THE GETTY CENTER LIBRARY THE PHOTOGRAPH AND AMBROTYPE MANUAL: A PRACTICAL TEEATISE ON THE ART OF TAKING rOSITIVE AND NEGATIVE PHOTOGRAPHS ON PAPER AND GLASS, COMMONLY KNOWN AS rHOTOGRAPHY, IX ALL ITS branches; CONTAINING ALL THK VARIOUS RECIPKS PRACTISED BY TilK MOST SUO- CESSFUL OPEUATORS IN THE UNITED STATES. BY N. G. BURGESS, PRACTICAL PIIOTOGEAPUEK, AND MANUFACTUBER OF CIIEMICAIS FOR THE ART. SEVENTH EDITION. NEW YORK: HUBBARD, BURGESS & CO., 7S EEADE AND 99 CHUECH STEEETS. LONDON: TRUBNER & CO. 18C1. I ■ Entered according to Act of Congress, in the year 1S58, Bx NATUAN G. BUIiGESS, la the Clerk's Office of the District Court of the United States for the Southern District of New York. THE GErrv CENTER LIBRARY PREFACE. Thk publication of the Ambrotype Manual, by tlie author of this work, a short tirae'since, and the great demand for the same, has induced him to enlai-ge that W(.>rk by the addition of the prac- tice of Photogra])hy in all its branches. It may not be inappropriate at the present time to refer to the progress of this wonderfnl art, since its first advent in 1839, and to note its tendencies and its effects, to trace its lead ins: features and results up to its present high posi- tion in the scientific world; and, finally, to mark out the commanding results which it is destined yet to achieve in its onward progress to pei-- fection. The Photogi-aphic Art was ushered into the world on the day when the immortal Daguerre, in 1839, announced his sublime discovery to the 4: PREFACE. French savans, and it Las steadily progressed from that day to the present time. It lias made many strides towards perfection, and has astonislied all with its accomplishments. In the short space of eighteen ^^ears, what has it not done ? "From the small and almost imperceptible im- pression upon the silver plate first exhibited by Daguerre, which cunld only be seen at a certain anule of lio'ht, and that very dimly, and of a blue- ish cold to*ne, to the magnificent photograph of the size of life, with all the perfect delineations of light and shade, wliat a wonderful advance ! And tliese great improvements have been so gi-adual, that few, if any, could mark the changes. Yet all will acknowledge, that the art is just now begin- ning to attest its true worth, f^^r wa now begin to receive the homage of all true lovers of art. The day has dawned in which the photographer can command even the service of the artist, whose highest pride should be to copy nature in all her works. For now we can exhibit true works of art drawn with the pencilings of the sun's rays, and drawn with such an unerring cori-ectness that it were sacrileo-e to touch it with the hand of the artist. It defies the artist's skill. It fairly out- PREFACE. vies the creations of a Rapliael or a Rubens in portraiture, and in the other certain works of the pencil. Tlie Photographic Art has become of such im- portance in this country, that many persons have embarked large amounts of capital in the manu- facture of materials for the use of the photographic artist. The inducement has been fully warranted irom the fact that all these persons who have in- vested in this branch of commerce have been fully rewarded. In view of these facts, it is thought proper and necessary to embody in this edition of the work a set of full and complete practical furmulae for the production of all kinds of Photographs on paper, as well as those on glass, known as Am- brutypes. The aim will be tu gi\'e only such known receipts as have been in actual practice b}'' the author and others, and to explain them in the plainest and most explicit manner possible, in order that the least practised operator may reap the benefit from the perusal of the work, as those of more mature experience. The practice of the art of taking Photographs on paper lias been attended with very diverse results in the United States, owing in a great degree to 1* 6 TKEFAGK. the fact tliat most persons who have embarked in it have heretofore been Dasjuerreian artists. Thev imagined thcit it only required the necessary skill and experience of a Daguerreian artist to ren- der them good Photographers. But this has been soon found to be a fallacy. There are many who are skilful in the process known as the Daguerreo- type, who can produce specimens of that art which would do credit to the profession, who nevertheless utterly fail in this Jiiglier branch of Photography. The reason is obviovis. They have vainly imagined that only the same care was necessary in tlie paper process that was demanded in the manipulation of the silver plate. Put how soon have their hopes of success been blasted ! Where the ordinary care bestowed upon a Daguerreotype would produce satisfactory results, the same care upon a Photo- gi-aph on paper would produce a worthless picture. Hence we see the necessity of looking into a higher range of art fur the perfection of this branch. And as we approach near the goal of perfection in this sublime art, so much the more does it de- mand of its votaries greater sacrifices on the altar of patience and perseverance, more nearly resem- Ijling the long and weary road of the successful painter, who rises in his profession through many PREFACE. 7 years of patient toil, with his pencil and his pallet, to the highest eminence. i\.nd the day ma_y nut be far distant when only those who have been fur many long and weary years followers of the Photographic Art, shall be- come masters of their profession. It is well, therefore, to fully comprehend the greatness of the task one assumes who embarks in this profession. And to become a perfect master of it, will require all the known resources of his perseverance. Therefore such aids as may be found in the experience of others, will be given here, and it is trusted may be found of essential service to those who may purchase the work and follow the art as a profession. To the amateurs this work will no doubt be ac ceptable as a practical treatise, leading them into the more intricate fields of practice not found in scientific works on kindred subjects. Fortunately for this beautiful art, the number of amateurs is increasing in the United States, and we trust they may continue to augment until the num- ber shall equal tliose of England and other Euro- pean countries. For like all beautiful arts, the tempting field of pleasurable labor here opened, is beckoning onwards a host of fellow-laborers, which 8 PREFACE. will render the task of ultimate success of very easy accomplisliment ; and it is trusted they will emulate those artists in England who have so will- ingly opened their stores of knowledge to the pho- tographic world, so that all may reap the benefit of their valued experience. CONTENTS. PAGE Preface 3 Introduction CIIAPTEE I. History and Prosrress of the Photographic Art— Its Introduction into the United States — The Discovery or Uses of the various Chemicals — Positive Photographs on Glass 19 CHAPTER II. Theory of the Photographic Process— Negative and Positive Pic- tures—Negatives on Paper and on Glass — Positives on Glass — Theory of the Positive and the Negative Process 30 NEGATIVE PROCESS. CHAPTER I. On the Practice of the Negative Process through all its details— The Manipulations— Cleaning the Plate- Coating with Collodion —Drying tlie same— Time in the Camera— Developing— Re-devel- oping for Intensity— Varnishing the Negative— Frames or Shelves for Negatives— General Remarks on the Manipulation of the Negative Process— Arrangement of the Light — Use of the Ca- mera, &c., &c S^ 10 CONTENTS. CHAPTER II. The Nitrate of Silver Bath for Negatives— Preparation of the same — Formation of tlie Iodide of Silver for the Nitrate Bath — On the practice of the Negative Batli — Observations on the use of the Negative Bath — On the Intensity of tlie Negative— Color of tlie Negative, &c., &c 43 CHAPTER III. On Photographic Printing— Salting Solutions — Salting the Paper — Silvering the Paper with Ammonia Nitrate of Silver — Plain Silver Solution — To prepare the Albumen for Paper Positives — Silvering Albumen Paper — On the practice of printing Negatives— Toning or fixing the Print — Wasliing the Positive Prints — Drying the Pictures — Varnishing and Mounting the Prints 56 CHAPTER IV. To copy Daguerreotypes and other Pictures into Photographs — Od Enlarging Pictures — To enlarge Pictures from Daguerreotypes, Anibrotypes, or Photographs ; and to produce Photographs from them — To make Life-size Photographs on Paper — Iron Plioto- graphs, or Instantaneous Printing — On taking Stereoscope Pic- tures, Photographic Views, &c., &c 69 CHAPTER V. On the Preparation of Negative Collodions — The Formulae for Neg- ative Collodions — Mixing various Collodions — Dissolving the Io- dides — Double Iodide Collodions — The celebrated German Pro- cess complete — The Negative Developing Solutions — Re-develop- ing Process — Bichloride of Mercury as a Re-developer — Fixii^g Solution — The Toning Baths — The Ammonia Nitrate of Silver Solution 81 CHAPTER VI. Details of the various Recipes in the Photographic Process— Quick Method of Silvering and Printing Paper — Best Method of Salting Papers-Test for good Collodion orGun-Cotton — Varnish for Posi- tives on Paper — Instantaneous Printing Process — New Method of CONTENTS. 11 varnishing Positives— To restore Prints that have changed color — Cleaning Glass Plates— To varnish Negatives— Dextrine Paste for mounting Pliotographs— Gum-Arabic and Gelatine— To restore Silver from Old Solutions— To remove AVater from Collodion, and to purify it— Test of Hyposulphite of Silver in Positive Prints — Printing various Backgrounds 97 CHAPTEll VII. Hints and Suggestions in regard to the Negative Process— Imper- fections peculiar to Negatives— How to avoid them— Cautions in taking Negatives— Hints and Suggestions in regard to printing Positives on Paper— Cautions in regard to them— Imperfections found in Positives — How to avoid them Ill AMBROTYPE PROCESS. CHAPTER VIII. The Camera^Plate-holders necessary for the Camera— Prepanng the Glasses— Plate-blocks for holding the Glasses— Cleaning Sub- stances — Cleaning the Glasses — Cleaning old Glasses — Removing tlie Varnish — Holding Glasses after they are cleaned— Glasses used a number of times — Quality of Glasses necessary for Am- brotypes 125 CHAPTER IX. Apparatus for Anibrotypes — Chemicals used — Substances for finish- ing the Picture — Preparation of the Nitrate Bath — To Iodize the Bath — Filtering Process — Adding Acid — Neutralizing the Bath — Full Directions for keeping the Bath in order — Renewal of the Nitrate of Silver 131 CHAPTER X. The Developing Solutions — Manner of Compounding them — Various Formula} for Developing Solutions — Test of Acetic Acid — The Fixing Solutions — Cyanide of Potassium — Hyposulphite of Soda — Adding Chloride of Silver 141 12 CONTENTS. CHAPTEE XI. On the Practice of the Art in all its Details, from the Cleaning of the Plate to the Application of the Fixing Solution — Drying the Picture 145 CHAPTER XII. Varnishing the Picture — Single Glass Process— Stereoscopic Am- brotype — Trel)Ie Glass Process — Tiie Double Glass Process — Cut- ting's Pateut-^The Patent-leather Process 151 CHAPTER XIII. The Manufacture of Gun-Cotton — Test of the Acids employed — Washing and Drying the Gun-Cotton — Preparation of the Collo- dion — Its Nature and Properties^ — Ether and Alcohol— To Iodize Collodion for Ambrotypes — Method of preserving Collodion, and keeping it ready fur use — Tests of good Collodion — To remove the color from Collodion 157 / CHAPTER XIV. Coloring Ambrotypes — Colors employed— Ambrotypes for Lockets — Taking Views — Copying Daguerreotypes by the Ainbrotype Process — Copying Engravings, Statuary, Machinery, i dei'ed apparent by that self-same reflection on sub stances capable of receiving the impression. The term Photography, ov painting hy lights is snfHciently definite for our purpose, and all we know about the actual theory is, that when certain conditions are observed with regard to light, an ini2:»ression may be obtained. But what is the real or definite action which takes place upon the surfece of the iodized plate, no man has been per- mitted to know. Photographs are known either as J^egatives or Positives. They are positive in the Daguerreotype and Ambrotyjje, and negative only in the glass pictures or paper pictures, from which positives are to be taken on paper, and on other similar substances. Tliese terms should be well understood by the operator who seeks success, as they form the basis of all photograj^hy. All pictures taken by the collodion process pos- sess either of the foregoing conditions. IS^egatives were first taken on paper, from which posiiives were produced by the process known as the Calotype, discovered and patented by Mr. Fox Talbot, of England. From the multiplicity of its in) perfections, it did not succeed, and no ])hoto- graplis were api)7*eciated by a dl-eeriiinir ]iublic 32 THEORY OF NEGATIVES AND POSITIVES. until those negatives taken on glass were produced and positives exhibited from them which were creditable as works of art. Negatives possess all the various phenomena in their production that are possessed by positives. They are in some respects more difficult to be ob- tained in great perfection, and in others are less so from their peculiar properties. They ai'e, in fact, only matrixes from which other pictures can be obtained. Therefore they are not perfect pictures of themselves, but only parts of a whole. The manipulation connected with the negative process is given briefly in this work, mainly with a view to impart certain information with regard to the positive process. The theory of the positive and negative processes IS the same, which consists in the reduction of the silver to an oxide on the surface of the glass by the action of light, and the subsequent application of well-known chemical substances. Tliese several conditions must be well observed in order to secure good resnlts. The iodide of silver must be well formed on the surface of the glass. The light given must be only so much as will produce the image, and reveal it after the application of the developing solution, and this must be of just the POSITIVES ON GLASS. 33 requisite strength to produce the reduction from the iodide to tlie oxide of silver. •The impression is therefore given solely by the action of light, or by certain properties of that mysterious body. Yet when the plate is removed from the camera, there is no apparent change pro- duced, but on applying the develoi5ing solution, the sleeping and invisible image awakes and starts into life, and commands from every beholder an expression of wonder and admiration. Fixing the picture is a subsequent operation, and is no part of the process of production, only so far as it may be necessary to render it perma- nent, and also to remove the unaffected iodide of silver, a portion of which is not at all changed by the light. Only those parts are affected which are necessary to produce the light and shade. Positives on glass are taken with chemicals varying slightly from those used in producing negatives, and also by a much shorter exposure in the camera. In fact, a positive is only a negative with a less degree of exposure to the action of light. All positives could of themselves become negatives were the time of exposure prolonged sufficiently to effect that result, though their uses as a means of producing subsequent positives on 34 AMBROTYPES IN THE UNITED STATES. paper is a matter of doubt, for there are certain other conditions necessary for success in the pro- duction of good negatives not known in the posi- tive process. These positives on glass are now so widely rec- ognized as ATnbrotypes^ that we shall venture to assume that name as one sufficiently significant and appropriate for our purpose. Ambrotypes are now so well known, that they may almost be said to be identified with the prog- ress of the art in the United States, and belong exclusively to this country. Tliey are not known as such in Europe. They are there classed under the head of Photographs, and the public here are frequently led into eiTor on this point, and suj)- pose, in fact, that Ambrotypes are a new creation — a new kind of picture only known here, while in truth they were first taken in Europe, and are merely photographs on glass, taken positively in- stead of negatively. Tiie details of the process, and the necessary manipulations, are of course to be found only in the practical portion of this work. The whole art consists, therefore, in the careful preparation of the glass plate, in the most scrupu- lous cleanliness and accuracy of the employment PHOTOGRAPHIC DIFFICULTIES. 35 of every material requisite to the process, and in a most implicit obedience to such rules as are laid down in tliis work for the guidance of those who would insure success. The results set forth in these pages were ob- tained after nnich patient labor and investigation on the part of a host of intelligent inquirers, who have successfully overcome difHculties which, could they have foreseen, would have appalled the most patient and determined mind. Happily for the photographer who now commences his operations, he may profit by the experience of others, and be spared the labor and investigation of earlier op- erators. The path for him is now rid of its most formi- dable difficulties,' and should he be induced to ex- amine carefully the abstruse philosophical princi- ples upon which this fascinating art depends, he mav, in his turn, become a contributor to its im- provement and advancement. The experience of the humblest may sometimes furnish a suggestion, which investigations of the most refined and cultivated may have long failed to accomplish. The art is greatly suggestive. It offers many fields of speculation, and the great aim of all who 36 TRIUMPH OF AKT OVER NATURE. practise it sliould be to perfect it as soon as possi- ble, for, like all the creations of man's genius, it is not yet complete. But the rapid strides it is now making towards long wislied-for perfection are so apparent, that we confidently look to the accom- plishment of the greatest end sought — namely, the reproduction of the colors of nature. This result once obtained, the artist could lay aside his easel and pallet. He could then retire from the arena where he now stands contending so unprofitably, in a pecuniary point of view, with the photogra- pher. But this seeming triumph of nature over art by the pencillings of the sunlight — the sun himself becomin«: the universal and sublime artist ! — is really the triumph of art over nature ; for since art, conscious of the weakness and imperfections of her best eiforts, has had the tact and skill to wheel the forces of nature into her own ranks, the result should be set down to her own credit, as her own victory. PART I. PRACTICAL DETAILS OF THE NEGATIVE PROCESS. POSITIVE PHOTOGRAPHS ON PAPER. CHAPTER I. ON THE PRACTICE OF THE NEGATIVE PROCESS THROUGH ALL ITS DETAILS THE MANIPULATIONS CLEANING THE PLATE — COATING WITH COLLODION DRYING THE SAME TIME IN THE CAMERA DEVELOPING KE-DEVELOPING FOR INTENSITY VARNISHING THE NEGATIVE FRAMES OR SHELVES FOR NEGATIVES GENERAL REMARKS ON THE MANIPULATION Of THE NEGATIVE PROCESS ARRANGEMENT OF THE LIGHT USE OF THE CAMERA, ETC., ETC. There are so many various plans suggested by practical operators in the Photographic Art, all varying so much in detail, that the author has thouglit proper to simply confine himself to one line of practice, which has been found to produce the best results. All negative Photographs at the present stage 40 NEGATIVE PHOTOGRAPHS. of the art are taken on glass, and they are called negatives from the fact that all the lio;hts and shades are reversed — i. e. where the portrait in life presents the high lights (or where the light foils the strongest, and it should appear the lightest), in the negative it appears the darkest. In like man- ner, where the dark shades are seen in a positive to be dark as in life, in the negative they are seen light, or to present the high lights. They present these peculiar phenomena only when viewed by transmitted light, or light passing through them, in which position they can only be seen with proper effect. When viewed as a positive, laid on a blackened substance, they resemble in some de- gree a positive that has been too long exposed in the camera. They cannot be viewed properly in any other manner than by transmitted light. However, they are never to be sealed up for sale in any form, but are always reserved by the artist to print from, any number of copies that may be desired. And herein consists the great beauty and perfection of this branch of photography. We have the power of multiplying ad infinitum^ even far greater than if it were printed from an engraving. The negative itself can be reproduced and multiplied so that exact fac-sitniles could be CLEANING THE PLATI-;. 4rl obtained, and even thousands printed by every negative, so nearly resembling each other, that none could distinguish the first original positive impression. Regarding the manipulation of negative process as a simple chemical operation, with certain chem- ical auxiliaries, it is very easy of accomplishment. When once properly understood, if certain rules are observed, it is more sure of success than most others in the art. The first requisite to success is the cleaning of the glass plate, which is easily done by I'ubbing it with a piece of cotton-flannel dipped in alcohol, slightly diluted with water ; and in case of using the glass the second time, a small quantity of rot- ten-stone, whiting, or tripoli poM'der, inay be added. Be careful to dust the glass with a flat camel's- hair brush just before pouring on the collodion. Holding the glass in the left hand, standing near the bath, pour the collodion on with a continuous stream from the bottle until there is enough, which when flowed over the whole surface of the glass will just cover it. Then let the superfluous quantity run off at the right-hand corner into the bottle, slightly moving the glass plate so that the 4* 42 TIMK IN THE CAMKRA. cullodiou M^ill not .dry in lines or ridges ; a qnick motion may be necessary to insure a perfect fiow of it over tiie surface. On holding the. glass up to transmitted light, it should appear perfectly clear and transparent, as though no collodion was upon its surface — at least, no lines, streaks, or spots. If any are visible, the negative will be faulty. Let it dry until it appears almost free from moisture ; now darken the room ; then place it in the bath for one or two minutes, or until the iodide of silver is perfectly formed on its surface, which can easily be ascertained by raising the plate from the bath. If the surface presents a uniform ap- pearance, clear and witliout any lines or streaks like grease or oil, then it is ready for the camera: a slight motion of the plate will produce this re- sult. The time of exposure in the camera is entirely a matter of judgment and expeiience. No definite rules can be laid down; but usually, in a strong light, with the ammonia collodion and the neutral bath, from fifteen seconds to one minute will an- swer. The time of exposure can easily be ascertained by a trial plate. DE\rRLOPING OF THE NEGATIVE. 43 THE DEVELOPING OF THE NEGATIVE. This requires great care and mnch practice, for if the process in all its details is correctly followed, and only a slight variation in the developing of the image, the resulting negative will be of no avail. As soon as possible after the light has acted upon the plate in the camera, remove it to the de- veloping-stand,or it may be held in the hand, and pour the solution well filtered upon the surface, but only just enough to cover it, retaining all the fi-ee r.itrate of silver which had adhered to the plate on its removal from the bath. The silver itself acts as a means of darkening the negative. The developing solution of protosulphite of iron, on page 89, will be found the most useful, and in- deed the only one recommended for good nega- tives. After allowing this solution to remain on the surface for a few seconds, the outlines of the negative will appear. Then, if not sufficiently in- tense, pour off the develo|)er, and cover it again two or three times, until sufficient intensity is ob- tained. The negative should gradually appear first in the high light, then the drapery ; and, lastly, it should seem to fade partially away. 44 VARNISHING NEGATIVES. FIXING THE NEGATIVE. Always fix the negative in a strong solution of hyposulphite of soda. This will of course remove the iodide of silver slowly, but tlie collodion is less liable to be attacked by the use of soda than by cyanide of potassium. A saturated solution will remove the iodide of silver more readily, although a less quantity of soda will answer. It is found that whatever quantity is employed, it loses its strength on the immersion of every plate, and must be frequently renewed. VAKNISIIING NEGATIVES. In order to preserve negatives in a proper state for future use, it is ^vel] to varnish them. If they are intended only to, print a few copies, a varnisli of gum-arabic is preferable, not very thick, about the consistency of collodion. If the negative is required for many ]v/Ints, the better course would be to varnish Avitli the wliite negative varnish. All vai'nislies are poured over the j)late in the same manner as collodion, and al- lowed to dry by l)eing ]^laced on its edge, secure from dust, until it has thoroughly dried. AKKANGEMENT OF THE LIGHT. 4:5 rPvAMES OR SIIELA^ES FOR IIOLDIKG NEGATIVES. It is very necessarv that the neo:atives shuuld bo kept in some secure place ; and two shelves, hav- ing grooves in them above and belov»'-, so that the glasses shall stand on the edges in them, is the best receptacle when not in nse. Shelves of various widths, according to the size of the glasses, are required, and with a door that shall close in front of each to exclude the dust, &c. The manipulation of the negative process is so very important, that certain hints are necessary to insure absolute success. The arrangement of the light upon the sitter is of vast importance. It should fall with a full force upon the drapery, if it is of a dark color; and the background, whicli is usually of a somber hue, should also be well lio-hted up from the skvliijjht. Arrange the subject in a favorable position to pro- duce the most pleasing effect of liglit and shade upon the face — carefully attending to the pointed light upon the eyes. Avoid the long line of light' upon theuL If possible, produce a uniform light on the drapery, as that portion is more likely to be clouded than any other. The position of the camera should demand a 46 EXPOSURE OF THE PLATE. careful stnd\-. Some cameras require to be eleva- ted more than others, which can be ascertained by actual experiment. Some will work more uni- formly over the whole plate M'hen arranged in an exact line with the face of the sitter. A skylight wliich is nearly flat, or one that is slightly elevated only on one side, has been found to produce the most pleasing effects in Photog- raphy, The length of time of exposure of the plate to the action of light is a matter of vast importance, because the intensity of the negative is affected thereby — which will be seen on application of the developing agent. If too long time has been em- ployed, the print will appear flat in details ; al- though the drapery may appear distinct, the round- ness will be lost. The middle tints of the fece which are so desirable, M'ill not appear. It is better to give a short time first, and bring up the intensity by developing. A short exposure in the camera, if the developing solutions are capable of producing a powerful negative, is found to be the best for strong and vigorous eflects. The point to arrive at is to allow just long enough exposure that the developing agent shall just bring out the negative of the required intensity, and no more. GLASS FOR NKGATIVES. 47 By a trial picture giving what may be supposed nearly the exact time, if too short the augmenta- tion of the next succeeding trials will eventuall}' arrive at the correct result. It may be proper to mention, that glasses used for negatives do not require to be of such purity as those designed for positives ; even good window- glass, which is selected as free from bubbles as possible, will answer a very good purpose. The expense, therefore, for material for Photographic negatives will not be very great, and the artist can retain them for future use after one or two im- pressions have been taken, so that any future day he may produce more pictures for his patron with- out any additional sitting. CHAPTER II. THE NITRATE OF SILVER BATH FOR NEGATIVES PREPARATION OF THE SAME FORMATION OF THE IODIDE OF SILVER FOR THE NITRATE BATH ON THE PRACTICE OF THE NEGA'^^^S BATH OBSERVATIONS ON THE USE OF THE NEGATIVE BATH ON THE IN- TENSITY OF THE NEGATIVE — -COLOR OF THE NEGA- TIVE, ETC., ETC. THE NITRATE OF SILVER BATH FOR NEGATIVES. The bath of nitrate of silver, which is most com- monly in use for negatives, is that known as the nitrate bath. Great care is essential to its proper preparation, and we shall proceed to lay down the precise form to make a bath that will produce the most satisfactory results. The proportion of ni- trate of silver required to each ounce of water is usually about fifty grains, though this is not abso- lutely essential. All negative baths require a certain degree ot working or use before they will act to the best ad- THE NITRATE OF SILVER BATH. 49 vantage. They should always be combined with a portion of iodide of silver ; and even that should be added again after long use, as many times that simple remedy will remove difficulties which were deemed insurmountable. Having' ascertained the number of ounces the bath contains (see page 50), weigh out the quan- tity of nitrate of silver necessary to produce, when dissolved, about fifty grains to each ounce of water. Dissolve about one ounce of the nitrate of silver in four or six ounces of water ; then dissolve the bal- ance of the nitrate of silver which will be required to fill the bath in the remaining ^Jortion of the water. For every ounce of nitrate of silver which is re- quired in the bath to render it fifty grains to each ounce of w^ater, there must be measured out three grains of iodide of ammonia. This is to be formed into iodide of silver b}^ fii'st dissolving the iodide of ammonia in about two ounces of water, and adding thereto say two fluid drachms of the solu- tion of nitrate of silver, in which one ounce of the silver has been dissolved in four ounces of water. This will immediately throw down a yellow pre- cipitate, which is the iodide of silver. Wash this precipitate three times with water, by filling the 5 50 rilK NITRATE OF SILVER BATH. graduate dish or bottle, which should contain at least six ounces of water, and allow it to settle ; then pour off the watei', leaving the iodide of sil- ver at the bottom. When this is well washed, add it to the ounce of silver previously dissolved in the four ounces of water. Shake it w^ell, then pour the whole into the bottle containing the bath. A niilivy appearance will be seen in the bath, which is well to remain in that state for a few hours to dissolve as much of the iodide of silver as possible. After filtering the bath until it becomes clear, it is ready for use. A bath prepared according to the foregoing, if requii-ed to be of sixty-four ounces of water, would contain the following proportions : 64 X 50 = 3200 grains, or of nitrate of silver 6 J ounces. Iodide of ammonia 20 grains. Water ....... 2 quarts. There will be in 6f ounces of silver, 3240 grains, allowing 480 grains to each ounce. The above quantity will be as near 50 grains to the ounce as will be required for all practical purposes. Distilled water is preferable in all cases. Though perfectly pure, soft water will answer, if it has not been kept long in wooden vessels. If it has been so kept, it can be first boiled and filtered PRACTICE OF THE NEGATIVE BATH. 51 tlirongli paper, to remove any traces of vegetable mattei"s. By referring to pp. 133 and 131, and the sub- sequent j^ages relating to tlie preparation of the nitrate of silver bath for Ambrotypes, much valua- ble information M-ill l>e found, which can be adopted in the negative bath. The bath will require neu- tralizing, should any excess of acid accrue in it. The process of neutralizing will be found on page 137. The negative collodion, which is more frequently used with a perfectly neutral bath, as above de- scribed, is that recipe found on page 82. ON THE PEACTICE OF THE NEGATIVE BATH. The use of the negative bath requires much care and attention, for herein lies one of the elements of success in the production of perfect negative impressions. By using the ammonia collodion constantly, the bath is liable to be changed, as it necessarily must be, in its chemical character. Iodide of silver is formed upon each plate, and consequently less sil- ver is contained in the solution, and alcohol is added to tlie compound from tiie collodion, as well as a trace of ether. It will soon be found to be 52 PRACTICE OF THE NEGATIVE BATH. slightly acid in testing with litmus-paper. This acid tendency sometimes is not objectionable ; but if there is too much of it, neutralize the bath, and- test with a hydrometer to ascertain the strength of silver. Always keep the strength equal to fifty grains to the ounce. In adding more silver to the bath, it may be effected more readily by first dis- solving the quantity required in a separate bottle from the one used expressly for the nitrate bath. Filter always before adding to the bath. Always be provided with two bottles, having glass stop- pers sufiiciently large to hold the contents of the nitrate bath, into one of which it may be filtered. It is recommended also to add silver often to the bath, if it is in constant use, because if the greater portion of the solution is removed (as some must necessarily be every time a plate is immersed) by adding a large quantity, the whole nature of the bath is changed. Many operators provide themselves with sufii- cient solutions for two or three baths. This is a plan highly recommended, as a bath actually im- proves by age, even if it is not worked every day. Old baths which have been laid aside as useless except for restoration, have, after many days, on a new trial been found to produce good results. PRACTICE OF THE NEGATIVE BATH. 53 There is a constant change taking place in the ni- trate baths, and there are many phenomena con- nected with them wholly unexplained as yet by the most successful operators. Sometimes an acid bath will work more surely for negatives than a neutral, and sometimes a neutral bath is preferred. The general rule to be observed is, that, if a bath is acid, the time of exposure in the camera is lengthened, and as we approach the neutral point the time is lessened. Therefore to work a bath as nearly neutral as possible, is the most sure of success. In order that the negatives should produce good positive pictures on paper, they should be very ti-ansparent in the dark portions, such as the dra- pery, &c., and of such intensity in the light parts that a ray of light can with difficulty be trans- mitted, and this must be combined with a regular gradation in the middle tints. These desirable results can be attained by using the collodion somewhat thicker for the negatives than for positives or Ambrotypes, as thereby a thicker deposit of silver is obtained on the surface of the glass. Also a stronger nitrate bath, and using it as nearly neutral as possible, and a longer exposure 5* 54 THE COLOR OF NEGATIVES. in tlie camera, together with less acid in the de- veloper; all these combined will produce the de- sired end, viz., an intensitji such as will print posi- tives having all the beauty ao much desired in good Photographs. The absolute intensity, how- ever, of a negative does not always depend upon the thickness of metallic silver, but to a certain ex- tent upon the color it may have when seen by transmitted light. Negatives also vary in color; some are translucent and of a bronze color, others are of a bluish-black, whilst some are of a gray color. The color most to be sought after is the bluish-black, because these are found to print more uniformly clear in their details. Sometimes the best negatives are those which may appear to be weak, because the chemical rays are more obstructed, and the print is consequently more uniform in its gradations of light and shade. Tlie color of the negatives depends on certain conditions of the bath, the time of exposure in the camera, the nature and strength of the developer, and the quantity of acetic acid contained in it. Sometimes the presence of organic matter, which wall collect in the bath, may affect the color and tone of the negatives. So that no positive rules can be laid down for the continued action of a UNCEKTATNTIES IN TIIIC ART. 55 bath ; practice alone must be the teacher in this branch of the art. Seeming uncertainties may appear to some who have not had much experience in the art as obsta- cles of great moment. But they will all vanish after a short time. These apparent contradictions and perplexities are only met with for any length of time in the experience of those persons who do not attend to the minute details of the art, such as cleaning well the plate, decanting the collodion, the proper length of time of developing the pic- ture, &c. The practice of this beautiful art must not be condemned because it contains a few seem- ing contradictions ; for if it was easily acquired, and always certain of success, there would be no incentive to excellence, and those persons who pos- sessed only a limited taste and experience, could rival the artist in the creations of his genius. It may therefore be deemed a fortunate circumstance to those who would wish to excel, that the road to full success lays through a few rugged passes, and lie who would reach the goal of perfect accom plishm^ent must encounter some difficulties. CHAPTER III. ON PHOTOGRAPHIC PRINTING SALTING SOLUTIONS SALTING THE PAPER SILVERING THE PAPER WITH AMMONIA NITRATE OF SILVER PLAIN SILVER SO- LUTION TO PREPARE THE ALBUMEN FOR PAPER POSITIVES SILVERING ALBUMEN PAPER ON THE PRACTICE OF PRINTING NEGATIVES TONING OR FIX- ING THE PRINT WASHING THE POSITIVE PRINTS — DRYING TIIK PICTURES VARNISHING AND MOUNT- ING THE PRINTS. The printing of the Photographs is that por- tion of the art wherein o-reat care and attention is demanded, and where much of the beauty and fin- ish of the picture is due. The success of it de- pends upon a perfectly proper understanding of the process. Having selected the best quality of paper, it may for convenience be cut into sizes such as will be required for use in the printing frames. Though this is not absolutely necessary, the large sheets, as they are manufactured and imported for use, can THE SALTING SOLUTIONS. 57 firet be salted, dried, and laid aside in some secure place, free from dust or fumes of chemicals. When wanted for use, they may be cut of what- ever size may be required. THE SALTING SOLUTIONS. One quart of pure soft water. 90 grains of liydrochlorate of ammonia, or common sal n.mmoniac. (Sal ammoniac is found to be the best preparation of salt, as it contains less impurities than any other known.) Dissolve and filter. Place this in a large flat dish, which may be of gutta-percha, earthenware, or porcelain, or even wood, if it is varnished thoroughly with gum-shel- lac varnish. The dish must be nearly tilled, and of sufficient dimensions to admit the whole sheet of paper if laid in it. The paper is to be immersed one sheet at a time, by laying hold of tlie sheet at two corners, and it must be drawn quickly through the solution twice, allowing the liquid to wet it as it may on the surface of the paper only, in effect to lay the solution of salt upon its surface without disturbing the fibres of the paper. Hang each sheet up separately to dry in a room free from dust or any chemical exiialations. The 58 SILVERING THE PAPER. better plan of suspending paper, either in the salt- ing or silvering process, is to use the yjatent clothes-pins, which can be arranged on a cord across the room. Great care should be observed in salting the paper to avoid stains, spots, or wrin- kles. The hands should never touch any portion of the paper except the corners. The salted pa- pers can be laid aside, and will keep for a great length of time. SILVERING THE PAPER. The paper already salted and dried, to be sil- vered, may be effected by two or three methods. The ammonia nitrate solution, the preparation of which is described on page 95, is the one mostly in use, and one that will produce, with plain salted paper, the most pleasing results. The silver solution Mhich may be required for use at one time, is first filtered into a clean bottle, and the paper laid u^^on a flat surface, covered with paper or card-board, is to be fastened down by the corners with pins or any other article which will cause it to remain stationary. The silver so- lution is then poured on the middle of the paper, enough to cover it ; and with a ball of cotton just newly prepared, carefully spread the silver over PLAIN SILVER SOLUTION. 59 the whole surface, by means of round lines or cir- cles, from the centre of the paper to the circum- ference. Tlio superfluous silver can be poured into a bottle, but not used again, as it is changed into a chloride of silver, owing to its contact with the salt of the paper. It may be reserved in the bot- tle, to mix with other silver solutions, that are use- less except for the restoration of the pure silver, as described on page 105. The same ball of cotton can be employed to silver all the papers that may be wanted at one time, if it is laid on a clean piece of paper, but a new one will be required for a sub- sequent preparation. Tlie silvered papers should be hung up to dry in ,a dark room, and only enough prepared that may be wanted for immediate use. In the winter sea- son, however, they can be used for two or three days after preparation, if kept carefully excluded from the light, in a portfolio or drawer. PLAIN SILVER SOLUTION. This can be used with the prejjared chloride of sodium paper, sold by dealers in Photographic materials, and consists of dissolving 2^ ounces of nitrate of silver in twelve ounces of water. This 60 TO PREPARR ALBUMEN PAPER, is also used for silvering the albumen paper, whicl is prepared as described on page 61. TKe chloride of sodium paper and tlie albumen paper is silvered by laying each sheet separately on the silver solution, contained in a flat dish, and allowing it to float for five minutes, care being ob- served that no air-bubbles collect under the paper. The silver solutions must always be filtered through cotton before applying them to the paper. It is only necessary to filter such quantity as may be wanted for immediate use. The bottles containino; the silver solutions should be blackened over with black asphaltum varnish, to exclude the light, and always kept as much as possible in a dark place. Papers maybe silvered in a light room, though not where the direct rays of the sun can Ml on them. TO PEEPAEE THE ALBUMEN PAPER. Take the whites of three or four fresh eggs, and beat them with a glass rod or flat piece of glass until the article l)ecomes of a frothy consistency. Remove the froth, and j)lace it in a cool place, and allow it to return to its liquid state again, in a long bottle. Pour off the clear portion of this, and add to SILVERING ALBUMEN PAPEE. 61 every fluid ounce say from one to four ounces of water, according to the strength of albumen that is required. To each ounce of this fluid of albu- men and water, which will readily combine, add fifteen grains of hydrochlorate of ammonia : filter. For salting paper with albumen, it should be floated three or four minutes. Thin paper is gen- erally preferred for the purpose. SILVEEING ALBUMEX PAPER. Albumen paper must always be silvered with plain silver, of the proportions given on page 59. It must also be floated on the surface of the solu- tion for four or five minutes, never brushed in, as in the ammonia niti-ate process. After using this silver solution with the albumen paper, there will a milky appearance be observed, which can readily be removed by mixing a small quantity of kaolin or china-clay with the silver, and, before using it, filter it clear. If the proper manipulation is attended to in the use of the albumenized paper, the results will be far more pleasing than by the ammonia nitrate process. The trouble and time required, how- ever, is much greater in the former than in the latter. Therefore the ammonia nitrate is generally 6 62 PRINTING FROM NEGATIVES. adopted by the profession as more certain in its results. PEINTING FKOM NEGATIVES. The usual time required to print a picture from a good negative, under the most favorable circum- stances, is about four minutes. It is proper to state, however, what are the most favorable cir- cumstances. They are good paper, good silvering solution, and a clear sun-light, with all the neces- sary details of the practice carefully followed, as in the foregoing directions. Negatives may be printed with a subdued light, and printed well, as there are many cloudy days when the prints are wanted. Of course, the time of exposure must be prolonged, and even an hour may sometimes be required to produce the neces- sary depth of color on the paper. The color which is to be obtained on the print before it is ready to remove from the printing frame, is of considerable importance. The best prints are generally those which are left long enough to assume a depth of shade nearly the in- tensity that may be wanted when finished and dried, rather darker than the color desired, in or- der that the time occupied in the toning bath shall TONING OR FIXING THE PKINT. 68 fix the color, to lighten the shades only in a slight degree, • Prints that are too dark on removal from the printing frame, can be rendered sufficiently light by a long action of the toning bath. But such prints will be the more likely to assume a yellow hue, and ultimately fade. The shortest time in the toning bath to produce the desired shade and color is recommended. Therefore prints should not gen- erally be overdone or over-printed when one toning bath is used. Tlie kind of j^rinting frames recommended are described on page 109. After the picture is removed from the printing frame, it must be carefully excluded from the light, by jjlacing it in a portfolio or drawer, or where no vapors can reach it. A number of prints may be jsrepared and laid aside, and all toned or fixed at once. TONING OR FIXING THE PRINT. The beautiful tone or color of the prints in their removal from the jDrinting frame, has been a sub- ject of remark by many operators, and various efforts have been made to preserve that most to be desired color, yet it lias never been accomplished. 64: TONING OR FIXING THE PKINT. As soon as the fixing solution comes in contact with the paper, a great change takes phice, which does indeed arrest tlie progress of the light, but produces another and entirely diverse change. As the art j)rogresses, some devotee may luckily ar- rive at the discovery of fixing the exact tone and color seen on its removal from the printing frame. The first operation of toning the picture is to place it in a bath of clear water, in a dark room, of course, or in a salt solution of two or three ounces of salt to one quart of water. This removes all the chloride of silver not acted upon by the light. They should remain in the salted solution only a short time, say one or two minutes, then place them in a bath of pure water to remove the superfluous salt. This plan of first placing the print in a solution of common salt may be omitted. It may be placed immediately on removal from the frame into the toning bath, or it may be laid in a portfolio, and excluded entirely from the light for several hours, then placed in the toning bath. After which they may be brought out in the light and placed in the toning bath, as found on page 94, and allowed to remain there until the desired color is attained, wliich will vary according to the strength of the bath and the depth of the print — WASHING POSITIVE PRINTS. 65 generally from ten to thirty minutes for ordinary prints, yet sometimes one or two liom's are neces- sary. They must be carefully watched in the bath, and as soon as sufiicient time has elapsed to produce the desired tone, remove them to a bath of clear water. WASHIN'G POSITIVE PEI^TS. This portion of the photographic jDrocess is of great importance, for unless the prints are well washed, so as to remove every trace of hyposul- phite of soda, they will invariably fade or turn yellow. Various methods are adopted to remove the hyposulphite, but the plan most likely to in- sure that result is of course recommended. The longer the jjrints remain in the water, and the oftener they are changed, will of course more eft'ect- ually remove the destroying agent. Strange, in- deed, that the very substance, hyposulphite of soda, which adds so much beauty to the Photograpli, should be the very one to cause its destruction. The most expeditious method is to place the print on a piece of plate-glass, and allow a stream of water to fall upon it for a few minutes. Then press it between clean white blotting-paper, re- peating the operation two or three times. It has 6* 66 WASHING POSITIVE PRINTS. been found that tlie oftener the water is changed in the washing process, the more beautiful the tones of the prints. Nor slioukl they remain for any great length of time in one vessel of water. The better plan to adopt, when it is possible, is to place the prints in a flat dish or tub, where they will float, and where a constant stream of water is running in, and of course another stream dis- charging as fast as the supply is given. A very small stream will suSice. By the foregoing ar- rangements, all those spots and stains so frequently met with will be avoided. The washing of Photographs may sometimes be completed by placing them in a large vessel of water, and allowing them to remain for several hours. This can only be done after they have been first immersed in several changes of water, say five or ten minutes in each. Still another plan of removing the hyposulphite of soda is highly recommended in the immersion of the prints in wariti water. By changing it often M'ith cold water, and allowing it to remain for about an hour in warm water, it will most effectually remove the traces of the soda. Lastly, press each print be- tween two thick pieces of plate-glass, and hang them up to dry. MOUNTING THE PICTURE. 67 All these various methods are adopted by the profession, and the successful operator will follow those most convenient of practice, carefully observ- ing, in order to produce excellent results, that the prints shall not remain more than ten minutes in the first or second bath of pure water, because the chemicals which pass into the water, and are so necessary to remove in order to fix the impres- sion permanently, are likely to injure the beauty and tone of the picture. DRYING, VARNISHING, AND MOUNTING THE PICTURE. The prints may be hung up in the clothes-pins to dry, but not in the sun. As soon as they are well dried, place them in a portfolio, or between leaves of white paper, and press them under some object, so that they shall not wrinkle. They are then ready for mounting and varnishing. The varnish for pictures is made as described on page 100, and may be laid on the picture before it is cut in the shape required, or it may be eflTected after it is on the card-board. A solution of dextrine, prepared as described on page 104, is the best for holding the print in its place ; yet simple gum-arabic will answer if it lias 68 MOUNTING THE PICTURE. been thoroughly strained and cleared of all parti- cles of dust. Tlie shape of the print may be made by laying a mat or border over it of any desired size, then marking with a pencil, and afterwards cutting it carefully with the scissors. Or it may be laid on a piece of plate-glass, with the mat laid over it, and cutting it into shape with a sharp penknife. In pasting the print upon tlie card-board, great care must be observed that no wrinkles are allowed on the surface, as they will invariably injure the print. After the prints are pasted on the boards, they should be laid under a pressure, so that great smoothness of surface shall be attained. A warm flat-iron is sometimes used with good success, by laying a piece of white paper over each print, and carefnlly pressing it smooth. CHAPTER IV. TO COPY daguerreotypp:s and other pictures into PHOTOGRAPHS ON ENLARGING PICTURES TO EN- LARGE PICTURES FROM DAGUERREOTYPES, AMBRO- TYPES, OR PHOTOGRAPHS AND TO PRODUCE PHO- TOGRAPHS FROM THEM TO MAKE LIFE-SIZE PHOTO- GRAPHS ON PAPER IRON PHOTOGRAPHS, OR IN- STANTANEOUS PRINTING ON TAKING STEREOSCOPE PICTURES, PHOTOGRAPHIC VIEWS, ETC., ETC. The copying of Daguerreotypes into other Da- guerreotypes, lias long been in practice. Latterly they have been successfnlly copied into Ambro- types and Photographs. But Photography has gone still further, and life-size pictures are now produced which, wlien painted by the skilful art- ist, have rivalled the creations of most painters, both in the correctness and faithfulness of the like- ness, which must needs be intallible. The last great achievement of the Photographic Art, is the production of life-size, full-lengtli por- 70 ENLAKGEMENT OF PICTURES. traits. This is accomplished by the means of the new solar camera, lately introduced, which bids fair to supersede all other methods of enlarging pictures. Those who may not possess the new solar camera, can adopt the following process, which will be found very useful and practical. TO ENLARGE PICTURES FROM DAGUERREOTYPES, AMBROTYPES, OR PHOTOGRAPHS— AND TO PRODUCE PHOTOGRAPHS FROM THEM. The following apparatus will be required for the process, viz. : One quarter-plate tube, and lens. One whole-plate camera box. One or two mirrors to be used as reflectors. One camera box, capable of holding a glass 14 by 17 inches. The pictures or portraits more frequently re- quired to be enlarged are the ordinary Daguerreo- types, from the fact that these are the kind of por- traiture the longest in use. Many are desirous of obtaining portraits of their deceased friends, life- size, and the demand for that class of pictures is consequently greater than any other. The plan more easily adopted, is first to take a negative from the Daguerreotype of the ordinary p;nlargement of pictures. 71 half or wliole plate size, which is effected by the use of a quarter-plate tube on a whole-size camera box. Place the picture to be enlarged, whether it be a Daguerreotype, Anibrotype, or Photograph, in the direct rays of the sun, or by reflecting the sun upon it with a mirror, then bringing the camera box as near the picture as will be required to produce the desired size ; the focus being taken, a negative can easily be obtained by exposure of thirty seconds to a minute and a half. The nega- tive should be as large as possible if on a half- plate, in order that it may be enlarged to life size by the next operation. From the print now obtained, which must be first pasted on a card-board, another negative can be produced, either of the cabinet or life size, with the quarter tube attached to the camera box, which must be capable of holding glasses of 11 by Itt inches, and 14 by 17. Place the pictures in the direct rays of the sun, or use a reflector as before, and any size may be taken, up to the size of life, — showing, of course, only the head and shoulders. The print from this negative M'ill not be so dis- tinct in the outline as though it was taken from life ; yet it will retain all the outline and suflicient of the details for all purposes of painting, and it 72 ENLARGEMENT OF PICTURES. may be printed either upon paper or canvas with the same facility as ordinary Photographic jjrint- ing. In order to insure a more perfect negative, it may sometimes become necessary to use more than one mirror as a reflector of the sun's rays upon the surface of the picture. The more powerful the re- flection the more distinct will be the negative. Tlie re-developing with bi-chloride of mercury, as given on page 92, is highly recommended in this process. A negative may be taken without the direct rays of the sun from any picture; but, in enlarg- ing, the i)owerful light of the sun is deemed al- most indispensable, as it greatly facilitates the pro- cess, and renders the time required much shorter, and secures a more intense and definite neo-ative. Should the Daguerreotype be an imperfect one, as is frequently tlie case, of course all the imper- fections will be magnified, yet they can be entirely removed by the skill of the painter. The usual time required for taking the negative, life-size, will vary from a minute to ten minutes. In consequence of the large size and the long dis- tance of the ground glass from the lenses, the time of exposure in the camera is greatly augmented. IRON PHOTOGRAPHS. 73 IRON" PHOTOGRAPHS, OR INSTANTANEOUS PRINT- ING OF NEGATIVES WITH A DEVELOPER. A process has lately been introduced for print- ing negatives, with the use of a preparation of iron : hence the name Iron Photographs. This process, liowever, is a revival of an old one. It will be found very useful on many occasions, when expedition is required, as a negative may be taken and the positive picture printed, washed, toned, and dried in the same time as an ordinary Ambrotype. The process is as follows : Water 1 pint. Citric acid 1 ounce. Ammonia citrate of iron . . . 1 ounce. Concentrated ammonia . . .1 ounce. Mix these ingredients, and filter, and keep in a glass-stoppered bottle, excluded from the light of day. Apply this solution with a flat camel's-hair brush on one side only of the photographic paper, care- fully laying it on even by brushing it in both di- rections. Then hang it up to dry in a dark room. When dry, it may be cut ijito suitable sizes for printing, and kept in a portfolio. The paper will assume a yellow color. Print with the ordinary 7 74: THE TONING BATH. printing frames, but only for a short time, until the faint outlines appear. Remove from the printing frame, and apply the developing solution either by immersing in a flat dish, or pouring it on the pa- per after laying it upon glass. THE DEVELOPING SOLUTIOK Nitrate of silver . . . . j ounce. Water 1 pint. Aqua ammonia ...... | ounce. Filter the solution, and use over again. THE TOXING BATH. Hyposulphite of soda .... 1 ounce. Water 1 pint. Nitro-muriatic acid . . . .10 drops. "Wash the print well after developing, and place it in this toning bath for a short time, and the color will be changed from the deep reddish hue that it has assumed by the developer, to a purple color. The print must now be washed quickly in three or four waters, and placed between sheets of blot- ting-paper, and dried by the spirit-lamp. Should the tone not be desirable, a modification of the toning bath may be made by changing the propor- tions of hyposulphite and the addition of chloride uf gold. The tone maybe improved snmetimes bv THE STEREOSCOPE. 75 exposure of the print for a few seconds to the di- rect rays of the snn. The addition of a saturated solution of gallic acid to the developer, in small quantities, will change the tone ; but it cannot be used over again. Therefore only mix enough for each print as it may be required for use. The sepia tone may be given these prints by omitting the hyposulphite bath entirely, merely washing them in water thoroughly after develop- ing, but they will be more liable to fade. Photographs by this new process may be printed from a weak negative, and even an ambrotype im- pression will answer. The tone of the prints will not be equal to those printed by the old process ; but sometimes expedition may be required, and Photographs can be taken and finished as soon as Daguerreotypes or Ambrotypes. THE STEREOSCOPE. Stereoscope pictures are considered by some operators as the most valued of the productions ot the Photographic Art. If they are properly exe- cuted, they are indeed the most curious and in- structive of any branch of Photography, though they have not received that attention in this coun- try which they have merited, — mainly, however. 76 THE STEREOSCOPE. from the fact that few operators have devoted much attention to their production. The most pleasing are Photograph views. The stereoscope is an instrument invented by Prof. Wheatstone, for combining two slightly dis- similar images, so that out of two flat pictures one apparently real or solid object is produced — having all the projections, concavatures, and other pecu- liarities of the object itself, and standing out in all the strength and solidity of an actual tangible ob- ject. Tlie reason why two flat images should produce the effect of solidity, and a slight consideration of the best means of producing these flat pictures, so that they shall produce in the most proper manner this extraordinary result, will now be given. Ordinary vision may be considered under the two heads of Monocular, or vision by one eye, and Binocular, or vision by two eyes. If we look through a telescope, microscope, or single opera- glass, or close one eye, we have monocular vision ; and by using two eyes, or spectacles, or double opera-glasses, we have binocular vision. Let us first consider monocular vision. If we close one eye and look at objects, we perceive them by their forms, sizes, colors, and gradations of light TIIK STEREOSCOPE. 77 and shade ; and reason and experience tell us that these appearances vary as the objects are near or distant from us. We find that as objects recede they become smaller, apparently, in size, and this decrease in size is according to fixed laws, upon which perspective is based. We also observe that light and shade are less marked, the colors less brilliant, the details less clear, and the whole of the objects less distinct; and according to these changes do we estimate relative distances. Upon this principle the artist, in his landscape, paints his distant objects small, vague, and indistinct, while the foreground is brought out strongly with abun- dance t)f detail; and in proportion as this is done skilfully, we admire it as an imitation of nature. There is, also, another means of judging of distance. The eye, like other optical instruments, has con- stantly to change its focus, according to distances to which it is directed, and this change of focus is another means of estimating distance. Stereoscopic pictures may be taken either with one or two cameras. If the object be still-life, a statue, or edifice, then one camera will do better than two, for you may set the camera at any point and work away until you produce a satisfactory impression. Having o])tained that, move the 78 oTHE STEREOSCOPE. camera to the other point of view, and again work until you have achieved your object. But if you should have a picture of living objects to take, it is very desirable to produce the two pictures simul- taneously by two cameras ; for taking a view of a street, for instance, where figures are accidentally introduced, you might have them in one picture and not in the other, or misplaced, unless you ob- tained both pictures at the same time. But for portraits, though it is desirable to take both im- pressions at once, it is not necessary. And now comes the important inquiry, how far removed should the cameras be from each other in order to produce the best effect ? or, in other words, how wide should the stereoscopic angle be ? This is a question often put, but not so easily answered. Strictly speaking, the natural standard may easily be cited, and an answer based on it be given. The eyes are 2j inches apart, and as each camera is to represent an eye, the centres of tlie two lenses should never be more than that separated. This is the strict theoretical doctrine laid down by Sir D. Brewster, nevertheless it is very seldom adopted in practice. It has been stated, tliat the more dis- similar the two stereoscopic images are, the greater the relief, ISTow, dissimilarity of image is obtained PHOTOGRAPH VIKWS. 79 by widening tlie distance between the two came- ras, and the greater the width or angle the greater tlie relief. As the stereoscope is chiefly valued for the production of this relief, the generality of stereoscopic pictures have been and are taken at too wide an ano-le, so that monstrous instead of natural relief is the result. If two pictures are taken at the same angle, no relief is obtained but that which is due to the magnifying power of the lenses. Increase the angle a little, and still greater relief is jiroduced ; increase the angle still more, and so on until you have passed the angle that produces natural relief, and reached that wdiich produces monstrosity. ISTearly all stereoscopes will have more or less of imperfection in the detail, owing to the fact that no two pair of eyes view the same pictures in the same focus. Hence we And some persons who cannot see the stereoscope pictures at all. PHOTOGRAPH VIEAYS. Yiews b}^ the Photographic process are attract- ing the attention of the artists in this country, and deservedly so. They are easily taken, because an ample supply of light is always obtained. Tlie only objection is the necessity of transporting the 80 PHOTOGRAPH VIRWS. various solutions to the localities where the view is to be taken. This difficulty is overcome by the new dry processes which have been published lately. The albumen process on paj)er, page 61, is highly recommended for views, as the tone of those pictures is more appropriate for this style of Photographs. It is not necessary here to enter into the details-, of the processes. Suffice it to say, that the same collodions are to be used, and the same developers, as in the process for taking portraits. The lenses of the ordinary camera, however, must be changed to convert it into a view camera. It is done simply by removing entirely the set of lenses in the rear of the tube, and placing the front lens in their stead, and reversing them. It will also be necessary to put a diaphragm, with a very small opening, in front of the tube, or near the location of the front lens. The time of exposure required in the camera with a small diaphragm, will neces- sarily be somewhat extended in order to produce vigorous negatives. The use of the diaphragm is absolutely necessary in order to correct the perspec- tive of near and distant objects. Also to cut ofi*a portion of the diffused light, which would other- wise injure the negative. CHAPTER V. ON THE PREPARATION OF NE;GATIVE COLLODIONS THE FORMULA FOR NEGATIVE COLLODIONS MIXING VARIOUS COLLODIONS DISSOLVING THE IODIDES DOUBLE IODIDE COLLODIONS THE CELEBRATED GER- MAN PROCESS COMPLETE THE NEGATIVE DEVEL- OPING SOLUTIONS RE-DEVELOPING PROCESS BI- CHLORIDE OF MERCURY AS A RE-DEVELOPER FIXING SOLUTION THE TONING BATHS — THE AMMONIA NI- TRATE OF SILVER SOLUTION. This chapter will be devoted to careful and de- tailed formulae for the preparation of the negative collodions, the developing solutions, and including all the various receipts necessary to be well under- stood in the practice of the Photographic Art. Indeed, this chapter will assume one most en- tirely of reference, and, as will be seen, it must frequently require mention in other portions of this work. 82 CADMIUM COLLODION. NEGATIVE COLLODIONS. For the preparation of negative collodions, we shall only give the proportions. The manner of dissolving the sensitive chemicals will generally be left to the judgment and experience of the operator, THE AMMONIA COLLODION. No. 1. Plain collodion ... 1 ounce. Iodide of ammonia ... 6 grains. Bromide of ammonia . . 3 grains. With the nitrate of silver bath neutral, and of a strength of 50 grains of silver to each ounce of water. CADMIUM COLLODION. No. 2. Plain collodion ... 1 ounce. Iodide of cadmium . . 7 gi'ains. Bi-omide of cadmium . . 3 grains. Nitrate bath 50 grains to the ounce. This collodion is greatly in use in warm climates. No. 3. Plain collodion ... 1 ounce. Iodide of potassium . . 8 grains. Bromide of ammonia . . 3 grains. Bath of 40 grains to the ounce. This collodion is highly recommended for nega- tives when combined equally with the ammonia THE COMPOUND CADMIUM COLLODION. 83 collodion JSTo. 1. It will be found to work in some baths when no other collodion will succeed. It may be used also for Ambrotypes. The practice of the most successful operators has taught them that the mixino; of two collodions of diverse proportions, and made of different chemi- cals, will be found the most useful, and work with more certainty. The author himself would, there- fore, enjoin this hint upon those who may practice from the foregoing formulae. THE COMPOUND CADMIUM COLLODION. No. 4. Plain collodion ... 1 ounce. 6 grains. Iodide of cadmium Bromide of cadmium Iodide of potassium Tincture of iodine . 3 grains. 5 grains. 5 drops. Nitrate bath of 50 grains to the ounce. The bath to be iodized witli iodide of cadmium. Dissolve tlie iodide of jjotassium in water, and the cadmium in alcohol. The foregoing collodion is the one highly recom- mended for use, especially in warm latitudes. It is the most durable, and it improves by age, re- taining its working qualities for several mpnths. The author has adopted the cadmium collodion, in many instances w^ith great success, especially when 84 DOUBLE-IUDIZKD COLLODION. it is combined in eqnal parts with the ammonia collodion No. 1. To unite the sensitive ingredients with all collo- dions, it is recommended to dissolve them first in a small quantity of alcohol when they are soluble in that substance, and only use water when they will not otherwise dissolve. Always dissolve the bromides first, and add the iodides to the same solution. The iodide of ammonia and bromide of ammonia will dissolve in alcohol if a small quan- tity of water is added. Iodide and bromide of cadmium will dissolve readily in alcohol alone. A DOUBLE-IODIZED COLLODIOK The following formula is compounded in a dif- ferent manner from any other, and is one that is highly recommended. Prepare two bottles of col- lodion separately, as follows No. 1. Plain collodion Bromide of potassium Iodide of potassium. Ko, 2. Plain collodion Iodide of ammonia Iodide of cadmium 1 ounce. 5 grains. ) Dissolved 8 grains. ) in water. 5 grains.) 3 grains. ) Dissolved grains. S in water. 'No. 1 will produce clear negatives, and perhaps rather weak. No. 2 will produce one very intense. TO SKNSITIZK THE COLLODION. 85 But mix these two collodions in equal proportions after they have well settled, and the most perfect half-tints are obtained. Should it be desirable to produce a negative of more intensity, use a larger proportion of No. 2. In like manner, if a mixture of equal proportions produces too much intensity, then increase tlie quantity of No. 1. It will be found on using the two collodions above, separately, that as one will produce a weak negative, and the other a deep one, they can be so modified by uniting them in the proper proportions, that any degree of intensity may be obtained. THE GERMAN PROCESS. The following method of preparing negative col- lodion has been found to be very excellent in its results, and is known as the German process, so modified and rendered practical that any operator can work it successfully. The plain collodion is to be made with 10 ounces of ether and 5 of alcohol, rendered of the requisite consistency by the addition of gun-cotton. TO SENSITIZE THE COLLODION. Nitrate of silver dis-!olved in water . 50 grains. Iodide of ammonia dissolved in water 40 grains. Mix the two solutions, and wash the precii^itate 8 86 NITRATE BATH. * in several waters ; lastl}^, wash in alcohol. Then make the following compound : Alcohol at 95° . . . 2 fluid ouQces. Iodide of ammonia . . 100 grains. Bromide of ammonia . . 40 grains. When dissolved, add the iodide of silver, and agitate the whole for several minutes ; -then filter through common filtering-paper, and add the liquid to 20 ounces plain collodion; agitate the collodion for a short time, and add to it as follows : Fluoride of ammonia ... 40 drops. Tincture of iodine .... 10 drops. This iodized collodion may be used in 12 hours, but is much improved by standing 3 or 4 days. The tincture of iodine used in the collodion is simply a saturated solution of alcohol at 95°, with pure crystals of iodine. NITRATE BATH. Distilled water .... 56 fluid oz. Nitrate of silver . . . 4i oz. by weight. Dissolve the silver in 8 oz. of the 56 oz. of water. Then add iodide of aTumonia . 10 grains. "White sugar or rock-candy . 120 grains. "When dissolved, add the remainder of the water, and in this condition let the bath stand 12 hours; KE-DEVELOPINQ. 87 then filter through common filtering-paper, add 30 drops glacial acetic acid, and it is fit for use. DEVELOPING SOLUTION FOR NEGATIVES. Pure soft watei- . . . .16 ounces. Sulphate of iron .... 1 ounce. Alcohol at 95° .... 1 ounce. Acetic jfcid, No. 8 . . , . 2 ounces. First dissolve the iron, then add the remaininof properties, and when filtered it is ready for use. FIXING SOLUTION. • This is simply an}'- quantity of water saturated with hyposulphite of soda. PvE-DEVELOPING. The negative is re-developed after it has been cleared up. Make a saturated solution of gallic acid in distilled water 1 ounce, then add 30 drops of the folio win o; solution : C5 Distilled water .... 1 ounce. Nitrate of silver .... 35 grains. When this solution is filtered, it may be used as follows :— After the negative has been fixed and washed, pour on it of the re-developing solution a quantity sufficient to cover the plate, and keep it 88 NEGATIVE DEVELOPING SOLUTIONS. on until tlie required intensity is obtained, then wash with water and dry. In developing and re- developing, the solutions must be kept gently and constantly moving on the plate ; for if allowed to stand still, or to remain for any length of time on one portion of the plate more than on other parts, the plate is liable to lines or streaks. -^ This re-developing process is not recommended, and if the collodion and bath are properly made, need never be adopted except it may be in dark weather, or when a child's likeness is taken. For it will always be found that the resulting negative is never so well adapted for printing. There- fore, as soon as one finds that he cannot pro- cure negatives sufficiently intense in an ordinary exposure without re-developing, he may be assured there is some portion of his chemicals at fault. The first opportunity should be embraced to reme- dy the difficulty : first, by changing the nature of the nitrate bath, then the collodion and developing agent. ^ THE NEGATIVE DEVELOPING SOLUTIONS. The developing solutions which are required for the negative pictures are not very numerous. The one mostly in use is composed of protosulphite of NEGATIVE DEVELOPING SOLUTIONS. 89 iron and acetic acid. With this alone, and the various modifications, all the different varieties of negatives are produced in this country. In Europe the developing solutions mostly in use are com- posed of pyrogallic acid. The developing process must be thoroughly un- derstood before good results can be obtained. And, firs|, the nature of the collodion and the ni- trate bath must be known in order to form the de- veloper so as to produce the best results wnth that combination. The following formula will be the best adapted for working the neutral bath of 50 grains to the ounce, with the ammonia or cadmium collodion, as prepared on page 82. Protosulphite of iron ... 2 ounces. Water 1 quart. Acetic acid, ISTo. 8 .... 6 ounces. The iron is first dissolved in the water and fil- tered, and the acetic acid is added in the above proportions, but only as it may be required for use. It will not develop properly if mixed and al- lowed to remain for several hours. It may some- times require a small quantity of alcohol to cause the solution to flow evenly over the plate. But the ■addition of flic alcohol lessens the intensity of the picture, therefore it is best to avoid its introduction 8* 90 EK'DRVELOPING TROCKSS. as much as possible. Indeed, its use lias been aban- doned by good operators. By increasing the quantity of iron, the develop- ing process proceeds more i-apidly, and by lessen- ing the quantity of acetic acid it is modified. In order, therefore, to ascertain the requisite quantity of each ingredient that may be necessary for the particular combinations of collodions and baths, it will be proper to vary the projDortions of iron and acetic acid. By a few changes in the proportions, and a few trials, nearly all varieties of collodion may be made to produce a good negative, if the bath is of the requisite strength and all other due proportions are observed. There will, however, be found another formula for re developing negatives on page 91, which is given in addition to the foregoing mainly with a view to enable any person to obtain an intense negative, even if theii' chemicals are not properly combined. RE-DEVELOPING PROCESS. Frequently the negatives, after being developed by the foregoing solutions, will not assume that degree of intensity that is desired. They may still KE-DEVELOPING PROCESS. 91 be made more intense by continning the process of developing in the following manner : Prepare two solutions as follows, viz. : No. 1. "Water 8 ouuces. Protosulphite of iron . . 2 ounces. Dissolve the iron and filter. The second solution is as follows : No. 2. Nitrate of silver . . . ^ ounce. Water ..... 8 ounces. The re-developing is attended with some diffi- culty, as there is great danger in producing lines or streaks on the negative. The following cautions must be observed : — Af- ter the first process of developing, wash carefully with a large quantity of water, still keeping the plate in the dark room upon the levelling-stand, or in the hand, and pour over its snrface enough of the solution No. 1 to nearly cover it ; then quickly pour enough of No. 2 to mix with it npon the plate, which must have a little motion in order to flow over the whole j)late as quickly as possible. It will be seen that no perceptible action takes place on the application of the iron solution ; but as soon as the silver is added, a quick and energetic action commences, and the intensity is increased to any 92 BICTILORIDK OF MKRCURY. desired depth. Great care must be observed not to continue this process too far, as the negative will become too intense, and full of lines and streaks. As soon as sufficient intensity is produced, wash quickly with water all traces of the developer. BICHLORIDE OF MERCURY AS A RE- DEVELOPER. Make a saturated solution of bichloride of mer- cury, and always have it in readiness in a glass- stoppered bottle. This can be used with great success in copying Daguerreotypes or Ambrotypes into negatives. The solution must be reduced considerably from the full strength of the saturated solution, but only the quantity required for use. The exact amount of dilution will depend upon the strength of the negative after it is developed by the protosnlphite of iron developer. The plate is first developed in the usual manner as soon as it is removed from the camei'a, then carefully washed, and, before the light has fallen ujxjn it, a weak solution of the bi- chloride of mercury is poured quickly over it. It will assume a deeper intensity immediately ; and when sufficiently so, it is to be washed and fixed in the hyposulphite in the usual manner. All FIXING SOLUTION. 93 negatives, rendered intense by the application of bichloride of mercury, will assume a deep bluish- black color, which can be modified by changing the strength of this re-developing agent. FIXING SOLUTION". This is always a saturated solution of hyposul- phite of soda. The plate is to be thoroughly washed with water after developing, and laid carefully in a flat dish containing the hyposulphite of soda ; and as soon as the iodide of silver is dissolved from the sur- face, which may be known by its becoming clear from that milky appearance, it must then be im- mediately washed entirely free from the least traces of soda. Then dried — or it may be varnished before drying, with a solution of gum-arabic, of the con- sistency of collodion which has been strained. Of course, the gum-arabic is to be poured over the surface in the same manner as collodion. TONING BATHS. The most useful and practical toning bath for paper, prepared with the ammonia nitrate of silver solution, is composed as follows : 94 TONING BATHS. "Water 1 quart. Nitrate of silver .... 60 grains. Chloride of gold .... 60 grains. Or four bottles of the ordinary chloride of gold. Hyposulphite of soda . . . 2 ounces. In preparing the foregoing bath, the following method should be adopted to insure the most com- plete success. Dissolve the hyposulphite of soda in about four or six ounces of the water taken from the quart,_ and the chloride of gold in about four ounces ot water, in separate bottles. Convert the 60 grains of nitrate of silver into the chloride of silver, by dissolving it first in three or four ounces of water, to which add 60 grains of common salt. Wash the precipitate in water three or four times, then pour off all the water, leaving the M^hite precipitate, which is the pure chloride of silver. Now pour this solution of chloride of silver and hyposulphite into the remaining portion of the water, and add the chloride of gold in solution to it. It will as- sume at first a wine color, and may appear of a darker hue in a few moments. It is now ready to receive the printed picture from the printing frame, or it may be first immersed in salt and water, as described on page 64:. This toning bath is intended only for paper salted AMMONIA NITRATE OF SILVER SOLUTION. 95 in the manner described on page 57, and silvered with tlie ammonia nitrate of silver solution, as de- scribed below. When not in use, it shonld be kept from the light in a glass-stoppered bottle. This bath, when once prepared in the foregoing manner, will improve by age and use, for the im- mersion of every print tends to increase the quan- tity of chloride of silver. A bottle of chloride ot gold must be added occasionally, dissolved in six or eight ounces of water. PREPARATION" OF THE AMMONIA NITRATE OF SILVER SOLUTION". Nitrate of silver 2 ounces. Distilled water 1 pint. Dissolve the silver in the pint of water, and pour out about two ounces into a separate bottle for future use. Now add of strong concentrated aqua ammonia, a few droj)S at a time, to the fourteen ounces solu- tion of silver and water. A dark brown precipi- tate is formed at first, which must be stirred with a glass rod, or, if in a bottle, it may be shaken. Continue to add more of the aqua ammonia, and stir tlie solution until it remains perfectly clear. Then add the two ounces which were reserved for 96 AMMONIA NITRATE OF SILVER SOLUTION. use, as referred to above. This will cause the solution to be slightly turbid, which can be filtered perfectly clear, and it is then ready for use. This preparation must be kept entirely excluded from the light of day. This solution must be filtered, and only in sufli- cient quantity for immediate use. A more sensitive preparation may be made by adding to the above about six drops of nitric acid. CHAPTER VI. DETAILS OF THE VARIOUS RECIPES IN THE PHOTO- GRAPHIC PROCESS QUICK METHOD OF SILVERING AND PRINTING PAPER BEST METHOD OF SALTING PAPER TEST FOR GOOD COLLODION OR GUN-COTTON VARNISH FOR POSITIVES ON PAPER INSTAN- TANEOUS PRINTING PROCESS NEW METHOD OF VAR- NISHING POSITIVES TO RESTORE PRINTS THAT HAVE CHANGED COLOR CLEANING GLASS PLATES TO VARNISH NEGATIVES DEXTRINE PASTE FOR MOUNTING PHOTOGRAPHS GUM-ARABIC AND GELA- TINE TO RESTORE SILVER FROM OLD SOLUTIONS TO REMOVE WATER FROM COLLODION, AND TO PURIFY IT TEST OF HYPOSULPHITE OF SILVER IN POSITFt'E PRINTS PRINTING VARIOUS BACKGROUNDS. This chapter will be devoted to the variety of practice in the Photographic Art. Many recipes will be given of tlie various forms of operating. Many will be found useful, and it is trusted that none will omit to note down the variety here be- 9 98 A QUICK METHOD OF SILVERING PAPER. cause they number so many. These must neees sarily be given promiscuously, from the fact that no process here written has any peculiar relation to another. AN EXPEDITIOUS METHOD OF SILVERING PAPER AND PRINTING THE SAME. Employ the ammonia nitrate of silver, the usual strength, and fasten the paper already salted upon a flat piece of board, by means of a pin or small nail, at each corner. Then, with a ball of clean cotton dijjped in a solution of silver jnst filtered, and placed in an open flat dish, carefully rub the paper in all directions. Then dry it quickly by a fire in the usual daylight. As soon as it is dry, place it immediately in the printing frame, and expose to the sun's rays. This will insure a picture with very little delay ; and if proper care has been observed in the operation, very excellent results may be obtained. Many successful artists have adopted the foregoing process with marked success. THE BEST ilETHOD OF SALTING PHOTOGRAPHIC PAPER. Always use the hydrochlorate of ammonia (sal ammoniac) in salting paper, and never over 90 TEST FOK GOOD COLLODION OR GUN-COTTON. 99 grains to the quart of water. A larger quantity impairs the tone. This j)reparation of sodium lias been found to produce the best results, from the fact that it is in a purer state than any other known forms of salt. Hence it should take the preference of all others in the salting process. The addition of gelatine to the salting solution is strongly recommended, say about one grain to every ounce of water. The gelatine should be of the purest quality, and it should first be dissolved in warm water, and added to the salting soUition, which itself must be warmed if in the winter season. Always filter the salting solution, so as to avoid any spots of dust or foreign substances that may collect in the dish. TEST FOR GOOD COLLODIOI^ OR GUN-COTTON. There is a sure test, and one that it is well to remember and apply, in making collodion. After the gun-cotton is well dissolved in the ether and alcohol, and of the requisite thickness, pour a small quantity of the plain collodion on a piece oi glass, allowing it to drain off in the same manner as in coating the plate with sensitized collodion. 100 VARNISH FOR POSITIVE PHOTOGRAPHS. If the glass appears perfectly clear and transparent after it is dried and held up to transmitted liglit, it may be used for working collodion ; but if there should appear any milkiness or opacity on the sur- face of the glass, there is a fault of the gun-cotton or the alcohol or ether. Unless a perfect, clear, and transparent film is obtained, the collodion, when properly sensitized, will not furnish good re- sults. The addition of a small quantity of alcohol will sometimes remedy the defect. YARNISH FOR POSITIVE PHOTOGRAPHS ON PAPER. The best varnish for paper pictures is undoubt edly gum-arabic and gelatine. The gum-arabic must be allowed to dissolve thoroughly, then with warm water dissolve the gelatine, using only a small quantity. The propor- tions are as follows : Gum-arabic dissolved, and about the con- sistency of collodion .... 1 ounce. Gelatine 2 drachms. Dissolve and filter through a cloth every time before using. To be laid on with a flat brush made of hogs' bristles. INSTANTANEOUS PRINTING PEOCESS. 101 INSTAJTTAXEOUS PRIJ^TIKG PROCESS. In dark, cloudy weather, or in winter, it is sometimes desirable to print positives, and the fol- lowing method will be found to be useful, as pic- tures can be produced in the least portion of day- light. It is as follows : — Float the papers each for five minutes in a solution of bichloride of mercury, prepared as follows : Saturated solution of bichloride of mercury 6 drachms. "Water 1 pint. Silver it in a j^lain silver solution, 40 grains to the ounce of water. But it must be so done in a dark room, and the lamp carefull}^ screened by means of a yellow glass. Expose only for about two to ten seconds in summer, and .not more than a minute ^n winter, and then in a very subdued light. Of course the paper must be jjlaced in the printing frame in a darkened room, and the frame itself carefully excluded from the light during the operation, except the time required to make the impression. Remove the picture still in the dark room, when it will appear very feeble, but it is seen to be developed by means of a solution of sulphate of iron, as follows : 9* 102 TO EESTOEE FEINTS. Sulphate of iron . . " . "Water 1 pint. Glacial acetic acid . . . . ^ ounce. Develop until the picture is of the required depth of color, then wash, and immediately fix with hyposulphite of soda ; and finally, carefully wash, as in the ordinary process. NEW METHOD OF VARNISHING POSITIVE PHO- TOGRAPHS ON PAPER. Dissolve by a slow heat two ounces of white wax and add two ounces of common Venice tur- pentine, and stir the mixture well. This, when cool, will be of the consistency of paste. After the Photographs are dried, spread this paste even- ly over the surface with a brush, and rub it with a piece of woollen flannel ; hang it up to dry in a warm room for six or twelve hours. The smell of the turpentine soon leaves the print, an dry- ing, as it will in a few seconds, and when, by just placing the finger on a corner of the plate, the collodion becomes of a glutinous nature, or, rather, as soon as it is set, immerse it in your bath, with the same lower portion of the plate down as'' when you were setting the film. The plate should never be entirely dry, but hold a medium between moisture and dryness. The light must now be excluded from the bath, either by covering it with a dark cloth, or closing the box containing the bath, or the door of the room, and the plate allowed to remain in the bath one or two minutes. It may then be carefully raised from the bath, and if a film of iodide of silver is formed sufficient for its removal to the camera, it will as- sume a perfectly smooth appearance on viewing the surface ; but if the glass is removed too soon, it will have the appearance of grease, and run in lines down the plate. In order to facilitate the process, you can move the glass slightly from side to side in your bath, 148 DEVELOPING THE PICTURE. raising it carefully, and viewing the surface, or the plate may remain in the bath three or four min- utes, during which time the person whose likeness is to be taken may be placed in position. On removing the plate from the bath, care should be observed that no daylight falls ujDon it. The nitrate of silver should be allowed to run off for a few seconds into the bath before placing it in photographic frames. After the plate is in the frames ready for tlie camera, it must always re- main in a perpendicular position, leaning against the wall, or some other substance. ITever allow it to be j)laced horizontally from the moment the glass is in the frame until it is developed, or lines will be produced on the plate. Before the next plate is placed in the frame, it must be carefully wiped dry with a dry cloth or towel. As short a time as possible should elapse after the glass is in the plate-holder before j)lacing it in the focus of the camera. The time required in the camera, of course, must be determined by ac- tual experiment. The plate is then taken to the developing stand, which must be so arranged tliat water can flow on the plate at any moment, after pouring on the developing solution. Holding the plate again TIME OF EXPOSURE NECESSARY. 149 in the left Land, as in using tlie collodion, over a large dish sufficient to receive all the solu- tion that will not remain on the surface, quickly pour over the developing solution on the right- hand side of the glass, enough to cover it all at the same instant, and move it over the whole surface, as in gilding a Daguerreotype plate. The picture will quickly appear; and as soon as the outlines of the drapery are seen distinctly, then apply the water to the surface in a gentle stream, 60 as not to remove the collodion film. A little care and experience will be necessaiy in the developing process, for in this consists the great beauty of the jncture. By a proper develop- ment all the fine half tints are produced, and the drapery is brought out with distinctness. It is preferred by some rather to over-time the picture in the camera, and use a shortened de- veloping process, yet the best results are attained by the exact time of exposure, combined with the proper development. It is well known that the longer the picture is developed, the lighter it be-* comes ; but beyond a certain length of time, a dis- agreeable tone is produced. It is necessary, there- fore, to allow sufficient time in the camera for the picture to be developed in the usual manner. 13* 1.50 DRYING THE PLATE. About ten or fifteen seconds, in ordinary tem- perature, is long enough for a successful develop- ment. This, however, is subject to a variety of changes, which must be learned by actual experi- ence. After thoroughly washing the solution from the glass on both sides, lay it in a flat dish containing the fixing solution, with the collodion side uppei- most. This may be performed in the light of day. If cyanide of potassium is used, it will remove the iodide of silver which has been unchanged by the action of the light in a few seconds. But if hyj)o- sulphate is used, it will require somewhat longer. As soon as the picture is seen clearly, be careful to remove it, to wash all the fixing solution from the glass with a good supply of soft water, as the slightest trace of these solutions will injure tiie picture. The plate can now be dried by a gentle heat of the fire, but not too quickly, as streaks wall be formed. It is now ready for the varnishes. The glasses may also be dried by the applica- tion of the spirit-lamp, care being used to avoid too great heat, which will cause the glass to break. CHAPTER III. VARNISHING THE PICTURE SINGLE GLASS PROCESS STEREOSCOPIC AMBROTYPE TREBLE GLASS PROCESS THE DOUBLE GLASS PROCESS CUTTING's PATENT THE PATENT LEATHER PROCESS. There are so manj kinds of varnishes in use, and such a variety of modes of sealing up the Arabrotypes, that one is in great doubt which is best to be adopted. We shall give all the various plans adopted by the profession, including the great process, known as Cutting's patent. SINGLE GLASS PROCESS. The j)lan mostly adopted of applying the var- nishes, is to pour them on like the collodion. All pictures which are put up with the single glasses are said to be improved by the application of the white varnish before the black is used ; yet by some it is asserted they are the same after the black is applied as though no white had been ap 152 VAENISHING THE PICTURES. plied. The white varnish will dry very soon if the plate is slightly warmed by the spirit-lamp, when the black can be added, and allowed to dry by laying it in a horizontal position, with the varnish iij)permost. The black varnish can be applied directly on the collodion side, withont the white varnish. In most instances the black varnish has a ten- dency to darken the picture — hence the picture when dried and ready for the varnish should ap- pear rather lighter than you desire it when finished. Pictures can also be varnished with the white varnish on the collodion side, and the black on the opposite side. These can be colored as in a Daguerreotype plate, and sealed up with a mat and glass in the same manner. They are some- times colored before the white varnish is applied. Many are sealed up with the collodion side colored, and not varnished with the white, but only black, on the reverse side. STEEEOSCOPIO AMBROTYFES. There is quite a novel method of sealing Am- brotypes, by some called stereoscopic, because they have a stereoscopic effect, even without the stere- oscopic lenses. The Ambrotype is first taken with TREBLE GLASS PROCESS. 153 a dark background, instead of the usual white one. After it is dried, a small camel's-hair brush is used to apply the black varnish to the reverse side of the glass, and only enough to cover the figure, and allowing the background to remain perfectly clear and transparent. Place a piece of white j^aper, or, what is better, Bristol board, on the back of the glass, and the picture will be seen to stand out from the background in relief. All the pictures sealed with the collodion side uppermost will require a glass over them for pro- tection. TEEBLE GLASS PEOCESS. By using a third glass instead of the white paper, a beautiful effect is produced, if the glass is coated with collodion, and exposed in the camera to the white background, and developed and fixed exactly as in the process of taking the portrait. Any desired shade can be attained, and a great variety of colors may be used, instead of white, the effect of which is very pleasing. Another beautiful effect may be produced by first taking a view from some engraving of scenery, tSrc. — coloring it, and using that for the third or back glass. 154 DOUBLE GLASS PEOCKSS. DOUBLE GLASS PEOCESS. The use of Canada balsam in sealing up Am- brotypes has been adopted by those who have heretofore used the " cutting'''' process. The bal- sam has been found on trial to be very difficult of application, and jDcrplexing. The adoption of good white varnish instead is much prefera- ble, being attended with less than half the trouble, and rendering the pictures more clear and transpa- rent. They can be colpred on the collodion side, and put up with the transparent case with great fa- cility. The varnish, however, should be a little thicker than ordinary white varnish, which can be ren- dered so by exposing it for a day or two to the open air, or the addition of a little more gum copal will answer the same end. Only a small quantity need be used, say one or two drops on the middle of the glass. Gently press the second glass upon the varnish, and it will im- mediately flow over the whole surface. The pic- ture can be sealed with the sealing-paper before it has flowed over entirely, which will prevent the PATENT LEATHER PROCESS. 155 superfluous varnish from running out at the sides of the glasses. Any white gums may be dissolved either in spirits of turpentine or alcohol, and used for the medium of holding the two glasses ; but the com- mon white varnishes have been found to answer quite as well as the Canada balsam. PATEIiTT LEATHER PROCESS. Ambrotypes can be easily transferred from the glass plate to the surface of patent leather by the following process : Add thirty drops of nitric acid to two ounces of alcohol, and after the picture is well dried upon the glass, pour enough of the alcohol, prepared as above, on the surface to cover it. Clean the japanned surface of the patent leath- er with soft canton flannel onlj-, and pour over the alcohol two or three times. Then lay the leather upon the surface of the picture, and place another glass over it, retaining the leather between the two glasses with the patent clothes-pins, or in any manner to press the glasses evenly over the leath- er, for about ten minutes ; they can then be sep- arated, and the picture will leave the glass and 156 APPLYING THE CANADA BALSAM. adhere to the leather, which, when dried, can be rubbed without any possibility of removal. APPLYING THE CANADA BALSAM. In applying the Canada balsam, or any thick- ened varnish, between the glasses, great care should be used in pouring it on the surface of the glass. It must be placed on the middle of the glass plate, say about two or three drops, and the additional glass carefully cleaned, and free from dust, laid over first on one edge, then to be pressed gently doNvn, and before the balsam spreads out to the edges, it can be sealed up with the adhesive paper. It will in a short time spread entirely over the surface, and render the picture clear and transparent. The application of the balsam is necessarily at- tended with more difficulty than any other var- nishes which are recommended, from its peculiar glutinous properties, and the tendency it has to ooze out at the edges after the picture is sealed. It can, however, be removed effectually by alco- hol, and rubbing it with canton-flannel, as all the balsams and gums are soluble in strong 95 per cent, alcohol. CHAPTER XIII. THE MANUFACTURE OF GUN-COTTON — TEST OF THE ACIDS EMPLOYED WASHING AND DRYING THE GUN- COTTON' — PREPARATION OF THE COLLODION' ITS NATURE AND PROPERTIES ETHER AND ALCOHOL TO IODIZE COLLODION FOR AMBROTYPES METHOD OF PRESERVING COLLODION, AND KEEPING IT READY FOB USE TESTS OF GOOD COLLODION TO REMOVE THE COLOR FROM COLLODION. A WORK like this would be incomplete without full and practical details relative to the prepara- tion of gun-cotton, and its conversion into col- lodion, although the manufacture of it is attended with considerable diificultj and uncertainty. It is recommended to beginners, therefore, to purchase their collodion of those more experienced opera- tors, when only a small quantity is required. In- deed, the manufacture of gun-cotton itself is liable to great variation, as well as being very deleteri- ous to health. It is found that even those who make collodion for sale, purchase their gun-cotton 14 158 THE DISCOVERY OF GUN-COTTON. ready made. Both gun-cotton and collodion are all perfectly iodized and warranted. They can be found for sale by most dealers in Daguerreotype goods. Collodion is so called from a Greek word, which signifies " to stick." It is a transparent fluid, pro- cured generally by dissolving gun-cotton in ether, or ether and alcohol. It was discovered by Professor Schoenbein, of Basle, Switzerland, in the year 1846, and was firat used for surgical purposes only, being smeared over fresh wounds and raw surfaces, in order to preserve them from contact with the air by the tough film which it leaves on evaporation. It is now sold by druggists for the same purpose ; but photographers have hailed the discovery of collo- dion as the final keystone to their wonderful art, and they draw large contributions from this sub- stance. It is consequently of great importance that its preparation should be the most complete and exact that can be attained. Gun-cotton is procured by immersing the pure clean fibres of cotton in sulphuric acid and nitric acid, or sulphuric acid and nitrate of potash. If a large quantity of gun-cotton is desired, the mixture of nitric and sulphuric acid is generally TO MAKE GUN-COTTON. 159 adopted. For photogmpliic purposes, however, the mixture of nitrate of j)otash and sulphuric acid is used as follows : TO MAKE GUN-COTTOK Granulated nitrate of potash, . 6 ounces, Sulphuric acid, 5 ounces, Pure cotton, .... . 160 grains. The nitrate of potash should be pulverized in a porcelain mortar, and the sulphuric acid added and mixed until a thick pasty substance is formed, when the cotton must be quickly immersed, and stirred with a glass rod, so as to thoroughly incor- porate the cotton in the mixture. Then pound the cotton slightly for a period of ten minutes. When the cotton assumes a stringy appearance, and on separating the fibres, it breaks easily, it must be quickly immersed in a quantity of water to re- move the acid, after which it is to be well washed for ten or fifteen minutes in water, constantly changing it, until all traces of the acid disappear. Great care is necessary to be observed in prej^ar- ing the gun-cotton. It should be made in an open space, where free circulation of air is obtained, in order that the deleterious fumes of the acid shall pass away. The quality of the ingredients is 160 WASHmG THE ACIDS. Inglily essential. The rectified nitrate of potash, known as " Dnpont's grannlated nitre," is prefer- able. The acid shonld be of the specific gravity of 1.860, and free from water. On mixing the acid and nitre, the temperature should be raised to about 140°, or it will become 80 if they are of the required quality, in conse- quence of the small quantity of water contained in the nitre. The most expeditious plan to wash the acid out is to have running water, as from a hydrant. As soon as the acid is completely washed out, which may be ascertained positively by using lit- mus-paper, the cotton is then to be placed in alco- hol, in order to remove all traces of water ; then by wringing it out in a clean towel, all the alcohol can be removed, and it is then ready to spread out on white paper to dry, which will be done in a few moments. If the manufacture of the gun-cotton, as above described, has been successful, the product will be capable of the following conditions : A small quan- tity will explode on the application of heat. It will dissolve readily in a solution of alcohol and ether,, in certain proj)ortions, without leaving much residuum. TKEPARATION OF COLLODION. 101 The manufacture of gun-cotton is usually attend- ed with many difficulties, and liable in all cases to result in failure from the slightest variation of the process, and withal is quite detrimental to health. It is therefore recommended to purchase the gun- cotton, when possible, thereby saving all the per- plexity and uncertainty attending its preparation. PEEPARATION OF THE COLLODIOK Assured that you have a good quality of gun- cotton, the preparation of the plain collodion is at- tended with very little difficulty. The proportions are as follows : Sulphuric ether, concentrated, sp. g. 720 . 10 ounces. Alcohol, 95 per cent., sp. g. 820 . . 6 ounces. Gun-cotton 80 grains. Mix these in the order above given, and shake them thoroughly, when the cotton will be seen to dissolve, and the substance to assume a glutinous appearance on the inner surface of the bottle. In. some instances it may require the addition of more gun-cotton to render the collodion of the required consistency. This can be ascertained by pouring a small quantity upon a piece of glass, and allow- ing the ether to evaporate. If a thick film is 14* 163 TO IODIZE COLLODION. formed on the glass sufficient to hold together, and to be raised up "without breaking very readily, it will answer ; but if it does not contain these requi- sites, add more gun-cotton. If too thick, then add more ether and alcohol, in the same relative pro- portions. Allow this to stand a few hours to settle, then decant into another bottle, leaving a small j)ortion at the bottom, which will remain undissolved by the ether and alcohol. This sediment may be re- served until the next lot is required, and added to it without loss. TO IODIZE THE COLLODION FOR AMBR0TYPE8. Pure collodion, .... 8 ounces. Bromo-iodide of silver, . . . 4 drachms. Prepared as described on page 185, Hydro-bromic acid, . . . .20 di-ops. Prepared as described on page 18Y. The iodizing of the collodion is also liable to a variety of uncertainties in the result. If there is any defect in the quality of the ether or the alco- hol, the collodion will not work with good results. This can only be known on trial. If the film sbould not prove thick enough on using, add 20 PRESERVING THg COLLODION. 163 grains of iodide of potassium and 10 grains of bromide of potassium, as follows : First dissolve the bromide in a drachm or two of water, then add the iodide. When both are well dissolved, add the whole to the eight ounces ; shake it well, and allow it to stand for a few days. It will as- sume at first a thick and opaque apj)earance, but will settle clear, if left in quiet for a suificient length of time for all the precipitate to fall. It can then be decanted into another bottle, ready for use. The remainder of the collodion recipes, together with the prej)arations of the iodides and bromides, and the various saturated solutions, will be given in a separate chapter. Collodion should be kept as much as possible from the light, although by some it is asserted that light does not affect its properties. Yet it must be apparent that if the collodion is affected by light in any form, it will certainly be if exposed to its rays for a long time. In no case should it be shaken after it is decanted. The most successful manner of using collodion is to be provided with three long bottles made ex- pressly for this purpose. Fill each one from the large bottle, allowing them to stand. Use from 164 TESTS OF COLLODION. each bottle, alternately. By this means there can be no possibility of disturbing the j)articles in the collodion, and one will also avoid many spots and lines upon the glass plates. Collodion requires to be perfectly clear and transparent in order to work successfully. The color may at times vary. On first mixing the in- gredients, it will assume a yellow hue, changing to a darker shade, and finally to a red. The color does not in any degree afiect the working proper- ties of the collodion. The tests of good collodion before working are, that it ajDpears clear and trans^iarent, devoid of small particles floating in it; that it be thick enough to forai a film readily on the glass, and that it dries with- perfect smoothness, without ridges or lines. But the best test is to make a trial picture with it, and the result will soon convince one of the success or failure of his production. TO EEMOYE THE COLOR FROM COLLODION. It may sometimes be necessary to remove the reddish color which is so often seen in Ambrotype collodion. In order to do this there can be added a few strips of 2dnc, or, what is more expeditious, TO REMOVE THE COLOR FROM COLLODION. 165 add three or four ounces of pure mercury, and shake it well for a few moments, when the whole will assume a beautiful yellow color. The mercury will subside, and the collodion may be poured off clear and transparent. CHAPTER XIV. COLOKmG AMBROTYPES COLORS EMPLOYED AMBRO- TYPES FOR LOCKETS TAKING VIEWS COPYING DAGUERREOTYPES BY THE AMBROTYPE PROCESS COPYING ENGRAVINGS, STATUARY, MACHINERY, ETC. The 23^23116^ of coloring tlie Ambrotype pic- tures has been questioned by many, and we may even doubt if they are improved by it ; but many persons desire to see themselves in their natural colors. The artist is therefore compelled to devise some plan of gratifying the public taste, and color his pictures true to life.. Many attempts have been made to color Am- brotypes, and seal them with the single glass, with the colors to be seen, but this plan has been found impracticable, except in a certain degree. Tlie colors may be seen through the glass if they are very deeply colored. The black varnish removes nearly all color, even when it is placed over the white varnish, and the COLOKS USED FOR AMBEOTTPES. 167 opacity of the collodion is such, also, that the colors themselves cannot be seen through the irlass but very slightly, even before the black varnish is applied. The only feasible plan of applying the colors is on the collodion, blackening the reverse side of the glass. The colors are applied to the ■ collodion after it is thoroughly dried, in the same manner as in the DagueiTeotype ; but it is neces- sary to color much more intensely, in order that the application of the white varnish may not re- move all the color, as it invariably will a por- tion of it. After the white varnish is applied and dried, the pictm-e can then be colored still more highly, if necessary, imtil the desired tint is ac- quired. The colors which are best adapted for this pur- pose are not those commonly used for Daguerreo- types. The following are those which can be ap- plied with the greatest facility, viz. : Chinese Vermillion. Chrome gi-een. Chrome yellow. Chinese blue. Purple, a mixture of Venetian red and blue. I The carmine used in the Daguerreotype will not adhere well to the Ambrotype, and the substitu- 168 COLORING JEWELRY, ETC. tion of Vermillion has been found to work ex- ceedingly well, and to render tlie flesh color quite as natural as in the use of the carmine for the Daguerreotype. The coloring of jewelry, &c., with moistened gold colors can be adapted to the collodion. With some improvement it will not be affected by the black varnish. The gilding is seen distinctly on either side of the picture ; yet by some it is con- sidered as being too conspicuous, and therefore discarded. The application of most varnishes to the pictures after they are colored has a tendency to darken the whole of the light and shades. It will therefore be necessary to make the impression rather lighter than it is desired to have it when finished Many operators put up their portraits after color- ing, without applying the white varnish over the collodion, merely blackening the reverse side with black varnish. It is not to be supposed that they are so durable, because the silver is liable, after a lapse of time, to become affected by the atmosj^here, and it must necessarily change. All collodion pictures are of course much better protected by the aj)pli cation of varnish. AMBROTYPJiS FOK LOCKETS. 169 It frequently happens that the liigh lights on the hair of many Anibrotype portraits are too ap- parent, producing what is termed gray hair. This ' may be removed by a simple process, as follows : Pi-epare some fine lampblack by holding a small piece of glass over an ordinary lamjj. A black dejjosit will be formed of the finest lamp- black. This can always be in readiness to darken the high lights ; which is effected by a wet brush, with a small portion of this lampblack laid on where a darker shade is required. AMBEOTYPES FOR LOCKETS. Portraits taken for lockets, breastpins, and me- dallions, by the Daguerreotype process, are easily inserted, but when taken on glass they are at- tended M'ith much more difficulty. A new and very useful invention has been made of a kind of plate, well adapted for locket pic- tures. They are known as the Melainotype plates, and are now employed by most operators fjr these kinds of pictures. Being composed of thin plates ofiron, and japanned, they require no application of the black varnish, and can be cut and fitted into lockets with the same facility as Daguerreotypes. Prepared paper is used by some operators for 15 170 VIKWS BY TUE AMBltOTYPE. these kinds of pictures, and p:iteiit-leather has been adopted by some. The process of taking them on patent-leather is given on page 155. All these various materials can be purchased of the dealers in photographic materials. "FOE TRANSFERRING AMBROTYPES TO PAPER. Gum-shellac 1| ounce. Borax ^ ounce. Wuter 8 ounces. Dissolve the borax in the water and add the shellac, which will require a slight degree of heat. Use the black-glazed paper, cut a little larger than the glass on which the Ambrotype is taken. Pour a portion of this solution on the paper, and allow it to partially dry ; then lay it over the Am- brotype, which nuist be well dried; and place. the whole under water for five or ten minutes, when the paper can be removed with the picture upon its surhice. Diy, and it is ready for use. TAKING VIEWS BY THE AMBROTYPE PROCESS. This is the most simple and easy process known in the art, because operators are always sure of a good light. The utility of it for taking views over that of the ordinary Dagucri-eotype will not be (juestioned when it is known that all objects ai'e COPYING DAGUERREOTYPES. ' 171 taken without reversing, and that, too, without the use of a reflector. The camera must be used with a small opening diaphragm, in order to reduce the light, and render the half tints discernible. Tlie bath must be removed to some place near the ob- ject to be taken, because the plate will not be sen- sitive only as long as moisture remains on its sur- face. If many minutes should elapse after the impression is taken, it will be necessary to plunge the plate into the nitrate bath for a few seconds before applying the developer. It will then cause the picture to appear, even if it had been partially dried on its surface. As little time as possible should intervene after the impression is given be- fore the developer is applied. All views nmst be sealed up with the black varnish applied to the collodion, otherwise they would apj)ear revereed. COPYING DAGUEEREOTYPES BY THE AMBROTYPE PROCESS. ^, A." ■ The durability of the Daguerreotype has long been doubted, yet many persons possess them which are in a good state of preservation, although taken ten or fifteen yeare ago. But this new process of positive photographs on glass possesses advantages over the Daguerreotype 172 CHANGING THE BACKGROUND. that will command the preference on the score of dm-ability. As this fact becomes more generally known, all those persons who possess a Daguerreo- type of a departed friend, will hasten to the Am- brotype artist, and have it reproduced with all the durability which this art possesses. Unfortunately, however, many Daguerreotypes cannot be copied as well by the Ambrotype process, in consequence of the dark background generally adopted, the Ambrotype requiring a white background in order to copy successfully. This difficulty can be over- come in a great degree, and the Ambrotype copy produced with a light background, having all the beautiful effects so much desired in this art. The original Daguerreotype must be first copied in the usual manner, with the black background apparent, of course, then dried, and the figure only blackened over on the reverse side, when a white piece of paper or pasteboard must be placed be- hind the glass, and a second copy taken with the white background apparent. The second copy will of couree be taken, possessing all requisites of a good Ambrotype. Many Daguerreotypes can be improved by this process, especially in the appearance of the back- ground. The necessity of a double copy is re- COPYING ENGRAVINGS, STATUARY, ETC. 178 quired to produce the Ambrotype effect, or the first copy may be sealed with only the white paper inserted for a background. Yet the effect is not so pleasing, nor is it so durable. COPYING ENGRAVINGS, STATUARY, MACHINERY, ETC. Copying engravings is a very simple process, as the surface is always even, and the objects easily arranged in a favorable light. A small opening diaphragm can be used, which will render the copy very distinct in its details, actually beautify- ing the engraving itself. In copying statuary, it will be necessary to have a darker background than the plain white one so often used ; yet it need not be entirely black — a dark blue or brown color will answer. One having a lighter centre, and darkened at the sides, would produce a pleasing effect. In copying models of machinery, this process is of an incalculable utility, as it can be readily seen. The exact counterpart can be produced with a perfect perspective, and no reversal of the object copied. 15" CHAPTER XV. ON THE MANNER OF ARRANGING THE LIGHT THE FALLING OF THE SAME ON THE DRAPERY USE OF A DIAPHRAGM LIGHT ON THE EYES USING SCREENS BACKGROUNDS REFLECTORS DIAPHRAGM TIME IN THE CAMERA OVER-EXPOSURE, AND UNDER-DE- VELOPING TAKING children's PORTRAITS. The proper adjustment of light for Ambrotypes is a subject which demands the utmost care, and is one which is of great importance to good suc- cess in photography. It has been found, of course, that a skylight is much more to be preferred than any side-light, although a very high side-light will answer for the purpose. A skylight that is not more than ten or fifteen feet from the sitter in the highest point, and falling over in such a manner that the lowest portion of it shall be five feet from the floor, has been found to work well. It is ab- solutely requisite that there should be a good volume of light on the drapery. This must be SCREENS AND BACKGROUNDS. 175 Been in the camera, for unless this is attained, the drapery will appear undefined. By using a diaphragm with a small opening, the light becomes rather more diffused — hence the middle tints and the gradations of light and shade are more clearly seen, as well as a more perfect outline and sharpness. In consequence of the great sensitiveness in Ambrotyping, a diaphragm can be used more frequently than in the Daguerre otype process. Of course in a weak light it can- not be adopted, neither can it be used when chil- dren are the subjects. ON SCREENS AND BACKGEOUNDS. Tliere are three colored screens needed in an ordinary skylight — viz., blue, white, and black — the blue to be used, in connection with the white, at the side of the face, to modify the intense white that may sometimes fall on the eye; the black screen to be placed between the sitter, and at a considerable distance from him and the lower por- tion of the skylight, to cut off the large light that sometimes falls on the eyes. This light 0)1 the eyes is a very important fea- ture in producing good pictures, and it is one which is often neglected. AVithout a round, dis- 176 PKEPARmG BACKGROUNDS. tinct light falling npon eacli eye, resembling a small jpin-head^ there can be no perfect picture produced. It will therefore be necessary to so alter and arrange the screens, and the position of the sitter, as to fulfil all these conditions before the impression is given. The background for Ambrotypes which has come into general use is the wliite one, because the effect is found to be more pleasing when finish- ed up with the black varnish. The intense white is not so aj^parent after the picture is finished. It assumes a much darker hue, resembling more nearly the neutral tint of the artist. If the film of the collodion is thin, the background will apj^ear still darker. The background should be made of strong cotton cloth, stretched on a frame of a size sufiicient to be taken in the camera, wdthout showing either side when taking groups. . An improvement can easily be made by coloring or whitewashing it with j)ure whitii^^ mixed with water, in which a small quantity of glue has been dissolved. Two coats of this whitewash will ren- der it a i^erfectly dead surface, w^hich is better adapted for the purpose than plain cotton cloth, al- though many operators use only the white cotton DEFINING THE DRAPERY. 177 cloth well bleached. As much distance as possi-- ble behind the sitter is recommended ; even five or six feet, when it can be attained, will produce the best effects. Other backgrounds than white are frequently employed. Blue, brown, and a light yellow pro- duce very excellent impressions, if a good distance is obtained, and a strong light falls on it at the same time. The light being well adjusted, and a goodi focus obtained as well as position, the time necessary for the exposure of the plate will of course vary according to the many conditions under which it is taken. The time will be entirely a matter of experiment, but it has been found by all success- ful ambrotypers that an over-exposure in the camera, combined with a short time in develop- ing, will produce the most satisfactory results. Tlie pictures will assume a much more desirable tone. The drapery will be well defined, and the general effect much improved by pursuing this course. It is only when children are to be taken that operators can develop slowly. The rule to be observed in children's portraits is, to sit as long as they will without moving, then develop until the picture appears. The tone is never so desirable 178 APPLYING THE WATEE, but the likeness will be there, which is often prized by the parents more than the most splendid pro- ductions of the artist. In developing, it may sometimes become neces- sary to arrest the process on the face, allowing it to continue on the drapery. This can be eflPected by j)ouring the water slowly on the face, and grad- ually extending it over the whole picture. Yery frequently beautiful effects can be produced by this means of manipulatina:. CHAPTER XVI. ALCOHOLIC SOLUTIONS FOE PEEPARIKG COLLODION IODIDE OF SILVER SOLUTION BROMIDE OF SILVER SOLUTION BROMO-IODIDE OF SILVER SOLUTION — • SATURATED SOLUTION OF IODIDE OF POTASSIUM IN ALCOHOL OF BROMIDE OF POTASSIUM TO MAKE HTDRO-BROMIC ACID. The references made in a former portion of this work to the manufacture of collodion will now be given. All the recipes here presented are highly rec- ommended. All these collodions will work, and work well, if the proper nitrate baths are used in connection with them. But it may be found that many of them will fail at the first trial, yet if a difierent modification of the bath is adopted, they will work successfully. The general rule laid down by the most expe- rienced photographers is, that if a collodion is heavily iodized, it will require a larger quantity of silver in the nitrate bath, and, vice versa^ a 180 keiin's ambkotype collodion. lightly iodized collodion will work with a bath of a less quantity of silver. The formula given in the chaj)ter on manipiila- ting, page ISO, is one which is said to be nsed by Rehn, of Philadel2:)hia. It certainly will produce very pleasing effects, and if cai-e is had in com- pounding, it cannot fail of absolute success. Tlie preparation of all collodions, however, is unavoidably attended with diverse results, from the great liability of some one of the ingredients being of an inferior quality. Nor can one be fully assured of success until the collodion is made and allowed to settle two or thi-ee days, and a trial had of the same. This will necessarily consume much time, and also cause disappointment. It is therefore sug- gested that, when convenient, the collodion which has already been tested by an experienced operatoi and maker should be used. Here follow the various recipes for collodions, and the baths which are necessary to accompany them. RehrHs celebrated Recipe for Ambrotype Collodion. No. 1. Collodion 8 ounces. Iodide of silver . . . .4 drachms. Hjdi-Q-bromic acid ... 20 drops. COLLODION RECIPES. 181 This collodion requires 40 grains of nitrate of silver to the ounce, with the usual developer. "N'o. 2. Collodion .... Bromo-iodide of silver Hydro-bromic acid Bath of 40 grains to the ounce. 8 ounces. 6 drachms. 25 drops Cutting's celebrated Patent Recipe for Ambrotype Collodion. No. 3. Collodion . Gum camphor Iodide of potassium 30-grain nitrate bath. "N'o. 4. Collodion . Iodide of potassium Iodide of silver solution Iodide of ammonia Iodine, pure 30-grain nitrate bath. No. 5. Collodion . Iodide of potassium Bromide of potassium Nitrate bath 30 grains to the ounce of water. No. 6. Collodion . . . . . Iodide of potassium Bromide of potassium . Saturated solution of iodide of po- ) on droDS tassium in alcohol f Nitrate bath of 30 grains. 16 1 ounce. 1 grain. 5 grains. 6 ounces. 25 grains. 2 drachms 5 grains. 1 grain. 17 ounces. 40 grains. 40 grains. >f water. 4 ounces. 12 grains. 16 grains. ) 2 ALCOHOLIC SOLUTIONS. ^o. 7. Collodion . . . . . 6 ounces. Iodide of silver solution . . 1 drachm. Hydro-bromic acid ... 18 drops. Bromide of potassium ... 5 grains. Iodide of potassium , . .15 grains. Saturated solution of iodide of po-) ^i^ draohmq tassiura in alcohol j ^ 40 grains in the nitrate batli. Veri/ sensitive Collodion for Children. No. 8. Collodion 8 ounces. Iodide of ammonia ... 40 gi-ains. Bromide of ammonia . . . 16 grains. 40 or 60 grain bath. ALCOHOLIC SOLUTIONS FOR PREPARING COLLODION. These solutions are to be prepared and allowed to remain several hours before using, and kept ex- cluded from the light. When thej are added to the collodion, they must always be perfectly clear and transparent, nor must any portion of the pre- cij)itate which is seen at the bottom of the prepar- ation fall into the collodion. It is recommended to prepare all these solutions some days even before they are needed, in order that the alcohol and potassium shall dissolve a gi'eater proportion of the iodides or bromides of Bilver. The greater the proj)ortion of silver taken IODIDE OF SILVER SOLUTION. 183 Up, the better cliemical effect will be produced in the collodion. These various preparations are the most difficult portion to be made in manufacturing the collodion, and require the greatest care and attention. IODIDE OF SILVER SOLUTION. Dissolve 80 grains of iodide of potassium in 4 ounces of water, and 120 grains of nitrate of silver in the same quantity, but in a separate bottle. (This i^rocess must not be conducted in a strong daylight, but in one greatly subdued, or in a dark room by the light of a lamp.) Then pour them together in a large graduated dish, or an open glass vessel, when a yellow precipitate will be formed. This is pure iodide of silver. Wash this precipi- tate with water three times, allowing it to settle a few minutes, and decant or pour the water off. Then wash it with alcohol twice, to displace the water, pouring it off. and leaving the iodide of silver in the dish. This must now be placed in a glass-stoppered bottle that will hold ten or twelve ounces. Dissolve the iodide of silver in eight ounces of alcohol, 80 per cent., in which has been satm'ated one ounce of iodide of potassium, as fol- lows : 184 BEOMIDE OF SILVER SOLUTION. Pulverize the ounce of iodide of potassium in a clean porcelain mortar, and add one or two ounces of alcohol from the eight ounces which is to be measured out for the iodide of silver solvent. Stir with a jDCstle the alcohol in the potassium, and a small portion will be taken up or dissolved. This must now be poured into the bottle which contains the w^ashed iodide of silver. Then proceed in the same manner, adding two ounces more of the al- cohol, stirring it well, and pouring into the bottle as much as will dissolve, until the whole eight ounces are added. There may be a portion of the iodide of potassium in the mortar not dissolved ; this can also be added to the iodide of silver. After shaking it, allow it to stand and settle per- fectly clear, when it will be ready for use. BROMIDE OF SILVER SOLUTION". Bromide of potassium ... 80 grains. Nitrate of silver .... 80 grains. Dissolve separately in four ounces of water; then mix it, when the bromide of silver is formed, and is seen in a precipitate at the bottom of the dish. Wash this precipitate with water three times, allowing it to settle a few minutes, and de- cant or pour the water off. Then wash it with BEOMO-IODIDE OF sAvKR SOLUTION. 185 alcohol twice, to displace the water, pouring it off, leaving the bromide of silver in the dish. This must now be j^laced in a glass-stoppered bot- tle that will hold ten or twelve ounces. Dissolve the bromide of silver in eight ounces of alcohol, 80 per cent, in which has been saturated one ounce of bromide of potassiiun. ' Pulverize the ounce of bromide of potassium in a clean porcelain mortar, and add one or two ounces of alcohol from the eight ounces which are to be measured out for the bromide of silver sol- vent. With the pestle stir the alcohol in the potassium, and a small portion will be taken up or dissolved. This must now be poured into the bottle which contains the washed bromide of silver. Then proceed in the same manner, adding two ounces more of the alcohol, stirring it well, and pouring into the bottle as much as will dis- solve, until the whole eight ounces are added. BEOMO-IODIDE OF SILVER SOLUTION. Dissolve separately in four ounces of water — Bromide of potassium ... 80 grains. Nitrate of silver .... 80 grains. Tlien mix and wash out with water three times, and with alcohol twice. Then pulverize one ounce 16 ■5f 186 IODIDE OF potIssium in alcohol. of iodide of potassium, and dissolve in eight ounces of alcohol, precisely in the same manner as de- scribed in the alcoholic solution of iodide of silver. These various solutions of silver, and iodides and bromides, are deemed very essential to success in ambrotyping. If they are prepared with care and attention, none can fail of success in making good collodion. They should be kept as much from the light as possible, and always in glass-stoppered bottles well filled, to prevent evaporation. SATUEATED SOLUTION OF IODIDE OF POTASSIUM IN ALCOHOL. Pulverize one ounce of iodide of potassium in a mortar, and add three ounces of SO per cent, alco- hol, stirring it for some minutes, and then allow- ing it to settle. Pour off the clear liquid into a bottle, and add a smaller quantity of alcohol, stir- ring this also in the same manner, and pouring off the clear solution into the bottle. Continue to add each time a smaller quantity of alcohol, until all the potassium is dissolved. BKOMIDE OF POTASSIUM IN ALCOHOL. 187 SATUEATED SOLUTION OF BROMIDE OF POTASSIUM IN ALCOHOL. Pulverize one ounce of bromide of potassium in a mortar, as described in the preparation of iodide of potassium above, adding alcohol, 80 per cent., in the same manner, until it is all dissolved. These saturated solutions will be found very use- ful to add to collodions that will not work well, or if the film is not of sufficient thickness on with- drawal from the bath. By adding a small quantity of each of these saturated solutions, any desired effect can be produced. They also enter in the properties of some of the collodion recij)es given in this work. The quantity of each saturated solution used, is for bromide of potassium just one half as much as of the iodide of potassium — that is to say, if one drachm of iodide is used, one half drachm of the bromide would be sufiicient. TO MAKE THE HYDRO-BROMIC ACID. Alcohol (95 per cent.) ... 4 ounces. . Water (distilled) .... 1 ounce. To tliis is added one drachm of pure bromine, — then shaken quickly, and allowed to remain for 188 TO MAKE HYDKO BROMIC ACID, twenty-four hours. It will assume at first a deep cherry-red color, but afterwards it will become clear again. Every twenty-four hours there must be added, say, five or six drops more of bromine, and continued for a week or ten days, adding a few drops every day, when it will be ready for use. It will eventually assume nearly a white trans- parent color, slightly inclined to yellow. This preparation is highly sensitive 'to light, and must be kept in a perfectly air-tight bottle, and not exposed to the light of day. CHAPTER XVll. PREPARATION OF THE VARNISHES WHITE COPAL VAR- NISH GUM-DEMAR VARNISH BLACK ASPHALTtJM VARNISH WHITE VARNISH OF SHELLAC AND COPAL THICKENED VARNISH FOR CEMENTING GLASSES, IN PLACE OF CANADA BALSAM GUM-SHELLAC VAR- NISH FOR PLATE-HOLDERS APPLYING THE VAR- NISHES. These varnishes for Ambrotypes are somewliat difficult to prepare, and likely .to soil the hands in their manufacture. It is well, therefore, to pur- chase them ready for use, thereby saving much trouble. However, a few recipes will be given for those who wish to manufacture their own. WHITE COPAL. Select the whitest j)ortions of white copal gum, and dissolve, say, one ounce in two ounces of tur- pentine. The coj^al is fii'st to be pulverized, and added to the turpentine, and allowed to dissolve. If the varnish is too thick for use, add more tur- pentine. • ii>l' BLACK VAKNISH. 4 GUM-DEMAR VAENISH. Gum-demar i ounce. Chloroform 2 ounces. These must be allowed to stand after shaking for two or three days, until the gum is all dissolved, then decanted off into a separate bottle, avoiding the sediment at the bottom. This varnish is highly recommended for using on collodion jjictures that have been colored. By pouring this carefully over, it will not disturb the color, and it dries readily, nor is it so liable to change by the action of light. BLACK ASPHALTUM VARmSH. Asphaltum, pulverized ... 1 ounce. Adding spirits of turpentine, and stirring it well in a mortar, until all is dissolved. Any consistency can be had which is desired, by adding more or less of the turpentine. A portion of the asphaltum may not dissolve ; this can be left in the bottom of the mortar, and rejected entirely. WHITE VARNISH OF SHELLAC AND COPAL. Alcohol, 95 per cent. New Zealand gum .... 1 ounce. Gum-shellac ), ounce. Gum- copal i ounce. GUM-SHKLLAC VAKNISH. 191 Add sufficient alcohol to these three gums to dissolve them in a mortar, and a transparent var- nish is obtained, of su]3erior quality. THICK WHITE VARNISHES FOR OEMENTIITG GLASSES WITHOUT THE USE OF CANADA BALSAM. Gum-copal pulverized in a mortar, adding spirits of tui-pentine gradually, but only enough to dissolve it to form a consistency of Venice turpentine, or balsam of fir, produces the finest efiect on the application of the two glasses. GUM-SHELLAC VARNISH FOR PLATE-HOLDERS. Dissolve sufficient of gum-shellac in 95 per cent, alcohol to render it the consistency of cream. This varnish should be always on hand ready for use, to varnish over the photographic frames or plate-holders, as the action of the acid in the bath will cause the glasses in the corner to become loosened. By applying this simple varnish with a brush, the glasses will remain in their places, and. prevent the action of the nitrate of silver. The proper time to apply this varnish is in the afternoon, after the plate-holders are laid aside, because it will require some time for them to dry. 192 APPLYING THE VAENISHES. Before applying tlie varnish, be careful to remove all moisture from the holders, and varnish all that portion of the plate-holders that is subject to being wetted bj the solution of the nitrate bath. APPLYING THE VARNISHES. The white varnishes are always applied in the same manner as the collodion — viz., by pouring it on the surface, and allowing it to run off at one corner into the bottle. It is necessary in applying most white varnishes that the glass plate should be slightly warmed, either by the fire or spirit-lamp, avoiding all dust or moisture. To entirely remove the dirty particles, it will be proper to filter the varnish through a thin white linen or cotton cloth. The black varnish can be applied in the same manner. It may be dried very quickly by placing it near a gentle heat, or laying it in the sun. Of course it must be laid in a perfectly horizontal position. X A soft camel's-hair brush may be used to apply the black varnish ; and if it is applied thin, it will dry in much less time. A second application of .the varnish can be made, should the first not prove intense enough. For protection, it is well to place a piece of PROTECTUSTG THE VARNISH. 193 pasteboard (which has been previously blackened with the black varnish apd dried) on the back of the glass, with the blackened side towards the varnish. This insures a perfect black on the col- lodion, even if the varnish is very thin ; and if held by transmitted light, it would have a brownish appearance. It likewise affords a protection to the glass, avoiding breakage in case the picture falls to the ground. Some operators have adopted the black-glazed paper. Tliis presents too high polish for good effects, and will sometimes be seen through the varnish. A perfectly deadened surface of black is required to produce the effect. Black cotton velvet answers the purpose, and, as will be seen, has been adopted in all the transparent cases used for Ambrotyi^es. Cases lined with black velvet are being adopted for these pictures. 17 CHAPTER XVIII. CAUSES OF FAILURE IN THE PRACTICE OF THE ART- FOGGING THE PICTURES TO DETECT THE FOGGING OF PLATES BLACK AND WHITE SPECKS ON THE PLATES TRANSPARENT AND OPAQUE SPOTS IM- PURITY OF CHEMICALS SPOTS OR STREAKS ON THE GLASS PLATES. The process is so full of variations in the details of practice, and the chemicals are so liable to be affected bj the slightest change, that many who are induced to adopt this art meet with difficulties in great abundance. Failures in the art were formerly considered a general rule, and a matter of certainty, while good pictures were regarded as fortunate exceptions. "We have, however, progressed so far, that this state of things has not been encountered in the practice of late years, and we are now enabled to proceed with some degree of certainty. Nevertheless, the art is not yet perfect, and FOGGING THE PICTUKE. 195 failures will meet the early practitioner at the threshold of his profession, and perhaps intimidate his too confident expectations of success. The various causes of failui-es will be explained in as clear and lucid a manner as possible ; jet there may be some causes overlooked which may occur to others that have not been observed. "We are indebted to Mr. Hardwich, of London, for much information on this subject, and it is hoped the author will not be deemed presumptuous if he profits by the experience of that ablest of photo- graphers of the present day. FOGGING THE PICTURE. The " fogging," as it is termed, will most fre- quently occur from a too careless exclusion of light. The liability to this failure is obvious, for the slightest trace of white daylight falling upon the plate will surely cause fogging. It will there- fore be highly important to guard against this oft recurring obstacle. Fogging is sometimes attributable to weak col- lodion, or to a bath too weak, and sometimes to over-developing. In order to detect the ultimate cause of this failure, when it occurs, a series of ex- periments may be made as follows : 196 TO DETECT FOGGING. PLAN" OF PEOCEEDmG IN OEDEPv TO DETECT THE CAUSE OF THE FOGGING. If the operator has had but little experience in the collodion process, and is using good Arnbro- tjpe collodion of great sensitiveness in a new bath, the probability is that the cause of fogging will be over-exposure. Having obviated this, which can easily be done by shortening the time, proceed to test the bath, and add sufficient acetic or nitric acid to give a faint acid reaction to test- paper. Next prepare a plate as usual, and immediately on its removal from the bath, pour on the devel- oper : after a few seconds wash, fix, and bring it out to the light. If any mistiness is perceptible, the developing room is in fault. On the other hand, if the plate remains abso- lutely clear under these circumstances, it is possi- hle that the cause of error may he in the camera. Prepare another plate, place it in the camera, and proceed exactly as if taking a picture, neglecting, however, to expose the plate to the action of light. Allow it to remain for two or three minutes, and then remove and develop as usual. If no indication of the cause of fogging be SPECKS UPON THE PLATES. 197 obtained by either of these ways, there is every reason to suj)pose that it is due to diffused light gaining entrance through the lenses, or some por- tion of the camera box. BLACK AND WHITE SPECKS UPON" THE PLATE. Opaque or transparent dots, thickly studding every part of the plate, are produced by the fol- lowing causes : 1. The use of collodion containing floating par- ticles. — Each particle becomes a centre of chemi- cal action, and produces a speck or black spot. Collodion should never be employed imme- diately after mixing, but placed aside to settle for several hours, after which the upper portion may be poured off for use. This is especially necessary when the double iodide of potassium and silver is employed : the salt is decomj)Osed to a certain ex- tent by dilution.^ and small particles of iodide of silver separate, which eventually settle to the bot- tom of the bottle. 2. Dust upon the surface of the glass at the time of pouring on the collodion. — Thoroughly cleaned glasses, if set aside for a few minutes, accumulate small particles of dust. Each plate, therefore, should be gently wiped with a silk handkerchief, 17* 198 TRANSPARENT SPOTS. or a buckskin buff made in the form of a ball, im- mediately before being used, and lastly dusted with a camel's-hair brush. 3. Where an inferior kind of glass is used. — The surface of an inferior quality of glass is ofteiv times roughed and studded with minute specks. Occasionally these can be removed by means of diluted acid. TKANSPARENT AND OPAQUE SPOTS. Spots are of two kinds — spots of opacity^ which appear yiach when seen by transmitted light, and white by reflected light, and spots of transparency^ the reverse of the others, being white wdien seen on negatives, and black on positives. Opaque spots are referable to an excess of devel- opment at the point where the spot is seen. They may be caused by — 1. The nitrate solution heing turhid., or from flakes of iodide of silver having fallen away into the solution by use of an over-iodized collodion ; from a deposit formed by degrees upon the sides of the gutta percha trough ; from the inside of the trough being dusty at the time of pouring in the solution. In order to obviate these inconveniences, it is well to make at least half as much again of FAULTS m THE PLAl-E-UOLDEE. 199 the niti'ate solution as is necessary, and to keep it in the large bottle, from which the npper part may be ponred off as it is required. 2. Faults 171 the plate-holder. — Sometimes a small hole exists in the slide, which admits a pen- cil of light, and produces a spot known by its being always in the same place. Occasionally the door works too tightly, so that small particles of wood, (fee, are scraped off and projected against the plate when it is raised ; or perhaps the opera- tor, after the exposure is finished, shuts down the slide too quickly, and causes a sj)lash in the liquid, which has drained down and accumulated in the groove below. This cause, although not a com- mon one, may sometimes occur. Spots of transparency are produced in a man- ner altogether different from that of the others. 1. They may generally be traced to some cause which renders the iodide of silver insensitive to light at that particular point., so that on the ap- plication of the developer no reduction takes place. 2. Concentration of the nitrate of silver on the surface of the film hy evaporation. — When the film becomes too dry after removal from the batli, tlie solvent power of the nitrate increases so much that it is apt to eat away the iodide, and produce spots. 200 IMPURITY OF CHEMICALS. 3. By raising the jplate off tlie nitrate Itath too quickly after its first immersion. 4. By pouring on the develojper entirely on one portion of the jplate^ by which the nitrate of silver is washed away, and the development prevented. 5. By use of glasses improperly cleaned. — Tliis cause is perhaps the most frequent of all. Great care should therefore be observed in cleaning the glasses, and in keeping them in good order, and in readiness for the collodion. IMPURITY OF CHEMICALS, ETC. Chemicals ai"e so liable to be of inferior quality, that this cause of failure is indeed one that appears almost insurmountable ;- yet, although a great diffi- culty here presents itself, there is a. possibility of obtaining good material, and they should be sought till they are found. The vapors of ammonia or bromine, or even iodine, will cause the plate to become covered with spots or stains. SPOTS OR STREAKS, ETC. Spots or streaks which are yet black, coming from the corner where the plate is held by the fin- gers, are caused by hyposulphite or cyanide of STREAKS IN COLLODION. 201 potassium in some manner running from the hand. Streaks that are parallel, running up and down the 'plate, are caused by the dust floating in the bath at the time of immersion. Streaks which lie in the bed of the collodion, looking like rivers laid down on a map, are caused by not washing the plate sufiiciently after the de- veloping solution has been applied. Streaks or lines resembling miislin, and streaks which have a cloudy appearance, occur when the collodion is thicker on some portion of the plate than on another. The streaks resembling leaves are also due to the same cause. If there is not a >!ufiicient quantity of acetic acid in the developer, it will not flow evenly over the plate, and will in- variably cause streaks. CHAPTER XII. CAUTIONS WITH REGARD TO USING THE VARIOUS CHEMICAL SUBSTANCES IN MAKING GUN-COTTON USE OF ETHER AND ALCOHOL USE OF CYANIDE OF POTASSIUM NITRATE OF SILVER — CLEANING THE HANDS SOLUTION FOR CLEANING THE HANDS HINTS ON THE VARIOUS PROCESSES CONNECTED "WITH POSITIVES AND NEGATIVES — TO RENDER COL- LODION HIGHLY SENSITIVE THE LAMPRATYPE PRO CESS, In the practice of the photographic art, great caution is necessary to be observed in regard to the various chemicals employed. By a singular coincidence of circumstances, very many of the chemicals are combustible, and are indeed of a very explosive nature, while those which are not inflammable are poisonous. It will therefore be the wish of every operator to avoid accidents, as they are always liable to occur un- less they are carefully guarded against. In preparing gun-cotton, the vapors arising from the combination of the acid and nitrate of potash DRYING GTJN-COTTON. 203 were very deleterious, if inhaled, as they are liable to be, because it is necessary to stir the cotton dur- ing the whole time of immersion. Always ]3re- pare it in the open air, or where a free circulation of it may be obtained. When the cotton is drying, avoid any contact of iire, or an approach to the fire, for it explodes at the temperature of 370° Fahrenheit, while gun- powder requires 500°. If gun-cotton is kept a long time in large quantities, spontaneous combus- tion may ensue, if any moisture comes in contact with it. In using ether and alcohol, be careful to remove the lamj) to a great distance from it. In pouring the collodion on the plate, one is very liable to accident, for the vapors of ether are rapidly pass- ing off. They will ignite even if the lamp is within one or two feet of the bottle. Coat the plates by the light of day, if possible, thereby avoiding the possibility of combustion of the collodion. In pouring ether or collodion from one bottle to another, jDractice the greatest care, as the vapors will ignite at a long distance from these substances, when they are made to evaporate. Cyanide of potassium will have the effect of a virulent poison, if taken in the system ; and even 204 TO CLEAIS TIIK HANDS. inlialing the fumes which constantly arise from it are injurious. Bj wetting the lips slightly with alcohol immediately afterwards, it will in some degree neutralize the unpleasant effects. Use no soap to remove the stains of nitrate of silver, but employ cyanide of potassium, which must be well washed with clean water to remove any traces of that substance. Should the skin be broken, a small quantity of cyanide will enter, causing considerable pain and inconvenience. Avoid the contact of the hands as much as pos- sible with the nitrate of silver solution, as well as dro23ping it upon the clothes. Wherever it may fall, it will cause a stain or mark that nothing but cyanide of potassium will remove. TO CLEAN THE HANDS. The most effectual way to clean the lingers when they become stained with nitrate of silver, is to moisten them and rub them with cyanide of potassium. This should be used as soon as possi- ble after the stains have been made. A piece of pumice-stone rubbed down to a flat surface is also very effectual in removing fresh stains. REMOVING STAINS OF SILVER. 205 Als^OTHER PLAK "Wash the hands with a solution of iodine, dis- solved in alcohol, and while they are wet wash with a strong solution of hyposulphite of soda, afterwards with water, to remove all traces of the salt, METHOD OF EEMOVIl^G THE STAINS OF SILVER FROM LIKEIvT, THE HANDS, ETC, Mix together — Common alcohol .... 20 parts. Iodine 1 part. Nitric acid 1 part. Hydrochloric acid .... 1 part. These produce a reddish liquid, which, when aj)- plied to stains caused by any salts of silver, im- mediately converts them into chloride and iodide of silver, soluble in hyposulphite of soda and cya- nide of potassium. The effect is especially marked on stained linen. When a black patch is touched with the liquid, by means of a little brush, it in- stantly turns yellow, with a violet border, if the linen has been starched. On washing with the hyposulphite, or with the cyanide, the violet tint immediately vanishes, and the yellow spot by de- 18 206 HINTS AND SUGGESTIONS. grees. It is well to wash the stained place after the application of the iodized solution, in order to remove the acids, which might produce independ- ent stains by contact with the hji^osulphite or the cyanide. For the hands, the operation is the same, except that, instead of using a brush, the skin may be rubbed with a piece of rag or cotton. HINTS AND SUGGESTIONS. The following hints and suggestions in regard to the practice may be observed with profit : Always keep the stoppers in the bottle, except when the bottle is in actual use. Always cover the nitrate of silver bath, except when in use. Always rinse the fingers well in clean water after develoj)ing a picture, or the next will prob- ably be injured. The frames for holding the glass plates in the plate-holder will require revarnishing, as the ni- trate of silver often acts on the wood, and produces Btains on the jjicture. Frequently wash the glass bottles containing the developing solution. Be careful that the towels and clothes for clean- DECANTING THE COLLODION. 207 ing the glasses are used for no other purpose, and are free from all contact of soap, &c. Kemove carefully any dried collodion which may form about the neck of the bottle. Particularly observe that in every thing con- nected with photography, the most scrupulous at- tention to cleanliness is indispensable to good suc- cess. Remember to decant from the large bottle a sufficient quantity of collodion every evening for use the following day into several small bottles, as the oftener it is decanted, the more pure the col- lodion. If the collodion is too thick, and requires the addition of more ether, the proper time to add it o'ill be when it is decanted. It may then be slightly agitated. Avoid in all cases the shaking of collodion, or of the varnishes. The collodion is always throwing down a precipitate which requires»many hours to fall again, if disturbed ; and the varnish will be- come full of air-bubbles, which on being applied to the surface of the plate, greatly injure it. In applying the thick varnish, or the balsam, between the two glasses, according to the "patent process," great care must be observed to avoid the 208 THE USE OF TEST-PAPEKS. air-bubbles. It should be poured only on the cen- tre of the glass, and then with only a drop or two. After the pouring, the balsam should form a slight line, running to the edge of the glass, otherwise air-bubbles will inevitably be produced. Avoid pressing the glasses after they are sealed. Use gutta-percha dishes for all photographic purposes, and avoid bringing them too near the fire, as they will melt at a low temperature. In using test-papers, observe the following pre- cautions : They should be kept in a dark place, and protected from the action of the air, or they soon become purple from carbonic acid, always present in the atmos^^here in small quantities. By immersion in water containing about one drop of , liquor potasse in four ounces, the blue color is re- stored. Test-papers prepared with porous paper show the red color better than those upon glazed or strongly sized paper. If the quantity of acid pres- ent, however, is small, it is not sufficient in any case simply to dip the paper in the liquid : a small strip should be thrown in, and allowed to remain for ten minutes or a quarter of an hour. If the paper, on immei'sion, assumes a wine-red, or purple tint, in place of a decided red, it is prob- COLLODION HIGHLY SENSITIVE. 'J()!« ably caused by carbonic acid gas. In that case the blue color returns when the paper is washed and held to the fire. Blue litmus-paper may be changed to the red paj)ers used for alkalies by soaking in water acidified with sulphuric acid, one drop to half a pint. TO RENDER ANY COLLODION HIGHLY SENSITIVE. By the addition of two or three drops of a solu- tion of iodide of iron in alcohol to every ounce of iodized collodion, it will cause it to make the im- pression in the camera in an incredible short space of time ; but as it soon injures the quality of the collodion, it is well not to sensitize only as much as is wanted for immediate use. TO DAREIEN AMBROTYPES, OR THE LAMPRATYPE. A new and ingenious plan has been devised and successfully carried into practice by Mr. S. A. Holmes, of New York, of rendering Ambrotypes much darker in the dark portions of the picture, and whiter in the white portions. For distinction, he has named them Lampratypes. The method of efiecting this is as follows : 18* 310 PEARL AMBROTYPES. THE LAMPRATYPE PROCESS. After the picture is well dried on the glass, and before applying any v.irnish, gently rub it, on the collodion side, with a round buck- skin butF ball, made of the softest quality of buckskin, and tied very lightly over cotton. This buff must be used for no other pur- pose. Pass the buif lightly across the plate in straight lines, and it will assume a darker hue until the desired shade is attained. By tliis same process a portion cf the hair that may be too light, can be rendered darker by rubbing it lightly with a brush, or eamel's- hair pencil ; or any portion of the drapery may be changed, to a darker shade, if desirable. TO MAKE THE PEAEL AMBEOTYPES. Dissolve one ounce of bi-chloride of mercury (corrosive subli- mate) in half an ounce of pure muriatic acid, and add to this six ounces of water ; or a saturated solution of bi-chloride in water will answer as well. As soon as the ambrotype is finished in the usual manner, and ready for drying, place it on a Daguerreotype gilding- stand, and pour sufficient of this solution over the plate to cover it, allowing it to remain for a few minutes. At first it will assume a dark color, and lines appear on its surface ; but if allowed to remain a short time, or if a small degree of heat from a spirit-lamp is ap- plied, it will soon change to a beautiful clear pearl white, the lights and shades being very transparent. When the requisite color is attained, great care must be used in washing the solution from the plate, as the collodion is affected by the acid. These pictures can only be slightly colored, and only the white arnish applied, and backed with a blackened glass, without any ansparent medium. Tlie black varnish cannot be applied to the collodion side, in con- cquenee of the great transparency. Impressions which are too short time in the camera, may be ren- ered white and sufficiently clear by this process — hence it is very useful for taking children's portraits, and has been adopted by many with great success. CHAPTER XX. VOCABULARY OP PHOTOGRAPHIC CHEMICALS ACETIC ACID ALCOHOL^AMMONIA BROMINE BROMIDE OF POTASSIUM CARBONATE OF SODA CYANIDE OF POTASSIUM CHLORIDE OF GOLD HYPOSULPHITE OF GOLD HYPOSULPHITE OF SODA IODINE IODIDE OF AMMONIA IODIDE OF POTASSIUM IODIDE OF SIL- VER PROTOSULPHATE OF IRON LITMUS NITRIC ACID NITRATE OF POTASH — NITRATE OF SILVER SULPHURIC ACID PROPERTIES OF ETHER PROPER- TIES OF WATER. A VOCABULARY of the principal chemicals used in the jDhotographic art is deemed necessary mainly for purposes of reference. It frequently may occur to the experienced oj^erator, that a more intimate knowledge of the construction of the ingredients used in the art is required, and this can be sup- plied in a good measure without a reference to large works on chemistry. This vocabulary is not to be considered as a complete one on the subject ; but only so far as 212 ACETIC ACID. one may require information specially connected with the practice of this art, will this be found useful. The symbols are omitted, for the reason that, if used, they would require further explanation, and continue to lead the more inexperienced chemist into difficulties, and would render the book too prolix with chemical terms. Some of these terms, however, are unavoidably introduced. ACETIC ACID. Acetic acid is a product of the oxidation of al- cohol. Spirituous liquids, when perfectly pure, are not affected by exposure to air ; but if a por- tion of yeast, or nitrogenous organic matter of any kind is added, it soon acts as ^ ferment^ and causes the spirit to unite with oxygen derived from the atmosphere, and so to become sour from formation of vinegar, or acetic acid, as it is properly termed. The most concentrated acetic acid is obtained by neutralizing common vinegar with carbonate of soda, and crystallizing out the acetate of soda so formed ; this acetate of soda is then distilled with sulphuric acid, which removes the soda and liber- ates acetic acid : the acetic acid being volatile, distils over, and may be condensed. ALCOHOL. 213 Properties of Acetic Acid. — The strongest acid contains only a single atom of water ; it is sold under the name of " glacial acetic acid^'' so called from its property of solidifying at a moderately low temperature. At about fifty degrees the crys- tals melt, and form a limpid liquid of pungent odor, and a density nearly corresponding to that of water. The specific gravity of acetic acid, how- ever, is no test of its real strength, which can only be estimated by analysis. In purchasing the commercial acid (which is generally known as Acetic Acid No. 8) for photo- gra^^hic purposes, it is important to distinguish the glacial acid from a liquid oi '•'' ten per cent, real acid''"' sometimes sold ; also it is well to test for the presence of sulphuric acid., which may be recog- nized by the white precipitate produced on adding a drop of solution of cldoride of barium. ALCOHOL. Alcohol is obtained by the careful distillation of any spirituous or fermented liquor. If wine or beer be placed in a retort, and heat applied, the alcohol, being more volatile than water, rises first, and is condensed in an appropriate receiver ; a portion of the vapor of water, however, passes over 21i AMMONIA. with the alcohol, and dilutes it to a ceriain degree, forming what is termed " spirits of wiiie." In or- der to render the alcohol thoroughly anhydrous^ it is necessary to employ the quick-lime^ which pos- sesses a still greater attraction for water. An equal weight of this powdered lime is mixed with the al- cohol, and the two are distilled together. Properties of AlcohoL — ^Pure anhydrous alco- hol is a limpid liquid, of an agreeable odor and pungent taste ; specific gravity at 60-794. It ab- sorbs vapor of water, and becomes diluted by expo- sure to damp air ; boils at 1.73 Fahrenheit, It has never been frozen. Alcohol distilled from carbonate of potash, has a specific gravity of '823, and contains 90 per cent, of real spirit. The specific gravity of ordinary rectified spirits of wine is usually about .840, and it contains 80 to 83 per cent, of absolute alcohol. AlklMONIA. The liquid known by this name is an aqueous solution of a volatile gas. Ammoniacal gas contains one atom of nitrogen combined with three of hydrogen. These elemen- tary bodies exhibit no aflSnity for each other, but PKOPEKTIES OF AMMONIA. 215 they can be made to unite under certain circum- stances, and the result is ammonia. Properties of Ammonia. — Ammoniacal gas is soluble in water to a large extent ; the solution possesses those properties which are termed allia- line. Ammonia, however, differs from the other alkalies in one important jDarticular — it is volatile ; hence the original color of turmeric paper, af- fected by ammonia, is restored on the application of heat. Solution of ammonia absorbs carbonic acid rapidly from the air, and is converted into carbonate of ammonia ; it should therefore be pre- served in stoppered bottles. Besides carbonate, commercial ammonia often contains chloride of ammonia, recognized by the white precii^itate given by nitrate of silver after acidifying with pure nitric acid. The strength of commercial ammonia varies greatly. That sold for pharmaceutical purposes, under the name of Liquor Ammoniae, contains about ten per cent, of real ammonia. The sj)ecific gravity of aqueous ammonia dimin ishes with the projjortion of ammonia present, the liquor ammonise being usually about 'PSO. 216 BROMIDE OF POTASSroM. • BEOMIKE. This elementary substance is obtained from the uncrystallizable residue of sea-water, termed hit- tern. It exists in the water in very minute pro- portion, and combined with magnesium, in the form of a soluble bromide. Properties. — Bromine is a deep reddish-brown liquid of a disagreeable odor, and fuming strongly at common temperatures; sparingly soluble in water (1 part in 23 — Lowig), but more abundantly so in alcohol, and especially in ether. Specific gravity 3'0. Bromine is closely analogous to chlorine and iodine in its chemical properties. It stands on the list intermediately between the two — its afiinities being stronger than those of iodine, but weaker than chlorine. It is a powerful poison. BROMIDE OF POTASSIUM. Bromide of potassium is prepared by adding bromine to caustic potash, and heating the pro- duct, which is a mixture of bromide of potassium and bromate of potash, to redness, in order to drive off the oxygen from the latter salt. It crystallizes in anhydi-ous tubes like the chloride and iodide of CYANIDE OF POTASSroM. 217 potassium ; it is easily soluble in water, but more sparingly so in alcohol; it yields red fumes of bromine when acted upon by sulj^huric acid. CARBON'ATE OF SODA. This salt was formerly obtained from the ashes of sea-weeds, but is now more economically manu- factured on a large scale from common salt. The chloride of sodium is iii'st conyerted into sulphate of soda, and afterwards the sulphate into carbo- nate of soda. Properties. — Tlie perfect crystals contain ten atoms of water, which are driven off by the appli- cation of heat, leaving a white powder — the anhy- drous carbonate. Cotwrnon washing soda is a neu- tral carbonate, contaminated to a certain extent with chloride of sodium and sulphate of soda. Carbonate of soda is soluble in twice its weight of water at 60°, the solution being strongly alkaline. CYANIDE OF POTASSIUM. This salt is a compound of prussic acid with po- tassium, and a very deadly poison. It is used in photography : added to nitrate of silver, it jnelds cyanide of silver, which is very sensitive to the action of light; but when added to the iodide and 19 218 CHLORIDE OF GOLD. the fluoride of potassium, it forms a triple salt of great sensitiveness. Cyanide of silver is insoluble in water, and in diluted nitric acid. It is decom- posed by hydrochloric acid, and changed into chlo- ride of silver. Solution of ammonia, the alkaline cyanides, and especially hyposulphite of soda, dis- solve it. The cyanide of potassium dissolves the iodide, chloride, and bromide of silver; hence it is used as a fixing agent for ambrotypes. It also dissolves the protoxides and suboxides of this metal when they are precipitated by gallic acid. A solution of the salt is useful, with the aid of a brush, to re- move the black spots which injure positive pictures on i^aper, only it must be applied with great cau- tion, and the print immersed in water immediately after its application, else it may destroy it entirely. CHLORIDE OF GOLD. This salt is formed by dissolving metallic gold in nitro-hydrochloric acid, or aqua regia^ and eva- porating at a gentle heat. The solution aifords deliquescent crystals of a deep orange-color. Pro])erties.- — The solution of terchloride of gold is of a bright yellow color when dilute, but nearly red if concentrated. As usually sold, it contains HYPOSULPHITE OF SODA. 219 an excess of hydrochloric acid ; but even if freed from this, it is still acid to test-paper, although neutral, chemically speaking. It is decomposed with precipitation of metallic gold by charcoal, sulphurous acid, and many of the vegetable acids ; also by protosulphate or protonitrate of iron. It tinges the cuticle of an indelible purple tint. It is soluble in alcohol, and also in ether. The addition of ammonia to terchloride of gold produces the dangerous explosive compound known 2iB fulminating gold. HYPOSULPHITE OF GOLD. Hyposulphite of gold is produced by the reac- tion of chloride of gold upon hyposulphite of soda. The salt sold in C(jmmerce as sel d'or is a double hyposulphite of gold and soda, containing one atom of the former salt to three of the latter, with fom* atoms of water of crystallization, HYPOSULPHITE OF SODA. This salt is very soluble in water at all tempera- tures. It is of great service in photography for " fixing" the positive pictures on paper, which it accomplishes by dissolving the salts of silver, such as the chloride, iodide, &c., which are insoluble in 220 IODINE. water, and so removing tliem from the picture, and thereby preventing any further chemical change in the impression. The solution of h}'po- sulphite of soda, after it retains some of the salts of silver in solution, is more useful for the fixing process, as it gives better black tones than when first employed. It is the best fixing material yet discovered, both for positives on paper and nega- tives on glass ; and by careful manipulation, al- most every variety of tone can be given *to the pictures. With faint positive pictures, it is best to soak them for a few hours in a bath of clean water before submitting them to the action of the hyposulphite of soda, by which means the soluble salts of silver are removed without affecting those parts acted upon by the light, which constitute the blacks. Thus we abridge the time necessary for the action of the hyposulphite, and the fixed image is found to be more vigorous than if it had been placed at once in the hyposulphite of soda. IODINE. Iodine is chiefly prepared at Glasgow, from Tcelp^ which is the fused ash obtained by burning sea- weeds. The waters of the ocean contain minute quantities of the iodides of sodium and magnesium, PROPERTIES OF IODINE. 221 which are separated and stored up by the growing tissues of the marine j)lant. Properties. — Iodine is met with in two forms — the commercial and the resublimed iodine. The former, which is sold at a lower price than the other, is sufficiently pure for most ])urposes. Iodine has a bluish black color and metallic lusti-e. It stains the skin yellow, and has a pun- gent smell, like diluted chlorine. It is extremely volatile when moist, boils at 350°, and produces dense violet-colored fumes, which condense in bril- liant plates. Specific gravity 4-946. Iodine is very sparingly soluble in water, one part requir- ing 7,000 parts for perfect solution. Even this minute quantity, however, tinges the liquid of a brown color. Alcohol and ether dissolve it more abundantly, forming dark-brown solutions. Iodine also dissolves freely in solutions of the alkaline iodides — such as the iodide of potassium, of sodi um, and of ammonium. Chemical jyrojperties. — Iodine belongs to the chlorine group of elements, characterized by form- ing* acids with hydrogen, and combining exten- sively with the metals. They are, however, com- joaratively indiflerent to oxygen, and also to each other. 19* 2-^3 IODIDE OF AMMONIA. Tlie iodides of the alkalies, and alkaline earths, are soluble in water ; also those of iron, zinc, cad- mium, etc. The iodides of lead, silver, and mer- cury are neaj'ly or quite insoluble. Iodine possesses the property of forming a com- pound of a deep-blue color with starch. In using this as a test, it is necessary, first, to liberate the iodine (if in combination) by means of chlorine, or nitric acid saturated with peroxide of nitrogen. The presence of alcohol or ether interferes to a certain extent with the result. IODIDE OF AMMONIA. The hydriodate of ammonia is a compound very easily decomposed : it must be kept suspended in a bottle containing a small quantity of carbonate of ammonia. Sensitive papers may be prepared by washing them with a solution of this substance previous to placing them upon the aceto-nitrate of silver ; an impression is received with great rapidity, which is developed with facility by gallic aid, to which a little acetate of ammonia has been added. • • IODIDE OF POTASSIUM. Iodide of potassium is one of the principal IODIDE OF SlL,VER. 223 chemical agents in photography. It serves to fonn the iodide of silver, which is the sensitive salt upon which light acts with the greatest energy. This iodide of silver is insoluble in water, but sol- uble in hyposulphite of soda, which is used for '"'' fixing''' the negative pictures. This salt is usually formed by dissolving iodine in solution of potasli until it begins to acquire a brown color ; a mixture of iodide of potassium and iodide of potash is thus formed ; but by evapora- tion and heating to redness, the latter salt parts witli its oxygen, and is converted into iodide of potassium. Properties. — It forms cubic and prismatic crys- tals, which should be very hard, and very slightly or not at all deliquescent. Soluble in less than an equal weight of water at 60° ; it is also soluble in alcohol, but not in ether. IODIDE OF SILVER. Iodide of silver is obtained by adding iodide of potassium to a solution of nitrate of silver ; de- composition ensues, the nitric acid leaves the silver and unites with the potash, while' the liberated iodine coinl)ines with the silver, and falls as a yel- low precipitate, which must be well wasbed in 224: PROTOSULPHATE OF IRON. distilled water, being insoluble therein, to remove the nitrate of potash, and then dissolved in a sat- urated solution of iodide of potassium. This mix- ture is to be added to the collodion in small quan- tities at a time, and agitated until dissolved. PEOTOSULPHATE OF IRO¥. This is the copperas or green vitriol of com- merce — a most abundant substance, and used ibi a variety of i3urposes in the arts. Commercial sul- phate of iron, however, being prepared on a large scale, mostly requires recrystallizing in order to ren- der it sufKciently pure for photographic purposes. Pure sulphate of iron is met with in the form of large, transparent, prismatic crystals, of a deli- cate green color ; by exposure to the air they grad- ually absorb oxygen, and become rusty on the surface. Solution of sulphate of iron, colorless at first, afterwards changes to a red tint, and de- posits a brown powder ; this powder is a hasic persulphate of iron, that is to say, a persulphate containing an excess of the oxide, or " hase?^ By adding sulphuric acid to the solution of protosul- phate of iron, the formation of a deposit is pre- vented, but the decomposition goes on slowly as before. NiTEic Acm. 225 LITMUS. Litmus is a vegetable substance, prepared from various lich^ns^ which are principally collected on rocks adjoining the sea. The coloring matter is extracted by a peculiar process, and afterwards made up into a paste with chalk, plaster of Paris^ etc. Litmus occurs in commerce in the form of small cubes, of a fine violet color. In using it for the preparation of test-papers, it is digested in hot water, and sheets of porous paper are soaked in the blue liquid so formed. The red papers are pre- pared in a similar manner, and afterwards placed in water which has been rendered faintly acid with sulphuric or hydrochloric acid. NITEIC ACID. This acid is obtained by distilling a mixture of equal parts, by weight, of nitrate of potash and sulphuric acid. It is very abundant in commerce, and is useful in photography to form the nitrate of silver ; and in combination with muriatic acid {aqua regia)^ to yield the chloride of gold : added to the sulphate of the protoxide of iron, it converts it into the sulphate of the peroxide. 226 NITRATE OF POTASH. It is also employed to darken the tone of the shadows of the jiositive paper pictures, after they have been submitted to the action of the hyposul- jAute of soda. Its action is similar to that of the muriatic acid used for the same purpose. As it possesses great solvent powers, it is very useful for removing the deposits left on the gutta- percha or porcelain dishes, &c. ; but the greatest care must be taken that no free acid appears in any of the preparations used in photography ; for however useful in its combinations with silver, &c., alone, it has a most destructive influence by its deoxydizing qualities, neutralizing the effects produced by the agency of light. NITRATE OF POTASH. This salt, also termed nit're or saltpetre, is an abundant natural product, found effloresced upon the soil in certain parts of the East Indies. It is also produced artificially in what are called nitre- beds. NITEATE OF SILVER. Nitrate of silver is the most important ingre- dient in photography. It is a compound of nitric acid with the metal silver in its highest state of NITKATE OF SILVER. 227 oxydation. It is decomposed by iodide of potas- sium, by whicli iodide of silver is obtained. The best nitrate of silver is in thin colorless crystalline plates, which are soluble in an equal weight of cold water. Exposed to light, this salt blackens, especially if any organic matter is present. Ad- vantage is taken of this peculiar property to pre- pare the sensitive solutions which are spread upon the paper and glass, and other media employed in obtaining photographic pictures. It is readily de- composed by chlorides, bromides, fluorides, cy- anides, &c., producing salts of exquisite sensibility; and if these, or some of them, are added to the iodide of potassium, in the first preparation of the paper, when they are submitted to the contact of the nitrate of silver, compounds are formed, ap- parently intermediate in their atomic constitution^ between the protoxide and the suboxide of silver. As soon as the light strikes these preparations in this condition, they pass from the state interme- diate between the protoxide and suboxide to the metallic state, the silver is reduced, and is preci- pitated in a dark-colored form by gallic or pyro- gallic acid, in various degrees of strength, accord- ing to the extent of the reduction. The chiel object and aim in the future of photography is in 228 SULPHURIC ACID. the direction of the developing agents. "We have found substances which require but an instantane- ous exposure to the action of light to effect that change, which, once set up, is continued and com- pleted by suitable developing agencies. SULPHURIC ACID. Sulphuric acid may be formed by oxydizing sul- phur with boiling nitric acid ; but this plan would be too expensive to be adopted on a large scale. The commercial process for the manufacture ol sulphuric acid is exceedingly ingenious and beau- tiful, but it involves reactions which are somewhat complicated, and do not admit of a superficial ex planation. Properties. — Anhydrous sulphuric acid is a white crystalline solid. The strongest liquid acid always contains one atom of water, which is closely associated with it, and cannot be driven off by the application of heat. Sulphuric acid possesses intense chemical powers, and displaces the greater number of ordinary acids from their salts. It chars organic substances, by removing the elements of water, and converts alco- hol into ether in a similar manner. The strength of a given sample of sulphuric acid may generally TEST OF SULPHUEIO ACID. 229 be calculated from its specific gravity, and a table is given by Dr. Ure for that purpose. Impurities of Commercial Sulphuric Acid. — Tlie liquid acid known as oil of vitriol is tolerably constant in composition, and seems to be as well adapted for photographic use as the pure sulphuric acid, which is far more expensive. The specific gravity should be about 1*836, at 60°. If a drop, evaporated upon platinum foil, gives a fixed resi- due, probably bisulphate of potash is present. A milkiness on dilution indicates sulphate of lead. Test for Sulphuric Acid^ either free or in com- hinatimi with Bases. — If the presence of sulphuric acid, or soluble sulphate, is suspected in any liquid, it is tested for by adding a few drops of a dilute solution of chloride of barium or nitrate of baryta. A white precipitate, insoluble in nitric acid., indi cates sulphuric acid. If the liquor to be tested is very acid, from nitric or hydrochloric acids, it must be largely diluted before testing, or a crystal- line precipitate will form, caused by the sparing solubility of the chloride of barium itself in acid solutions. 20 230 PBOPERTIES OF ETHER. ETHER. Ether is obtained by distilling a mixture of sul- phuric acid and alcohol. The term sulpJiiiHc ap- plied to the commercial ether has reference only to the manner of its formation. Properties of Ether. — It is neither acid nor al kaline to test-paper. Specific gravity at 60°, about •720. Boils at 98° Fahrenheit. The vapor is ex- ceedingly dense, and may be seen passing off from the liquid, and falling to the ground — hence the danger of pouring ether from one bottle to another, if a flame be near at hand. Ether does not mix with water in all propor- tions — hence if the two are shaken together, after a short time the former rises and floats upon, the surface. In this way a mixture of ether and alco- hol may be separated from each other, as in the common process of washing ether. The water employed, however, always retains a certain por- tion of ether (about a tenth part of its bulk), and acquires a strong ethereal odor. Washed ether also contains water in small proportion. Bromine and iodine are both soluble in ether, and gradually react upon and decompose it. The strong alkalies, such as potash and soda. PROPERTIES OF WATER. 231 also decompose ether slightly after a time, but not immediately. Exposed to air and light, ether is oxydized, and acquires a peculiar odor. Ether dissolves fatty and resinous substances readily, but inorganic salts are mostly insoluble in this fluid ; hence it is that iodide of potassium and other substances dissolved in alcohol are precipi- tated to a ceilain extent by the addition of ether. WATER. Water is an oxide of hydrogen, containing sin- gle atoms of each of the gases. Distilled water is water which has been vapor- ized and again cowidensed ; by this means it is freed from earthy and saline impurities, which are not volatile, and hence remain behind in the body of the retort. Pure water leaves no residue on evaporation, and should remain perfectly clear on the addition of nitrate of silver ; also it should be neutral to test-paper. Impurities of common Water. — Hard water, as it is termed, usually contains sulphate of lime and carbonate of lime, dissolved in carbonic acid ; also chloride of sodium in greater or less quantity. On boiling the water, the carbonic acid gas is evolved, and the greater part of the carbonate of lime (if 232 PROPERTIES OF WATER. any is present) deposits, and forms an earthy in crnstation on the boiler. In testing water for sulphates and chlorides, acidify a portion with a few drops oi pure nitric acid, free from chlorine ; then divide it into two parts, and add to the first chloride of barium, and to the second nitrate of silver, — a milkiness, in either case, indicates the presence of impurity. The photogra/phic nitrate hatJi cannot be used as a test for chlorides, since the iodide of silver it con- tains is precipitated on dilution. Rain-ioater^ having already undergone a natural process of distillation, is free from inorganic salts if collected in clean vessels ; bmt it usually contains a minute portion of ammonia, and often organic matter, which tinges it of a brown color. WEIGHTS AND MEASURES. 233 WEIGHTS AND MEASURES. The weight generally employed in Photography is the apothecaries' weight ; but some of the chem- icals are sold by avoirdupois ; for what reason no one can explain. Nitrate of silver is usually sold by that weight, as well as most of the liquids. The acids and al- kalies, however, are generally sold by apotheca- ries' weight. apothecaries' weight. 1 grain. 20 := 1 scruple 60 = 3=1 drachm 480 = 24 = 8= 1 ounce 5760 = 288 = 96 = 12 = 1 pound. AVOIRDUPOIS WEIGHT. 1 pound . . . . =16 ounces. 1 ounce . . . . =16 drachms. 1 drachm , . . . = 26*343 grains. (1 ounce avoirdupois . . = 437'5 grains.) IMPERIAL MEASURE. 1 gallon =8 pints. 1 pint =20 ounces. 1 ounce . . , . . = 8 drachms. (1 fluid ounce of water weighs 437.5 grains, or 1 ounce avoir dupois.) 20* 234 WEIGHTS AND MEASUEES. FLUID MEASURE. 1 minim . , . . = 0'9I 60 = 1 fluid drachm . =: 54-7 avoird. 480 = 8=1 fluid ounce = 437-5 — 1 oz. 9600= 160= 20 = 1 pint = 8-750= 1.25 lb. 76,800 = 1280 = 160 = 8 =2 gal'n = 70-000 = 10 lbs. (1 pound avoirdupoi.i contains 700U grains.) 1 pound Troy .... contains 5760 grains. 1 imperial gallon of water ... '' 70,000 " I imperial pint of water contains 20 ounces, or 8750 " 1 cubic inch of water " " " 252-4 " 1 ounce avoirdupois . " " " 437-5 " 1 ounce Troy . . " " " 480 1 gramme ..." " " 15-4 " 1 decigramme . . " " " 1-5 " 1 litre of distilled water " " " 15,406-3 " The grain is the unit of weight ; but as three standards of weight are employed, much uncer- tainty and confusion often arise in the mind of the photographer as to which ounce or drachm is meant. The apothecaries' weight is generally un- derstood to be the one employed ; but it would save much trouble if the formulae for the various preparations were always given in grains. INDEX. PAOB Albumen paper, to prepare 60 " " to silver 61 Ambrotypes on paper 170 " " on patent leather 155 Art, PliotogTiiphic, History of the 19 Art, triumph of, over Nature 86 Atnbrotype clieinicals 3S " views, to take 170 Ambrotypes in the United Statea 34 " stereoscopic 152 " for lockets 169 " to color 1G6 " to darken 209 " to copy from Daguerreotypes 171 " ai)|iaratus for 131 Actino-Hydroiiieter for nitrate bath 136 Alcoholic solutions for collodions 182 Alcoholic solution of iodide of silver 183 " of bromide of silver 184 " of bromo-iodide of silver 185 " saturated, of iodide of potassium 186 •' saturated, of bromide of potassium 187 Ammonia-nitrate of silver solution for positives 95 Acetic acid — its nature and properties 212 Alcohol — its nature and properties 213 Backgrounds, to print various shades 107 Bath, nitrate of silver, preparation of 133 '• to iodize 134 236 INDEX. PAOK Bath, nitrate of silver, to test the 136 " •' to neutralize 137 " '■ adding acid to • 13G " gutta-percha, arrangement of 133 " flowing tlie 139 " renewal of the ,. 14" " to keep the, in order l'*8 " silver, for cliloride of sodium papers 59 " for toning and coloring 93,94 " chloride of gold "3 " water, fur positives "^ Backgrounds for Ambroty pes 1 '" Black and white specks on plates 1^^ Bromide of silver, alcoholic solution of 184 Bromo-iodide, alcoholic solution of 1°^ Bromide of potassium, saturated solution of 1^7 Bromine— its nature and properties 210 Bromide of potassium — its properties 21d Camera, time of exposure in the 46 " solar, for life size '^ " importance of a good l-'^ Collodion, negative, to prepare ^2 " ammonia °' " cadmium " °" " compound cadmium °3 " double iodized °'* " to remove water from lo6 " to purify old lf"5 " to pour on tlie glass plate 146 " Ambrotype, preparation of 161 " to iodize, for Ambrntypes 162 " to be kept from the light 163 " tests of good 164 " to remove color from 164 " recipes for Ambroty pes ISl " to render any, highly sensitive 209 " for negatives, preparation of 82 " recipes for negatives 82 -S3 " mode of coating glass plates with 146 " first used 27 " signification of 27 " to preserve and keep ready for use 1 ''3 Chloroform for collodion 1*^' Copying Daguerreotypes into Photographs 69-70 INDEX. 237 PAQK Canada balsam, application of 155 Cautions in using chemicals, &c 202 Cleaning the hands 204 " glass-plates for Aiiihrotypes 126 " " for negatives 41, 103 Chemicals, Ambrotj-pe 132 " impurities of 200 Colors for Ambrotypes IGT Children's portraits, to take 177 Chloride of silver, adding to fixing solution 144 Cyanide of potassium, properties of 217 " " danger of using 203 Chloride of gold 213 Carbonate of soda 217 Daguerreotypes to copy life size 69-70 " " in Ambrotype 171 Diaphragm, use of 175 Developing solution for negatives 89 " " for iron Photographs 74 " " for Ambrotypes 141 " " various recipes for 143 " " for negatives 89 Dextrine paste for Pliotogniphs 104 Double glass process 152 Drying positive prints 67 " the picture 150 Enlarging pictures to life size 69 Engi'aving name on negatives 113 Engravings, to copy, in Ambrotype 173 Ether— its properties 230 " caution in using 203 Ether and alcohol to form collodion 160 Failure, causes of 194 Filtering process 135 Fixing solutions, preparations of, for Ambrotypes 144 Fixing bath for negatives 93, 44 " for positive jiajier 94 Fixing solution for negntives 44, 93 " for positives 94 Fogging the i>icturcs 114, 195 " cause of, and to detect 114,196 238 INDEX. PAGB German process for negatives 85, 86, 87 Gum Arabic paste for positives 104 " " varnisli for negatives 44 Glasses, preparation of, for Ainbrotypes 126 " cleaning substances for 126 " cleaning new 127 " cleaning old 123 " cleaning, tliat have been varnished 129 " best adapted for Anibrotypes 130 " proper for negatives m 47 " cleaning, for negatives 41 " to hold, after cleaning 45 Gun-cotton, discovery of 153 " preparation of 159 " test of acids employed for 160 " to wash and dry 160 " caution in preparing 203 Hints and snggestions on positives and negatives 112, 206 " " " " on paper 117 " " on negatives 112 History of Photography 19 Hydro-bromic acid, to prepare 1S7 Hydrometer, actino, for nitrate of silver bath 136 Hyposulphite of soda 219 ofgold 219 " of silver, to lest its presence in positives 107 Iodine — its preparation and properties 220 Iodide of ammonia — its preparation and properties 224 " of potassium — its preparation and properties 222 " " alcoholic solution of 183 " ofsilver — its preparation and properties 223 " " alcoholic solution of 183 Iron Photographs, to make 73 Instantaneous printing 101 Imperfections in negatives 114 " in positives 120 Jewelry, to color, on Ambrotypes 168 Lampratype process 210 Light, to arrange, for Ambrotypes 174 " " for negatives 45 INDEX. 239 PAGE Light on the eyes, to arrange 17(5 Litin-us — its nature and properties 225 Mnteiials for Ambrotypes, in finisliing 132 Maeliinery, to copy, in Ambrotype ]7:J Manipulations by the Ambrotype process 146, 147, 148, 149, 150 " by tlie negative process 41 Mounting Photograplis 67 Melainotype plates 169 Negative process, theory of the 32 " practice of the 39 Negatives on glass 40 •' definition of 40 " on glass, to take 41 " developing solutions for 43 " fixing solution for 44 " to develop 43 " frames to liold 45 " the color of 54 " silvery appearance of 116 Negative bath, the practice of the 51 " •' changes of the < 53 '• collodions, to prepare 81, 82, S3 Nitrate of silver bath for negatives 48, 49 " " preparation of, for Ambrotypes 49 " " to iodize 49 " " to neutralize 137 Nitric acid — its nature and properties 225 Nitrate of potasli — its nature and'properties 226 Nitrate of silver — its nature and properties 226 Old collodion, to purify 106 " to remove water from 106 Pearl Ambrotypes, to make 210 Plates, to clean, on flat board 120 Plate-holders, varnish for 191 Plates, to hold, in proper position 147-143 Plate-holders necessary for Ambrotypes 125 Patent-leather process 155 Patent, Fox Talbot's, notice of 22 Plate-blocks for holding glasses 126 Plate-vise for holding glxsses j IjiO Paper, Photographic, quality of 117 240 INDEX. PAGB Paper, to dry salted 5S Practice of the negative process 89 Printing, instantaneous 101 " frames 109 Prints, to restore faded 102 " from negatives 62 " positives with chloride of sodium paper and pure silver 29 " " with ammonia-nitrate of silver ,. ... 58 Photographic printing 56 " views 79-80 " process, theory of the 30 Photographs, to wash 65 " to mount 67 " to varnish 67 " to print 56 " positive, on glass 29 Photography — its history and progress 19 " its introduction into the United States 28 " chemicals first employed in 20 Pictures, negative and positive, on glass and paper 31 Positive process, theory of the 32 " fixing the 63 " washing the 65 " drying the 67 " mounting the 67 " printing the 62-63 Pyrogallic acid, solution for negatives 88 Protosulphate of iron — its nature and properties 224 Quick method of printing 93 Kc-developing processes 87, 90, 92 Ketouching negatives 113 " " for views 112 " positives on paper 1 19 Eemoving stains from the hands 204 " " from linen and clothes 205 Rehn's recipe for Ambrotype collodion 180 Statuary, to copy, in Ambrotype 173 Screens and backgrounds 175 " blue and white 177 Stains, to remove, from the hands 204 " to remove, from clotlics 205 Single glaaa process ; 161 INDKX. 241 PAGE Silver, to add, to negative bath 52 Silver solution, plain 59 " " ammonia nitrate 95 Silver, to recover, from old solutions 103 Silvering the pnptr 5S Salting solutions for paper 57 Stereoscope pictures, to make 75, 76, 77, 78 " pliilosopiiy ol'the 76 Stereoscopic Ambrotjpes 152 Skylight, arrangement of 174 Spots or streaks on plates 115, 2U0 Solutions, developing, for Ambrotypes 141, 142, 143 " " for negatives 87 Solution, alcoholic, of iodide of potassium 1S6 " " of bromide of potassium 187 " " of iodide of silver lS:i " " of bromide of silver 1S4 " " of bromo-iodide of silver 1S5 Sulphuric acid— its nature and properties 228 " " impurities of 2J9 " " test of 229 Treble glass process 153 Transparent and opaque spots 19S Toning or fixing tlie print 63 " bath for positives on jjaper 93, 94 " '• for iron Photographs 74 Transferring Ambrotypes on paper 1 70 Uncertainties of the art 55 Varnishing the pictures 152 Varnishes, to prepare 1S9 " applying the 192 Varnish, for negatives 44 " new, for Photographs 102 " to remove superfluous 156 " thick white, instead of Canada balsam 191 " used instead of Canada balsam 155 " white copal 1$9 " gum-demar 190 " black asphaltum ] 90 " white of .shellac and copal 190 " gum-shellac, for plate-holders 191 Vocabulary of Photographic chemicals 211 21 242 INDEX. PACB Washing positive prints 65, 66, 118 " the positive pictures 65 Water, properties of 231 '■ impurities of 231 " distilled 231 ■Weislits and Measures, tubles of 233, 234 Window-glass for negatives 47 SCOVILL MllFACTURIXC COMPiNV, 4 BEEKMAN ST., N. Y., Manufacturers, Importers, and Dealers in all Articles pertaining to the PiioToGRAPnio, Ambuotype, and Daguerreotype Processes. ScoviLL Manufacturing Co. liave always on hand A FULL assortment OF MATERIALS FOR PHOTOGRAPHS AND AMBROTYPES, At WHOLESALE and RETAIL. Consisting of CHXSIMXCALS Of the PUREST QUALITY, fully warranted. Also, APPAEATTJS, GUTTA PERCHA, PORCELAIN, and GLASSWARE, of all kinds used in tlia Art; CASES, MATTINGS, PIIESERVEIIS, and GILT FRAMES, Of every known pattern and finish. Together with .ill kinds of Of "White, f White, and other qu.Mities, in large varieties. Particular attention is called to the desi<:ned e^cprossly for Inyins over AMnp.oTYPKS and P Ar.irEP.nF,oTYPF.9. im- partinsr to the AMitnOTYi'R a hi^h artisiic tirii>h, even withont the nppliiaiii>n of the white varnish. The ntility of this Glass is prommnced unsurpassed by the most successful Artists, and it is sold as low as the ordinary Plate Glass. Also, a New Article of highly polished BIiACK GLASS, on which Ambrotypks are taken, supersedins the necessity of using black varnish. Tliis needs only to be known to bo adopted. Collodion (Iodized and Plain), Gun Cotton, &c., Made expressly for them by one of the most successful operators in the country. ^ ■ » Agents for IfarrUon'x Improved Comera-i, Taglialnie'fi Coliodiometert, and Actino- Hydrometers for tenting Chemicals, cf-c, d-c. Address SCOVILL MANUFACTURING CO., 4 Beekman St., Nkw Youk. HOLMES, BOOTH &1I1YDENS, MAKUFACTUREIIS & IMPORTERS OF EVERY VARIETY OF m^ Mm>i :s\\psis^\ WE '91 DA&UERREOTYPE, AND PlOTOSMPHie GOOD§, OF THE BEST QUALITY ONLY. HOLMES, BOOTH AND HAYDENS' CAMERAS, From i to mammoth size, warranted. 81 CHAMBERS STREET, XEW YORK. MMiiufaolory at Waterbury, Conn. Pill iiiiiiits FOR THE AMBROTIPE, PIIOTOORAPIIIC, AND DEPOT FOR Anthony's Celebrated Iodized Collodion for Am- brotypes, Anthony's Iodized Collodion for Negatives, Diamond Varnish for Ambrotvpes, Negative Varnish, Photographic Varnish, " Black Varnish Pure IVentral \itrate of Silver, Pure Iodides of Potassium, Cadmium, & Ammonium, " Bromides " " « And Pure Chemicals of all kinds used in the Art. Plate Glass for Ambrotypes, in great quantities, and of every quality. Gutta Percha Baths, Trays, &c. Ambrotype Preservers and Mattings. An experience of seventeen years in the business gives us confidence in ottering our goods. Catalogues furnished on api)lication. E. ANTHONY, Manufacturer of Dayuerreolijpe and Amhrolijpe Cases and Apparatus, 501 Broadv(ray, New York. AMBROTYPE SHIELDS ON HAND, AND MADE TO OEDER. Agents for C. C. Harrison''- Cv.\.v.TZKTT.r> Camfp.as. K ^(if GETTY CENTER LIBRARY 3 3125 00104 5190