,this etext was created by ,gregory ,walker1 in ,austin1 ,texas1 for the ,digital ,daguerreian ,archive ,project--electronic texts from the dawn of photography4 ,internet3 gwalkernetcom4com ,compu,serve3 #gcegg1fgg ,the location of the illustrations in the text are marked by hipho4gif on a separate line4 ,i hope this etext inspires a wider interest in the origins of photography and in the modern practice of the ,daguerreian ,art4 ,,the ,,history ,,and ,,practice ,,of ,,the ,,art ,,of ,,photography2 ,,or ,,the ,,production ,,of ,,pictures ,,through ,,the ,,agency ,,of ,,light4 ,,containing ,,all ,,the ,,instructions ,,necessary ,,for ,,the ,,complete ,,practice ,,of ,,the ,,daguerrean ,,and ,,photogenic ,,art1 ,,both ,,on ,,metallic ,,plates ,,and ,,on ,,paper4 ,by ,,henry ,h4 ,,snelling4 ,,illustrated ,,with ,,wood ,,cuts4 ,new ,york3 ,,published ,,by ,g4 ,p4 ,,putnam1 #aee ,broadway1 #ahdi4 ,entered according to act of ,congress in the year #ahdi1 by ,h4 ,h4 ,snelling1 in the ,clerk's office1 of the ,district ,court of the ,southern ,district of ,new ,york4 ,new ,york3 ,,printed ,,by ,,busteed ,mc,c,o,y1 #afc ,fulton ,street4 ,,to ,,edward ,,anthony1 ,,esq41 ,,an ,,esteemed ,,friend4 ,whose gentlemanly deportment1 liberal feelings1 and strict integrity have secured him a large circle of friends1 this work is ,respectfully ,dedicated ,by the ,,author4 ,,preface4 ,the object of this little work is to fill a void much complained of by ,daguerreotypists--particularly young beginners4 ,the author has waited a long time in hopes that some more able pen would be devoted to the subject1 but the wants of the numerous1 and constantly increasing1 class1 just mentioned1 induces him to wait no longer4 ,all the ,english works on the subject--particularly on the practical application1 of ,photogenic drawing--are deficient in many minute details1 which are essential to a complete understanding of the art4 ,many of their methods of operating are entirely different from1 and much inferior to1 those practised in the ,united ,states3 their apparatus1 also1 cannot compare with ours for completeness1 utility or simplicity4 ,i shall1 therefore1 confine myself principally--so far as ,photogenic drawing upon metalic plates is concerned--to the methods practised by the most celebrated and experienced operators1 drawing upon ,french and ,english authority only in cases where ,i find it essential to the purpose for which ,i design my work1 namely3 furnishing a complete system of ,photography2 such an one as will enable any gentleman1 or lady1 who may wish to practise the art1 for profit or amusement1 to do so without the trouble and expense of seeking instruction from professors1 which in many cases within my own knowledge has prevented persons from embracing the profession4 ,to ,english authors ,i am principally indebted for that portion of my work relating to ,photogenic drawing on paper4 ,to them we owe nearly all the most important improvements in that branch of the art4 ,besides1 it has been but seldom attempted in the ,united ,states1 and then without any decided success4 ,of these attempts ,i shall speak further in the ,historical portion of this volume4 ,every thing essential1 therefore1 to a complete knowledge of the whole art1 comprising all the most recent discoveries and improvements down to the day of publication will be found herein laid down4 ,,contents ,i4 ,a ,,brief ,,history ,,of ,,the ,,art4 ,,ii4 ,,the ,,theory ,,on ,,light4--,,the ,,photographic ,,principle ,,iii4 ,,synopsis ,,of ,,mr4 ,,hunt',s ,,treatise ,,on ,,the ,,influence ,,of ,,the ,,solar ,,rays ,,on ,,compound ,,bodies1 ,,with ,,especial ,,reference ,,to ,,their ,,photographic ,,application4 ,,iv4 ,a ,,few ,,hints ,,and ,,suggestions ,,to ,,daguerreotypists4 ,v4 ,,daguerreotype ,,apparatus4 ,,vi4 ,,the ,,daguerreotype ,,process4 ,,vii4 ,,paper ,,daguerreotypes4--,,etching ,,daguerreotypes4 ,,viii4 ,,photogenic ,,drawing ,,on ,,paper4 ,,ix4 ,,calotype ,,and ,,chrysotype4 ,x4 ,,cyanotype--,,energiatype--,,chromatype --,,anthotype--,,amphitype ,,and ,,crayon ,,daguerreotype4 ,,xi4 ,,on ,,the ,,probability ,,of ,,producing ,,colored ,,pictures ,,by ,,the ,,solar ,,radiations--,,photographic ,,deviations--,,lunar ,,pictures--,,drummond ,,light4 ,,xii4 ,,on ,,coloring ,,daguerreotypes4 ,,xiii4 ,,the ,,photographometer4 ,,index4 ,,introduction ,new ,york1 ,january #bg1 #ahdi4 ,e4 ,,anthony1 ,,esq4 ,dear ,sir1--,in submitting the accompanying ,history and ,practice of ,photography to your perusal1 and for your approbation1 ,i do so with the utmost confidence in your ability as a practical man1 long engaged in the science of which it treats1 as well as your knowledge of the sciences generally2 as well as your regard for candor4 ,to you1 therefore1 ,i leave the decision whether or no ,i have accomplished my purpose1 and produced a work which may not only be of practical benefit to the ,daguerrean artist1 but of general interest to the reading public1 and your decision will influence me in offering it for1 or withholding it from1 publication4 ,if it meets your approbation1 ,i would most respectfully ask permission to dedicate it to you1 subscribing myself1 ,with esteem1 ,ever truly yours1 ,,henry ,h4 ,,snelling ,new ,york1 ,february #ast1 #ahdi4 ,mr4 ,h4 ,h4 ,,snelling4 ,dear ,sir--,your note of ,january #bgth1 requesting permission to dedicate to me your ,history and ,practice of ,photography1 ,i esteem a high compliment1 particularly since ,i have read the manuscript of your work4 ,such a treatise has long been needed1 and the manner in which you have handled the subject will make the book as interesting to the reading public as it is valuable to the ,daguerrean artist1 or the amateur dabbler in ,photography4 ,i have read nearly all of the many works upon this art that have emanated from the ,london and ,paris presses1 and ,i think the reader will find in yours the pith of them all1 with much practical and useful information that ,i do not remember to have seen communicated elsewhere4 ,there is much in it to arouse the reflective and inventive faculties of our ,daguerreotypists4 ,they have heretofore stumbled along with very little knowledge of the true theory of their art1 and yet the quality of their productions is far in advance of those of the ,french and ,english artists1 most of whose establishments ,i have had the pleasure of visiting ,i feel therefore1 that when a sufficient amount of theoretic knowledge shall have been added to this practical skill on the part of our operators1 and when they shall have been made fully acquainted with what has been attained or attempted by others1 a still greater advance in the art will be manifested4 ,a ,,good ,daguerreotypist is by no means a mere machine following a certain set of fixed rules4 ,success in this art requires personal skill and artistic taste to a much greater degree than the unthinking public generally imagine2 in fact more than is imagined by nine-tenths of the ,daguerreotypists themselves4 ,and we see as a natural result1 that while the business numbers its thousands of votaries1 but few rise to any degree of eminence4 ,it is because they look upon their business as a mere mechanical operation1 and having no aim or pride beyond the earning of their daily bread1 they calculate what will be a fair per centage on the cost of their plate1 case1 and chemicals1 leaving ,,mind1 which is as much ,,capital as anything else 7where it is exercised17 entirely out of the question4 ,the art of taking photographs on ,,paper1 of which your work treats at considerable length1 has as yet attracted but little attention in this country1 though destined1 as ,i fully believe1 to attain an importance far superior to that to which the ,daguerreotype has risen4 ,the ,american mind needs a waking up upon the subject1 and ,i think your book will give a powerful impulse in this direction4 ,in ,germany a high degree of perfection has been reached1 and ,i hope your countrymen will not be slow to follow4 ,your interesting account of the experiments of ,mr4 ,wattles was entirely new to me1 and is another among the many evidences that when the age is fully ripe for any great discovery1 it is rare that it does not occur to more than a single mind4 ,trusting that your work will meet with the encouragement which your trouble in preparing it deserves1 and with gratitude for the undeserved compliment paid to me in its dedication1 ,i remain1 very sincerely1 ,your friend and well wisher1 ,e4 ,,anthony4 ,,photography4 ,,chap4 ,i4 ,a ,,brief ,,history ,,of ,,the ,,art4 ,as in all cases of great and valuable inventions in science and art the ,english lay claim to the honor of having first discovered that of ,photogenic drawing4 ,but we shall see in the progress of this history1 that like many other assumptions of their authors1 priority in this is no more due them1 then the invention of steamboats1 or the cotton gin4 ,this claim is founded upon the fact that in #ahjb ,mr4 ,wedgwood recorded an experiment in the ,journal of the ,royal ,institution of the following nature4 ,a piece of paper1 or other convenient material1 was placed upon a frame and sponged over with a solution of nitrate of silver2 it was then placed behind a painting on glass and the light traversing the painting produced a kind of copy upon the prepared paper1 those parts in which the rays were least intercepted being of the darkest hues4 ,here1 however1 terminated the experiment2 for although both ,mr4 ,wedgwood and ,sir ,humphry ,davey experimented carefully1 for the purpose of endeavoring to fix the drawings thus obtained1 yet the object could not be accomplished1 and the whole ended in failure4 ,this1 by their own showing1 was the earliest attempt of the ,english savans4 ,but this much of the principle was known to the ,alchemists at an early date--although practically produced in another way--as the following experiment1 to be found in old books1 amply proves4 ,dissolve chalk in aquafortis to the consistence of milk1 and add to it a strong solution of silver2 keep this liquor in a glass bottle well stopped2 then cutting out from a piece of paper the letters you would have appear1 paste it on the decanter1 and lay it in the sun's rays in such a manner that the rays may pass through the spaces cut out of the paper and fall on the surface of the liquor the part of the glass through which the rays pass will be turned black1 while that under the paper remains white2 but particular care must be observed that the bottle be not moved during the operation4 ,had not the alchemists been so intent upon the desire to discover the far famed philosopher's stone1 as to make them unmindful of the accidental dawnings of more valuable discoveries1 this little experiment in chemistry might have induced them to prosecute a more thorough search into the principle1 and ,photogenic art would not now1 as it is1 be a new one4 ,it is even asserted that the ,jugglers of ,india were for many ages in possession of a secret by which they were enabled1 in a brief space1 to copy the likeness of any individual by the action of light4 ,this fact1 if fact it be1 may account for the celebrated magic mirrors said to be possessed by these jugglers1 and probable cause of their power over the people4 ,however1 as early as #aeef the fact was established that a combination of chloride and silver1 called1 from its appearance1 horn silver1 was blackened by the sun's rays2 and in the latter part of the last century ,mrs4 ,fulhame published an experiment by which a change of color was effected in the chloride of gold by the agency of light2 and gave it as her opinion that words might be written in this way4 ,these incidents are considered as the first steps towards the discovery of the ,photogenic art4 ,mr4 ,wedgwood's experiments can scarcely be said to be any improvement on them since he failed to bring them to practical usefulness1 and his countrymen will have to be satisfied with awarding the honor of its complete adaptation to practical purposes1 to ,,mm4 ,niepce and ,daguerre of ,france1 and to ,professors ,draper1 and ,morse of ,new-,york4 ,these gentlemen--,,mm4 ,niepce and ,daguerre--pursued the subject simultaneously1 without either1 however being aware of the experiments of his colleague in science4 ,for several years1 each pursued his researches individually until chance made them acquainted1 when they entered into co-partnership1 and conjointly brought the art almost to perfection4 ,m4 ,niepce presented his first paper on the subject to the ,royal ,society in #ahbg1 naming his discovery ,heliography4 ,what led him to the study of the principles of the art ,i have no means1 at present1 of knowing1 but it was probably owing to the facts recorded by the ,alchemists1 ,mrs4 ,fulhame and others1 already mentioned4 ,but ,m4 ,daguerre1 who is a celebrated dioramic painter1 being desirous of employing some of the singularly changeable salts of silver to produce a peculiar class of effects in his paintings1 was led to pursue an investigation which resulted in the discovery of the ,daguerreotype1 or ,photogenic drawing on plates of copper coated with silver4 ,to this gentleman--to his liberality--are we ,americans indebted for the free use of his invention2 and the large and increasing class of ,daguerrean artists of this country should hold him in the most profound respect for it4 ,he was not willing that it should be confined to a few individuals who might monopolise the benefits to be derived from its practice1 and shut out all chance of improvement4 ,like a true1 noble hearted ,french gentleman he desired that his invention should spread freely throughout the whole world4 ,with these views he opened negociations with the ,french government which were concluded most favorably to both the inventors1 and ,france has the glory of endowing the whole world of science and art with one of the most surprising discoveries that honor the land4 ,notwithstanding this1 it has been patented in ,england and the result is what might have been expected3 ,english pictures are far below the standard of excellence of those taken by ,american artists4 ,i have seen some medium portraits1 for which a guinea each had been paid1 and taken too1 by a celebrated artist1 that our poorest ,daguerreotypists would be ashamed to show to a second person1 much less suffer to leave their rooms4 ,,calotype1 the name given to one of the methods of ,photogenic drawing on paper1 discovered1 and perfected by ,mr4 ,fox ,talbot of ,england1 is precisely in the same predicament1 not only in that country but in the ,united ,states1 ,mr4 ,talbot being patentee in both4 ,he is a man of some wealth1 ,i believe1 but he demands so high a price for a single right in this country1 that none can be found who have the temerity to purchase4 ,the execution of his pictures is also inferior to those taken by the ,german artists1 and ,i would remark en passant1 that the ,messrs4 ,mead exhibited at the last fair of the ,american ,institute1 7of #ahdh17 four ,calotypes1 which one of the firm brought from ,germany last ,spring1 that for beauty1 depth of tone and excellence of execution surpass the finest steel engraving4 ,when ,mr4 ,talbot's patent for the ,united ,states expires and our ingenious ,yankee boys have the opportunity1 ,i have not the slightest doubt of the ,calotype1 in their hands1 entirely superceding the ,daguerreotype4 ,let them1 therefore1 study the principles of the art as laid down in this little work1 experiment1 practice and perfect themselves in it1 and when that time does arrive be prepared to produce that degree of excellence in ,calotype they have already obtained in ,daguerreotype4 ,it is to ,professor ,samuel ,f4 ,b4 ,morse1 the distinguished inventor of the ,magnetic ,telegraph1 of ,new ,york1 that we are indebted for the application of ,photography1 to portrait taking4 ,he was in ,paris1 for the purpose of presenting to the scientific world his ,electro-,magnetic ,telegraph1 at the time1 7#ahch17 ,m4 ,daguerre announced his splendid discovery1 and its astounding results having an important bearing on the arts of design arrested his attention4 ,in his letter to me on the subject1 the ,professor gives the following interesting facts4 ,the process was a secret1 and negociations were then in progress1 for the disclosure of it to the public between the ,french government and the distinguished discoverer4 ,m4 ,daguerre had shown his results to the king1 and to a few only of the distinguished savans1 and by the advice of ,m4 ,arago1 had determined to wait the action of the ,french ,chambers1 before showing them to any other persons4 ,i was exceedingly desirous of seeing them1 but knew not how to approach ,m4 ,daguerre who was a stranger to me4 ,on mentioning my desire to ,robert ,walsh1 ,esq41 our worthy ,consul1 he said to me2 'state that you are an ,american1 the inventor of the ,telegraph1 request to see them1 and invite him in turn to see the ,telegraph1 and ,i know enough of the urbanity and liberal feelings of the ,french1 to insure you an invitation4' ,i was successfull in my application1 and with a young friend1 since deceased1 the promising son of ,edward ,delevan1 ,esq41 ,i passed a most delightful hour with ,m4 ,daguerre1 and his enchanting sun-pictures4 ,my letter containing an account of this visit1 and these pictures1 was the first announcement in this country of this splendid discovery4 ,i may here add the singular sequel to this visit4 ,on the succeeding day ,m4 ,daguerre paid me a visit to see the ,telegraph and witness its operations4 ,he seemed much gratified and remained with me perhaps two hours2 two melancholy hours to him1 as they afterwards proved2 or while he was with me1 his buildings1 including his diorama1 his studio1 his laboratory1 with all the beautiful pictures ,i had seen the day before1 were consumed by fire4 ,fortunately for mankind1 matter only was consumed1 the soul and mind of the genius1 and the process were still in existence4 ,on his return home1 ,professor ,morse waited with impatience for the revelation of ,m4 ,daguerre's process1 and no sooner was it published than he procured a copy of the work containing it1 and at once commenced taking ,daguerreotype pictures4 ,at first his object was solely to furnish his studio with studies from nature2 but his experiments led him into a belief of the practicability of procuring portraits by the process1 and he was undoubtedly the first whose attempts were attended with success4 ,thinking1 at that time1 that it was necessary to place the sitters in a very strong light1 they were all taken with their eyes closed4 ,others were experimenting at the same time1 among them ,mr4 ,wolcott and ,prof4 ,draper1 and ,mr4 ,morse1 with his accustomed modesty1 thinks that it would be difficult to say to whom is due the credit of the first ,daguerreotype portrait4 ,at all events1 so far as my knowledge serves me1 ,professor ,morse deserves the laurel wreath1 as from him originated the first of our inumerable class of ,daguerreotypists2 and many of his pupils have carried the manipulation to very great perfection4 ,in connection with this matter ,i will give the concluding paragraph of a private letter from the ,professor to me2 ,he says4 ,if mine were the first1 other experimenters soon made better results1 and if there are any who dispute that ,i was first1 ,i shall have no argument with them2 for ,i was not so anxious to be the first to produce the result1 as to produce it in any way4 ,i esteem it but the natural carrying out of the wonderful discovery1 and that the credit was after all due to ,daguerre4 ,i lay no claim to any improvements4 ,since ,i commenced the compilation of this work1 ,i have had the pleasure of making the acquaintance of an ,american gentleman--,james ,m4 ,wattles ,esq4--who as early as #ahbh--;and it will be seen1 by what ,i have already stated1 that this is about the same date of ,m4 ,niepce's discovery--had his attention attracted to the subject of ,photography1 or as he termed it ,solar picture drawing1 while taking landscape views by means of the camera-obscura4 ,when we reflect upon all the circumstances connected with his experiments1 the great disadvantages under which he labored1 and his extreme youthfullness1 we cannot but feel a national pride--yet wonder--that a mere yankee boy1 surrounded by the deepest forests1 hundred of miles from the populous portion of our country1 without the necessary materials1 or resources for procuring them1 should by the force of his natural genius make a discovery1 and put it in practical use1 to accomplish which1 the most learned philosophers of ,europe1 with every requisite apparatus1 and a profound knowledge of chemistry--spent years of toil to accomplish4 ,how much more latent talent may now be slumbering from the very same cause which kept ,mr4 ,wattles from publicly revealing his discoveries1 viz2 want of encouragement--ridicule6 ,at the time when the idea of taking pictures permanently on paper by means of the camera-obscura first occurred to him1 he was but sixteen years of age1 and under the instructions of ,mr4 ,charles ,le ,seuer1 7a talented artist from ,paris7 at the ,new ,harmony school1 ,indiana4 ,drawing and painting being the natural bent of his mind1 he was frequently employed by the professors to make landscape sketches in the manner mentioned4 ,the beauty of the image of these landscapes produced on the paper in the camera-obscura1 caused him to pause and admire them with all the ardor of a young artist1 and wish that by some means1 he could fix them there in all their beauty4 ,from wishing he brought himself to think that it was not only possible but actually capable of accomplishment and from thinking it could1 he resolved it should be done4 ,he was1 however1 wholly ignorant of even the first principles of chemistry1 and natural philosophy1 and all the knowledge he was enabled to obtain from his teachers was of very little service to him4 ,to add to this1 whenever he mentioned his hopes to his parents1 they laughed at him1 and bade him attend to his studies and let such moonshine thoughts alone--still he persevered1 though secretly1 and he met with the success his perseverance deserved4 ,for the truth of his statement1 ,mr4 ,wattles refers to some of our most respectable citizens residing at the west1 and ,i am in hopes that ,i shall be enabled to receive in time for this publication1 a confirmation from one or more of these gentlemen4 ,be that as it may1 ,i feel confident in the integrity of ,mr4 ,wattles1 and can give his statement to the world without a doubt of its truth4 ,the following sketch of his experiments and their results will1 undoubtedly1 be interesting to every ,american reader and although some of the profound philosophers of ,europe may smile at his method of proceeding1 it will in some measure show the innate genius of ,american minds1 and prove that we are not far behind our trans-atlantic brethren in the arts and sciences4 ,mr4 ,wattles says3 ,in my first efforts to effect the desired object1 they were feeble indeed1 and owing to my limited knowledge of chemistry--wholly acquired by questioning my teachers--,i met with repeated failures but following them up with a determined spirit1 ,i at last produced1 what ,i thought very fair samples--but to proceed to my experiments4 ,i first dipped a quarter sheet of thin white writing paper in a weak solution of caustic 7as ,i then called it7 and dried it in an empty box1 to keep it in the dark2 when dry1 ,i placed it in the camera and watched it with great patience for nearly half an hour1 without producing any visible result2 evidently from the solution being to weak4 ,i then soaked the same piece of paper in a solution of common potash1 and then again in caustic water a little stronger than the first1 and when dry placed it in the camera4 ,in about forty-five minutes ,i plainly percieved the effect1 in the gradual darkening of various parts of the view1 which was the old stone fort in the rear of the school garden1 with the trees1 fence1 c4 ,i then became convinced of the practicability of producing beautiful solar pictures in this way2 but1 alas6 my picture vanished and with it1 all--no not all--my hopes4 ,with renewed determination ,i began again by studying the nature of the preparation1 and came to the conclusion1 that if ,i could destroy the part not acted upon by the light without injuring that which was so acted upon1 ,i could save my pictures4 ,i then made a strong solution of sal4 soda ,i had in the house1 and soaked my paper in it1 and then washed it off in hot water1 which perfectly fixed the view upon the paper4 ,this paper was very poor with thick spots1 more absorbent than other parts1 and consequently made dark shades in the picture where they should not have been2 but it was enough to convince me that ,i had succeeded1 and that at some future time1 when ,i had the means and a more extensive knowledge of chemistry1 ,i could apply myself to it again4 ,i have done so since1 at various times1 with perfect success2 but in every instance laboring under adverse circumstances4 ,i have very recently learned1 that1 under the present patent laws of the ,united ,states1 every foreign patentee is required to put his invention1 or discovery1 into practical use within eighteen months after taking out his papers1 or otherwise forfeit his patent4 ,with regard to ,mr4 ,talbot's ,calotype patent1 this time has nearly1 if not quite expired1 and my countrymen are now at perfect liberty to appropriate the art if they feel disposed4 ,from the statement of ,mr4 ,wattles1 it will be perceived that this can be done without dishonor1 as in the first instance ,mr4 ,talbot had no positive right to his patent4 ,photography2 or sun-painting is divided1 according to the methods adopted for producing pictures1 into ,,daguerreotype1 ,,chromatype1 ,,calotype1 ,,energiatype1 ,,chrysotype1 ,,anthotype and ,,cyanotype1 ,,amphitype4 ,,chap4 ,,ii4 ,,the ,,theory ,,on ,,light4--,,the ,,photographic ,,principle ,some philosophers contend that to the existence of light alone we owe the beautiful effects produced by the ,photogenic art1 while others give sufficient reasons for doubting the correctness of the assumption4 ,that the results are effected by a principle associated with light and not by the luminous principle itself1 is the most probable conclusion4 ,the importance of a knowledge of this fact becomes most essential in practice1 as will presently be seen4 ,to this principle ,mr4 ,hunt gives the name of ,,energia4 ,,the ,,nature of ,light is not wholly known1 but it is generally believed to be matter1 as in its motions it obeys the laws regulating matter4 ,so closely is it connected with heat and electricity that there can be little doubt of their all being but different modifications of the same substance4 ,i will not1 however1 enter into a statement of the various theories of ,philosophers on this head1 but content myself with that of ,sir ,isaac ,newton2 who supposed rays of light to consist of minute particles of matter1 which are constantly emanating from luminous bodies and cause vision1 as odoriferous particles1 proceeding from certain bodies1 cause smelling4 ,the effects of light upon other bodies1 and how light is effected by them1 involve some of the most important principles1 which if properly understood by ,daguerreotypists would enable them to improve and correct many of the practical operations in their art4 ,these effects we shall exhibit in this and the following chapters4 ,before we enter on this subject it will be necessary to become familiar with the ,,definitions of some of the terms used in the science of optics4 ,luminous bodies are of two kinds2 those which shine by their own light1 and those which shine by reflected light4 ,transparent bodies are such as permit rays of light to pass through them4 ,translucent bodies permit light to pass faintly1 but without representing the figure of objects seen through them4 ,opaque bodies permit no light to pass through them1 but reflect light4 ,a ray is a line of light4 ,a beam is a collection of parallel rays4 ,a pencil is a collection of converging1 or diverging rays4 ,a medium is any space through which light passes4 ,incident rays are those which fall upon the surface of a body4 ,reflected rays are those which are thrown off from a body4 ,parallel rays are such as proceed equally distant from each other through their whole course4 ,converging rays are such as approach and tend to unite at any one point1 as at b4 ,fig4 #c4 ,diverging rays are those which continue to recede from each other1 as at e4 ,fig4 #c4 ,a ,focus is that point at which converging rays meet4 ,,motion ,,of ,,light--,rays of light are thrown off from luminous bodies in every direction1 but always in straight lines1 which cross each other at every point2 but the particles of which each ray consists are so minute that the rays do not appear to be impeded by each other4 ,a ray of light passing through an aperture into a dark room1 proceeds in a straight line2 a fact of which any one may be convinced by going into a darkened room and admitting light only through a small aperture4 ,illustration3 ,fig4 #a 7hipho#a4;gif7 ,light also moves with great velocity1 but becomes fainter as it recedes from the source from which it eminates2 in other words1 diverging rays of light diminish in intensity as the square of the distance increases4 ,for instance let a fig4 #a1 represent the luminous body from which light proceeds1 and suppose three square boards1 b4 c4 d4 severally one1 four and sixteen square inches in size be placed2 b one foot1 c two feet1 and d four feet from a1 it will be perceived that the smallest board b will throw c into shadow2 that is1 obstruct all rays of light that would otherwise fall on c1 and if b were removed c would in like manner hide the light from d--,now1 if b recieve as much light as would fall on c whose surface is four times as large1 the light must be four times as powerful and sixteen times as powerful as that which would fall on the second and third boards1 because the same quantity of light is diffused over a space four and sixteen times greater4 ,these same rays may be collected and their intensity again increased4 ,rays of light are reflected from one surface to another2 ,refracted1 or bent1 as they pass from the surface of one transparent medium to another2 and ,inflected1 or turned from their course1 by the attraction of opaque bodies4 ,from the first we derive the principles on which mirrors are constructed2 to the second we are indebted for the power of the lenses1 and the blessings of sight1--for the light acts upon the retina of the eye in the same manner as on the lens of a camera4 ,the latter has no important bearing upon our subject4 ,when a ray of light falls perpendicularly upon an opaque body1 it is reflected bark in the same line in which it proceeds2 in this case the reflected ray returns in the same path the incident ray traversed2 but when a ray falls obliquely1 it is reflected obliquely1 that is1 it is thrown off in opposite direction1 and as far from the perpendicular as was the incident ray1 as shown at ,fig4 #b2 a representing the incident ray and b the reflected4 ,the point1 or angle c made by the incident ray1 at the surface of the reflector e f1 with a line c d1 perpendicular to that surface1 is called the angle of incidence1 while the angle formed by the reflected ray b and the perpendicular line d is called the angle of reflection1 and these angles are always equal4 ,illustration3 ,fig4 #b 7hipho#b4;gif7 ,it is by this reflection of light that objects are made visible2 but unless light falls directly upon the eye they are invisible1 and are not sensibly felt until after a certain series of operations upon the various coverings and humors of the eye4 ,smooth and polished surfaces reflect light most powerfully1 and send to the eye the images of the objects from which the light proceeded before reflection4 ,glass1 which is transparent--transmitting light--would be of no use to us as a mirror1 were it not first coated on one side with a metalic amalgam1 which interrupts the rays in their passage from the glass into the air1 and throws them either directly in the incident line1 or in an oblique direction4 ,the reason why trees1 rocks and animals are not all mirrors1 reflecting other forms instead of their own1 is1 that their surfaces are uneven1 and rays of light reflected from an uneven surface are diffused in all directions4 ,parallel rays falling obliquely upon a plane mirror are reflected parallel2 converging rays1 with the same degree of convergence2 and diverging rays equally divergent4 ,stand before a mirror and your image is formed therein1 and appears to be as far behind the glass as you are before it1 making the angle of reflection equal to that of incidence1 as before stated4 ,the incident ray and the reflected ray form1 together1 what is called the passage of reflection1 and this will therefore make the actual distance of an image to appear as far again from the eye as it really is4 ,any object which reflects light is called a radiant4 ,the point behind a reflecting surface1 from which they appear to diverge1 is called the virtual focus4 ,rays of light being reflected at the same angle at which they fall upon a mirror1 two persons can stand in such a position that each can see the image of the other without seeing his own4 ,again2 you may see your whole figure in a mirror half your length1 but if you stand before one a few inches shorter the whole cannot be reflected1 as the incident ray which passes from your feet into the mirror in the former case1 will in the latter fall under it4 ,images are always reversed in mirrors4 ,convex mirrors reflect light from a rounded surface and disperse the rays in every direction1 causing parallel rays to diverge1 diverging rays to diverge more1 and converging rays to converge less--they represent objects smaller than they really are--because the angle formed by the reflected ray is rendered more acute by a convex than by a plane surface1 and it is the diminishing of the visual angle1 by causing rays of light to be farther extended before they meet in a point1 which produces the image of convex mirrors4 ,the greater the convexity of a mirror1 the more will the images of the objects be diminished1 and the nearer will they appear to the surface4 ,these mirrors furnish science with many curious and pleasing facts4 ,concave mirrors are the reverse of convex2 the latter being rounded outwards1 the former hollowed inwards--they render rays of light more converging--collect rays instead of dispersing them1 and magnify objects while the convex diminishes them4 ,rays of light may be collected in the focus of a mirror to such intensity as to melt metals4 ,the ordinary burning glass is an illustration of this fact2 although the rays of light are refracted1 or passed through the glass and concentrated into a focus beneath4 ,when incident rays are parallel1 the reflected rays converge to a focus1 but when the incident rays proceed from a focus1 or are divergent1 they are reflected parallel4 ,it is only when an object is nearer to a concave mirror than its centre of concavity1 that its image is magnified2 for when the object is farther from the mirror1 this centre will appear less than the object1 and in an inverted position4 ,the centre of concavity in a concave mirror1 is an imaginary point placed in the centre of a circle formed by continuing the boundary of the concavity of the mirror from any one point of the edge to another parallel to and beneath it4 ,,refraction ,,of ,,light3--,i now pass to the consideration of the passage of light through bodies4 ,a ray of light failing perpendicularly through the air upon a surface of glass or water passes on in a straight line through the body2 but if it1 in passing from one medium to another of different density1 fall obliquely1 it is bent from its direct course and recedes from it1 either towards the right or left1 and this bending is called refraction2 7see ,fig4 #c1 b47 ,if a ray of light passes from a rarer into a denser medium it is refracted towards a perpendicular in that medium2 but if it passes from a denser into rarer it is bent further from a perpendicular in that medium4 ,owing to this bending of the rays of light the angles of refraction and incidence are never equal4 ,transparent bodies differ in their power of bending light--as a general rule1 the refractive power is proportioned to the density--but the chemical constitution of bodies as well as their density1 is found to effect their refracting power4 ,inflammable bodies possess this power to a great degree4 ,the sines of the angle of incidence and refraction 7that is1 the perpendicular drawn from the extremity of an arc to the diameter of a circle17 are always in the same ratio2 viz3 from air into water1 the sine of the angle of refraction is nearly as four to three1 whatever be the position of the ray with respect to the refracting surface4 ,from air into sulphur1 the sine of the angle of refraction is as two to one--therefore the rays of light cannot be refracted whenever the sine of the angle of refraction becomes equal to the radius99 of a circle1 and light falling very obliquely upon a transparent medium ceases to be refracted2 this is termed total reflection4 99 ,the ,,radius of a circle is a straight line passing from the centre to the circumference4 ,since the brightness of a reflected image depends upon the quantity of light1 it is quite evident that those images which arise from total reflection are by far the most vivid1 as in ordinary cases of reflection a portion of light is absorbed4 ,i should be pleased to enter more fully into this branch of the science of optics1 but the bounds to which ,i am necessarily limited in a work of this kind will not admit of it4 ,in the next chapter1 however1 ,i shall give a synopsis of ,mr4 ,hunt's treatise on the ,influence of the ,solar ,rays on ,compound ,bodies1 with especial reference to their ,photographic application--a work which should be in the hands of every ,daguerreotypist1 and which ,i hope soon to see republished in this country4 ,i will conclude this chapter with a brief statement of the principles upon which the ,photographic art is founded4 ,,solar and ,stellar light contains three kinds of rays1 viz3 #a4 ,colorific1 or rays of color4 #b4 ,calorific1 or rays of heat4 #c4 ,chemical rays1 or those which produce chemical effects4 ,on the first and third the ,photographic principle depends4 ,in explaining this principle the accompanying wood cuts1 7figs4 #c and #d7 will render it more intelligible4 ,if a pencil of the sun's rays fall upon a prism1 it is bent in passing through the transparent medium2 and some rays being more refracted than others1 we procure an elongated image of the luminous beam1 exhibiting three distinct colors1 red1 yellow and blue1 which are to be regarded as primitives--and from their interblending1 seven1 as recorded by ,newton1 and shown in the accompanying wood cut4 ,these rays being absorbed1 or reflected differently by various bodies1 give to nature the charm of color4 ,thus to the eve is given the pleasure we derive in looking upon the green fields and forests1 the enumerable varieties of flowers1 the glowing ruby1 jasper1 topaz1 amethist1 and emerald1 the brilliant diamond1 and all the rich and varied hues of nature1 both animate and inanimate4 ,illustration3 ,fig4 #c 7hipho#c4;gif7 ,now1 if we allow this prismatic spectrum 7b4 ,fig4 #c47 to fall upon any surface 7as at c47 prepared with a sensitive photographic compound1 we shall find that the chemical effect produced bears no relation to the intensity of the light of any particular colored ray1 but that1 on the contrary1 it is dispersed over the largest portion of the spectrum1 being most energetic in the least luminous rays1 and ever active over an extensive space1 where no traces of light can be detected4 ,fig4 #d1 will give the student a better idea of this principle4 ,it is a copy of the kind of impression which the spectrum1 spoken of1 would make on a piece of paper covered with a very sensitive photographic preparation4 ,the white space a4 corresponds with the most luminous1 or yellow ray1 7#e1 ,fig4 #c7 over limits of which all chemical change is prevented4 ,a similar action is also produced by the lower end of the red ray c2 but in the upper portion1 however we find a decided change 7as at d74 ,the most active chemical change1 you will perceive1 is produced by the rays above the yellow a2 viz4 #d1 #c1 #b and #a 7as at b7 the green 7#d7 being the least active1 and the blue 7#c7 and violet 7#a7 rays the most so1 the action still continuing far beyond the point b which is the end of the luminous image4 ,illustration3 ,fig4 #d 7hipho#d4;gif7 ,suppose we wish to copy by the ,daguerreotype1 or ,calotype process1 any objects highly colored--blue1 red and yellow1 for instance predominating--the last of course reflects the most light1 the blue the least2 but the rays from the blue surface will make the most intense impression1 whilst the red radiations are working very slowly1 and the yellow remains entirely inactive4 ,this accounts for the difficulty experienced in copying bright green foliage1 or warmly colored portraits2 a large portion of the yellow and red rays entering into the composition of both--and the imperfections of a ,daguerreotype portrait of a person with a freckled face depends upon the same cause4 ,a yellow1 hazy atmosphere1 even when the light is very bright1 will effectually prevent any good photographic result--and in the height of summer1 with the most sensative process1 it not unfrequently happens that the most annoying failures arise from this agency of a yellow medium4 ,a building painted of a yellow color1 which may reflect the sun's rays directly into the operator's room will have the same effect4 ,daguerreotypists1 being ignorant of these facts1 are very apt to charge their want of success to the plates1 or chemicals1 or any thing but the real cause2 and it would be well to bear these facts constantly in mind and as far as possible avoid them4 ,this1 may be accomplished1 in a measure1 by a choice of location or by having the glass of your windows tinged with blue2 or a screen of thin blue paper may be interposed between the light and sitter4 ,in selecting subjects1 all striking contrasts in color should be avoided1 and sitters for portraits should be cautioned not to wear anything that may produce the effect spoken of--dark dresses always being the best4 ,the action of light both combines and decomposes bodies4 ,for instance1 chlorine and hydrogen will remain in a glass vessel without alteration if kept in the dark2 but if exposed to the rays of the sun1 they immediately enter into combination1 and produce hydrochloric acid4 ,on the other hand1 if colorless nitric acid be exposed to the sun1 it becomes yellow1 then changes to red1 and oxygen is liberated by the partial decomposition effected by the solar rays4 ,of the organic substances none are more readily acted upon by light than the various combinations of silver4 ,of these some are more1 and others less sensitive4 ,if ,chloride of silver1 which is a white precipitate formed by adding chloride of sodium 7common salt7 to a solution of nitrate of silver1 be exposed to diffused light1 it speedily assumes a violet tint1 and ultimately becomes nearly black4 ,with iodide of silver1 bromide of silver1 ammonio-nitrate of silver1 and other salts of this metal1 the result will be much the same4 ,some bodies1 which under the influence of light1 undergo chemical changes1 have the power of restoring themselves to their original condition in the dark4 ,this is more remarkably displayed in the iodide of platinum1 which readily recieves a photogenic image by darkening over the exposed surfaces1 but speedily loses it by bleaching in the dark4 ,the ioduret of ,daguerre's plate1 and some other iodides1 exhibit the same peculiarity--,this leads us to the striking fact1 that bodies which have undergone a change of estate under the influence of day-light have some latent power by which they can renovate themselves4 ,possibly the hours of night are as necessary to inanimate nature as they are to the animate4 ,during the day1 an excitement which we do not heed1 unless in a state of disease1 is maintained by the influence of light and the hours of repose1 during which the equilibrium is restored1 are absolutely necessary to the continuance of health4 ,instead of a few chemical compounds of gold and silver1 which at first were alone supposed to be photographic1 we are now aware that copper1 platinum1 lead1 nickel1 and indeed1 probably all the elements1 are equally liably to change under the sun's influence4 ,this fact may be of benefit to engravers1 for if steel can be made to take photographic impressions1 the more laborious process of etching may be dispensed with4 ,in fact1 in the latter part of this work1 a process is described for etching and taking printed impressions from ,daguerreotype plates4 ,as yet this process has produced no decided beneficial results--but future experiments may accomplish some practical discovery of intrinsic value to the art of engraving4 ,a very simple experiment will prove how essential light is to the coloring of the various species comprising the vegetable and animal kingdoms4 ,if we transplant any shrub from the light of day into a dark cellar1 we will soon see it lose its bright green color1 and become perfectly white4 ,another effect of light is that it appears to impart to bodies some power by which they more readily enter into chemical combination with others4 ,we have already said that chlorine and hydrogen1 if kept in the dark1 will remain unaltered2 but if the chlorine alone be previously exposed to the sun1 the chlorine thus solarised will unite with the hydrogen in the dark4 ,sulphate of iron will throw down gold or silver from their solutions slowly in the dark2 but if either solution be first exposed to sunshine1 and the mixture be then made1 in the dark1 the precipitation takes place instantly4 ,here is again1 evidence of either an absorption of some material agent from the sunbeam1 or an alteration in the chemical constitution of the body4 ,it was from understanding these principles and applying them that philosophers were enabled to produce the ,calotype1 ,daguerreotype1 c4 ,for the effects and action of light on the camera1 see ,chapter ,v4 ,some advances have been made towards producing ,photographic impressions in color--the impossibility of which some of our best and oldest artists have most pertinaciously maintained4 ,the colored image of the spectrum has been most faithfully copied1 ray for ray1 on paper spread with the juice of the ,cochorus ,japonica1 7a species of plant7 and the fluoride of silver2 and on silver plate covered with a thin film of chloride4 ,the day may be still remote when this much to be desired desideratum shall be accomplished in portrait taking2 but ,i am led to hope that future experiments may master the secret which now causes it to be looked upon1 by many1 as an impossibility4 ,that great advantages have resulted1 and that greater still will result from the discovery of the ,photographic art1 few will deny4 ,the faithful manner in which it copies nature1 even to the most minute details1 renders it of much value to the painter2 but a few minutes sufficing to take a view that formerly would have occupied several days4 ,its superiority in portraits1 over miniature or oil painting has been tacitly acknowledged by the thousands who employ it to secure their own1 or a friends likeness1 and by the steady increase in the number of artists who are weekly1 aye daily springing up in every town and village in the land4 ,,chap4 ,,iii4 ,,synopsis ,,of ,,mr4 ,,hunt',s ,,treatise ,,on ,,the ,,influence ,,of ,,the ,,solar ,,rays ,,on ,,compound ,,bodies1 ,,with ,,especial ,,reference ,,to ,,their ,,photographic ,,application4 ,,oxide ,,of ,,silver exposed for a few hours to good sunshine1 passes into a more decided olive color1 than characterises it when first prepared by precipitation from nitrate of silver4 ,longer exposure renders this color very much lighter1 and the covered parts1 are found much darker1 than those on which the light has acted directly4 ,in some instances where the oxide of silver has been spread on the paper a decided whitening process in some parts1 after a few days exposure1 is noticed4 ,oxide of silver dissolved in ammonia is a valuable photographic fluid2 one application of a strong solution forming an exceedingly sensitive surface4 ,the pictures on this paper are easily fixed by salt or weak ammonia4 ,,nitrate ,,of ,,silver4--,this salt in a state of purity1 does not appear to be sensibly affected by light1 but the presence of the smallest portion of organic matter renders it exceedingly liable to change under luminous influence4 ,if a piece of nitrated paper is placed upon hot iron1 or held near the fire1 it will be found that at a heat just below that at which the paper chars1 the salt is decomposed4 ,where the heat is greatest1 the silver is revived1 and immediately around it1 the paper becomes a deep blue2 beyond this a pretty decided green color results1 and beyond the green1 a yellow or yellow brown stain is made4 ,this exhibits a remarkable analogy between heat and light1--before spoken of in chap4 ,,ii--and is of some practical importance in the preparation of the paper4 ,,prismatic ,,analysis4--,the method of accomplishing the prismatic decomposition of rays of light by the spectrum has already been described on pages #bb and #bc4 ,the color of the impressed spectrum1 on paper washed with nitrate of silver1 is at first1 a pale brown1 which passes slowly into a deeper shade2 that portion corresponding with the blue rays becoming a blue brown2 and under the violet of a peculiar pinkey shade1 a very decided green tint1 on the point which corresponds with the least refrangible blue rays1 may be observed1 its limits of action being near the centre of the yellow ray1 and its maximum about the centre of the blue1 although the action up to the edge of the violet ray is continued with very little diminution of effect2 beyond this point the action is very feeble4 ,when the spectrum is made to act on paper which has been previously darkened1 by exposure to sunshine under cupro-sulphate of ammonia1 the phenomena are materially different4 ,the photographic spectrum is lengthened out on the red or negative side by a faint but very visible red portion1 which extends fully up to the end of the red rays1 as seen by the naked eye4 ,the tint of the general spectrum1 too1 instead of brown is dark grey1 passing1 however1 at its most refracted or positive end into a ruddy brown4 ,in its ,photographic application1 the nitrate of silver is the most valuable of the salts of that metal1 as from it most of the other argentine compounds can be prepared1 although it is not of itself sufficiently sensible to light to render it of much use4 ,,chloride ,,of ,,silver4--,this salt of silver1 whether in its precipitated state1 or when fused1 changes its color to a fine bluish grey by a very short exposure to the sun's rays4 ,if combined with a small quantity of nitrate1 the change is more rapid1 it attains a deep brown1 then slowly passes into a fine olive1 and eventually1 after a few weeks1 the metalic silver is seen to be revived on the surface of the salt4 ,great differences of color are produced on chlorides of silver precipitated by different muriates4 ,nearly every variety in combination with the nitrate1 becomes at last of the same olive color1 the following examples1 therefore1 have reference to a few minutes exposure1 only1 to good sunshine2 it must also be recollected that the chloride of silver in these cases is contaminated with the precipitant4 ,muriate of ammonia precipitates chloride to darken to a fine chocolate brown1 whilst muriate of lime produces a brick-red color4 ,muriates of potash and soda afford a precipitate1 which darkens speedily to a pure dark brown1 and muriatic acid1 or aqueous chlorine1 do not appear to increase the darkening power beyond the lilac to which the pure chloride of silver changes by exposure4 ,this difference of color appears to be owing to the admixture of the earth or alkali used with the silver salt4 ,the prismatic impression on paper spread with the chloride of silver is often very beautifully tinted1 the intensity of color varying with the kind of muriate used4 ,spread paper with muriate of ammonia or baryta and you obtain a range of colors nearly corresponding with the natural hues of the prismatic spectrum4 ,under favorable circumstances the mean red ray1 leaves a red impression1 which passes into a green over the space occupied by the yellow rays4 ,above this a leaden hue is observed1 and about the mean blue ray1 where the action is greatest1 it rapidly passes through brown into black1 and through the most refrangible rays it gradually declines into a bluish brown1 which tint is continued throughout the invisible rays4 ,at the least refrangible end of the spectrum1 the very remarkable phenomenon has been observed1 of the extreme red rays exerting a protecting influence1 and preserving the paper from that change1 which it would otherwise undergo1 under the influence of the dispersed light which always surrounds the spectrum4 ,not only the extreme red ray exerts this very peculiar property1 but the ordinary red ray through nearly its whole length4 ,in photographic drawing this salt is of the utmost importance4 ,mr4 ,talbot's application of it will be given hereafter in another portion of this work4 ,,iodide ,,of ,,silver--,perfectly pure1 undergoes very little change under the influence of light or heat2 but if a very slight excess of the nitrate of silver be added it becomes infinitely more sensitive than the chloride4 ,the spectrum impressed upon paper prepared with a weak solution of the hydriodate of potash presents some very remarkable peculiarities4 ,the maximum of intensity is found at the edge of the most refrangible violet rays1 or a little beyond it1 varying slightly according to the kind of paper used1 and the quantity of free nitrate of silver present4 ,the action commences at a point nearly coincident with the mean red of the luminous spectrum1 where it gives a dull ash or lead color1 while the most refrangible rays impress a ruddy snuff-brown1 the change of tint coming on rather suddenly about the end of the blue or beginning of the violet rays of the luminous spectrum4 ,beyond the extreme violet rays1 the action rapidly diminishes1 but the darkening produced by these invisible rays1 extends a very small space beyond the point at which they cease to act on the chloride of silver4 ,in its photographic application1 it is1 alone1 of very little use2 but in combination with other reagents it becomes exquisitely sensitive4 ,with gallic acid and the ferrocyanate of potash it forms two of the most sensitive photographic solutions with which we are acquainted4 ,these are used in the calotype process4 ,,ioduret ,,of ,,silver4--,if upon a plate of polished silver we place a small piece of iodine1 and apply the heat of a lamp beneath the plate for a moment1 a system of rings is speedily formed4 ,the first ring1 which spreading constantly forms the exterior of the circle1 is of a bright yellow color2 within this1 there arises1 successively1 rings of green1 red and blue colors1 and then again a fine yellow circle1 centred by a greyish spot on the place occupied by the iodine4 ,on exposing these to the light1 the outer yellow circle almost instantly changes color1 the others slowly1 in the order of their position1 the interior yellow circle resisting for a long time the solar influence4 ,these rings must be regarded as films of the ioduret of silver1 varying1 not only in thickness1 but in the more or less perfect states of combination in which the iodine and metal are4 ,the exterior circle is an ioduret in a very loose state of chemical agregation2 the attractive forces increase as we proceed towards the centre1 where a well formed ioduret1 or probably a true iodide of silver1 is formed1 which is acted upon by sunlight with difficulty4 ,the exterior and most sensitive film constitutes the surface of ,daguerreotype plates4 ,the changes which these colored rings undergo are remarkable2 by a few minutes exposure to sunlight1 an inversion of nearly all the colors takes place1 the two first rings becoming a deep olive green2 and a deep blue inclining to black4 ,the nature of the change which the ioduret of silver undergoes on ,daguerreotype plates1 through the action of light1 ,mr4 ,hunt considers to be a decided case of decomposition1 and cites several circumstances in proof of his position4 ,these with other facts given by ,mr4 ,hunt in his great work on the ,photographic art1 but to voluminous to include in a volume of the size to which ,i am obliged to confine myself1 should be thoroughly studied by all ,daguerreotypists4 ,,prismatic ,,analysis4--,the most refrangible portion of the spectrum1 7on a ,daguerreotype plate7 appears1 after the plate has been exposed to the vapor of mercury1 to have impressed its colors2 the light and delicate film of mercury1 which covers that portion1 assuming a fine blue tint about the central parts1 which are gradually shaded off into a pale grey2 and this is again surrounded by a very delicate rose hue1 which is lost in a band of pure white4 ,beyond this a protecting influence is powerfully exerted2 and notwithstanding the action of the dispersed light1 which is very evident over the plate1 a line is left1 perfectly free from mercurial vapor1 and which1 consequently1 when viewed by a side light1 appears quite dark4 ,the green rays are represented by a line of a corresponding tint1 considerably less in size than the luminous green rays4 ,the yellow rays appear to be without action1 or to act negatively1 the space upon which they fall being protected from the mercurial vapor2 and it consequently is seen as a dark band4 ,a white line of vapor marks the place of the orange rays4 ,the red rays effect the sensitive surface in a peculiar manner2 and we have the mercurial vapor1 assuming a molecular arrangement which gives to it a fine rose hue2 this tint is surrounded by a line of white vapor1 shaded at the lowest extremity with a very soft green4 ,over the space occupied by the extreme red rays1 a protecting influence is again exerted2 the space is retained free from mercurial vapor and the band is found to surround the whole of the least refrangible rays1 and to unite itself with the band which surrounds the rays of greatest refrangibility4 ,this band is not equally well defined throughout its whole extent4 ,it is most evident from the extreme red to the green2 it fades in passing through the blue1 and increases again1 as it leaves the indigo1 until beyond the invisible chemical rays it is nearly as strong as it is at the calorific end of the spectrum4 ,images on ,daguerreotype plates which have been completely obliterated by rubbing may be restored1 by placing it in a tolerably strong solution of iodine in water4 ,,bromide ,,of ,,silver4--,this salt1 like the iodide1 does not appear to be readily changed by the action of light2 but when combined with the nitrate of silver it forms a very sensitive photographic preparation4 ,paper prepared with this salt1 blackens over its whole extent with nearly equal intensity1 when submitted to the prismatic spectrum4 ,the most characteristic peculiarity of the spectrum is its extravagant length4 ,instead of terminating at the mean yellow ray1 the darkened portion extends down to the very extremity of the visible red rays4 ,in tint it is pretty uniformly of a grey-black over its whole extent1 except that a slight fringe of redness is perceptible at the least refracted end4 ,beyond the red ray1 an extended space is protected from the agency of the dispersed light1 and its whiteness maintained2 thus confirming the evidence of some chemical power in action1 over a space beyond the luminous spectrum1 which corresponds with the rays of the least refrangibility4 ,this salt is extensively used in photographic drawing4 ,,preparations ,,of ,,gold4--,chloride of ,gold1 freed from an excess of acid is slowly changed under the action of light2 a regularly increasing darkness taking place until it becomes purple1 the first action of the light being to whiten the paper1 which1 if removed from the light at this stage1 will gradually darken and eventually develope the picture4 ,this process may be quickened by placing the paper in cold water4 ,chloride of gold with nitrate of silver gives a precipitate of a yellow brown color4 ,paper impregnated with the acetate of lead1 when washed with perfectly neutral chloride of gold1 acquires a brownish-yellow hue4 ,the first impression of light seems rather to whiten than darken the paper1 by discharging the original color1 and substituting for it a pale greyish tint1 which by slow degrees increases to a dark slate color2 but if arrested1 while yet1 not more than a moderate ash grey1 and held in a current of steam1 the color of the parts acted upon by light--and of that only--darkens immediately to a deep purple4 ,here ,i must leave the subject of the action of light upon metalic compounds--referring to ,mr4 ,hunts work for any further information the student may desire on the other metals--as ,i find myself going beyond my limits4 ,i cannot1 however1 entirely dismiss the subject without giving a few examples of the action of light on the juices of plants1 some of which produce very good photographic effect4 ,,corchorus ,,japonica--,the juice of the flowers of this plant impart a fine yellow color to paper1 and1 so far as ascertained1 is the most sensitive of any vegetable preparation2 but owing to its continuing to change color even in the dark1 photographic images taken on paper prepared with it soon fade out4 ,,wall ,,flower4--,this flower yields a juice1 when expressed with alcohol1 from which subsides1 on standing1 a bright yellow finely divided faecula1 leaving a greenish-yellow transparent liquid1 only slightly colored supernatant4 ,the faecula spreads well on paper1 and is very sensitive to light1 but appears at the same time to undergo a sort of chromatic analysis1 and to comport itself as if composed of two very distinct coloring principles1 very differently affected4 ,the one on which the intensity and sub-orange tint of the color depends1 is speedily destroyed1 but the paper is not thereby fully whitened4 ,a paler yellow remains as a residual tint1 and this on continued exposure to the light1 slowly darkens to brown4 ,exposed to the spectrum1 the paper is first reduced nearly to whiteness in the region of the blue and violet rays4 ,more slowly1 an insulated solar image is whitened in the less refrangible portion of the red4 ,continue the exposure1 and a brown impression begins to be percieved in the midst of the white streak1 which darkens slowly over the region between the lower blue and extreme violet rays4 ,,the ,,red ,,poppy yields a very beautiful red color1 which is entirely destroyed by light4 ,when perfectly dried on paper the color becomes blue4 ,this blue color is speedily discharged by exposure to the sun's rays1 and papers prepared with it afford very interesting photographs4-- ,future experiments will undoubtedly more fully develope the photogenic properties of flowers1 and practically apply them4 ,certain precautions are necessary in extracting the coloring matter of flowers4 ,the petals of fresh flowers1 carefully selected1 are crushed to a pulp in a mortar1 either alone or with the addition of a little alcohol1 and the juice expressed by squeezing the pulp in a clean linen or cotton cloth4 ,it is then to be spread upon paper with a flat brush1 and dried in the air4 ,if alcohol be not added1 it must be applied immediately1 as the air changes or destroys the color instantly4 ,most flowers give out their coloring matter to alcohol or water--but the former is found to weaken1 and in some cases to discharge altogether these colors2 but they are in most cases restored in drying4 ,paper tinged with vegetable colors must be kept perfectly dry and in darkness4 ,to secure an eveness of tint on paper it should be first moistened on the back by sponging1 and blotting off with bibulous paper4 ,it should then be pinned on a board1 the moist side downwards1 so that two of its edges--the right and lower ones--project a little over those of the board4 ,incline the board twenty or thirty degrees to the horizon1 and apply the tincture with a brush in strokes from right to left1 taking care not to go over the edges which rests on the board1 but to pass clearly over those that project2 and also observing to carry the tint from below upwards by quick sweeping strokes1 leaving no dry spaces between them4 ,cross these with other strokes from above downwards1 leaving no floating liquid on the paper4 ,dry as quickly as possible1 avoiding1 however1 such heat as may injure the tint4 ,,chap4 ,,iv4 ,a ,,few ,,hints ,,and ,,suggestions ,,to ,,daguerreotypists4 ,there are very few who may not be capable of practising the ,photographic art1 either on paper1 or metalic plates--but1 like all other professions1 some are more clever in its various processes than others4 ,impatience is a great drawback to perfect success1 and combined with laziness is a decided enemy4 ,besides this1 no one can excel in ,photography who does not possess a natural taste for the fine arts1 who is not quick in discerning grace and beauty--is regardless of the principles of perspective1 foreshortening and other rules of drawing1 and who sets about it merely for the sake of gain--without the least ambition to rise to the first rank1 both in its practice and theory4 ,there is no profession or trade in which a slovenly manner will not show itself1 and none where its effects will be more apparent than this4 ,in order to be great in any pursuit1 we must be ourselves1 and keep all things1 in order4 ,in your show and reception rooms1 let neatness prevail2 have your specimens so placed--leaning slightly forward--as to obtain the strongest light upon them1 and at the same time prevent that glassiness of appearance which detracts so materially from the effect they are intended to produce4 ,if possible1 let the light be of a north-western aspect1 mellowed by curtains of a semitransparent hue4 ,your show-cases1 at the door1 should be kept well cleaned4 ,i have often been disgusted while attempting to examine portraits in the cases of our artists1 at the greasy coating and marks of dirty fingers upon the glass and frame enclosing them4 ,believe it1 many a good customer is lost for no other reason4 ,in your operating room1 dust should be carefully excluded4 ,it should be furnished with nothing apt to collect and retain dust2 a carpet is therefore not only a useless article1 but very improper4 ,a bare floor is to be prefered2 but if you must cover it use matting4 ,there is no place about your establishment where greater care should be taken to have order and cleanliness2 for it will prevent many failures often attributed to other causes4 ,a place for every thing1 and every thing in its place1 should be an absolute maxim with all artists4 ,do not oblige the ladies1 on going away from your rooms1 to say--,that ,h4 is a slovenly man2 see how my dress is ruined by sitting down in a chair that looked as if it had just come out of a porter house kitchen and had not been cleaned for six months4 ,in choosing your operating room1 obtain one with a north-western aspect1 if possible2 and either with1 or capable of having attached1 a large skylight4 ,good pictures may be taken without the sky-light1 but not the most pleasing or effective4 ,a very important point to be observed1 is to keep the camera perfectly free from dust4 ,the operator should be careful to see that the slightest particle be removed1 for the act of inserting the plate-holder will set it in motion1 if left1 and cause those little black spots on the plate1 by which an otherwise good picture is spoiled4 ,the camera should be so placed as to prevent the sun shining into the lenses4 ,in taking portraits1 the conformation of the sitter should be minutely studied to enable you to place her or him in a position the most graceful and easy to be obtained4 ,the eyes should be fixed on some object a little above the camera1 and to one side--but never into1 or on the instrument1 as some direct2 the latter generally gives a fixed1 silly1 staring1 scowling or painful expression to the face4 ,care should also be taken1 that the hands and feet1 in whatever position1 are not too forward or back ward from the face when that is in good focus4 ,if any large surface of white is present1 such as the shirt front1 or lady's handkerchief1 a piece of dark cloth 7a temporary bosom of nankeen is best17 may be put over it1 but quickly withdrawn when the process is about two thirds finished4 ,a very pleasing effect is given to portraits1 by introducing1 behind the sitter1 an engraving or other picture--if a painting1 avoid those in which warm and glowing tints predominate4 ,the subject of these pictures may be applicable to the taste or occupation of the person whose portrait you are taking4 ,this adds much to the interest of the picture1 which is otherwise frequently dull1 cold and inanimate4 ,mr4 ,j4 ,h4 ,whitehurst of ,richmond1 ,va41 has introduced a revolving background1 which is set in motion during the operation1 and produces a distinctness and boldness in the image not otherwise to be obtained4 ,the effect upon the background of the plate is equally pleasing2 it having the appearance of a beautifully clouded sky4 ,in practising ,photographic drawing on paper1 the student must bear in mind that it is positively essential1 to secure success in the various processes1 to use the utmost precaution in spreading the solutions1 and washes from the combination of which the sensitive surfaces result4 ,the same brush should always be used for the same solution1 and never used for any other1 and always washed in clean water after having been employed4 ,any metalic mounting on the brushes should be avoided1 as the metal precipitates the silver from its solution4 ,the brushes should be made of camels or badger's hair and sufficiently broad and large to cover the paper in two or three sweeps2 for if small ones be employed1 many strokes must be given1 which leave corresponding streaks that will become visible when submitted to light1 and spoil the picture4 ,these few preliminary hints and suggestions1 will1 ,i trust1 be of some service to all who adopt this pleasing art as a profession2 and will1 with a due attention to the directions given in the practical working of the ,daguerreotype1 ,calotype1 etc41 ensure a corresponding measure of success4 ,,chap4 ,v4 ,,daguerreotype ,,apparatus4 ,the entire ,daguerreotype process is comprised in seven distinct operations2 viz3 #a4--;,cleaning and polishing the plate4 #b4--;,applying the sensitive coating4 #c--,submitting the plate to the action of light in the camera4 #d4--;,bringing out the picture2 in other words rendering it visible4 #e4--;,fixing the image1 or making it permanent--so that the light may no longer act upon it4 #f4--;,gilding3 or covering the picture with a thin film of gold--which not only protects it1 but greatly improves its distinctness and tone of color4 #g4--;,coloring the picture4 ,for these various operations the following articles--which make up the entire apparatus of a ,daguerrean artist--must be procured #a4--,,the ,,camera4--7,fig4 #e474 ,the ,camera ,obscura of the ,italian philosophers1 although highly appreciated1 on account of the magical character of the pictures it produced1 remained little other than a scientific toy1 until the discovery of ,m4 ,daguerre4 ,the value of this instrument is now great1 and the interest of the process which it so essentially aids1 universally admitted4 ,a full description of it will therefore be interesting4 ,illustration3 ,fig4 #e 7hipho#e4;gif7 ,the camera is a dark box 7a71 having a tube with lenses 7b7 placed in one end of it1 through which the radiations from external objects pass1 and form a diminished picture upon the ground glass 7g7 placed at the proper distance in the box to receive it2 the cap c covering the lenses at b until the plate is ready to receive the image of the object to be copied4 ,thus a 7fig4 #f47 representing the lens1 and b the object desired to be represented1 the rays 7c1 c7 proceeding from it fall upon the lens1 and are transmitted to a point1 which varies with the curvature of the glass1 where an inverted image 7d7 of b is very accurately formed4 ,at this point1 termed the focus1 the sensitive photographic material is placed for the purpose of obtaining the required picture4 ,illustration3 ,fig4 #e 7hipho#f4;gif7 ,the great desideratum in a photographic camera is perfect lenses4 ,they should be achromatic1 and the utmost transparency should be obtained2 and under the closest inspection of the glass not the slightest wavy appearance1 or dark spot should be detected2 and a curvature which as much as possible prevents spherical aberration should be secured4 ,the effect produced by this last defect is a convergence of perpendiculars1 as for instance2 two towers of any building1 would be represented as leaning towards each other2 and in a portrait the features would seem contracted1 distorted and mingled together1 so as to throw the picture out of drawing and make it look more like a caricature than a likeness4 ,if the lens be not achromatic1 a chromatic aberration takes place1 which produces an indistinct1 hazy appearance around the edges of the picture1 arising from the blending of the rays4 ,the diameter and focal length of a lens must depend in a great measure on the distance of the object1 and also on the superficies of the plate or paper to be covered4 ,for portraits one of #a #a_/b inches diameter1 and from #d #a_/b to #e #a_/b inches focus may be used2 but for distant views1 one from #b inches to #c inches diameter1 and from #h to #ab inches focal length will answer much better4 ,for single lenses1 the aperture in front should be placed at a distance from it1 corresponding to the diameter1 and of a size not more than one third of the same4 ,a variety of movable diaphragms or caps1 to cover the aperture in front1 are very useful1 as the intensity of the light may be modified by them and more or less distinctness and clearness of delineation obtained4 ,these caps alway come with ,voitlander instruments and should be secured by the purchaser4 ,though the single acromatic lens answers very well for copying engravings2 taking views from nature or art1 for portraits the double should always be used4 ,the extensive manufacture of the most approved cameras1 both in ,europe and in this country1 obviates all necessity for any one attempting to construct one for their own use4 ,lenses are now made so perfect by some artisans that1 what is called the quick working camera will take a picture in one second1 while the ordinary cameras require from eight to sixty4 ,the camera in most general use is that manufactured by ,voitlander and ,son of ,germany4 ,their small size consists of two seperate acromatic lenses2 the first1 or external one1 has a free aperture of #a #a_/b inches2 the second1 or internal1 #a #e_/h inches2 and both have the same focus1 viz3 #e #c_/d inches4 ,the larger size differs from the smaller4 ,the inner lens is an achromatic #c #a_/d inches diameter1 its focal length being #cj inches4 ,the outer lens is a meniscus--that is bounded by a concave and convex spherical surface which meet--having a focal length of #ah inches4 ,for every distant view1 the aperture in front is contracted by a diaphram to #a_/h of an inch4 ,by this means the light is reflected with considerable intensity and the clearness and correctness of the pictures are truly surprising4 ,,the ,,america instruments are constructed on the same principle and many of them are equally perfect4 ,mr4 ,edward ,anthony of #bje ,broadway1 ,new ,york city1 has constructed1 and sold cameras fully equal to the ,german and for which ,voitlander instruments have been refused in exchange by the purchaser4 ,the ordinary camera box 7see fig4 #e1 a7 varies in size to suit the tube1 and is termed medium1 half1 or whole4 ,within the box is a slide to assist in regulating the focus1 and in enlarging or diminishing the picture4 ,in one end of this slide is a springed groove into which the ground-glass spectrum 7g fig4 #e7 is slid1 for the purpose of more conveniently arranging the focus4 ,after the plate is prepared it is placed in the holder--partly seen at e1 fig4 #e1 and covered with the dark slide f1 fig4 #e2 the spectrum is then withdrawn and the holder takes its place1 and the lids d1 d1 are closed after removing the dark slide f4 ,the plate is now ready to receive the image1 and the cap c may be removed to admit the light into the box4 ,a camera constructed by ,voitlander is thus described by ,mr4 ,fisher4 ,it is made entirely of brass1 so that variations of climate has no effect upon it4 ,it is very portable and when packed in its box1 with all the necessary apparatus and materials for practising the ,daguerreotype art1 occupies but very little space4 ,it is not1 however1 well adapted for the ,calotype process4 ,illustration3 ,fig4 #g 7hipho#g4;gif7 ,the brass foot ,a 7fig4 #g471 is placed on a table1 or other firm support1 and the pillar ,b4 screwed into it2 the body of the camera1 ,c1 ,c is laid into the double forked bearing ,d4 ,d4 ,the instrument is now properly adjusted by means of the set screws1 e1 e1 e1 in the brass foot1 or it may be raised1 lowered1 or moved1 by the telescope stand1 and when correct1 fixed by the screw b4 ,the landscape to be delineated is viewed either through the small lens1 g1 or with the naked eye on the ground glass plate ,h1 the focus being adjusted by the screw ,i4 ,the optical part of the instrument consist of the small set of achromatic lenses already described4 ,when the portrait or view is deliniated on the ground glass to the entire satisfaction of the operator1 the brass cap ,l is placed over the lens1 and the entire body is removed away into the dark1 taking care not to disturb the position of the stand4 ,the body is now detached at the part ,h1 and the prepared paper or plate enclosed in the brass frame work introduced in its place2 the whole is again placed upon the pedestal1 the brass cap ,l is removed1 by which the paper or plate is exposed to the full influence of the light1 after which the cap is again replaced4 ,mr4 ,woodbridge1 of this city1 has constructed an instrument for taking full length portraits on plates #aj by #ac inches1 which is worthy of some notice4 ,it is a double camera1 consisting of two boxes1 placed in a frame1 one above the other1 and so arranged as to slide easily up and down4 ,after the focus has been adjusted1 on the object1 in both cameras1 the plate is put into the upper box1 in the manner already described1 until the superior portion of the figure is complete2 it is then placed in the second box and the lower extremities obtained4 ,the adjustment of the instrument is so complete that a perfect union of the parts is effected in the picture without the least possible line of demarkation being visible4 ,fig4 #h gives a front view of this instrument4 ,illustration3 ,fig4 #h 7hipho#h4;gif7 ,fig4 #i represents ,talbot's ,calotype ,camera1--a very beautiful instrument4 ,the copying camera box has an extra slide in the back end1 by which it may be considerably lengthened at pleasure4 ,,ii4--,,camera ,,stand4--,the best constructed stands are made of maple or black walnut wood1 having a cast iron socket 7a1 ,fig4 #ab17 through which the sliding rod b passes1 and into which the legs c1 c1 with iron screw ferules are inserted4 ,the platform d is made of two pieces1 hinged together1 as at e1 and having a thumb screw for the purpose of elevating or depressing the instrument4 ,illustration3 ,fig4 #i 7hipho#i4;gif7 ,,iii4 ,,mercury ,,bath4--,fig4 #ac gives a front view of the mercury bath now in general use in this country for mercurializing and bringing out the picture4 ,it is quite an improvement on those first used4 ,to make it more portable it is in three pieces1 a b and c2 having a groove e on one side to receive the thermometre tube and scale by which the proper degree of heating the mercury is ascertained4 ,into the top are nicely fitted two or three iron frames1 with shoulders1 for the plate to rest in1 suitable for the different sizes of plates4 ,the bath is heated by means of a spirit lamp placed under it4 ,from two to four ounces of highly purified mercury are put into the bath at a time4 ,,iv4 ,,plate ,,blocks ,,and ,,vices4--,there are several kinds of this article in use2 ,i shall describe the two best only4 ,illustration3 ,fig4 #aj 7hipho#aj4;gif7 ,fig4 #aj gives an idea of the improvement on the ,english hand block4 ,the top a is perfectly flat and smooth--a little smaller than the plate1 so as to permit the latter to project a very little all around--having at opposite angles c c two clasps1 one fixed the other moveable1 but capable of being fastened by the thumb screw d1 so as to secure the plate tightly upon the block4 ,this block turns upon a swivle1 b1 which is attached to the table by the screw c1 ,this block is only used for holding the plate while undergoing the first operation in cleaning4 ,illustration3 ,fig4 #aa 7hipho#aa4;gif7 ,fig4 #aa1 shows the form of ,lewis' newly patented plate vice1 which for durability1 simplicity and utility is preferable to all others4 ,it consists of a simple platform and arm of cast iron1 the former1 a1 having a groove1 d1 in the centre for fixing the different sizes of plate beds1 e--and the latter supporting the leaves1 e f4 ,on this vice which is secured to a table1 or bench1 the plate receives its finishing polish with rouge1 or prepared lampblack4 ,mr4 ,lewis gives the following directions for its use4 ,as the cam wears tighten it with the adjusting screw 7g7 so as to allow the lever 7f7 to fall back into a horizontal position2 the plate being in its place at the time4 ,oil the wearing parts occasionally4 ,some ,daguerreotypists1 however1 use a foot lathe with buff wheels of various forms2 but this vice is sufficient for all ordinary purposes4 ,illustration3 ,fig4 #ab 7hipho#ab4;gif7 ,illustration3 ,fig4 #ac 7hipho#ac4;gif7 ,v4 ,,coating ,,boxes4--,the usual form for iodine and bromine boxes is see1 at figs4 #ad and #ae4 ,they are far superior to those in use with the ,english operators4 ,each consists of a wooden box 7a17 having firmly embeded within it a stout glass jar 7c71 the edges of which are ground4 ,over this is placed the sliding cover b1 double the length of the box1 one half occupied by a piece of ground glass 7e71 tightly pressed upon the glass pot by a spring 7i7 beneath the cross bar g1 and fits the pot so accurately that it effectually prevents the escape of the vapor of the iodine1 bromine or other accelerating liquid contained therein4 ,the other half of the lid is cut through1 shoulders being left at the four angles for the different sizes of frames1 designed to recieve the plate while undergoing the coating process4 ,when the plate is put into the frame1 the cover b is shoved under the second lid h and when coated to the proper degree1 it resumes its former position and the plate is placed in the holder of the camera box4 ,to test the tightness of the box1 light a piece of paper1 put it into the pot and cover it with the sliding lid4 ,the burning paper expels the air from the pot1 and if it be perfectly tight you may raise the whole box by the lid4 ,,vi4 ,,glass ,,funnels4--,are a necessary article to the ,daguerreotypist1 for filtering water1 solutions1 c4 ,illustration3 ,fig4 #ad 7hipho#ad4;gif7 ,,vii4 ,,gilding ,,stand4--,for nervous persons the gilding stand is a useful article4 ,it is adjusted to a perfect level by thumb screws placed in its base4 ,,viii4 ,,spirit ,,lamps4--,the most useful and economical of those made are the ,britania1 as they are less liable to break2 and the tube for the wick being fastened to the body by a screw renders it less liable to get out of order or explode4 ,glass is the cheapest1 and for an amateur will do very well1 but for a professed artist the ,britania should always be obtained4 ,,ix4 ,,color ,,box4--,these are generally found on sale at the shops1 and usually contain eight colors1 four brushes and a gold cup4 ,the artist would1 however1 do well to obtain1 all the colors mentioned in the last chapter of this work1 and be sure to get the very best1 as there are various qualities of the same color1 particularly carmine1 which is very expensive1 and the cupidity of some may induce them to sell a poor article for the sake of larger profits4 ,illustration3 ,fig4 #ae 7hipho#ae4;gif7 ,,still4--,daguerreotypists should always use distilled water for solutions1 and washing the plate1 as common water holds various substances in solution which detract very materially from the excellence of a photograph1 and often gives much trouble1 quite unaccountable to many4 ,for the purpose of distilling water the apparatus represented at ,fig4 #af is both convenient and economical4 ,it may be either wholly of good stout tin1 or of sheet iron tinned on the inside1 and may be used over a common fire1 or on a stove4 ,a is the body1 which may be made to hold from one to four gallons of water1 which is introduced at the opening b1 which is then stopped by a cork4 ,the tube d connects the neck a of the still with the worm tub1 or refrigerator ,b1 at e1 which is kept filled with cold water by means of the funnel c1 and drawn off as fast as it becomes warm by the cock f4 ,the distilled water is condensed in the worm--and passes off at the cock b1 under which a bottle1 or other vessel1 should be placed to receive it4 ,the different joints are rendered tight by lute1 or in its absence1 some stiff paste spread upon a piece of linen and wrapped around them will answer very well2 an addition of sealing wax over all will make them doubly secure4 ,illustration3 ,fig4 #af 7hipho#af4;gif7 ,,hygrometer4--,this is an instrument never to be found1 ,i believe1 in the rooms of our operators1 although it would be of much use to them1 for ascertaining the quantity of moisture floating about the room2 and as it is necessary to have the atmosphere as dry as possible to prevent an undue absorption of this watery vapor by the iodine c41 and to procure good pictures1--its detection becomes a matter of importance4 ,mason's hygrometer1 manufactured by ,mr4 ,roach and sold by ,mr4 ,anthony1 #bje ,broadway1 ,new ,york is the best in use4 ,it consists of two thermometre tubes placed1 side by side1 on a metalic scale1 which is graduated equally to both tubes4 ,the bulb of one of these tubes communicates1 by means of a net-work of cotton1 with a glass reservoir of water attached to the back of the scale4 ,fig4 #ag and #ah represent a front and back view of this instrument4 ,fig4 #ag is the front view1 showing the tubes with their respective scales2 the bulb b being covered with the network of cotton communicating with the reservoir c fig4 #ah1 at d4 ,illustration3 ,fig4 #ag 7hipho#ag4;gif7 ,illustration3 ,fig4 #ah 7hipho#ah4;gif7 ,the evaporation of the water from this bulb decreases the temperature of the mercury in the tube b in proportion to the dryness of the atmosphere1 and the number of degrees the tube b indicates below that of the other1 shows the real state of the atmosphere in the room2 for instance1 if b stands at forty and a at sixty-one the room is in a state of extreme dryness1 the difference of twenty-one degrees between the thermometers--let a stand at any one point--gives this result4 ,if they do not differ1 or there is only four or five degrees variation1 the atmosphere of the room is very moist and means should be taken to expel the superfluous quantity4 ,,head ,,rests4--,the button head rest with chair back clip1 ,a fig4 #ai--;is much the best for travelling artists1 as it can be taken apart1 into several pieces and closely packed2 is easily and firmly fixed to the back of a chair by the clamp and screw a and b1 and is readily adjusted to the head1 as the buttons c1 c and arms d1 d are movable4 ,sometimes the button rest is fixed to a pole1 which is screwed to the chair2 but this method is not so secure and solid as the clip and occupies more room in packing4 ,both the pole and clip1 are furnished in some cases with brass band rests instead of the button2 but the only recommendation these can possibly possess in the eyes of any artist1 is their cheapness4 ,illustration3 ,fig4 #ai 7hipho#ai4;gif7 ,for a ,daguerreotypist permanently located the independent iron head-rest1 ,b fig4 #ai1 is the most preferable1 principally on account of its solidity4 ,it is entirely of iron1 is supported by a tripod 7a7 of the same metal and can be elevated by means of a rod 7b7 passing through the body of the tripod1 to a height sufficient for a person1 standing1 to rest against4 ,illustration3 ,fig4 #bj 7hipho#bj4;gif7 ,,galvanic ,,battery4--,this article is used for the purpose of giving to imperfectly coated plates a thicker covering of silver4 ,the form of battery now most universally employed for electrotype1 and other galvanic purposes1 is ,smee's--,fig4 #bj4 ,it consists of a piece of platinized silver1 ,a1 on the top of which is fixed a beam of wood1 ,b1 to prevent contact with the silver4 ,a binding screw ,c is soldered on to the silver plate to connect it with any desired object1 by means of the copper wire1 e4 ,a plate of amalgamated zinc1 ,d1 varying with the fancy of the operator from one half to the entire width of the silver is placed on each side of the wood4 ,this is set into a glass vessel1 ,p1--the extreme ends of the wood resting upon its edge--on which the acid with which it is charged has no effect4 ,the jar is charged with sulphuric acid1 7common oil of vitriol7 diluted in eight parts its bulk of water4 ,the zinc plates of the battery have been amalgamated with quicksilver1 and when the battery is set into the jar of acid there should be no action percieved upon them when the poles ,f1 ,g1 are not in contact4 ,should any action be percieved1 it indicates imperfect amalgamation2 this can be easily remedied by pouring a little mercury upon them immediately after removing them from the acid1 taking care to get none upon the centre plate ,a4 ,directions for use4--,a sheet of silver must be attached to the wire connected with the centre plate ,a of the battery1 and placed in the silver solution--prepared as directed below4 ,the plate to be silvered is first cleaned with diluted sulphuric acid1 and then attached to the wire1 ,g1 proceeding from the zinc plates ,d1 ,d1 and placed in the silver solution1 opposite the silver plate attached to the pole ,f1 and about half an inch from it4 ,a slight effervescence will now be percieved from the battery1 and the silver will be deposited upon the ,daguerreotype plate1 while at the same time a portion of the silver plate is dissolved4 ,to prepare the solution of silver4--,dissolve one ounce of chloride of silver in a solution of two ounces of cyanide of potassium1 previously dissolved in one quart of water4 ,the oxide of silver may be used instead of the chloride4 ,this solution is put into a tumbler1 or other vessel4 ,illustration3 ,fig4 #ba 7hipho#ba4;gif7 ,illustration3 ,fig4 #bb 7hipho#bb4;gif7 ,this battery with the necessary articles for using it may be obtained of ,e4 ,anthony1 #bje ,broadway1 ,new ,york city4 ,the other articles required by every operator may be simply enumerated1 viz3 ,sticking1 or sealing paper4 ,a pair of pliers1 or forceps4 ,porcelain pans or dishes1 for applying the hyposulphite of soda and washing after the imagine is fixed1 something in form like fig4 #bc4 ,a support for holding the plate while being washed1 like fig4 #bd4 ,updater's note3 ,figures #bc and #bd were missing from the image set4 ,illustration3 ,fig4 #be 7hipho#be4;gif7 ,,buff ,,sticks4--,fig4 #be4--,these are usually from one to three feet in length1 and about three inches wide--some think two and a half sufficient4 ,the underside1 which is convex1 is covered with a strip of finely prepared buckskin1 or velvet1 well padded with cotton or tow4 ,all the articles enumerated in this chapter may be obtained1 of the very best quality and at the most reasonable rates1 of ,mr4 ,e4 ,anthony1 #bje1 ,broadway1 ,new ,york4 ,,chap4 ,,vi4 ,,the ,,daguerreotype ,,process4 ,the process of taking ,daguerreotype pictures differs very materially from all others of the photographic art1 inasmuch as the production of the image is effected upon plates of copper coated with silver4 ,the silver employed should be as pure as possible2 the thickness of the plate is of little consequence1 provided there be sufficient silver to bear the cleaning and polishing--is free from copper spots1 is susceptible of a high polish1 an exquisitely sensitive coating and a pleasing tone4 ,these qualities are possessed to an eminent degree by the ,french plates4 ,having already enumerated the various processes--and the apparatus necessary for the manipulation1 ,i will here give a list of the chemicals to be used1 and then proceed to explain them more fully4 ,the requisite chemicals are-- ,,nitric ,,acid1 ,,rouge1 ,,dry ,,iodine1 ,,mercury1 ,,drying ,,powder1 ,,hyposulphite ,,of ,,soda1 ,,cyanide ,,of ,,potassium1 ,,chloride ,,of ,,gold2 ,,or ,,rottenstone1 ,,hyposulphite ,,of ,,gold4 ,,tripoli1 ,,chloride ,,of ,,silver4 ,,chloride ,,of ,,iodine1 their compounds1 or other ,,bromine accelerating mixtures4 ,,first ,,operation4--,cleaning and polishing the plate4--,for this purpose the operator will require the-- ,plate ,blocks1 ,plate ,vice ,spirit ,lamp1 ,polishing ,buffs1 ,nitric ,acid1 diluted in fifteen times its bulk of water ,galvanic ,battery1 to galvanize the plate1 if it is too imperfect to be used without1 previous cleaning it1 as directed in the last chapter4 ,rottenstone1 ,tripoli1 which is too often dispensed with4 ,rouge1 or lampblack--the first being most preferable4 ,the ,english operators mix the two together4 ,prepared cotton ,wool1 or ,canton flannel4 ,if the first is used1 it should be excluded from the dust1 as it is not so easily cleansed as the latter4 ,the plate is secured1 with its silver side upward1 to the block1 by the means described on page #eh--;having previously turned the edges backward all around4 ,the amount of cleaning a plate requires1 depends upon the state it is in4 ,we will suppose one in the worst condition2 dirty1 scratched1 and full of mercury spots1 all of which imperfections are more or less to be encountered4 ,the mercury spots are to be removed by burning the plate4 ,to do this hold the plate over the flame of a spirit lamp1 more particularly under the mercury spots1 until they1 assume a dull appearance1 when the lamp is to be removed1 and the plate allowed to cool1 after which it is attached to the block4 ,place the block upon the swivle1 and hold it firmly with the left hand2 take a small knot or pellet of cotton1 or1 if you like it better1 a small piece of canton flannel--wet it with a little diluted nitric acid2 then sift some finely prepared rottenstone--,davie's199 if you can get it--upon it1 and rub it over the plate with a continual circular motion1 till all traces of the dirt and scratches are removed2 then wipe off the rottenstone with a clean piece of cotton1 adopting1 as before1 a slight circular motion1 at the same time wiping the edges of the plate4 ,even the back should not be neglected1 but throughly cleansed from any dirt or greasy film it may have received from handling4 99 ,sold by ,e4 ,anthony4 ,when this is thoroughly accomplished1 mix a portion of your tripoli with the dilute nitric acid1 to the consistence of thick cream4 ,then take a pellet of cotton and well polish the plate with this mixture1 in the same manner as with the rottenstone4 ,continue the process till1 on removing the tripoli with a clean pellet1 the plate exhibits a clear1 smooth1 bright surface1 free from all spots1 or scratches4 ,any remains of the acid on the plate may be entirely removed ,by sifting on it a little ,drying powder1 and then wiping it carefully off with a fine camels hair brush1 or duster4 ,the finishing polish is now to be given4 ,for this purpose the rouge--or a mixture of rouge and lamp-black1 in the proportion of one part of the former to seven of the latter--is used4 ,it should be kept either in a muslin bag1 or wide mouth bottle1 over which a piece of muslin is tied--in fact1 both the rottenstone and tripoli should be preserved from the dust in the same manner4 ,with a little of this powder spread over the buff--described on page #ec--the plate recieves its final polish2 the circular motion is changed for a straight one across the plate1 which1 if intended for a portrait1 should be buffed the narrow way2 but if1 for a landscape or view of a house1 the length way of the plate4 ,the operation of cleaning the plate at first appears difficult and tedious1 and many have been deterred from attempting this interesting art on that account2 but1 in reality1 it is more simple in practice than in description1 and with a little patience and observation1 all difficulties are easily overcome4 ,great care must be taken to keep the buff free from all extraneous matter1 and perfectly dry1 and when not in use it should be wrapped up in tissue paper1 or placed in a tight box4 ,the plate should be buffed immediately before the sensitive coating is given2 particles of dust are thus effectually removed2 the temperature of the plate is also increased by the friction1 and the required tint more readily obtained4 ,,second ,,operation4--,applying the sensative coating4--,the apparatus and chemicals required1 are an ,iodine box--see fig4 #ad page #ec4 ,bromine box--similar to the iodine box but a trifle deeper4 ,dry ,iodine4 ,bromine1 or a compound of ,bromine and ,chloride of ,iodine1 or other sensitive mixture4 ,most of our best operators use the compound ,bromine and ,chloride of ,iodine4 ,in the early days of the ,daguerreotype1 ,iodine alone was used in preparing the plate1 and although it still plays a very important part1 other preparations1 called accelerating liquids1 quickstuff1 c41 are used1 and the discovery of which has alone ensured the application of the ,daguerreotype successfully to portrait taking--for when first introduced among us it took from five to ten minutes to produce a tolerable good view1 while now but the fraction of a minute is required to obtain an accurate likeness4 ,to iodize the plate perfectly it must be placed over the iodine vapor immediately after buffing4 ,scatter from a sixteenth to the eighth of an ounce of dry iodine over the bottom of your coating box1 and slightly cover it with cotton wool4 ,the plate is then dropped into the frame b1 fig4 #ab1 with its silvered surface downward1 and thrust under the lid h4 ,the bright surface of the plate is soon coated with a film of iodine of a fine yellow color2 it is then removed and placed over the accelerating solution4 ,it is not absolutely necessary to perform this operation in the dark1 although a bright light should be avoided4 ,not so the next part of the process1 viz2 giving the plate its extreme sensitiveness1 or coating with the accelerating liquids4 ,in this great caution should be used to prevent the slightest ray of light impringing directly on the plate1 and in examining the color reflected light should always be used4 ,a convenient method of examining the plate1 is to make a small hole in the partition of the closet in which you coat1 and cover it with a piece of tissue paper2 by quickly turning the plate so that the paper is reflected upon it the color is very distinctly shown4 ,most of our operators are not so particular in this respect as they should be4 ,,accelerating ,,liquid4--,of these there are several kinds1 which differ both in composition and action--some acting very quickly1 others giving a finer tone to the picture although they are not so expeditious in there operations2 or in other words1 not so sensitive to the action of light4 ,these are adopted by ,daguerreotypists according to their tastes and prejudices4 ,they are all applied in the same way as the coating of iodine4 ,the following are the best4 ,bromine water--,this solution is much used in ,france1 and1 ,i shall therefore give its preparation1 and the method of using it1 in the words of ,m4 ,figeau4 ,put into a bottle of pure water1 a large excess of bromine2 shake the mixture well1 and before using it1 let all the bromine be taken up4 ,an ascertained quantity of this saturated water is then diluted in a given quantity of distilled water1 which gives a solution of bromine that is always identical4 ,m4 ,figeau recommends one part of the saturated solution to thirty parts its bulk of water2 but ,m4 ,lesebour finds it more manageable if diluted with forty times4 ,in case pure distilled1 or rain water cannot be procured1 a few drops of nitric acid--say six to the quart--should be added to the common water4 ,put into the bromine box a given quantity of this solution1 sufficient to well cover the bottom2 the plate1 having been iodized to a deep yellow1 is placed over it2 the time the plate should be exposed must be ascertained by making a few trials2 it averages from twelve to forty seconds4 ,when once ascertained1 it is the same for any number of plates1 as the solution1 which of course would become weaker and weaker1 is changed after every operation1 the same quantity being always put into the pot4 ,chloride of ,iodine4--,this is prepared by introducing chlorine gass into a glass vessel containing iodine2 the iodine is liquified1 and the above named compound is the result4 ,operators need not1 however1 be at the trouble and expense of preparing it1 as it can be obtained perfectly pure of ,mr4 ,anthony1 #bje ,broadway1 ,n4 ,y41 as also all of the chemicals herein enumerated4 ,the compound is diluted with distilled water1 and the plate submitted to its action till it is of a rose color4 ,chloride of iodine alone1 is seldom if ever used now by ,american operators1 as it does not sufficiently come up to their locomotive principle of progression4 ,the next is also eschewed by the majority1 although many of our best artists use no other1 on account of the very fine tone it gives to pictures4 ,bromide of ,iodine4--,this is a compound of bromine and chloride of iodine4 ,in mixing it1 much depends upon the strength of the ingredients2 an equal portion of each being generally used4 ,perhaps the best method of preparing it1 is to make a solution in alcohol of half an ounce of chloride of iodine1 and add the bromine drop by drop1 until the mixture becomes of a dark red color2 then dilute with distilled water1 till it assumes a bright yellow4 ,put about half an ounce of this compound into the pot1 and coat over it to a violet color1 change the solution when it becomes too weak to produce the desired effect4 ,another4--,mix half an ounce of bromine with one ounce of chloride of iodine1 add two quarts pure distilled water1 shake it well and let it stand for twelve hours then add twenty-five drops of muriatic acid1 and let it stand another twelve hours1 occasionally shaking it up well4 ,dilute six parts of this solution in sixteen of water4 ,coat over dry iodine to a deep yellow1 then over the sensitive to a deep rose color--approaching purple--then back1 over dry iodine from four to eight seconds4 ,roach's ,tripple ,compound4--,this is one of the very best sensitive solutions1 and is very popular among ,daguerreotypists4 ,to use this1 take one part in weight1 say one drachm1 of the compound and dilute it with twelve of water2 coat over dry iodine to yellow1 then over the compound to a rosy red4 ,the effect in the camera is quick1 and produces a picture of a fine white tone4 ,gurney's ,sensitive4--,this is another preparation of bromine1 and gives a fine tone4 ,to two parts of water add one of the sensitive1 and put just sufficient in the box to cover the bottom1 or enable you to coat in from eight to ten seconds4 ,coat over dry iodine to a dark yellow1 and over the quick till you see a good change1 then back over the dry iodine from two to three seconds4 ,bromide of ,lime1 or ,dry ,sensitive4--,this is a compound but recently introduced1 and is becoming somewhat of it favorite1 owing principally to the slight trouble it gives in its preparation1 and the tone it imparts to the picture4 ,to prepare it1 fill your jar about half or quarter full of dry slacked lime1 then drop into it bromine1 till it becomes a bright orange red4 ,the plate is generally coated over this compound1 after the iodine coating to yellow1 to a violet1 or plum color2 but it will work well under any circumstances1 the color being of little consequence1 if coated from thirty to ninety seconds1 according to its strength4 ,mead's ,accelerator4--,i merely mention this as being in the market1 not knowing any thing in regard to its merits4 ,the directions given for its use are as follows3 ,mix one-third of a bottle with a wine glass full of water1 coat the plate over dry iodine to a dark gold color1 then over the accelerator to a violet1 then back over dry iodine1 or chloride of iodine1 from three to five seconds4 ,chloride of ,bromine4--,m4 ,bissou1 a ,french experimentalist1 has found that bromine associated with chlorine1 prepared in a similar manner to chloride of iodine1 already described1 a solution of bromine being substituted for the iodine1 is a very sensitive solution2 by means of it daguerreotype proofs are obtained in half a second1 and1 thus very fugitive subjects are represented1 making it the very best compound for taking children4 ,so quick is its operation1 that even persons or animals may be taken in the act of walking4 ,hungarian ,liquid4--,this1 ,i believe1 has never been used here1 or imported into this country1 and the composition of it is not generally known1 even in ,europe1 where it has taken precedence of all others4 ,it acts quickly and with considerable certainty4 ,it is used by diluting it with from ten to fifteen times its bulk of water1 putting a sufficient quantity into the jar to cover the bottom4 ,the plate being previously iodized to a light yellow1 is submitted to this mixture till it assumes a light rose tint4 ,bromine and ,fluoric ,acid1 in combination1 are used by some ,daguerrean artists as a sensitive1 but any of the above compounds are better2 besides this1 the fluoric acid is a dangerous poison1 and the quick made from it will not repay the risk to the health in using it4 ,as ,i have before said1 great caution should be observed in examining the color of the plate1 even by the feeble light allowed1 which1 when attained1 must be immediately placed in the holder belonging to the camera and covered with the dark slide4 ,you then pass to the ,,third ,,operation4--,submitting the ,plate to the action of ,light in the ,camera4--,experience alone must guide the operator as to the time the plate should be exposed to the influence of the light2 this being dependent on a variety of circumstances1 as clearness of the atmosphere--and here1 a reference to the hygrometer will be of advantage--time of day1 object to be taken1 and the degree of sensitiveness imparted to the plate by the quickstuff4 ,as ,i have before said1 the artist should be careful to see that the interior of the camera is clean and free from dust1 as the small particles flying about1 or set in motion by the sliding of the holder into the box1 attach themselves to the plate1 and cause the little black spots1 by which an otherwise good picture is frequently spoiled4 ,care should also be taken in withdrawing the dark slide1 in front of the plate1 from the holder1 as the same effect may be produced by a too hasty movement4 ,the lens is the last thing to be uncovered1 by withdrawing the cap c4 fig4 #e41 which should not be done until you have placed the sitter in the most desirable position4 ,when1 according to the judgment and experience of the operator1 the plate has remained long enough to receive a good impression1 the cap is replaced over the lens1 and the dark slide over the plate1 which is then removed from the camera4 ,daguerreotypists generally mark time by their watches1 arriving at the nearest possible period for producing a good picture by making several trials4 ,as a ready method of marking short intervals of time is1 however1 a very important consideration1 and as any instrument which will enable an artist to arrive at the exact period1 must be an improvement1 and worthy of universal adoption1 ,i will here describe one invented by ,mr4 ,constable of ,england1 which he calls a ,sand ,clock1 or ,time ,keeper4--,it consists of a glass tube1 about twelve inches long1 by one in diameter1 half filled with fine sand1 similar to that used for the ordinary minute glasses1 and1 like them1 it has a diaphram1 with a small hole in the centre through which the sand runs4 ,the tube is attached to a board which revolves on a centre pin2 on the side is a graduated scale1 divided into half seconds2 the tube is also provided with a moveable index4 ,this instrument is attached1 in a conspicuous place1 to the wall4 ,the glass tube being revolved on its centre1 the index is set to the number of half seconds required1 and the sand running down1 the required time is marked without the possibility of error4 ,in practice it will be found to be a far more convenient instrument for the purpose than either a clock or a seconds watch1 and is applicable both for the camera and mercury box4 ,if the artist finds it desirable or necessary to take the object to be copied in its right position1 that is reverse the image on the spectrum1 he can do so by attaching a mirror 7which may be had of ,mr4 ,anthony1 or ,mr4 ,roach7 to the camera tube1 at an angle of forty-five degrees4 ,if1 after taking the plate from the camera1 it be examined1 no picture will yet be visible1 but this is brought about by the ,,fourth ,,process4--,bringing out the ,picture1 or rendering it ,visible4--,we now come to the use of the mercury bath1 ,fig4 #aa4 ,to the bath a thermometer is attached1 to indicate the proper degree of beat required1 which should never be raised above #agj deg4 ,fahrenheit4 ,the plate maybe put into one of the frames 7see ,fig4 #aa17 over the mercury1 face downwards1 and examined from time to time1 by simply raising it with the fingers1 or a pair of plyers4 ,this operation1 as well as the others1 should take place in the dark closet4 ,illustration3 ,fig4 #bf 7hipho#bf4;gif7 ,updater's note3 hipho#bf4;gif and hipho#bg4;gif are both captioned ,figure #bg4 ,sometimes1 to prevent the necessity of raising the plate1 an additional cover or top is made use of4 ,it consists of a box fitted closely to the inner rim of the bath1 and having an inclined top 7a1 ,fig4 #bg47 ,the top is cut through and fitted with frames for each size of plate1 like those already described1 and in the back is a piece of glass 7b17 through which to view the progress of mercurialization1 and an additional piece 7c17 on one side1 colored yellow1 to admit the light4 ,the outline only of the top is here given1 in order to show every portion of it at one view4 ,the picture1 being fully developed1 is now taken out and examined2 it must not1 however1 be exposed to too strong a light4 ,if any glaring defects be perceived1 it is better not to proceed with it1 but place it on one side to be re-polished2 if1 on the contrary1 it appears perfect1 you may advance to the ,,fifth ,,operation4--,fixing the ,image so that the light can no longer act upon it4--,the following articles are required for this purpose3 ,two or three porcelain or glass dishes1 in form1 something like fig4 #bd4 ,a plate support1 fig4 #be4 ,few1 ,i believe1 now make use of this1 although it is a very convenient article4 ,hyposulphite of ,soda1 ,a pair of ,plyers4 ,in ,europe1 they also use a drying apparatus1 ,fig4 #bg1 but this1 like the plate support1 is a matter of little consequence1 and may be dispensed with4 ,i will1 however1 describe it1 for the benefit of those who may wish to use it4 ,illustration3 ,fig4 #bg 7hipho#bg4;gif7 ,updater's note3 hipho#bf4;gif and hipho#bg4;gif are both captioned ,figure #bg4 ,a vessel made of copper or brass1 tinned inside1 and large enough to take in the largest plate1 but not more than half an inch wide1 is the most convenient4 ,it must be kept perfectly clean4 ,hot distilled water is poured into it1 and the temperature kept up by a spirit lamp4 ,hyposulphite of ,soda4--,having made a solution of hyposulphite of soda1 and well filtered it--the strength is immaterial2 about half an ounce of the salt to a pint of distilled water is sufficient--pour it into one of the porcelain dishes1 put into another plain1 and into a third distilled water4 ,immerse the plate with its face downwards into the hyposulphite1 and the whole of the sensitive is removed1 and the light has no farther action upon it2 it is then to be removed from the hyposulphite and plunged into the plain water1 or placed upon the support1 fig4 #be1 and the water poured over it4 ,it is then washed in a similar manner with the distilled water and well examined1 to see that not the slightest particle of dust rests on the surface4 ,the next step is to dry it4 ,this may be readily accomplished by holding the plate with your plyers1 and pouring distilled water over it--if it is hot1 so much the better4 ,apply the spirit lamp to the back1 at the corner held by the plyers1 at the same time facilitating the operation with the breath2 pass the lamp gradually downwards1 finishing at the extreme corner4 ,the last drop may now be removed by a little bibulous paper4 ,a single drop1 even1 of distilled water allowed to dry on any part of the surface1 is certain to leave a stain which no after process can remove4 ,to illustrate the necessity for having perfectly clean water1 and free from all foreign matter--only to be avoided by using that which is distilled--in these processes1 ,i will relate a little anecdote4 ,an operator in this city 7,new ,york7 frequently made complaint to me1 that his plates were occasionally very bad2 coming out all over in little black and white spots and spoiling many very good pictures1 regretting at the same time that perfect plates were not made1 for he had lost many customers in consequence of these defects4 ,these complaints being somewhat periodical1 ,i suggested that the fault might be in the hyposulphite1 or chloride of gold solutions1 or particles of dust floating about in the room1 and not in the plate4 ,a few days after he stated1 that his plates having served him again in the same way1 he procured a fresh supply of hyposulphite of soda and chloride of gold1 but after applying them the result was no better4 ,he then1 by my advice1 thoroughly cleaned his wash dishes1 bottles and water pail1 made fresh solutions and had no further trouble1 becoming satisfied that the plates suffered an undue share of censure4 ,,sixth ,,process4--,gilding the ,picture4--,this is an improvement the honor of which is due to ,m4 ,figeau1 and may take place either before the drying process1 or at any subsequent period2 but it improves the picture so materially that it should never be neglected4 ,the articles necessary for gilding are-- ,a ,pair of ,plyers2 or a ,gilding ,stand 7see fig4 #ai7 and ,chloride of ,gold2 or ,hyposulphite of ,gold4 ,the latter is imported by ,mr4 ,e4 ,anthony1 #bje ,broadway1 ,new ,york1 and is decidedly the best article for the purpose4 ,one bottle simply dissolved in a quart of water will make a very strong solution1 and gives a richness to the picture impossible to be obtained from the chloride of gold4 ,the process is precisely similar to that described below for chloride of gold1 taking care to cease the moment the bubbles are well defined over the surface of the plate4 ,many ,daguerreotypists1 after a superficial trial1 discard the hyposulphite of gold as inferior2 but ,i have no hesitation in asserting that the fault lies with themselves2 for in every case within my knowledge1 where its use has been persisted in until the correct method has been ascertained and the nature of the gilding has become familiar1 it is always preferred4 ,in illustration of this fact ,i will relate an anecdote3 ,a gentleman to whom it had been recommended1 purchased a bottle1 and after making one or two trials of it1 wrote to his correspondent--,send me two bottles of chloride of gold1 for ,i want no more of the hyposulphite2 it is good for nothing4 ,a few weeks after he sent for three bottles of the condemned article1 confessing that he had found fault unnecessarily2 for1 that since he had become familiar to its use1 he must acknowledge its superiority1 and would use no other gilding4 ,the ,solution of ,chloride of ,gold is prepared by dissolving in a pint of distilled water1 fifteen grains of chrystalized chloride of gold4 ,this solution will be of a yellow tint4 ,in another pint of distilled water dissolve fifty-five grains of hyposulphite of soda2 pour gradually1 in very small quantities1 the gold into the hyposulphite of soda1 stirring the solution at intervals2 when finished the mixture should be nearly colorless4 ,place the plate on its stand1 or hold it in the plyers1 in a perfectly horizontal position--silver surface upward--having previously slightly turned up the edges1 so that it may hold the solution4 ,wet the surface with alcohol1 letting any superfluous quantity drain off4 ,the alcohol is of no farther use than to facilitate the flowing of the gold mixture over the surface4 ,now pour on1 carefully1 as much of the preparation of gold as will remain on the plate4 ,the under part of the plate is then to be heated as uniformly as possible with the spirit lamp2 small bubbles will arise1 and the appearance of the portrait or view very sensibly improved4 ,the process must not be carried too far1 but as soon as the bubbles disappear the lamp should be removed1 and the plate immersed in distilled water1 and dried as before directed4 #gth4 ,,coloring ,,the ,,picture4--,i very much doubt the propriety of coloring the daguerreotypes1 as ,i am of opinion1 that they are little1 if any1 improved by the operation1 at least as it is now generally practised4 ,there are several things requisite in an artist to enable him to color a head1 or even a landscape effectively1 and correctly1 and ,i must say that very few of these are possessed by our operators as a class4 ,these requirements are1 a talent for drawing--taste--due discrimination of effect--strict observance of the characteristic points in the features of the subject--quick perception of the beautiful1 and a knowledge of the art of mixing colors1 and blending tints4 ,the method now pursued1 ,i do not hesitate to say1 and have no fears of being contradicted by those capable of critisizing is on the whole ruinous to any daguerreotype1 and to a perfect one absolutely disgusting4 ,the day may come when accurate coloring may be obtained in the camera4 ,until that day1 if we cannot lead taste into the right channel1 we will endeavor to give such instructions that ,daguerreotypists may proceed with this part of his work with a better understanding of the principles involved4 ,for this purpose ,i have prepared a short chapter on the art of coloring1 which may be found in the latter part of this volume4 ,to ,preserve ,daguerreotypes they must be well sealed and secured in a case1 or frame4 ,these1 of course1 are selected according to the taste of the customer1 the principal requisite being good glass4 ,most ,daguerreotypists prefer the white ,french plate glass--and many think1 very erroneously1 that none is good unless it is thick--but the great desideratum is clearness and freedom from blisters2 even glass a little tinged with green or yellow is to be preferred to the ,french plate when cloudy or blistered and there is very little of it comes to this market that is not so4 ,it is to be hoped that some of our glass factories will manage to manufacture an article expressly for daguerreotypes2 and ,i would recommend them to do so1 for they would find it quite an item of profit annually4 ,before enclosing the picture in the case you should be careful to wipe the glass perfectly clean1 and blow from the picture any particles of dust which may have fallen upon it4 ,then take strips of sticking paper1 about half or three quarters of an inch wide1 and firmly and neatly secure it to the glass1 having first placed a mat between them to prevent the plate being scratched by the glass4 ,,to ,,make ,,sealing ,,paper4--,dissolve one ounce of gum arabic1 and a quarter of an ounce of gum tragicanth in a pint of water2 then add a teaspoonful of benzoin4 ,spread this evenly on one side of good stout tissue paper2 let it dry1 and then cut it up in stripes1 about half or three quarters of an inch wide1 for use4 ,if it becomes too soft for summer use1 add gum arabic2 if too hard and cracking1 add benzoin or gum tragicanth2 if it gets too thick1 add water4 ,,colored ,,daguerreotypes ,,on ,,copper4--,to effect this1 take a polished plate of copper and expose it to the vapor of iodine1 or bromine1 or the two substances combined2 or either of them in combination with chlorine4 ,this gives a sensitive coating to the surface of the plate1 which may then be submitted to the action of light in the camera4 ,after remaining a sufficient time in the camera1 the plate is taken out and exposed to the vapor of sulphuretted hydrogen4 ,this vapor produces various colors on the plate1 according to the intensity with which the light has acted on the different parts2 consequently a colored photographic picture is obtained4 ,no further process is necessary as exposure to light does not effect the picture4 ,by this process we have an advantage over the silvered plate1 both in economy1 and in the production of the picture in colors4 ,,instantaneous ,,pictures ,,by ,,means ,,of ,,galvanism4--,it will be seen by the following valuable communication that galvanism can be successfully applied in producing pictures instantly2 a process of great importance in securing the likeness of a child1 or in taking views of animated nature4 ,colonel ,whitney informs me that he once took a view of the steeple of the ,st4 ,louis ,court ,house after sundown by this means1 and also secured the image of a man in the act of stepping into a store1 and before he had time to place his foot1 raised for that purpose1 on the door step4 ,mr4 ,whitney is well known as the talented editor of the ,sunday ,morning news4 ,new ,york1 ,january #af1 #ahdi4 ,mr4 ,h4 ,h4 ,,snelling4 ,dear ,sir1--,as you are about publishing a history of the ,daguerreotype1 and request a description of my mode of taking pictures instantaneously by the aid of galvanism1 ,i comply with great pleasure4 ,in the year #ahda1 while practicing the art in ,st4 ,louis1 ,mo41 ,i was at times1 during the summer1 much troubled with the electric influence of the atmosphere1 especially on the approach of a thunder-storm4 ,at such times ,i found the coating of my plates much more sensitive than when the atmosphere was comparatively free from the electric fluid1 and the effect was so irregular that no calculation could counteract the difficulty4 ,this satisfied me that electricity was in some measure an important agent in the chemical process1 and it occurred to me that the element might be turned to advantage4 ,i determined1 therefore1 to enter on a series of experiments to test my theory4 ,finding it impossible to obtain an electric machine1 and unwilling to abandon the examination1 it occurred to me1 that the galvanic influence might answer the same purpose4 ,i therefore proceeded to make a galvanic battery in the following simple manner4 ,i obtained a piece of zinc about two inches long1 one inch wide1 and an eighth of an inch thick4 ,on this ,i soldered a narrow strip of copper1 about six inches long1 the soldered end laid on one side of the zinc1 and extending its whole length4 ,the battery was completed by placing the zinc in a glass tumbler1 two-thirds full of dilute sulphuric acid1 strong enough to produce a free action of the metals4 ,the upper end of the copper slip extending above the tumbler was sharpened to a point1 and bent a little over the glass4 ,the method of using1 was thus3--,after preparing the plate in the usual manner and placing it in the camera1 in such manner as to expose the back of the plate to view1 the battery was prepared by placing the zinc in the acid1 and as soon as the galvanic fluid began to traverse 7as could be known by the effervescence of the acid1 operating on the zinc and copper7 the cap of the camera was removed1 and the plate exposed to the sitter2 at the same instant the point of the battery was brought quickly against the back of the plate1 and the cap replaced instantly4 ,if the plate is exposed more than an instant after the contact the picture will generally be found solarized4 ,by this process ,i have taken pictures of persons in the act of walking1 and in taking the pictures of infants and young children ,i found it very useful4 ,very respectfully yours1 ,,thomas ,r4 ,,whitney4 ,,chap4 ,,vii ,,paper ,,daguerreotypes4--,,etching ,,daguerreotypes4 ,mr4 ,hunt describes a process1 discovered by himself by which the ,daguerrean art may be applied to paper4 ,his description is as follows3-- ,placing the paper on some hard body1 wash it over on one side--by means of a very soft camel's hair pencil--with a solution of sixty grains of bromide of potassium1 in two fluid ounces of distilled water1 and then dry it quickly by the fire4 ,being dry1 it is again washed over with the same solution1 and dried as before4 ,a solution of nitrate of silver--one hundred grains to an ounce of distilled water--is to be applied over the same surface1 and the paper quickly dried in the dark4 ,in this state the papers may be kept for use4 ,when they are required1 the above solution of silver is to be plentifully applied1 and the paper placed wet in the camera1 the greatest care being taken that no day light--not even the faintest gleam--falls upon it until the moment when you are prepared1 by removing the dark slide1 to permit the light1 radiating from the object you wish to copy1 to act in producing the picture4 ,after a few seconds the light must be again shut off1 and the camera removed into a dark room4 ,the necessity of removing the camera is now avoided by the use of the dark slide1 already described1 covering the picture in the holder1 which alone may be removed4--,amer4 ,aut4 ,it will be found by taking the paper from the holder1 that there is but a very faint outline--if any--yet visible4 ,place it aside1 in perfect darkness until quite dry2 then place it in the mercurial vapor box 7meaning bath7 and apply a very gentle heat to the bottom4 ,the moment the mercury vaporizes1 the picture will begin to develope itself4 ,the spirit lamp must now be removed for a short time1 and when the action of the mercury appears to cease1 it is to be very carefully applied again1 until a well defined picture is visible4 ,the vaporization must then be suddenly stopped1 and the photograph removed from the box4 ,the drawing will then be very beautiful and distinct2 but much detail is still clouded1 for the developement of which it is only necessary to place it in the dark and suffer it to remain undisturbed for some hours4 ,there is now an inexpressible charm about the pictures1 equaling the delicate beauty of the daguerreotype2 but being very susceptible of change1 it must be viewed by the light of a taper only4 ,the nitrate of silver must now be removed from the paper1 by well washing it in soft water1 to which a small quantity of salt has been added1 and it should afterwards be soaked in water only4 ,when the picture has been dried1 wash it quickly over with a soft brush dipped in a warm solution of hyposulphite of soda1 and then wash it for some time in distilled water1 in order that all the hyposulphite may be removed4 ,the drawing is now fixed and we may use it to procure positive copies1 7the original being termed a negative17 many of which may be taken from one original4 ,the action of light on this preparation1 does indeed appear to be instantaneous4 ,the exquisite delicacy of this preparation may be imagined1 when ,i state that in five seconds in the camera1 ,i have1 during sunshine1 obtained perfect pictures1 and that when the sky is overcast1 one minute is quite sufficient to produce a most decided effect4 ,this very beautiful process is not without its difficulties2 and the author cannot promise that1 even with the closest attention to the above directions1 annoying failures will not occur4 ,it often happens that some accidental circumstance--generally a projecting film or a little dust--will occasion the mercurial vapor to act with great energy on one part of the paper1 and blacken it before the other portions are at all effected4 ,again1 the mercury will sometimes accumulate along the lines made by the brush1 and give a streaky appearance to the picture1 although these lines are not at all evident before the mercurial vapor was applied4 7,a brush sufficiently large--and they may be easily obtained--will1 in a measure1 prevent this difficulty4--,amer ,au47 ,i have stated that the paper should be placed wet in the camera2 the same paper may be used dry1 which often is a great convenience4 ,when in the dry state a little longer exposure is required2 and instead of taking a picture in four or five seconds1 two or three minutes are necessary4 ,the durability of daguerreotypes has been1 and is still1 doubted by many1 but experiment has proved that they are more permanent than oil paintings or engravings4 ,,etching ,,daguerreotypes4--,there are several methods of accomplishing this object2 discovered and applied by different individuals4 ,the first process was published at ,vienna by ,dr4 ,berres1 and consisted in covering the plate with the mucilage of gum arabic1 and then immersing the plate in nitric acid of different strengths4 ,mr4 ,figeau1 of whom ,i have already spoken1 likewise discovered a process for the engraving of ,daguerreotypes2 and founded on the belief that the lights of a ,daguerreotype plate consists of unaltered silver1 while the dark or shadows consists of mercury or an amalgam of mercury with silver4 ,he finds that a compound acid1 consisting of a mixture of nitric1 nitrous1 and muriatic acids1 or of nitric mixed with nitrate of potass and common salt1 has the property of attaching the silver in presence of the mercury without acting upon the latter4 ,bi-chloride of copper answers the purpose also1 but less completely4 ,when the clean surface of a ,daguerreotype plate is exposed to the action of this menstruum1 particularly if warm1 the white parts1 or lights are not altered1 but the dark parts are attacked1 and chloride of silver is formed1 of which an insoluble coating is soon deposited1 and the action of the acid soon ceases4 ,this coat of chloride of silver is removed by a solution of ammonia1 and then the acid applied again1 and so on1 until the depth of biting in is sufficient4 ,however1 it is not possible1 by repeating this process1 to get a sufficient force of impression2 a second operation is required1 in order to obtain such a depth as will hold the ink1 to give a dark impression2 for this purpose the whole plate is covered with drying oil2 this is cleared off with the hand1 exactly in the way a copper plate printer cleans his plate4 ,the oil is thus left in the sinkings1 or dark bitten in parts only4 ,the whole plate is now placed in a suitable apparatus1 and the lights or prominent parts of the face are gilt by the electrotype process4 ,the whole surface is now touched with what the ,french engravers call the ,resin ,grain1 7grain de resine71 a species of partial stopping out1 and it is at once bitten in to a sufficient depth with nitric acid1 the gilding preserving the lights from all action of the acid4 ,the resin grain gives a surface to the corroded parts suitable for holding the ink1 and the plate is now finished and fit to give impressions resembling aquatint4 ,but as silver is so soft a metal that the surface of the plate might be expected to wear rapidly1 the discoverer proposes to shield it by depositing over its whole surface a very thin coat of copper by the electrotype process2 which when worn may be removed at pleasure down to the surface of the noble metal beneath1 and again a fresh coat of copper deposited2 and so an unlimited number of impressions obtained without injuring the plate itself4 ,if1 as has been asserted1 steel may be rendered sufficiently sensitive1 to take photographic impressions1 to what a revolution will the art of engraving be subject by the discovery of this process4 ,,chap4 ,,viii4 ,,photogenic ,,drawing ,,on ,,paper4 ,we shall now proceed to describe the various processes for ,photogenic drawing on paper2 first1 however1 impressing on the mind of the experimenter1 the necessity which exists for extreme care in every stage of the manipulation4 ,in this portion of my work ,i am entirely indebted to the works of ,professors ,hunt1 ,fisher and others4 ,i4 ,,apparatus ,,and ,,materials4--,paper4--,the principal difficulty to be contended with in using paper1 is the different power of imbibition which we often find possessed in the same sheet1 owing to trifling inequalities in its texture4 ,this is1 to a certain extent1 to be overcome by a careful examination of each sheet1 by the light of a candle or lamp at night1 or in the dark4 ,by extending each sheet between the light and the eye1 and slowly moving it up and down1 and from left to right1 the variations in its texture will be seen by the different quantities of light which pass through it in different parts2 and it is always the safest course to reject every sheet in which inequalities exist4 ,paper sometimes contains minute portions of thread1 black or brown specks1 and other imperfections1 all of which materially interfere with the process4 ,some paper has an artificial substance given to it by sulphate of lime 7,plaster of ,paris72 this defect only exists1 however1 in the cheaper sorts of demy1 and therefore can be easily avoided4 ,in all cases such paper should be rejected1 as no really sensitive material can be obtained with it4 ,paper-makers1 as is well known1 often affix their name to one half the sheet2 this moiety should also be placed aside1 as the letters must frequently come out with annoying distinctness4 ,well sized paper is by no means objectionable1 indeed1 is rather to be preferred1 since the size tends to exalt the sensitive powers of the silver4 ,the principal thing to be avoided1 is the absorption of the sensitive solution into the pores2 and it must be evident that this desideratum cannot be obtained by unsized paper4 ,taking all things into consideration1 the paper known as satin post would appear to be preferable1 although the precautions already recommended should be taken in its selection4 ,brushes4--,the necessary solutions are to be laid upon the paper by brushes4 ,some persons pass the paper over the surface of the solutions1 thus licking up1 as it were1 a portion of the fluid2 but this method is apt to give an uneven surface2 it also rapidly spoils the solutions4 ,at all events1 the brush is the most ready and the most effectual means4 ,distilled ,water4--,all the water used1 both for mixing the solutions1 washing the paper1 or cleaning the brushes1 must be distilled1 to obtain good results1 for reasons before specified4 ,blotting ,paper4--,in many instances1 the prepared paper requires to be lightly dried with bibulous paper4 ,the best description is the white sort4 ,in each stage of the preparation distinct portions of bibulous paper must be used4 ,if these be kept seperate and marked1 they can be again employed for the same stage2 but it would not do1 for example1 to dry the finished picture in the same folds in which the sensitive paper had been pressed4 ,a very convenient method is to have two or three quarto size books of bibulous paper1 one for each seperate process4 ,nitrate of ,silver4--,in the practice of the photographic art1 much depends on the nitrate of silver4 ,care should be taken to procure the best2 the crystalized salt is most suitable for the purpose4 ,while in the form of crystal it is not injured by exposure to light1 but the bottles containing the solutions of this salt should at all times be kept wrapped in dark paper1 and excluded from daylight4 ,,ii4 ,,different ,,methods ,,of ,,preparing ,,the ,,paper4--,preparation of the ,paper4--,dip the paper to be prepared into a weak solution of common salt4 ,the solution should not be saturated1 but six or eight times diluted with water4 ,when perfectly moistened1 wipe it dry with a towel1 or press it between bibulous paper1 by which operation the salt is uniformly dispersed through its substance4 ,then brush over it1 on one side only1 a solution of nitrate of silver4 ,the strength of this solution must vary according to the color and sensitiveness required4 ,mr4 ,talbot recommends about fifty grains of the salt to an ounce of distilled water4 ,some advise twenty grains only1 while others say eighty grains to the ounce4 ,when dried in a dark room1 the paper is fit for use4 ,to render this paper still more sensitive1 it must again be washed with salt and water1 and afterwards with the same solution of nitrate of silver1 drying it between times4 ,this paper1 if carefully made1 is very useful for all ordinary photographic purposes4 ,for example1 nothing can be more perfect than the images it gives of leaves and flowers1 especially with a summer's sun2 the light1 passing through the leaves1 delineates every ramification of their fibres4 ,in conducting this operation1 however1 it will be found that the results are sometimes more and sometimes less satisfactory1 in consequence of small and accidental variations in the proportions employed4 ,it happens sometimes that the chloride of silver formed on the surface of the paper is disposed to blacken of itself1 without any exposure to light4 ,this shows that the attempt to give it sensibility has been carried too far4 ,the object is1 to approach as nearly to this condition as possible without reaching it2 so that the preparation may be in a state ready to yield to the slightest extraneous force1 such as the feeblest effect of light4 ,cooper's ,method4--,soak the paper in a boiling hot solution of chlorate of potash 7the strength matters not7 for a few minutes2 then take it out1 dry it1 and wet it with a brush1 on one side only1 dipped in a solution of nitrate of silver1 sixty grains to an ounce of distilled water1 or1 if not required to be so sensitive1 thirty grains to the ounce will do4 ,this paper possesses a great advantage over any other1 for the image can be fixed by mere washing4 ,it is1 however1 very apt to become discolored even in the washing1 or shortly afterwards1 and is1 besides1 not so sensitive1 nor does it become so dark as that made according to ,mr4 ,talbot's method4 ,daguerre's ,method4--,immerse the paper in hydrochloric 7or as it is more commonly called1 muriatic7 ether1 which has been kept sufficiently long to become acid2 the paper is then carefully and completely dried1 as this is essential to its proper preparation4 ,it is then dipped into a solution of nitrate of silver1 and dried without artificial heat in a room from which every ray of light is carefully excluded4 ,by this process it acquires a very remarkable facility in being blackened on a very slight exposure to light1 even when the latter is by no means intense4 ,the paper1 however1 rapidly loses its extreme sensitiveness to light1 and finally becomes no more impressionable by the solar beams than common nitrate paper4 ,bromide ,paper4--,of all common photographic paper1 the best1 because the least troublesome in making1 and the most satisfactory in result1 is that which is termed bromine paper1 and which is thus prepared3--,dissolve one hundred grains of bromide of potassium in one ounce of distilled water1 and soak the paper in this solution4 ,take off the superfluous moisture1 by means of your bibulous paper1 and when nearly dry1 brush it over on one side only1 with a solution of one hundred grains of nitrate of silver to an ounce of distilled water4 ,the paper should then be dried in a dark room1 and1 if required to be very sensitive1 should a second time be brushed over with the nitrate of silver solution4 ,in preparing the papers mentioned above1 there are two circumstances which require particular attention4 ,in the first place1 it is necessary to mark the paper on the side spread with the solutions of nitrate of silver1 near one of the extreme corners4 ,this answers two purposes3 in the first place it serves to inform the experimentalist of the sensitive surface2 and secondly1 it will be a guide as to which portion of the papers has been handled during the application of the solution1 as the impress of the fingers will probably come out upon the photograph4 ,the second caution is1 that the application of the sensitive solution 7nitrate of silver17 and the subsequent drying of the paper1 must be always conducted in a perfectly dark room1 the light of a candle alone being used4 ,illustration3 ,fig4 #bi 7hipho#bi4;gif7 ,,iii4 ,,photogenic ,,process ,,on ,,paper4--,method4--,the simplest mode is to procure a flat board and a square of glass1 larger in size than the object intended to be copied4 ,on the board place the photographic paper with the prepared side upwards1 and upon it the object to be copied2 over both lay the glass and secure them so that they are in close connection by means of binding screws or clamps1 similar to g4 g4 fig4 #bi4 ,should the object to be copied be of unequal thickness1 such as a leaf1 grass1 c41 it will be necessary to place on the board1 first1 a soft cushion1 which may be made of a piece of fine flannel and cotton wool4 ,by this means the object is brought into closer contact with the paper1 which is of great consequence1 and adds materially to the clearness of the copy4 ,the paper is now exposed to diffused daylight1 or1 still better1 to the direct rays of the sun1 when that part of the paper not covered by the object will become tinged with a violet color1 and if the paper be well prepared1 it will in a short time pass to a deep brown or bronze color4 ,it must then be removed1 as no advantage will be obtained by keeping it longer exposed2 on the contrary1 the delicate parts yet uncolored will become in some degree affected4 ,the photogenic paper will now show a more or less white and distinct representation of the object4 ,the apparatus figured at #bi consists of a wooden frame similar to a picture frame2 a piece of plate glass is fixed in front2 and it is provided with a sliding cover of wood1 c41 which is removed when the paper is ready to be exposed to the action of the light4 ,the back1 d41 which is furnished with a cushion1 as just described1 is made to remove for the purpose of introducing the object to be copied1 and upon it the prepared paper2 the back is then replaced1 and1 by aid of the cross piece and screw1 e41 the whole is brought into close contact with the glass4 ,the objects best delineated on these photographic papers1 are lace1 feathers1 dried plants1 particularly the ferns1 sea-weeds and the light grasses1 impressions of copper plate and wood engravings1 particularly if they have considerable contrast of light and shade--7these should be placed with the face downwards1 having been previously prepared as hereafter directed7--paintings on glass1 etchings1 c4 ,to fix the ,drawings4--,mr4 ,talbot recommends that the drawings should be dipped in salt and water1 and in many instances this method will succeed1 but at times it is equally unsuccessful4 ,iodide of potassium1 or1 as it is frequently called1 hydriodate of potash1 dissolved in water1 and very much diluted1 7twenty-five grains to one ounce of water17 is a more useful preparation to wash the drawings with2 it must be used very weak or it will not dissolve the unchanged muriate only1 as is intended but the black oxide also1 and the drawing be thereby spoiled4 ,but the most certain material to be used is the hyposulphite of soda4 ,one ounce of this salt should be dissolved in about a pint of distilled water4 ,having previously washed the drawing in a little lukewarm water1 which of itself removes a large portion of the muriate of silver which is to be got rid of1 it should be dipped once or twice in the hyposulphite solution4 ,by this operation the muriate which lies upon the lighter parts will become so altered in its nature as to be unchanged by light1 while the rest remains dark as before4 ,it will be evident from the nature of the process1 that the lights and shadows of an object are reversed4 ,that which is originally opaque will intercept the light1 and consequently those parts of the photogenic paper will be least influenced by light1 while any part of the object which is transparent1 by admitting the light through it1 will suffer the effect to be greater or less in exact proportion to its degree of transparency4 ,the object wholly intercepting the light will show a white impression2 in selecting1 for example1 a butterfly for an object1 the insect1 being more or less transparent1 leaves a proportionate gradation of light and shade1 the most opaque parts showing the whitest4 ,it may be said1 therefore1 that this is not natural1 and in order to obtain a true picture--or1 as it is termed1 a positive picture--we must place our first acquired photograph upon a second piece of photogenic paper4 ,before we do this1 however1 we must render our photograph transparent1 otherwise the opacity of the paper will mar our efforts4 ,to accomplish this object1 the back of the paper containing the negative1 or first acquired photograph1 should be covered with white or virgin wax4 ,this may be done by scraping the wax upon the paper1 and then1 after placing it between two other pieces of paper1 passing a heated iron over it4 ,the picture1 being thus rendered transparent1 should now be applied to a second piece of photogenic paper1 and exposed1 in the manner before directed1 either to diffused day-light or to the direct rays of the sun4 ,the light will now penetrate the white parts1 and the second photograph be the reverse of the first1 or a true picture of the original4 ,instead of wax1 boiled linseed oil--it must be the best and most transparent kind--may be used4 ,the back of the negative photograph should be smeared with the oil1 and then placed between sheets of bibulous paper4 ,when dry the paper is highly transparent4 ,,iv4 ,,application ,,of ,,photogenic ,,drawing4--,this method of photogenic drawing may be applied to useful purposes1 such as the copying of paintings on glass by the light thrown through them on the prepared paper--,imitations of etchings1 which may be accomplished by covering a piece of glass with a thick coat of white oil paint2 when dry1 with the point of a needle1 lines or scratches are to be made through the white lead ground1 so as to lay the glass bare2 then place the glass upon a piece of prepared paper1 and expose it to the light4 ,of course every line will be represented beneath of a black color1 and thus an imitation etching will be produced4 ,it is also applicable to the delineation of microscopic objects1 architecture1 sculpture1 landscapes and external nature4 ,a novel application of this art has been recently suggested1 which would doubtless prove useful in very many instances4 ,by rendering the wood used for engravings sensitive to light1 impressions may be at once made thereon1 without the aid of the artist's pencil4 ,the preparation of the wood is simply as follows3--,place its face or smooth side downwards1 in a plate containing twenty grains of common salt dissolved in an ounce of water2 here let it remain for five minutes1 take it out and dry it2 then place it again face downwards in another plate containing sixty grains of nitrate of silver to an ounce of water2 here let it rest one minute1 when taken out and dried in the dark it will be fit for use1 and will become1 on exposure to the light1 of a fine brown color4 ,should it be required more sensitive1 it must be immersed in each solution a second time1 for a few seconds only4 ,it will now be very soon effected by a very diffused light4 ,this process may be useful to carvers and wood engravers not only to those who cut the fine objects of artistical design1 but still more to those who cut patterns and blocks for lace1 muslin1 calico-printing1 paper hangings1 etc41 as by this means the errors1 expense and time of the draughtsman may be wholly saved1 and in a minute or two the most elaborate picture or design1 or the most complicated machinery1 be delineated with the utmost truth and clearness4 ,,chap4 ,,ix4 ,,calotype ,,and ,,chrysotype4 ,the materials and apparatus necessary for the ,calotype process are-- ,two or ,three ,shallow ,dishes1 for holding distilled water1 iodide1 potassium1 c4--the same water never being used for two different operations4 ,white ,bibulous ,paper4 ,photogenic ,camera--,fig4 #i4 ,pressure ,frame--,fig #bi4 ,paper1 of the very best quality--directions for the choice of which have been already given4 ,a ,screen of ,yellow ,glass4 ,camels' or ,badgers' hair ,brushes3--,a seperate one being kept for each wash and solution1 and which should be thoroughly cleansed immediately after using in distilled water4 ,that used for the gallo-nitrate is soon destroyed1 owing to the rapid decomposition of that preparation4 ,a ,graduated ,measure4 ,three or ,four ,flat ,boards1 to which the paper may be fixed with drawing pins4 ,a ,hot ,water ,drying ,apparatus1 for drying the paper will also be found useful4 ,in preparing the ,calotype paper1 it is necessary to be extremely careful1 not only to prevent the daylight from impringing upon it1 but also to exclude1 if possible1 the strong glare of the candle or lamp4 ,this may be effected by using a shade of yellow glass or gauze1 which must be placed around the light4 ,light passing through such a medium will scarcely affect the sensitive compounds1 the yellow glass intercepting the chemical rays4 ,preparation of the ,iodized ,paper4--,dissolve one hundred grains of crystalized nitrate of silver in six ounces of distilled water1 and having fixed the paper to one of the boards1 brush it over with a soft brush on one side only with this solution1 a mark being placed on that side whereby it may be known4 ,when nearly dry dip it into a solution of iodide of potassium1 containing five hundred grains of that salt dissolved in a pint of water4 ,when perfectly saturated with this solution1 it should be washed in distilled water1 drained and allowed to dry4 ,this is the first part of the process1 and the paper so prepared is called iodized paper4 ,it should be kept in a port-folio or drawer until required3 with this care it may be preserved for any length of time without spoiling or undergoing any change4 ,mr4 ,cundell finds a stronger solution of nitrate of silver preferable1 and employs thirty grains to the ounce of distilled water3 he also adds fifty grains of common salt to the iodide of potassium1 which he applies to the marked side of the paper only4 ,this is the first process4 ,preparation of the paper for the ,camera4--,the second process consists in applying to the above a solution which has been named by ,mr4 ,talbot the ,gallo-,nitrate of ,silver2 it is prepared in the following manner3 ,dissolve one hundred grains of crystalized nitrate of silver in two ounces of distilled water1 to which is added two and two-third drachms of strong acetic acid4 ,this solution should be kept in a bottle carefully excluded from the light4 ,now1 make a solution of gallic acid in cold distilled water3 the quantity dissolved is very small4 ,when it is required to take a picture1 the two liquids above described should be mixed together in equal quantities2 but as it speedily undergoes decomposition1 and will not keep good for many minutes1 only just sufficient for the time should be prepared1 and that used without delay4 ,it is also well not to make much of the gallic acid solution1 as it will not keep for more than a few days without spoiling4 ,a sheet of the iodized paper should be washed over with a brush with this mixed solution1 care being taken that it be applied to the marked side4 ,this operation must be performed by candle light4 ,let the paper rest half a minute1 then dip it into one of the dishes of water1 passing it beneath the surface several times2 it is now allowed to drain1 and dried by placing its marked side upwards1 on the drying apparatus4 ,it is better not to touch the surface with bibulous paper4 ,it is now highly sensitive1 and ready to receive the impression4 ,in practice it is found better and more economical not to mix the nitrate of silver and gallic acid1 but only to brush the paper with the solution of the nitrate4 ,mr4 ,talbot has recently proposed some modifications in his method of preparing the calotype paper4 ,the paper is first iodized in the usual way2 it is then washed over with a saturated solution of gallic acid in distilled water and dried4 ,thus prepared he calls it the io-gallic paper3 it will remain good for a considerable time if kept in a press or portfolio4 ,when required for use1 it is washed with a solution of nitrate of silver 7fifty grains to the ounce of distilled water71 and it is then fit for the camera4 ,exposure in the ,camera4--,the calotype paper thus prepared possesses a very high degree of sensibility when exposed to light1 and we are thus provided with a medium by which1 with the aid of the photogenic camera1 we may effectually copy views from nature1 figures1 buildings1 and even take portraits from the shadows thrown on the paper by the living face4 ,the paper may be used somewhat damp4 ,the best plan for fixing it in the camera is to place it between a piece of plate glass and some other material with a flat surface1 as a piece of smooth slate or an iron plate1 which latter1 if made warm1 renders the paper more sensitive1 and consequently the picture is obtained more rapidly4 ,time of ,exposure4--,with regard to the time which should be allowed for the paper to remain in the camera1 no direct rules can be laid down2 this will depend altogether upon the nature of the object to be copied1 and the light which prevails4 ,all that can be said is1 that the time necessary for forming a good picture varies from thirty seconds to five minutes1 and it will be naturally the first object of the operator to gain by experience this important knowledge4 ,bringing ,out the ,picture4--,the paper when taken from the camera1 which should be done so as to exclude every ray of light--and here the dark slide of the camera plate holder becomes of great use--bears no resemblance to the picture which in reality is formed4 ,the impression is latent and invisible1 and its existence would not be suspected by any one not acquainted with the process by previous experiment4 ,the method of bringing out the image is very simple4 ,it consists in washing the paper with the gallo-nitrate of silver1 prepared in the way already described1 and then warming it gently1 being careful at the same time not to let any portion become perfectly dry4 ,in a few seconds the part of the paper upon which the light has acted will begin to darken1 and finally grow entirely black1 while the other parts retain their original color4 ,even a weak impression may be brought out by again washing the paper in the gallo-nitrate1 and once more gently warming it4 ,when the paper is quite black1 as is generally the case1 it is a highly curious and beautiful phenomenon to witness the commencement of the picture1 first tracing out the stronger outlines1 and then gradually filling up all the numerous and complicated details4 ,the artist should watch the picture as it developes itself1 and when in his judgment it has attained the greatest degree of strength and clearness1 he shall stop further proceedings by washing it with the fixing liquid4 ,here again the mixed solution need not be used1 but the picture simply brushed over with the gallic acid4 ,the ,fixing ,process4--,in order to fix the picture thus obtained1 first dip it into water2 then partly dry it with bibulous paper1 and wash it with a solution of bromide of potassium--containing one hundred grains of that salt dissolved in eight or ten ounces of distilled water4 ,the picture is again washed with distilled water1 and then finally dried4 ,instead of bromide of potassium1 a solution of hyposulphite of soda1 as before directed1 may be used with equal advantage4 ,the original calotype picture1 like the photographic one described in the last chapter1 is negative1 that is to say1 it has its lights and shades reversed1 giving the whole an appearance not conformable to nature4 ,but it is easy from this picture to obtain another which shall be conformable to nature2 viz41 in which the lights shall be represented by lights1 and the shades by shades4 ,it is only necessary to take a sheet of photographic paper 7the bromide paper is the best71 and place it in contact with a calotype picture previously rendered transparent by wax or oil as before directed4 ,fix it in the frame1 ,fig4 #bi1 expose it in the sunshine for a short time1 and an image or copy will be formed on the photogenic paper4 ,the calotype paper itself may be used to take the second1 or positive1 picture1 but this ,mr4 ,talbot does not recommend1 for although it takes a much longer time to take a copy on the photogenic paper1 yet the tints of such copy are generally more harmonious and agreeable4 ,after a calotype picture has furnished a number of copies it sometimes grows faint1 and the subsequent copies are inferior4 ,this may be prevented by means of a process which revives the strength of the calotype pictures4 ,in order to do this1 it is only necessary to wash them by candlelight with gallo-nitrate of silver1 and then warm them4 ,this causes all the shades of the picture to darken considerably1 while the white parts are unaffected4 ,after this the picture is of course to be fixed a second time4 ,it will then yield a second series of copies1 and1 in this way1 a great number may frequently be made4 ,the calotype pictures when prepared as we have stated1 possess a yellowish tint1 which impedes the process of taking copies from them4 ,in order to remedy this defect1 ,mr4 ,talbot has devised the following method4 ,the calotype picture is plunged into a solution consisting of hyposulphite of soda dissolved in about ten times its weight of water1 and heated nearly to the boiling point4 ,the picture should remain in about ten minutes2 it must then be removed1 washed and dried4 ,by this process the picture is rendered more transparent1 and its lights become whiter4 ,it is also rendered exceedingly permanent4 ,after this process the picture may be waxed1 and thus its transparency increased4 ,this process is applicable to all photographic papers prepared with solutions of silver4 ,having thus fully1 and it is hoped clearly1 considered the process1 it may be necessary before dismissing the calotype from notice1 to add one or two remarks from the observations and labors of some who have experimented in this art4 ,dr4 ,ryan in his lectures before the ,royal ,polytechnic ,institution1 has observed1 that in the iodizing process the sensitiveness of the paper is materially injured by keeping it too long in the solution of iodide of potassium1 owing to the newly formed iodide of silver being so exceedingly solvable in excess of iodide of potassium as in a few minutes to be completely removed4 ,the paper should be dipped in the solution and instantly removed4 ,there is another point1 too1 in the preparation of the iodized paper in which suggestions for a slight deviation from ,mr4 ,talbot's plan have been made4 ,in the first instance1 it is recommended that the paper be brushed over with the iodide of potassium1 instead of the nitrate of silver1 transposing1 in fact1 the application of the first two solutions4 ,the paper1 having been brushed over with the iodide of potassium in solution1 is washed in distilled water and dried4 ,it is then brushed over with nitrate of silver1 and after drying is dipped for1 a moment in a fresh solution of iodide of potassium of only one-fourth the strength of the first1 that is to say1 one hundred and twenty-five grains of the salt to a pint of water4 ,after this it is again washed and dried4 ,the advantage derived from this method1 is a more sensitive paper1 and a more even distribution of the compounds over the surface4 ,another deviation from ,mr4 ,talbot's method has been suggested1 as follows3 ,brush the paper over with a solution of one hundred grains of nitrate of silver to an ounce of water4 ,when nearly1 but not quite1 dry1 dip it into a solution of twenty-five grains of iodide of potassium to one ounce of distilled water1 drain it1 wash it in distilled water and again drain it4 ,now brush it over with aceto-nitrate of silver1 made by dissolving fifty grains of nitrate of silver in one ounce of distilled water1 to which is added one sixth of its volume of strong acetic acid4 ,dry it with bibulous paper1 and it is ready for receiving the image4 ,when the impression has been received1 which will require from one to five minutes according to the state of the weather1 it must be washed with a saturated solution of gallic acid to which a few drops of the aceto-nitrate of silver1 made as above1 have been added4 ,the image will thus be gradually brought out1 and may be fixed with hyposulphite of soda4 ,to obtain the positive picture1 paper must be used brushed over with an ammonio-nitrate of silver1 made thus3 forty grains of nitrate of silver is to be dissolved in one ounce of distilled water1 and liquid ammonia cautiously added till it re-dissolves the precipitate4 ,a pleasing effect may be given to calotype1 or indeed to all photographic pictures1 by waxing them at the back1 and mounting them on white paper1 or if colored paper be used1 various beautiful tones of color are produced4 ,,positive ,,calotype4 ,at a meeting of the ,british ,association1 ,professor ,grove described a process by which positive calotype pictures could be directly obtained2 and thus the necessity to transfer by which the imperfections of the paper are shown1 and which is moreover a troublesome and tedious process1 is avoided4 ,as light favors most chemical actions1 ,mr4 ,grove was led to believe that a paper darkened by the sun 7which darkening is supposed to result from the precipitation of silver7 might be bleached by using a solvent which would not attack the silver in the dark1 but would do so in the light4 ,the plan found to be the most successful is as follows3 ordinary calotype paper is darkened till it assumes a deep brown color1 almost amounting to black2 it is then redipped into the ordinary solution of iodide of potassium1 and dried4 ,when required for use it is drawn over dilute nitric acid--one part acid to two and a half parts water4 ,in this state1 those parts exposed to the light are rapidly bleached1 while the parts not exposed remain unchanged4 ,it is fixed by washing in water1 and subsequently in hyposulphite of soda1 or bromide of potassium4 ,mr4 ,grove also describes a process for converting a negative calotype into a positive one1 which promises1 when carried out1 to be of great utility4 ,let an ordinary calotype image or portrait be taken in the camera1 and developed by gallic acid2 then drawn over iodide of potassium and dilute nitric acid and exposed to full sunshine2 while bleaching the dark parts1 the light is redarkening the newly precipitated iodide in the lighter portions and thus the negative picture is converted into a positive one4 ,the calotype process has been applied to the art of printing1 in ,england1 but it possesses no advantages whatever over the method1 with type1 now so gloriously brought to perfection2 and ,i can hardly think it will ever be made of any utility4 ,for the benefit of the curious1 however1 ,i will give ,mr4 ,talbot's method4 ,some pages of letter-press are taken printed on one side only2 and waxed1 to render them more transparent2 the letters are then cut out and sorted4 ,to compose a new page lines are ruled on a sheet of white paper1 and the words are formed by fixing the seperate letters in their proper order4 ,the page being ready1 a negative photograph is produced from it1 from which the requisite number of positive photogenic copies may be obtained4 ,another method1 which requires the use of the camera1 consists in employing large letters painted on rectangular pieces of wood1 colored white4 ,these are arranged in lines on a tablet or board1 by slipping them into grooves which keep them steady and upright1 thus forming a page on an enlarged scale4 ,it is now placed before a camera1 and a reduced image of it of the required size is thrown upon the sensitive paper4 ,the adjustments must be kept invariable1 so that the consecutive pages may not vary from one another in the size of the type4 ,mr4 ,talbot has patented his process1 but what benefit he expects to derive from it1 ,i am at a loss to determine4 ,enlarged copies of calotype or ,daguerreotype portraits may be obtained by throwing magnified images of them1 by means of lenses1 upon calotype paper4 ,,the ,,chrysotype4 ,a modification of ,mr4 ,talbot's process1 to which the name of ,chrysotype was given by its discoverer1 ,sir ,john ,herschel1 was communicated in ,june #ahdc to the ,royal ,society1 by that distinguished philosopher4 ,this modification would appear to unite the simplicity of photography with all the distinctness and clearness of calotype4 ,this preparation is as follows4 ,the paper is to be washed in a solution of ammonio-citrate of iron2 it must then be dried1 and subsequently brushed over with a solution of the ferro-sesquicyanuret of potassium4 ,this paper1 when dried in a perfectly dark room1 is ready for use in the same manner as if otherwise prepared1 the image being subsequently brought out by any neutral solution of gold4 ,such was the first declaration of his discovery1 but he has since found that a neutral solution of silver is equally useful in bringing out the picture4 ,photographic pictures taken on this paper are distinguished by a clearness of outline foreign to all other methods4 ,,chap4 ,x4 ,,cyanotype--,,energiatype--,,chromatype --,,anthotype--,,amphitype ,,and ,,crayon ,,daguerreotype4 ,the several processes enumerated at the head of this chapter1 are all discoveries of ,english philosophers1 with the exception of the third and last named4 ,anthotype was first attempted by ,m4 ,ponton a ,french savan1 although it was reserved to ,mr4 ,hunt to bring the process to its present state4 ,the ,crayon ,daguerreotype is an improvement made by ,j4 ,a ,whipple1 ,esq41 of ,boston4 ,i4 ,,cyanotype4 ,so called from the circumstance of cyanogen in its combinations with iron performing a leading part in the process4 ,it was discovered by ,sir ,john ,herschel4 ,the process is a simple one1 and the resulting pictures are blue4 ,brush the paper over with a solution of the ammonio-citrate of iron4 ,this solution should be sufficiently strong to resemble sherry wine in color4 ,expose the paper in the usual way1 and pass over it very sparingly and evenly a wash of the common yellow ferro-cyanate of potass4 ,as soon as the liquid is applied1 the negative picture vanishes1 and is replaced by a positive one1 of a violet blue color1 on a greenish yellow ground1 which at a certain time possesses a high degree of sharpness1 and singular beauty of tint4 ,a curious process was discovered by ,sir ,john ,herschel1 by which dormant pictures are produced capable of developement by the breath1 or by keeping in a moist atmosphere4 ,it is as follows4 ,if nitrate of silver1 specific gravity #a4bjj be added to ferro-tartaric acid1 specific gravity #a4jbc1 a precipitate falls1 which is in a great measure redissolved by a gentle heat1 leaving a black sediment1 which1 being cleared by subsidence1 a liquid of a pale yellow color is obtained1 in which the further addition of the nitrate causes no turbidness4 ,when the total quantity of the nitrated solution added amounts to about half the bulk of the ferro-tartaric acid1 it is enough4 ,the liquid so prepared does not alter if kept in the dark4 ,spread on paper1 and exposed wet to the sunshine 7partly shaded7 for a few seconds1 no impression seems to be made1 but by degrees1 although withdrawn from the action of light1 it developes itself spontaneously1 and at length becomes very intense4 ,but if the paper be thoroughly dried in the dark1 7in which state it is of a very pale greenish yellow color17 it possesses the singular property of receiving a dormant or invisible picture1 to produce which from thirty to sixty seconds' exposure to sunshine is requisite4 ,it should not be exposed too long1 as not only is the ultimate effect less striking1 but a picture begins to be visibly produced1 which darkens spontaneously after it is withdrawn4 ,but if the exposure be discontinued before this effect comes on1 an invisible impression is the result1 to develope which all that is necessary is to breathe upon it1 when it immediately appears1 and very speedily acquires an extraordinary intensity and sharpness1 as if by magic4 ,instead of the breath1 it may be subject to the regular action of aqueous vapor1 by laying it in a blotting paper book1 of which some of the outer leaves on both sides have been dampened1 or by holding over warm water4 ,,ii4 ,,energiatype4 ,under this title a process has been brought forward by ,mr4 ,hunt4 ,it consists of the application of a solution of succinic acid to paper1 which is subsequently washed over with nitrate of silver4 ,the image is then to be taken either in the camera or otherwise1 as required1 and is brought out by the application of the sulphate of iron in solution4 ,although this process has not come into general use1 its exact description may be interesting to the general reader1 and we therefore subjoin it4 ,the solution with which the paper is first washed is to be prepared as follows3 succinic acid1 two drachms2 common salt1 five grains2 mucilage of gum arabic1 half a fluid drachm2 distilled water1 one fluid drachm and a half4 ,when the paper is nearly dry1 it is to be brushed over with a solution of nitrate of silver1 containing a drachm of the salt1 to an ounce of distilled water4 ,it is now ready for exposure in the camera4 ,to bring out the dormant picture it is necessary to wash it with a mixture of a drachm of concentrated solution of the green sulphate of iron and two drachms and a half of mucilage of gum arabic4 ,subsequently1 however1 it has been found that the sulphate of iron produces upon all the salts of silver effects quite as beautiful as in the succinate4 ,on the iodide1 bromide1 acetate1 and benzoate1 the effects are far more pleasing and striking4 ,when pictures are produced1 or the dormant camera image brought out1 by the agency of sulphate of iron1 it is remarkable how rapidly the effect takes place4 ,engravings can be thus copied almost instantaneously1 and camera views obtained in one or two minutes on almost any preparation of silver4 ,the common sulphate of copper solution has the same property4 ,,iii4 ,,chromatype4 ,many efforts have been made to render chromatic acid an active agent in the production of photographs4 ,m4 ,ponton used a paper saturated with bichromate of potash1 and this was one of the earliest photogenic processes4 ,m4 ,becquerel improved upon this process by sizing the paper with starch previous to the application of the bichromate of potash solution1 which enabled him to convert the negative picture into a positive one1 by the use of a solution of iodine1 which combined with that portion of the starch on which the light had not acted4 ,but by neither of these processes could clear and distinct pictures be formed4 ,mr4 ,hunt has1 however1 discovered a process which is so exceedingly simple1 and the resulting pictures of so pleasing a character1 that1 although it is not sufficiently sensitive for use in the camera1 it will be found of the greatest value for copying botanical specimens1 engravings1 or the like4 ,the paper to be prepared is washed over with a solution of sulphate of copper--about one drachm to an ounce of water--and partially dried2 it is then washed with a moderately strong solution of bichromate of potash1 and dried at a little distance from the fire4 ,paper thus prepared may be kept any length of time1 in a portfolio1 and are always ready for use4 ,when exposed to the sunshine for a time1 varying with the intensity of the light1 from five to fifteen or twenty minutes1 the result is generally a negative picture4 ,it is now to be washed over with a solution of nitrate of silver1 which immediately produces a very beautiful deep orange picture upon a light dim colored1 or sometimes perfectly white ground4 ,this picture must be quickly fixed1 by being washed in pure water1 and dried4 ,with regard to the strength of the solutions1 it is a remarkable fact1 that1 if saturated solutions be employed1 a negative picture is first produced1 but if the solutions be three or four times their bulk of water1 the first action of the sun's rays darkens the picture1 and then a very bleaching effect follows1 giving an exceedingly faint positive picture1 which is brought out with great delicacy by the silver solution4 ,it is necessary that pure water should be used for the fixing1 as the presence of any muriate damages the picture1 and here arises another pleasing variation of the ,chromatype4 ,if the positive picture be placed in a very weak solution of common salt the image slowly fades out1 leaving a faint negative outline4 ,if it now be removed from the saline solution1 dried1 and again exposed to sunshine1 a positive picture of a lilac color will be produced by a few minutes exposure4 ,several other of the chromates may be used in this process1 but none is so successful as the chromate of copper4 ,,iv4 ,,anthotype4 ,the expressed juice1 alcoholic1 or watery infusion of flowers1 or vegetable substances1 may be made the media of photogenic action4 ,this fact was first discovered by ,sir ,john ,herschel4 ,we have already given a few examples of this in the third chapter4 ,certain precautions are necessary in extracting the coloring matter of flowers4 ,the petals of fresh flowers are carefully selected1 and crushed to a pulp in a marble mortar1 either alone or with the addition of a little alcohol1 and the juice expressed by squeezing the pulp in a clean linen or cotton cloth4 ,it is then to be spread upon paper with a flat brush1 and dried in the air without artificial heat4 ,if alcohol be not added1 the application on paper must be performed immediately1 as the air 7even in a few minutes71 irrecoverably changes or destroys their color4 ,if alcohol be present this change is much retarded1 and in some cases is entirely prevented4 ,most flowers give out their coloring matter to alcohol or water4 ,some1 however1 refuse to do so1 and require the addition of alkalies1 others of acid1 c4 ,alcohol has1 however1 been found to enfeeble1 and in many cases to discharge altogether these colors2 but they are1 in most cases1 restored upon drying1 when spread over paper4 ,papers tinged with vegetable colors must always be kept in the dark1 and perfectly dry4 ,the color of a flower is by no means always1 or usually1 that which its expressed juice imparts to white paper4 ,sir ,john ,herschel attributes these changes to the escape of carbonic acid in some cases2 to a chemical alteration1 depending upon the absorption of oxygen1 in others2 and again in others1 especially where the expressed juice coagulates on standing1 to a loss of vitality1 or disorganization of the molecules4 ,to secure an eveness of tint on paper1 the following manipulation is recommended3--,the paper should be moistened on the back by sponging and blotting off4 ,it should then be pinned on a board1 the moist side downwards1 so that two of its edges 7suppose the right-hand and lower ones7 shall project a little beyond those of the board4 ,the board then being inclined twenty or thirty degrees to the horizon1 the alcoholic tincture 7mixed with a very little water1 if the petals themselves be not very juicy7 is to be applied with a brush in strokes from left to right1 taking care not to go over the edges which rest on the board2 but to pass clearly over those that project2 and observing also to carry the tint from below upwards by quick sweeping strokes1 leaving no dry spaces between them1 but keeping up a continuity of wet spaces4 ,when all is wet1 cross them by another set of strokes from above downwards1 so managing the brush as to leave no floating liquid on the paper4 ,it must then be dried as quickly as possible over a stove1 or in a warm current of air1 avoiding1 however1 such heat as may injure the tint4 ,in addition to the flowers already mentioned in my third chapter1 the following are among those experimented upon and found to give tolerable good photographic sensitives4 ,i can only enumerate them1 referring the student1 for any further information he may desire on the subject1 to ,mr4 ,hunt's work2 although what ,i have said above is sufficient for all practical purposes2 and any one1 with the ambition1 can readily experiment upon them1 without further research1 on any other flower he may choose4 ,viola ,odorata--or sweet sented violet1 yields to alcohol a rich blue color1 which it imparts in high perfection to paper ,senecio ,splendens--or double purple groundsel1 yields a beautiful color to paper4 ,the leaves of the laurel1 common cabbage1 and the grasses1 are found sufficiently sensitive4 ,common ,merrigold yields an invaluable faecula1 which appears identical with that produced by the ,wall-flower1 and ,cochorus japonica mentioned before1 and is very sensitive1 but photographs procured upon it cannot be preserved1 the color is so fugitive4 ,from an examination of the researches of ,sir ,john ,herschel on the coloring matter of plants1 it will be seen that the action of the sun's rays is to destroy the color1 effecting a sort of chromatic analysis1 in which two distinct elements of color are separated1 by destroying the one and leaving the other outstanding4 ,the action is confined within the visible spectrum1 and thus a broad distinction is exhibited between the action of the sun's rays on vegetable juices and on argentine compounds1 the latter being most sensibly affected by the invisible rays beyond the violet4 ,it may also be observed1 that the rays effective in destroying a given tint1 are in a great many cases1 those whose union produces a color complementary to the tint destroyed1 or1 at least1 one belonging to that class of colors to which such complementary tint may be preferred4 ,for instance1 yellows tending towards orange are destroyed with more energy by the blue rays2 blues by the red1 orange and yellow rays2 purples and pinks by yellow and green rays4 ,v4 ,,amphitype4 ,this process is a discovery of ,sir ,john ,herschel and receives its name from the fact that both negative and positive photographs can be produced by one process4 ,the positive pictures obtained by it have a perfect resemblance to impressions of engravings with common printer's ink4 ,the process1 although not yet fully carried out1 promises to be of vast utility4 ,paper proper for producing an amphitype picture may be prepared either with the ferro-tartrate or the ferro-citrate of the protoxide1 or the peroxide of mercury1 or of the protoxide of lead1 by using creams of these salts1 or by successive applications of the nitrates of the respective oxides1 singly or in mixture1 to the paper1 alternating with solutions of the ammonia-tartrate or the ammonia-citrate of iron1 the latter solution being last applied1 and in more or less excess4 ,i purposely avoid stating proportions1 as ,i have not yet been able to fix upon any which certainly succeed4 ,paper so prepared and dried takes a negative picture1 in a time varying from half an hour to five or six hours1 according to the intensity of the light2 and the impression produced varies in apparent force from a faint and hardly perceptible picture to one of the highest conceivable fulness and richness both of tint and detail1 the color being in this case a superb velvety brown4 ,this extreme richness of effect is not produced unless lead be present1 either in the ingredients used1 or in the paper itself4 ,it is not1 as ,i originally supposed1 due to the presence of free tartaric acid4 ,the pictures in this state are not permanent4 ,they fade in the dark1 though with very different degrees of rapidity1 some 7especially if free tartaric or citric acid be present7 in a few days1 while others remain for weeks unimpaired1 and require whole years for their total obliteration4 ,but though entirely faded out in appearance1 the picture is only rendered dormant1 and may be restored1 changing its character from negative to positive1 and its colors from brown to black1 7in the shadows71 by the following process3--,a bath being prepared by pouring a small quantity of solution of pernitrate of mercury into a large quantity of water1 and letting the subnitrated precipitates subside1 the picture may be immersed in it1 7carefully and repeatedly clearing off all air bubbles17 and allowed to remain till the picture 7if any where visible17 is entirely destroyed2 or if faded1 till it is judged sufficient from previous experience2 a term which is often marked by the appearance of a feeble positive picture1 of a bright yellow hue1 on the pale yellow ground of the paper4 ,a long time 7several weeks7 is often required for this1 but heat accelerates the action1 and it is often completed in a few hours4 ,in this state the picture is to be very thoroughly rinsed and soaked in pure warm water1 and then dried4 ,it is then to be well ironed with a smooth iron1 heated so as barely not to injure the paper1 placing it1 for greater security against scorching1 between clean smooth paper4 ,if then the process have been successful1 a perfectly black positive picture is at once developed4 ,at first it most commonly happens that the whole picture is sooty or dingy to such a degree that it is condemned as spoiled1 but on keeping it between the leaves of a book1 especially in a moist atmosphere1 by extremely slow degrees this dinginess disappears1 and the picture disengages itself with continually increasing sharpness and clearness1 and acquires the exact effect of a copper-plate engraving on a paper more or less tinted with a pale yellow4 ,i ought to observe1 that the best and most uniform specimens which ,i have procured have been on paper previously washed with certain preparations of uric acid1 which is a very remarkable and powerful photographic element4 ,the intensity of the original negative picture is no criterion of what may be expected in the positive4 ,it is from the production by one and the same action of light1 of either a positive or negative picture according to the subsequent manipulations1 that ,i have designated the process1 thus generally sketched out1 by the term ,amphitype1--a name suggested by ,mr4 ,talbot1 to whom ,i communicated this singular result2 and to this process or class of processes 7which ,i cannot doubt when pursued will lead to some very beautiful results17 ,i propose to restrict the name in question1 though it applies even more appropriately to the following exceedingly curious and remarkable one1 in which silver is concerned3 ,at the last meeting ,i announced a mode of producing1 by means of a solution of silver1 in conjunction with ferro-tartaric acid1 a dormant picture brought into a forcible negative impression by the breath or moist air4 7,see ,cyanotype47 ,the solution then described1 and which had at that time been prepared some weeks1 ,i may here incidentally remark1 has retained its limpidity and photogenic properties1 quite unimpaired during the whole year since elapsed1 and is now as sensitive as ever1--a property of no small value4 ,now1 when a picture 7for example an impression from an engraving7 is taken on paper washed with this solution1 it shows no sign of a picture on its back1 whether that on its face is developed or not2 but if1 while the actinic influence is still fresh upon the face1 7i4e41 as soon as it is removed from the light71 the back be exposed for a very few seconds to the sunshine1 and then removed to a gloomy place1 a positive picture1 the exact complement of the negative one on the other side1 though wanting of course in sharpness if the paper be thick1 slowly and gradually makes its appearance there1 and in half an hour or an hour acquires a considerable intensity4 ,i ought to mention that the ferro-tartaric acid in question is prepared by precipitating the ferro-tartrate of ammonia 7ammonia-tartrate of iron7 by acetate of lead1 and decomposing the precipitate by dilute sulphuric acid4 ,when lead is used in the preparation of ,amphitype paper1 the parts upon which the light has acted are found to be in a very high degree rendered water proof4--,sir ,j4 ,herschel4 ,this process is a new invention of our countryman1 ,j4 ,a4 ,whipple1 ,esq41 of ,boston1 and has been patented by ,m4 ,a4 ,root1 ,esq41 of ,philadelphia4 ,it will be seen1 however1 from the previous pages of my work that ,mr4 ,root is mistaken in regard to his being the first improvement patented in this country1 although it is unquestionably the first by an ,american4 ,of this improvement ,mr4 ,root says3 ,,vi4 ,,crayon ,,daguerreotype4 ,the improvement to which you refer is denominated ,the ,crayon ,daguerreotype4 ,this invention made by ,mr4 ,j4 ,a4 ,whipple1 is the only improvement in ,daguerreotyping1 ,i believe1 for which ,letters ,patent for the ,united ,states were ever issued4 ,the pictures produced by this process--which is of the simplest description imaginable--have the appearance and effect of very fine ,crayon ,drawings1 from which the improvement takes its name4 ,some of our most distinguished artists have given it their unqualified admiration4 ,among them1 our ,mezzotinto ,engravers1 especially ,john ,sartain1 ,esq41 who1 from his rich embellishments to most of the leading ,magazines and ,annuals of the country1 as well as from the celebrity of the superb ,magazine which bears his name1 is so well known and so well qualified to judge of its merits4 ,as an auxiliary to the artist1 in furnishing heads to the ,magazines1 or other works1 it is invaluable2 the great object which it accomplishes being to give a finer effect and more distinct expression to all the features--the whole power of the instrument being directed to1 and confined to the head4 ,the late hour at which this subject has been brought to our notice prevents so full a description as we would otherwise have been glad to furnish4 ,the ,new ,england ,states have been disposed of2 negotiations for any of the others can be made through ,m4 ,a4 ,root1 #adj ,chestnut street1 ,philadelphia4 ,a series of beautiful portraits are about being prepared by the ,crayton ,process for the express purpose of being placed on the exhibition at the ,art ,union1 when amateurs1 artists1 and the public generally will have an opportunity of witnessing its effect4 ,we are especially gratified with this striking improvement1 from the advantages which it promises to the ,daguerrean art4 ,it is admirably designed to excite a new interest on the subject through the community1 and in this way--and from its tendency to render the art more generally useful1 and to elevate and distinguish it--to make it to all a matter of more general importance4 ,yours respectfully1 ,m4 ,a4 ,,root4 ,in our second edition1 we hope--with ,mr4 ,root's permission--to lay the whole process before the public1 although our artists must bear in mind that ,mr4 ,root's patent secures to him the exclusive right of its application4 ,,chap4 ,,xi4 ,,on ,,the ,,probability ,,of ,,producing ,,colored ,,pictures ,,by ,,the ,,solar ,,radiations--,,photographic ,,deviations--,,lunar ,,pictures--,,drummond ,,light4 ,having before noticed the fact that some advances had been made towards taking ,daguerreotypes in color1 by means of solar rays1 and expressed the hope that the day was not far distant when this might be accomplished1 ,i here subjoin ,mr4 ,hunt's remarks on this subject4 ,mr4 ,biot1 in #ahdj1 speaking of ,mr4 ,fox ,talbot's beautiful calotype pictures1 considers as an illusion the hope to reconcile1 not only the intensity but the tints of the chemical impressions produced by radiations1 with the colors of the object from which these radiations emanated4 ,it is true that three years have passed away1 and we have not yet produced colored images2 yet ,i am not inclined to consider the hope as entirely illusive4 ,it must be remembered that the color of bodies depends entirely upon the arrangement of their molecules4 ,we have numerous very beautiful experiments in proof of this4 ,the bi-niodide of mercury is a fine scarlet when precipitated4 ,if this precipitate is heated between plates of glass1 it is converted into crystals of a fine sulphur yellow1 which remain of that color if undisturbed1 but which becomes very speedily scarlet if touched with any pointed instrument4 ,this very curious optical phenomena has been investigated by ,mr4 ,talbot and by ,mr4 ,warrington4 ,perfectly dry sulphate of copper is white2 the slightest moisture turns it blue4 ,muriate of cobalt is of a pale pink color2 a very slight heat1 by removing a little moisture1 changes it to a green4 ,these are a few instances selected from many which might be given4 ,if we receive a prismatic spectrum on some papers1 we have evidence that the molecular or chemical disturbance bears some relation to the color of each ray1 or1 in other words1 that colored light so modifies the action of ,,energia that the impression it makes is in proportion to the color of the light it accompanies1 and hence there results a molecular arrangement capable of reflecting colors differently4 ,some instances have been given in which the rays impressed correspond with the colors of the luminous rays in a very remarkable manner499 ,one of the most decided cases is that of the paper prepared with the fluoride of soda and nitrate of silver4 ,sir ,john ,herschel was1 however1 the first to obtain any good specimens of photographically impressed prismatic colorations4 99 ,see ,mr4 ,hunt's ,researches on ,light4 ,it was noticed by ,daguerre that a red house gave a reddish image on his iodized silver plate in the camera obscura2 and ,mr4 ,talbot observed1 very early in his researches1 that the red of a colored print was copied of a red color1 on paper spread with the chloride of silver49999 9999 ,in #ahdb1 ,i had shown me a picture of a house in the ,bowery1 which had been repaired a few days previous1 and in the wall a red brick left4 ,this brick was brought out on the ,daguerreotype plate of precisely the same color as the brick itself4 ,the same artist also exhibited to me1 the full length portrait of a gentleman who were a pair of pantaloons having a blue striped figure4 ,this blue stripe was fully brought out1 of the same color1 in the picture4--,,amer4 ,,ed4 ,in #ahdj ,i communicated to ,sir ,john ,herschel some very curious results obtained by the use of colored media1 which he did me the honor of publishing in one of his memoirs on the subject from which ,i again copy it4 ,a paper prepared with muriate of barytes and nitrate of silver1 allowed to darken whilst wet in the sunshine to a chocolate color1 was placed under a frame containing a red1 a yellow1 a green1 and a blue glass4 ,after a week's exposure to diffused light1 it became red under the red glass1 a dirty yellow under the yellow glass1 a dark green under the green1 and a light olive under the blue4 ,the above paper washed with a solution of salt of iodine1 is very sensitive to light1 and gives a beautiful picture4 ,a picture thus taken was placed beneath the above glasses1 and another beneath four flat bottles containing colored fluids4 ,in a few days1 under the red glass and fluid1 the picture became a dark blue1 under the yellow a light blue1 under the green it remained unchanged1 whilst under the blue it became a rose red1 which in about three weeks changed into green4 ,many other experiments of a similar nature have been tried since that time with like results4 ,in the summer of #ahdc1 when engaged in some experiments on papers prepared according to the principles of ,mr4 ,talbot's calotype1 ,i had placed in a camera obscura a paper prepared with the bromide of silver and gallic acid4 ,the camera embraced a picture of a clear blue sky1 stucco-fronted houses1 and a green field4 ,the paper was unavoidably exposed for a longer period than was intended--about fifteen minutes1--a very beautiful picture was impressed1 which1 when held between the eye and the light1 exhibited a curious order of colors4 ,the sky was of a crimson hue1 the houses of a slaty blue1 and the green fields of a brick red tint4 ,surely these results appear to encourage the hope1 that we may eventually arrive at a process by which external nature may be made to impress its images on prepared surfaces1 in all the beauty of their native coloration4 ,,photographic ,,deviations4 ,before taking leave of the subject of photogenic drawing1 ,i must mention one or two facts1 which may be of essential service to operators4 ,it has been observed by ,daguerre1 and others1 in ,europe1 and probably by some of our own artists1 that the sun two hours after it has passed the meridian1 is much less effective in the photographic process1 than it is two hours previous to its having reached that point4 ,this may depend upon an absorptive power of the air1 which may reasonably be supposed to be more charged with vapor two hours before noon4 ,the fuse of the hygrometer may possibly establish the truth or falsity of this supposition4 ,the fact1 however1 of a better result being produced before noon being established1 persons wishing their portraits taken1 will see the advantage of obtaining an early sitting1 if they wish good pictures4 ,on the other hand1 if the supposition above mentioned prove true1 a too early sitting must be avoided4 ,if we take a considerable thickness of a dense purple fluid1 as1 for instance1 a solution of the ammonia-sulphate of copper1 we shall find that the quantity of light is considerably diminished1 at least four-fifths of the luminous rays being absorbed1 while the chemical rays permeate it with the greatest facility1 and sensitive preparations are affected by its influence1 notwithstanding the deficiency of light1 nearly as powerfully as if exposed to the undecomposed sunbeams4 ,it was first imagined that under the brilliant sun and clear skies of the south1 photographic pictures would be produced with much greater quickness than they could be in the atmosphere of ,paris4 ,it is found1 however1 that a much longer time is required4 ,even in the clear and beautiful light of the higher ,alps1 it has been proved that the production of the photographic picture requires many minutes more1 even with the most sensitive preparations1 than it does in ,london4 ,it has also been found that under the brilliant light of ,mexico1 twenty minutes1 and half an hour1 are required to produce effects which in ,england would occupy but a minute2 and travellers engaged in copying the antiquities of ,yucatan have on several occasions abandoned the use of the photographic camera1 and taken to their sketch books4 ,dr4 ,draper99 has observed a similar difference between the chemical action of light in ,new ,york and ,virginia4 ,this can be only explained by the supposition that the intensity of the light and heat of these climes interferes with the action of the ,,energic rays on those sensitive preparations which are employed4 99 ,i would here take occasion to remark that our country man1 ,dr4 ,draper1 is very frequently quoted by ,mr4 ,hunt in his ,researches4 ,,lunar ,,pictures--,,drummond ,,light4 ,the ,roman ,astronomers state that they have procured ,daguerreotype impressions of the ,nebula of the sword of ,orion4 ,signor ,rondini has a secret method of receiving photographic images on lithographic stone2 on such a prepared stone they have succeeded in impressing an image of the ,nebula and its stars2 and from that stone they have been enabled to take impressions on paper1 unlimited in number1 of singular beauty1 and of perfect precision4 ,experiments have1 however1 proved that no heating power exists in the moon's rays1 and that lunar light will not act chemically upon the iduret of silver4 ,it was at one time supposed that terrestrial or artificial light possessed no chemical rays1 but this is incorrect--,mr4 ,brande discovered that although the concentrated light of the moon1 or the light even of olefiant gas1 however intense1 had no effect on chloride of silver1 or on a mixture of chloride and hydrogen1 yet the light emitted by electerized charcoal blackens the salt4 ,at the ,royal ,polytechnic ,institution pictures have been taken by means of sensitive paper acted upon by the ,drummond ,light2 but it must of course be distinctly understood1 that they are inferior to those taken by the light of the sun1 or diffused daylight4 ,if our operators could manage to produce good pictures in this way they would put money in their pockets1 as many who cannot find time during the day would resort to their rooms at night4 ,i throw out the hint in hopes some one will make the experiment4 ,i have learned1 since the above was written1 that an operator in ,boston succeeded a short time since in procuring very good pictures by the aid of the ,drummond ,light2 but that the intensity of the light falling directly upon the sitter's face caused great difficulty1 and he abandoned it4 ,this may1 probably1 be remedied by interposing a screen of very thin tissue paper tinged slightly of a bluish color4 ,,chap4 ,,xii4 ,,on ,,coloring ,,daguerreotypes4 ,nearly1 if not quite all the various colors used in painting may be made from the five primitive colors1 black1 white1 blue1 red and yellow1 but for the ,daguerrean artist it would be the best policy to obtain such as are required by their art already prepared4 ,in a majority of cases1 the following will be found sufficient1 viz4 ,carmine4 ,prussian ,blue4 ,white4 ,chrome ,yellow1 ,gamboge1 ,yellow ,ochre2 or all three499 99,gamboge is best for drapery2 ,ochre for the face4 ,light ,red4 ,indigo4 ,burnt ,sienna4 ,bistre1 or ,burnt ,umber4 ,if1 in coloring any part of a lady's or gentleman's apparel1 it is found necessary to produce other tints and shades1 the following combinations may be used3 ,orange--,mix yellow with red1 making it darker or lighter by using more or less red4 ,purple--,this is made with ,prussian blue1 or indigo and red4 ,carmine and ,prussian blue producing the richest color1 which may be deepened in the shadows by a slight addition of indigo or brown4 ,greens--,prussian blue and gamboge makes a very fine green1 which may be varied to suit the taste of the sitter or operator1 by larger portions of either1 or by adding white1 burnt sienna1 indigo1 and red1 as the case may require4 ,these combinations1 under different modifications1 give almost endless varieties of green4 ,brown--,may be made of different shades of umber1 carmine and lamp-black4 ,neutral tint--,is composed of indigo and lamp-black4 ,crimson--,mix carmine and white1 deepening the shaded parts of the picture with additional carmine4 ,flesh ,color--,the best representative of flesh color is light red1 brightened in the more glowing or warmer parts1 with carmine1 softened off in the lighter portions with white1 and shaded with purple and burnt sienna4 ,lead ,color--,mix indigo and white in proportions to suit4 ,scarlet--,carmine and light red4 ,for ,jewelry cups of gold and silver preparations accompany each box for ,daguerreotypists1 or may be procured separately4 ,the method of laying colors on ,daguerreotypes is one of considerable difficulty1 inasmuch as they are used in the form of perfectly dry impalpable powder4 ,the author of this little work is now experimenting1 in order1 if possible1 to discover some more easy1 artistic and unexceptionable method4 ,if successful1 the result will be published in a future edition4 ,the rules we shall give for coloring ,daguerreotypes depends1 and are founded1 upon those observed in miniature painting1 and are intended more as hints to ,daguerrean artists1 in hopes of leading them to attempt improvements1 than as instructions wholly to be observed4 ,the writer is confident that some compound or ingredient may yet be discovered which1 when mixed with the colors1 will give a more delicate1 pleasing1 and natural appearance to the picture than is derived from the present mode of laying them on1 which in his estimation is more like plastering than coloring4 ,,in ,,coloring ,,daguerreotypes1 the principal shades of the head are to be made with bistre1 mixed with burnt sienna1 touching some places with a mixture of carmine and indigo4 ,the flesh tints are produced by the use of light red1 deepened towards the shaded parts with yellow ochre1 blue and carmine mixed with indigo1 while the warmer1 or more highly colored parts have a slight excess of carmine or lake4 ,color the shades about the mouth and neck with yellow ochre1 blue1 and a very little carmine1 heightening the color of the lips with carmine and light red1 letting the light red predominate on the upper1 and the carmine on the lower lip2 the shades in the corner of the mouth being touched slightly with burnt sienna1 mixed with carmine4 ,in coloring the eyes1 the artist will of course be guided by nature1 observing a very delicate touch in laying on the colors1 so as to preserve as much transparency as possible4 ,a slight touch of blue--ultramarine would be best if it would adhere to the ,daguerreotype plate--in the whites of the eye near the iris1 will produce a good effect4 ,in coloring the heads of men it will be necessary to use the darker tints with more freedom1 according to the complexion of the sitter4 ,for women1 the warmer tints should predominate1 and in order to give that transparency so universal with the softer sex--and which gives so much loveliness and beauty to the face--a little white may be judiciously intermingled with the red tints about the lighter portions of the face4 ,in taking a picture of a lady with light or auburn hair1 by the ,daguerrean process1 much of the beauty of the face is destroyed1 on account of the imperfect manner in which light conveys the image of light objects to the spectrum of the camera4 ,this may be obviated in some measure by proper coloring4 ,to do this1 touch the shaded parts with burnt sienna and bistre1 filling up the lighter portions with yellow ochre1 delicate touches of burnt sienna1 and in those parts which naturally have a bluish tint1 add very delicate touches of purple--so delicate in fact as hardly to be perceived4 ,the roots of the hair at the forehead should also be touched with blue1 and the eyebrows near the temples made of a pinkish tint4 ,the chin of a woman is nearly of the same color as the cheeks in the most glowing parts4 ,in men it is stronger1 and of a bluish tint1 in order to produce the effect given by the beard4 ,in portraits of women--the middle tints on the side of the light1 which are perceived on the bosom and arms1 are made of a slight mixture of ochre1 blue and lake1 7or carmine71 to which add1 on the shaded sides1 ochre1 bistre and purple1 the latter in the darker parts4 ,the tints of the hands should be the same as the other parts of the flesh1 the ends of the fingers being a little pinkish and the nails of a violet hue4 ,if any portion of the fleshy parts is shaded by portions of the dress1 or by the position of the hand1 this shade should be colored with umber mixed with purple4 ,,to ,,color ,,the ,,drapery4--,violet ,velvet--,use purple made of ,prussian blue and carmine1 touching up the shaded parts with indigo blue4 ,green ,velvet--,mix ,prussian blue and red-orpiment1 shade with purple1 and touch up the lights with a little white4 ,red ,velvet--,mix a very little brown with carmine1 shading with purple1 marking the lights in the strongest parts with pure carmine1 and touch the most brilliant slightly with white4 ,white ,feathers--,may be improved by delicately touching the shaded parts with a little blue mixed with white4 ,white muslin1 linen1 lace1 satin1 silk1 etc41 may also be colored in the same way1 being careful not to lay the color on too heavily4 ,,furs--,red ,furs may be imitated by using light red and a little masticot1 shaded with umber4 ,gray ,furs--black and white mixed and shaded with bistre4 ,sable--white shaded lightly with yellow ochre4 ,these few directions are quite sufficient for the art1 and it is quite unnecessary for me to pursue the subject further4 ,i would1 however1 remark that the ,daguerreotypists would find it greatly to their advantage to visit the studies of our best artists1 our public galleries of paintings1 and statuary1 and wherever else they can obtain a sight of fine paintings1 and study the various styles of coloring1 attitudes1 folds of drapery and other points of the art4 ,in coloring ,daguerreotypes1 artists will find the magnifying glass of much advantage in detecting any imperfections in the plate or in the image1 which may be remedied by the brush4 ,in selecting brushes choose those most susceptible of a fine point1 which may be ascertained by wetting them between the lips1 or in a glass of water4 ,,chap4 ,,xiii4 ,,the ,,photographometer4 ,the last number 7for ,march1 #ahdi7 of the ,london ,art-,journal1 gives the following description of a recent improvement in ,photographic ,manipulation1 and as ,i am desirous of furnishing everything new in the art1 ,i stop the press to add it1 entire1 to my work4 ,since the photographic power of the solar rays bears no direct relation to their luminous influence1 it becomes a question of considerable importance to those who practice the beautiful art of photography1 to have the means of readily measuring the ever changing activity of this force4 ,several plans more or less successful1 have been devised by ,sir ,john ,herschel1 ,messrs4 ,jordan1 ,shaw and ,hunt4 ,the instrument1 however1 which is now brought forward by ,mr4 ,claudet1 who is well known as one of our most successful ,daguerreotypists1 appears admirably suited to all those purposes which the practical man requires4 ,the great difficulty which continually annoys the photographic amateur and artist1 is the determination of the sensibility of each tablet employed1 relatively to the amount of radiation1 luminous and chemical1 with which he is working4 ,with the photographometer of ,mr4 ,claudet this is easily ascertained4 ,the following woodcuts and concise description will sufficiently indicate this useful and simple apparatus4 ,illustration3 ,fig4 #cj 7hipho#cj4;gif7 ,for an instrument of this kind it is important in the first place to have a motion always uniform1 without complicated or expensive mechanism4 ,this is obtained by means founded upon the principle of the fall of bodies sliding down an inclined plane4 ,the sensitive surface is exposed to the light by the rapid and uniform passage of a metal plate1 ,a1 ,b1 7,fig4 #ca17 having openings of different length1 which follow a geometric progression4 ,it is evident that the exposure to light will be the same for each experiment1 because the plate furnished with the proportional openings falls always with the same rapidity1 the height of the fall being constant1 and the angle of the inclined plane the same4 ,each opening of this moveable plate allows the light to pass during the same space of time1 and the effect upon the sensitive surface indicates exactly the intensity of the chemical rays4 ,the rapidity of the fall may be augmented or diminished by altering the inclination of the plane by means of a graduated arc1 ,c1 ,d1 7,fig4 #cj17 furnished with a screw1 ,e1 by which it may be fixed at any angle4 ,the same result may be obtained by modifying the height of the fall or the weight of the moveable plate4 ,the photogenic surface1 whether it be the ,daguerreotype plate1 the ,talbotype paper1 or any other preparation sensitive to light1 is placed near the bottom of the inclined plane1 ,f4 ,it is covered by a thin plate of metal1 pierced with circular holes1 which correspond to the openings of the moveable plate at the moment of the passage of the latter1 during which the sensitive surface receives the light wherever the circular holes leave it exposed4 ,illustration3 ,fig4 #ca 7hipho#ca4;gif7 ,the part of the apparatus which contains the sensitive surface is an independent frame1 and it slides from a dark box into an opening on the side of the inclined plane4 ,a covering of black cloth impermeable to light is1 attached to the sides of the moveable plate1 enveloping the whole inclined plane1 rolling freely over two rollers1 ,r1 ,r1 placed the one at the upper and the other at the lower part of the inclined plane4 ,this cloth prevents the light striking the sensitive surface before and after the passage of the moveable plate4 ,it will be seen that this apparatus enables the experimentalist to ascertain with great precision the exact length of time which is required to produce a given amount of actinic change upon any sensitive photographic surface1 whether on metal or paper4 ,although at present some calculation is necessary to determine the difference between the time which is necessary for exposure in direct radiation1 and to the action of the secondary radiations of the camera obscura2 this is1 however1 a very simple matter1 and it appears to us exceedingly easy to adapt an instrument of this description to the camera itself4 ,by this instrument ,mr4 ,claudet has already determined many very important points4 ,among others1 he has proved that on the most sensitive ,daguerreotype plate an exposure of 4#jjja part of a second is sufficient to produce a decided effect4 ,regarding photography as an auxiliary aid to the artist of no mean value1 we are pleased to record a description of an instrument which1 without being complicated1 promises to be exceedingly useful4 ,in this opinion we are not singular2 at a recent meeting of the ,photographic ,club1 to which this instrument was exhibited1 it was with much real satisfaction that we learned that several of our most eminent artists were now eager and most successful students in ,photography4 ,the beautiful productions of the more prominent members of this club excited the admiration of all1 particularly the copies of architectural beauties1 and small bits of landscape1 by ,messrs4 ,cundell and ,owen4 ,we think that now the artist sees the advantage he may derive from the aid of science1 that both will gain by the union4 ,i hope the above description will induce our townsman1 ,mr4 ,roach1 to successfully produce an instrument that will meet the wants of our artists in that part of the ,daguerrean process referred to4 ,,finis4 ,,index4 ,accelerating ,liquids4 #fe ,amphitype4 #aaf ,anthotype4 #aac ,apparatus4 ,daguerreotype4 #dc ,calotype #ig ,photogenic #hg ,application of ,photogenic ,drawing4 #ie ,applying the ,sensitive4 #fd ,bringing out the ,picture4 #ga ,bromine ,box4 #ea ,chloride of #fh ,roach's ,tripple ,compound of #fg water4 #fe ,bromide of ,iodine4 #fg of ,lime4 #fh ,paper4 #ia of silver4 #ce ,brushes4 #hh ,buff ,sticks4 #fj ,calotype process4 #ig paper4 ,exposure in ,camera of #ajj ,pictures4 ,bringing out ib4 ,fixing #aja ,camera4 ,description of the #dc ,stand4 #di ,woodbridge's ib4 ,calotype4 #ej ,voigtlander #de ,chloride of ,bromine4 #fh of ,gold4 #cf to make a solution of #ge of ,iodine4 #ff of ,silver4 #ca ,chromatype4 #aab ,chrysotype4 #ajf ,cleaning and ,polishing the plate4 #fa ,coating ,boxes4 #ea ,color ,boxes4 #ec ,colored ,daguerreotypes on ,copper4 #gg ,coloring the ,picture4 #gf ,daguerreotypes4 #abi ,concave ,mirrors4 #ai ,convex ,mirrors #ai ,corchorus ,japonica4 #cg ,crayon ,daguerreotypes4 #abj ,cyanotype #aji ,daguerreotype ,apparatus4 #dc ,process4 #fa ,plates4 #fb ,daguerreotypes4 ,crayon #gg on paper #ha ,dedication4 iii ,definitions of terms used in optics1 #ae ,different methods of preparing photogenic paper4 #hi ,directions for use of ,galvanic ,battery4 #eh ,distilled water #hh ,drummond light4 #abh ,dry ,sensitive4 #fh ,drying apparatus4 #gb ,effects of light on bodies #be ,energiatype #aaa ,etching ,daguerreotypes4 #hc ,fifth operation4 ,fixing the picture4 #fa ,first operation4 ,cleaning the plate #fa ,fluoric acid4 #fi ,fourth operation-,bringing out the picture4 #ga ,funnels4 #ec ,galvanic ,battery4 #eg ,solution for use of #eh ,gilding stand4 #ec the picture4 #gd ,gold4 ,chloride of #cf ,to make solution of #ge ,hyposulphite2 or ,salt of #gd ,preparation of4 #cf ,gurney's ,sensitive4 #fg ,head ,rests4 #eg ,hints and ,suggestions4 #ci ,history of ,photography4 #c ,hungarian ,liquid4 #fi ,hygrometers4 #ee ,hyposulphite of ,gold4 #gd of ,soda4 #bh ,instantaneous pictures by means of ,galvanism4 #gg ,introduction4 i ,iodine1 ,dry #fd ,chloride of #ff ,bromide of #fg ,box4 #ea ,iodide of silver4 #cb ,ioduret of silver4 #cc ,iodize the ,plate4 ,to #fd ,iodized ,paper for ,calotypes4 ,to prepare #ih ,to prepare for the ,camera ib4 ,lamps1 ,spirit #ec ,light4 ,theory on #ad ,motion of #af ,reflection of #ag ,refraction of #bj on bodies4 ,effects of #be ,prismatic analysis of #bb ,lime1 ,bromide of #fh ,lunar ,pictures4 #abg ,mead's ,accelerator4 #fh ,mercury ,bath #ej ,nitrate of ,silver4 #hi ,oxide of ,silver4 #bi ,on coloring ,daguerreotypes #abi ,on the probability of ,producing colored ,photographs4 #abc ,paper4 blotting2 or bibulous1 #hh ,daguerreotypes4 #ha preparation of #hi suitable for ,photographs4 #hg ,photogenic drawing on ib ,photographic principle1 the #bb ,photographic process on paper4 #ib drawing4 ,application of #ie ,to fix the #ic deviations4 #abf ,photographometer1 ,the #ace ,plate ,support4 #ei ,blocks4 #ej ,vice4 #ea ,poppy1 ,the ,red #cg ,porcelain dishes4 #ei ,positive ,calotype #ajd ,preface4 v ,preparation of ,iodized ,paper4 #ih of ,gold4 #cf ,prismatic ,spectrum4 #bb ,analysis of ,light4 ib ,reflection of ,light4 #ag ,refraction of ,light4 #bj ,roach's ,tripple ,compound of ,bromine4 #fg ,sand ,clock4 #gj ,sealing paper4 ,to make #gg ,second operation4 #id ,sensitive4 ib ,silver4 ,bromide of #ce ,chloride of #ca ,iodide of #cb ,ioduret of #cc ,nitrate of #hi ,oxide of #bh ,solution of ,chloride of #ei ,sixth operation4 #gd ,soda ,hyposulphite of #gb ,solar and ,stellar ,light4 #ba ,still for purifying water1 #ed ,submitting the ,plate to the action of ,light #fi ,synopsis of ,mr4 ,hunt's ,treatise on ,light1 #bi ,talbotype ,camera4 #ej ,theory on ,light4 #ad ,third operation4 #fi ,wall ,flower4 #cg