THE 
 
 HISTORY AND PRACTICE 
 
 OF THE! 
 
 ART OF PHOTOGRAPHY; 
 
 OK THE 
 
 PRODUCTION OF PICTURES, 
 
 THROUGH THE AGENCY OF LIGHT. 
 
 CONTAINING 
 
 ALL THE INSTRUCTIONS NECESSARY FOR THE COMPLETE PRAC- 
 TICE OF THE DAGUERREAN AND PHOTOGENIC ART, 
 BOTH ON METALLIC PLATES AND ON PAPER. 
 
 BY HENRY H. SNELLING. 
 
 SECOND EDITION, CORRECTED AND REVISED. 
 
 SHlustratefc toftf) 3WooU Cuts. 
 
 NEW- YORK : 
 
 PUBLISHED BY G. P. PUTNAM, 
 
 155 Broadway. 
 
 1850. 
 
Entered according to act of Congress in the year 1849, 
 by H. H. Snelling, in the Clerk’s office, of the District 
 Court of the Southern District of New York. 
 
 GETTY CENTER LIBRARY 
 
TO 
 
 EDWARD ANTHONY, ESQ., 
 
 AN 
 
 ESTEEMED FRIEND 
 
 Whose gentlemanly deportment, liberal feelings, 
 and strict integrity have secured him a large circle 
 of friends, this work is 
 
 Respectfully Dedicated 
 
 By the 
 
 AUTHOR. 
 
PREFACE 
 
 
 The object of this little work is to fill a void much com- 
 plained of by Daguerreotypists— particularly young begin- 
 ers. 
 
 The author has waited a long time in hopes that some 
 more able pen would be devoted to the subject, but the wants 
 of the numerous, and constantly increasing, class, just men- 
 tioned, induces him to wait no longer. 
 
 All the English works on the subject — particularly on the 
 practical application, of Photogenic drawing — are deficient in 
 many minute details, which are essential to a complete un- 
 derstanding of the art. Many of their methods of operating 
 are entirely different from, and much inferior to, those prac- 
 tised in the United States : their apparatus, also, cannot 
 compare with ours for completeness, utility or simplicity. 
 
 I shall, therefore, confine myself principally— so far as 
 Photogenic drawing upon metalic plates is concerned — to the 
 methods practised by our most celebrated and experienced 
 operators, drawing upon French and English authority only 
 
VI. 
 
 in cases where I find it essential to the purpose for which 
 I design my work, namely : furnishing a complete system of 
 Photography ; such an one as will enable any gentleman, or 
 lady, who may wish to practise the art, for profit or amuse- 
 ment, to do so without the trouble and expense of seeking 
 instruction from professors, which in many cases within my 
 own knowledge has prevented persons from embracing the 
 profession. 
 
 To English authors I am principally indebted for that 
 portion of my work relating to Photogenic drawing on paper. 
 To them we owe nearly all the most important improve- 
 ments in that branch of the art. Besides, it has been but 
 seldom attempted in the United States, and then without 
 any decided success. Of these attempts I shall speak fur- 
 ther in the Historical portion of this volume. 
 
 Every thing essential, therefore, to a complete knowledge 
 of the whole art, comprising all the most recent discoveries 
 and improvements down to the day of publication will bo 
 found herein laid down. 
 
PREFACE TO SECOND EDITION. 
 
 The rapid sale of the first edition of the Art of Photography, 
 has made it incumbent upon me to issue a second several 
 months sooner than my most sanguine wishes led me to hope , 
 and it is with no ordinary feelings of gratitude that I return 
 thanks for the liberal patronage bestowed upon my humble 
 effort. 
 
 The circumstance gives me pleasure, also, on other grounds 
 than the mere personal gratification every author must feel at 
 the rapid sale of his works. It has convinced those who 
 thought the enterprise a hazardous one — from an erroneous 
 opinion that sufficient intelligence did not exist among the 
 Daguerrean Artists of America, to appreciate the advantages 
 of a text book of the kind presented — that our operators are 
 not all machines, set in motion like a steam-engine, incapable 
 of improvement beyond a certain point. The rapid sale of 
 the first edition proves conclusively, that our artists, not 
 satisfied with the mere mechanical knowledge of the art, are, 
 on the contrary, even desirous of improving both it and 
 themselves. 
 
 They are now celebrated throughout the civilized world as 
 the very best Photographists, and it is with a national pride 
 
Vill. 
 
 that I record the fact, that many English, French and Ger- 
 man travellers of distinction have visited the' galleries of our 
 artists for the purpose of taking home specimens of their skill 
 and excellence, and, to use the words of one of them, “to 
 show the artists of England how far they are behind their 
 trans-atl antic brethren.” 
 
 While we have such men as Whipple, of Boston, Brady 
 and Lawrence, of New- York, Boot, of Philadelphia, White- 
 hurst, of Baltimore, Davie, of Utica, and a host of others, from 
 Maine to Texas, whose names we should be glad to mention 
 had we the space to spare, sending forth their thousands of ex- 
 quisitely executed Daguerreotypes yearly, and ever ready to 
 search out and adopt improvements, we have no fear that the 
 meed of excellence now awarded to our American artists will 
 ever be taken from them. 
 
 Among the improvements of the day, we would again no- 
 tice the “ Crayon Daguerreotypes,” invented by Mr. Whipple, 
 of Boston, who will accept our thanks for his favors. 
 
 To Mr. Davie, of Utica, we are also indebted for many im- 
 provements in the art ; among which, is his plate vice and 
 buffing lathe, described in another part of this work. In our 
 next edition — if we be so fortunate as to issue one — we trust to 
 be able to give to the world such as he does not, at present, 
 consider it prudent to make public. While on the subject, 
 however, we must apologize to Mr. Davie for the error we 
 committed in the matter of the Plate vice , (Fig. 11,) described 
 on page 51. This valuable article was the invention of Mr. 
 Davie, and not of the Messrs. Lewis, and in justice to Mr. 
 Davie, I am bound to make this correction. It has been 
 proved conclusively, that seven months previous to the appli- 
 cation of Messrs. Lewis for a patent, Mr. Davie manufactured 
 
IX. 
 
 them at Utica, and sold them to artists in every part of West- 
 ern New-York ; and I distinctly remember having seen it ex- 
 hibited in this city by Mr. Davie, at least three months pre- 
 vious to Messrs. Lewis’s claim to the invention. 
 
 The Messrs. Lewis have done much in the improvement 
 of Daguerreotype apparatus, and have the satisfaction of know- 
 ing that their articles are almost universally adopted. They 
 deserve our thanks for their enterprise, but in speaking favor- 
 ably of them, 1 must not forget what is due to others ; neither 
 should they, in their praiseworthy efforts to improve, endeavor 
 to deprive another of his undoubted rights. I have deemed it 
 necessary to say this much in regard to the matter in extenua- 
 tion of my own error ; the Messrs. Lewis well know that it is 
 not partiality on my part, a reference to Chap. V. being proof 
 to the contrary. 
 
 It will be perceived that I have made several valuable ad- 
 ditions to the 4 ‘ Art of Photography,” which I trust will prove 
 acceptable, particularly the chapter on “ Position,” which I 
 have inserted at the request of several artists. 
 
INTRODUCTION 
 
 New York, January 27, 1849. 
 
 E. Anthony, Esq. 
 
 Dear Sir, — In sub mi ting the accompanying “ History 
 and Practice of Photography to your perusal, and for your 
 approbation, I do so with the utmost confidence in your abi- 
 lity as a practical man, long engaged in the science of which 
 it treats, as well as your knowledge of the sciences gener- 
 ally, and your regard for candor. To you, therefore, I 
 leave the decision whether or no I have accomplished my 
 purpose, and produced a work which may not only be of prac- 
 tical benefit to~ the Daguerrean artist, but of general inte- 
 rest to the reading public, and your decision will influence 
 me in offering it for, or withholding it from, publication. 
 
 If it meets your approbation, I would most respectfully 
 ask permission to dedicate it to you, subscribing myself, 
 With esteem, 
 
 Ever truly yours, 
 
 Henry H. Snelling. 
 
 New York, February 1st, 1849. 
 
 Mr. H. H. Snelling. 
 
 Dear Sir — Your note of January 27th, requesting 
 permission to dedicate to me your “History and Practice of 
 Photography,” I esteem a high compliment, particularly 
 since I have read the manuscript of your work. 
 
 Such a treatise has long been needed, and the manner in 
 
 
XI. 
 
 which you have handled the subject will make the book as 
 interesting to the reading public as it is valuable to the 
 Daguerrean artiste or the amateur dabbler in Photography. 
 I have read nearly all of the many works upon this art that 
 have emanated from the London and Paris presses, and I 
 think the reader will find in yours the pith of them all, with 
 much practical and useful information that 1 do not remem- 
 ber to have seen communicated elsewhere. 
 
 There is much in it to arouse the reflective and inventive 
 faculties of our Daguerreotypists. They have heretofore 
 stumbled along with very little knowledge of the true theory 
 of their art, and yet the quality of their productions is far 
 in advance of those of the French and English artists, most 
 of whose establishments I have had the pleasure of visiting. 
 I feel therefore, that when a sufficient amount of theoretic 
 knowledge shall have been added to this practical skill on 
 the part of our operators, and when they shall have been 
 made fully acquainted with what has been attained or at- 
 tempted by others, a still greater advance in the art will be 
 manifested. 
 
 A good Daguerreotypist is by no means a mere machine 
 following a certain set of fixed rules. Success in this art 
 requires personal skill and artistic taste to a much greater 
 degree than the unthinking public generally imagine ; in 
 fact more than is imagined by nine-tenths of the Daguer- 
 reotypists themselves. And we see as a natural result, that 
 while the business numbers its thousands of votaries, but 
 few rise to :>ny degree of eminence. It is because they look 
 upon their business as a mere mechanical operation, and 
 having no aim or pride beyond the earning of their daily 
 bread, they calculate what will be a fair per centage on the 
 cost of their plate, case,* and chemicals, leaving mind, which 
 is as much capital as anything else (where it is exercised,) 
 entirely out of the question. 
 
 The art of taking photographs on paper, of which your 
 work treats at considerable length, has as yet attracted but 
 
little attention in this country, though destined, as I fully 
 believe, to attain an importance far superior to that to which 
 the Daguerreotype has risen. 
 
 The American mind needs a waking up upon the subject, 
 and I think your book will give a powerful impulse in this 
 direction. In Germany a high degree of perfection has been 
 reached, and I hope our countrymen will not be slow to 
 follow. 
 
 Your interesting account of the experiments of Mr. Wat- 
 tles was entirely new to me, and is another among the many 
 evidences that when the age is fully ripe for any great dis- 
 covery, it i& rare that it does not occur to more than a sin- 
 gle mind. 
 
 Trusting that your work will meet with the encourage- 
 ment which your trouble in preparing it deserves, and with 
 gratitude for the undeserved compliment paid to me in its 
 dedication, 
 
 I remain, very sincerely, 
 
 Your friend and well wisher, 
 
 E. Anthony. 
 
PHOTOGRAPHY 
 
 CHAP. I. 
 
 A BRIEF HISTORY OF THE ART. 
 
 As in all cases of great and valuable inventions in sci- 
 ence and art the English lay claim to the honor of having 
 first discovered that of Photogenic drawing. But we 
 shall see in the progress of this history, that like many 
 other assumptions of their authors, priority in this is no 
 more due them, then the invention of steamboats, or the 
 cotton gin. 
 
 This claim is founded upon the fact that in 1802 Mr. 
 Wedgwood recorded an experiment in the Journal of the 
 Royal Institution of the following nature. 
 
 “A piece of paper, or other convenient material, was 
 placed upon a frame and sponged over with a solution of 
 nitrate of silver ; it was then placed behind a painting 
 on glass and the light traversing the painting produced a 
 kind of copy upon the prepared paper, those parts in 
 which the rays w^ere least intercepted being of the darkest 
 hues. Here, however, terminated the experiment; for 
 although both Mr. Wedgwood and Sir Humphry Davey 
 experimented carefully, for the purpose of endeavoring 
 
4 
 
 HISTORY OF THE ART. 
 
 to fix the drawings thus obtained, yet the object could 
 not be accomplished, and the whole ended in failure.” 
 
 This, bjr their own showing, was the earliest attempt of 
 the English savans. But this much of the principle was 
 known to the Alchemists at an early date — although 
 practically produced in another way — as the following 
 experiment, to be found in old books, amply proves. 
 
 “ Dissolve chalk in aquafortis to the consistence of 
 milk, and add to it a strong solution of silver ; keep this 
 liquor in a glass bottle well stopped ; then cutting out 
 from a piece of paper the letters you would have appear, 
 paste it on the decanter, 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 black, while that under the paper remains white ; 
 but particular care must be observed that the bottle be 
 not moved during the operation.” 
 
 Had not the alchemists been so intent upon the desire 
 to discover the far famed philosopher’s stone, as to make 
 them unmindful of the accidental dawnings of more 
 valuable discoveries, this little experiment in chemistry 
 might have induced them to prosecute a more thorough 
 search into the principle, and Photogenic art would not 
 now, as it is, be a new one. 
 
 It is even asserted that the Jugglers of India were for 
 many ages in possession of a secret by which they were 
 enabled, in a brief space, to copy the likeness of any in- 
 dividual by the action of light. This fact, if fact it be, 
 may account for the celebrated magic mirrors said to be 
 possessed by these jugglers, and probable cause of their 
 power over the people. 
 
HISTORY OF THE ART. 
 
 5 
 
 However, as early as 1556 the fact was established 
 that a combination of chloride and silver, called, from its 
 appearance, horn silver, was blackened by the sun’s rays ; 
 and in the latter part of the last century Mrs. Fulhame 
 published an experiment by which a change of color 
 was effected in the chloride of gold by the agency of 
 light; and gave it as her opinion that words might be 
 written in this way. These incidents are considered as 
 the first steps towards the discovery of the Photogenic 
 art. 
 
 Mr. Wedgwood’s experiments can scarcely be said to 
 be any improvement on them since he failed *to bring 
 them to practical usefulness, and his countrymen will 
 have to be satisfied with awarding the honor of its com- 
 plete adaptation to practical purposes, to MM. Niepce 
 and Daguerre of France, and to Professors Draper, and 
 Morse of New- York. 
 
 These gentlemen — MM. Niepce and Daguerre — pur- 
 sued the subject simultaneously, without either, however 
 being aware of the experiments of his colleague in sci- 
 ence. For several .years, each pursued his researches 
 individually until chance made them acquainted, when 
 they entered into co-partnership, and conjointly brought 
 the art almost to perfection. 
 
 M. Niepce presented his first paper on the subject to 
 the Royal Society in 1827, naming his discovery Heli- 
 ography. What led him to the study of the principles of 
 the art I have no means, at present, of knowing, but it 
 was probably owing to the facts recorded by the Alche- 
 mists, Mrs. Fulhame and others, already mentioned. But 
 M. Daguerre, who is a celebrated dioramic painter, being 
 desirous of employing some of the singularly changeable 
 salts of silver to produce a peculiar class of effects in his 
 
6 
 
 HISTORY OF THE ART. 
 
 paintings, was led to pursue an investigation which re- 
 sulted in the discovery of the Daguerreotype, or Photo- 
 genic drawing on plates of copper coated with silver. 
 
 To this gentleman — to his liberality— are we Ameri- 
 cans indebted for the free use of his invention ; and the 
 large and increasing class of Daguerrean artists of this 
 country should hold him in the most profound respect foi 
 it. He was not willing that it should be confined to a 
 few individuals who might monopolise the benefits to be 
 derived from its practice, and shut out all chance of im- 
 provement. Like a true, noble hearted French gentleman 
 he desired that his invention should spread freely through- 
 out the whole world. With these views he opened nego- 
 ciations with the French government which were conclu- 
 ded most favorably to both the inventors, and France has 
 the u glory of endowing the whole world of science and 
 art with one of the most surprising discoveries that honor 
 the land.” 
 
 Notwithstanding this, it has been patented in England 
 and the result is what might have been expected : En 
 glish pictures are far below the standard of excellence ol 
 those taken by American artists. I have seen some me- 
 dium portraits, for which a guinea each had been paid, 
 and taken too, by a celebrated artist, that our poorest Da- 
 guerreotypists would be ashamed to show to a second 
 person, much less suffer to leave their rooms. 
 
 Calotype, the name given to one of the methods of 
 Photogenic drawing on paper, discovered, and perfected 
 by Mr. Fox Talbot of England, is precisely in the same 
 predicament, not only in that country but in the United 
 States, Mr. Talbot being patentee in both. He is a man 
 of some wealth,! believe, but he demands so high a price 
 
HISTORY OF THE ART. 
 
 7 
 
 for a single right in this country, that none can be found 
 who have the temerity to purchase. 
 
 The execution of his pictures is also inferior to those 
 taken by the German artists, and I would remark en pas- 
 sant, that the Messrs. Mead exhibited at the last fair of 
 the American Institute, (of 1848,) four Calotypes, which 
 one of the firm brought from Germany last Spring, that 
 for beauty, depth of tone and excellence of execution sur- 
 pass the finest steel engraving. 
 
 When Mr. Talbot’s patent for the United States ex- 
 pires and our ingenious Yankee boys have the opportu- 
 nity, I have not the slightest doubt of the Calotype, in 
 their hands, entirely superceding the Daguerreotype. 
 
 Let them, therefore, study the principles of the art as 
 laid down in this little work, experiment, practice and 
 perfect themselves in it, and when that time does arrive 
 be prepared to produce that degree of excellence in Calo- 
 type they have already obtained in Daguerreotype. 
 
 It is to Professor Samuel F. B. Morse, the distinguish- 
 ed inventor of the Magnetic Telegraph, of New York, 
 that we are indebted for the application of Photography, 
 to portrait taking. He was in Paris, for the purpose of 
 presenting to the scientific world his Electro-Magnetic 
 Telegraph, at the time, (1838,) M. Daguerre announced 
 his splendid discovery, and its astounding results having 
 an important bearing on the arts of design arrested his 
 attention. In his letter to me on the subject, the Profes- 
 sor gives the following interesting facts. 
 
 u The process was a secret, andnegociations were then 
 in progress, for the disclosure of it to the public between 
 the French government and the distinguished discoverer. 
 M. Daguerre had shown his results to the king, and to a 
 few only of the distinguished savans, and by the advice 
 
8 
 
 HISTORY OF THE ART. 
 
 of M. Arago, had determined to wait the action of the 
 French Chambers, before showing them to any other per- 
 sons. I was exceedingly desirous of seeing them, but 
 knew not how to approach M. Daguerre who was a 
 stranger to me. On mentioning my desire to Robert 
 Walsh, Esq., our worthy Consul, he said to me ; 1 state 
 that you are an American, the inventor of the Telegraph, 
 request to see them, and invite him in turn to see the Te- 
 legraph, and I know enough of the urbanity and liberal 
 feelings of the French, to insure you an invitation.’ I 
 was successfull in my application, and with a young 
 friend, since deceased, the promising son of Edward De- 
 levan, Esq., I passed a most delightful hour with M. Da- 
 guerre, and his enchanting sun-pictures. My letter con- 
 taining an account of this visit, and these pictures, was 
 the first announcement in this country of this splendid 
 discovery.” 
 
 “ I may here add the singular sequel to this visit. On 
 the succeeding day M. Daguerre paid me a visit to see 
 the Telegraph and witness its operations. He seemed 
 much gratified and remained with me perhaps two hours ; 
 two melancholy hours to him, as they afterwards proved ; 
 for while he was with me, his buildings, including his 
 diorama, his studio, his laboratory, with all the beauti- 
 ful pictures I had seen the day before, were consumed 
 by fire. Fortunately for mankind, matter only was con- 
 sumed, the soul and mind of the genius, and the process 
 were still in existence.” 
 
 On his return home, Professor Morse waited with im- 
 patience for the revelation of M. Daguerre’s process, 
 and no sooner was it published than he procured a copy 
 of the work containing it, and at once commenced taking 
 Daguerreotype pictures. At first his object was solely 
 
HISTORY OF THE ART. 
 
 9 
 
 to furnish his studio with studies from nature ; but his 
 experiments led him into a belief of the practicability of 
 procuring portraits by the process, and he was undoubted- 
 ly the first whose attempts were attended with success. 
 Thinking, at that time, that it was necessary to 'place 
 the sitters in a very strong light, they were all taken with 
 their eyes closed. 
 
 Others were experimenting at the same time, among 
 them Mr. Wolcott and Prof. Draper, and Mr. Morse, 
 with his acustomed modesty, thinks that it would be dif- 
 ficult to say to whom is due the credit of the first Da- 
 guerreotype portrait. At all events, so far as my know- 
 ledge serves me, Professor Morse deserves the laurel 
 wreath, as from him originated the first of our inumer- 
 able class of Daguerreotypists ; and many of his pupils 
 have carried the manipulation to very great perfection. In 
 connection with this matter I will give the concluding 
 paragraph of a private letter from the Professor to me ; 
 He says. 
 
 u If mine were the first, other experimenters soon made 
 better results, and if there are any who dispute that I 
 was first, I shall have no argument with them ; for I was 
 not so anxious to be the first to produce the result, as to 
 produce it in any way. I esteem it but the natural carry- 
 ing out of the wonderful discovery, and that the credit 
 was after all due to Daguerre. I lay no claim to any im- 
 provements. ” 
 
 Since I commenced the compilation of this work, I 
 have had the pleasure of making the acquaintance of an 
 American gentleman — James M. Wattles Esq. — who as 
 early asl828 — and it will be seen, by what I have already 
 stated, that this is about the same date of M. Niepce’s 
 
10 
 
 HISTORY OF THE ART 
 
 discovery — had his attention attracted to the subject of 
 Photography, or as he termed it u Solar picture draw- 
 ing,’’ while taking landscape views by means of the ca- 
 mera-obscura. When we reflect upon all the circum- 
 stances connected with his experiments, the great disad- ‘ 
 vantages under which he labored, and his extreme youth- 
 fullness, we cannot but feel a national pride — yet wonder 
 — that a mere yankee boy, surrounded by the deepest for- 
 ests, hundred of miles from the populous portion of our 
 country, without the necessary materials, or resources for 
 procuring them, should by the force of his natural genius 
 make a discovery, and put it in practical use, to accom- 
 plish which, the most learned philosophers of Europe, 
 with every requisite apparatus, and a profound knowledge 
 of chemistry — spent years of toil to accomplish. How 
 much more latent talent may now be slumbering from the 
 very same cause which kept Mr. Wattles from publicly 
 revealing his discoveries, viz ; want of encouragement — 
 ridicule ! 
 
 At the time when the idea of taking pictures perma- 
 nently on paper by means of the camera-obscura first oc- 
 curred to him, he was but sixteen years of age, and under 
 the instructions of Mr. Charles Le Seuer, (a talented ar- 
 tist from Paris) at the New Harmony school, Indiana 
 Drawing and painting being the natural bent of his mind, 
 he was frequently employed by the professors to make 
 landscape sketches in the manner mentioned. The beau- 
 ty of the image of these landscapes produced on the paper 
 in the camera-obscura, caused him to pause and admire 
 them with all the ardor of a young artist, and wish that 
 by some means, he could fix them there in all their beau- 
 ty. From wishing he brought himself to think that it 
 was not only possible but actually capable of accomplish- 
 
HISTORY OF THE ART. 
 
 11 
 
 ment, and from thinking it could, he resolved it should be 
 done. 
 
 • He was, however, wholly ignorant of even the first 
 principles of chemistry, and natural philosophy, and all 
 the knowledge he was enabled to obtain from his teachers 
 was of very little service to him. To add to this, when- 
 ever he mentioned his hopes to his parents, they laughed 
 at him, and bade him attend to his studies and let such 
 moonshine thoughts alone — still he persevered, though 
 secretly, and he met with the succes his peseverance de- 
 served. 
 
 For the truth of his statement, Mr. Wattles refers to 
 some of our most respectable citizens residing at the west, 
 and I am in hopes that I shall he enabled to receive in 
 time for this publication, a confirmation from one or 
 more of these gentlemen. Be that as it may, I feel con- 
 fident in the integrity of Mr. Wattles, and can give his 
 statement to the world without a doubt of its truth. 
 
 The following sketch of his experiments and their re- 
 sults will, undoubtedly, be interesting to every American 
 reader and although some of the profound philosophers of 
 Europe may smile at his method of proceeding, it will in 
 some measure show the innate genius of American minds, 
 and prove that we are not far behind our trans-atlantic 
 brethren in the arts and sciences. 
 
 Mr. Wattles says : u In my first efforts to effect the de- 
 sired object, they were feeble indeed, 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 spirit, I at last 
 produced, what I thought very fair samples — but to pro- 
 ceed to my experiments. 
 
 “ I .first dipped a quarter sheet of thin white writing 
 
12 
 
 HISTORY OF THE ART. 
 
 paper in a weak solution of caustic (as I then called it) 
 and dried it in an empty box, to keep it in the dark ; 
 when dry, I placed it in the camera and watched it with 
 great patience for nearly half an hour, without produc- 
 ing any visible result ; evidently from the solution being 
 to weak. I then soaked the same piece of paper in a solu- 
 tion of common potash, and then again in caustic water 
 a little stronger than the first, and when dry placed it in 
 the camera. In about forty-five minutes I plainly perciev- 
 ed the effect, in the gradual darkening of various parts of 
 the view, which was the old stone fort in the rear of the 
 school garden, with the trees, fence, &c. I then became 
 convinced of the practicability of pToducing beautiful solar 
 pictures in this way ; but, alas ! my picture vanished and 
 with it, all — no not all — my hopes. With renewed deter- 
 mination I began again by studying the nature of the 
 preparation, and came to the conclusion, that if I could 
 destroy the part not acted upon by the light without in 
 juring that which was so acted upon, I could save my 
 pictures. I then made a strong solution of sal. soda I 
 had in the house, and soaked my paper in it, and then 
 washed it off in hot water, which perfectly fixed the view 
 upon the paper. This paper was very poor with thick 
 spots, more absorbent than other parts, and consequently 
 made dark shades in the picture where they should not 
 have been ; but it was enough to convince me that I 
 had succeeded, and that at some future time, when I had 
 the means and a more extensive knowledge of chemistry, 
 I could apply myself to it again. I have done so since, at 
 various times, with perfect success ; but in every instance 
 laboring under adverse circumstances.” 
 
 I have very recently learned, that, under the present 
 patent laws of the United States, every foreign patentee 
 
HISTORY OF THE ART. 
 
 13 
 
 is required to put his invention, or discovery, into prac- 
 tical use within eighteen months after taking out his 
 papers, or otherwise forfeit his patent. With regard to 
 Mr. Talbot’s Calotype patent, this time has nearly, if not 
 quite expired, and my countrymen are now at perfect li- 
 berty to appropriate the art if they feel disposed. From 
 the statement of Mr. Wattles, it will be perceived that 
 this can be done without dishonor, as in the first instance 
 Mr. Talbot had no positive right to his patent. 
 
 Photography ; or sun-painting is divided, according to 
 the methods adopted for producing pictures, into 
 
 DAGUERREOTYPE, 
 
 CALOTYPE, 
 
 CHRYSOTYPE, 
 
 CYANOTYPE, 
 
 CHROMATYPE, 
 
 ENERGIATYPE, 
 
 anthotype and 
 
 AMPHITYPE. 
 
CHAP. IL 
 
 THE THEORY ON LIGHT.™ THE PHOTOGRAPHIC PRINCIPLE 
 
 Some philosophers contend that to the existence of 
 light alone we owe the beautiful effects produced by the 
 Photogenic art, while others give sufficient reasons for 
 doubting the correctness of the assumption. That the 
 results are effected by a principle associated with light 
 and not by the luminous principle itself, is the most proba- 
 ble conclusion. The importance of a knowledge of this 
 fact becomes most essential in practice, as will presently 
 be seen. To this principle Mr. Hunt gives the name of 
 Energia. 
 
 The Nature of Light is not wholly known, but it is 
 generally believed to be matter, as in its motions it obeys 
 the laws regulating matter. 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 
 substance. I will not, however, enter into a statement 
 of the various theories of Philosophers on this head, but 
 content myself with that of Sir Isaac Newton ; who sup- 
 posed rays of light to consist of minute particles of mat- 
 ter, which are constantly emanating from luminous bodies 
 and cause vision, as odoriferous particles, proceeding 
 from certain bodies, cause smelling. 
 
16 
 
 LIGHT. 
 
 The effects of light upon other bodies , and how light is 
 effected by them , involve some of the most important prin- 
 ciples, which if properly understood by Daguerreotypists 
 would enable them to improve and correct many of the 
 practical operations in their art. These effects we shall ex- 
 hibit in this and the following chapters. 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 optics. 
 
 Luminous bodies are of two kinds ; those which shine 
 by their own light, and those which shine by reflected 
 light. 
 
 Transparent bodies are such as permit rays of light to 
 pass through them. 
 
 Translucent bodies permit light to pass faintly, but 
 without representing the figure of an object seen through 
 them. 
 
 Opaque bodies permit no light to pass through them, 
 but reflect light. 
 
 A ray is a line of light. 
 
 A beam is a collection of parallel rays. 
 
 A pencil is a collection of converging, or diverging rays. 
 
 A medium is any space through which light passes. 
 
 Incident rays are those which fall upon the surface of 
 a body. 
 
 Reflected rays are those which are thrown off from a 
 body. 
 
 Parallel rays are such as proceed equally distant from 
 each other through their whole course. 
 
 Converging rays are such as approach and tend to 
 unite at any one point, as at b fig. 3. 
 
LIGHT. 
 
 17 
 
 Diverging rays are those which continue to recede 
 from each other, as at e. Fig. 3. 
 
 A Focus is that point at which converging rays meet. 
 
 Motion of Light — Rays of light are thrown off from 
 luminous bodies in every direction, but always in straight 
 lines, which cross each other at every point ; but the par- 
 ticles of which each ray consists are so minute that the 
 rays do not appear to be impeded by each other. A ray 
 of light passing through an aperture into a dark room, 
 proceeds in a straight line ; a fact of which any one may 
 be convinced by going into a darkened room and admiting 
 light only through a small aperture. 
 
 Light also moves with great velocity, but becomes 
 fainter as it recedes from the source from which it emi- 
 nates ; in other words, diverging rays of light diminish 
 in intensity as the square of the distance increases. For 
 instance; let a fig. 1, represent the luminous body from 
 Fig. 1. 
 
 which light proceeds, and suppose three square boards, 
 b. c. d. severally one, four and sixteen square inches in 
 size be placed ; b one foot, c two feet, and d four feet 
 from a, it will be perceived that the smallest board b will 
 throw c into shadow ; that is, obstruct all rays of light 
 that would otherwise fall on c, and if b were removed c 
 would in like manner hide the light from d — Now, if b 
 recieve as much light as would fall on c whose surface is 
 four times as large, the light must be four times as pow- 
 
 I 
 
18 
 
 LIGHT. 
 
 erful, and sixteen times as powerful as that which would 
 fall on the second and third boards, because the same 
 quantity of light is diffused over a space four and sixteen 
 times greater. These same rays may be collected and 
 their intensity again increased. 
 
 Rays of light are reflected from one surface to another ; 
 Refracted , or bent, as they pass from the surface of one 
 transparent medium to another ; and Inflected , or turned 
 from their course, by the attraction of opaque bodies. 
 From the first we derive the principles on which mirrors 
 are constructed ; to the second we are indebted for the 
 power of the lenses , and the blessings of sight, — for the light 
 acts upon the retina of the eye in the same manner as on 
 the lens of a camera. The latter hasjno important bearing 
 upon our subject. 
 
 When a ray of light falls perpendicularly upon an 
 opaque body, it is reflected back in the same line in 
 which it proceeds ; in this case the reflected ray returns 
 in the same path the incident ray traversed ; but when a 
 ray falls obliquely, it is reflected obliquely, that is, it is 
 thrown off in an opposite direction, and as far from the 
 perpendicular as was the incident ray, as shown at Fig. 2 ; 
 a representing the incident ray and b the reflected. 
 The point, or angle c made by 
 the incident ray, at the surface 
 of the reflector e /, with a line 
 c d y perpendicular to that sur- 
 face, is called the angle of in- 
 cidence , while the angle form- 
 ed by the reflected ray h and 
 the perpendicular line d is 6 c*T f 
 
 called the angle of reflection , and these angles are always 
 equal. 
 
LIGHT. 
 
 19 
 
 It is by this reflection of light that objects are made vi- 
 sible ; but unless light falls directly upon the eye they are 
 invisible, and are not sensibly felt until after a certain 
 series of operations upon the various coverings and humors 
 of the eye. Smooth and polished surfaces reflect light most 
 powerfully, and send to the eye the images of the objects 
 from which the light proceeded before reflection. Glass, 
 which is transparent — transmitting light — would be of no 
 use to us as a mirror, were it not first coated on one side 
 with a metalic amalgam, which interrupts the rays in 
 their passage from the glass into the air, and throws them 
 either directly in the incident line, or in an oblique di- 
 rection. The reason why trees, rocks and animals are not 
 all mirrors, reflecting other forms instead of their own, is, 
 that their surfaces are uneven, and rays 6f light reflected 
 from an uneven surface are diffused in all directions/ 
 
 Parallel rays falling obliquely upon a plane mirror are 
 reflected parallel ; converging rays, with the same degree 
 of convergence ; and diverging rays equally divergent. 
 
 Stand before a mirror and your image is formed therein, 
 and appears to be as far behind the glass as you are be- 
 fore it, making the angle of reflection equal to that of in- 
 cidence, as before stated. The incident ray and the re- 
 flected ray form, together, what is called the passage of 
 reflection, and this will therefore make the actual distance 
 of an image to appear as far again from the eye as it 
 realty is. Any object which reflects light is called a 
 radiant. The point behind a reflecting surface, from 
 which they appear to diverge, is called the virtual focus. 
 
 Rays of light being reflected at the same angle at 
 which they fall upon a mirror, two persons can stand in 
 such a position that each can see the image of the other 
 •without seeing his own. Again ; you may see your 
 
20 
 
 LIGHT. 
 
 whole figure in a mirror half your length, but if you 
 stand before one a few inches shorter the whole cannot be 
 reflected, as the incident ray which passes from your feet 
 into the mirror in the former case, will in the latter fall 
 under it. Images are always reversed in mirrors. 
 
 Convex mirrors reflect light from a rounded surface 
 and disperse the rays in every direction, causing parallel 
 rays to diverge, diverging rays to diverge more, and con- 
 verging 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 surface, and it is the diminishing of the vis- 
 ual angle, by causing rays of light to be farther extended 
 before they meet in a point, which produces the image of 
 convex mirrors. The greater the convexity of a mirror, 
 the more will the images of the objects be diminished, 
 and the nearer will they appear to the surface. These 
 mirrors furnish science with many curious and pleasing 
 facts. 
 
 Concave mirrors are the reverse of convex ; the latter 
 being rounded outwards, the former hollowed inwards — 
 they render rays of light more converging — collect rays 
 instead of dispersing them, and magnify objects while the 
 convex diminishes them. 
 
 Rays of light may be collected in the focus of a mirror 
 to such intensity as to melt metals. The ordinary burning 
 .glass is an illustration of this fact ; although the rays ot 
 light are refracted, or passed through the glass and con- 
 centrated into a focus beneath. 
 
 When incident rays are parallel, the reflected rays con- 
 verge to a focus, but when the incident rays proceed from 
 a focus, or are divergent, they are reflected parallel. It is 
 only when an object is nearer to a concave mirror than its 
 
LIGHT. 
 
 21 
 
 centre of concavity, that its image is magnified ; for when 
 the object is farther from the mirror, this 1 centre will ap- 
 pear less than the object, and in an inverted position. 
 
 The centre of concavity in a concave mirror, is an im- 
 aginary point placed in the centre of a circle formed by 
 continuing the boundaiy of the concavity of* the mirror 
 from any one point of the edge to another parallel to and 
 beneath it. 
 
 Refraction of light: — I now pass to the consider- 
 ation of the passage of light through bodies. 
 
 A ray of light falling perpendicularly through the air 
 upon a surface of glass or water passes on in a straight 
 line through the body ; but if it, in passing from one 
 medium to another of different density, fall obliquely, it is 
 bent from its direct course and recedes from it, either to- 
 wards the right or left, and this bending is called refraction; 
 (see Jig. 3, b.) If a ray of light passes from a rarer into a 
 J denser medium it is refracted towards a perpendicular in 
 that medium ; but if it passes from a denser into rarer it is 
 bent further from a perpendicular in that medium. Owing 
 to this bending of the rays of light the angles of refraction 
 and incidence are never equal. 
 
 Transparent bodies differ in their power of bending 
 light — as a general rule, the refractive power is propor- 
 tioned to the density — but the chemical constitution of 
 bodies a's well as their density, is found to effect their re- 
 fracting power. Inflamable bodies possess this power 
 to a great degree. 
 
 The sines of the angle of incidence and refraction (that 
 is, the perpendicular d^wn from the extremity of an arc 
 to the diameter of a circle,) are always in the same ratio ; 
 viz : from air into water, the sine of the angle of refrac- 
 tion is nearly as four to three, whatever be the position ot 
 
22 
 
 LIGHT. 
 
 the ray with respect to the refracting surface. From air 
 into sulphur, 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 radius * of a circle, and light falling very obliquely 
 upon a transparent medium ceases to be refracted ; this 
 is termed total reflection. 
 
 Since the brightness of a reflected image depends upon 
 the quantity of light, it is quite evident that those images 
 which arise from total reflection are by far the most vivid, 
 as in ordinary cases of reflection a portion of light is ab- 
 sorbed. 
 
 I should be pleased to enter more fully into this branch 
 of the science of optics, but the bounds to which I am 
 necessarily limited in a work of this kind will not admit 
 of it. In the next chapter, however, I shall give a sy- 
 nopsis of Mr. Hunt’s treatise on the u Influence of the So- 
 lar Rays on Compound Bodies, with especial reference to 
 their Photographic application” — A work which should 
 be in the hands of every Daguerreotypist, and which I 
 hope soon to see republished in this country. I will con- 
 clude this chapter with a brief statement of the principles 
 upon which the Photographic art is founded. 
 
 Solar and Steller light contains three kinds of rays, 
 viz : 
 
 1. Colorific , or rays of color. 
 
 2. Calorific, or rays of heat. 
 
 3. Chemical rays, or those which produce chemical 
 effects. 
 
 On the first and third the photographic principle de- 
 pends. In explaining this principle the accompanying 
 wood cuts, (figs. 3 and 4) will render it more intelligible. 
 
 * The radius of a circle is a straight line passing from the centre to the 
 circumference. 
 
LIGHT. 
 
 23 
 
 If a pencil of the sun’s rays fall upon a prism, it is bent 
 in passing through the transparent medium ; and some 
 rays being -more refracted than others, we procure an 
 elongated image of the luminous beam, exhibiting three 
 distinct colors, red, yellow and blue, which are to be re- 
 garded as primitives — and from their interblending, seven, 
 as recorded by Newton, and shown in the accompanying 
 wood cut. These rays being absorbed, or reflected dif- 
 ferently by various bodies, give to nature the charm of 
 color. Thus to the eye is given the pleasure we deri-ve 
 in looking upon the green fields and forests, the enumera- 
 ble varieties of flowers, the glowing ruby, jasper, topaz, 
 amethist, and emerald, the brilliant diamond, and all the 
 rich and varied hues of nature, both animate and inani- 
 mate. * 
 
 Fig. 3. 
 
 Now, if we allow this prismatic spectrum (b. fig. 3.) 
 to fall upon any surface (as at c.) prepared with a sen- 
 sitive photographic compound, we shall find that the 
 chemical effect produced bears no relation to the intensity 
 of the light of any particular colored ray, but that, on the 
 
24 
 
 LIGHT. 
 
 Fig. 4. 
 
 contrary, it is dispersed over the largest portion of the 
 spectrum, being most energetic in the least luminous 
 rays, and ever active ove* an extensive space, where no 
 traces of light can be detected. Fig. 4, will give the 
 student a better idea of this principle. It is a copy of 
 the kind of impression which the spectrum, spoken of, 
 would make on a piece of paper covered with a very 
 sensitive photographic preparation. The white ^ space a . 
 corresponds with the most luminous, or yellow ray, 
 (5, fig. 3) over the limits of which all chemical change is 
 prevented. A similar ac- 
 tion is also produced by 
 the lower end of the red 
 ray c ; hut in the upper 
 portion, however we find 
 a decided change (as at d) . 
 
 The most active chemical 
 change, you will percieve, 
 is produced by the rays a- 
 bove the yellow a ; viz. 
 
 4, 3, 2 and 1 (as at b ) the 
 green (4) being the least 
 active, and the blue (3) 
 and violet (1) rays the 
 most so, the action still 
 continuing far beyond the 
 point b which is the end 
 of the luminous image. 
 
 Suppose we wish to copy 
 by the Daguerreotype, or 
 Calotype process, any objects highly colored — blue, red 
 and yellow, for instance predominating — the last of course 
 reflects the most light, the blue the least ; but the rays 
 
LIGHT. 
 
 25 
 
 from the blue surface will make the most intense impres- 
 sion, whilst the red radiations ate working very slowly, 
 and the yellow remains entirely inactive. This accounts 
 for the difficulty experienced in copying bright green 
 foliage, or warmly colored portraits ; a large portion of 
 the yellow and red rays entering into the composition of 
 both — and the imperfections in a Daguerreotype portrait 
 of a person with a freckled face depends upon the same 
 cause — ( See note to 2d Ed., p. 28.) 
 
 A yellow, hazy atmosphere, even when the light is 
 very bright, will effectually prevent any good photogra- 
 phic result — and in the height of summer, with the most 
 sensative process, it not un frequently happens that the 
 most annoying failures arise from this agency of a yellow 
 medium. A building painted of a yellow color, which 
 may reflect the sun’s rays directly into the operator’s 
 room will have the same effect. Daguerreotypists, being 
 ignorant of these facts, are very apt to charge their want 
 of success to the plates, or chemicals, or any thing but 
 the real cause ; and it would be well to bear these facts 
 constantly in mind and as far as possible avoid theffi. 
 This, may be accomplished, in a measure, by a choice of 
 location or by having the glass of your windows tinged 
 with blue ; or a screen of thin blue paper may be inter- 
 posed between the light and sitter. In selecting subjects, 
 all striking contrasts in color should be avoided, and sit- 
 ters for portraits should be cautioned not to wear any- 
 thing that may produce the effect spoken of— dark dresses 
 always being the best. 
 
 The action of light both combines and decomposes 
 bodies. For instance, chlorine and hydrogen will re- 
 pnain in a glass vessel without alteration if kept in the. 
 dark ; but if exposed to the rays of the sun, they imme- 
 
26 
 
 LIGHT. 
 
 diately enter into combination, and produce hydrochloric 
 acid. On the other hand, if colorless nitric acid be exposed 
 to the sun, it becomes yellow, then changes to red, and 
 oxygen is liberated by the partial decomposition effected 
 by the solar rays. 
 
 Of the organic substances none are more readily acted 
 upon by light than the various combinations of silver. 
 
 Of these some are more, and others less sensitive. If 
 Chloride of silver, which is a white precipitate formed by 
 adding chloride of sodium (common salt) to a solution of 
 nitrate of silver, be exposed to diffused light, it speedily 
 assumes a violet tint, and ultimately becomes nearly black. 
 With iodide of silver, bromide of silver, ammonio-nitrate 
 of silver j and other salts of this metal, the result will be 
 much the same. 
 
 Some bodies, which under the influence of light, un- 
 dergo chemical changes, have the power of restoring 
 themselves to their original condition in the dark. This is 
 more remarkably displayed in the iodide of platinum, 
 which readily recieves a photogenic image by darkening 
 over the exposed surfaces, but speedily loses it by bleach- 
 ing in the dark. The ioduret of Daguerre’s plate, and 
 some other iodides, exhibit the same peculiarity — This 
 leads us to the striking fact, that bodies which have un- 
 dergone a change of estate under the influence of day- 
 light have some latent power by which they can reno- 
 vate themselves. Possibly the hours of night are as neces- 
 sary to inanimate nature as they are to the animate. During 
 the day, an excitement which we do not heed, unless in a 
 state of disease, is maintained by tbe influence of light ; 
 and the hours of repose, dur5ng which the equilibrium is 
 restored, are absolutely necessary to the continuance of 
 health. 
 
LIGHT. 
 
 27 
 
 Instead of a few chemical compounds of gold and silver, 
 wnich at first were alone supposed to be photographic, 
 we are now aware that copper, platinum, lead, nikel, and 
 indeed, probably all the elements, are equally liably to 
 change under the sun’s influence. This fact may be of 
 benefit to engravers, for if steel can be made to take pho- 
 tographic impressions, the more laborious process of etch- 
 ing may be dispensed with. In fact, in the latter part of 
 this work, a process is dsscribed for etching and taking 
 printed impressions from Daguerreotype plates. 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 engraving. 
 
 A very simple experiment will prove how essential 
 light is to the coloring of the various species comprising 
 the vegetable and animal kingdoms. If we transplant any 
 shrub from the light of day into a dark cellar, we will 
 soon see it lose its bright green color, and become perfect- 
 ly white. 
 
 Another effect of light is that it appears to impart to 
 bodies some power by which they more readily enter into 
 chemical combination with others. We have already said 
 that chlorine and hydrogen, if kept in the dark, will re- 
 main unaltered ; but if the chlorine alone be previously 
 exposed to the sun, the chlorine thus solarised will unite 
 with the hydrogen in the dark. Sulphate of iron will 
 throw down gold or silver from their solutions slowly in 
 the dark ; but if either solution be first exposed to sun- 
 shine, and the mixture be then made, in the dark, the 
 precipitation takes place instantly. Here is again, evidence 
 of either an absorption of some material agent from the 
 sunbeam, or an alteration in the chemical constitution of 
 the body. It was from understanding these principles and 
 
28 
 
 LIGHT. 
 
 applying them that philosophers were enabled to produce 
 the Calotype, Daguerreotype, &c. For the effects and 
 action of light on the camera, see Chapter V. 
 
 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 maintained. The colored image of the 
 spectrum has been most faithfully copied, ray for ray, on 
 paper spread with the juice of the Cochorus Japonica , 
 (a species of plant) and the fluoride of silver ; and on 
 silver plate covered with a thin film of chloride. The day 
 may be still remote when this much to be desired decid- 
 eratuni in portrait taking will be accomplished ; but I 
 am led to hope that future experiments may master the 
 secret which now causes it to be looked upon, by many, 
 as an impossibility. 
 
 That great advantages have resulted, and that greater 
 still will result from the discovery of the Photographic 
 art, few will deny. The faithful manner in which it copies 
 nature, even to the most minute details, renders it of much 
 value to the painter ; but a few minutes sufficing to* take 
 a view that formerly would have occupied several days. 
 Its superiority in portraits, over miniature or oil painting 
 has been tacitly acknowledged by the thousands who em- 
 ploy it to secure their own, or a friends likeness, and by 
 the steady increase in the number of artists who are week- 
 ly, aye daily, springing up in every town and village in 
 the land. 
 
 The following extract from a very interesting article in 
 the North British Review, gives facts that every Daguer- 
 reotypist should remember : 
 
LIGHT. 
 
 29 
 
 In the valuable work of Professor Draper, of New- 
 York, there are many important observations, relative to 
 the theory and practice of photography. The belief that 
 he was the first person who discovered, what he calls, 
 “ the antagonizing action of the two halves of the spec- 
 trum,” the blue, or more refrangible half, having a decom- 
 posing agency on iodide of silver, and the red, or less re- 
 frangible half, a protecting agency. He states that “ there 
 is a certain condition of the sky, namely, when it has 
 such a degree of brightness that the sensitive surface is 
 slightly stained by it, under the decomposing effect of its 
 light, is exactly balanced by the protecting agency of the 
 other rays — so. exactly balanced, that it is immaterial 
 whether the exposure be for one minute or an hour, for 
 the resulting action is the same.” An equilibrium in 
 these two opposite actions, to a greater or less extent, 
 seems to take place even with the solar rays in tropical 
 regions, as if the sun’s light there was intrinsically differ- 
 ent from what it is here. 
 
 In opposition, however, to the idea of such an antago- 
 nizing action, Dr. Draper, himself, afterwards affirms, 
 “ that the red, orange, and yellow rays which protect the 
 plate from the ordinary photogenic action, were them- 
 selves capable, when insulated, of producing a 'peculiar 
 photogenic effect;” while Mr. E. Becquerel maintains, as 
 we have seen, “ that they have the property of continuing 
 the action of the ordinary photogenic rays, when once 
 commenced.” In this state of the subject, M. Claudet 
 began a series of experiments which led to valuable re- 
 sults, and of which he has enabled us to give the follow- 
 ing abstract : 
 
 ‘‘Having directed a camera, with an iodized plate, to 
 the sun when his disc was quite red , he left it there for 
 
30 
 
 LIGHT. 
 
 twenty minutes. The sun had passed over a great space 
 on the plate, which was marked with a long and perfectly 
 defined image of his disc, so that not only had the red 
 sun produced no photogenic action, but the red rays had 
 destroyed the effect produced by the previous action of 
 the sky. By moving the camera from right {0 left, and 
 from left to right, and lowering it each time by means of 
 a screw, he made the sun pass rapidly over five or six 
 zones of the iodized plate. The lines of his passage 
 were marked with long black bands, while the intervals 
 between them were white , proving again that the red rays 
 had destroyed the previous photogenic action. 5 ’ M v 
 Claudet obtained the same result with red , orange and 
 yellow glasses. The impression of black lace taken by 
 white light, was destroyed by the rays passing through a 
 red glass, and the same effect was produced in different 
 periods of time by -orange and yellow glasses. But what 
 was very remarkable, M. Claudet discovered, that after the 
 photogenic effect was destroyed, the plate was restored to 
 its former sensitiveness to white light ; nay, we may ex- 
 pose the plate to these two actions alternately, for any 
 number of times, and yet it will be sensitive to the vapor 
 of mercury, if its last exposure has been the white light, 
 and will be deprived of that sensitiveness if its exposure 
 has been to the destroying action of the red , orange, or 
 yellow rays. Hence, M. Claudet arrives at the important 
 practical result, that the Daguerreotype plates may be 
 iodized in open daylight ; and that, in order to restore 
 their sensitiveness, which that light has destroyed, we 
 have only to place them for a few minutes under a red 
 glass, before we place them in a camera. M. Claudet has 
 shown, that the discovery by Dr. Draper, of a photogenic 
 action in the red half of the spectrum is true also for the 
 
light. 
 
 31 
 
 rays which pass through red , orange , and yellow glasses, 
 thus proving that these rays have two contrary actions, 
 one destructive of the effects of the photogenic rays, and 
 another analogous to the effect of these rays. 
 
 The photogenic action of the red ray is, according to 
 M. Claudet, 5,000 times slower or weaker than that of 
 white light ; that of the orange rays, 500 times ; and that 
 of the yellow , 100 times. 
 
 The destructive action of the red rays is LOO times 
 slower or weaker than that of white light ; the orange 50 
 times, and the yellow only 10 times. 
 
 When a plate has been exposed to the destructive 
 action of any particular ray, it cannot be affected photo- 
 genically by the same ray which acted destructively, and 
 it is sensitive only to the other rays ; and the photogenic 
 or destructive action of any ray cannot be continued by 
 another. Hence, M. Claudet draws the important con- 
 clusion, that the solar spectrum is endowed with three diffe- 
 rent photogenic actions , and; three different destroying 
 actions, corresponding to the red , yellow , and blue rays. 
 The rays of each of these colours is endowed with a pho- 
 togenic power peculiar to itself, which causes the mercu- 
 rial vapor to adhere to the iodized plate, and yet these 
 three actions are so different that we cannot, by combining 
 them artificially, make one assist the other, on account of 
 their antagonistic Character. The effect of the blue rays 
 is destroyed by the red and yellow , each of which is in its 
 turn destroyed by the blue , while the yellow and red mu- 
 tually destroy each other. Hence, it would appear that 
 the iodide of potash remains always the same under these 
 different influences, and that there is no separation or dis- 
 engagement of its constituent elements. 
 
CHAP. III. 
 
 SYNOPSIS OF MR. HUNT’S TREATISE ON “ THE INFLUENCE 
 OF THE SOLAR RAYS ON COMPOUND BODIES, WITH ES- 
 PECIAL REFERENCE TO THEIR PHOTOGRAPHIC APPLI- 
 CATION. ’’ 
 
 Oxide of silver exposed for a few hours to good sun- 
 shine, passes into a more decided olive color, than cha- 
 racterises it when first prepared by precipitation from 
 nitrate of silver. Longer exposure renders this color 
 very much lighter, and the covered parts, are found much 
 darker, than those on which the light has acted directly. 
 In some instances where the oxide of silver has been 
 spread on the paper a decided whitening process in some 
 parts, after a few days exposure, is noticed. Oxide of 
 silver disolved in ammonia is a valuable photographic 
 fluid ; one application of a strong solution forming an 
 exceedingly sensitive surface. The pictures on this paper 
 are easily fixed by salt or weak ammonia. 
 
 Nitrate of silver.— This salt in a state of purity, 
 does not appear to be sensibly affected by light, but the 
 presence of the smallest portion of organic matter renders 
 it exceedingly liable to change under luminous influence. 
 
 If a piece of nitrated paper is placed upon hot iron, or 
 held near the fire, it will be found that at a heat just be- 
 low that at which the paper chars, the salt is decom- 
 posed. Where the heat is greatest, the silver is revived, 
 
34 SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 and immediately around it, the paper becomes a deep 
 blue ; beyond this a pretty decided green color results, and 
 beyond the green, a yellow or yellow brown stain is 
 made. This exhibits a remarkable analogy between 
 beat and light, — before spoken of in chap. II — and is of 
 some practical importance in the preparation of the 
 paper. 
 
 Prismatic analysis. — The method of accomplishing 
 the prismatic decomposition of rays of light by the spec- 
 trum has already been described on pages 22 and 23. The 
 color of the impressed spectrum, on paper washed with 
 nitrate of silver, is at first, a pale brown, which passes 
 slowly into a deeper shade ; that portion corresponding 
 with the blue rays becoming a blue brown ; and under 
 the violet of a peculiar pinkey shade, a very decided 
 green tint, on the point which corresponds with the least 
 refrangible blue rays, may be observed, its limits of ac- 
 tion being near the centre of the yellow ray, and its 
 maximum about the centre of the blue, although the ac- 
 tion up to the edge of the violet ray is continued with 
 very little diminution of effect ; beyond this point the ac- 
 tion is very feeble. 
 
 When the spectrum is made to act on paper which has 
 been previously darkened, by exposure to sunshine under 
 cupro-sulphate of ammonia, the phenomena are materially 
 different. The photographic spectrum is lengthened out 
 on the red or negative side by a faint but very visible red 
 portion, which extends fully up to the end of the red 
 rays, as seen by the naked eye. The tint of the general 
 spectrum, too, instead of brown is dark grey, passing, 
 however, at its most refracted or positive end into a rud- 
 dy brown. 
 
 In its Photographic application, the nitrate of silver is 
 
SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 35 
 
 the most valuable of the salts of that metal, as from it 
 most of the other argentine compounds can be prepared, 
 although it is not of itself sufficiently sensible to light to 
 render it of much use. 
 
 0 Chloride of Silver. — This salt of silver, whether in 
 its precipitated state, or when fused, changes its color to 
 a fine bluish grey by a very short exposure to the sun’s 
 rays. If combined with a small quantity of nitrate, the 
 change is more, rapid, it attains a deep brown, then slow- 
 ly passes into a fine olive, and eventually, after a few 
 weeks, the metalic silver is seen to be revived on the 
 surface of the salt. Great differences of color are pro- 
 duced on chlorides of silver precipitated by different mu- 
 riates. Nearly every variety in combination with the 
 nitrate, becomes at last of the same olive color, the 
 following examples, therefore, have reference to a few 
 minutes exposure, only, to good sunshine; it must also 
 be recollected that the chloride of silver in these cases is 
 contaminated with the precipitant. 
 
 Muriate of ammonia precipitates chloride to darken to 
 a fine chocolate brown, whilst muriate of lime produces a 
 brick-red color. Muriates of potash and soda afford a 
 precipitate, which darkens speedly to a pure dark brown, 
 and muriatic acid, or aqueous chlorine, do not appear to 
 increase the darkening power beyond the lilac to which 
 the pure chloride of silver changes by exposure. This 
 difference of color appears to be owing to the admixture 
 of the earth or alkali used with the silver salt. 
 
 The prismatic impression on paper spread with the 
 chloride of silver is often very beautifully tinted, the in- 
 tensity of color varying with the kind of muriate used. 
 Spread paper with muriate of ammonia or baryta and you 
 obtain a range of colors nearly corresponding with the 
 
36 
 
 SYNOPSIS OF MR. HUNT S TREATISE. 
 
 natural hues of the prismatic spectrum. Under favorable 
 circumstances the mean red ray, leaves a red impression, 
 which passes into a green over the space occupied by the 
 yellow rays. Above this a leaden hue is observed, and- 
 about the mean blue ray, where the action is greatest, it 
 rapidly passes through brown into black, and through the 
 most refrangible rays it gradually declines into a bluish 
 brown, which tint is continued throughout the invisible 
 rays. At the least refrangible end of the spectrum, the very 
 remarkable phenomenon has been observed, of the extreme 
 red rays exerting a protecting influence, and preserving 
 the paper from that change, which it would otherwise 
 undergo, under the influence of the dispersed light which 
 always surrounds the spectrum. Not only the extreme red 
 ray exerts this very peculiar property, but the ordinary 
 red ray through nearly its whole length. 
 
 In photographic drawing this salt is of the utmost im- 
 portance. Mr. Talbot’s application of it will be given 
 hereafter in another po'rtion of this work. 
 
 Iodide of silver — Perfectly pure, undergoes very 
 little change under the influence of light or heat ; but it 
 a very slight excess of the nitrate of silver be added it 
 becomes infinitely more senitive than the chloride 
 
 The spectrum impressed upon paper prepared with a 
 weak solution of the hydriodate of potash presents some 
 very remarkable peculiarities. The maximum of intensity 
 is found at the edge of the most refrangible violet rays, 
 or a little beyond it, varying slightly according to the 
 kind of paper used, and the quantity of free nitrate of 
 silver present. The action commences at a point 
 nearly coincident with the mean red of the luminous 
 spectrum, where it gives a dull ash or lead color, while 
 the most refrangible rays impress a ruddy snuff-brown, 
 
37 
 
 SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 the change of tint coming on rather suddenly about 
 the end of the blue or beginning of the violet rays 
 of the luminous spectrum. Beyond the extreme violet 
 rays, the action rapidly diminishes, but the darkening 
 produced by these invisible rays, extends a very small 
 space beyond the point at which, they cease to act on the 
 chloride of silver. 
 
 In its photographic application, it is, alone, of very 
 little use ; but in combination with other re-agents it be- 
 comes exquisitely sensitive. With gallic acid and the 
 ferrocyanate of potash it forms two of the most sensitive 
 photographic solutions with which we are acquainted. 
 These are used in the calotype process. 
 
 Ioduret of silver. — If upon a plate of polished silver 
 we place a small piece of iodine, and apply the heat of a 
 lamp beneath the plate for a moment, a system of rings is 
 speedily formed. The first ring, which spreading constantly 
 forms the exterior of the circle, is of a bright yellow col- 
 or; tvithin- this, there arises, sucessively, rings of green, 
 red and blue colors, and then again a fine yellow circle, 
 centred by a greyish spot on the place occupied by the 
 iodine. On exposing these to the light, the outer yellow 
 circle almost instantly changes color, the others slowly, in 
 the order of their position, the interior yellow circle re- 
 sisting for a long time the solar influence. These rings 
 must be regarded as films of the ioduret of silver, varying, 
 not only in thickness, but in the more or less perfect states 
 of combination in which the iodine and metal are. The 
 exterior circle is an ioduret in a very loose state of chem- 
 ical agregation ; the attractive forces increase as we pro- 
 ceed towards the centre, where a well formed ioduret, or 
 probably a true iodide of silver, is formed, which is acted 
 upon by sunlight with difficulty. The exterior and most 
 
38 SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 sensitive film constitutes the surface of Daguerreotype 
 plates. The changes which these colored rings undergo 
 are remarkable ; by a few minutes exposure to sunlight, 
 an inversion of nearly all the colors takes place, the two 
 first rings becoming a deep olive green ; and a deep blue 
 inclining to black. 
 
 The nature of the change which the ioduret of silver 
 undergoes on Daguerreotype plates, through the action of 
 light, Mr. Hunt considers to be a decided case of decom- 
 position, and cites several circumstances in proof of his 
 position. These with othei facts given by Mr. Hunt in 
 his great work on the Photographic art, but to volum- 
 nious to include in a volume of the size to which I am 
 obliged to cofine myself, should be thoroughly studied by 
 all Daguerreotypists. 
 
 Prismatic analysis. — The most refrangible portion of 
 the spectrum, (on a Daguerreotype plate) appears, after 
 the plate has been exposed to the vapor of mercury, to 
 have impressed its colors ; the light and delicate film of 
 mercury, which covers that portion, assuming a fine blue 
 tint about the central parts, which are gradually shaded 
 off into a pale grey ; and this is again surrounded by a 
 very delicate rose hue, which is lost in a band of pure 
 white. Beyond this a protecting influence is powerfully 
 exerted ; and notwithstanding the action of the dispersed 
 light, which is very evident over the plate, a line is left, 
 perfectly free from mercurial vapor, and which, conse- 
 quently, when viewed by a side light, appears quite 
 dark. The green rays are represented by a line of a cor- 
 responding tint, considerably less in size than the lumi- 
 nous green rays. The yellow rays appear to be without 
 action, or to act negatively, the space upon which they 
 fall being protected from the mercurial vapor ; and it 
 
SYNOPSIS OF MR HUNT’S TREATISE. 39 
 
 consequently is seen as a dark band. A white line of 
 vapor marks the place of the orange rays. The red rays 
 effect the sensitive surface in a peculiar manner ; and we 
 have the mercurial vapor, assuming a molecular arrange- 
 ment which gives to it a fine rose hue ; this tint is sur- 
 rounded by a line of white vapor, shaded at the lowest 
 extremity wfith a very soft green. Over the space occupi- 
 ed by the extreme red rays, a protecting influence is again 
 exerted ; the space is retained free from mercurial vapor 
 and the band is found to surround the whole of the least 
 refrangible rays, and to unite itself wflth the band which 
 surrounds the rays of greatest refrangibility. This band 
 is not equally well defined throughout its whole extent. 
 It is most evident from the extreme red to the green ; it 
 fades in passing through the blue, and increases again, 
 as it leaves the indigo, until beyond the invisible chemi- 
 cal rays it is nearly as strong as it is at the calorific end 
 of the spectrum. 
 
 Images on Daguerreotype plates which have been 
 completely obliterated by rubbing may be restored, by 
 placing it in a tolerably strong solution of iodine ip water. 
 
 Bromide of silver. — This salt, like the iodide, does 
 not appear to be readily changed by the action of light ; 
 but when combined with the nitrate of silver it forms a 
 very sensitive photographic preparation. 
 
 Paper prepared with this salt, blackens over its whole 
 extent with nearly equal intensity, when submitted to the 
 prismatic spectrum. The most characteristic peculiarity 
 of the spectrum is its extravagant length. Instead of 
 terminating at the mean yellow ray, the darkened portion 
 extends down to the very extremity of the visible red 
 rays. In tint it is pretty uniformly of a grey-black over 
 its whole extent, except that a slight fringe of redness is 
 
 3 
 
40 SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 perceptible at the least refracted end. Beyond the red ray 
 an extended space is protected from the agency of the dis- 
 persed light, and its v/hiteness maintained ; thus confir- 
 ming the evidence of some chemical power in action, 
 over a space beyond the. luminous spectrum, which cor- 
 responds with the rays of the least refrangibility. 
 
 This salt is extensively used in photographic drawing. 
 
 Preparations of Gold. — Chloride of Gold, freed from 
 an excess of acid is slowly changed under the action of 
 light ; a regularly increasing darkness taking place until 
 it becomes purple, the first action of the light being to 
 whiten the paper, which, if removed from the light at this 
 stage, will gradually darken and eventually develope the 
 picture. This process may be quickened by placing the 
 paper in cold water. 
 
 Chloride of gold with nitrate of silver gives a precipi- 
 tate of a yellow brown color. Paper impregnated with 
 the acetate of lead, when washed with perfectly neutral 
 chloride of gold, acquires a brownish-yellow hue. The 
 first impression of light seems rather to whiten than dark- 
 en the paper, by discharging the original color, and sub- 
 stituting for it a pale greyish tint, which by slow degrees 
 increases to a dark state color ; but if arrested, while yet 
 not more than a moderate ash grey, and held in a current 
 of steam , the color of the parts acted upon by light — and 
 of that only — darkens immediately to a deep purple. 
 
 Here I must leave the subject of the action of light up- 
 on metalic compounds — referring to Mr. Hunts work for 
 any further information the student may desire on the 
 other metals — as I find myself going beyond my limits. 1 
 cannot, however, entirely dismiss the subject without 
 giving a few examples of the action of light on the juices,. 
 
 
SYNOPSIS OF MR. HUNT’S TREATISE. 41 
 
 of plants, some of which produce very good photographic 
 effects. 
 
 Corchorus japonica — The juice of the flowers of this 
 plant impart a fine yellow color to paper, and, so far as 
 ascertained, is the most sensitive of any vegetable pre- 
 paration ; but owing to its continuing to change color 
 even in the dark, photographic images taken on paper 
 prepared with it soon fade out. 
 
 Wall flower. — This flower yields a juice, when ex- 
 pressed with alcohol, from which subsides, on standing, 
 a bright yellow finely divided fsecula, leaving a greenish- 
 yellow transparent liquid, only slightly colored superna- 
 tant. The feecula spreads well on paper, and is very 
 sensitive to light, but appears at the same time to under- 
 go a sort of chromatic analysis, and to comport itself as if 
 composed of two very distinct coloring principles, very 
 differently affected. The one on which the intensity and 
 sub-orange tint of the color depends, isspeedily destroyed, 
 but the paper is not thereby fully whitened. A paler yel- 
 low remains as a residual tint, and this on continued ex- 
 posure to the light, slowly darkens to brown. Exposed 
 to the spectrum, the paper is first reduced nearly to 
 whiteness in the region of the blue and violet rays. More 
 slowty, an insulated solar image is whitened in the less 
 refrangible portion of the red. Continue the exposure, 
 and a brojvn impression begins to be percieved in the 
 midst of ihe white streak, which darkens slowly over the 
 region between the lower blue and extreme violet rays. 
 
 The red poppy yields a very beautiful red color, which 
 is entirely destroyed by light. When perfectly dried on 
 paper the color becomes blue. This blue color is speed- 
 ily discharged by exposure to the sun’s rays, and papers 
 prepared with it afford very interesting photographs. — 
 
42 
 
 SYNOPSIS OF MR. HUNT’S TREATISE. 
 
 Future experiments will undoubtedly more fully devel- 
 ope the photogenic > properties of flowers, and practically 
 appty them. 
 
 Certain precautions are necessary in extracting the 
 coloring matter of flowers. The petals of fresh flowers, 
 carefully selected, are crushed to a pulp in a rhortar, 
 either alone or with the addition of a litte alcohol, and 
 the juice expressed by squeezing the pulp in a clean linen 
 or cotton cloth. It is then to be spread upon paper with 
 a flat brush, and dried in the air. If alcohol be not added, 
 it must be applied immediately, as the air changes or des- 
 troys the color instantly. 
 
 Most flowers give out their coloring matter to alcohol 
 or water— ^-but the former is found to weaken, and in 
 some cases to discharge altogether these colors ; but they 
 are in most cases restored in drying. Paper tinged with 
 vegetable colors must be kept perfectly dry and in dark- 
 ness. 
 
 To secure an eveness of tint on paper it should be first 
 moistened on the back by sponging, and blotting off with 
 bibulous paper*. It should then be pinned on a board, the 
 moist side downwards, so that two of its edges — the right 
 and lower ones — project a little over those of the board. 
 Incline the board twenty or thirty degrees to the horizon, 
 and apply the tincture with a brush in strokes from right 
 to left, taking care not to go over the edges which rests on 
 the board, but to pass clearly over those that project ; 
 and also observing to carry the tint from below upwards 
 by quick sweeping strokes, leaving no dry spaces be- 
 tween them. Cross these with other strokes from above 
 downwards, leaving no floating liquid on the paper. Dry 
 as quickly as possible, avoiding, however, such heat as 
 may injure the tint. 
 
CHAP. IV. 
 
 A FEW HINTS AND SUGGESTIONS TO DAGUERREOTYPISTS. 
 
 There are very few who may not be capable of prac 
 tising the Photographic art, either on paper, or metalic 
 plates — but, like all other professions, some are more 
 clever in its various processes than others. 
 
 Impatience is a great drawback to perfect success, and 
 combined with laziness is a decided enemy. Besides 
 this, no one can excel in Photography who does not pos- 
 sess a natural taste for the fine arts, who is not quick in 
 discerning grace and beauty — is regardless of the prin- 
 ciples of perspective, foreshorting and other rules of 
 drawing, and who sets about it merely for the sake of 
 gain — without the least ambition to rise to the first rank, 
 both in its practice and theory. There is no profession 
 or trade in which a slovenly manner will not show itself, 
 and none where its effects will be more apparent than 
 this. 
 
 In order to be great in any pursuit, we must be dili- 
 gent, and keep all things, in order. In your show and 
 reception rooms, let neatness prevail ; have your speci- 
 mens so placed — leaning slightly forward — as to obtain 
 the strongest light upon them, and at the same time pre- 
 vent that glassiness of apearance which detra'cts so ma- 
 terially from the effect they are intended to produce. If 
 possible, let the light be of a north-western aspect, mel- 
 
44 
 
 HINTS AND SUGGESTIONS. 
 
 lowed by curtains of a semi-transparent hue. Your show- 
 cases, at the door, should be kept well cleaned. I have 
 often been disgusted while attempting to examine por- 
 traits in the cases of our artists, at the greasy coating and 
 marks of dirty fingers upon the glass and frame enclosing 
 them. Believe it, many a good customer is lost for no 
 other reason. 
 
 In your operating room, dust should be carefully ex- 
 cluded. It should be furnished with nothing apt to col- 
 lect and retain dust ; a carpet is therefore not only a use- 
 less article, but very improper. A bare floor is to be 
 prefered ; but if you must cover it use matting. There 
 is no place about your establishment where greater care 
 should be taken to have order and cleanliness ; for it will 
 prevent many failures often attributed to other causes. 
 u A place for every thing, and every thing in its place,’’ 
 should be an absolute maxim with all artists. Do not 
 oblige the ladies, on going away from your rooms, to 
 say — u That H. is a slovenly man ; 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 months.” 
 
 In choosing your operating room, obtain one with a 
 north-western aspect, if possible ; and either with, or ca- 
 pable of having attached, a large sky-light. Good pic- 
 tures may be taken without the sky-light, but not the 
 most pleasing or effective. 
 
 A very important point to be observed, is to keep the 
 camera perfectly free from dust. The operator should 
 be careful to see that the slightest particle be removed, 
 for the act of inserting the plate-holder will set it in mo- 
 tion, if left, and cause those little black spots on the 
 plate, by which an otherwise good picture is spoiled. 
 
HINTS AND SUGGESTIONS. 45 
 
 The camera should be so placed as to prevent the sun 
 shining into the lenses. 
 
 In taking portraits, 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 ob- 
 tained. The eyes should be fixed on some object a little 
 above the camera, and to one side — but never into, or on 
 the instrument, as some direct ; the latter generally gives 
 a fixed, silly, staring, scowling or painful expression to 
 the face. Care should also be taken, that the hands and 
 feet, in whatever position, are not too forward or back- 
 ward from the face when that is in good focus. 
 
 If any large surface of white is present, such as the 
 shirt front, or lady’s handkerchief, a piece of dark cloth 
 (a temporary bosom of nankeen is best,) may be put over 
 it, but quickly withdrawn when the process is about two 
 thirds finished. 
 
 A very pleasing effect is given to portraits, by intro- 
 ducing, behind the sitter, an engraving or other picture — 
 if a painting, avoid those in which warm and glowing 
 tints predominate. The subject of these pictures may be 
 applicable to the taste or occupation of the person whose 
 portrait you are taking. This adds much to the interest 
 of the picture, which is otherwise frequently dull, cold 
 and inanimate. 
 
 Mr. J. H. Whitehurst of Richmond, Va., has intro- 
 duced a revolving background, which is set in motion 
 during the operation, and produces a distinctness and bold- 
 ness in the image not otherwise to be obtained. The 
 effect upon the background of the plate is equally pleas- 
 ing ; it having the appearance of a beautifully clouded 
 sky. 
 
 In practising Photographic drawing on paper, the stu- 
 
46 
 
 HINTS AND SUGGESTIONS. 
 
 dent must bear in mind that it is positively essential, to 
 secure success in the various processes, to use the utmost 
 precaution in spreading the solutions, and washes from 
 the combination of which the sensitive surfaces result. 
 The same brush should always be used for the same solu- 
 tion, and never used for any other, and always washed in 
 clean water after having been employed. Any metalic 
 mounting on the brushes should be avoided, as the metal 
 precipitates the silver from its solution. The brushes 
 should be made of camels or badger’s hair and sufficiently 
 broad and large to cover the paper in two or three 
 sweeps ; for if small ones be employed, many strokes 
 must be given, which leave corresponding streaks that 
 will become visible when submitted to light, and spoil 
 the picture. 
 
 These few preliminary hints and suggestions, will, I 
 trust, be of some service to all who adopt this pleasing 
 art as a profession ; and will, with a due attention to 
 the directions given in the practical working of the Da- 
 guerreotype, Calotype, etc., ensure a corresponding mea- 
 sure of success. 
 
CHAP. V, 
 
 DAGUERREOTYPE APPARATUS. 
 
 The entire Daguerreotype process is comprised in 
 seven distinct operations ; viz : 
 
 1. — Cleaning and polishing the plate. 
 
 2. — Applying the sensitive coating . 
 
 3 — Submitting the plate to the action of light in the 
 camera. 
 
 4. — Bringing out the picture ; in other words rendering 
 it visible. 
 
 5. — Fixing the image , or making it permanent — so that 
 the light may no longer act upon it. 
 
 6. — Gilding: or covering the picture with a thin film oj 
 gold — which not only protects it, but greatly improves its 
 distinctness and tone of color. 
 
 7. — Coloring the picture. 
 
 For these various operations the following articles — 
 which make up the entire apparatus of a Daguerrean ar- 
 tist — must be procured. 
 
 1. — The Camera. — {Fig. 5.). The Camera Obscura 
 of the Italian philosophers, although highly appreciated, 
 on account of the magical character of the pictures it pro- 
 duced, remained little other than a scientific toy, until the 
 discovery of M. Daguerre. The value of this instrument 
 is now great, and the interest of the process which it so 
 
48 
 
 DAGUERREOTYPE APPARATUS. 
 
 essentially aids, universally admitted. A full description 
 of it will therefore be interesting. 
 
 Fig. 5. 
 
 The camera is a dark box (a), having a tube with len 
 ses ( b ) placed in one end of it, through which the ra- 
 diations from external objects pass, and form a diminished 
 picture upon the ground glass ( g ) placed at the proper 
 distance in the box to receive it ; the cap c covering the 
 lenses at b until the plate is ready to receive the image of 
 the object to be copied. 
 
 Thus a {jig. 6.) representing the lens, and b the object 
 desired to be represented, the rays (c, c) proceeding from 
 it fall upon the lens, and are transmitted to a point, which 
 varies with the curvature of the glass, where an inverted 
 image ( d ) of b is very accurately formed. At this point, 
 termed the focus, the sensitive photographic material is 
 placed for the purpose of obtaining the required picture. 
 
 The great desideratum in a photographic camera is 
 perfect lenses. They should be achromatic, and the utmost 
 
DAGUERREOTYPE APPARATUS. 
 
 49 
 
 Fig. 6. 
 
 transparency should be obtained ; and under the closest 
 inspection of the glass not the slightest wavy appearance, 
 or dark spot should be detected ; and a curvature which 
 as much as possible prevents spherical aberration should 
 be secured. The effect produced by this last defect is a 
 convergence of perpendiculars, as for instance ; two tow- 
 ers of any building, would be represented as leaning to- 
 wards each other ; and in a portrait the features would 
 seem contracted, distorted and mingled together, so as to 
 throw the picture out of drawing and make it look 
 more like a caricature than a likeness. If the lens be 
 not achromatic, a chromatic aberration takes place, which 
 produces an indistinct, hazy appearance around the edges 
 of the picture, arising from the blending of the rays. 
 
 The diameter and focal length of a lens must depend 
 in a great measure on the distance of the object, and also 
 on the superficies of the plate or paper to be covered. 
 For portraits one of 1^ inches diameter, and from 4K to 
 5X inches focus may be used ; but for distant views, one 
 from 2 inches to 3 inches diameter, and from 8 to 12 
 - inches focal length will answer much better. For single 
 lenses, the aperture in front should be placed at a distance 
 
50 
 
 DAGUERREOTYPE APPARATUS. 
 
 from it, corresponding to the diameter, and of a size not 
 more than one third of the same. A variety of movable 
 diaphrams or caps, to cover the aperture in front, are very 
 useful, as the intensity of the light may be modified by 
 them and more or less distinctness and clearness of delin- 
 eation obtained. These caps alway come with Voitlander 
 instruments and should be secured by the purchaser. 
 
 Though the single acromatic lens answers very well for 
 copying engravings; taking views from nature or art, foi 
 portraits the double should always be used. The exten- 
 sive manufacture of the most approved cameras, both in 
 Europe and in this country, obviates all necessityTor any 
 one attempting to construct one for their own use. Lens- 
 es are now made so perfect by some artisans that, what 
 is called the u quick working camera ” will take a pic- 
 ture in one second, while the ordinary cameras require 
 from eight to sixty. 
 
 The camera in most general use is that manufactured 
 by Voigtlander and Son of Germany. Their small size 
 consists of two seperate acromatic lenses ; the first, or 
 external one, has a free aperture of IK inches ; the se- 
 cond, or internal, inches ; and both have the same fo- 
 cus, viz : 5% inches. The larger size differs from the 
 smaller. The inner lens is an achromatic 3% inches dia- 
 meter, its focal length being 30 inches. The outer lens 
 is a meniscus — that is bounded by a concave and convex 
 spherical surface which meet — having a focal length of 
 18 inches. For every distant view, the aperture in front 
 is contracted by a diaphram to y z of an inch. By this 
 means the light is reflected with considerable intensity 
 and the clearness and correctness of the pictures are truly 
 surprising. 
 
 TheAmerica instruments are constructed on thesame 
 
DAGUERREOTYPE APPARATUS. 
 
 51 
 
 principle and many of them are equally perfect. Mr. 
 Edward Anthony of 205 Broadway, New York city, has 
 constructed, and sold cameras fully equal to the German 
 and for which Yoigtlander instruments have been refused 
 in exchange by the purchaser. 
 
 The ordinary camera box {see fig. 5, a) varies in size 
 to suit the tube, and is termed medium, half, or whole 
 Within the'box is a slide to assist in regulating the focus, 
 and in enlarging or diminishing the picture. In one end 
 of this slide is a springed groove into which the ground- 
 glass spectrum ( g fig. 5) is slid, for the purpose of more 
 conveniently arranging the focus. After the plate is 
 prepared it is placed in the holder — partly seen at e,fig. 5, 
 and covered with the dark slide /, fig. 5 ; the spectrum is 
 then withdrawn and the holder takes its place, and the 
 lids d, d, are closed after removing the dark slide f. The 
 plate is now ready to receive the image, and the cap c 
 may be removed to admit the light into the box. 
 
 A camera constructed by Yoigtlander is thus described 
 by Mr. Fisher. u It is made entirely of brass, so that varia- 
 tions of climate has no effect upon it. It is very portable 
 and when packed in its box, with all the necessary ap- 
 paratus and materials for pract^ing the Daguerreotype art, 
 occupies but very little space. It is not, however, well 
 adapted for the Calotype process. ” 
 
 “ The brass foot A (fig. 7.), is placed on a table, or 
 other firm support, and the pillar B. screwed into it ; the 
 body of the camera, C, C is laid into the double forked 
 bearing D. D. The instrument is now properly adjusted 
 by means of the set screws, e, e, e, in the brass foot, or 
 it may he raised, lowered, or moved, by the telescope 
 stand, and when correct, fixed by the screw b. The 
 landscape to be delineated is viewed either through the 
 
52 
 
 DAGUERREOTYPE APPARATUS 
 
 Fig. 7. 
 
 small lens, gr, or with the naked eye on the ground glass 
 plate iT, the focus being adjusted by the screw I. The 
 optical part of the instrument consist of the small set of 
 achromatic lenses already described. When the portrait 
 or view is deleniated on the ground glass to the entire sa- 
 tisfaction of the operator, the brass cap L is placed over 
 the lens, and the entire body is removed away into the 
 dark, taking care not to disturb the position of the stand. 
 The body is now detached at the part iJ, and the prepay 
 red paper or plate enclosed in the brass frame work intro- 
 duced in its place ; the whole is again placed upon the 
 pedestal, the brass cap L is lemoved, by which the paper 
 or plate is exposed to the full influence of the light, after 
 which the cap is again replaced. 
 
 Mr. Woodbridge, of this city, has constructed an in- 
 strument for taking full length portraits on elates 10 by 
 
DAGUERREOTYPE APPARATUS. 
 
 53 
 
 13 inches, which is wor- 
 thy of some notice. It is 
 a double camera, consist- 
 ing of two boxes, placed 
 in a frame, one above the 
 other, and so arranged as 
 to slide easily up and 
 down. After the focus 
 has been adjusted, on the 
 object, in both cameras, 
 the plate is put into the 
 upper box, in the manner 
 already described, until 
 the superior portion of 
 the figure is complete > 
 it is then placed in the 
 second box and the lower 
 extremities obtained. The 
 adjustment of the instru- 
 ment is so complete that 
 a perfect union of the parts is effected in the picture 
 without the least possible line of demarkation being visi- 
 ble. Fig. 8 gives a front view of this instrument. 
 
 Fig. 9 represents Talbot’s Calotype Camera, — a very 
 beautiful instrument. 
 
 The copying camera box has an extra slide in the back 
 end, by which it may be considerably lengthened at plea- 
 sure. 
 
 II. — Camera Stand.-— The best constructed stands are 
 made of maple or blackwallnut wood, having a cast iron 
 socket (a, fig. 12,) through which the sliding rod b pas- 
 ses, and into which the legs c, c, with iron screw ferules are 
 inserted. The platform d is made of two pieces, hinged 
 
 Fig. 8. 
 
54 
 
 DAGUERREOTYPE APPARATUS. 
 
 together, as at e,< and having a Fig. 9. 
 thumb screw for the purpose of 
 elevating or depressing the instru- 
 ment. 
 
 III. Mercury bath. — Fig. 13 
 gives a front view of the mercury 
 bath now in general use in this 
 country for mercurializing and 
 bringing out the picture. It is 
 quite an improvement on those first 
 used. To make it more portable 
 it is in three pieces, a h and c ; hav- 
 ing a groove e on one side to receive 
 the thermometre tube and scale by 
 which the proper degree of heat- 
 ing the mercury is ascertained. Into 
 the top are nicely fitted two or three iron frames, with 
 shoulders, for the plate to rest in, suitable for the differ- 
 ent sizes of plates. The bath is heated by means of a 
 spirit lamp placed under it. From two to four ounces 
 of highly purified mercury are put into the bath at a time. 
 
 IV. Plate blocks and vices. — There are several kinds 
 of this article in use ; I shall describe the two best only. 
 
 Fig. 10 gives an idea of the improve- Fig. 10. 
 ment on the English hand block. The 
 top a is perfectly flat and smopth — a 
 little smaller than the plate, so as to 
 permit the latter to project a very little 
 all around-having at opposite angles 
 c c two clasps, one fixed the other moveable, but capable 
 of being fastened by the thumb screw d , so as to secure 
 the plate tightly upon the block. This block turns upon 
 
DAGUERREOTYPE APPARATUS. 
 
 55 
 
 aswivle ? b , which is attached to the table by the screw c, 
 This block is only used for holding the plate while under- 
 going the first operation in cleaning. 
 
 Fig. 11. 
 
 Fig. 11, shows the form of Lewis’ newly patented 
 plate vice, which for durability, simplicity and utility is 
 preferable to all others. It consists of a simple platform 
 and arm of cast iron, the former, a, having a groove, d , 
 in the centre for fixing the different sizes of plate beds, e 
 — and the latter supporting the levers e f. On this vice 
 which is secured to a table, or bench, the plate receives 
 its finishing polish with rouge, or prepared lampblack. 
 Mr. Lewis gives the following directions for its use. u As 
 the cam wears tighten it with the adjusting screw ( g ) so 
 as to allow the lever (/) to fall back into a horizontal 
 position ; the plate being in its plac& at the time. Oil 
 the wearing parts occasionally.” 
 
 Some Daguerreotypists, however, use a foot lathe 
 with buff wheels of various forms ; but this vice is suffi- 
 cient for all ordinary purposes. 
 
 V. Coating boxes. — The usual form for iodine and 
 
56 
 
 DAGUERREOTYPE APPARATUS. 
 
 Fro. 12. 
 
 Fig. 13. 
 
 bromine boxes is seen at figs. 14 and 15. They are far 
 superior to those in use with the English operators. Each 
 consists of a wooden box ( a ,) having firmly embeded 
 within it a stout glass jar (c), the edges of which are 
 ground. Over this is placed the sliding cover 6, double 
 the length of the box, one half occupied by a piece of 
 ground glass (e), tightly pressed upon the glass pot by a 
 spring (i) beneath the cross bar g , and fits the pot so ac- 
 curately that it effectually prevents the escape of the va- 
 por of the iodine, bromine or other accelerating liquid 
 contained therein. The other half of the lid is cut 
 through, shoulders being left at the four angles for the 
 different sizes of frames, designed to recieve the plate 
 while undergoing the coating process. When the 
 plate is put into the frame, the cover b is shoved un- 
 der the second lid h and when coated to the proper de- 
 gree, it resumes its former position and the plate is placed 
 in the holder of the camera box. To test the tightness 
 of the box, light a piece of paper, put it into the pot and 
 cover it with the sliding lid. The burning paper expels 
 
DAGUERREOTYPE APPARATUS. 
 
 57 
 
 the air from the pot, and if it be perfectly tight you may 
 raise the whole box by the lid. 
 
 VI. Glass Funnels. — Are a necessary article to the 
 Daguerreotypist, for filtering water, solutions, & c. 
 
 Fig. 14. 
 
 VII. Gilding Stand. — For nervous persons the gilding 
 stand is a useful article. It is adjusted to a perfect level 
 by thumb screws placed in its base. 
 
 VIII. Spirit lamps. — The most useful and economical of 
 those made are the Britania, as they are less liable to 
 break ; and the tube for the wick being fastened to the 
 body by a screw renders it less liable to get out of order 
 or explode. Glass is the cheapest, and for an amateur 
 will do very well, but for a professed artist the Baitania 
 should always be obtained. 
 
 IX. Color Box. — These are generally found on sale 
 at the shops, and usually contain eight colors, four 
 brushes and a gold cup. ' The artist would, however, do 
 well to obtain, all the colors mentioned in the last chap- 
 ter of this work, and be sure to get the very best, as there 
 are various qualities of the same color, particularly car- 
 mine, which is very expensive, and the cupidity of some 
 may induce them to sell a poor article for the sake of 
 larger profits. 
 
58 
 
 DAGUERREOTYPE APPARATUS. 
 
 Fig. 15. 
 
 Still. — Daguerreotypists should always use distilled 
 water for solutions, and washing the plate, as common 
 water holds various substances in solution which detract 
 very materially from the excellence of a photograph, and 
 often gives much trouble, quite unaccountable to many. 
 For the purpose of distilling w~ater the apparatus repre- 
 sented at Fig. 16 is both convenient and economical. 
 
 It may b& either wholly of good stout tin, or of sh£et 
 iron tinned on the inside, and may be used over a com- 
 mon fire, or on a stove. A is the body, which may be 
 made to hold from one to four gallons of water, which 
 is introduced at the opening 6, which is then stepped by 
 a cork. The tube d connects the neck a of the still with 
 the worm tub, or refrigerator B , at e, which is kept filled 
 with cold water by means of the funnel c, and drawn off 
 as fast as it becomes warm by the cock /. The distilled 
 water is condensed in the worm — and passes off at the 
 cock 6, under which a bottle, or other vessel, should be 
 placed to receive it. The different joints are rendered 
 tight by lute, or in its absence, some stiff paste spread 
 upon a piece of linen and wrapped around them will an- 
 
DAGUERREOTYPE APPARATUS. 
 
 59 
 
 swer very well ; an addition of sealing wax over all will 
 make them doubly secure. 
 
 Fig. 16. 
 
 Hygrometer. — This is an instrument never to be 
 found, 1 believe, in the rooms of our operators, although it 
 would be of much use to them, for ascertaining the quan- 
 tity of moisture floating about the room ; 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 &c., and to procure good pictures, — its detection 
 becomes a matter of importance. Mason’s hygrometer, 
 manufactured by Mr. Roach and sold by Mr. Anthony, 
 205 Broadway, New York is the best in use. 
 
 It consists of two thermometre tubes placed, side by 
 side, on a metalic scale, w~hich is graduated equally to 
 both tubes. The bulb of one of these tubes communi- 
 cates, by means of a net-work of cotton, with a glass re- 
 servoir of water attached to the back of the scale. Fig. 
 17 and 18 represent a front and back view of this instru- 
 ment. 
 
60 
 
 DAGUERREOTYPE APPARATUS. 
 
 Fig. 17 is the front view, showing the tubes with their 
 respective scales ; the bulb b being covered with the net- 
 work of cotton communicating with the reservoir c fig. 
 
 Fig. 17 Fig. 18. 
 
 18, at d. 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 atmosphere^ and the 
 number of degrees the tube b indicates below that of the 
 other, shows the real state of the atmosphere in the room ; 
 for instance, if b stands at forty and a at sixty-one the 
 room is in a state of extreme dryness, the difference of 
 twenty-one degrees between the thermometers — let a 
 stand at any one point — gives this result. If they do not 
 differ, or there is only four or five degrees variation, the 
 
DAGUERREOTYPE APPARATUS. 
 
 61 
 
 atmosphere of the room is very moist and means should 
 be taken to expel the superfluous quantity. 
 
 Headrests. — The button head rest with chair back 
 clip, A fig. 19 — is much the best for travelling artists, as 
 it can be taken apart, into several pieces and closely 
 packed, is easily and firmly fixed to the back of a chair 
 by the clamp and screw a and 6, and is readily adjusted 
 to the head, as the buttons c,c and arms (/, d are movable. 
 
 Sometimes the button rest is fixed to a pole, which is 
 screwed to the chair ; but this method is not so secure 
 and solid as the clip and occupies more room in packing. 
 Both the pole and clip, are furnished in some cases with 
 brass band rests instead of the button ; but the only re- 
 commendation these can possibly possess in the eyes of 
 any artist, is their cheapness. Fig. 19. 
 
 For a Daguerreotypist 
 permanently located thein- 
 dependent iron head-rest, B 
 fig. 19, is the most prefera- 
 ble, principally on account 
 of its solidity. It ts en- 
 tirely of iron, is supported 
 by a tripod a) of the same 
 metal and can be elevated 
 by means of a' rod ( b ) pas- 
 sing through the body cf 
 the tripod, to a height suf- 
 ficient for a person, stand 
 ing, to rest against. 
 
 Galvanic Battery. — This article is used for the pur- 
 pose of giving to imperfectly coated plates a thicker 
 covering of silver. The form of battery now most uni- 
 
62 
 
 DAGUERREOTYPE APPARATUS. 
 
 Fig. 20. 
 
 versally employed for electrotype, and other galvanic 
 purposes, is Smee’s — Fig. 20. 
 
 It consists of a piece of pla- 
 tinized silver, A, on the top 
 of which is fixed a beam of 
 wood, B, to' prevent contact 
 with the silver. A binding 
 screw C is soldered on to the 
 silver plate to connect it with 
 any desired object, by means 
 of the copper wire, e. A 
 plate of amalgamated zinc, 
 
 D, varying with the fancy of 
 the operator from one half to 
 the entire width of the silver^ 
 is placed on each side of the 
 wood. This is set into a glass 
 vessel, P, — the extreme ends 
 of the wood resting upon its 
 edge — on which the acid 
 with which it is charged has 
 
 no effect. The jar is charged with sulphuric acid, (com- 
 mon oil of vitriol) diluted in eight parts its bulk of water. 
 The zinc plates of the battery have been amalgamated 
 with quicksilver, and when the battery is set into the jar 
 of acid there should be no action percieved upon them 
 when the poles F, G, are not in contact. Should any 
 action be percieved, it indicates imperfect amalgamation • 
 this can be easily remedied by pouring a little mercury 
 upon them immediately after removing them from the 
 acid, taking care to get none upon the centre plate A. 
 
 Directions for use . — A sheet of silver must be attached 
 to the wire connected with the centre plate A of the 
 
DAGUERREOTYPE APPARATUS. 
 
 63 
 
 battery, and placed in the silver solution — prepared as di- 
 rected below. The plate to be silvered is first cleaned 
 with diluted sulphuric acid, and then attached to the 
 wire, G, proceeding from the zinc plates D, D, and 
 placed in the silver solution, opposite the silver plate at- 
 tached to the pole F, and about half an inch from it. A 
 slight effervescence will now be percieved from the bat- 
 tery, and the silver will be deposited upon the Daguerreo- 
 type plate, while at the same time a portion of the silver 
 plate is dissolved. 
 
 To prepare the solution of silver . — Dissolve one ounce 
 of chloride of silvei in a solution of two ounces of cya- 
 nide of potassium, previously dissolved in one quart of 
 water. The oxide of silver may be used instead of the 
 chloride. This solution is put into a tumbler, or other 
 vessel, 
 
 This battery with the necessary articles for using it 
 may be obtained of E. Anthony, 205 Broadway, New' 
 York city. 
 
 The other articles required by every operator may be 
 simply enumerated, viz : 
 
 Sticking, or sealing paper. 
 
 A pair of plyers, or forceps. 
 
 Porcelain pans or dishes, for applying the hyposul- 
 
 Fig. 22. 
 
 Fig. 21. 
 
 4 
 
64 
 
 DAGUERREOTYPE APPARATUS. 
 
 phite of soda and washing after the imagine is fixed, 
 something in form like fig. 21. 
 
 o O 
 
 A support for holding the plate while being washed, 
 like fig. 22 
 
 Fig. 23. 
 
 Buff Sticks. — Fig . 23. — These are usually from one to 
 three feet in length, and about three inches wide — some 
 think two and a half sufficient. The underside, which is 
 convex, is covered with a strip of finely prepared buck- 
 skin, or velvet, well padded with cotton or tow. 
 
 All the articles enumerated in this chapter may be ob- 
 tained, of the very best quality and at the most reasonable 
 rates, of Mr. E. Anthony, 205 Broadway, New York. 
 
CHAP. VI. 
 
 THE DAGUERREOTYPE PROCESS. 
 
 The process of taking Daguerreotype pictures differs 
 very materially from all others of the photographic art, 
 inasmuch as the production of the image is effected upon 
 plates of copper coated with silver. The silver employ- 
 ed should be as pure as possible ; the thfckness of the 
 plate is of little consequence, provided there be sufficient 
 silver to bear the cleaning and polishing — is free from 
 copper spots, is susceptible of a high polish, an exquisite- 
 ly sensitive coating and a pleasing tone. These qualities 
 are possessed to an eminent degree by the French plates. 
 
 Having already enumerated the various processes — and 
 the apparatus necessary for the manipulation, I will here 
 give a list of the chemicals to be used, and then proceed 
 to explain them more fully. The requisite chemicals 
 are — 
 
 NITRIC ACID, ROUGE, 
 
 DRY IODINE, MERCURY, 
 
 DRYING POWDER, HYPOSULPHITE OF SODA, 
 
 CYANIDE OF POTASSIUM, CHLORIDE OF GOLD ; OR 
 ROTTENSTONE, HYPOSULPHITE OF GOLD. 
 
 TRIPOLI, CHLORIDE OF SILVER. 
 
 chloride of iodine, ) their compounds, or other accele- 
 bromine ) rating mixtures. 
 
 First operation. — Cleaning and polishing the plate.-~ 
 For this purpose the operator will require the — 
 
68 
 
 DAGUERREOTYPE PROCESS. 
 
 Plate Blocks , 
 
 Plate Vice 
 
 Spirit Lamp , 
 
 Polishing Buffs , 
 
 Nitric Acid , diluted in fifteen times its bulk of water 
 
 Galvanic Battery, to galvanize the plate, as directed 
 in the last chapter if it is to imperfect to be used without, 
 previous to cleaning it. 
 
 Rottenstone , 
 
 Tripoli , which is too often dispensed with. 
 
 Rouge , or lampblack — the first being most preferable* 
 The English operators mix the two together. 
 
 Prepared cotton Wool , or Canton flannel. If the first 
 is used, it should be excluded from the dust, as it is not 
 so easily cleansed as the latter. 
 
 The plate is secured, with its silver side upward, to the 
 block, by the means described on page 58 — having pre- 
 viously turned the edges backward all around. The 
 amount of cleaning a plate requires, depends upon the 
 state it is in. We will suppose one in the worst condi- 
 tion ; dirty, scratched, and full of mercury spots, all of 
 which imperfections are more or less to be encountered. 
 The mercury spots are to be removed by burning the 
 plate. To do this hold the plate over the flame of a spirit 
 lamp, more particularly under the mercury spots, until 
 they assume a dull appearance, when the lamp is to be 
 removed, and the plate allowed to cool, after which it is 
 attached to the block. 
 
 Place the block upon the swivle, and hold it firmly 
 with the left hand ; take a small knot or pellet of cotton, 
 or, if you like it better, a small piece of canton flannel — • 
 wet it with a little diluted nitric acid; then sift some fine- 
 
DAGUERREOTYPE PROCESS. 
 
 67 
 
 ly prepared rottenstone — Davie’s,* if you can get it — upon 
 it, and rub it over the plate with a continual circular mo- 
 tion, till all traces of the dirt and scratches are removed ; 
 then wipe off the rottenstone with a clean piece of cotton, 
 adopting, as before, a slight circular motion, at the same 
 time wiping the edges of the plate. Even the back 
 should not be neglected, but throughly cleansed from any 
 dirt or greasy film it may have received from handling. 
 
 When this is thoroughly accomplished, mix a portion 
 of your tripoli with the dilute nitric acid, to the consist- 
 ence of thick cream. Then take a pellet of cotton and 
 well polish the plate with this mixture, in the same man- 
 ner as with the rottenstone. Continue the process till, 
 on removing the tripoli with a clean pellet, the plate ex- 
 hibits a clear, smooth, bright surface, free from ail spots, 
 or scratches. Any remains of the acid on the plate may 
 be entirely removed by sifting on it a little Drying pow- 
 der, and then wiping it carefully off with a fine camels 
 hair brush, or duster. The finishing polish is now to be 
 given. 
 
 For this purpose the rouge — or a mixture of rouge and 
 lamp-black, in the proportion of one part of the former to 
 seven of the latter — is used. It should be kept either in 
 a muslin bag, or wide mouth bottle, over which a piece 
 of muslin is tied — in fact, both the rottenstone and tripoli 
 should be preserved from the dust in the same manner. 
 With a little of this powder spread over the buff — described 
 on page 60 — the plate recieves its final polish ; the cir- 
 cular motion is changed for a straight one across the plate, 
 which, if intended for a portrait, should be buffed the 
 narrow way ; but if, for a landscape or view of a house, 
 the length way of the plate. 
 
 * Sold by E. Anthony. 
 
68 
 
 DAGUERREOTYPE PROCESS. 
 
 The operation of cleaning the plate at first appears 
 difficult and tedious, and many have been deterred from 
 attempting this interesting art on that account ; but, in 
 reality, it is more simple in practice than in description, 
 and with a little patience and observation, all difficulties 
 are easily overcome. Great care must be taken to keep 
 the buff free from all extraneous matter, and perfectly 
 dry, and when not in use it should be wrapped up in 
 tissue paper, or placed in a tight box. 
 
 The plate should be buffed immediately before the 
 sensitive coating is given ; particles of dust are thus 
 effectually removed ; the temperature of the plate is also 
 increased by the friction, and the required tint more 
 readily obtained. 
 
 Second operation. — Applying the sensitive coating .— 
 The apparatus and chemicals required, are an 
 
 Iodine box — see jig. 14 page 53. 
 
 Bromine box — similar to the iodine box, but a trifle 
 deeper. 
 
 Dry Iodine. 
 
 Bromine , or a compound of Bromine and Chloride of 
 Iodine, or other sensitive mixture. 
 
 Most of our best operators use the compound Bromine 
 and Chloride of Iodine. In the early days of the Da- 
 guerreotype, Iodine alone was used in preparing the plate, 
 and although it still plays a very important part, other pre- 
 parations, called accelerating liquids, quickstuff, &c., 
 are used, and the discovery of which has alone ensured 
 the application of the Daguerreotype successfully to por- 
 trait taking — for when first introduced among us it took 
 from five to ten minutes to produce a tolerable good 
 view, while now but the fraction of a minute is required 
 to obtain an accurate likeness. 
 
DAGUERREOTYPE PROCESS. 
 
 69 
 
 To iudlze the plate perfectly it must be placed over the 
 iodine vapor immediately after buffing. Scatter from a 
 sixteenth to the eighth of an ounce of dry iodine over the 
 bottom of your coating box, and slightly cover it with 
 cotton wool. The plate is then dropped into the frame 
 b,fig. 14, with its silvered surface downward, and thrust 
 under the lid h. The bright surface of the plate is 
 soon coated with a film of iodine of a fine yellow color ; 
 it is then removed and placed over the accelerating 
 solution. It is not absolutely necessary to perform this 
 operation in the dark, although a bright light should be 
 avoided. Not so the next part of the process, viz; giv- 
 ing the plate its extreme sensitiveness, or coating with the 
 accelerating liquids. In this great caution should be used 
 to prevent the slightest ray of light impringing directly on 
 the plate, and in examining the color reflected light 
 should always be used. A convient method of examin- 
 ing the plate, is to make a small hole in the partition of 
 the closet in which you coat, and cover it with a piece 
 of tissue paper ; by quickly turning the plate so that the 
 paper is ledected upon it the color is very distinctly 
 shown. Most of our operators are not so particular in 
 this respect as they should be. 
 
 Accelerating liquids.— Of these there are several 
 kinds, which differ both in composition and action — some 
 acting very quickly, others giving a finer tone to the pic- 
 ture although they are not so expeditious in there opera- 
 tions; or in other words, not so sensitive to the action of 
 light. These are adopted by Daguerreotypists accord- 
 ing to their tastes and predjudices. They are all applied 
 in the same w'ay as the coating of iodine. The following 
 are the best. 
 
 Bromine water — This solution is much used in Franco 
 
70 
 
 DAGUERREOTYPE PROCESS. 
 
 and, I shall therefore give its preparation, and the method 
 of using it, in the words of M. Figeau. u Put into a 
 bottle of pure water, a large excess of bromine ; shake 
 the mixture well, and before using it, let all the bromine 
 be taken up. An ascertained quantity of this saturated 
 water is then diluted in agiven quantity of distilled water, 
 which gives a solution of bromine that is always identi- 
 cal. ” M. Figeau recommends one part of the saturated 
 solution to thirty parts its bulk of water ; but M. Lesebour 
 finds it more manageable if diluted with forty times. In 
 case pure distilled, or rain water cannot be procured, a 
 few drops of nitric acid — say six to the quart — should be 
 added to the common water. 
 
 Put into the bromine box a given quantity of this solu- 
 tion, sufficient to well cover the bottom ; the plate, having 
 been iodized to a deep yellow, is placed over it; the time 
 the plate should be exposed must be ascertained by mak- 
 ing a few trials ; it averages from twelve to forty seconds. 
 When once ascertained, it is the same for any number oi 
 plates, as the solution, which of course would become 
 weaker and weaker, is changed after every operation, the 
 same quantity being always put into the pot. 
 
 Chloride of Iodine . — This is prepared by introducing 
 chlorine gass into a glass vessel containing iodine ; the 
 iodine is liquified, and the above named compound is the 
 result. Operators need not, however, be at the trouble 
 and expense of preparing it, as it can be obtained prefectly 
 pure of Mr. Anthony, 205 Broadway, N. Y., as also 
 all of the chemicals herein enumerated. The compound is 
 diluted with distilled water, and the plate submitted to its 
 action till it is of a rose color. Chloride of iodine alone, 
 is seldom if ever used now by American operators, as it 
 does not sufficiently come up to their locomotive princi- 
 
DAGUERREOTYPE PROCESS. 
 
 71 
 
 pie of progression. The next is also eschewed by the 
 majority, although many of our best artists use no other, 
 on account of the very fine tone it gives to pictures. 
 
 Bromide of Iodine . — This is a compound of bromine 
 and chloride of iodine. In mixing it, much depends upon 
 the strength of the ingredients; an equal portion of each 
 being generally used. Perhaps the best method of pre- 
 paring it, is to make a solution in alcohol of half an 
 ounce of chloride of iodine, and add the bromine drop 
 by drop, until the mixture becomes of a dark red color; 
 then dilute with distilled water, till it assumes a bright 
 yellow. Put about half an ounce of this compound in- 
 to the pot, and coat over it to a violet color, change the 
 solution when it becomes too weak to produce the de- 
 sired effect. 
 
 Another . — Mix half an ounce of bromine with one 
 ounce of chloride of iodine, add two quarts pure distil- 
 led water, shake it well and let it stand for twelve hours ; 
 then add twenty-five drops of muriatic acid, and let it 
 istand another twelve hours, occasionally shaking it up 
 well. Dilute six parts of this solution in sixteen of 
 water. Coat over dry iodine to a deep yellow, then 
 over the sensitive to a deep rose color— approaching 
 purple — then back, over dry iodine from four to eight 
 seconds. 
 
 Roach’s Tripple Compound . — This is one of the very 
 best sensitive solutions, and is very popular among Da- 
 guerreotypists. To use this, take one part in weight, say 
 one drachm, of the compound and dilute it with twelve 
 of water ; coat over dry iodine to yellow, then over the 
 compound to a rosy red. The effect in the camera is 
 quick, and produces a picture of a fine white tone. 
 
 Gurney^s Sensitive .—' This is another preparation of 
 
 4# 
 
72 
 
 DAGUERREOTYPE PROCESS. 
 
 bromine, and gives a fine tone. To two parts of water 
 add one of the sensitive, and put just sufficient in the box 
 to cover the bottom, or enable you to coat in from eight 
 to ten seconds. Coat over dry iodine to a dark yellow, 
 and over the quick till you see a good change, then back 
 over the dry iodine from two to three seconds. 
 
 Bromide of Lime , or Dry Sensitive . — This is a com- 
 pound but recently introduced, and is becoming some- 
 what of a favorite, owing principally to the slight trouble 
 it gives in its preparation, and the tone it imparts to the 
 picture. To prepare it, fill your jar about half or quar- 
 ter full of dry slacked lime, then drop into it bromine, 
 till it becomes a bright orange red. The plate is gene- 
 rally coated over this compound, after the iodine coating 
 to yellow, to a violet, or plum color ; but it will work 
 well under any circumstances, the color being of little 
 consequence, if coated from thirty to ninety seconds, ac- 
 cording to its strength. 
 
 Mead's Accelerator . — I merely mention this as being 
 in the market, not knowing any thing in regard to its 
 merits. The directions given for its use are as follows : 
 Mix one-third of a bottle with a wine glass full of water, 
 coat the plate over dry iodine to a dark gold color, then 
 over the accelerator to a violet, then back overdry iodine, 
 or chloride of iodine, from three to five seconds. 
 
 Chloride of Bromine. — M. Bissou, a French experi- 
 mentalist, has found that bromine associated with chlo- 
 rine, prepared in a similar manner to chloride of iodine, 
 already described, a solution of bromine being substituted 
 for the iodine, is a very sensitive solution ; by means of 
 it daguerreotjrpe proofs are obtained in half a second, and 
 thus very fugitive subjects are represented, making it the 
 very best compound for taking children. So quick is its 
 
DAGUERREOTYPE PROCESS. 
 
 73 
 
 operation, that even persons or animals may be taken in 
 the act of walking. 
 
 Hungarian Liquid,.— This, I believe, has never been 
 used here, or imported into this country, and the compo- 
 sition of it is not generally known, even in Europe, 
 where it has taken precedence of all others. It acts 
 quickly and with considerable certainty. It is used by 
 diluting it with from ten to fifteen times its bulk of water, 
 putting a sufficient quantity into the jar to cover the 
 bottom. The plate being previously iodized to a light 
 yellow, is submitted to this mixture till it assumes a 
 light rose tint. 
 
 Bromine and Fluoric Acid , in combination, are used by 
 some Daguerrean artists as a sensitive, but any of the 
 above compounds are better ; besides this, the fluoric 
 acid is a dangerous poison, and the quick made from it 
 will not repay the risk to the health in using it. 
 
 As I have before said, great caution should be observ- 
 ed in examining the color of the plate, even by the feeble 
 light allowed, which, when attained, must be imme- 
 diately placed in the holder belonging to the camera and 
 covered with the dark slide. You then pass to the 
 
 Third Operation. — Submitting the Plate to the ac- 
 tion o f Light in the Camera. — Experience alone must 
 guide the operator as to the time the plate should be ex- 
 posed to the influence of the light ; this being dependent 
 on a variety of circumstances, as clearness of the atmo- 
 sphere — and here, a reference to the hygrometer wili be 
 of advantage — time of day, object to be taken, and the 
 degree of sensitiveness imparted to the plate by the quick- 
 stuff. As I have before said, the artist should be care- 
 ful to see that the interior of the camera is clean and free 
 from dust, as the small particles dying about, or set in 
 
74 
 
 DAGUERREOTYPE PROCESS. 
 
 motion by the sliding of the holder into the box, attach 
 themselves to the plate, and cause the little black spots, 
 by which an otherwise good picture is frequently spoiled. 
 Care should also be taken in withdrawing the dark slide, 
 in front of the plate, from the holder, as the same effect 
 may be produced by a too hasty movement. The lens is 
 tlie last thing to be uncovered, by withdrawing the cap 
 c. ng. 5., which should not be done until you have placed 
 the sitter in the most desirable position. When, accord- 
 ing to the judgment and experience of the operator, the 
 plate has remained long enough to receive a good inpres- 
 sion, the cap is replaced over the lens, and the dark slide 
 over the plate, which is then removed from the camera. 
 
 Daguerreotypists generally mark time by their watches, 
 arriving at the nearest possible period for producing a 
 good picture bv making several trials. As a ready meth- 
 od of marking short intervals of time is, however, a very 
 important consideration, and as any instrument which wiil 
 enable an artist to arrive at the exact period, must be an 
 improvement, and worthy of universal adoption, I will here 
 describe one invented by Mr. Constable of England, which 
 he calls a 
 
 Sand Clock , or Time Keeper . — “ It consists of a glass 
 tube, about twelve inches long by one in diameter, half 
 filled wdth fine sand, similar to that used for the ordinary 
 minute glasses, and, like them, it has a diaphram, with 
 a small hole in the centre through which the sand runs. 
 The tube is attached to a board which revolves on a centre 
 pin ; on the side is a graduated scale, divided into half 
 seconds ; the tube is also provided with a moveable in- 
 dex. This instrument is attached, in a conspicuous 
 place, to the wall. The glass tube being revolved on its 
 centre, the index is set to the number of half seconds re- 
 
DAGUERREOTYPE PROCESS. 
 
 75 
 
 quired, and the sand running down, the required time is 
 marked without the possibility of error. In practice it, 
 will be found to be a far more convenient instrument for 
 the purpose than either a clock or a seconds watch, and 
 is applicable both for the camera and mercury box.” 
 
 If the artist finds it desirable or necessary to take the 
 object to be copied in its right position, that is reverse the 
 image on the spectrum, he can do so by attaching a mir- 
 ror (which may be had of Mr. Anthony, or Mr. Roach) 
 to the camera tube, at an angle of forty-five degrees. 
 
 If, after taking the plate from the camera, it be ex- 
 amined, no picture will yet be visible, but this is brought 
 about by the 
 
 Fourth Process. — Bringing out the Picture, or render- 
 ing it Visible . — We now come to the use of the mercury 
 bath, Fig. 13. To the bath a thermometer is attached, 
 to indicate the proper degree of heat required, which 
 should never be raised above 170° Fahrenheit. The 
 plate maybe put into one of the frames (see Fig. 13,) 
 over the mercury, face downwards, and examined from 
 time to time, by simply raising it with the fingers, or a 
 pair of plyers. This operation, as well as the others, 
 should take place in the dark closet. Fig. 24. 
 Sometimes, to prevent the necessity 
 of raising the plate, an additional 
 cover or top is made use of. It con- 
 sists of a box fitted closely to the 
 inner rim of the bath, and having 
 an inclined top (a, Fig. 24.) The top 
 is cut through and fitted with frames 
 for each size of plate, like those 
 already described, and in the back 
 is a piece of glass (b,) through which to view* the progress 
 
76 
 
 DAGUERREOTYPE PROCESS. 
 
 of mercurialization, and an additional piece (c,) on one 
 side, colored yellow, to admit the light. The outline 
 only of the top is here given, in order to show every 
 portion of it at one view. 
 
 The picture, being fully developed, is now taken out 
 and examined; it must not, however, be exposed to too 
 strong a light. If any glaring defects be perceived, it is 
 better not to proceed with it, but place it on one side to 
 be re-polished ; if, on the contrary, it appears perfect, you 
 may advance to the 
 
 Fifth Operation.— -Fixing the Image so that the light 
 can no longer act upon it . — The following articles are 
 required for this purpose : 
 
 Two or three porcelain or glass dishes, in form, some- 
 thing like fig. 21 . 
 
 A plate support, fig. 22. Few, I believe } now make 
 use of this, although it is a very convenient article. 
 
 Hyposulphite of Soda , 
 
 A pair of Flyers. 
 
 In Europe, they also use a drying apparatus, Fig 
 25, but this, like the plate support, 
 is a matter of little consequence, and 
 may be dispensed with. I will, 
 however, describe it, for tbe benefit 
 of those who may wish to use it. 
 
 A vessel made of copper or brass, 
 tinned inside, and large enough to 
 take in the largest plate, but not 
 more than half an inch wide, is the 
 most convenient. It must be kept perfectly clean. Hot 
 distilled water is poured into it, and the temperature 
 kept up by a spirit lamp. 
 
 Hyposulphite of Soda . — Having made a solution of 
 
 Fig. 25. 
 
DAGUERREOTYPE PROCESS. 
 
 77 
 
 hyposulphite of soda, and well filtered it-— the strength 
 is immaterial : about half an ounce of the salt to a pint 
 of distilled water is sufficient — pour it into one of the 
 porcelain dishes, put into another plain, and into a third 
 distilled water. ' Immerse the plate with its face down- 
 wards into the hyposulphite, and the whole of the sen- 
 sitive is removed, and the light has no farther action up- 
 on it ; it is then to be removed from the hyposulphite 
 and plunged into the plain water, or placed upon the 
 support, fig. 22, and the water poured over it. It is 
 then washed in a similar manner with the distilled water 
 and well examined, to see that not the slightest particle 
 of dust rests on the suface. The next step is to dry 
 it. 
 
 This may be readily accomplished by holding the plate 
 with your plyers,and pouring distilled water over it— -if it 
 is hot, so much the better. Apply the spirit lamp to the 
 back, at the corner held by the plyers, at the same time 
 facilitating the operation with the breath ; pass the lamp 
 gradually downwards, finishing at the extreme corner. 
 The last drop may now be removed by a little bibulous 
 paper. A single drop, even, of distilled water allowed to 
 dry on any part of the surface, is certain to leave a stain 
 which no after process can remove. 
 
 To illustrate the necessity for having perfectly clean 
 water, and free from all foreign matter — only to be avoid- 
 ed by using that which is distilled — —in these processes, 
 I will relate a little anecdote. 
 
 An operator in this city (New York) frequently made 
 complaint to me, that his plates were occasionally very 
 bad; coming out all over in little black and white spots, 
 and spoiling many very good pictures, regretting at the 
 same time that perfect plates were not made, for he had 
 
78 
 
 DAGUERREOTYPE PROCESS. 
 
 lost many customers in consequence of these defects. 
 These complaints being somewhat periodical, I suggested 
 that the fault might be in the hyposulphite, or chloride 
 of gold solutions, or particles of dust floating about in 
 the room, and not in the plate. 
 
 A few days after he stated, that his plates having served 
 him again in the same way, he procured a fresh supply 
 of hyposulphite of soda and chloride of gold, but after 
 applying them the result was no better. He then, by 
 my advice, thoroughly cleaned his wash dishes, bottles 
 and water pail, made fresh solutions and had no further 
 trouble, becoming satisfied that the plates suffered an 
 undue share of censure. 
 
 Sixth Process. — Gilding the Picture. — This is an im- 
 provement the honor of which is due to M. Figeau, and 
 may take place either before the drying process, or at any 
 subsequent period; but it improves the picture so mate- 
 rially that it should never be neglected. The articles ne- 
 cessary for gilding are — 
 
 A Pair of Plyars ; or a Gilding Stand and Chloride of 
 
 Gold ; or Hyposulphite of Gold. 
 
 The latter is imported by Mr. E. Anthony, 205 Broad- 
 way, New York, and is decidedly the best article for the 
 purpose. One bottle simply dissolved in a quart of water 
 will make a very strong solution, and gives a richness to 
 the picture impossible to be obtained from the chloride 
 of gold. The process is precisely similar to that des- 
 cribed below for chloride of gold, taking care to cease 
 the moment the hubbies are well defined over the surface of 
 the plate. Many Daguerreotypists, after a superficial 
 trial, discard the hyposulphite of gold as inferior ; but I 
 have no hesitation in asserting that the fault lies with 
 themselves ; for in every case within my knowledge ? 
 
DAGUERREOTYPE PROCESS. 
 
 79 
 
 where its use has been persisted in until the correct me- 
 thod has been ascertained, and the nature of the gilding 
 has become familiar, it is always preferred. In illustra- 
 tion of this fact I will relate an anecdote : 
 
 A gentleman to whom it had been recommended, pur- 
 chased a bottle, and after making one or two trials of it, 
 wrote to his correspondent — “ Send me two bottles ot 
 chloiide of gold, for I want no more of the hyposulphite; 
 it is good for nothing.” A few weeks after he sent for 
 three bottles of the condemned article, confessing that he 
 had found fault unnecessarily; for, that smce he had be- 
 come familiar to its use, he must acknowledge its supe- 
 riority, and would use no other gilding. 
 
 The Solution of Chloride of Gold is prepared by dis- 
 solving in a pint of distilled water, fifteen grains of chrys- 
 talized chloride of gold. This solution will be of a yel- 
 low tint. In another pint of distilled water dissolve fifty- 
 five grains of hyposulphite of soda; pour gradually,' in 
 very small quantities, the gold into the hyposulphite of 
 soda, stirring the solution at intervals; when finished the 
 mixture should be nearly colorless. 
 
 Place the plate on its stand, or hold it in the plyers, in 
 a perfectly horrizontal position — silver surface upward — 
 having previously slightly turned up th3 edges, so that 
 it may hold the solution. Wet the surface with alcohol, 
 letting any superfluous quantity drain off. The alcohol 
 is of no farther use than to facilitate the flowing of the 
 gold mixture over the surface. Now pour on, carefully, 
 as much of the preparation of gold as will remain on the 
 plate. The under part of the plate i? then to be heated 
 as uniformly as possible with the spirit lamp; small bub- 
 bles will arise, and the appearance of the portrait or 
 view very sensibly improved. The process must not be 
 
80 
 
 DAGUERREOTYPE PROCESS. 
 
 carried too far, but as soon as the bubbles disappear the 
 lamp should be removed, and the plate immersed in dis- 
 tilled water, and dried as before directed. 
 
 7th. Coloring the Picture. — I very much doubt 
 the propriety of coloring the daguerreotypes, as I am of 
 opinion, that they are little, if any, improved by the 
 operation, at least as it is now generally practised. 
 
 There are several things requisite in an artist to enable 
 him to color a head, or even a landscape effectively, and 
 correctly, and I must say that very few of these are pos- 
 sessed by our operators as a class. These requirements 
 are, 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 beau- 
 tiful, and a knowledge of the art of mixing colors, and 
 blending tints. 
 
 The method now pursued, I do not hesitate to say, and 
 have no fears of being contradicted by those capable of 
 critisizing, is on the whole ruinous to any daguerreotype, 
 and to a perfect one absolutely disgusting. The day may 
 come when accurate coloring may be obtained in the ca- 
 mera. Until that day, if we cannot lead taste into the 
 right channel, we will endeavor to give such instructions 
 that Daguerreotypists may proceed with this part of their 
 work with a better understanding of the principles in- 
 volved. For this purpose I have prepared a short chap- 
 ter on the art of coloring, which may be found in the 
 latter part of this volume. 
 
 To Preserve Daguerreotypes they must be well sealed 
 and secured in a case, or frame. These, of course, are 
 selected according to the taste of the customer, the prin- 
 cipal requisite being good glass. Most Daguerreotypists 
 prefer the white French plate glass — and many think, 
 
DAGUERREOTYPE PROCESS. 
 
 81 
 
 very erroneously, that none is good unless it is thick — 
 but the great desideratum is clearness and freedom from 
 blisters; even glass a little tinged with green or yellow 
 is to be preferred to the French plate wdien cloudy or 
 blistered, and there is very little of it comes to this mar- 
 ket that is not so. It is to be hoped that some of out 
 glass factories will manage to manufacture an article ex- 
 pressly for daguerreotypes ; and I would recommend them 
 to do so, for they would find it quite an item of profit 
 annually. 
 
 Before enclosing the picture in the case you should be 
 careful to wipe the glass perfectly clean, and blow from 
 the picture any pat tides 'of dust w r hich may have fallen 
 upon it. Then take strips of sticking paper, about half 
 or three quarters of an inch wide, and firmly and neatly 
 secure it to the glass, having first placed a “ mat” be- 
 tween them to prevent the plate being scratched by the 
 glass. 
 
 To make Sealing Paper. — Dissolve one ounce of 
 gum arabic, and a quarter of an ounce of gum tragicanth 
 in a pint of water; then add a teaspoonful of benzoin. 
 Spread this evenly on one side of good stout tissue paper; 
 let it dry, and then cut it up in stripes, about half or 
 three quarters of an inch wide, for use. If it becomes 
 too soft for summer use, add gum arabic; if too hard and 
 cracking, add benzoin or gum tragicanth ; if it gets too 
 thick, add water. 
 
 Colored Daguerreotypes on Copper. — To effect this, 
 take a polished plate of copper and expose it to the va- 
 por of iodine, or bromine, or the two substances com- 
 bined ; or either of them in combination with chlorine. 
 This gives a sensitive coating to the surface of the plate, 
 which mav then be submitted to the action of light in the 
 
82 
 
 DAGUERREOTYPE PROCESS. 
 
 camera. After remaining a sufficient time in the camera, 
 the plate is taken out and exposed to the vapor of sul- 
 phuretted hydrogen. This vapor produces various colors 
 on the plate, according to the intensity with which the 
 light has acted on the different parts ; consequently a co- 
 lored photographic picture is obtained. No further pro- 
 cess is necessary as exposure to light does not effect the 
 picture. 
 
 By this process we have an advantage over the silvered 
 plate, both in economy, and in the production of the 
 picture in colors. 
 
 INSTANTANTANEOUS PICTURES BY MEANS OF GALVANISM. 
 
 — It will be seen by the following valuable communi- 
 cation that galvanism can be successfully applied in 
 producing pictures instantly ; a process of great import- 
 ance in securing the likeness of a child, or in taking 
 views of animated nature. Colonel Whitney informs 
 me that he once took a view of the steeple of the St. 
 Louis Court House after sundown by this means, and 
 also secured the image of a man in the act of stepping 
 into a store, and before he had time to place his foot, 
 raised for that purpose, on the door step. Mr. Whitney 
 is well know'll as the talented editor of the Sunday 
 Morning news. 
 
 New York, January 16, 1849. 
 
 Mr. H. H. Snelling. 
 
 Dear Sir, — As you are about publishing a history of 
 the Daguerreotype, and request a description of my mode 
 of taking pictures instantaneously by the aid of galvan- 
 ism, I comply with great pleasure. 
 
 In the year 1841, while practicing the art in St. Louis, 
 Mo., I was at times, during the summer, much troubled 
 with the electric influence of the atmosphere, especially 
 
DAGUERREOTYPE PROCESS. 
 
 83 
 
 on the approach of a thunder-storm. At such times I 
 found the coating of my plates much more sensitive 
 than when the atmosphere was comparatively free from 
 the electric fluid, and the effect was so irregular that no 
 calculation could counteract the difficulty. This satis- 
 fied me that electricity was in some measure an impor- 
 tant agent in the chemical process, and it occurred to me 
 that the element might be turned to advantage. I de- 
 termined, therefore, to enter on a series of experiments to 
 test my theory. .Finding it impossible to obtain an elec- 
 tric machine, and unwilling to abandon the examination, 
 it occurred to me, that the galvanic influence might an- 
 swer the same purpose, i therefore proceeded to make 
 a galvanic battery in the following simple manner. I 
 obtained a piece of zinc about two inches long, one inch 
 wide, and an eighth of an inch thick. On this I soldered 
 a narrow strip of copper, about six inches long, the sol- 
 dered end laid on one side of the zinc, and extending its 
 whole length. The battery was completed by placing 
 the zinc in a glass tumbler, two-thirds full of dilute sul- 
 phuric acid, strong enough to produce a free action of 
 the metals. The upper end of the copper slip extending 
 above the tumbler was sharpened to a point, and bent a 
 little over the glass. 
 
 The method of using, was thus : — After preparing the 
 plate in the usual manner and placing it in the camera, in 
 such manner as to expose the back of the plate to view, 
 the battery was prepared by placing the zinc in the acid, 
 and as soon as the galvanic fluid began to traverse (as 
 could be known by the effervessence of the acid, oper- 
 ating on the zinc and copper) the cap of the camera was 
 removed, and the plate exposed to the sitter ; at the same 
 instant the point of the battery was brought quickly 
 
84 
 
 DAGUERREOTYPE PROCESS. 
 
 against the back of the plate, and the cap replaced in- 
 stantly. If the plate is exposed more than an instant after 
 the contact, the picture will generally be found solarized. 
 By this process I have taken pictures of persons in the 
 act of walking, and in taking the pictures of infants and 
 young children I found it very useful. 
 
 Very respectfully, yours, 
 
 Thomas R. Whitney. 
 
 Before we conclude this part of our subject, we must 
 give a brief notice of a very remarkable invention of M. 
 Martens, by which an extensive panoramic view, amount- 
 ing even to an angle of ] 50°, may be taken by the Da- 
 guerreotype. The object-glass is fixed upon a pivot, 
 and put in motion by an endless screw, so as to present a 
 narrow aperture in front of it, in succession, to the land- 
 scape or group of figures to be copied. When the long 
 iodized plate, curved cylindrically, is placed in the appa- 
 ratus, the cover is taken from the object-glass, and the 
 handle is turned slowly and steadily round; slowly when a 
 dark object is in the field, and quickly when a luminous 
 object is there. By means of a common achromatic ob- 
 ject-glass, one inch and four-tenths in diameter, views 
 have been produced thirty-eight centimetres long and 
 twelve wide; and these views, one of which we have 
 seen, are as perfect as if they had been taken by the com- 
 
 mon camera. 
 
CHAP. VIL 
 
 PAPER DAGUERREOTYPES. ETCHING DAGUERREOTYPES. 
 
 Mr. Hunt describes a process, discovered by himself 
 by which the Daguerrean art may be applied to paper. 
 His description is as follows: — 
 
 il Placing the paper on some hard body, wash it over 
 on one side — by means of a very soft camel’s hair pen- 
 cil — with a solution of sixty grains of bromide of potas- 
 sium, in two fluid ounces of distilled water, and then 
 dry it quickly by the fire. Being dry, it is again washed 
 over wdth the same solution, and dried as before. A so- 
 lution of nitrate of silver — one hundred grains to an 
 ounce of distilled water — is to be applied over the same 
 surface, and the paper quickly dried in the dark. In 
 this state the papers may be kept for use. 
 
 ct When they are required, the above solution of sil- 
 ver is to be plentifully applied, and the paper placed wet 
 in the camera, the greatest care being taken lhat no day 
 light — not even the faintest gleam — falls upon it until the 
 moment when you are prepared, by removing the dark 
 slide, to permit the light, radiating from the object you 
 wish to copy, to act in producing the picture. After a 
 few seconds the light must be again shut off, and the 
 camera removed into a dark room.’’ The necessity of 
 removing the camera is now avoided by the use of the 
 dark slide, already described, covering the picture in the 
 holder., which alone may be removed. — Amer. Aut. 
 
85 
 
 PAPER DAGUERREOTYPES. 
 
 “ It will be found by taking the paper from the bolder, 
 that there is but a very faint outline — if any — yet visible. 
 Place it aside, in perfect darkness until quite dry ; then 
 place it in the mercurial vapor box (meaning bath) and 
 apply a very gentle heat to the bottom. The moment 
 the mercury vaporizes, the picture will begin to develope 
 itself. The spirit lamp must now be removed for a short 
 time, and when the action of the mercury appears to 
 cease, it is to be very careful^ applied again, until a 
 well defined picture is visible. The vaporization must 
 then be suddenly stopped, and the photograph removed 
 from the box. The drawing will then be very beautiful 
 and distinct; but much detail is still clouded, for the de- 
 velopement of which it is only necessary to place it in 
 the dark and suffer it to remain undisturbed for some 
 hours. There is now an inexpressible charm about the 
 pictures, equaling the delicate beauty of the daguerreo- 
 type ; but being very susceptible of change, it must be 
 viewed by the light of a taper only. The nitrate of sil- 
 ver must now be removed from the paper, by well wash- 
 ing it in soft water, to which a small quantity ef salt has 
 been added, and it should afterwards be soaked in w r ater 
 only. When the picture has been dried, wash it quickly 
 over with a soft brush dipped in a warm solution of hy- 
 posulphite of soda, and then w r ash it for some time in 
 distilled w r ater, in order that all the hyposulphite may be 
 removed. The drawing is now fixed and we may use it 
 to procure positive copies, (the original being termed a 
 negative,) many of w r hich may be taken from one origi- 
 nal.” 
 
 “ The action of light on this preparation, does indeed 
 appear to be instantaneous. The exquisite delicacy of 
 this preparation may be imagined, when I state that in 
 
ETCHING DAGUERREOTYPES. 
 
 87 
 
 five seconds in the camera, I have, during sunshine, ob- 
 tained perfect pictures, and that when the sky is over- 
 cast, one minute is quite sufficient to produce a most de- 
 cided effect.” 
 
 u This very beautiful process is not without its difficul- 
 ties; and the author cannot promise that, even with the 
 closest attention to the above directions, annoying fail- 
 ures will not occur. It often happens that some acci- 
 dental circumstance — generally a projecting film or a lit- 
 tle dust — will occasion the mercurial vapor to act with 
 great energy on one part of the paper, and blacken it 
 before the other portions are at all effected. Again, the 
 mercury will sometimes accumulate along the lines made 
 by the brush, and give a streaky appearance to the pic- 
 ture, although these lines are not at all evident before the 
 mercurial vapor was applied. (A brush sufficiently large 
 — and they may be easily obtained — will, in a measure, 
 prevent this difficulty ! — Amer Au.) I have stated that 
 the paper should be placed wet in the camera ; the same 
 paper may be used dry, which often is a great conve- 
 nience. When in the dry state a little longer exposure 
 is required ; and instead of taking a picture in four or 
 five seconds, two or three minutes are necessary.” 
 
 The durability of daguerreotypes has been, and is still, 
 doubted by many, but experiment has proved that they 
 are more permanent than oil paintings or engravings. 
 
 Etching Daguerreotypes. — There are several me- 
 thods of accomplishing this object ; discovered and ap- 
 plied by different individuals. 
 
 The first process was published at Vienna by Dr. Ber- 
 res, and consisted in covering the plate with the mucil- 
 age of gum arabic, and then immersing the plate in ni- 
 tric acid of different strengths. 
 
88 
 
 ETCHING DAGUERREOTYPES. 
 
 Mr. Figeau, of whom I have already spoken, like- 
 wise discovered a process for the engraving of Daguerreo- 
 types ; and founded on the belief that the lights of a Da- 
 guerreotype plate consists of unaltered silver, while the 
 dark or shadows consists of mercury or an amalgam of 
 mercury with silver. He finds that a compound acid, 
 consisting of a mixture of nitric, nitrous, and muriatic 
 acids, or of nitric mixed with nitrate of potass and com- 
 mon salt, has the property of attacking the silver in pres- 
 ence of the mercury without acting upon the latter. 
 Bi-chloride of copper answers the purpose also, but less 
 completely. 
 
 “ When the clean surface of a Daguerreotype plate is 
 exposed to the action of this menstruum, particularly if 
 warm, the white parts, or lights are not altered, but the 
 dark parts are attacked, and chloride of silver is formed, 
 of which an insoluable coating is soon deposited, and the 
 action of the acid soon ceases. This coat of chloride of 
 silver is removed by a solution of ammonia, and then 
 the acid applied again, and so on, until the depth of 
 biting in is sufficient. However, it is not possible, by re- 
 peating this process, to get a sufficient force of impres- 
 sion ; a second operation is required, in order to obtain 
 such a depth as will hold the ink, to give a dark impres- 
 sion ; for this purpose the whole plate is covered wfith 
 drying oil ; this is cleared off with the hand, exactly in 
 the way a copper plate printer cleans his plate. The oil 
 is thus left in the sinkings , or dark bitten in parts only. 
 The whole plate is now placed in a suitable apparatus, 
 and the lights or prominent parts of the face are gilt by 
 the electrotype process. The whole surface is now 
 touched with what the French engravers call the u Resin 
 Grain, 5 ’ {grain de resine ) , a species of partial stopping 
 
ETCHING DAGUERREOTYPES. 
 
 89 
 
 out, and it is at once bitten in to a sufficient depth with 
 nitric acid, the gilding preserving the lights from all ac- 
 tion of the acid. The resin grain gives a surface to the 
 corroded parts suitable for holding the ink, and the plate 
 is now finished and fit to give impressions resembling 
 aquatint. But as silver is so soft a metal that the surface 
 of the plate might be expected to wear rapidly, the dis- 
 coverer proposes to shield it by depositing over its whole 
 surface a very thin coat of copper by the electrotype 
 process ; which when worn may be removed at pleasure 
 down to the surface of the noble metal beneath, and 
 again a fresh coat of copper deposited ; and so an unlim- 
 ited number of impressions obtained without injuring 
 the plate itself.” 
 
 If, as has been asserted, steel may be rendered suffi- 
 ciently sensitive, to take photographic impressions, to 
 what a revolution will the art of engraving be subject by 
 the discovery of this process. 
 
CHAP. VIII. 
 
 PHOTOGENIC DRAWING ON PAPER. 
 
 We shall now proceed to describe the various processes 
 for Photogenic drawing on paper ; first, however, im- 
 pressing on the mind of the experimenter, the necessity 
 which exists for extreme care in every stage of the man- 
 ipulation. In this portion of my work I am entirely in- 
 debted to the works of Professors Hunt. Fisher and others. 
 
 I. Apparatus and Materials. — Paper. prin- 
 cipal difficulty to be contended with in using paper, is the 
 different pow r er of imbibition which we often find pos- 
 sessed in the same sheet, owing to trifling inequalities in 
 its texture. This is, to a certain extent, to be overcome 
 by a careful examination of each sheet, by the light of a 
 candle or lamp at night, or in the dark. By extending 
 each sheet between the light and the eye, and slowly 
 moving it up and down, and from left to right, the varia- 
 tions in its texture will be*seen by the different quanti- 
 ties of light which pass through it in different parts ; and 
 it is always the safest course to reject every sheet in which 
 inequalities exist. Paper sometimes contains minute 
 portions of thread, black or brown specks, and other 
 imperfections, all of which materially interfere with the 
 process. Some paper has an artificial substance given to 
 it by sulphate of lime (Plaster of Paris) ; this defect only 
 exists, however, in the cheaper sorts of demy, and 
 therefore can be easily avoided. In all cases such paper 
 
92 
 
 PHOTOGENIC DRAWING ON PAPER. 
 
 should be rejected, as no really sensitive material can be 
 obtained with it. Paper-makers, as is well known, often 
 affix their name to one half the sheet ; this moiety should 
 also be placed aside, as the letters must frequently come 
 out with annoying distinctness. Well sized paper is by 
 no means objectionable, indeed, is rather to be preferred, 
 since the size tends to exalt the sensitive powers of the 
 silver. The principal thing to be avoided, is the ab- 
 sorption of the sensitive solution into the pores ; and it 
 must be evident that this desideratum cannot be obtained 
 by unsized paper. Taking all things into consideration, 
 the paper known as satin post would appear to be prefer- 
 able, although the precautions already recommended 
 should be taken in its selection. 
 
 Brushes . — The necessary solutions are to be laid upon 
 the paper by brushes. Some persons pass th^paper over 
 the surface of the solutions, thus licking up, as it were, 
 a portion of the fluid ; but this method is apt to give an 
 uneven surface ; it also rapidly spoils the solutions. At 
 all events, the brush is the most ready and the most ef- 
 fectual means. 
 
 Distilled Water . — All the water used, both for mixing 
 the solutions, washing the paper, or cleaning the brushes, 
 must be distilled, to obtain good results, for reasons be- 
 fore specified. 
 
 Blotting Paper . — In many instances, the prepared pa- 
 per requires to be lightly dried with bibulous paper. The 
 best description h the white sort. In each stage of the 
 preparation distinct portions of bibulous paper must be 
 used. If these be kept seperate and marked, they can 
 be again employed for the same stage ; but it would not 
 do, for example, to dry the finished picture in the same 
 folds in which the sensitive paper had been pressed A 
 
PREPARATION OF THE PAPER. 
 
 93 
 
 very convenient method is to have two or three quarto 
 size books of bibulous paper, one for each seperate pro- 
 cess. 
 
 Nitrate of Silver . — In the practice of the photographic 
 art, much depends on the nitrate of silver. Care should 
 be taken to procure the best ; the crystalized salt is most 
 suitable for the purpose While in the form of crystal it 
 is not injured by exposure to light, but the bottles con- 
 taining the solutions of this salt should at all times be 
 kept wrapped in dark paper, and excluded from day- 
 light. 
 
 II. Different Methods of Preparing the Paper. 
 — Preparation of the Paper . — Dip the paper to be pre- 
 pared into a weak solution of common salt. The solution 
 should not be saturated, but six or eight times diluted 
 with water. When perfectly moistened, wipe it dry with 
 a towel, or press it between bibulous paper, by which 
 operation the salt is uniformly dispersed through its sub- 
 stance. Then brush over it, on one side only, a solu- 
 tion of nitrate of silver. The strength of this solution 
 must vary according to the color and sensitiveness re- 
 quired. Mr. Talbot recommends about fifty grains of the 
 salt to an ounce of distilled water. Some advise twenty 
 grains only, while others say eighty grains to the ounce. 
 When dried in a dark room, the paper is fit for use. To 
 render this paper still more sensitive, it must again be 
 washed with salt and water, and afterwards with the 
 same solution of nitrate of silver, drying it between times. 
 This paper, if carefully made, is very useful for all or- 
 dinary photographic purposes. For example, nothing 
 can be more perfect than the images it gives of leaves and 
 flowers, especially with a summer’s sun; the light, pass- 
 ing through the leaves, delineates every ramification ot 
 
94 
 
 PREPARATION OP THE PAPER. 
 
 their fibres. In conducting this operation, however, it 
 will be found that the results are sometimes more and 
 sometimes less satisfactory, in consequence of small and 
 accidental variations in the proportions employed. It 
 happens sometimes that the chloride of silver formed on 
 the surface of the paper is disposed to blacken of itself, 
 without any exposure to light. This shows that the at- 
 tempt to give it sensibility has been carried too far. The 
 object is, to approach as nearly to this condition as possi- 
 ble without reaching it ; so that the preparation may be 
 in a state ready to yield to the slightest extraneous force, 
 such as the feeblest effect of light. 
 
 Coopers Method . — Soak the paper in a boiling hot so- 
 lution of chlorate of potash (the strength matters not) for 
 a few minutes; then take it out, dry it, and wet it with 
 a brush, on one side only, dipped in a solution of nitrate 
 of silver, sixty grains to an ounce of distilled water, or, 
 if not required to be so sensitive, thirty grains to the 
 ounce will do. This paper possesses a great advantage 
 over any other, for the image can be fixed by mere wash- 
 ing. It is, however, very apt to become discolored even 
 in the washing, or shortly afterwards, and is, besides, 
 not so sensitive, nor does it become so dark as that made 
 according to Mr. Talbot’s method. 
 
 Daguerreh Method . — Immerse the paper in hydrochlo- 
 ric (or as it is more commonly called, muriatic) ether, 
 w r hich has been kept sufficiently long to become acid; 
 the paper is then carefully and completely dried, as this is 
 essential to its proper preparation. It is then dipped into 
 a solution of nitrate of silver, and dried without artifi- 
 cial heat in a room from which every ray of light is care- 
 fully excluded. By this process it acquires a very re- 
 markable facility in being blackened on a very slight ex- 
 
PREPARATION OF THE PAPER. 
 
 95 
 
 posure to light, even when the latter is by no means in- 
 tense. The paper, however, rapidly loses its extreme 
 sensitiveness to light, and finally becomes no more im- 
 pressionable by the solar beams than common nitrate pa- 
 per. 
 
 Bromide Paper . — Of all common photographic paper, 
 the best, because the least troublesome in making, and 
 the most satisfactory in result, is that which is termed 
 bromine paper, and which is thus prepared : — Dissolve 
 one hundred grains of bromide of potassium in one ounce 
 of distilled water, and soak the paper in this solution. 
 Take off the superfluous moisture, by means of your 
 bibulous paper, and when nearly dry, brush it over on 
 one side only, with a solution of one hundred grains of 
 nitrate of silver to an ounce of distilled water. The 
 paper should then be dried in a dark room, and, if re- 
 quired to be very sensitive, should a second time be 
 brushed over with the nitrate of silver solution. 
 
 In preparing the papers mentioned above, there are 
 two circumstances which require particular attention, 
 [n the first place, it is necessary to mark the paper on 
 the side spread with the solutions of nitrate of silver, 
 near one of the extreme corners. This answers tw'o 
 purposes : in the first place it serves to inform the ex- 
 perimentalist of the sensitive surface; and secondly, it 
 will be a guide as to which portion of the papers has 
 been handled during the application of the solution, as 
 the impress of the fingers will probably come out upon 
 the photograph. The second caution is, that the appli- 
 cation of the sensitive solution (nitrate of silver,) and 
 the subsequent drying of the paper, must be always 
 conducted in a perfectly dark room, the light of a can- 
 dle alone being used. 
 
 5 * 
 
96 
 
 PHOTOGENIC PROCESS ON P^PER. 
 
 III. Photogenic Process on paper. — Method 
 The simplest mode is to procure a flat board and 
 a square of glass, larger in size than the object in- 
 tended to be copied. On the board place the photogra- 
 Fig. 28. 
 
 phic paper with the prepared side upwards, and upon it 
 the object to be copied ; over both lay the glass and se- 
 cure them so that they are in close connection by means 
 of binding screws or clamps, similar to g. g. fig. 28. 
 Should the object to be copied be of unequal thickness, 
 such as a leaf, grass, &e., it will be necessary to place 
 on the board, first, a soft cushion, which may be made 
 of a piece of fine flannel and cotton wool. By this 
 means the object is brought into closer contact with the 
 paper, which is of great consequence, and adds mate- 
 rially to the clearness of the copy. The paper is now 
 exposed to diffused daylight, or, still better, to the di- 
 rect rays of the sun, when that part of the paper not 
 covered by the object will become tinged with a violet 
 color, and if the paper be well prepared, it will in a 
 short time pass to a deep brown or bronze color. It 
 must then be removed, as no advantage will be obtained 
 
PHOTOGENIC PROCESS ON PAPER. 
 
 97 
 
 by keeping it longer exposed ; on the contrary, the de- 
 licate parts yet uncolored will become in some degree af- 
 fected. The photogenic paper will now show a more or 
 less white and distinct representation of the object. The 
 apparatus figured at 28 consists of a wooden frame simi- 
 lar to a picture frame ; a piece of plate glass is fixed in 
 front ; and it is provided with a sliding cover of wood, 
 c., which is removed when the paper is ready to be ex- 
 posed to the action of the light. The back, d ., which 
 is furnished with a cushion, as just described, is made 
 to remove for the purpose of introducing the object to be 
 copied, and upon it the prepared paper ; the back is then 
 replaced, and, by aid of the cross piece and screw, e., 
 the whole is brought into close contact with the glass. 
 
 The objects best delineated on these photographic pa- 
 pers, are lace, feathers, dried plants, particularly the 
 ferns, sea-weeds and the light grasses, impressions of 
 copper plate and wood engravings, particularly if they 
 have considerable contrast of light and shade — (these 
 should be placed with the face downwards, having been 
 previously prepared as hereafter directed) — paintings on 
 glass, etchings, &c. 
 
 To fix the Drawings. — Mr. Talbot recommends that 
 the drawings should be dipped in salt and water, and in 
 many instances this method will succeed, but at times it 
 is equally unsuccessful. Iodide of potassium, or, as it is 
 frequently called, hydriodate of potash, dissolved in wa- 
 ter, and very much diluted, (twenty-five grains to one 
 ounce of water,) is a more useful preparation to wash 
 the drawings with ; it must be used very weak or it will 
 not dissolve the unchanged muriate only, as is intended } 
 but the black oxide also, and the drawing be thereby 
 spoiled. 
 
98 
 
 PHOTOGENIC PROCESS ON PAPER. 
 
 But the most certain material to be used is the hypo- 
 sulphite of soda. One ounce of this salt should be dis- 
 solved in about a pint of distilled water. Having pre- 
 viously washed the drawing in a little lukewarm water, 
 which of itself removes a large portion of the muriate of 
 silvejywhich is to be got rid of, it should be dipped once 
 or twice in the hyposulphite solution. By this operation 
 the muriate which lies upon the lighter parts will be- 
 come so altered in its nature as to be unchanged by light, 
 while the rest remains dark as before. 
 
 It will be evident from the nature of the process, that 
 the lights and shadows of an object are reversed. That 
 which is originally opaque will intercept the light, and 
 consequently those parts of the photogenic paper will be 
 least influenced by light, while any part of the object 
 which is transparent, by admitting the light through it, 
 will suffer the effect to be greater or less in exact propor- 
 tion to its degree of transparency. The object wholly 
 intercepting the light will show a white impression ; in 
 selecting, for example, a butterfly for an object, the in- 
 sect, being more or less transparent, leaves a propor- 
 tionate gradation of light and shade, the most opaque 
 parts showing the whitest. It may be said, therefore, 
 that this is not natural, and in order to obtain a true pic- 
 ture — or, as it is termed, a positive picture — we must 
 place our first acquired photograph upon a second piece 
 of photogenic paper. Before we do this, however, we 
 must render our photograph transparent, otherwise the 
 opacity of the paper will mar our efforts. 
 
 To accomplish this object, the back of the paper con- 
 taining the negative , or first acquired photograph, should 
 be covered with white or virgin wax. This may be done 
 by scraping the wax upon the paper, and then, after 
 
APPLICATION OF PHOTOGENIC DRAWING. 
 
 99 
 
 placing it between two other pieces of paper, passing a 
 heated iron over it. The picture, being thus rendered 
 transparent, should now r be applied to a second piece of 
 photogenic paper, and exposed, in the manner before di- 
 rected, either to diffused day-light or to the direct rays 
 of the sun. The light will now penetrate the white parts, 
 and the second photograph be the reverse of the first, or 
 a true picture of the original. 
 
 Instead of wax, boiled linseed oil— it must be the best 
 and most transparent kind— may be used. The back of 
 the negative photograph should be smeared with the oil, 
 and then placed betw'een sheets of bibulous paper. When 
 dry the paper is highly transparent. 
 
 IV. Application of Photogenic Drawing. — This 
 method of photogenic drawing may be applied to many 
 useful purposes, such as the copying of paintings on 
 glass by the light thrown through them on the prepared 
 paper — Imitations of etchings, which may be accom- 
 plished by covering a piece of glass with a thick coat of 
 white oil paint; when dry, with the point of a needle, 
 lines or scratches are to be made through the white lead 
 ground, so as to lay the glass bare ; then place the glass 
 upon a piece of prepared paper, and expose it to the 
 light. Of course every line will be represented beneath 
 of a black color, and thus an imitation etching will be 
 produced. It is also applicable to the delineation of mi- 
 croscopic objects, architecture, sculpture, landscapes and 
 external nature. 
 
 A novel application of this art has been recently sug- 
 gested, which would doubtless prove useful in very many 
 instances. By rendering the wood used for engravings 
 sensitive to light, impressions may be at once made 
 thereon, without the aid of the artist’s pencil. The pre- 
 
V 
 
 100 APPLICATION OF PHOTOGENIC DRAWING. 
 
 paration of the wood is simply as follows : — Place its 
 face or smooth side downwards, in a plate containing 
 twenty grains of common salt dissolved in an ounce of 
 water ; here let it remain for five minutes, take it out and 
 dry it ; then place it again face downwards in another 
 plate containing sixty grains of nitrate of silver to an 
 ounce of water ; here let it rest one minute, when taken 
 out and dried in the dark it will be fit for use, and will 
 become, on exposure to the light, of a fine brown color. 
 Should it be required more sensitive, it must be im- 
 mersed in each solution a second time, for a few seconds 
 only. It will now be very soon effected by a very dif- 
 fused light. 
 
 This process may be useful to carvers and wood en- 
 gravers ; not only to those who cut the fine objects of ar- 
 tistical design, but still more to those who cut patterns 
 and blocks for lace, muslin, calico-printing, paper hang- 
 ings, etc., as by this means the errors, expense and time 
 of the draughtsman may be wholly saved, and in a mi- 
 nute or two the most elaborate picture or design, or the 
 most complicated machinery, be delineated with the ut- 
 most truth and clearness. 
 
CHAP. IX. 
 
 CALOTYPE AND CHRYSOTYPE. 
 
 The materials and apparatus necessary for the Calotype 
 process are — 
 
 Two or Three Shallow Dishes , for holding distilled 
 water, iodide, potassium, &c. — the same water never 
 being used for two different operations. 
 
 White Bibulous Paper. 
 
 Photogenic Camera — Fig . 9 . 
 
 Pressure Frame — Fig 28 . 
 
 Paper , of the very best quality — directions for the 
 choice of which have been already given. 
 
 A Screen of Yellow Glass. 
 
 Camels ’ or Badgers ’ hair Brushes : — A seperate one 
 being kept for each wash and solution, and which should 
 be thoroughly cleansed immediately after using in dis- 
 tilled water. That used for the gallo-nitrate is soon des- 
 troyed, owing to the rapid decomposition of that pre- 
 paration. 
 
 A Graduated Measure. 
 
 Three or Four Flat Boards , to which the paper may 
 be fixed with drawing pins. 
 
 A Hot Water Drying Apparatus , for drying the paper 
 will also be found useful. 
 
 Iu preparing the Calotype paper, it is necessary to be 
 extremely careful, not only to prevent the daylight from 
 
102 
 
 1H£ CALOTM'E. 
 
 impringing upon it, but also to exclude, if possible, the 
 strong glare of the candle or lamp. This may be effected 
 by using a shade of yellow glass or gauze, which must 
 be placed around the light. Light passing through such 
 a medium will scarcely affect the sensitive compounds, 
 the yellow glass intercepting the chemical rays. 
 
 Preparation of the Iodized Paper . — Dissolve one hun- 
 dred grains of crystalized nitrate of silver in six ounces 
 of distilled water, and having fixed the paper to one of 
 the boards, brush it over with a soft brush on one side 
 only with this solution, a mark being placed on that side 
 whereby it may be known. When nearly dry dip it into 
 a solution of iodide of potassium, containing five hun- 
 dred grains of that salt dissolved in a pint of water. 
 When perfectly saturated with this solution, it should be 
 washed in distilled water, drained and allowed to dry. 
 This is the first part of the process, and the paper so pre- 
 pared is called iodized paper. It should be kept in a 
 port-folio or drawer until required : with this care it may 
 be preserved for any length of time without spoiling or 
 undergoing any change. 
 
 Mr. Cundell finds a stronger solution of nitrate of sil- 
 ver preferable, and employs thirty grains to the ounce of 
 distilled water : he also adds fifty grains of common salt 
 to the iodide of potassium, which he applies to the 
 marked side of the paper only. This is the first pro- 
 cess. 
 
 Preparation of the paper for the Camera. — The second 
 process consists in applying to the above a solution which 
 has been named by Mr. ’Talbot the “ Gallo-Nitrate of 
 Silver;” it is prepared in the following manner: Dis- 
 
 solve one hundred grains of crystalized nitrate of silver 
 in two ounces of distilled water, to which is added two 
 
THE CALOTYPE. 
 
 103 
 
 and two-third drachms of strong acetic acid. This so- 
 lution should be kept in a bottle carefully excluded from 
 the light. Now, make a solution of gallic acid in cold 
 distilled water : the quantity dissolved is very small. 
 When it is required to take a picture, the two liquids 
 above described should be mixed together in equal quan- 
 tities ; but as it speedily undergoes decomposition, and 
 will not keep good for many minutes, only just sufficient 
 for the time should be prepared, and that used without 
 delay. It is also well not to make much of the gallic 
 acid solution, as it will not keep for more than a few 
 days without spoiling. A sheet of the iodized paper 
 should be washed over with a brush with this mixed so- 
 lution, care being taken that it be applied to the marked 
 side. This operation must be performed by candle light. 
 Let the paper rest half a minute, then dip it into one of 
 the dishes of water, passing it beneath the surface seve- 
 ral times ; it is now allowed to drain, and dried by 
 placing its marked side upward, on the drying appara- 
 tus. It is better not to touch the surface with bibulous 
 paper. It is now highly sensitive, and ready to receive 
 the impression. In practice it is found better and more 
 economical not to mix the nitrate of silver and gallic 
 acid, but only to brush the paper with the solution of the 
 nitrate. 
 
 Mr. Talbot has recently proposed some modifications in 
 his method of preparing the calotype paper. The paper 
 is first iodized in the usual way ; it is then washed over 
 with a saturated solution of gallic acid in distilled water 
 and dried. Thus prepared he calls it theio-gallic paper: 
 it will remain good for a considerable time if kept in a 
 press or portfolio. When required for use, it is washed 
 with a solution of nitrate of silver (fifty grains to the 
 
104 
 
 THE CALOTYPE. 
 
 ounce of distilled water), and it is then fit for the ca- 
 mera. 
 
 Exposure in the Camera . — The calotype paper thus 
 prepared possesses a very high degree of sensibility when 
 exposed to light, and we are thus provided with a me- 
 dium by which, with the aid of the photogenic camera, 
 we may effectually copy views from nature, figures, 
 buildings, and even take portraits from the shadows 
 thrown on the paper by the living face. The paper may 
 be used somewhat damp. 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 fiat surface, as a piece oi 
 smooth slate or an iron plate, which latter, if made 
 warm, renders the paper more sensitive, and consequently 
 the picture is obtained more rapidly. 
 
 Time of Exposure . — With regard to the time which 
 should be allowed for the paper to remain in the camera, 
 no direct rules can be laid down ; this will depend alto- 
 gether upon the nature of the object to be copied, and 
 the light which prevails. All that can be said is, that 
 the time necessary for forming a good picture varies from 
 thirty seconds to five minutes, and it will be naturally 
 the first object of the operator to gain by experience this 
 important knowledge. 
 
 Bringing Out the Picture . — The paper when taken 
 from the camera, which should be done so as to exclude 
 every ray of light — and here the dark slide of the ca- 
 mera plate holder becomes of great use — bears no resem- 
 blance to the picture which in reality is formed. The 
 impression is latent and invisible, and its existence would 
 not be suspected by any one not acquainted with the 
 process by previous experiment. The method of bring- 
 ing out the image is very simple. It consists in wash- 
 
THE C ALOTYPE' 
 
 105 
 
 ing the paper with the gallo-nitrate of silver , prepared in 
 the way already described, and then warming it gently, 
 being careful at the same time not to let any portion be- 
 come perfectly dry. In a few seconds the part of the 
 paper upon which the light has acted will begin to darken, 
 and finally grow entirely black, while the other parts re- 
 tain their original color. Even a weak impression may 
 be brought out by again washing the paper in the gallo- 
 nitrate, and once more gently warming it. When the 
 paper is quite black, as is generally the case, it is a 
 highly curious and beautiful phenomenon to witness the 
 commencement of the picture, first tracing out the 
 stronger outlines, and then gradually filling up all the 
 numerous and complicated details. The artist should 
 watch the picture as it developes itself, and when in his 
 judgment it has attained the greatest degree of strength 
 and clearness, he shall stop further proceedings by wash- 
 ing it with the fixing liquid. Here again the mixed so- 
 lution need not be used, but the picture simply brushed 
 over with the gallic acid. 
 
 The Fixing Process. — In order to fix the picture thus 
 obtained, first dip it into water; then partly dry it with 
 bibulous paper, 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 water. The 
 picture is again washed with distilled water, and then 
 finally dried. Instead of bromide of potassium, a solu- 
 tion of hyposulphite of soda, as before directed, may be 
 used with equal advantage. 
 
 The Original calotype picture, like the photographic 
 one described in the last chapter, is negative, that is to 
 Say, it has its lights and shades reversed, giving the 
 A r hole an appearance not conformable to nature. But it 
 
106 
 
 THE CALOTYPE. 
 
 is easy from this picture to obtain another which shall be 
 conformable to nature ; viz., in which the lights shall be 
 represented by lights, and the shades by shades. It is 
 onty necessary to take a sheet of photographic paper 
 (the bromide paper is the best), and place it in contact 
 with a calotype picture previously rendered transparent 
 by wax or oil as before directed. Fix it in the frame, 
 Fig. 28 , expose it in the sunshine for a short time, and 
 an image or copy will be formed on the photogenic paper. 
 The calotype paper itself may be used to take the second, 
 or positive, picture, but this Mr. Talbot does not recom- 
 mend, for although it takes a much longer time to take a 
 copy on the photogenic paper, yet the tints of such copy 
 are generally more harmonious and agreeable. After a 
 calotype picture has furnished a number of copies it some- 
 times grows faint, and the subsequent copies are inferior. 
 This may be prevented by means of a process which re- 
 vives the strength of the calotype pictures. In order to 
 do this, it is only nesessary to wash them by candle-light 
 with gallo-nitrate of silver, and then warm them. This 
 causes all the shades of the picture to darken considerably, 
 while the white parts are unaffected. After this the pic- 
 ture is of course to be fixed a second time. It will then 
 yield a second series of copies, and, in this way, a great 
 number may frequently be made. 
 
 The calotype pictures when prepared as we have stated, 
 possess a yellowish tint, which impedes the process 
 taking copies from them. In order to remedy this defect, 
 Mr. Talbot has devised the following method. The ca- 
 lotype picture is plunged into a solution consisting of hy- 
 posulphite of soda dissolved in about ten times its weight 
 of water, and heated nearly to the boiling point. The 
 picture should remain in about ten minutes ; it must then 
 
THE CALOTYPE. 
 
 107 
 
 be removed, washed and dried. By this process the 
 picture is rendered more transparent, and its lights be- 
 come whiter. It is also rendered exceedingly permanent 
 After this process the picture may be waxed, and thus 
 its transparency increased. This process is applicable to 
 all photographic papers prepared with solutions of silver. 
 
 Having thus fully, and it is hoped clearly, considered 
 the process, it may be necessary before dismissing the 
 ealotype from notice, to add one or two remarks from the 
 observations and labors of some who have experimented 
 in this art. Dr. Ryan in his lectures before the Royal 
 Polytechnic Institution, has observed, that in the iodi- 
 zing process the sensitiveness of the paper is materially 
 injured by keeping it too long in the solution of iodide of 
 potassium, owing to the newly formed iodide of silver 
 being so exceedingly solvable in excess of iodide of po- 
 tassium as in a few minutes to be completely removed. 
 The paper should he dipped in the solution and instantly 
 removed. There is another point, too, in the preparation of 
 the iodized paper in which suggestions for a slight deviation 
 from Mr. Talbot’s plan have been made. In the first im 
 startce, it is recommended that the paper be brushed over 
 with the iodide of potassium, instead of the nitrate of 
 silver, transposing, in fact, the application of the first 
 two solutions. The paper, having been brushed over 
 with the iodide of potassium in solution, is washed in 
 distilled water and dried. It is then brushed over with 
 nitrate of silver, and after drying is dipped for a moment 
 in a fresh solution of iodide of potassium of only one- 
 fourth the strength of the first, that is to say, one hun- 
 dred and twenty-five grains of the salt to a pint of water.- 
 After this it is again washed and dried. The advantage 
 derived from this method, is a more sensitive paper, and 
 
108 
 
 THE CALOTYPE. 
 
 a more even distribution of the compounds over the sur- 
 face. 
 
 Another deviation from Mr. Talbot’s method has been 
 suggested, as follows : 
 
 Brush the paper over with a solution of one hundred 
 grains of nitrate of silver to an ounce of water. When 
 nearly, but not quite, dry, dip it into a solution of twenty- 
 five grains of iodide of potassium to one ounce of distilled 
 water, drain it, wash it in distilled water and again drain 
 it. Now brush it over with aceto-nitrate of silver, made 
 by dissolving fifty grains of nitrate of silver in one ounce 
 of distilled water, to which is added one sixth of its vo- 
 lume of strong acetic acid. Dry it with bibulous paper, 
 and it is ready for receiving the image. When the im- 
 pression has been received, which will require from one 
 to five minutes according to the state of the weather, it 
 must be washed with a saturated solution of gallic acid 
 to which a few drops of the aceto-nitrate of silver, made 
 as above, have been added. The image will thus be 
 gradually brought out, and may be fixed with hyposul- 
 phite of soda. To obtain the positive picture, paper 
 must be used brushed over with an ammonio-nitrate of 
 silver, made thus : forty grains of nitrate of silver is to be 
 dissolved in one ounce of distilled water, *and liquid am- 
 monia cautiously added till it re-dissolves the precipitate. 
 
 A pleasing effect may be given to calotype, or indeed 
 to all photographic pictures, by waxing them at the back, 
 and mounting them on white paper, or if colored paper 
 be used, various beautiful tones of color are produced 
 
 POSITIVE CALOTYPE. 
 
 At a meeting of the British Association, Professor 
 Grove described a process by which positive calotvp 
 
POSITIVE CALOTYPE. 
 
 109 
 
 pictures could be directly obtained ; and thus the neces- 
 sity to transfer by which the imperfections of the paper 
 are snown, and which is moreover a troublesome and 
 tedious process, is avoided. As light favors most chem- 
 ical actions, Mr. Grove was led to believe that a paper 
 darkened by the sun (which darkening is supposed to re- 
 sult from the precipitation of silver) might be bleached 
 by using a solvent which would not attack the silver in 
 the dark, but would do so in the light. The plan found 
 to be the most successful is as follows : ordinary calotype 
 paper is darkened till it assumes a deep brown color, 
 almost amounting to black ; it is then redipped into the 
 ordinary solution of iodide of potassium, and dried. When 
 required for use it is drawn over dilute nitric acid — one part 
 acid to two and a half parts water. In this state, those 
 parts exposed to the light are rapidly bleached, while the 
 parts not exposed remain unchanged. Itis fixed by wash- 
 ing in water, and subsequently in hyposulphite of soda, 
 or bromide of potassium. 
 
 Mr. Grove also describes a process for converting 
 a negative calotype into a positive one, which promises, 
 when carried out, to be of great utility. 
 
 Let an ordinary calotype image or portrait be taken in 
 the camera, and developed 1 by gallic acid ; then drawn 
 over iodide of potassium and dilute nitric acid and ex- 
 posed to full sunshine ; while bleaching the dark parts, 
 the light is redarkening the newly precipitated iodide in 
 the lighter portions and thus the negative picture is con- 
 vened into a positive one. 
 
 The calotype process has been applied to the art of 
 printing, in England, but it possesses no advantages 
 whatever over the method, with type, now so gloriously 
 brougnl to perfection ; and I can hardly think it will 
 
no 
 
 CHRYSOTYPE. 
 
 ever oe made of any utility. For the benefit of the cu- 
 rious, however, I will give Mr. Talbot’s method. 
 
 Some pages of letter-press are taken printed on one 
 side only; and waxed, to render them more transparent ; 
 the letters are then cut out and sorted. To compose a 
 new page lines are ruled on a sheet of white paper, and 
 the words are formed by fixing the separate letters in their 
 proper order. The page being ready, a negative photo- 
 graph is produced from it, from which the requisite num- 
 ber of positive photogenic copies may be obtained. 
 
 Another method, which requires the use of the came- 
 ra, consists in employing large letters painted on rectan- 
 gular pieces of wood, colored white. These are arranged 
 in lines on a tablet or board, by slipping them into grooves 
 which keep them steady and upright, thus forming a 
 page on an enlarged scale. It is now placed before a 
 camera, and a reduced image of it of the required size is 
 thrown upon the sensitive paper. The adjustments must 
 be kept invariable, so that the consecutive pages may not 
 vary from one another in the size of the type. Mr. Tal- 
 bot has patented his process, but what benefit he expects 
 to derive from it, I am at a loss to determine 
 
 Enlarged copies of calotype or Daguerreotype portraits 
 may be obtained by throwing magnified images of them, 
 
 by means of lenses, upon calot3^pe paper. 
 
 * 
 
 THE CHRYSOTYPE. 
 
 A modification of Mr. Talbot’s process, to which the 
 name of Chrysotype was given by its discoverer, Sir 
 John Herschel, was communicated in June 1843 to the 
 Royal Society, by that distinguished philosopher. This 
 modification would appear to unite the simplicity of pho- 
 tography with all the distinctness and clearness of calo- 
 type. This preparation is as follows. 
 
CHRYSOTYPE. 
 
 Ill 
 
 The paper is to be washed in a solution of ammonio- 
 citrate of iron; it must then be dried, and subsequently 
 brushed over with a solution of the ferro-sesquicyanuret 
 of potassium. This paper, when dried in a perfectly 
 dark room, is ready for use in the same manner as if 
 otherwise prepared, the image being subsequently brought 
 out by any neutral solution of gold. Such was the first 
 declaration of his discovery, but he has since found that 
 a neutral solution of silver is equally useful in bringing 
 out the picture. Photographic pictures taken on this 
 paper are distinguished by a clearness of outline foreign 
 to all other method:. 
 
 PICTURES ON GLASS. 
 
 Messrs. Langenheim, of Philadelphia, having made some 
 noise in regard to the taking of photographic pictures on 
 glass, and claiming the exclusive use by right of inven- 
 tion, I deem it proper to give the method of M. Evrard, 
 of Lille, France, which, not being patented in this 
 country, is free to all. M. Evrard’s process is as follows : 
 
 “ The principle of the discovery is a matrix of albumen, 
 rendered sensible to the action of light by aceto-nitrate of 
 silver, and spread in a thin layer on a plate of glass. — 
 The process, is to take a certain number of the white of 
 eggs, and remove all the non-transparent part, and then 
 add a few drops of a saturated solution of iodate of potas- 
 sium ; then beat the eggs into froth, and allow it to settle. 
 The plate of glass is well cleaned with alcohol, and the 
 albumen is then spread over the glass in a thin layer with 
 another piece of glass. The glass must have a perfect 
 thin coat adhering to it, when it is hung up by one of the 
 corners to drain off the excess. The glass is then placed 
 flat upon a level board, screened from dust, and allowed to 
 
112 
 
 PICTURES ON Gt ASS. 
 
 dry. When dry, it is submitted to a good heat, but not 
 so much that the albumen will peel of. ‘After this, the 
 glass is dipped into a solution of aceto-nitrate of silver, 
 face downwards, after which it is removed and immersed 
 in a basin of clean water, being stirred in it for a few 
 seconds, then taken out, held up by a corner, and is 
 completely sensitive, moist or dry, to receive photographic 
 impressions. It is then placed in the camera obscura, 
 after which it is dipped in a bath of galic acid, to which 
 is added a little of aceto-nitrate of silver. Care is taken 
 not to let the glass remain too long in this. After being 
 dipped in the galic acid, it is washed in water, and then 
 immersed in a solution of the bromide of potassium, (20 
 parts to 100 of water,) after which it is carefully and well 
 washed in water, and left to dry in a horizontal position 
 in a dark room. 
 
CHAP. X. 
 
 GYANOTYPE— ENERGIATY^E CHROMATYPE ANTHOTYPE— 
 
 AMPHITYPE AND U CRAYON DAGUERREOTYPE . V 
 
 The several processes enumerated at the head of this 
 chapter, are all discoveries of English philosophers, with 
 the exception of the third and last named. Anthotype was 
 first attempted by M. Ponton a French savan, although it 
 was reserved to Mr. Hunt to bring the process to its pre- 
 sent state. The u Crayon Daguerreotype ” is an im- 
 provement made by J. A Whipple, Esq., ©f Boston 
 
 I. CYANOTYPE ; 
 
 So called from the circumstance of cyanogen in its 
 combinations with iron performing a leading part in the 
 process. It was discovered by Sir John Herschel. The 
 process is a simple one, and the resulting pictures are 
 blue. 
 
 Brush the paper over with a solution of the ammonio- 
 citrate of iron. This solution should be sufficiently 
 strong to resemble sherry wine in color. Expose the 
 paper in the usual way, and pass over , it very sparing- 
 ly and evenly a wash of the common yellow ferro^cyanate 
 of potass. As soon as the liquid is applied, the negative 
 picture vanishes, and is replaced by a positive one, of a 
 violet blue color, on a greenish yellow ground, which at 
 a certain time possesses a high degree of sharpness, and 
 singular beauty of tint. 
 
114 
 
 CYANOTYPE. 
 
 A curious process was discovered by Sir John Hers- 
 chel^by which dormant pictures are produced capable ot 
 developement by the breath, or by keeping in a moist at- 
 mosphere. It is as follows. 
 
 If nitrate of silver, specific gravity 1.200 be added to 
 ferro-tartaric acid, specific gravity 1.023, a precipitate 
 falls, which is in a great measure redissolved by a gentle 
 heat, leaving a black sediment, which, being cleared by 
 subsidence, a liquid of a pale yellow color is obtained, in 
 which the further addition of the nitrate causes no tur- 
 bidness. When the total quantity of the nitrated solu- 
 tion added amounts to about half the bulk of the ferro- 
 tartaric acid, it is enough. The liquid so 'prepared does 
 not alter if kept in the dark. Spread on paper, and ex- 
 posed wet to the sunshine (partly shaded) *for a few se- 
 conds, no’impression seems to be made, but by degrees, 
 although withdrawn from the action of light, it developes 
 itself spontaneously, and at length becomes very intense. 
 But if the paper be thoroughly dried in the dark, (in 
 which state it is of a very pale greenish yellow color,) it 
 possesses the singular property of receiving a dormant or 
 invisible picture, to produce which from thirty to sixty 
 seconds’ exposure to sunshine is requisite. It should not 
 i,e exposed too long, as not only is the ultimate effect 
 less striking, but a picture begins to be 'visibly produced, 
 which darkens spontaneously after it is withdrawn. But 
 if the exposure be discontinued before this effect comes 
 on, an invisible impression is the result, to develope which 
 all that is necessary is to breathe upon it, when it im- 
 mediately appears, and very speedily acquires an extra- 
 ordinary intensity and sharpness, as if by magic. Instead 
 of the breath, it may be subject to the regular action of 
 aqueous vapor, by laying it in a blotting paper book, of 
 
ENERGIATYPE. 
 
 115 
 
 which some of tne outer leaves on both sides have been 
 . dampened, or by holding over warm water. 
 
 II. ENERGIATYPE. 
 
 Under this title a process has been brought forward by 
 Mr. Hunt. It consists of the application of a solution of 
 succinic acid to paper, which is subsequently washed 
 over with nitrate of silver. The image is then to be 
 taken either in the camera or otherwise, as required, and 
 is brought out by the application of the sulphate of iron 
 in solution. Although this process has not come into 
 general use, its exact description may be interesting to 
 the general reader, and we therefore subjoin it. 
 
 The solution with which the paper is first washed is 
 to be prepared as follows : succinic acid, two drachms ; 
 common salt, five grains ; mucilage of gum arabic, half 
 a fluid drachm ; distilled water, one fluid drachm and a 
 half. When the paper is nearly dr} 7- , it is to be brushed 
 over with a solution of nitrate of silver, containing a 
 drachm of the salt, to an ounce of distilled water. It is 
 now ready for exposure in the camera. 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 arabic. 
 
 Subsequently, however, it has been found that the 
 sulphate of iron produces upon all the salts of silver ef- 
 fects quite as beautiful as in the succinate. On the io- 
 dide, bromide, acetate, and benzoate, the effects are far 
 more pleasing and striking. When pictures are pro- 
 duced, or the dormant camera image brought out, by the 
 agency of sulphate of iron, it is remarkable how rapidly 
 the effect takes place. Engravings can be thus copied 
 almost instantaneous^, and camera views obtained in one 
 
116 
 
 CHROMATYPE. 
 
 or two minutes on almost any preparation of silver. The 
 common sulphate of copper solution has the same pro- 
 perty. * 
 
 III. CHROMATYPE. 
 
 Many efforts have been made to render chromatic acid 
 an active agent in the production of photographs. M. 
 Ponton used a paper saturated with bichromate of potash, 
 and this was one of the earliest photogenic processes. 
 M. Becquerel improved upon this process by sizing the 
 paper with starch previous to the application of the bi- 
 chromate of potash solution, which enabled him to con- 
 vert the negative picture into a positive one, by the use 
 of a solution of iodine, which combined with that por- 
 tion of the starch on which the light had not acted. But 
 by neither of these processes could clear and distinct 
 pictures be fortned. Mr. Hunt has, however, disco- 
 vered a process which is so exceedingly simple, and the 
 resulting pictures of so pleasing a character, that, al- 
 though it is not sufficiently sensitive for use in the ca- 
 mera, it will be found of the greatest value for copying 
 botanical specimens, engravings, or the like. 
 
 The paper, to be prepared is washed over with a solu- 
 tion of sulphate of copper — about one drachm to an 
 ounce of water — and partially dried ; it is then washed 
 with a moderately strong solution of bichromate of pot- 
 *ash, and dried at a little distance from the fire. Paper 
 thus prepared may be kept any length of time, in a port- 
 folio, and are always ready for' use. 
 
 When exposed to the sunshine for a time, varying 
 with the intensity of the light, from five to fifteen or 
 twenty minutes, the result is generally a negative pic- 
 ture. It is now to be washed over with a solution of ni- 
 trate of silver, which immediately produces a very beau- 
 
ANTHOTYPE. 
 
 117 
 
 tiful deep orange picture upon a light dim colored, or 
 sometimes perfectly white ground. This picture must 
 be quickly fixed, by being washed in pure water, and 
 dried. With regard to the strength of the solutions, it 
 is a remarkable fact, that, if saturated solutions be em- 
 ployed, a negative picture is first produced, but if the 
 solutions be three or four times their bulk of water, the 
 first action of the sun’s rays darkens the picture, and 
 then a very bleaching effect follows, giving an exceed- 
 ingly faint positive picture, which is brought out with 
 great delicacy by the silver solution. 
 
 It is necessary that pure water should be used for the 
 fixing, as the presence of any muriate damages the pic- 
 ture, and here arises another pleasing variation of the 
 Chromatype. If the positive picture be placed in a very 
 weak solution of common salt the image slowly fades out, 
 leaving a faint negative outline. If it now be removed 
 from the saline solution, dried, and again exposed to 
 sunshine, a positive picture of a lilac color will be pro- 
 duced by a few minutes exposure. Several other of the 
 chromates may be used in this process, but none is so 
 successful as the chromate of copper. 
 
 IV. ANTHOTYPE. 
 
 The expressed juice, alcholic, or watery infusion of 
 flowers, or vegetable substances, may be made the media 
 of photogenic action. This fact was first discovered by 
 Sir John Herschel. We have already given a few ex- 
 amples of this in the third chapter. 
 
 Certain precautions are necessary in extracting the co- 
 loring matter of flowers. The petals of fresh flowers are 
 carefully selected, and crushed to a pulp in a marble mor- 
 tar, either alone or with the addition of a little alcohol, 
 and the juice expressed by squeezing the pulp in a clean 
 
118 
 
 ANTHOTYPE. 
 
 linen or cotton cloth. It is then to be spread upon paper 
 with a flat brush, and dried in the air without artificial 
 heat. If alcohol be not added, the application on paper 
 must be performed immediately, as the air (even in a 
 few minutes), irrecoverably changes or destroys their 
 color. If alcohol be present this change is much retard- 
 ed, and in some cases is entirely prevented. 
 
 Most flowers give out their coloring matter to alcohol 
 or water. Some, however, refuse to do so, and require 
 the addition of alkalies, others of acid, &c. Alcohol 
 has, however, been found to enfeeble, and in many cases 
 to discharge altogether these colors ; but they are, in 
 most cases, restored upon drying, when spread over pa- 
 per. Tapers tinged with vetegable colors must always 
 be kept in the dark, and perfectly dry. 
 
 The color of a flower is by no means always, or 
 usually, that which its expressed juice imparts to white 
 paper. Sir John Herschel attributes these changes lothe 
 escape of carbonic acid in some cases ; to a chemical al- 
 teration, depending upon the absorption of oxygen, in 
 others; and again in others, especially where the ex- 
 pressed juice coagulates on standing, to a loss of vitality, 
 or disorganization of the molecules. To secure an 
 eveness of tint on paper, the following manipulation is 
 recommended: — The paper should be moistened on the 
 back by sponging and blotting off: It should then be 
 
 pinned on a board, the moist side downwards, so that 
 two of its edges (suppose the right-hand and lower ones) 
 shall project a little beyond those of the board. The 
 board then being inclined twenty or thirty degrees to the 
 horizon, the alcoholic tincture (mixed with a very little 
 water, if the petals themselves be not very juicy) is to 
 be applied with a brush in strokes from left to right, 
 
ANTHOTYPE. 
 
 119 
 
 taking care not to go over the edges which rest on the 
 board ; but to pass clearly over those that project ; and 
 observing also to carry the tint from below upwards by 
 quick sweeping strokes, leaving no dry spaces between 
 them, but keeping up a continuity of wet spaces. When 
 all is wet, cross them by another set of strokes from 
 above downwards, so managing the brush as to leave no 
 floating liquid on the paper. It must then be dried as 
 quickly as possible over a stove, or in a warm current of 
 air, avoiding, however, such heat as may injure the 
 tint. 
 
 In addition to the flowers already mentioned in my 
 third chapter, the following are among those experiment- 
 ed upon and found to give tolerable good photographic 
 sensitives. I can only enumerate them, referring the 
 student, for any further information he may desire on the 
 isubject, to Mr. Hunt’s work ; although what I have said 
 above is sufficient for all practical purposes ; and any 
 one, with the ambition, can readily experiment upon 
 them, without further research, on any other flower he 
 may choose. 
 
 Viola Odorata — or sweet sented violet, yields to alco- 
 hol a rich blue color, which it imparts in high perfec- 
 tion to paper 
 
 Senecio Splendens — or double purple groundsel, yields 
 a beautiful color to paper. 
 
 The leaves of the laurel, common cabbage, and the 
 grasses, are found sufficiently senstive. 
 
 Common Merngold yields an invaluable feecula, which 
 appears identical with that produced by the Wall-flower, 
 and Cochorus japonica mentioned before, and is very 
 sensitive, but photographs procured upon it cannot be 
 preserved, the color is so fugitive. 
 
1-20 
 
 AMPHITYPE 
 
 From an examination of the researches of Sir John 
 Herschel on the coloring matter of plants, it will be 
 seen that the action of the sun’s rays is to destroy the 
 color, effecting a sort of chromatic analysis, in which 
 two distinct elements of color are separated, by destroy- 
 ing the one and leaving the other outstanding. The ac- 
 tion is confined within the visible spectrum, and thus a 
 broad distinction is exhibited between the action of the 
 sun’s rays on vegetable juices and on argentine com- 
 pounds, the latter being most sensibly affected by the in- 
 visible rays beyond the violet. 
 
 It may also be observed, that the rays effective in des- 
 troying a given tint, are in a great many cases, those 
 whose union produces a color complimentary to the tint 
 destroyed, or, at least, one belonging to that class of co- , 
 lors to which such complementary tint may be preferred. 
 For instance, yellows tending towards orange are de- 
 stroyed with more energy by the blue rays ; blues by the 
 red, orange and yellow rays ; purples and pinks by yel- 
 low and green rays. 
 
 V. AMPHITYPE. 
 
 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 process. 
 The positive pictures obtained by it have a perfect resem- 
 blance to impressions of engravings with common prin- 
 ter’s ink. The process, although not yet fully carried 
 out, promises to be of vast utility. 
 
 Paper proper for producing an amphitype picture may 
 be prepared either with the ferro-tartrate or the ferro-ci- 
 trate of the protoxide, or the peroxide of mercury, or of 
 the protoxide of lead, by using creams of these salts, or 
 by successive applications of the nitrates of the respec- 
 
AMPHITYPE. 
 
 121 
 
 tive oxides, singly or in mixture, to the paper, alterna- 
 ting with solutions of the ammonia-tartrate or the ammo- 
 nia-citrate of iron, the latter solution being last applied, 
 and in more or less excess I purposely avoid stating 
 proportions, as I have not yet been able to fix upon any 
 which certainly succeed. Paper so prepared and dried 
 takes a negative picture, in a time varying from half an 
 hour to five or six hours, according to the intensity of 
 the light ; 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 detail, the color being in this case a superb velvety 
 brown. This extreme richness of effect is not produced 
 unless lead be present, either in the ingredients used, or 
 in the paper itself. It is not, as 1 originally sup- 
 posed, due to the presence of free tartaric acid. 
 The pictures in this state are not permanent. They fade 
 in the dark, though with very different degrees of rapidity, 
 some (especially if free tartaric or citric acid be present) 
 in a few days, while others remain for weeks unimpaired, 
 and require whole years for their total obliteration. But 
 though entirely faded out in appearance, the picture is 
 only rendered dormant, and may be restored, changing 
 its character from negative to positive, and its colors from 
 brown to black, (in the shadows), by the following pro- 
 cess : — A bath being prepared by pouring a small quan 
 tity ol solution of pernitrate of mercury into a large 
 quantity of water, and letting the subnitrated precipitates 
 subside, the picture may be immersed in it, (carefully 
 and repeatedly clearing off all air bubbles,) and allowed 
 to remain till the picture (if any where visible,) is en- 
 tirely destroyed ; or if faded, till it is judged sufficient 
 from previous experience ; a term which is often marked 
 
122 
 
 AMPHITYFE. 
 
 by the appearance of a feeble positive picture, of a bright 
 yellow hue, on the pale yellow ground of the paper. A 
 long time (several weeks) is often required for this, but 
 heat accelerates the action, and it is often completed in a 
 few hours. In this state the picture is to be very tho- 
 roughly rinsed and soaked in pure warm water, and* then 
 dried. It is then to be well ironed with a smooth iron, 
 heated so as barely not to injure the paper, placing it, for 
 greater security against scorching, between clean smooth 
 paper. If then the process have been successful, a per- 
 fectly black positive picture is at once developed. At 
 first it most commonly happens that the whole picture is 
 sooty or dingy to such a degree that it is condemned as 
 spoiled, but on keeping it between the leaves of a book, 
 especially in a moist atmosphere, by extremely slow de- 
 grees this dinginess disappears, and the picture disen- 
 gages itself with continual^ increasing sharpness and 
 clearness, and acquires the exact effect of a copper-plate 
 engraving on a paper more or less tinted with a pale yel- 
 low. 
 
 I ought to observe, that the best and most uniform spe- 
 cimens which I have procured have been on paper pre- 
 viously washed with certain preparations of uric’acid, 
 which is a very remarkable and powerful photographic 
 element. The intensity of the original negative picture 
 is no criterion of what may be expected in the positive 
 It is from the production by one and the same action of 
 light, of either a positive or negative picture according 
 to the subsequent manipulations, that I have designated 
 the process, thus generally sketched out, by the term 
 Amphitype , — a name suggested by Mr. Talbot, to whom 
 I communicated this singular result ; and to this process 
 or class of processes (which I cannot doubt when pur- 
 
AMPHITYPE. 
 
 123 
 
 sued will lead to some very beautiful results,) I propose 
 to restrict the name in question, though it applies even 
 more appropriately to the following exceedingly curious 
 and remarkable one, in which silver is concerned : 
 
 At the last meeting 1 announced a mode of producing, 
 by means of a solution of silver, in conjunction with 
 ferro-tartaric acid, a dormant picture brought into a for- 
 cible negative impression by the breath or moist air. ( See 
 Cyanotype.) The solution then described, and which 
 had at that time been prepared some weeks, I may here 
 incidentally remark, has retained its limpidity and photo- 
 genic properties, quite unimpaired during the whole year 
 since elapsed, and is now as sensitive as ever, — a property 
 of no small value. Now, when a picture (for example 
 an impression from an engraving) is taken on paper 
 washed w r ith this solution, it shows no sign of a picture 
 on its back, whether that on its face is developed or not,; 
 but if, while the actinic influence is still fresh upon the 
 face, (i.e.y as soon as it is removed from the light) , the 
 hack be exposed for a very few seconds to the sunshine, 
 and then removed to a gloomy place, a positive picture , 
 the exact complement of the negative one on the other side , 
 though wanting of course in sharpness if the paper be 
 thick, slowly and gradually makes its appearance there, 
 and in half an hour or an hour acquires a considerable in- 
 tensity. I ought to mention that the u ferro-tartaric 
 acid” in question is prepared by precipitating the ferro- 
 tartrate of ammonia (ammonia-tartrate of iron) by ace- 
 tate of lead, and decomposing the precipitate by dilute 
 sulphuric acid. When lead is used in the preparation 
 of Amphitype paper, the parts upon which the light has 
 acted are found to be in a very high degree rendered wa- 
 ter proof . — Sir J. Herschcl 
 
124 
 
 CRAYON DAGUERREOTYPE. 
 
 This process is a new invention of our countryman, 
 J. A. Whipple, Esq., of Boston, and has been patented 
 by M. A. Root, Esq., of Philadelphia. It will be seen, 
 however, from the previous pages of my work that Mr. 
 Root is mistaken in regard to his being the first improve- 
 ment patented in this country, althongh it is unquestion- 
 ably the first by an American. Of this improvement 
 Mr. Root says : 
 
 VI. U CRAYON DAGUERREOTYPE.” 
 
 u The improvement to which you refer is denominated 
 u The Crayon Daguerreotype.” This invention made by 
 Mr. J. A. Whipple, is the only improvement in Daguer- 
 reotyping, I believe, for which Letters Patent for the 
 United States were ever issued. The pictures produced 
 by this process — which is of the simplest description 
 imaginable — have the appearance and effect of very fine 
 “ Crayon Drawings,” from which the improvement takes 
 its name. Some of our most distinguished artists have 
 given it their unqualified admiration. Among them, our 
 Mezzotinto Engravers, especially John Sartain, Esq., 
 who, from his rich embellishments to most of the leading 
 Magazines and Annuals of the country, as well as from 
 the celebrity of the superb Magazine w r hich bears his 
 name, is so well known and so well qualified to judge of 
 its merits. As an auxiliary to the artist, in furnishing 
 heads to the Magazines, or other works, it is invaluable; 
 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 to, and 
 confined to the head.” 
 
 “ 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 furnish. The New England 
 
CRAYON DAGUERREOTYPE. 
 
 125 
 
 States have been disposed of ; negotiations for any of the 
 others can be made through M. A. Root, 140 Chestnut 
 street, Philadelphia.” 
 
 “ A series of beautiful portraits are about being pre- 
 pared by the u Crayon Process” for the express purpose 
 of being placed on the exhibition at the “ Art UniqpiS' 
 when amateurs, artists; and the public generally will 
 have an opportunity of witnessing its effect. We are es- 
 pecially gratified with this striking improvement, from 
 the advantages which it promises to the Daguerrean art.” 
 
 “ It is admirably designed to excite a new interest on 
 the subject through the community, and in this way — and 
 from its tendency to render the art more generally useful, 
 and to elevate and distinguish it— -to make it to all a mat- 
 ter of more general importance.” 
 
 “ Yours respectfully, 
 
 u M. A. Root.” 
 
 In our second edition, we hope— with Mr. Root’s per- 
 mission— to lay the whole prO'cess before the public, al- 
 though our artists must bear in mind that Mr. Root’s pa- 
 tent secures to him the exclusive right of its application. 
 
CHAP. XI. 
 
 ON THE PROBABILITY OF PRODUCING COLORED PICTURES 
 BY THE SOLAR RADIATIONS PHOTOGRAPHIC DEVIA- 
 TIONS LUNAR PICTURES DRUMMOND LIGHT. 
 
 Having before noticed the fact that some advances had 
 been made towards taking Daguerreotypes in color, by 
 means of solar rays, and expressed the hope that the day 
 was not far distant when this might be accomplished, I 
 here subjoin Mr. Hunt’s remarks on this subject. 
 
 Mr. Biot, in 1840, speaking of Mr. Fox Talbot’s 
 beautiful calotype pictures, considers as an illusion “ the 
 hope to reconcile, not only the intensity but the tints of 
 the chemical impressions produced by radiations, with 
 the colors of the object from which these radiations ema- 
 nated.” It is true that three years have passed away, and 
 we have not yet produced colored images; yet I am not 
 inclined to consider the hope as entirely illusive. 
 
 It must be remembered that the color of bodies de- 
 pends entirely upon the arrangement of their molecules. 
 We have numerous very beautiful experiments in proof of 
 this. The bi-niodide of mercury is a fine scarlet when 
 precipitated. If this precipitate is heated between plates 
 of glass, it is converted into crystals of a fine sulphur 
 yellow, which remain of that color if undisturbed, but 
 which becomes very speedily scarlet if touched with any 
 pointed instrument. This very curious optical phenome- 
 
128 ON PRODUCING COLORED PICTURES. 
 
 na has been investigated by Mr. Talbot and by Mr. War- 
 rington. Perfectly dry sulphate of copper is white ; the 
 slightest moisture turns it blue. Muriate of cobalt is of 
 a pale pink color; a very slight heat, by removing a lit- 
 tle moisture, changes it to a green. These are a few in- 
 stances selected from many which might be given. 
 
 If we receive a prismatic spectrum on some papers, we 
 have evidence that the molecular or chemical disturbance 
 bears some relation to the color of each ray, or, in other 
 words, that colored light so modifies the action of Ener- 
 gia that the impression it makes is in proportion to the 
 color of the light it accompanies, and hence there results 
 a molecular arrangement capable of reflecting colors dif- 
 ferently. Some instances have been given in which the 
 rays impressed correspond with the colors of the lumin- 
 ous rays in a very remarkable manner.* One of the most 
 decided cases is that of the paper prepared with the fluo- 
 ride of soda and nitrate of silver. Sir John Herschel 
 was, however, the first to obtain any good specimens of 
 photographically impressed prismatic colorations. 
 
 It was noticed by Daguerre that a red hoyse gave a 
 reddish image on his iodized silver plate in the camera 
 obscura; and Mr. Talbot observed, very early in his re- 
 searches, that the red of a colored print was copied of a 
 red color, on paper spread with the chloride of silver. t 
 
 u In 1840 I communicated to Sir John Herschel some 
 very curious results obtained by the use of colored me- 
 dia, which he did me the honor of publishing in one of 
 
 * See Mr. Hunt’s “ Researches on Light.” 
 
 t In 1842, I had shown me a picture of a house in the Bowery, which had 
 been repaired a few days previous, and in the wall a red brick left. This 
 brick was brought out on the Daguerreotype plate of precisely the same color 
 as the brick itself. The same artist also exhibited to me, the full length por- 
 trait of a gentleman who wore a pair of pantaloons having a blue striped 
 figure. This blue stripe was fully brought out, of the same color, in the pic- 
 ture.— Amer. Ed 
 
ON PRODUCING COLORED PICTURES. 129 
 
 his memoirs on the subject from which I again copy it.” 
 u A paper prepared with muriate of barytes and ni- 
 trate of silver, allowed to darken whilst wet in the sun- 
 shine to a chocolate color, was placed under a frame con- 
 taining a red, a yellow, a green, and a blue glass. After 
 a week’s exposure to diffused light, it became red under 
 the red glass, a dirty yellow under the yellow glass, a 
 dark green under the green, and a light olive under the 
 blue. 
 
 c( The above paper washed with a solution of salt of 
 iodine, is very sensitive to light, and gives a beautiful 
 picture. A picture thus taken was placed beneath the 
 above glasses, and another beneath four flat bottles con- 
 taining colored fluids. In a few days, under the red glass 
 and fluid, the picture became a dark blue, under the yel- 
 low a light blue, under the green it remained unchanged, 
 whilst under the blue it became a rose ned, which in 
 about three weeks changed into green. Many other ex- 
 periments of a similar nature have been tried since that 
 j time with like results. 
 
 u In the summer of 1843, when engaged in some expe- 
 riments on papers prepared according to the principles of 
 Mr. Talbot’s calotype, I had placed in a camera obscura 
 a paper prepared with the bromide of silver and gallic 
 acid. The camera embraced a picture of a clear blue 
 sky, stucco-fronted houses^ and a green field. The pa- 
 per was unavoidably exposed for a longer period than 
 was intended — about fifteen minutes, — a very beautiful 
 | picture was impressed, which, when held between the 
 eye and the light, exhibited a curious order of colors. 
 The sky was of a crimson hue, the houses of a slaty blue, 
 and tne green fields of a brick red tint. Surely these re- 
 sults appear to encourage the hope, that we may even- 
 
130 
 
 PHOTOGRAPHIC DEVIATIONS. 
 
 tually arrive at a process by which external nature may 
 be made to impress its images on prepared surfaces, in all 
 the beauty of their native coloration.” 
 
 PHOTOGRAPHIC DEVIATIONS. 
 
 Before taking leave of the subject of photogenic draw- 
 ing, I must mention one or two facts, which may be of 
 essential service to operators. 
 
 It has been observed by Daguerre, and others, in Eu- 
 rope, and probably by some of our own artists, that the 
 sun two hours after it has passed the meridian, is much 
 less effective in the photographic process, than it is two 
 hours previous to its having reached that point. This 
 may depend upon an absorptive power of the air, which 
 may reasonably be supposed to be more charged with va- 
 por two hours before noon. The use of the hygrometer 
 may possibly establish the truth or falsity of this supposi- 
 tion. The fact, however, of a better result being pro- 
 duced before noon being established, persons wishing 
 their portraits taken, will see the advantage of obtaining 
 an early sitting, if they wish good pictures. On the 
 other hand, if the supposition above mentioned prove 
 true, a too early sitting must be avoided. 
 
 If we take a considerable thickness <3f a dense purple 
 fluid, as, for instance, a solution of the ammonia-sul- 
 phate of copper, we shall find that the quantity of light 
 is considerably diminished, at least four -fifths of the lu- 
 minous rays being absorbed, while the chemical rays 
 permeate it with the greatest facility, and sensitive pre- 
 parations are affected by its influence, notwithstanding 
 the deficiency of light, nearly as powerfully as if exposed 
 to the undecomposed sunbeams. 
 
 It was first imagined that u under the brilliant sun and 
 clear skies of the south, photographic pictures would 
 
LUNAR PICTURES — DRUMMOND LIGHT. 
 
 131 
 
 be produced with much greater quickness than they could 
 be in the atmosphere of Paris. It is found, however, 
 that a much longer time is required. Even in the clear 
 and beautiful light of the higher Alps, it has been proved 
 that the production of the photographic picture requires 
 many minutes more, even with the most sensitive pre- 
 parations, than it does in London. It has also been 
 found that under the brilliant light of Mexico, twenty 
 minutes, and half an hour, are required to produce ef- 
 fects which in England would occupy but a minute ; and 
 travellers engaged in copying the antiquities of Yucatan 
 have on several occasions abandoned the use of the pho- 
 tographic camera, and taken to their sketch books. Dr. 
 Draped has observed a similar difference between the 
 chemical action of light in New York and Virginia. 
 This can he 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 employed. 
 
 LUNAR PICTURES DRUMMOND LIGHT. 
 
 The Roman Astronomers state that they have pro- 
 cured Daguerreotype impressions of the Nebula of the 
 sword of Orion. Signor Rondini has a secret method of 
 receiving photographic images on lithographic stone ; on 
 such a prepared stone they have succeeded in impressing 
 an image of the Nebula and its stars ; u and from that 
 stone they have been enabled to take impressions on pa- 
 per, unlimited in number, of singular beauty, and of 
 perfect precision.” Experiments have, however, proved 
 that u no heating power exists in the moon’s rays, and 
 that lunar light will not act chemically upon the iduret of 
 silver.” 
 
 * I would bere take occasion to remark that our countryman, Dr. Draper, is 
 very frequently quoted by Mr, Huut in his “ Researches.” 
 
132 
 
 DRUMMOND LIGHT. 
 
 It was at one time supposed that terrestrial or artificial 
 light possessed no chemical rays, bu,t this is incorrect — 
 Mr. Brande discovered that although the concentrated 
 light of the moon, or the light even of olefiant gas, how- 
 ever intense, had no effect on chloride of silver, or on a i 
 mixture of chloride and hydrogen, yet the light emitted 
 by electerized charcoal blackens the salt. At the Royal 
 Polytechnic Institution pictures have been taken by means 
 of sensitive paper acted upon by the Drummond Light ; 
 but it must of course be distinctly understood, that they 
 are inferior to those taken by the light of the sun, or dif- 
 fused daylight. ,■ 
 
 If our operators could manage to produce good pic- 
 tures in this way they would put money in their pockets, 
 as many who cannot find time during the day would re- 
 sort to their rooms at night. I throw out the hint in 
 hopes some one will make the experiment. 
 
 I have learned, since the above was written, that an 
 operator in Boston succeeded a short time since in pro- 
 curing very good pictures by the aid of the Drummond 
 Light; but that the intensity of the light falling directly 
 upon the sitter’s face caused great difficulty, and he aban- 
 doned it. This may, probably, be remedied by inter- 
 posing a screen of very thin tissuepaper tinged slightly of 
 a bluish color. 
 
 TO TAKE COLORED DAGUERREOTYPES. 
 
 Since our first edition was published, the following pro- 
 cess has been discovered in Europe : 
 
 “ A silver plate, such as is employed in the Daguerreo- 
 type process, is connected by a copper wire with one pole 
 of a galvanic battery ; a piece of platina foil being con- 
 nected by a copper wire likewise, with the other pole. A 
 
COLORED DAGUERREOTYPES. 
 
 133 
 
 solution of muriatic acid in water being prepared — about 
 one part acid to two of water — the plate and platina are 
 plunged into it, and brought near each other, but not in 
 contact. Of course, the circuit being made up through 
 the acid solution, a chemical action is established over 
 the surface of the silver plate ; the chlorine of the decom- 
 posed muriatic acid attacking the silver and forming chlo- 
 ride of silver over the surface. As the film of chloride of 
 silyer is produced, and gradually thickens, it passes 
 through the colors of Newton’s thin plates, and at length 
 assumes a lilac, which is the sensitive coating. These 
 plates have not yet been rendered sufficiently sensitive to 
 ensure any action, except from the direct rays of the sun. 
 But if a prismatic spectrum, of a well defined character, 
 is allowed to fall upon the prepared plate, it will be found, 
 after an exposure of a few minutes, that a distinct im- 
 pression of the seven colored rays are obtained in color , 
 every ray being represented by its own color on the plate, 
 the red being the most intense, and the yellow the least so. 
 
CHAP. XII. 
 
 . * 
 
 ON COLORING DAGUERREOTYPES. 
 
 Nearly, if not quite all the various colors used in 
 painting may be made from the five primitive colors, 
 black, white, blue, red and yellow, but for the Daguer- 
 rean artist it would be the best policy to obtain such as 
 are required by their art already prepared. In a majority 
 of cases, the following will be found sufficient, viz. 
 
 Carmine. 
 
 Prussian Blue. 
 
 White. 
 
 Chrome Yellow, Gamboge, Yellow Ochre; or all 
 three.* 
 
 Light Red. 
 
 Indigo. 
 
 Burnt Sienna. 
 
 Bistre, or Burnt Umber. 
 
 If, in coloring any part of a lady’s or gentleman’s 
 apparel, it is found necessary to produce other tints and 
 shades, the following combinations may be used : 
 
 Orange — Mix yellow with red, making it darker or 
 lighter by using more or less red. 
 
 Purple — This is made with Prussian blue, or indigo 
 and red. Carmine and Prussian blue producing the 
 
 * Gamboge is best for drapery ; Ochre for the face. 
 
136 
 
 ON COLORING DAGUERREOTYPES. 
 
 richest color, which may be deepened in the shadows by 
 a slight addition of indigo or brown. 
 
 Greens — Prussian blue and gamboge makes a very fine 
 green, which may be varied to^ suit the taste of the sit- 
 ter or operator, by larger portions of either, or by adding 
 white, burnt sienna, indigo, and red, as the case may 
 require. These combinations, under different modifica- 
 tions, give almost endless varieties of green. 
 
 Brown — May be made of different shades of umber r 
 carmine and lamp-black. 
 
 Neutral tint — Is composed of indigo and lamp-black. 
 
 Crimson — Mix carmine and white, deepening the 
 shaded parts of the picture with additional carmine. 
 
 Flesh Color — The best representative of flesh color is 
 light red, brightened in the %more glowing or warmer 
 parts, with carmine, softened off in the lighter portions 
 with white, and shaded with purple and burnt sienna. 
 
 Lead Color — Mix indigo and white in proportions to 
 suit. 
 
 Scarlet — Carmine and light red. 
 
 For Jewelry cups of gold and silver preparations ac- 
 company each box for Daguerreotypists, or may be pro- 
 cured separately. 
 
 The method of laying colors on Daguerreotypes is one 
 of considerable difficulty, inasmuch as they are used in 
 the form of perfectly dry impalpable powder. The au- 
 thor of this little work is now experimenting, in order, 
 if possible, to discover some more easy, artistic and un- 
 exceptionable method. If successful, the result will be 
 published in a future edition. 
 
 The rules we shall give for coloring Daguerreotypes 
 depends, and are founded, upon those observed in mi- 
 niature painting, and are intended more as hints to Da- 
 
ON COLORING DAGUERREOTYPES. 
 
 137 
 
 guerrean artists, in hopes of leading them to attempt im- 
 provements, than as instructions wholly to be observed. 
 
 The writer is confident that some compound or ingre- 
 dient may yet be discovered which, when mixed with the 
 colors, will give a more delicate, pleasing, and natural 
 appearance to the picture than is derived from the pre- 
 sent mode of laying them on, whichdn his estimation is 
 more like plastering than coloring. 
 
 In Coloring Daguerreotypes, the principal shades 
 of the head are to be made with bistre, mixed with 
 burnt sienna, touching some places with a mixture of 
 carmine and indigo. The flesh tints are produced by the 
 use of light red, deepened towards the shaded parts with 
 yellow ochre, blue and carmine mixed with indigo, while 
 the warmer, or more* highly colored parts have a slight 
 excess of carmine or lake. Color. the shades about the 
 mouth and neck with yellow ochre, blue, and a very 
 little carmine, heightening the color of the lips with car- 
 mine and, light red, letting the light red predominate on 
 the upper, and the carmine on the lower lip ; the shades 
 in the corner of the mouth being touched slightly with 
 burnt sienna, mixed with carmine. 
 
 In coloring the eyes, the artist will of course be guided 
 by nature, observing a very delicate touch in laying on 
 the colors, so as to preserve as much transparency as 
 possible. 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 iris, will produce a good 
 effect. 
 
 In coloring the heads of men it will be necessary to 
 S use the darker tints with more freedom, according to the 
 complexion of the sitter. For women, the warmer tints 
 should predominate, and in order to give that transpa- 
 
138 
 
 ON COLORING DAGUERREOTYPES. 
 
 rency 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 face. 
 
 In taking a picture of a lad} 7 " with light or auburn hair, 
 by the Daguerrean process, much of the beauty of the 
 face is destroyed, on account of the imperfect manner in 
 which light conveys the image of light objects to the 
 spectrum of the camera. This may be obviated in some 
 measure by proper coloring. To do this, touch the 
 shaded parts with burnt sienna and bistre, filling up the 
 lighter portions with yellow ochre, delicate touches of 
 burnt sienna, and in those parts which naturally have a 
 bluish tint, add very delicate touches of purple— so de- 
 licate in fact as hardly to be perceived. The roots of the 
 hair at the forehead should also be touched with blue, 
 and the eyebrows near the temples made of a pinkish 
 tint. 
 
 The chin of a woman is nearly of the same color as 
 the cheeks in the most glowing parts. In men it is 
 stronger, and of a bluish tint, in order to produce the 
 effect given by the beard. 
 
 In portraits of women — the middle tints on the side of 
 the light, which are perceived on the bosom and arms, 
 are made of a slight mixture of ochre, blue and lake, (6r 
 carmine), to which add, on the shaded sides, ochre, bis- 
 tre and purple, the latter in the darker parts. The tints 
 of the hands should be the same as the other parts of the 
 flesh, the ends of the fingers being a little pinkish and 
 the nails of a violet hue. If any portion of the fleshy 
 parts is shaded by portions of the dress, or by the jposi- 
 tion of the hand, this shade should be colored with um- 
 ber mixed with purple. 
 
 
ON COLORING DAGUERREOTYPES. 139 
 
 To Color the Drapery. — Violet Velvet — Use pur- 
 ple made of Prussian blue and carmine, touching up the 
 shaded parfs with indigo blue. 
 
 Green Velvet — Mix Prussian blue and red-orpiment, 
 shade with purple, and touch up the lights with a little 
 white. 
 
 Red Velvet — Mix a very little brown with carmine, 
 shading with purple, marking the lights in the strongest 
 parts with pure catmine, and touch the most brilliant 
 slightly with white. 
 
 White Feathers — Maybe improved by delicately touch- 
 ing the shaded parts with a little blue mixed with white. 
 White muslin, linen, lace, satin, silk, etc., may also be 
 colored in the same way, being careful not to lay the co- 
 lor on too heavily. 
 
 Furs — Red Furs may be imitated by using light red 
 and a little masticot, shaded with umber. Gray Furs — 
 black and white mixed and shaded with bistre. Sable — 
 white shaded lightly with yellow ochre. 
 
 These few directions are quite sufficient for the art, and 
 it is quite unnecessary for me to pursue the subject fur- 
 ther. I would, however, remark that the Daguerreo- 
 typists would find it greatly to their advantage to visit the 
 studies of our best artists, our public galleries of paint- 
 ings, and statuary, and wherever else ’they can obtain a 
 sight of fine paintings, and study the various styles of 
 coloring, atitudes, folds of drapery and other points of 
 the art. In coloring Daguerreotypes, artists will find the 
 magnifying glass of much advantage in detecting any im- 
 perfections in the plate or in the image, which may be 
 remedied by the brush. In selecting brushes choose those 
 most susceptible of a fine point, which may be ascertained 
 by wetting them between the lips, or ia a glass of water. 
 
CHAP. XIII. 
 
 THE PHOTOGRAPHOMETER. 
 
 The last number (for March, 1849) of the a London 
 Art-Journal, gives the following description of a recent 
 improvement in Photographic Manipulation, and as I am 
 desirous of furnishing everything new in the art, I stop 
 the press to add it, entire, to my work. 
 
 16 Since the photographic power of the solar rays bears 
 no direct relation to their luminous influence, it becomes 
 a question of considerable importance to those who prac- 
 tice the beautiful art of photography, to have the means 
 of readily measuring the ever changing activity of this 
 force. Several plans more or less successful, have 
 been devised by Sir John Herschel, Messrs. Jordan, 
 Shaw and Hunt. The instrument, however, which is 
 now brought forward by Mr. Claudet, who is well 
 known as one of our most successful Daguerreotypists, 
 appears admirably suited to all those purposes which the 
 practical man requires. The great difficulty which con- 
 tinually annoys the photographic amateur and artist, is 
 the determination of the sensibility of each tablet em- 
 ployed, relatively to the amount of radiation, luminous 
 and chemical, with which he is working. With the 
 photographometer of Mr. Claudet this is easily ascer- 
 
142 
 
 THE PHOTOGRAPHOMETER. 
 
 tained. The following woodcuts and concise description 
 will sufficiently indicate this useful and simple apparatus. 
 
 Fig. 29. 
 
 t£ For an instru- 
 ment of this kind it 
 is important in the 
 first place to have a 
 motion always uni- 
 form, without com- 
 plicated or expen- 
 sive mechanism. — > 
 
 This is obtained by 
 means founded upon 
 the principle of the 
 “ fall of bodies sliding 
 down an inclined 
 plane. The sensi- 
 tive surface is ex- 
 posed to the light by the rapid and uniform passage of a 
 metal plate, a, b, (Fig. 30,) having openings of different 
 length, which follow a geometric progression. It is evi- 
 dent that the exposure to light will be the same for each 
 experiment, because the plate furnished with the propor- 
 tional openings falls always with the same rapidity, the 
 height of the fall being constant, and the angle of the 
 inclined plane the same. Each opening of this moveable 
 plate allows the light to pass during the £ame space of 
 time, and the effect upon the sensitive surface indicates 
 exactly the intensity of the chemical rays. The rapidity 
 of the fall may be augmented or diminished by altering 
 the inclination of the plane by means of a graduated arc, 
 c, d, (Fig. 29,) furnished with a screw, e, by which it 
 may be fixed at any angle. The same result may be ob- 
 tained by modifying the height of the fall or the weight 
 
 If 
 
THE PHOTOGRAPHOMETER 
 
 143 
 
 of the moveable plate. The photogenic surface, whether 
 
 Fig. 30. 
 
 it be the Da- 
 guer reo type 
 plate, the Tal- 
 botype paper, 
 or any other 
 prepar ati on 
 sensitive to 
 light, is placed 
 near the bot- 
 tom of the in- 
 clined plane, 
 f. It is co- 
 vered by a 
 thin plate of 
 metal, pierced 
 with circular 
 holes, which 
 correspond to 
 the openings 
 of the move- 
 able plate at 
 the moment of 
 the passage of 
 the latter, du- 
 ring which the 
 sensitive sur- 
 face receives 
 
 the light wherever the circular holes leave it exposed. 
 
 u The part of the apparatus which contains the sensi- 
 tive surface is an independent frame. and it slides from 
 a dark box into an opening on the side of the inclined 
 plane 
 
144 
 
 THE PHOTOGRAPHOMETER, 
 
 u A covering of black cloth impermeable to liglitis, 
 attached to the sides of the moveable plate, enveloping 
 the whole inclined plane, rolling freely over two tollers, 
 r, r, placed the one at the upper and the other at the 
 lower part of the inclined plane. This cloth prevents 
 the light striking the sensitive surface before and after 
 the passage of the moveable plate. 
 
 u It will be seen that this apparatus enables the expe- 
 rimentalist 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 
 surface, whether on metal or papei. Although at pre- 
 sent some calculation is necessary to determine the differ- 
 ence between the time which is necessary for exposure in 
 direct radiation, and to the action of the secondary ra- 
 diations of the camera obscura ; this is, however, a very 
 simple matter, and it appears to us exceedingly easy to 
 adapt an instrument of this description to the camera it- 
 self. 
 
 u By this instrument Mr. Claudet has already deter- 
 mined many very important points. Among others, he 
 has proved that on the most sensitive Daguerreotype 
 plate an exposure of .0001 part of a second is sufficient 
 to produce a decided effect. 
 
 u Regarding photography as an auxiliary aid to the 
 artist of no mean value, we are pleased to record a des- 
 cription of an instrument which, without being compli- 
 cated, promises to be exceedingly useful. In this opi- 
 nion we are not singular; at a recent meeting of the 
 Photographic Club, to which this instrument was ex- 
 hibited, it was with much real satisfaction that we 
 learned that several of our most eminent artists were now 
 eager and most successful students in Photography. The 
 
THE PHOTOGRAPHOMETER. 
 
 145 
 
 beautiful productions of the more prominent members of 
 this club excited the admiration of all, particularly the 
 copies of architectural beauties, and small bits of land- 
 scape, by Messrs. C undell and Owen. We think that 
 now the artist sees the advantage he may derive from the 
 aid of science, that both will gain by the union.” 
 
 I hope the above description will induce our townsman, 
 Mr. Roach, to successfully produce an instrument that 
 will meet the wants of our artists in that part of the Da- 
 guerrean process referred to. 
 
 davie’s improved buffing lathe. 
 
 This is a recent and decided improvement for polishing 
 plates, accurately figured 
 
 There is ho part of the 
 Daguerreotype process 
 requiring more thorough 
 manipulation than that 
 of cleaning and polish- 
 ing the plate, and none 
 wherein the operator has 
 met with less satisfac- 
 tion. The hand buff, 
 though good, does not 
 give that finely finished 
 surface so desirable in a 
 good picture ; and the 
 lathes commonly used, 
 are apt, in some instan- 
 ces, to go to the other 
 extreme, and wear the 
 plate bare of silver. Of the many efforts made to im- 
 prove the buffing-wheel, none have come so near perfec- 
 tion as the above alluded to. 
 
 at 31. 
 
 Fig. 31. 
 
146 davie’s improved buffing lathe. 
 
 It occupies but little space, and requires slight exer- 
 tion. The buffer is a cone of cast iron, twenty-three 
 inches in diameter, neatly covered with wood, and form- 
 ing a free surface six and a half inches wide. This cone 
 runs in a well adapted case, which stands firmly on four 
 handsomely turned legs, attached to the box by screws. 
 The cone is turned by a treadle with the left foot. Con- 
 nected with the machine, are four holders for the different 
 sizes of plates. It is certainly a very neat affair, and will 
 undoubtedly do its work quicker and better than any- 
 thing of the kind now in use. 
 
CHAP. XIV. 
 
 RECIPES. 
 
 Since the publication of the first edition of the Art of 
 Photography, so many inquiries have been made for the 
 recipes used in the art, I have deemed it advisable to 
 append everything of the kind to the present issue, that 
 can possibly be of any benefit to the operator. I would, 
 however, express the opinion, -that in most instances it 
 would be preferable to purchase the compounds of gpod 
 chemists, or the dealers in Daguerreotype stock, than to 
 trust to your own compounding. However, those who 
 wish to make experiments, or search into effects and 
 causes, will herein find ample scope for their ambition. 
 
 BROMINE. 
 
 Bromine is prepared by passing a current of chlorine 
 through the unchrystalizable residuum of sea-water, called 
 bittern, which then assumes an orange tint, in conse- 
 quence of bromine being set free from its combinations ; 
 sulphuric ether is then agitated with it, and the mixture 
 is allowed to stand until the ethereal portion holding the 
 bromine in solution floats upon the surface. This is then 
 carefully decantered, and agitated with a solution of po- 
 tassium. by which means bromide of potassium and bro- 
 mate of potash are formed. The whole is next evaporated 
 to dryness, and submitted to a dull heat ; the residuum is 
 
148 
 
 RECIPES. 
 
 then powdered, mixed with pure peroxide of manganese, 
 and placed in a retort; sulphuric acid, diluted with, half 
 its weight of water, is now poured in. Red vapors imme- 
 diately arise, are condensed into drops of bromine, and 
 are collected by plunging the neck of the retort to the 
 bottom of a small receiver containing cold water. The 
 bromine forms a stratum beneath the water, and may be 
 collected and purified by distillation from dry chloride of 
 calcium. 
 
 Bromide of Iodine.— -See page 67. 
 
 Bromide of Lime.- — See page 68. 
 
 Another method of preparing this favorite, and undoubt- 
 edly one of the very best accelerators used in the art, is, 
 after observing the directions on page 68, to drop Hydro- 
 fluoric acid into the mixture until it becomes a light 
 orange, approaching red ochre color. A small piece of 
 alum, finely powdered, and well shaken in, will benefit it 
 materially. 
 
 Bromine, Chloride of. — Transmit a current of dry 
 ■ chlorine through hromi , and condense the disengaged 
 vapors in a receiver surrounded with ice. A volatile red- 
 dish fluid is produced, which may be diluted with water 
 in the proportions given on page 68, and it is ready for 
 the coating-box. 
 
 chlorine. 
 
 To obtain this, mix together in a glass flask or retort, 
 strong muriatic acid, with half its weight of finely pow- 
 dered peroxide of manganese. The tube of the flask must 
 be inserted into a clean dry glass bottle, reaching nearly 
 to its bottom. Chlorine gas is immediately evolved, and 
 being heavier than the air, will displace the latter without 
 mixing with it. When the bottle is full, which may be 
 
RECIPES. 
 
 149 
 
 known by the gas overflowing the mouth, the tube should 
 be removed into another bottle, and the full one securely 
 closed with a ground stopper, previously greased. Con- 
 tinue thus to fill your bottles until you have the desired 
 quantity. Several other methods are used for procuring 
 this gas, but the above is simple and sufficient. 
 
 Liquid Chlorine may be made by mixing' 87 parts of 
 sulphuric acid with 124 parts of water, and pouring it 
 upon 100 parts of dry muriate of soda and 30 parts of 
 oxide of manganese, previously mixed together and placed 
 in a retort. Conduct the gas evolved into 200 parts dis- 
 tilled water. 
 
 CHLORIDE OF GOLD. 
 
 This is a very simple compound, and may be made as 
 follows : 
 
 Take three parts nitro-rnuriatic acid, put it into a cup, 
 and drop into it a piece of pure gold one-third its weight, 
 and let it evaporate until chlorine vapor begins to be dis- 
 engaged ; then set it aside to chrystalize. Care should 
 be taken to place the cup in a draught of air, that you 
 may not be troubled by the fumes arising from it. A 
 gentle heat may be applied to the bottom of the cup by 
 means of your spirit-lamp, taking care not to get it too 
 hot ; or, the cup may be put into a saucepan of boiling 
 water, sufficiently small to permit the cup to rest on its 
 rim, with about three-fourths the body of the latter im- 
 mersed. 
 
 The crystals of chloride of gold made in this way, are 
 of an orange-red color, and maybe dissolved in 'water 
 fifteen grains to a pint. To this, add forty-five grains 
 hyposulphite of soda, and when thoroughly combined, 
 filter the mixture through bibulous paper till it becomes 
 
150 
 
 RECIPES. 
 
 colorless. Gild the picture over the spirit-lamp until the 
 bubbles are well defined -over the plate. 
 
 Thompson’s chloride of gold. 
 
 Take one dollar’s worth virgin gold, put it in a porcelain 
 cup, and pour on about an ounce of nitro-muriatic acid. 
 Place a feeble alcoholic flame under it, just enough to make 
 it simmer — stir it occasionally with a glass rod ; when 
 the gold is all dissolved, add about one hundred grains 
 common salt ; if there is not sufficient acid to saturate 
 the salt, add more, stirring it with your glass rod until it 
 is perfectly dry. It is then ready to bottje. To fifty 
 grains of hyposulphite of soda dissolved in a pint of water, 
 put eighteen grains of chloride of gold. Filter as usual. 
 
 * HYPOSULPHITE OF GOLD. 
 
 Take 85 parts terchloride of gold and !6 parts sodium ; 
 dissolve them in a little distilled water, and evaporate 
 over a gentle heat until a pellicle forms ; then. put it aside 
 to chrystalize. 
 
 ANOTHER. 
 
 Dissolve a given quantity of chloride in an excess of 
 distilled water, and add four times its weight of hyposul- 
 phite of soda previously dissolved in distilled water to 
 excess. Into this, drop the gold solution, shaking it up 
 well at intervals. After letting it stand in the dark until 
 it is bleached, filter and evaporate to dryness. To this 
 residuum add 200 times its weight of distilled water, and 
 three grains burnt alum ; agitate and evaporate to dry- 
 ness as before. Twenty-five grains of this salt will make 
 a quart of strong solution, which should be filtered till it 
 becomes colorless. Use as directed on page 74. 
 
RECIPES. 
 
 151 
 
 IODINE. 
 
 This chemical element is found in animal, vegetable 
 and mineral substances, but exists in the greatest abund- 
 ance in the vegetable. It is prepared by extracting all the 
 soluble part of kelp by water; and crystalizing the soda 
 by evaporation ; to the mother-lye add oil of vitriol in ex- 
 cess — say, one ounce of vitriol to eight of lye— -and boil 
 the liquid ; then strain it and mix the filtered liquor with 
 as much manganese as there was oil of vitriol used ; on 
 applying heat, the iodine sublimes in the form of grayish 
 blatfk scales, with a metallic lustre. 
 
 The boiling is conducted 'in a leaden vessel ; and a 
 cylindrical leaden still, with a very short head, and con- 
 nected with two or three globular glass receivers, is used 
 for the subliming apparatus. Care must be taken to 
 watch the process, and prevent the neck of the still be- 
 coming choked with condensed iodine. 
 
 CHLORIDE OF IODINE. 
 
 When dry chlorine is passed over dry iodine, at com- 
 mon temperature, heat is evolved, and a solid chloride 
 results. It is orange yellow when the iodine is fully satu- 
 rated, and reddish orange when the iodine is in excess. — 
 The process is effected by placing the iodine in a flask, 
 and attached to a retort containing chlorine. 
 
 Thompson’s accelerator. 
 
 This is one of the best sensitives we know of, and Mr. 
 Thompson will accept our thanks for contributing it to 
 our work. 
 
 Make a strong solution of lime in one quart of water — 
 add to it half an ounce of chloride of iodine, and then 
 
152 
 
 RECIPES. 
 
 drop in sufficient bromine to take up the chloride of 
 iodine ; the best way is to first put iji the one-eighth of 
 an ounce of bromine, and add a few drops daily until the 
 chloride of iodine is taken up — care being taken not to 
 get too much — then put in sixty grains nitrate of silver, 
 shake it well, and add thirty drops nitro-muriatic acid. 
 Put in the box about a tablespoonful of pulverize? alum, 
 and add one part quick with six of water. Coat over dry 
 iodine to" a light lemon color, then over the quick to a 
 deep orange, and back over the iodine one quarter the 
 time required by the quick. 
 
 THOMPSON'S. DRY QUICK. 
 
 Take a lump of lime and soak it in alcohol about two 
 hours, then expose it to the air until it is as fine as flour. 
 To one pint of lime add half ounce bromine and three 
 tablespoonsful pulverized alum. Put one-third of this 
 into a half-plate box, and as it becomes weak, add more, 
 and so on until you have the whole pint. After this, a 
 few drops of bromine occasionally will make it last six 
 months. 
 
 HYPOSULPHITE OF SODA. 
 
 This may be made by boiling a diluted solution of 
 caustic soda with sulphur until saturated ; then pass sul- 
 phurous acid gas into the solution until it is strongly im- 
 pregnated. Filter a small portion of the mixture, and if 
 it have aj Dale yellow color, you may filter the whole, and 
 evaporate it by boiling to syrupy consistence. If there 
 remains any sulphuret of soda, mix the syrup with half 
 its weight of alcohol, shake it well, and then set it aside 
 to crystalize. 
 
RECIPES. 
 
 153 
 
 NITRATE OF SILVER. 
 
 Digest pure metallic silver in one and a half times its 
 weight of nitric acid diluted with water, and evaporate 
 the solution to dryness. Nitrate of silver is soluble in its 
 own weight of cold water, and half its weight of hot, and 
 also in four times its weight of alcohol. 
 
 OXIDE OF SILVER. 
 
 This oxide may be obtained by adding to a solution of 
 the nitrate of silver pure barytic water, or Time water; it 
 may be obtained, also, from its solution in nitric acid, by 
 the addition of the pure alkalies. 
 
 CHLORIDE OF SILVER. 
 
 To one part oxide silver solution add one part hydro- 
 chloric acid. Evaporate to dryness. It is insoluble in 
 water, but may be dissolved in ammonia and hyposulphu- 
 rous acid. 
 
 IODIDE OF SILVER. 
 
 This compound is formed by adding a solution of the 
 hydriodate of potash to a solution of nitrate of silver, in 
 about equal proportions. 
 
 BROMIC ACID. 
 
 Formed by passing five equivalents of oxygen into one 
 of bromine. From bromate of baryta, by means of sul- 
 phuric acid, free bromic acid may be obtained. 
 
 GALLIC ACID. 
 
 This acid is obtained from gall nuts, and consists of 
 four parts carbon, three parts oxygen, and three parts hy- 
 drogen. It crystalizes in white plates, is soluble in 
 
15A 
 
 RECIPES. 
 
 * 
 
 three parts boiling, or twenty parts cold water ; it is very 
 soluble in alcohol, and sublimes by heat. 
 
 CHLORIDE OF POTASSIUM. 
 
 Is made by exposing to the action of heat the chlorate 
 of potassa. The oxygen of the acid and the alkali is 
 driven off, leaving a compound of chlorine and potassium 
 in the vessel. It is also procured by putting potassium 
 into dry chlorine gas. It consists of 36 parts of chlorine 
 to 40 of potassium. 
 
 CYANIDE POTASSIUM. 
 
 Is formed by heating to redness the peroxide of manga- 
 nese, and the fero-cyanuret of potassium in a glass bottle. 
 Soluble in water. 
 
 BROMIDE OF POTASSIUM. 
 
 Put one part bromine, and one part potassium in a glass 
 bottle, and heating them till they combine. Soluble in 
 water and alcohol, and crystalizes from this solution into 
 anhydrous cubic crystals. 
 
 IODIDE OF POTASSIUM. 
 
 Is made in the same way as the bromide of potassium — 
 iodine being substituted for bromine. Soluble in water 
 and alcohol, and yields colorless cubic crystals. 
 
 CHLORATE OF POTASSA. 
 
 Pass a current of chlorine gas through a solution of 
 potassa until the alkali is neutralized-; boil the solution 
 a few minutes, and then evaporate it until a pellicle forms 
 upon its surface. On cooling, the chlorate crystalizes, 
 and leaves the muriate of potassa in solution. Re-dissolve 
 these crystals in distilled water, and again evaporate to 
 
RECIPES. 
 
 155 
 
 dryness, and you obtain pure chlorate of potassa in scales 
 of a pearly lustre. # 
 
 MERCURY. 
 
 Mercury exists native, but may be obtained by mixing 
 iron filings, or lime, and native cinnabar, and exposing 
 the mixture to heat in an earthen or iron retort ; the 
 sulphur of the cinnabar combines with the iron or lime, 
 and the mercury is distilled over, and must b.e collected 
 under water, the neck of the retort being immersed in that 
 fluid. Crude mercury, (such as is sold by druggists,) 
 may be distilled in the same way, and obtained perfectly 
 pure. 
 
 Pure mercury does not tarnish when exposed to the air, 
 nor does any film collect on the surface when shaken in a 
 bottle. 
 
 HYDROFLUORIC ACID. 
 
 This acid is prepared by mixing one part fluor-spar 
 with two parts sulphuric acid, in a leaden retort, exposed 
 over a charcoal fire. A powerful corrosive and poison- 
 ous acid is distilled over, which must be collected in 
 leaden bottles surrounded with ice. Glass must not be 
 employed, as the acid destroys it — lead only must be 
 used. 
 
 CHLORIDE OF CALCIUM. 
 
 Is formed by heating lime strongly in chlorine gas, in 
 proportion as 36 to 20. It may also be prepared by heat- 
 ing dry muriate of lime to ignition. It is very deliques- 
 cent, and dissolves in a fourth part its weight of water, 
 and is soluble in alcohol. 
 
156 
 
 RECIPES. 
 
 BUFF-POWDER. 
 
 * ft 4 * 
 
 Take two parts rouge, one part- calcined ivory, two 
 parts plumbago, one part oxide tin, mix well together, and 
 you have an excellent finishing polish. If you wish to 
 save the trouble of compounding it, buy it of the dealers. 
 
 PHOTOGINE. • 
 
 This is a very fine article for cleaning the plate previ- 
 ous to buffing ; those who use it pronounce it superior to 
 the finest rottenstone. It is used with alcohol, precisely 
 in the same manner as the latter. 
 
 * FOSSIL POWDER. 
 
 This is a good article for drying off the plate after using 
 the rottenstone or photogenie, and previous to buffing. — 
 To use it, dust a little over the plate, and wipe it off with 
 a large camel’s hair brush. It removes every particle of 
 moisture. 
 
 ' i « •. 
 
 TO MAKE PASTE FOR SEALING PAPER. 
 
 Take six parts of the best glue ; boil and strain it very 
 clear ; add three parts isinglass, also boiled and strained ; 
 put them in a double glue pot, with a quarter of a pound 
 fine brown sugar, and boil it very thick; pour it into 
 moulds, and when cold, cut it into cakes of convenient 
 size, and dry them. When desired for sealing paper, dis- 
 solve one of the cakes in warm water, and spread it on 
 stout tissue, or other very thin paper. 
 
 SEALING-WAX. 
 
 Take two parts well powdered gum-shellac, and one 
 part resin, of the whitest kind, and melt them together 
 
RECIPES. 
 
 157 
 
 over a slow fire, adding one part vermilion, ivory black, 
 verdigris, verditer, masticot, or any other color you may 
 desire. Beeswax is a good substitute for shellac, if the 
 latter is not to be h^d. Work it into sticks while cooling, 
 if desirable. 
 
 TO DISINFECT A ROOM OF BROMINE VAPOR. 
 
 Sprinkle ammonia about the room, or burn ground 
 coffee on hot coals. 
 
 TO PURIFY WATER. 
 
 Put a piece of alum, about the size of a hickory nut, 
 into a pail of water ; let it stand for half an hour, and 
 then decant it carefully into another vessel. To neutral- 
 ize rfny carbonates that may be held in solution, add four 
 or five drops of nitric acid for every quart of water. 
 
 As pure or soft water is absolutely necessary toDaguer- 
 reotypists, a simple process for ascertaining whether it is 
 so or not will be useful. To do so, take a glass-full, and 
 add a few drops solution of soap in alcohol ; if the water be 
 pure, it will continue limpid — if impure, white flakes will 
 be formed on the surface. 
 
 TO TAKE DAGUERREOTYPES ON IVORY. 
 
 Immerse ivory in a weak solution of nitrate of silver, 
 and let it remain until the solution has given it a deep 
 yellow color ; then put it into a glass of clean water, and 
 expose it in the rays of the sun until it becomes black; 
 polish it, and a brilliant silver surface is the result. Coat 
 it in the usual manner, submit it to the light in the 
 camera, and finish and gild as you would the ordinary 
 plate. 
 
CHAP. XV. 
 
 RESEARCHES ON THE THEORY OF THE PRINCIPAL PHE- 
 NOMENA OF PHOTOGRAPHY IN THE DAGUERREOTYPE 
 PROCESS. 
 
 BY A. CLAUDET.* 
 
 The principal phenomena in the Daguerreotype process 
 which have not yet been satisfactorily explained, are those 
 referring to the following points : 
 
 1st. What is the action of light on the sensitive coat- 
 ing? 
 
 2d. How does the mercurial vapor produce the Da- 
 guerreotype image ? 
 
 3d. Which are the particular rays of light that impart 
 to the chemical surface the affinity for mercury ? 
 
 4th. What is the cause of the difference in achromatic 
 
 * M. Claudet is not only one of the most theoretical but 'practical 
 Daguerreotypists of Europe, and no man in the Old World deserves 
 more credit for his persevering energy in experimenting and improv- 
 ing his art. He does not confine himself to the mere role of making 
 money ; his whole soul seems wrapped up in the study of his art, and 
 instead of making it a mechanical business, he raises it to its proper 
 sphere among the arts and sciences. I wish I could point to more 
 than one artist in this country to emulate him. Our operatives should 
 not be content with the superiority of their pictures over those of 
 Europeans, but they should know the cause, and knowing should be 
 able to explain it. They should study their art, and the sciences con- 
 nected with it, much more than at present. Notts verrons. 
 
 8 
 
160 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 lenses, between the visual and photogenic foci ] Why do 
 they constantly vary ? 
 
 5th. What, are the means of measuring the photogenic 
 rays, and of finding the focus at which they produce the 
 image ? 
 
 These are the various subjects I shall have to treat in 
 the present paper. At the last meeting of the British As- 
 sociation, which took place at Swansea, I announced that 
 the decomposition of the chemical surface of the Da- 
 guerreotype plate by the action of certain rays of light pro- 
 duced on that surface a white precipitate, insoluble in the 
 hyposulphite of soda, which, when examined by the mi- 
 croscope, had the appearance of crystals reflecting light, 
 and which, when seen by the naked eye, were the cause 
 of a positive Daguerreotype image. This fact had not been 
 observed before. The opinion of Daguerre himself, and 
 other writers, was, that the action of lights on the 
 iodide of silver, had only the effect of darkening the sur- 
 face and producing a negative image ; but it escaped 
 them, that under the darkened iodide of silver another ac- 
 tion had taken place, and that the hyposulphite of soda 
 could disclose a positive image. I have proved this unex- 
 pected fact in obtaining by the action of light only, and 
 without mercury, images having the same appearance as 
 those developed under the action of mercurial vapor. 
 This direct and immediate effect of light is certainly re- 
 markable; but the Daguerreotypist’s process is not 
 founded on that principle on account of the slowness of 
 its action. It is fortunate that long before light can pro- 
 duce the white coating I have alluded to, it produces ano- 
 ther effect, which is, the wonderful property of attracting 
 the vapor of mercury. This vapor is condensed in white 
 powder, leaving also, when examined by the microscope. 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 161 
 
 the appearance of reflecting crystals. The cause of the 
 Daguerreotype image is due to that property, which was 
 entirely discovered by Daguerre. 
 
 Mr. Moser has given an ingenious theory of the ac- 
 tion of mercury. ******* 
 * * * It is more probable that light exercises two 
 
 actions on the iodide of silver, whether it is or is not 
 combined with chloride of bromium. By one the iodide 
 is decomposed, and the silver set free is precipitated on 
 the surface in a white powder or small crystals by the 
 other, which begins long before the former ; the parts af- 
 fected by light have been endowed with an affinity for 
 mercurial vapor. 
 
 By means of my photographometer, (see Chap. XIII.) 
 to the principles of which I shall presently refer, I have 
 been enabled to ascertain that the pure light of the sun 
 produces, in about two or three seconds, the decomposi- 
 tion of the bromo-iodide of silver, which is manifest by 
 the white coating ; while the same intensity of light de- 
 termines the affinity for mercurial vapor in the wonderful 
 short space of about yoVo P art °f a second, so that the 
 affinity for mercury is produced by an intensity of light 
 three thousand times less than that which effected the de- 
 composition manifested by the white coating. 
 
 For this reason it is difficult to suppose that the two ac- 
 tions are the same. We must admit that they are diffe- 
 rent. Long before it can operate on the decomposition 
 of the chemical surface, light imparts to the sensitive 
 coating the affinity for mercurial vapor, and this appears 
 to be the principle of the formation of the image in the 
 Daguerreotype process. 
 
 * * * * I stated that the red, orange and yel- 
 low rays destroyed the action of white light, and that 
 
162 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 the surface recovered its former sensitiveness after hav- 
 ing been submitted to the action of those rays. I inferred 
 from that curious fact, that light could not have decom- 
 posed the surface, for if it had decomposed the compound, 
 it would be difficult to understand how the red, orange 
 and yellow rays could combine again elements so volatile 
 as iodide and bromine, after they had been separated from 
 the silver. 
 
 The action of light which can be destroyed by the red, 
 orange and yellow rays, does not determine the decompo- 
 sition, which would require an intensity three thousand 
 times greater. It is the kind of action produced with an 
 intensity three thousand times less, giving the affinity for 
 mercury, which is completely destroyed by the red, orange 
 or yellow rays. It seems, therefore, that I was right in 
 saying that there was no decomposition of the com- 
 pound during the short action which is sufficient to give 
 the affinity for mercury, or in ascribing the formation of 
 the image only to that affinity, while light, or the chemi- 
 cal rays which accompany it, communicate to the surface 
 the affinity for mercury, and the red, orange, or yellow 
 rays withdraw it. I must remark here a singular ano- 
 maly, viz., that when the sensitive surface is prepared 
 only with iodine without bromine, the red, orange, or yel- 
 low rays, instead of destroying the action of white light, 
 continue the effects of decomposition, or of affinity for 
 mercury. 
 
 This phenomenon was announced first by Mr. Edward 
 Becquerel, and immediately after M. Gaudin found that 
 not only these rays continue the action by which mercury 
 is deposited, but that they develope, without mercury, an 
 image having the same appearance as that produced by 
 mercurial vapor. M. Gaudin not knowing the fact of the 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 163 
 
 white coating, which is the result of decomposition by the 
 action of light, could not explain the cause of the image 
 brought out under the influence of the yellow rays. 
 
 I have observed, that the iodide of silver without bro- 
 mine is about one hundred times more sensitive than the 
 bromo-iodide of silver, to the action of light, which pro- 
 duces the decomposition of the compound forming the 
 white precipitate of silver, while it is one hundred times 
 less sensitive for the effect which gives the affinity for 
 mercury ; another reason for supposing that the two ac- 
 tions are different. It may be, that in the case of the 
 ioide of silver alone, the decomposition being more ra- 
 pid, and the affinity for mercury slower than when bro- 
 mine is added to the compound, the red, orange and yel- 
 low rays having to act only upon a commencement of de- 
 composition, have the power, by their own photogenic in- 
 fluence, to continue the decomposition when begun. This 
 is the explanation of the development of the image under 
 red, orange, or yellow glasses, according to M. Gaudin’s 
 discovery ; but in the case of bromo-iodide, the red, 
 orange and yellow rays have to exert their action on the 
 affinity for mercury, begun a long time before the decom- 
 position of the compound, and they have the power of de- 
 stroying that affinity. 
 
 Thus it would appear that all the rays of light have the 
 property of decomposing the iodide of silver in a longer 
 or shorter time, as they have that of producing the affinity 
 for mercury, or the bromo-iodide of silver, with this diffe- 
 rence, that on the former compound the separate actions 
 of the several rays continue each other, and on the se- 
 cond compound these separate actions destroy each other. 
 W e can understand that in the first case all the rays can 
 operate the same decomposition ; and that in the second 
 
164 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 the affinity for mercury, when given by one ray, is de- 
 stroyed by another. This would explain the various phe- 
 nomena of the formation of the two different deposits I 
 have described, and also explain the anomaly of the con- 
 tinuation of the action of light by the red, orange and 
 yellow rays, according to M. Ed. Becquerel’s discoveries 
 on the iodide of silver, and of the destruction of that ac- 
 tion by the same rays, according to my own observation, 
 on the bromo-iodide of silver. 
 
 The red, orange and yellow rays, when acting upon an 
 unaffected surface, are considerably less capable than the 
 most refrangible rays, of imparting the affinity for mercu- 
 rial vapor on both the iodide and bromo-iodide of silver ; 
 and they destroy that affinity when it has been produced 
 on the bromo-iodide by the photogenic rays. It follows 
 from that fact, that when the red, orange and yellow are 
 more abundant in the light than the other rays, the photo- 
 genic effect is retarded in proportion to the excess of their 
 antagonistic rays. This happens when there exists in the 
 atmosphere some vapors which absorb the most refrangi- 
 ble rays. In these circumstances the light appears rather 
 yellow, but is very difficult to judge by the eye, from the 
 exact color of the light, and the proportion of photogenic 
 rays existing in the atmosphere at any given moment. 
 
 The vapors of the atmosphere which make the light ap- 
 pear yellow, act as any other medium interrupting the 
 blue rays and those which are the most refrangible. I 
 prove by very simple experiment, the comparative photo- 
 genic action of rays which have passed through such 
 media, and of those which have met with no similar ob- 
 stacles ; and also that that media which intercept the pho- 
 togenic rays, will allow the illuminating rays to pass 
 freely If I cover an engraving one-half with light yellow 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 165 
 
 glass, and place it before my camera obscura to represent 
 the whole upon a Daguerreotype plate, I find that during 
 the time which has been necessary to obtain the image 
 of the half not covered, not the slightest effect has been 
 produced on the half covered with the yellow glass. 
 Now, if I cover one-half with deep blue glass, and the 
 other with the same light yellow glass, the engraving will 
 be distinctly seen through the yellow glass, and not at all 
 through the blue. In representing the whole, as before, 
 on the Daguerreotype plate, the half which was clearly 
 seen by the eye has produced no effect, and the other 
 which could not be seen, is as fully represented, and in 
 nearly as short a time as when no blue glass had been in- 
 terposed ^ ^ ^ ^ ^ ^ 
 
 In considering how difficult it is to judge by the eye 
 alone of the photogenic state of the light, we can under- 
 stand how the photographer is constantly deceived in the 
 effect he tries to produce, having no means to ascertain 
 beforehand, with any degree of certainty, the intensity of 
 the light. * * * 
 
 The photographometer gives the means of comparing 
 the degree of sensitiveness of two photogenic surfaces 
 differently prepared and of different kinds. This is done 
 by employing two moveable plates with seven vertical 
 openings, and two plates with seven corresponding holes. 
 Receiving both the same light during the same time, the 
 number of spots on each surface will indicate the compa- 
 rative sensitiveness of the two. 
 
 It is a remarkable fact, that the photogenic light cannot 
 be measured except by geometrical progression ; the dif- 
 ference of the effect in an arithmetical progression being 
 imperceptible. In comparing the intensity of any two 
 
166 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 spots following each other, although one has received 
 double the light of the next, it is difficult to find any sen- 
 sible difference in the color given by the deposit of mer- 
 cury ; it is for this reason that I have adopted the geome- 
 trical progression. 
 
 The photographometer has, therefore, taught me that 
 when a Daguerreotype picture is too black, I must double 
 the time of exposure for the next, in order to obtain a 
 marked difference ; and that when it is too white, or too 
 much done, I must, for the next, considerably reduce the 
 time of exposure. 
 
 This enables the photographer to try several experi- 
 ments in order to improve the sensitiveness of his prepa- 
 ration, and to adopt the best. There cannot be a surer 
 and simpler method of comparing two different degrees of 
 sensitiveness. By this means I have found that the sen- 
 sitiveness of the prepared plate increases by being kept 
 sometime before using it. A plate prepared one or two 
 days beforehand , is tivice as sensible as one prepared im- 
 mediately. When the prepared plates are kept in well- 
 shut dark boxes, they may be prepared several days ; I 
 have employed some three or four weeks after they had 
 been prepared, and I have found them exceedingly sensi- 
 tive, and producing good pictures. 
 
 Since the publication of my photographometer, I have 
 made an improvement which renders it more complete. 
 Instead of one series of seven round holes, I have intro- 
 duced four series; and by means of sliding blades, I can 
 open and shut at will any one of these four series. This 
 enables me to continue by repeated falls the geome- 
 trical progression from 1 to 512 on one plate, and when a 
 second plate is added, from 1 to 8,192; so that I can 
 compare and follow the different effects of light in a con- 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 167 
 
 siderable range of intensities. This is done in the follow- 
 ing manner : After giving one fall with all the slides open, 
 I shut one and give another fall, then shut the second and 
 give two falls, and so on, always doubling the number of 
 falls for every new slide shut. It is by this means that I 
 have been able to discover at what degree of intensity of 
 light the effect called solarization is produced. On a 
 well-prepared plate of bromo-iodide it does not begin 
 under an intensity of 512 times greater than that which 
 determines the first effect of mercury. I also learn at 
 what degree the decomposition producing the white preci- 
 pitate without mercury manifests itself, both on iodide and 
 bromo-iodide of silver. On the first it is 100 times 
 quicker than on bromo-iodide, and on the last it is pro- 
 duced by an intensity 300 times greater than that which 
 developes the first affinity for mercury. 
 
 In the course of my experiments I have noticed a cu- 
 rious fact, which became very puzzling to me until I was 
 able to assign a cause for it. I shall mention it here, be- 
 cause it may lead to some further discoveries. I had ob- 
 served, that sometimes the spaces under the round holes 
 which had not been affected by light during the operation 
 of the photographometer, in a sufficient degree to deter- 
 mine the deposit of mercury, were, as it was to be ex- 
 pected, quite black ; while the spaces surrounding them 
 were, in an unaccountable manner, slightly affected by 
 mercury. At first I could not explain the phenomenon, 
 except in supposing that the whole plate had previously 
 been by accident slightly affected by light, and that the 
 exposure through the hole to another sort of light, had 
 destroyed the effect. I was naturally led to that expla- 
 nation, having observed before, that one kind of light 
 destroys the effect of another, as for example, that the 
 
 8 * 
 
168 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 effect of light from the north is destroyed by the light 
 from the south , when certain vapors existing in the east 
 part of the atmosphere impart a yellow tint to the light 
 of the sun. 
 
 But after repeated experiments, taking great care to 
 protect the plate from the least exposure to light, and re- 
 collecting some experiments of Moser, I have found that 
 the affinity for mercury had been imparted to the surface 
 of the Daguerreotype plate by the contact of the plate 
 having the round holes, while the spaces under the holes 
 had received no similar action. But it must be observed, 
 that this phenomenon does not take place every time. 
 Some days it is very frequent, and at some others it does 
 not manifest itself at all. 
 
 In considering that the plate furnished with round holes 
 is of copper, and that the Daguerreotype plate is of silver, 
 plated on copper, it is probable that the deposit of mer- 
 cury is due to an electric or galvanic action, determined 
 by the contact of the two metals ; and perhaps, the cir- 
 cumstance that the action does not take place every time 
 would lead to suppose that it is developed by some pecu- 
 liar electric state of the ambient atmosphere, and to a de- 
 gree of dampness in the air, which would increase the 
 electric current. May we not hope that by understand- 
 ing the. condition in which the action is produced, and by 
 availing ourselves of that property, it would be possible 
 to increase on the Daguerreotype plate the action of light? 
 for it is not improbable that the affinity of mercury im- 
 parted to the plate, is also due to some electrical influence 
 of light. How could we explain otherwise that affinity 
 for mercury given by some rays, and withdrawn by some 
 others, long before light has acted as a chemical agent? 
 
 From the commencement of photography it was well 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 169 
 
 known that the rays operating being the most refrangible, 
 had a shorter focus than those producing white light ; for 
 this reason : Daguerre himself recommended the use of 
 achromatic lenses, in which all the rays were supposed to 
 coincide nearly at the same focus ; all the cameras obscures 
 are furnished with achromatic lenses, and constructed so 
 that the plate could be placed exactly at the same distance 
 as the ground glass upon which the image had appeared 
 the best defined. But with these cameras obscurae, it was 
 very difficult to obtain a photographic image so perfect as 
 that seen on the ground glass, and it was only now and 
 then, and as if by accident, that good pictures could be 
 produced. 
 
 I soon observed this anomaly, and imagined it was due 
 to some error in the respective position of the two frames, 
 one holding the ground glass, and the other containing 
 the plate, which by warping, or some other causes, might 
 have been shifted at different distances from the object 
 glass. Not being able to assign any other reason for the 
 error, I constructed a camera obscura in which the ground 
 glass and the plate were exactly placed in the same frame. 
 In doing so, I was in hopes to avoid the least error or de- 
 viation ; but to my surprise, the more correct I was in my 
 adjustment, the less I could obtain a well defined Daguer- 
 reotype picture. This proved to me that I had to seek 
 for another cause of the difficulty, and before going any 
 further I decided to try if the visual focus was, or not, 
 really coinciding with the photogenic focus. For the ex- 
 periment, I placed at a distance from the camera obscura 
 several screens on different plans. These screens being 
 covered with black lines, I could see them very distinctly 
 on the ground glass. I tried the focus upon one of the 
 screens. To my surprise and delight, I invariably found 
 
170 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 that the one that appeared well defined on the ground 
 glass, was confused on the Daguerreotype plate, and vice 
 versa. This was sufficient to prove to me the cause of 
 the difficulty I had been laboring under, viz., that the 
 visual focus was not coinciding with the photogenic focus. 
 But the most surprising feature of that discovery was, 
 that the photogenic focus was larger than the visual 
 focus ; at first consideration it should have been shorter, 
 as the rays operating in photography are the most refran- 
 gible, although I could not at first understand the cause of 
 that anomaly ; it was sufficient to me to know, that in 
 order to have a well defined Daguerreotype picture, 1 had 
 only to set the focus on the ground glass for an object 
 nearer the camera, at the distance indicated by the va- 
 rious screens. In continuing my experiment, I found 
 some lenses in which the photogenic focus was shorter, 
 and some others in which the two foci were coinciding. 
 
 M. Lerebour, of Paris, was the first, who, on my sug- 
 gestion, examined the subject. He stated that by altering 
 the proportions between the angles inscribed in the curves 
 either of the crown or flint glass, he could render at 
 will the photogenic focus longer or shorter than the visual 
 focus ; and by the same means could bring them to the 
 same point. There is no question that M. Lerebour was 
 right, as far as the result referred to the chromatic correc- 
 tion ; but if, according to the density of the two glasses, 
 certain curvatures are required to correct the spheraical 
 aberration, these curvatures cannot be altered with impu- 
 nity, only for the purpose of changing the direction of the 
 most refrangible rays. For this reason, I have always 
 preferred lenses in which the spherical aberration is the 
 most perfectly corrected, without caring if the photogenic 
 rays are or not coinciding with the visual rays, having the 
 
RESEARCHES IN PHOTOGRAPHY, 
 
 171 
 
 means of ascertaining how I could obtain on my Daguer- 
 reotype plate the best defined image. In fact, from my 
 own observations, that the red, orange, and yellow rays are 
 antagonistic to the photogenic rays, that the last rays have 
 a greater power when the former are proportionately less 
 abundant, I am of opinion, that when the photogenic 
 rays are only condensed on the plate, and that the others 
 are disposed on the spaces more or less distant from the 
 photogenic point, the action is more rapid ; rapidity be- 
 ing the object in photography. I prefer lenses in which the 
 two foci are separated, although the operation is a little 
 more difficult, and requires considerable care. 
 
 The question of the photogenic focus is involved in 
 another kind of mystery, which requires some attention. 
 I have found that with the same lens there exists a con- 
 stant variation in the distance between the two foci ; they 
 are never in the same relation to each other ; they are 
 sometimes more or less separated ; in some lights they are 
 very distant, and in some others they are very near, and 
 even coincide. For this reason I constantly try their po- 
 sition before I operate. I have not yet been able to disco- 
 ver the cause of that singular phenomenon ; but 1 can state 
 positively that it exists. At first I thought that variations 
 in the density of the atmosphere might produce the altera- 
 tion in the distance between the two foci, or that, when the 
 yellow rays were more or less abundant, the usual rays 
 were refracted on different points of the axis of the foci, 
 according to the mean refrangibility of the rays composing 
 white light at the moment. But a new experiment proved 
 to me that these could not be the real causes of the varia- 
 tion, 1 generally employ two object glasses, one of 
 shorter focus for smaller pictures, and the other of larger 
 for larger images. In both, the photogenic focus is larger 
 
172 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 than the visual focus : but when they are much separated 
 in one, they are less in the other. Sometimes when they 
 coincide in one, they are very far apart in the other, and 
 sometimes they both coincide. This I have tried every 
 day for the last twelve months, and have always found the 
 same variations. This density of the atmosphere, or the 
 color of light, seems to have nothing to do with the pheno- 
 menon, otherwise the same cause would produce the same 
 effect in both lenses. I must observe, that my daily expe- 
 riments ou my two object glasses, were made at the same 
 moment, and at the same distance for each, otherwise 
 any alteration in the focal distance would disperse more 
 or less the photogenic rays, which is the case as I have as- 
 certained it. The lengthening or shortening the focus 
 according to the distance of the object to be represented 
 has for effect to modify the achromatism of the lenses. 
 
 An optician, according to M. Lerebours calculations, 
 can, at will, in the combination of the two glasses com- 
 posing an achromatic lens, adapt such curvatures or angles 
 in both, by which the visual focus will coincide with the 
 photogenic focus : but he can obtain this result only from 
 one length of focus. The moment the distance is altered 
 the two foci separate ; because the visual and photogenic 
 rays must be refracted at different angles in coming out of 
 the lens, in order to meet at the focus given for one dis- 
 tance of the object. If the distance is altered, the focus 
 becomes longer or shorter ; and as the angle at which diffe- 
 rent rays are refracted remains nearly the same, they can- 
 not meet at the new focus, and they form two images if 
 the visual and photogenic rays were refracted parallel to 
 each other in coming out of the lens, they would coincide 
 for every focus ; but this is not the case ; it seems there- 
 fore impossible that lenses may be constructed in which 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 173 
 
 the two foci will agree for all the various distances until 
 we have discovered two kinds of glasses in which the 
 densities will be in the same ratio as their dispersive 
 power. 
 
 There is no question so important in photography as 
 that which refers to finding the true photogenic focus of 
 every lens for various distances. I have described the 
 plan I have adopted for that purpose. By means of that 
 very simple instrument, every photographer can always 
 obtain well defined pictures with any object glasses. But 
 there is another method of ascertaining the difference be- 
 tween the two foci, which has been lately contrived by 
 Mr. G. Knight, of Foster-lane, London. As that gentle- 
 man has been kind enough to communicate to me the 
 very ingenious and simple apparatus by which he can find 
 at once the exact difference existing between the visual 
 and photogenic focus, and place the Daguerreotype plate 
 at the point where the photogenic focus exists, I am 
 very glad that he has intrusted me with the charge of 
 bringing his invention before the British Association. 
 For the scientific investigation of the question, Mr. 
 Knight's apparatus will be most invaluable, as it will af- 
 ford to the optician the means of studying the phenome- 
 non with mathematical accuracy. 
 
 Mr. Knight’s apparatus consists in a frame having two 
 grooves, one vertical, in which he places the ground glass, 
 and the other forming an angle with the first. The 
 planes of the two grooves intersect each other in the mid- 
 dle. After having set the focus upon the ground glass, this 
 last is removed, and the plate is placed on the inclined 
 groove. Now, if a newspaper, or any other large sheet 
 printed, is put before the camera, the image will be repre- 
 sented on the inclined plate, and, it is obvious, that in its 
 
174 
 
 RESEARCHES IN PHOTOGRAPHY. 
 
 inclination, the various points of the plate will meet a dif- 
 ferent focus. The centre of the plate will coincide with 
 the visual focus, and in the other direction it is longer. 
 The frame is furnished with a scale of division having the 
 zero in the centre ; when the image is represented on the 
 Daguerreotype, by applying against it another moveable 
 scale of division, similar to the other, the operator can 
 find what is the division above or under zero at which the 
 image seems the best defined ; and after having removed 
 from the camera the experiment frame, and set the focus 
 as usual upon the ground glass, he has only to move the 
 tube of the object glass by means of the rack and pinion, 
 and to push it in or out of a space corresponding with the 
 division of the scale indicating the deviation of the true 
 photogenic focus.* The tube of the object glass is foi 
 that purpose marked with the same scale of division. 
 
 Before concluding, I shall call the attention of all pet 
 sons conversant with optics, to the singular fact I hav / 
 observed respecting the constant variation of the foci. L 
 have not been able yet to find its cause, and I leave its in- 
 vestigation to more competent persons. 
 
 I must remark that the principal difficulty of obtaining 
 well defined pictures, is due to the dispersion of the chem- 
 ical rays which are spread by glass prisms on a more or 
 less elongated space ; so that a spectrum formed by such 
 glass prisms, may be shorter or longer according to the 
 dispersive power of the glass composing the prism. It 
 happens, therefore, that in some object glasses that dis- 
 persion may be less than in some others ; and in such 
 
 * This fact has long been known to Daguerreotypists in the United 
 States, and camera boxes are now constructed to obviate the diffi- 
 culty. 
 
RESEARCHES IN PHOTOGRAPHY. 
 
 175 
 
 lenses the variation of the two foci will be less observa- 
 ble. It appears, besides, that with the same glass, the dis- 
 persion is greater or smaller according to the quality of 
 light or other atmospheric influences, and also according 
 to the angle of incidence. Sometimes the various screens 
 intended to try the focus, appear all well defined, although 
 the screens are placed at different distances from the ca- 
 mera, in a range of twelve or fifteen inches. In this case, 
 it is not so important to find the very best focus ; and the 
 image may be well defined whether the object is placed 
 at twelve or fifteen inches nearer or further from the ca- 
 mera. But in some other circumstances, in setting the 
 focus on one screen, the next, which is three inches dis- 
 tant, is confused, and the following still more ; in those 
 cases, the dispersion is at its maximum ; and it is then 
 that it is of the greatest importance to attend to trying 
 the focus before operating. 
 
CHAP. XVI. 
 
 POSITION. 
 
 True grace is inherent in nature, and is the attribute 
 of the soul overflowing with a God-like perception of the 
 grand and beautiful in nature ; it is as far beyond the 
 reach of the mind, grovelling in the depths of ignorance, 
 to the. one as to the other ; and it is for this reason that 
 we find so many, who, although they may admire a fine 
 picture, statue, or edifice, are at fault, when asked the 
 wherefore. 
 
 We have only to look upon the red man of the forest, 
 in his wild, free state, for a confirmation of this fact. 
 Nature is his only study, and from that he looks up to 
 nature’s God ; views Him through His works — knowing 
 little, it is true, of His great omnipotence and tender mer- 
 cies — and looks upon Him with a sublimity of awe that is 
 evident in every step, every motion, every gesture, and 
 every thought of his mind. It may be thought by some 
 that I am romancing in this picture of the Indian charac- 
 ter ; but a long sojourn among the north-western tribes, a 
 knowledge of their religions rites, and scenes often wit- 
 nessed in the forest and the council chamber, convinces 
 me that in the savage breast there lurks a true conception 
 of the graceful and beautiful. 
 
 Still I would not have it supposed, for a moment, that 
 any one is debarred from appreciating and acquiring 
 grace ; although it were not possible to bend the lordly 
 
178 
 
 POSITION. 
 
 oak in unison with the graceful lily or violet, yet its un- 
 seemly and tortuous branches end rough exterior may be 
 trained and trimmed by skillful hands to delight the refined 
 taste, while it is deprived of none of its grandeur. 
 
 So it is with the human form. Education, that great 
 moulder of the mind, exerts its powerful influences, 
 changes the boor to the philosopher, the awkward hind to 
 the stately gentleman, and 
 
 “ Just as the twig is bent the tree inclines;” 
 
 but only just in proportion to the natural instinct of the 
 mind, and the bent given to it, will it duly observe and ap- 
 preciate. 
 
 The body may be said to be under the same natural 
 law. We have only to visit any dancing-school, study the 
 character and ability of the teacher and his pupils, to un- 
 derstand this fact fully. If he be one in whom grace 
 abounds, you will see him gradually mould that awkward 
 miss or boorish master into personifications of grace and 
 elegance ; but if he be a mere automaton, who, without one 
 idea on the poetry of motion, has resolved to turn into dollars 
 and cents what little knowledge of the art he has occasion- 
 ally picked up, you will see that awkward miss and boorish 
 master, still the awkward miss, still the boorish master ; 
 while the naturally graceful will, by their own natural in- 
 stinct, in grace improve. Dancing academies, properly 
 conducted, are the schools of grace. There is this differ- 
 ence, however, between a natural and a cultivated taste ,* 
 the first leads while the latter follows. 
 
 Any one can be a Daguerreotypist, but every one can- 
 not be successful. A picture may be mechanically well 
 done, yet not be pleasing to the eye or the taste ; and 
 where an operator is proverbially deficient in producing 
 
 
POSITION. 
 
 179 
 
 sucn as are, he must expect to see his next door neigh- 
 bor who excels him in taste, as well as being his equal 
 in mechanical skill, receive the patronage he deserves. 
 
 To obviate this superiority, is in the power of almost 
 every one, who is not too indolent to study. Allison on 
 Taste, is a good book to begin with ; but do not stop 
 there ; go to the studios of our best artists, study the posi- 
 tions of their finest productions, observe the manner in 
 which they dispose of the drapery, the position of the 
 figure, and the effect of light and shade. Next visit ex- 
 hibitions of statuary of acknowledged merit, and study 
 them carefully ; drink in deeply the criticisms of those 
 whose tastes are above reproach, and fix indelibly in 
 your mind such comparisons as are considered just. By 
 this means you will be enabled to form a better judgment 
 in regard to the merits and demerits in the figure of your 
 sitter, and place them in the most striking, graceful, and 
 pleasing position. 
 
 It is as necessary to study the various conformations of 
 the body, in order to place it in ease and elegance, as to 
 learn the alphabet before you can write a word ; and as 
 every individual differs more or less in structure from 
 another, the points of difference should be noted, and po- 
 sition given accordingly. 
 
 These are matters which must, of necessity, be left to 
 the taste of the artist, and if he finds himself deficient, he 
 must endeavor to follow the directions above given, or 
 seek the advice and instruction of those who are capable 
 of giving them. But I have said, in a general way, as 
 much as time and space will permit, and will now endea- 
 vor to particularize, although I candidly admit that I give 
 my own views entirely ; and as they may differ from other 
 and more competent tastes, they must be taken only for 
 
180 
 
 POSITION. 
 
 what they are worth, and their deficiencies or errors avoid- 
 ed by the study of other authors. 
 
 Fig. 32. 
 
 A large skylight with a screen of blue tissue paper — or 
 the glass may be tinged with blue — gives the best light for 
 Daguerreotype purposes, as well as for oil painting. In 
 the first place, because the light is more evenly diffused 
 about the room, and enables the operator to place the sit- 
 ter so as to form the best and most pleasing contrasts oi 
 light and shade. In the second place, the blue tissue 
 paper has the property of separating the yellow or non- 
 photographic rays of light from the photographic, and ad- 
 mitting the latter only into the room. 
 
POSITION. 
 
 181 
 
 Fig. 83. 
 
 As I have said in my “Hints and Suggestions,” Chap. 
 IV., the sitter should be placed so as to hide any defects 
 in the conformation of the body or limbs, and to bring 
 out all the good points. I know of no fixed rule to be ob- 
 served, but should judge from my own observation, that 
 where a person is short, and inclined to corpulency, as great 
 a distance from the object glass as possible, with a slight 
 inclination to one side, would be an advantage ; while to 
 a tall, spare figure, a nearer approach to the spectrum, and 
 a full front of the body, would produce good effect. If 
 the arms and legs are long in proportion to the body, a 
 slight contraction of the first; and the latter drawn up 
 near the chair, but not to so great a degree as to be awk- 
 ward, will improve the picture. The hands should rest 
 perfectly easy on the lap, neither too low or too high ; or 
 
182 
 
 POSITION. 
 
 one may rest upon a table, and the other support the folds 
 of drapery or hold a book. In any case it should be 
 so placed as to observe the unities of figure — a short, 
 thick hand should present the thumb in the foreground, 
 the first, third, and second fingers being slightly bent un- 
 der. A very long hand looks best with the back in view, 
 and a really beautiful one, neither too longer short, should 
 present a two-thirds view, allowing it to taper off gracefully 
 from the second joint of the little finger to the tip of the 
 first. To thrust the legs forward at an inclination of 
 forty or forty-five degrees, is very inelegant ; and to lean 
 back in the chair with one arm hanging over it, and the 
 thumb of the other stuck in the button-hole, is any thing 
 but graceful. A slight bend to the body forward, and a 
 little to one side, will always improve the position and 
 render the picture pleasing. A shawl or cloak thrown 
 easily and gracefully over the shoulders, and so disposed 
 as to hide any deformity, and give strong contrast between 
 light and shade, will prove very effective. 
 
 Never allow your sitter to sit “ bolt upright ” and look 
 directly into the camera, for reasons already given; it is 
 very bad taste, and it is equally so to place either of the 
 arms “ a-kimbo” or in a group, for one to put an arm over 
 the chair-back and on the shoulder of the other. In a pic- 
 ture where two persons are to be represented, it would be 
 much more elegant either to let one stand leaning grace- 
 fully on the chair of the other, at a table, or against a pil- 
 lar ; in either case they should be turned partially to- 
 wards each other, as if in the act of conversing. Or they 
 may be seated opposite at a table, the right arm of the 
 one and the left arm of the other resting upon it, their bo- 
 dies slightly bent, with an inclination to the right and left 
 
POSITION. 
 
 183 
 
 if in conversation. The shoulders should be suffered 
 to fall off naturally, and not be crowded upon the neck. 
 
 Where a group of more than two is taken, the judg- 
 ment of the operator alone must be consulted, as their po- 
 sitions must depend upon the size and sex, and the na- 
 ture of the light. I have seen beautiful effect produced 
 (in a family group) by seating the husband in the chair, 
 the wife on an ottoman at his feet, resting, with a slight in- 
 clination, upon his knee, and looking affectionately up 
 into his face ; while one child playfully climbed the back 
 of his chair, and looked over his shoulder into his face, a 
 second stood by his side playing with his watch seals and 
 key, while to complete the picture, the eldest, a lovely 
 girl of eight years, stood on the opposite side, just behind 
 the mother, caressing the ringlets that gracefully hung 
 from the parental head over the shoulder. 
 
 What positions could be more beautiful, graceful, or 
 affectionate ? At the same time it brought every figure 
 in perfect focus, and the result was, a picture magnificent 
 in the extreme. 
 
184 
 
 POSITION. 
 
 An inspection of Figures 32 and 33, will give an idea 
 of the difference between a graceful picture and one ex- 
 cessively awkward. 
 
 Fig. 34. 
 
POSITION. 
 
 i. So 
 
 Fig. 35 . 
 
 The position of the face should next be considered. 
 There are many points to be observed in placing the head 
 in a position to be the most effective. I have noticed that 
 in a majority of instances, that the most homely faces make 
 the handsomest pictures ; this is a fact that will be duly 
 appreciated by all. and will undoubtedly lead to the query 
 why it is so? and I answer that it is mainly owing to the 
 fact that ugly faces have more strongly marked outlines 
 
186 
 
 POSITION. 
 
 than those that are beautiful; the image produced there- 
 fore by the camera possesses greater contrast in light and 
 shade, which, while they give a greater depth of tone and 
 a more pleasing effect, do not betray the defects. There 
 are, of course, exceptions, but they are few, and might be 
 remedied by proper position. 
 
 We will take for instance, Figures 34 and 35 as an il- 
 lustration. They are both portraits of our worthy and 
 gallant President in different positions. While the first 
 represents him in a very unfavorable position, the other 
 shows him as he really is, when animated and graceful. 
 
 In Daguerreotypiug, I should, as a general thing, 
 adopt the following rules, although in some instances I 
 should possibly have to deviate. # 
 
 A full round face, with large mouth, small eyes and 
 nose, I should make what is called a half face, that is, 
 where the whole of one side, and a very small portion of 
 the other is seen, being but a slight remove from the pro- 
 file likeness — Fig. 34. 
 
 Of a moderately full face, with aquiline nose and hand- 
 some mouth and eyes,* I would make a three-quarter pic- 
 ture, wherein all the features of one portion of the face 
 would be visible, and about one-fourth of the other. 
 
 A face in which the features were a little more promi- 
 nent, a three-quarter view would be preferable. 
 
 And one in which the lines are very strongly marked, 
 and bordering upon projecting angles, I should decidedly 
 make a full front view. 
 
 Always endeavor to throw life into the expression of 
 your sitter’s face by animate conversation, ora pleasant 
 and polished witticism, avoiding all approach to the broad 
 grin. 
 
 I am not aware that any one else has made these obser- 
 
POSITION. 
 
 187 
 
 vations, and there may be those who will differ from me ; 
 be that as it may, I give them for what they^ may be worth, 
 and shall be happy — if my ideas are erroneous — to have 
 them corrected by an older and abler hand. I have re- 
 deemed my promise to those who desired the insertion of 
 this chapter to the best of my ability ; not venturing to 
 express my own opinions until several applications to those 
 W'hom I consider as more competent had failed, to meet 
 that encouragement I was led to expect. I might occupy 
 two hundred pages of a work of this size on this subject, 
 without exhausting it; but I trust what I have said will be 
 sufficient for our present purpose. 
 
APPENDIX. 
 
 LUNAR PICTURES.— See page 127. 
 
 Mr. Snelling : 
 
 .Sir, — In reference to the article upon this subject, I 
 would state that I succeeded in obtaining, with one of 
 my instruments, a distinct and strongly marked impres- 
 sion of the moon. On that occasion I used a half size 
 cam'era and a medium plate, as prepared for taking a 
 portrait. I found that one minute in the camera was 
 sufficient time to obtain a strong picture, but that if suf- 
 fered to remain longer, the indistinctness consequent 
 upon the moon’s motion, was as clearly exhibited as 
 the movement of a sitter for a portrait. After this ex- 
 periment, I endeavored to obtain an impression of some 
 object illuminated by the moon’s rays, and selected for 
 this purpose a white wooden building. On the ground 
 glass the image was strongly marked, a pane of glass 
 in a window of the building reflecting the light like a 
 concave mirror. The plate w~as then exposed in the 
 camera for three-quarters of an hour, but no impression 
 was obtained. 
 
 The above trial was made upon a clear, moonlight 
 night in November. My next experiment was to obtain 
 an image of some object illuminated by a candle. For 
 this purpose I used a page of music. Its image on 
 the glass was much stronger than that given by the 
 moon in the previous experiment. The plate was .al- 
 lowed to remain in the instrument five minutes, but no 
 impression was obtained save of the candle flame. The 
 image on the plate, if the expression could be used, was 
 strongly “ solarized ,” a circumstance that deserves in- 
 vestigation. Another trial was made, and the time re- 
 duced to one minute, and a good picture of the flame 
 
144 
 
 APPENDIX. 
 
 on all the different processes of obtaining pictures by 
 the agency of light, renders it a most valuable assistant 
 to artists. 
 
 I have to offer many apologies for my inability to 
 reply to your inquiries at an earlier moment. 
 
 With regard, &C., 
 
 John Roach, Optician. 
 
 Daguerrian Depot, 
 
 79, Nassau Street. 
 
INDEX 
 
 Page 
 
 Accelerating Liquids. .... 69 
 
 Amphitype. . . . . .120 
 
 Antliotype. . . . . . 117 
 
 Apparatus. Daguerreotype .... 47 
 
 Calotype . . . . 101 
 
 Photogenic .... 91 
 
 Application of Photogenic Drawing. . . 99 
 
 Applying the Sensitive. ... 68 
 
 Bringing out the Picture. .... 75 
 
 Bromine. To make . . . « 147 
 
 Bromine Box. ..... 55 
 
 Chloride of .... 72,148 
 
 Roach’s Triple Compound of . . 71 
 
 Water. ..... 69 
 
 Bromide of Iodine. .... 71,148 
 
 of Lime. ..... 72 
 
 Paper. ..... 95 
 
 of Silver. ..... 39 
 
 Bromic Acid. ..... 153 
 
 Brushes. ...... 92 
 
 Buff’ Sticks. ..... 64 
 
 Buff Powder. ..... 156 
 
 Calotype Process. ..... 101 
 
 Paper. Exposure in Camera of . . 104 
 
 Pictures. Bringing out . • . ib. 
 
 Fixing . , . 105 
 
 Camera. Description of the . ... 47 
 
 Stand. ..... 53 
 
 Woodbridge’s . . . . ib. 
 
 Calotype . . • • . 54 
 
 Voightlander .... 49 
 
 Chlorine . . . • * . 148 
 
 Chloride of Bromine. • • • • 72 
 
vi 
 
 INDEX. 
 
 Chloride of Calcium. 
 
 of Gold. . 
 
 To make a solution of 
 
 of Iodine, 
 of Silver. 
 
 Chromatype. 
 
 Chrysotype. 
 
 Cleaning and polishing the plate. 
 
 Colored Daguerreotypes. To take 
 Coating Boxes. 
 
 Color Boxes. 
 
 Colored Daguerreotypes on Copper 
 Coloring the Picture. 
 
 Daguerreotypes. 
 
 Concave Mirrors, 
 
 Convex Mirrors. 
 
 Corchorus Japonica. 
 
 Crayon Daguerreotypes. 
 
 Cyanotype. . 
 
 Daguerreotype Apparatus. 
 
 Process. 
 
 Plates. 
 
 Daguerreotypes. Crayon 
 on paper. 
 
 Davie’s Improved Buffing Lathe. 
 
 Dedication. 
 
 Definitions of terms used in optics. 
 
 Different methods of preparing photogenic paper. 
 Directions for use of Galvanic Battery. 
 
 Distilled water. 
 
 Drummond light. . . * 
 
 Dry Sensitive. 
 
 Drying apparatus. 
 
 Effects of light on bodies. 
 
 Energiatype. . . • 
 
 Etching Daguerreotypes. 
 
 Fifth operation. Fixing the picture. 
 
 First operation. Cleaning the plate. 
 
 Fluoric Acid. t . . . 
 
 Fossil Powder. 
 
 Fourth operation. Bringing out the picture. 
 Funnels. . 
 
 Page 
 
 155 
 
 40, 149, 150 
 
 79 
 70 
 
 35, 153 
 116 
 110 
 65 
 
 132 
 55 
 57 
 8 L 
 
 80 
 
 133 
 20 
 ib. 
 41 
 
 133 
 113 
 
 47 
 
 65 
 
 66 
 81 
 85 
 
 145 
 iii 
 16 
 93 
 62 
 92 
 132 
 
 72 
 76 
 
 26 
 
 115 
 87 
 
 65 
 ib. 
 
 73 
 
 156 
 75 
 57 
 
INDEX. 
 
 
 vii 
 
 Page* 
 
 Galvanic Battery. 
 
 
 . 61 
 
 Solution for use of . 
 
 
 62 
 
 Gallic Acid. 
 
 
 153 
 
 Gilding stand. . . 
 
 
 57 
 
 the picture. . 
 
 
 78 
 
 Glass. Pictures on 
 
 • 
 
 111 
 
 Gold. Chloride of 
 
 • 
 
 40 
 
 To make solution of 
 
 • 
 
 79 
 
 Hyposulphite ; or Salt of 
 
 
 78 
 
 Preparation of 
 
 
 40 
 
 Gurney’s Sensitive.* 
 
 
 71 
 
 Head Rests. 
 
 
 61 
 
 Hints and Suggestions. 
 
 
 43 
 
 History and Photography. 
 
 
 3 
 
 Hungarian Liquid. . 
 
 
 73 
 
 Hygrometers. • 
 
 
 59 
 
 Hydrofluoric Acid. 
 
 
 155 
 
 Hyposulphite of Gold.. 
 
 
 . 78, 150 
 
 of Soda. 
 
 
 . 29, 152 
 
 Instantaneous pictures by means of Galvanism. 
 
 81 
 
 Introduction, 
 
 
 . i 
 
 Iodine. Dry .... 
 
 
 . 68,151 
 
 Chloride of 
 
 
 .. 70, ib. 
 
 Bromide of , . 
 
 
 , 71 
 
 Box. .... 
 
 
 55 
 
 Iodide of Silver. 
 
 
 36 
 
 loduret of Silver. . 
 
 
 . 37, 153 
 
 Iodize the Plate. To 
 
 
 68 
 
 Iodized Paper for Calotypes. To prepare 
 
 
 102 
 
 To prepare for the Camera 
 
 . ib. 
 
 Lamps. Spirit 
 
 
 57 
 
 Light, Theory on 
 
 
 15 
 
 Motion of . 
 
 
 17 
 
 R eflection of . 
 
 
 18 
 
 Refraction of 
 
 • 
 
 21 
 
 On bodies. Effects of 
 
 • 
 
 26 
 
 Prismatic Analysis of 
 
 • 
 
 23 
 
 Lime. Bromide of 
 
 
 . 72 
 
 Lunar Pictures. 
 
 
 131 
 
 Mead’s Accelerator. . 
 
 
 . 72 
 
 Mercury. . 
 
 9 * 
 
 • 
 
 155 
 
viii 
 
 INDEX. 
 
 Mercury Bath. 
 Nitrate of Silver. 
 
 • 
 
 • 
 
 • 
 
 
 Page 
 
 54 
 
 93, 153 
 
 Oxide of Silver. 
 
 
 
 
 30, ib. 
 
 On coloring Daguerreotypes. 
 
 
 
 
 133 
 
 On the probability of producing colored Photogra 
 
 iphs. 
 
 127 
 
 Paper, blotting; or bibulous. 
 
 
 
 
 92 
 
 Daguerreotypes* 
 
 
 
 
 85 
 
 preparation of 
 
 
 
 
 93 
 
 suitable for Photographs. 
 
 
 
 
 91 
 
 Photogenic drawing on 
 
 
 
 
 ib. 
 
 Paste for sealing paper. 
 
 
 
 
 156 
 
 Photographic principle. The 
 
 
 
 
 23 
 
 Photogine. 
 
 
 • 
 
 
 156 
 
 Position. 
 
 
 • 
 
 
 177 
 
 Potassium. Chloride of 
 
 
 • 
 
 • 
 
 154 
 
 Cyanide of 
 
 
 
 
 ib. 
 
 Bromide of 
 
 
 
 
 ib. 
 
 Iodide of 
 
 
 
 
 ib. 
 
 Potassa. Chlorate of 
 
 
 
 
 ib. 
 
 Photographic process on paper. 
 
 
 
 
 96 
 
 drawing. Application of 
 
 • 
 
 
 99 
 
 To fix the 
 
 
 n 
 
 
 97 
 
 deviations. 
 
 
 • 
 
 
 '130 
 
 Photographometer. The 
 
 
 
 
 141 
 
 Plate Support. 
 
 
 • 
 
 
 63 
 
 Blocks. 
 
 
 • 
 
 
 54 
 
 Vice. 
 
 
 • 
 
 
 55 
 
 Poppy. The Red 
 
 
 
 
 41 
 
 Porcelain dishes. 
 
 
 
 
 63 
 
 Positive Calotype. • 
 
 
 • 
 
 
 108 
 
 Preface. 
 
 
 • 
 
 
 V 
 
 Preparation of Iodized Paper. 
 
 
 • 
 
 
 102 
 
 of Gold. 
 
 
 • 
 
 
 40 
 
 Prismatic Spectrum. 
 
 
 • 
 
 • 
 
 23 
 
 Analysis of Light. 
 
 
 • 
 
 « 
 
 ib. 
 
 Recipes. 
 
 
 
 • 
 
 147 
 
 Reflection of Light. . . 
 
 
 
 
 18 
 
 Refraction of Light, 
 
 
 
 
 21 
 
 Researches on the Theory of the principal pheno- 
 mena of Photography in the Daguerreotype 
 Process. ... 
 
 Roach’s Triple Compound of Bromine. • 
 
 159 
 
 71 
 
I 
 
 INDEX. ix 
 
 Paoe 
 
 Sand Clock. ...... 74 
 
 Sealing paper. To make. .... 81 
 
 Sealing Wax. . . * • • 1 56 
 
 Second operation. . . . . . 98 
 
 Sensitive. ..•••• ib. 
 
 Silver. Bromide of . . . . 39 
 
 Chloride of . . . . . 35, 153 
 
 Iodide of .... * 36 
 
 Ioduretof . .... 37 
 
 Nitrate of . . • . 93 
 
 Oxide of ..... 29 
 
 Solution of Chloride of • 63 
 
 Sixth operation. . . . . . 78 
 
 Soda, Hyposulphite of . . . . 76 
 
 Solar and Stellar Light. .... 22 
 
 Still for purifying water. .... 58 
 
 Submitting the Plate to the action of Light . 73 
 
 Synopsis of Mr. Hunt’s Treatise on Light. . 30 
 
 Talbotype Camera. . . . . 54 
 
 Theory on Light. . . . . . 15 
 
 Thompson’s Chloride of Gold. . . . 150 
 
 Accelerator. . . . . 151 
 
 Dry Quick. . . . 152 
 
 Third operation. . . . . . 73 
 
 To disinfect a room of Bromine vapor. . . 157 
 
 To purify water. . .... ib. 
 
 To take Daguerreotypes on Ivory. . . . ib. 
 
 Wall flower. .... 41 
 


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