual trial of it, which, with refpecft to its ftanding, requires fome time; but its other qualities’ may be more eafily judged of. VCL. I, F With 66 Of the Substances With refpeft to the brightnefs, Its merit may be eafily proved by grinding a little of it on a pallet or done, with white lead and where it may either be judged of by the mory of thole who are very converfant in the ufe of it, or by comparing it with a fample of any other. In relation to the tranfparency, it is alfo eafy to judge of it, by grinding a little In the fame manner, with oil only, where a muddinefs will be perceived, if the lake be in the leaft opake; or a little of it may be put in this ftate, on the glafs of a v/indow, where its thicknefs or clearnefs will of courfe be apparent to the minuteft degree. This indeed is the only method ufed in general by colourmen for deciding on all the qualities of lake; but it is very inconclufive with regard to any but tranf- parency. In refpeft to the Handing of lake, it is much more nice and difficult to deter- mine; and indeed there can fcarcely be any cer- tainty about it but by actual experience. The colourmen having put a fmall quantity of any which they are defirous to try on a window, in the manner juft before mentioned, let it ftand there for fome time to fee if the colour fly. Other perfons think they have a more ex- peditious and certain, though lefs known me- thod, by trying it with the juice of lemon ; which, if the juice turn the lake to an orange colour, or make any other change in it, gives a proof, as they conclude; of the badnefs, or of the contrary, if no alteration be produced. But neither of thefe methods are infallible; for it is USED IN Painting. 67 Is pradllcable to prepare lake which will under- go both thefe tefts, and yet not ftand well when ufed in a pifture ; though the {landing the juice of lemon is fome prefumption that the lake will hold its colour, and the being altered by it is a pretty certain proof of the contrary. There is another defedl, with refpeft to fome purpofes, which is apt to be found in lake ; it is the fattening in oil. This can be only known by grinding fome of it in the oil, and keeping . It the proper time in bladders. When, if it be found to have this fault, it may be deemed utterly unfit for the ufe of colourmen. If, ne- verthelefs, it have no other bad qualities, it is not at all the worfe for this, with regard to thofe who have no occafion to keep colours in bladders, but mix them as wanted on the pallat. There is another kind of lake brought from China, which is extremely beautiful; but as it will not mix well with either water or oil, tho’ it. diflblves entirely in fpirit of wine, it is not of any ufe in our kinds of painting hither- to. This lake has, by fome unaccountable blunder, got the name of faffower among thofe who paint in water, and has, indeed, been fo called in more than one pamphlet written on the ufe of water colours. But there is not the leaft affinity betwixt it and the real fafflower, which is the dried flowers of the carthamus or ballard faffron, and is a well known fubftance, as being a common dying drug. F 2 Ojy 68 Of the Substances Of rofe lake^ coimnonly called rofe pink,' Rose pink is a lake like the former, except that the earth or bafis of the pigment is prin- cipally chalk, and the tinging fubftances ex- traded from Brafil or Campeachy (commonly called Peachy) wood. As it never can be expeded to ftand when ufed with oil or water, it is feldom employed for any purpofes but the coarfe work of houfe- painters, or for paper-hangings, unlefs fome- times with varnifli, where it is fecured from flying, and, when beautiful, may be diftributed for lake. Rofe pink may be prepared in the following manner. Take Brazil wood fix pounds, or three ‘‘ pounds of Brazil and three of Peachy wood. Boil them an hour with three gallons of wa- ter, in which a quarter of a pound of allum is diffolved. Purify then the fluid by ftrain- “ ing through flannel, and put back the wood into the boiler with the fame quantity of allum, and proceed as before ; repeating ‘‘ this a third time. Mix then the three quantities of tindure together, and evapo- rate them till only two quarts of fluid re- main; which evaporation muft be perform- ed firft in the pewter boiler, and after- wards in the balneo maricc^ defcribed p. 28. Prepare in the mean-time eight pounds of chalk by wafliing over ; a pound of allum “ being USED IN Painting. 69’ ^ being put Into the water ufed for that pur- pofe, which, after the chalk is walked, muft be poured off and fupplied by a frefh quantity, till the chalk be freed from “ the fait formed by the allum ; after which it muft be dried to the confiftence of ‘‘ ftiff clay. The chalk, and tindiure as above prepared, muft be then well mixed together by grinding, and afterwards laid out to dry where neither the fun or cold air can reach it; though if it can be conveniently done, a gentle heat may be ufed.” The goodnefs of rofe pink lies chiefly in the brightnefs of the colour and the finenefs of its fubftance ; which laft quality depends on the walking well the chalk. The more the hue of rofe pink verges on the true crimfon, that is to fay, the lefs purple it is, the greater its value. Red oker. Red oker is a native eartn; but what is commonly ufed is made red by calcination ; being yellow when dug out of the earth, and the fame with the yellow oker commonly ufed. It is chiefly brought from Oxford- fliire, where it is found in great plenty, and burnt afterwards, by thofe who prepare it, in large ovens. The quality it has, in com- mon with other okers, of Handing infalli- bly, renders it very ufeful, as well in the more j^elicate as in coarfer paintings in oil, notwith^ F 3 ftand- 70 Of the Substances ft'anding It is not bright. But in order to its being fit for nicer purpofes, it ought to be wafhed over; though for others, it may be ufed in the ftate in which it is found in the fhops. The cheapnefs of red oker renders it fcarcely worth while to adulterate it; but, either from fuch practices, or from the difference of their natural ftate, fome parcels are greatly better than others. The marks of goodnefs are brightnefs of colour, and the being of a crumbly chalky texture, ftiewing no gritty roughnefs when rubbed betwixt the Ltr A MARINE is a preparation of calcined lapis la%uU. It is, when per- fe£t, an extreme bright blue colour, with a tranfparent effedf in oil, and in fome degree in water, and will ftand, when ufed in paint- ing, without the leaft hazard of flying, with whatever vehicle or pigment it be mixed. For thefe reafons, ultramarine is of the higheft value in every kind of painting, being equally ferviceable in all, even in enamel; and though the invention of Pruflian blue, on account of its much lower price, has greatly leflened the ufe of it, yet this exclufion of it may be con- fingers. Class II. Of blue colours. Of ultramarine. fidered USED IN Painting. 7 ^ fidered as an Injury to painting in general, as the Ikies of landlkips, and many other parts of modern pidfures, fhew the lofs of it by their changing from a warm, or clear blue, to a faint greenifh or olive teint. There have been a great variety of methods taught and pradlifed for preparing the ultra- marine. The older methods were, after a calcination in a crucible, to mix a compofition of pitch, refin. Burgundy pitch, foap, wax, and other ingredients, and to form a pafte of them with the calcined matter. This pafte was then put into VN^ater for feveral days, and afterwards diflblved, by fucceflive quantities of warm water poured on it, till it let go the colour of the calcined lapis lazuli^ which was recovered by the fame means as is diredled for the wafhing over colours in p. 42. This me- thod however of employing a variety of ingre- dients in the cement was not only unnecef- fary, but injurious to the colour, which was never perfectly freed by the warm water from them; and for this reafon, the methods have been continually varied by thofe who have at-, tempted to prepare this pigment. I fiiall how- ever give the beft of the more modern, and fubjoin one of older date, which I believe, neverthelefs, to be equally good, though not near fo troublefome. ‘‘ Take the lapis la%uU^ and break it into very fmall pieces, or rather a grofs powder. Put it into a crucible, and cover it fecurely, to prevent the coals from falling amongft it, F 4 ' “ Calcine (C 72 Of the Substances Calcine it then with a ftrong fire for an hour if there be any large quantity, or lefs time in proportion, and quench it, when taken out of the fire, in vinegar ; ftirring them well together, and fuffer it to remain in that flate for a day or two. Pour off ‘‘ then the vinegar, except what may be ne- “ ceiTary for moiftening the calcined lapis lazuli in grinding, which operation it muft then undergo, in a mortar of flint or glafs, till ‘‘ reduced to the greateft degree of finenefs thofe means may effed;. But, if it appear yet too ha rd to be eafily ground, give it ano~ ‘‘ ther fliort calcination, and quench it a fecond time in vinegar. The vinegar muft then “ be wafhed off from the powder, by the putting it to feveral fucceflive quantities of ‘‘ clean watery each of which muft be pour- ed off when the lapis lazuli has been well ftirred about in them, and is again fettled to ‘‘ the bottom. It muft then be ground on a porphyry ftone, with a mullar, till it be per- fedly impalpable, and then dried; in which “ ftate it is duly prepared to mix with the ‘‘ following cement. — Take of Burgundy pitch, nine ounces, — of white refin, and Venice turpentine, fix ounces, — of virgin, w^ax one ounce and half, —and of linfeed oil, ‘‘ one ounce and a quarter. Mix them to- “ getiier by melting in a pipkin over the fire ; and fuffer them to boil till they acquire fo ftifF a confiftence that, being dropt into wa- ter while of this boiling heat, they will not fpread USED IN Painting. 73 fpread on the furface of it, but form a roundifh mafs or lump. The cement be- ing thus formed, may be poured out of the pipkin in the water, and made into cakes “ or rolls for ufe. Of this cement, take an ‘‘ equal weight with that of the calcined lapis ' la%uUy and melt it in a glazed earthen pip- kin; but not fo as to render it too fluid. Then add to it the calcined matter by very flow degrees, ftirring them together with an ivory fpatula till the whole appear per- fe£liy mixed. Being thus mixed, heat the “ compofition to a foinething greater degree, and caft it into a large bafon full of cold water. When it has cooled to a confifl- ence to bear fuch treatment, knead it well like the dough of bread, with the hands rub- bed over with linfeed oil, till all the parts be thoroughly incorporated with each other. ‘‘ Then make the mafs into a cake, which may be either kept till fome other conve- ‘‘ nient. time in cold water, or immediately proceeded with in the following manner. Put the cake into an earthen difh or bafon; the bottom of which fhoiild be rubbed with linfeed oil, and pour on it water of the warmth of blood. Let it fland a quar- ter of an hour; and as the v/ater foftens the cake, it will not loofe the fined part of the calcined matter ; which, on gently ftirring the water, but without breaking the cake ‘‘ or feparating it into lefler parts, will be fufpended i^ the w^ater ; and muft be pour- ed 74 Of the Substances ed ofF with it into another veffel. The “ quantity of water muft be then renewed, and the fame operation repeated a fecond or third time; and as the mafs appears Hack in affording the colour, it muft be moved and ftirred, in the manner of kneading, with the ivory fpatula, but not broken into fragments or fmall parts; and when fo ‘‘ much of the colour is extracted as to render it neceffary for the obtaining more, ‘‘ the heat of the water muft be increafed to the greateft degree. The quantities of the calcined matter (which is now the ultramarine) that were firft wafhed off, and appear of the fame degree of deepnefs and brightnefs, may be put together, and the fame of thofe of the fecond degree, the laft waftiings making a third. The water being then poured off from each of thefe parcels, put on a lixivium formed of ‘‘ two ounces of fait of tartar, or pearl-afties, diffolved in a pint of water, and filtered through paper after the folution is cold. This lixivium muft be put on boiling hot, and the ultramarine ftirred well about in it, ‘‘ and then the mixture fet to cool. The powder being fubfided, the dear lixivium muft be poured off, and clean water put in ‘‘ its place, which muft be repeated till the whole of the falts of the lixivium are wafhed away. The ultramarine muft afterwards be dried, and will be then duly prepared for ufe,’’ Another USED IX Painting yj Another method of purifying the ultra- marine from the cement .may be ufed, which is the pricking the yolks of eggs with a pie, and moiftening the matter to be purified with the foft part that will run out, and ‘‘ working them together in a glafs or flint mortar; after which the mixture miifl be put into the lixivium, and proceeded with ‘‘ as is above diredled. In order to free the ultramarine from that “ part of the water which cannot be poured “ oiF from it without carrying away part of the pow:der, let it be put in a deep pot, fuch “ as the cups made for coffee. After the whole is poured off that can be without lofs, “ fet the pot fo on a table or ftand that ftrings “ put into it may hang below the bottom. “ Then take three or four thick threads of ‘‘ loofe twilled cotton, and having wet them, ‘‘ put one end of each into the fluid; and let the other, being brought over the edge of ‘‘ the pot, hang three or four inches below ‘‘ the bottom of it. By this means the water, ‘‘ being attraded by the threads, will drop from the lower end till the whole be nearly drained away. The matter may then be ‘‘ poured upon a porphyry, or polilhed marble, and fuffered to dry.” The other method I have propofed to give differs from the above only in the ufmg vir- gins wax and the bell white refin melted to- gether in equal quantities, inftead of the more compound cement; and this gives up the colour 70 Of tiie^.Substances colour, Oil its being infufed in warm water, much fooner than the other. The other methods of preparing ultramarine differ chiefly in the manner of feparating the colour from the cement and feculencies; which fome recommend to be done by fqueezing and working the mafs with the hand in warm water, after it has lain in fome time to foften. Others advlfe the putting the mafs in the form of a flat cake on a board in a fituation fome- what declining from an horizontal pofitlon and making water drop on the board above the cake, that it may flow through it, and wafli out the ultramarine ; to facilitate which, the parts of the cake muft be frequently opened and flirred with a flick. But this method is more troublefome and lefs efficacious than that above given. Ultramarine may be alfo prepared without any cement, by calcining it ; and when levi- gated and wafhed over, foaking it in diflilled vinegar made hot. The ultramarine will, in this way of preparation, be produced in great- er quantities ; but it will be lighter coloured than when refined by the cement. It is, how- ever, a very good method of preparing it for the painting fkies, and fome other ufes. As it is of the lafl confequence to the pro- ducing fine ultramarine that the lapis lazuliy of which it is made, fhould be good, this may be judged of by infpedion from the deep- ^ nefs and clearnefs of the blue colour; and in order to be more certain of the value, it is pro^ pec USED IN Pa I NT IN G. 77 per to heat a fmall piece red hot ; which, if it retain afterwards its hardnefs and colour, may be accounted good. But if it become crumbly and turn brown, or appear to have fpecks of dulnefs, it may then be juftly fufpeded, or rather condemned. The different parcels of ultramarine pro- duced from the fame parcel of lapis la%idi^ ac- cording to the above procefs, will differ greatly in their value : the manner of judging of which muft be by the degree of brightnefs and deepnefs of the colour. There is how- ever no being precifely certain of the worth of any, but by comparing it with a fpecimen of known value; and to do that with great accu- racy, a little of each fhould be thinly rubbed on white paper, or mixed with white flac and oil, by means of the pallet-knife, fo as to form light teints of the fame degree ; where the brightnefs will fhew itfelf more diflinguifli- ably than in darker. Ultramarine, on account of Its great price, is fubjedtobe adulterated. This may be done by two fubftances, viz. a precipitation or ma- giftery of copper made by alkaline fait, and fine fmalt. The firft of thefe is the moft in- jurious, becaufe the magiftery of copper, if the ultramarine fophifticated with it be ufed in painting either with oil or Vv^ater, will change its hue and turn black, particularly in oil ; and in enamel painting, as foon as fluxed, it will become a green, and confequently make the effed of the ultramarine vary from what; is ^8 Of the Substances is- intended. The latter, that is, the adulte- ration with fine fmalt, is more difficult to be performed, on account of the hardnefs of the foialt, which being in fa£t a hard kind of glafs, IS fcarcely to be levigated by art, fo as to be equally fine with the ultramarine, rendered Impalpable by the calcination it has undergone. This adulteration of ultramarine with fmalt does not deprave it with relation to enamel painting, as it will flux with the fame propor- tionable teint according to the appearance which it has in its fimple ftate ; and ufed as a water colour, it will ftand equally well with that unfophiftlcated; but In oil painting, though it will ftand well, yet it will never mix kindly with the oil, but fall from it if the mixture hh very moifty, or form a pafty fubftance, if it be ftiffer, that will not work freely. The* adulteration of ultramarine, by the ma- giftry of copper, may be eafily detefted, by pouring fome diluted fpirit of nitre, on a fmall quantity, which, if there be any copper, will foon diflblve, and form a greenifh blue folutlon. The adulteration with fine fmalt is more diffi- cult to be diftinguiffied if the fmalt be finely levigated. One of the moft certain methods of difeovering it, is, to put fome of the fuf- peded ultramarine into a cup of clear water and wafli it over, examining the grofler part, if any there be, which remains when the finer is thus feparated from it. By this mean§ the fmalt, if there be any, not being near fo finely pulverized as the ultramarine, v/ill be left, and USED IN Painting, 79 and being thus feparated and compared with the ultramarine divided from it, the difference will become very fenfible. The adulterated may like wife, if the proportion of fmalt be not very fmall, be diftinguifhed from the pure by trying with oil on the principle before men- tioned, that fmalt will not mix fo kindly with oil as ultramarine. A very fine kind of fmalt, loaded ftrongly with the colour, has been fometimes impofed for a coarfe kind of ultra- marine; but the difference of their working in oil will eafily afford the means of diflin- guifhing them, and if they be tried in enamel painting, the fmalt will flux without any ad- dition, being itfelf a glafs, which is otherwife with refpe£t to the ultramarine, as it always requires the addition of fome vitreous body to flux it Of ultramarine ajhcs. -The pigment called ultramarine ashes, is the refiduum or remains of the lapis lazuli^, after the ultramarine has been extrafted from it by the above given, or any fimilar procefs; but as the coloured particles which remain are mixt with thofe of another kind contained in the lapis la%uli^ whether earths or metalline fubftances, thefe allies muff of courfe be much lefs valuable than even the worft ultramarine. Sometimes, neverthelefs, when the operation of the extracting the colour from the calcined lapis lazuli has not fucceeded well, a confide- rable So Of the Substances rable fhare of the ultramarine Is left behind with the recrement, and greatly enhances the worth of the aflies ; and indeed, as it is cer- tain that what colour they poffefs, when ge- nuine, will never fly, they always bear a good price. The appearance of thefe aflies is, that of ultramarine a little tinged with red, and di- luted with white. But they are frequently adulterated, and made by the fophlftication to look better than they would in a genuine ftate. This adulteration renders them much lefs cer- tain of flanding, if, as It is moft frequently the cafe, it be made by precipitating copper in the manner before mentioned in the cafe of the adulteration of the ultramarine. This is eafily, however, detected by the method above given, of putting fome of it into a fmall quantity of fpirit of nitre, which, if there be any copper in it, wnll be tinged green. The ultramarine aflies are alfo fonietimes adulterated with fmalt, as well as the ultramarine itfelf; and the confequences of the fophlftication are the fame in this cafe as were, before mentioned of the other. The means of deteftion are alfo the fame. As the ultramarine aflies will not flux without the addition of fome vitreous body ; while, on the other hand, the fmalt, being glafs, requires no fuch addition to its fluxing with a proper heat. The method of preparing the ultramarine aflies is as follows. ‘‘ Take the cement of the ultramarine which remains after the colour is extraded, and I USED IN Painting. 8i and mix it with four times its weight of liii- feed oil. Let tlie mixture be fet in a glazed pipkin over the fire, and when it is thus boiled a fhort time put it into a glafs veffel, ‘‘ fufficiently large to contain it, of a cylin- drical figure, of which veffel the diameter muft be fmall in proportion to the length. ‘‘ But care muft be taken that the matter, “ when put into this glafs, be cool enough not to endanger the breaking it. This glafs ‘‘ muft then be put into a balneum marics-^ which muft be made as hot as poflible without boiling, and kept there till the “ colour appear to be all fubfided to the bot- ‘‘ tom. The oil muft then be poured off till ‘‘ the colour appear to rife with it, and the “ remainder, with the colour in it, muft be put into another glafs of the fame kind with as much frefh oil as will rife five or fix inches above the colour. This glafs muft be treated in the fame manner as the firft, and when the colour has fubfided, the oil muft: be poured off, and a frefh quantity put in its place. This having been likewife poured “ off, the colour muft then* be well waflied, to free it from the remaining oil, firft in boiling water, and afterwards in fome of the lixivium above-mentioned made boiling hot alfo. As much of the lixivium being poured off, when the colour has fubfided, as can be feparated from it that way, the colour muft be thoroughly freed from the ‘‘ remainder by frequent ablutions with clean VoL, I, G water; 82 Of THE Substances water; after which the water muft be taken ' off by the means above directed for the ultra- marine, till the matter be of a proper degree of moifture for grinding. It muft then be thoroughly well ground on a porphyry and walked over, that all the harder and infuffi- ciently calcined parts may be reduced to an impalpable powder; in order to which, the ‘‘ remaining groffer parts, after the finer have been feparated by the walking over, muft be again ground till the whole be perfectly fine. The fame means muft be afterwards ufed to bring the alhes to a dry powder that were before direfied for the ultramarine.’^ Cy' Priijfian blue, Prussian blue is the fixt fulphur of ani- mal or vegetable coal, combined with the earth of allum, and may be made from almoft any animal, and many kinds of vegetable fub- ftances; though, from reafons of experience, it is generally made of the coal of blood only. It is ufed in all kinds of painting except en- amel, and is prepared of many different de- grees of brightnefs, and ftrength, as well as of different teints, fome parcels being, though rarely, of a true unmixed blue, but the far greateft part of a purple hue ; though the proportion of the tinge of red, which caufesthe tendency to purple, is frequently in degree Various, according to the different manner of, or accidents attendant on the management of the USED IN Painting 83 the procefs. With refped to ftanding, Pruf- iian blue can neither be efteemed the mofl; perfedt, nor the moft faulty colour. When it is very dark, that is, when the tinging par- ticles bear a large proportion to the earth, or bafis, it will fomeiimes hand extremely well; but it is apt then to want brightnefs and be very purple. On the other hand, when it is light, or with a fmall proportion of the ting- ing part, it is more frequently bright and cool, as it is called, that is, clear of any mixture of red; but extremely fubjedl to fly, or to turn to a greyifh green. This is not how- ever univerfal, for I have feen fome very dark which has been pretty bright and cool, as likewife fome that has been light which would ftand perfedly well. The common Pruflian blue, however, found in the {hops, which is prepared almoft wholly at prefent by igno- rant and fordid people, and fold at very low prices, can be very little depended upon in paintings of confequence. Whoever there- fore would have this pigment perfed', fliould either prepare it,- or procure it to be prepared in the proper and true manner; and then con- fidering the high price of ultramarine, and the foulnefs of indigo, it may be deemed an ac- quifition to the art of painting. The Pruflian blue may be prepared in per- fedion by the following procefs. “ Take of blood, any quantity, and evapo- rate it to perfed drynefs. Of this dry blood ‘‘ powdered, take fix pounds, and of th^ beft G 2 pearl- 84 Of THE Substances “ pearl-afhes two pounds; mix them well ‘‘ together in a glafs or ftone mortar, and then put the mixt matter into large crucibles or earthen pots, and calcine it in the furnace defcribed, p. 23, the- top of the crucible ‘‘ or pot being covered with a tile, or other fuch convenient thing, but not luted. The calcination fhould be continued fo long as “ any flame appears to llTue from the matter, or rather till the flame become very flender and blue; for if the fire be very flrong, a fmall flame would arife for a very long time, “ and a great part of the tinging matter would be dilfipated and loft. When the matter ‘‘ has been fufficiently calcined, take the veffels ‘‘ which contain it out of the fire, and as quickly as poflible throw it into t'wo or three gallons of water, and as it foaks there, break it with a wooden fpatula, that no lumps may remain; put it then in a proper tin .veflel, and boll it for the fpace of three quarters of an hour or more. Filter it while hot through paper in the tin cul- “ lenders, defcribed page 28, and pafs fome water through the filter when it is run dry, to wafh out the remainder of the lixivium of the blood and pearl- aflies; the earth re- maining in the filter may be then thrown away. In the mean time diflblve of clean alluiri four pounds, and of green vitriol or copperas two pounds in three gallons of water. Add this folution gradually to the filtered lixivium, fo long as any efferye- fcence USED IN Painting. 8^ fcence appear to arife on the mixture ; but when no ebullition or ferment follows the ‘‘ admixture, ceafe to put in more. Let the ‘‘ mixture then ftand at reft, and a green ‘‘ powder will be precipitated; from which, when it has thoroughly fubfided, the clear part of the fluid muft be poured off, and frefti water put in its place, and ftirred well about with the green powder, and, after a ‘‘ proper time of fettling, this water muft be poured off like the firft. Take then of ‘‘ fpirit of fait double the weight of the green vitriol, which was contained in the quantity of foluticn of vitriol and allum added to ‘‘ the lixivium, w^hich will foon turn the green matter to a blue colour; and after fome ‘‘ time add a proper quantity of water, and w^afh the colour in the fame manner as has been directed for lake, &c. and when pro- perly w'afhed, proceed in the fame manner to dry it in lumps of convenient fize.” By the proportions as given in this procefs, if it be rightly conducted, the Pruflian blue produced will be both deep and bright; but where it is defired to be of a lighter colour, the quantity of dried blood muft be leflened; for if it be even reduced to one half, a beautiful light blue may be made. The proportion of vitriol may, if only half the proportion of blood be ufed, be alfo reduced to half, and likewife the fpirit of fait in proportion to that; the only ufe of fuch fpirit being to re-diffolve the oker or iron precipitated from the vitriol. G 3 But 86 Of the Substances But if any abatement be made In the quantity of vitriol, an equivalent weight of the allum muft be fubftituted in its place, that there may be a fuificient proportion of one or other of thefe falts to precipitate the fulphur of the blood from the lixivium. If the quantity of fpirit of fait prefcribed fail, however, to convert the precipitated mat- ter from green to perfedl blue, a greater pro- portion muft be ufed; for though the quan- tity directed be fully fufficlent when the fpi- rit is of due ftrength, yet as it is frequently found weak when purchafed of the chymiftsa or thofe who fell it, there can be no certain dependence laid on any rule, without obferving that the effedl be correfpondent. Pruflian blue, when made in great quanti- ties, may, for expedition, be dried by heat, and this may be performed by means of a fmall furnace, conftrucLed in the following manner: let a horizontal funnel of brick-work be built, with a vent at one end, opening into a chim- ney. This funnel muft be of fuch breadth as will admit its being covered by plates of tin, and its length muft be regulated by the quan- tity of matter there may be occafion to dry. The plates of tin fhould be well varniftied over, as well on the under as upper fide, by drying oil, boiled to a thick confiftence and black co- lour, and then rendered again fluid by means of oil of turpentine. They fhould be ce- mented to each other, where they join by J)utty mixed with the above varnifh i but they may be USED IN Painting. 87 be fixed to the brick-work, which they reft upon by fire-lute and Dutch, or other tiles, laid over the edges. In the front of this fun- nel muft be made a fmall fire-place for burn- ing charcoal, which muft vent itfelf into it inftead of a chimney. The Piuflian blue to be dried muft be laid in the form of a cake upon thefe tin plates, and then fcored acrofs with a piece of horn both ways, by which means, as the moifture exhales and the mafs ih rinks, each fquare, formed by the fcoring, will be a feparate lump. Okers, and all other earths, as alfo vermilion, may be dried in the fame way on thefe plates : but as thofe fub- ftances have nothing gummy or adhefive in their texture, they may be laid on paper upon the plates, which will prevent their ccntradt- ing any foulnefs from them. The goodnefs of Prufliaii blue muft be dif- tinguifhed by its brightnefs, deepnefs, and coolnefs ; and where thefe qualities are found together in any parcel, it may be depended upon that it will ftand well ; for whatever is added to it to fophifticate it, or whatever is done amifs in the procefs, will always render it more foul and purple. The moft certain way to judge of it is therefore to try it with white lead, or flake white and oil, where the above qualities will difplay themfelves, or ap- pear M^anting, in a much more diftinguiftiable manner than in the lumps of the unmixed pig- ment In the preparation of the coarfer kind of common Pruflian blue, a great part of the G 4 oker # R8 Of the Substances oker or iron precipitated from the vitriol is left in the pigment; but in good Pruffian blue there ought to be no iron, for in time it overpowers the blue of the fulphur of the coal, and fhews its own proper tinge of yellow in the paint, as may be feen in all blue wain- fcots, or other work done by houfe-painters ; which in a fhort fpace of time turn to an olive or greenlfh grey colour. The prefence of iron in Pruffian blue may be difcovered by boiling a fmall quantity of what is fufpefted in a lixi- vium of pearl-affies, to make a feparation of the colour from the remaining earth ; which, if it partake of the other, will appear yellow when waffied and dried; but if free from it^ white or grey. ' Of verdiic7\ Verditer is the mixture of chalk and q)recipitated copper, which is formed by ad-^ ding the due proportion of chalk to the folu- tion of copper, made by the refiners in pre- cipitating the filver from the aqua fortis^ in the operation called parting, in which they have oc- cafion to diffolve it, in order to its purification. Verditer is, when good, a cool full blue, but without the leaf!; tranfparency either in oil or water. It is of a moderate degree of bright- nefs, and would have confequently a confider- able value in the nicer paintings, where it would fupply the place of ultramarine, or at leafl; of the ultramarine affies, if it could be depended upon. But in oil it is very fubjeft to * USED IN Pa I NT IN G. 89 to turn greenifli, and fometimes black; and in water, where it is fafer, it is yet not always found to hold. For which reafons it is rejected, except in paper-hangings and other coarfe work, or in varnilh, where this objedlion to it ceafes. Verditer is only to be had at a* cheap rate from the refiners, who a;e at no expence in the making it, but that of the chalk and la- bour, as they could find no other ufe for the folution of copper made by precipitating the lilver from the aqua forth ^ in one of their moft common operations, were they not to apply it to this. The manner in which it may be bell done by them is as follows. Take any quantity of chalk, and having rendered it properly fine by w^afiiing over ‘‘ carefully, add it gradually to the folution of copper, fo long as any change appears to be produced by it from the ebullition excited; or the due proportion may be perceived by “ the fiuid' s lofing its green tinge and becom- ing colourlefs. Let it then fiand at reft till the fediment be fubfided, and pour off the clear part of the fiuid from the pow'der; “ adding in its place dean water, which muft ‘‘ be feveral times renewed till the falts be en- tirely wafhed out. The fedim.ent, which is the verditer, muft be afterwards freed from the fluid by filtering through paper covered with a cloth, and laid out in lumps of a middling fize to dry.” The verditer as commonly fold requires no fubfequent preparation for its being ufed; only wLere, 90 Of the Substances where, as is frequently the cafe, from ufing fiich chalk in the making of it as is not puri- fied, it is found gritty, and not fufficiently fine, and Ihould then be freed from this grit or foul- nefs by wafhing over. Thofe who defire to make verditer them- felves, may prepare the folutions of copper, by adding copper filings gradually to aqua forth of any kind, or putting plates of copper into it, and then proceeding as is above direfted for the refiners folution. It is not fo expenfive, when prepared In this manner, but that it will well anfwer to thofe who cannot conveniently pro- cure that prepared by the refiners. Verditer is not fubje£t to be adulterated, as nothing 'cheaper of the fame appearance can be mixed with it. Its goodnefs muft be dif- tinguifhed by the darknefs and brightnefs of the colour ; and that is likewife to be preferred which is of the fulleft blue teint, and not in- clining to green, as It may be inferred from thence that the colour will ftand the better. A much deeper and brighter kind of verditer may be made, by ufing a filtered folution of pearl-afhes, in the place of the chalk, and pro- ceeding, as to all other particulars, according to the above directions. Bleu de cendres, or fanders blue^ This colour, or rather name, is of late in- troduction, and has taken its rife, in all pro- bability, from fome French painters having taught i!sED IN Painting. 91 taught theufe of verditer in water colours un« der the name cendre bleu^ which the French in common ftyle give to it. This has been corrupted into fanders blue, and the late writers, who have pretended to teach the art of painting in water colours, &c. have, amongft other blunders and abfurdities, Ipoken of this as a diftind; colour from verditer, known and in common ufe. There is nothing, how- ever, to be found, on the moft diligent in- quiry, in the colour-fhops, under this name, but common verditer, or a fpecies of it where the precipitation of the copper appears to be made in part upon ftarch, as well as chalk. But this by no means anfwers the defcription of the author of a pamphlet publilhed by Mr. Peel in the year 1731, who fays, “ Sanders blue is of very good ufe, and may ferve as a fhade for ultramarine or the blue bice, where the fhades are not required to be ex- tremely deep, and is of itfelf a pleafant blue to be laid between the lights and fhades of “ fuch a flower as is of a Mazarine blue.” By jwhich it is plain the fanders blue meant here cannot be any kind of verditer, as that is always lighter than the ultramarine itfelf, and can therefore never be a fliade to it; un- lefs the fpecies of verditer mentioned above has been prepared darker than at prefent, as is pradicable, and fold under fuch a name, this author miift have made fome miftake, or im- pofed upon the public, by writing what oc- curred to his imagination without regard to fad. If g2 Of the Substances If any, however, may defire to prepare a dark verditer, of the kind here fpoken of, they may do it in the following manner. Take of the refiners folution of copper made in the precipitation of lilver from the ‘‘ fpirit of nitre; ordiffolve copper in fpirit of “ nitre or aqua forth ^ by throwing in filings or putting in flips of copper gradually, till ‘‘ all effervefcence ceafe. Add to it of ftarch, finely powdered, the proportion of one-fifth “ or fixth of the weight of the copper diffol- ved. Make then a folution of pearl-afhes, and filter it, and put gradually, to the fo- lution of copper, as much as will precipi- tate the whole of the copper, which may be known by the fluid’s becoming clear and colourlefs, though before highly tinged vdth green. Wafti the powder, which will be ‘‘ precipitated, in the manner directed for ‘‘ lake, &c. and, when it is fo v/ell drained of water by means of a filter as to be of a proper confiftence, grind the whole well together, and lay it out to dry,” Of indigo. Indigo Is a tinging matter extracted from certain plants by means of putrefadlion, and a coagulation by the air. It is brought from the Eafl and Weft-Indies, and cannot, as far as .is hitherto known, be prepared in thefe colder climates, on account of the tender nature of the plants which produce it. It was formerly almoif USED IN Painting. 93 almofl the only blue colour ufed in painting, either with oil or water, except ultramarine, which, from its great price, could only be ap- plied to very nice purpofes. But, at prefent, the invention of Pruflian blue, and the foul- nefs of the indigo brought from the French or our own plantations, which is greatly infe- rior in brightnefs to that made in the Spanifti Weft-Indies, which was formerly imported here, have almoft banifhed the ufe of it as a paint, except for paper-hangings, or fuch grofs ufes. Where the beft Spanifti indigo, never- thelefs, can be procured, it is preferable for many purpofes to Pruffian blue, of the fame degree of brightnefs, from its certainty of {landing ; but it is never found either of th'e iirft degree of brightnefs, nor fo cool as to be fit for all the ufes to which PrulTian blue can be applied. There is no other preparation neceflary to the ufing indigo in painting, except a perfed: levigation, to which, for nicer purpofes, wafh- ing over may be added. The goodnefs of indigo may be difcerned by its darknefs and brightnefs ; and, as it is al- ways apt to be purple, coolnefs gives a great additional merit to the beft for the ufes of painting. Of fmalt. Smalt is glafs coloured with zafler, and ground only to a very grofs powder. Its texture 94 Of the Substances texture does not permit it to be worked with either brufh or pencil ; but it is iifed for foine purpofes, by fire wing it on any ground of oil- paint while wet ; where it makes a bright warm blue fhining furface, proper for large fun-dials, and other fuch applications. It is prepared from fluxing zafter with glafs of falts ; the proportion of w^hich may be one- feventh part, or more or lefs, according to the degree of deepnefs required in the fmalt. It is ufed alfo in enamel painting, and in paint- ing on glafs, for which purpofes it is of great life. The goodnefs of fmalt confifts in its being dark, bright, and cool, though it always verges on the purple. Befides the common kind of fmalt, there is a very fine fort made in Saxony, but prohibited, under great penalties, from being carried out of the country; it has, however, been brought hither, and fold fometimes under the name of ultramarine, and at others under its own name. The price has always been high, but has varied from fix guineas an ounce to fifteen fiiillings, in confequence of quantities procured by Jews in Saxony at a low rate, in confe- quence of the Pruflians feizing all the works of this kind during the late war. This fort of fmalt is not made of zafFer, but of the fineft calx of cobalt, free from the fand which enters into the compofition of zafFer mixt with feme proper flux. It is exceedingly ftrong of colour, and dark ; and therefore ferves for many USED IN Painting. 95 many purpofes which ultramarine and com- mon fmalt cannot fo well anfwer. It is much harder than the common fmalt, and therefore requires fome flux to be added. It may be diftinguiflied from ultramarine, not only by its dark hue, but by the trial with fire above-mentioned, in the cafe of common fmalt. For though it will not run perfedly without fome flux, yet it will become a hard femivi- trified mafs, if urged with a flrong heat, while the ultramarine, in the fame degree of heat, will remain a powdery calx as before its being ex- pofed to the action of the fire. Of hlce^ Bice is fmalt reduced to a fine powder by levigation. It is a light warm blue colour, and was formerly ufed in oil, more frequently in water colours; but from its unfuitable texture it is now greatly dlfufed. Its goodnefs lies in the brightnefs and cool- nefs. This holds good only of the original and true bice; for at prefent feveral compo- fitions of indigo and verditer, with chalk or other cheap fubftances, are fold in the name of bice. Of litmus^ or lacmiis. Litmus is a blue pigment brought hither from abroad, and formed from archal, a fpecies of mofs, brought from the Canary and Cape de f)G Of the Substance^ cle Verd iflands, being in fadL the fame with that from which the purple tindure called ar- chal, below treated of, is made. It is onlyufed in miniature paintings, and cannot be there well depended upon, as the leaf!: approach of acid changes it inftantly from blue to red ; though it will ftand if no fuch accident inter- vene. Litmus is brought from Holland at a cheap rate, and will go fo far in painting with w'ater colours, the only kind of painting where it can be ufed, that it is needlefs to give the preparation. But if any are defirous, for cu- riofity, to know the procefs, it is thus per- formed. Add quick-lime and putrified urine, or fpirit of urine diftilled from lime, to the archal, previouHy bruifed by grinding* This mixture muft be fuffered to ftand till “ it acquire a very blue colour. After which the fluid muft be fuffered to evaporate, and the remaining mafs, when it be of the con- ‘‘ fiftence of a pafte, muft be laid on boards to dry in fquare lumps.” The goodnefs of litmus may be judged of by the brightnefs and dulnefs of its co- lour. But the beft is^-worth little for paint- ing, as it is very apt to change and fly. Class USED IN Painting, 97 Class III. Of yellow colours. Of Kinfs yellow. K ing’s yellow is a pure orpiment, or arfenic coloured with fulphur. It is ufed for painting in oil and varnifh, and is of an extreme bright colour, and, when good, a true yellow ; it will likewife ftand well, being ufed alone, but when mixed with white le^d and feveral other pigments, its colour flies or^ changes. On this account, and for the addi" tional reafons of its being efteemed a poifon, and having a moft naufeous fmell, it is re- jeded by many. Others, neverthelefs, find too much advantage in its great brightnefs, as well in the ufe of it as a yellow, as when mixed with blue pigments to form a green, not to have recourfe to it on fome occafions. This pigment muft be prepared by mixing fulphur and arfenic by fublimation, which may be done in the following manner. Take of arfenic powdered and flowers of “ fulphur in the proportion of twenty of the firft to one of the fecond; and having put them into a fublimer, fublime them in a fand-heat with fuch a furnace as is de- ‘‘ fcribed p. 21, according to the general di* reffions given p. 32. The operation be- ing over, the King’s yellow will be found in the upper part of the glafs, which muft be carefully feparated from any caput mor^ VoL. I. H tuum g8 Oi^ THE Substances ‘‘ tuum or foul parts that may be found in the glafs with it. It muft be afterwards reduced “ to an equal powder by levigation.” It may like wife be obtained from common orpiment, by fubliming it, inftead of the arfenic and fulphur, in the fame manner; but the produce will be fmall in this method. The king’s yellow maybe rendered warmer, that is, more inclined to orange, by increafmg the proportion of the fulphur ; or the contrary effe£t may be produced by diminifliing it. King’s yellow cannot be adulterated with- out diminifhing its brightnefs ; and therefore that, which is beft in this refped, may be efteemed good In others. Coolnefs, or the being free from red, is likev/ife a merit. Of Naples yellow. Naples yellow is a warm yellow pig- ment rather inclining to orange, but in a very minute degree. It is feldom ufed but in painting vnth oil, where it is generally found to Hand well; but, if it touch iron along with the leaft watery moifture, it will be changed by it. As it is brighter than moft yellows ufed in oil, and indeed than all at fprefent in ufe, except the King’s yellow, it is much received into praftice. It has been fuppofed to be a native earth, and is faid to be found In the neighbourhood of Naples; but this is dubious, as the different parcels of it vary too much from each in fpecihc qualities to allow the fuppofi- tion USED IN Painting. 99 tlon of their being native earths of the fame kind, at leaft with refped: to fiich as are to be obtained from our fhops ; for I have met with fome that was of a very different compofition from the common. The uncertainty with re- gard to the genuinenefs renders this pigment lefs valuable, as it is lefs to be depended upon with rfefped: to its holding its colour. Whe- ther, however, it is an earth that is at prefent generally fophifticated, or what the prepara- tion of it is, we are at prefent ignorant, as it is brought from abroad. This makes it more difficult to give marks of its genuinenefs ; w^hich may therefore be beff gathered from Its appearance, and manner of mixing with the oil, in which the more adulterate kinds differ from the common. Though Naples yellow is of a gritty tex- ture, yet it is beff to ufe it as it is obtained, and only grind it with the oil, for it does not well bear levigation with water. But if fuch levi— gation be neverthelefs prad:ifed on it, the greateft care muff be taken to employ an ivory fpatula in the place of a pallet-knife, which would certainly injure the colour if it were touched with it while wet ; and even when moiftened with oil, the iron is in fome degree injurious to it. Of yello^JD oker. Yellow oker is a mineral earth, which is found in many places, but of different de- H 2 grees ^oo Of THE Substances grees of purity. When free from other earths ^ind heterogeneous matter, it is a true yellow of moderate brightnefs; and, as its texture fuits it for all kinds of painting, and that it will never fly in the leaft, it is a very valuable colour with refpedf to its utility, though of low price. There Is no other preparation of yellow oker neceflary than levigation, and for nicer purpofes wafhing over, to undergo which its texture is extremely fuitable. The goodnefs of yellow oker may be diftln- guifhed by the brightnefs and fulnefs of its yellow colour, and if it be bright it cannot be too cool. There are fome kinds of yellow ' oker which are very bright, and which being well prepared by wafhing are fold by fome colourrnen at a confiderably greater price than the common. But thefe better kinds are counterfeited, and even the beft fometimes fet off to more advantage by mixing Dutch pink with the oker. This impofition muft be guarded againft, which may be done by heat- ing it to the degree that will turn paper brown, which, if it be genuine, will make little or no alteration in It; but if it be adulterated in this manner, will give an apparent foulnefs to it. Of Dutch pink. Dutch fink Is a pigment formed of chalk, coloured with the tinging particles of French berries, lOI USED IN Painting. berries, or other vegetables. It is principally vifed for coarfer purpofes in water, not bear- ing well to be worked in oil, nor can it be depended upon with regard to its handing fo as to be fit for paintings of any confequence. There are a variety of methods of prepar- ing Dutch pink; but the following is very cheap and eafy, and makes a moft beautiful pigment. ‘‘ Take of French berries one pound, and of turmeric-root powdered four ounces ; boil them in a gallon of water two hours, “ and then flrain off the tincture through ‘‘ flannel, and boil it again with an ounce of ‘‘ allum till it be evaporated to one quart. Pre- “ pare in the mean-time four pounds of chalk by wafhing it over, and afterwards drying it, and mix the chalk with the tindlure by grinding them together, and then lay out the Dutch pink thus made to dry on ‘‘ boards.” Dutch pink is fometimes prepared in the fame manner with flarch and white lead. The goodnefs of Dutch pink confifls in its being of a full gold coloured yellow and very bright. It admits of no adulteration but what would appear by the diminution of the bright- nefs, and therefore the eye can determine. ' Of KjigVifh pink, English pink is only a lighter and coarfer kind of Dutch pink, and may be prepared in H 3 the 102 Of the Substances the fame manner, the quantity of chalk being increafed in proportion, as it is intended to be inferior to the Dutch. Of light pink. Light pink Is of tvv^o kinds, the one the fame with the Dutch pink, only with greatly lefs colour; the other the fame with the brown pink, that is, tranfparent in oil, but with lefs colour. The firfl: kind, like the Dutch pink, is only fit for ufing in water, and there likewife only in paintings where the holding of the colour is not of - great confequence. The other is by feme ufed in oil paintings, in the fame manner as brown pink, its tranf- parency making it have a gooji effe£l in fhades for fome purpofes; but it is not a judicious pradice, for all thefe colours formed of vege- tables are very uncertain with refpedl to their ftanding, and the native earths, or prepared okers, properly managed, wdll anfwxr equally t^e fame ends. The preparation of the firft kind of light pink may be in the fame manner as that of the Dutch pink, only diininiihing the propor- tion of the French berries and turmeric to one half. The other kind of light pink may be pre- pared In the following manner. Take of French berries one pound, boil them with a gallon of water for an hour; and. USED IN Painting 103 and, having ftrained off the fluid, add to it two pounds of pearl-aflies, diflTolved and pu- rifled by filtering through paper. Precipitate with allum difTolved in water, by adding the folution gradually, fo long as any ebullition ihall appear to be raifed in the mixture. “ When the iediment has thoroughly fubfided, pour off the water from it, and wafli it with feveral renewed quantities of water, proceeding as has been before diredled in ‘‘ the cafe of lake, &c. Drain off the remain- ing fluid in a filter with a paper covered with a linen cloth; and, laflly, dry it on boards in fmall fquare pieces.” Light pink may be likewife prepared from fuftic w^ood, weld, and feveral other vege- table fubftances, which afford copioufly a yellow^' tinge. ' The goodnefs of light pink lies principally in its brightnefs and tranfparency; and, when defigned for the flhops, care fhould be taken that it do not fatten in the oil, which will happen if the falts be not thoroughly w^afhed out of it. Gamboge. Gamboge is a gum brought from the Eaft- Indies. It diffolves in wrater to a milky con- fiftence, and is then a bright light yellow. It is ufed only in water, but there it is of great fervice, being the principal, or, indeed, almofl the only yellow cpmmonly employed. H 4 Gamboge 104 Substances Gamboge requires no preparation, but dlf- iblves immediately on rubbing it, with the ad- dition of water. The goodnefs of gamboge may be diftin- guilhed by its appearance, while in the ftate of a gum, of a deep warm bright colour, and the more it approaches to tranfparency the better. Of maficot. Masticot, as a pigment for painting, (for the wood is likewife ufed for a white glazing for earthen ware) Is flake white, or white lead gently calcined, by which it is changed to a yellow of lighter or deeper teint, accord- ing to the degree of calcination. It is not greatly ufed at prefent, the colour not being Tery bright ; but as it will ftand perfectly in oil and in water, as well as flake white, or white lead, it certainly might be ufed for many purpofes, as it works wuth the pencil better than moft other pigments. It may be prepared by putting the flake white, or white lead, on an earthen or ftone difh before a ftrong fire, and continuing it .there till the colour be fufficiently yellow, each fide of the plate being put next to the fire in its turn, that the whole of the mafticot may be equally calcined. Otherwife the mat- ter to be calcined may be put into a crucible, and the crucible placed in a moderate heat in a common fire; care being taken to remove it as foon as the mafticot appears of a proper coloyr5 USED IN Painting, 105 coloufj, which muft be diftinguifhed by taking a part of it out ; for the colour does not ihev/ itfelf properly while the matter is hot. The calcination being finiflied, the parts which are of the teint wanted muft be picked our from the reft, and put together. For, with the greateft care, it is difficult to calcine the whole equally; and confequently to avoid rendering Tome parts of a deep yellow or orange. There is no further preparation neceflary for the ufing mafticot either in oil or water painting, except the grinding it with the vehicle. Common orpiment. Common orpiment is a foffile body com- pofed of arfenic and fulphur, with a mixture frequently of lead, and fometimes other me- tals. It was formerly ufed as a yellow in painting, but at prefent is very feldom em- ployed in its unrefined ftate, unlefs to colour the matted bottoms of chairs, or other fuch coarfe work. When purified by fubliming, it becomes the King’s yellow, of which we have before fpoken. It is of a pale greenifh yellow colour, and might be ufeful for feveral purpofes, if its naufeous fmell, and fup- pofedly poifonous quality, did not make the meddling with it difagreeable, particularly in oil, where its bad fcent is greatly increafed. The goodn^fs of. orpiment confifts in the bright- io6 Of the Substances brightiiefs and ftrength of its colour; and the warmer, or rather the lefs inclining to green, the better it is for the purpofes of paint- ing. Of gall fanes. Gall stones are concretions of earthy matter and bile formed in the gall bladder, or bile ducats of beafts. It is ufed by thofe, who know the fecret of its excellence, in water; with which being rubbed, and treated as gam- boge, it becomes a deep warm yellow, that for its brightnefs and dark fliade, when not too thin fpread, as well as holding its colour, is very valuable.. As the gall ftones are not always to be pro- cured, a fiditious kind may be prepared, which will greatly anfwer the fame purpofe. They may be made in this manner. Take a quart of the bile of oxen, as frefix as poffible; put it into a proper pewter veffel, and fet it to boil in bahieo tnariee, having added to it a quarter of an ounce of clear gum Arabic; evaporate the whole to about an eighth, and then remove it into a China cup or bafon of proper fize, and evaporate it to drynefs, colleding it in- to a mafs as it becomes of a ftiff con- fiftence.” This may be ufed as the gall ftones ; and, being more tranfparent, will be found of very great advantage in water painting. Terra USED IN Painting. loy Tcr?^a dl Sienna imburnt, TERRA DI SIENNA, as we have faid before, fpeaking of it as a red when calcin- ed, is a native ochrous earth, brought from Italy. In its uncalcined ftate it is a deepifii warm yellow, and but flightly tranfparent either in oil or water. It is much lefs ufed uncalcined th^n calcined ; but, neverthelefs, as it is a deeper yellow by inany degrees than any of the other okers, and of a fuperior brightnefs, it -might be ufed with advantage, as it wdll hand equally with the beft. Wheu ten^a dl Sienna is ufed uncalcined, it ought to be extremely well levigated and wafhed over; otherwife it is apt to lie heavy in the oil, which is probably the chief reafon why it is fo feldom ufed in an uncalcined ftate, though as much wanted for fome purpofes as the calcjned for others. Turpeth mineral. Turpeth mineral is a preparation of inercury, by calcining it together with oil of vitriol. It is an ^xceftive bright true yellow, of a great body like vermilion, and will ’ftand equally well v/ith that, and it works likewife with oil or water much in the fame manner. Thefe qualities render it very valuable for many purpofes, as it is much brighter than any other io8 Of the Substances yellow ufed in oil, except King’s yellow, and is free from the naiifeoiis fmell of that pig- ment as well as cooler. This coolnefs, and its bearing to be mixed with Pruffian blue, from whence a much finer green can be pro- duced by it than from the King’s yellow with- out ultramarine, give it, on the whoie, greatly the preference. It has not, however, that I know of, been ufed in painting by any except thofe to whom I have recommended it ; and who, on trial, have found it anfwer to what I have here faid of it. The turpeth mineral may be beft prepared in the following manner. Take of pure quickfilver, and oil of vi- triol, each fix pounds. Put them into a re- tort, to which, being placed in the fand- bath, fit on a receiver, and diftil them with a ftrong fire while any fumes appear to rife into the receiver, urging it at laft with as great a heat as the furnace will bear. When the retort is again cold, remove it out of the fand-bath; and, having broken it, take the white mafs, which will be found at the bottom of it, and break it to a grofs pow- der; and, having put it in a glafs mortar, pour water on it, which will immediately convert it to a yellow colour. Let it then be thoroughly ground in this mortar, with water, and afterwards wafhed with feveral fucceflive quantities. It muft then be thoroughly well levigated on a ftone, and dried.” USED IN Painting. 109 The turpeth mineral may be had from the iliops of any chymifts or dealers in medicines ; but is not at prefent in thofe of colourmen. As it is now to be procured, it requires a pre- vious levigatlon in water before it be ufed, be- ing for the moft part (though faultily) leviga- ted for the ufes of the medicine only in a very flight manner. The marks of goodnefs in the turpeth mineral are the brightnefs of the co- lour, and its fulnefs or warmth; for as it never inclines more to the red than a true yellow, the lefs it verges on the green the better it confequently is for the purpofes of painting. OJ the yellow wajh from the French bennies. This is a folution of the gum of the French berries in water. It is ufed as a walking colour in water painting; and as it may be made of almoft any degree of deepnefs, and is pretty bright, It is applicable to many material pur- pofes, fince nothing can be made of the gam- boge but light teints. This colour will Hand alfo extremely well, and being more diluted or laid on thicker, will, in confequence of its tranfparency, give a variety of lhades. The yellow berry walh may be thus pre- pared. ‘‘ Take a pound of the French berries, and put to them a gallon of water, with half an ounce of allum ; boil them an hour in the pewter veiTel deferibed p, 25, and then fJ- ‘‘ ter iio Of the Substances ter off the fluid, through paper if it be de« figned for nicer purpofes, or flannel for more ordinary.) Put them again into the boiler, and evaporate the fluid till the colour appear of theftrengthdefired; or part may be taken out while lefs ftrong, and the reft evapo- “ rated to a proper body.” The goodnefs of the French berries may be diftinguifl'ied by their appearing large, plump, and heavy; and if they have thefe qualities, the darker they appear, the better; but unlefs they are large and plump, the darknefs may only arife from their being gathered before they are duly ripe. "Turmeric wajlo. ^ The TURMERIC WASH is the gum of the turmeric root diflblved in water. The qualities and ufes of it are much the fame as the yel- low berry wafh, only it is a brighter and cooler yellow; but, in order to procure a bright tincture, it muft be diflblved in fpirit of wine inftead of water. In order to which the fol- lowing method may be purfued. ^ Take two ounces of proof fpirit, and add to it one ounce of. water. Being put in a ‘‘ proper phial, add two drams of turmeric root in powder. Shake them well together, and then let them hand three or four days, re- peating the fhaking as often as convenient, and a ftrong tindure will be thus obtained.” Of nsED IN Painting. 1 1 1 Of tinchire of faffron. Tincture of saffron is ufed as a yellow wafli with water colours. It is made by pour- ing hot water on the heft Englifh fafFron in a proper phial or other veflel, which Ihould be placed for fome time in a heat next to that which would make the water boil, and the tindlure fhould then be filtered from the dregs through a piece of linen doth. The propor- tion of the fafFron to the water muft be re- gulated by the intention of having' the colour / deeper or paler. This tindure is a fine -warm yellow, and, when very ftrong, makes a very proper fhade for the gamboge or other light yellows that are bright; and it will fland equal- ly well with any of the i^getable tindures. Zedoary wafj, I The ZEDOARY WASH may be prepared by boiling an ounce of zedoary root in a quart of water, till the w'ater appear fuffici- ently tinged to make aftain on paper of a full yellow colour. The fluid muft then be ftraiii- ed through linen to free it from the dregs. This wafti will be much ftronger of colour than can be made of turmeric without fpirit of wine, and it is a cooler yellow than FafFron, though full as bright. It is valuable for many purpofes in painting with water colours, as flowers, yellow draperies, &c. It ma}^ be fuf- fered J.12 Of the SltBSTANCES fered , to dry in fhells, and will again dliTolve and fpread kindly with the addition of water. Class IV. Of green colours. Erdigrise is a ruft or eorrofiori of copper formed by the action of fome vegetable acid, commonly that of the fkin and pulp of grapes remaining after they have undergone a preffure for wine. It is brought from France and Italy hither, and ufed in moft kinds of painting where green is required. Verdigrlfe makes a blue green colour in paint ; but is generally ufed in yel- low, which, by a proper mixture, renders it a true green. It is bright, when good, but very foon flies when ufed in oil. When ufed in water painting, as it is diflblved previoufly in vinegar, which changes it to another fubflance* it is however rendered more durable.- It is needlefs to give any procefs for the making verdigrlfe, becaufe it may be pur- chafed much cheaper than it can be made in fmall quantities, and therefore only the pro- per object of a confiderable manufa(fiure. Such a manufadtury is eftabliflied lately in this coun- try by Meflieurs — and Maud, who have received two premiums, on that account, of the fociety for the encouragement of arts, &c. on the moft fatisfadtory proof, that the ver- digrife produced by them was even fupe- Of verdigrlfe. nor USED IN Painting. 113 rlor to the foreign, as well for the purpofes of ‘painting as any other ufes. There is no preparation of it neceffary to the ufing verdigrife in oil or varnifh, except a fuf- ficient levigation; but in water painting, as is- faid before, it muft be diflblved in vinegar; when in fafl: it ceafes to be verdigrife, and is, inftead of a corrofion, a fait of copper; the fame with the chryftals of verdigrife, we fhall next treat of, only in a diifolved ftate. Solution in vinegar is not, however, the only method by which verdigrife may be ufed in water painting, for it will dilfolve in the juice of rue, and produces a fine full green colour equally fit for wafhing with that diifolved in vinegar. The goodnefs of verdigrife may be diilin- guifhed by the fulnefs of its blue green colour, and inclining rather towards a chryftaline tex- ture than the form of a powder; to which, muft be added its being free from feculencies, and foluble in a confiderable proportion in boiling water. Chryjlah of verdigrife^ called difllled verdigrife^ Distilled verdigrise is the fait pro- duced by the folution of copper, or common verdigrife, in vinegar. The chryftals thus formed are of an extreme bright green colour, and in varnifh, where they ftand perfedlly well, they have a very fine effed. In oil they hold their colour well enough to anfwer many VoL. I. I pur- 1 14 Of the Substances piirpofes, where colours are not required ta be greatly durable; but in paintings of confe- quence they cannot be depended upon, being apt to turn black with time. The chryftals of verdlgrife may be prepared in the following manner. 'Take of the beft verdigrife four ounces, and of diftilled vinegar two quarts. The verdigrife being well pounded, let them be “ put into a circulating veffel, that may be formed of a mattrafs, (which is a round ^ bodied glafs with a long ftrait neck) and a “ Florence flafk, which muft have its neck inverted into the mattrafs, the thick end be- ing broken off. This circulating veflel muft be placed in a gentle fand-heat, or other warm fituation, where it muft continue, being frequently fliaken, till the vinegar has diffolved as much as it can of the verdi- grife. Remove the verdigrife and vinegar ** then into a proper glafs for decanting the fluid, when it fhall become clear, from the fediment ; and when it has flood a due time to fettle, let it be carefully poured off and evaporated to about half a pint, which ‘‘ may be beft done with a fand-heat, in a glafs body or cucurbit, having its neck cut off to form a wide mouth. It may be fet to fhoot in the fame veffel, or in a glafs receiver with a wide neck; and, when ‘‘ the chryftals are formed, they muft be “ taken out, and carefully dried in the ^ fhade. « A USED IN Painting. 115 A freflx proportion of vinegar may be added to the remains of the verdigrife, and at the fame time the firfl; quantity left undiflblved ; and the mothers, or fluid re- “ maining after the chryftals were formed, may be put into it; by which means, the “ other parts of the procefs being repeated, a fecond quantity of the chryftals will be ob- talned.” The diftilled vinegar produces the moft beautiful chryftals of verdigrife; but com- mon vinegar is more frequently ufed by thofe who prepare them, as it is much cheaper, and will afford very good coloured chryftals, if care be taken in the evaporation, not to fuffer any part of it to burn to the glafs ; to avoid which accident, it is proper that the veffel wherein the evaporation is made fhould not be funk deep in the fand, but only fet upon it, or furrounded a little above the bottom. The goodnefs of the diftilled verdigrife may be perceived by the clearnefs of the chry- ftals, and the bright green colour of them when powdered; for, being faline chryftals, they do not admit of any fophiftication, and can be only faulty through impurity. Of fap green. Sap green is the concreted juice of the buckthorn-berries expreffed from them. ti6 Of the Substances It is a yellow green, and only ufed In water painting, where it is very ufeful for fome purpofes as a wafhing colour, making a ftrong and pretty bright ftain. l^ap green may be prepared in the following manner. “ Take any quantity of buckthorn-berries before they be ripe, and prefs out the juice “ in fuch a prefs as is ufed for making cyder ‘‘ or verjuice, or by any other method. ‘‘ Strain this juice through flannel, and then ‘‘ let it Hand to fettle; and, when it has ‘‘ flood a proper time, decant off the clearer part of the fluid from the fediment. Put this juice into a flone or earthen veflTel, and evaporate it till it begins to grow of a thick confiflence; then remove it into the pewter ‘‘ veflel defcribed p. 25, and finilh the eva- poratlon in halneo martce^i colledling the ‘‘ matter into one mafs as it acquires a proper ‘‘ confiflence.” The marks of goodnefs in fap green are the tranfparency, brightnefs, and flrength of co- lour it appears to have when rubbed on paper. Prnlfian green, PrussiangreenIs the fame with the Pruf- fian blue, except that, in the preparation, the precipitated oker of the vitriol is fuffered to re- main with the precipitated earth of dltim and the fulphur of the coal; the addition of the fpirit of fait, by which, in the regular procefs J USED IN Painting, 117 for the Pruflian blue, the oker is redlflblved, being omitted; whence, this oker being yellow, a green is produced by it through the efFefl: of the blue of the fulphur. The qualities of the Pruffian green are much the fame with thofe of the blue, except the difference of colour, and that it is not fo tranfparent, nor, with regard to any I have hitherto feen, fo bright; neither can it be fo well depended upon for (landing as the Pruffian blue when rightly prepared, though it is nearly equal in that point to the common. As the qualities are fo much the fame, the ufes to which the Pruf- fian green may be applied are much the fame with thofe of the blue, excepting difference of hue; and at one time this colour was gain- ing ground among painters of fome kinds ; but it has fince then been negledled, and at prefent feems almoft wholly laid afide, though I am not fenfible of the reafon why this pig- ment might not be of advantage in many kinds of painting, as well as the common Pruffian blue. The manner of preparing this pigment may be as follows. ‘‘ Proceed in all points as in the procefs ‘‘ given for the Pruffian blue, till the folu- “ tion of allum and vitriol be mixed with that of the pearl-afhes and fulphur of the ‘‘ coal, and the green precipitation made. Then, inftead of adding the fpirit of fait, ‘‘ omit any further mixture, and go on to wafh the fediment, which is the Pruffian I 3 green. ii8 Of the Substances green, and afterwards to dry it in the fame ** manner as is dire^ed for the blue.’^ The goodnefs of the Pruffian green confifts in the deepnefs and brightnefs of the colour, and the more it is of a true teint of green, the better it is. Terra verte* Terra verte is a native earth, which in all probability is coloured by copper. It is of a blue green colour, much of that teint which is called fea--green. What we have in com- mon here is not very bright, but being femi- tranfparent in oil, and of a ftrong body in water, and handing equally well with the beft pigments, it is very much adapted to anfwer fome purpofes in both kinds of paint- ing, though it is not fo generally ufed by thofe to whom it would be ferviceable as it merits. Mr. d’Acofta fays, in his book of foffils, that there is a kind which is very bright, and is found in Hungary; if it could be procured here, it would certainly be a very valuable acquifition to oil painting, as the greens we are forced at prefent to compound from blue and yellow are feldom fecure from flying or changing. Terra verte^ as brought from abroad. Is of a very coarfe texture, and requires to be well levigated and waflied over; but no other preparation is neceffarily previous to its ufe. The only method of diftinguilhing its good- USED IN Painting. 119 nefs is by the brightnefs and ftrengtli of its colour. Class V. Of orange colours. T here is not any fimple pigment, pre- pared commonly, which can properly • come into this clafs, the effeft of orange be- ing produced in practice by the mixture of red and yellow; but the following preparation being of my own invention, and ferviceable to fome who have already made a confiderable life of it, I thought it proper to infert it for the be- nefit of others who may want fuch a pigment. Of orange lake^ This ORANGE LAKE is the tinging part of annatto precipitated together with earth of allum. It is of a very bright orange colour, and would work well with either oil or water; but cannot be depended upon, when ufed either of thofe ways, for (landing long. It is, however, a very fine colour for varnifh paint- ing, where the fear of flying is out of queflion; and is alfo of an admirable good effed; for putting under chryflal for the imitation of the vinegar garnet, for which purpofe it has been ufed with great fuccefs. The manner of the preparation of the orange lake may be as follows. “.Take of the befl annatto four ounces, and of pearl-afhes orie pound; put them I 14“ together 120 Of the Substances together into a gallon of water, and boll them half an hour, and then ftrain the fo- lution through paper. Make, in the mean- time, a folution of a pound and a half of allum in another gallon of water, and mix it gradually with the folution of the pearl- afties and annatto, obferving to ceafe any further addition when the fluid becomes colourlefs, and no further ebullition enfues on the commixture. Treat the fediment or precipitated matter then in the fame manner as has been before directed for other kinds of lake, only this need not be formed into drops, but may be dried in fquare bits, or round lozenges.’* Class VI. Of purple colours. Of the true Indian redn TRUE Indian red is a native j ochrous earth of a purple colour ; and, before the cheapnefs of the fiditious kind occa- lioned it to be rejeded by the colourmen, and confequently difufed by painters, was conftantly brought from the Eaft-Indies and fold in the Ihops. At prefent it is very rarely to be found; but when it can be met with, it is certainly very valuable (there being no other uncompounded purple colour in ufe with oil) as well for the force of its efFed as for the certainty of its ftanding. But the common kind, now falacloufly called by its name, has been, tJSED IN Painting. i2t been, by degrees, from accommodating it to the purpofes of houfe-painters, made to vary from it, till it is become intirely a different co- lour, being a broken orange inftead of a purple. The true Indian red, when it can be pro- cured, needs no other preparation than grind- ing or wafhing over. It may eafily be di- ftinguifhed from any fid;itious kind by its being more bright than any other oker which can be made fo purple; and if it be rendered artificially purple by any addition, the fire will foon betray it, into which the genuine may be put without any hazard of change. Of archaic or orchaL Arc HAL is a purple tindlure procured from a kind of mofs, bearing the fame name, by fo- lution in fpirit of urine diftilled with lime. It may be made in fm’all quantities by thole who cannot procure it of the manufadlurcrs by this eafy procefs. ‘‘ Take an ounce of the archal weed or mofs, as it is fold at the dry falters, and “ having bruifed it well, put it into a glafs “ phial with half a pint of weak fpirit of fal Ammoniacus diftilled with lime. Stop the “ phial clofe, and leave the archal to infufe till a ftrong bluifh purple tindfure be formed.’* It is an extreme bright purple fluid, and would be a beautiful wafh if it could be de- pended upon ; but it is apt to dry to a reddifh brown colour, and therefore at prefent much . , difufed 122 Of THE Substances difufed in painting, though it had formerly a place in the common fet of water colours- it is ufed in great quantities for fome purpofes of dying, and prepared by people wlxo make it their bufmefs, and may be had cheap of them, or the dry-falters ; but is fcarcely worth the trouble of procuring for the ends of painting- ths logwood ' Logwood is brought from America, and affords a ftrong purple tincture in water, which will ftain of a bluifli purple colour almoft any body whatever capable of receiving fuch tinge. It is ufed frequently in miniature ipainting to make a purple walh, which is varied to a more red or blue colour by the addition or omiffion of Brafil wood. This wafh may be prepared in the following manner. Take an ounce of ground logwood, and boil it in a pint of water till one half of the ‘‘ fluid be wafted. Strain it then through flannel while of a boiling heat, and add to “ it, when ftrained, about ten grains of pearl- afhes, or about the bulk of a fmall French “ bean. If it be defired to be a more red purple, about half an ounce of Brafil wood may be added to the logwood, or in pro- portion as the ccjour wanted may require; and in this cafe the pearl-afties muft be ufed very fparingly, or not added at all, unlefs the tincture appear too red.’^ - Class USED IN Painting. 12 Class VII. Of brown colours. Of brow?t pink. B Rown pink Is the tinging part of fomc vegetable of a yellow or orange colour, precipitated upon the earth of allu-m, cuttle-fifli bone, or fome fuch-like calcarious fubftance. It is, when good, a concentrate yellow, which, as a pigment, is tranfparent in oil, gives the ef- fed: of a dark colour, and ferves for deep ihades. It is fometiines prepared of a warmer, and fometimes of a cooler teint; and as each fort fuits the purpofes of particular kinds of painters, each kind is preferred by fome, ac- cording to their wants. Brown pink would be of great value in painting, if it could be de- pended upon with regard to its Handing ; and it was formerly, when all the colours of this kind were more honeftly and judicioufly pre- pared, in almoft general ufe in this part of the world. But at prefent it is difficult to find any that does not fly, or has not fome other bad quality, particularly that of fattening to an exceffive degree, and therefore it is much difufed, and will probably, in a fhort time, be intirely exploded from pradice. There are many methods of preparing brown pink, as there are a great variety of vegetables which afford a yellow tinge very copioufly, and which, treated in the fame manner as is pradifed for making lakes, will afford 124 Of THE Substances afford fuch a pigment ; but the moft com- mon, and one of the bell: methods, is as fol- lows. Take of the French berries one pound, ‘‘ of fuffic wood in chips half a pound, and of pearl-afhes one pound. Boll them in the tin boiler, with a gallon and a half of water, for an hour, and then ftrain off the tliuffure through flannel while the fluid is boiling hot. Having prepared in the mean- time a folution of a pound and a half of allum, put it gradually to the tincture fo long as an ebullition ihall appear. Proceed then to v/afh the fediment as in the man- ner diredted for the lakes; and, being ‘‘ brought by filtering through paper with a linen cloth to a proper confiftence;, dry it on boards in fquare pieces.” Brown pink may be made of the cuttle- fifli bone diffolved in aqua forth j in the manner defcribed, p. 6i, for lake; and in that cafe the precipitation may be made with this folution inftead of the folution of allum, by adding it to the tindture fo long as it appears to make any ebullition on the mixture. The folutions of the allum and cuttle-filh bones may be otherwife mixt together, and ufed for the fame end, which will be found much better than that of the cuttle-fifh bone alone. For though the common opinion is, that lake or brown pink will ftand better, when the bafis is cuttle-fifh bone, than when it is earth of allum, yet the earth of allum is neceffary for attradt- USED IN Fainting. 125 ing and bearing down with It the tinging matter; which, efpecially that of the French berries, is apt to remain diflblved in the fluid, and to be carried off with it in wafhing the brown pink. Brown pink is alfo made without the ufe of falts in the following manner. “ Take two pounds of the berries, and boil them in a gallon of water for two hours, and then ftrain off the tlnd:urc carefully through flannel. Prepare in the mean-time a pound and a half of cuttle-fiih. bone, by feparating the foft inner part, “ which is capable of being reduced to pow- ‘‘ der, from the hard exterior part, that mufl; be thrown away, and levigating it well with water on a marble. Add then the cuttle-fifii ‘‘ bone to the tindure, and evaporate them in balneo mari<^ till the matter becomes of a ftilF confiftence; when the whole being well mixt by grinding, it may be laid on ‘‘ boards to dry.” The goodnefs of brown pink muft be judg- ed of by its tranfparency and force of colour when mixed with oil; but its qualities of ftand- ing well, and not fattening in oil, which are both defeds that frequently attend it, can only be afcertained by trial and experience. Of bi/lrc. Bistre Is the burnt oil extraded from the foot of wood. It is a brown tranfparent co- lour, 126 Of the Substances lour, having much the fame effeO: in water painting, where alone it is ufed, as brown pink in oIL Though this colour is extremely ferviceable in water colours, and much valued by thofe who know and can procure it, yet it is not in general ufe here, on account, I imagine, of its being not eafily had of a per- fed; kind; for I have never heard of any that was good, except what has been brought from France. Perhaps the principal reafon for this is, that dry beech-wood affords the beft foot for making it; and it is not eafy to procure fuch here without mixture of the' foot of green wood, or other combuftibles that deprave it for this purpofe; or, it is poflible, that they who have pretended to prepare it have been ignorant of the proper means, there not being any recipe or diredion in books that treat of tli^efe matters, from whence they could learn them. Biftre may, however, be prepared with great eafe in the following manner. Take any quantity of foot of dry wood, ‘‘ but let it be of beech wherever that can be procured ; put it into water in the pro- “ portion of two pounds to a gallon, and ** boil them half an hour. Then, after the fluid has flood fome little time to fettle, ** but while yet hot, pour off the clearer part from the earthy fediment at the bottom; and if on flanding longer it form another earthy fediment, repeat the fame method; ‘‘ but this ilrould be done only while the fluid remains U 5 BD IN Painting. 127 remains hot. Evaporate then the fluid to drynefs, and what remains wili be good biftre, if the foot was of a proper kind,” The goodnefs of biftre may be perceived by its warm deep brown colour, and tranfparency when moiftened with water. brown oker. Brown 0K£R is a foffile earth, the fame with the other okers, except with regard to purity and the teint of its colour, which depends on calcination, either by fubterranean fires or arti- ficially. It is of a warm brown or foul orange colour; and, as it can be abfolutely depended upon for Handing, it is valued by fome in nicer kinds of painting, but moft ufed, being of very low price, for coarfer purpofes. When brown oker is ufed for more delicate kinds of painting, It ought to be well levigated after it comes out of the hands of the colour- men, if had of them in the grofs ftate in which it is commonly fold. But whoever would have it in the moft perfect condition, muft wafli it over, which treatment fliould indeed be be- llowed on all pigments of an earthy texture. Colcgn^ or Collen^s earib, COLOGN EARTH is a foflile fubftance. It is of a dark blackifli brown colour, a little in- clining towards purple. The principal ufe of it in painting is as a water colour, and its greateft n8 Of the Substances greatefi: efFecl Is in the fore grounds of pic- tures, where great force is required. It is not, however, at prefent much ufed even as a water colour, and more rarely in oil, as there the fame teint can be eafily formed of blue, black, and any of the ochrous reds, \vhich are pigrnents abfolutely fafe with re- Ipeft to ftanding. The goodnefs of Cologn earth muft be judged of by the ftrength of the colour, and the fuitablenefs of the teint to the pur- pofes for which it is ufed. It requires no other preparation than to be ground perfectly fine with water. T^erra Japonlca-^ or Japan earth. Terra Japonica is a gummous fub- fiance extracted from fome kind of vegetable. It diffolves to a great degree in water, and is of a full brown colour, a little inclining to red. It is fometimes ufed as in water paint- ing; and as it is there a wafhing colour, may have a very good effedt in many cafes. In oil, its gummy texture renders its ufe Improper, as it does not admit of its mixing kindly with that vehicle. The goodnefs of terra Japonica may be di- ftinguifhed by the clearnefs of its colour, and its appearing free from heterogeneous matter or impurities. It requires no preparation, but It is dif- folved in water, and freed from any fecu- lencies. Of F USED IN Painting. 129 Of timbre. Umbre is an ochrous earth of a brown co- lour. It was formerly ufed in moft kinds of painting, but is at prefent neglected, except by fome in water colours. It is valuable on account of its property of ftanding well, which it has in common with moft other native earths, and it is fuppofed to have a more dry- ing quality than other okers, wh’ch has oc- cafioned it to be much ufed. in the making drying oils, the japanners gold fize, and the black oil lacquer. The umbre is frequently burnt previous to its being ufed, which renders it more eafy to be levigated; but it gives it at the fame tune a redder hue. Whether it be ufed in a burnt or unburnt ftate, it is neceffary, however, to wafti it over when it is ufed in miniature painting, or for any nicer purpofes, and that is all the preparation it requires. Of afphaltum. Asphaltum is a bituminous matter of a confiftence like tar, found in the earth in fome parts of Afia, and probably elfewhere. It has a warm brown colour, and retaining in fome degree its tranfparency when dry, it anfwcx^s the end of brown pink in oil painting, with the additional advantage of being fecure from flying. It is not in general uie, nor probably VoL. I. K eaiily 130 ,Of the Substances ealily to be procured poor; but it is certainly ufeful, when to be obtained good. The only objedion I have ever heard to it is, that it turns fometimes blackifh; but I never law an inftance of that, though I have knovv^n it ufed by feveral; and belie\T that appearance is not owing to any change in its colour, but to that denfity of its fubftance which it contra£ts in drying, and which Ihould be allowed for in the application of it. There is no preparation necelTary to af- phaltum previous to its ufe, but it ought to be carefully preferved in a proper phial with a wide neck, otherwife it is fubjed: to dry, and become too thick for the purpofes of painting. Afphaltuin Is very liable to be adulterated by the mixture of turpentine, pitch, and other cheap fubftances of a balfamic confiftence, with it; and it is not eafy to diftinguilh the fraud, but by the appearance. When the af- phaltum is good, it ought to be perfedlly tranfparent, but of a warm deep brown colour. Of the Spanijh juice^ or the extract of liquorice. The Spanish juice is the fucculent part of the liquorice-root, extrafted by decoftion in water, and then ftrained off from the woody or iindlffolvable part of the root, and evapo- rated to drynefs. It is fometimes prepared in this country, but moftly brought from abroad. USED IN Painting. 13 i and is now much ufed as a brown colour in miniature painting, from its requiring no trou- ble to procure it, or render it fit for immediate life, and from the fcarcit'y of good biftre. The latter neverthelefs, when it is to be had, is greatly preferable to the Spanifh juice, as well on account of the clearnefs of its colour, as from its being free from that vifcid or fticky quality which attends the other on the leafl inoifture. Class VIII. Of white colours. Of white flake. W hite flake ' is lead corroded by means of the prelTing of the grape, and confequently, in fadt, a cerufe prepared by the acid of grapes. It is brought here from Italy, and far furpafles, both 'with regard to the purity of its 'whitenefs and the certainty of its Handing, all the cerufe or white lead made here in common. It is ufed in oil and varnlfli painting for all purpofes where a very clean white is required; but no kind of cerufe ought to be ufed in water.cdlours for paintings* that are intended to endure time, as it will generally turn black, and appear at., length as if the lead itfelf had been ufed infiead of any preparation of it. White flake is ufually had of the colour- men in a prepared ftate, under the name of (lake white^ being levigated and mixed up K 2 with 132 Of the Substances with ftarch, and moft frequently with white lead, or much worfe fophiftications. Who- ever, therefore, would be certain of ufing this pigment pure, fliould procure the white flake in lump as it is brought over, and levigate it themfelves, wafhing it over alfo’; and, if it be neceflary, in order to the mak- ing it work more freely, they may grind it up afterwards with ilarch in the proportion they fliall find on trial moil fuitable to their purpofe. The tefl: of goodnefs in white flake is the degree of whitenefs, which muft be diftin- guifhed by comparing it with a fpecimen of any other parcel after it has been rendered of due finenefs; but where it is fufpected to be adulterated by any other mixture than that of white lead, the fophiftication and pro- portion of the fpurious matter may be afcer- tained by the fame means as are below ad- vifed to be ufed for the examination of white lead. White lead. White lead, or ceruse, Is the corro- fion or ruft of lead formed by means of vinegar. It is made in our own country, and is much cheaper than white flake, but inferior in white- nefs, and the other qualities which render this pigment advantageous in painting. It is, how- ever, the white employed for all common pur- pofes in oil painting, and alfo the body or fo- lid USED IN Painting. 133 lid bafis of the paint in many mixt colours, where the teint is of a lighter nature, or the coloured pigments will bear diluting with white. It is made by dipping or brufliing plates of lead in vinegar, or any other cheap acid, and putting them in a cellar or any cool damp place; but as this is carried on as a large ma^ nufa<51:ure by thofe who are concerned in it, and who can confequently afford it at a much lower rate than any can prepare it for their own ufe» it is unneceffary to enter on a further detail with refpedl to the manner. There is no previous preparation neceffary in the cafe of white lead to its ufe, except wafhing over where it is intended for more delicate purpofes; but then indeed it is always beft to fubftitute the flake white. Notwithflanding the low price of white lead, yet, being confumed in great quantities, it is for the mofl part adulterated by the ma- nufaflurers of, or wholefale dealers in it. The common fophiflication is with chalk or pow- dered talc, as being the cheapeft ingredients with wTIch it can be mixt without changing too much its appearance. This in a lelfer de- gree is of no great moment, as they only diminifh the quantity of body or covering matter in the paint; but when in a greater proportion, they not only produce a great lofs by rendering a larger quantity neceffary to do the fame work, but deprave the paint highly >yith refpedl to its other qualities. K 3 The 134 Substances The adulteration of white lead may be moft eafily examined by comparing a piece of any that is fufpefted with another piece, known to be pure, of equal bulk, and the difference of weight will fhew the fraud where the hetero- genous matter is in great proportion, as it will neceflarily be of a much lighter nature than lead. But where the quantity of the adulterating matter is lefs, or the proportion of it vv^ould be more exactly known, the fol- lowing method fhould be ufed. Take an ounce of the white lead fuf- ped:ed, and mix it well with about half an ‘‘ ounce of pearl-afhes, or of any fixt alka- line fait, and about a quarter of an ounce of charcoal-duft, and, having put them “ into a crucible, give them a llrong heat. The lead will by this means be reduced to its metallic ftate, and, being weighed, will fhew by what it may fall {hort of the weight of an ounce, the proportion of the adulteration, about a tenth part being al- lowed for the corroding acid which formed ‘^" part of the w^hite lead.’’ Of calcined^ or burnt hartjhorn. Calcined hartshorn is the earth which makes the bafis of horn, or indeed all other ani- mal fubftances, rendered pure by the adHon of fire, which feparate from it all laline and ful- phureous fubftances. It is of the firft degree of whitenefs, and not fubjedl to be changed by the USED IN Painting. 135 the air or time, and is, on account of ihefe qualities, almoft the only white now ufed in water painting for nicer purpofes, white lead or flake, from the objeftion before mentioned with refpe and fo adulterated moreover with charcoal-duli, which renders it of a blue caftj 140 Of the Substances caft, that it is wholly exploded from all more delicate purpofes, and lamp black ufed in the place of it, though inferior, with regard to the purity and clearnefs of the black colour, to this w^hen good. As the ivory black, notwithftanding, has its merit in moft kinds of painting, w^hen its pre- paration is properly managed, (particularly in water and varnifh) thofe who defire to have it may prepare it themfelves in perfedtion by the following means. Take plates, chips, or fh^vings of ivory, and foak them in hot linfeed oil or if filings are to be more eafily procured, they may be ufed moiflened with the hot oil. Put them into a veffel which will bear the fire, cover-^- ing them with a fort of lid made of clay and fand, which fhould be dried, and the cracks repaired before the veffel be put into the fire. Procure th s veffel to be p^ced In a tobacco- pipe-maker’s or potter’s furnace, or any other fuch fire, and let it remain there du-r ring one. of their heats. When it (hall be taken out, the ivory will be burnt properly, and muff be afterwards thoroughly well le- vigated on the ftone with water; or it (hould indeed, to have it perfedlly good, be alfo wafhed over.” Thofe who have a calcining furnace, fuch as is deferibed p 23, may very commodioufly burn the ivory in it, and the fire need not be continued longer than w^hile the fumes that arife from the veffel containing the ivory ap<^ pear USED IN Painting. 141 pear to flame. This operation may likewife be performed in the fubliming furnace de- fc'ribed p. 16, by putting the ivory in a retort coated with the fire-lute, and fixing the retort as is dire( 51 ;ed, p. 33, for the fublimers; and a proper receiver being fitted to the retort, the fumes will be detained in it, and the fmell pre- vented from being in the leaft troublelbme ; the fire muft in this cafe be continued w^hile any grofs fumes come over. The goodnefs of ivory black may be per- ceived by its full black colour, not inclining too much to blue, and by its finenefs as a powder. OJ' Hue black. Blue black is the coal of fome kind of wood, or other vegetable matter, burnt in a clofe heat v. here the air can have no accefs. The bell kind is faid to be made of vine-ftalks and tendrils; but there are doubtlefs many other kinds of vegetable fiibfiances from w hich It may be equally w*ell prepared. It is, w^hen good, a fine bluifh black colour, ufeful in moft kinds of paintings for many purpofes ; but is rarely to be had at prefent w^ell prepared, and therefore much negledled in moft nicer cafes. Thofe who defire to have blue black per- fectly good, may prepare it in the manner above directed for the ivory black, from the vine-ltalks or tendrils, or any other twfigs of wood of an acid tafte or tough texture, but the 143 Of the Substances the foaking in oil, prefcribed for the ivory, mud be here omitted. The goodnefs of the blue black confifts in the • cleannefs and blue caft of its black colour, and the perfeftnefs of its levigation, which Ihould be managed as diredted for the ivory black. Of Indian ink. Indian ink is a black pigment brought hither from China, which, on being rubbed with water, diffolves and forms a fubftance refembling ink, but of a confiftence extremely well adapted to the working with a pencil. On this account, it is not only much ufed as a black colour in miniature painting, but is the black now generally made ufe of for all fmaller drawings in chiaro oh fair 0 (or where the effedl is to be produced from light and flnade only). The preparation of Indian ink, as well as of the other compofitions ufed by the|Chinefe as paints, is not hitherto revealed on any good authority; but it appears clearly from experi- ments to be the coal of fifh bones, or fome other animal or vegetable fubllance, mixed with ifinglafs fize, or other fize, and, moft probably, honey or fugar-candy to prevent its cracking. A fubdance, therefore, much of the fame nature, and applicable to the fame purpofes, may be formed in the following manner. Take i USED IN Painting. ' 143 Take of ifinglafs fix ounces, reduce it to ‘‘ a fize, by diflblving it over the fire inllouble its weight of water. Take then of Spanifli ‘‘ liquorice one ounce, and diflblve it alfo in double its weight of water, and grind up ‘‘ with it an ounce of ivory black, prepared as above diredled in p. 140. Add this mix- ‘‘ ture to the fize while hot, and ftir the whole together till all the ingredients be thoroughly incorporated; then evaporate away the water in balneo maria^ and caft the remaining compofition into leaded moulds greafed, or make it up in any other form.” The colour of this compofition will be equally good with that of the Indian ink; the ifinglafs fize, mixt with the colours, works with the pencil equally well with the Indian ink; and the Spanifh liquorice will both ren- der it eafily diflblvable on the rubbing with water, to which the ifinglafs alone is fome- what reludlant, and alfo prevent its cracking and peeling off from the ground oh which it is laid. CHAP. '144 the Substances CHAR III. Of the vehicles, dryers, and other fubftances ufed in painting for the laying on and binding the colours. SECT. I. Of the vehicles^ dryers^ in general. T H E qualities neceffary in all vehicles (except in the cafe of crayons and ena- mel painting) are that they fhould be of a pro- per degree of fluidity to fpread the colour, — that they fliould be of fi:ch a nature, with re- fpefl: to their attradlive difpofition, as fits them to combine well with the coloured pigments, - — that they fliould become dry within a due time, — and that they fliould be capable of leav- ing a proper tenacious body, when they are become dry, as well to bind the colours to the ground as to make them adhere to each other where more than one kind is ufed. But the combination of all thefe neceflary qualities being to be found in no one fubflance, (except oil in forne cafes) compofitions have been formed to fuit the feveral intentions in a manner accommodated to each particular occafion. The psED IN Painting. • 145 The principal vehicles hitherto ufed are oils, — water, — fpirit of wine, — and turpentine. But, as water and fpirit of wine alone, want the proper undfuous confidence fcr fpreading the colours, and dry away to- tally, without leaving any glutinous fubitance to bind and fix fuch of the pigments as are of an earthy or incohering texture, gums, — fize, — fugar, — and other fuch vifcid fub- ftances have been fuperadded to fupply the defects, and render them of due confiltence and body. Though oils, fimply ufed, are a perfect ve- hicle of colours in fome cafes, yet In many others, having been found to dry too flowly, means have been fought after, by the ad- dition of other bodies, to alter this quality in fuch as may be defedtive in it, which has confequently introduced another kind of fub- ftances into the materia piBoria, Thefe fub- ftances, from their being employed in the intention of remedying this fault in the oils of not drying fufficlently faft, are called DRYERS, Thefe are either Ingredients of a different nature added to the oils, with- out any preparation of them; or part of the oils themfelves, into which this quality has been introduced by the operation of heat, either in their fimple ftate, or with the ad- dition of the other drying ingredients. The oil, thus changed, being thence rendered ca- pable, on its commixture with other oils, to caufe them to dry fafter, is called drying oil^ VoL. I. * L and < 1^6 Of the Substances - and frequently ufed in the fame intention as other dryers. < As water in its fmiple ftate is for the moft part incapable of being a vehicle to colours, they being in general of an earthy or inco- hering texture, it is necelfary to give it a more ^ n the contrary, differs oppofitely from both of them in fome very effential circum- ftances. In Substances In fpeaking therefore of the fattening of oils or colours^ attention fhould be had to the not confounding thefe three feveral kinds one with anotlier. This can fcarcely be avoided in fome cafes, but by confidering the occafion where the term is ufed, and judging from the drcumflances which kind is meant* Thefe are the feveral qualities by which oils are rendered fuitable to, or improper for, the piirpofes of painting. When they dry quickly, are colourlelk, (efpecially through age) and are fomewhat fat in the fecond of the above fenfes of that word, they are per fed with refped to the vrants of painters. Where they dry, though more flowly, they may,, neverthelefs, be im- proved to it tolerable ftate by additions; and where they are difcoloured, they may ferve for fome ufes; but where, as is frequently found, they will dry only in a great length of time, or not at all, they are abfolutely unlit for this application. SECTION IIL Of particular oih. Of Imfeed oiL L Inseed oil Is exprefied from the feed of line by thofe who manufadure it in large quantities, and have mills turned by water for the more expeditious difpatch of the work. It USED IN Painting. 155 It h the principal oil ufed in all kinds of paint- ings ; or, indeed, the only kind, except for fome very nice purpofes, wliere its brownnels renders it unfit. The general defe6:s of lin- feed oil are this brown colour, and a tardinefs in drying; both which are in a much greater degree in fome parcels than others. There is alfo fometimes found fuch, as, in confequence of its being commixed with the oil of fome other vegetable (accidently growing v/ith it) that partakes of the nature of olive oil, can- not be brought to dry by any art or means whatever. The goodnefs of linfeed oil, therefore, con- fifts in its nearer approach to a colourlefs ftate, and in its drying foon. Its ftate, with refpecl to the firft quality, may of courfe be diftin- guilhed by infpedion only; but the latter can only be difcovered by adtual trial of it, for there is no particular appearance, or other perceptible mark, attending this quality. Linfeed oil is in general ufed without any other preparation than the mixing it with the proper dryer; but the keeping it a confider- able time before it be ufed will always be found to improve it. It is, neverthelefs, ufed fometimes, after it is prepared into the ftate of drying oil, not to commix and make other unprepared parcels dry,- but alone, as the foie vehicle of the colours. The convenience of this is the fpeedy drying of the paint fo com- pofed; but it cannot be pradlifed where the beauty of the colour is of the leaft confer quence, ic6 Of the Shbstakces quence, for the oil imparts in this cafe a very ftrong brown to the mixture. OJ' nut oiL Nut oil is the oil of walnuts preffed out of the kernels by means of a fcrew-prefs. It is ufed for the mixing with flake white, or other pigments, where the clearnefs of the colour is of great confequence, and would be injured by the brownnels of linfeed oil. It is ufed without any other preparation than keeping, which is always of advantage to it, both with regard to its colour and qua- lity of drying. The faults of nut oil, when not good, are the being turbid and not perfectly colourlefs, and the drying too flowly. The firft (hews itfelf, but the other muft be examined by trial. If, however, there be no adulteration in the cafe, time will generally cure it of all thefe defedts. Whoever would have nut oil perfedlly good, fliould peel off the fkin of the kernels before they be prefled, in the fame manner as when they are eaten; for the fkins contain an acrid oil of a very different nature from that of the white fubfliance of the kernel, which is ex- tremely fubjedt to turn brown, or even black, and confequently tinge the other when com- mixt with it. Of USED IN Painting. ^57 Of p oppy oil. Poppy oil Is exprefled from the ripe feed of poppies, in the fame manner as nut oil from the walnuts. Its qualities and ufes, as like- wife its defefts and the remedy for them, are alfo much the fame as thofe of the nut oil ; only when it is perfectly good, it is more clear and limpid, and will dry better tlian the bed nut oil whatever. Oil of fpike or lavender. Oil ot spike or lavendek are elfential or diftilled oils, obtained by diftilling the fpike, or any other lavender, with water. It is ufed in painting only as the vehicle for laying on the compofitioR formed of the flax and co- lours in enamel painting ; which by its fluidity it renders capable of being worked with a pencil; its volatile nature afterwards making it wholly dry away without leaving any matter that might effed: the fubftances of the enamel, which -would be otherwife if any but an ef- fentlal oil were ufed. ^ Oil of fpike or lavender is fubjed: to be adulterated by the oil of rofemary ; which, though much of the fame nature, yet being of a lefs unduous or thick confidence, is not fo well adapted to make the colours fpread and work well with the pencil. This adul- teration is not eafily difcoverable, where it cannot 'IJ8 Of the Substances cannot be diftingiilfhed by the finell; and the beft method therefore to be certain of the goodnefs of the oil of fpike or lavender for this purpofe is to make an actual trial of it. SECTION IV, Of particular dryers. Of drying oil. D rying oil, or other oils, is formed of linfeed oil, prepared by the means of boiling, fometimes with the addition or other fubftances, and fometimes without. The fubftances added to oil in this preparation are very various ; there being many different re- cipes in the hands of different perfons, fome of which prefcribe a lefs number of ingredi- ents, and others almoft every kind. Thefe fubftances are white vitriol, fugar of lead, feed- lac, gum maftic, gum fandarac, gurn animy, gum copal, umbre, colcothar, litharge, and Ted lead. But the firft eight of thefe articles being dearer, when great quantities of drying oil are prepared for common purpofes, they are ufually omitted, and the others, or fome of them, only employed; and indeed, if the linfeed oil be good, and boiled for a proper ' time, even alone it will have nearly the fame properties as if the moft efficacious of thefe fubftances U3SD IK Painting. 159 fubftances be added to it. I will, however, give two of the moft approved recipes for pre- paring drying oil with the addition of the ufual ingredients. The one for the kind fuppofed proper for the more nice and delicate paint- ing, the other for common work. Take of nut or poppy oil one pint, of gum fandarac two ounces, of white vitriol, and fugar of lead, each one ounce. Boil the whole tiil the folid ingredients be diffolved, and the mixture be of the colour of linfeed oil.’’ This oil will dry faft, and mixed with an equal quantity of nut oil, and the proportion , of oil of turpentine each perfon may find moft convenient to ufe, will prove an eKcelient mixture / for all purpofes where a fmall de- gree of yellow is not injurious ; or, in oilier words, for all purpofes but forming the pureft white telnt. It will alfo, when mixt v\^ith any other oil, r^ender it capable of drying well without the leaft hazard of fattening, hov/- ever difpofed to it; and it may be therefore iifed for all nicer purpofes where common drying oil would be injurious by the brov/n- nefs of its colour. Drying oil may be well prepared for coarfer work, according to the commonly-approved method, in the following manner. ‘‘ Take of linleed oil one gallon, of litharge of gold or filver one pound, of white vi- triol half a pound, of fugar of lead, gum Arabic, and umbre, each a quarter ^of a pound. i6o Of the Substances “ pound. Boil them fo long as the difcolour-' ‘‘ ing the oil, which is the gradual confe** “ quence of’ the boiling, will permit it; for ‘‘ the oil muft not be burnt till it approach too near to blacknefs.’^ The drying oil prepared in a fimple man- ner, as by thofe who make it for fale, will not differ much from the above in its qualities, though it be prepared as follows. Take linfeed oil one gallon, red lead one pound and a half. Boil them fo long as the colour will bear it.” This laft may be much improved by the addition of gum fandarac, and will then be perhaps more ufeful than the more complex and expenfive compofition above given. In- deed a gallon of linfeed oil, in which two pounds of gum fandarac and one pound of gum Arabic has been dilfolved, is the drying oil I would recommend for common purpofes ; and it need not be boiled near fo high as that fold in the fhops. For, as the gums give it a very confiderable body, the colours may be brought to a proper ftate for v/orking by a lit- tle of this wTth a larger proportion of fpirit of turpentine, either with or without the addition of unprepared oil ; and confequently the pro- portion of brov/n given to the colour is lefs than where a greater quantity of the oil muft be ufed. The drying oil of any kind may be boiled in an earthen pipkin, or iron pot ; but great care muft be taken in the operation, if it be performed USED IN Painting. i6i performed within any building, that the mat- ter do not boil over; which, when it happens, greatly endangers the firing fuch building. It is therefore much better, efpecially where any larger quantities are made, to have an iron, furnace that can be moved about, or to build an occafional one of bricks; which, for this purpofe, may be done without mortar. It need only be a cylinder of bricks, in which a frame with bars to fupport the fuel is fixed, with a hole about eight inches above the bars for feeding the fire, and another in the higheft part of the hollow for venting the fmoke. When the drying oil is taken off the fire, it may, while yet hot, be ftrained through flannel; but if umbre, or any ingredients which will not dlflblve are added to it. It fhould firll ftand to fettle, that the clearer part may be poured off from the grofler; and after flraln- ing, if any fediment appear, the oil fliould be again decanted off from it, and the foul part heated and pafled again through the flannel. Of oil of turpentine. Oil of turpentine Is diftilled from tur- pentine. It is an ethereal oil which quickly exhales in the air, and if mixt with linfeed, nut, or poppy oils, inj flying off carries with it the more volatile part of fuch oils, and caufes them to dry much fooner than they would otherwife. On this account it is very generally ufed as a dryer to mix with the VoL. I, M other j6z Of the Substances other oils; for which purpofe it has greatly the advantage over drying oil, with regard to colour, as it is perfedly tranfparent and white. It is ufed without any other preparation than mixing iu either alone or together with drying oil, with the other oils and colours; and it its not fubjed to any adulteration, ex- cept the diflblving crude turpentine or refin in it, which do not greatly injure It with regard to this application of it. Such adulteration may howxvcr be perceived, when In a greater proportion, by a flight degree of yellow colour and glutinous confiftence ; the unfophifticate being quite limpid, and without the leaft tenacity. When in a lefs proportion, the adulteration may be difcovered by evaporating part of what is fufpe£ted with a very gentle heat, as a refmous or terebinthinate fub- ftance will be left behind, if any fuch have , been mixt with the oil. Of fiigar of lead. Sugar of lead is a chymical prepa- ration ofdead by diffolving it in vinegar, and reducing the fait formed by the combination of the lead with the acid of vinegar to a chryftaline ftate. But as fugar of lead may - always be had at the fliops of chymifls, drug- gifts, and colourmen, and at a much lefs ex- pence than it can be made in fmall quantities, it is needlefs to give any more particular recipe USED IN Painting. 163 recipe for the making It for the purpofes of painting. It is fuppofed to have a quality when mixt with oils of rendering them much more prone to dry, and on that account is very frequently ufed, as well in the making drying oil, as in the common ufe of the oils where it is ground up with them together with the colours. It requires no other treatment but to be well commixt with the oil with which it is ufed, and it is not fubjedt to any adulteration if it be obtained in its chryftaline form and not powdered; for there the appearance alone is fufficient to Ihew whether it is clear from any mixture of heterogeneous matter. It is, notwithftanding, the general confi- dence which painters have in this fubftance as a dryer, dubious whether the ufe of it, except in the preparation of drying oil, anfwers in any material degree the end; for though, it may aflift the heat in producing that change in oils which renders them drying oils, yet it does not neceflarily follow that any fuch efFefl: is produced by it without heat ; though it is very probable that the fuppofition of this has been the occafion of its being introduced into praftice as a dryer that will operate on oils by barely mixing it with them. Of\ white vitriol. White vitriol is a mineral fubftance found in Hungary and many other places. It is ufed in the fame manner, and for the M 2 fame 164 Of the Substances fame purpofes in painting as fugar of lead^ with which it is generally joined in pradice, both in the making drying oils, and the ad- mixture with the common oils and colours- It is not liable to be adulterated, on account of its low price; but it has not been unufual to fell common green vitriol or copperas calcined to whitenefs in the place of it ; and as they are very different fubftances, this ought to be guarded againft. Thofe who are acquainted with the appearance of both, may eafily di- ftinguifh them by view. But others may make themfelves certain they are not impofed upon in this particular, by putting a fmall piece into the fire on a poker, or any other way; when, if the parcel in queflion be true white vitriol, no rednefs will come upon it; but if it be the green vitriol calcined to whitenefs, it will turn red by this greater heat, and have the appear- ance of Indian red, or brown oker. .. „ What was faid of the dubioufnefs of the efficacy of fugar of lead as a dryer, except in the preparation of drying oil, holds equally good with refpeft to white vitriol, though, from a ftrong perfuafion of the contrary, it is ufed very generally, and in a large propor- tion. SECT, USED IN Painting. SECTION V. « Of the fubfances ufed for renderhig water a proper vehicle for colours. Of gum Af'ahic. G um Arabic is a tranfparent gum brought from Africa and the Levant, that is eafily foluble in water, hich it renders vifcid. From thefe qualities, and the drying with a_ confiderable degree of tenacity, it is the beft ingredient for making an aqueous vehicle for colours hitherto known in Eu- rope. When good, however, as it is apt to become perfectly dry, it is fubjefl: to crack and feparate from the cartoon or grounds on which the colour is laid with It, from whence fome mixture becomes neceffary to remove this defedb. The goodnefs of gum Arabic muft be con- cluded from its tranfparent whitenefs, the be- ing perfed:ly dry and brittle, and free from all duft and heterogeneous matter. Gum Senegal, which is of lower price, is frequently fold for it; but this fraud may be eafily guarded againft by taking care to obferve that it be not foft and clammy, which qualities are always in fome degree found in gum Se- negal. There is no other preparation neceffary for gum Arabic, previoufly to being ufed with IM 3 the i66 Of THE Substances the water, except powdering it, in order to its diffolving the more eafily ; only it is proper to pick out all brown and difcoloured pieces, or any foulnefs that may accidentally be in it. Of gum Senegal. Gum Senegal is much of the fame nature as gum Arabic, and applicable to many of the fame ufes; but it is apt to retain fome propor- tion of moifture, which confequently renders it more foftand clammy. This property makes it, when alone, a lefs fit ingredient for a ve- hicle for water colours than gum Arabic; but yet, neverthelefs, a third or fourth part of the gum Senegal, mixed with the gum Arabic, will greatly improve it. For, as the guru Senegal is too flow and reludtant to the drying perfectly, fo the gum. Arabic on the contrary dries in too great a degree ; and a due mixture of them therefore produces the proper me- dium or temparament betwixt the two ex- tremes. The treatment of the gum Senegal, wdieii ufed in a vehicle for water colours, mud be in all other points the fame as the gum Arabic, Office. I Size is made of leather boiled in water till it becomes of a vifcid confiflence. It Is a very proper ingredient for a vehicle for colours ufed in water in larger works; but USED IN Painting. 167 its reluftance to be rediffolved after it has been mixed with colours and is become dry, renders the employing it incommodious in mi- niature painting. Size is commonly prepared In great quantities by thofe who make a trade of manufadluring it, together with glue, from all refufe pieces of leather and (kins of beafts ; but where it is wanting in painting for nicer purpofes, it fhould be prepared from the cut- tings and fhreds of the glovers in the follow- ing manner: Take any quantity of the flrreds or cut- tings of glovers leather, and put to each “ pound a gallon oP water; boil them fix or “ eight hours, recruiting the water, fo that it ‘‘ lhall not diminifli'to lefs than two quarts. ‘‘ Then take it off the fire, and firain the fluid through flannel while hot; and afterwards ‘‘‘ evaporate it again, till it become of the con- fiftence of a jelly when cold.” Of ftigar and fugar-candy. Sugar and white sugar-candy are ufed as ingredients to render water a vehicle for colours in miniature painting. The in- tention of them is to prevent the colours from cracking when mixed «with gum i^rabic; which the fugar prevents, by hindering that perfedt drynefs and great flirinking which happens on the ufe of gum Arabic alone, and alfo to make the gum water work more kindly . M 4 with i68 Of the Substances with the pencil. There is no preparation of the lugar and fugar-candy neceffary before they be ufed, except powdering to make them melt the more eafily. Starch. Starch is fometimes uled inflead of fugar*? candy for mixing with the colours that are ufed in ftrong gum water, to make them work more freely, and to prevent their cracking. It is a kind of fecret with fome perfons who lay a confiderable ftrefs upon it. Of ifmglafs. Isinglass is a glue formed from the car-^ tilages of a large fifh, which is found in the rivers that flow into the northern feas. It is ufed in miniature painting, in the fame manner as the gums Arabic or Senegal, for rendering water a proper vehicle, by giving it a due vifcidity for fpreading and binding thepigments of an earthy texture. SECT, USED IN Painting. 169 SECTION VL Of the fubftances ufed to t^ender fpirit of wine a vehicle for colours. Of feed-lac, S Eed-lac is a fubflance formed on the boughs of trees by fmall flies as their nidus or habitation. It diffolves in fpirit of wine, and being left dry again by the eva- poration of the fpirit, re-attains its original hard and tough texture. It is therefore extremely beneficial in defending and fecuring colours from any Injuries the air or flight violence might do them. But the brownnefs of its colour, and its not rendering the fpirit of wine, in which it is diffolved, of a confiftence fufficiently thick and vlfcid to fufpend the powdered pigments when they are commixed with it, are defefts which greatly deflroy its value as an ingredient for making fpirit of wine a proper vehicle for colours. It may, however, be improved for this purpofe by the addition of turpentine and other fubftances, as we Ihall obferve in its due place. The goodnefs of feed-lac confifts in its ap- proaching towards a tranfparent colourlefs ftate, and being free from heterogeneous matter and opake parts ; for as the brownnefs is its greateft defedt, the diminution of that quality * ponfequently inhances its value. The ^ 4 lyo Of the Substances The preparation of feed-lac for mixing with the fpirit of wine, is to pick out, or wafh from it by means of water, all the little woody or other feculent parts, and then to powder it grofsiy ; for If It be reduced to a fine powder the whole will run together, and cohere fo as to hinder the fpirit of wine from commix- ing with the particles and diflblving them. Thofe who want feed-lac for ufing with' co- lours where whitenefs or brightnefs are de- manded, muft pick out the lighteft coloured grains, and ufe them only, referving the browner for coarfer purpofes. Of Jljell-lac, Shell-lac Is a fubftance brought hither In very thin pieces, and partaking greatly of the nature of feed-lac; from which, neverthelefs, it differs fo much in fome properties as clearly Ihews they are not the fame fubftance under a different form, as has been fuppofed by many. Shell-lac diflblves in fpirit of wine as well as feed-lac, but never becomes perfedly clear and tranfparent. To compenfate however for this defied:, it renders the fpirit much more vifcid, and capable of keeping the colours fufpended, from whence it derives a con- fiderable value in this kind of painting. The goodnefs of fliell-Iac confifts in its ap- proaching to tranfparency and whitenefs ; but it is never found without a great degree of brownnefs. There is no more prepartion of "lheU« USED IN Painting. 171 ihell-lac than feed-lac required prevloufly to its being ufed for this purpofe with fpirit of wine, the reducing it to grofs powder being the whole. Of turpentine. Turpentine is capable of diflblving in fpirit of wine and giving it a viicid confiftence, on which account it is fometimes ufed along with other bodies to render the fpirit a fit ve- hicle for colours. A compofition formed of it with maftic, fandarac, refin, and in fome cafes feed-lac, will ferve for purpofes where the painted body is not fubjec^ to great rubbing or any violence; but with refped; to hardnefs and durablenefs, all fuch compofitions fall far fhort of the folution of fhell-lac. Turpentine muft be ciiofen by its clearnefs and purity, and requires no preparation pre- vioufly to its being applied to this purpofe. Of the gums mafic and fandarac. The MASTIC and sandarac are much of the fame nature, and applied to the fame purpofes with regard to painting. They are gum refins intirely white and tranfparent when good, and diffolve perfectly in fpirit of wine, on which accounts they are ufed for rendering fpirit of wine a vehicle for colours; but they are of fo foft a nature, and fo ready to melt with a flight heat, that the colours laid on with them would fully and be injured even by a gentle 172 Of the Substances gentle handling. On this account they re«. quire to be mixed with feed-lac; and, to in- fpiffate the mixture fufficiently to fufpend the colours, fome turpentine is alfo neceffary. Maftic and fandarac muft be chofen for their whitenefs and tranfparency, and require no other preparation for this ufe of them than Xo be well picked and powdered. Oy' reftn. Resin is the caput mortuum or reftduum left in the diftillation of turpentine for extraft- ing the oil. It is of two kinds, white and brown ; the white is made when the turpen- tine is diftilled with water ; the brown, when no water is added to it. The white turpentine is ufed for rendering fpirit of wine a vehicle for colours in the fame manner^as maftic or fandarac, with which it agrees in its qualities, except that it is yet lefs hard and more liable to fully on handling, and the fame preparation, ^nd treatment is required for it as for them. CHAP. USED IN Painting. 173 C H A P. IV- Of the manner of compounding and mixing the colours with their proper vehicles for each kind of painting. SECT. I. Of the colours proper to be ufed with oils^ and the 7na7mer of compounding and mixmg the?n with the oils and dryers. T he colours proper to be ufed in oil for recU are Vermillion; native cinna- bar; lake; fcarlet oker; common Indian red; terra di Sienna burnt; (and mixt with white) red oker; Spanlfh brown; Venetian red; and red lead: — for ultramarine; Pruffian blue; ul- tramarine aflies; verditer; indigo; andfmalt: — • for King’s yellow; Naples yellow; yel- low oker; Dutch pink; lig^ht pink; mallicot; common orpiment; terra di Sienna unburnt; (and mixed with white) and turpeth mineral : — for green^ terra verte; verdigrife; diftilled verdigrife; or chryftals of verdigrife; and Pruf- fian green: — for purple^ true Indian red: — for brown ^ burnt tei'ra di Sienna; (unmixed with white) brown pink; brown oker; urn- bre; 174 Of the Substances bre; and afplialtvim : — for ^hite^ white flake; and white lead: — for blacky lampblack; ivory black; and blue black. Thefe are all the colours which are at prefent In ufe for oil painting in this country; and when they are perfect In their kinds, they are fully fufficient to anfwer every purpofe. The immediate preparation of them, and the manner of compounding them ■wnth the oils and dryers, may be managed thus. Okers of every kind, as alfo all the earthy and metallic bodies, in which are included ul- tramarine and its afhes, ought to be well levi- gated by a good Itone and mullar with water, and waflied over before they be mixed with the oils, when they are intended for more de- licate purpofes. Lake, brown pink, and Pruf- fian blue, which being of a gummy or gluti- nous nature, would again acquire a cohefion, if levigated in water, may be ground to an im- palpable powder, by adding fpirit of wine to them Inftead of the water, in which ftate they will then continue when they again become dry, and be much more eafily and thoroughly commixed with the oils. Lamp black de- mands no preparation, nor does the afphaltum require to be commixed with oil, but with fpirit of turpentine to thin it, if it be of too thick a confiftence to work with the pencil. In levigating lake or any of the pinks, as alfo King’s yellow, Naples yellow, or verdigrife with water or fpirit of wine, great care mufl: be taken not to ufe a knife or other iron im- plement. U 3 SD IN Painting. *175 plement, which would greatly injure tlie co- lours. Inftead of fuch knife, a thin piece of horn may be employed to take the colours off from the ftone, or to fcrape them together as they are grinding. Caution fhould likewife be ufed wnth regard to the boards on which they are dried, and the place where they are repofited during the drying ; for the fun or duft will be very apt to deprave fome of them in this ftate, if they be not well kept out. The pigments being thus duly prepared, may be ground with the oils, either on a ftone or mullar when they are wanted in greater quan- tities, or are intended to be kept; or by the pallet-knife on the pallet where they are immediately to be ufed. But they fhould be perfectly mixed, or the oil will be apt to feparate, and the colours fail of their due brightnefs and effed. For convenience, the colours defigned for the nicer kinds of paint- ing, after they are ground with the oil, are put into pieces of bladders and tied into a kind of ball. In this ftate fuch as be perfed will continue good a long time, and the bladder being prickt and fqueezed, the colour is forced out by fmall quantities as is required for ufe. For coarfer work, the colours demanded in great quantity are ground by hand or horfe- mills with the oil, and the others on a ftone with a mullar; after v/hich they are put in pots, and there mixed with’ oil of turpentine' and \ y 6 Of the Substances find drying oil, according to the particular pur*^ pofes to which they are employed. Lake, Pruffian blue, brown pink, King’s yellow, and fometimes vermilion, are apt to l3e backward in drying, and require therefore to be mixed with oil that is old and well dif- pofed to dry ; and where brightnefs is requifite, the nut or poppy oil fhould be ufed with oil of turpentine; but where the brightnefs is of lefs moment, old linfeed oil, with a third of drying oil, and the fame proportion of oil of turpentine, may be fubftituted. The propor- tion however of thefe, and all dryers, muft be adequated to the occafion, as difcretion may did:atc, according to the quicker or liower difpofition of the pigments ufed, and the time that may be conveniently allowed for them to dry. Flake white fhould be alfo ufed with nut or poppy oil only, and to thefe oils many add white vitriol and fugar of lead, as well as the oil of turpentine, when they are to be ufed with this or other pigments that are too flow in drying. But the efFe£t of thofe fubftances, when ufed in this man- ner, is verv dubious, as I have obferved be- fore. SECT. USED IK Painting. . 177 SECTION II. Of the fever al methods of painting in water ^ as difimguijhed by the colour s^ vehicles^ and grounds^ required for different purpofes. T H E methods of painting In water, re- quired for different purpofes, are di- ftlnguiflied into three feveral kinds. The firft called painting in *water colours^ and more ufually, as it is for the greateft part confined to painting in fmall, miniature painting. The fecond is called painting in dijlemper^ or Ji%e painting. The third is called painting in frefco^ from its being frequently ufed for walls, al- coves, or other buildings in the open ain The kind called painting in water colours^ or miniature^ having for moftly its fubjeft, por- traits, flower pieces, or other delicate perform- ances, finer colours are required, and more nice and elaborate means are ufed for rendering the water a proper vehicle; whence the choice of colours, and the peculiar preparation of the water by the addition of fit fubffances to ren- der it fuch a vehicle, give occafion for this to be confidered as a diftind: method of painting. The kind called painting in dijleinper^ being for fcenes, canvafs-hangings, or cielings, and other coarfer work; lefs expenfive colours, and VoL. I. N fim- lyS Of the Substances fimpler means in the preparation of the ve- hicle are employed; which, therefore, con- ftitutes this alfo a diftlnc^ method of painting. The third, called painting in frefco^ being on w^alls or other parts of buildings, where the plaifter of the wall itfelf without any other pre- paration is to form the ground, a very peculiar choice of colours is neceffary, and water alone fuffices as a vehicle without any addition of other fubftances. Whence this Hkewife be- comes a diftindl method of painting.- SECTION IIL Of the colours to be ufed in the paint- ing WITH WATER 'COLOURS, OV in miniature; with the manner of mixture^ or compofition of them with the proper vehicles. T he colours ufed in what Is painting in water colours^ or mhiiature pahiU ing^ are — for red^ lead; carmine; lake; rofe pink; vermilion; red lead; fcarletoker; com- mon Indian red; red oker; Venetian red; Spa- nilli brown: — for blue^ ultramarine; ultrama- rine alhes; Pruffian blue; verditer; indigo; fmalt ; blue bice ; and litmus : — for yellow-^ gamboge; Naples yellow; Dutch pink; Eng- lilh pink; gall-ftone; mafticot; French berry wafh ; tfSED IN Painting. 179 walh; turmeric wafli; zedoarywafh; and tinc- ture of faflFron : — fov green^ fap green; verdi- grife; diftilled verdigrife; 2ind terra verte : — for purple^ true Indian red ; archal ; and logwood wafli: — ^for biftre ; umbre; brown okerj; Cologn earth; and terra Japo 7 iica \ — for whltCy flake white; white lead; calcined hartfhorn; pearl white; troy white; lake white; and egg- Ihell white: — for blacky Indian ink; lamp black; ivory black; and blue black. As water is a much lefs kindly fubftance for the fpreading and working colours than oil, fo there is a variety of treatment neceflary for rendering it a proper vehicle for the different fubftances that are to be ufed with it. Who- ever, therefore, would have a complete fet of water colours, muft not attempt to pro- cure them by one general method of manage- ment, as in the cafe of oil, for all indifcrimi- nately ; but mufl attend to the nature of each, and accommodate to it fuch a compofition of the water, and what elfe may be neceffary to give It a due confiftence, as may beft fuit each kind. This reftrldllon, neverthelefs, fliould be always obferved, that nothing be ufed in the compofition of water colours, however well it may make the colours work at the firfl: admixture, but what will again, even though the compofition become perfed:ly dry, fo dif- folve and foften on the addition of a frefh quantity of water, as, by rubbing with the pencil to regain the fluid ftate as on the firfl mixture, and to fuffer the colour to work N 2 equally jSo Of the Substances equally well as then. The heft fyftems fof the admixture of the variety of water colours hitherto given to the public, has been very de- fedlive in fome material particulars, and the principal reafon of it has been their confin- ing themfelves to the ufe of gum water, and omitting that of ifmglafs fize. I {hall therefore be the more explicit in the diredtions 1 fhall give for the management of each kind; and am fatisfied, that whoever follows what I advife will find themfelves under no difficulty in ufing all the variety of colours that are proper to be commixt with water. But, in order to avoid the repetition of the fame thing in many places, it is proper firfl to fhew the manner of preparing properly the gum water and ifmglafs fize.' The gum water may be thus prepared : Take three quarters of an ounce of gum Arabic and a quarter of an ounce of gum Senegal ; powder them, and then tie them up in a linen rag ; leaving fo much un- filled room in the bag as to admit its be- ‘‘ ing flattened by the preifure of the hand. Having fqueezed the bag till it be flat, put it into a quart of hot water ; and there ‘‘ let it continue, moving it fometimes about, and ftirring the water for about twenty- four hours ; the gums will then be dif- folved, and the bag mufl be taken out. The fluid being divided into two parts, to one half of it add a quarter of an ounce of white fugar-candy powdered, and keep the other USED IN Painting. i8i other in its pure ftate. By this means, a ftrong and weak gum water, each pro- ‘‘ per for their particular purpofes, will be obtained.” The following method is the moft advife- able for the making of ifinglafs fize. Take half an ounce of the beaten ifin- glafs, and a pint and a half of water; boil them till the ifinglafs be wholly diffolved, ^ and then drain the fluid, while hot, through a linen rag ; divide the fize thus made into two parts, and to one of them add an equal meafure of hot water ; by which means a ftrong and weak fize will be like- wife obtained.” Having thus prepared the gum water and fize, a proper aflbrtment of mufcle fliells, or fmall ivory difhes, muft be fuited to the co- lours, accommodating the fize of each to the due proportion of each kind of colour; as it is proper to mix up a much greater quantity of white^biftre, and the coarfer forts, than of carmine, ultramarine, and lake, which are to be fparingly ufed, on account of their great' price, and are only neceffary for the lights, and higher touches, in the objeds of the fame colour. A very fmooth China or Dutch tile muft be provided, as alfo a fmall .ivory pallet-knife ; for though an iron one might be employed for fome purpofes, yet it is fo noxi- ous and injurious to the colours in other cafes, that the ufe of it is beft rejected for the whole. N 3 Vermilion, i82 Of the Substances Vermilion, ultramarine, ultramarine a.fhes? red lead, fcarlet oker, common Indian redj true Indian red, yellow oker, Venetian red> brown oker, verditer, indigo, mafticot, umbre, terra verte^ bice, Cologn earth, white lead, calcined hartihorn, ivory black, and blue black, having been prevloufly well ground and wafhed over, muft be mixed firft on the tile, by means of the pallet-knife, with as much of the ftrong gum water as will bring them to the right temper to work with the pencil. Then while they are yet wet, they muft be fcraped from oft' the tile and fpread with the finger in the {hells intended for them, where they will be ready for ufe at all times, on moiftening them duly with a little frefh water rubbed upon them by the finger or pencil. Pruifian blue, lake, and Naples yellow, if It be ufed, ihould be firft reduced to an impalpable powder, which may be belt done for this purpofe by levigation on the ftone in fpirit of wine. Then they, as alfo carmine, biftre, Dutch pink, and Engliih pink, fhould be well mixed, by grinding on the tile or pallet with the ivory knife, with as much of the weaker gum water before mentioned as will bring them to a proper confiftence; after which they ihould be difpofed of in their proper ihells, as was before direfted for the other. Gamboge, Indian ink, fap green, gall-ftone, and terra Japonica^ as they become of a vifcid and adhefive nature when wet, require no gum USED IN Painting. 183 gum water. They fhould be only moiftened and rubbed on the fhells till the furface be incriifted with a proper quantity; which by the addition of a little water may be worked off with the pencil in the fame manner as the other colours. Verdigrife, though ufed with water colours, cannot, neverthelefs, be brought to a proper ftate for working by means of water. The method of rendering it fit to be ufed in water ' colours is to powder it, and then pour on it a quantity of vinegar in the manner before directed for the making the chryftals of ver- , digrife. This vinegar, when it has diffolved as much of the verdigrife as it can take up, muft be poured off free from the fettlings or undiflblved part of the verdigrife, and muft be put into a bottle to be kept for ufe. The kind of bottles the moft fit for ufing with this, or the following fubftances in miniature paint- ing, would be a fmall fort of fuch as are made for ink bottles, in which the widenefs of the neck, and the fhallownefs of the body, make it eafy to dip the pencil; and the broadnefs of the bottom, proportionably to the height, pre- vents their being fo liable to be thrown down as thofe of any other form. The verdigrife may likewife be prepared for miniature paint- ing by means of the juice of rue; which, being poured on the’ verdigrife after it is well pow- dered, will diffolve it in the fame manner as vinegar, and render it fit for ufe by the fame treatment. The verdigrife thus diffolved be- N 4 comes 184 Of the Substances comes a truer green than when vinegar is em-»- ployed, and it is much better adapted to mi- niature painting in this ftate ; for, as the juice of rue has not the acid quality of the vinegar, it does not, like that, change or deftroy feveral of the other colours, particularly the litmus blue and archal, and is therefore greatly pre- ferable; for, indeed, the folution of verdi- grife, though a very good green wafh, is not to be ufed with a variety of other colours without great care; and for this reafon fap green for the moft part is cliofen to fupply its place. • The litmus blue muft likewife undergo a preparation by other means than the addition of water before it be fit to be ufed in miniature painting ; the moft approved method of which is as follows. “ Take an ounce of litmus, and boil it in fmall beer wort till there remain only about one fourth of the fluid. Strain* it ‘‘ then, while boiling hot, through flannel; ‘‘ and when it is cold, being then of a glu- tinous confiftence, add as much warm water to it as will bring it to due flu- idity for working. This muft be ufed in “ the fame kind of bottle as the verdi- grife.’’ Archal, the yellow berry wafh, and turme- ric wafh, logwood wafh, and tinfture of faf- fron, need no other preparation than has been before mentioned in their original produdion; but they muft be put in the fame bottles, and vsED IN Painting. 185 tired as the Iblution of verdigrife and litmus blue. Gamboge, Indian ink, fap green, gall- ftone, and terra Japonica^ as they really dif- folve and become tranfparent in water, are true walhing colours, as are alfo thofe laft mentioned, which are to be in a fluid form. But neither the verdigrife, litmus, or the yellow wafhes, are fafely to be ufed for glaz- ing over other colours, as they are either liable to fuffer themfelves by fuch treat- ment, or to do injury to thofe they are laid upon. Carmine, ultramarine, and blflre, are alfo ufed as wafhing colours, as they will have an effedl of that nature when fpread very thin; but they are not, neverthelefs, properly fpeaking, wafhing colours, as they are in fadl opake. As the producing this effect of waftiing is of great ufe, as well in miniature painting as in the colouring of prints and maps, I will here impart a method by which the end may be compaffed in a very ferviceable degree, even in the cafe of vermilion, red lead, Pruf- fian blue, lake, or even the moft opake co- lours. This is to be done by mixing the pig- ments I have before direbled to be com- pounded with the ftrongeft gum waters, with the ftrongeft kind of ifinglais fize above-men- tioned, and to fubftitute likewife the weak- eft fize in the place of the weaker gum ^^ater, for the colours where that is ordered. / i86 Of the Substances So prepared, the heavier colours will wort and fpread as well as carmine, biftre, or any other fubftances, except thole wholly fluid; and may be ufed with great convenience and advantage, not only where wafliing colours are wanted, but likewife for {hading, touch- ing, and finifhing, or any of thofe purpofes where the free working of the colours is par- ticularly requifite in miniature painting. In the Pruflian blue, lake, &c. it is proper, how- ever, in order to prevent their cracking, to add fugar-candy or honey to the fize, in the proportion of half the weight of the ifinglals; in which cafe they will be found to work more commodioufly in this vehicle than any other formed of water. Of which advan- tage the Chinefe are fo fenfible, that all their other compofitions for ufing colours in water feem to be of this kind, as well as that moft ufeful one called Indian ink. I S E C T* USED IN Painting. 187 SECTION IV. Of^ the colotcrs fit to be ufed m difemper^ or painting with fzCy and the majiner of mixing or co?n- pounding the?n with the proper vehicles. B y dijlemper Is meant all paintings on fcenes, hangings of rooms, or other parts of buildings, where fize is ufed. The lame colours which are employed in miniature painting may be ufed in this kind with fize. Only this method being principally confined to fcenes and grofler forts of work, where the effed; depends more on the perfpective art and the oppofition of the colours than on their brightnefs, the dearer kinds are wholly omit- ted, or fparingly ufed. The beft method of compounding the co- lours with the vehicles is to mix the fize in water; then to levigate the colours in part of it, and afterwards to put each kind in a proper pot, adding as much more of the melted fize as will bring it to a due confiftence for working, and mixing the whole well together in the pot with a proper brufh, or wooden fpatula. If the quantity of 'water originally put to the fize do not render It fufficiently fluid for grinding the colours, the i8S Of the SuBSTANgE^ the fault may be eafily remedied by add-- ing warm water to it; and the fame may be done likewife, if, after the mixture of colours, the whole be found too ftiff for working. The compofitlons of the colours and fize muft be prevented from drying, by tying blad- ders over the pots, or fome other fuch means; for when once they are grown dry, they can- not be brought again to a working ftate with- out difficulty and trouble. Though the grounds, the laying in, and groffer parts of this kind of painting, be done by this mixture of the colours with fize, yet in higher finiffied works that require the finer colours, the more delicate parts may be beft executed by ufing the gum waters or ifinglafs as above direded in miniature paint- ing. By this means the mixing up greater quantities of the dear colours may be avoided, though otherwife neceffary, as it is imprafti- cable to keep minute quantities from dry-r ing, which, in the fize, renders them unfit for working till they are again reduced to proper condition by means of heat; but in the others is not attended with the leaft incouvg-^ ni^nce. SECT. tsED IN Painting. 189 SECTION V, Of the colours proper to he ufed m frefcG paintings and the mixture of them with the water. T he colours ufed in frefco paintings may be all fuch as will (land the air without flying, and bear the contad: of wet lime without changing. Thefe qualities are fcarcely to be found in thofe formed of the parts of vegetables, and therefore mineral and folTile bodies fhould be employed. With this rejftridlion, any of the colours before mention- ed, either as proper in oil or water may be admitted, but more efpecially thofe which de- rive their colour from nature. The method of compounding the colours for this kind of painting with the water, is by Amply mixing them wuth the water after being previoufly well levigated, obferving fuch proportion as will render them mofi: agreeable to the pencil. SECT, Of the Substances 190 SECTION VI. Of the colours proper to be ufed in varnijlo paintings and the 7nanner of mixing and compoundmg them ^doith the proper vehicles. I N painting In varnifli, all pigments or folid colours whatever may be ufed, and the peculiar difadvantages which attend feveral kinds, with refpe£t to oil or water, ceafe with regard to this fort of vehicle ; for they are fecured by it, when properly managed, from the leaft hazard of changing or flying, and will all work well, provided they be pre- vioufly reduced to the ftate of an impalpable The preparation of colours .for this ufe confifts therefore in bringing them to a due flate of finenefs. This may be beft done by grinding on the flone fuch as are of a co- hering texture, as lake, Pruffian blue, indigo, verdigrife, and diftilled verdigrife, in fpirit of wine, or oil of turpentine ; which laft I think the better of the two for this ufe. But all the okers, or other earthy fubftances, together wdth vermilion, red lead, and turpeth mi- neraV require only to be previoufly well wafhed over; and carmine, ultramarine, and King’s yellow, are neceflarily in due ftate when USED IN PAIN.TINC. I9I ■when weir prepared in their original manu- fadure. The beft compofition of varnlfh for fpread- ing and penciling the colours, with refpeft to the convenience of working, and the bind- ing and preferving of them, is fhell-lac with fpirit of wine. This, when judicloufly ma- ■ naged, gives fuch a firmnefs and hardnefs to the work, that, if it be afterwards further fe- cured with a moderately thick coat of feed-lac varnifh, it will be almoft as hard and durable as glafs, and will bear any rubbing, or wear, or even fcratching with a fharp-pointed inftru- ment, almoft as well as enamel. The man- ner of preparing the fhell-lac varnlfh is as fol- lows. “ Take of the beft fhell-lac five ounces; break it into a very grofs powder, and put^ “ it into a bottle that will hold about three pints or two quarts. Add to it one quart of reftified fpirit of wine, and place the “ bottle in a gentle heat, where it muft con- tinue two or three days, but fl"iOuld be fre- quently well fhaken. ,The gum will then be diffblved, and the folution fhould be ‘‘ filtered through a flannel bag; and when ‘‘ what will pafs through freely is come off, it fhould be put into a proper-fized bottle, and kept carefully flopped up for ufe. ‘‘ The bag may alfo then be prefled with the “ hand till the remainder of the fluid be forced out; which, if it be tolerably clear, may be employed for coarfer purpofes, or kept to be 292 Of the Substances be added to the next quantity that fliall be made.’’ The fhelMac varnifh being thus prepared, a proper quantity of it muft be put into fmall phials of a long form, or into frnall tin vei- fels nearly of the form of glafs phials, but in fuch proportion that they may never be filled above tv/o thirds. The colours muft be added to the varnlih in thefe phials very gra- dually, and well (haken with it as each quan- tity is put in, till the proportion appear fit for working, which muft be known by trying with a pencil. If the varnifli appear too thick, the fault muft be remedied by the adding a little rectified fpirit of wine, which will at any time immediately dilute the mix- ture to the proper degree. The phials, or tin veflels, in which the colours mixed with the varnifh are kept, muft be always fecurely ftopt, to prevent the exhalation of the fpirit, and they may be preferved in a working ftate in that manner for almoft any length of time. But they muft be always well fhaken before they be ufed, as well as during the time of ufing, at proper intervals, otherwife the colour will be apt to fettle to the bottom. This is by much the beft method hitherto found out of painting In varnifh ; the fhell- lac not only rendering the fpirit of wine ca- pable of fufpending the colours much better than any other compofition of this nature, but giving them tenacity and hardnefs that would render paintings on copper almoft eter- USED IN Painting. 193 nal, if not injured by fire or fome extraordi- nary violence. It were to be wifhed, that in very elaborate works this method had been always purfued inftead of painting in oih which is fubjedl; to fo many accidents from flight external violences, befides the decay and injurious change which the oil and colours fuffer from their own internal nature, and the improper means of cleaning, that few pic- tures or paintings of older date are to be found perfedt. There are, however, other compofitions of varnifh, which are ufed for painting; as the feed-lac varnifh, and alfo the following ; which requires, however, previoufly, the pre- paration of the maftic varnifh, that muft be thus made. Take five ounces of maftic in powder, and put it into a proper bottle with a pound “ of fpirit of turpentine. Set them to boil in balneo mari(^ till the maftic be diflfolved; and if there appear to be any foulnefs, ftrain off the folution through flannel.’’ The maftic varnifh being thus prepared, it may be converted into a proper varnifh for painting by the following method. ‘‘ Take then gum animi one ounce, grind “ it on the ftone with water till it become an impalpable powder. Then dry it ‘‘ thoroughly, and grind it again with half an ounce of turpentine, and afterwards with the colours, moiftening it with the maftic varnifh till the mixture be of a due VoL. I. O confiftence 194 Of the Substances confluence for working with the penciL It miift then be put into phials or tin vef- fels, as was before dired:ed for the compo- ‘‘ fition with fhell-lac, and diluted, where there may be occafion, with fpirit of tuiv pentine.’’ This is inferior in all refpeds to the fhell- lac compofition, except where touches of pure white, or very bright colours are wanted, which fiiffer by the brown nefs of the fhell- lac, and are preferved in this that is nearly colourlefs. On which account, in the painting of flowers or draperies in miniature, the fine colours may be ufed with advantage this way to heighten the lights, and the reft may be painted with the Ihell-lac varnifli. The method of painting in varnifh is, how- ever, more tedious than in oil or water. It is therefore now' very ufual in the japan work, for the fake of difpatch, to lay the colours on with oil, diluted ,with oil of turpentine, taking care to have the mixture very thin, and to make' the work rife from the furface as little as ^ polfible. When the whole is perfe£Uy dry, it is again laid over with feveral coats of thick feed-lac varnifh, which fecures the colours extremely well, though not fo as to render the whole equally hard and ftrong with the w^ork done in fliell-lac varnifli. The method of painting varnlflied work with oil may be greatly improved, by dif- folving the white gums or refin in the oils, as was before advifed, p. 158, for common oil painting, USED IN Painting. 195 painting, in cafe of more delicate and valu- able undertakings. This compofition being diluted with oil of turpentine, would work equally well with, dry much harder, and aflimulate more with the texture of -the varnifh -laid over or under the paintings, than the oils fimply ufed. It would like wife be attended with another advantage; which is, that the work would be fooner dry, and fit to receive the upper coats of varnifh, which in large manufacllures is an objedt of confequence. The manner of preparing the feed-lac var- nifh and ufing it, being the fame for this as for other purpofes, will be fhewn in its pro- per place. CHAP. V. Of the nature and preparation of paftils or crayons. P Astils or CRAYONS are compofitions of colours, which are reduced to the tex- ture of chalk, and ufed dry in the form and manner of pencils for painting on paper. There is confiderable difficulty and nicety in the making to bring them to that due tex- ture or confiftence which admits of their fpending freely on the paper, without being fo crumbly or brittle as not bear to have the O 2 point igG Of the Substances' point to be duly fharpened. For, if they be rendered too cohefive by gums or fuch fub- ftances as give them tenacity, they will not caft as they ought. On the other hand, if the particles are not fufficiently bound toge- ther, they take no proper hold of the grain of the paper, but lie on it like duft ; and the pencils in this condition are apt continually to have the points broken, or moulder away on the leaft ufe, to an undue thicknefs. To pro- duce this lit texture, fo indifpenfibly requifite to the perfedtion of crayons, many fubftances have been ufed to mix with the coloured pigments, and to give them a proper cohe- rence. But notwithftanding the repeated ex- periments that have been made by numbers of perfons for the improvement of this art, it is very rare to find a fet of fuch crayons as may be called good. They are not, indeed, to be at all produced but by an exercife of fome judgment and flcill in the compofition of each particular; and there are few perfons who either have fuch, or will exercife their fkill and knowledge in fufficient degree. Re- cipes are therefore blindly followed ; which, as the different parcels of each kind of fub- ftance differ greatly in the proportion of their qualities, though they may agree in the ge- neral nature of them, fometimes produce good, and fometimes bad crayons, by the very lame rules. Whoever, therefore, would be mailer of a perfe£l fet of crayons, muft in- form himfelf of the feveral fubftances and their USED IN Painting. 197 their nature, which are proper for the eom- • pofition of them, and then having general di- refcions for the manner, mull proportion and adjuft the quantity of the ingredients to each other by actual trials of the elfed. This may, neverthelefs, be done with very little trouble, and without the danger of any lofs accruing from the greateft error in the com- pohtion, fince the crayons can always be wrought over again, with fuch additions of thofe ingredients in which the proportion is defedive as will remedy the fault. 1 fhali, for thefe reafons, enumerate the feverai fub- hances that are employed for forming cray- ons, and fliew what particular intentions they are to anfwer, and the method of managing them to effed that end. I fliaii then give the particular mixtures which I believe to be bed: for producing each kind of colour, with the neareft general proportion of the in- gredients. But the adapting the quantities more exadly to each other in every particular cafe I muff leave to the operator, who muft try the refult of his compofitions by drying a fmall quantity of each fort formed into a crayon, after he has made the mixture. This being tried on the proper paper, if it appear faulty, the proportion of the ingredients muft be better adj lifted by adding more of that which appears to be deficient, till the due effed be produced. All the colours which are pigments, and can be reduced to an impalpable powder, may O 3 Be ' ix )8 Of th£ Substances be ufed for forming crayons. But it is proper, neverthelefs, to be cautious, efpecially in more elaborate works and paintings of any value, with regard to fuch as are fubjeft to fly or change; particularly rofe pink, Englifh pink, lake, and Pruflian blue, which are apt to turn pale, and fometimes entirely lofe their hue. With refpedl to white, the ufe of flake white, or white lead, is beft avoided, on account of their frequently turning black, as there are others which will even work better, and are no way liable to any fuch change. But nei- ther lake nor Pruflian blue are to be wholly rejefted for this purpofe, when they are known to be thoroughly good, as they will Hand extremely well when prepared in a right manner ; only great care fhould be taken to be certain of the qualities of any parcel be- fore it be ufed, as the far greateft part of the iake to be now met with will fly, and the Pruflian blue turn pale and green In fuch manner as to vary the teint greatly from its original ftate. Befldes the coloured pigments which are ufed Amply, fome white fubflances are necef- fary for 'the forming a proper body to fuch as are of lighter teints, or where the colours are to be diluted and weakened, as in ftraw colours, pinks, carnations, &c. There have been many different forts of bodies applied to this purpofe, which mofl of them, by proper management, may be made to anfwer the end. The principal are flake white, white lead, tobacco-pipe-clay, plaifler USED IN Painting. 199 plaifter of Paris, Spanifli or troy white, fimple chalk, and ftarch. But pearl white, that has been hitherto overlooked, is in fome cafes fuperior to any of them. In this application of white bodies to form the ground or bafis of pale coloured crayons, the greateft care Ihould be taken; likewife, when carmine, lake, or any coloured pigment, prepared from parts of vegetables or animals, are ufed, that the fub- ftance employed be fuch as will not prey upon or change the colour ; which chalk, flake white, and white lead, with the colours, are extremely apt to do when they are mixt together with the addition of any moifture. But in all fuch cafes the pearl white and plaifter of Paris fhould be ufed; and with refped: to the latter, it miift be wholly free from lime, or it will be worfe even than the others. It is befl; indeed in general to avoid any fuch mixture of thefe colours, by fubflltuting the coloured earths, or other mi-» neral fubftances, in the place of thofe prepared from vegetable or animal fubftances, as they can fcarcely be affefted or changed by any matter ufed in painting; and will, in general, equally well anfwer the purpofe, except in the cafe of carmine, the unrivalled brightnefs of which, makes it neceflary for pinks and car- nations, as great purity and force of colour are there required. Flake white and white lead are not fo fre- quently ufed as chalk and tobacco-pipe-clay for the grounds of crayons; neither, indeed, are they fo fit for many purpofes, as they O 4 will coo Of the Substances will not mix well with many of the coloured pigments, and are liable to form too brittle pencils when cut to moderate points. The white lead has befides the dangerous quality of being fubjedt to have its whitenefs changed into the proper metallic colour of the lead, as we fee in many of the older drawings and {ketches where it has been ufed. The great whitenefs of the flake, neverthelefs, recom- mends it where touches of a very great light are required. It may not be amifs, therefore, to have a crayon of it for fuch occafions; but it Is beft to omit wholly its ufe in all cafes where the other whites will anfwer the pur- pofe. Tobacco-pipe-clay was formerly in great ufe for forming the paler crayons; but it is much neglefled now, except in thofe made for fale. For, befides its drying to be too hard, and not fpending freely on the paper, it gives the colours a htavinefs and deadnefs that may be avoided by the ufe of other whites; to fome of which it is therefore on all accounts inferior. It may however ferve for ordinary occafions, as it will produce crayons by being Amply mixed with the coloured pigments; and therefore requires much lefs {kill and trouble to be compounded with them than the fofter whites that demand the aid of fome binder or glutinous body to give them a due cohefion. Plaifter of Paris has alfo been frequently ufed for the bafis of pale crayons, to which purpofe it 201 USED IN Painting. k LS in one refped: well adapted; becaufe, wdien it is pure, that is to fay, made only of the powdered alabafter. It is very Innocent with refpedt to the more tender colours; but then it is too cohefive, and wants the flakinefs of chalk; which defedl has been attempted to be remedied by the dipping the crayons formed of it in olive or linfeed oil. Spanifh or troy white, which, as we have feen before, is chalk and allum calcined and wafhed over, is ufed by fome for a ground for the pale crayons. The difference in its eifeO: from fimple chalk wailied over confifts only in its being lefs liable to prey on the colours made from the parts of vegetables or animals. But as the pearl white, or plaifter, are much lefs hazardous in that point than either, the ufe of it feems no way necelfary. Chalk is the beft adapted by its texture to the forming the ground of pale crayons of any of the whites hitherto ufed, as it will caft more freely, and at the fame time retain a due cohefion, when mixt with proper binders or glutens, better than any of the other whites now in pradicc. It is, therefore, much the beft fubftance for mixing with all the coloured pigments which are not fubjedt to be changed; but with refpedt to fuch as are, the pearl white, or plaifter of Paris, fhould be fubftituted in its place. It is alfo the beft for forming white crayons for common purpofes, which may be done by a very fimple treatment as below .directed, Starch 'JOi Of the Substances Starch has been frequently ufed along with fame of the other whites for giving a due tex- ture to crayons. But it is no where neceffary, except in the cafe of white flake; and, as the prepared flake white of the fhops contains a large proportion, it is unneceflary when that is ufed, which will generally be the cafe, as the levigation of the white flake is too trouble- fome for thofe who do not make fuch matters their bufinefs. The laft clafs pf fubftances ufed in the com- pofition of crayons, and on which indeed prin- cipally depends their perfedlion, is the binders or glutens required to give pulverine bodies, of which the crayons are compofed, a due tena- city to render them capable of being formed into mafl'es that will bear the form and em- ployment of pencils. There has been a va- riety of different matters applied to this pur- pofe, moft of which may in fome degree ef- fecl it ; but the principal are ale wort, — gum tragacanth, gum Arabic, — fize, — milk, — oatmeal, — fugar-candy, — olive oil, — and lln- feed oil. The vrort of ale or beer, either in its ori- ginal ftate or rendered more thick by boil- ing, has been found to anfwer the end of a binder, for the forming crayons, where chalk or earthy bodies are ufed, better than any of the others, as it gives them a proper cohelion, by its vicidity, without drying to that brittle ftate to which the gums are fubjed. It is not, Iv3wever, in the cafe of vermilion, and fome other USED IK Painting. 203 other fubftances, which have no cohefive at- tradlion of themfelves, iufiicient alone to give the due tenacity ; and muft therefore be af- lifted by gum tragacanth, or fize, or fome fuch other vifcid matter. Gum tragacanth is ufed as a binder, by dif- folving it in the ale wort, or whatever fluid is employed for the tempering crayons. It is pre- ferable, for this purpofe, to gum Arabic, or the other gums which diflblve in aqueous fluids, becaufe it thickens in the water, and mixes itfelf equally throughout the whole fub- ilance of the compofition when dry ; whereas the others are apt to form a cruft on the out- fide of the inafs, and render the puftils or crayons of an unequal texture. Gum Arabic has been alfo ufed for temper- ing crayons in the fame view as gum traga- canth; but, for the reafon juft given, is much inferior to it. Size is alfo fometimes applied to the fame purpofe in making crayons as gum traga- canth, and differs not greatly from it in its eftedt. Milk has been ufed for the compofition of crayons, in the fame view as the ale wort, where only a fmall addition of cohefive power was required to be added to the folid bodies which formed them. But it is only in fuch cafes, it can be of any avail, as the ale wort, or others of greater efheacy, are in moft cafes wanted, Oatmeal, 204 Of the Substances Oatmeal, or rather the decodlion of it, made, as in the cafe of water-gruel and ftrained, has likewife been employed for the fame end as milk, and anfwers well enough in the cafe of the deep Pruffian blue, indigo, and fuch bodies as are apt to dry gummy; becaufe, though the decoftion of oatmeal gives only a fmall degree of cohefion, yet it prevents that coale- fcence from the attraction of the parts of thofe bodies on each other which produces this brittlenefs. Olive oil, as likewife the linfeed, have been ufed to give the crayons a more flaky and chalky texture, by dipping into it, after they have been duly heated, fuch as are made of plaifter of Paris, or tobacco-pipe-clay, in order to foften them, and remove that unkindly cohefion which prevents the flicking freely on the paper. Wax has been alfo ufed by fome in the light] of a great improvement as a binder to crayons. The pretended utility of it is, that it will render the crayons fo tenacious and fixt on the cartoon as not only to be fecure from {baking oif by any concuflion, but even to bear the rubbing with a brufli. This qua- lity does not, however, compenfate for the great defeCt all fuch crayons will be found to have; which is, that they cannot make any of thofe delicate touches and finiihing that give the merit to crayon painting. On which account they can only be employed for coarfe purpofes, and are confequently of very little confequencQ USED IN Painting. ^05 confequence to painting in thofe cafes where crayons have advantages over other methods. I fhall here give fome general inftruftions for the compounding crayons of the feveral colours and teints; but at the fame time mull leave it to the difcretion of the operator to adjull the exa6l proportion of the binders or glutens by actual trial, as the fubllances ufed vary too much in the degrees of their qualities in different parcels to admit of any llandard proportion being given. Of white crayons. For forming white crayons for common purpofes, chalk in its natural ftate is fiipe- rior to any compofition. It fhould be chofen white, pure, and of the moll cohering tex- ture ; and it mull be cut firft into fquares by means of fmall faws made for this ufe, of three inches length, and a quarter of an inch in thicknefs, and afterwards formed into a proper pencil fhape by taking off the corners with a penknife and duly Hoping the point. Where an extraordinary degree of white- nefs is required, a crayon may be made from flake white as prepared by the colourmen. It mull be well powdered and moillened with milk to the confluence of a palle, and then formed in the pencil fhape and dried, but without heat, as that would tend to injure the whitenefs, by changing the colour of the flake in the fame manner as in the produftiou of mallicot. If the 2q6 Of the Substances the crayon thus made appear to want tenacity, it muft be worked over again with a frelh quantity of milk ; or a little gum tragacanth may be added to the milk. This crayon, however, fliould not be ufed where chalk will he fufficiently bright; for all kinds of cerufe, as I obferved before, are fubjedt to have their colour changed by accidents not eafily to be guarded againft. red crayons*. For red crayons of the fcarlet hue, vermi- lion and red lead may be ufed, with ale wort boiled, till it appear flightly glutinous to the ‘touch, and further infpiffated by the ad- dition of gum tragacanth ; the proportion of which may be a fcruple to a pint of the thick wort. With this gluten, the vermilion, or red lead, muft be reduced to the ftate of a pafte, by grinding them together; and then formed into the proper fhape, and dried with a gentle heat. Where the orange caft of red lead Is not particularly wanted, it is fafer to ufe vermi- lion; for though red lead will ftand much better ufed this way than in oil, yet the ver- milion is ftill more fecure, as nothing can change It without a burning heat. The paler crayons of the fame colour may be made, by mixing waflied chalk with any of thefe colours, which may be done in three proportions; the firft with an equal weight of the / USED IX Painting. 207 the chalk, the fecond with double the weight, and the third wdth treble. But if other teints are wanting, the proportion may be varied otherwife according to the occalion. Thefe compofitions fliould be formed in the manner above-mentioned, by means of ale wort in- fpiffated by boiling ; but the w^ort fhould be thicker where the quantity of the chalk is lefs, according to the three proportions ; becaufe, after it has been moiftened, and is again dried, chalk has a confiderable cohefion of itfelf. The fcarlet oker gives a fouler red crayon, but yet very ufeful, if it be compounded with the ale wort infpiffated both by boiling and the addition of gum tragacanth, in the proper manner diredred for vermilion. Scarlet oker may likevx^ife be formed by compofition with chalk, into paler teints, in the fame way as vermilion. Common Indian red may be likewife treated in a parallel manner, and will give other teints of red. Red oker requires no compofition; but if it be chofen pure, and of a good colour, will afford ufeful crayons by the fame manage- ment as chalk. Lake mi^fi; be ufed for crirnfon crayons, and may be brought, when well ground with ale wort, to a proper texture ; but if, as is the nature of fome parcels, it appear too gummy, make it up with the decocllon of oatmeal in- ftead of the ale w^ort. It is proper to be very careful 2oS Of the Substances careful In the choice of lake for crayons ; for^ as it is very apt to fly when not properly pre- pared, the confequence in crayon painting is in inch cafes very bad, fince it will much fooner change when ufed in that manner than in oil. The paler teints of the lake muft be pro- duced by the admixture of feveral proportions of white, in the fame manner as the fore- going colours. The white employed fhould not, neverthelefs, be chalk, for the reafons before given ; but pearl white, or plaifter of Paris. I think the former much the beft; but in the compounding it into crayons with the lake, a ftronger binder is required than in the cafe of chalk. The ale wort fhould therefore be well infpiffated by boiling for thofe crayons w^here the proportion of lake is greatefi: ; but, for the others, it fhould be adequately rendered yet more vifcid by the addition of gum tragacanth. It woqld be extremely proper to have cray- ons of carmine, if the price did not make the ufe of it too expenfive. Confidering that cir- cumftance, it is more expedient to ufe it rub- bed in by the leather roller in the manner be- low directed, by which it may be conveniently laid on where it may be neceflary. A fmall cray on compounded of the beft and moft fcarlet lake, with about a third part of carmine, fhould, however, not be wanting. They may be worked up with milk, and a little decodion of oatmeal, with a fmall pro- portion USED IN Painting. 209 portion of gum tragacanth; but fome carmine is fufficiently glutinous, and requires no binder; which ought therefore 10 be fii ft tried before the binders are added. Small crayons muft likewife be made of carmine and pearl white in different propor- tions', and the ale wort muft be more or iefs infpiflated according to the quantity of white; but as the carmine differs greatly in different parcels as to its gummy confiftence, this muft be regulated by difcretion. Rofe pink, when good, forms a crayon which has merit with regard to its beauty, if its defedt in other refpecfts did not forbid the ufe of it. It may be made into crayons without any compofition, in the fame manner as chalk, where it is of fo firm a texture as it is com- monly found to be ; but where it happens to be of a loofer, it muft be' brought to a proper ftate of cohefion by ale wort. It is, neverthe- lefs, fcarcely worth while to take the trouble of forming it any way into crayons, as the colour will always fly if the cold air have accefs to it, and it can never therefore be pru- dently employed in paintings of any value. Of blue crayonL For a deep blue crayon, the darkeft Pruf- fian blue may be formed into a crayon by grinding it with the deco£tion of oatmeal. If the tenacity be not fufficient, the ale wort- muft be added. VOL. I. p Indigo, 210 Of the Substances Indigo, when good, will likewlfe produce a deep blue crayon, with ale wort infpiffated by boiling. For paler blues, Pruffian blue of different degrees of lightnefs may be ufed with ale wort; but the ale wort muft be infpiffated by boil- ing, or the addition of fize or gum tragacanth in proportion to the lightnefs; the darker kinds of Pruffian blue being of a more gluti- nous nature than the lighter. Verdi ter will alfo make a good blue crayon, but it muft be ufed with ale wort ftrongly infpiffated. Bice fhould likewife compofe another crayon, treated as verditer. Crayons fliould likewife be formed of ver- diter, or bice, with chalk in different pro- portions, and compounded by means of the ale wort thickened by boiling. Ultramarine being too dear to form cray- ons, fhould be ufed in the manner above di- redled for carmine. Of yellow crayons. The prepared orpiment, or pigment called King’s yellow, forms the brighteft and fulleft coloured yellow crayon; but the poifonous quality, and naufeous feent of it, are fuch faults as render it on the whole much inferior to that next mentioned. The King’s yellow may, however, be formed into a crayon with ale wort infpiffated by /» USED IN PainTINO. by boiling and the addition of gum traga- canth, but it muft be dried without any heat. The turpeth mineral, well levigated and walhed over, makes a very fine crayon, of a cool, but very bright yellow colour. It may be treated for this end exactly in the manner above dired:ed for vermilion. Dutch pink and t ngllfh pink make crayons of a pretty good yellow colour, but are not fo fecure from flying as the two above -mentioned* When they are of a firm texture, they may be ufed as the chalk, without any other prepara- tion than cutting them into a proper form; but where they are of a more foft and crumbly fubftance, they muft be worked up with the infpiflratcd ale wort. Yellow oker may alfo be formed into a crayon in the fame manner as chalk, or it may be ground and wafhed over, and then ufed with the infpiflated ale wort. More diluted teints of yellow may be pro- cured by mixing chalk with any of the above- mentioned pigments, and forming them into crayons in the manner before-mentioned for the other colours. Of green crayons The chryftals of yerdigri^e, properly ma« naged, make the brighteft green crayon. They fhould be reduced to a very fine powder by grinding on the ftone with fpirit of wine. Pa or 212 Of the Substances* or oil of turpentine, and then formed into pafte by ale wort highly boiled, and infpiffated ftill further by gum tragacanth; but as little fluid as poffible fhould be employed in their compofition. They fhould likewife be dried without heat. Verdigrife will make a light blue green crayon, if treated in the fame manner. Pruffian blue and turpeth mineral, com- pounded in different proportions, form alfo a variety of good green crayons. They muft be worked up with ale w'ort thickened by boiling. Pruffian blue and Dutch pink make likewife a pretty bright green crayon, being formed by means of the infpiffated ale wort. Verditer and turpeth mineral form a good pale green; but they require ale wort both thickened by boiling and the addition of gum tragacanth. / Blue bice and turpeth mineral, or Dutch pink, make another kind of light green crayon, being treated in the fame manner, ex- cept that when Dutch pink is employed the ale wort requires only to be well thickened by boiling. Crayons may likewife be formed of any of the above-mentioned green pigments and chalk, by the means before diredted with re- gard to the other colours. f Of tJSED IN Painting. 213 f Of orange crayons. King’s yellow, or turpeth mineral, with red lead, or vermilion, makes a bright orange crayon. They muft be compounded with ale wort thickened, as well by gum tragacanth as boiling. Orange crayons may llkewife be formed from Dutch, or Englifh pink, compounded with red lead, or vermilion; but the ale wort need not in this compofition be fo ftrongly ■infpiffated as for the laft. Chalk may be added to either of thefe in different proportions, to vary the teints in the manner above directed for the reft; or good crayons of a paler orange, where brightnefs is not required, may be formed from Spanifh annatto compounded with chalk, and worked up with ale wort (lightly inTpiffated. The Spanifh annatto ufed alone, being levi- gated with oil of turpentine, and formed by the addition of the decodion of oatmeal ufed in the moft fparing manner, makes llkewife a very good crayon of the full orange colour. But the preparation of this is more trouble- fome than thofe given above, which will In general anfwer the fame purpofe. Of purple crayons. A very bright purple crayon may be formed of deep Prulfian blue and carmine, - com- P 3 pounded 214 Substances pounded by means of the decofliion of oat- meal; but this being expenfive, muft be made fmall, and referved only for thofe cafes where great brightnefs is neceffary.. Deep Pruffian blue and lake, treated as the above, form a crayon next in brightnefs to the above. For a lefs bright purple indigo may be ufed in the place of the Pruffian blue ; but the teint will not be fo deep, and ale wort flightly infpiffated may be ufed inftead of the deco(3;ion of oatmeal. For coarfer purples indigo may be com- pounded with vermilion; but they will be much paler than the above, and for this compofition the ale wort muft be well thick- ened by boiling, and a flight addition of gum tragacantho 0/' brown crayons^ For forming a full brown crayon, neither • inclining to the olive nor orange, mix brown oker and biftre, and work them up with the ale wort infpiffated moderately by boiling. Spaniffi brown, umbre, and the common and true Indian red, may likewife be com- pounded in the fame manner with biftre in- to crayons of different teints of brown, and ivory black may be added, where neceffary, to darken them and increafe the variety. Spanifh brown and umbre may be like- wife formed alone into brown crayons, by means USED IN Painting. 215 means of the ale wort infpiflated by boiling, and a fmall addition of gum tragacanth. For dilated browns calcined fuller’s earth may be employed, either alone, or mixt with chalk in different proportions. The crayons muft be formed by means of ale wort mode- rately infpiflated by boiling. Diluted browns may likewife be formed by adding chalk to any of the above compofitions for browns. Of black ayid grey crayons. Black crayons may be formed out of pieces of charcoal well burnt, by cutting them into a proper fhape in the manner directed for chalk. The kind of charcoal, faid to he the beft for th^s purpofe, is that made from the wood of the willow. Good black crayons may likevclfe be form- ed of ivory black mixt with a little very deep PrufTian blue or indigo. It muft be worked up by ale wort boiled thick with a fmall addi- tion of glovers fize. ‘ Grey crayons may be formed of the ivory or lamp black, mixt v;ith chalk in different proportions, and compounded by means of ale wort well infpiffated by boiling. The carmine, ultramarine, or any other co- lour which may be too dear, or not had in fufficient quantity to form crayons, may be ufed by means of the leather roll above-men- tioned.' This roll is only a piece of fhamoy P 4 leather 2i6 Of the Substances leather formed into a kind of long cone, by rolling it in a fpiral manner, and then twining thread tightly round it to keep it from un- folding. The leather muft be fp managed in the rolling as to form a point of the de- gree of bluntnefs required, or if it be too blunt ir may be fharpened with a penknife. With the point of this roll breathed upon, the car- mine, &c. may be taken and laid on the painting in fuch touches as may be required, and the effed will be nearly the fame as if the point of a crayon had been ufed. This roll will likewife be found ufeful in fweetening (as it is called) the colours, by rubbing the edges of the teints together, where the fur- face is not large enough to admit the finger to do that office. CHAP. VI. Of the grounds for the feveral kinds of painting. SECT. I. Of the grounds for oil painting. T he fubftance or matter on which oil paintings are made, unlefs in very par- ticular cafes, are canvas, wood, or copperr plate. USED IN Painting. 217 plate. The preparation or covering of thefe, in order to their receiving the proper colour- ing, muft be therefore different, according to the different fubftance in queftion. The pieces of canvas, prepared by proper primings, are then by painters called cloths^ and are the moft common grounds for oil painting. / But thefe cloths, though they are difpenfed with in general, becaufe painters think it too much trouble to prime them themfelves, and therefore make fhift with what the colour- men will afford them, who on their fide likewife confult nothing but the cheapeft and eafieft methods of difpatching their work, are yet at prefent prepared In a faulty manner in feveral refpeds. In the firfl: place, the whole covering is apt to peel and crack off from the cloth, by the improper texture of the under coat, which is formed of fize and w^hiting, and is both too brittle and too little adhefive, either to the cloth or upper coat, to anfwer well the purpofe. In the fecond place, the oil employed in the compofition of any paint ufed on fuch grounds is extremely apt to be abforbed or fucked in by them, and confe- quently to leave the colours with which it was mixt deftitute, in a great degree, of what is neceffary for their proper temperament. This is called, though improperly, the finking in of the colours^ and is attended with fe- veral inconveniencies ; particularly, that the effed of the painting appears very imper- fedly, while the colours are in .this ftate 2i8 Of the Substances and deprives the painter, as well as others, of the power of judging properly of the truth of the performance. It is jndeed praftifed fometimes to varnifh over the ground, which will prevent the finking in ; but there is a hazard in this, that the upper coat may leave the ground, and the painting confequently come off. Whoever therefore would have good cloths, free entirely from this difadvan- tage, muft direft the preparation of them themfelves, and they may produce them in perfedion by the following means. Let the cloths be firft well foaked with drying oil laid on hot; and when nearly dry, let two or three coats of drying oil and red oker, mixed as thick as can be worked, be fpread over it. Then, the laft being dry, let the cloth be brufhed over with hot drying oil, as long as it appears to fink in; and, laftly, let it be covered with a coat of white lead and oil, rendered grey, or of any other colour defired, by admixture ‘‘ of the proper pigments. This laft coat “ may be polifiied to a due degree by rub- bing with a pumice ftone, or by glazing it with the glafs polilhers ufed for linen, and called callender Jlones,^'^ In priming wood, or preparing it to receive the oil colours, the fame errors are generally committed; for the method almoft univerfally pradifed, is to clear-coat, (as it is called) with fize and whiting, and then to cover it with white lead and oil. But the ill effeds of fuch USED IN’ Painting* 219 fuch a method are ftill greater, in this cafe, than In that of canvas; lince, if any moifture find accefs to the wood, the paint rifes in blii^ ters, which are liable to be biirft, and to caufe a flaking off, and peeling of the paint, in a very detrimental manner. For paintings of any value, the wood iliould, therefore, be briifhed over with hot drying oil as long as it will foak in, and then covered with a coat of white lead, or flake, coloured accord- ing to what may be defired. Even in the cafe of houfe or coach-painting, the clear-coating with fize and Vvhiting ought to be omitted; and, in its place, a coat of drying oil wdth fome w^hite lead and oker, but not fo much as to make it ftift, fliculd be ufed as the firft priming, inflead of the fize and whiting. This method would both preferve the w^ood much better and prevent the bliflering’ and peeling, and, in fome degree, the finking in of the colours that attend the common method. When copper-plates are ufed, there is no occafion for any other priming than one coat of oil, and lead, or oker, rendered of the colour defired ; but fuch plates are feldom employed but for delicate and elaborate paint- ings. The furface of the priming ought to be made as fmooth as the plate itfelf, by rub- bing with the pumice flone, or glazing wnth the Callender flone. But there is another me- thod very effedual for making a fine ground on the copper-plates, which is, the ufing flake white and fat oil, with any colour required; which '120 Of the Substances which being laid on the plates placed in an horizontal pofition to dry, will polifh itfelf very highly by the running of the oil. The oil ufed for this purpofe ftiould be thoroughly fat ; which-, though not at prefent to be had of colourmen, may be eafily made by the method below taught, with very little expence and trouble. This method of producing grounds by fat oil, perfectly fmooth, fecured from any finking in of the colours, and in all other refpedfs much better than any other, may be praftifed with advantage on cloths or wood, as well as copper-plates, the cloths being firft prepared for the laft coat in the manner before directed, and the wood foaked with drying oil. SECTION IL . Of the grounds for painting in water colours^ or primature painting. T '^HE fubftance on which paintings with water colours are ufually made, are cartoon paper, (or a kind defigned for this purpofe) common paper, or vellum, and ivory. When paper of any proper kind is ufed, it is fufficient to prime it with ifinglafs, hze thickened properly with pearl white, and any pigment which will afford the colour the ground is defired to be. But common paper may USED IN PAINTINC. S2I inay be rendered ftronger and fitter to receive the colours by laying on the back of it a coat of ftarch boiled with water to a moderate confiftence, and rendered yet more tenacious by the addition of a little ifinglafs. This ihould be laid on very fmoothly with a brufh; and the paper, when near dry, muft be put betwixt the leaves of a book, or betwixt two fiieets of paper and two boards, and compref- fed by a weight laid on the books or boards. Two fheets of paper cemented together by the ftarch and ifinglafs, and treated in the fame manner, make a very commodious fubftance for painting in miniature. It has been advifed to pounce, paper defigned for painting with water colours, or to rub them over with allum water. But as the intention of this is only to guard againft the defed of paper that will not take ink or other aqueous fluids with- out running, it is much better to avoid the life of all fuch paper; for the pounce prevents the colours working freely v/ith the pencil, and the allum water changes feveral of the colours; as for example, the litums, and archal, if ufed, would be turned to a red from blue or purple. Vellum has been likewife dired;ed to be pounced by fome of thofe who have pretended to teach the beft methods of managing water colours. But, if it be good, it requires no other preparation than the ftraining on a pafte- board, or other fuch proper body, and priming it in the manner directed for paper ; and if it Ihould Of the Substances fhould happen to be greafy, the rubbing it ovef with the gall of any beaft will remedy the defeat, without the inconvenience produced by the ufe of pounce. The ftraining the vel- lum on the pafte-board muft be effeded by cementing them together with the ftarch pre- pared as above, or with ifinglafs fize, which is better for this purpofe. The vellum muft be alfo cut fo much bigger than the pafte-board that it may lap over on every fide; in the doing which, care muft be taken that it be equally ftretched on each fide, fo as to render the whole perfectly even. When ivory is ufed as a ground, it muft be firft rubbed over with the juice of garlic, and then ftained by any waftiing colour of the teint defired as a ground, if any other be preferred to white. SECTION III. Of thegrounds for painting m difemper^ T he fubftance or matter on which paint- ings in diftemper are generally made, are canvas or wood. When canvas is ufed, as for feenes, &c. it muft be coated with ftrong fize and whiting till it be of a thicknefs to take a water polifh, and then it fhould be primed with plaifter of Paris free from lime, and mixed up with fize, as USED IN Painting. 223 as before diredted for the plaifter, as it will then bear lake, carmine, or other colours pre- pared from vegetables, without preying upon, or changing them. The manner of giving the water polilh is by rubbing over the ground with a wet cloth till it be perfedly fmooth. When wood is ufed, it Ihould be firft brufhed over feveral times with thin fize ; or, in cafe the furface be not quite fmooth, with ftrong fize and plaifter of Paris, to fill up the inequalities or holes, if there be any. SECTION IV. Of the ground for tainting in frefco. T H E ground for painting in frefco is jftucco, which may be laid floated and prepared in the ufual manner that flucco is treated. But no more muft be laid at one time than can be painted before it be dry ; becaufe afterwards the colours, which have no vehicle in this kind of painting but water, will not cohere with the ground after it be once dry. As this ground can be completely pre- pared by the common workmen in ftucco, it feems needlefs at prefent to give a more mi- nute defcription here. SECT, 'Of the Substances 2^4 SECTION V. Of the grounds for varnifj paintings T he fubftance or matter on which var- nifh paintings are made, is, for the moft part, copper, iron, and wood. As the paint- ing ground is not covered with the colours in moft works of this kind, it muft confequently be of the varnifh itfelf the work conlifts of. But where it is intended to be painted over, as in the cafe of regular pidtures, a priming maybe given of ftieli or feed-lac varnifh mixed with the proper colours for the ground defired. CHAP. VIL Of the methods of varnifhing and preferving pidures and paintings. T H E method of preferving paintings in oil, is, by coating them with fome t'ranfparent and hard fubftance, as a varnifh, to fecure the colours from the injuries of the air or moifture, and to defend the furface front feratches or any damages the painting might receive from flight violences. The fubftances that have been, or may be xjfed for this purpofe, are gum Arabic, glair or whites USED IN Painting. ■ 125 'xhltes of eggs, ifinglafs fize, and varnifhcs formed of gum refins, difiblved in fpirit of wine, or oil of turpentine; which laft, where oil of .turpentine is ufed, are called oil var- niflies. . . Gum Arabic has been ufed, diffolved In wa- ter, as a varnifh for pictures and paintings, on account of its being both more eafily laid on and taken off than the varnifhes formed of fpirit of wine, or oil of turpentine. It is more eafily laid on, becaufe it may be made exactly of that degree of vifcidity with which it can be beft worked with a brufh or pencil; and becaufe it is totally free from that accident called chiUing^ which attends all varnifh made with fpirit of wine. ' There is, however, along with thefe, another quality of fo bad a kind that its effects more than countervail thefe advantages in the ufe of gum Arabic as a varnifh for paintings ; this is, that, as it dries, it is extremely apt to crack, and give fuch ap- pearance of flaws and fcratches as obfcure and difform the painting to an intolerable degree, and therefore this gum is at prefent much rejedled with refpedt to its application, and the fubflance we fhall next confider fubftituted in its place. The addition of fugar, or fugar- canciy, will greatly prevent the cracking of gum ’Arabic; but then it gives a vifcidity or fticki- nefs to the gum that makes the face of the painting fully, and is in a manner equally de- trimental with the cracking of the gum. VoL* L CL Glair 226 ^ Of the Substai\^ces Glair of eggS, beat to an unduoiis confrif^- ence, and fprcad with a proper brufh over the paintings, anfwers much the fame end as gum Arabic ; but has the like advantages with much lefs of the bad quality of crackmg ; for vVhich reafon it is generally preferred to that gum*' It has, neverthelefs, one great defedt,* which is its not lalVing, for it requires to be renewed . frequently, as either moifture or great drynefs'of the air injure it. It is ufiial to mix a littlb braiidy or fphit of wine with the glair of the eggs, in order to make it work more freely with a bruflv; as- alfo a lump of fogar to- give it more body, and prevent its^ craking; from which, after all, it will not be entirely free, after it has fome time laid on,, if the picture be put into very dry place.. Ifmglafs fize may be ufed for a varmfFi in the fame manner as the folution of gum Ara- bic, or the glair of eggs ; and if a litle honey or fugar, about a fourth or fifth of the weight of the iiinglals be added to^ it, it will cover more effeftually than either of tbem^, and yet be free from cracking. Thisds not, however, fo lafting a varnifh as the gum refins, efpe- dally if the painting or pidture be brought into a damp lituatioii ; and indeed, in all cafes, it is apt to turn very yellow with time* But where there is a profped; -of having oc- cafion to take off the varnifli for altering the painting, this will be found a very, good one, as it may be entirely removed by means of a Ipunge and hot water. There USED IN Painting. ^27 There have been many compofitlons in- vented for fpiritand oil varniflies for paintings; but the multiplying a number of ingredients in fuch compofitions is by no means attended with advantages that are eouivalent to the trouble. I will, however, give one of the applauded recipes of each kind ; and then fubjoin to it another more fimple, which I believe will bet- ter anfwer the purpofe. Take of gum fandarac half a pound, of “ V enice turpentine one ounce and a half, of ‘‘ the gums animi and copal, each three quar- ters of an ounce, of maftic half an ounce, of ‘‘ Benjamin, gum elemi, and white refin, each two drams, of redfified fpirit of wine one pound. Powder the Benjamin and gum animi, and put to them and the Venice tur- pentine, contained in a proper-fized phial, “ eight ounces of the fpirit of wine. To the copal and refin powdered, put, in like man- ner, in a phial, fix ounces; and to the ‘‘ powdered gum elemi two ounces. Let them ftand, fhaking the phials frequently, till the gums, &c* be diflblved. Then ftrain all the folutions through a piece of fine li- ‘‘ nen into one bottle ; and after the mixture has flood fome days, decant off as much as will feparate clear, and keep it in a bottle well ‘‘ flopt for ufe.” Some omit the copal, which Is in faft fo much the fame with the animi that there is ho certain mark of diflindlion known, and put in Its place the fame quantity of gum (^2 farco- 228 Of thf Substances liircocol ; but it is not of any confequence which is admitted, nor whether three parts In four of the ingredients be rejefted, for the following will anfwer the end equally well. Take of the gum^ maftic and fandarac, powdered grofsly, each fix ounces, of Ve- nice turpentine half an ounce ; difl'olvc “ them in a quart of highly-redfified fpirit of wine, and ftrain off the folution as the ‘‘ aboteo If this be wanted harder, an equal weight of the gums animi or copal may be added, and the quantity^ of fpirit of wine doubled.” In the uiing this kind of varnifti, great care muff be taken that the picture receive no damage from it ; for the diffolving power of the fpirit of wine will fometimes reach the oil of the painting, and confequeritly difturb the colours. The varnifii fliould therefore be fpread with as little and as gentle work of the pencil as poffible; and care firould be taken llkewiie that the painting be thoroughly dry before the operation be attempted. There is alfo another nice circumftance to be attended to in the ufe of this kind of varniih, which is, to avoid what is called the chiUing of it. This will certainly happen, if the varnifii be not laid on in a very warm place, or the picture itfelf warm- ed to a moderate degree ; and it will be Hill more liable to happen, if the fpirit of wine em- ployed be not very highly rectified. If the varnifii USED IN Painting. 229 yarnifh appear to be chilled^ (that is, when the parts of the gums do not attract each other, but precipitate from the phlegm, left by the fpirit on its evaporating away, in the form of a powder, which gives a miily turbid appear- ance to the furface, inftead of a tranfparent ihining one) another coat fhould be laid over it, which will in general remedy the mifehief. Indeed lefs than ^ two or three coats of this kind of varnifh is not fufficient to prderve the painting^ and bring'’ out a due effedt of the co- lours, if they are in that flate called ///, occafioned by the attradliqn of the cloth on the oils mixed with them. The following is a recipe for an oil of turpentine varnifh bf the more compound kind. ' ' “ Take of the gums maftic and fandarac> ‘‘ each four ounces, of white refm two ounces, of the gums farcocol, animi, copal, and oli- banum, each one ounce. Powder them grofsly, and put them into a phial with two pound's of oibof tufperitine. Stop the phial, but not too faft left it burft, and place it ‘‘ in any heat, the greater the better, under that which will make it boil. ' Let it- ftand “ there till the giims be diflblved,' or at leaft fo much of them as will be diffolved; then ftrain off the folution for ufe.’’ . j The ingredients, except the maftic and fandarac, may be omitted at difcre'tioh; and with refpedl to the gums animi and copal, un- der which names a variety of gums brought 0^3 from C30 Of the Substances from the Eaft and Weft-Indies, as well as Africa, pafs, there are a very few parcels which .will be found to diifolve in oil of turpentine. Indeed I have never found any that would be fo diffolved; but recipes like this have been given upon very good authority. The follow- ing therefore will be found a much cheaper. Ids troublefome, and equally good varnifh with that made with this complex mixture. * Take of gum fandarac two ounces, of maflicand olibanum each an ounce and half; ‘‘ or three ounces of maltic, and Venice tur-^ pentine half an ounce; powder the mi, and diflolve them in half a pound of oil of tur- pentine, proceeding as in the above.” When this kind of varnifh is ufed, it is par- ticularly necefl'ary that the painting fhould be thoroughly dry, and the pencil ufed as gently" and fparingly in the laying it on as poffible; for the oil of turpentine is extremely ready to diifolve the oil of the ^painting, if it be the ’Jeaft within its power ; on which account the varnilhes of this fort are' much lefs ufed now than ’formerly. This varnifh, howeVer, will fpread much more’ eafily than that wdth fpirit of wine, and is not. fuhjed:' to Viilll, even though it be laid o‘h without the aid of any Avarmth. But it is proper, heverthelds, to he very careful that there be no damp or'moifture on the furface of- the painting, which wmild ])revent the varnifli from taking hold, and wholly fruftrate the intention of it. ' ■ > Varnifl^ies ' ruSED JS PaINTJN;G. 23I Varnillies have been ufed, likewife, formed .of the gums fandarac, olibanum, and Arabic, with white refin and turpentine, diflblved in linfe^d oil, but they are greatly out of ufe now; as fuch varnillies are flow in drying, and the linfeed oil will turn yellow, befides the .difad- yantage arihng from the impradicabillty o£ ever taking them off the painting again, vvhat- ever occafion there may be for it. But a yery fecure and good varnilh may, neverthelefs, be made, bydiflblving two ounces of fandarac and olibanum, wdth half an ouiice of Venice turpentine, in half a pound of oil nut or poppy oil that is white; and if too fat for other ufe, the better. All ^thefe yarniflies muft be carefully laid on with a pencil or brufh, according to the circuin- flances befor.e intimated to be proper for each kind. But With refped: to thofe made of fpiiit of wdne, or o-il of turpentirie, particular cai'ie muft be taken not to pafs the pencl] or brufh more than once over the fame place ; for, otherwife, it will produce ftreaks and inequa-' lities, which fpoil the effe(ft. Paintings in miniature are pr.efcrvM by means of plates of glafs, or the talc, called ilinglafs, placed in the frame before them. There is no particular method to be obfcrved in doing this, but to make the frame lb compadl that the air may have no accefs, w^hich otherwife will fometimes prey upon the colours. Paintings in diftemper, where they are of ^ confequence e^ugh to merit fuch care, may CL4- 232 Of the Substances be rendered more durable, and preferved from foulnefs, by varnilHng them with hot fize boiled to a flrong confiftence, in which a fif- teenth or twentieth part of honey has been diflblved. Paintings in frefco, being defigned to bear the inclemency of the air and weather, are calculated, from the nature of the colours and grounds, to preferve themfelves without any protedion or means of fecurity. Paintings in varnifli require no means of prefervation, but from violence; the yarnifh itfelf being a very iufficient defence of the colours agairift the air, moifture, or all other fubftances that might effedt them. ' Crayons muft be preferved as paintings with w^ater colours, by plates of glals or ifmglafs! There have been many experiments made to difcover a method of varnifliing and giving adhefion to the colours, to prevent their being fc eafily rubbed off,' or indeed ihaken off, with any very brifk mbtiori. There are feveral methods of fixing crayons now pradtifed, one of which is faid to be that of Mr. La Tour, the famous French painter in crayons.. ' But all thefe methods are at preient kept as clofe fecrets in the hands of perfons who pradlife them, ' None of them, however, go much farther than to prevent the colours from being fhaken off by the concuffion of carriages, or other accidents that may fhake the place where they are hung. ’ The fame may be done by various usEij IN Painting. 233 eafy means; as nothing more is required than to conimix fome tenacious body with the colours, either during the time of painting, or after they are laid on. The method hi- therto moft purfiied, has been by fpreading fome^fluid oil varnifh, fuch as has been men- tioned before for the prefervation of oil pic- tures, on the back of the cartoon, gr paper, on which the crayon painting is made, after it is finiflied. But this mull de done with great care as to the proportion, otherwife the teints of the painting will be changed by fome of them growing darker, in confequence of their 1 being rendered in a fmall degree tranfparent.' Another method is to lay fuch a varnifh, or nut oil a little infpilfated by fome of the- fame varnifhes, on that fide of the cartoon, or paper, which is to be painted upon, before the painting be begun; which when dry will hold the colours in a very confiderable man- ner. But the painting muft, in this cafe, be finifhed before the varnifh or oil grow dry, otherwife the Intention will be defeated. By pradlice and experience, either of thefe me- thods may be made to anfwer in a confiderable , degree. CHAP. 234 the Substances C II A P. VIII. Of mending and cleaning pidlures and paintings. S E C T. I. Of friending piBures. W HERE pidifrcs been torn, or parts of them deftroyed, various me- thods have been ufed for repairing them, and making good the damaged or defective parts. But there is one fimple method, by mean s of the oil fattened together with the colours in what is called by painters the fmufh-pot, or veffel where they rub off the paint frorn the pencils, and put the fcrapings of the pallet, which, employed in the following manner, effedually anfwers the end, at leaf: equally well with the moft complex and elaborate method. Where pifliures are only cut or torn with- out any lofs of their fubftance, they fhould be kid on a flat even board or table. ' The torrt or divided parts being carefully put together with fome of the matter of the fmuih-pot laid as a cement, in and over the joint, they muft be kept in that fituation till this cement be thoroughly dry. The rifing or inequa- lity of the cementing matter with the furtace muft then be taken off neatly by means of a pen- USED IN Painting. 235 a penknife, and the part afterwards properly coloured to correfpond with the pidure. Where the cloth is worn out in parts, or deftroyed by any accidents, the defeftive places may be eafily made good by the following manner. Having laid the pidture on a flat board, cut out with a penknife fuch jagged or damaged pieces as cannot be brought to lie fmooth and even. Then form a piece of caji- vas bigger than the whole intended to be co- vered, and plaifter it over with the above-men- tioned fat oil and colours taken from the fmufli- pdt,‘on the outflde of the cloth, and fit it pro- perly as a patch to the place it is to make good, taking care that the marging,or that part which projedt's on every fide of the hole, have good hold of the canvas of the pidlure, and be prefled clofe every where to it. Then let it remain till It be thoroughly dry, and fill afterwards the inequality, or finking of that part of the pidture where the patch lies, with the fame matter from the fmulh-pot, raifing it fome- what higher than the furface of the pidture, to allow for the drying; and if it rife too high, when dry, take it down with a penknife.. After this is perfedtly dry alfo the part may be painted according to what the pidture requires, and it will be found to be equally found and durable with any other part. Where a pidlure is cut or torn into feveral pieces, the parts of it may be joined together and cemented down in the proper places on a piece of frefh canvas, by the fame means. SECT. 236 Of the Substances SECTION II. Of cleaning piSiw^es and pamtmgs. ^ I '•HE art of cleaning pictures and paint- § • ings is of great confequence to the pre- ferving valuable works of that kind, but has been very little underftood even by thofe who profefs to ptadlife it. On this account many very valuable pidures have been damaged ; and indeed few efcape without damage, in a greater br lefs degree, which come under thb hands of thofe who pretend to make it their bufinefs, and yet moft generally know, no other than one fingle way' of treating all the fubjedts they are to operate upon, however different rhay he the condition' or circum- ftances of them. ' As a painting may be, however, fouled with a variety of different kinds of matter, many of which will not be diffolved, or fuffer their texture to be deftroyed by the fame fub- fiances, it ia neceffary to know what will dif- folve or corrode each fuch kind. For there is no other means of removing or taking off any foulnefs, than by diffolving or corroding, by fome proper menftruurn,’ the matter which conllitutes it, except by actual violence, which' the tender nature of oil paintings by no means fuffers them to bear. Of thefe fubftances, which will ‘remove, by diffolving or corrod- ing it, the matter which may foul paintings, USED IN Painting. 237 ibme are very apt, llkewife, to. aft upon and diflblve the oil in the painting itfelf, and con- sequently to dilbfder or bring off the colours. While others are, on the contrary, paffive and innocent, with refpefl to the painting; and may be ufed freely, or indeed in any quantity whatever, without the leaft inconvenience of this kind. As paintings to be cleaned are likewife var- nlflied with a variety of fubftances of different natures, which fometimes require to be taken off, and at other times are much better left re- maining, it is very neceffary to be able to judge wdiat is heft to be done in this point. It is likewife requifite to know the means by which each fort of varnifh may be taken off without injury to the painting. . For in fafl, without this, there is no way of cleaning pictures in fome circumftances, but by fcouring till as w^ell the furface of the pidure as the foulnefs be cleared away. I fliall therefore firft give fome account of the nature of the fubftances^ wdiich are, or may be ufed for cleaning paint- ings in oil, as it regards this application of them ; and then fhew how they may be ufed as well for the taking, off the varnifh as the removing any foulnefs that may lie either upon or under it. The firft, and moft general fubftance ufed for cleaning pidures, is .water. This will re- move many kinds of glutinous bodies, and foulnefs arifing from’ them; ,fuch as fugar, honey, glue, and manv others; and. alfo take off 238 Of the Substak^ces off any varnifh of gum Arabic, glair of eggs, or Ifmglafs, and is therefore the greatell in- ftrument in this work. It may be ufed with- out any caution with regard to the colours ; as it will not in the leaft affedl the oil which holds them together. Olive oil, or butter, though not applied to this purpofe, through an ignorance of their efficacy, will remove many of thofe fpots or foulnefs which refill even foap, as they will diliblve or corrode pitch, refin, and other bodies of a like kind, that otherwife require fpirit of wine and oil of turpentine, which en- danger the painting ; and they may be ufed very freely, not having the leaft effect on the oil of the painting. Wood-alhes, or what will better anfwer the purpofe, when ufed in a proper proportion, pearl-afhes, being melted in water, make a proper diflblvent for moft kinds of matter which foul paintings. But they muft be ufed with great difcretion, as they will touch or corrode the oil of the painting, if there be no varnifh of the gum refins over it, fo as to ren- der the colours liable to be injured by very little rubbing. The ufe of them, or foap, is however, in ’many cales, unavoidable; and in general they are the only fubftances employed for this purpofe. Soap is much of the fame nature with the laft-mentioned fubftances, being indeed only oil incorporated with falts of the fame kinds, rendered more powerfully diffolvent by means of USED IX Painting, 239 of quick-lime. For which reafon it Is fome- thing more efficacious, but confequently more hazardous, as it will the fooner get hold of the oil of the paintings. It ffiould, therefore, not be ufed but on particular fpots that elude all other methods, and there with great caution. Spirit of wine, as it will dilfolve all the gums and gum refine, except gum Arabic, is very neceffary for the taking off from pid;ures varniffies compofed of fuch fubftances; but it corrodes alfo the oils of the paintings, and foftens them in fuch manner as makes all rubbing dangerous while they are under its influence. Oil of turpentine will likewife diffolve fome of the gums ufed for varnifli; but fpirk of wine will in general much better anfwer that purpofe. There are, however, fome- times fpots of foulnefs, which will give way to fpirit of turpentine, that refill moft other fubflances ufed in this Intention, and it may therefore be tried where they appear to fall, but very fparingly and with great caution, as it will very foon adl even on the dry oil of the painting. Effence of lemons has the fame powers as oil of turpentine; but is, moreover, a much ftronger diffolvent, and ffiould, therefore, only be ufed in defperate cafes, where fpots feem indelible with regard to all other me- thods. Spirit of lavender and rofemary, and other effential oils, have the fame diffolving qualities as effence of lemons; but they are in general 240 Of the Substances general dearer, and fome of them too power- ful to be trufted near the colours. Whenever paintings are varnilhed with gum Arabic, glair of eggs, or ifinglafs, the varnifh fhould be taken off when they are to be cleaned. This may be eafily diftinguifhed by wetting any part of the painting, which will feel clammy if varnilhed with any fubftance dif- folvable in water. In fuch cafes, the taking off the varnifh will frequently alone render the painting intirefy clean; for if it have been laid on thick, and covered the furface every where, the foulnefs muft neceffarily lie upon It. The manner of taking off this kind of varnifh muft be done by means of hot water and a fpunge, the pidfufe or painting bting laid horizontally. The water may be near boiling hot, and may be ufed copioufty at' firft with the fpunge; but when the varnifh appears to be foftened, and the painting more naked, it fhould be ufed cooler. If the varnifh adhere fo as not to be eafily brought off by a fpunge, a gentle rubbing with a linen cloth may be ufed, the cloth being frequently wrung and wet again wTth frefh water a little warmifh. Where paintings appear by the above trial to be varnifhed with the gum refins, or fuch fubftances as cannot be diffolved In water, it is proper, neverthelefs, to wafh them well with water pretty warm by means of a fpunge, which will fometimes be alone fufficient to clean them even in this cafe. But if there yet appear any foulnefs, rub the painting over with USED IN Painting. 24! v/ith olive oil, made warm, or buLter; and if any parts appear fmeary, or any foulnefs feem to mix with the oil or butter, purfue the rubbing gently, taking off the foul oil, and adding frefh till all fuch foulnefs be wholly removed. Let the oil be then wiped off with a woollen cloth, and if the picture require further cleaning, the wood-afhes, or pearl-afhes, muft be ufed in the following manner; which, indeed, as to the firft part, is not widely different from the method com- monly ufed. Take an ounce of pearl-afhes, and dU- folve them in a pint of water, or take two pounds of wood-afhes, and add to them three quarts of water, arid ftir them well in the water once or twice in an hour for half a day. Then, when the earthy part of the afhes has fubfided, pour off the clear fluid, and evaporate it to a quart, or if it appear acrid to the tafte at that time, three pints may be left. Wafh, by means of “ fpunge, the painting well with either of thefe folutions, or lyes (which are in faft the fame thing) made warm, and rub any particular fpots of foulnefs gently with a linen cloth till they difappear ; but if they are found to remain unchanged by the ‘‘ lye, do not endeavour to take them off by mere force of rubbing, for that would in- “ fallibly damage the colours under the fpots before they could be removed ; for in this cafe they fhould be left to be tried by the VoL. 1/ R fpirit ^4- Of the Substances fpirit of Vvine, or the effential oils of turpen- tine and lemons. Where thick fpots feein to give way in part, but yet refill in a great degree to this lye, a little ftrong foap-fuds may in fome cafes be*ufed, if with great caution. But it Ihould be prevented as much as poffible from touching any part of the painting, except the fpot itfelf; and, ‘‘ as that difappears, the foap lliould be di- luted with water, that it may not reach the oil of the colours in its full llrength. If, however, all this be done upon a ftrong ‘‘ coat of varnifh, there wall be lefs hazard; “ and, in fuch cafes, the wafhing freely with the wood-afti lye, or weak foap-fuds, will frequently do the buftnefs effedtually with- ‘‘ out any material damage. But it requires “ fome judgment to know where paintings may be fo freely treated; and, with refpedl to thofe of great value, it is always heft to “ proceed by more circumfpedl methods, and to try the more fecure means I have above directed, before thefe rougher be iifed.” Some ufe the \vood-afhes with the addition of wuater only, without feparating the folution of .the ialts from the earth; which, when lb ufed, aflifls in rubbing off the foulnefs from the painting. But all Inch practices are to be condemned, as the finer touches of the paint- ing are always damaged in a greater or lels degree w^here any abrading force is employed in cleaning it. Where USED IN Painting. 243 Where fpots appear after the ufe of all the above-mentioned methods, fpirit of wine, or, if that fail, oil of turpentine, and in the further cafe of its default, ellence of lemons muft be applied. The fpots ihould be lightly moiltened with them, avoiding to fuffer them to touch any more of the furface than what is covered with the foulnefs, and the part fhould be immediately rubbed with a linen cloth, but very gently, observing at the lame time to defift if the colours appear the leaft affefc— ed. After a little rubbing, olive oil fhould be put on the fpot where oil of turpentine and effence of lemons are ufed, and water where fpirit of wine is applied, which being taken off by a woollen cloth, if the foulnefs be not wholly removed, but appears to give way, the operation muft be repeated till it be intirely ^ removed. Where paintings appear to have been var- nifhed with thofe fubftances that will not dlf- folve in water, and after the careful ufe of the above means ftlll to retain the foulnefs, or where, as is very often found, the turbidnefs, or want of tranfparency, or the yellow colour of the varnifh deprave the painting fo as to de- ftroy its value, Inch varnifli muft be taken cfr» The doing of this, though attended with the greateft difftculty to thofe who proceed by the methods now in ufe, and which in- deed is feldom done by them at all, but with the deftrudion cf the more delicate teints and touches cf the painting, is yet very R 2 eafily ¥ 'i44 Substances eafily and fafely prafticable by the following method. Place the pidure or painting in a hori- zontal fituation, and moiften, or rather flood, by means of a fpunge, the furface with very ftrong redified fpirit of wine; “ but all rubbing, more than is neceflary to fpread the fpirit over the whole furface, mull be avoided. Keep the painting thus moill- ened, by adding frefli quantities of the fpirit for fome minutes; then flood the ‘‘ whole furface copioufly with cold water, with which likewife the fpirit and fuch part of the varnilh as it has diflblved “ may be walked off. But in this ftate of it, all rubbing, and the flighteft violence on the furface of the painting, would be very detrimental. When the . painting is dry, this operation mull be repeated at dif- cretion till the whole of the varnilh be ‘‘ taken off.” In pidures and paintings which have been long varnifhed, it will be found fometimes that the varnilh has been a compofition of lin- feed oil, or fome other fubftantial oil, with gums and refins. If fuch paintings cannot be brought to a tolerable ftate by any of the above-mentioned means, which may in this cafe be freely ufed, the mifchief may be deemed to be without remedy; for it is abfolutely impradicable to take off fuch a varnilh, as it is more compad and indiflbluble than the oil of the painting itfelf, and could only be wrought USED IN Painting. 245 wrought upon by thofe menllrua and diflbl- vents which would, adt more forcibly on the paintings. Such pidtures muft, therefore, be left in tTie ftate they are found, except by be- ing freed from any foulnefs that may lie upon this varnilh, and may be cleared away by the methods we have before diredled. The coat of this varnifh may indeed be fometimes made thinner, by anointing the furface of the painting with effence of lemons, and then putting on olive oil, which, when rubbed off by a foft woollen cloth, will carry away the eflence with fuch part of the varnilh as it may have diffolved. But this requires great nicety, and can never be pradlifed without fome hazard of difordering the colours of the painting. of the nature, preparation, and ufe of the feveral fubftances employed in ENCAUSTIC painting. T he manner of painting called at pre- fent Encaustic, differs from all others in this particular, that wax is always em- C H A P. IX. SECT. I. nature of encaufiic painting. R 3 ployed 246 Of the Substances ployed In it as a binder to the colours, being united with them by means of heat applied In iuch a degree' as will melt it. The name of encoiijlic was given to this method of painting, on the fiippofi- tion of its being the fame with that pra(^ifed by the ancients, v/hen they are faid encaiif.o pmgore ; and tliere is fume foundation from Several paflages in Pliny for fuch a notion. This manner of painting has been lately at- tempted by feveral methods, In that firft adopted, the wax was mixed vvdth oil of tur- pentine, and fometimes other ingredients, and the compofitlon was ufed as a vehicle for lay- ing on the colours. This method appeared of very little life, and experience has fince fliewn that it anfwered the purpofe much better, ei- ther to lay the wax on the ground, and paint upon it afterw^ards with the colours in water, or to lay the wax on the back of the cloth or cartoon, either before or after the painting was made on it. In all thefe methods, after the painting Is made, the pidlure is to be ex- pofed to fuch a degree of heat as will melt the wax, that it may be diffufed through all the particles of the colours, and bind them to the ground as well as fccure them from the accefs of air or moiflure. The laft method lias been applied as well to paintings with crayons as with water, but the crayons muft be accommodated in their compofition to this purpofe. Many USED IN Painting. 247 Many advantages and conveniencles, as well with regard to the eafy practice as durability, have been afcribed to this method of p>ainting by thofe who are favourers of it. But it has not yet prevailed in common prac- tice, partly from the backwardnefs pro- feflbrs of arts of this kind have to take the pains, or lofe the time neceffary to gain a facility or perfedion in the execution of nevir methods, and partly from the increafed dif- ficulties and trouble arifing from feveral cir- cumftances of finifhing a pidure completely in this way. HE grounds ufed for encauftk paint- ing have been very different, and in- deed fhould be fo for different purpofes. They have had for their bafis, canvas^ Imcn clothe faper^ plaijle7\ and wood^ and almoft all thefe have been differently prepared. According to the method of Count Caylas, who firft introduced this manner of painting, the cloth, or wood, which were the fub- ftances he made the bafis of his grounds, WTre to be firnply rubbed over with a piece SECTION IL the grou7tds ufed in encmfic pamting. of ' 248 Of the Substances of bees wax, the furface of the cloth or wood being either in a perpendicular or horizontal fituation, near a fire that would melt the wax fo as to make it adhere; if the cafe of cloth, it was previoufly fixed to a proper ftrain- ing frame ; but when he ufed colours, on this ground, that were tempered with water, it was found neceflary, in order to make them adhere fufficiently till the pifture was finilhed, and the wax expofed to the melting heat, to rub the whole waxed ground over with Spa- nifh chalk or whiting. According to the method direded by Mr, Muntz, who has written a treatife on this man- ner of painting fince that publifhed by Count Caylas, and who appears to have rendered it more pradicable by the improvements he has made, the ground, when the painting is on cloth, is to be thus prepared, “ Take any kind of linen~^ cloth, which is “ of a clofe texture, foft, and even, and ex- tend it on a {training frame, as is done in the cafe of cloths ufed for oil painting. ‘‘ Lay it on a fmooth table, with that fide “ downwards on which the colours are to be “ laid. Let it be then rubbed feveral times over with a piece of common bees wax, ‘‘ or virgins wax, till it appear that the cloth be equally covered with a coat of wax ‘‘ of a confiderable thicknefs. If the linen ‘‘ be fine, this is all that is requifite to prepare “ it for being painted upon; but if it is coarfe, it muft be turned with the fide uppermoft that USED IN Painting. 249 that IS to receive the colours ; or, in other ‘‘ words, the reverfe of the waxed fide, and “ the furface muft be well, but gently, rub- bed with a pumice-ftone, to take off* all the knots and unevennefs, which might ‘‘ prevent the free and accurate working of the pencil. In the preparation of a clotli for this kind of painting, regard muft be had to the preventing any of the waxed part of it ^from touching the ftraining “ frame when the picture is finiflied. In “ order to this, the cloth, when the wax is “ laid on, fhould be ftrained on a frame of the magnitude of which the pidiure is in- ‘‘ tended to be; and fo much cloth fhould be left beyond the outward edge as will be fufficient to ftrain it on a larger frame, that will admit the waxed part to be a little within its inner edges after the picture is finifhed, If this be not done, the wood touching the wax, at the time it is melted, would imbibe a part of it; and confequently robbing the colours, render fo much of the pidture imperfedt.” This method can, neverthelefs, only be ap- plied to cloth or paper, where the wax can pafs through the fubftance. Therefore, in the cafe of wood, ftone, metal, or plaifter, the former method of Count Caylas muft be adhered to. It fucceeds indeed, extremely well with regard to plaifter, on account of the gritty or rough fubftance ; only, in this cafe, the dead colouring muft be painted firft, and the 2JO Of the Substances the colours fixed by melting the wax before the finifiiing be begun; and then either chalk mufl; be ufed, as at firft, to make the colours adhere, or the colours themfelves mufl; be tem- pered with oil of turpentine and a little wax. When wood, flone, or metals are ufed, this roughnefs of fiiriace being wanting, it mufl: be fupplied artificially, by laying a ground of equal parts of chalk and wax, and fixing them ; and then the painting may be performed as well as upon cloth. When paper is ufed, it requires the aid of a fmooth board, or a plate of copper, or fome other metal. Th’S board or plate mufl; be firfl v/ell coated with wax, in the fame manner as was above diredled for the cloth; and then the paper mufl be faflen- ed upon it by the corners. Paper thus pre- pared may be painted upon by colours tem- pered in water, and, when the pidlure is finiflied, they may be fixed by melting the wax as in the foregoing cafes. The fame may be done with cloth and a board, or a plate of metal, where that may be thought more convenient than waxing the back of the cloth. In the 'cafe of crayons, there are two me- thods of forming grounds propofed by Mr. Muntz. The one is with cloth wuthout paper. The other with cloth covered with paper. The firfl is in this manner. “ Take any kind of linen cloth, of which the texture is clofe and even, and flretch it on a {training frame. Rub the back of ‘‘ it ' USED IN Painting. 251 it with a piece of bees wax, iifing heat, as ‘‘ in the manner above directed. The cloth being thus \vaxed, prepare any teint or colour, that is thought beft to work upon, “ by mixing fome proper pigment with ‘‘ an equal quantity of chalk, and temper- ing them with water. With this com- polition, paint over the cloth on the fide that is to be the ground of the picture, or, in other words, the reverfe of the waxed “ fide, laying an even and thick coat of the colour proper for the ground. When this colour is dry, bring the picture near the fire, as in the other before mentioned cafes, and ‘‘ melt the wax ; which will then pafs “ through the cloth and fix the ground. This, when cool, will be found a very firm and good body to work upon with the crayons. If, however, it fhould happen that the quantity of wax fhould not be fufficient for the body of the colour, a frefli quantity muft be fupplied by another coat ■ ^ on the reverfe or back; but as this muft be laid on without heat, the wax fliould be dilTolved in oil of turpentine, and applied with a brufh as direded below, and the canvas ,muft afterwards be again expofed to fuch heat as will melt the wax, that this frefh quantity may pafs through the cloth, and be abforbed ‘‘ by the colour. This muft be cautioufiy managed, as it is of great importance in crayon painting to have the ground in good 2^2 Of the Substances ‘‘ good order to receive the colours of the paftils*’’ The other method of forming a ground for crayons in this manner of painting, that is where cloth and paper are joined together, is thus performed. Take linen cloth, and ftretch it upon a ‘‘ ftraining frame, in the manner above di- refted. Make then a pafte with fine “ wheaten flour, or ftarch and water. When the pafte is almoft fufficiently boiled, “ add to it, of common turpentine, fuch a ‘‘ quantity, as will be, in proportion to the pafte, about a twelfth part of the weight. Stir the compofition well together, and let it fimmer over the fire five or fix mi- nutes. Take it then off the fire, and let it ftand to cool a little. After which, before it be quite cold, pafte the paper to the cloth with it in the common method, ‘‘ and leave them to dry. In the mean-^^tirne, “ diflblve fome wax in oil of turpentine, by ‘‘ adding the wax in fhavings to the oil, ‘V and placing the mixture near a fire. The ‘‘ proportion of the one to the other muft “ be fuch, that the compofition, when cold, will be of the confiftence of a thin pafte, butyet fo fluid as to admit of being fpread ‘‘ by a brufh. The cloth and paper being perfedtiy dry, hold them over, or before ‘‘ a fire at a convenient diftance; and, with a brufh, lay a coat of the wax and tur- pentine on both fides the conjoined cloth ‘‘ and USED IN Painting. 253 and paper, in fuch a degree of thicknefs that both furfaces may fhine in every part, without the appearance of any dull fpots. This being done, place the cloth before ‘‘ the fire for about half an hour, or, if in fummer, expofe it to the fun. By this means, the oil of turpentine evaporating, the wax will become folid again, and be fit to receive any compofition of colour for a ground to paint upon ; which ground muft be laid on and fixt, according to the ‘‘ direftions above given in the cafe of cloth “ without paper.” Thefe are the grounds which have been ufed for all the feveral methods hitherto in- vented and communicated to the public. The greateft part of them are not merely grounds to receive the painting, but pre- vious depofits of the wax on the cloth, paper, &c. in order to its being commixt with the colour, by means of a melting heat, when the pidure is finifhed ; as, according to feveral of the methods, the wax could not be conveved to them afterwards. A L jM O S T every colour admitted In oil painting may be ufed in the eii- caufHc method, as pradifed in Mr. Muntz’s SECTION II. colours to be t/fed in encaujlk painting. manner, 2J4 Substances manner, except fome few, that by their gum- my or ftony texture will not fuffer fuch a cohelion with the wax as will properly hx them. In this light, Mr. Muntz excepts to brown, and light pink, and unburnt ta^ra di Sitnncu But, befides thofe, which may be trufted with fafety in oil, there are ibme which may be allowed here, that cannot be admitted in oil painting. Thefe are, red lead, redorpiment, cryflals of verdigrife, and red pre- cipitate of mercury; which, on account of their brightnefs, are very advantageous where they can be ufed. In fhort, whatever colours are of fuch texture that they may be ufed commo- dioufly, and with good effedl, in relation to the painting, may have a place here; as the wax, inclofing every particle of them, and confe- qucntly preventing all accefs of air and moillure to them, renders them perfeftly durable. The colours which diffblve in wa- ter, or when ground in it, fuffer a cohefion of their particles, and grow hard on again becoming dry, are palpably unfit, as they refift the imbibing the wax and its commix- ture with them. Excluding all thefe, there is, neverthelefs, a great latitude of choice, and indeed in a very ample provifion of colours, even of the firft degree of bright- nefs, which this manner of painting allows,, a very great part of its merit confifts. As many of the colours grow deeper on ^ ^tj'ieir being fixed Vvuth the wax than they were before, or even than when they are molft- , USED IX Painting. 255 molftened with water, allowance miift be made in the painting for fiich change. In or- der to facilitate this, Mr. Muntz has propofed the expedient of making a ilandard, or re- gulator, in the following manner. ‘‘ Take two pieces of linen cloth, of about a foot in length, and three or four inches in width, and wax them as above di- redted. On one of them paint all the fimple colours on the unwaxed fide in fucceflive fpaces lengthways, of about an inch each ‘‘ in breadth. On the other piece, paint the compound teints ; and mark them with numbers according to their order and gradation; making a memorandum in “ writing on a piece of paper of what fim- pie colours, and the refpedtive proportions each teint is formed. When the colours are “ dry, cut the cloths lengthways into two equal parts, and fix the colours on one part of each of them, by expofing it to the proper degree of heat, for melting the “ wax, in the manner below diredded. By comparing the pieces where the colours are ‘‘ fixt with thole where they are unfixt, the difference will of courfe appear, wdiich the wax produces on the colours ; and by this iiandard of it, due allowance may be made, in the ufing the colours, for the “ change that is to happen after the fixing.” It is a great advantage to theefredl, to ufe a great body of colour, which not only ren- ders the teint ftronger and brighter, but pre- vents 256 Of the Substances vents their varying unequally after fixings from the undue commixture of the wax with the colours. The colours are to be ground very fine in water, and then preferved of a due degree of moiftnefs for painting by water only. For no other vehicle is to be added; as gum, fize, or any other fubftance that would give co- hefion to the particles of the colours, would prevent the wax from commixing duly with them. This exclufion of any unftuous or fizy vehicle is one of the greateft difadvan- tages attending this method of painting. For, though Mr. Muntz fays, you may give greater freedom to the penclU cind blend and piveeten the colours better in this way of painting than any other^ yet it is obvious, that many of the colours will not work kindly in water, nor indeed any, but fuch as commix intimately with it, and thicken the water by their own fubftance ; and thefe coalefcing again, when dry, refufe the admiflion of the wax, and are therefore exceptionable, as was before men- tioned. In order to retouch any larger parts of the painting, which may require it, after the co- lours are dry, this method muft be praftifed. Take a large foft hair pencil, and moi- ften gently with water thofe places which are to be repainted ; and then what is ** neceflary may be done, as well as when the colours were originally wet. But great care muft be obferved not to ufe fo USED IN Painting. 257 fo much violence as may ruffle or dif- place the colours, which are very loofe in “ this ftate, as they have no glutinous vehicle to bind and fix them. In larger pidures, ‘‘ where the cloth is ftronger, the colours ‘‘ may be moiftened by brufhing the backfide ‘‘ of them with water, which notwithanding the wax will find its way through. But this muft be done gradually and fparingly as to the quantity of water, or otherwife the colours may be rendered too wet, “ and the painting difordered. In very delicate paintings, the ufe of the fteam of water is fafer than the brufh, care being taken to keep the ‘painting fo far diftant “ from the heat of the water as not to melt the wax.’’ SECTION III. Of the manner of fxing the colours in the praBice of painting in encauflic.^ T H E pidure being finlfhed, and the colours dry, prepare a clear coal fire, and fet the pidure, with the painted fide towards it, at about two feet diftant from this fire. Let it grow warm, and then by degrees bring it clofer to the fire, till it be only one foot diftant, but never advance it nearer. The pidure may be held perpen- VoL. I. S dicularly, 258 Of the Substances dicularly, or a little inclined, as may be found moft convenient, and when it is too large to receive the effedt of the heat at once, hrft one part, and then the other, may be brought parallel to the fire at the diftance prefcribed. When no farther change ap- pears to be made in the pidture, but that the whole furface is fhining, and the colours rendered darker and fuller in an equal de- gree, it may be concluded the wax is fuf- ficiently melted, and duly abforbed by the colours. The picture muft then be removed from the fire in the fame gradual manner it was made to approach it, and kept from any rude touch till the wax be intirely fet and grown hard. If there be found any defedlive parts where the wax has not undergone the due degree of heat required to melt it, fuch parts muft be perfedted, by bringing a red-hot poker, or other fuch metallic body near them. But if there ftill appear any fpots, where, after the duly melting the wax to commix it with the colours, a deficience of it is yet feen, fuch fpots ftiew a defedl: in the quantity of wax, and the deficiency muft be fupplied by rubbing a proper quantity on the back, and melting it by means of the hot poker, or other proper implement of metal in the fame manner. SECT, USED IN Painting. 259 SECTION IV. Of the manner of painting with crayons in eiwaufiic. T he paftlls, or crayons, ufed in en- cauflic painting, may be the fame with thofe ufed in the common way of crayon painting, except that fuch as are too tena- cious, in confequence of an over great pro- portion of any clayey body, or of any gum- moue or fizy fubftanCe, added to bind the colour, muft be rejected. The beft method, however, of diftinguifhing fuch crayons as are fit for encauftic painting, from fuch as are faulty with regard to it, is to make an adual trial of them on the proper ground prepared as above, and to fix them afterwards by heat, as before directed, by which means, with very little trouble, the imperfection, if there be any, will be immediately perceived in the real degree. When it is found that any cray- ons, which feem faulty in their texture, are neverthelefs wanted on account of their co- lour to produce any particular teint, a proper variation muft be made in the compofition of them, and lefs of the clay or vifcid matter added to give the tenacity muft be ufed. If the trial of the crayons be made on the pro- per ground in the manner before direded, p. 251, 252, for the encauftic painting with the S 2 pencil, 26o Of the Substances pencil, a complete ftandard will be produced^ for fhewing the difiFerence of the teints, before ' and after they are fixed, which is not lefs neceflary in this kind of encauftic painting than in the other. The manner of ufing the crayons In the encauftic way of painting is the fame as in the common method of crayon painting, the dif- ference of the one from the other lying only in the preparation of the ground; — the choice of crayons of a fit texture to receive the wax, as above-mentioned; — and the fixing the cray- ons after the painting is finifhed, by means of melting the wax, previoufly laid on the cloth, or ground, as in other encauftic painting. The fixing the crayons may be performed exactly in the fame manner as is direfted page 257, in the cafe of encauftic painting with the pencil, the principles of both being intirely the fame. If, moreover, there appear to be occafion to retouch after the fixing, it may be done as often as required, and wax diflblved in oil of turpentine may be each time applied to the back, and the pidure again expofed to the due degree of heat, as in the other methods. * CHAR ^SED IN Painting, 261 CHAP. X. Of the nature, preparation, and ufe of the feveral fubiftances employed in enamel painting. SECT. I. Of the ge72cral nature of ena7nel paintmg. E namel painting differs from all other kinds, in the vehicle employed for the colours, (to hold the parts together, and bind them to the ground they are laid upon.) This is glafs, or fome vitreous body, which being mixt with the colours, and fufed or melted, by means of heat, becomes fluid, and having incorporated with the colours in that ftate, forms, together with them, a hard mafs when grown cold. It anfwers, therefore, the fame end in this, as oil, gum water, fize, or var- nifh, in the other kinds of painting. The glafs, or vitreous body, applied to this purpofe of mixing with the colours. In order to bind them to the grounds. Is called a Jlux^ and makes one principal clafs of the fubftances ufed in enamel painting. When this flux is eafily fufible, that is to fay, melts with a lefs degree of heat, it is, in the ftile of thofe who work in enamel, faid to be SOFT^ and S 3 vrhen 262 Of the Substances when It is reludlant to melt, and requires a greater degree of heat, it is called HARD, Thefe terms are as well applied to the matter of the enamel grounds, and all other vitreous fubftances concerned, as to the fluxes. It is, in general, a perfection of the flux to be foft, or run eafily into fufion. But the great point, with refpeCt to this particular, is, that when feveral mixtures of colours and fluxes are ufed at the fame time, they fhould all correfpond to each other in the degree of this qualicy; orherwife, fome would be rendered too fluid, and perhaps run the matter of the enamel ground into fufion, and mix with it, while others remained folld and infufficiently fufed themfelves. It is always neceflary, likewife, that the enamel of the ground fhould be con- fiderably harder than the mixtures for the colours, for if they both melt with the fame degree of heat, they will neceflarily run to- gether. It being requifite that the body painted in enamel fhould undergo a heat fufficient to melt foft glafs, the matter of fuch body can only be gold, filver, copper, porcelain, or China-ware, hard glafs, and earthen-ware. And where the metals are ufed, if the paint- ing be of the nature of a picture, or demand a variety of colours, it is neceflary that a ground of white, or fome other colour Ihould be laid on the metal, the body of which ground mufl neceflTarily be of the fame vitreous nature as the flux, but harder; as nothing elfe can endure USED IN Painting. 263 endure fo great a heat that is capable of incor- porating with, and binding the matter of the white, or other colour, to the furface of the metal. The grounds, therefore, make another principal clafs of the fubftances ufed in enamel painting. The third clafs is the colours, which muft llkewife be bodies capable of fuffering the heat of melted glafs, and fuch as wdll either them- felves be converted into glafs, or kindly incor- porate with it in a melted ftate. This of courfe confines the matter of fuch colours to metals, earths, or other mineral bodies, all vegetable and animal fubftances being calcined and analized with a greatly lefs degree of heat than the low’'eft fufficient to work en- amel. The fourth kind of fubftance is what I fhall call the fecoiidary vehicle^ which is, fome fluid body for laying on the ground, and work- ing with the pencil the flux and colours when mixt together, fince, as they form only a dry powder, they could not be ufed as paint without fome fuch medium. But as this Is to ferve only for fpreading and laying on the matter of the enamel, and not, like other ve- hicles, to affift in holding the colours together, and binding them to the ground, (that being in this kind of painting the office of the flux) it is neceflafy that it fhould be fome fuch fub- ftance as will evaporate and dry away with^ out leaving any part behind, as it would otherwife be heterogeneous matter, with re- S 4 gard 264 Of the Substances gard to the enamel, and confequently inju- rious to it. Effential oils have been there- fore ufed for this purpofe, as they have the quality of w^holly drying away on the firft approach of heat, together with a flight undluofity, which renders them capable of making the matter of the enamel work pro- perly with the pencil. The preparation of thefe feveral fubftances have been, till late, greatly monopolized by the Venetians, except what were prepared at Drefden fmce the eftablifhment of the China inanufadlures. The few others who have had any knowledge of this matter, have prac- tifed the preparing only fome kinds; and even at prefent, there are, perhaps, none in this country who make more than a fmall part of the variety neceflfary. For though many pof- fefs the knowledge of fome particular articles, yet they are ignorant v/ith regard to others, which are again, perhaps, known to thofe who are ignorant of thefe. As there has been hitherto no means afforded to the pradlifers of it of learning the particulars of this art in a fyfcem, and a deeper knowlege of the principles and practice of chymiftry is requi- fite to the attaining it, without being taught, than could well fall to the fhare of painters, or other artifls; I fliall, therefore, be more minute in my inffruftions for the making the feveral kinds of the grounds, fluxes, and colours, in order that they who are concerned in, or may be defirous to apply themfelves to USED IN Painting. 265 to the art of painting in enamel, which is now become the bafis of a confiderable manufac- ture in this country, may furnifh themfelves with whatever is neceffary in its greateft per- fedtion. Befides the knowledge of the preparation of the above fubftances, and of that part of the art of ufing them, which belongs to painting in general, there is another requifite. This is the burnings as it is called, the grounds, in order to forming them on the body to be paint- ed, or enameled; as alfo the colours with the fluxes after they are laid on the grounds. What is meant by BUR.N1NG^ is the giving fuch a heat to the matter, when laid on the body to be painted, as will fufe or melt it, and confequently give to the flux or vitreous part of the compolition the proper qualities of a vehicle for binding the colours to the ground, and holding the parts together. As this re- quires a particular apparatus, I fliail endeavour to fliew the method of conftrudling it in the moft expedite and eafy manner; and to give fuch cautions for the condudl of the opera- tion, both for burning the grounds and paint- ing, as may bell; enable thofe, who are lefs experienced in it, to attain to perfection in this art. It cannot be expected, neverthelefs, confiderlng the nicety of the fubjedt, fuch directions can be given as will infure fuccefs in the firfi: trials, with regard to feveral of the prccefles, or even the general operations ; but whoever wdll make themfelves mafters of the prin- 266 Of the Substances principles on which they depend, which are all along intimated, will eafily be able to cor- red: their own errors. A judgment, formed by fome little expe- rience, is likewife requifite for the preparing well the colours with certainty. For as dif- ferent parcels of the fame fubftance vary fre- quently in their qualities, with regard to the degree or proportion, it is necelTary to make allowance accordingly in the proportion of the quantities in the mixtures. This cannot be done till fome little previous trial be made, and the power of judging of them be gained by an experimental acquaintance with them. But as the materials in general are very cheap, and the experiments may be made in the fame fire where adual bufinefs is done, whoever would excel in the art of preparing and ufing enamels fhould take a confiderahle fcope of experimental inquiry into the effed: of all the various proportions and commixtures of the fubftances ufed. SECTION II. Of the apparatus^ or fet of utenfls for the preparing and laying on the grounds and colours in enatnel painting. T H E apparatus necelfary for preparing and ufing the feveral fubftances em- ployed in enamel painting, confifts of a fur- nace USED IN Painting. 267 nace for calcining and fufing the matter of which the colour is compofed ; as alfo for burning or fufing the grounds and colours af- ter they are laid on of proper muffles or coffins for fecuring the enamelled paintings from the injury of the fire while they are burning; — of pots for fufing the compofitions for colours and fluxes, or the mixtures of them together ; — of crucibles for calcining copper and other metals, in order to the pre- paring the colours; — of mortars of glafs, agate, or flint, or of ftones, and mullars for por- phyry, or flint, for the pounding and levi- gating the feveral kinds of matter ; — of tongs for taking the pots, muffles, &c. out of the fire; — of bruihes, pencils, and a fine fearce or fieve. The furnaces for burning enamel are con- ftrufted of very various fize or figure, accord- ing to the nature and qualities of the work; and fome are made to be heated with com- mon coal, and others with char-coal, but at prefent not frequently. The befl form for a furnace for enamelling pidures, or other pieces of the fame magnitude, where the difpatch of great numbers are not wanted, is the fol- lowing, which is made to work with a fixt muffle, in or out of which the work may be put or taken without opening the door of the furnace, and annoying the operator with the heat; who, for the fame reafon, likewife may conveniently infped the work in the muffle. The 268 Of the Substances The iron-work muft be firft prepared. It confifts of a frame and bars, fuch as is de« fcribed in p. i6, the area of which together muft be ten inches by feven ; — of a door and frame, fuch alfo as is defcribed in p. 1 6 , which muft be five inches high, and feven long ; — and of a plate or ftrong bar to lay over the opening of the front, as below diredted, which muft be ten inches long ; with another of the fame magnitude to lay over the door and frame ; and one of eight inches to lay over the vent into the chimney; — and of a frame for bearing the fixt muffie. This frame muft fuit the figure of the muffle ; except, that it muft be only three inches in depth, with the back part open, for the muffle to pafs through it into the cavity of the furnace ; and that the plate which forms the bottom muft projed: an inch and an half of each fide, beyond the arch or covering, for the brick-work to have good hold of it. But this will be better imder- ftood by confidering the form of this kind of muffle, as below defcribed. ' The iron-work being prepared, let a chim- ney of twelve or fourteen feet height be raifed; the cavitv of which muft be an area of feven j or eight inches fquare, in the front wall of which chimney a hole muft be left for ad- mitting the fmoke of the furnace. The hole muft be fo placed that the lower part may be five feet above the foundation of the chim- ney; and it may be four inches high, and fix long^ the plate prepared for this purpofe be- USED IN Painting. 269 ing laid over to fupport the brick-work above It. The chimney being ralfed to a proper height, let a pedeftal or foundation to the furnace be built, by adding two walls to thofe of the- chlmney, fo as to inclofe an area fifteen in- ches in depth from the front, and eight in- ches wide ; the front being left open from the default of a fourth wall. This pedeftal muft' be raifed four feet and a half high; and then the frame and bars for fupporting the fuel, with their crofs-bars, muft be laid; the fur- thermoft crofs-bar being laid clofe to the back of the hollow area; or, in other vrords, to the wall of the chimney. The plate or fiat- bar muft be alfo laid clofe to the outermoft crofs-bar of thofe for bearing the fuel, in order that the brick-work may be carried over the hollov^r area, and inclofe the fquare cavity of the furnace entirely. The brick-work muft be then raifed fix inches higher, in the fame manner as before ; only the front muft now be carried up, as well as the fides; which, to- gether with the wall of the chimney, forms a complete inclofed area for holding the fuel, jBut particular care muft be taken in laying the firft courfe of this brick-work, that the fiat ends of the crofs-bars, in which thofe defigned to bear the fuel are faftened, be well fecured by the bricks which lie over them. When the cavity for holding the fuel is , thus formed, the door and frame muft be placed in their proper fituation, and the brick-work muft be car- 270 Of the Substances carried up on the two fides to the level of the top of the frame ; but, in the fide moft con- veniently fituated, the iron frame for bearing the muffle muft be fixed in the raifing this part of the brick-work. This frame muft be placed about four inches higher than the bot- tom of the door, and two inches from the back or furthermoft part of the furnace ; care being taken that the brick-work have good hold of the parts of the frame formed for that purpofe. The bricks contiguous to the frame fiiould be properly Hoped to the hole formed by it, that the opening into the muffle may be wider and more commodious for the taking out and putting in the work to be burnt, as alfo for the more eafy infped;ion of it while burning. The brick-work being brought to a level with the top of the frame of the door, the plate or flat iron bar provided for that pur- pofe muft be laid over it, in order to fupport the building over it. The fides of the fur- nace muft then be ralfed five inches higher, and the cavity or hollow covered with a dome of fire-ftone, made a little concave on the in- ner or under fide, and of any figure the ftone will beft admit on, the outward or upper. This dome muft reft on the brick -work, and they Ihould be fo fitted to each other as to make as clofe a joint as poflible ; fo that a coat of fire-lute being laid on the bricks when the dome is put on, the furnace may be perfedlly tight. Windfor bricks fhould be employed for all that part of the furnace which is above the USED IK Painting. 271 the bars for bearing the fuel, and they fliould be laid in Windfor loom. Where greater quantities of pieces are to be enamelled, and difpatch is required, furnaces mull; be built in the manner proper for con- taining coffins inftead of a muffle ; fqr the conftruding which the following is a very good method. This furnace mull; be built till the fabric rife within two inches of the top of the door, in the fame manner as the former, except with regard to the dimenfions, and the adding a back wall againft that of the chimney, which muft be eight inches in breadth, and twenty inches in length. The dimenfions of the ca- vity of the chimney, till it rife to the height of five feet ten inches, muft be twelve inches in breadth, and feven or eight inches in depth, from the front; and the hollow or area under the bars for bearing the fuel muft be eleven inches and a half deep from the back wall to the front, and twelve inches wide; and that of the furnace where the fuel is to lie, eight inches in depth from the front wall to the back wall, and twelve inches in breadth; to which dimenfions the bars and crofs-bars muft be fuited. The building being carried up to the height here mentioned, a door and frame, of the fame form with that for feeding the fire, muft be fixt in the moft convenient fide of the furnace ; the intention of which door is to ferve for putting in and taking out the coffins; and it muft therefore be placed fo that one end Oi< THE Substances end of the frame may be clofe to the chlm-^ ney. The dlmenlions of this door muft be ten inches in height, and eight in breadth. Then the brick- work of the cli^mney may be. proceeded with in the fame manner as be- fore; except that the back wall againft the chimney muft be raifed no higher. But the fpace it would take, if carried up higher, muft be added to the cavity or hollow area of the furnace; the top of this wall ferving as a fupport to the coffins, which are to be placed upon it. Two pieces of fire-ftone neverthelefs, of ten inches length, and of the thicknefs of two inches fquare, muft be put with their lower part fixed at about three in- ches diftance in the brick-work from the wall of the furnace, that the coffins refting upon them, the flame and heat of the fire may pafs under as well as over them, and heat every part equally. Two vents into the chimney muft be, likewife, made clofe to each fide wall of the furnace; and may be placed at the height of two inches above the level of the top of this wall, and of the dimenfions of four in- ches in breadth, and three in height. When thefe feveral parts have been completed, and the whole fabric is raifed fifteen inches above the level of this wall, a dome of fire-ftone muft be fitted to it, in the fame manner as was direded for the former furnace; only it is neceflary, in this cafe, that though the inner or under fide be concave, the upper ffiould be flat, for the coffins to ftand upon it to heat before tJSED IN Painting. ' 2^3 before they be put into the furnace, to pre- vent their cracking frotn too fudden an effedl of the fire. It is fometimes praftlfed to burn enamel ori a hearth with charcoal, in order to which no apparatus is neceflary but a proper hearth of fire-ftone or bricks^ and a Ikreeri of brick, or fome fuch other material, through which to pafs the nozzle of the bellows to blow the fire without burning them^ The bellows for this purpofe muft be made in the manner of thofe ufed for chymical ex- periments, to work with a weight, and to be moved by the operator as he (lands by the fire; but a very fmall pair of that kind will ferve for this purpofe. Melting pots for fufing the fluxes or colours are indifpenfibly neceffary, the common cru- cibles being of too loofe a texture to contain vitreous bodies when perfectly liquefied. Thefe melting pots are not to be purchafed, but muft be made for the exprefs purpofe. The proper materials are tobacco-pipe-clay, or Stur- bridge clay (which is much cheaper here) two parts, and crucibles ground to powder (or, in default of them, fine fand) [one part, which muft be tempered with water, and well mixed together. The dimenfions muft be regulated by the quantity of matter to be fufed, and the ftiape may be a little conical, rather deep than fhallow, to form which a folid mold of wood fhould be procured for working them upon to bring them to a regular figure. When VoL. I. T they Of the Substances they are formed, they muft be well drled^ and then thoroughly baked before they be iifed. Muffles, and where the quantity Is great, coffins formed of the fame matter, are requi- site for the burning, as well the grounds, as paintings iri enamel. The ufe of muffles is to preferve the enamel from being injured by the falling of the coals upon it, or by the fmoke and fumes of the coal, whicli in many cafes is very detrimental to the colours. The : matter of which the muffles may be fabricated | may be the fame with that juft now given for j the melting pots, and they muft be alfo dried ■ and well baked before they be ufed. The ; form of the muffles may be of two kinds; the one, that commonly ufed for eflays; the ■ other, a elofe muffle fixt in the fire, which is j a much more commodious method than the j having them loofe. ) The fhape of the common muffle is only a ■ flat fquare piece bent into the form of an arch, of fuch dimenlions, that, being laid over the ■ enamel work to be burnt, it wdil cover it, Thefe may ’be beft made by fpreading the matter, properly tempered, on a piece of wood, * turned to make a round correfpondent to the i arch of the muffle, and working it. even on the outfide by a knife, or other flat inftrument, and it may be left on this mold, or round piece of wood, till it be moderately dry and firm. It is proper alfo to make a bottom to ] this kind of muffle, on vvhich the plate may be ) kid ; \ USED IN Painting. 275 laid; but this may be either a detached part, or joined to it. It is only a flat piece formed of the fame fubftance, and of fuch a magni- tude as to fuffer the muffle to reft upon it every where; and, if loofe, to have a margin of half an inch for the better taking it out of the fire; but if fixt to the muffle, it need only be of the fame extent with it. The fixt muffle muft be of the fame general figure v/irh the loofe kind; but the bottom muft be always a proper part of it, and exactly of the fize fuitable to the extent of the arched part, without any margin. The fize of this kind of muffles muft be adapted to the fort of enamel work to be burnt in them; the breadth fliould be fuch as will fuffer the pieces to be eafily put in and taken out, and the height of the arch, where the form of the pieces does not require it to be higher, fhould not be above two inches. The end of this arch within the fire muft be , clofed up, fo that when the muffle is paffed through the iron frame in the fide of the furnace made to fupport it, and the joint made good by fire-lute, the hollow or ca- vity of it may be intirely doled, except the mouth or opening on the outfide of the furnace. The length of this kind of muffle fhould be fufficient to admit its paffing five or fix inches into the fire, and yet having a pro- per proportion remaining to projed on the outfide fomewhat beyond the iron frame. But thefe proportions are to be adjufted by the T 2 room 276 Of the Substa^^ces room wanted. There muft be a falfe boU6h7' likewife made to this kind of mufHe, which muft fit the other bottom, fo as to Aide in and out of the muffle upon it; but it ftiould be made of fuch length, that when it is thruft home into the muffle, a part of it may pro-* that proper hold may be always taken for drawing it out. The defign of this falfe bottom is, that the enamel work to be burnt, being laid upon it, may be put into the muffle and taken out without that difficulty and hazard of injury which would otlierwife refult from the form of the muffle. Coffins for burning larger quantities of enamel work may be made of the fame matter with the above. The figure of them may be that of fquare boxes, of the length, when Intended for a furnace of the dimen- fions above given, of ten inches, of the breadth of fix, and of the height of feven; which meafures fhould include alfo the thick- nefs of the fubftance of which they are form- ed. In the cavity of thefe boxes, little co- lumns, or projeding parts, ftiould be placed againft the fides rifing to half the height of the cavity, in order that a fquare plate or piece of the form and fize of the area may be laid on them hollow, as a flooring to fup-;. port a fecond range or layer of the enamel work; and a lid muft be likewife fitted to reft in a proper groove made in the fides of the boxes or coffins, at the top of them, that the fire \ USED IN PaI.NTING. ^77 lire and fmoke may be wholly excluded froiu the cavity. Crucibles of proper fizes mull likewlfe be had for calcining the metals; but as they are to be obtained every where ealily, it is needlefs to fay more of them. Mortars for levigation muft be likewife had of various fizes; they fliould be either of agate, flint, or glafs; for thofe of iron, or copper, would be liable to deprave greatly many of the colours, and to thefe fhould be added a por- phyry flone and muliar, marble being too foft to bear the attrition of many of the fub- ftances ufed in enamel, without imparting too much of its ovv^n fubftance in confequence of fuch abrafion. Searces or fieves of fine lawn muft be alfo provided for fiftlng feme of the levigated fub- ftances, as alfo for fpreading the powdered enamel to form the grounds; they fhould be like thofe of the apothecaries and druggifts, with a cover and under part for preventing that wafte of the matter which attends the fiftlng in the open air. Tongs, with points bended at right angles, muft alfo be procured for taking out of the fire the crucibles and melting pots. An iron inftrument, like a baker’s peel, is likewife necelTary where the coffins are ufed ; the flat part muft be fomething broader than the coffins, and of nearly the fame length, and the handle fhould be about three feet in length, T 3 To Of the Substances To thefe muft be added brufhes, pendlsg tiles, and other common implements of paint- ing; but as they are to be had every where, and their ftriulture is generally underftood, it is not neceffary to be more particular about them. SECTION III. Oy' the general nature and application of the fubjiances ufed in enajnel paintings with their previous preparation. Of the fubfances ufed for forming fuxes. I ^ylTNIUM, or red lead, is ufed as a flux- V A body for forming the enamel for grounds, as alfo in compounding fluxes for the colours. It requires no preparation for thefe purpofes, only it is proper it fliould be pure, which may l3e known by the method before given, p. 50, This flux renders the enamel foft, but, producing feme proportion of yellow colour, is not fit for all ufes. bhxT ALKALINE SALT of vegetables is fometimes ufed alfo in forming the mixture for enamel grounds, as likewife in forne com- pofitions of fluxes for the colours. It makes a lefs foft enamel than the lead, but is free from yellow. usED‘ ix\ Painting. 279 yeFiow, or any other colour, and therefore proper for fome piirpofes. Borax is a fait of very peculiar qualities, amongft which is, that of promoting vitrifica- tion, and the fufion of any glafs when vitrified, in a greater degree than any other fubftance known; on which account it is of the greateft confequence in forming fluxes for enamel. It requires, neverthelefs, either to be previa oufly calcined or brought to a vitreous ftate, which it fuffers' from the application of mode- rate heat alone; and it muft alfo be finely powdered before it be mixed with other in- gredients in fluxes'. Its ufe is not much known- in common practice, though of the greateft confequence to the art of enamelling; as not only a fet of fofter colours may be produced by the aid of it than can be otherwife had, but the degree of each may be brought to cor- refpond, by the employing it in different pro^ portions, according to the refpedive hardnefs- of the other ingredients, vrhich differs fo much as not to be regulated juftly by any other means. Common salt may be*aifo ufed as a flux in enamelling, particularly where there is oc- cafion for glazings; where, as it is extremely fluid, and free of tfenacity when fuftd, as alfo lefs fubjedr to crack than any other vitreous body, it is’ of great ufe ; but for fluxes for grounds and colours in enamel, it is not fre- quently necefl'ary to multiply ingredients, as the above three fubftance s may, pro- T 4 perly 28 o Of the StJBSTANCES perly applied, fufEciently anfwer moft purpofes. . The fame reafoning extends to nitre and arfenic; which, though they have the qualities of fluxes, poflTefs yet along with them fuch others, with refpeft to their effeft on feveral of the fubflances that compcfe the colours, as renders the methods of ufing them difficult and complex. Of the fuhfances ufed for forming the body of enamel^ or fuxes. White sand is ufed as a body for the fluxes and grounds of enamel; it fhould be reduced previoufly to an impalpable powder, in order that it may be mixed more intimately with the other ingredients, which not only accelerates the vitrification, but renders the glafs greatly more perfed. The kind of fand, proper for this purpofe, is that brought from Lynn in Norfolk, and called by the name of that place. Flints are ufed for the fame purpofe as the white fand, and it is proper to ufe them when that cannot be procured of the right kind. They require to be calcined before they are applied to any purpofe of vitrification. This is to be done by putting' them into any fire, and continuing them there till the whole fub« fiance become white, when they mufi; be taken out, and, while of their full heat, im- merfed in cold water, and kept there for fome time. By fuch treatment they will be ren- dered USED IN Painting. 281 dered of a very brittle and calcarioiis texture, and very eafy to be powdered, which muft be done to a perfedl degree for the reaibn above given. Where fmall quantities of the matter of any kind of enamel is to be prepared, cal- cined flints are preferable to fand, as they are much more eafily reduced to an impalpable powder, and the trouble of the previous cal- cination is very little. There is a fort of ftone, which the French call moilon^ that forms the upper crufl, and lies round the free-ftone in moft quarries. This fione will lofe its tenacity in a moderate fire, and, when calcined, runs much fooner into vitrification than either flints or fand. It is therefore, when it can be obtained, a better matter for the body of fluxes or foft enamel_ than either of the other ; as it will, with the fame proportion of the fluxing ingredients, make a much fofter flux; or it otherwife ad- mits of the diminution of the proportion of fome of them ; which, for reafons we fhall fee below, is in certain cafes an advantage. Of the fiihfances ufed for producing a white colour in enamel^ or for formhig the grounds. Putty, or CALCINED tin, is ufed as a body of colour for the enamel grounds. As tin is very troublefome in calcining, requiring along continuance of fire, and to be fpread into a very large furface, it is much the beft way to procure it for the purpofes of enamelling ready cal- 282 Of the Substances calcined, of thofe who make it their proper bufinefs to calcine it for the ufe of lapida-^ ries, and other artifts who ufe it; for they have large furnaces, fitly conftruded for per- forming that operation in large quantities, and can confeqiiently afford it much cheaper than it can be prepared in fmall quantities, be- fides the fparing the trouble. It muft be de- manded of them by the name of putty^ and care muft be taken that it be not fophifticated, which it feldom fails to be before it comes out of their hands for common purpofes. The fo- phiftication, which is generally by chalk, lime, or fome fuch white earth, may be thus diftin- guifhed. Put the putty into a crucible with fome tallow or other greafe, and give it the heat of fufion, or what is fufficient to melt it, fupplying the greafe in frefti quantities as it burns away, till the calcined tin appear to have regained its metallic ftate. Suffer then the remainder of the greafe to burn away, and the chalk or earth, if any were mixt with it, will be found fwimming on the furface of the metal, to which, however, the afhes of the greafe muft be fuppofed to have added fome little quantity. There is, neverthelefs, another body with which the putty or calx of tin may be adulterated, that will not difcover itfelf by this method of redudiion of the tin. It is white lead, which, in this manner of treat- ment, would run into fufion and mix with the tin, and could therefore not be diftin-^ guiflied from it. But it may be eafily ren- dered USED IX Painting. 283 clered perceptible by another manner of pro- ceeding, which is, to take the putty fufpedied to be adulterated v/ith it, and having put it into a crucible, without any admixture, and in- verted another crucible over it as a cover, to give it a moderate heat, carefully avoiding that the fmoke or coal of the fire may have any accefs to it to change its colour. If there be any wdiite lead mixed with the putty, it will fliew itfelf when removed from the fire, and become cold in a yellow or brown colour. If no fuch colour fupervene, but the putty appear equally white as before it w^as heated, a conclufion may be fafeiy made that it was not adulterated Vvith white lead, or that, if fophiflicated at all, it muft be by fome white earth, which may be made perceptible by the reduction of tin in the manner before mea- tioned. Where a very pure white is wanted for enamel, the eafielt and bell method is to calcine the tin by means of nitre, which. may be thus done. ‘‘ Take half a pound of faltpetre, and put it into a melting pot, fuch as is de- “ fcribed p. 273, and put it into a fire to “ melt. When it is melted, throw in gra- dually ten ounces, or half a pound of ‘‘ tin filings, wdiich Ihould be rafped as fine as poffible; but give time for the explofion that will follows to ceafe betwixt each quantity that is thrown in, fiirring, how- ever, the matter in the mean-time with the end ^84 'Op the Substances end of a tobacco-pipe. After the whole is ‘‘ put into a melting pot, ftir it again well “ about for fonie time, and then take it out of the fire, . pouring all the matter out of ‘‘ the pot that can be got from it by that means, and then foak the pot in water till the remainder be foft enough to be fcraped from it; taking great care not to let any part of the fubftance of the pot be com- ‘‘ mixed with the calcined matter. That “ which is moiftened, in order to be got out of the pot muft be dried and put to the other, and the whole well pounded, and “ kept ftopt up in a bottle for ufe. There is no occafion for edulcoration, or walhing the falts from the calx for this purpofe, becaufe they are by no means detrimental, but rather advantageous to the enamel.” Antimony has been alfo applied to the fame ufe as tin ; but the expence and trouble of reducing it to a calx, which muft be by deflagrating it with nitre, renders the ufe of tin much more expedient. Morret, in his notes of Neri, recommends equal parts of the antimony and nitre ; but as that propor- tion does not calcine the antimony to white- nefs, but produces the crocus metallorum^ or liver of antimony, which is of a foul orange or reddifh yellow colour, it is by no means fufficient. He fays likewife, that regulus of antimony will anfwer the fame end; but in this he is ftill further miftaken; for the re- gulus, which is a metallic body, in fome de- gree / USED IN Painting. 285 gree malleable, could never be reduced to pow- der, as he direds all the ingredients in the compofition he prefcribes to be ; nor if it were, would it form a white body on the fufion with the other matter. When antimony is ufed for the colour- ing white enamel, it fhould be previoufly calcined by means of nitre, in the following manner. ‘‘ Take of antimony one part, fait petre three parts. Powder them well together, “ and then throw it, by a fpoonful at a time, into a crucible heated red hot, waiting be- ' twixt each time till the explofion the mix- ture will make, be entirely over. When the whole matter is put into a crucible, and has remained fome time in a quiet ftate, take it out of the fire, and proceed in all refpects as was above diredled for the tin, when calcined in this manner.’’ The calx of antimony fo produced will be of a finer white than the calx of tin can be eafily brought to, unlefs by this method of calcination, and therefore more fit for pur- pofes where great purity of colour is wanted, either in grounds or painting. But as the tin prepared in the fame manner may be rendered very white, it will be lefs expenfive, as it requires lefs nitre to calcine it, and produces a much greater proportion of calx than’ the antimony. Arsenic is alfo ufed for forming a white colour in enamel; but it is a very nice matter to s86 Of the Substances to manage it well, as it is very foon changed by the heat into a tranfparent body, being itlelf a ftrong flux, and it is therefore much better to omit the ufe of it, unlefs for fome particular purpofes, in the fl:ate of white glafs, as I fhall below have occaflon to mention. Arfenic is alfo iifed as a flux; but its efreds on fome colours renders it not very fafe without great knowledge of its qualities, and caution in its application* Of the fubfances tifcd for producing red, blue^ yellow, colours in enameL Ultramarine (the preparation of which we have before given) is ufed in enamel where very bright blues of a lighter teint are wanted ; and fometimes, indeed, In other cafes, by thofe who do not underhand the right life of zaffer and fmalt. But there are few in- fiances where zaffer, when perfedly good, fluxed with borax and a little calcined flint, or Venetian glafs, to take off the fufible quality of the borax, will not equally well anfwer with the befl ultramarine. The ultramarine re- quires no preparation, when ufed in enamel painting, previoufly to its being mixt with the proper flux; and what relates to its general qualities, and the means of diftinguifhing its goodnefs or genuinenefs, we have, along with its preparation before taught, p. 71? and the following. Ultra- USED IN Painting. 287 Ultramarine ashes are ufed where light femi-tranfparent blues are wanted. But they are fo frequently adulterated with pre- cipitations of copper, which, of courfe, turn green on fluxing, that it is very neceflary to be cautious in the ufe of any parcel not pre- vioully tried. Zaffer is ufed for producing blue, green, purple, and black colours in enamel. It is an earth obtained by calcining a kind of ftone, called cobalt; and when it is mixed with any kind of vitreous bodies, it vitrifies and at the fame time affumes a ftrong blue colour, but, for the mofl: part, verging to the purple. It is to be had, in a ftate proper for ufe, of thofe colourmen who make it their particular bufi- nefs to fupply the glafs-makers with colours. The goodnefs of zafFer can fcarcely be known but by an adual trial of it, and comparing the effect of it with that of fome other known to be good, and ufed in the fame proportion. Magnesia is an earth which, v/hen fluxed with any vitreous body, produces a broken crimfon, or foul rofe colour. It is to be had, prepared fit for ufe, except a more per- fect; levigation, from thofe who fell colours to the glafs-makers. It is ufeful not only for fome purpofes as a red, but for feveral com- pofitions for black, purple, and fome browns. The goodnefs of magnefia mufl: be de- termined by the fame means as that of zafFer- Smalx 188 Of the Substances Smalt is, as before mentioned, zaffef vi- trified with proper additions which are ge- nerally fixt alkaline falts and fand, or calcined flints, and is fometimes ufed in a blue in enamel. But, being hard, it requires, for fuch purpofes, to be ufed with a flux ; which increafing the body of glafs in too great a proportion for the tinge, is apt to dilute the colour too much, where great force is wanted; and therefore the ufe of the zafFer itfelf is in moft: cafes preferable. There have neverthelefs been, as v/as above obferved, fome parcels of fmalt, or vitrified calx of cobalt, brought from Saxony, which are of an extreme ftrong body of colour, and will bear any proportion of flux neceflary to ren- der them as foft as may be required, without weakening the colour too much for any pur- - pofe. Common fait, how^ever, ground very fine, and mixt with a fourth part of its weight of borax, (which is much the moft power- ful and kindly flux for zafFer) will run pretty well, and may be ufed where either a full colour is not demanded, or where the work will admit of the colours being laid on thick. The goodnefs of fmalt may be judged of by its bright and deep colour, and the lefs it in- clines to the purple, the better. In order to judge of the ftrength of the colour, the fmalt fhould be reduced to a fine powder ; for, in a groffer ftate, every degree of finenefs renders it fo different that a judgment cannot be eafily formed of it. Smalt is to be had of all USED IN Painting. 289 all colourmen, and is not fubje£t to any adulterations, which would not be obvious on infpedtion. Gold is ufed in enamel to produce a crlm- fon or ruby colour, which, by the miftaken fenfe of the Latin word purpureus^ has been called purple by all the Englifh and French writers. It muft be previoufly reduced to the ftate of a precipitated powder, by diflblving in aqua regia^ and making a precipitation by means of tin, fixt alkaline fait, or fome other metallic or alkaline body. There have been feveral methods ufed for the making this pre- cipitate of gold, but the following will an- fwer the end certain, when the procefs is duly conduced; but the fuccefs depends on fuch nice principles that it is very difficult to fuc- ceed to the utmoft degree of perfedfion. Take of pure fpirit of nitre eight ounces; add to it of fal Ammo?iiacus^ fcraped per- fedlly clean, and powdered, two ounces ; which will convert the fpirit of nitre to aqua regia. Diffolve, in four ounces of this aqua regia^ put into a proper phial, half an ounce of purified gold, in the ftate it is to be had of the refiners, under the ‘‘ name of grain gold. In order to hafteii ‘‘ this folution, the phial may be put into a gentle heat, where it muft continue till the gold intircly difappear. Take, in the mean-time, about the fame quantity of aqua regia in another phial, and put into it filings or fmall bits of pure block tin, fo VoL. I. TJ long Of the Substances long as any brifk efFertefcence arife on the : adding frefli quantities ; but this mud be done gradually, efpecially if the filings be ufed ; otherwife the mixture will heat fo much as to boll over, or break the phial; drop then thirty or forty drops of the folu- tion of the gold into a half pint glafs of water, and immediately after about fifteen or twenty drops of the folution of tin. The gold will be then precipitated in a red powder from the folution in the aqua regia ‘‘ dropped into the water ; and this operation mud be repeated till the w"hole quantity of ‘‘ the folution be thus treated. When the ‘‘ lad quantity of the red powder has been precipitated, pour off the clear fluid, and fill the glafs with fpring water ; w^hich, when the red powder has fettled, mud be poured off likewife. Hold then a fpunge wet, but well fqueezed, to the furface of the fluid remaining with the powder ; and vrhen as much of the water as can be con- veniently feparated from it, by that means, '' is drawn off, lay the powder on a marble ‘‘ or porphyry done to dry taking, great care that it Gontraft no dud or foulnefs.’^ This powder is the gold purple^ or precipitate of gold\ and is now fit to be commixt with the pro- per flux. If the procefs fucceed, it will, by this preparation, be of a fine crimfon colour, and perfectly anfwer the purpofes of enamel painting. Indead USED IN Painting. .291 Inftead of ufing the folution of tin to preci- pitate the gold, the crude tin is moft fre- quently employed; but the precariouinefs of this method, which reouires much more at- tention than that above given, over-balances the trouble of making the folution. For, if the folution be mixed with as much w^ater in this method as in the other, it is very flowly acted upon by the tin; and if it be not diluted with fo much water, it forms a gelatinous body, when ftrongly faturated with the tin, which can never be feparated from the preci- pitated gold, but by means that are deftruc- tive of its qualities as an enamel colour. When the crude tin is ufed, however, the folution muft be diluted with about treble its quantity of water ; and the tin muft not be longer continued in it than while the gold ap- pears to continue to form a red powder on the furface of it, on its being freed from that which before adhered to it. It is better^ neverthelefs, on the whole, to ufe the two folutions, as it is more eafy to preferve a fcaret colour by that means; for, if the tin be too long continued in the mixture, it gives the colour a tendency to the purple. When a red colour is wanted, which verges greatly on the purple, a precipitation of the gold ihould be made by means of any fixt alkaline fait. Which may be thus done. Take the folution of gold in aqua regia as before directed, and drop in it a folu- tion of fait of tartar (which muft be made U 2 t)y zgi Of the Substances by melting halt an ounce of fait of tartar iit a quarter 'of a pint of water) fo long a^ there appear an effervefcence or ebullition on the further addition. Let the precipi- tated powder then fettle, and proceed as “ was above diredted for the ca/x cajfii^ or precipitation with tin. The powder thus ‘‘ produced is called aiirum fulminans^ from its quality of exploding when expofed to a moderate heat ; which muft therefore be carefully guarded againft in the ufe of it, by keeping it out of the reach of any fuch heat till it be mixed with the flux for ena- melling; and it will be the lefs hazardous, from being thoroughly well freed from the ‘‘ fait, formed in its produdtion, by wafhing.’^ The gold may be likewife precipitated in the fame manner by volatile falts ; in which cafe the volatile fait in the proportion of half the weight of the aqua regia may be dliTolved in four times its own weight of water. But this method does not produce fo fcarlet a red in the gold precipitation as that of ufmg the folution of tin, as before diredled. This precipitation may be alfo made by mercury dilTolved in aqua regia ; and it is faid that a finer colour is produced by this method than with tin ; as likewife, that if the aurum fulminans^ or any of the other precipitations, be fufed with common fulphur, they will be rendered of a much brighter red; but the ful- phur muft in this cafe be fulfered to burn away, Thefe methods, neverthelefs, are at- tended USED IN Painting. 293 tended with much more difficulty and hazard than the fimple method firft given; and, per- haps, unlefs by accidents, not be commanded, will not produce a better pigment for enamel painting. Befides the application of gold to form a red colour, it Is ufed to produce the effedt of gilding in enamel; for which purpofe it muft be reduced to the flate of a powder by preci- pitation, or mechanical prepartion. The gold precipitate which is found to an- fwer this purpofe beft, in the cafe of gilding glafs, is that prepared by means of volatile fait as above ; but as this requires greater heat than can be admitted in the cafe of enamel, it is proper to employ thofe which are made by metallic fubftances. The preci- pitate, which moftly retains the luPere of the gold, is that made by means of a folution of green vitriol or copperas in this manner. ‘‘ Take a folution of gold in nqua regia^ prepared as above diredled ; and add to it gradually a folution of green vitriol or copperas in water, till it appears that no further precipitation of the gold be made, on adding a frefh quantity. The folution of the copperas may be made by putting one dram of it powdered into an ounce of water, and (baking them fill the whole appear to be dilTolved. After which the folution muft “ (land, and the clear part be poured off from the fediment, if any be found. The fluid muft be poured off from the precl- U 3 pitated ^94 Substances pitated gold, as foon as It is perfeftly fub- fided ; and the precipitation muft be well wafhed, by pouring on it feveral fucceiTive quantities of water. Roman or blue vi- triol may be employed for this purpofe inftead of the green, but it is fomewhat dearer, and has no advantage over the other. The gold precipitate thus obtained ‘‘ is very bright and fhining. A fimilar kind may be prepared by putting flat bars or plates of copper into the folution of the gold in aqua regia ; but the precipitate is of a brown colour, without any luftre or fhining appearance.” Silver is ufed for producing a yellow co- lour in enamel. It miiil be previoufly re- duced to the ftate of a powder, which may be done either by precipitation from fpirit of nitre, or by calcination with fulphur. The precipitation of filver from fpirit of nitre, may be performed by diffoiving an ounce of filver in two or three ounces of fpirit of nitre, and precipitating and edulcorating It ex- actly in the fame manner as was above di- redfe'd for precipitating the gold from aqua re- gia^ by means of copper for gilding in enamel. A precipitation may otherwife be made by pouring brine on the folution of filver in the fpirit of nitre, but 1 think the other method preferable. The calcination of filver with fulphur may be thus performed. Put plates of filver into a crucible, with as much of the flowers of fulphur betwixt ‘‘ them. USED IN Painting. 295 them as will cover the furface of each plate, and then place the crucible in a fire that will heat it red hot. When it is thus heat- ed, take it out of the fire, and the filver will be friable or brittle, and mull be re- duced to a fine powder in a mortar of glafs, agate, or Hint. The calcination may be otherways made by mixing filings of filver ‘‘ ivith flowers of fulphur, in the proportion of one ounce of thedilver to half an ounce of the fulphur, and heating them red hot in a crucible; or the fulphur may be thrown into. the crucible after the filver is already made red hotd’ . Copper is ufed in enamel painting for the forming green, blue, and red colours ; but it mull be previoufly either calcined or re-? duced to the flate of a powder by precipi- tation. The calcination may be performed by means of fulphur, in the fame mann«r as is above direcled for filver. It requires a ftrong fire for two hours, when the copper will be found converted into a blackifh red pov/der, wdiich muft be well levigated by grinding and fifting. The copper fo prepared,’ is called Ferretto of Spain, It may be otherwife cal- cined, by ftratifying it, in the fame manner, with Roman vitriol; but a much longer con- tinuance of fire is required in this method.;’ and Nerifays, it ought to be fix times repeated to have the ferretto perfectly fine. When all this is done, neverthelefs the fubftance produced cannot be really different, . notwith-r* U 4 ftand- 296 Of the Substances ftandmg the Intimation of Ncri to the con- trary, from that of copper calcined with ful- phur, if the quantity of fulphur employed be fmall, and the time of the calcination well adjufted. This muft be judged of by the goodnefs of the ferretto when prepared ; the criterion or mark of which is its appearing red when levigated. For, if It verge to the black, or purple, either the calcination has been too long continued, or the proportion of fulphur employed was too great. Inftead of crude copper, the kind of latten, called by artificers in metals, offidiie^ may be ufed ; but as the plates of it are too thin to be treated in the way of ftratificatlon, or lay- ers, as the quantity of fulphur ufed would be much too great a proportion, it is better to clip the affidue with fciflfars into fmall Ihreds, and mix it by that means with the flowers of ful- phur; and the extreme thinnefs of the plates, in this cafe, renders the neceflary time of cal- cination very fhort. Copper or brafs In thin plates, latten, or aflidue, may be otherwife calcined without fulphur, by expofing them to a firong heat for a confiderable time. But as foon as the heat has rendered them friable, or brittle enough to bear levigatlon, it is the beft way to powder the matter, and place it again in the fire thinly fpread on a tile, or other fuch convenient thing, fUrring it fonietimes, that every part may be expofed to the open heat. By this means, the calcination may be much accele- rated. USED IN Painting. 297 rated. A due regard lliould be .had like- wife in this cafe to the red colour of the cal- cined matter, as well as in the cafe of that calcined with fulphur. But, notwithflanding, that it is requifite for many purpofes to have the copper cal- cined only to a ftate of rednefs, yet it may be expedient, likewife, for fome particular ufes, to prepare other quantities wnth a higher cal- cination. This mufl be continued till the copper appear of a dark purplifh grey, or light black, when powdered, though it mull yet retain fome tinge of the red; for if the calcination be pufhed beyond that point, the calx becomes very difficult to be fluxed, and does not afford any colour in a kindly manner to the enamel. The other method of reducing copper to an impalpaple powder, is by precipitation \ to which end the copper muft be difiblved in any acid, (for all will diffolve it) and precipi- tated, by adding of a folution of pearl-afhes in water, in the fame manner as was diredled, p. 92, for making the kind of verditer called fanciers bluCy except in the life of ffarch, which inufl be here omitted. For making green colours in enamel, this will be found prefer- able to the calcined copper. To avoid the trouble of diiTolving the cop- per, as above advifed, Roman vitriol, which is only a combination of copper with oil of vitriol, may be ufed in the place of fuch folu- tion. It muff be previoufly difiblved, by .add- ing hot water to it in a powdered ftate, and then tg}i Of the Substances then the copper may be precipitated, by means of pearl-aflies, in the fame manner as from any other folution of it. Iron is ufed to produce an orange red, or foul fcarlet colour in enamel, as alfo a tranf- parent yellow, and to affift likewife in the formation of greens and other compound co- lours. It is prepared many ways, both by corrofion and precipitation; fome of which indeed make a real difference, but moft of them lead to the fame end. The only diffe- rence, in fa£t, is this : When the iron is highly oalcined, and freed in a great degree, not only from all acid, but even its own fulphur, the appearance of the crude calx will verge moft upon a purple colour, and produce a foul purple enamel, if compounded only with a quantity of flux not fufficient to vitrify it ; but though, when compounded with a greater quantity of flux, it will vitrify into a tranf- parent yellow, fomewhat inclined to the red. But when it is lefs, or not at all calcined, and retains its own fulphur, or perhaps fome pro- portion of acid ufed in the preparation, it will in proportion be yellow, or verge towards the yellow, when ufed with the lefs proportion of flux, and produce a cooler or lefs red yellow, when ufed with a quantity fufficient to vitrify it. Inftead of ufing the crude iron in thefe preparations where it is to be precipitated or calcined, it is much better to ufe common green vitriol, which confifts only of iron and the acid of vitriol ; from whence confe- USED IN Painting. 299 quently the iron may be obtained in the ftate to which thefe preparations lead by eafier and lefs expenfive means than when ufed crude, iiiit the preparation of the ruft, formed by vinegar, requires the iron itfelf; and, if found neceffary, is, neverthelefs, the only inftance where the precipitated bafis of vitriol will not anfwer the fame end as the iron. The firft preparation of iron is, therefore, the ruft by corrofion with vinegar, which may be thus made. Take of iron filings any quantity, the finer they are the lefs trouble they will give “ in the preparation, and fprinkle them with vinegar, rubbing them together after it is added, that every part may be moiftened equally. Spread them in any cool place, “ where they may be free from duft, on a board or paper, and let them remain there till the moifture appear to be dried away, “ and then try if they be fo corroded as to bear powdering. If they be found to be brought to a ftate that will admit this, it muft be performed on a porphyry ftone with ' ‘‘ a mullar, or in a glafs or agate mortar. But ‘‘ if they appear not fufficiently corroded, they muft again be moiftened with vinegar, and laid out as before, and, when become fit, powdered in this manner. The pow- dered ruft muft then be fifted through a fine fearce, and the grofler part, that will not ,pafs, moiftened again with the vinegar, wdiich muft be repeated till none of the ‘‘ iron, » ( 300 Of the Substances ‘‘ iron, worth further notice, remain uncor- roded. The whole muft then again be levigated, till it be a perfeftly impalpable powder, which will be then fit for ufe.” The iron, prepared thus by vinegar, is pro- per for making a tranfparent or glazing yellow in enamel, or for compounding with blues to form green colours. But this procefs Is greatly more troublefome and laborious than thofe below given, and is attended with no be- nefit in the produce, except that this ruft will afford a cooler or lefs red yellow than the others, and may therefore be of advantage, in forne particular cafes, for forming very bright greens. It has been ufed to calcine the rufl, pre- pared thus with vinegar, to form what is called the crocus inartis ; but it is a very injudicious method of proceeding; becaufe, where cal- cination is to be ufed, the vitriol, or the iron corroded by fulphur, are equally good, and fave a confiderable trouble and delay. Iron is fometimes calcined per fe^ that Is, without any mixture, by expofing the filings, fpread with a large furface, to the aftion of flame for a confiderable time, which converts the iron into a crocus martis^ that, when levi- gated, is fit for ufe. But this preparation is alfo troublefome and inconvenient, requiring a ftrong and continued fire; and, when made, affords nothing but what may be much eafier obtained by the methods below given. Iron USED IN Painting. 301 Iron is alfo calcined by means of fulphur, which 'mull be performed in the fame manner as was diredted above, page 295, for the calcined copper. There is not, neverthelefs, any difference betwixt this and the calcined vitriol. The precipitation and calcination of green vitriol are the moft expedient preparations of iron, and anfwer all the purpofes of the others fully, except in the inftance before mentioned of not producing quite fo cool a yellow as the ruft formed by vinegar. The precipitation of vitriol may be formed in the following manner. “ Take any quantity of green vitriol and diffolve it in water. Add to it gradually a “ folution of pearl-afhes in water, (which need not in this cafe be purified if the falts ‘‘ be clean) till no more effervefcence arife; ‘‘ and then pour off the fluid when the pre- “ cipitated powder has fettled. The remain- ing fluid, which cannot be poured off, may ‘‘ be feparated from the powder by means “ of a filter, and the powder then dried; ‘‘ for as the falts will be no way injurious to the enamel, there is no occafion for wafhing ‘‘ in this cafe.’’ This oker, or precipitated Iron, wdll nearly anfwer the fame end as the ruft by vinegar, and wdll afford a tranfparent yellow almoft as cool; this is therefore the beft, and much-the eafiefl preparation of iron for forming greens, by the admixture of blue. The 302 Of the Substances The calcined vitriol muft be prepared from crude vitriol, where a red colour is w^anted, in the fame manner as was before direded^ p. 51, for the fcarlet oker, which is itfelf in- deed the fubftance in this cafe wanted, and will either afford, with lefs flux, a red colour in enamel, verging to the orange, or with more flux, a tranfparent yellow of the w^armer caft. But where calcined iron is wanted for forming more purple teints, the precipitated oker, as produced by the above means, fhould be taken and calcined with a ftrong fire, till it acquire the degree of purple defired, to which it may be brought by a much fliorter calcination than any other preparation of iron. Antimony is ufed for producing a yellow colour in enamel, as well as the wd:iite before mentioned; and, indeed, it is the mofl: ufeful, and mofl ufed of any fubftance W'hatever for that purpofe. It is prepared only by leviga- tion, to which its texture, notwithftanding its being a femi-metal, very well fuits it. An orange colour, but not bright, may alfo be produced by antimony calcined with an equal weight or lefs of nitre, and then feparated from the fcoria that will furround it, and levigated. But as there are methods of compounding an orange colour from preparations necefiary for other purpofes, there is no great occafion to have recourfe to this. There is a great dif- ference in the antimony itfelf in different par- cels, fome being greatly debafed by mineral fulphur, and others .more free from it. That USED IK Painting. 303 IS beft which Is ftrlated, and has more the ap- pearance of metal, or rather feems formed from needles laid parallel to each other ; the blacker and more fpungy being more impreg- nated with crude fulphur. But antimony is fo cheap, that It Is of no confequence, if the better part only of any parcel be ufed, and the reft thrown away; and one fide in almoft every lump is good; as, in the fufing to fepa- rate it from the ore, the moft metalline part of courfe fubfides and finks to the bottom of the mafs. Glass of antimony is alfo ufed fome- times in enamel painting, being itfelf a fine tranfparent orange colour ; but as it wants body, it has no great effedl: but in compofitions. They w^ho have occafion for this glafs may purchafe it at fo eafy a rate as renders it fcarcely worth while to prepare it themfelves, being manu- fadlured at Venice, and elfewhere, in very large quantities, by thofe who make it their bufinefs. The only care fhould be, to choofe fuch as is not adulterated by the admixture of glafs of other kinds, which may be diftinguifhed by the force and deepnefs of the colour, or the want of them. Mercury is fometimes alfo ufed In enamel painting; but it requires to be prepared by fome chymical procefs before it can be ufed. There are two preparations already pradfifed ' for medicinal purpofes, which fit it alfo for enamel painting the beft of any. The pro- duce of one is called turpeth mineral; for which •504 Of the Substances which we have already given the procefs, p. 1085 by a careful treatment of which, a fine cool yellow may be produced in enamel. The other affords the red precipitate, which is a fine fcarlet red, but extremely tender with refped; to the fire. As this fubllance can be procured at a very moderate rate of thofe who vend it as a medicine, and requires a particular nicety in the operation, I fhall wave giving any procefs for it here, efpecially as every book which treats of the chymical pharmacy contains one; and, indeed, the ufe of both this and the turpeth mineral demand fo delicate a management' of the fire, and are fo liable to have their efFe£t deftroyed by a fecond burn- ing, (if, as is fo frequently the cafe, it fhould be neceffary) that I cannot greatly recommend them in preference to other preparations, which will anfwer the fame ends nearly as well with eafe and fafety. Orpiment has been alfo ufed in enamel for producing a yellow colour; but it is very tender with regard to the fire, and requires fo foft a flux, while at the fame time antimony, properly managed, will fo well fupply the place of it, that it is rarely ufed. Powdered bricks have been alfo ufed for compounding yellow colours in enamel; but as they aft only in confequence of the oker they contain, they are certainly inferior to the prepared okers we have given, efpecially as they are liable to great impurities, and are harder, or require a greater force of flux than USED IN JOINTING. 32 1 the pure okers or cakined Iron. When they are ufed, they fhould be chofen of the red^ deft colour, the fofteft and evened texture, and intirely free from all ftones or cinders. The Windfor bricks, therefore, are much the beft that are to be procured here, as they an- fwer to the circumftances required much bet- ter than any other. Tartar is alfo ufed in forming enamel colours, though not from any tinging quality it has in itfelf, but for its effecfts in modifying magnefia, and fome other fubftances. The crude red tartar fhould be chofen for this pur- pofe, and requires no other preparation but to be freed from all impurities, and well levi- gated. Thefe are the feveral fubftances that are ma- terially neceflary for compofmg as well the grounds as colours and fluxes in enamel. There have been many others introduced into the pradtice of particular perfons, and fome indeed into more general ufe ; and the prepa- rations of thofe have been likewife greatly varied and multiplied. But what I have given are more than fufKcient for every purpofe; as all the variety of teints, with all the de- grees of the attendant qualities, may be pro- duced by a proper application to them; and the increafmg unneceflarily the number of fimples and original preparations can only lead to confufion and embarrafment. Whoever, VoL. I, X more- 322 Of the Substances moreover, acquires a moderate knowledge of the principles and fubjeds here laid before them, may eafily proceed to examine or ufe any other colouring fubftance which is fitted by its texture to endure the heat of vitrifica- tion. SECTION IV. Of the compouitding and preparing the fluxes for enamel painting* I N order to the underftanding, and confe- quently managing more advantageoufly the feveral compofions for fluxes, it will not be improper to inquire a little more particu- larly into the nature of the ingredients, and their operation on each other, as well as the proportion of power each has in producing its proper effed: ; fince, by this means, the feveral mixtures may be better adapted to the purpofe, on each occafion, by thofe who ufe them, when their nature and degree of efficacy is well underftood, than they poffibly can by any particular recipes, though, in order to give fuch an initiative knowledge of each par- ticular as may lead to proper experiments, I fhall fubjoin a complete fet of fuch recipes, as well for the preparation of thefe as the colours. There are two kinds of fubftances enter the compofition of enamel fluxes. The one the proper USED IN Painting. 32;; proper matter of the flux, being fuch bodies in- dued with a great propenfity to run into the vitreous fufion, or be converted into glafs, and which ad:, in this view, not merely in a paflive capacity, by becoming glafs them- felves, but, when become fo, changes and aflimilates other bodies to their own vitreous nature. This kind confifts of falts, lead, and arfenic. The other kind confifts of the correc- tives of thefe proper fluxings, which, with- out the admixture of fuch corredtives, would be found to have qualities that would deprave them for the feveral purpofes of enamel paint- ing. For fait, when vitrified alone, or with a fmall proportion of other bodies, are ftill liable to be diflblved by aqueous moifture; and glafs, under fuch circumftances, is ex- tremely apt to fuffer a corrofion by the air, and turn black and dull on its furface ; whence it is necelTary to combine fome other bodies with the falts, which may counterad; thefe bad tendencies, and render the compofition dura- ble. Lead and arfenic, likewife, when formed into glafs, of which they compofe the prin- cipal part, are liable to corrofion by the air, and to acquire fpecks and a dull furface, which makes it neceffary to add fuch fubftances to them as will prevent this effed:. Thefe corredive bodies of the proper matter of, the flux, which therefore make the other kind of fubftances of which enamel fluxes are com- pofed, are calcined flints, fand, or fuch cal- carious mattery which being perfed:ly white, X 2 and 324 Of the Substances' and refiftlng, in a vitreous flate, the corroding^ or diffolving adion of all menftrua, give body and firmnefs to the fluxing compofitions with- out difcolouring, or any other way changing the proper fluxing qualities, except by dimi- nifhing, in a certain degree, their vitrifac- tive power, and confequently rendering them ibmewhat weaker as fluxes than they would be alone. The mofl: adlve flux amongft falts is borax ^ w^hich, indeed, poflefles this power in the greateft. degree hitherto known of any fiinple whatever. The next is Icad^ which vitrifies with a very moderate degree of heat, and aflimilates to glafs, with itfelf, not only many kinds of earth, but all metals and femi-me- tals, except gold and filver in their intire ftatc. Arfenic is the next powerful flux, only it requires to be fixed by conjoining it with fome other body already vitrified, otherwife it fubllmes and flies away before it arrives at the vitrifadive heat. The feveral kinds of falts have the next degree of fluxing power, and among them fea fait poflefles the greateft. But they are not fufficiently ftrong themfelves to form an enamel flux foft enough to be ufed in painting; though, as they are colourlefs, which is not the cafe of vitrified lead, they are very neceffary to be compounded with lead, or ufed in its place, alfifted by boraxy where abfence of every degree of colour is neceflTary in the flux. Of USED IN Painting. 3^S Cy' the general method of prfar'uig fluxes. The method of preparing the feveral fluxes below given is the fame for all. The ingre- dients are to be well levigated with each other on a porphyry ftone, with a mullar of the fame matter, or of flint; or in a mortar of agate, or flint with an agate peflle, except where great quantities are to be prepared, in which cafe a mortar and peflle of the com- mon green glafs may be previoufly ufed for the fake of expedition. Being levigated, the matter fliould be put into pots of a proper fize, made of the fub- ftances, and in the manner .dire(Ted p. 273, and placed in a furnace where the heat is nearly that of a flrong culinary fire. For though a greater heat accelerates the vitrification, yet it renders the compofition harder, that is, weak- ens its fluxing power. When the vitrification is perfedt, which muft be known by the mat- ter’s becoming tranfparent, and free from air bubbles, it muft be taken from the fire, and poured out on an iron plate clear of any ruft. Then being powdered when cold, if the operation appear to have fucceeded, the pro- duce muft be kept for ufe ; but, if any tur*f bidnefs or foulnefs appear in particular parts, fuch parts fliould be picked out; or, if the whole be depraved with fpecks, or be cloudy, it fliould be again powdered and fufed, and then treated in the fame manner as at firft. X 3 - Of 326 Of the Substances Of glafs of lead. Simple glafs of lead, though a foft flux, Is not proper to he ufed alone; for the air, as was before mentioned, corroding it, a cloudi- nefs or fkim is apt to come on the furface, which gives a dulnefs and unpleafing appear- ance to the enamel, and fometimes fouls the brighter colours. As this glafs forms, how- ever, in a more compound ftate, one of the beft fluxes, the preparation of it Amply is ne- cefi'ary to be knov/n; for though the ingre- dients which 'compofe it might be fluxed to- gether with the other ingredients of the fluxes and colours, yet it is better to vitrify it fepa- rately flrft, and confequently purify it from thofe feculences and drofs which are apt to be formed in the flrfl: fufion. The manner of preparing glafs of lead, fuch as is to be under- llood to be meant in the fucceeding recipes, is as follows : “ Take of red lead two pounds, of flints calcined , and levigated as above directed, p. 280, or, in default of flints, of white land ground to flne powder, one pound ; vitrify and prepare them according to thQ general diredions before given.’* Compofition of a fux^ for common purpofes^ mo-y deratcly foft, I. “ Take of the glafs of lead one pound, of pearl-afhes Ax ounces, of fea fait two ounces. Treat USED IN Painting. 327 Treat them according to the general direc- tions for fluxes.’’ This is a very cheap flux, and will ferve extremely well for all purpofes where a tinge of yellow will not be injurious, or where the flux is not required to be extremely foft. Compofition of a foft fu^ for commo 7 i pirrpofes. N° 2. Take of the glafs of lead one pound, of pearl-afhes fix ounces, or borax four ounces, of arfenic one ounce. Proceed according to the general directions.” This is a very foft flux, and will vitrify a very large proportion of zalfer, or the precipi- tated powders, or calxes of metals. It is there- fore very proper for forming ftrong glazing colours, where harder fluxes are ufed with the reft, or for all purpofes where there is any neceflity for, or convenience in, burning the enamel with a flighter heat. Compofition of a tranfparent fux^ perfcdily white i and moderately foft, N-3. ‘‘ Take of common flint glafs powdered ‘‘ one pound, of pearl-afhes fix ounces, of fea fait two ounces, of borax one ounce. Pro- ceed as with the others.” This is proper for purples, crimfons, and fuch colours as are injured by any tinge of yel- X 4 lowi 328 Of the Substances low; as alfo for white, where purity is re- quired. It is rather harder than N® i, above given, but that may be corre<5Ied, where ne- ceffary, by any intermediate proportion of bo- rax between that given here and in the next. Compofition of a iranfparent fhnc perfeEily •white ^ and very foft, N"4. ‘‘ Take of common flint glafs powdered one pound, of pearl-afhes and borax each ‘‘ four ounces, of common lalt and arfenic each two ounces. Mix and flux them accord- ing to the general directions. But they muft remain in fufion longer, if any cloudi- nefs appear in confequence of the arfenic; which, though indued with a ftrong fluxing power, when in a vitreous ftate, does not neverthelefs vitrify, when the proportion is large with refpeCt to the other ingredients, fo quickly as they do, but gives a milky turbidnefs to the glafs till its own vitrifi- “ cation be perfeCt.” This is a very foft flux, and proper in all cafes, w^here fuch is neceffary, and the yellow tinge of the common foft flux above given would be detrimental. But the proportion of borax or arfenic may be varied as is above in- timated, either in this, or any of the other compofitions; or the arfenic and fea fait omitted according to the occafion. The pro- portions USED IN Painting. 329 portions of the other Ingredients fhould how- ever be adhered to, becaufe they are fuch as are mofl: advantageous with refpeft to the re- lations the qualities of each have to the other, and to the general intention. Of the 'white Venetian glafs as a flux. The principles on which fluxes are formed, and the nature of the fubftances proper to form them, having been very little under- flood, or indeed known, and the compofitions of the fluxes ufed having been kept fecret at Venice and Drefden, or by the few elfe- where who - have learnt them, it has been almoft uhiverfKly pradifed to ufe the white Venetian glafs as a flux. It has not, never- thelefs, that I know of, been lately imported Into this country, or any where regularly fold for this purpofe, but obtained by thofe who ufe it, by feeking out drinking glaffes, fmall vafes, or other fuch wrought pieces. Indeed I am in fome doubt Vvhether the fame glafs be now made at Venice, or elfewhere, but that w^hat is found is the remains of a kind formerly made, and difperfed all over Europe, wrhile the Venetians had the monopoly of fuch fort of manufadures wholly in their hands. This glafs is of a moderate foftnefs, and agrees very well wdth the colours in general; but having a milky turbidnefs, muft certainly be lefs advantageous to the tranf- parent or glazing colours than afflux per- 330 Of the Substakces fe£lly pellucid. The compofition of this glafs is not known at prefent to any here, for all the kinds defcribed by Neri feem much harder than this; though, as he gave all the compo- fitions then in ufe in Italy, and particularly underftood the Venetian manufacture, one might have expeCted he would have taken it in, as it muft have been made in very large quantities, from the copious remains of it we find in every part of Europe. This glafs may be known from any common kind by its having a milky turbidnefs, by which it may be diftinguiflied from all tranfparent forts, and by its yet coming much nearer to tranf- parency than any of the white opake kinds made at prefent. SECTION V. Of the compofition and preparation of white enamel for grounds and other purpofes. Compofition of common white enamel of moderate hardnefsn N® I. | "*AKE of glafs of lead one pound, of JL pearl-afhes and calx of tin each half a pound. The ingredients being thoroughly mixt. USED IN Painting. 331 mixt, by grinding them together on a por- phyry ftone, or by pounding and rubbing them well in a glafs mortar, put them into a proper melting pot, and give them a mo- derate heat till they incorporate thoroughly: but the fufion fhould not be either ftrong “ or long continued; for, if the glafs be perfed:ly liquefied, the calx of tin is apt to “ fubfide; and, confequently, to be unequally mixt in the mafs when cold. When the heat has had its due efted;, take the pot out of the fire, and pour the matter on a clean iron .plate, or into molds to form it into cakes, like the Venetian enamel, if it be fo defired.” This is fofter than the common white glafs, and about the degree of the common Venetian enamel. It is not very white, nor confequently fit for dial-plates, or other purpofes where the clearnefs of colour is required; but for paintings where it will be covered, or where pure white is not neceiTary, it will extremely w^ell anfwer all purpofes. Compofition of a very foft white enamel for common purpofes^ N®. 2. Take of glafs of lead one pound, of pearl- allies and calx of tin each half a pound, of borax and common fait each two ounces, and of arfenic one ounce. Treat them .as the 332 Of the Substances the foregoing; but be very fparing of the heat, and take the matter out of the fire as foon as it forms one homogeneous mafs, ‘‘ without fuffering it to fufe til! it be perfedlly fluid.” This is very foft, and will fcarcely admit, if ufed as a ground, the fluxing of colours upon it, without running into fufion itfelf with the fame heat; and, confequently, mixing with and depraving them; but where it is ufed without any view to painting over it, either in its own proper colour, or mixed with any other, particularly with black, it is preferable to hard enamel, becaufe it can be wrought with a much lefs heat, and, confequently, is both more eafy to be managed, and lefs liable to give oceafion to the warping or calcining the metal plates, or other bodies, on which it is laid. Compofitlon of enamel of moderate hardnefs^ bu^ more perfebily white. N“ 3- Take of flint glafs one pound, of calx of tin or putty, of the firft degree of whitenefs, half a pound, of pearl-alhes and common fait each four ounces, and of borax one ounce. Treat them as the foregoing; but ‘‘ the fire may be more freely ufed than in the cafe of the laft.” This enamel, if the calx of tin or putty be perfectly good, will be very white, and is pro^ per USED IN Painting. 333 per for dial-plates^ or other fuch ufes, where the purity of the white ground is eflentlal to the value of the work. It will alfo bear colours very well, where fuch a ground is wanted for any painting ; but if it be found too foft, in proportion to the fluxes of the colours, it may be prepared of a greater degree of hardnefs by omitting the borax. Compofitmi of a foft enamel more prerjecily white. 4. Take of flint glafs one pound, of pearl- afhes and common fait each four ounces, of borax two ounces, and of arfenic one ounce. “ Treat them according to the general direc- tion; but be fparing of the fire as with No 2.’’ This is too foft for a ground for colours, but is fit for any other purpofes where enamel of greater whitenefs is required, as alfo for ufing with other colours where there is occafion to paint with white. Compofition of a very foft enameU of the frf degree of whiten proper for pamting. 5. Take of flint glafs one pound, of anti- mony, calcined to perfedl whitenefs, accord- “ ing to the diredions in p. 258, or of tin, “ calcined with nitre, according to the direc- tions in p. 283, half a pound; of pearhafhes ‘‘ and 334 Substances and common fait each three ounces, of borax three ounces, and of arfenic one ounce* Proceed according to the general direc- tions; but be very careful to avoid fuch a “ fufion as will render the matter perfedly liquid.’^ This compofitlon produces an enamel ex- tremely white and very foft, and is proper to ufe in painting for linen, or other objeds where ftrong touches of white are advan- tageous. If it be found too foft, according to the tone of the fluxes for the other colours, the arfenic may he omitted, and part of the borax; but it will, in this proportion, fuit the other colours, when the fluxes are judlcioufly adapted to each kind. Of coimnon white glafs as an enamel groujid*. The white glafs made at Mr. Bowie’s glafs- houfe In Southwark, is frequently ufed for the grounds of enamel dial-plates, and other painted works. It is a glafs rendered of an opake whitenefs by the admixture of a large proportion of arfenic, which, intimately mixed with the glafs by a flight fufion, not fiifficient to produce a vitrific incorporation, retains its opacity, and confequently gives a white- nefs to the glafs; though, if the fufion were long enough continued, it would aflimilate with the glafs, and the whole mafs .confe- quently become perfedly tranfparent. This tendency to lofe its opacity, of courfe renders USED IK Painting. 33^ the ufe of it as a ground enamel more limited and difficult; becaufe where colours are to be iifed which require repeated burning, or to be continued a longer time in the fire, there will be a great hazard of changing the opake whitenefs Into tranfparency, or fuch an ap- proach to it as deftroys the effed: of the ground; and, indeed, in the burning it, even as a ground, particular care is required in the manner. It is likewife harder than the Ve- netian common glafs, or any of the above pre- ' parations of ground enamel, as likewife much more brittle, and liable to crack and peel off from the body painted with it ; but, notwith- ftanding thefe difadvantages, its low price, and great wffiitenefs, which much furpafles that of the Venetian, or any enamel commonly to be had, have recommended it to the pradice of many wffio are concerned in cheaper works of enamel. SECT, Of the Substances CHAP. VI. Of the compofition of the colouring fub- fiances^ together with the proper fluxes^ in order to the painting with all the variety of colours in enameL Compofition for the fcarlet or crimfon ref im^ properly called purple of gold* I. T^AKE of the fluxes, N° i, or 2, or i Venetian glafs, fix parts, and of the “ calx caffii^ or precipitate of gold by tin, as diredted p. 289, one part; mix them well together and paint with them.” This will produce a very fine crimfon colour, according to the teint of the precipitate of gold ufed; for it may be prepared very crimfon by the means above directed, as I have more than once feen, though, as it is com- monly prepared, it verges to the rofe or purple. If the effed of red be not ftrong enough, but the colour tend too much to tranf- parency, it may have a greater body given it by adding more of the precipitated gold. Com'^ Compojltion for tranfparent fcarlet^i or crimfon colour. 2 . “ Take the flux N° 2, fix parts, the preci- pitate of gold with tin one part Flux them “ together, with a flrong fire, till the whole appear a tranfparent deep red glafs. Then pour out the matter on a clean iron plate, ‘‘ and levigate it well, when it will be fit for painting.” This preparation will anfwer the end of lake in oil painting, either for glazing or making dark fhades of red. A greater quan- tity of the gold precipitate may be added where a flronger force of colour is defired to be had, and the compofition muft in that cafe be longer continued in fufion. But the flux will not always vitrify more than this proportion, fo as to render it perfedly tranf- parent. If this preparation be mixed, after it has been levigated, with a fixth part more of the gold precipitate, and ufed without a fecond fluxing,' it will give a very fine deep crimfon, extremely ferviceable in many cafes. Compoftion for d bright orange red. N° 3. P 0 :.. “ Take of the fluxes 2 or 4, two parts^; of red precipitate of mercury one part. Mix “ them for painting.” VoL. I. This Of the Substances Tills makes a very bright orange red, but Is very delicate, requiring only juft lb much heat as will run the parts of the flux together. It is therefore difficult in its ufe where harder compofitions are to be burnt with it. Compofttion fora cheaper^ hut fouler fcarlet red, “ Take of the flux i, two parts, and of the fcarlet okeras prepared in p. 51, one part. Mix them well together, and avoid too much or too long heat.’’ This is the common ted in China, and other enamel paintings. It may be enlivened by mixing one part of glafs of antimony with One part of the flux, inftead of ufing the flux alone. Compofition of a cheap crimfon, ' 4. Take of the flux No i, four parts, of magnelia one fourth of a part, and fufe them till the whole mafs be tranfparent. Mix them then with one part of copper calcined to rednefs, and paint with the compofition. Where this is required to be tranfparent, the calcined copper fhould be vitrified with the other ingredients ; but this requires great care to take the compo- fition out of the fire as foon as the vitrifica- tion is perfeded.” A little bsEii .IX Painting: 339 A little white enamel, or, what is better, a little of the tin calcined, by means of nitre, as in p. 283, may be added, to give the co- lour a body. But this neceiTarily dilutes the colour, and weakens the force of it. This red is very tender, and requires only fd much heat as will incorporate the fub- ftances together. But If it be found too foft for the tone of the fluxes of the colours, in- head of ufing the flux, flint glafs with a fmall part of flux may be employed for mixing with the magnefia. The management of this colour, is^ how- ever, fo diffieult and nice, where it is ufed in very light touches, that in nicer paintings it is better to ufe the precipitate of gold properly broken by the admixture of other colours, where a fouler crimfon is wanted, than to be troubled vflth watching this. But in grofler works, where the colours are ufed in great quantities, and laid on with a ftronger body, this becomes very ferviceable. In the recipes given for the red formed by calcined copper, it has been ufual to order an equal, or fome fuch proportion of red tartar. But where the glafs contains any lead, I am. apt to believe a rediuflion of it would follow, which would decompound the body of the flux, and render the compofition harder. If tartar be ufed, the flux ought to be formed therefore of glafs of falts. Y 2 Com-^ 340 Of THE Substances ■ Compofitio7i for pitik and rofe reds. N°5. Take any of the above compofitions, and add of any of the white enamels, or of the calx of tin prepared with nitre, oi‘ “ calx of antimony, as much as fliall be fuf- ficient to dilute the colour to the degree re- qulred.^’ Compofitlon for the brightef blue, N° 6. ‘‘ Take of the fluxes i or 2, or of the Venetian glafs fix parts, of the fineft ultramarine one part. Mix them well for painting. If a tranfparent blue be defired from ultramarine, a fixth or eighth part mufl: be added to the flux 2, and the mixture kept in fufion till the ultramarine be perfectly vitrified, and the whole become tranfparent.” If the body of colour be not fufficient, more ultramarine may be added ; but, in or- der to fpare it, a fmall proportion of zafFer, fluxed with four or fix times its weight of borax, may be added ; which, if the zafFer be perfectly good, will make the ultramarine appear much darker, without impairing its brightnefs* Com^ tJSED IN Painting, 341 Compofition of a lighter blue, N" 7. Take of the fluxes N"* 3, or 4, five parts> of ultramarine afties one part. Mix them for painting.’’ This is iifed by thofe who do not know the proper manner of ufing zaffer; but as the pure ultramarine afhes have a ftrong tinge of the red, and are never of the firft degree of brightfiefs, the fame effed:, or indeed a fu- perior one, may be produced by the compofi- tions below given. If the ultramarine afhes are adulterated with copper, as is moft frequently the cafe, a green ^nd not a blue will be produced. Cheaper light tranfpare?it blue, N" 8. Take of the deepeft coloured common fmalt and ufe it Amply ; or, if it be too hard for the other colours, as frequently “ is the cafe, add to it a fmall proportion of calcined borax.” If the fmalt be good, the colour will not want brightnefs; but it will always be warm, and tending to the purple. Its cheapnefs is however a great recommendation in many cafes Y 3 Com^ 342 Of the Substances Compofition of a deep tranf parent blue. N° 9. ‘‘ Take of any of the fluxes four parts, of zaffer one part. Mix and fufe them with a ftrong fire till the whole mafs be per- fectly tranfparent ; but, if the quantity of flux be not fufficient to yitrify the zaffer, add more, or a fmall proportion of borax. When the vitrification of the whole is per- feft, pour out the compofition, and levi- gate it for ufe.” This will produce a very fine tranfparent blue; and, being extremely deep, will make very ftrong fhades, and give the efFeG of blacknefs, where there is a ftrong body of it laid on. This may be done with lefs zaffer, when a lefs ftrong effefl: of the colour is wanted, Compofition of a very dark tranfparent blue, N° 10. “ Take of the fine Saxon fmalt, mentioned p. 288, and mix with, it one fourth of its “ weight of calcined borax, or one third of its weight of purified pearl-afhes.” This will run eafily, and will produce a very fine dark blue of the deepefl hue. But where this kind of fmalt cannot be obtained, compofition N° 9, muft fupply its place ; and if USED IN Painting. 343 if the zafrer be good, will not be a bad fub-^ ilitute; but it cannot be expected to have the full brightnefs of ultramarine, Compofitiofi of a fiy blue, N® II. Take of any of the above preparations^ and add of any of the white enamels, or calxes of tin or antimony, as much as wilf be fufficient to produce a blue of that light- ‘‘ nefs which may be wanted.” By forming a blue in this manner, from the compofition 6, the effeft of the ultra- marine afhes may be fully produced as is above intimated, without the defeds that are ge- nerally found in them. Compoftion of a%ure blue from copper, N"" 12. Take of the fluxes 3, or 4, five parts, of copper calcined to a purple colour and of zafter each one part. Mix and flux them well together, and then levigate with the mixture, of the calx of antimony or tin, calcined by nitre, one part, and keep the matter for painting.” This Is fo precarious with refped to the fuccefs, that it is rarely ufed ; ' but it will fometimes produce a good blue, and is then cooler and. better -for. fome purpofes than the >; Y 4 blues 344 Substances blues formed either of zaffer and white, Of the ultramarine afhes. Compofition of a bright opake full yellow, N° 13. Take of the fluxes N° i, or 2, four parts, of filver calcined with fulphur, as in p. 294, and of antimony each one part. Mix and flux them well together till the whole be perfectly vitrified. Then levigate with “ them, one part of antimony or tin, cal- cined by means of nitre, and keep the mat- ‘‘ ter for painting.^* This is a full true yellow, and the brlghteft coloured compofition that can be ufed. It may be made deeper by diminilhing the pro- portion of the calx of antimony or tin. Compofition of a bright tranfparent yellow^ 14. Take of the fluxes N® i, or 2, fix parts, of calcined filver two parts, and of anti- ‘‘ mony one half part. Flux them well till V the whole be tranfparent ; and then levi- gate the colour for ufe. Where great tranf- ‘‘ parency is wanted, the antimony may be omitted.’* This is a very deep bright yellow; and pro- per for {hades or glazing, where great force and purity of colour is required ; but for mofl purpofes the cheaper tranfparent yellow will an- USED IN Painting. 345 anfwer the fame end, not being greatly faulty in point of brightnefs* Comp ofit ion of a bright tranfparcnt yellow from ftilver and iron, 15. ^ Proceed as in the above, only inftead of the antimony take the precipitated iron as obtained from vitriol, according to the di- ‘‘ red;ions in p. 301.” This will be more tranfparent in general than the fame preparation with antimony; which, differing in the proportion of crude fulphur it contains, does not always fubmit to be ‘vitrified to a greater degree of tranf- parency. The yellow prepared in this man- ner will likev^ife be very cool and true, and confequently proper for forming fome kinds of greens. f Compofition of a cheaper opake full yellow, N° 16. Take of the fluxes N® i, or 2, or Ve- netian glafs, fix parts, of antimony one part, and of the iron precipitated from vi- triol half a part. Mix and flux them well together till the matter be thoroughly vi- ‘‘ trifled, and then levigate them with one part of tin calcined to whitenefs.^’ This will differ only from the yellov/ of N® 13, in not being quite fo bright and full, but 346 Of the Substances but will, neverthelefs, be a very ftrong pure yellow, and fit for all ufes where the greateft brightnefs is not requifite, Compofition of a warmer opake yellow, N° 17. Proceed as In the above, only inftead of the precipitated iron take the fcarlet oker prepared as in p. 51/’ Compofition of a cheaper iranf parent warm deep yellow to anfwer the purpofes of brown pink, 18. Take of the fluxes N° i, or 2, fix parts, and of, the precipitated iron one part; mix and fufe them in a flrong fire till the mafs be tranfparent,” This will verge towards the orange, but will not be fufficlently bright to anfwer the purpofe of a pure yellow. It is, however, extremely valuable for fhading yellow, and other ufes where a brown is required. Compofition of a warmer tranf parent yellow^ for the fame purpofes as the preceding, N° 19. Take of the fluxes N° i, or 2, fix parts, of fcarlet oker one part, and of glafs of antimony half a part ; mix and fufe them till the mafs be tranfparent,” This USED IN Painting. 347 This differs from the laft only in verging fomewhat more to the red. Compoftiion of a tranf parent yellow from orpime?it, N° 20. Take of the flux No 2, three parts, and of the refined orpiment, or King’s yellow, one part ; mix them by levigation for ufe.” This compofitlon is extremely tender, and muft have no more- fire than will juft make the parts of the flux cohere. If this yellow be defired warmer, a little glafs of antimony may be added, or a pro- portion of red orpiment may be ufed with the yellow. Compofitlon of lighter yellozvs^ 21. Add to any of the above common calx of tin or putty; or, if great brightnefs be neceflary, the calx of tin or antimony calcined by mean^ of nitre.” Compofitlon. of a very bright opake green, 22. Take of ultramarine and yellow, N° 13, each one part, of the fluxes N° i, or 2, two parts. Mix them well^ together for ' ,painting.” Qoni’f. 348 Of the Substances Gompofition of a bright tranf parent green. N® 2J. ‘‘ Take of the fluxes N° i or 2, fix parts, and of copper precipitated by alkaline falts ^ one part. Mix and flux them till the mafs be tranfparent.” This will be a very fine deep green, bur Inclining to the blue, which may be eafilr correfted, when not agreeable to the purpofe. by the adding a proper quantity of the tranf- parent yellows N° 14 or 15.. Compofumi of a bright tranfpavent green by mixture. N" 24. Take of th^ yellow 15, and of the blue N° 9, equal parts. Levigate them well together for ufe.’’ Cheaper eampofltion of an opake grecn^ N" 25. Take of the ftuxeaN^^ \ or 2, fix parts, ‘‘ of copper calcined to a purple colour, ‘‘ and of the opake yellow N° 16, each one part. . Mix and flux them well, and then levigate them for ufe with one part of the calx of tin.’* Cheaper USED IN Painting. 349 Cheaper cornpofition of an opake green by mirdure, N^. 26. Take of the yellow N° 16, and the blue ‘‘ 9, each equal parts. By varying the proportion of thefe mixtures, fea greens, grafs green, or any other teints, may be produced at will. Cornpofition for lighter greens. 27. Add the calxes of tin or antimony to any ‘‘ of the above, in the proportion the light- “ nefs of the colour requires.’’ Cornpofition for a bright orange colour. 28. Take of the yellow N° 14, two parts, of the red N° i, one part, and of the yellow N° II, half a part. Levigate them together ‘‘ for ufe.” N. B* The compofitions which are not directed to be fufed when ufed alone, muft not undergo any in the mixtures to be made of them, but muft only be levigated with the other ingredients, and ufed for painting in that ftate. Com-' 350 Of the Substances Coinpofition for a bright tra^if parent orangei No 29: ‘‘ Take of the red N° 2, and of the yellow 14, equal parts. Mix them well to-^ gether.^’ Compcfitlon for lighter tranfparcnt orange extremely bright, N° 36. “ Take of the above and glafs of anti- mony equal parts. Levigate and mix them ‘‘ for ufe.” When glafs of antimony is ufed, the fire tnuft be fpared both as to time and degree. Compofition of a cheaper tranfparcnt orafige, 31. Take of the fluxes N° 1, or 2, fix partSj» of copper calcined to rednefs one part, and “ of red tartar one part ; flux them till the matter become tranfparcnt, but avoids if poffible, continuance in the fire a moment longer; levigate it till It appear red, and mix with it an equal part of glafs of anti- monyf’ Compofition 35 J USED IN Painting. Compofjlon of a bright op ake purple. N° 32. Take of the red N® i, and the blues N° 6 and 9, each half a part. Mix them ‘‘ for life.” Covipofition of a bright tranf parent purple. 33- “ Take of the red N° 2, and of the blue N"" 9. Mix them for ufe.” Compofition of a cheaper opake purple. 34. ‘‘ Take of the fluxes N° 3, or 4, fix parts, “ of zaffer one part, and of magnefia half a ^ part; fufe them with a ftrong heat till the whole be tranfparent, and then add of the red N° 4, one part, and of the calx of tin half a part. Mix and levigate them well together for ufe.” Compofition of a cheaper tranfparent purple, 35- Take of the fluxes N° 3, or 4, fix parts, of magnefia one half part, and of zaffer one fixth of a part. If a red purple be wanted, omit the zaffer.” This 352 Or THE Substances This, and the foregoing, may both be varied, either to a more red or a mofe blue purple, by diminifliing or increafmg the pro- portion of zaffer. If the lafl: be wanted more red, it may be mixed with a proper quantity of the glafs of antimony. Compofition of an opake brown colour Indming to yed. N" 36. Take of the red N° 3, four parts, and of “ the blue N° 9, one part. Mix them for ufe.’^ Compofition of a tranfparent red brown colour, 37 - ^ “ Take of the purple 33, and glafs of antimony equal parts, and of the yellow N° 1 9, one fifth of a part. Levigate them ‘‘ together for ufe.’^ Compofition of an opake olive browH colour, 38. Take of the yellow 16, two parts, of the blue N° 9, half a part, and of the red N° 3, a fourth of a part. Levigate them together for ufe.’^ CompofttioH USED IN Painting. iS3 ' Compojition of a tranfparent olive brown colour. N° 39. “ Take of the yellow 18, one paft, and of the blue N° 9, and glafs of antimony, “ each half a part. Levigate them together for ufe.” Thefe may all be varied by changing the proportions of the ingredients, or they may be converted into different teints of light . browns by adding the due quantities of calx of tin, which may be commixt with them 'when the mixture is made of the other ingre- diefits, or afterwards. Compofition of black moderately hard^ N040. .Take of the flux N° fix parts, of zaf- fer one part, of glafs of antimony half a part, and of the fcarlet oker and mag- nefia each a fourth of a part. Mix and fufe them till the matter become a clear black . ‘‘ of the deepeft call.” Compofition of a black very foft. ' N°4i. Subftitute flux 2, inflead of N© t, and proceed as in the laft.’’ , VoL. L Z ' This 5J4 Oft h e So b s t a n c e s This compofition is extremely well accom-^ modated to the painting enamel dial-plates, or painting on enamel or China grounds in the manner of prints, or chiaro obfcuro. For as it will run with a very fmajl degree of heat, the flightefl: touches may be brought to fliew themfelves perfedbly without the leaft hazard of fufing the ground, fo as to run them toge- ther. The above compofitlons may be diverfified by recompounding them v/ith each other, fo as to form all the variety 'of teints to fuit every purpofe ; and the hardnefs or foftnefs of the fluxes may be likewile adapted to each occa- fion by mixing them together. With refpe£t to the proportions in every compofition, they may likewife be varied according to, the pur- pofes they are ufed for, there being no po- fitive rules to be laid dovim in thefe matters with relation to quantities ; for the different degrees in which different parcels of the in- gredients poflefs the requifite qualities, as well as many other' circumftances, prevent the effefl: from being the fame, even in com- pofitions exactly alike, as far as regards the quantities. I have hov/ever endeavoured to give fome leading proportions of each kind, by which thfe neceffary mixtures may be ad- jufted according to every occafion, by a flight confideration on the properties of the Ingre- dknts> tJSED IN Painting. 355 dients, which I have to this end previouny explained. It is by this knowledge only, and a proper occafional application to it, that any artift can ever arrive at great perfedtion in the ufe of enamel colours 5 for the want of it has in general obliged everi the moft Ikilful and experienced, who work in enamel^ to adhere in many cafes implicitly and blindly to the ftridl forms of recipes, where the pre- parations have by no i^eans been fo well adapted to their purpofes as they might have been by flight alterations. SECTION VIL Of the manner ing the enamel grounds. T H E matter of the enamel muft be fird finely levigated and fearced, and the body to be enamelled fliould be made perfedly clean. The enamel muft be then laid on as ^ven as poflible by a brufh or pencil, being firft tempered with oil of fpike, and the dif- tance of time betwnxt the laying on the ground and burning the piece fhould not be too great, becaufe the oil will exhale and leave the matter of the enamel a dry incohering powder, which will be liable to be rubbed or fhaken off by the leaft violence. This is the common me- thod; but there is a much better way of ma- Z 2 naging of laying on and burn-^ 3 5 ‘5 O F T I I E S U B S T A N c £ S naging this part of the work by means' of ^ fearce, in which the enamel is fpread with very little trouble, arid the greateft part of thd oil of fpike laved. The method of perform- ing this is, to rub the furface to be enamelled over with oil of fpike; and then, being laid ori a flieet of paper or piece of leather, to fave that part of the enamel which does not fall on a proper objeQ:, to fearce the matter upon the piled furface till it lie of a proper thicknefs^ But great care mtift be taken in this method of proceeding not to {hake or move too for- cibly the pieces of work thus covered with the powdered enamel. It is ufual to add oil of turpentine to the oils of fpike or lavender, in order to make them go further, and fave the ex.pence aV tending the free ufe of them ; and others add alfo a little olive or linfeed oil, or fome, in the place of them, crude turpentine. - The ufe of the fpirit of turpentine is very, allov/- able, for it is the fame for this purpofe as the oils of fpike or lavender, except that it .wants the glutinous quality which m.akes them ferviceable in fpreading the enamel. But with refpedt to the ufe of the phs of olive and linfeed, or any other fubftantial oil, it is very detrimental, tending to reduce the metalline calxes, and leaving a fmall pro- .portlon of black coal or afhes, which muft neceffarily injure the white colour of the Whea USED IN Painting. 357 Whea plates, as in the cafe of pictures, dial-plates, &c. are to be enamelled, they fhould always be made convex on the outfide, and concave within ; and all pieces of ena- mel formed of metal, where the figure does not admit of their being thick and folid, fhould be of the fame kind or form ; other- wife they will be very apt to warp in the heat, and cannot be brought ftraight, after they are taken out of the fire, without ^:racking the enamel. For this reafon, likewlfe, it is pro- per 'to enamel, the work all over, as well on the yn'ong as right fides, to prevent the heat from calcining the metal, which would both contribute to its warping and weaken the texture of it. ^Fhe enarnel being laid on the body to be ehamelled, . when the fixt muffle is ufed the piece nnuft be gently lifted on to the falfe bot- tom, and put in that ftate into the muffle fixt in the furnace defcribed p. 268, by thrufting the falfe bottom into it as far as it will go. Fut it is beft to defer this till the fire be per- fedlly in order, which may be known by putting a bit of tile or China with fome enamel oh it of the fame tone with that ufed as a proof ; and another proof of the fame kind may be alfo put along with the work into the muffle, which, being taken out, may fliew how the operation proceeds. When confiderable quantities of pieces are to be enamelled, as in the cafe of manufac- tures, 'inftead of putting' them into muffles, ‘ ■ '• " 3 coffins. 35B Of THE Substances coffins, or caffbons, fuch as are deferibed p. 276, are to be ufed for expedition, that a great number may be put into the fire toge-» ther. Where this method is to be purfued, the pieces of work to be enamelled are to be laid on the bottom of the coffin till it be covered ; and then the fecond flooring or falfe bottom is to be fixed in its place, and covered in the fame manner ^ after which the lid is to be put on, and well fecured, in the joints it forms with the fides of the coffin, by fire- lute. The proof, in this cafe, fhould be laid on the lid, on the part next the fide door of the furnace ; and it may be expedient, efpeci- aliy till the working of the furnace, and the kind of enamel ufed be very v/ell under- flood, to have two or three of thefe proofs. The enamel work being put thus into the coffins, they fhould be fet on the dome of the furnace, which muft be of the kind de- feribed p. 272, that they may be rnoderately heated before they be put into the furnace, wdiich would otherwife endanger their crack- ing. When they are fo heated, proof having been made by means of a fmall bit of China, or copper covered with the enamel, that the fire be of a due force, they mult be con- veyed into the furnace through the fide door, and muft reft on the pieces of fire-ftone placed for that purpofe on the flooring in the back part of the furnace. It is requifite, neverthelefs, , that the conveying them into the furnace fhould be managed with particu- USED IN Painting. 359 lar care, to prevent the fhaking off the ena- mel; and it miifl: be done by means of the peel or Inftrument deferibed page 277, adapted to this purpofe ; on which the cofnn being laid, it muff be gently thrufl into the furnace till the coffin be in its proper fitua- tion, with refpeft to diftance from the {ides of the furnace. Then the further end of the peel muft be turned ilowly towards the front of the furnace, the coffin being at the fame time ffioved off from it by means of the flat end of the tongs before deferibed, introduced through the door for feeding the fire, till it ftand intirely on the lire-ftones, after whicli the peel muft be withdrawn. The operation being finifhed, the peel muft be again intro- duced under the coffin, by raifing firft the neareft end of it, by means of the tongs, through the door in the front ; and after- wards the other parts gradually, till the peel fupport it. They muft then be drawn out together, and the coffin may be heft placed on the dome of the furnace, that, by cooling more gradually, the temper of the enamel may be improved. If it be required to burn a fingle piece or two in this kind of furnace, it may be done by means of the common or loofe muffle, de- feribed p. 274. Tn which cafe, the enamel work being laid on the bottom or flooring of the muffle, and the muffle put over it, the whole muft be conveyed into the furnace by means of the tongs with turned points, through Z 4 either 360 Of the Substances cither of the doors. A proof may be at the £ime time put in, on a piece of tile or fpare bottom of a muffle, and the proceedings in other refpeds may be the fame as with the fixt muffle, or the coffins. Where there is no furnace, and it is defired to burn enamel work on^an open hearth, pre- paration muft be made according to the direc- tions in p. 273 ; and the flooring of the muffle being laid at a proper diftance from the nozzle of the bellows, the work muft be laid on it, and covered with the muffle. This being done, pieces of charcoal muft be heaped over them ; and the fire being lighted, muft be blown up with the bellows till it be fufficient to flux the enamel, which muft be examined by the proof put into the fire along, with the work. The coals muft then be taken off from the muffle, and the muffle, with the flooring and enamelled work, re- moved out of the fire, but kept near it to prevent their cooling too faft. If there be more work to be burnt, another muffle, &c. may be immediately put in the place of the other, and the fame operation repeated ; for it is a matter of indifference whether the coals be burning when the work is put on the hearth, or kindled afterwards. Pit-coal may be ufed in the furnace, where enamel is burnt with the fixt muffle, or in coffins; which is indeed one principal con-^ veniency attending the ufe of them, as it faves a confiderable expence of charcoal. But USED IN Painting.' , , 361 But where the open muffle is ufed, charcoal alone fhould be employed, as the fumes of mineral coal are very detrimental to fome colours, .and deftrudive of the grounds, if whitened by arfenic, as the .common white glafs. S E C T I O N VIII. Of the manner of laying on aiid burn- mg the enamel colours^ I ^HE colours .being prepared as above ■ JL direfted, muft be reduced to powder by due levigation and waffling over, where they are required to be extremely fine, and there is' no‘ un vitrified -fait in the mixture. They muft then be tempered on a China or Dutch tile with oil of 'fpike or lavender, to which moft artlfts add likewife oil of turpen- pentine, and fome (but I think erroneoufly,, 'as I have before mentioned) a little linfeed or olive oil, and in this ftate they are to be ufed as paint of any other kind. But it fhould be avoided to mix more of the colours with the eflential oils than will be immediately ufed, becaufe they dry away extremely fall, and would not only- be wafted, but give a cohefion to the particles of the colours that 'would make them work lefs freely when again diluted with the oil. - The 362 Of THE Substances The colours being thus laid on the pieces t6 be painted, the proceeding muft be in all re- fpc^s the fame as with the grounds, in what-r 0ver manner they are to be burnt, either ir\ the muffles or coffins ; but greater nicety muil be obferved with refpedt to the fire, as the effeds of any error in that point are of much greater confequence in the burning the colours than the grounds, efpecially if the white of the grounds be formed from the calx of tin or antimony, and not arfenic. Pit-coal, as was above obferved, may be employed for burning as well the colours as the grounds where the muffle or coffins are ufed, or any other method purfued that wholly hinders the fmoke and fumes from having any accefs to the enamel. CHAP. XL of the method of painting on glafs, by burning, or with tranfparent colours that vitrify. SECT. I. Of the general nature of faintingon glafs with vitreous colours. T he art of painting on glafs with colours that vitrify has been efteemed, as far as regards the compofition and burning of the colours. , USED IN Painting. 363 colours, a myftery known perfeftly in the former ages, but loft in a great degree to the prefent times. It will appear, however, on due examination, that the cafe is far other- wife, and that the loft ftate of this art is owing to a very different caufe. It will be proved, that from default of artifls who cul- tivate this manner of painting, which probably \vouId not find many patrons at prefent, the dexterity or experience of making an advan- tageous ufe of the colours, fo as to form good pi(ffures, is alone wanting. But that as to the knowledge of the preparation of the colours, and the method of burning them, we poffefs them from the modern improvements of chymiffry in a much more extenfive degree than the former times. From whence it may be juftly concluded, that if any able painters were to apply themfelves to this way of working, undoubtedly much better pic- tures would be now produced than thcfe we fo much value as remains of an art of which we miftakenly fuppofe the methods of exe- cution at prefent loft. The great progrefs which Mr. Paterfon, in Effex-ftreet in the Strand, London, has made in an undertaking to efta- blifh a manufadlure of painted glafs, is an evident proof of this, feveral of the pieces produced by him exhibiting colours in an equal, or, perhaps, much greater perfedion than is found in the old paintings. For the fake therefore of others, who, from vievcs either of .profit of afhufement, 'may choofe to apply them-^ 364 Of the Substances themfelves to the reviving this fpecies of painting, I will give fiich lights into the nature of the fubjeci:, and the manner of purfuing it pradlically, as may enable any who can paint in oil, water, or other vehicles, foon tc become mafters of every thing peculiar tc this art. The painting with vitreous colours on glaP depends intlrely on the fame principles aa painting in enamel, and the manner of exe- cuting it is likewife the fame, except th?v in this the tranfparency of the colours being indifpenfibly requifite, no fubftances can be ufed to form them but fuch as vitrify perfectly, fince, without fuch vitrification, there can be no tranfparency. In other words, the whole myftery confifis in finding a fet of colours which are conftituted or compofed of fuch fubftances, as, by the admixture of other bodies, may promote their vitrification and fufion, are capable of being converted into glafs, and melting, when in that ftate, with lefs heat than will melt fuch other kinds of glafs as may be chofen for the ground or body to be painted ; in tempering thefe colours, fo as to make them proper to be , worked with a pencil; — and In burning, or reducing them by heat to a due ftate of fufion, without injuring or melting the glafs which conftitutes the body painted. _ • The circumftances of this art are fo analo- gous to thofe of the art of enamelling, that the fame means wilb as I have before intimated, ferve Used in Painting. 365 ferve for almoft every particular purpofe that Occurs in the profecution of it. 1 have there- fore but little occafion to enter into the de- tail either of the preparation of the colours or the ufe of them ; as it will be fufhcient to refer for moft particulars to what has been before faid, and only to flrew how the" methods there taught are applicable to this intention. SECTION II. Of glafs as a grotmd for paint mg with vitreous colours^ or by hur7ting. T he firft objeft to be regarded is the choice of grounds, wdiich fhould be plates, or veiTels of glafs, that is of the lirft de- gree of hardnefs, but at the fame time colour^ lefs, and without fpecks or weavings. The glafs which has thefe qualities, in the greateft degree, is the beft of the kinds of that iifed for windows, except fuch as is made for iooking-glafles, which, though moft colour- iefs and clear, is fofter, from the quantity bf borax and other fluxes which enter into ;its compofition. This fort, w-hich is called crown glafs, being a glafs of falts, is hard and 'tranfparent, and, being ready formed into plates, may confequently be had in a ftate proper for ufe. But w^here paintings of any 366 Of the Substances confequence are undertaken, a compofitlo^ ftill better fuited*to this purpofe ihould be employed, and the glafs wrought in the lame manner as the looking-glaft plates alQi^e are at prefent* When larger obj efts are to be depifted than the fize of fingle plates of glafs can contain, it is pradtifed to join feveral fquares together, which may be prepared for the painting in this manner : An even board of the lize of the whole of the plates laid together, fhould be fprinkled with a mixture of refm and pitch, which being melted by a flat iron held over it, the plates of glafs fhould be placed on the board as clofe to each other as poifible, and will be firmly fixed in the fituation they are laid, by the cement of refin and pitch as it cools* The glafs being fo fixt, muft b^ cleaned from any of the cement which may have run through the joints, firft by feraping, and after by rubbing -with fpirit of turpentine^ It will then be in a condition to be painteej with the ground colours, which being per^ formed, the plates may be taken off the boar4 by palling the flat iron heated over them at a proper diftance, which melting the cement, will let them loo.fe from the board, and they may then be burnt feparately without any inconvenience. They may then again be fixed on the board by means of the cement, and the painting completed, or proceeded with to the degree that requires another burning. SECT. USED IN Painting. 367 SECTION III. Of the fluxes and colours to be ufled in painting on glafs by burning. HE fame fubftances and manner of 1 preparation of fluxes and colours, ■which ferve for the purpofes of enamelling, will ferve equally well for the purpofes of painting on glafs by burning, except, as was before obferved, that all thofe bodies which will not perfeftly vitrify with fuch a force of flux and heat, as can be applied expediently with refped: to the glafs which forms the ground painted upon, muft be wholly omitted^ I ftiall therefore wave any particular in- flrudfions for the preparations of the fluxes and colours for this kind of painting as need- lefs repetition, and only enumerate the com- pofitions before given, which are proper to be tifed in each intention, by referring to the numbers prefixed, and fubjoining dire£lions for the particular treatment of them, when applied to this end, where any fuch is ne- eeJTary, The fluxes above given may be ufed as there prepared, and the fame difcretion muft be exercifed in adjufting the fh'onger or weaker to the ground as^ in the cafe of ena- msl. But if the hardeft of the two kinds of fluxes 368 Of the Substances fluxes fhould be found too foft in any inflance of its application,, it may be mixed with a due pr'oportion (which muft be found by trial) of the glafs of- the ground levigated to perfedl finenefs. To produce white in this kind of painting, the artifice of leaving the ground unpainted, or flightly obfcured where a fouler teint Is wanted, muft be ufed inftead of an aftual white body, ^ unmodified light * tranfmitted through the glafs fupplying the place of the reflected, and with the fame effed: in thefe circumftances as the refleded in the others. ' The lighter teints of all the colours, fuch as rofe, or pink colour of crimfon or fcarlet, —carnation of orange, — ftraw colour of yel-^ fow,-^and Tky colour of blue, muft be pro^ duced on the i'ame principle as white, by lay* ing on a lefs body of the colour, and coiife- quently fuffering it to be diluted by the light pafling through the glafs, inftead of that re^ flcded when bodies are mixt with the colours. The method of effeding this muft there^ fore be either to fpread the colours thinly on the ground, or when the compofitions -given appear to have yet too great a body, to dilute the colour- by mixing with it .an ad- ditional quantity of flux; or, if that render the mixture too foft, of levigated glafs the fame with the ground. In this manner, teints of all degrees of lightnefs may be pro- duced with equal : certainty and eafe, as by the addition .of' white in .. enamel .and other — kinds USED In painting. 369 kinds of painting ; and with this further ad^ vantage, that, if the colours are wanting in brightnefs, they yet bear up and fupport their force much more than thofe equally foul would in the other method of ufe. I fhall therefore omit any dire(ftions for the pro- ducing the diluted colours, (that is to fay, thofe which in other kinds of painting are to be formed by the addition of white) as like- wife all fuch others as are to be obtained by the compofitions above exhibited in treating of enamel, and proceed only to enumerate them, fubjoining only remarks on a cafe or two where they are peculiarly material. For a bright red, take 2, which will be crimfon or purple, according to the colour of the gold ufed ; — for a fouler red, take 4, but it is extremely tender, and muft not be run to perfed: fufion, nor continued long in the fire: — when a more fcarlet red is wanted, mix 2 with glafs of antimony. For a very bright blue, take N° 6, rendered perfectly tranfparent by fufion. But this being formed of ultramarine, which, when good, is of very high price, the ufe of it may in moft cafes be avoided by fubftituting the following compofitions, as the effed which colours have in this way of painting is fo ad- vantageous, even to thofe that are fouler, as renders brightnefs of lefs confequence than in any other cafe : — for a full blue, which will not be wanting in brightnefs, but rather in- clining to warmth, take N° 9 : — for a very VoL. I, A a cool the Substances cool blue, take N® 12, without the calx of antimony or tin: — for a truer blue than either of the lafi:, mix them in the proporrion that will produce the teint defirecl; but the blue of N° 12 verges more towards the green, than in proportion to the warmth of N® 9, when good. For every bright yellow, take N® 14, with" out the calx of antimony or tin, or N® 15 ; — • for a cheaper yellow, take N° 1 8 : for a cheap warm yellow, take 19. For a very bright green, take N° 18, pre- pared tranfparent, and 14, without anti7 mony, and mix them in that proportion which will render the green produced more inclining to the blue or yellow^, according to the occafion ; but this compofition being ex- penfive on account of the ultramarine in N° 14, and extremely great brightnefs being feldom elfential, as was before obferved, in thls kind of painting, the following, may, in moft cafes, be fubftituted for it to advantage : — for a cheaper bright green, take N° 23, vdth the addition of a proper quantity of N° 18, if it be required to incline more to the yellow ;“for a cheap, but lefs bright green, take 9 and 1 8, and mix them in the proportion to form the teint wanted. For a bright orange colour, take N° 2 and N« 14, without antimony : — for a cheaper, but more diluted orange, .take glafs of antimony, or a mixture of it with the foregoing : — for the diluted orange, cajled carnatio?!^ take glafs of tJSEi) IN PAINTli^G. 371 of antimony ten parts, the purple of N° 35, the zaffer being omitted in the preparation of it, one part, and mix them with the fluxes N° I, or 2, according to the body of the co- lour defired. For black, take N'' 40 or 41* For a red brown, take N° 37 for an. olive brown, take N° 39 : or foul any of the reds or yellows before given with a due proportion of black. From the combinations of fome of thefe, all the other variety of teints, both with re- fpedt to difference of hue or of lightnefs of colour, may be produced ; and, if the man- ner of painting fhould ever make it neceffary to diminifh the tranfparency of any of them, it may be done by adding a fmall quantity of any of the cbmpofitions for white enamel, in that proportion wihich will produce the effed: defired. SECTION IV. Of the manner of laying the colours on glafs grounds^ and burning them. T he fame affinity betwixt painting in enamel and on glafs by burning, which renders the preparation of the colours fo much the fame in both, extends itfelf alfo to the manner of laying the colours on the grounds, and burning them. A a 2 The 372 Of the Substance's The manner of tempering the colours, and painting with them on glafs, may therefore be exadlly the fame as was before directed for enamel ; the oils of fpike or lavender, and of turpentine, being alike fuitable in this cafe as in the other. But with refped: to the manner of burning the colours, though the general methods muft be the fame, yet a va- riation in certain particulars is in fome cafes neceflary, which I fliall therefore take no- tice of here. Smaller plates, or other figured bodies of glafs, may have the colours burnt in the fixt or loofe muffles; but larger plates require cof- fins, which may be formed in the fame man- ner as was dire£led for enamel. Though, as the form of the plates in this cafe are flat, and not convex, as is neceffary in the other, a number of layers or ftrata may be put into the fame coffin ; for it is not material how near the furfaces of the plates are to each other, provided they do not touch. The befl method of placing them to advar^tage in the coffins is to have iron plates adapted to the coffins. Thefe iron plates fhould have at every corner a fmall bit of iron going off at right angles, that the plates being put over each other may be fupported by thefe bits of iron afting as fhort pillars, and kept at fuch diftance from each other as will fuffer the glafs to lie betwixt them clear of all contad: with any other body, as far as re- gards their upper furface. The bottom plate, neverthe- USED IN Painting. 373 Tieverthelefs, muft have no pillars, as there will be nothing under it but the fubftance of the coffin. Thefe iron plates muft be made fo much bigger than the plates of glafs that the latter may lie upon them clear of the pillars, which ffiould reft on the iron plates under them, and not on the glafs. The iron plates being in this manner adapted to llie coffins, the bottom muft be put into it, and one of the plates of glafs laid upon that, but at fuch an exa^ft diftance from each fide that the pillars of the next iron plate may not reft upon it, but on the bare part of the iron plate under it. Another plate of glafs muft be then laid in the fame manner on this plate of iron, and the fame proceeding continued till the coffin be filled; then the lid muft be luted on, and the fame method obferved in all other particu- lars as was before directed for the burning enamel paintings. As there may be occafion, however, to ufe larger coffins for painted glafs than enamel, the dimenfions of the fur- nace muft, when fuch are wanted, be varied accordingly. But it will not in this cafe be neceffary to Inlarge the area of that part of the furnace which contains the fuel in depth; for. If it be increafed in length, from fide to fide, in proportion to the increafed magnitude of the coffins, it will fufficiently ajagment the body of fire. A a 3 CHAP. 574 Of the Substances CHAP, XIL Of gilding enamel and glafs by burning, T here are two methods of gilding enamel and glafs by burning or anneal- ing; the one is the producing a cohefion of the gold with the glafs or enamel, by the inter- mediate of a flux ; the other, by producing the like efFecfl; without any. But the prin- ciple is the fame neverthelefs in both; and is in fadt no other than the caufing the gold to adhere to the enamel or glafs, in confequence of the fufion or approach to that flate, either of the flux ufed, or the body of enamel or glafs itfelf, by which the gold is cemented to I'uch body. The flux, w^hen any is ufed, may be either fimple glafs of borax, or any of the above directed preparations of fluxes powdered. There are other differences likewife in the manner of this gilding, which refpe£t the ffate of the gold ; for it may be either ufed in the form of leaf gold, or in that of powder, either mechanically made, or by precipitation. When leaf gold is employed for . gilding enamel or glafs, in this way, without any flux, the enamel or glafs may be moiffened with a very w^eak folution of gum Arabic, and again dried. Being fo prepared, it fhould be breath- ed USED IN Painting. 375 ed upon till it become a little adhefive or ilicky, and then it fhould be laid upon a leaf of gold ; and if that be not fufficlent to cover it, the remaining part muft be laid on others, and the work afrefh breathed upon, if it ap- pear dry before the whole fiirface be gilded. When the gold is thus united to the enamel or glafs, by the cementing quality of the gum Arabic, which is ufed in order to keep it clofe and even to the body to be 'gilded, the work is ready for burning. If the leaf gold be ufed for gilding enamel or glafs with the aid of any flux, fuch flux, being finely levigated, fhould be tempered with a very weak folution of gum Arabic, and very thinly fpread on the part of the work to be gilded; and when the gum water is near dry, the leaf gold fhould be laid on the part thus prepared for it ; or if the work be kept beyond the time, it muft be breathed upon till it become ftlcky; the gold thus fixed on the work, it is in a ftate proper for burning. The advantage in omitting to ufe any flux is the rendering the gold lefs prominent and uneven, with refped; to the body gilded, which is in fome cafes material. But uulefs the ground, whether of enamel or glafs, be very foft, it requires a flrong heat to make the gold take hold of it; and this, in the cafe of enamel, endangers the ground, or any paint- ing upon it ; for, if the degree of heat be not Yery* nicely adjufted, the glafs or enamel vrill A a 4 run 376 Of the Substances run into too liquid a ftate in forne inftances^ and in others not be foftened fufEciently to cohere with the gold. The advantage of uling a flux lies in avoiding both thefe inconveni- encies; and particularly in the cafe of very hard glafs, the being certain that the gold will cake; which is, without this medium, fometimes dubious. But the flux lying under the gold, prevents it neceflarily from being fo level with the furface, or having the fame evennefs as when laid on the body itfelf without any in- termedium. Before vv^e fpeak of the method of iifing the gold In powder for gilding in this way, it is proper to mention the manner of preparing this powder, which may be befl: made in the following manner: “ Take any quantity of gold, and diflblve it in aqua regia^ according to the diredlons given in p. 289, in the procefs for making the calx cajfti^ or gold purple. When it is diflblvcd, make a precipitation of the gold, by putting into the folution flips of copper plate, which mufl be continued there till ‘‘ they no longer produce any effervefcence ‘‘ in the fluid. Thefe flips of copper being then taken out, and the gold adhering to ‘‘ them gently beaten off, the fluid muft be poured off from the precipitate, and frefli water put into its place, which muft be re- newed in like manner feveral times, till the fait formed by the copper and aqua re-> gla be intirely wafhed from the gold ; which USED IN Painting. 377 which being dried will be ready for ufe.” The precipitation may otherwife be made by adding a folution of Roman vitriol, or of copperas, or common green vitriol, to the fo- lution of gold, as was above dired:ed p. 293, and, indeed, this method is more expeditious, as the precipitation is inftantaneoufly made. In the prefent practice, the aurmn fiilminans^ or precipitation by alkaline falts, is made by thofe who gild glafs in the greatefi: perfection of any here, and the volatile alkali is employed for the precipitation by the chymift who pre- pares it for this purpofe; but when this kind of precipitate is chofen, the life of any flux mull be avoided, and a very confiderable degree of heat applied. Where it will not anfwer the trouble to pre- pare precipitated powders, that formed of leaf gold, in the manner below taught, may be ufed in its place ; but the precipitates arc more impalpable powders than can be obtained by any different method, and will take a finer burnifh than any other kind, when employed in this fort of gilding. The manner of ufing the precipitaf-es of gold in gilding of glafs or enamek except with refpeft to the aiirum fiilminans^ may be varied two ways as well as that of the leaf gold, viz. by adding to it, or omitting any flux. The convenience of ufing flux is the fame vrith that before mentioned, with the further advantage of rendering the gilding extremely durable, even to 378 Of the Substances to a degree of bearing to be fcraped; but the difadvantages are greater, for not lying under the gold, as in the other cafe, but being mixt with It, the flux deftroys the rich metalline look, and what is ftill much worfe, in many cafes prevents its taking a burnifli with the true luftre. In which way foever the powder is ufed, it is to be tempered with the oil of fplke, and worked as the enamel colours, and the quan-r tity of flux, when any is ufed, may be a third of the weight of the gold. When the gold is thus laid on, the work is ready for burning, which operation miift be performed in the fame manner, excepting what regards the de- grees of heat in all the different methods of gilding that have been here mentioned. In cafes w’^here the glafs is very hard, or where the opportunity of a llrong heat cannot be conveniently obtained, the expedient of ufing a flux in the following maniier may be adopted with great advantage, “ Grind glafs of borax to a fine powder* and, having tempered it with oil of fpike, lay It on the glafs where the gilding is to be “ made. Burn then the glafs with the degree of heat that will run the borax, and when it is cold apply the precipitate, or leaf gold, and burn it again as in other cafes.’* In this manner the advantage of a flux may .be gained, without the inconveniencies before mentioned, and the gold will take with a very gentle heat. It is, indeed, attended with double USED IN Painting. 379 double trouble and hazard ; but In the cafe of iifmg leaf gold, where a very good burnifli may be wanted, this method will perhaps be found, on the whole, the moft eligible, The manner of proceeding for burning or annealing the work in this kind of gilding is the lame with the treatment of the enamel, or glafs in the ufe of the colours, except that the pieces may either be put into the muffles orcoffins; or, in the cafe oftheglafs, if there be no painting, the operation may be performed in the naked fire. After the work is burnt, if it be defigned to be burnifhed, a proper luftre may be given to it by rubbing the gilded part with a dog’s tooth, or with a fine agate, or iron bur- nifher. of the taking off mezzotinto prints with oil, water, or varnifh colours. n|^HE painting on glafs by means of mezzo- i tinto prints is performed by transfer- ring the ink of the print to the furface of a glafs; and thus, having obtained a drawing, colour it by proper pigments tempered with oil, varnifh, or oil of a vehicle. This tranf- ferring the ink from the print to the glafs is C H A P. xm. painting upon them effedgd '’So Of the Substances cfteded by cementing the face of the prints to the liirface of the glafs, by means of fome glutinous body which will not dilTolve in water, and then deftroying the texture of the paper by water, fo that it may be rubbed intirely off from the cement upon the glafs, leaving, at the fame time, the whole of the ink of the print upon the cement and glafs, in the fame manner as if the original impreffion had been made there. The particular method of performing this Is as follows. Procure a piece of the bed: crown glafs, as near as poffible in fize to the print to be taken off, and varnifli it thinly over "with turpentine, rendered a little more fluid by the addition of oil of turpentine. Lay the print then on the glafs, beginning at one end, and preffing it gently down in every part in proceeding to the other. This is requifite to prevent any veficles of air being formed in the laying it on, by the paper touching the cement unequally in different parts,' and to fettle the whole more clofely to the glafs, it is well to pafs over it a wooden roller of about the diameter of tv/o Inches. Dry then the glafs, wuth the print thus laid upon it at the firft, till the turpentine be perfedfly hard, and afterwards molflen the paper well with watei* till it be thoroughly foaked. After this, rub off the paper intirely from the cement, by gently rolling it under the finger, and let it dry without any heat; the impreffion of the •USED IN Painting. 30 i print will be found perfect on the glafs, and may be painted over with either oil or varnifli colours. . The choice and treatment of the colours for painting in this way upon glafs, in either oil or varnifli, may be the fame as for any other methods, and it is therefore needlefs to enumerate any further particulars, but to refer to the parts of this work where the nature and preparation of them, as well as the manner of compofition witk the oils and varnifh, is before explained. CHAP. XIV. of colouring or wafliing maps, prints, See. T he colouring maps, or other prints, Is performed either by fpreading opake colours fo thinly on the fubjed: that the full effed of the printing may appear under them, or by ufing tranfparent colours, which ftain the ground and dry away without leaving any opake body; this laft method is called wq/Jjing\ The ufing opake colours, or fuch as have a folid body, in this way on prints, depends intirely on the kind of vehicle ufed; for if the colour be fufpended by the vehicle, that it can be fpread fo as to lie in The moft fparfed, and yet equal manner, it may be applied to this 382 Of the Substances this purpofe with fuccefs, and fuch as are very ftrong and bright, even though of the moll opake body, as vermilion, verditer, ultra- marine, or turpeth mineral, will anfwer the end. The bell method of doing this is the ufing the ifmglafs fize, as I before intimated, pre- pared with fugar or honey, according to the dired:ions given in p. 180, which makes the colours of this fort work fo freely that they may be diffufed almoft as eafily as the trans- parent kinds, and v/ith nearly as good effedt. The proportion of the llrength of the fize to each particular fort is likewife beforemen- tioned in p. 1 85, and it is therefore unneceffary to give it here; but it is proper in molt cafes to dilute the compofition more for the wafhing maps, and fpreading the colour over large furfaces, than when employed in paint- ing. Befides the opake, there are a number of colours which are femi-tranfparent, and yet have a body in a greater or lefs degree. Thefe are carmine, biftre, and gall-ftone, in the firll degree, with lake and Pruffian blue in the fecond ; all which may be treated in the fame manner, but require very dilFerent proportion in the ftrength of the fize; for the firll of thefe clafles ought to have as little as poffible of the fize, and the latter to be more copioufly furnilhed with it. The tranfparent colours Ihould be preferred for this purpofe to either of the other kinds, as their effeft is better, and they require no pre- USED IN Painting. 38 j preparation. The colours are, — -for rca\ red ink; — for blue ^ litmus; — forgrecn^ fap green, and verdigrife (in vinegar) ; — for yellow^ gam- boge, the yellow berry wafh, and turmeric wafh; — for purple^ the logwood walh, and archal; — for brown^ Spanifh liquorice; — and for blacky Indian ink. Thefe require only to be diflblved in water, which fhould be more copioully added where they are employed for wafhing prints, or colouring large grounds of any kind. With refped: to the manner of ufing any of thefe claffes in the colouring maps and prints, there is nothing more required than in any other painting, except that it mufl; be carefully obferved, in employing the opake or femi- tranfparent colours, never to cover any parts fo ftrongly with them as to prevent the di- ftindt appearance of the fhades of the printed defign, as they are to fhew themfelves through the colours, and form the fhades of the pidlure made by the colouring. In the illuminating (as it is called) maps, as little peculiar in the manner is necefiary as in the cafe of other prints ; only, the intent of colouring them being to diftinguiili the di- vifions of the maps with refpedt to countries, diftrids, &c. care mufl: be taken not to lay the fluid colours on fo copioufly as to flow be- yond the limits of what they are intended to cover. The reft depends on the difpofmg of the variety of colours fo in different parts as to give them a ftrong and pleafing effed, which mufl 384 THE Substances nuift depend more on fancy and good tafte than on any rules. There is indeed one thing in particular, which it may be proper to re-^ mark, fhould be ahways avoided; it is the laying thofe colours that have any affinity of likenefs clofe to each other; for by an error in this particular they will be rendered much lefs effectual with refped: to the purpofe they are to ferve, as it is by fuch a difpofition made more difficult to the eye to diftinguiffi the limits and bounds they are intended to mark out. And moreover, for want of diie appo- fition, the diverfification of the colours is made lefs pleafmg when they are feen at a diftance, and confidered only with refpedl to their ornamental appearance. There is one other rule I will likewife recommend the obfervance of, though many think they are giving moft perfedtion to their vcork when they moft deviate from it; it is, the never ufing too ftrong and de^p colours for this purpofe, as they render the legible characters of the maps lefs diftinCt and perceptible. Such a praCtlce is therefore repugnant in a certain degree to the principal intention of the maps, and moreover gives them a tawdry glaring appearance, which is very inconfiftent with good tafte; one great principle of which is fimplicity, and the avoiding a falfe and unmeaning ftiowinefs. PART Of the feveral arts ufed in making out- line iketches of defigns from naturej or depicted reprefentations, and- of the means of taking calls and im- prelTions from figures, bulls, medals, leaves, &c. C H A P; I. Of the devices employed for the more eafily obtaining a jull outline iii 'making defigns from nature, and the various methods of off-tracing, calking, and reducing pictures, prints, or drawings. T he drawing accurately and readily after nature, and depidled reprefentations, by the unaffifted hand and eye, requires greater practice and comnaand of pencil thaa fail to the lhare of many, who, neverthelefs, may not want abilities to colour or Ihade a pic- ture or drawing when a proper outline Iketch is VoL. I. Bb pre* 3cS6 Of Sketches from Nathre previoufly procured. The convenience of* quicker difpatch is moreover a matter of im- portance even to thofe who are moft expert in this art. On thefe accounts, various means have deviled to lead and diredt the eye or hand, in forming juft outlines of the principal objects which compofe the defign. Thefe means confifl of a multiplicity of methods, founded on different principles. .Ill the drawing after nature, the Interpofing a tranfparent plane is commonly pradifed; through which plane theobjedsbeing feen from a fixt point of view, the outlines of their parts are traced upon it by chalk or feme kind of crayon; — or fuch tranfparent body is divided into fquares, through which the objeds being viewed, the eye may be enabled to form and difpofe them with more certainty, on a paper or other proper ground, divided into a fimilar number of fquares; — or fome refleded image is obtained by means of a camera obfeuxa^ which affords an opportunity both of drawing the figure, and imitating the natural colour of the objeds. Thefe are the devices employed for drawing after nature; but, where pidures> prints, or drav/ings are to be copied, a- much greater variety are ufed. The moft common method is by off-tracings as it is called, whidi is the laying feme tranfparent fubftance over the pidure, print, or drawing, and paffing over the outlines of the principal parts with a pencil or crayon, which deli- neation is to be afterwards transferred from this AND DEPICTED REPRESENTATIONS. 387 tranfparent body to the ground intended for the painting or drawing. The fecond me- thod, which is indeed only another kind of off-tracing, pradlifed fometimes in the cafe of prints and drawings, is effected by laying the originals on the 'ground of paper or vellum, defigned for the copy, the back of the original being frneared with black, or with vermilion, mixt with a little butter, or a paper fo pre- pared being laid betwixt the original and copy, and tracing over the principal parts of the defign with a needle, or fome other fuch like inftrument, by which means an outline fketch of it will be formed on the ground of the copy. This' method is called calking^ and is performed alfo in another way, by pun<5lur- ing or pricking the original print or drawing, and producing an outline on a new ground, by tranfmitting a coloured powder through the punftured holes. The third is by diffolving part of the printing ink by means of foap, and impreffing it on a iVefh ground in that ftate. Another method much praftifed, is the ufing fquares in the manner above fpoken of, in the expedients for drawing after nature, except that here they are to be laid upon the pidure. This method is likewife applied to the more certain copying of piftures or drawings, where the new defign is to differ in magnitude from the original, in which cafe it is called redu^iioii. For the anfwering this laft purpofe, there is likewife another method, ,B b 2 by 3S8 Of Sketches from Nature by means of a machine I fhall below defcribe^ for off-tracing, in a manner, where, by fimply drawing over the lines of the original, the new fketch may be made greater or lefs at pleafure. The particular manner of ufing the tranf- parent plane for taking defigns from nature, is, by framing a piece of tiffany or fine lawn of the fize of the pidlure or drawing intend- ed, and fixing it fo that the whole view of what is to be painted may be feen through it; a fight-board, that is, a flat piece of wood, with a hole in it, being placed parallel to the tiffany or lawn in fuch manner that the eye may command the whole view through it, at the fame time that the hand may reach with convenience to draw upon It. The outlines of the objed: as they appear through the hole in the fight-board, mufl then be traced out on the tiffany or lawn, by a crayon formed of white or red chalk, charcoal, or any proper fubftance, by which means a fketch of the defign will be produced. In order ,to form a more complete drawing from this crude fketch on paper or vellum, the tiffany or lawn containing it muft be carefully laid on fuch paper or vellum in an horizontal po- fition, and, being well fixt down upon it, muft be ftruck with fome flat body in every part ; by which means the chalk or matter of the crayon will be transferred from the old to the new ground, and produce the fame de- lineation AND DEPICTED REPRESENTATIONS. 389 lineatlon of the object upon it as was before on the other. The impreffion, thus made on the new ground, fliould be then over-traced with a black lead pencil, and afterwards corredled, if there be occafion, from the natural view through the fight-board, and this paper or vellum will then contain a proper outline drawing, if the delign was intended for a painting in water colours. But when this method is purfued with a view to a painting in oil, the tiffany or lawn, after the fketch is . drawn, muft be laid upon the ground of the intended pidure, and proceeded with in the fame manner as with the vellum or paper, only in this cafe the over-tracing mull be made with fome kind of crayon inftead of the black lead pencil. It is advifed by fome to ufe paper made tranfparent by means of oil of turpentine, in^ Head of the tiffany and lawn; but the ufe of it is only practicable in this way in a darkened room, or other confined place, and the paper thus prepared does not become tranfparent enough, even then, to flievv^ minute or remote objects fo diflindlly as is neceffary. If, how- ever, any choofe to ufe it, the ufual preparation of the paper is only to brufh it feveral times over with oil of turpentine, and to fuffer it to dry. The tranfparency will be much im- proved, if a third of nut or poppy oil be added to the oil of turpentine, or otherwife a B b 3 little 390 Of Sketches from Nature little crude turpentine or colourlefs varnlfli^ any of which will render the oil of turpen- tine more efficacious for this purpofe, and fave the trouble and expence of rubbing the paper fo often over as Is otherwife neceffary. The paper employed for this purpofe fhould be that fan-paper^ which is to be had of the fanmakers; or, if that cannot be pro- cured, fine poft paper may be fubftituted; and where the defign is too large to be con- tained in one ffieet, feveral may be joined to- gether, by laying the edges of the ffieets a very little over each other, and cementing them by ifmglafs glue, which, if neatly done, will effed: the tranfparency in the joints but in a very minute degree. 'When the original fketch is made on tranfparent paper, the trace- ing or drawing may be performed by a black lead pencil inftead of a crayon, which renders the drawing much more perfed and durable ; and, being thus completed, it may be ufed for off-tracing the fketch on any ground intended for a painting in either oil or water. If it be intended for a pidure in oil colours, the back of the paper may be fmeared with pounded black lead, charcoal duff, or any powdered crayon; or, what is much better, vermilion mixed with juft fo much butter as will make it adhere to the paper. It muff then be laid on the ground of the pidure, and over-traced by a copper or iron ftift, or blunted needle, xvhich will make an impreffion of thS fketch on AND DEPICTED REPRESENTATIONS. 39X on the ground, by means of the colour on the back of the paper; or another paper may be coloured with the black lead or vermilion, inftead of the back of the traipparent paper, and being laid betwixt that and the ground will anfwer the fame end. .The means are no way different where the fketch is to be tranfmitted to paper inftead of oil. But in colouring the back of the tranfparent paper, or that inter- pofed where any fuch is ufed, care fliould be taken that the colour be'fo wdped off as not> to fmear the ground, or produce any eifedt, except where comprefled by the indrument in the over-tracing, and this indeed fliouid be regarded to a certain degree even with the oil ground. Where the iketch is large and made on feveral fheets of paper, it is conve-r nient to have weights to place on the four corners of the conjoined ilieets, to keep them even and fteady on the ground. They are bed formed of fquare pieces of lead witli handles, and may be about two or three ■ pounds weight each. The iketch on tranfparent paper may be otherwife tranfmitted to any ground by punc- turing it with holes made near each other in the lines of the drawing, and then fixing it on the ground, and d tiding over it black lead or any other coJourcd matter finely powdered, and tied up in a fine linen cloth. This duft pairing the holes of the prickt paper, will deli- neate the dcetch on the new ground, fo that B b 4 it 392 Of Sketches from Nature it may then be over-traced by any kind of pencil or crayon. Glafs has been alfo ufed in the fame view as the lawn or tranfparent paper; but its texture hinders it from being well ma- naged with chalk, or any crayon or pencil; though there is a method that has not, as far as I know of, been hitherto pra(9:ifed, by which a (ketch might be well obtained by the life of glafs. This method is, by drawing the outlines of the objedls with black colour in drying oil, and, when the (ketch is finifhed, laying the paper intended to receive the copy gently, and without any rubbing or (hifting on the glafs, having firfi; moiftened it with water ; by which means the black paint will be tranfmitted to the paper, as the moifture exhales from it, and an imprefliou made fu(E- ciently exadt for the purpofe. The manner of a(Tifting the eye, in defign- ing from nature by means of a plane divided into fquares, is by drawing crofs-lines parallel to each other on a tiffany or lawn framed, or on tranfparent paper or glafs. This may be done with common writing ink, or any other way that will render the lines vifible, and the divided plane muft be then placed before the fight-board in the fame manner as was be- fore diredled for tracing the outlines. The ground on which the (Icetch is intended to be taken muft be alfo formed into an equal number of fquares, and the objeds being feen through the fquares of the tranfparent plane^ AND DEPICTED REPRESENTATIONS. 393 plane, will by this means be much more eafily dilpoled in their proper lituation, and formed of a juft magnitude, by placing them in the correfpondent fquare of the ground, than where the eye had no fuch medium to com- pare and judge by. But though the above fubftances are moft commonly ufed, there is a more fimple and effetftual way of doing this, which is by making a frame of a proper fize, and dividing the area, which it forms into fquares, by threads of a moderate thicknefs. In which way, the objedfts to be drawn are confequently more within 'the power of the eye than when the moft tranfparent body is ufed. The drawing by the alfiftance of fquares, to thofe who have the leaft command of hand, is by much the moft expedient way. But in order to render this, or the other me- thods more commodioufly practicable, where it is to be done in the open air, a portable machine fhould be made for fupporting the frame of the tranfparent plane and the fight- board. This machine may be conftructed by joining three long legs together, in the manner of the furveyors inftruments, in a block, and fixing the frame, by means of a foot which will Aide into the fame box, that it may be raifed higher or lower. The fight-board muft have a foot likewife, by which it may be raifed higher or lower; though this muft not be fixed into the bfoek, but into a Aiding piece, which iuuft pafs through the block horizontally; fo that 394 C)f Sketches' from Nature that the foot of the fight-board being fixt into it at right angles, the board may be brought nearer to, or drawn farther from the tranfpa- rcnt plane at pleafure. The fecond method ufed to facilitate the drawing after nature, to wit, by the refleded image of the objeft, is performed by the ca- mera obfciira^ of which a portable kind adapt- ed to this purpofe is commonly made by the opticians. It is needlefs, therefore, to give any defcription of thefe inftruments ; and the ftrudlure of them immediately explains the manner of their ufe on a very flight examina-r tion. Where they are not at hand, and a profpedt through any particular wdndow is de- fired to be taken, an occafional camera may be formed. This is to be done by boring a hole through the window fhutter at a conve- nient height, and putting one of the glafles, called the ox-eye, into the hole; when, all other light being fhut out, except what paffes through this hole, and a proper ground of pa- per or vellum, &c. being held at a due dif- tance from the hole, the refledled image of the profpedl will be formed upon the ground., If this ground be formed of paper, and fixed fteady by a proper frame, the image will ap- pear very perfectly on the reverfe or backfide of it, and the artifl: may ftand at the back and trace the outlines of the neceflfary parts with great convenience, and may even ftretch the colouring, . if he think it expedients Thougl^ AND DEPICTED REPRESENT ATIO.NS. 395 Though the taking views of nature by the camera has feveral convenlencies, and feems very advantageous, yet there is one very ma- terial objection to its ufe. This is, that the lhadows lofe their force in the reflected image; and ohjeds, by the refraccion, are made to ap- pear rounder, or different fometimes both in their magnitude and fite, frqm what they really are, which being oppugnant to the truth of any drawing, almoft wholly deftroys the expedience there would be otherwife found in this manner. The method of making iTetches of outlines from pidlures, prints, or drawdng, by off-trace- ing, is performed by a variety of methods. The mold common, where the fize of the painting does not forbid it, is to take a fneet of paper prepared by oil of turpentine, or the other means, as above directed for the taking views from nature ; and, having faftened it even on the pidlure or print to be copied, to trace over the principal parts with a black lead , pencil. By this means an outline being ob- tained, it may be imparted to any other "ground, in the manner before defcribed, when the fame kind of outline is formed by draw- ing after nature. Where larger pieces are to be copied, lawn and tiffany may be ufed inftead of the tranfparent paper; or feveral fheets of the paper may be joined together by means of ifinglafs blue ; and when the outline is traced by chalk, or other proper crayon, the fubfequent proceeding may be the like alfo, ip 39^ Of Sketches from Nature ill this cafe, as above, where the fame kind of outline is taken from nature. Goldbeaters- fkin, and horn as prepared in plates for Ian- thorns, as alfo the talc or foffile ifinglafs, and dried hog’s bladder, have been likewife ap- plied to this purpofe. But where horn, or ifinglafs are ufed, being rigid bodies that will not yield to impart an impreffion by re- tracing, they may be beft treated in the man- ner above advifed, in the cafe of glafs, when employed for taking views from nature ; which is, by tracing the outlines with black in oil, and printing a new ground, of paper with it. Another common method of off-tracing, in the cafe of prints, or drawings, is to fix them againft a window, or other hard tranf- parent body placed in a ftrong light, in a perpendicular pofition ; and put a piece of paper, vellum, or any other body fufficiently tranfparent, before them, to perform, the off-tracing, by the view which is this way given of the objeds in the print or draw- ing. The other method of off-tracing, called calkrng^ which is fometimes practiced in the cafe of prints and drawings, is performed by tracing on the print, or drawing itfelf, inftead of the tranfparent body laid over it, as in the other manner. The back of it muff be previoufly prepared, by rubbing it over with black lead powder, or other fuch matter; or a pape^ blacked on the un^ AISTD DEPICTED REPRESENTATIONS. 397. der fide may be ufed Inftead of blacking the print or drawing. By either of thefe methods an outline will be made on any ground 'of vellum or paper laid under the print, and if feveral grounds of very thin paper be laid together under the print, with each a blackened paper over them, fo many impreffions may be made at one time* The fame effed: may be produced by pundur- ing or pricking out the proper outlines in the print or drawing, and then ufing it for im- parting the Iketch to another ground, with the black lead powder, &c. in the manner above defcribed in fpeaking of the ufe of the oiled paper. When the print or drawing is thus prepared by punduring, it may be employed for tranfmitting the iketch to any number of grounds. The manner of ufing foap, for taking off the impreffion of a print on a new ground, is this: Smear the original over with the com- mon foft foap, commixt with water till it be of the confiftence of a thin jelly, and then lay it even on the ground intended to receive the impreffion, which muft be alfo previoufly inoiftened with water. After which, being covered with feveral other papers, the whole muft be comprefted, by paffing a wooden roller over them, or by rubbing ftrongly on them with the calender glafs ufed for glazing li- nen, or by any parallel means. The im- preffion of the original will by this means be imparted to the new ground; v/hich muft be ' fir ft 39S Of Sketches from Nature firfl: dried, and then carefully waflied with a fpunge and water to take off the foap. It has been faid by feme, that this treatment wnll do very little injury to the original print; but, befides the impradlicability of ever thoroughly cleanfing it from the foap, a part of the print- ing ink is taken from it, and a proportionable ffare of the effedl of the original impreffioa deftroyed. A method parallel to this is fometimes ufed with prints and drawings; which is, by hold- ing them up to the light, and tracing the pro- per outlines on the back with a black lead pen- cil, or any kind of crayon, and then laying the traced fide on a ground proper to receive the impreffion, going over them with a roller or calender glafs, in the fame manner as when the' impreffion is taken by means of fbap. On the fame principle, in the cafe of copartments^ cyphers, or any other regular figures, where both fides are alike, when one half is drawn or traced, the other half may be procured by doubling the paper exadlly in the place where the two halves fhould join, and then preffing or rolling over the outfide of the ffietched part; by which treatment a correfpondent impref- fion of the defign wdll be made on the other fide, and the "whole fketch wdll be fmiffied without the trouble of drawdng or tracing out the lecond half. The method of copying defigns by the ufe of the fquares, either in order to paint in equal magnitude, or with a view to reduflion, is thus : AND DEPICTED REPRESENTATIONS. 399 thus : Divide the original into a convenient number of fquares, by ruling lines acrofs it with any kind of crayon; and then do the fame on the ground, in a correfpondent man- ner. The fquares on the new ground may be either increafed, diminifhed, or made equal as to their fize, with refpeft to thofe of the original, according to the intended proportion of the new piece. The principal ufe of the fquares, in this cafe, is fo much the fame as when they are applied to the taking draw- ings from nature, that it is needlefs to dwell longer on them now. I fhall only intimate, that, to thofe who can draw at all, the ufe of the fquares is much more advifable here, as well as in drawing after nature, than any of the other methods; as it is much more im- proving, and on the whole lefs troublefome, to make a corredl flcetch this way than by any other. The manner of redudlion, or, if that be not neceffary, of tracing out an outline, where the magnitude of the original is to be- preferved, by the machine above men- tioned, which was formerly called a pa- rallelogram^ and by fome at prefent a ma- thematical compafs^ cannot be fhewn, with- out firft defcribing fully, or exhibiting fay a figure, the conftrucfion of the inftrument. I fhall therefore endeavour to .explain the ftrudure and manner of fabrication of it, as- well as thofe of a machine fomewhat com- plex admit; and what may efcape the con- ception 400 Of Sketches from Nature^ ceptlon in the verbal defcription, may be fupplieJ by the inipedion of the figure an- nexed. This inftruinent is cbmpofed of a board, or table, with ten pieces of wood fixed upon it, in a moveable manner ; and by fuch a con- ftrudion, that when one is moved, the whole of the reft move alfo fimilarly, wfith refped to the diredions, but under greater or lefs angles. The board or table may be of fir deal, and is ufually made in the form of a parallelogram. The magnitude of it, as well as of the other parts of the machine, muft be according to that of the pidures, &c. it is intended to be ufed for reducing. But for the fake of giving the comparative pro- portions, we will ftate it at three feet in length, and the breadth may be about a foot and a half. It muft be plained very even,- but fhould not be of too thin fubftance, left it warp, and it muft be covered with cloth ftretched even upon it, and fattened down to it. The ten pieces of wood muft be formed like rulers ufed for writing, and, in the pro- portion here taken, they may be a foot long, and about half an inch in breadth, and the fifth or fixth of an inch in thicknefs. They muft be fattened to each other in fuch man- ner that every one muft be crofled by ano- ther in the centre, and by two others at fuch diftance from the centre as exadly di- vides the two half lengths on each fide of it; except the two which form the extremities, and And depicted Representations. 40! and can be only croffed in the centre and in the middle of one part, which, in each ex- tremity, will be the part oppofite to that fo crolfed in the other, as will immediately ap- pear on the pieces being laid together in the pofition here directed. The fallening muft be by pins, or rivets, oh which each piece may be turned with perfedt freedorri ; and near each end of every piece muft be made a hole or a female fcrew, into which a crayon, port- crayon, or pencil may be fixed, either by or without a fcrew. At the ends of thofe pieces vrhich make the extremities, there muft be a fmaller hole for a pin to be pafTed through to faften the conjoined pieces to the board. In order to the more commodioufly fixing the feveral parts of the inftrument to the board or table, it may be proper to have female fcrews at the places of the table where the rulers are to be pinned down, according to the different applications of the inftrument; and the pins for faftening the refpe£live parts muft in this cafe have male fcrews at their extremities, correfpondent to the female fcrews in the table. By thefe directions clofely followed, the parts of the inftrument may be completely formed and put together ; but to explain the manner of ufing it, the figure is here given, as it is more eafy to refer to the parts of that, than to fuch as have only a verbal fpeci- fication. VoL. I. C c . Let . 402 Of Sketches frOxM NaturS Let the leg or extremity of the piece A he faftened to the board in the part of it as here delineated, and let the pidure, &c. be placed under the end of the piece i>, a ftrong pin blunted, or other fuch rigid body being put through the end of it, and placed in the centre of the pidure, or any other part where it may be convenient to begin the tracing. Let the ground intended to receive the draw- ing, or fketch, be then placed at £, the next leg to that faftened to the board, if the defign of the original be intended to be diminifhed in the utmoll degree the machine can effed, or to any of the other legs nearer to the origi- nal, according to the proportion of the dimi- nution required. A crayon, or pencil, muft then be fixed in the hole of the piece made for that piirpofe, andunufi: reft on the ground ef the fleetch, which ground muft be fo AND DEPICTED REPRESENTATIONS. 463 placed, that the crayon or pencil may be im- mediately over the part of it which cotrefponds with the part of the original touched by the blunted pin. The pidfure and ground of the fketch mufl: then be faftened firmly to the board, and the artift bearing with his left hand gently on the crayon or pencil over the ground, muft trace, with the blunted pin or jftift fixed in the hole of the moft diflant leg, the outlines of the original, which will fo move the crayon or pencil on the ground for the fketch that a correfpondent line will be marked there, but with the diminution of the defign in the proportion defired. When the enlargement of the original is defired, the reverfe muft be pracftifed with re- gard to the fituation of the original and copy; for if the original be placed under E, the piece next to that faftcned to the board, and the new ground be put under the end of the leg where the original was before placed, the fubfequent management being the fame as before in all other refpedls, the iketch will be augmented in an equal degree to what it was diminifhed before. If a fketch of equal magnitude be defired, the faftening of the conjoined pieces to the table or board muft be at Z), in the centre of the whole, and the original and new ground placed under the pieces at each extremity, or any other correfpondent pieces that may be moft commodious. C e 2 This ^04 Of Casts and Impressions.- Thls machine may be ufed for ofr-tracing maps, or other fuch Ampler defigns, or may afford amufement by off-tracing pictures, &zc» to thofe who have no facility in drawing. But to the abler and more expert in thefe arts, where defigns that demand fpirit and pencif are in queftion, it feems an expedient below their regard, as performing by an imperfedl mechanical aid what they can execute better by their own natural powers. G H A P. II. of the means of taking; cafts and impreffions from figures, bufts, medals, leaves, &c. T he method of taking cafts of figures and bufts, as at prefent pradfifed, is moft generally by the ufe of plaifter of Paris ; or, in other words, alabafter calcined by a gentle heat. The advantage of -ufing this fubftance preferable to others, confifts in this, that notwithftanding a flight calcination re- duces it to a pulverine ftate, it becomes again^ a tenacious and cohering body by being moift- ened with water, and afterwards fuffered to* dry. By this means either a concave or con- vex figure may be given by a proper mold or model to it when wet, and retained by the hardnefs Of Casts and Impressions. 405 iiardnefs it acquires when dry, and from thefe qualities it is fitted to the double ufe of making both cafts and molds for forming thofe calls. The plaifter is to be had ready pre- pared of thofe who make it their bufinefs to to fell it, and the only care is to fee that it is genuine. The particular manner of making calls de- pends on the form of the fubjed to be taken. Where there are no projedling parts it is very fimple and eafy, as likewlfe where there are fuch as form only a right or any greater angle with the principal furface of the body. Rut where parts project in lelier angles, or form curves inclined towards the principal furface of the body, the work is more diffi- cult. I fhall therefore firll explain thofe particulars of the manner which are general to all kinds, and then point out the extra- ordinary methods to be ufed where diffi- culties occur. The firll ftep to be taken is the forming the mold, which is, indeed, done by much the fame means, as the call is afterwards made in it. In order to this. If the original or model be a bafs-relief, or any other piece of a flat form, having Its furface firll well greafed, it mull be placed on a proper table, or other fuch fupport, and furrounded by a frame, the fides of which mull be at fuch a diftance from it as will allow a proper thick- nefs for the fides of the mold. A due quan- jtity of the plaifter, that Is, what will be fuf- C c 3 ficienl 4o6 Of Casts and Impressions, licient to cover and rife to fuch a thicknefs as may give fufficient ftrength to the mold, as alfo to fill the hollow betwixt the frame and the model, muft be moiftened with water, till it be juft of fuch confiftence as will allow it to be poured upon the model. The plaifter, thus moiftened, muft be then put on the model as foon as poftible; for it muft not be delayed after the water is added to the plaifter, which would otherwife concrete or fet, fo as to become niore troublefom^ in the working, or unfit to be ufed. The whole muft then be fuffered to remain in this condition till the plaifter has attained its hardnefs, and then the frame being taken away the preparatory caft or mold, thus formed, nmj be taken off from the fubjeT intire. Where the model or original fubjeft is of a round or ereft form, a different method muft be purfued, and the mold muft be di- vided into feveral pieces; or, if the fubjeft confifl's of detached and projefting parts, it is frequently moft expedient to caft fudi parts feparately, and afterwards join them together. Where the original fubject or model forms a round, or fpheroid, or any part of fuch round, or fpheroid, more than one half the plaifter muft be ufed without any frame to keep it round the model, and muft be tem- pered with water to fuch a confiftence that it may be wrought with the hand like very foft pafte. But though it muft not be fo fluid Of Casts a.nd Impressions. 407 Lis when prepared for flat-figured models, it mufi; yet be as moHl as if compatible with its cohering fufficiently to hold together. Being thus prepared, it muft be put upon the model, and comprelfed with the hand, or any flat inftrument, that the parts of it may adapt themfelves in the mofl; perfedt manner to thofe of the fubjedl, as well as be compact with refpedl to themfelves. When the model is fo covered to a convenient thicknefs, the whole muft be left at reft till the plaifter be fet and firm, fo as to bear dividing without falling to pieces, or being liable to be put out of its form by flight violence. It mull then be divided into pieces, in order to its being taken oif from the model, by cutting it with a knife, or with a very thin blade; and, being divided, muft be cautioufly taken off, and kept till dry. But it muft be always carefully obferved, before the feparation of the parts be made, to notch them crofs the joints, or lines of the divifion, at proper diftances, that they may with eafe and certainty be properly conjoined again, which would be much more precarious and troublefome without fuch directive marks. The art of properly dividing the molds, in order to make them leparate from the model, conftitutes the greateft objedl: of dexterity and fliill in the art of calling, and does . not admit of rules for the moft advantageous condud: of it in every cafe. But I lliall endeavour to explain the principles on whicfl it depends in C c -4 . fuch 4o8 Of Casts and Impressions. fuch manner that by a due application of them all difficulties may at any time be fur- mounted, and an expertnefs even of manner acquired by a little pradlice. With refpeft to the cafe in queflion, where the fubjeft is of a round or fpheroidal form, it is beft to di- vide the mold into three parts, which will then eafily come off from the' model, and the fame holds good of a cylinder^ or any regular curve figure. The mold being thus formed and dry, and the parts put together, it muff be firft greafed and placed in fuch a pofition that the hollow may lie upwards, and then filled with plaifter commlxt with water, in the fame pro- portion and manner as was directed for the calling the mold ; and wffien the caft is per- fedlly fet and dry, it muff be taken out of the mold and repaired where it is neceffary, which finifhes the whole operation. This is all that is required with refpefl: to fubjedls where the furfaces have the re- gularity above-mentioned ; but where they form curves which interfedl each other, the condud; of the operation m^iifl be varied wnth refped to the manner of taking the caft of the mold from off the fubjed or model; and where there are long projcd- ing parts, fuch as legs or arms, they fhould, as was obferved before, be wrought in fe- parate cafts. The method of dividing properly the molds cannot be reduced, as I intimated, to any particula/ ' Of Casts and Lmpressions. 409 particular rules, but muft depend in fome degree on the lldll of the operator, who may ealily judge from the original fubjeds, by the means here fuggefted, what parts will come .off together, and what require to be fepa- rated. The principle of the whole confifts only in this, that where under- workings^ as they are called, occur, that is, wherever a ftraight line drawn from the bafis or infertion of any projed;Ion would be cut or eroded by any part of fuch projedion, fuch part cannot be taken off without a divifion. This muft be made either in the place where the projedion would crofs the ftraight line; or, as that is frequently difficult, the whole projedHon muft be feparated from the main body, and divided alfo lengthways into two parts. Where there are no projedions from the principal furfaces, but the body is fo formed as to ren- der the furface a compolition of fuch curves, that a ftraight line being drawn parallel to the furface of one part would be cut by the outline; in one or more places of another part, a divifion of the whole ftiould be made, fo as to reduce the parts of if into re- gular curves, which muft then be treated 4s fuch. Where detached parts of a long form, as legs, arms, .fpears, fwords, &c. occur in any figure, they fhould be caft in feparate molds, and if fuch parts are of a. compound ftrudure, the fame rules as were before in- timated muft be obefrved in the manage- ment 410 Of Casts and Impressions. ment of them, as are already direded for the principal part. In larger maffes, where there would other- wife be a great thicknefs of the plaifter, a corps or body may be put within the mold, in order to produce a hollow in the caft, which both faves the expence of the plaiftef and renders the caft lighter. This corps may be of wood, where the forming a hollow of a ftraight figure, or fuch as is conical with the bafis outward, will an- fwer the end. But if the cavity require to be round, or of any curve figure, the corps can- not be then drawn while intire, and confe- quently fhould be of fuch matter as will fuiter itfelf to be taken out piece-meal. In this cafe, therefore, the corps is beft formed of clay, which muft be worked upon wires to give it tenacity, and fufpended in the hollow of the mold, by crofs-wires lying over the mouth; and when the plaifter is fufficiently fet to bear handling, the clay muft be picket! out by a proper inftrument. Where it is defired to render the plaifter harder, the water with which it is tempered fhould be mixed with parchment fize prepared as below direfted, which will make it very firm and tenacious. In the fame manner, figures, bufts, &c. may be caft of lead, or any other metal, in the molds of plaifter, only the expence of plaifter, and the tedioufnefs of its becoming fufficiently dry, w^hen ^in a yery large mafs, to bear the Of Casts and Impressions. 411 heat of melted metal, render the ufe of clay, compounded with fome other proper mate- rials, preferable, where large fubjed:s are in queftion. The clay, in this cafe, Ihould be waflied over till it be perfectly free from gravel or Hones, and then mixed with a third or more of fine fand to prevent its cracking; or, inftead of fand, coal afhes fift- ed till they be perfectly fine are preferable. Whether plaifter or clay be ufed for the cafting in metal, it is extremely neceffary to have the mold perfectly dry, otherwife the moifture, being rarlfied, will make an ex- plofion that will blow the metal out of the mold, and endanger the operator, or at leaft crack the mold in fuch manner as to fruftrate the operation. Where the parts of a mold are larger, or proje 61 : much, and confequently require a greater tenacity of cohefion of the matter they are foriTicd of to keep them toge- ther, flocks of cloth, prepared like thofe defigned for the paper hangings, or fine cotton pluckt or cut till it is very fhort, fliould be mixt with the afhes or fand before they be added to -the clay to make the corapofition for the mi old. The proportion fhould be according to the de- gree of cohefion required; but a finall quantity will anfwer the end, if the other ingredients of the compofition be good, and the parts of the mold properly linked together by means of the wires above directed. There is a method of taking cafis In metals from fmall animals, and the parts of vege- tables. 41^ Of Casts and Impressions. tables, which, though not much known or ufed in this country, may be neverthelefs pradifed for fome purpofes with advantage, particularly for the decorating grottoes or rock-work, where nature is imitated. The proper kinds of ani- mals are lizards, foakes, frogs, birds, or infeds ; the call of which being properly coloured will .be exad reprefentations of the originals. This is to be performed by the following method. A colBn or proper chefl for form- ing the mold being prepared of clay, or four pieces of boards fixe4 together, the animal, or parts of vegetables^ muft be fufpended in it by a ftring, and the leaves, tendrils, or other detached parts of the vegetables, or the legs, wings, &c. of the animals, properly feparated and adjufted in their right pofition by a fmall pair of pincers. A due quantity of plaifter of Paris, and calcined talc, in equal quantities, with fome alumen plumofiim^ mull then be tempered with water to the proper confiftence for calling, and the fubjed from whence the call is to be taken, as alfo the hides of the coffin moiftened with fpirit of \yine. The coffin or chefl muft be then filled with the tempered compofition of the plaifter and talc; but, at the fame time, a piece of flraight ftick or wood muft be put to the principal part of the body of the fubjed, and pieces of thick wire to the extremities of the other parts, in order that they may form, when drawn out after the matter of the mold is properly fet and firm, a channel for pouring in the melted Of Casts and Impressions. 41J inelted metal, and vents for the air, which otherwife, by the rarefadion it would undergo from the heat of the metal, w^ould blow it out, or burft the mold. In a fhort time the plaifler and talc wull fet and become hard, when the IVick and wires may be drawn out, and the frame or coffin in wffilch the mold w^as caft taken away. The mold muft then be put firft into a moderate heat, and afteiwvards, when it is as dry as it can be rendered by that degree, removed into a greater, which may be gradually increafed till the wffiole be red- hot. The animal, or part of any vegetable, wffiich was included in the mold, will then be burnt to a coal, and may be totally calcined to affies, by blowdng for fome time gently into the channel and pafiages made for pouring in the metal, and giving vent to the air, which wdll, at the fame time that it incinerates the remainder of the animal or .vegetable matter, blow out the affies. The mold muft; then be fuftered to cool gently, and wdll be perfecft, the deftrudion of the fubftance of the animal, or vegetable, having produced a hollow of a figure correfpondent to it ; but it may be neverthelefs proper to fhake the mold, and turn it upfide dowm, as alfo to blcrw with the bellows into each of the air vents, in order to free it wholly from any remainder of the affies; or, where there may be an opportunity of filling the hollow with quickfilver w^ith- out expence, it will be found a very effedual method of clearing the cavity, as all duft, affies, 414 Casts and Impressioi\^s. afiies, or fmall detached bodies, will necef- farily rife to the furface of the qulcldilver,; and be poured out with it. The mold being thus prepared, it muft be heated very hot when ufed, if the call be made with copper or brafs ; but a lefs degree will ferve for lead or tin. The melted metal muft be then poured in, the mold gently ftruck, and fuffered to reft till it be cold. At which time it muft be carefully taken from the caft, but without the leatt force ; for fuch parts of the matter as appear to adhere more ftrongly, muft be foftened by foaking in water till they be intirely loofened, that none of the more delicate parts of the caft may be broken off or bent. Where the aliimcn piilmofiim^ or talc, can- not be eafily procured, the plaifter may be ufed alone ; but it is apt to be calcined by the heat ufed in burning the animal or vegetable from whence the caft is taken, and to become of too incohering and crumbly a texture. For cheapnefs, Stiirbridge clay, or any other pot- ter’s of other good clay^ wafhed over till it be perfedly fine, and mixed with an equal part of fand and fome flocks cut fmalfi may be em- ployed. Pounded pumice ftone and plaifter of Paris, taken in equal quantities, and mixed with wafhed clay in the fame proportion, is faid to make excellent molds for this and parallel ufes. Cafts of medals, or fuch fmall pieces as are of a fimilar formj may be made in plaifter by Of Casts and Impressions. 415 by the method directed for bafs relieves. In- deed there is nothing more required than to form a mold, by laying them on a proper board; and, having furrounded them by a rim made of a piece of a card or any other pafteboard, to fill the rim with foft tempered plaifter of Paris, which mold, when dry, will ferve for feveral calls. It is neverthelefs a better method to form the mold of melted fulphur, which will produce a >fharper im- preffion in the call, and be more durable than thofe made of plaifler. The calls of medals are likewife frequently made of fulphur, which being melted, mull: be treated exadlly in the fame manner as the plaifter. Calls may be made likewife with iron, with very little additional trouble, provided it be prepared in the following manner. Take any iron bar, or piece of a fimilar form, and, having heated it red-hot, hold it over a velTel containing water, and touch it very llightly with a roll of fulphur, which will immediately diflblve it, and make it fall in drops into the water under it. As much iron as may be wanted being thus dilTolved, pour the water then out of the veflel, and pick out the drops formed by the melted iron from thofe of the fulphur, which contain little or no iron, and will be diftinguilhable from the other by their co- lour and weight,’’ The 4i6 Of Casts and Lmpression^. The Iron will, by this means, be rendered fo fufible, or eafy to be melted, that it will run with lefs heat than will melt lead, and may be employed for making cafts of medals, and many other fuch purpofes, with great convenience and advantage. Impreilions of medals, having the fame effed as cafts, may be made alfo of ifmglafs glue by the following means. Melt the ifm- glafs, beaten as when commonly ufed, in an earthen pipkin, with the addition of as much water as will cover it, ftirring it gently till the whole be diffolved; then, with a brufh of camel’s hair, cover the medal, which fhould be previoLifly w^ell cleanfed and warmed, and then laid horizontal on a board or table greafed in the part around the medal. Let them reft afterwards till the glue be properly hardened^ and then with a pin raife the edge of it, and feparate it carefully from the medal ; the caft will be thus formed by the glue as hard as horn, and fo light that a thoufand will fcarcely w^eigh an ounce. In order to render the relief of the medal more apparent, a fmall quantity of carmine may be mixed with the melted ifmglafs, or the medal may be pre- vioufly coated with leaf gold by breathing on it, and then laying it on the leaf, which will by that means adhere to it; but the ufe of the leaf gold is apt to impair a little the fharpnefs of the impreffion. There is like wife a method of making im-*- preffipns of the fame kind in lead, which is this. Of Casts and Impressions. 417 tills. Lay the medal on a poft, or other firm • body of wood, and cover it with a piece of very thin plate of lead, and lay over that another • piece of thicker plate. Then place on them end-ways a piece of wood turned of a round figure, which may be a foot or more in length, and of fuch thicknels that its diameter may be fomewhat greater than that of the medal. Strike then forcibly on the upper end of the wood with a mallet, or fome fuch inftrument, and the undermoft plate of lead will receive the impreffionof the medal; to preferve which, the concave of the reverfe may be filled up with* refin, mixed with an equal part of brick- duft, and melted. The impreflion fhould be made with one ftroke, which will produce a fufficient effed:, if given with due ftrength, and in a perpendicular diredioh. Impreffions may be even taken from fealing wax or fulphur in this manner, if the pieces be no way con- cave or bending on their under fide. Impreffions of medals may be Ijkewife taken in putty, but it ffiould be the true kind made of earth of tin and drying oil. Thefe may be formed in the molds previoufly taken in plaifter or fulphur, or molds may be made in its own fubftance in the manner direded for thofe of the plaifter. Thefe impreffions .will be very fharp and hard, but the greateft difadyantage that attends them is their drying very flowly, and being liable in the mean-time to be damaged. VoL. I. t) cj ' Iln- 45 8 Of Cast's And‘ Impress502^"s'. Impreffions of prints, or other engravlng^y may be taken from copper-plates by cleaning them thoroughly, and pouring plaifter upon them; but the effedl in this way is not ftrong. enough for the eye, and therefore the follow- ing method is preferable where fuch im*- preffions on plaifter are defired^ Take vermilion, or any other coloured pig- ment finely powdered, and rub it pver the' plate; then pafs a folded piece of paper, or the flat part of the hand over the plate, to take off the colour from the lights or parts^ where there is no engraving. The proceeding muft then be the fame as where no colour is ufed. This laft method is alfo applicable to the making iinpreflions of copper-plates on paper with dry colours; for the plate being prepared as here directed, and laid on the paper properly molftened, and either pafled under the rolling-prefsj or any other way ftrongly forced down on the paper, an im- preffion of the engraving will be obtained. Impreflions may be likewife taken from copper-plates, either on plaifter or paper, by means of the fmoke of a candle or lamp ; if, inftead of rubbing them witft any colour, the plate be held over the candle or lamp till the whole furface become black, and then wiped off by the flat of the hand or paper. Thefe methods are not, however, of very great ufe in the cafe of copper-plates, except where impreffions may be defired on occalions- v;here printing ink cannot be procured; but as- they Of Casts and Impressions. 419 they may be applied like wife to the taking impreffions from fnufl'-boxes, or other en- graved fubjed:s, by which means defigns may be inftantly borrowed by artifts or curious per- fons, and preferved for any ufe, they may in fuch inftances be very ufeful. The expedient of taking impreffions by the fmoke of a candle or lamp may be employed alfo for botanical purpofes, in the cafe of leaves; as a perfe6l and durable reprefentation of not only the general figure, but the contex- ture and difpofition of the larger fibres, may be extemporaneoufly obtained at any time. The fame may be, neverthelefs, done in a more perfed: manner by the ufe of linfeed oil, ei- ther alone or mfixed with a fmall proportion of colour^ where the oil can be conveniently procuredi But the other rnethod is valuable, on account of its being pradicable at almoft all feafons, and in all places, within the time that the leaves will keep frefh and plump. In tak- ing thefe imprelTionS, it is proper to bruife the leaves, fo as to take olF the projedions of the large ribs, which might prevent the other parts from plying to the paper. Leaves, or alfo the petals, or flower leaves ' of plants, may themfelves be preferved on pa- per, with their original appearance, for a con- iiderable length of time, by the following means. Take a piece of paper, and rub it over with the ifinglafs glue, treated as above direded for taking impreffions from medals ; and then lay the leaves in a proper pofition. D d 2 Qtx 420 Of Casts And Impressions. on the paper. The glue laid on the paper' being fet, brufh over the leaves with more of the fame, and that being dry llkewlfe, the operation will be finlfhed, and the leaves fo fecured from the air and moifture that they will retain their figure and colour much longer than by any other treatment. Butter-flies, or other fmall animals of a flat figure, may alfo be preferved in the fame manner. PARt PART IIL Of gilding, filvering, bronzing, jar-' panning, laquering, and the ftaining different kinds of fubftances, with all the variety of colours. T he gilding different fubftances is per-' formed by a variety of means accom- modated to the nature of' each; but the principle is the fame in all, (except with refpeetwdxt the ufe and omilfion of the gold fize, in this way of gilding, lies in two particulars. The one is, that the fizing dries fafter according to the proportion of the quan- tity of the gold fize to the fat oil, and is con- feqiiently fo much the fooner fit to be gilded- The other is, that the gilding Is alfo rendered, in the fame proportion, lefs fhining andgloffy, which is efteemed a perfedion in this kind of gildings - Of. Gilding. 42^ gilding; though, taking away the prejudice of fafhlon, I fhall think the moft fhlning the moft beautiful, and of the flirongeft effeft. The fat oil, or the compound of that and the . gold fize, muft be ground witli fome yellow oker, and then, by means of a brulh, laid thinly over the work to be gilt. But, in doing this, care muft be taken to pafs the brufli into all the hollows and cavities, if the fubjeft b«^ carved, or have any other way projeding parts. For where the fize fails to be laid cn, the gold will never take till the work be again repaired by going over the defective places with frefti fize, which fhould be avoided as much as poi- fible. Where great perfedion is required, the gold fhould not be laid on the firft fizing ; but that being fufFered to dry, the work ftiould be again fized a fecond time, and fome who are very nice even proceed to a third. The work being thus fized, muft be kept tilF It appear in a proper condition to receive the gold, which muft be diftinguiflied by touch- ing with the finger. If it appear then a little adhefive or clammy, but not fo as to be brought off by the finger, it is in a fit condi- tion to be gilt. But if it be fo clammy as to doub or come off on being touched, it is not fufficiently dry, and muft be kept longer; or, if there be no clamminefs or fticky quality re- maining, it is too dry, and muft be fized over again before it can be gilt. When the work is thus ready to receive the gold, the leaves of gold, wliere the furfaee is 430 Of Gilding. is liiffidently large and plain to contain tlieni^ may be laid on entire, either by means of the fquirrel’s tall, or immediately from the papef in which they were originally put; a method that, by thofe who have the proper dexterity of doing it, is found to be much the fimpleit and quickefl, as well as belt, for the perfec- tion of the work. Being laid on the proper parts of the work, the leaves mult then be fettled to the ground, by coulpreffing thofe which appear to want it gently with the fquir- rel’s tall or cotton ball; and if any part of the gold has flown off, or been difplaced, fo as to leave a naked or uncovered fpot, a piece of another leaf, of fize and figure eorrefpondent to fuch fpotj mull be laid upon it. Where the parts are too fmall to admit of the laying on whole leaves, or where vacancies are left after laying on whole leaves which are lefs than require others to cover them, the leaves which are to be ufed mull be fi.rll turned from the paper upon the culhion, defcribed above amongll the inllruments. They mull then be cut, by, fcoring over them, with the knife, (above defcribed llkewife) into fuch divifions or flips as may be moll commodioully laid on the parts of the work to be covered; after which, being feparated, and taken up as they are wanted, by means of the cotton wool, to which being breathed upon they v/ill adhere, they mull be laid in the places they are defigned to cover, and gently prefled by the cotton till they touch every where, and lie even on the ground. Where OfGildi^jg. 431 Where the work is very hollow, and fmall pieces are wanted to cover parts that lie deep • and out of the reach of the fquirrel’s tail or the cotton, they may be taken up by the point of a fitch pencil, (being firft breathed upon) and by that means conveyed to, and fettled in their proper place. Thofe who are accuftomed to it, ufe the pencil commodioufly for a great part of the work where large parts of the leaves cannot be ufed. The whole of the work being thus covered, fliould be fuffered to remain till it be dry, and it may then be brufhed over by a camel’s hair pencil, or foft hog’s hair brufli, to take off from it all loofe parts of the gold. If, after the brufhing, any defedtive parts or vacancies appear in the gilding, fuch parts mull be again lized, and treated in the fame manner as the whole was before; but the ja- panners’ gold fize alone is much better for this purpofe than either the fat oil alone, or any mixture. SECTION IV. ; Of burnijh gilclmg^ with the prep 'ara^ tion of the prope?^ fzes^ c. T he gilding with burniilit gold is fel- dom practifed but upon wood, and at prefent moftiy in the cafe of carved work, or where carved work is mixed with plain. The' chief 43^ Gild INC. chief difference In the manner betwixt this ind oil gilding lies in the preparing the work to re-^ ceive the gold, and in the fubftituting a fize made of parchment, or the cuttings of glover’s lectther in the place of the fat oil, as a cement. The proportion of the fize ihould, there- fore, be previoufly known, and may be as follows. ‘‘ Take a pound of cuttings of parchment, or of the leather ufed by glovers; and; having added to them fix quarts of water, boil them till the quantity of fluid be re- duced to two quarts, or till, on the taking out alittle, it will appear like a jelly on grow- Ing cold. Strain it through flannel while hot, and it will be then fit for ufe.” This fize is employed in burnilh gilding, not only in forming the gold fize, or cement for binding the gold to the ground, but alfo in priming, or previoufly preparing the work. But before I ptoceed to Ihew the manner of ufing it fo, it is neceffary to give the compofi- tlons for the proper cement or gilding fize em- ployed in this kind of gilding. There are a multiplicity of recipes for this eompofition which are approved of by different perfons, but as in general they vary not effentially from each other, I will only give two, wdiich I be- lieve to be each the befl: in their kinds. ‘‘ Take any quantity of bole armoniac, and add fome water to it, that it may foak till it grow foft. Levigate it then on the fl;one, but not with more water than will prevent “ its Of GilI)ing. 433 its bang of a Itiff confiftence, and add to it ‘‘ a little purified Ibet or tallow fci aped, and grind them together. When this is wanted for ufe, dilute it to the confiftence of cream, by parchment or glovers fize mixt with double its quantity of water and ma le warm; Some melt the fuet or tallow, and “ mix it previoufly with five or fix times its ‘‘ weight of chalk before it is put to the bole, to facilitate their commixture, to which, in ‘‘ this wet ftate, they are otherwife fomewhat repugnant. It is alfo fometimes pradlifed to put foap-fuds to the bole, which will con- tribute to its uniting with the tallowi” This is the fimpleft compofition, and equally good with the following, or any other ; but for the indulgence of the variety of opinions^ which reigns in all thefe kinds of matters, I will infert another. Take of bole in fine powder one pounds and of black lead two ounces. Mix them well by grinding, and then add of olive oil two dunces, and of bees-wax one ounce “ melted together, and repeat the grinding ‘‘ till the whole be thoroughly incorporated. ‘‘ When this mixture is to be ufed, dilute it with the parchment or glovers fize, as was direfted in the former recipe. But till the ‘‘ time of ufmg them, both this and the fore- “ going fhould be kept immerfed in water, “ which will preferve them good.” To prepare the wood for burnifh gilding, it fhould firft be well rubbed with fifh- VoL. I. E e fkiu? 434 ^ G I L D I N G.' ftin, and then with Dutch ruflies; but this can only be pradtifed in the larger and plainer parts of the work,' otherwife it may damage the carving, or render it lefs fharp by wearing- off the points. It muft then be primed with the glovers lize, mixed w^lth as much w^hiting. as will give it a tolerable body of colour; which mixture muft be made by melting the fize, and ftrewing the whiting in a powdered Hate gradually into it, ftirring them well to- gether, that they may be thoroughly incorpo- rated. Of this priming feven or eight coats fhould be given, time being allowed for the drying of each before* the other be put on,- and care fliould be taken in doing this, to^ work the priming well with the brulh into all the cavities or hollows there may be in the carved work. After the laft coat is laid on,- and before it be'quite dry, a brufli pencil, dipt in water, fhould be pafl'ed over the whole to fmooth it and take away any lumps or inequa- lities that may have been formed, and w^hen it is dry, the parts which admit of it fhould be again rufhed over till they be perfeftly even. The work fhould then be repaired, by freeing all the cavities and hollow parts from the priming, w’^hicb may choak them or injure the relief of the carving; after which, a water polifh ihould be given to the parts defigned to be burnifhed, by rubbing them gently with a fine linen rag moiftened with water. The work being thus prepared, when it is to be gilt, dilute the compofition of bole, &c. with Of Gilding. 435 with warm fize mixt with two-thirds of water^ and with a brufh fpread it over the whole of the work, and then fufxer it to dry, and go over it again with the mixture in the fame manner at leaft once more. After the laft coat, rub it in the parts to be burnifhed with a foft cloth, till it be perfectly even. Some add a little vermilion to the gilding fize, and others colour the work, if carved, before it be laid on, with yellow and the glovers fize, to which a little vermilion, or red lead, fhould be added* This laft method is to give the appearance of gilding to the deeper and obfcure parts of the carving, where the gold cannot, or is not thought neceflary to be laid on. But this pradiice is at prefent much difufed, and inftead of it, fuch parts of the work are coloured after the gilding, which treatment is called mattings The work being thus properly prepared, fet it in a pofition almoft perpendicular, but de- clining a little from you, and having the gild- ing fize, place all the neceflary inftruments above defcribed ready, as alfo a bafon of clean water ready at hand; wet then the upper- moft part of the work, by means of a large camel’s hair pencil dipped in the water, and then lay on the gold upon the part fo wet, in. the manner above directed for the gliding in oil, till it be completely covered, or become too dry to take the gold. Proceed afterwards to wet the next part of the work, or the fame over again if neceifary, and gild it as the E e 2 - firft, 43^> Of Gild IK'D. firft, repeating the fame method till the v^’ho^f be finifhed. Some wet the work with brandy^ or fpirit of wine, inftead of water; but I do' not conceive any advantage can arife from it that may not be equally obtained by a judicious ufe of water. This manner is moreover much more troublefome and difficult, as well as ex- penhve ; for only a fmall part muft be wet at one time, and the gold laid inftantly upon it, or the brandy or fpirits will fly off, and leave the ground too dry to take the gold. The work being thus gone over with the gilding, muft be then examined, and, fuch parts as require it, repaired by wetting them with the camel’s hair pencil, and covering them with the gold ; but as little as poffible of the perfeft part of the gilding fhould be wet^ as the gold is very apt to turn black in this ftate. When the repaired part alfo is dry, the work may be matted if it require it; that is, the hollow parts muft be covered with a co- lour the neareft in appearance to gold. For this purpofe fome recommend red lead, with a little vermilion ground up with the white of an egg; but I think yellov/ oker, or Dutch pink, with red lead, would better anfwer the end ; or the terra di Sienna very llightly burnt or mixed with a little red lead would have a much better effedl, and be more durable than any other mixture fo near the colour of gold in fhade. Iflnglafs fize will likewife equally well fupply the place of the whites of eggs in the compofition for matting. Of G I l d I n g.. 437 The work being thus gilt, it muft remain about twenty-four hours, and then the parts of it that are defigned to be burnlihed muft be poliihed with the dog’s tooth, or with the 'burnifhers of agate or flint made for this pur- -pofe; but it fhould be previoufiy tried whether k be of the proper temper as to the drynefs; for though twenty-four hours be the moft general fpace of time in which it becomes lit, yet the difference of feafon, or the de- gree of wet given to the work, makes the drying irregular, wdth regard to any fixt period. The way of diftingulihing the fitnefs of the work to take the burnifh, is to try tvro or three particular parts at a diftance from each other, which, if they take the polifli in a kindly manner, the wbole may be concluded flt; but if the gold peel oft, or be difordered by the rubbing, the work mufl; be deemed not yet dry enough ; and if the gold abide well ■the rubbing, and yet receives the polifh flowly, it is a proof of ita being too dry, which fliould be always prevented by watching the proper time; for the work, when too dry, both requires much more labour to burnilh it, and fails at laft of taking fo fine a polifli. 43S Of G I l d I n SECTION V. Of japanners gilding. HE japanners gilding is performed by means of gold powder, or imitations of it, cemented to the ground by a kind of gold fize much of the nature of drying oil ; for the making which, there are various recipes followed by different perfons. I fliall, however, only give one of the more compound, that is much approved, and another very fimple, but which, neverthelefs, is equally good for the purpofe with the mod elaborate. The more compound gold fize may be thus, made. Take of gum animi and afphaltum each one ounce, of red lead, litharge of gold, and umbre, each one ounce and a half. Re- duce the groffer ingredients to a fine powder, and having mixed them, put them, to- gether with a pound of linfeed oil, into a proper veffel, and boil them gently, conftantly ftirring them with a flick or to- “ bacco-pipe, till the whole appear to be in- corporated. Continue the boiling, fre- quently ftirring them, till, on taking out a “ finall quantity, it appear thick like tar as it grovs^s cold. Strain the mixture then “ through flannel, and keep it carefully ftopt up in a bottle, having a wide mouth, for ‘‘ life. Of Gilding. 439 life. But when it is wanted, it muft be ground with as much vermilion as wilt give it an opake body, and at the fame time diluted with oil of turpentine, fo as to render it of a confiftence proper for w^ork- “ ing freely with the pencil.’*' 1 he afphaltum does not, I conceive, con- tribute to the intention of gold fize, and the litharge of gold, and red lead, are both the fame thing, with refpe in the ftamps, with the above mixtures of powdered chryftal [and gum water; and, wiping, the other parts of them perfedlly clean, place them then^on ,the paper or vellum, laid over fome fheets of paper, , taking, care .that the. letters may be in theexad}: pofitlon where they ought to lie ; ftrike then the ftamp in a perpendicu- lar direction, but not too forcibly, and take it off in the iame direction. The letters will be left in their proper places by this means, and will have thcTa.me proportions as their arche- types in the ftamps. Where OfGilding. 451 Where leaf gold is ufed for making em- bofled letters in manufcripts, the above com- pofition cannot be ufed ; but there are feveral others which will very well fupply its place, of which the following has been given as very excellent. ‘‘ Take the whites of eggs, and beat them “ to an oily confiftence. Then take as much ‘‘ vermilion as will be required to thicken the “ whites of the eggs to the confiftence of pafte. Form the letters of this pafte, by means of the ftamps, in the manner before direyhich it may be fiiffered to dry, and then watef-polifh'ed by rubbing it with a fine linen rag flightly moiftened. It is then in a ftate fit for receiving the gold, only it mufl be again gently moiftened at that time, and the leaves may then be laid on, being cut according to the breadth they are to cover, and preffed clofely down by a cotton ball; and after the gilding is thoroughly dry and firm,^ it may be poliflit in the manner of. tlie foregoing kinds. • ^ • :U.r .> . . ^ * I . . ; ^ ■ r X ... . ^ ^ r ^ MU I SECT, r Of Gilding. 453 SECTION VII. Of gilding leather. I L eather may be gilded for common occalions by all the fame methods which have been given for gilding paper or vellum ; except that where the gold fize is ufed there ' is no occafion to wet the leather, to prevent the running of the oil out of the bounds. Either leaf gold or the powders may therefore be ^employed as well for leather as paper; but, unlefs in fome fine work, or for very par- ticular purpofes, the German gold powder would anfwer as well as the true gold. It is needlefs confequently to repeat here the me- thods above fhewn with refpe'61 to the gilding paper for covers to books, &c. which equally well fuit for this purpofe in general; but as there is a manner of gilding leather peculiar to the book-binders, it is reqiiifite to ex- plain it. ^ The method of gilding ufed by the book- binder is to have the letters, or copartments, fcrolls, or other ornaments, cut in fteel ftamps; not by finking, as in mofl other cafes, but by the projection of the figure 'from the ground. Thefe ftamps are made hot, and leaves of gold being laid on the parts accommodated* to the pattern or defign of the gilding, the hot ftamps are preft ftrongly on the gold and F f 3 leather; 454 Of Gilding. leather, and bind the gold to it in the hollows formed by the ftamp, the other redundant part of the gold being afterwards brulhed or rubbed off. The manner pradifed by the profeffed leather-gilders for the making hangings for rooms, ikreens, &c. is not properly gilahig^ but laqtiering^ being done by means of leaf filver, coloured by a yellow varnifh, on the fame principle with the laquered frames of pidures, &c. which were formerly in ufe. It is an important manufadure, as the leather ornamented in this manner not only admits of great variety of defigns in emboffed work, refembling either gilding or filver, but alfo of the addition of paintings of almoft every foit. The manner of performing this kind of leather gilding is as follows. The fkins aie firft procured in a dry ftate after the common dreffmg and tanning. Thofe moft proper for this purpofe are fuch as are of a firm clofe texture; on which ac- count, calf, or goat fkins are preferable to fheep. But in that condition they are too hard and ftifF for gilding in this way. In order therefore to foften them, they are firft put for fome hours in a tub of water, where they are, during fuch time, to be frequently ftirred about with a ftrong flick. They are then taken out, and, being held by one cor- ner, beaten againft a flat ftone. They are next made fmooth by fpreading them on the ftone, and rubbing them ftrongly over by an iron Of Gilding. 455 iron inftriiment refembling a blade, but with the lower edge formed round, and the up- per edge 'fet- in ' a wooden handle, pafling horizontally the whole .length of "the blade. This inftrument the workman hides on the furface of the'fkin as it lies on the ftoije, at the fame time preffing and leaning on it with all his weight. /When one of the fkins’ is finifhed, another is laid over it, and treated in the fame manner, and the others over that. The fkins being thus prepared, are joined toge- ther, to form pieces of the fize required for any particular purpofe. In order to their joining properly, they are cut into a fqiiare, or rather oblong fquare form. To which end, a ruler or fquare is ufed, or the fkins are placed on a table or block, \correfponding in fize and figure to a wooden print of the kind we fhall have occafion to fpeak of below, and as much of the fkins is taken off as leaves it of the form and dimenfions of the table or block. Any defedlive parts, or holes in the fkin, are then to be 'made good ; which is done by paring away with a penknife,* half the thi^nefs of the fkin for fome little fpace round the whole, or defective part; put- ting a patch, or cofrefpondent piece of the fame kind of fkin over it. This patch; or piece, is to have a margin pared to half' the thicknefs, to fuit the pared part of ' the fkin, and is then to be fixed in its place, by means of fize made of parchment, or glover’s cut^ tings, in the manner deferibed before p. 432. F^f 4 After 4j6 Gilding. After the (kins are thus prepared, the next operation is the fizing them, which is done by means of a kind of foft glue, or ftiff fize, that anfwers to the gold fize, ufed in other kinds of gilding or filvering prepared from parchment, or glovers cuttings. This is, in fadt, the fame with that directed to be ufed for joining the pieces, only it muft be re- duced by longer boiling to a thicker confift- ence, which Ihould be that of‘ a very ftiff jelly. To fize a fkin or piece, the workman takes a piece of the fize of the bignefs of a nut ; which, however, he does not ufe whole, but cuts into two parts. With one of thefe parts he rubs all the fkin, or piece of leather ftrongly; and when it is by this means fpread over the whole furface of the leather, he rubs it with the palm of his hand to difperfe it more equally and uniformly over every part. To the effeding this end, the heat .of the hand contributes as well as the motion, as it melts the fize to a certain degree of fluidity, and renders it confequently more capable of being diflufed over the whole furface. The workman then leaves the fkin for fome time to dry, and afterwards fpreads the other part of the fize on it, in the fam.e manner as the firft, which finifhes the operation of fizing. It is neceflary to allow fome fpace of time betwixt the laying on the two parts of the fize ; for if the whole was laid on together, or the firft part before the other was dry to a cer- Of Gilding. 457 a certain degree, the whole 'would diffolve, and be forced forwards before the hand, in- ftead of being fpread by it. In the profecu- tion of this bufmefs, the workman therefore, as foon as he has fpread the firft part of the fize, takes another Ikin and treats it in the fame manner, which filling up the interval of time proper for drying the firlt, he returns then to that, and puts on the other part of the fize, and by this alternative treatment of them employs the whole of his time with- out any lofs by waiting till either be dry. The fide of the Ikin on which the hair grew, or what is called the grain of the leather, is' always chofen for receiving the fize and filver. This is neceffary to be obferved, becaufe that fide is evener and of a clofer texture than the other. The fkins, being thus fized, are ready for receiving the leaves of filver, which are thus laid on. The workman who filvers them ilands before a table, on which he fpreads two fkins before they are dry after the fizing. On the fame table, on the right hand, he puts alfo a large book of leaf filver on a board, which, near 'One end of it, has a peg fufficientiy long to raife it in fuch manner as to make it flops like a writing defk. The book being thus placed, he takes out one by one the leaves of filver, and lays them on the fkin previoufly fized as above. This he does by means of a fmall pair of pincers, formed by two little rods of wood faftened to- gether 45^ Of Gilding gether at one end, and glued to a fmall piece of wood, cut into the form of a triangle, in- tended to keep the ends of the two rods at a diftance from each other, and to make them anfwer the purpofe, when prelTed by the fingers, of taking hold of the leaves of filver. On the fide of the piece in which the rods are joined to form the pincers, there is put a kind of turf, or fmall brufh, of an irregular form, made of foxes, or any other kind of foft hair. With thefe pincers, the workman takes hold of one of the leaves in the book, and puts it on a piece of cartoon, larger than the leaf, of a figure nearly fquare, and which has the corners of the end, that is to be placed in the hand of the workman, bent. This piece of cartoon is called a pa- let. The workman takes it in his left hand, and having put on it a leaf of filver, he turns it downward, and lets the leaf fall on the fkin, fpreading it as much as he can, and bringing, as near as poffible, the fides of it to be parallel to thofe of the fquare of leather, or fkin. If it happen that any part of it gets double, or is not duly fpread, he fets it right, raifes it fometimes, and puts it in its place, or rubs it gently with the kind of brufh, or hair pencil, which is at the end of the pin- cers; but moft generally, the workman only lets the leaf fall in its place, fpread out on the furface of the leather, without either touch- ing or preffing it, except in the cafe we fhall mention below. After he has done with this Of Gilding. 459 ‘tins leaf, he lays a- new one in the fame line, and continues the fame till fuch line be complete. He then begins cldfe to the edge of this row of leaves, and forms another in the fame man- ner, and goes on thus till the whole d^in be entirely covered with the leaf filver. This work is very eafily and readily performed, as the leaves, which are of a fquare form, are put on a plain furface, which is alfo rectan- gular. The flcin being thus covered with the filver, the workman takes a fox’s tail, •made into the form of a ball at the end, and iifes it to fettle the leaves by prefling and ftriking them to make them adhere to the fize, and adopt themfelves exactly to the places they are to cover. He afterwards rubs the whole furface gently with the tail, with- out ftriking, which is done to take off the loofe and redundant parts of the filver, and at the fame time to move them to thofe places of the furface where there was before any defedt of the filver; and where, confequently, the fize being bare, thefe will now take. The reft of the loofe filver is brufhed for- wards to the end of the table, where a bag or linen cloth is placed to receive it, The fldns, when they are thus filvered, are hung to dry on cords, fixt by the ends to oppofite walls, at fuch height as to fufpend the fkins out of the way of the workman. To hang them on thefe cords, a kind of crofs is iifed formed of a ftrong flick, wnth a fhorter piece of the fame fixed crofs-wife at the 460 Of G I l d I n g, the end of It, over which the lldn being hung without any doubling, and with the filvered outwards, it is conveyed and tranf- ferred to the cord in the fame Hate. The fkins are to dry in this condition a longer or fhorter time according to the feafon and the weather. In fummer four or five hours is fufficlent, or thofe fkins which have been filvered in the morning may remain till the evening, and thofe in the evening till next morning ; but in winter a longer time is re- quired, according to the ftate of the weather. There is no occafion, neverthelefs, to wait till they be intirely dry, as they may be put In any back yard or garden expofed to the wind, and the heat of the fun. For this purpofe they fitould be put over two boards joined together, where they muft be kept ftretched out by means of fome nails, But in this cafe the filvered fide muft be next the boards, in order to prevent any dirt from falling on it, and flicking to the fize, which would hinder their taking well the burnifh that will be mentioned below. The heat and the drynefs of the air muft determine alfo the time of their hanging in this ftate ; but experience alone can teach how to judge of this point. It is proper the ikin Ihould be free from moifture, but yet that they Ihould retain all their foftnefs; in fummer this will happen in a few hours, and they will be then in a condition to be burnifhed. The Of Gilding. 461 The burnlfher which is iifed for this pur- pofe is a flinty of which various figures may be allowed, and which rnuft be mounted dif- ferently with a handle, according to the difference of the figure. A cylindrical form is often chofen, in which cafe one of the ends fhould be of a round figure, of about an inch and a half diameter, and have the fur- face extremely fmooth, as the poliftiing is performed with this furface. The flint is fixed in the middle of a piece of wood of a foot length, the whole of which length is ne- ceffary to its ferving as a handle, or the work- man takes hold of it at each end with each of his hands, thofe parts being roundifh, and the middle being left of a greater thick- nefs, in order to admit of a hole of a proper' depth for receiving the flint, fo as to keep it quite firm and fteady. All the art required in the manner of burnifhing is to rub the leaf filver ftrongly; for which purpofe the workman applies both hands to the burniflier, dwelling longer on thofe parts which appear moft dull. In order to perform this opera-' tion, the fkin is put and fpread even on a fmooth fl;one of a requifite fize, placed on a table, where it may be fo firm and fteady as to bear all the force of preflure the work- man can give in Aiding the burniflier back- wards and forwards over every part of the flcin.^ It would fave a great deal of labour to employ, inftead of this method of burnifhing, that ufed by the polifliers of glafs, and alfo by 462 Of Gilding. by the card-makers. This method confifts In fixing the burnifher at the end of a flrong crooked flick, of which the other end is faftened to the cieling. The flick being fo difpofed as to adt as a fpring, of which the , force bears on the fkin, it exempts the work- man from this part of the labour, and leaves him only that of Aiding the burnifhers along, the fkin in the diredtions the polifhing re- quires. The objedtions to this method are, that fome parts of the fkin require a greiatef prefiure than others, and that fometimes dirt flicking to the fize, which pafies through the joining of the filver, will fcratch the work, if the workman in going along did not fee and remove it, which he cannot fo well do in ufing the fpring burnifher. But certainly thefe inconveniencies have obvious remedies when they ^ are underAood. The ufing the fpring burnifher for the gre.ateft part of the work does not prevent taking the aid of the common one for finiAiing, if any parts, that appear imperfedtiy poliAied, fhall render it necefiary, and the workman may well afford the trouble of examining the fkin and cleant ing it thoroughly by the labour he will fave in this way; or, perhaps, it is always beft to do this office^ before any kind of polifhing, be begun, rather than to leave it to be done- during the polifhing» In fome manufadtures, the burnifhing is performed by paffing the filvered fkins be- twixt two cylindrical rollers jof ile.el . witk polifhed Of Gilding, 463 pollflied faces. If this be well executed it muft give a confiderable brilliance to the filver, and take away all thofe warpings and inequa- lities in the leather which tend to render the filvered furface lefs equal and fhlning. The fkins or leather being thus filvered and burniflit, are now prepared to receive the yellow laquer or varnifh, which gives the appearance of gilding. The perfedion of this work depends obvioufiy, in a great de- gree, on the colour and other qualities of the compofition ufed as fuch varnifh, for which different artifts in this way have different re- cipes, each pretending, in general, that his o\yn is beft, and making confequently a fecret. of it. The following is, however, at leaft equal to any hitherto ufed, and may# be pre- pared without any difficulty, except fome little nicety in the boiling. Take of fine white refin four pounds and a half, of common refin the fame quantity, of gum fandarac two pounds and a half, and of .aloes two. pounds. Mix them together, after having .bruifed thofe which are in great pieces, and put them into an earthen pot over a good fire made of charcoal, or over any other fire where there is no flame. Melt all the ingredients in this manner, ftirring them well with a. fpatula, that they may be thoroughly mixt together, and be prevented alfo from ftick- ing to the bottom of thepot. When they are perfectly melted and mixt, add gradu- ally 4^4 Of Gilding. ally to them feven pints of linfeed oil, and ftir the whole well together wdth the fpatula. Make the whole boll, ftirring it “ all the time, to prevent a kind of fediment that wdll form, I’rom flicking to the bottom of the vefTel. When the varnifh is almoft fufficiently boiled, add gradually half “ an ounce of litharge, or half an ounce of red lead, and when they are diffolved pafs- the varnifh through a linen cloth, or flannel bag.” The time of boiling fuch a quantity of varnifh may be, in general, about feven or eight hours. But as the force of the heat and other circumflances may vary, it does not admit of any precife rule. The means of judging of this is by taking a little quantity out of the pot with a filver fpoon, or other fuch inflrument, and touching it wdth the finger; when, if the varnifh appear, on cooling, of the confillence of a thick fyrup, become foon after ropy, and then drying, glue the fin- gers together, and give a fhining appearance, it may be concluded the time of boiling is fufficient. But if thefe figns are found w^ant- ing, the contrary mufl be inferred, and the boiling mufl; be continued till they do arife. When the quantity of ingredients is dimi- nifhed, the time of boiling may be alfo con- tradled. A pint of oil, and a correfpondent proportion of fine • refin and aloes, has pro- duced a varnifh perfedly good in an hour and a half. • ’ ' In Of Gilding. 465 In this procefs it is very neceffary to have a pot that will not be half filled with all the ingredients, and alfo to guard with the great- eft caution againft any flame coming near the top of the pot, or the vapour which rifes from it during the boiling; for it is of fo combuftible a nature, it would immediately take fire, and the ingredients themfelves would burn in fuch a manner as would not only defeat the operation, but occafion the hazard of other inconveniences. The varnifh 'thus prepared attains a brown appearance ; but, when fpread on filver, gives it a colour greatly fimilar to that of gold. If, however, it fhould not be found after this proceeding that the force of yellow was fufficiently ftrong, an addition of more aloes muft be made before the boiling be difeon- tinued. Care muft be taken, neverthelefs, in doing this, not to throw in a large lump at once; becaufe fuch an efFervefcence is ex- cited, in that cafe, as would endanger the varnifh - rifing over the edge of the veffel, and producing a flame that would inftantly make the whole take fire. On the other hand, if the varnifh feem too ftrong of the colour, fandarac -muft be added with the fame precaution, which, increafing the quan- tity of varnifh, will dilute the colour. The laying the laquer, or varnifh on the filvered leather, is performed in the open air, and fhould be done in fummer, when it is hot and dry. It is thus performed. The fkins VoL. I. G g are 400 Of G I l d I n g. are again to be ftretched and fafleneJ with nails to the fame boards on v/hich they were* before fixt to complete the drying after the filvering; but with this difference, that the filvered fide muft be outwards. Eighty or twenty {kins may be treated thus at the fame time, there being two or three on each board. All the boards fhould be then ranged on treffels parallel to each other, in fuch man- ner that all, both of them and the fkins, may be clofe to each other. Every thing being thus prepared, the principal v/orkmen fpreads fome of the white of eggs over each fkin. The life of this is to fill up fmall inequalities in the furface of the fkin, and to prevent the varnifli paffing through the Interftices of the filver, ' and being abforbed by the leather. Some omit this, and with advantage, if thefe inconveniencies could be avoided without it, ■as it renders the varnifh more apt to crack and peel off the filver. But where it is omitted, the varnifli fhould be of a thicker eonfiftence, the furface of the leather of a firm denfe texture, and the leaves of filver of a greater thicknefs than the common. When the white of eggs is dry, the work- man who lays on the varnifh fets it on the table before him in a pot , being, as before direfbed, pretty near the eonfiftence of a thick fyrup. He then dips the four fingers of one of his hands in the varnifh, and ufes them as a pencil to fpread it on the fkin. In doing this, he holds the fingers at a fmall but equal diftance O ^ fe I L b I N G. 467 diftance from each other, and putting the ends of them on the fkin near one of the edges of it, and he then moves his hand fo that each finger paints a kind of S with the varnifh, from one end of the fkin to the othef- He afterwards dips his fingers again in the Varnifh, and repeats the fame operation again, on the next part of the ihin, till the whole be gone over in the fame manner. This might be done with a pencil or proper brufli, but the workman finds the ufing the fingers only to be the readied method for didribut- ing the varnifh equally over the fkin. After the varnifh is thus laid on the fkin, it is to be fpread, w^hich is dill done by the hand folely. The method is to rub the flat of the open hand over every part of the fkin on which the varnifh has been put by the fingers, and by that means diffufe it evenly over every part. After this, it is to be immediately beaten by flrokes of the palms of the hands, which are to be frequently repeated on every part in general, but in a greater degree on thofe places where the varnifh appears to lie thicker than on the red; and in doing this, both hands are, for difpatch, employed at the fame time. When this operation is finiflied, the fkins are dill to be left on the boards where they were dretcht and nailed ; and thofe boards are, therefore, either continued till that time on the treflels where -the varnifh was put on the fkin, or, if they be wanted for freih fkins, taken off, and fixt up againfl the G g 2 wall >6S O F G J L D I N C wall of the place, or any other proper lup^ port. The time of drying depends of courfe on the heat of the fun and weather, but at a feafonable time does not exceed a few hours. It is to be known, as to each particular parcel of Ildns, by examining them with the finger.' If on touching them they be found free from any hickinefs, or, in the ftyle of workmen, tackinefs, or, that the finger makes no im- preffion on the varnilh, they may be con- cluded fufficicntly dry, and the contrary when they are found to be otherwife. This coat of varnifh being dry, the fkins are to be again put on the trelfels as before, and another coat laid on exaflly In the fame manner as the firft. In doing this, examination muft be made whether any of the fkins appear ftonger or weaker coloured than the others, in order that the defeft may be now remedied, by making this coat thicker or thinner, as may appear necelfary. When this coat is dry, the varnifh for producing the appearance of gilding Is completed ; and if it has been well performed, the leather will have a very fine gold colour, with a confiderable degree of polifli or brightnefs. When there is an intention to have one part of the leather fi.lver, and the other gold, a pattern is formed on the furface by printing,, calking, or ftamping a defign on the furface after the filverlng. The fldn is then to be varniflied, as if the VvTole were intended to be gold ; but after the laft coat, inflead of drying. the Of Gilding. 469 die varnlfh, it is to be Immediately taken off that part which is intended to be filver, accord- ing to the defign printed or calked upon it, by a knife, with which the workman ferapes off all that he can without injuring- the filver, and afterwards by a linen cloth, wdth which all that remains is endeavoured to be wiped* or rubbed off. •' The fkins, being thus filvered and varnlfhed, are made the ground of various deligns for emboffed work and painting. The emboffed wmrk or relief is raifed by means of printing with a rolling prefs, fuch a-s is ufed for cop- per-plates ; but the defign is here to be en- graved on wood. The painting may be of any kind, but oil is principally ufed, as being durable and moft eafily performed. There is nothing more neceffary in this cafe than in painting on other grounds, .except that, where varnifh or water is ufed, the furface be clean from any oily or greafy matter. SECTION VIIL Of gilding of glafs without a7mealing or burning. G lass may be gilt by applying, as a cement, any gold fize, or other fize, gum water, or varnith; and, when it is of a G g 3 proper 47® Of Gilding^ proper degree of drynefs, laying on the gold, as in the other methods of gilding. The work may alfo be polifhed afterwards in the fame manner, if the burnifht appearance be defired ; but where that is intended, it is pro-^ per to add bole armoniac, chalk, or other fuch fubhance, to the cement. When drinking glaffes are to be gilt, - with- out burning, the cement fhould be either feme gold fize formed of oil, or fome kind of var- nifh compounded of the gum refms, that will not dilTolve in water, but require either fpirit of wine or oil of turpentine for their folution. At prefent, neverthelefs, this is not only neg- lected by thofe who gild drinking glafles for fale, but glaffes gilded with gum . rabic, or the fizes which will diffolve in water, are im- pofed upon the public for the German glalfes gilt with the annealed gold, and fold at a dear rate under that pretence; though after they have been ufed for a very fhort time, the gold peels and rubs off in fpots when the glaffes are cleaned, and renders them very unfightiy. As the glaffes with gilt edges are at prefent much in fafhion, and the true kind are brought from Germany, or elfewhere, the incitement of the cultivating this branch of gilding here would not be an unfit objeCt of the premiums of the worthy fociety for the encouragement of arts; fince, fpr the doing this work in perfection, there is nothing more wanting than that dexterity of the manoeuvre which arifes from a little praCtife in matters of this kind. Of Silvering. 473* kind, as I have before fhewn in treating par^- ticularly of this article, p. 374, by a general method, and explained fully there, and elie- where, the nature of the fubitances proper to be employed, as far as refpefts this ope- ration. CHAP. II. Of jfilyering. S ILVERING may be pradlfed on the fame fubftances, and by all the fame methods, either with leaf or powder, we have before pointed out with regard to gilding ; variation ’ being made in a few circumftances below mentioned. It is neverthelefs but fel- dom ufed, notwithftanding the elfed: would be very beautiful and proper in many cafes ; and there is an extreme good reafon for fuch a negled: of it. This reafon is, its tarniffring in a very fliort time, and acquiring frequently, befides the general depravity of the white- nefs, fuch fpots of various colours as render it very unfightly ; and this tarnifli and fpeck- ing is not only the conftant refult of time, but will be often produced inftantly by any extraordinary moifture in the air, or damp- nefs, as well as by the fumes and effluvia of many bodies which may happen to ap- proach it. s 4 Where 47^ Of S I l V e r I k g. Wherever, therefore, filvering is admitlei, a ftrong varnlfh ought to be put over it; and this even is not fulBcient wholly to fecure it from this defedlive confequence. The var- nifli muft be fome of the compofitions of maf^ tic, fandarac, the gums animi, or copal, and white refin; (the particular treatment of which in the forming varnifhes will be found in other parts of this work) for the other fubftances ufed for compounding varnifhes are too yel- low. Some put a coat of ifinglafs fize over the filver; but, befides that the fize itfelf injures the whitenefs in time, by turning yellow, it preferves the filver but in a fmall degree. Experience has fhewn, in the cafe of the filvered leather, what the varnifli may be compofed of that anfwers befl for this pur- pofe, and the kind before given, p. 463, un- der that head, may be «^pplied to other pur^ pofes. The methods of making the filver pow- ders are alfo the fame as thofe of gold, ex- cept with regard to one of the German pow- ders, which is correfpondent both in its ap- pearance and ufe, abating the difference of colour, to the anriim Mofaicum^ or mufivum\ whence it has been indeed, though improperly, called the argentum mufivum,. The procefs for this being, therefore, different from any before given, it is proper to infert it fully, as follows. ‘‘ Take of very pure tin one pound. Put it into a crucible, and fet it on a fire to melt; Of Silvering. .473 melt; when it begins to run Into fufion, add to it an equal proportion of bifmutb or tin glafs, and ftir the mixture with an iron rod, or the fmall end of a* tobacco^ “ pipe, till the whole be intirely melted and “ incorporated. Take the crucible then from “ the fire, and after the mielted ccmpofiti^n “ is become a _ little cooler, but while it is “ yet in a fluid ftate, pour into it a pound of “ quickfilver gradualhf, flirring it in the ‘‘ mean-time, that the mercury may be thoroughly conjoined with the other ingre- “ dients. When the whole is thus commixt, pour the mafs out of the crucible on a ftone, ‘‘ where, as it cools, it will take the form of an amalgama or metalline pafte, which wdll “ be eafily brulfed into a flaky powder, and is then fit ifor ufeT This .powder may be either tempered in .the manner of the fliell gold, with gum w’ater, or rubbed over a ground properly fized, ac- cording to any of the methods above directed for gold powder, and it will take a very good polllh from the dog’s tooth or burnifhers, and hold Its colour much better, with a flight coat of varnifh over it, than any true filver powder or leaf. The fizes for filvering ought not to be mixed, as in the cafe of gold,- with yellow, or bole armoniac, but with fome white fub- flance, wTofe effecl may prevent any fmall failures in the covering the ground wdth the filver from being feen, in the fame manner as 474 Silvering, as the yellow fubftances do the gold. This may be done with flake white, or white lead, when the fizes formed of oil are ufed; but whiting is the proper matter in the burnifh fize for filvering, or wherever the glovers or parchment fize is ufed. Some recommend tobacco-pipe-clay in the place of whiting, and add a little lamp black to give a filver- like greyiflmefs to the compofition. Leather is fllvered by thofe who have the manufadtures of hangings, flcreens, &c. though not fo frequently with a view to the retaining its own colour as to produce the imitation of gilding, of which the wfliole pro- cefs is before given, p. 454. In fome cafes, neverthelefs, the appearance of filver is re- tained, and it is therefore proper to take fome notice of the manner of performing this work. The proceeding in filvering the leather is to be in all refpedfs the fame as when it Is to have the appearance of gilding (of which the particular manner has been before fhewn under the article of gilding leather) till that part of the procefs where the v^arnifh or laquer, which is to give the yellow colour, is to be laid on. Inftead of this yellow varniffi, a clear colourlefs one is to be fubflituted, where the appearance of filver is to be preferved; but this is neceffary only in order to prevent the tarnifh and difcolouring, which of courfe happens in a fhort time to filver expofed in a naked and undefended ftate to the air. The moft common yarnilh ufed for this purpofe is only Of Silvering. 475 only parchment iize, prepared as above diredled, page 432, which is preferred to others on. account of its cheapnefs. This is made warm in order to render it Hiiid, and then laid on with a fpunge inftead of a pencil or brufh. There is no reafon, however, as this kind of varnitli is liable to fufter by moifture, and grow foul and difcoloured, that better kinds, fuch as thofe of Martin, or others, which are ufed for papier mache^ w'ood, &c. fhould not be employed here, provided they be co- lourlefs. The more hard and tranfparent, and the more they are of a refmous nature, the more brilliant and white, and the more durable will be the filvery and polilht appearance of the filvered leather. Some, inftead of parchment fize, life that made of ifmglafs, which may be prepared according to the me- thod laid down p. 432. This refifls moilfure, and will keep its colour and tranfparency better than the other kinds of fize; but all of them grow yellow and cloudy with time, efpecially if any damp or moifture have accefs to them. Indeed filver, fecured even by the beft varnidi, will' ftill in time take a tarnifh and lofe its beauty, and therefore the giving the leaf filver on leather the appearance of gold, even though attended with fome addi- tional expence, is preferable in mod: cafes. Leather filvered in this manner may be or- namented by printing in relief, and by paint- ing in the fame manner as that reprefenting gilding, though, on account of the want of durability. 47-6 Of Bronzing. durability, this is much feldomer praftlfed. U is pofTible that fome amalgama of quickfilver, or other compofition might be found, that would have the refemblance of filver, and yet refift tarnifhing, which would not only be a ■great improvement, by the furnilhing a durable kind of lilvering for leather, paper, &c. but alfo fave part of the expence of leaf filver for a ground for gilded lieather. This has been at- tempted in France with fome fuccefs, but not to the degree of perfection wifhed for. CHAP* IIL of bronzing. B ronzing is colouring by metalline powders, plainer, or other bufts and figures, in order to make them appear as if caft of copper or other metals. This is fometimes done by means of cement, and fometimes Vv^ithout, in the in- ftance of plaifter figures; but the bronzing is more durable and fecure when a cement is ufed. The gold powders, and the aurum MofaU ciim^ we have before given the preparation of, are frequently employed for this purpofe; but the proper bronzing ought to be of a deeper and redder colour, more refembling copper, whicfi Of Bronzing. 477^ ’which effeft may be produced by grinding a very fmall quantity of red lead with thefe po’wders; or the proper powder of copper may be ufed, and may be prepared as follows. ‘‘ Take filings of copper, or dips of cop- per-plates, and difiblve them in any kind of aqua forth put into a glafs receiver, or other proper formed veffel. When the “ aqua forth is faturated with the copper, take out the flips of the plates; or, if filings wxre ufed, pour off the folution from what re- mains undifTolved, and put into it fmall bars of iron, which will precipitate the copper from the aqua forth in a powder of the proper appearance and colour of copper. Pour off the water then from the pow^der, ‘‘ and wafh it clean from the falts, by feverai fucceflTive quantities of frefh water.” Where the appearance of brafs is defigned, the gold powders, or the aurum Mofaicum^ may be mixt with a little of the powder called argentum fnuftvum^ of w^hich the preparation is above given. Where the appearance of filver Is v/anted, the argentum mufivum is the befl: and cheapeft method, particularly as it will hold its colour much longer than the true filver ufed either in leaf or powder. Where no cement is ufed in bronzing, the powder muft be rubbed on the fubjedt intended to be bronzed, by means of a piece of foft leather, or fine linen rag, till the whole fur- face be coloured. The 478 Of BRONzir;G. ■ The former method of ufing a cement m bronzing was to mix the powders with ftrong gum w^ater, or ifinglafs fize ; and tlien with a brulh, or pencil, to lay them on the fubjedt. But at prefent fome ufe the japanners gold fize, and proceed in all refpeds in the fame manner as in gilding with the powders in other cafes; for which ample dired:ions have been before given. This is the beft method hitherto practifed. For the japanners gold fize binds the pow^ders to the ground, without the leaft hazard of peeling or falling off; wTlch is liable to hap- pen when the gum w^ater, or glovers, or ifin- glafs fizes are ufed. Though, notwithftand- ing the authority of the old pradtife for the contrary, even thefe cements will much better fecure them when they are laid on the ground, and 'the pow’^ders rubbed over them, than when both are mixed together, and the effect, particularly of the aiirum Mofaicurriy will be much better in this way than the other. The gold fize fhould be fuffered, in this cafe, to ap- proach rnuch nearer to drynefs than is proper in the cafe of gilding wnth leaf gold, as the powders would ctherwnfe be rubbed againft it in the laying them on. The fidtitious filver powder, called the or- gentum miifivum^ may, as above-mentioned, be applied in the manner of bronze, by thofe w^hofe caprice difpofes them to filver figures or bulls. But it is the only fort of filver powder that Ihould be ufed in this way, for the Of Japanning. 479 the reafon above given, and all fiich kind of filvering Is much better omitted; for the whitenefs itfelf of plaifter in figures or bulls, and much more a glolTy or fliining whitenefs, is injurious to their right effedl, by its eluding the judgment of the eye, with refped: to the proper form and proportion of the parts, from the falfe and pointed refledions of the lights, and the too faint force of the lhades. To re- move which inconvenience it is probable w^as the firft inducement to bronzing. CHAR IV. of japanning. SECT. I. Of japannmg in generaL B y japanning is to be here underflood the art of covering bodies by grounds of opake colours in varnifh, which may be either afterwards decorated by paintings or gilding, or left in a plain ftate. This is not at prefent pradifed fo frequently on chairs, tables, and other furniture of houfes, except tea-waiters, as formerly. But the introdudion of it for ornamenting coaches, fnufF-boxes, and Ikreens, in which there is a rivaifhip betwixt ourfelves and the French, renders the cultivation and propa- 480 O F J A P A K N I N d. propagation of this art of great importance tcJ commerce. I ihall therefore be more explicit Infhewing the methods both nowand formerly in life, with the application of each to the feveral purpofes to which they are beft adapted, and point out at the fame time feveral very material improvements that are at prefent enjoyed only by particular perfons, or not at all hitherto brought into pradice. The fubftances Vvhich admit of'^ being ja- panned are almoft every kind that are dry and rigid, or not too flexible, as wood, metals, leather, and paper prepared. Wood and metals do not require any other preparation but to have theii* furfaces per- fectly even and clean. But leather fliould be fecurely ftrained either on frames, or on boards, as its bending or forming folds would otherwife crack and force off the coats of var- nifh. Paper alfo fliould be treated in the fame manner, and have a previous ftrdng coat of fome kind of fize; but it is rarely made the fubje£l of japanning till it is converted into papier mache^ or wrought, by other means, into fuch form that its original ftate, parti- cularly with rerpedh to flexibility, is loft. One principal variation in the manner of japanning is the ufing or omitting any priming or undercoat on the work to be japanned. In the older praCcice, fuch priming was always ufed, and is at prefent retained in the French manner of japanning coaches and fnuff-boxes of the papier machei But in the Birmingham manufac- Of Japanning. 481: manufadlure here, it has been always .re- jected. The advantage of ufing fuch priming or undercoat is, that it rhakes a faving in the quantity of varnifli ufed ; becaufe the matter of which the priming is compofed fills up the Inequalities of the body to be varnifhed, and makes it eafy, by means of rubbing and water- polifhing, to gain an even furface for the var- nifh. This was therefore fuch a convenience In the cafe of wood, as the giving a hardnefs and firmnefs to the ground was alfo in the cafe of leather, that it became an eftablifhed me- thod, and is therefore retained, even in the inftance of the papier mache^ by the French, who applied the received method of japan- ning to that kind of work on its introdudion. There is, neverthelefs, this inconvenience al- ways attending the ufe of an undercoat of fize, that the japan coats of varnifh and co- lolour will be conftantly liable to be cracked and peeled off by any violence, and will not endure near fo long as the bodies japanned in the fame manner, but without any fuch prim- irig. This may be eafily obferved in compar- ing the wear of the Paris and Birmingham fnuff-boxes; which latter, when good of their kind, never peel, or crack, or fuffer any da- mage, unlefs by great violence, and fuch a continued rubbing as waftes away the fub- ftance of the varnifh; while the japan coats of the Parifian boxes crack and fly off in flakes, whenever any knock or fall, particularly near the edges, expofes them to be injured. But VoL. I. H h the 482 6 F J A P A N N 1 N G* the Binnlngham manufadurers, who origin- ally pradifed the japanning only on metals, to whidi the realbn above given for the life of priming did not extend, and who took up this art of tliemfelves as an invention, of courfe omitted at firft the ufe of any fuch undercoat; and not finding it more neceffary in the in- ftance of papier machc than on metals, con« tinue ftlll to rejed it ; on which account the boxes of their manufadure are, with regard to the wear, greatly better than the French. The laying on the colours varnifh inftead of gum water, is alfo another variation from the method of japanning formerly pradifed. But the much greater ftrength of the work, where they are laid on in varnifh or oil, has occafioned this way to be exploded, with the greateft reafon, in k\\ regular manufadures. However, they who may pradife japanning on cabinets, or other fuch pieces, as are not expofed to much wear or violence, for their amufement only, and confequently may not find it worth their while to encumber them- felves with the preparations neceffary for the other methods, may paint with water colours on an undercoat laid on the wood, or other fubftance, of which the piece to be japanned is formed, and then finifh with the proper coats of varnifh, according to the methods be- low taught. If the colours are tempered with the ftrongeft ifinglafs fize and honey, inftead of gum water, and laid on very flat and even, the work will not be much inferior in appear- ance Of Japanning. 48 j ance to that done by the other method, and will laft as long as the common old Japan work, except the beft kinds of the true Ja- pan. It is pradtifed likewife, in imitation of what Is fometimes done in the Indian work, to paint with water colours on grounds of gold ; in which cafe the ifinglafs fize, with fugar- candy or honey, as above diredted, is the bell: vehicle. Imitations are alfo made of Japan work, by colouring prints, gluing them to wood- work, and then giving them a Ihining ap- pearance, by the ufe of fome white varnilh* OJ japanning grounds^ The proper japan grounds are either fuch as are formed by the varnilh and colour, where the whole is to remain of one ftmple colour, or by the varnilh either coloured or without colour, on which fome painting, or other de- coration, is afterwards to be laid. It is ne- celTary, however, before I proceed to fpeak of the particular grounds, to Ihew the man- ner of laying on the priming or undercoat^ where any fuch is ufed. This priming is of the fame nature with that called clear 'coating, (or vulgarly clear coaling) pradtifed erroneoufly by the houfe- painters, and confifts only in laying on, and drying in the moll even manner, a compoli- tion of fize and whiting. The common fize H h '2 484 O ^ Japanning; has been generally ufed for this purpofe ; but where the work is of a nicer kind, it is better to employ the glovers or the parchment fize, and if a third of ifinglafs be added, it will be ftill better j and if not laid on too thick, much lefs liable to peel and crack. The work (hould be prepared for this priming by being well fmoothed with the fifh-fkin, or glafs fhaver ; and, being made thoroughly clean, fhould be brufhed over once or twice with hot fize, di- luted with two-thirds of water, if it be of the common llrength. The priming fhould therr be laid on with a brufh as even as poffible, and fhould be formed of a fize whofe confift- ence is betwixt the common kind and glue, mixt with as much whiting as will give it a fufficient body of colour to hide the furface of whatever it is laid upon, but not more. If the furface be very even on which the priming Is ufed, two coats of it, laid on in this manner, will be fufficient ; but if, on trial with a fine rag wet, it will not receive a proper water polifh, on account of any ine- qualities not fufficiently filled up and covered, two or more coats muft be given It; and whe- ther a greater or lefs number be ufed, the work fhould be fmoothed, after the laft coat but one is dry, by rubbing it with the Dutch rufhes. When the laft coat is dry, the water polifh fhould be given, by paffing over every part of it with a fine rag gently moiftened, till the whole appear perfeftly plain and even. The ..priming Will then be completed, and the work OfJapanning. 485 work ready to receive the painting, or co-^ loured varnifh; the reft of the proceedings be-^ ing the fame in this cafe as where no priming is ufed. Of common grounds of varnifh^ which are to he painted upon. Where wood or leather is to be japanned, and no priming is ufed, the beft preparation is to lay two or three coats of coarfe varnifh compofed in the following manner. Take of re, 437 420 35 28 1 39 ^ 394 57 Calking, what, 387 : — how performed, Camera OBscyRA, its ufe in drawing, Carmine, Casts from large fubje6ls, 709 : — from fmall animals or ve getables, 41 1 : — from medals or other fmall fubjedts, 414 Ceruse, or white lead, > 132 Chrystals of verdigrife (commonly called diftilled vcr- digrife) Ji> Cinnabar native^ 48 — — how counterfeited by the fidfitious, 48 Classes of the colours, 8 Cleaning pidlures 236 Clear coating, (vulgarly called clear coaling) what, 219 Cloths for oil painting, what, 217: how bed; pre- pared, 218 Coffins for burning enamel and painted glafs, 276 CoLOGN or Collen’s earth, 127 Colouring maps, prints, tiz. 381 Colours, what, 1 : kinds of, 3: — hlach^ 138: — rhlue^ 70: — hrovjn^ 123: green^ 112: — orange^ ^J9-“ — = — p?nple^ 120 : — vjhite^ 131 : — yellow^ 97 ; — -compoh-. tion with the proper vehicles, 173 : proper to be iifed with oils, 173 : — proper to be ufed with water or in miniature painting, 178 -proper to be ufed in diftemper, or painting with fize, 187 : — proper to be ufed in frefco painting, 180 : pioper to be ufed in varnifh, 189: — for enamel, of what formed, 263 — black, 353 : blue, 340: brown, 352 green, 34.7: orange, 349: red, 336 ■purple, 351 : white, 281 : yellow, 344 : for painting on glafs by burning, 371 without burning, Coolness in colours, what. 379 7 Copper, its ufc and preparation for forming colours in lenamcl, 295 : — powder of, 477 : — calcined, 296 Cover iN'G .INDEX. Covering, as a qualitv in colours, wThat, ' 6 Crayons, general natiffe of, 195: white, 205 ; red, 206: — blue, 209: — yellow, — 210: — green, 21 1: — orange, 213: — purple, 213: — brown, 214: — black and grey, 215 Cr 330 • how burnt, 335 : — — colours^ of what formed, 263: blacky 353* 340* green, 347 brown, 352 : red, 336: -purple, 351 : ■vjhite, 28 1 orange, 349; yellow, 344 ‘how laid, and burnt, 361 :• inllruments of, _ 266 Encaustic painting, general nature of, 245: — colours proper for, 253: — howto be fixt, 257: — ftandardYor Ihewing the difference of fixt and unfixt, 255: crayons, manner of painting with, 259: paftils or crayons proper for, _ 259 English pink, 301 Evaporation, 40 Ex tract of liquorice, 130 F. Fat oil, w’hat, 143: — how prepared, 426 Fattening of colours, what, 6: how produced, 14: of toils, what, 152 Filtration, how to be performed, ^ 37 Filters, ... 28 Fire- INDEX. fiRE-LUTE, P'lake white, Flints, as a body for enamel, 280 Fluxes in enamel painting, v/hat, 278 : — fubflances ided in compounding, 280 : — particular conipofition of, 326 : — for painting on glafs, ^67 Flying of colours, what, ^ Foulness of colours, what, ^ Fresco what, i8o Furnaces for making colours, 14 : — for calcining Pruf- fian blue, 23 : — for enamelling, 267 : — for fublimlng King’s yellow, 21 : — for vermilion, 15 G. Gall stones, 106 Gamboge, 103 Gilding in general, 421: — ynds of, 422: — in oif, 426 : — with burniiht work, 331 : — japanners, 438 : — enamel or glafs by burning, 374 : without burning, 469 : — -paper, vellum, and parchment, 444 : , ■ — leather, by general methods, 453: — according to the manner of the leather-gilders, 454 Glair cf eggs^ as a varnhh for pictures, 226 Glass aS a ground for painting wdth vitreous colours, • or by burning-, 265 : — how painted with vitreous co- lours, and burnt, 367: — how gilt by burning, 374: —howl gilt without burning, 469 : — af antimony^ as an enamel colour, 303 ; of leaf as an enamel fiux, 326 : Venetian^ as a flux, 'gicy.-*-co 7 nmon c>x Bowleses white^ as an enamel ground, ’ 334 Glazing with colours, w^hat, 5 Gold, its ufe in enamel, 289, piirple or precipitated of, 290 : — leaf 422 : -Dutch^ 423 lafs or enamei for gilding ng, 440:- 37fe:- -p wder proper proper for whiit, 445 now japanners prepared, 445 : — iize for japanners gildiiig, 438 : for burniui gilding, 432 Green colours, 1 12 : — Prv.ffan^ 1 16 : — tap, 1 15 Grounds for oil painting, 216: — ^^for water colours, 220: — for painting in diftemper, 222: — for frefco -for varnlm painting 5. 224:- c for cn- paintmg, 223 cauftic painting, 247 : — for enamel, of what formed, 28 1 compolition and preparation of, 330 how INDEX. how laid on and burnt, 371 : — for japan work, 4^3* Gum Arabic^ 165: — Se 7 iega!^ 166; — -fanderaCy 171-: — - Gum WATER, how prepared, 180 H. Hardness of enamel, and fluxes, what. Hartshorn, caleined or burnt, Horn, how to be flained of various colours, j. I. Japanning, general nature of, Japan grounds for, 483:^— black, 493; blue, 489: — green, 491 orange, 492 :■ 493 -- -yellow, 491 :■ -white, 487: -red, 490 ; — -purple, 492:- 9.62 J34 5^5 479 tortoife-lhell, ed, 465 how varniQied, 496 -how polifhed, 'how paint- -how gilded, 501: . 501 Impressions, how to be taken from various fubjecSls, 404 Indian ink, 142 Indian red, true, 120 : common or hclitious, 53 Indigo, ' 9s Instruments for making coiGurSj 13: for enamel- ling, 266 for gilding 424 Iro N, its ufe in, and preparation for forming colours in how to be caft with a fmall heat, -Jize^ how prepared, 415 181 130 J39 515 enamel, 298 Isinglass, 168 Juice, Spanish, Ivory black,. ^ ■ Ivory, how to be ftained of various colours, K. King’s yellow, 97 1 L» Lac feedj 169: -7^^//, 170 Lac M us, or Litmus ' 95 Lake, common^ 59: heauuful^ prepared from Eralil wood, 64: ^Chinefs or Indian^ 67: — rofe or rofe pin 68 ; — ^ — orangey 1 1 9 Lamp blaCxK, 138 LAquERiNG, what, and how performed, 454 Laquer for imitating gold, 463 : for tin, 505 : defending brafs work, 504- Lavender I N D E X. LaVende'r, Oil ofy as a fecondary vehicle in enamel painting. J 57 Lead, red^ 49: — white^ 132 \—fugar of, 362 Leaf-gold, qualities and kinds of. 422 Leather, how gilded, 453 Leaves, impreflions of, 194; — ^how to be preferved for a long time, 419 Levigation, how to be performed, 4 ^ Light pink. 102 Linseed oil. 1 54 Liquorice, extra6l of, or. Spanifli juice^ 33a Litmus, or Lacmus, 95 Logwood wafn. 122 Lute, called fire-lute, 14: — common,' 33 M. Maps, how to be wafhed with colours. 381 Magnesia, its nature and ufc in enamel, 287 Marble, how to be ftained of various colours. 521 Mastic 171 Mast I COT, 104 Mathematical compaffes, ox parallelogram. 390 Matting^ what, 435: — how performed. 435 Medals, cafis of, how to be taken, 414 : — imprefiions of, how to be made, 416 Melting pots for enamel, 273 Mending pidlures, 234 Mercup.y, its ufe in enamel colour, 3 c »3 Metzotjnto prints, how taken ofF on glafs and painted. 379 178 278 Miniature painting, what, Minium, 49 : — ^as an enamel flux. Moilon, as a body for enamel. 281 Muffles for burning enamel, or painted glafs,- 274. N. ) Naples yellow. 98 Native cinnabar. 48 Nut oil, 156 0. Off tracing, what, 386: — how performed, 395 Oil, general nature of, as a vehicle in painting, 150 : — particular or Ji%e paintings 1 8 performed, 222: — INDEX. particular kinds of, 154.: — 158: — of la^cendtY^ J 5 7 '.-^Ur.fccd^ 1 54 : — nut^ 1 56 : — poppy y 157 : — of r«r- pentine^ 16 1 Oker, Iroivn^ 127; — red^ 69: — -fcarlet^ 51: — yelloiu^ 99 Opacity of colours, what, 5 Operations fubfcrvient to the preparing colours, 31 Orange colours^ 119: — lake^ 1 1 9 Orchal, or Archai., I2i Or P I M ENT, comimn^ 105 ; — refinedy or King’s yellow, 97 : — its ufe as an enamel colour, 304 P. Painting in oU^ what necelTary to it, 173: how performed, 216 : — in miniature^ or with zuater colours v/har, 178: how performed, 220: in dijhmper 7: in fre fee ^ what, 189; — how — in Uarnijh^ what, 190: how performed, 224 : — :n glafs with vitreous colours, 362; ^with oil, water, or varnifli colours, 379 Pallet what, 424: — for gilding, what, 425 Paper, as aground for water colours, 220: — *how gilt, 444: — how ftained of various colours, 519' Pastil?, or Crayons, 195 Parchment, how gilt, 444 :-^how ftained, 519 Parallelogram, or Mathematical compasses, what, and how ufed in drawing, 399 Pearl white, 136 Pictures, how to be preferved, 224: how to be mended, 234 : — how cleaned, 236 Pigments, what, 3 Pink, hrown^ 129: — Dutch^ ico: — Englijh^ ici lights 102 : — refe^ or rofe loke^ Polish for water, Poppy oil. Precipitate of gold (called purple of gold) 290: of gold in its metalline form, 376: of copper^ 297; — in its metalline form, 477 : — of iron^ 299 Precipita rioN, what, 37 Preserving piefures or other paintings, 224 Priaiing cloths for painting, 218: paper for water gilding, 388 ; — for japan, v/ork. 5C0 6S 228 157 colours, 220: wood lor oil painting, 218: for varniih paintings, 224 : — copper-plates for oil painting, 219: — for varnifiL painting, 224 VoL. L- Ld Prints t INDEX. Prints, how taken ,ofF upon glafs, and painted, 379:— how to be waflied with colours, 381 Prussian 82, — green^ u6 Purple colours, 120:— of gold, what, and how pre- pared, ^ ^ '290 Putty, or calcined tin, how prepared for ufing as a white colour in enamel painting, 281 R. Red caloursy 43:— <2^, 49; — oker^ 69 REDUCTioN'in defigning, what, 387 — how per- formed, 399 Resin, 172 Retorts, 27 Rose Pink, 68 . , S. Safflower, 67 Saffron, tinf^ure of, in Salt, fixt alkaline, as an enamel flux, 278 : — common, as an enamel flux, 279 Sand, as a body for enamel, 280 Sanderac, lyr Sanders blue, or Bleu de cendres^ 90 Sap Green, i 1 5 Scarlet oker, 51 Seed-lac, 169 Secondary vehicle in enamel painting, w^hat, 263 Senegal gum, 166 Shell-lec, 170: — varnifli, J91 Shell gold, - 445 Silver, its ufe in forming, and preparation for colours in enamel, 294 powders, how prepared, 472 Silvering, how performed, 471 : leather for hang- ings, . 474 Sinking of the colours, what, 217 Size, co?nmm^ 166: — of glovers cuttings^ 167: — parch- ment^ 432: — ifinglafs^ 168: — gold for japanners, 438: 473 288 36 261 Spike, -for burnifh gilding, 432 : — for filvering. Smalt, 93 : — its ufe in enamel. Solution, what. Softness of enamel and fluxes, what, brown^ 55; — liquorice^ 130: — white^ I N D E X. Spike, oil of 157 Spirit (or oil) of turpentine^ 16 1 : — of wine^ as a vehicle for colours, 169: how rectified to any degree extern poraneouOy, S TAILING wood black, 514:. ■blue, 510 49S green, 5(3 509 : ■mahogany colour, 512- —red, bone. or -purple, 513: yellow, 508: ivory, or horn, black, 518; blue, 517: green, 516: red, 516: yellow, 515:- purple, 517: tortoife fheli, 517: paper, parchment, blue, 520 : -purple, 521 : yellow, 519: alabafter, marble, and other ftones, of various colours., 5^^, Standing of colours^ what, 4 SrARch, how ufed for rendering water a vehicle, 168 Stones, how to be ftained of v^arious colours, 521 Sublimation, 31 SUBLIMERS, ' 25 Sugar, and fugar-candy^ how ufed for rendering water a vehicle for colours, 167: — of lead^ as a dryer, 162 T. Tartar, its ufe in forming enamel colours, 'Terra Japonica, or Japan earth, Terra vertf, T'erra di sienna, burnt, 56: — unburnt, 'I'iNCTURE of faffron, T IN, how calcined for enamel. Transparency of colours, what, 'Troy white, T URMERIC wajh^ 'i'uRPEN TINE, 171: — 5/7, or fpirit of Turpeth Mineral, -212 128 I18 107 III 281 5 137 iio 16 [ 107 V. U. \ feed-lac^ common, 497 : — —finer, 48/: coarfe, 485: floell-lac^ 191: maftic^ 1 93: compound for painting, 193: — of gum Arabic for pre^ ferving pidfures, 225 : — -compound for preferving paint- ings, 227". fimpler kind of, 228: — compound in oil of turpentine for preferving painting*^, 229: fimpler kind of, 230 Varnish- X. or , H4-- how 2?4 lecon- to be 444 54 1 N D E Varnishing pictures, Vehicles, what, 2: — nature dary in cnanvel painting, what, Vellum, as a ground for painting, 221:- g'lf) Veki-tia.n REiy, Ver D I G R 1 s E, 112 \—difiilhcl or chryjials of^ V ERDITER, Vermilion, Umere, Vitriol, grceri^ how calcined, 1&: — how 301 : — zvhite^ Ultramarine, 70: as * a colonr for enamel, 286 : — afljes^ 79 : as a culoirr for enamel, 287 UxNDERWORK ill calfing, v/har, and how to be 1 1 88 43 12v9 precipitated, i^3 Utensils for making colours, ing, 266 : — for gilding, W. ^3- 409 — for enamel paint- 424 Warmth in colours^ what, 7 Wash from French berries, 109': — from turmeric, no: — from logwood, 122: — from zedoary, ni Washing with colours, what, 5: — over, what, and how to be performed, 41 : — maps, prints, hz, 381 Water what, 178: — as a vehicle, 165: — gwn^ ho w prepared, 180: — how rendered a proper vehicle for colours, 165 Wnri'E colours^ 131: — -flake^ 13 1 : — leacl^ 1321 — pearly 136: — enamel^ 281 : — Spanijh or troy^ ^37* — Jhell^ 138: — vitri'J^ 163 AVood, how to be ifained of various colours, 434 Y. Yellow colours^ 97: — King's^ i — Naples; 98: — ske?\ 99: ’ivajh from the French berries, 109: from turmeric, no: — from faff ron, iir Z. Zai'FER, its nature and ufe in enamel, 287 Zed OR AY zva^fh^ lu FINIS. ♦ ■y . 'V . 0 ?Z (/. ' ■g V