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MANIPULATIONS 
 
 IN THE 
 
 SCIENTIFIC ARTS. 
 
 PART III. 
 
 PHOTOGENIC MANIPULATION. 
 
PHOTOGENIC MANIPULATION: 
 
 PART I. 
 
 CONTAININa 
 
 THE THEORY AND PLAIN INSTRUCTIONS 
 
 IN THE ART OF 
 
 PHOTOGRAPHY, 
 
 OR 
 
 THE PRODUCTION OF PICTURES THROUGH THE AGENCY 
 OF LIGHT: 
 
 INCLUDING 
 
 CALOTYPE, I CHROMOTYPE, 
 
 PLUOEOTYPE, CHRYSOIYPE, 
 
 EEREOTYPE, 1 CYMOTYPE, 
 
 CATALISSISOTYPE AND ANTHOTYPE. 
 
 BY 
 
 EGBERT J. BINGHAM, 
 
 CHEMICAL ASSISTANT IN THE LABOEATORY OF THE LONDON INSTITUTION. 
 
 lllustratetr tg 512aootrfuts. 
 
 FIFTH EDITION. 
 
 LONDON: 
 
 PUBLISHED BY GEORGE KNIGHT AND SONS, 
 
 MANUFACTURERS OF CHEMICAL APPARATUS AND 
 PHILOSOPHICAL INSTRUMENTS. 
 
 FOSTER- LANE, CHE APS IDE. 
 
Entered at Stationers' Hall. 
 
 London : 
 
 Printed by Stewart and Murray, 
 Old Bailey. 
 
PREFACE. 
 
 In consequence of the lamented death of Mr. G. T. 
 FisheR; the author of Photogenic Manipulation/^ I 
 was requested to prepare a Fourth Edition of that 
 work for the press j but on commencing my task, I 
 found that the rapid strides which have been made in 
 this interesting art, since the last edition was pub- 
 lished, would require such extensive alterations, that 
 the composition of an entirely new work appeared 
 preferable. I hope the amateur will find in the fol- 
 lowing pages, a complete Manual, embracing all the 
 information requisite to his success in obtaining 
 pictures, by that mysterious agent — Light. 
 
 Robert J. Bingham. 
 
 London Institution^ August 1847 . 
 
CONTENTS. 
 
 Introductory Remarks : — 
 
 Definition of Photography 
 
 Brief History of the Science 
 
 Ritter’s Experiments .... 
 
 Actinism ..... 
 
 Wedgewood’s Experiments • 
 
 Heliography ..... 
 
 Discovery of the Calotype 
 Apparatus and Materials : — 
 
 Paper ...... 
 
 Bibulous Paper .... 
 
 Distilled Water ..... 
 
 Methods of applying the Solutions 
 
 Nitrate of Silver .... 
 
 Process for making Hyposulphite of Soda 
 Methods of Preparing Photographic Paper : — 
 Nitrate Paper ..... 
 
 Chloride Paper .... 
 
 Bromide Paper ..... 
 
 Varieties of Photographic Paper 
 Making the Photographs : — 
 
 Pressure Frame ..... 
 
 Simple form of Pressure Frame 
 Negative and Positive Photographs 
 Method of Multiplying Designs 
 New method of Forming the Matrix . 
 
 Time of Exposure .... 
 
 Experiment of Mr. Hunt 
 
 On the Chemical Change produced . 
 
 Fixing Process .... 
 
 Applications of Photographic Drawing 
 Curious Restoration of Pictures . 
 
 Camera Pictures : — 
 
 Description of the Camera . 
 
 Portable Camera . • • • . 
 
 Sliding Front . • • • • 
 
 page 
 
 1 
 
 . 2 
 
 2 
 
 . 3 
 
 4 
 
 . 5 
 
 6 
 
 . 6 
 
 9 
 
 . 9 
 
 10 
 . 13 
 
 14 
 
 . 14 
 
 15 
 . 17 
 
 17 
 
 . 19 
 20 
 
 . 21 
 21 
 
 . 22 
 22 
 . 23 
 23 
 . 24 
 26 
 . 27 
 
 . 28 
 30 
 . 31 
 
VIll 
 
 CONTENTS. 
 
 The Lenses 
 
 
 
 
 
 PAGE 
 
 32 
 
 Spherical Aberration . • 
 
 
 
 
 
 • 32 
 
 Position of the Diaphrams 
 
 
 
 
 
 33 
 
 Chromatic Aberration 
 
 
 
 
 
 . 34 
 
 Adjustment to the Chemical Focus 
 
 
 
 
 
 35 
 
 Calotype ; — 
 
 
 
 
 
 
 Apparatus required 
 
 
 
 
 
 . 36 
 
 Preparation of the Iodized Paper 
 
 
 
 • 
 
 
 37 
 
 Applying the Sensitive Mixture . 
 
 
 
 
 
 . 39 
 
 Exposure in the Camera 
 
 
 
 • 
 
 
 41 
 
 Portraits 
 
 
 
 
 
 . 42 
 
 Views 
 
 
 
 • 
 
 
 43 
 
 Developing the Picture . 
 
 
 
 
 
 . 44 
 
 Fixing the Process 
 
 
 
 
 
 44 
 
 Obtaining the Positive Picture . 
 
 
 
 
 
 . 47 
 
 Sir David Brewster’s Method 
 
 
 
 
 
 49 
 
 Fluorotype : — 
 
 
 
 
 
 
 Preparation of the Paper 
 
 
 
 
 
 . 50 
 
 Bringing out the Picture 
 
 
 
 
 
 51 
 
 Ferrotype or Energiatype : — 
 
 
 
 
 
 
 Description of the Process 
 
 
 
 
 
 52 
 
 Chromatype 
 
 
 
 
 
 
 Description of the Process 
 
 
 . 
 
 
 
 . 54 
 
 Modification . 
 
 
 
 
 
 55 
 
 Process by Mr. Mungo Ponton 
 
 
 , 
 
 
 
 . 55 
 
 Modification by M. Edmund Becquerel 
 
 
 . 
 
 , 
 
 56 
 
 Principles upon w’hich the Process depends 
 
 
 
 . 57 
 
 Chrysotype : — 
 
 
 
 
 
 
 Discoverer 
 
 , 
 
 
 
 
 57 
 
 Description of the Process 
 
 
 . 
 
 
 
 . 58 
 
 Cyanotype : — 
 
 
 
 
 
 
 Discoverer 
 
 , 
 
 
 • 
 
 , 
 
 58 
 
 Description of the Processes 
 
 
 • 
 
 
 
 . 58 
 
 Positive Calotype : — 
 
 
 
 
 
 
 Discoverer . , 
 
 , 
 
 
 , 
 
 , 
 
 60 
 
 Description of the Process 
 
 
 • 
 
 
 
 . 60 
 
 Catalissisotype : — 
 
 
 
 
 
 
 Discoverer 
 
 . 
 
 
 , 
 
 , 
 
 61 
 
 Description of the Process 
 
 
 . 
 
 
 
 . 61 
 
 Gaudinotype 
 
 . 
 
 
 • 
 
 . 
 
 62 
 
 Anthotype : — 
 
 
 
 
 
 
 Discoverer 
 
 
 . 
 
 
 
 . 62 
 
 Description of the Processes . 
 
 . 
 
 
 , 
 
 . 
 
 63 
 
 Action of Light upon Plants 
 
 
 • 
 
 
 
 . 64 
 
 Concluding Observations . 
 
 • 
 
 
 • 
 
 • 
 
 65 
 
PHOTOGENIC MANIPULATION. 
 
 INTRODUCTORY REMARKS. 
 
 1. Several names have been given to this new art, 
 and nearly all of them serve as definitions of it ; it 
 has been called Photography, from two Greek words, 
 meaning, drawing by light. MM. Niepce and Daguerre 
 originally called their process Heliography, or drawing 
 by the sun ; the last name, like the first, being also 
 derived from the Greek. Mr. Talbot has named a 
 process invented by him, the Calotype, or, beautiful 
 picture, but this name has lately been altered to Tal- 
 botype, in compliment to its discoverer, and a process 
 of producing photographs on metallic plates by M. 
 Daguerre is known as the Daguerreotype, and for a 
 similar reason. 
 
 2. To the Alchemists, with all their charlatanry, we 
 are indebted for the germs of a great many important 
 chemical discoveries. The early history of Photography 
 is an illustration of this remark ; for it seems that in 
 their fruitless researches after Elixir vit<z^ &c., they 
 obtained a compound, which we know as the chloride 
 of silver, but which they called, from its appearance, 
 horn silver, and so far back as the year 1556, they 
 
 * From ligF‘t, and ypa<poj to write, to depict 
 
 PART I. B 
 
2 
 
 PHOTOGENIC MANIPULATION. 
 
 noticed that this substance was blackened by exposure 
 to light ; and we have on record one or two experi- 
 ments, expressed, it is true, in a very mysterious way, 
 but which appear to indicate that they had applied this 
 property as a means of forming pictures. 
 
 3. Here the matter appears to have rested, until that 
 eminent chemist, Charles "William Scheele, noticed that 
 the chloride of silver was affected very differently by 
 the different-coloured rays of light ; it being blackened 
 in the violet and blue rays, whilst pure red and yellow 
 light had no effect upon it. But a still more extraor- 
 dinary fact was observed, in 1801, by Ritter, of Jena, 
 whilst repeating the experiments of Scheele ; for he 
 found, on throwing the solar spectrum upon a piece of 
 paper impregnated with chloride of silver, not only that 
 there was a greater blackening effect at the blue or 
 more refrangible end of the spectrum, but that the paper 
 was darkened beyond any of the visible rays of light. 
 
 4. These experiments of Ritter appear to have given 
 rise to the idea, that there must be some peculiar and 
 separate fluid accompanying light, which produces all 
 the chemical changes we notice and attribute to mere 
 light. Several modern philosophers have experimented 
 upon this subject, of whom the most distinguished are 
 Mr. Robert Hunt, and Sir F. W. John Herschel. Mr. 
 Hunt gave to this peculiar principle or influence the 
 name of Energia, but Sir John Herschel, at a meet- 
 ing of the British Association, proposed that it should 
 be called Actinism, and this name appears to be 
 generally adopted. To return, however, to our short 
 history. In the year 1800, the famous Dr. (afterwards 
 Sir William) Herschel, in making some experiments 
 
INTRODUCTORY REMARKS. 
 
 3 
 
 on coloured glasses, prepared for the purpose of de- 
 fending his eye from the heat of the sun, when examining 
 it with his large telescopes, noticed, that if he used 
 a deep red glass, although it obstructed an immense 
 quantity of light, yet it had little or no protecting 
 influence from the heat. On the contrary, a blue or 
 gray glass defended his eye very perfectly ; this 
 induced him to examine the subject, and he discovered 
 that not only had the red ray of light the greatest 
 amount of heating power, but that he could detect heat 
 even below the red ray, in other words, he could detect 
 heat in the spectrum without any light accompanying it. 
 
 5. This is an analogous experiment with heat, to 
 that of Ritter’s with regard to chemical power, and we 
 
4 
 
 PHOTOGENIC MANIPULATION. 
 
 are, therefore, led to divide the influence proceeding from 
 the sun into three distinct and separate fluids, viz., Ac- 
 tinism, Light, and Heat. The relation of these one to 
 another, and their relative intensities in different parts 
 of a decomposed sunbeam, are clearly shown in 
 which the various colours of the spectrum are indicated 
 in the order in which they occur, between the points A 
 and B. We have already stated that Sir William 
 Herschel found the greatest amount of heat in the red 
 ray ; this is shown at D ; from this point the curve 
 of greatest heat declines, until it arrives at the lavender 
 ray a, where it is altogether lost, but where the actinic 
 power is greatest. It will be observed that this power 
 extends to some distance beyond the spectrum as far 
 as d. It also extends downwards as far as the lumi- 
 nous rays G, where a negative influence is exerted, after 
 passing which, the curve again increases, and a second 
 maximum is found at F, the chemical power entirely 
 ceasing at e. Upon reference to the curves formed in 
 the diagram, it would appear that these three forces 
 are antagonistic one to another ; for where we have 
 the greatest amount of light, there is the least heat, 
 and where the greatest heat, less actinic power. 
 
 6. In the year 1801, we find the first notice of a 
 picture being taken by light, by the celebrated Joseph 
 Wedgewood, the porcelain manufacturer, who endea- 
 voured to apply it for making designs for his ware. 
 His process was to sponge leather or paper over with 
 a solution of nitrate of silver, and to place it behind 
 a painting on glass, or other objects of which he 
 wished a copy. The light passed through this with 
 
INTRODUCTORY REMARKS. 
 
 5 
 
 different degrees of intensity, and the paper or leather 
 behind it was darkened, according as the glass was more 
 or less permeable to its rays. But the greatest difficulty 
 in this process was, to render the picture produced per- 
 manent, the same agent — light — which produced them, 
 infallibly destroyed them. Sir Humphry Davy and 
 Mr. Wedgewood were equally unsuccessful in their en- 
 deavours to remove this difficulty. 
 
 7. In 1814, M. Niepce, of Chalons-on-Soane, turned 
 his attention to this subject, and he found the resins to 
 be curiously affected by the action of light, with regard 
 to their solubility, and the result of his researches was 
 the discovery of a process named Heliograph These 
 pictures were produced upon metal plates, having the 
 polished surface of the metal to form the shadows of 
 the picture, and a resin forming the light parts ; they 
 were very indistinct, and wanted depth. M. Niepce, 
 through accident, became acquainted with M. Da- 
 guerre, and they agreed to pursue their experiments 
 together, and amongst other things they tried the effect 
 of sulphur and of iodine to deepen the shadows of 
 their Heliographs ; and it is extremely probable that M. 
 Daguerre noticed a darkening effect in some of those 
 plates, upon exposure to light, and that this laid the 
 foundation for his brilliant discovery of the Daguerreo- 
 type, which was announced in 1839. 
 
 8. About this time, Mr. Fox Talbot sent a paper to 
 the Royal Society, with an account of his discoveries in 
 this branch of science. f The process he communicated 
 
 * From HXtocr the sun, and ypa(p(jj to depict, to draw. 
 
 t Published in the London and Edinburgh Philosophical Maga- 
 zine, vol. xiv. p. 126. 
 
6 
 
 PHOTOGENIC MANIPULATION. 
 
 was upon paper, whilst that of Daguerre was upon sil- 
 vered plates. Mr. Fox Talbot’s more recent discovery, the 
 Calotype, was somewhat the result of accident ; he had 
 prepared papers in a variety of ways, and only exposed 
 them for a certain limited time in the camera, these 
 were thrown on one side in a drawer, and left as 
 failures ; but he was surprised to find, on examining one 
 or two which had been washed with gallic acid, that 
 perfect pictures had appeared of the objects at which 
 the camera bad been directed. 
 
 9. These processes excited a great amount of interest 
 and attention, and the photographic art has advanced 
 since this time with great rapidity. A number of 
 different methods of taking pictures by sunlight have 
 been published ; the most important of which we 
 shall endeavour to make the reader fully acquainted 
 with, our object being to instruct him in all the little 
 requisites to success as a photographer, and at the 
 same time to point out some of the chemical principles 
 upon which the different processes depend. 
 
 APPARATUS AND MATERIALS. 
 
 10. Paper , — The selection of good paper is the most 
 important and troublesome matter the photographer 
 has to contend with. There are a great many points to 
 be attended to in choosing paper fitted for photographic 
 processes. In the first place, it is essential the paper 
 should be quite uniform in thickness. This may be 
 ascertained by holding it between the eye and a strong 
 
APPARATUS AND MATERIAS. 
 
 7 
 
 light : a gas or candle light is preferable to daylight. 
 It will be found on examining most paper in this way, 
 that the sheet is full of irregularities in thickness, and 
 very often minute holes may be detected. These defects 
 exist mostly in very highly glazed thin papers. A mo- 
 derately thick paper is not at all objectionable, provided 
 it has been made without sulphate of lime ; this is an 
 impurity which occurs in some kinds and should be 
 carefully avoided. The paper should be well sized , for it 
 is found that the organic matter in the size renders the 
 paper, when prepared, much more sensitive ; but it is 
 also important in another respect, for the photographer 
 will sometimes find that, upon applying the solutions, 
 transparent patches will appear, i, e., the solution will 
 penetrate quite through the paper in some parts, while 
 the rest will dry properly on the surface. This will be 
 found to be the case in nearly all new paper. It ap- 
 pears to be essential that the size should have had some 
 time to get hard and insoluble, for we have never found 
 this defect in old paper. Several descriptions have 
 been made by the manufacturers purposely for the calo- 
 type, &c. ; but, being new, they are all more or less 
 liable to this defect. It has been stated that this may be 
 overcome by applying a varnish on one side of the paper, 
 but we have not obtained any good results by this plan. 
 
 11. A paper having much blue in its composition 
 should be avoided. The colouring matter contains 
 several substances which considerably injure a good 
 photograph. It generally gives a disagreeable dirty 
 appearance to the light parts. This defect exists 
 in some of Whatman's papers, which otherwise 
 
8 
 
 PHOTOGENIC MANIPULATION. 
 
 would be excellent. A description known as thick 
 yellow wove post, made by Turner, Chatford Mill, is 
 decidedly the best paper we have found for the calotype 
 process. It should be chosen as old as possible ; we 
 have some made in 1840, and find it excellent; 
 the only defect is that a number of little brown spots 
 appear when the iodide of potassium is applied ; these 
 consist of iodide of iron ; but this defect is fully coun- 
 terbalanced by other advantages. This year’s paper 
 will not do, for the reason stated (§ 10). 
 
 12. For obtaining the positive pictures (§ 30), the tex- 
 ture of the paper is not of so much consequence. We 
 find the best for this purpose to be a variety manufactured 
 by Nash; it contains no water-mark, and is very white: 
 it also contains a small quantity of the chloride of lime 
 used for bleaching the paper, but which is accidentally 
 a great advantage, for the silver wash may be applied 
 without any previous preparation of the paper ; and the 
 chlorine exists in the paper in the proper equivalent 
 proportion. We have seen some very fine pictures said 
 to have had their negative photographs taken (§ 30) 
 upon this paper, but we confess that in our hands it has 
 not proved at all successful for this purpose. The defect 
 is, it is too new (§ 10); and the positive pictures ob- 
 tained are very coarse and woolly in appearance (§ 30). 
 
 13. For some purposes, unsized paper answers very 
 well ; for Mr. Ponton’s process (§ 69) with the bichro- 
 mate of potash, good blotting-paper is very good. In 
 choosing paper for Mr. Hunt’s Chromotype, great care 
 should b^ taken to have no chloride in the texture of 
 the paper, otherwise the pictures can never be rendered 
 permanent. 
 
APPARATUS AND MATERIALS. 
 
 9 
 
 14. Bibulous Paper , — This should be chosen with- 
 out colour, and of the description called white machine 
 wove ; this has an even regular surface, which is an 
 advantage. Fresh paper should be used for each 
 stage of the process, and for each picture ; but old 
 paper may be used for absorbing moisture by interpos- 
 ing a clean piece at the back and front of the photo- 
 graph, and it is as well to keep the paper used in the 
 different processes distinct, for, should a piece of paper 
 be accidentally used for drying a finished picture that 
 had previously been employed in absorbing some of the 
 sensitive solution, it would infallibly spoil it. 
 
 15. Water , — It has been recommended that the 
 photographer should always use distilled water : this, 
 in a great many of the processes, is not at all essen- 
 tial. Common water generally contains muriate of 
 soda, and some sulphates, &c., in solution ; and there- 
 fore, in making a solution of nitrate of silver, or in 
 diluting a solution, we should avoid using it ; for it will 
 of course precipitate the silver in the state of chloride ; 
 rain or distilled water must be used in this case, 
 although, where we cannot possibly get either, common 
 water may be used, by allowing the precipitate to settle. 
 The only consequence is, that the solution will be 
 rendered very slightly weaker by the precipitation of a 
 small amount of silver. In all the other manipulations 
 required, common water answers very well, and has 
 this advantage, — the photographer need not be sparing 
 in its amount, and the picture may have a thorough 
 washing without much expense. Distilled water may 
 be obtained of any chemist, or the amateur may readily 
 ^distil it himself. 
 
10 
 
 PHOTOGENIC MANIPULATION, 
 
 Fig. 2. 
 
 Fig. 2. represents a convenient and economical still 
 for the purpose. The whole is made of tinned iron, 
 and can be used on a common fire, a is the body, 
 holding about a gallon of water, which is introduced at 
 the opening 5, which is then stopped by a cork. The 
 tube d connects the neck of the still with the worm 
 tub or refrigeratory e, which is filled with cold water, a 
 supply being kept up through the funnel c, the hot 
 water is drawn off through the cock f ; the different 
 joints are rendered tight by lute, or, in the absence of it, 
 some stiff paste spread on a piece of tape, and put 
 round them answers very well. The distilled water 
 is condensed in the worm, and passing off at the pipe 
 is collected and preserved for use in a glass bottle. A 
 glass retort connected with a Liebig’s condenser forms 
 a very convenient apparatus for distilling water, and 
 may be heated either by an argand lamp, gas-light, or 
 small chauffer. 
 
 16. Brushes, and Methods of applying the Solu- 
 tions . — The general method of applying solutions to the 
 paper is by means of a brush, and for certain processef 
 
MATERIALS AND APPARATUS, 
 
 11 
 
 answers very well. They should be made of a soft mate- 
 rial, and not bound with metal, for this has an injurious 
 action upon several of the solutions ; they may be ob- 
 tained constructed purposely for the photographer. 
 Each brush should be kept for its own particular solu- 
 tion ; that used for applying the nitrate of silver must 
 not be used for the iodide of potassium, or any muriate, 
 &c. ; and they should always be well washed after 
 using. In the absence of proper brushes, the solu- 
 tions may be very readily applied by a sponge tied to 
 the end of a piece of wood. This is an economical 
 plan and good, inasmuch as, when contaminated in any 
 way, it may readily be replaced ; the only disadvantage 
 is, that it is apt to disturb the surface of the paper. 
 The brush used for applying the gallo-nitrate of silver 
 in the calotype process is soon destroyed, and requires 
 extreme care in washing, to remove all the gallo-nitrate, 
 after each time of using ; the smallest quantity left in 
 the brush being enough to spoil a clean solution. Old 
 gallo-nitrate appears to act in a similar way to yeast, a 
 very minute quantity sets up a decomposition in a clean 
 and perfectly fresh solution. An instructive experiment 
 on this point is the following : — expose a drop of gallo- 
 nitrate of silver to sunshine, until it begins to darken, 
 then take it into a dark room, and allow it to fall into 
 fresh and clear gallo-nitrate that has not been exposed 
 to light, and it will be found to become rapidly dis- 
 coloured. [This, according to modern scientific par- 
 lance, would be called catalysis, or, action hy presence; 
 i. e., some phenomena we don’t know much about, and 
 give it a name instead of an explanation.] This action 
 
12 
 
 PHOTOGENIC MANIPULATION. 
 
 we have just mentioned is the great source of failures in 
 the calotype process, and too much care cannot be 
 taken to keep the brushes, &c., perfectly clean. 
 
 A method of applying the solution, which removes 
 this difficulty to a great extent, is to pour the liquid into 
 a flat porcelain dish (fig. 5), or, what is better, upon 
 the surface of a piece of plate glass, previously adjusted 
 by set screws so as to be perfectly level, and then 
 carefully to apply the paper so as to take up a certain 
 amount of the moisture ; this will become very easy 
 after a few trials. After laying the paper upon the 
 solution, the finger should be gently passed over the 
 surface so as to press out any bubbles of air that might 
 interfere, care being taken not to draw any of the 
 liquid over the back of the paper. Before floating the 
 paper on the solution, about a quarter of an inch in 
 breadth at one edge should be folded upwards, so as to 
 enable the paper to be lifted without staining the fingers ; 
 this part should, however, be previously moistened a 
 little, so as to make the expansion of the paper uniform 
 with that wetted by the solution. 
 
 17. It is sometimes an advantage, and particularly in 
 preparing positive (§ 30) paper, when using a shallow 
 earthenware dish, to draw the paper over the edge 
 in taking it out of the solution ; this will draw off the 
 superfluous moisture, and leave an evenly moistened 
 surface. Both the plate glass and the earthenware 
 vessel should be well washed after each operation, 
 and care should be taken that they do not get scratched ; 
 if so, it will be found that the gallo-nitrate will often 
 remain in these scratches, and on pouring a fresh sola- 
 
APPARATUS AND MATERIALS. 
 
 13 
 
 tion on the plate, and applying the paper, it will be 
 found to be stained something in the same style that 
 bookbinders call “ marbling.” 
 
 18. Chemicals — Nitrate of Silver, — This should be 
 crystallized, and not the fused lunar caustic, the latter 
 often being considerably adulterated with various sub- 
 stances ; it generally contains both nitrate of copper 
 and nitrate of potash ; it is a little lower in price, but the 
 crystallized salt will be found to be more economical in 
 use. Any contamination with copper will be readily de- 
 tected by the salt being deliquescent, and the pictures 
 produced will be found not to be permanent. Another 
 matter to be attended to is this : — nitrate of silver very 
 often contains a quantity of free nitric acid : this may 
 be readily detected by the smell, and it may be remedied 
 by dissolving in distilled water, and driving it olF by 
 heat. In doing so, the salt will recrystallize, and a great 
 quantity of the acid will have been driven off with the 
 water. 
 
 The other chemicals required in the ordinary pro- 
 cesses are, — iodide of potassium, bromide of potassium, 
 and gallic acid. 
 
 Acetic Acid, — The strength of this acid should be 
 known ; it is generally sold containing very variable 
 quantities of real acid. 
 
 Chloride of Sodium, — Common salt is an impure 
 chloride of sodium, but answers very well. Various 
 other chlorides have been used, such as the chloride of 
 barium, strontium, calcium, &c., and which we shall 
 refer to presently, 
 
 Hij 2^0 sulphite of Soda, -^This should be pure, and 
 
14 
 
 PHOTOGENIC MANIPULATION. 
 
 free from sulpliuret of sodium. We give a method by 
 ■which it may be prepared : one ounce of sublimed sul- 
 phur is to be mixed with one ounce and a half of lime, 
 previously slaked by the addition of hot water, and the 
 mixture put into a clean earthen vessel. Three quarts 
 of water are added, and the whole is to be boiled for 
 two hours. The clear liquid may then be filtered off 
 into several wide basins or dishes, and allowed to re- 
 main freely exposed to air. When just made, the liquor 
 is of a deep yellow colour, but by exposure to air it will 
 become quite colourless. The time of exposure varies 
 according to the strength of the solution, and the 
 amount of persulphuret of calcium contained in it. 
 This liquid, when colourless, is a solution of the hypo- 
 sulphite of lime ; it should be filtered before use. The 
 hyposulphite of soda may be made by adding common 
 carbonate of soda; a white precipitate will fall, which 
 is carbonate of lime, and hyposulphite of soda will re- 
 main in solution. The bottle containing this solution 
 should be lightly stoppered, otherwise sulphuret of so- 
 dium is sometimes formed. 
 
 19. Different Methods of Preparing Photographic 
 Paper , — If we brush a solution of nitrate of silver, 
 having about 100 grains of the salt dissolved in an 
 ounce of water, over a piece of paper, and allow 
 it to dry, we shall have a paper moderately sensitive 
 to light ; about one hour’s good sunshine will com- 
 pletely blacken it. This paper will serve very well for 
 copying lace, leaves, ferns, &c. ; and there is this ad- 
 vantage in using it, the picture can be fixed by soaking 
 in hot water. The experimentalist will find very diffe- 
 
APPARATUS AND MATERIALS. 
 
 15 
 
 rent effects in using different sorts of paper. A highly- 
 sized paper answers best with the simple nitrate of sil- 
 ver ; it appears to combine with the size, and form a 
 sensitive surface. By soaking in hot water, all the un- 
 decomposed nitrate of silver and size is dissolved out 
 together : but, however, this is far from being the best 
 or most economical process. 
 
 20. Papers prepared with the Chloride of Silver ^ — 
 If we form a solution of nitrate of silver, and then add to 
 it a solution of chloride of sodium, a white bulky preci- 
 pitate will fall, which consists of chloride of silver, whilst 
 there will remain in the solution nitrate of soda. The 
 following diagram will roughly explain this interchange 
 of substances. 
 
 Common Salt. 
 
 r 
 
 
 ^ Chlorine. 
 
 Sodium. 
 
 Chloride \ 
 
 
 of J 
 
 
 Silver, j 
 
 
 ^ Silver. 
 
 Nitric Acid. 
 
 V. . . 
 
 J 
 
 Nitrate of Silver. 
 
 Nitrate 
 
 of 
 
 Soda. 
 
 From this it will be evident that if we wash paper over, 
 first, with chloride of sodium, and allow it to dry, and 
 then wash it over with nitrate of silver, the above 
 interchange will take place, and the insoluble chloride 
 will be precipitated in the pores of the paper. This 
 forms an extremely sensitive surface, when a little excess 
 of nitrate of silver is present ; hence, in giving the fol- 
 lowing proportions for sensitive papers, care has been 
 
16 
 
 PHOTOGENIC MANIPULATION. 
 
 taken to allow this excess to be present, for it is a 
 curious fact, but well worthy of attention, as it is of 
 importance in the calotype process, that neither the 
 chloride, iodide, nor bromide of silver, are sensitive to 
 light when perfectly pure and free from organic mat- 
 ter. We shall now give the proportions for forming the 
 chloride papers. 
 
 21. Dissolve 60 grains of common salt in 3 ounces 
 of water, (it is not necessary it should be distilled water), 
 then weigh 60 grains of nitrate of silver, and dissolve 
 this in one ounce of distilled ivater ; dip a sheet of 
 good writing-paper in the solution of common salt, 
 absorb the superfluous moisture by bibulous paper, or 
 a clean dry cloth, and then allow it to dry ; then brush 
 over the surface the solution of nitrate of silver, — this 
 must be done rapidly and evenly. Should any part of 
 the paper not have been touched by the brush, that 
 part must not be filled in separately, but the whole 
 sheet must be brushed over again very regularly ; care 
 must be taken that the solution should be evenly spread 
 over the whole surface alike, otherwise part of the 
 paper will exhibit black patches on exposure to light, 
 before the other part is sensibly darkened. The silver 
 solution maybe applied by means of the porcelain dish, 
 as explained (§ 16.) ; this paper should be allowed 
 to dry in the dark, and when dry will be ready for use. 
 These proportions may be varied according to the colours 
 wished to be obtained in the finished drawing; it will be 
 found, by using an excess of salt, that the paper will not 
 be very sensitive, and it will darken to a disagreeable 
 light slate colour, and there will be no depth in the pic- 
 
APPARATUS AND MATERIALS. 
 
 17 
 
 ture ; a less proportion of salt will give a very sensitive 
 surface having a dark-slate colour, a still less quantity 
 gives a great depth and blackness in the drawing, and a 
 smaller quantity will give a rich bronze colour, and 
 so on, passing through all the shades of brown until 
 we come to a very red brick colour having little 
 depth. These principles will serve to guide the ama- 
 teur, who will thus be enabled to vary the colours, and 
 obtain any tone of picture his taste may dictate. The 
 same rules will also hold good with the bromide paper, 
 which we shall now give directions for preparing. 
 
 22. Bromide Paper , — Dissolve 60 grains of bromide 
 of potassium, and soak the paper in the solution ; absorb 
 the superfluous moisture, and then wash it over with 
 a solution of nitrate of silver having 100 grains to the 
 ounce, observing the same precautions as with the 
 chloride paper ; if required to be very sensitive, it may 
 receive a larger quantity of silver. This is a very sensi- 
 tive paper, and M. Biot says, he thinks nothing can be 
 found more sensitive to light than the bromide of silver. 
 
 23. The fluoride, tartrate, benzoate, and iodide of sil- 
 ver, have all been used, and they all modify the colour 
 and the quickness of the picture very considerably ; and, 
 in preparing the chloride papers, it will be found that 
 the results will vary considerably by using different 
 chlorides : — viz. the chloride of barium, used in the 
 same proportion as the other chlorides, gives rise to a 
 picture having a deep red ground ; the chloride of cal- 
 cium, the chloride of lime, muriate of ammonia, muriate 
 of iron, and the chlorate of potash, recommended by 
 Mr. Cooper, the vapours of muriatic acid, recommended 
 
 PART I. c 
 
18 
 
 PHOTOGENIC MANIPULATION. 
 
 by Dr. Scbafhaeutl, and a great number of others, all 
 modify the results considerably. 
 
 24. But the best kind of photographic paper is that 
 prepared with the ammonia nitrate of silver, and used 
 upon a paper before spoken of (§ 12.), made by Nash ; 
 a single wash of this solution, of the strength of 30 
 grains to the ounce of water, being sufficient to obtain 
 a very sensitive surface, and will give a picture of a 
 beautiful tone. The preparation of this ammonia nitrate, 
 which requires a little care, I give below : — 
 
 25. Dissolve 30 grains of nitrate of silver in one 
 ounce of distilled water, then cautiously add, drop by 
 drop, strong solution of ammonia {liquor ammonice), 
 until a precipitate of oxide of silver which is at first 
 formed, is re-dissolved. Care should be taken that no 
 more ammonia be added than is just sufficient to effect 
 this, for if more be used, the paper will be almost insen- 
 sible to light ; it is better to adopt the precaution of 
 not entirely re-dissolving the precipitate, but to allow 
 a little cloudiness in the liquid; this will settle in a 
 few hours, and the liquid become quite clear. 
 
 26. In preparing these papers, the experimenter 
 should be cautious not to touch the prepared surface 
 with his fingers; this generally gives rise, on exposure 
 to light, to annoying representations of the markings 
 of the skin, from the communication of organic mat- 
 ter, which, as already stated, quickens the action of 
 light. It is also a necessary precaution to mark the 
 prepared side of the paper. The ammonia nitrate paper, 
 and indeed all the very sensitive papers, should not be 
 made more than a few hours before they are required for 
 use; they become yellow and discoloured by long keeping. 
 
APPARATUS AND MATERIALS. 
 
 19 
 
 27. Making the Photograph . — We Iiave now de- 
 scribed several methods by which paper may be prepared 
 in such a way that it will very quickly blacken all over, 
 if exposed to light ; but it will be obvious that, if we 
 shaded any part and exposed the other, the part covered 
 would still remain white, and the whiteness would 
 correspond to the form of the body shading it. If a leaf 
 be placed upon a sheet of such prepared paper, and 
 exposed to sunshine, the paper will become black all 
 around the leaf, but underneath it, it will not have been 
 blackened, except partially, under those parts of the leaf 
 less opaque than the rest. The light will shine through 
 these parts with different degrees of intensity, and there 
 will be a corresponding marking ; the fibres of the leaf 
 will shade more light than some of the other parts, and 
 therefore will remain white ; but it is necessary, in order 
 to obtain a perfect copy of the leaf, that no other light 
 should get to the paper under the leaf, than what would 
 shine through the more transparent parts. For this 
 
 Fig. 3. 
 
20 
 
 PHOTOGENIC MANIPULATION. 
 
 purpose, it is necesary that the object to be copied 
 should be pressed close to the paper. — An apparatus 
 contrived for this purpose is shown in Fig. 3. It consists 
 of a thick piece of plate glass fitting into a frame ; 
 upon this glass, the object to be copied is placed, and 
 over this the sheet of prepared paper ; the board D is 
 then laid over the paper, and the requisite pressure 
 applied by means of a cross piece with a screw E. 
 These frames are sometimes supplied with a sliding cover 
 of wood C, by which the paper can be exposed to light 
 when convenient. 
 
 28. A more simple form of pressure-frame is shown 
 at Fig. 4; this consists simply of a piece of board 
 
 Figs. 4. and 5. covered with soft flannel, 
 
 upon which is laid the pre- 
 pared paper, and then the 
 object to be copied ; a 
 piece of thick plate glass is 
 then laid over this, and 
 screwed down by means of 
 four thumb screws, attach- 
 ed to pieces of narrow wood 
 fixed across each end of 
 the glass. 
 
 In copying an object which has thick parts, as the 
 stems and thick fibres of plants, it is requisite to press 
 the paper over them close to the glass ; this is done by 
 putting a thick piece of flannel or a soft cushion in the 
 pressure-frame beneath the paper, or the stems may some- 
 times require paring down with a penknife when too thick. 
 
 29. Engravings may be beautifully copied by this 
 process, particularly when they are moderately strong 
 
APPARATUS AND MATERIALS. 
 
 21 
 
 in light and shade : they should be placed with the 
 printed side downwards. Ferns form exceedingly 
 beautiful objects. Sea-weeds, feathers, wings of in- 
 sects, and paintings on glass, serve to diversify the 
 specimens. They should all be pressed as closely as 
 possible to the glass, otherwise there will be a want of 
 proper definition in the photograph. Engravings should 
 be chosen which have been printed upon even and 
 uniform paper; for, in copying the engraving, we also 
 copy all the defects of the paper : they should also 
 have no writing or printing upon the back, for this 
 would also be copied. 
 
 30. In the first copy of a print by this process, the 
 light and shade will not be true to nature; the dark 
 parts of the picture will obstruct the greatest amount 
 of light, consequently the paper will remain white 
 underneath these shadows, while the white parts of the 
 print will allow the light to shine through ; therefore 
 the photographic paper will be darkened just in pro- 
 portion to the light and shade, but in an opposite 
 rnanner. This is what is technically called a negative 
 photograph ; and in order to obtain the light and shade 
 true to nature, or a 'positive photograph, we must place 
 the negative copy, (of course, having previously fixed 
 it) upon another piece of prepared paper, and expose 
 this arrangement again to sunshine; this will again 
 reverse the light and shade, and this copy will, there- 
 fore, be correct. 
 
 31. A pretty method of multiplying designs is the 
 following : — Cover a piece of glass with a coating of 
 black varnish, and then with a steel point remove the 
 varnish, according to any design you may wish to mul- 
 
22 
 
 PHOTOGENIC MANIPULATION. 
 
 tiply ; a piece of photographic paper placed under- 
 neath this will, of course, be blackened where the varnish 
 has been removed, and an exact copy of the design will 
 be made; in which way any number of copies can of 
 course be made; but this requires some artistic skill ; 
 nevertheless we have seen some very beautiful spe- 
 cimens produced in this manner. Instead of the 
 glass, a piece of ordinary photographic paper may be 
 blackened all over, by exposure to the sun, and then 
 submitted to the fixing process (§ 36), we should then 
 prepare a solution of cyanide of potassium moderately 
 strong; and with a quill pen dipped into this, trace 
 any design we may wish to have multiplied : this will 
 remove the blackened surface, or in other words, dis- 
 solve the oxide of silver from the paper; it should then 
 be washed in water and dried, when it may be used as 
 a negative, and any number of positive (§ 30) pictures 
 may be produced from it. 
 
 32. Time of Exposure , — This will, of course, vary 
 with the degree of sensitiveness imparted to the paper, 
 and the degree of capacity in the objects to be copied, 
 the strength of the light, &c.; but the operator will 
 easily determine this in a few trials. It is as well to 
 make the impression rather darker than you wish it to 
 be when finished; for the fixing process hereafter 
 described (§ 34.) will render the photograph a shade or 
 two lighter. It is sometimes an advantage to render 
 the engraving, or negative photograph, more transparent; 
 this may be done by warming it, and then rubbing it 
 over with white wax, and absorbing the excess by bibu- 
 lous paper; or it may be covered with Canada balsam, 
 
APPARATUS AND MATERIALS. 
 
 23 
 
 or boiled linseed oil. These substances, however, have 
 a tendency to make the paper yellow, unless used very 
 sparingly, and which effect would just defeat the object 
 we had in view in waxing them, viz.-— to obtain a copy 
 from them more quickly. 
 
 33. On the Chemical Change produced , — We will 
 now briefly notice the change which has been set 
 
 up by the action of the light, and for this pur- 
 
 pose will relate a very instructive experiment made 
 by Mr. Hunt, which will give a clear view of the 
 subject. That gentleman prepared some very pure 
 chloride of silver, and placed it in a glass tube 
 
 containing a little pure distilled water ; the tube 
 
 was then hermetically sealed, and exposed to light; 
 the consequence was, that the chloride became 
 darkened, or in other words, it was decomposed into 
 its elements, viz, silver and chlorine ; the dark powder 
 being silver and oxide of silver in a state of minute 
 division, and the chlorine formed a solution in the 
 water. This was proved, by breaking the tube and 
 pouring off the water ; a solution of nitrate of silver 
 was then added, when an immediate precipitate of 
 white chloride of silver took place ; this was collected 
 and weighed. A little dilute nitric acid was then 
 added to the darkened chloride; this dissolved any 
 silver that might be present; and it was found, on 
 calculation, to be exactly equivalent to the amount of 
 chlorine found in the distilled water. We could not 
 resist giving this experiment, it being so exceedingly 
 neat, and to the purpose. The first action in these 
 papers, when exposed to light, is this, — that the chlorine, 
 
24 
 
 PHOTOGENIC MANIPULATION, 
 
 bromine, or nitric acid, with which the silver is com- 
 bined, is set free, and dark oxide of silver is left in the 
 paper. A still greater exposure to light sets free the 
 oxygen, and metallic silver is left ; this forms the dark 
 parts of the picture, and the undecomposed chloride of 
 silver the lighter parts. We have, therefore, a com- 
 plete picture, but which would not bear exposure to the 
 light ; for this would act on the remaining chloride in 
 the lighter parts of the picture, and darken it; our 
 picture would, therefore, disappear, and we should have 
 a mere black sheet of paper. The object with the photo- 
 grapher will, therefore, now be, to remove this chloride 
 of silver from the unsunned parts, without injury to 
 the oxide of silver in the shadows. This we shall 
 consider in describing the 
 
 34. Fixing Process . — It is known to chemists that the 
 chloride of silver is soluble in a solution of ammonia; we 
 may, therefore, dissolve the undecomposed chloride out 
 of the paper by this agent; and it does so very eiFec- 
 tually ; but, unfortunately, it also has the property of 
 dissolving oxide of silver. We shall, therefore, have our 
 picture moderately well fixed by soaking in ammonia; 
 but without great care, the oxide of silver forming the 
 shadows will also be dissolved out. The ammonia used 
 as a fixing agent should be rather weak. 
 
 35. Common salt has been recommended by Mr. 
 Fox Talbot to fix the photograph. In this case, the 
 action is also by dissolving out the chloride of silver, 
 that substance being soluble in chloride of sodium or 
 common salt ; it is probable, however, that this sub- 
 stance also acts, to a certain extent, by getting rid of 
 
APPARATUS Ai^D MATERIALS. 
 
 25 
 
 any excess of nitrate of silver, by converting the 
 whole into a chloride, — the chloride being almost 
 insensible to light, without free nitrate of silver being 
 present, as before stated (§ 20.); however, organic mat- 
 ter is always present, which, as well as free nitrate of 
 silver, determines the blackening action of light. Pho- 
 tographs soaked in a solution of common salt are 
 therefore but imperfectly fixed ; they should always be 
 washed in abundance of water after immersion in the 
 solution of salt. Iodide and bromide of potassium 
 may be also used with like success, the rationale being 
 the same. 
 
 36. But the best substance to use is a salt called the 
 hyposulphite of soda, and by proper precautions pic- 
 tures may be perfectly fixed by it. 
 
 The photograph should be placed in a flat porcelain 
 dish, Fig. 5, and wetted throughout with cold water ; 
 a quantity of hot water should then be poured upon 
 it and allowed to remain a little time, which will shortly 
 become milky from the quantity of muriates and sul- 
 phates contained in ordinary water (§ 20) : this should 
 then be poured off, and a fresh quantity of hot water 
 placed in the dish ; it may now be allowed to stand 
 in a shaded place until quite cold, and the photograph 
 then rinsed with a little common water, and pressed be- 
 tween folds of blotting paper. It is now moderately well 
 fixed, but not perfectly ; all the size and nitrate of 
 silver will have been dissolved out of it ; a solution 
 of hyposulphate of soda should then be prepared, 
 having about a quarter of an ounce of the salt dis- 
 solved in a pint of water ; a little of this should then 
 
26 
 
 PHOTOGENIC MANIPULATION. 
 
 be poured into a flat dish, and the photograph gently laid 
 with its back upon the surface of the solution, taking 
 care the face is not touched by it ; the solution will 
 gradually permeate the paper, and a red appearance 
 will be given to the drawing ; the solution should then 
 be quickly made to run over the surface, and the pic- 
 ture withdrawn and placed in a vessel of cold water. 
 The advantage of allowing the hyposulphite to act 
 upon the back of the picture is this, that the greater 
 part of the silver will be dissolved without injuring the 
 photograph, whereas, if it had been wholly immersed, 
 the solution would have acted considerably upon the 
 drawing. This will be found to be more particularly 
 the case with weak impressions, or those which have 
 been produced by feeble light. 
 
 The photograph may be allowed to remain in cold 
 water a considerable time, or until the water is quite taste- 
 less in which it is soaked. The hyposulphite of silver is 
 extremely soluble, and it is a curious fact that it has an 
 extremely sweet taste. It is an advantage to press all the 
 water out of the paper once or twice before putting it into 
 fresh water, as it is quite necessary to get rid of all this 
 hyposulphite of silver, for if any remains it gives rise 
 to the formation of sulphuret of silver, which inevi- 
 tably spoils the photograph, — hot water immediately gives 
 rise to the formation of this substance. It is as well to 
 remind the amateur that, from the extreme solubility of 
 the hyposulphite of silver, a great quantity of water 
 is required rather than long soaking; the paper may 
 be dried by pressure between clean bibulous paper. 
 
 37. Application, — Mr. Fox Talbot has patented a 
 
CAMERA PICTURES. 
 
 27 
 
 great number of applications of this new art, and has 
 exercised great ingenuity in anticipating some purposes 
 to which it may be applied ; one plan he has recorded 
 in his specification is printing by photography, for 
 which purpose, he directs that a number of letters should 
 be cut out and waxed, or rendered transparent by some 
 of the methods now in use ; these should be sorted and 
 cemented on a sheet of paper in the order in which we 
 wish them ; a copy is obtained from this, which is of 
 course a negative, and any number of positives may 
 be taken from the negative picture. 
 
 Photography has been applied as a means of making 
 the designs upon blocks of wood for woodcuts and 
 for calico printing ; for this purpose the surface of the 
 block is washed over with the solutions in the same 
 way as they are directed to be applied to paper, and 
 they may undergo the same processes in fixing. 
 
 It has also been stated that an Italian gentleman 
 has applied photography to delineating figures upon a 
 lithographic stone with great success, and the pictures 
 are stated to be produced with great rapidity, but the 
 process has not been made known. 
 
 It is a curious and interesting fact, that nearly all 
 paper photographs may be rendered invisible, and 
 again restored at pleasure. If a photographic picture, 
 prepared by any of these methods and fixed as directed, 
 be dipped into a solution of corrosive sublimate (the 
 strength of the solution is of no material consequence), 
 the picture is observed gradually to fade, and after a 
 time, varying according to the strength of the solution, 
 it will entirely disappear. It may thus be preserved 
 
28 
 
 PHOTOGENIC MANIPULATION. 
 
 for an indefinite length of time as an apparently blank 
 piece of paper, but can at once be restored by washing 
 it with hyposulphite of soda, the rapidity with which 
 its restoration is effected is almost marvellous. 
 
 CAMERA PICTURES. 
 
 38. We have hitherto described the most simple kind 
 of photographs, — those produced by direct radiation 
 through the object to be copied ; but the most interest- 
 ing and important variety of sun pictures are those 
 produced by light, reflected from the object to be copied 
 upon the prepared surface ; in order to produce these 
 results, the manipulation is a little more complicated, 
 and requires a more expensive apparatus : but the 
 effects produced are well worth the little additional 
 trouble and expense. We allude to the method of 
 obtaining views and portraits from nature by means 
 of the Camera Obscura, an instrument which it is neces- 
 sary to describe at some length, as upon its perfection 
 a good deal of the success of the amateur will depend. 
 
 39, Camera Ohscura . — This instrument has hitherto 
 been described in optical treatises as little more than a 
 philosophical plaything ; the requirements of photogra- 
 phy have, however, induced opticians to make modi- 
 fications in its construction, and almost every optician 
 has altered it to suit his own particular fancy ; but we 
 shall only describe those forms of the instrument quite 
 adapted for the purpose, and which have been tested by 
 us, and found practically the most useful and con- 
 venient for the photographic processes on paper. 
 
CAMERA PICTURES. 
 
 29 
 
 Fig. 6. 
 
 40. Fig. 6. represents the most simple and inexpen- 
 sive form of the apparatus ; it consists of a wooden box A, 
 having at one end a meniscus or concavo-convex lens 
 screwed into a sliding brass tube B, so as to be able to 
 push it toward or away from a piece of dimmed glass C 
 which is enclosed in a frame, and made to slide into a 
 groove at the other end of the box. On pointing the 
 camera at any object, there will be a reduced represen- 
 tation of it on the ground glass C, more or less clear ; 
 but this image may.be rendered quite distinct by ad^ 
 
30 
 
 PHOTOGENIC MANIPULATION. 
 
 justing the distance of the lens from the ground glass, 
 D represents the sliding frame for holding the prepared 
 paper, this fits into the same groove in the camera as 
 the ground glass, and is provided with a sliding' door 
 
 E, so that the light can be made to fall on the prepared 
 paper after its introduction into the camera ; the paper 
 is 'affixed by one or two morsels of wafer upon the door 
 
 F, of the frame. 
 
 41. Portable Camera^ — Fig. 7. represents a much 
 more complete and convenient form of camera; the 
 
 Fig. 7. 
 
 sides of the box, A, are hinged together, and so contrived 
 that, upon taking out the back and front, the box 
 folds into a very small compass, and the whole can be 
 packed into the box, B ; the slide for containing the 
 paper is also very convenient, inasmuch as it is so con- 
 trived that two pieces of prepared paper may be 
 enclosed and exposed to light in succession, it is shown 
 
CAMERA PICTURES. 
 
 31 
 
 in a a. The pieces of prepared paper are laid, the 
 prepared side downwards, upon the squares of glass 
 a a, having a piece of black paper interposed between 
 the two, to prevent the light acting upon one, whilst the 
 other is being impressioned ; the two halves of the slide 
 are then folded together, and secured by a brass clasp 
 at each side. Upon reference to Fig. 6. it will be seen 
 that one slide is represented as drawn upwards, this 
 would let the light act upon one piece of paper ; this 
 shut down, the frame turned round in the camerabox,and 
 the other drawn up, would then uncover the other piece. 
 
 42. But a very convenient and useful modification 
 in this camera, is the sliding front, h ; the part of the 
 camera front bearing the lens is made to slide in a dove- 
 tail in the other part of the front, so that the operator is 
 able to raise or depress the lens to the extent of about one 
 inch or one inch and a half. In raising or depressing 
 the lens, we also raise or lower the horizontal line of 
 the landscape (or other object at which the camera is 
 pointed) upon the ground glass; now, as will be seen in 
 our directions for taking views, it is absolutely essential 
 in order to obtain correct perspective — for example, 
 in copying a building — that we should not raise the 
 camera at an angle, but that it should be perfectly 
 horizontal. Now, supposing the operator to be standing 
 on the ground, it will be found that if the camera is 
 horizontal, one-half of the picture will be occupied by 
 the object we wish to have represented, and the other 
 half by the foreground, which we could just do as well 
 without, and it is very probable the effect of the 
 picture will be spoiled, by some of the upper part of 
 the object not being represented. Now this difficulty 
 
32 
 
 PHOTOGENIC MANIPULATION. 
 
 is completely overcome in this case, by raising the 
 object-glass""a little higher, when part of the ground 
 will be cut off, and the whole of our object represented, 
 without having to move the camera out of its hori- 
 zontal position ; consequently, the true perspective will 
 be retained. 
 
 43. As some little care is required in the construction 
 of a camera, it may be as well to make the reader 
 acquainted with two or three points to be attended to, and 
 some of the optical principles on which its use depends. 
 Fig. 8. represents the lens, and the directions of the 
 
 Fig. 8. 
 
 rays of light in forming the image. If we hold a double 
 convex lens opposite any object, we shall find that 
 an inverted image of that object will be formed on a 
 piece of paper held behind it ; but the lens being 
 doubly convex, the rays which pass through it will go 
 to the same distance from every part of its surface, 
 therefore the image a will be found in the same curve 
 as the lens A. This may be corrected to a great extent 
 by using a lens of the periscopic form ; this was first 
 suggested by Dr. Wollaston : by this means the rays 
 a A, b B, are rendered longer than the central rays, 
 c, c. This lens, when used in the camera, should have 
 the concave side towards the object, and in order still 
 more to reduce the error of figure, a small diaphragm 
 
CAMERA PICTURES. 
 
 33 
 
 should be placed in front of the lens. The diagram, 
 Fig. 9, represents this arrangement, and the position 
 of the stop is shown at a, when it will be seen that it 
 just admits the rays of light from the object, and no 
 more. If a stop, having the same opening, had been 
 placed farther in advance of the lens, it is evident that 
 it must have cut off some of the rays of light from the 
 
 Fig. 9. 
 
 upper and lower parts of the figure, or if the tube had 
 been made longer, the same effect would have taken 
 place ; this is a very common fault in the construction 
 of cameras, and should therefore be attended to. 
 
 44. By using a small opening in front of the lens, 
 we are enabled to cover a greater extent of surface, 
 and more correctly, than by using a larger opening, but 
 it is at the sacrifice of light ; for the larger the opening 
 we employ there will of course be a greater amount of 
 light upon the prepared surface, and we shall obtain a 
 picture more quickly ; but in order to obtain the 
 greatest amount of distinctness, we must employ a 
 very small opening. It is better that the operator 
 should have two or three sizes, of about half, three- 
 fourths, and one inch and a quarter in diameter ; and 
 supposing the lens to be nine inches in focal length, we 
 
 PART I. D 
 
34 
 
 PliOTOGENlC MANIPULATION. 
 
 shall be enabled, by having an opening of about three- 
 fourths of an inch, to cover a surface of nearly five 
 finches square. As a general rule, with a moderately 
 small opening, a lens will cover a square surface of 
 about six-tenths of its focal length ; that is, supposing 
 a lens to be of twenty inches focus, it will enable us to 
 have our prepared paper six-tenths of twenty inches 
 square = twelve inches square. This is a general rule ; 
 for, of course, if the object is very close to the glass, 
 the distance of the paper from the lens will have to be 
 increased, and instead of twenty inches focal length, it 
 may be twenty-five or twenty-six, and the size of the 
 paper may be increased in proportion. 
 
 45. Another important matter to be attended to, is 
 what is called Chromatic Aberration, Fig. 10. 
 
 Fig. 10. 
 
 Let a represent a ray of white light falling on the 
 lens L; it will not pass through colourless, but will 
 suffer decomposition into the primitive colours of which 
 white light is composed. Now all these colours have a 
 different degree of refrangibility, or are differently bent 
 out of their straight course ; therefore all these colours 
 will have a different focal distance for the image a, a ; 
 the visual focus, or that of the yellow ray, being at y, 
 whilst the focus for the violet rays will be at u, and for 
 the red at Now, it has been stated (§ 5.), that the 
 
CAMERA PICTURES. 
 
 35 
 
 rays by which the photographic image is produced are the 
 violet, whilst those which act most intensely on the organ 
 of vision are the yellow. It will therefore be evident, 
 that, when we adjust the focus of the camera, we shall 
 obtain the focus of the yellow ray, whilst the image 
 produced by the violet rays will not be properly dis- 
 tinct ; it is necessary, therefore, after having obtained 
 the best visual focus, to push the lens a little nearer 
 the paper so as to get the violet rays to act on the paper. 
 This distance is about one-thirtieth of the whole focal 
 length of the object glass, with a moderate-sized open- 
 ing ; of course, with a smaller diaphragm the chromatic 
 aberration will be a little less, but as a general rule 
 to the photographer, the lens should be pushed in one- 
 thirtieth of the focal distance, after having obtained 
 a distinct and well-defined image. The instrument- 
 makers generally mark on the brass tube containing the 
 lens, a scale which indicates at once the proper focus. 
 
 46. Lenses are made with a combination of glasses, 
 in which this chromatic aberration is overcome ; but 
 there is this disadvantage attending them, that in 
 achromatizing a periscopic lens, we increase the 
 error of figure, and therefore cannot cover so large 
 a field ; however, for the more delicate operation of the' 
 Daguerreotype where extent of surface is not so much 
 an object as minuteness of detail, an achromatic lens 
 is preferable. A great amount of attention has been 
 paid to this point, and combinations of lenses are now 
 made beautifully achromatic, but the expense is 
 enormously increased, and for the processes on paper 
 we can recommend, from our own experience, a single 
 
 D 2 
 
36 
 
 PHOTOGENIC MANIPULATION. 
 
 meniscus lens, and believe that, if properly adjusted to 
 the chemical focus, equally as good pictures may be 
 produced by it as by a more expensive form. 
 
 CALOTYPE. 
 
 47. We are indebted to Mr. Fox Talbot for the dis- 
 covery of this process, by which a paper may be pre- 
 pared of an extraordinary degree of sensitiveness. The 
 sensitive papers before described may be used in the 
 camera, but they require such an enormous time to pro- 
 duce an image, that on this account they are all 
 but useless, two or three hours being in general neces- 
 sary for exposure before an image is produced ; whilst 
 in the calotype, in a very few seconds, the paper re- 
 ceives the impression. Before, however, describing the 
 process, we shall enumerate the apparatus required. 
 
 Two or three flat porcelain dishes for holding the 
 solutions of iodide of potassium, nitrate of silver, hypo- 
 sulphite of soda, distilled water, &c. Fig. 5. 
 
 A sheet of plate glass, supported upon adjusting 
 screws, to apply the gallo-nitrate. 
 
 Camel or badger hair brushes. 
 
 A steam apparatus for developing the picture, shown 
 at Fig. 12 ; or, in the absence of this apparatus, a basin 
 of hot water will do very well. 
 
 A graduated glass to measure out the gallo-nitrate ; 
 this should not be made too narrow, but should admit 
 of being readily cleaned ; this cleaning being absolutely 
 essential after every time of using, inattention to which 
 will cause many failures. 
 
CALOTYPE. 
 
 37 
 
 A board for laying the paper upon whilst applying 
 the solutions. 
 
 48. Preparation of the Iodized Paper , — ^The paper 
 having been selected with the precautions before stated 
 (§ 10.), it should be laid upon the board, having two or 
 three sheets of blotting paper underneath it, so as to 
 absorb any moisture that may by chance get over the 
 side of the paper ; it should be held by the finger at 
 one corner and washed over by candle-light with a 
 solution of nitrate of silver, having about 20 grains of 
 the salt dissolved in one ounce of distilled water ; this 
 should be allowed to dry at a little distance from the 
 fire, and then altogether immersed in a solution com- 
 posed as follows : — 
 
 Dissolve in a pint of water 
 
 250 grains iodide of potassium, 
 
 125 „ chloride of sodium (common salt), 
 
 125 „ bromide of potassium. 
 
 It may be allowed to remain for about half a minute 
 in this solution, so as to insure the whole of the pre- 
 viously applied nitrate of silver being converted into 
 the mixed iodide, chloride, and bromide of silver, for 
 should there be any free nitrate of silver left in the 
 paper, it will be liable to darken spontaneously, and the 
 operator will be annoyed by finding that upon applying 
 the gallo-nitrate to excite the paper, it will blacken all 
 over ; at the same time, care should be taken that 
 it does not remain too long in the solution, for if it 
 should, the iodide of silver being very soluble in iodide 
 of potassium, the whole will be dissolved out. 
 
 49. The object of the operator in this part of the 
 
38 
 
 PHOTOGENIC MANIPULATION. 
 
 process being to leave an iodide of silver in the pores 
 of the paper, perfectly free from impurity, it is 
 necessary, after the paper has been immersed in the 
 iodide of potassium, to remove the excess of this salt 
 and a nitrate of potass, which is formed, by well washing 
 in common water. For this purpose the operator 
 should provide himself with three or four large vessels 
 of water, and after the first piece of paper has been 
 immersed in the iodide of potassium, it should be placed 
 in vessel No. 1 and gently agitated, and left until the 
 next piece of paper is ready for washing, when the first 
 iodized piece should be removed into vessel No. 2, and 
 the second piece of paper submitted to the same wash- 
 ing and agitation as the first, and so on, until the first 
 prepared piece has passed through three or four vessels 
 of water, when it should be taken out and the super- 
 fluous moisture removed by clean blotting-paper, and 
 then left to dry spontaneously ; the paper should then 
 be preserved from the light in a portfolio until required 
 for use. 
 
 50. We have sometimes found it an advantage when 
 washing the paper, to let a drop of the water from the 
 paper fall into a solution of nitrate of silver ; if there 
 should be a precipitate, it will indicate that the whole 
 of the iodide has not been washed out ; but should 
 there be no precipitate, the operator may consider that 
 the soluble salts have all been removed. This is a 
 useful test in one or two respects, first, because the 
 paper should not be washed more than is absolutely 
 necessary, for it has a tendency to make the paper 
 woolly, which will then print imperfectly ; secondly, it 
 
CALOTYPE. 
 
 59 
 
 is essential that the whole of the iodide should be 
 removed, for if not, the amateur will find that the 
 requisite degree of sensitiveness to light will not be ob- 
 tained, for it will convert the excess of nitrate we add 
 in order to make the paper sensitive, into iodide of 
 silver, which, when pure, is absolutely insensible to 
 light, as already stated. (§ 20.) 
 
 51. Applying the Sensitive Mixture,— This consists 
 in the application to the iodized paper of a mixed solution 
 of gallic acid and of nitrate of silver, called by Mr. Fox 
 Talbot, Gallo-nitrate. It is prepared as follows we 
 give the formulse as originally published by Mr. Fox 
 Talbot, for we believe, after all the modifications which 
 have been made, that his proportions are the best. — 
 Dissolve 100 grains of crystallized nitrate of silver, 
 in two ounces of distilled water, to which is added one- 
 sixth of its volume of strong acetic acid (which will be 
 two and two-thirds of a drachm) ; this solution should 
 be kept in a bottle excluded from the light. Now 
 make a saturated solution of gallic acid in cold distilled 
 water, the quantity dissolved is very small ; when re- 
 quired for use, the two liquids should be mixed together 
 in equal quantities, and then poured upon the plate 
 glass; having adjusted it by the set screws, so that the 
 solution will not run off, the sheet of iodized paper 
 should then be carefully applied to the wet surface, 
 and the air bubbles gently pressed out by passing the 
 finger over the back of the paper. As soon as the 
 paper has ceased to curl upwards, it should be removed 
 from the glass, and very gently pressed between folds 
 of blotting-paper, but only just enough to remove any 
 
40 
 
 PHOTOGENIC MANIPULATION. 
 
 shining patches of moisture on the surface, and then 
 placed at once in the frame of the camera, for it is now 
 extremely sensitive, and should be used directly, for with 
 this strength of solution the paper almost immediately 
 blackens spontaneously. To obviate this, Mr. Fox 
 Talbot directs that the paper should be immersed for 
 an instant under water, after the application of the 
 gallo-nitrate, and then blotted off. It is evident that 
 this is equivalent to using a more dilute solution ; it 
 is, therefore, better, instead of using the solution so 
 strong as Mr. Fox Talbot recommends, to dilute it 
 twenty or thirty times its bulk with water, and then 
 apply this to the paper, when it will be found to 
 preserve its whiteness for ten or twelve hours, if care- 
 fully excluded from light. As a general rule, the longer 
 we wish to keep paper after the sensitive solution is ap- 
 plied, the more the gallo-nitrate should be diluted ; but 
 when w'e wish for very sensitive paper, the dilution 
 should not be more than three or four times the bulk 
 of the mixed liquids. Another matter must be at- 
 tended to carefully if we wish to obtain clean and 
 clear pictures : — if the acetic acid we use be of the 
 greatest possible strength, or the crystallizable acid, 
 then the amount stated to be added by Mr. Fox Talbot 
 is the proper quantity ; but if weaker, then we must 
 add a larger quantity ; for Mr. Cundell has pointed out 
 (Phil. Mag. No. CXCII.) that one great cause of the 
 failure of calotypists, is in having their paper blackened 
 all over, or becoming of a dirty colour by the absence of 
 the requisite quantity of this acid* The operator may ^ 
 therefore, be sure that if his paper becomes discoloured 
 
CALOTYPE. 
 
 41 
 
 'vvlien every care lias been taken in the other parts of 
 the process, that he has not got enough acetic acid in 
 the solution. The tendency of this acid appears to 
 be, to keep the white parts of the picture clean and 
 white, but too much destroys the sensitiveness of the 
 paper. 
 
 52. Exposure in the Camera. —• The camera is to 
 be placed upon some firm and steady support, and 
 pointed at the object we wish to represent. A clear 
 and distinct focus is then to be obtained upon the 
 ground glass, and the tube afterwards pushed in a cer- 
 tain distance to the chemical focus (§ 45.) ; the ground 
 glass is then removed, and replaced by the frame con- 
 taining the prepared paper, and the slide in front drawn 
 up for a certain time, which depends entirely upon 
 the amount of light existing at the time, the size of 
 the diaphragm in front of the lens, the sensitiveness of 
 the paper, and the colour of the object to be copied, 
 &c. All these matters the amateur must determine by 
 experience, and with a few trials of his apparatus he 
 will easily determine the time. It varies from about 
 half a minute to five minutes ; an exposure for a longer 
 time seldom produces good results. The operator 
 must bear in mind that any object of a yellow colour 
 will take a much longer time than a white or blue, and 
 when the light is yellow from clouds, or when near sun- 
 set, the picture will also take much longer to be pro- 
 duced. Generally, in views or buildings a much better 
 effect is produced when the sun shines on the object 
 for a few seconds, as we are about to withdraw the 
 paper ; it sharpens and gives a much greater intensity 
 
42 
 
 PHOTOGENIC MANIPULATION. 
 
 to the lights, whilst, if there had been sunshine during 
 the whole of the exposure, the shadows would have been 
 very heavy. 
 
 Portraits . — In copying the human face divine,*' 
 two or three hints may not be unacceptable to the 
 amateur. The sitter should be placed in an easy, na- 
 tural position, and remain perfectly still during the 
 operation, A very ludicrous effect is often given from 
 an inattention to this, for it is obvious, if a person as- 
 sumes two or three positions during the exposure of the 
 paper, there will be a corresponding number of images 
 impressed, and we may thus have a representation of 
 one or two additional noses, fingers, or eyes, or the 
 nose or eye may have a greater breadth, or be consi- 
 derably elongated ; to avoid this, a rest for the head 
 should be made use of, one form of which is repre- 
 sented (fig, 11) ; this is to be attached firmly to the 
 Fig. 1 1 . back of the chair, and the person allowed 
 to assume the desired position ; the rest 
 should then be adjusted so that the arm 
 having the curved piece of brass attached 
 just touches the back of the head ; this will 
 keep it sufficiently still for all the minute 
 markings to be very accurately copied. 
 In order to operate with success, the 
 model should be well illuminated, but at 
 the same time care should be taken to 
 avoid the direct rays of the sun ; for 
 this purpose a sort of canopy should be placed over 
 the head, made of blue calico, so that the shade 
 may fall beyond the feet; this will also prevent 
 
CALOTYPE, 
 
 43 
 
 too much light falling on the forehead and the top of 
 the shoulders ; too much light falling directly from 
 above has the disadvantage of not shewing the eyes 
 with distinctness, the shadows from the eyebrows and 
 forehead falling on them. With respect to the proper 
 backgrounds, those who undertake portraits will ar- 
 range them according to their own tastes : some paint 
 a landscape, library, or balcony roughly, and place it 
 behind the sitter ; these look very well for a full length 
 portrait, in a group : for a plain background, an old 
 blanket gives a very even and uniform tint. As a 
 general rule, the camera should be placed about the 
 height of the eyes ; by this means, the upper or intel- 
 lectual part of the head will be slightly enlarged, the 
 eyes may be directed towards the camera. 
 
 53. Views , — ^The operator must be very careful, 
 when directing the camera to a building, &c. that it 
 should be perfectly horizontal; for if the camera is 
 pointed upwards, so as to take in the whole of the 
 object, the picture will have a very bad effect, for the 
 building will appear in the picture as if falling, and 
 none of the perpendicular lines will be erect. Some 
 have recommended that the operator should endeavour 
 to have the camera placed at about one-third of the 
 height of the building, but we think pictures have a 
 more pleasing and natural effect if taken from the 
 street, at about the height of the eye, so as to get the 
 same angles in the picture we are generally accustomed 
 to, in viewing any object. It is generally better to 
 have the camera at about the distance of double the 
 height of the object; of course, it must be left to the 
 
44 
 
 PHOTOGENIC MANIPULATION, 
 
 taste and management of the operator, as to the con- 
 trasts, &c. in the picture. The object upon which we 
 place more importance, and of which we desire the most 
 clear representation, we should adjust the focus of the 
 camera more clearly upon ; but should the landscape 
 embrace various objects, at different distances, it will 
 be necessary to use a very small opening in front of 
 the object-glass, otherwise only one or two objects will 
 be distinctly in focus, and the rest indistinct. 
 
 54. Developing the Picture , — When the paper has 
 been exposed in the camera the requisite time, there 
 is, to all appearance, seldom any impression, it being 
 generally as blank as before, but the picture exists, 
 though in a latent state. In order to render it 
 visible, Mr. Fox Talbot directs that the paper 
 should be again washed over with a solution of the 
 gallo-nitrate of silver, and then exposed to a gentle 
 heat. The best method of applying this gallo- 
 nitrate, is to pour it, as before directed (§ 51), upon 
 the piece of plate glass (taking care that it is thoroughly 
 clean), and then apply the paper to the surface until 
 it is moderately wet ; any air bubbles 
 should be pressed out, by passing the 
 finger over it as before mentioned. 
 The paper should then be held in 
 front of the jet of steam, which should 
 be allowed to act equally all over the 
 paper, when the picture will slowly 
 develope itself. Fig. 12 represents a 
 convenient apparatus for the pur- 
 pose. Should any part of the picture 
 
CALOTYPE. 
 
 45 
 
 not appear sufficiently distinct, the jet of steam may be 
 allowed to play upon it for a short time longer than the 
 other parts. The paper should not he allowed to be- 
 come dry in this process, otherwise the heat will em- 
 brown it, but it may be rewetted with the gallo-nitrate, 
 and again exposed to heat. A very simple and very 
 effectual plan is to develope the picture by means of 
 the steam and heat arising from a basin of hot water — 
 the picture should be held horizontally, and moved 
 about over the steam. Some have recommended a dry 
 heat, viz., by a vessel heated with hot water, but this 
 plan is very apt to embrown the picture, the moisture 
 being so soon evaporated, whereas with the steam, a 
 considerable amount of water is condensed, and the 
 paper is therefore kept moist. After the picture has 
 obtained its greatest intensity, it should be agitated in 
 a little common water — this being renewed once or 
 twice — and it may, after a pressure between the folds 
 of clean blotting paper, be submitted to the operation of 
 
 55. Fixing the Picture. — Mr. Fox Talbot originally- 
 directed that it should be immersed in a solution of 
 bromide of potassium, containing 100 grains of that 
 salt dissolved in ten ounces of distilled water. After 
 remaining for a little time in this solution, it should be 
 well washed in common water, and dried with blotting 
 paper. But a much better plan is to immerse it in a 
 solution of the hyposulphite of soda for a short time, 
 and then wash it well in water, renewing it a number 
 of times. It is better it should be soaked for. three or 
 four hours, and then dried with bibulous paper. (§ 36.) 
 
 The following deviation from Mr. Fox Talbot's pro- 
 
46 
 
 PHOTOGENIC MANIPULATION. 
 
 cess answers extremely well when the paper is to be 
 used and the image brought out immediately ; the pic- 
 tures obtained by its means are generally very clean, 
 and the light parts very white ; for portraits, and where 
 great quickness is required, we have found it excellent. 
 
 Apply to the paper a solution of nitrate of silver, 
 containing 100 grains of that salt to 1 ounce of dis- 
 tilled water. When nearly, but not quite, dry, dip it 
 into a solution of iodide of potassium, of the strength of 
 25 grains of the salt to 1 ounce of distilled water, drain 
 it, wash it, as before directed (§ 51.), and then allow it 
 to dry. Now brush it over with aceto-nitrate of silver, 
 made by dissolving 50 grains of nitrate of silver in 1 
 ounce of distilled water, to which is added one-sixth its 
 volume of strong acetic acid. Dry it with bibulous 
 paper, and it is now ready for receiving the image. 
 When the impression has been received, it must be 
 washed with a saturated solution of gallic acid, and 
 exposed to a steam heat. (§ 54.) The image will be 
 gradually brought out, and may be fixed with hypo- 
 sulphite of soda. It will be observed that in this pro- 
 cess the solutions of nitrate of silver and of gallic acid 
 are not mixed before application to the paper, as in 
 Mr. Talbot’s process ; we therefore can use a brush for 
 applying the solutions, which is sometimes an advan- 
 tage ; of course, separate brushes must be used for the 
 nitrate of silver and for the gallic acid. In preparing 
 calotype paper, too much care cannot be taken, not 
 only to prevent the daylight falling on it, but also to 
 exclude, if possible, the strong glare of a candle or 
 lamp. The candle should be removed some distance 
 
CALOTYPE. 
 
 47 
 
 from the paper, or a yellow screen should be placed 
 around it. This must be particularly attended to when 
 the paper is intended to be kept some time after the 
 sensitive mixture has been applied, for the slightest im- 
 pression of light will in a little time develope itself 
 strongly, if not visibly ; it will make its appearance when 
 the picture is brought out, giving the light parts a dirty 
 appearance, or, very probably, the paper will blacken 
 all over. 
 
 56. Obtaining the Positive Photograph . — The pic- 
 ture just described, as being obtained in the camera, is 
 a negative picture, similar to those we have mentioned 
 in the description of the common photographic papers. 
 (§ 30.) It is therefore necessary that a positive picture, 
 or one with the lights and shades as they occur in 
 nature, should be obtained ; this can be produced very 
 quickly on the calotype paper, but it is unadvisable, 
 as the tone of the picture is not so pleasant as that 
 obtained by the common photographic processes. 
 
 19.) The ammonio-nitrate paper is decidedly the 
 best. The negative calotype picture should be laid, 
 with its face downwards, upon a piece of dry ammonio- 
 nitrate paper, and secured at two of the corners by 
 morsels of wafer, and then placed in the pressure 
 frame, Fig. 4, and exposed to light, until the necessary 
 degree of intensity in the positive picture is produced. 
 This can be readily ascertained by taking it out of the 
 frame, and raising it gently, so as not to disturb its 
 position, or draw it apart from the wafers; the rest of 
 the process with the positive picture being precisely 
 the same as at (§ 34). 
 
48 
 
 PHOTOGENIC MANIPULATION. 
 
 57. Mr. Fox Talbot has described a plan by which 
 the tone of the positive picture is altered considerably. 
 He directs that, after removal from the light, it should 
 be placed in a weak solution of iodide of potassium. 
 This will convert the whole of the free nitrate of silver 
 into the yellow iodide of silver. It should then be im- 
 mersed in a boiling solution of the hyposulphite of 
 soda, — the yellow colour will be removed from the 
 lights, and a very peculiar tone left on the picture. 
 This is a very perfect method of fixing, the photograph 
 seldom becoming dark, as is the case sometimes with 
 other methods of fixing. 
 
 58. This method has also been applied by the same 
 gentleman to fix the negative photographs ; the ne- 
 gative picture should be immersed in a hot solution 
 of the hyposulphite until the yellow colour disappears 
 from the iodized paper, and be then washed as usual. 
 This is stated by Mr. Talbot to produce better positive 
 pictures, but in our hands it has not proved successful, 
 the hot hyposulphite appears to injure the picture con- 
 siderably. 
 
 59. The calotype process just described is exquisitely 
 sensitive, very beautiful impressions from prints, leaves, 
 ferns, and pieces of lace, may be produced in a few 
 minutes by exposure to moonlight, a candle, or gas 
 light, but for producing the same effect in sunshine a 
 fraction of a second is sufficient. Some operators 
 render the negative pictures transparent, this is some- 
 times an advantage when we wish to print very quickly ; 
 it may be done as described (§ 32). 
 
 Sir D. Brewster has proposed an important modifi- 
 
CALOTYPE. 
 
 49 
 
 cation of this method of obtaining positive photo- 
 graphs. He states that the present mode gives a rough- 
 ness of shade which destroys the softness of the 
 picture. To obviate this he interposes a sheet of white 
 paper without water-mark, and of uniform texture. 
 The diffusion of the light thus occasioned shades off, 
 as it were, all the sharp lines and points, and gives a 
 higher degree of softness to the picture. Two, or 
 even three sheets may be interposed in strong sun light. 
 A similar effect may be obtained in a less degree by 
 placing the back of the negative upon the positive 
 paper, so as to cause the light to traverse the thick- 
 ness of the negative, and this may be combined with 
 one or more sheets of clean paper ; but this will be 
 appropriate only for portraits, and it has the advan- 
 tage (sometimes required) of making the individual 
 look another way. “ To those,” adds Sir David, 
 “ who see the experiments above described for the first 
 time, the effect is almost magical ; and when the nega- 
 tive is removed, we see only a blank sheet of white 
 paper, and our surprise is very great when, upon lifting 
 this sheet, we discover beneath it a perfect picture, 
 which seems, as it were, to have passed through the 
 opaque and impervious screen.” 
 
 The calotype process has been much simplified by 
 Mr. Hunt, to whom we are indebted for the greater 
 number of processes on paper at present known, 
 and whose valuable researches on the chemical effects 
 of light have added so greatly to our knowledge of 
 that mysterious agent. 
 
 60 . Mr. Hunt has shown that the action of light on 
 
 PART I. E 
 
So 
 
 PHOTOGENIC MANIPULATION. 
 
 nearly all the salts of silver may be hastened, and the 
 effects developed by gallic acid, or other reducing 
 agents, and he has given several formulae for producing 
 pictures. We give one which we have found the best, 
 but the principle is the same in all. An insoluble salt 
 of silver is formed in the paper having a slight excess 
 of the nitrate, this is exposed to light, and then brought 
 out by a solution of gallic acid, or proto-sulphate of 
 iron. The following Mr, Hunt calls 
 
 FLUOROTYPE. 
 
 61. A sheet of paper is to be washed, first, with a 
 solution of bromide of potassium, and then with the 
 fluate of soda, or, which will be found the better plan, 
 the two salts may be united. The strength should be 
 as follows : 
 
 { Bromide of potassium, 20 grains. 
 
 Distilled water, . . 1 fluid ounce. 
 
 f Fluate of soda, . , 5 grains. 
 
 \ Distilled water, . . 1 fluid ounce. 
 
 Mix a small quantity of these solutions together when 
 the papers are to be prepared, and wash them once 
 over with the mixture, and when dry, apply a solution 
 of nitrate of silver, sixty grains to the ounce of water. 
 These papers keep for some weeks without injury, and 
 become impressed with good images in half a minute 
 in the camera. The impression is not sufficiently 
 strong when removed from the camera for producing 
 positive pictures, but may be rendered so by a secon- 
 dary process. 
 
 62. The photograph should first be soaked in water 
 
rLUOROTYPE. 
 
 51 
 
 for a few minutes, and then placed upon a slab of por- 
 celain, and a weak solution of the proto-sulphate of 
 iron brushed over it ; the picture immediately acquires 
 great intensity, and should then be stopped directly, 
 or the blackening will extend all over the paper ; it 
 may be fixed by being soaked in water, and then 
 dipped into a solution of hypo- sulphite of soda, and 
 again soaked in water as in the other processes. 
 
 63. We find it is better to add to the proto-sulphate 
 of iron a little acetic or sulphuric acid : this will be found 
 to prevent the darkening of the lights of the picture to 
 a great extent, and it will be found better not to pre- 
 pare the paper long before it is required for use, this 
 being one reason why the picture often becomes dusky 
 on application of the proto-sulphate. Reasoning upon 
 the principle that the action of light is to reduce the 
 salts of silver in the paper to the metallic state, and 
 that any substance which would reduce silver would 
 also quicken the action of light, we were led to the fol- 
 lowing experiment : The proto-chloride of tin possesses 
 the property of reducing the salts both of silver and of 
 gold ; a paper was prepared with the bromide of silver, 
 and previously to exposing it to light, it was washed 
 over with a very weak solution of the chloride of tin ; 
 the action of light upon the paper was exceedingly en- 
 ergetic ; it was almost instantaneously blackened, and 
 a copy of a print was obtained in a few seconds; 
 this was performed last summer. I have lately tried 
 once or twice to repeat the experiment, but without 
 success ; the paper being blackened in the dark spon- 
 taneously. I hope, however, to have some leisure shortly, 
 
 E 2 
 
52 
 
 PHOTOGENIC MANIPULATION. 
 
 and shall endeavour to perfect the process, which gives 
 a good deal of promise. 
 
 FERROTYPE OR ENERGIATYPE. 
 
 64. Mr. Hunt some little time ago announced a 
 process, he at the time called the Energiatype, from an 
 opinion of his, that the effects produced were not by 
 light, but resulted from a peculiar principle he de- 
 nominated Energia; he has, however, since altered it 
 to Ferrotype, which includes all the processes in 
 which proto- sulphate of iron is used as a reducing 
 agent. The original process was as follows : — a 
 solution is prepared by dissolving two drachms of 
 succinic acid, and five grains of common salt, in one 
 fluid drachm and a half of distilled water, having 
 previously added half a drachm of mucilage of gum 
 arabic ; this is applied to the paper, and when dry, 
 is to be washed over with a solution of nitrate of 
 silver, containing sixty grains to the ounce of water; 
 it is allowed to dry in the dark, when it is fit for 
 use. It may be preserved in a portfolio, and placed in 
 the camera when wanted. The time necessary for 
 exposure varies from two to eight minutes, but like the 
 calotype no image is visible ; in order to bring out 
 the dormant picture, it is necessary to wash it with a 
 saturated solution of proto-sulphate of iron, to which 
 has been added two drachms and a half of mucilage 
 of gum arabic ; we find it is an improvement in this 
 process as well as in the Fluorotype, and, indeed, in all 
 
FERROTYPE OR ENERGIATYPE. 
 
 53 
 
 cases when the proto-sulphate of iron is used, to add to 
 it a little acetic acid. 
 
 65. It is not essential to use the succinate of silver, for 
 Mr. Hunt finds that the picture may be produced either 
 with the benzoate, the bromide, the iodide, the arseniate, 
 and, indeed, nearly any one of the salts of silver. The 
 proto-sulphate of iron has this advantage, that pictures 
 may be produced much quicker by its means than by 
 any other method ; when used instead of gallic acid in 
 developing an ordinary calotype picture, the quickness 
 is extraordinary, and engravings, &c. may be copied 
 absolutely instantaneously. 
 
 66. Mr. Hunt has modified this process in a very 
 ingenious way ; he has taken advantage of the property 
 possessed by the oils of cassia and of cloves in preci- 
 pitating metallic silver, as in Drayton’s process for 
 silvering mirrors, but he finds that the silver will be 
 precipitated more readily when the light has acted. 
 The following is the process : — 
 
 The paper, after having been submitted to the 
 influence of light, is immersed in spirits of wine 
 containing in solution a small quantity of the essential 
 oils of cassia and of cloves, and as soon as the spirit 
 I has penetrated the paper, it is to be pressed between 
 folds of blotting paper previously saturated with the 
 same solution, and then pressed together between two 
 pieces of plate glass ; in the course of an hour or two 
 the picture will be developed very beautifully, and may 
 be fixed in the ordinary way. 
 
54 
 
 PHOTOGENIC MANIPULATION, 
 
 CHROMATYPE. 
 
 67. This is another process for which w€ are also 
 indebted to Mr, Hunt, and it has this advantage, that 
 it is a positive process ; that is, a copy of an engraving 
 is produced at once, with the lights and shades correct; 
 it is also one of the most simple and easily managed, 
 and the pictures produced are very beautiful. The 
 process was made known at the Meeting of the British 
 Association, August 1843. 
 
 One drachm of sulphate of copper is dissolved in 
 half an ounce of distilled water, to which is added half 
 an ounceof a saturated solution of bichromate of potash; 
 this solution is applied to the surface of the paper, and, 
 when dry, it is fit for use, and may be kept for any 
 length of time without spoiling. When exposed to 
 sunshine, the first change is to a dull brown, and if 
 checked in this stage of the process we get a negative 
 picture, but if the action of the light is continued, the 
 browning gives way, and we have a positive yellow 
 picture on a white ground. In either case, if the paper, 
 when removed from the sunshine, is washed over with 
 a solution of nitrate of silver, a very beautiful positive 
 picture results. In practice, it v/ill be found advan- 
 tageous to allow the bleaching action to go on to some 
 extent; the picture resulting from this will be clearer 
 and more defined than that which is procured when 
 the action is checked at the brown stage. To fix these 
 pictures it is necessary to remove the nitrate of silver, 
 which is done by washing in pure water ; if the water 
 
CHROxMATYPE. 
 
 55 
 
 contains any muriates the picture suffers, and long 
 soaking in such water entirely destroys it, or if a few 
 grains of common salt are added to the water the ap- 
 parent destruction is very rapid. The picture is, how- 
 ever, capable of restoration ; all that is necessary being 
 to expose it to sunshine for a quarter of an hour, when it 
 revives; but instead of being of a red colour, it becomes 
 lilac, the shades of colour depending upon the quantity 
 of salt used to decompose the chromate of silver which 
 forms the shadow parts of the picture. 
 
 68. Mr. Hunt has since modified this process — we 
 
 give his account : A neutral solution of the chloride 
 
 of gold is mixed with an equal quantity of the solution 
 of bichromate of potash. Paper washed with this 
 solution, and exposed to light, speedily changes, first 
 to a deep brown, and ultimately to a bluish-black. 
 If an engraving is superposed, we have a negative copy, 
 blue or brown, upon a yellow ground. If this photo- 
 graph is placed in clean water, and allowed to remain 
 in it for some hours, very singular changes take place. 
 The yellow salt is all dissolved out, and those parts of 
 the paper left beautifully white. All the dark portions 
 of the paper become more decided in their character, 
 and, according as the solarization has been prolonged 
 or otherwise, or the light has been more or less intense, 
 we have either crimson, blue, brown, or deep black 
 negative photographs.’^ 
 
 69. A process with the bichromate of potash has 
 also been announced by Mr. Mungo Ponton. Paper 
 should be soaked in a saturated solution of the bichro- 
 mate of potash, and then exposed to sunshine; a delicate 
 
56 
 
 PHOTOGENIC MANIPULATION. 
 
 buff coloured negative picture upon a yellow ground 
 will be the result. To fix these pictures, all that is 
 necessary is to soak them in common water, when the 
 yellow colour will disappear, and they will be per- 
 fectly white, — this is a simple and easy process, the 
 rationale of which appears to be this : — Bichromate of 
 potash consists of chromic acid and potash ; under the 
 influence of light the starch in the size of the paper 
 and the chromic acid react upon one another, and it is 
 very probable that the acid is partially reduced, for, with 
 paper having very little size, the bichromate bears a 
 much longer exposure. A knowledge of these facts 
 has led to a pretty modification of this process by 
 M. Edmund Becquerel : he directs that paper should 
 be steeped, in a weak solution of iodine in alcohol and 
 then copiously washed in water, it will then assume a 
 beautiful blue tint ; if this tint be uniform the paper is 
 deemed proper for the experiment, otherwise the ope- 
 rator must size it himself with starch. It is afterwards 
 to be steeped in accordance with Mr. Ponton’s method, 
 in a concentrated solution of bichromate of potash, and 
 the superfluous moisture removed by bibulous paper 
 and dried ; it is now ready for exposure to light ; in 
 order to copy an engraving it will require a time vary- 
 ing from one minute to fifteen according to the thick- 
 ness of the paper of the engraving and the intensity of 
 the light. After the exposure, wash the paper well and 
 dry it ; when it is dry, steep it in a weak alcoholic 
 solution of iodine, and when it has remained some time 
 wash it in water and then dry it between the folds of 
 blotting paper, but not before the fire, for the com- 
 
CHRYSOTYPE. 
 
 57 
 
 pound of iodine and starch is discoloured at about 212° 
 Fahrenheit. If it is thought that the copy is not suffi- 
 ciently brought out, repeat the immersion several times ; 
 by this means you may obtain any degree of intensity 
 of tone that you may wish the picture to have. In this 
 process the chromic acid seizes upon the starch over 
 those parts which have been exposed to light. Now 
 as starch possesses the property of forming with iodine 
 a combination of a very fine blue, it is evident that on 
 those parts of the paper which have not been impressed 
 by the solar rays, the starch will not have combined 
 with the chromic acid ; the iodine will therefore form 
 the blue iodide of starch, and thus represent shade by 
 shade. 
 
 CHRYSOTYPE. 
 
 70. This is a process discovered by Sir John 
 Herschel, in which iron and# gold are used as photo- 
 genic materials. Good paper is to be washed with a 
 solution of the ammonio-citrate of iron, and dried, and 
 afterwards washed over with a solution of the ferro- 
 sesqui-cyanuret of potassium. This paper should be 
 dried in a perfectly dark room, when it will be ready for 
 use in the camera. After it has been exposed a short 
 time, the picture may be developed by washing it with 
 a neutral solution of gold, of such a strength as to ap- 
 pear of the colour of sherry wine ; the image instantly 
 becomes visible, and may be fixed by well washing in wa- 
 ter, dried by blotting paper, and then washed in a weak 
 solution of the iodide of potassium. Should the picture 
 
58 
 
 PPIOTOGENIC MANIPULATION. 
 
 not have been well washed previously to the application 
 of the iodide of potassium, the lights will become dis- 
 coloured, but they will speedily whiten again sponta- 
 neously. 
 
 CYA NOTYPE. 
 
 71. Sir John Herschel is also the originator of this 
 process, or rather a number of processes, for it includes 
 all pictures taken with salts of iron, particularly when 
 in combination with cyanogen. Paper is washed over 
 with a moderately strong solution of the ammonio- 
 citrate of iron, and exposed in the ordinary way until 
 a faint negative picture makes its appearance. A 
 saturated solution of the common ferro-prussiate of 
 potash, in which is dissolved a little gum arabic, is 
 then to be rapidly passed over the paper when the nega- 
 tive picture vanishes, and is replaced by a greenish-blue 
 one, with a greenish-yellc^w ground. This picture re- 
 quires no fixing. 
 
 72. Another method, which requires a longer expo- 
 sure to the sunshine, but possesses this advantage— the 
 lights of the picture are white, and the shadows of 
 a beautiful blue* The following is the method of pre- 
 paration ; — Wash paper over with a solution of nitrate 
 of mercury, and, when dry, with a saturated solution 
 of sesqui-cyanuret of potassium. It is now ready for 
 exposure,' which should be continued until the required 
 degree of intensity in the colour is produced. The 
 picture may be fixed by soaking in cold water, to 
 which a little alum has been added. 
 
CYANOTYPE. 
 
 59 
 
 73. A very interesting and curious process was dis- 
 covered by Sir John Herschel, by which latent pictures 
 can be produced, which are capable of being de- 
 veloped by the breath, or by a moist atmosphere. If 
 solution of nitrate of silver, specific gravity 1*200, be 
 added to ferro-tartaric acid, specific gravity 1*023, a 
 precipitate falls, which may be again nearly redissolved 
 by a gentle heat ; a yellow liquid is obtained, in which 
 further addition of the nitrate causes no turbidness. 
 When the total quantity of the nitrate solution amounts 
 to one-half the bulk of the ferro-tartaric acid, it is 
 enough. The liquid so prepared does not alter in the 
 dark. The paper is to be spread over with this solu- 
 tion and exposed wet to sunshine (but partially 
 shaded) ; for a few seconds no impression seems 
 to have been made, but by degrees, although with- 
 drawn from the light, it developes itself spontane- 
 ously, and at length becomes very intense. But 
 if the paper be thoroughly dried in the dark, it pos- 
 sesses the singular property of receiving a dormant or 
 invisible picture, to produce which (if it be, for instance, 
 an engraving which is to be copied) from thirty seconds 
 to a minute's exposure to sunshine is requisite. It 
 should not be continued longer than that time, as not 
 only the ultimate effect is less striking, but a picture 
 begins to be visibly developed, and which darkens 
 spontaneously after it is withdrawn. But if the ex- 
 posure 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 imme- 
 diately appears, and very speedily acquires an extra- 
 
60 
 
 PHOTOGENIC MANIPULATION. 
 
 ordinary intensity and sharpness, as if by magic. 
 Instead of the breath, it may be subjected to the regu- 
 lated action of aqueous vapour, by laying it in a 
 blotting-paper book, of which some of the outer leaves 
 have been damped by holding them over warm water. 
 
 POSITIVE CALOTYPE. 
 
 74. At the second Meeting, at York, of the British 
 Association, Professor Grove described a process by 
 which positive pictures could be taken at once, without 
 the trouble of having to make a negative in the first 
 instance. Ordinary calotype paper is darkened till it 
 assumes a deep brown colour, almost amounting to 
 black ; it is then redipped in the ordinary solution of 
 iodide of potassium, and dried. When required for 
 use it is drawn over diluted nitric acid, one part acid, 
 and two and a half parts water. In this state, those 
 parts exposed to light are rapidly bleached, while the 
 parts not exposed remain unchanged. It is fixed by 
 washing in water, and subsequently in hyposulphite of 
 soda, or bromide of potassium. 
 
 Mr. Grove likewise described on the same occasion 
 another process which promises, when carried out, to 
 be of great utility. It is the conversion of a negative 
 calotype into a positive one, and was thus stated : Let 
 an ordinary calotype image or portrait be taken in the 
 camera, and developed by gallic acid ; then drawn over 
 iodide of potassium and dilute nitric acid and exposed, 
 to full sunshine ; while bleaching the dark parts, the 
 light is redarkening the newly precipitated iodide in the 
 
CATALISSISOTYPE. 
 
 61 
 
 lighter portions, and thus the negative picture is con- 
 verted into a positive one. 
 
 CATALISSISOTYPE. 
 
 75. The above name has been given to a process 
 described by Dr. Wood: — The paper to be prepared 
 is steeped in distilled water, to which has been added 
 hydrochloric acid in the proportion of two drops of 
 the former to three ounces of the latter; when well 
 soaked, the moisture is to be lightly absorbed, and 
 washed over with a mixture of half a drachm of syrup 
 of ioduret of iron, in two and a half drachms of water, 
 into which one or two drops of a solution of iodine 
 may be dropped. It is now to be dried with bibulous 
 paper, and washed over evenly with a solution of 
 nitrate of silver, twelve grains of the salt to the ounce 
 of water. It is now ready for the camera, the time of 
 exposure varying from a second to half a minute, ac- 
 cording to the degree of light. When removed from 
 the camera no picture is visible, but if left in the dark 
 it gradually developes itself, and ultimately becomes 
 extremely perfect. It is fixed by washing first in water, 
 and afterwards in a solution of bromide of potassium 
 (twenty grains to an ounce), after which it must be 
 again carefully washed and dried. 
 
 76. A process has been proposed by M. Gaudin, 
 (which appears to be a modification of one men- 
 tioned by Dr. Schafhaeutl and of Mr. Hunt's Ferro- 
 type) : — The paper is exposed for a minute in the 
 vapour of hydrochloric acid, after which a nearly 
 
62 
 
 PHOTOGENIC MANIPULATION. 
 
 saturated solution of nitrate of silver is to be brushed 
 over its surface, and allowed to dry. The dry sheet 
 is placed in the camera in the dark. On removal 
 no trace of the image will be visible ; but upon wetting 
 the paper with a nearly saturated solution of sulphate 
 of iron, slightly acidffied by the addition of a few 
 drops of sulphuric acid, the picture is immediately 
 developed. The time necessary for exposure in the* 
 camera is much about the same as for the calotype. 
 To fix the picture, which is a negative one, it must 
 be first washed in distilled water, and subsequently in 
 distilled water, to which has been added ten per cent, 
 of caustic ammonia. This is stated to be a good paper 
 for obtaining positive pictures from negative ones ; for 
 which purpose, however, the sulphate of iron need not 
 be used. The paper should be exposed until the edges 
 are blackened. 
 
 ANTHOTYPE* 
 
 77. This is a general name given to those methods 
 of producing pictures, in which the coloured juices of 
 plants are the photographic agents ; nearly the whole 
 have been described by Sir John Herschel. The petals 
 of the flowers should be crushed in a marble mortar, 
 and the juice expressed by squeezing the pulp in a 
 clean cloth. It should then be spread upon the 
 paper with great care, so as to be perfectly uniform all 
 over, and then dried by spontaneous evaporation. 
 It is better to add a little alcohol, as it prevents the 
 
 * From arOog, a flower, and rvTrog^ a picture. 
 
ANTIIOTYPE. 
 
 63 
 
 paper from becoming changed by the air, which some- 
 times occurs very quickly when this precaution is not 
 taken. The following are some of the results which are 
 mentioned by Sir John Herschel : — 
 
 The flowers of the Cor chorus japonicus impart a fine 
 yellow colour to paper, and, upon exposure to sun- 
 light, in about half an hour it is rendered quite white. 
 
 Common Ten Weeks' Stocks , — Papers prepared with 
 the alcoholic extract of this flower are of a very bright 
 red. and are sensibly decolorated in a few hours. The 
 red poppy gives a very beautiful red colour, which is 
 speedily bleached by the light, — and nearly all the 
 coloured flowers yield materials which may be used to 
 produce photographic pictures, — they are positives, 
 and are more or less permanent ; and it is an extremely 
 interesting study to observe the various effects pro- 
 duced by different vegetable preparations. Dr. Draper 
 and Mr. Hunt have followed out this subject in its 
 more extended view, viz., the action of light upon 
 plants, but they appear to differ in many of their 
 results. Mr. Robert Hunt placed seeds under different 
 coloured glasses ; these seeds were found by him to 
 germinate under the yellow glass, but were not found to 
 live and flourish ; however, if removed, after germina- 
 tion, and placed under the blue, they grew and were 
 very healthy. Mr. Hunt has been commissioned by the 
 British Association to pursue this subject. From the 
 investigations of this gentleman, it is certain that the 
 whole of the carbon of a plant, and which constitutes 
 the greater part of its solid matter, has been derived 
 from the atmosphere in which it exists united with 
 
64 
 
 PHOTOGENIC MANIPULATION. 
 
 oxygen and carbonic acid. This carbonic acid is decom- 
 posed by plants, when under the influence of light, into 
 carbon and oxygen gas ; the plant assimilates the car- 
 bon, and forms it into organized matter, and oxygen is 
 liberated. Now this occurs just according, and in pro- 
 portion, to the amount of light, or rather, to the cpian- 
 tity of actinic power existing at the time ; for it has 
 been shewn, that under yellow, green, or red glasses, 
 plants grow but very imperfectly ; or, in other words, 
 they are unable to decompose the carbonic acid, in con- 
 sequence of the absence of the chemical or blue rays. 
 Every person must have noticed the sickly appearance 
 of vegetation, if grown in a place where light is partially 
 excluded ; the leaves are nearly white, and if the plant 
 does flower and bear fruit, the leaves are pale and 
 scentless, and the fruit insipid. We have familiar ex- 
 amples of this when the gardener wishes to bleach celery 
 or endive ; he covers up the plants with earth, light is 
 excluded, and they become quite white ; the interior of 
 a cabbage is white, and for a similar reason. These 
 are interesting facts, for they shew how mutually de- 
 pendent animals and plants are one on another. It is 
 absolutely essential to animal life that the requisite 
 quantity of oxygen should exist in the air, which 
 myriads of animals are continually abstracting, in order 
 to keep up a process of combustion, the product of 
 which is carbonic acid ; for on inhaling the oxygen from 
 the air, it combines with the carbon contained in our 
 bodies, and forms this noxious gas, which is exhaled, 
 and deteriorates the atmosphere. Now, under the in- 
 fluence of light, this carbonic acid is decomposed by 
 
ANTIIOTYPE. 
 
 65 
 
 the vegetable kingdom, and pure oxygen gas set free, 
 to be again absorbed by animals. In the words of Mr. 
 Hunt, “ It is not possible to conceive a more perfect or 
 more beautiful system of harmonious arrangement than 
 this. If the vegetable world was swept away, animal 
 life would soon become extinct ; and if all animal ex- 
 istence was brought to a close, the forest would fall, 
 and the flowers of the field, which now clothe the earth 
 with gladness, perish in the utterness of a lamentable 
 decay.'’ 
 
 We have now conducted the reader through some of 
 the most important and useful of the photographic 
 processes on paper. The next part will be devoted 
 entirely to a description of the Daguerreotype, Thermo- 
 graphy, and other processes with metallic plates. 
 
 F 
 
INDEX. 
 
 Anthotype, § 77. 
 
 Aberration, § 44. 
 
 Chromatic, § 45. 
 
 Ammonia, fixing Photographs 
 by, § 34. 
 
 Alchemists ; early History of 
 Photography, § 2. 
 
 Actinism, § 4, 5. 
 
 Applying the Solutions, § 16. 
 
 Acetic Acid, § 18. — Use of, § 51. 
 
 Ammonio-nitrate Papers, § 24. 
 
 Directions for prepar- 
 ing, § 25. 
 
 Applications of Photography, 
 §37. 
 
 Blotting Paper, § 14. 
 
 Bromide of Potassium, § 18. 
 
 Papers, § 22. 
 
 Fixing by, § 35. 
 
 Brushes, use of, § 16. 
 
 Brewster’s, Sir David, method of 
 taking Positives, § 59. 
 
 Catalissisotype, § 75. 
 
 Cyanotype, § 71. 
 
 Chrysotype, j 70. 
 
 Chromatype, § 67. — Modification 
 of, § 68. 
 
 Camera, § 39. 
 
 Improved form of Slid- 
 ing Front, § 42. 
 
 Double Slide, § 41. 
 
 Camera, Optical, Principles of, 
 § 43. 
 
 — Pictures, § 38. 
 
 Chloride of Silver, § 20. 
 
 Papers pre- 
 pared by, § 20. 
 
 Chloride of Sodium, Fixing by, 
 § 35. 
 
 Chemical change in Photographic 
 processes, § 33. 
 
 Calotype, Simplification of, § 60. 
 
 Positive, by Professor 
 
 Grove, § 74. 
 
 Davy, Sir H., and Mr. Wedg- 
 wood, § 6. 
 
 Distilled Water, § 15. 
 
 Distilling, Apparatus for, § 15. 
 
 Diaphragms, use of, § 43. 
 
 Developing Calotype Pictures, 
 § 54. 
 
 Energiatype, process of, j 64. 
 
 Energia, § 4, 5. 
 
 Ferro-sesqui-cyanuret of Potas- 
 sium, use of, § 72. 
 
 Fixing Photographs, § 34. 
 
 Calotypes, § 55. 
 
 Fluorotype, § 61. 
 
 Ferrotype, § 64. 
 
 Grove’s, Professor, Positive Ca- 
 lotypes, § 74. 
 
 Gaudin, M., process by, § 76. 
 
INDEX. 
 
 Herschel’s, Sir John, Chrysotype, 
 process of, § 70. 
 
 • Cyanotype, § 71. 
 
 Experiments on 
 
 the Heat Rays, § 4. 
 
 Hunt’s, Mr. Robert, Chromatype, 
 process of, § 67. 
 
 Energiatype, § 64. 
 
 Fluorotype, § 61. 
 
 Experiment of, 
 
 § 33. 
 
 Hyposulphite of Soda, § 18. 
 
 Fixing of 
 
 Photographs by, § 36. 
 
 of Silver, Solu- 
 bility of, § 36. 
 
 Horn Silver, § 2. 
 
 Iodized Paper, Method of Mak- 
 ing, § 48. 
 
 Lenses, Remarks on, § 44, 45. 
 
 Muriatic Acid, Vapour of, § 23, 
 76. 
 
 Negative and Positive Photo- 
 graph, § 30. 
 
 Nitrate of Silver, Purity of, § 18. 
 
 Niepce, Experiments of, § 7. 
 
 Old Gallo-Nitrate, Property of, 
 
 § 15. 
 
 Oils of Cassia and Cloves, § 66. 
 
 Papers for Photographs, $ 10, 11. | 
 
 Paper, Bibulous, § 14. 
 
 Bromide, § 22. 
 
 Chloride, § 20. 
 
 Protosulphate of Iron, § 62. 
 
 Photography, Davy and Wedg- 
 wood’s Experiments in, § 6. 
 
 Ponton, Mr. Mungo, Process of, 
 § 69. 
 
 Paper for, § 13. 
 
 Photograph, Making the, § 27. 
 
 Pressure Frames, § 27, 28. 
 
 Positive Pictures, Method of ob- 
 taining, § 56. 
 
 Sir David Brewster’s, 
 
 §59. 
 
 Rays of Light, Different effects 
 upon Chloride of Silver, § 3. 
 
 Ritter’s experi- 
 ments on, § 3. 
 
 Resins affected by Light, § 7. 
 
 Scheele, Discovery of, § 3. 
 
 Sensitive Mixture, application of, 
 § 51. 
 
 Talbot, Calotype process of, § 47. 
 
 Announcement of, § 8. 
 
 Photographic Paper of, 
 
 § 21 . 
 
 Time of Exposure, § 32. 
 
 Wood’s, Dr. Catalissisotype, 
 § 75. 
 
MANIPULATIONS 
 
 IN THE 
 
 SCIENTIFIC ARTS. 
 
 PAET IV. 
 
 PHOTOGENIC MANIPUEiATXON 
 
PHOTOGENIC MANIPULATION: 
 
 FART II. 
 
 CONTAINING 
 
 THE THEORY, AND PLAIN INSTRUCTIONS 
 
 IN THE ART OF 
 
 PHOTOGRAPHY, 
 
 OR 
 
 THE PRODUCTION OF PICTURES THROUGH THE 
 AGENCY OF LIGHT. 
 
 DAGUEEREOTYPE. 
 
 By ROBERT J. BINGHAM, 
 
 CHEMICAL ASSISTANT IN THE LABORATORY OF THE LONDON INSTITUTION. 
 
 HlustratelJ SjSaootrcuts . 
 
 FOURTH EDITION. 
 
 LONDON: 
 
 PUBLISHED BY GEORGE KNIGHT AND SONS, 
 
 MANUFACTURERS OF CHEMICAL APPARATUS AND 
 PHILOSOPHICAL INSTRUMENTS, 
 
 FOSTER - LANE, CHEAPSIDE. 
 
 1848 . 
 
Entered at Stationers' Hall, 
 
 London : 
 
 Printed by Stewart and Murray, 
 Old Bailey. 
 
CONTENTS. 
 
 Page 
 
 Daguerreotype : — 
 
 Choice of the Plates . . . .10 
 
 Cleaning and Polishing the Plates . . 10 
 
 Cleaning by the Lathe . . . .11 
 
 Burning out the Oil . . . . 13 
 
 Plate- Holders . . . . .15 
 
 Preparation of the Rottenstone . . . 17 
 
 Use of the Essential Oils . . . .18 
 
 Simple Method of Cleaning and Polishing . 19 
 
 Applying the Iodine . • . .21 
 
 Description of the Iodine and Bromine Pans . 21 
 
 New Form of Bromine Pan . . . .23 
 
 Experiment of Mr. Robert Hunt . . 23 
 
 Proportion of Iodine and Bromine on the Plate . 24 to 27 
 
 M. Fizeau’s Method of using Bromine Water . 29 
 
 Bromide of Iodine . . . . .32 
 
 Hungarian Solution . . * . 33 
 
 Woolcott’s American Mixture . . .34 
 
 Chloride of Bromine .... 35 
 
 Bromide of Lime . . . . 36 to 38 
 
 The Camera : — 
 
 Description of a Daguerreotype Camera . . 39 
 
 Voigtlander's Brass Camera . . .40 
 
 The Lenses ..... 41 
 
CONTENTS. 
 
 American Form of Camera . 
 
 Paofe 
 
 42 
 
 Knight’s Moveable Back 
 
 43 
 
 Use of the Moveable Back 
 
 . 43 
 
 Mirror for Reversing the Picture 
 
 44 
 
 Submitting the Plate in the Camera . 
 
 . 45 
 
 Time of Exposure 
 
 45 
 
 Developing the Picture 
 
 . 46 
 
 Description of the Mercury Box . 
 
 46 
 
 Constable’s Sliding Scale 
 
 . 47 
 
 Constable’s Sand Clock . 
 
 47 
 
 New Form of Mercury Box 
 
 . 48 
 
 Removing the Sensitive Coatings 
 
 49 
 
 Gilding the Picture 
 
 . 50 
 
 Preparation of the Solution of Gold 
 
 50 
 
 Washing and Drying Process 
 
 . 51 
 
 Solarization, how removed 
 
 52 
 
 Electro-silvering the Plate 
 
 . 53 
 
 Electro-gilding .... 
 
 53 
 
 Colouring Daguerreotypes 
 
 . 53 
 
 Professor Page’s Method of Colouring 
 
 54 
 
 Conclusion . . . . 
 
 . 54 
 
 . . . . . 
 
 57 
 
 Index 
 
PHOTOGENIC MANIPULATION. 
 
 PART II. 
 
 DAGUERREOTYPE. 
 
 1. In the first part of Photogenic Manipulation^ we 
 have described a variety of processes by which impres- 
 sions can be obtained upon paper by the action of light. 
 This second portion of our Manual, it is our intention to 
 devote entirely to the method of producing pictures 
 upon silver plates, a beautiful art, well known through- 
 out Europe as the Daguerreotype/’ (1.) (7.) 
 
 2. This art has been patented in England, although 
 the discoverers, Daguerre and Niepce, had a handsome 
 pension allotted to them on condition that the process 
 should be given ‘‘ freely to the whole world.” 
 
 3. The manipulation requisite to obtain a perfect 
 picture by this process appears at first to offer more 
 difficulties to a beginner than most of the other photo- 
 graphic processes ; but, in reality, this is not the case, 
 for, with care and attention to the details subsequently 
 given, very little difficulty will be found. 
 
 4. The entire process may be divided into six dis- 
 tinct operations : — 
 
 1st. Cleaning and polishing the silver surface of the 
 plate. 
 
 2nd. Applying the iodine and other sensitive coat- 
 ings. 
 
 PART II. 
 
 B 
 
10 
 
 PHOTOGENIC MANIPULATION. 
 
 3rd. Obtaining the impression on the plate by means 
 of the camera. 
 
 4th. Rendering the impression so obtained visible by 
 the aid of mercury. 
 
 5th. Removing the sensitive coating of iodine and 
 bromine. 
 
 6th. Fixing the picture by means of a coating of 
 gold, and drying the plate. 
 
 5. These processes we shall now proceed to describe 
 at length, after devoting a little space to the choice of 
 the plates. Of these several varieties are sold ; those 
 of English manufacture are perhaps the best adapted 
 for a beginner, being stouter than the French ones, 
 and the surface of silver being thicker, they will allow 
 of being more frequently cleaned. 
 
 6. The silver, however, on the English plate, is not so 
 pure as on the French. The former generally contains 
 a quantity of lead, which is, to a certain extent, 
 detrimental. This evil may be overcome by electro- 
 silvering them, a process described in Electrotype 
 Manipulation^ by Mr. C. V. Walker. The French 
 plates should not be inferior to those marked 1.40, 
 and there are some marked 1.20 that are still better, 
 and, though more expensive, they are perhaps in the 
 end less costly. No one should use plates less 
 than ] .40 without being sure of obtaining a satisfac- 
 tory daguerreotype the first trial, for they will scarcely 
 admit of being repolished, especially if the picture has 
 been fixed with the hyposulphite of gold. Good 
 plates should have no specks or scratches on the 
 surface, and if any trace of copper be observed on 
 the silver surface, the plate should be rejected. 
 
 7. We shall now proceed to describe the first pro- 
 cess, viz., cleaning and polishing the silvered surface of 
 the plate. For this innumerable plans have been pro- 
 posed ; almost every operator, after a time, adopting 
 some method of his own. At many of the daguerreo- 
 type establishments, the plates are cleaned in a lathe. 
 
DAGUERREOTYPE. 
 
 11 
 
 Fig. 13 represents one 
 suited for this purpose. 
 
 A is a circular piece of 
 wood about 7 inches dia- 
 meter, covered with thick 
 cotton velvet, and termed 
 a bulF ; there should be 
 two of these ; by means of 
 the lathe they can be re- 
 volved very rapidly. The 
 first, or cleaning buff, is 
 charged by being mois- 
 tened with olive oil, and 
 then powdered over with 
 French tripoli, or very fine 
 rotten-stone. It is best 
 applied by putting some 
 into a muslin bag, and 
 striking the buff with it. 
 
 The second, or polishing 
 buff, is dusted over in the 
 same manner, with a mix- 
 ture of equal parts of prepared charcoal and the best 
 rouge. Great care should be taken to keep this buff 
 perfectly clean, and, especially, free from grease. 
 
 8. Some have recommended — that the cotton- 
 velvet on this buff should be previously soaked in 
 a strong solution of soda, dissolved in hot water, in 
 order more effectually to get rid of any greasy 
 matter. It should then be nailed on the circular 
 board, without any part of its surface being touched 
 by the fingers. Ammonia has been recommended 
 instead of soda, but the latter is decidedly the better 
 of the two ; for, if there be any grease in the velvet, 
 the ammonia will form a soap with it, more inju- 
 rious to the plate than the grease itself. Our plan 
 is, to nail on and use the velvet in the state it is sold, 
 and by using plenty of charcoal and rouge, after polish- 
 ing a few plates, the velvet becomes quite clean. 
 
 B 2 
 
 Fig. 13. 
 
12 
 
 PHOTOGENIC MANIPULATION. 
 
 Washing in soda is liable to render the velvet 
 harsh. 
 
 A method of holding the plate against the revolving 
 buff is now required; for this purpose, the plate- 
 holder B, Fig. 13, is used. It consists of a square plate 
 of iron, rather larger than the silver plate, round which is 
 fixed a flat rim, forming a space the size of the latter. 
 This rim is not quite so thick as the plate, the silvered 
 surface of which must be above it. A brass boss is placed 
 at the back of the holder, having a cup-shaped hole 
 in its centre, into which the steel spindle C fits 
 loosely. Two of these holders are required for 
 each sized plate, one to be used with the No. 1, or 
 oil buff; the other, which must be kept perfectly clean, 
 and free from grease, for the finishing buff. The plate 
 being placed in the holder, the latter is held firmly 
 against the bulF No. 1 by the spindle, which is also 
 placed against the rest of the lathe. Motion is now 
 given to the bulF, and after a few revolutions the plate 
 should be examined. A fixed impression will some- 
 times require much cleaning, particularly if gilded 
 deeply, whilst, with a proof not fixed, a few turns will 
 be enough. It may perhaps be difficult to conceive, 
 without seeing the apparatus at work, how the plate 
 can be cleaned with a revolving plate-holder, the buff 
 also revolving ; but the reader must recollect that the 
 plate-holder is not held in the centre of the buff, or in 
 other words, the centre of the plate-holder and the 
 centre of the lathe do not coincide — for, if so, the plate 
 would obviously not be cleaned — but if the two centres 
 are a very little removed from each other, then the plate 
 and buff revolve in opposite directions, and thus the plate 
 is very perfectly and evenly cleaned and polished, for 
 every instant the buff cutsthe plate in adifferentdirection. 
 
 9. We will now suppose the operator has laid bare 
 an even surface of silver : the next step is to get rid of 
 all the oil. The greater part may be removed by means 
 of cotton wool. The plate should then be laid, face 
 downwards, upon a piece of cotton velvet, and rubbed 
 
DAGUERaEOTYPE. 
 
 13 
 
 backwards and forwards until an apparently clean and 
 pure surface is obtained. This, however, is not the 
 case ; for the surface is still chemically greasy. The 
 plate now requires what is technically called burning; 
 that is, decomposing the remaining oil by lieat. For 
 this purpose the operator will require a spirit-lamp and 
 a pair of plyers or the stand used also for the fixing 
 process, fig. 36. The plate should be held by one cor- 
 ner with the plyers, and the flame of the spirit-lamp 
 applied to the under surface, until white spots or clouds 
 appear on the previously bright surface ; the lamp 
 should then be withdrawn, and the plate suffered to 
 cool. This process requires a little care ; for if the 
 plate be not heated enough, white clouds will form in 
 an after process, viz., whilst gilding. This is an ex- 
 tremely annoying circumstance, as we seldom attempt 
 to gild any except really good pictures. 
 
 10. If the plate be heated too much, it will be almost 
 impossible afterwards to obtain that fine black polish 
 which is so essential to a good daguerreotype, the 
 shadows will appear full of innumerable minute white 
 spots, giving a grey appearance to the whole picture. 
 Especial care should be taken when manipulating with 
 French plates, as, on account of their being so much 
 thinner, they bear but a slight heat, and, if overdone, 
 are liable to bend. It is safer, and perhaps a better 
 plan to clean these with spirit alone, and not attempt 
 to use any oil, they will not then require burning ; 
 more time, however, will be required in cleaning them. 
 After the plate has been burnt and suffered to cool, it 
 is applied to the finishing buff, all possible precaution 
 being taken to keep it free from grease. When a 
 number of plates are to be done, it is best to oil, buff, 
 and burn them all, before commencing the polish- 
 ing process on the second buff. Plenty of the mixed 
 charcoal and rouge should be used, and the plate applied 
 to the buff until a fine polish is obtained ; the pressure 
 should be moderately strong at first and then gradu- 
 ally lessened ; the plate should be finished by a quick 
 
14 
 
 PHOTOGENIC MANIPULATION. 
 
 revolution and a very light pressure with the plate 
 holder ; the plate should be taken away from the bufF 
 during its revolution, and it will then be quite ready 
 for the next or iodizing process, but in inexperienced 
 hands this is rather a difficult thing to do, particularly 
 with large plates, for they are apt to fly out of the 
 holder and be damaged by falling. If it can be 
 accomplished, the plate will present a fine black 
 polish, with no visible marks of the velvet, whilst if 
 the lathe is stopped, and the plate then taken off, it 
 will have a circular grain on its surface, indicating the 
 direction of the last revolution of the buff ; the plate 
 should either have no visible grain, or it should have 
 one in a direction across the narrow part of the plate 
 if intended for a portrait, or, if for a view, the length- 
 way, that is in the same direction as the horizontal 
 lines of the picture. 
 
 11. To lay the grain of the plate, daguerreotypists 
 use a straight buff, represented by fig. 14. 
 
 Fig. 14. It consists of a piece of wood covered 
 with clean cotton velvet, and slightly 
 curved so as to allow for the deviation 
 from the parallel direction which the 
 motion of the hand invariably takes in 
 the operation of buffing ; the plate is 
 then to be held in the left hand, and 
 lightly buffed in the direction required, 
 having previously dusted a little of the 
 charcoal powder on the buff ; the clean- 
 ing and polishing process has now been 
 finished, and we may at once proceed to 
 iodize the plate. We have described at 
 some length the method of cleaning and 
 polishing with the lathe, because, by its 
 means, plates may be more quickly pre- 
 pared than by any other plan ; however, 
 there are other methods quite as effectual, 
 although they occupy a little longer time, 
 still they are preferred by some. 
 
DAGUERREOTYPE. 
 
 15 
 
 12. Figs. 15 and 16 represent two forms of plate holders 
 Fig. 15. Fig. 16. instruments for supporting 
 
 the latter to project about one-sixteenth of an inch 
 all round. Tiie plate is secured by two small pieces 
 of brass, one of which is moveable, and fixed by 
 a screw attached to the opposite angle of the board. 
 It is provided with a handle, by which the whole 
 is conveniently held in the hand. In place of a 
 handle, a small clamp is sometimes substituted, by 
 which it may be fixed to a table. Fig. 16 is another 
 very ingenious and simple form of plate-holder. It 
 consists of a block of wood somewhat in the form of 
 a dice-box. On one end is fixed by a single screw a 
 piece of board a trifle smaller than the plate, this can 
 be readily changed for larger or smaller as required ; 
 on the upper part of these boards is fixed one or 
 more pieces of Indian rubber, the surface being 
 melted by applying to it a hot iron. This renders the 
 rubber permanently adhesive, so that the back of the 
 plate when pressed against it adheres firmly ; at the 
 same time, when removed by a little force, the back 
 is left perfectly clean. 
 
 13. Perhaps the best form of plate-holder is the one 
 shown at fig. 17, 
 and is much used 
 
 in America, and Fig. 17. 
 
 particularly adapt- 
 ed for the thin 
 
 the plate in the hand while 
 being cleaned and polished. 
 Fig. 15 is the French pattern. 
 It consists of a flat board, a 
 trifle smaller than the plate, 
 so as to allow the edges of 
 
 French plates. It 
 consists of an iron 
 clamp, screwing 
 down upon the 
 
16 
 
 PHOTOGENIC manipulation. 
 
 edge of a block a trifle smaller than the plate to be 
 cleaned. By a contrivance of the publishers of this 
 treatise, these blocks are made to shift, so that with one 
 clamp and different blocks any size plate may be cleaned. 
 They can also be reversed, so as to be buffed either way 
 of the plate. Having fixed the daguerreotype plate 
 in one of the holders described, or, in their absence, on 
 a sheet of white paper, a little tripoli is sprinkled upon 
 it, and a small piece of finely-carded cotton being folded 
 into a round pellet or knot, is moistened with good olive 
 oil, and the plate rubbed with it by a continuous circular 
 motion until all scratches, mercury, or traces of the last 
 picture disappear ; then wipe off the oil and tripoli with a 
 clean piece of cotton, at the same time wiping the edges 
 and back of the plate with a cloth ; and in order to get rid 
 of all appearance of oil, the plate should be rubbed upon 
 a piece of cotton velvet until a fine black polish is 
 obtained : now proceed to burn out the oil as directed 
 (§ 9), and allow it to cool. A little very fine tripoli 
 should then be dusted upon the plate, moistened 
 with a few drops of spirits of wine ; with a knot 
 of cotton, rub the plate with a circular motion until 
 the white film which appeared upon heating the plate 
 has been removed, adding more alcohol if necessary ; 
 with another pellet of cotton, dry and clean off the 
 tripoli. Water, acidulated with nitric acid, may be 
 used (as originally recommended by Daguerre) instead 
 of the alcohol ; but we think it is more apt to stain the 
 plate if not well managed. Pure water, or weak solu- 
 tion of caustic potass, will answer equally well. 
 
 14. M. de Northomb asserts that alcohol in which a 
 little caustic potass is dissolved gives the impression a 
 fine tone of colour.^ 
 
 15. The plate having been cleaned, but not polished, 
 ought to present a uniform grey surface, without any 
 stains or scratches ; and if breathed upon, the vapour 
 should be condensed in one uniform sheet on it. The 
 
 * Lerebour’s Traite de Photograph ie. 
 
DAGUERREOTYPE. 
 
 17 
 
 disappearance of the film should be attended to ; for 
 any stain not at first visible will be indicated towards 
 the end of the evaporation. Assuming that the plate is 
 quite clean, the polishing process may be commenced. 
 For this purpose, the plate may be fixed to one of the 
 plate-holders, figs. 15, 16, 17, and briskly polished with 
 the buff, fig. 2, having previously dusted on it a little 
 prepared charcoal ; always observing to give the final 
 polish in a direction across the intended picture (10), and 
 with a very light hand. The pressure at the termination 
 of the buffing should not be more than the weight of the 
 buff. The plate will now be ready for iodizing. Some 
 operators prefer using two buffs, dispensing with the 
 cotton and alcohol, and using the first buff in their 
 place, on which they apply charcoal powder, and polish 
 off the white film formed by heating the plate ; with the 
 second buff they give the final polish to the plate. 
 Clean buff or wash leather may also be substituted 
 for the cotton velvet on the buffs. This is an American 
 plan, and is now much used in Paris. 
 
 16. Rottenstone will do in the place of the tripoli. 
 It may be prepared sufficiently fine in the following 
 way : — Select a piece of rottenstone (not the powder) 
 having a light buff colour, reduce the stone to powder 
 in a mortar, and then throw it into a basin of clean 
 water, allow it to stand a few minutes, and pour off the 
 supernatent liquid, which will have in suspension all 
 the finer particles of the rottenstone, the sand and 
 coarser particles remaining at the bottom of the vessel. 
 By allowing the liquid to stand a shorter or longer time, 
 we may obtain the rottenstone of any degree of fineness. 
 In order to get rid of the water, the liquid should be 
 left undisturbed until it has become quite clear; the 
 water should be carefully poured away, and the paste 
 of rottenstone dried on a plate at the fire, or it may be 
 used in this pasty state. 
 
 17. In France, the essential oils of bergamotte, citron, 
 turpentine, or lavender, have been much used for 
 
18 
 
 PHOTOGENIC MANIPULATION. 
 
 polishing the plates ; and this plan is stated by M. 
 Charles Chevalier, in his last work on the Daguerreo- 
 type, to be superior to all others.* This we believe to 
 be quite true, provided we could obtain the essential 
 oil quite pure, and free from adulteration with the fixed 
 oils ; but this is a difficult matter. It may be easily 
 detected ; for the essential oils are very volatile, and 
 are dissipated at a very slight heat. The fixed oils, on 
 the contrary, are not volatile; and on applying a strong 
 heat, they decompose into gas, but do not volatilize : 
 therefore, if we drop on a piece of paper suspected 
 essential oil, it will cause a greasy stain ; but on the 
 application of heat to the under surface of the paper, 
 the stain will disappear, and the paper appear as clean 
 as before, if the oil is pure ; but if there is the smallest 
 quantity of fixed oil, the stain will still remain, notwith- 
 standing the heat. One advantage the pure essential 
 oils have in cleaning is this — the plate requires no 
 burning. 
 
 18. The method recommended is to mix in a bottle 
 some tripoli and oil of lavender; allow a drop of this 
 mixture to fall upon the plate, then with a knot of 
 cotton rub the plate for a little time, clean off the oil 
 with a fresh piece of cotton and dry tripoli, and at 
 once give the final polish with the velvet buffi The 
 following we have found to be a very ready and easy 
 method of polishing, and it has this advantage, a 
 holder for the plate is not required ; provide a smooth 
 deal board about two feet long and eighteen inches in 
 width, on this fasten a piece of clean cotton velvet of 
 the same size ; this velvet should be marked off into a 
 number of divisions, each about the size of the ordi- 
 nary buff ; a board of the size directed may be 
 divided into six parts, each four inches in width, and 
 eighteen inches in length ; each of these, although on 
 the same board, is to be regarded as a distinct buff, 
 
 * Nouveau Renseignemens sur I’usage du Daguerreotype, par 
 Charles Chevalier. Paris, Palais Royal, 163. 1846. 
 
DAGUERREOTYPE. 
 
 19 
 
 and must be kept clean and free from the materials 
 used on its neiglibour. When we wish to clean a 
 plate, the first buff on the right hand is to be dusted 
 with some fine tripoli, and then moistened with a little 
 of the best oil of turpentine (this essential oil may be 
 got, under the name of camphine, at the oil shops') ; 
 the plate should be laid with its face on the velvet, and 
 rubbed quickly up and down, care being taken that 
 the pressure exerted by the fingers on the back of the 
 plate be not too much confined to one part. This 
 should be particularly attended to when cleaning a 
 thin French plate ; but should any part of the plate be 
 more difficult to clean than the rest, the pressure 
 should be applied to the back just at that part. 
 After a good surface is obtained, the plate should be 
 passed on to buff No. 2, and rubbed until the whole of 
 the turpentine and tripoli has apparently been re- 
 moved. It may then be passed on to No. 3, on which 
 a mixture of some very dry prepared charcoal and 
 rouge has been dusted. On this buff the whole of the 
 grain on the surfaces of the plate left by the tripoli 
 should be removed, and a beautiful black polish left. 
 In order to receive the finishing polish, and to lay 
 the grain’’ in the proper direction (§ 10, II.) it is to 
 be passed on to No. 4, and rubbed briskly and lightly 
 over the surface ; on this buff the dry prepared char- 
 coal alone is used. Care should be taken, before 
 buffing a plate, that the buff, the charcoal, and rouge 
 are quite dry. This is very important, and parti- 
 cularly so when we make use of rouge as a polishing 
 powder ; if the rouge or the buff be at all damp, a red 
 stain will appear in patches over the plate when we 
 attempt to gild it. 
 
 19. After the plate has been cleaned and polished by 
 any of the plans we have described, it is ready for the 
 second process, viz., applying the iodine and other 
 sensitive coatings ; but previous to submitting it to the 
 action of these substances, any particles of dust left by 
 
20 
 
 PHOTOGENIC MANIPULATION. 
 
 the polishing process must be removed. This is readily 
 accomplished by passing lightly over the surface of the 
 plate a knot of clean cotton, or a broad camel’s hair 
 tool similar to those used by gilders for the application 
 of the gold leaf. It is advisable that the last buffing 
 should be given only a short time previous to the iodiz- 
 ing, as it causes the plate to be much sooner iodized. 
 Perhaps this is occasioned by the action raising, in a 
 slight degree, the temperature of the plate. Care should 
 be taken to apply the buff the last time as evenly as 
 possible, or the iodine will be liable to attach itself to 
 one part more than another. In order to remove this 
 difficulty, Mr. Kilburn places his plate on a gas stove 
 for a few seconds, previous to transferring it to his iodine 
 box ; by thus raising the temperature of the plate above 
 that of the atmosphere, no moisture can be condensed 
 on its surface. This is undoubtedly a great advantage ; 
 but the true reasons for the last polish being given to 
 the plate just before its being used we believe to be 
 this : — It is well known, since the publication of Moser’s 
 experiments upon the formation of images on metallic 
 and other plates in the dark by ‘‘ invisible light^' that 
 all bodies radiate a certain amount of organic matter, 
 according to their degree of cleanness. Now, a daguerreo- 
 type plate, when clean, is just in a position to receive 
 and condense this organic matter on its surface, which 
 is injurious to its sensibility, and to the clearness of 
 the resulting proof; this effect takes place in proportion 
 to the time in which it has remained opposite a relatively 
 impure surface. For this reason, the plate should be 
 used directly after having been buffed,’^ or if not used 
 immediately, it should be deposited in a clean plate- 
 box. No plate-box should be used for a finished 
 plate that has before been used for an oily or dirty one. 
 
 20. 2d Process — Applying the iodine, and other sen~ 
 sitive coatings , — For this purpose, the operator will 
 require an — 
 
DAGUERREOTYPE. 
 
 21 
 
 Iodine box or pan. 
 
 A bromine pan. 
 
 Some iodine and bromine, or other accelerating 
 compound. 
 
 21. The most simple form of apparatus for applying 
 the coating of iodine or bromine is shown in fig, 18, 
 It consists of a porcelain pan, which 
 
 may either be square or round. Fig. 18. 
 
 The round form, however, has this 
 advantage, although it occupies 
 more space : the frame holding the 
 plate may be turned round during 
 the operation of iodizing without 
 taking it off the pan. By this 
 means, the vapour may often be 
 prevented attacking one part of the 
 plate more than another. The edge 
 is ground flat, and it is provided with a ground glass 
 cover, fitting it air-tight. About three-eighths of an 
 inch below the top, is a ledge on which rests a frame, 
 B, made either of hard wood varnished, slate, or glass, 
 for the purpose of holding the plate over the iodine or 
 the solution. 
 
 22. This apparatus is sometimes made of a square 
 form, and is fitted into a wooden box. This has some 
 advantages. We believe it originated in France, and 
 
 was there used for the application of the vapour of 
 bromine. It is represented in fig. 19. It consists of a 
 box, in the interior of 
 
 which there is a shal- Fig. 19. 
 
 low earthenware or 
 glass pan, having a 
 plate glass cover, B, 
 fitting air-tight. This 
 in the figure is shewn 
 partly withdrawn. 
 
 On the top of the 
 box there is a ledge 
 upon which rests the frame, C, to hold the plate whilst 
 
22 
 
 PHOTOGENIC MANIPULATION. 
 
 being prepared ; one end, D, of the box is hinged, so as to 
 allow the pan to be withdrawn if necessary. This is a very 
 convenient apparatus ; and we believe it to be the best, 
 if we adopt the plan of determining the necessary ex- 
 posure of the plate to the iodine and bromine by the 
 time it is submitted to their influence. (§ 28) But this 
 plan is not always followed ; for by a number of opera- 
 tors the original plan of Daguerre is adopted, viz., the 
 plate is allowed to remain over the iodine and bromine 
 vapour until a certain colour makes its appearance on 
 the plate. For this purpose, an apparatus con- 
 structed similar to fig. 20 is used. 
 
 A is a mahogany box, 
 inclosing a glass pan 
 about three inches deep. 
 On the top are a set of 
 moveable frames to hold 
 different sized plates. B 
 is a piece of plate glass, 
 which, sliding beneath 
 the frames, serves as an 
 air-tight cover to the glass 
 pan. C is a portion of 
 the back of the box made 
 to slide out or fall down 
 so as to admit a ray of light through a piece of white 
 paper placed over this part of the glass. In front, 
 and immediately opposite to this opening, is a second, 
 D, made to fall down, and on the inner portion of this 
 is placed a piece of silvered glass, so that when held 
 at a certain angle a distinct image of the plate is 
 seen in the mirror, and the changes of colour it may 
 undergo at once rendered visible to the eye of the 
 operator. Two of these boxes are required, one for 
 applying the vapour of iodine, the other for the 
 bromine or other accelerating agent. 
 
 Fig. 21 represents another form of this apparatus, 
 both pans being placed in the same box, the frame 
 holding the plate sliding in a groove from the one to 
 
 Fig. 20. 
 
DAGUERREOTYPE. 
 
 23 
 
 the other; each Fig. 21. 
 
 is provided with 
 a distinct glass 
 cover. The 
 frames for the 
 plates should 
 be well varnish- 
 ed when made 
 in wood, or they 
 are liable to ab- 
 sorb the iodine 
 and bromine va- 
 pour, and pre- 
 vent its colouring the edge of the plate. 
 
 23. Iodizing , — A few crystals of iodine should be 
 distributed evenly over the bottom of one of the pans 
 described, the plate should then be carefully placed, 
 face downwards, in a frame over it, the iodine will 
 slowly rise into vapour and attack the clean silver 
 surface, which will gradually assume a variety of 
 colours, according to the thickness of the coating 
 of iodine ; the first tint which will appear upon 
 the plate is a pale yellow ; this colour gradually 
 deepens until it assumes a deep golden colour ; from 
 this it changes into very deep blood red, and then 
 immediately to pale rose; this rose tint deepens, and 
 at last passes to a blue ; by allowing the iodine to 
 continue its action upon the plate, the blue gradually 
 disappears and there is apparently little colour upon 
 the plate, but in reality a yellow colour is again 
 appearing, and if the action be still continued, the 
 rose and blue again appear ; in fact, the plate would 
 assume a variety of colours, succeeding each other, 
 just in the order of the first series. 
 
 24. Mr. Hunt has described a very interesting experi- 
 ment on this subject. “ If a piece of iodine be placed 
 upon a silver plate and then gently warmed, a series 
 of concentric coloured rings will make their appear- 
 ance. The first ring, which is constantly spreading, 
 
24 
 
 PHOTOGENIC MANIPULATION, 
 
 forms the exterior of the circle, is of a bright yellow 
 colour ; within this there arises, successively, rings 
 of green, red, and blue colours, and then again a 
 fine yellow circle centred by a greyish spot occupied 
 by the iodine. On exposing these to light, it will be 
 found that the outer yellow circle almost instantly 
 changes colour, and that the others slowly change in 
 the order of their positions, whilst the interior yellow 
 circle resists, for a long time, the solar influence. It 
 it is an instructive experiment to form these rings, and 
 cover one half and expose the other to light ; we shall 
 thus be led to appreciate the proper colour the plate 
 should assume when exposed to the iodine vapour. 
 
 25. If iodine alone be used,^ then it would appear 
 that the second golden yellow colour is the most sensi- 
 tive to light, but since the discovery of the accelerating 
 action of bromine or chlorine when combined with 
 iodine on the plate, we have been led to believe that 
 any of the first series of colours may be used on the 
 plate provided we afterwards expose it for a propor- 
 tionate time to the bromine or chlorine ; for instance, 
 if we only allow the plate to assume a golden yellow 
 colour, a very small quantity of bromine will make the 
 plate very sensitive, but if the plate has been iodized 
 to a full rose, then a larger quantity of bromine must 
 be absorbed in order that the plate should be rendered 
 sensitive ; it is, therefore, obvious, that any of the first 
 series of tints may be used, provided the operator is 
 able to apply the correct quantity of bromine. We 
 think the best tint for iodizing is a full golden 
 yellow, nearly approaching the rose ; and this tint a 
 novice is perhaps the best able to appreciate, for 
 it will generally be found, however evenly and skil- 
 fully the plate has been polished, that on some part of 
 it a rose tint has made its appearance, when the other 
 
 * See an interesting paper by M. Clandet in the Phil. Mag,, 
 March 1848. He there states, the second yellow to be twenty-five 
 times more sensitive than the first. 
 
DAGUERREOTYPE. 
 
 25 
 
 part has arrived at a full golden yellow ; the most 
 convenient method of determining the proper colour, 
 if the simple form of apparatus figs. 18 or 19 is used, is 
 to allow a ray of light to enter the dark room and fall 
 upon a piece of white paper ; then to reflect the ray of 
 light from the paper to the eye by means of the plate, 
 and which, of course, will reflect its own colour only. 
 We speak of “ the dark room^' but it is not 
 essential that the iodizing process should be carried on 
 in the dark, it is only a matter of convenience, for 
 the eye is better able to appreciate the right tint when 
 there is no other light but that reflected from the plate. 
 With the apparatus, figs. 20 and 21, we have only to 
 look on the mirror until we perceive the plate is of the 
 proper tint, and then close the pan ; this is a much 
 more convenient plan, for it saves the trouble of lifting 
 the plate from the pan every time we wish to observe 
 the colour ; after the plate has assumed the proper 
 tint, it is then ready for the broming operation, which 
 communicates the utmost degree of sensitiveness to 
 the action of light. 
 
 26. In the process, as originally described and 
 patented by Daguerre, iodine alone was used for 
 giving the plate its sensitive coating; for this purpose, 
 he directed that, after the plate had been well polished, 
 it should be submitted to the vapour of iodine, until it 
 assumed a golden yellow colour, it was then ready for 
 the action of light upon it, in the camera; and he 
 stated, that if, by any inattention or mischance, the 
 plate was suffered to go beyond this colour and assume 
 a rose or blue tint, it should be rejected, and the whole 
 process of polishing again gone through. The process 
 with iodine alone, was exceedingly slow ; a por- 
 trait, which could be taken in ten seconds at the pre- 
 sent time, would, if we followed the process of 
 Daguerre, occupy at least half an hour, even with our 
 improved forms of camera and object glasses; and if the 
 
 c 
 
26 
 
 PHOTOGENIC MANIPULATION. 
 
 patented camera of Daguerre were used, we do not 
 think an image could be obtained in double that time. 
 Of course, no portrait could be produced, for it would 
 be impossible to obtain a likeness, if the “ patient’^ had 
 to sit quite immoveable for that time. The proofs 
 obtained at this time were exceedingly imperfect, and 
 if no advances had been made in this original process, 
 we have very little doubt that the term Daguerreotype 
 would, in a short time, have been but little known 
 except to M. Daguerre, and by the records of the patent 
 office. Fortunately, however, M. Claudet paid some 
 attention to the subject, and obtained the first license 
 for practising the art in England. 
 
 27. In some of the experiments of this gentleman, 
 he found that the plate was rendered much more sensi- 
 tive if it were exposed to chlorine, in addition to iodine; 
 by this means he was enabled to obtain some tolerably 
 good portraits. Since this time, the art has steadily 
 progressed, and some of the proofs obtained by Kilburn, 
 Claudet, and Highschool, are astonishing specimens of 
 sun-drawn pictures; views are now obtained absolutely 
 instantaneously ; in fact, in some cases it is impossible 
 to open and shut the camera too quickly. In order 
 that the plate should acquire this extreme degree of 
 sensitiveness, various methods are adopted : but in all 
 the different plans, the vapour of bromine is made use 
 of, either alone or in combination with chlorine or 
 iodine. These different methods we shall describe, 
 beginning with the most simple. 
 
 28. Bromine water , — This may be prepared as 
 follows : — pour into a glass stoppered bottle, nearly 
 full of water, a few drops of bromine, and shake them 
 together, the undissolved bromine will fall to the 
 bottom, and the water will assume a bright red colour ; 
 one part of this clear solution is to be added to about 
 forty parts of water. This is readily and accurately 
 accomplished by means of the simple graduated tube 
 
DAGUERREOTYPE. 
 
 27 
 
 shown in Fig. 22 ; or instead of using a measure, a 
 certain tint of colour may be ob- ^ 
 tained, in common water, by 
 adding the saturated solution, 
 drop by drop, until the required 
 tint is produced, which must be 
 previously determined by experi- 
 ment. A bottle of water, tinged 
 with gamboge, may be kept as 
 a standard of comparison. 
 
 Bromine water can be used in 
 any of the pans we have de- 
 scribed. After having obtained, 
 by the iodine, a full yellow colour, 
 we transfer the plate to the bro- 
 mine, we shall find it will con- 
 tinue to change in a similar man- 
 ner, as if we had left it over 
 the iodine ; from the yellow it will speedily pass to a 
 rose, and if we continue the action, it will change to a 
 blue. By means of these changes, we ascertain the 
 quantity of bromine applied to the plate. The opera- 
 tor should endeavour to make himself perfect master of 
 these tints as they succeed each other, for it is found 
 that the iodine and bromine should bear a certain pro- 
 portion the one to the other ; and the following table 
 shows the relative tints to be obtained on the plate 
 when bromine water is used : — 
 
 Fig. 22. 
 
 1 st Iodine. 
 Straw colour. 
 Light yellow. 
 Golden yellow, 
 Blood red. 
 Damask rose. 
 Deep rose. 
 
 Bromine. 
 
 Yellow. 
 
 Golden yellow. 
 Light rose. 
 Damask rose. 
 Deep rose. 
 Light blue.* 
 
 2 d Iodine. 
 
 Full yellow. 
 
 Rose. 
 
 Deep rose. 
 
 Light blue. 
 
 Blue. 
 
 Indication of 2d yellow. t 
 
 * This tint may be obtained by stopping the action when all the 
 rose colour has just disappeared. 
 
 t At this time there is apparently little colour upon the plate 3 it 
 is just at the time the last trace of blue has disappeared. 
 
 C 2 
 
28 
 
 PHOTOGENIC MANIPULATION. 
 
 29. It will be observed, in the first column of this 
 table, we have given the tints to be obtained by means 
 of iodine ; the plate is then placed over the bromine 
 water, until it assumes the proper colour for the parti- 
 cular tint to which it has been iodized ; this is indi- 
 cated in the second column. After this, the plate 
 should be again placed over the iodine, until the colour 
 mentioned in the third column is obtained. Too much 
 care cannot be taken to get these relative quantities of 
 iodine and bromine correctly upon the plate, for if 
 there is too small a quantity of bromine in proportion 
 to the iodine, the plate will not be very sensitive to the 
 light, and it will be impossible to bring a proof fully 
 
 out,’’ without being solarized. (§ 69) Again, if we put 
 on too much bromine, the sensitiveness also diminishes, 
 the plate becomes covered with a veil, the mer- 
 cury will be found to deposit itself very readily on 
 every part of the plate where it ought not, viz. on the 
 deepest shadows, and very often over the whole sur- 
 face ; the ‘‘tone” of the proof is also very poor, and 
 has a flat and cold, grey appearance, and the plate will 
 be very liable to solarize. 
 
 30. There is a certain quantity of bromine necessary 
 for each tint of iodine, and this exact quantity the 
 photographer must obtain before he can expect a 
 favourable result. If the full equivalent of bromine 
 be applied, the operator will find that the proof will 
 develope itself very perfectly^ every part will be 
 “ done” enough, and no part solarized, even if the 
 contrasts in the picture are very great ; and the plate 
 will also be found to be very sensitive, but, as a draw- 
 back to this kind of picture, the tone is cold and grey, 
 the white parts are not very white and clear, and the 
 whole has a flat appearance. This is the kind of 
 picture generally obtained in France, and by the gen- 
 erality of American operators. If a little less bromine 
 be applied, then the tone of the picture is changed ; 
 the white parts are very distinct and white, the shadows 
 
DAGUERREOTYPE. 
 
 29 
 
 Rre very deep and black ; this makes a fine bold 
 picture ; in the hands of some operators, this method 
 produces the finest pictures, and is practised by some 
 of our first English artists, but some care is required in 
 the management of the light, and the direction it is 
 thrown upon the model, for the plate is more apt to 
 solarize when prepared in this way, than when it has 
 the full proportion of bromine. 
 
 31. We have described, in the preceding paragraph, 
 a method of applying the requisite quantity of bromine, 
 by noticing the colour produced on the plate, just in 
 proportion as the film of bromo-iodide of silver is more 
 or less thick. This plan is generally followed in 
 England, but in France the greater number of opera- 
 tors have hitherto adopted a method first described by 
 M. Fizeau, in a pamphlet published in Paris by that 
 gentleman. His method is, to expose the plate for a 
 certain time to a solution of bromine of a determinate 
 strength ; the solution is renewed for each plate. This 
 plan is perhaps the best given in his own words, which 
 we shall take the liberty of quoting. 
 
 32. To prepare a solution of bromine of an ascer- 
 tained degree of strength, and adapted to the opera- 
 tions we are speaking of, the first thing to be considered 
 is, the saturated solution of bromine in water ; this 
 saturated water is prepared by putting into a bottle 
 pure water, and a large excess of bromine ; shake the 
 mixture well for a few minutes, and before using it let 
 all the bromine be taken up. 
 
 33. An ascertained quantity of this saturated water 
 is then diluted in a given quantity of pure water, which 
 gives a solution that is always identical ; this dosing is 
 performed very simply, in the following manner : — take 
 a small glass tube, and having marked on it a line, 
 measuring a small quantity, fig. 22. Have also a 
 bottle with a similar line, measuring a quantity equal to 
 forty times that of the tube ; then fill the bottle of 
 water up to the mark, and fill the tube also to the 
 
30 
 
 PHOTOGENIC MANIPULATION. 
 
 mark with the saturated solution of bromine ; then add 
 this measure to the bottle of water. 
 
 34. The proportions above mentioned have been 
 established when calculating upon having perfectly 
 pure water ; but it is well known that the water of 
 river springs is not pure ; but these different kinds of 
 water may all be used with equal advantage^ by adding 
 a few drops of nitric acid, until they have a very slight 
 acid reaction ; five or six drops per quart suffice for 
 most kinds of water. 
 
 35. A bright yellow liquid is thus obtained, which 
 must be kept perfectly air tight. It is the normal solu- 
 tion which we shall simply call bromine water, to dis- 
 tinguish it from the saturated water. The bromine 
 pan should be flat-bottomed, and shallow ; it should 
 have an air-tight cover of plate glass. The form of 
 apparatus, fig. 19, may be employed; the tube before 
 mentioned being used for putting into the pan a 
 determinate quantity of the bromine water ; enough 
 should be placed in the pan to cover the bottom of 
 the vessel. 
 
 36. We have before stated, that the plate should be 
 exposed to the bromine water of a certain strength, for 
 a given time. Now, in order that the bromine water 
 should be of the same strength in successive experi- 
 ments, it is evident it must be renewed for each plate. 
 This is the only practicable method of obtaining a 
 constant quantity of vapour given off in the same 
 time. 
 
 37. The time necessary for the plate to be exposed 
 to the action of the bromine water, must be determined 
 by experiment, for it will vary according to the size of 
 the box, the quantity of liquid used, &c. It is usually 
 between thirty and sixty seconds, and when once 
 determined, it will be constant with the same box, and 
 the same strength of solution. 
 
 38. The method of operating is as follows : place 
 the pan upon a table, fill the pipette with bromine 
 
DAGUERREOTYPE. 
 
 31 
 
 water, draw out a little way the glass slide, and allow the 
 bromine water to run into the pan, and again close the 
 vessel ; the liquid must cover evenly the bottom of the 
 pan ; if not level, it must be adjusted ; the level will be 
 easily seen through the glass slide. When everything 
 is thus arranged, the iodized plate is to be placed in its 
 frame over the pan ; the slide withdrawn, and the 
 necessary time counted ; after this has elapsed, th( 
 slide should be shut, and the plate immediately placeci 
 in the dark box of the camera. 
 
 39. For a second operation, this bromine water must 
 be thrown away, and a fresh quantity used. The 
 bottle containing the bromine water should be kept 
 away from the direct light of the sun, and care should 
 be taken that no organic matter fall into the bottle, 
 such as grease, chips of cork, &c. These enter into 
 new combinations with the bromine, and lead to error 
 as to its amount in solution. 
 
 40. This plan is very good in the hands of a careful 
 operator, who will pay attention to the little matters 
 which are quite necessary to ensure success ; but we 
 are much inclined to prefer, if we use bromine 
 water, ‘‘ working” to colour, in the manner recom- 
 mended. 
 
 41. There are some solutions in which bromine is 
 combined with chlorine and iodine, which are used as 
 accelerating agents. The great difficulty experienced 
 in the use of bromine water is, the small change of colour 
 produced by its requisite action on the plate : now 
 it is evident that, if we combine bromine in equivalent 
 proportions with iodine, we may put rather more than 
 twice the amount of colour on the plate than we could 
 if we used bromine alone, and still have the same 
 amount of bromine on the plate ; because rather more 
 than one - half of the colour from the bromide of 
 iodine will be due to its iodine alone, and the other 
 half will be due to the bromine ; by this means the 
 change of colour will be much more distinctly seen, 
 
32 
 
 PHOTOGENIC MANIPULATION. 
 
 and a little more or less colour will not be of so much 
 consequence as if we had used bromine alone ; to this 
 bromide of iodine we may add chlorine forming chloro- 
 iodide of bromine ; this will take nearly another third 
 part of the colouring on the plate. 
 
 We shall describe a few of these compounds, their 
 use, and the method of making them. 
 
 42. Bromide of Iodine . — This compound is very 
 easily prepared, as follows : — Introduce into a small 
 bottle about a drachm of bromine, add to this iodine 
 grain by grain, until the last quantity of iodine added 
 does not dissolve ; the bromine will then be quite 
 saturated with iodine, any small excess of iodine 
 will not do any harm, but may remain at the bottom 
 of the vessel ; when required for use, a few drops 
 should be added to a bottie of water, until it assumes 
 the colour of light sherry wine : the plate should be 
 iodized to a clear yellow, and then exposed over this 
 mixture until it becomes of a deep rose colour. If 
 iodized more deeply, it should be exposed to the 
 bromide of iodine for a longer period ; this will be 
 easily determined in a few trials ; or it may be exposed 
 to this solution for a certain time, in the same manner 
 as to the bromine water. This plan is strongly recom- 
 mended by M. de Valicours in his excellent and very 
 complete treatise on the daguerreotype.* He gives the 
 following directions for its use in this way. 
 
 43. The plate having been iodized either to a deep 
 yellow, just changing to a rose (transition due jaune 
 au rose), a bright rose, or a very dark rose or violet, 
 pour into the pan a quantity of diluted bromide of 
 iodine of which the strength is known, sufficient to 
 cover all the bottom of the pan ; after about a minute 
 has elapsed place the plate over the vessel, and 
 begin to count seconds ; the time will, of course, 
 vary according to the size of the vessel, the strength 
 
 * Galvanoplastie et Daguerreotype, par M. de Valicours. 
 
DAGUERREOTYPE. 
 
 33 
 
 of the solution, &c. however, as some indication of 
 the requisite time, we may state, for a plate iodized 
 to a deep yellow, thirty or forty seconds, a bright rose 
 forty or fifty, for the deep rose or violet fifty or sixty 
 seconds may be required. 
 
 44. M. Claudet uses the bromide of iodine, but in 
 an extremely diluted state; he makes the solution 
 so weak that it requires about half an hour to apply 
 the requisite quantity of vapour, and his argument 
 is very plausible ; he states that by this plan there 
 is a much greater certainty of obtaining an uniform 
 quantity of the mixed vapours on the plate, for a 
 few seconds, or even a minute or two, more or less, 
 does not make so much difference to the plate, as 
 a second or even half of one, does, when the solution 
 is used very strong ; he uses numbers of small earthen- 
 ware pans, not inclosed in any case, to hold the 
 solution, and prepares either eight or sixteen plates, 
 according to their size, at one time. 
 
 45. When the bromide of iodine is used, it is better 
 on the first trial to observe the colour of the plate, and 
 at the same time notice how long it takes to attain 
 that colour with a certain strength of solution ; by this 
 means it is very easy afterwards to prepare a number 
 by merely exposing them for the observed time over 
 the bromide, for the mixture is very constant in its 
 action, and remains so for some time. There are various 
 methods of preparing bromide of iodine recommended ; 
 but we have given the only one by which constant 
 results can be obtained ; for if we adopt some of the 
 other plans, the operator is never certain of obtaining 
 the same amount of bromine on the plate each time, 
 the bromine evaporates and leaves merely iodine in 
 solution ; this colours the plate equally as well as 
 the bromide of iodine, but of course communicates to 
 it no sensitiveness. 
 
 46. Hungarian solution , — This is a very favourite 
 solution with most amateurs^ and deservedly so. It 
 
34 
 
 PHOTOGENIC MANIPULATION. 
 
 was invented by M. Guerin, who has retained a secret 
 the method of its preparation ; it may be used in 
 the same way as the bromide of iodine, but it is 
 better to use it rather weak, otherwise small spots 
 will form on the plate ; any tint of iodine may be 
 used, or the plate may be exposed over the Hun- 
 garian solution alone, without having previously 
 iodized it; this plan, however, gives a very grey, poor 
 tone, but the plate is very sensitive. When this 
 mixture, or the bromide of iodine is used, the plate 
 should not be exposed the second time to the iodine ; 
 but when the required tint is obtained, the plate 
 should be carefully placed in the camera box ; this 
 removal, of course, should be performed in a dark 
 room. 
 
 47. Wolcott’s accelerating mixture . — This mixture 
 is a very good one, and employed by Mr. Beard at 
 all his establishments. It consists of chlorine in com- 
 bination with bromine. We are not acquainted with 
 the exact method of its preparation ; but a mixture 
 not unlike it may be made by dissolving bromine in a 
 mixture of two parts muriatic acid, and one of nitric 
 acid, the bromine is added to this until it will dissolve 
 no more. The red liquid thus obtained is to be 
 decanted from any excess of bromine, and when re- 
 quired for use, two drachms should be mixed with 
 eight ounces of water, allowed to remain for about 
 half an hour, and then used in the apparatus, 
 fig. 20 ; the same tints should be obtained on the 
 plate as directed for bromine water. (§28) 
 
 48. Chloride of bromine , — This may be prepared 
 by passing a current of chlorine, through a vessel 
 containing bromine, by means of the apparatus fig. 
 23. A mixture of two parts muriatic acid, and one 
 of black oxide of manganese, should be placed into 
 the flask A. To this flask a bent tube is adapted, 
 passing through an opening in the two-necked bottle 
 B. This tube should dip into a little bromine placed 
 
35 
 
 in the bottom 
 of it; another 
 tube should 
 proceed from 
 this, and just 
 dip below the 
 surface of 
 some water in 
 another ves- 
 sel C ; a very 
 gentle heat is 
 then to be 
 applied to the 
 
 flask containing the manganese and acid, a current 
 of chlorine gas will pass through the bromine con- 
 tained in B ; in a short time the bromine will change 
 colour, and a volatile yellowish-red fluid is obtained; 
 this should be diluted with water and used in the 
 same way as Wolcott’s mixture. In this and 
 all accelerating solutions not containing iodine, the 
 plate should be placed over the iodine a second 
 time, as directed for bromine water (§ 28). Chlo- 
 ride of iodine may also be prepared in this appa- 
 ratus. Iodine should be placed in vessel B, and then 
 gently heated ; when the current of chlorine is passed, 
 the lamp may be removed from the iodine; the action 
 should be stopped after the liquid produced becomes 
 of a brownish-red colour. 
 
 49. We shall conclude our notice of accelerating 
 compounds by an extract from the Philosophical Ma- 
 gazine, in which is described a method of using bro- 
 mine which we think possesses many advantages ; 
 the arrangements, fig. 20 or 21, are the best adapted 
 for this compound ; if an earthenware pan is used, it 
 should be thoroughly dried, this is readily accom- 
 plished, by placing it in a common oven at a moderate 
 heat for about an hour, this will effectually remove the 
 moisture out of the substance of the pan, which it is 
 very necessary to get rid of, for after the vessel has 
 
 DAGUERREOTYPE. 
 
 Fig. 23. 
 
36 
 
 PHOTOGENIC MANIPULATION. 
 
 been used for containing liquid of any kind, it obsti- 
 nately retains moisture, which infallibly spoils the bro- 
 mide of lime if placed in it. 
 
 50. “ ^ An improvement in the Daguerreotype pro- 
 cess by the application of some new compounds of bro- 
 mincy chlorine and iodine, with lime,^' — All persons 
 who have practised the daguerreotype must have re- 
 marked, that in warm weather a considerable deposi- 
 tion of moisture takes place upon the glass or slate 
 cover used to confine the vapour in the bromine or 
 accelerating pan. This moisture must also necessarily 
 condense upon the cold metallic surface of the plate 
 during the time it is exposed to the bromine vapour. 
 In fact, I have been informed by a number of profes- 
 sional daguerreotypists (and I have experienced the 
 difficulty myself), that they were unable to obtain 
 perfect pictures during the excessive heat of the late 
 season; and a very clever and enterprising operator, 
 who last year made a tour on the continent, and 
 brought home some of the finest proofs I have ever 
 seen, entirely failed this season in obtaining clear and 
 perfect pictures, from the constant appearance of a 
 mist or cloud over the prepared surface. This ap- 
 pears to be caused by the deposition of moisture 
 upon the plate, arising from the water in which the 
 bromine is dissolved. To obviate this some have re- 
 commended the pan to be kept at a low temperature in 
 a freezing mixture; and M. Daguerre, in a communi- 
 cation to the French Academy of Sciences, recom- 
 mends the plate to be heated : but in practice both 
 these plans are found to be unsuccessful. (See Lere- 
 bour’s Traite de Photographie.) 
 
 51. ‘‘ It appeared to me, that if we could avoid the 
 use of water altogether in the accelerating mixture, not 
 
 * By R. J. Bingham, Chemical Assistant in the Laboratory of 
 the London Institution. — From the London and Edinburgh Philoso’ 
 phical Magazine, for October 1846. Communicated by the Author. 
 
DAGUERREOTYPE. 
 
 37 
 
 only would the difficulty I have mentioned be avoided, 
 but a much more sensitive surface would be obtained 
 on the plate. With this view I endeavoured to com- 
 bine bromine with lime, so as to form a compund ana- 
 logous to bleaching powder. In this I was successful, 
 and find that bromine, chloride of iodine, and iodine, 
 may be united with lime, forming compounds having 
 properties similar to the so-called chloride of lime. 
 
 52. “ The bromide of lime^ may be produced by al- 
 lowing bromine vapour to act upon hydrate of lime for 
 some hours : the most convenient method of doing this 
 is to place some of the hydrate at the bottom of a 
 flask, and then put some bromine into a glass capsule 
 supported a little above the lime. As beat is developed 
 during the combination, it is better to place the lower 
 part of the flask in water at the temperature of about 
 50° F. : the lime gradually assumes a beautiful scarlet 
 colour, and acquires an appearance very similar to that 
 of the red iodide of mercury. The chloro-iodide of 
 lime may be formed in the same manner: it has a deep 
 brown colour. Both these compounds, when the va- 
 pour arising from them is not too intense, have an 
 odour analogous to that of bleaching powder, and 
 quite distinguishable from chlorine, bromine, or iodine 
 alone. 
 
 53. “ Those daguerreotypists who use chlorine in 
 combination with bromine, as in Wolcott's American 
 mixture, or M. Guerin’s Hungarian solution, which is 
 a compound of bromine, chlorine, and iodine, may ob- 
 tain similar substances in the solid state, which may 
 be used with great advantage. By passing chlorine 
 
 * I call this substance bromide of lime, although there is a diffi- 
 culty as to tlie composition of bleaching powder, and which would 
 also apply to the compounds 1 describe. Some chemists regard the 
 chloride of lime to be a compound of lime, water and chlorine. 
 Balard thinks it is a mixture of hypochlorite of lime and chloride of 
 calcium; and the view of Millon and Prof. Graham is, that it is a 
 peroxide of lime, in which I equivalent of oxygen is replaced by 
 one of chlorine. 
 
38 
 
 PHOTOGENIC MANIPULATION. 
 
 over bromine, and condensing the vapours into a 
 liquid, and then allowing the vapour of this to act 
 upon lime, a solid may be obtained having all the pro- 
 perties of the American accelerator ; or by combining 
 the chloro-iodide of lime with a little of the bromide, 
 a mixture similar to that of M. Guerin’s may be pro- 
 duced : but I greatly prefer, and would recommend 
 the pure bromide of lime, it being, as I believe, the 
 quickest accelerating substance at present known. 
 By slightly colouring the plate with the chloro-iodide, 
 and then exposing it for a proper time over the bro- 
 mide, proofs may be obtained in a fraction of a second, 
 even late in the afternoon. A yellow colour should be 
 given by the use of the first substance; and the proper 
 time over the bromide is readily obtained by one or 
 two trials. With about a drachm of the substance in 
 a shallow pan, I give the plate ten seconds the whole 
 of the first day of using the preparation, and add about 
 three seconds for every succeeding one. The com- 
 pound should be evenly strewed over the bottom of the 
 pan, and will last with care about a fortnight. 
 
 54. ‘‘ The great advantage of this compound is, that 
 it may be used continuously for a fortnight without 
 renewal ; and, unlike bromine water, its action is un- 
 affected by the ordinary changes of temperature. 
 
 “ I have hastened to communicate this during the 
 present fine weather, believing that it will be accept- 
 able to all interested in this beautiful application of 
 science.” 
 
 We now come to the third operation, namely, ob- 
 taining the impression on the plate by means of the 
 Camera. 
 
39 
 
 THE CAMERA. 
 
 55. Camera . — This apparatus, which we have before 
 described in Part I, is adapted more particularly for the 
 processes on paper, and the only modification abso- 
 lutely necessary to render the same instrument useful 
 for the daguerreotype is the frame for holding the 
 plate in the place of paper during the time it is 
 exposed to the light ; however, as it is more con- 
 venient to have a camera purposely constructed for the 
 daguerreotype, we shall proceed to describe two or 
 three of the forms best adapted for this process. Fig. 
 24 represents one form, half the body A sliding into 
 the other half B, this has the advantage of rendering 
 the instrument more portable and allowing a greater 
 range of focus, and, if required, lenses of different 
 focal lengths can be used with the same camera. 
 
 Fig. 24. 
 
 56. Fig. 25 represents the German, or Voigtlander’s 
 Camera; it is made entirely of brass, so that variation 
 of climate has no effect upon it. It is very portable, 
 and when packed in its box, with all the necessary 
 apparatus and materials for practising the Daguerreo- 
 type art, occupies but little space. 
 
 The brass foot A, is placed on a table, or other firm 
 support, and the pillar B screwed into it ; the body of 
 
40 
 
 PHOTOGENIC MANIPULATION. 
 
 Fig. 25. 
 
 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 be raised, lowered, or moved from one side to the 
 other, by the telescope-stand, and when correct, fixed 
 by the screw b. The landscape or portrait to be de- 
 lineated is viewed either through the small lens g, or 
 with the naked eye on the ground glass plate H, the 
 focus being adjusted by the screw I. The optical part 
 of the instrument consists of the small set of achro- 
 matic lenses presently to be described. When the 
 view or portrait to be taken is delineated on the ground 
 glass to the entire satisfaction 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 H, and the plate inclosed in the 
 brass frame K introduced in its place ; the whole is 
 
DAGUERREOTYPE. 
 
 41 
 
 again placed on the pedestal, the brass cap L is 
 removed by which the paper or plate is’exposed to the 
 full influence of the light, after which the cap is again 
 replaced. 
 
 57. Mr. Beard patented a camera in which lenses 
 were altogether laid aside, and their place supplied by 
 a concave mirror. The advantages derived from this 
 construction is the greater rapidity with which it acts, 
 but there are many inconveniences attached to it ; it is 
 only applicable to the small-sized plates, neither is it 
 so portable or easy of management as the others. 
 
 58. The lenses * — The diameter and focal length of 
 these 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 J in. 
 diameter, and from 4^ in. to in. focus may be 
 used ; but for distant views, one from 2 in. to 3 in. 
 diameter, and from 8 in. to 16 in. focal length, will be 
 found to answer better. For single lenses the aper- 
 ture, in front, should be placed at a distance from it 
 corresponding to the diameter, and of a size not more 
 than one-third of the same. A variety of moveable 
 apertures or diaphragms are often useful, as by them 
 the intensity of the light may be modified, and more 
 or less distinctness and clearness of delineation ob- 
 tained. 
 
 59. Though the single achromatic lens answers very 
 well for copying engravings, taking views from nature, 
 buildings, &c., for the portrait, figures, and groups 
 from life, it is almost entirely superseded by the double 
 achromatic, which acts very much quicker; and these 
 have been brought to the greatest state of perfec- 
 tion by M. Voigtlander, of Vienna, under the direction 
 of Dr. Petzval, professor of mathematics in that uni- 
 versity. His small-size arrangement consists of two 
 separate achromatic lenses : the first, or external one, 
 has a free aperture of 1^ in. ; the second. If in. ; and 
 both have the same focus, viz. 5| in. 
 
 D 
 
42 
 
 PHOTOGENIC MANIPULATION. 
 
 The larger size differs from the smaller ; the inner 
 lens is an achromatic 3| in. diameter, its focal length 
 30 in. ; the second, or outer lens, is a meniscus, having 
 a focal length of 18 in. The combined length of the 
 two being 10| in. For very distant views the aper- 
 ture in front is contracted to fths of an inch. By these 
 means the light is reflected with considerable inten- 
 sity, and the clearness and correctness of the delinea- 
 tion are truly surprising. 
 
 60. Fig. 26 shows the American form of camera, 
 modified by Messrs. Knight and Sons ; it is a very 
 
 Fig. 26. 
 
 convenient arrangement ; admits of great variation in 
 the length of focus, and may be used for copying da- 
 guerreotypes where the focus is required to be of the 
 same length as the object to be copied is distant from 
 the object glass ; in this case the image formed on the 
 ground glass will be of the same size as the object 
 at which the camera is directed. The plate frames in 
 this camera are so made that the plate can be used 
 either in a horizontal or vertical position without the 
 trouble of turning the camera on its side, and a con- 
 siderable number of these frames containing the pre- 
 pared plates, can be packed within the camera. 
 
 61. Another, and a very important improvement in 
 
DAGUERREOTYPE. 
 
 43 
 
 this camera has been made by the last named gentle- 
 men, namely, a readier and less expensive contrivance 
 for altering the position of the plate with respect to 
 the object-glass, by which means two objects, differ- 
 ing slightly in their distance from the object-glass are 
 brought to the same focus on the ground glass or 
 plate. Fig, 27 represents the moveable frame for the 
 purpose. 
 
 62. We shall endeavour to explain the advantage 
 derived from occasionally placing 
 the plate out of its upright posi- 
 tion. It is well known that the 
 focus of any object varies ac- 
 cording as it is more or less re- 
 moved from the object-glass ; 
 thus, the proper focus of an ob- 
 ject near the lens will differ from 
 that of one placed immediately 
 behind it. Thus in Fig. 28, 
 let the line A B represent an 
 
 Fig. 28. 
 
 object situated obliquely to the lens D, the point A will 
 have its focus behind the lens at a, the point B being 
 nearer the lens will have its focus at a greater distance, 
 at 6. Now, by the ordinary arrangement of camera, only 
 one of these points, as a, could be obtained correctly in 
 focus, the line a h representing the ground glass, but by 
 
 Fig. 27. 
 
44 
 
 PHOTOGENIC MANIPULATION. 
 
 Fig. 29. 
 
 making the back of the camera moveable, we can 
 place the ground glass as indicated by the dotted line 
 a b ; therefore, both these points, a b, or any part 
 of the object on the line A B, will thus be in correct 
 focus, and both the face, knees, and hand of the 
 sitter drawn in the figure, will be properly represented ; 
 this is, to a certain extent, a great advantage, and 
 particularly so with a short focus lens having a large 
 opening, but it will also be at once perceived that the 
 only parts properly in focus will be where the line 
 A B touches the figure, the pattern of the waistcoat 
 would, in this instance, be slightly out of focus. 
 
 63. Fig. 29 represents a mirror for reversing the sides 
 of the image, and is to be fitted on to the end of the 
 object-glass ; this is necessary when we wish the 
 
 objects represented to appear in the 
 same position as they do naturally ; 
 thus, if we point the camera at a man 
 writing, in the representation his pen 
 will appear to be held in the left hand, 
 but if the mirror be used, the sides 
 will be reversed and the pen appear 
 in the right hand ; a glass prism is 
 sometimes used for this purpose, but it 
 is very much more expensive and diffi- 
 cult to obtain perfect and free from striae ; it is true 
 there are two reflections, and, therefore, two images 
 formed on the ground glass by the mirror, one image 
 being formed by reflection from the surface of the mer- 
 cury at the back of the glass, and the other a faint 
 image from the surface of the glass, but, practically, 
 this is of little importance, for the latter image is sel- 
 dom of sufficient intensity to impress the plate. When 
 the mirror is used it lengthens the time of exposure 
 of the plate about one-half as much again. 
 
 64. Figs. 30, 31, 32, and 33, show four different 
 forms of the camera stand, the two middle ones possess 
 the advantage of portability, hence, they are best adapted 
 fUr the tourist taking views from nature ;; the first 
 
DAGUERREOTYPE. 
 
 45 
 
 Fig. 33. Fig. 32. Fig. 31. Fig. 30. 
 
 however, is the better suited for taking portraits 
 or figures from life, and the latter combines the ad- 
 vantages of both. In order to obtain an image 
 on the prepared plate, the camera is placed on one of 
 the above stands opposite to the object, an image of 
 which will be formed on the ground glass more or less 
 distinct; the lens should then be moved by the rack 
 and pinion to or from the ground glass until a clear 
 image is obtained. The glass is then removed and the 
 frame containing the plate introduced in its place, the 
 slide is next withdrawn and the light allovved to act 
 upon the prepared surface, the proper time for the light 
 to act upon the plate depends upon so many circum- 
 stances, the hour of the day, the season of the year, 
 and the preparation of the plate, that it is impossible 
 to give any rule ; but the time, with a good lens, a 
 bright day, and a properly prepared plate, in the open 
 air, ought not to exceed ten or fifteen seconds ; after 
 the proper time has elapsed the frame should be closed, 
 the plate taken out of the camera, and submitted to 
 the next operation, namely, bringing out the picture 
 by the vapour of mercury, for if the plate is examined 
 after the necessary action of light, no picture will be 
 perceived. 
 
46 
 
 PHOTOGENIC MANIPULAriON. 
 
 We come now to the fourth operation, rendering 
 the impression obtained in the camera visible by the 
 aid of mercury. 
 
 65. Fig. 34 represents an apparatus for this pur- 
 
 pose. The box is made of wood 
 Fig. 34, of the form represented in the 
 figure. The bottom is of iron, 
 slightly dished in the centre ; 
 this is for containing a small 
 quantity of mercury, the bulb of 
 a thermometer dips into this^ the 
 stem being bent in such a man- 
 ner that the scale comes outside 
 the front of the box, the mercury 
 being heated by the spirit lamp. 
 The thermometer indicates the 
 temperature obtained. The 
 plates are supported in a groove, 
 placed for this purpose inside the lid ; this process 
 is generally carried on in a dark room, but the box 
 may be so contrived as not to render this necessary, 
 the dark frame fitting the camera and containing the 
 plate being made so as to adapt itself to the top of the 
 mercury box, so that when placed in it, the slide may 
 be withdrawn as in the camera. When required to be 
 very portable, the legs are made to fold beneath the 
 box, the plate may be examined from time to time by 
 raising the lid and allowing a light from a bullVeye 
 lantern to fall upon the plate for a short time.* 
 
 66. The plate should be allowed to remain in the 
 mercury-box until the picture is fully developed, or 
 until it will take up no more mercury. This is readily 
 seen ; for when the picture has been in the mercury- 
 box too long, the shadows begin to turn grey, and are 
 covered with very minute particles of mercury. The 
 proper time for the plate to be removed is just before 
 this effect takes place. It is better to allow the plate 
 
 * It is convenient to tie up the mercury in a little bag and place 
 it over the bulb of the thermometer. 
 
DAGUERREOTYPE. 
 
 47 
 
 CO 
 
 K 
 
 to remain over the mercury as long as possible ; for by 
 so doing the picture acquires a more clear and white 
 appearance. Should there be any small trace of 
 solarization, a prolonged exposure to the mercury will 
 sometimes remove it. The heat to be applied to the 
 mercury-box should not exceed 200° Fahrenheit : it is 
 better to bring out the picture at about 150° ; it takes 
 a little longer time, but there is less risk of spoiling the 
 picture, and it will be found that the details are gene- 
 rally better developed by employing a low heat. Should 
 the mercury be made too hot, it will deposit itselfpj 
 in the deepest shadows, and spoil the proof. 
 
 67. Mr. Constable, of Brighton, has con- 
 trived a sliding-scale, represented fig. 35, 
 by which, at a single glance, is seen 
 the time the plate should be exposed in 
 the mercury-box, regulated by the tem- 
 perature both of the apartment and mer- 
 cury. 
 
 68. And here we may mention another 
 useful instrument for which we are indebted 
 to the above gentleman. Fig. 36 represents 
 his sand- clock, or timekeeper. It consists 
 of a glass tube, 10 or 12 inches long, and 
 about 1 in. diameter, half-filled with fine 
 sand, similar to that used for the ordinary 
 minute glasses, and like them it has a dia- 
 phragm with a small hole in the centre, 
 through which the sand runs. The tube 
 is attached to a board by a centre, on 
 which it turns. On the upper portion of 
 this board, and on one side, is a scale, 
 graduated into minutes and seconds, pro- 
 vided with a moveable index. The instru- 
 ment when in use is fixed firmly, and per- 
 fectly upright to the wall ; the tube being 
 revolved on its centre, the index is set 
 to the number of minutes and seconds 
 
48 
 
 PHOTOGENIC MANIPULATION. 
 
 required to be marked. In practice, it will be found 
 more convenient than a clock or seconds watch, and 
 is applicable for either the mercury-box or bromine 
 pan (§ 22, 28.) 
 
 69. As the picture is brought out, or rendered 
 visible by the mercury, it will be readily seen whether 
 the plate has been exposed a sufficient time in the 
 camera ; for if those parts most illuminated only appear 
 very distinctly, then we shall be certain it has been too 
 short a time in the camera ; but should it have been 
 left the right period, the first efiect of the mercury will 
 develope the whole of the picture, but very faintly, and 
 further mercurializing will develope it strongly. But 
 if the plate has been too long exposed in the camera, 
 it will have a blue appearance in those parts most 
 illuminated by the sun, and if the exposure has been 
 still longer, the lights and shades of the picture will be 
 reversed. The blue appearance given by the too-pro- 
 longed action of light is technically called solariza- 
 
 70. There are several 
 forms of mercury-box. Fig. 
 37 represents a very portable 
 one. It was the opinion of 
 Daguerre that the mercurial 
 vapour could only be pro- 
 perly applied to the plate at 
 an angle of 45®, and mer- 
 cury-boxes are still generally 
 constructed for the plate to 
 be held at this particular 
 angle ; but this is not of the 
 slightest consequence, for a 
 plate may be mercurialized in any position, and we 
 have used a mercury-box made from an old plate-box, 
 where the plates are held vertically. This form of 
 mercury-box occupies very little space, and a number 
 
 Fig. 37. 
 
DAGUERREOTYPE. 
 
 49 
 
 of plates can be mercurialized at once. The plates can 
 be observed by drawing up the rod on the bottom of 
 which each plate rests, or by having a piece of yellow 
 glass in front of the box. All mercury-boxes should 
 have stout iron bottoms. Some are made out of thin 
 sheet iron: these retain the heat a very little time, and 
 the operator has the trouble of heating them every few 
 minutes. When made thick, they retain their tem- 
 perature constant for some time when once heated, and 
 a small flame may be allowed to burn under them 
 without any danger of the bulb of the thermometer 
 breaking. There is also an arrangement by which 
 the mercury-box can be raised or lowered to or from the 
 lamp until it is found the temperature remains constant. 
 
 71. 5th Operation, — Removing the Sensitive Coatings 
 of Iodine and Bromine , — For this process the following 
 apparatus is required : — 
 
 Two or three porce- Fig. 38. 
 
 lain vessels of the 
 form A, fig. 38. 
 
 A pair of plyers 
 for small plates, and 
 the support B, fig. 
 
 37, for large ones. 
 
 Hyposulphite so- 
 da, and distilled wa- 
 ter. 
 
 72. Having made a solution of hyposulphite of soda 
 by dissolving about | oz. of the salt in a pint of dis- 
 tilled water, a small quantity should be poured into one 
 of the porcelain dishes, and the plate suddenly im- 
 mersed with its face upwards, the whole of the coloured 
 coating of iodine and bromine will be promptly removed. 
 The plate is then taken out, and placed in a vessel of 
 distilled water until the next and final operation. On 
 
50 
 
 PHOTOGENIC MANIPULATION. 
 
 removing the plate from the mercury-box, it should be 
 kept in the dark until the sensitive coatings are 
 removed, as the light darkens them, and renders the 
 operation more difficult. 
 
 73. Sixth and last process, viz. — Fixing the picture 
 by means of a coating of gold, and drying the plate. 
 The only apparatus required for depositing the film 
 of gold on the plate, is a levelling stand and a small 
 glass funnel. Some hyposulphite of gold, or cry- 
 stallized chloride of gold, and hyposulphite of soda 
 and distilled water. 
 
 74. If the double salt of hyposulphite of gold be 
 used, 15 grains of it are to be dissolved in a pint of 
 distilled water. But if the crystallized chloride of 
 gold and hyposulphate of soda are obtained separate, 
 then 15 grains of the former are to be dissolved 
 in a pint of distilled water, and in another pint of 
 distilled water 45 grains of the latter ; pour gradually, 
 in very small quantities, the gold into the hyposulphite, 
 stirring the solution all the time, when finished, the 
 mixture should be nearly colourless, the plate being 
 removed from the distilled water in which it was placed, 
 
 and whilst still wet, should be placed 
 Fig. 39. on a fixing stand, fig. 39. A little fil- 
 tering paper is then to be placed in the 
 glass funnel, and the gold solution 
 poured into it, and allowed to drop 
 on the plate. As much solution should 
 be placed on the plate as it will hold : 
 should it not be it level, it is ad- 
 justed by the levelling screws. A 
 small spirit lamp flame should then 
 be applied to the under surface of the 
 plate, and kept in motion, so as to heat 
 all parts of the plate alike. Small bubbles will form, 
 and the image will assume a dark appearance ; pre- 
 sently the picture will brighten, and a great intensity 
 of light and shade will be produced, the gold should 
 
DAGUERREOTYPE. 
 
 51 
 
 then be poured off, and the plate well washed with 
 distilled water, it now only requires drying. 
 
 75. The apparatus (fig. 40) may be used for this 
 purpose, a is a vessel of sufficient size to take the 
 largest plate, but not more than 
 half an inch in width ; it is best 
 made of copper or brass, tinned or 
 plated inside, which must be kept 
 perfectly clean ; hot distilled water 
 is poured into it, and the tem- 
 perature kept up by the spirit 
 lamp. The plate supported by 
 the holder c is immersed and 
 then gradually withdrawn, at the 
 same time the operator should 
 gently blow upon the surface, it 
 may by this method be brought out perfectly dry. 
 Small plates are readily dried, by holding them by one 
 corner with the pliers, and pouring hot distilled water 
 on them, applying the spirit lamp to the back at 
 the upper corner, at the same time facilitating the 
 operation with the breath, passing the lamp gra- 
 dually downwards, finishing at the extreme corners. 
 The last drop may be removed by a little bibulous 
 paper, the film of water must dry off evenly, and 
 leave no drop behind on the surface, for this would 
 infallibly cause a stain which it would be difficult 
 to remove ; should a drop separate from the rest, it 
 is better to return the plate into clean water, and com- 
 mence again the drying operation ; if the plate be quite 
 clean, there will be no difficulty in drying off the picture, 
 but if there is the smallest quantity of grease either on 
 the plate, or in the water, or communicated by the fin- 
 gers, it will be impossible to get the water off properly, 
 the only plan to adopt in this case is to pour over the 
 plate a little strong alcohol, and slightly wipe the 
 plate at the same time with a camel’s hair pencil ; 
 the alcohol should then be washed off with water 
 
52 
 
 PHOTOGENIC MANIPULATION. 
 
 until no strise appear on the plate, and then another 
 attempt made to dry the picture. The proof is now 
 finished, and in order to preserve it, should be put into 
 a plate-box, and kept from the air, or it may at once 
 be mounted in a paper or other frame, of which several 
 varieties may be obtained. An old picture injured or 
 stained by exposure to air, may very often be cleaned 
 by washing it in a solution of the cyanide of potas- 
 sium, at the same time passing a soft camel’s hair 
 pencil over it ; it should then be washed and dried as 
 before (§ 74). 
 
 76. It is often an advantage to use the gold solution 
 of one- half the strength before recommended, there is 
 less risk of the film of gold becoming too thick and 
 breaking up, as is often the case when the heat 
 is continued too long ; another advantage is, that it 
 enables the operator to “ gild down* a stain which 
 often appears at the beginning of the gilding process ; 
 for by continuing the heat there is very little danger of 
 exfoliation of the gold, and the stain very often dis- 
 appears ; the operator will soon discover the kind of 
 stain which will disappear by continued gilding; if 
 there are any traces of oil left in the plate by the clean- 
 ing process, white stains will appear ; these cannot be 
 got rid of by continuing the gilding, they get worse, 
 and if they appear, it is very little use proceeding far- 
 ther with the proof, for it will only render it more 
 difficult to clean, 
 
 77. Solarization may often be removed by long ap- 
 plication of beat, using weak gold ; but a better plan 
 for removing slight solarization, is to deposit a thin 
 film of silver upon the plate by means of the galvanic 
 battery, the conducting wire from the zinc end of the 
 battery should be connected with the daguerreotype 
 plate, the opposite silver electrode placed in the so- 
 lution, and when all is ready the plate is to be dipped 
 into the silvering liquid for about two seconds only, 
 
DAGUERREOTYPE. 
 
 53 
 
 if left in the solution longer than this time, a thick 
 film will be deposited, and the proof clouded, (full 
 directions for electro-silvering will be found in Elec- 
 trotype Manipulation, published by Messrs. Knight). 
 After the plate has received this silver coating, it should 
 then be gilded as before described, if carefully man- 
 aged, this will be found a very good method of re- 
 moving solarization. 
 
 78. The gilding can also be accomplished by elec- 
 tricity, and this gives a very warm tone to I he picture, 
 this plan may be used by the artist to modify his 
 results. Mr. Beard fixed all his proofs in this way 
 at one time, but we believe he has now abandoned the 
 plan. 
 
 79. Colouring Daguerreotypes . — It has often been 
 asserted that this has been accomplished by solar 
 influence alone, but we think without any foundation. 
 All the colouring in daguerreotypes is applied by the 
 pencil. For this purpose, the artist will require a few 
 colours in the state of an impalpable powder, having 
 been ground up with a little gum-arabic and spirits of 
 wine, and then dried. The principal colours used are 
 ultramarine, carmine, chrome-yellow, and Prussian 
 blue. A little of the colour should be taken up on the 
 point of a fine cameBs-hair pencil, and applied by a 
 slight circular motion to the parts we wish to tint, 
 which should then be breathed upon, and the super- 
 fluous colour dusted off by a thicker camel’s-hair pencil. 
 If the colour is not deep enough, a little more of the 
 powder should be applied, and the plate again breathed 
 upon and dusted off. By combining these colours, 
 any tint we wish may be obtained : any slight lines or 
 spots of colour may be applied in the wet state, in the 
 same way as ordinary water-colours ; but only a very 
 small quantity should be used. The general fault with 
 amateurs is, that they use too much colour — but, un- 
 less in very skilful hands, we think a coloured daguerreo- 
 type is a spoilt one : it is something analogous to paint- 
 ing a fine engraving. 
 
54 
 
 PHOTOGENIC MANIPULATION. 
 
 80. We have some doubts as to the propriety of 
 noticing the following process for colouring daguerreo- 
 types, proposed by Professor Page of New York — 
 The impression being obtained upon a highly- 
 polished plate, and made to receive by galvanic agency 
 a very slight deposit of copper from the cupreous 
 cyanide of potassa (the deposit of copper being just 
 enough to change the colour of the plate in the slightest 
 degree), is washed very carefully with distilled water, 
 and then heated over a spirit-lamp until the light part 
 assumes a pearly, transparent appearance. The whiten- 
 ing and cleaning up of the picture by this process is 
 far more beautiful than by the ordinary method of fixa- 
 tion by a deposit of gold. A small portrait, fixed in 
 this way more than a year since, remains unchanged. 
 As copper assumes various colours, according to the 
 depth of oxidation upon its surface, it follows, that if a 
 thicker coating than the first mentioned can be put 
 upon the plate without impairing the impression, various 
 colours may be obtained during the fixation. It is im- 
 possible for me to give any definite rules concerning 
 this last process ; but I will state, in a general way, 
 that my best results were obtained by giving the plate 
 such a coating of copper as to change the tone of the 
 picture — that is, give it a coppery colour, and then 
 heating it over a spirit-lamp until it assumes the colour 
 desired, I have now an exposed picture treated in this 
 way at the same time with the two above mentioned, 
 and it remains unchanged. It is of a beautiful green 
 colour, and the impression has not suffered in the least 
 by oxidation. For pure landscapes, it has a pleasing 
 effect ; and by adopting some of the recent inventions 
 for stopping out the deposit of copper, the green colour 
 may be had whenever desired. In some pictures a 
 curious variety of colours is obtained, owing to the 
 varying thickness of the deposit of copper, which is 
 governed by the thickness of the deposit of mercury 
 
 * Silliman's Journal of Science. 
 
DAGUERREOTYPE. 
 
 55 
 
 forming the picture. In one instance, a clear and 
 beautiful ruby colour was produced, limited in a well 
 defined manner to the drapery, while all other parts 
 were green. To succeed well in the first process, viz. 
 that for fixation and the production of the pearly ap- 
 pearance, the impression should be carried as far as 
 possible without solarization ; the solution of the hypo- 
 sulphite of soda should be pure and free from the 
 traces of sulphur, the plate should be carefully washed 
 with distilled water, both before and after it receives the 
 deposit of copper — in fact, the whole experiment ought 
 to be neatly performed, to prevent what the French 
 significantly call taches upon the plate, when the copper 
 comes to be oxidized.'^ 
 
 All the different processes necessary to produce 
 a perfect daguerreotype have now been described : 
 upon several points we have dwelt at some length, 
 even at the risk of being tedious ; however, as we 
 intended this little work to be a practical, and, as 
 far as possible, a complete manual of this new and 
 increasingly interesting art, we may, perhaps, be ex- 
 cused if we have insisted and enlarged upon matters, 
 which if not altogether interesting to the practised ma- 
 nipulator, are yet quite important and necessary to be 
 known to a beginner in the art. 
 

 I' 
 
 i 
 
INDEX. 
 
 Accelerating Solutions, ^ 27 
 to 54 
 
 Bromine Pans, § 21 
 Bromide of Lime, § 49 to 54 
 method of pre- 
 paring, § 52 
 
 use, § 53 
 
 of Iodine, § 40, 42 
 
 M. Valicours, 
 
 § 42 
 
 Buffs for Lathe, § 7 
 straight for hand, § 1 1 
 
 Cleaning and Polishing Plates, § 
 7 to 18 
 
 — by 
 
 the Lathe, § 7 
 
 with 
 
 Caustic Potass solution, § 14 
 Colour, method of working Bro - 
 mine Water by, § 28, 29 
 Chloride of Bromine, process 
 for preparing, § 48 
 Chloride of Iodine, § 48 
 Chloro-Bromide of Lime, § 53 
 Camera, § 55 
 
 Voigtlander’s, § 56 
 
 Beard’s Patent, § 57 
 
 Lenses for, § 58, 59 
 
 American form of, § 60 
 
 Knight’s improved, ^ 60, 
 
 61 
 
 moveable back 
 
 Camera, use of, § 61 
 
 stands for, § 64 
 
 Chloride of Gold, § 73 
 Constable’s, Mr., Sand Clock 
 and Sliding Scale, § 67, 68 
 Colouring Daguerreotypes, § 79 
 
 Prof. 
 
 Page’s plan of, § 80 
 
 Daguerreotype patented in Eng- 
 land, § 2 
 
 operations, § 4 
 
 fixing, $ 71 
 
 gilding, § 73 
 
 plates, choice, § 6 
 
 to clean, ib. 
 
 exposure in 
 
 Camera, § 64 
 
 mercurializ- 
 ing § 65 
 
 removing sen- 
 sitive coating from, § 71 
 washing, § 75 
 
 — colouring, § 
 
 79, 80 
 
 Drying Apparatus, § 75 
 
 Essential Oils for cleaning plates, 
 
 § 17 
 
 Adulteration detected, 
 
 §17 
 
 Electro-silvering Daguerreotype, 
 $ 77 
 
 — gilding Daguerreotype, § 
 
 78 
 
 to, 61 
 
 K 
 
58 
 
 INDEX. 
 
 Fizeau, M. method of using 
 Bromine Water, § 31 to 39 
 Fixing the Picture, § 73 
 
 Guerin, M. Hungarian Solution, 
 § 46 
 
 Gilding Daguerreotype, § 74 
 
 Hunt, Mr. Experiment of, § 24 
 Hungarian Solution, § 46 
 Hyposulphite Bath, § 71 
 Gold, § 74 
 
 Iodizing process, § 23 to 25 
 
 apparatus for, § 21, 22 
 
 Introduction, § 1 
 
 Lathe, cleaning Plates by, § 77 
 Lenses for Camera, § 58 
 
 Moisture, injurious effect of, on 
 Plate, § 50 
 
 Mirror for reversing image, § 63 
 Mercury Box, § 65 
 
 improved form of 
 
 Fig. 36, § 70 
 
 Plates, choice of, § 5, 6 
 
 French, § 6 
 
 electro-silvering, § 6 
 
 cleaning, § 7 
 
 Plate-holders, § 12, 13 
 Pagers, Professor, method of 
 colouring Daguerreotype, § 80 
 
 Rottenstone, preparation of, § 16 
 
 Sand Clock, Mr. Constable's, 
 § 67 
 
 Sliding Scale, § 68 
 
 Solarization, how to remove, § 77 
 
 Wolcott^s Solution, § 47