Y MADE EASY 
 
 PRACTIC L MANUAL 
 
 PHOTOGRAPHY 
 
 CONTAINING FULL AND PLAIN DIRECTIONS FOR THE ECONOMICAL 
 PRODUCTION OF REALLY GOOD 
 
 DAGUERREOTYPE PORTRAITS 
 
 AND EVERY OTHER VARIETY OF 
 
 PHOTOGRAPHIC PICTURES 
 
 ACCORDING TO TJ 
 
 LATEST IMPROVEMENTS. 
 
 l C{&(* , ALS0 ’ 
 
 THE y INJUSTICE AND VALIDITY OF THE PATENT 
 CONSIDERED, 
 
 With suggestions for rendering such a Patent a virtual Dead 
 Letter , etc . 
 
 BY A 
 
 PRACTICAL CHEMIST AND PHOTOGRAPHIST 
 
 LONDON 
 
 E. MACKENZIE, 111, FLEET STREET; CLEAVE, 1, SHOE LANE 
 CLARK, 17, WARWICK LANE, AND ALL BOOKSELLERS. 
 
 PRICE ONE SHILLING AND SIXPENCE. 
 
&GfifSi+£ir\ 6 ^ 4 
 
PHOTOGRAPHY MADE EASY, 
 
 PRACTICAL MANUAL 
 
 OP 
 
 PHOTOGRAPHY, 
 
 CONTAINING FULL AND PLAIN DIRECTIONS FOR THE ECONOMICAL 
 PRODUCTION OP REALLY GOOD 
 
 DAGUERREOTYPE PORTRAITS, 
 
 AND EVERY OTHER VARIETY OP 
 
 PHOTOGRAPHIC PICTURES, 
 
 ACCORDING TO THE 
 
 LATEST IMPROVEMENTS. 
 
 THE INJUSTICE AND VALIDITY OF THE PATENT 
 CONSIDERED, 
 
 With suggestions for rendering such a Patent a virtual Dead 
 Letter , etc . 
 
 BY A 
 
 PRACTICAL CHEMIST AND PHOTOGRAPHIST. 
 
 J?ec£mH lEBttton. 
 
 LONDON! 
 
 E. MACKENZIE, PUBLISHER, 111, FLEET STREET. 
 
 LW. hi OlABK, PRINTER, RED LION COURT. 1 
 
Digitized by the Internet Archive 
 in 2016 
 
 https://archive.org/details/practicalmanualoOOhogg 
 
AVING long made this fascinating 
 Art a favourite study and pursuit, 
 and succeeded in producing some sin- 
 gularly good results, the author of 
 this little Treatise, after repeated 
 solicitations from his friends, has at 
 length consented to make his process 
 public. 
 
 However, lest it should be imagined 
 that our purpose has already been 
 forestalled, we must venture one slight 
 remark in the first place. We can 
 at once deny that a work of this kind 
 is uncalled for on our part, merely because many other — 
 60 denominated— Manuals of Photography have recently 
 issued from the press. In fact, the author is persuaded 
 that a really practical work upon the subject is yet a desi- 
 deratum, and he has every reason to believe that the public 
 is mostly of the same opinion. Indeed, he might be fully 
 justified in affirming that — with, perhaps, one or two 
 honourable exceptions— previously published Manuals of 
 Photography have been, too frequently, mere compila- 
 tions “made” — like the Jew pedlar’s razors — “to sell” 
 or, at the best, the production of some theorist. 
 
 The Daguerreotype process, or, as we prefer calling it, 
 photographic delineation of objects upon metallic plates — 
 the most beautiful of recent discoveries — will, it is hoped , 
 be rendered as interesting to the readers, as it has been to 
 £ the writer of this little Manual of the Art, by their being 
 
 freely presented with the results of not only his personal experience in 
 the process, but by adding also the improvements suggested by the 
 researches of the many eminent scientific men, whose attention hag 
 
IT 
 
 INTRODUCTION. 
 
 been so ardently devoted to the progress of the art, and whose labours 
 have given to the discovery a degree of perfection which seems 
 almost incredible, considering its yet brief existence. The disgrace^ 
 ful patent by which certain parties have sought to render photography 
 a sealed process to the scientific, and thus to deprive the art itself of 
 the benefit likely to accrue from the well conducted experiments of less 
 selfish men than those who boast themselves its “ discoverers,” demands 
 primary attention. 
 
 England is the only country in the whole world (the art having been 
 distinctly and fairly presented by the French Government to the whole 
 world) where such “exclusive right” exists; and even here it required not 
 a little tact and talent — with some prevarication on the part of Daguerre’s- 
 friend Arago — to retain so unjust a monopoly. This “ patent,” indeed, 
 will not admit of any justification — it is, to say the least, but an “ ill re- 
 turn ” for the liberal reward so freely and so readily bestowed by the 
 French Chamber of Deputies,* upon MM. Daguerre and Niepce, — a re- 
 ward which, in all probability, would never have been extended to them, 
 and their families, had it been foreseen that it would have enabled them 
 to exercise all future power over an invention thus purchased from them. 
 M. Duchatel, Secretary of State, explicitly assigned as a reason for re- 
 warding the discoverers with handsome pensions that “ the invention did not 
 admit of being secured by patent , for , as soon as published , all might avail 
 themselves of its advantages !” Most certainly the conduct of M. Daguerre 
 and his associates in this affair is unworthy the liberal spirit which should 
 actuate the follower of science or of art. 
 
 Before proceeding to describe, in due order, the various processes of 
 the wonders to be achieved by this “ new found art,” it may first be ne- 
 cessary that we should apprize the reader that attempts have been made, 
 and still are continued, to prevent English amateurs and scientific men 
 from improving upon this invention! “ Thus far shalt thou go — and no 
 further,” exclaims Monopoly! 
 
 That a monopoly does exist cannot be denied, and that it exists in a 
 manner both unjust and injurious is equally apparent. It is upheld by 
 means of a patent which, in its origin, was bad, and in its continuance is, 
 we affirm, disgraceful, as must be admitted by any unprejudiced per- 
 
 * In the month of July, 1839, the French Chamber of Deputies granted an 
 annual pension of 6,000 francs to M. Daguerre, and one of 4,000 francs to the 
 son of M. Niepce, with a reversion of half the respective amounts to their 
 wives, in consideration of their making pullit the details of this important 
 addition to the powers of science. 
 
INTRODUCTION. 
 
 V 
 
 son, at all versed in the subject of the patent and common law of the 
 country; and the public should be rendered thoroughly aware, that some- 
 thing like a deception must have been practised upon her Majesty’s 
 Attorney General, when he allowed this patent right to be legalized , in 
 the letter , we should say, for never can it be in the spirit. It was clear 
 that Daguerre had no property in the invention when this obnoxious 
 patent was granted as he had previously and entirely sold it to the 
 French Government — and had engaged, in addition to what he then 
 knew to render public all his future improvements and discoveries 
 in the art. We deny, in the first place, that he had the power to 
 sell his original discovery in this or any other country; it only 
 admits of a doubt whether he might fairly withhold the use of the 
 after-improvements from us until we had paid for them. Daguerre 
 knows that France thoroughly purchased his secret, and that while 
 she liberally rewarded him, she offered it freely as a gift to the 
 whole world — a boon to universal science — a donation to the arts — and 
 that she nobly sought to open out a source of amusement and instruc- 
 tion to every class of society. In the words of an able Edinburgh 
 Reviewer — “ All the nations of Europe, save one, and the whole hemi- 
 sphere of the new w'orld, have welcomed the generous gift. They have 
 received the free use of it for all their subjects; they have improved its 
 processes; they have applied it to the arts; they have sent forth travel- 
 lers to distant climes to employ it in delineating their beauties and their 
 wonders. In England alone, the land of free trade — the enemy of mo- 
 nopoly — has the gift of her neighbour been received with contumely and 
 dishonour. It has been treated as contraband, not at the Custom-house, 
 but at the Patent Office , and much as we admire the principle of our 
 patent laws, as the only reward of mechanical genius under governments 
 without feeling and without wisdom, we would rather see them utterly 
 abrogated, than made, as they have been in this case, an instrument of 
 injustice. While every nation in the world has a staff of pilgrim philo- 
 sophers, gathering on foreign shores the fragments of science and prac- 
 tical knowledge for the benefit of their country, England marshals only 
 a coast-guard of patent agents, not to levy duties, but to extinguish 
 lights ; not to seize smugglers, but to search philosophers ; not to trans- 
 mit their captures to the national treasury, but to retain them as fees 
 and profits to interested individuals.” 
 
 “ Nor does the fate of the Calotype redeem the treatment of her sister 
 art. The Royal Society refused to publish its processes in their transac- 
 tions. No Arago — no Gay Lassac, drew to it the notice of the Govern- 
 
 ment — no recommendation for a national reward — no enterprising artists 
 
vi 
 
 INTRODUCTION. 
 
 started for our colonies to portray their scenery, or repaired to our 
 insular rocks and glens to delineate their beauty, and their grandeur. 
 The inventor was left to find the reward of his labours (which has been 
 satisfactorily proved, led to the discovery of Daguerre’s process) in the 
 very doubtful privileges of a patent ; and thus have these two beautiful 
 and prolific arts been arrested on English grounds, and doomed to four- 
 teen years’ imprisonment in the labyrinths of Chancery Lane!” 
 
 We may also quote the well-known fact that the Patent Law of Eng- 
 land does not extend its “ protection ” to the invention of a Foreigner ! 
 Are we not, then, justified in demanding how it came to pass that, the 
 official guardians of the law were entrapped into the admission of so sin- 
 gular a departure from the plainly written “letter,” and the as plainly 
 indicated “ spirit ” of that law ? Surely the Attorney General could not 
 have been blinded to the fact that M. Daguerre was neither a native, nor 
 a denizen of Great Britain? On the contrary, the strangely worded pre- 
 amble to the specification of this patent, satisfactorily evidences that the 
 invention was known, by all parties, as that of an alien, and that the 
 applicants for the patent, sought to establish an illegal precedent. Yes, 
 we need only quote Mr. Miles Berry’s own words, upon applying for the 
 patent, to demonstrate that he acted merely as an agent in this matter; — 
 “A certain foreigner , residing in France , instructed him to petition Her 
 Majesty to grant her Royal Letters Patent for the exclusive use of this dis- 
 covery within this kingdom ; and that he believes the said foreigner to be the 
 inventor or discoverer of this process for the spontaneous reproduction of 
 images or pictures by the action of light! ” 
 
 It would be an insult to the scientific men of England to suppose them 
 capable of standing tamely by submitting to so great a wrong, in which 
 not only themselves, but the nation must be deeply interested. We have 
 had one recent exhibition of an attempt of the patentee to put down even 
 the sale of the apparatus. Mr. Egerton (to whom the art is mubh 
 indebted for superior and economical forms of apparatus) has been 
 subjected to much annoyance and heavy law charges, in consequence of 
 the patentee having, on an ex-parte statement, obtained an injunction 
 against him, which injunction, however, after three days patient hearing, 
 on the 2nd June last past, the Vice-Chancellor dissolved with costs. 
 
 We append the Vice-Chancellor’s judgment, as reported in one 
 of the leading morning journals: — “The injunction was certainly too 
 large, for it prohibited not only the vending, &c., the likenesses, but also 
 the sale of the apparatus ; whereas there was not in the specification one 
 word about the sale of the apparatus, which consisted of the most ordi- 
 nary instruments. The plaintiff was not entitled to monopolise the use 
 
INTRODUCTION. 
 
 V& 
 
 of these instruments, but merely to use them in a particular process. 
 However, what the Court went upon was this: — In his affidavit Mr. 
 Beard had stated that he had no knowledge of the infringement till the 
 1st February, 1845, nor sufficient evidence until the 26th of the same 
 month. Now, it might be quite true that though he had no legal evi- 
 dence, yet he must have had some suspicion. And if the defendant’s 
 answer, which in this respect was uncontradicted, were true, the plaintiff 
 had, though not full, yet some information. The affidavits were so con- 
 structed that the plaintiff might swear truly, though not so fully, to the 
 satisfaction of the Court, as to sustain the injunction. It was to be ob- 
 served that from the way in- which it was pressed on, the injunction was, 
 in fact, obtained ex-parte. be would not say that the affidavits were untrue, 
 hut that they were not sufficiently explicit. It was quite clear that at the 
 meetings referred to, the defendant had represented to the plaintiff what 
 he was about, and that the plaintiff must have known, that if not an in- 
 fringement, yet something very like an infringement was going on. Now, 
 it was the bounden duty of the plaintiff, when he sought the aid of this 
 Court, to communicate these facts. He had not done so, and the Court, 
 therefore, acting on the invariable rule, that where a party obtaining an 
 injunction had concealed any material facts within his own knowledge, 
 that the injunction could not be sustained, would dissolve this injunction 
 with costs, with liberty to the plaintiff to mould his action as he pleased, 
 and also to inspect the defendant’s process.” 
 
 We should hope there is sufficient spirit, and a sufficient sense of justice, 
 among our scientific men, to resist the flagrant abuse which it is sought 
 to continue, because, forsooth, a patent has been enrolled. We suppose 
 that the question will ultimately assume a definite shape among the stern 
 realities of the law. We can only believe that its settlement will be on 
 so firm a basis, as to ensure justice to the scientific world in future times. 
 That a precedent will be created, calculated to warn speculators from 
 meddling with the rights of science, either in a narrow or illiberal spirit, 
 and calculated to preserve an infant art from being handled either in a a 
 improper , or in a rapacious manner. 
 
 Look at the matter in another light ; shall the use of an instrument—? 
 discovered two centuries ago, in fact — be placed in jeopardy by a flimsy 
 patent for an improvement of to-day? If so, the next improvement may 
 deprive us of the use of the microscope, or the telescope, and science will 
 be in fetters, bound by the strong arm of the laws of England, exerted in a- 
 line of conduct the most unjust. The scientific many may be sacrificed 
 for the aggrandisement of the few, whose chief pretensions to superior 
 merit possibly is, that they know how to reap a rich harvest while the 
 
INTRODUCTION. 
 
 viii 
 
 sickle is confided to their individual keeping. Exclusively of these con- 
 siderations, we firmly believe the patent of Daguerre to be invalid at the 
 present time for another reason, the process being so entirely different 
 from that set forth in the patent itself; and we will defy any chemist to 
 prove the pure Iodine of Silver (the preparation Daguerre professes to use 
 in his patent) either to be sensitive to light, or applicable to portraiture. 
 The other portions, means, and appliances of the process, likewise, radi- 
 cally vary; and, indeed, we should not have the slightest difficulty in 
 proving that the patentee never used the apparatus , or adhered to the 
 directions of Daguerre in the production of his portraits. In fact, we em- 
 phatically affirm that the existing process is totally different from that of 
 Daguerre — the process now generally adopted embodying the improve- 
 ments and labours of scientific men of various countries. 
 
 It is strictly laid down in the law of patents, that the person apply- 
 ing for the same, after the usual preamble, “ shall lay claim to the parts of 
 the discovery that may be justly new , and of his invention also ; the adaptation 
 of anything old , and the improvement thereon.” The reason for this is to 
 enable the public to steer a clear course, and to place them not entirely 
 in the clutches of any patentee. But such was the disgraceful hurry 
 with which this discovery was taken through the patent office, that this 
 very important compliance with the law was totally forgotten , nothing new is, in 
 fact, claimed, and yet every thing newly discovered by scientific men, and 
 likely to prove of value in the process, is immediately seized upon, at- 
 tempted to be tacked to this — as we maintain it to be — invalid patent, 
 and claimed by the patentee as a part and parcel thereof. Persons are 
 threatened with proceedings, and the terrors of an injunction held over 
 their heads, if they dare make use of an instrument discovered by Bap- 
 tista Porta in 1650, and used by Wedgwood, Sir H. Davy, and Sir 
 Anthony Carlisle, forty years ago, or more, to produce pictures upon 
 the various preparations of the Iodine and Chloride of Silver; it was in 
 1827, M. Niepce came to England, and communicated to the Royal 
 Society an account of his experiments, together with several pictures on 
 metal plates, (now in the possession of Dr. R. Brown, of the British Mu- 
 seum,) spontaneously produced by the action of light in the camera 
 obscura; and more recently by Mr. Fox Talbot. Indeed, the latter might, 
 more justly than Daguerre, lay claim to the actual discovery, not only 
 of the paper process, but of the metallic, as it was well known that, in 
 1838, he had discovered a method of rendering a silver plate sensitive to 
 light, by exposing it to Iodine, and Daguerre’s process was not published 
 or known until August, 1839, just twelve months afterwards !! 
 
 We are also intimately acquainted with a scientific man, who made 
 
INTRODUCTION. 
 
 IX 
 
 both a mercury box and a camera , to be used in the Photographic manipula- 
 tions as early as 1829, ten years before Daguerre's process was published; 
 and there seems to us nothing unreasonable in the supposition that, as 
 Daguerre was in the habit of paying frequent visits to this country with 
 his dioramic views, he might thus have received some knowledge of what 
 scientific men were here pursuing, and applied the information thus ac- 
 quired to his own purposes and profit ! The properties of Hyposulphate 
 of Soda were also well known, and pointed out as a solvent of metallic 
 compounds, especially those of silver, as early as 1823; this salt, there- 
 fore, cannot be considered new, or its application. 
 
 In truth, there can be little of real strength in this patent right Force 
 it into a court of law — there test the validity and power of this would-be 
 crushing patent Can there be a doubt as to what the result shoidd or would 
 be, in any sensible man’s mind? Yet if the patent should be pronounced 
 good, then let the whole body of scientific men meet to petition the Queen 
 in council to remove so obnoxious a clog upon the developement of one of 
 the most wonderful scientific processes of modern days. If with any 
 show of fairness the patentee can prove himself ill-repaid for his ori- 
 ginal outlay — considering the transaction a mere speculation, (he having, 
 we have heard, and feel inclined to believe, already realised about five- 
 and-twenty thousand pounds by it — not a little return for his investment, 
 even in these money-getting days)* — let arbiters be appointed to inquire 
 into the whole affair, and award a proper amount. Let it be ten times 
 the amount we should believe possible, under all the circumstances of the 
 case, it would be easily raised amongst the immense number so deeply 
 interested in this important subject. 
 
 If this cannot be done, beyond a doubt scientific men will seek to avoid 
 the patent by making use of other materials than it embraces; there is a 
 wide field open, and a little steady perseverance may entirely super- 
 
 * We may here state that we have received a strong confirmation upon 
 this point, by having seen a letter in the hand writing of the patentee 
 himself, wherein he sets forth amongst the many inducements for a person 
 to buy a license to work the process in the country, the very large gains 
 accruing : he says that the profit upon the portraits 
 
 Charged 1 Guinea is about 18s. 
 
 Ditto 
 
 30s. Ditto 
 
 25s. 
 
 Ditto 
 
 2 Guineas Ditto 
 
 34s. 
 
 Ditto 
 
 4 Guineas Ditto 
 
 70s. 
 
 exclusive of the charge of 5s. for colouring each portrait, the cost of which 
 is not a penny. After this statement, and a knowledge of the great demand 
 for these portraits, nothing more need be urged for its truth. 
 
X 
 
 INTRODUCTION. 
 
 sede the present method. It has just been announced that an American 
 gentleman has discovered a mode of rendering plates very sensitive in 
 the camera without either iodine or bromine ; no doubt others "will quickly 
 discover the same here. This would make the present patent an almost 
 virtual dead letter. 
 
 Mr. Fox Talbot also pointed out how other metallic surfaces could be 
 made sensitive enough to form a good picture. Might not this hint be 
 easily improved and rendered available? One of the most simple modes, 
 is the exposure of a polished copper plate to the vapour of bromide of 
 iodine, submitted to the light in the camera, and afterwards placed over 
 the vapour of sulphuretted-hydrogen, or of one of the liquid hydro- 
 sulphurets. This vapour produces the picture in different colours 
 upon the plate ; and as this image is not destroyed by any subsequent ex- 
 posure to light, no further fixing process is requisite. 
 
 Very tolerable results may be obtained by using plates of copper 
 silvered, with the ordinary silvering compound of chloride of silver, com- 
 mon salt, and cream of tartar. The copper being brought to a perfect 
 polish, is well washed with salt and water; a little of the silvering com- 
 pound is briskly rubbed over the plate, until it presents a uniform coating 
 of white silver ; the plate is immediately washed in clean salt and water, 
 and dried near the fire, by carefully rubbing it with very clean cloths, or 
 what is better, cotton wool. We have found the polish much improved 
 by passing the plate through a very weak solution of iodine in water; 
 a thin film of ioduret of silver is thus formed. It is then exposed to sun- 
 shine, and afterwards rubbed with cotton wool dipped in very fine pre- 
 pared chalk or rotten stone, by which the iodized surface is removed, and 
 a^beautifully polished face left to operate on. It is then iodized, and used 
 in the same manner as the other plates. 
 
 Gold plates may be rendered as sensitive to the action of light in the 
 camera, as those of silver. Platina is also worthy of attention, and is at 
 the present time cheaper than gold. 
 
 Silvered paper may be carefully stuck on a card — when dry sprinkled 
 with dry tripoli, and polished with cotton wool, and the iodizing 
 effected as well as on metallic plates. A piece of glass well covered 
 with silver leaf, may be treated in the same way, and used with- 
 out polishing. In the place of crude quicksilver, it may be submitted 
 to the fumes of the well-known substance, calomel (red precipi- 
 tate), &c. The iodine of iron, zinc, or other preparations, may yet 
 be substituted for the pure iodine in the patent, and the patent possibly 
 remain uninfringed. There are other beautiful processes that can be 
 adopted, and present a large scope for investigation and improvement. 
 
INTRODUCTION. 
 
 XI 
 
 The Ferrotype of Mr. Hunt we can especially commend, and we, our- 
 selves, with prepared polished surfaces of ivory, have effected some 
 beautiful results, and these, we hope shortly, in a definite shape, to lay 
 before the public. 
 
 We have also been more than once tempted to experimentalize and 
 seek a photogenic agent in a substance chemically composed to imitate 
 the common egg shell; having been struck with the beautiful colours 
 with which the egg can be easily stained, when so prepared, to amuse and 
 delight children. The results of our own attempts have not as yet been 
 sufficiently satisfactory, but we are not without hope, that, by causing the 
 object to impinge upon the surface, and through the application of a 
 heated vapour, to be ultimately successful. 
 
 It will be seen from the remarks that we have found occasion to 
 make that our own conviction is strong, that the Daguerreotype pro- 
 cess should be as free to the world, from let or constraint, as the sun- 
 beams themselves ; and we think that such a conviction is not only the 
 general, but palpably the correct one. We believe it a duty that we owe 
 to the public as well as to ourselves, that we should allude, in plain terms, to 
 the manoeuvres of those interested in establishing — and of those who assidu- 
 ously seek to perpetuate — a monopoly of that which clearly belongs to 
 every one, — an invention likely to be exercised and improved by every 
 scientific experimentalist. And it is fit that if we behold artifices em- 
 ployed, discreditable to the scientific world, for the sole purpose of foster- 
 ing private ends, that we should visit their originators with reprehension.* 
 
 With respect to photography itself as comprising the subject of these 
 pages, we would address that class especially who have the happy faculty 
 or ability of appreciating whatever in nature and art is “ beautiful ex- 
 ceedingly.” To such, the directions our little work may contain, will, we 
 would assume, be found of service, and of interest. It may be as well, 
 therefore, to proceed at once to such details as may assist an operator in 
 the production of a truly good photographic picture. 
 
 * In the Times of June 16th, 1845, there appeared an advertisement, in 
 which the honourable (?) minded patentee offers to “ reward handsomely,” 
 any individual who may thereby be bribed into a betrayal of private confi- 
 dence, by supplying him with evidence against any party who may happen 
 to exercise the Protographic process — for scientific improvement, or mere 
 recreation not excepted — without having first purchased a “ license 99 from the 
 Patentee himself. Nay, so anxious is he to obtain evidence against these 
 parties, that he has even resorted— as in the case of Mr. Egerton — to the 
 very disreputable manoeuvre of sending a spy to the suspected person, for 
 
xii 
 
 INTRODUCTION. 
 
 The author, however, trusts to be considered as not too egotistical, 
 when lie declared this treatise to be the fruit of very many days de- 
 voted to the contemplation and patient pursuit of the delightful Art 
 of Photography. In a sentence, the author knows that “precept and 
 practice” are here combined, and he looks with confidence to his readers 
 affirming them to be judiciously so, well knowing they can appreciate 
 the really practical and useful, without the additional guarantee of the 
 Author’s name. 
 
 the purpose of holding out a pecuniary inducement for the infringement of 
 his patent. 
 
 For the benefit of our readers, we will give an extract from this said ad- 
 vertisement : — “ The exercise of the invention within England or the 
 colonies, whether for public or private use, by any person not duly licensed, 
 being an undoubted infringement upon the rights of the patentee, Mr. 
 Beard will feel it imperative (the more so by the recent judgment of the 
 Vice-Chancellor) to take immediate proceedings both in equity and at law 
 against any person he may discover so infringing, and information with 
 necessary proofs relating thereto will he liberally rewarded 
 
 London , July 1845. 
 
THE DAGUERREOTYPE PROCESS. 
 
 CHAPTER I. 
 
 OW we shall proceed to describe, in 
 due order, the various photographic 
 processes; and above all things, we 
 wish to impress on the mind of the 
 experimenter the necessity which 
 exists for extreme care in every stage 
 of the manipulation; we cannot lay 
 down a royal road to acquire an art 
 which involves the most delicate 
 chemical changes — requiring the most 
 patient perseverance to surmount the 
 difficulties which surround it — and more than ordinary caution in 
 selecting materials for use. 
 
 The entire process is comprised in the nine distinct operations, which 
 we shall endeavour to explain as simply as possible, at the same time 
 entering into all necessary detail. 
 
 1. Cleaning and polishing the plate. 
 
 2. Applying the coating of iodine. 
 
 3. Subjecting the plate to the vapours of bromine-water, or other acce- 
 lerating substances. 
 
 4. Exposing the plate in the camera. 
 
 5. Subjecting the plate to the action of mercury. 
 
 6. Depriving the plate of its sensitive coating in the hyposulphite 
 solution. 
 
 7. Washing the plate in pure distilled water, and drying it over a 
 spirit-lamp. 
 
 8. Fixing the image, with solution of the chloride of gold. 
 
 9. Washing the plate with distilled water, and drying over a spirit- 
 lamp. 
 
 We must once more impress upon our readers the necessity of proceed- 
 ing with patience through each different operation, which, after a little 
 practice, will be found very easy, but which, if not attended to, failure 
 will inevitably be the result. 
 
!4 
 
 THE CLEANING PROCESS. 
 
 THE CLEANING PROCESS. 
 
 Cleaning the Plate , Sfc . — Be careful in selecting good plates to begin 
 with : the French are very inferior ; the best are the Soho -manufactured 
 plates; and should have a strong metallic lustre, without specks; and the 
 slightest trace of copper should cause any plate to be rejected. A slight 
 line or scratch is no obstacle to obtaining a fine impression, provided 
 always the scratches do not reach the copper; and care must be taken, 
 when operating for a portrait, to place the head upon the part of the 
 plate which is free from imperfections. The articles employed in the 
 cleaning operation are cotton -wool, calcined tripoli, prepared lampblack, 
 olive oil, nitric acid diluted with about sixteen parts of water, and cotton 
 velvet buff. As it is a principal object in cleaning the plate to obtain a 
 surface of silver perfectly pure, care must be taken that the articles used 
 for that purpose are free from impurities, and that the plates should not 
 be prepared in any place where there may exist vapours arising from 
 acids, volatile oils, iodine, bromine, & c. It is, therefore, recommended, as 
 a necessary precaution in the former respect, that the cotton- wool should, 
 previous to its being soaked, for about an hour, in a weak solution of 
 ammonia (hartshorn), then washed in clean water, and dried before the 
 fire, by which means it will be effectually purified from any greasy or 
 or other noxious substance. The calcined tripoli should be reduced to an 
 impalpable powder, and preserved for use in a small muslin bag, which 
 should be placed in a box, so as to preclude the possibility of the slightest 
 admixture of dust with the tripoli powder. The lampblack should be 
 prepared by rendering it red hot, in a crucible, till vapours cease to arise 
 from it ; the crucible should then be removed from the fire, and closely 
 covered up until it has cooled, when the lampblack should be reduced to 
 a fine powder, in a mortar, and preserved for use in the same manner as 
 the tripoli. 
 
 The Soho plates, as sent out by Mr. Egerton, 1, Temple-street, White- 
 friars, are so highly polished that they require but little doing to them 
 to render them fit for immediate use; the very best polishing process 
 and one that will never find fail, is obtained by using a small lathe. We 
 have a circular block of wood, well covered with a piece of fine blanket, 
 over which the velvet is stretched very tight, screwed on to the headstock 
 spindle, against which we press the plate, held in a steelholder, moving it 
 slightly backwards and forwards upon the lathe rest , keeping the velvet 
 well dusted with the prepared charcoal, or, what is better, prepared char- 
 coal with a very small quantity of the finest rouge mixed with it. 
 
 The velvet should previously be freed from its gum and grease by 
 
THE CLEANING PROCESS. 
 
 15 
 
 steeping it for an hour in boiling water, draining and drying it without 
 touching it with the fingers. 
 
 We make use of the usual shaped handbuff to give the plate its final 
 polish, dust a little of the prepared lampblack on the velvet, and briskly 
 polish, holding the plate, if a small one, on the ends of the fingers of the 
 left hand, and using the buff with the right; if a large plate, place it face 
 downwards on the rubber, moving the plate up and down by means of 
 the fingers, with a slight degree of pressure, taking care that for portraits 
 the movement should not be in the direction of the face, but across it; 
 and it is also best for this last polish to be given in a rather dark room, or 
 by the light of a candle, as the clear daylight affects the bright surface of 
 the silver, injuring its sensibility. 
 
 On examining the polished plate from a certain angle it will present a 
 black appearance, and, if every particle of dust and tripoli is not removed 
 (by a soft camel-hair brush or cotton wool) from its surface previous to 
 subjecting the plate to the fumes of iodine, black specks will subsequently 
 be discernible on it. 
 
 It is worthy of remark that the elevation of temperature produced by 
 the buff causes the plate to become iodized much sooner, and its combina- 
 tion with the surface is thereby rendered more perfect. 
 
 If the plate be one that has been previously used, it should be placed, 
 silver side upwards, upon a piece of clean white paper, and shake a small 
 quantity of the tropoli over it; a few drops of olive oil should then be 
 applied, and with a knot of the cotton and a light hand proceed to clean 
 the plate by a series of circular movements, equally over its surface, 
 adding more tripoli as required. The time usually expended for produ- 
 cing a good surface is about ten minutes. It should then be heated over 
 a spirit-lamp for a short time, taking a fresh pledget of wool, and, shaking 
 more tripoli over the plate, gradually wipe off the oil, using a fresh piece 
 of cotton as required : when the whole of the oil is apparently removed 
 the plate ought to be heated over a spirit-lamp till small white spots are 
 observed to form on the surface; it may then be allowed to cool: when 
 cold, apply, by means of a piece of cotton- wool, a few drops of the dilute 
 nitric acid over the plate, which will immediately indicate if it has been 
 sufficiently heated by its flowing easily over its surface, without running 
 into distinct globules, which it would otherwise do; if the acid wets the 
 surface easily, dust a little tripoli over it, and with a fresh piece of cotton- 
 wool dry the acid off in the same manner as you did the oil, but, if the 
 acid does not adhere to the plate, it will require to be rubbed with the 
 tripoli for a little time longer before drying it off. 
 
 We have also found finely-levigated rotten- stone equally effective^ 
 
16 
 
 THE IODIZING PROCESS. 
 
 although much cheaper than tripoli. It is necessary that the operator 
 should always remember to finish the plate with the velvet buff, well 
 dusted with the prepared charcoal and rouge. Before quitting the clean- 
 ing process, it may be as well here to reiterate that everything done in 
 this respect should tend to the one important object of finally leaving 
 the plate chemically clean , and with as pure a surface of polished silver for 
 the iodine to combine with as it is possible to obtain. 
 
 The second operation is that of 
 
 THE IODIZING PROCESS. 
 
 Iodizing of the Plate . — To effect this we use a glass pan, enclosed in a 
 square box, with a piece of plate glass double the length of the pan to 
 slide over the top, in the one half side of which an aperture is cut, capable 
 of admitting a small wooden frame, having a narrow groove just to receive 
 the plate, and prevent it from falling through. The accompanying small 
 diagram will, however, best explain the construction of the iodizing- 
 box: — 
 
 A represents the square box, containing a round glass pan B, with 
 ground edges, upon the top of which slides the plate glass cover C, with 
 an aperture D , to receive the grooved frame upon which the plate to be 
 iodized rests. E is a small hole of two inches square, cut in the wooden 
 box, corresponding with one made in a panel of the dark room, through 
 which the light is admitted and received upon the piece of looking-glass 
 at jF, placed at a convenient angle, so as to embrace the plate undergoing 
 the iodizing process and the patch of white light admitted from the oppo- 
 site side of the box. 
 
 The practical utility of this arrangement for the iodizing box or pan will 
 be readily perceived. The white reflected light, and the plate undergoing 
 its changes, being at once presented to the eye by means of the small piece 
 of looking-glass, the same colour can always be obtained upon the plate 
 
THE IODIZING PROCESS. 
 
 17 
 
 and the process stopped at the precise moment of time. The construction of 
 this box also effectually precludes an escape of the fumes of the iodine 
 from the box itself, which we have before demonstrated, has occasionde 
 a greater number of failures than any other cause of non-success. In- 
 deed the photographic experimentalist cannot be “over careful” in the se- 
 lection, and so forth, of the apartment in which his plates are to be pre- 
 pared, inasmuch as damp or fresh paint, and a variety of other apparently, 
 very trivial causes, will affect the surface of the preparing plate. 
 
 The most unphilosophical observer of nature must be cognizant of the 
 well-known fact that, when we expose to a warmer air any cold body, 
 the humidity contained in the former becomes condensed ; and to this 
 cause we may attribute the difficulty experienced by the photographist 
 when operating in any atmosphere affected by moisture, frequently the 
 case in that of an ordinary room, but more especially at this season of 
 the year. 
 
 The vapour arising, even at the slightest variation o f temperature , between, 
 the surface of a body and the surrounding air, contains in suspension a 
 non-volatile substance, which subsequently becomes what might be called 
 the atmospheric deposit; for, so soon as an equal temperature is esta- 
 blished between the air and the surface of that body, the humid vapour 
 which had condensed upon it then becomes volatile, and, depositing as a 
 sediment that which it previously held in suspension, again mixes with the 
 air, and is again saturated with that impure substance for a subsequent 
 deposit. It is quite evident that this moist coating is very injurious. 
 Thus, if you breathe several times on the plate, when first taken out ot 
 the camera, the mercurial vapour will not then “ bring out” the image. In 
 order, therefore, to paralyse this baneful effect as much as possible, the 
 temperature of the workroom must remain at about 60 deg. Fahrenheit, 
 and the plate may be kept even higher than that of the air which sur- 
 rounds it during each of the operations. Leaving this slight, but not, as 
 we think, unnecessary, digression from our main subject, we will now pro- 
 ceed with our 
 
 Directions for Iodizing . — Insert the polished plate in the groove, pushing 
 the glass cover sufficiently to place the plate directly over the iodine cover- 
 ing the bottom of the glass pan. Allow the plate to remain until the 
 golden yellow colour is obtained ; then draw back the cover, take out the 
 plate, and transfer it quickly to the accelerating pan, in which it should 
 continue from two seconds to a minute, to be determined by the strength 
 of the mixture (which we shall more fully describe presently). The 
 colour should now be slightly deepened, and, the roseate hue just begin- 
 ning to appear, the plate retransferred to the iodizing pan, where the 
 
 c 
 
18 
 
 THE IODIZING PROCESS. 
 
 colour can be deliberately observed by comparison with the white re- 
 flected light. The plate must be permitted to remain in this position 
 until the colour is again slightly changed — now to a beautiful damask- 
 rose tint, which should appear uniformly all over the surface of the plate. 
 It must then be quickly removed to the black slide-box of the camera, 
 and is ready for immediate use. If, however, it is carefully excluded from 
 light and air, the peculiar sensitiveness of the plate will be little impaired, 
 although it remain unemployed three or four hours; but it cannot be re- 
 lied on after a much longer period. Some, indeed, have asserted that the 
 plate is rendered more sensitive by being prepared the previous day : this, 
 however, is an absurdity. We have repeatedly tried the effect, and have 
 invariably been confirmed in our view by the result. In hot summer 
 weather, indeed, even after one hour, we cannot, with any degree of cer- 
 tainty, use the plate without first exposing it to the iodine for a second. 
 The pictures produced by the above directions have their deep shades of 
 the blackest and best description, and the whites very clearly and dis- 
 tinctly brought out. The process possesses the advantage also of giving 
 an extremely sensitive coating to the plate. To give your pictures that 
 softness and creaminess (if we may so express it) of appearance that some 
 admire, it will be necessary to deepen the colour. In the first iodizing 
 process, proceed at once to the rose colour, over the accelerating sub- 
 stance get the damask rose, and in the last iodizing bring it to the steel - 
 blue colour. Some prefer operating without putting the plate the second 
 time over the iodine, supposing it rendered less sensitive by so doing, and 
 they immediately transfer it from the accelerating liquid to the dark box 
 of the camera; but we have found so much uncertainty in this method 
 that we cannot recommend it, although we must say that occasionally we 
 have seen a fine picture obtained by such means. 
 
 It may not be amiss here to point out the best means of accustoming 
 the eye to the instantaneous appreciation of the beautiful gradations of 
 colour that the plate necessarily undergoes in the process of iodizing. 
 Spread a small quantity of soap, dissolved in spirits of wine, upon a piece 
 of common flint glass. Breathe upon this through a piece of glass tube- 
 ing, when a succession of prismatic coloured rings will appear. In like 
 manner, as is the case with thin laminae of air, all transparent bodies de- 
 posited in thin layers reflect colours which vary in degrees according to 
 their strata. We may, therefore, assume as a general law that the depo- 
 sition of the iodine upon the plate must conform to the following order, 
 which it will be seen has some relation to the prismatic succession of 
 colours : — A pale straw colour, a yellow; a dark yellow or orange , a rose 
 colour, more or less dark in tint, or red violet; steel blue , and indigo; and. 
 
THE ACCELERATING PROCESS. 
 
 19 
 
 lastly, green. After obtaining this last-named colour, the plate re-assumes a 
 light yellow tint, and continues to pass successively a second time (with 
 some slight alterations) through all the above-enumerated shades. But if 
 the process is allowed to pass beyond the steel blue of the first gradation 
 the plate must be removed, and its surface re- cleaned and polished; for it 
 will have been rendered almost insensible to the action of light in the 
 camera; and, even should a picture be obtained on such a plate, it will 
 appear very dull and defective. 
 
 THE ACCELERATING PROCESS. 
 
 * A pan precisely similar to that which we have already described as 
 to be used in the iodizing may properly be employed for the accelerating 
 liquid. The time required to conduct this portion of the process with 
 success will vary, according to the strength of the mixture in great part, 
 from five seconds to a minute. The object to be attained is the colour 
 which we have previously indicated as necessary; and one trial will readily 
 enable the operator to determine the exact period requisite, in the first in- 
 stance, to effect this object. It will be found, however, that after a few 
 hours the accelerating mixture will become gradually weaker, and, there- 
 fore, it will be necessary to increase in proportion the time of subjecting 
 the plate to its influence. 
 
 One thing must carefully be avoided — the getting too much of the acce- 
 lerative upon the plate. We have ourselves been excessively annoyed by 
 failures proceeding from this cause, although by having the plate under 
 the eye the colour will always determine when sufficient has been deposited, 
 so that by a little precautionary attention this annoyance seldom need 
 occur. 
 
 We next come to consider the different solutions made use of as an ac- 
 celerator. The first and, perhaps, the one more generally adopted is a so- 
 lution of bromine. To prepare this we put hi to a bottle of distilled water 
 an excess of bromine, which, being shaken together for some time, will be- 
 come a saturated solution of bromine. One drachm of this to eight ounces 
 of water will be sufficient to pour into the pan at any one time. The 
 colour it should present would be a bright yellow. 
 
 The second article is a solution of chloride of bromine. This is to be 
 made by putting into a retort some chloride of lime upon which sufficient 
 sulphuric acid is poured to cover it. The beak of the retort must be 
 previously inserted into a vehicle containing a solution of bromine; luting 
 
 * These pans, neatly fitted, may be had of Mr. Egerton before referred to. 
 In fact, all his apparatus is of the best and latest improvement. 
 
20 
 
 THE ACCELERATING PROCESS. 
 
 will be required to prevent the escape of the chlorine gas, which, being 
 very deleterious, should on no account be inhaled by the operator. One 
 or two drachms are to be employed to about eight ounces of distilled water, 
 so that the mixture may appear of a bright yellow colour in the pan. But 
 the mixture we more particularly recommend was prepared by a Mr. 
 Wolcott (to whom we subsequently refer).* 
 
 This mixture cannot be said to have a “ fair trial” when used in a pot, 
 having a cover which has to be lifted off, instead of being provided with 
 the previously recommended sliding cover. Cold weather, as our expe- 
 rience testifies, is most unfavourable to this part of the process ; the com- 
 bination of the iodine with the silver is then very tedious and imperfect, 
 and the most careful employment of the accelerator will not then prevent 
 that from attacking the silver, instead of quickening and combining with 
 the iodine. The temperature of the apartment ought not therefore to be 
 lower than 60 ° — cold and damp being equally deleterious. The mixture 
 is prepared for use by stirring, wth a glass rod, about thirty or forty drops 
 in half a pint of water, and allowing it to stand for an hour previous to 
 exposing the plate over it. 
 
 An exposure of the iodized plate for about five seconds over this fluid 
 will be sufficient, and the pictures produced by it are unequalled in bril- 
 liancy and cleanness of appearance; but the principal advantage to be 
 derived from its employment we consider to be the extreme sensibility it 
 induces, and the consequent rapidity with which the operation may be 
 conducted upon the plates in the camera — the critical moment of the da- 
 guerreotype. We are convinced that there is nothing in use at all equal 
 to it. 
 
 Hitherto the operation of iodizing has been described as of so delicate 
 a nature that it was thought absolutely necessary to perform it in a 
 totally darkened room. We are certain, from practical experience, how- 
 ever, that it may be conducted in an ordinary room, or even out in the open 
 air, with this precaution only, that, if under a powerful light, before being 
 quite ready to transfer into the dark box, it will but require removal into 
 a shaded place, and to be preserved from direct contact with the rays of 
 light. f It is very useful to be acquainted with this fact, as by some ac- 
 cident we may get the plate exposed, or the object may move after the 
 focus of the camera has been for too brief a period directed to it. On 
 
 * May be bad of Mr. Egerton. 
 
 t We are led to believe that the plate is rendered more sensitive by being 
 examined, and the colour noticed in the broad daylight, after its exposure to 
 the sensitive mixture, always taking the precaution to place it for a second 
 or two over the iodine in the dark room. 
 
THE ACCELERATING PROCESS. 
 
 21 
 
 such occasions some persons have repeated all the tedious processes of 
 cleaning, polishing, and iodizing, instead of which it is merely necessary to 
 place the plate for two or three seconds over the iodine, when it will be 
 rendered again in a fit state, and the operator again will be ready to 
 proceed with a hope of being more successful. 
 
 We have been informed that some gentleman has laid claim to this as 
 a recent discovery of his own. This claim is most absurd, inasmuch as 
 very many persons who constantly have been engaged in the art have long 
 been aware of the means of thus restoring the plate. It was a knowledge 
 of this fact, indeed, and a little consideration of what other purpose it 
 might be rendered available to, that led a very intelligent and scientific 
 machinist (to whom the photographic art is much indebted, and whose 
 death at the end of last year we record with much regret), Mr. Wolcott, 
 an American, to apply for a patent for a process whereby the gradations 
 of light and shade shall generally be rendered (as he describes it) “ more 
 true to nature, and which shall prevent the picture from being as much 
 injured from any error in the time of its exposure to the action of the 
 light in making the impression as it otherwise would be.” 
 
 The following is an account of the operation : — 
 
 “ When it is supposed that the plate has been sufficiently long exposed 
 to the action of the light to produce the picture, if it was immediately 
 exposed to the vapour of mercury, instead of arresting the operation, the 
 light is allowed to act a longer time on the plate; the plate is then re- 
 moved and exposed to the vapour of iodine, bromine, chlorine, or a mix- 
 ture of any of them, or to any other vapour or vapours that shall have 
 the effect of lessening the deposit of the mercury when the plate is after- 
 wards exposed to it. And if the more volatile substances, such as iodine, 
 bromine, or chlorine, are used, they should be very much diluted with 
 water or otherwise; in using iodine, for instance, one part of a saturated 
 solution in water, mixed with 200 parts more of water, will generally be 
 found sufficiently strong: whichever substance is used it should be put 
 into a vessel with a sliding cover, extending so far beyond the side of the 
 vessel as to have an opening in the part beyond of nearly the size of the 
 plate, with a rebate large enough for the plate to go into and nearly 
 through the cover. When the plate is placed in the cover it may be slid 
 over the vessel without allowing the vapour to escape, thus ensuring 
 great regularity in successive operations ; otherwise the vessel may be 
 covered with a porous earthenware or other cover, which would allow the 
 vapour to pass through it and act on the plate, which should be brought 
 very near to its upper surface. If the vapour is applied through the 
 cover it should be much stronger. In the case of iodine being used, it 
 
22 
 
 THE ACCELERATING PROCESS. 
 
 may be put in in the form of crystals. As the proper time of the plate’s 
 exposure to vapour, after the impression is made, will be varied so much 
 by the extra time that the light has been allowed to act on the plate, by 
 the strength of the vapour, by the closeness of the vessel, by temperature, 
 and by other circumstances, no exact time of exposure can be stated. 
 It is recommended, first, to get an impression which is known to be 
 overdone, and expose it for a short time to the vapour, and then to the 
 mercury. If the picture when formed is still found to be overdone, the 
 next impression tried (being as much overdone as the last) must be ex- 
 posed longer to the vapour, or the vapour must be made stronger; by 
 this means a few experiments will give the proper time of exposure, 
 which will serve as a guide for all future operations. If the impression 
 is found to be entirely or too much obliterated in the trial, it shows that 
 the vapour is too strong, or the exposure continued too long. The vapour 
 of iodine is recommended as being the most convenient in practice. The 
 extra time of exposure of the plate to the action of the light may be 
 from one quarter longer to several times as long, according to the nature 
 of the object to be copied: thus, if it is a living object, it will not do to 
 increase the time so much on account of the risk of moving : and in cases 
 where the extremes of light and shade are very great, a much longer time 
 should be used, that the lower lights may not be obliterated by the appli- 
 cation of the vapour. Wolcott and Johnson’s patent, therefore embraces 
 the exposing photographic plates after the impression is made by the light 
 to any vapour that shall prevent the adhesion of as much mercury to the 
 plate in its after exposure to the vapour of mercury as would have ad- 
 hered if such previous exposure to vapour had not taken place.” 
 
 Mr. Shaw recently delivered a lecture at the Royal Institution, “ upon 
 some photographic phenomena, being original investigations pursued by 
 him for the purpose of determining some of the conditions which either 
 accelerate or retard the decomposition by light of the salts of silver gene- 
 rally.” Mr. Shaw did not communicate any novel information, but he 
 confirmed our views as regards the very small quantity of bromine or 
 chlorine necessary to communicate the greatest degree of sensitiveness to 
 the iodized plate. Mr. Shaw errs, however, when he affirms that after 
 removing the plate from the camera, and exposing it to the vapour of 
 iodine, bromine, or chlorine, however largely diluted , the nascent picture is 
 totally obliterated . Surely when the Royal Institution lecturer ventured 
 on such on assertion as this he must have been ignorant of Mr. Wolcott’s 
 experiments and patent, as above described by us. Most certainly some 
 of the specimens we have seen produced, according to Wolcott’s direc- 
 tions, have been of a very superior character, especially when objects 
 
THE ACCELERATING PROCESS. 
 
 28 
 
 with much white , and greatly liable to solarize , have been introduced into 
 the picture. Mr. Shaw’s experiments led him — as our own did us long 
 since — to the important practical conclusion that the plate need not be 
 longer prepared in the dark ; but that the sun’s light may be fearlessly 
 permitted to fall on it, merely taking the precaution to expose it for an 
 instant to the vapour of bromine or iodine before placing it in the dark 
 box in which it is conveyed to the camera. 
 
 Mr. Shaw then states that pure iodine of silver is not, as is generally sup- 
 posed, sensitive to light: it only becomes so when one of the substances 
 used in its combinations is in excess . Our own views and results are 
 clearly confirmed in Mr. Shaw’s continued experiments on chloride of sil- 
 ver by light; and, as they may prove of great service to our readers, we 
 shall append them: — 
 
 “ The chloride used was obtained from the nitrate of silver and hydro- 
 chloric acid. This salt, having been spread on slips of glass, was secured 
 in glass tubes containing an atmosphere of the gas selected for experiment. 
 The tube was then exposed to daylight, and the consequent darkening of 
 the chloride observed. These investigations led Mr. Shaw to the in- 
 teresting discovery that chloride of silver, after having been darkened by 
 light, when placed in the dark for two or three hours, reassumes its 
 original whiteness, the chlorine combining under these circumstances with 
 the reduced metal. On being again submitted to daylight, the chloride 
 was again darkened, and again bleached by being placed in the dark; and 
 Mr. Shaw proved that this alternate effect might be repeated indefinitely 
 without diminishing the sensitiveness of the salt. Trom this curious pro- 
 perty of chloride of silver, Mr. Shaw was led to the construction of a 
 photometer. In the course of his researches, Mr. Shaw arrived at 
 another important discovery. He ascertained that some gases and va- 
 pours have a specific action on the chemical agency of light without 
 reference tohheir colours. He observed that rays of light passing through 
 a stratum of bromine had more influence on the chloride of silver than 
 when they passed through an equal stratum of chlorine, notwithstanding 
 the far deeper colour of the former gas. Mr. Shaw concluded by de- 
 scribing another photometer, which, being constantly exposed to light* 
 exhibits, by the change produced in it, the relative intensity of the light 
 at the time of the observation. This instrument consists of a wedge- 
 shaped glass vessel, filled with chlorine, and furnished with a long strip 
 of glass, in the middle of which is a band of chloride of silver, the strip of 
 glass being of an uniform grey colour. When this instrument is exposed 
 to light, the darkening commences on the lower end of the band of chlo- 
 ride of silver, and gradually progresses upwards until the effect of the 
 
24 
 
 EXPOSING THE PLATE IN THE CAMERA. 
 
 light is wholly counteracted by the retarding power of the gas through 
 which it passes, and its contact with the salt. Mr. Shaw expressed his 
 opinion that, by observations made on this instrument at regular inter- 
 vals, a curve might be deduced, indicating the varying intensity of th 
 light throughout the day.” 
 
 EXPOSING THE PLATE IN THE CAMERA. 
 
 We have now arrived at that stage of the process in which the prepared 
 plate is to be exposed to the action of light in the camera. This instru- 
 ment being fixed firmly on some convenient plane surface, opposite the 
 object of which a copy is desired, its focus must he so carefully adjusted 
 as to allow a perfectly clear and distinct image to be presented on the 
 piece of ground glass, which, of course, should be placed in exactly the 
 same position as the plate is to occupy, the ground side of the glass cor- 
 responding with the prepared surface of the plate when in use. The de- 
 sired focus obtained, the light may then he shut off, the ground-glass 
 slide withdrawn, and the slide containing the plate introduced in its stead 9 
 The camera may, after this, he opened, and the light allowed to fall upon 
 the plate through the lens. The time requisite for the remaining of the 
 plate in the camera mainly depends on the intensity of light acting upon 
 the object to be produced on its surface; the season of the year, the time 
 of day, the brightness or clearness of the atmosphere, are, of course, to be 
 regarded, and the colour of the object itself must also be taken into ac- 
 count, since all colours are not equally photographic. For instance* 
 yellows, vermilion, and green, have scarcely any action upon the sensitive 
 plate, whereas blues, violets, and lakes have a very energetic one. 
 
 The photographic intensity very materially decreases in proportion as 
 the sun approaches the horizon. Thus from eleven to one o’clock a mere 
 fraction of a second will suffice to produce a picture (a landscape or 
 edifice) in the open air, with a short focus lens, whereas at five or six 
 o’clock in the evening from five to ten seconds will be occupied in produ- 
 cing the same effect. 
 
 All this seems, at first sight, very embarrasing; but, in reality, the diffi- 
 culty can be readily overcome by making a few careful experiments, to 
 become acquainted with the working powers of the apparatus used. 
 When, indeed, an operator has acquired some experience, conjoined with 
 a-perfect knowledge of his instrument, he will be enabled readily to deter- 
 mine, without fear of failure, the time during which the plate ought to 
 remain in the camera. 
 
 The following are some of the indications by which the operator will 
 know whether the plate has remained too long or too short a time in the 
 
EXPOSING THE PLATE IN THE CAMERA. 
 
 25 
 
 camera : — The exposure will have lasted too long, and the impression be 
 completely burnt up or solarized , when all the objects reproduced are 
 apparent, but with an inverse intensity to that which they had in nature; 
 that is to say, the whites have become blueish, and the parts which should 
 be black approximate more or less to wdiite. If the plate has not been 
 subjected long enough to the action of light, the impression will be vague, 
 its outlines faintly marked, and the details either indistinct or not at all 
 apparent. 
 
 So many conditions are requisite to a successful operation, that, indeed, 
 it might be said that failure is the rule, and success the exception. The 
 operator has constantly to overcome new difficulties, and the greatest is, 
 perhaps, the want of power to appreciate the amount of operating rays 
 existing at every moment. No photometer can be constructed; for the 
 acting rays are not always in the same ratio to the intensity of light. It 
 is true that, if it were possible to measure the comparative quantity of 
 blue, yellow, and red lights, at all times, then it would be of considerable 
 assistance in judging of the amount of photogenic light. But even this 
 test would not be sufficient, for the acting rays are not strictly identical 
 with the blue rays. Still to be able to ascertain that there were no yellow 
 or red vapours in the atmosphere, making, as it were, screens of those 
 colours between the sun and the object, would be, no doubt, an important 
 assistance. 
 
 It is to the influence of these vapours that the difference found by 
 operators in various climates is due, which difference seemed at first irra- 
 tional, but which can now easily be explained. 
 
 When the daguerreotype was first discovered, it was expected that 
 southern climates would be more favourable than northern for the pro- 
 cess, and that, in countries where the sun constantly shines, the opera- 
 tion would be considerably shorter. This has not been proved to be the 
 fact, and the following reason may be given for such an apparent anomaly. 
 Light is more intense in the northern latitudes up to a certain degree, on 
 account of its being reflected in all directions by the clouds disseminated* 
 in the atmosphere; whilst in the drier climates the open sky, instead of 
 reflecting light, absorbs a great quantity of it. Of course, in speaking of 
 clouds, it cannot be meant that a completely covered sky is more favour- 
 able than a sky without any clouds, for in this case the sun is entirely 
 obscured. But still there are days when, although the disk of the sun is 
 not seen from any part of the horizon, the thin clouds allow a much more 
 ^considerable quantity of photogenic rays to be diffused and retained in 
 the lower strata of the atmosphere than when there are no clouds, and 
 that by some imperceptible vapours the light has a yellow or red tint. 
 
26 
 
 EXPOSING THE PLATE IN THE CAMERA. 
 
 There is a curious fact which would seem to corroborate the argument 
 in favour of greater intensity of light in northern climates. It is known 
 that, by a provision of nature, all races of men are constitutionally 
 adapted to the climates in which they are destined to live, that the in- 
 habitants of the tropics can bear a much higher temperature than the in- 
 habitants of the north. May it not be the same for light? The eyes of 
 the inhabitants of the cloudy and snowy countries are adapted to bear a 
 stronger light than those living in the south. In the course of my daguer- 
 reotype experience, I have observed that there is a comparatively greater 
 number of Englishmen, than of Frenchmen, Spaniards, and Italians, 
 capable of sitting for tlieir portraits in a strong light, without being much 
 incommoded. If this fact is correct, such a provision of nature would 
 prove that generally light is more intense in the northern climates, and 
 that it decreases gradually towards the equator. 
 
 It was at A first expected that the climate of England, and countries 
 similarly situated, would be unsuitable to the daguerreotype operation; 
 nevertheless, it has turned out that this is one of the most favourable 
 climates for the practice of the process. 
 
 There is another curious fact connected with the photogenic operation, 
 which is, that on the summits of high mountains the action of light upon 
 the plate is not so intense as in the lower regions. A clever operator was 
 sent two years ago into Italy to take daguerreotype views of the most in- 
 teresting spots of that country. After having visited Home, Florence,. 
 Naples, Venice, and other towns, and succeeded in producing a beautiful 
 and curious collection, he wished, in crossing the Alps on his journey 
 home, to obtain some views of the glaciers, and other Alpine scenes ; but, 
 what was his surprise in finding that he could not obtain in one hour, and 
 one hour and a half, in full sunshine, an image of these snowy mountains, 
 having the same degree of force and distinctness as views which he had 
 produced in less than fifteen minutes in the lower countries which he had 
 just visited. The skill of this operator was great; he tried several times, 
 and always with the same difficulty, and at length he abandoned the idea 
 of bringing with him a perfect specimen. 
 
 The cause of this fact may be ascribed to the reason given before, that 
 a sky without clouds absorbs a great quantity of light, and that upon 
 high mountains the rarity of the atmosphere would occasion a certain loss 
 of light. But it remains to be ascertained to what degree the light is - 
 absorbed, or otherwise affected by the variation in the density of the air 
 at great elevation above the surface of the earth. 
 
 It has been found that that part of the spectrum which gives the most 
 light (the yellow ray), will not produce chemical change. Under the 
 
TAKING PORTRAITS. 
 
 27 
 
 influence of the brilliant light of equtorial climes it has only been with 
 the greatest difficulty that photographic pictures could be produced, 
 owing to the excess of the yellow rays over the blue in the solar beams 
 of those regions. If we interpose between any object and the sun a 
 chrome yellow glass, although it will be most brilliantly illuminated, and 
 throw a beautiful image in the focus of the camera, it will be found 
 impossible to copy it, even by the most sensitive processes, in many 
 hours. 
 
 An explanation of these remarkable effects has been attempted, on the 
 hypothesis that the principle producing the remarkable chemical changes, 
 to which we have been referring, is not light, but some power associated 
 with it, which does not affect the eye or produce colour. It would appear, 
 from experiments which have been described by Mr. Hunt, that we can 
 separate, to a certain extent, these influences one from the other by 
 coloured media — and in the experiment above quoted we see that power- 
 ful chemical action may be exerted quite independent of Light. 
 
 TAKING PORTRAITS. 
 
 Portraits are taken with great rapidity in the open air; from five to 
 twenty seconds being usually sufficient, under a clear sky. A Voigt- 
 lander lens is best for portraiture, and for views also — no English lens 
 being at all comparable, as we believe, with the Voigtlander for inducing 
 beauty of detail, correct delineation, or, indeed, rapidity of operation. 
 
 The position of the camera will, of course, be regulated by circum- 
 stances ; but, generally speaking, the instrument should be placed nearly 
 on a level with the face. Care must be taken to keep the whole of that 
 portion of the person appearing in the plate as much as possible in the 
 same plane; otherwise any projecting limb — a hand ora leg, for instance 
 — will not be in a correct focus, and consequently be greatly magnified or 
 otherwise represented out of proportion. The direct rays of the sun are 
 best avoided ; and, to effect this, the person whose portrait is to be taken 
 should be seated under a canopy of white calico, with a screen of similar 
 material on either side, so as to equalise or diffuse the light as much as 
 possible, leaving the near side of the subject rather more illuminated 
 than the other, in order to produce a pleasing effect of light and shade 
 in the picture, due attention being also paid to position, arrangement of 
 attire, and so forth, with a view to artistic effect 
 
 The stiff, formal, and anything but natural or pleasing expression of 
 the daguerreotype pictures, generally exhibited in the metropolis, plainly 
 indicate that those pictures (?) are the productions of individuals whom 
 we must assume to be wholly ignorant of the simplest rules of art, using 
 the term as signifying something more than the mere mechanical hand- 
 
28 
 
 VIEWS. 
 
 ling of given materials. Often are badly-painted backgrounds intro- 
 duced, and these are frequently so stupidly managed as to distract 
 attention from what should be the main feature, and the entire picture 
 is thus rendered repulsive to the eye of a person of the slightest taste. 
 The more, indeed, that we see of photographic monstrocities, fathered by 
 individuals who may have forsaken the tradesman’s calling for the 
 daguerreotype — knowing, perhaps, little of, and caring, perhaps, less for, 
 the art itself than for the profit attached to the exercise of a monopoly 
 under a patent right — the more we are convinced that the process will 
 attain higher perfection, and consequently be rendered worthier of popu- 
 larity, in the hands of the amateur cultivating the art from a love of its 
 exceeding beauty and sensible of its many inherent attractions, than 
 from its remaining under the sole control of persons with “ vested rights.” 
 The amateur, possessing more talent, possibly, in the ordering of a pic- 
 ture, 'will more certainly bestow requisite time and attention than those 
 may be able to do, to whom we refer as now bringing the newly-dicovered 
 art into the market. 
 
 A dark drab-colour stuff forms an excellent back-ground. A table, 
 books, vases of flowers, &c., may be introduced with discrimination; but 
 much white should be carefully avoided. These hints being duly attended 
 to, we may anticipate comparative perfection in the representation of the 
 more prominent objects, joined to great precision in the details, with an 
 admirable gradation of shade, which may render the photographic image 
 a masterpiece of art or nature, or both conjointly, when the effects of 
 which it is capable are considered. 
 
 VIEWS. 
 
 The points from which buildings or views can be taken with the best 
 advantage, vary so greatly, that the operator must be left pretty much to 
 his own discretion, in choosing a position. As a general rule in taking a 
 building, monuments, &c., it is advisable to place the camera at a distance 
 of about twice its greatest dimensions, and, if practicable, at about one- 
 third its height. If the whole of the building or buildings be not in the 
 same plane, select the most important portion to be most clearly defined, 
 or take several views, in each of which certain points are brought out 
 more distinctly.] [If an old and new building are to be introduced in the 
 Same picture, which should, if possible, be avoided, a black screen or - 
 handkerchief, or some other opaque body should be placed over the lens 
 for a moment or two, so as to cut off the rays of light reflected from the 
 brighter portions of the object, the position of which may be previously 
 observed on the ground glass. The same precaution should be taken 
 
THE MERCURIALIZING PROCESS. 
 
 29 
 
 when the sky is very blue, or strongly illuminated by the sun. The best 
 time for taking views, is undoubtedly the earlier part of the day. 
 
 Engravings, Drawings, &c. may be copied very beautifully with a 
 little care; the whole of the model being in the same plane, there is little 
 difficulty in producing a good effect. The object to be copied must be 
 placed in a good light, taking care to have every part equally illuminated. 
 To secure sharpness, the model is placed in the open daylight, and a 
 small diaphram introduced before the lens to reduce the aperture and cut- 
 off part of the external light. 
 
 Machinery, Statuary, and Articles of Yertu, require to be 
 arranged in suitable positions, so that the light may fall upon the object 
 most effectively. 
 
 the mercurializing process. 
 
 In withdrawing the plate from the camera an exposure of it to the ex- 
 ternal light should be avoided, and it should immediately be conveyed to 
 the mercurializing box, and there be submitted to the vapour of mercury, 
 in the cup at the bottom of the box, about two ounces of quicksilver, 
 tied up in a piece of chamois leather or linen rag, of course being first 
 placed. The plate is to be placed in the proper position, and the mercury 
 in the cup gradually heated by means of a small spirit lamp standing, 
 under it until the thermometer indicates about 140 or 150 degrees of 
 heat. It will be necessary to continue this heat from seven to about 
 fifteen minutes, or even longer, to develop the picture, which may be 
 examined from time to time by the aid of an artificial light. This ope- 
 ration is generally rendered more certain by the mercury being heated, 
 before the plate is introduced, to about 120 degrees, in order that any 
 damp air that may have collected in the box may be expelled. Indeed, 
 this will shorten the time required in the conduct of this portion of the 
 process. Should it so happen that no outline be visible in about three or 
 four minutes, it may arise from one of the following causes — either the 
 picture has been removed too soon from the influence of light in the 
 camera, some atmospheric or chemical vapour floating in the room has 
 affected it, or the mercury may not have been sufficiently heated. It 
 must, nevertheless, be borne in mind that the details are usually much 
 better developed when the picture has been brought out slowly, and with 
 a degree of heat never exceeding 160 Falir. Attention must be paid to 
 keeping the mercury -box free from dust, and any mercurial particles 
 adhering to the sides and top must be previously well removed by the aid 
 of a stiff brush. A small painter’s tool will answer the purpose best. 
 The reason for this precaution is, that otherwise some small globules ot 
 
30 
 
 THE IIYPOSULPHATE BATH. 
 
 mercury might be detached and fly upon the face of a good picture on the 
 slightest movement being accidentally given to the box. 
 
 We find in this part of the process that those parts of iodized silver 
 plate, upon which the light has acted with most power, receive, in the ex- 
 posure to the vapours of mercury, the largest quantity of that vapour 
 over their surfaces, and the gradations of light are marked very beauti- 
 fully by the thickness of these mercurial films. 
 
 The character and tone of the picture almost exclusively depends upon 
 the mixture employed, as may be seen by inspecting those produced by 
 Beard and Claudet. The one uses a chloride, and the other a euchloride 
 of bromine. Claudet also applies the vapour of the chlorine and bromine 
 separately to the iodized plate. Beard, for some time used two mixtures 
 he called A and B, with iodine stirred together in one pot, and when 
 operating in the open air this answers very well. 
 
 The A mixture is a chloride of iodine formed by distilling with a great 
 heat — one part of iodine, and three of chlorate of potass. The B mixture 
 is iodic acid, made by passing into a flask, containing iodine — an excess of 
 gas arising from a mixture of oxide of manganese and sulphuric acid. But 
 the very best pictures taken at Beard’s was with the Wolcott’s mixture, 
 as we have been assured. 
 
 It may be worthy of observation that the image on plates may be com- 
 pletely obliterated by rubbing, but it may be again restored by placing it 
 in a tolerably strong solution of iodine in water. Some very curious 
 results have been obtained by operating on silvered plates, with iodine 
 in various ways. A silvered plate, with some leaves placed upon it and 
 pressed close with a glass, was immersed in a solution of iodine in water, 
 and in this state exposed to the light. An ioduret of silver was rapidly 
 formed and blackened; this blackened coating was dissolved off, and 
 another formed. Thus successive layers of the salt were formed and 
 removed, until at the expiration of an hour all the silver was gone from 
 the exposed parts of the plate. Upon removing the leaves, it was found 
 that a most beautiful impression of them remained on the copper, and 
 they were of a rich green colour. 
 
 THE HYPOSULPHITE BATH. 
 
 When the picture is fully developed, and the whites clearly brought 
 out (without the small white pinheads of mercury appearing over the surface), - 
 the plate is to be removed from the influence of the mercury, and allowed 
 to cool a short time before plunging in the hyposulphite of soda bath, 
 previously prepared by dissolving about two drachms of the crystalised 
 salt in half a pint of distilled water. Here it will be suffered to remain 
 a few minutes until all the iodine be removed from the plate, the operator 
 
FIXING THE PICTURE. 
 
 31 
 
 agitating the solution to facilitate the object now in view. From hence 
 it is to he taken and well washed in a basin of clean water, and then 
 convey it quickly into the washing and drying apparatus. This consists 
 of a small filter, or barrel of distilled water, with a stopcock, which allows 
 the water to flow into an enclosed copper trough, passing off at a spout. 
 The flow of water is then turned off, and the spirit lamp — with a large 
 flame — applied, which, quickly bringing the water in the copper trough 
 to near the boiling point, admits of the plate — by the heat thus given 
 being withdrawn — by slowly pushing up a small handle, connected with 
 the wire frame on which the plate rests in the interior of the trough, and 
 blowing from the mouth upon the plate as it appears to drive off in 
 vapour the adhering globules of water, thus entirely preventing the 
 spotting so frequently observed when hot water has simply been poured 
 over the plate as usually recommended.* 
 
 The hyposulphite crystals should be very clear and bright, the brown 
 lumps being rejected; and it should be carefully ascertained that they 
 contain no excess of sulphur, or, in other words, the operator must not 
 obtain a sulphate instead of a sulphite , or he will have the mortification of 
 observing numerous blueish and milky spots appear in the subsequent 
 process, which, in a short time, will completely spoil a picture. 
 
 FIXING THE PICTURE. 
 
 Fixing the Picture . — If this is intended to be effected immediately, it 
 will be sufficient, upon withdrawing the plate from the hyposulphite solu - 
 tion, to sluice it abundantly with water, and place it on the fixing-stand — 
 a small upright stand, with adjusting screws, to allow of the plate resting 
 on a perfect level. Then so much of the solution of the chloride of gold 
 as the plate will contain should be poured upon it. The spirit-lamp is 
 then to be held under all parts of the plate successively until it becomes 
 thickly studded with small bubbles, and the image begins first to assume 
 a dark appearance. In one or two minutes afterwards it acquires a great 
 degree of intensity. The lamp must now be removed, and the plate left 
 for a few minutes until it has become somewhat cool. The liquid being 
 then poured off, the plate should be put into the washing apparatus, and 
 dried with the spirit-lamp as before directed. 
 
 In the operation we have just described the following phenomena have 
 taken place : — Silver has been dissolved, and gold has been precipitated 
 upon the silver, and also upon the mercury, but with different results. 
 The silver, which by its polish forms the dark parts of the picture, is in 
 
 * This apparatus may be obtained fitted up very cheaply of Mr. Egerton, 
 1, Temple Street. 
 
32 
 
 FIXING THE PICTURE. 
 
 some degree browned by the thin coating of gold which covers it, whence 
 results an increased intensity in the black parts. The mercury, on the 
 contrary, which, under the form of infinitely small globules, forms the 
 whites, increases in strength and brilliancy by its amalgamation with the 
 x gold, whence results a greater degree of fixity, and a remarkable aug- 
 mentation in the light parts of the image. 
 
 The solution of the chloride of gold is prepared in the following man- 
 ner : — Take seven grains of the chloride of gold, weighed very quickly 
 in glass scales, as it is an extremely deliquescent salt; dissolve in a 
 quarter of a pint of distilled water, and twenty-one grains of the hypo- 
 sulphite of soda dissolve in another quarter of a pint of distilled water; 
 .then gradually pour the solution of gold into that of the soda, stirring it 
 all the while with a glass rod. The mixture, which is at first of a slightly 
 yellow colour, soon becomes perfectly limpid. 
 
 Should this solution change colour, or have deposited any brown pre- 
 cipitate at any time, it must be immediately rejected, as it will be no 
 longer fit for use ; to avoid which as much as possible, it will be better to 
 keep it perfectly excluded from light, and only a small quantity should 
 be mixed at any one time. 
 
 There has been recently introduced from Paris by Mr. Egerton a white 
 salt of gold, that is not so liable to spoil, or so difficult to manage as the 
 chloride of gold, and the result of the use of which upon the picture is 
 equally brilliant. 
 
 It has also been tried, and we believe with success, to fix the image in 
 a silver bath, prepared by dissolving cyanide of silver and cyanide of 
 potassium in distilled water. This is the process, adopted: — Upon 
 removing the picture from the mercury, it should be plunged into 
 this silver bath, in which it should remain for a few seconds until the sen- 
 sitive coating is dissolved. A galvanic current being then established in 
 the usual way with the battery, in eight or ten seconds the picture will be 
 fixed. 
 
 Its advantages are stated to be — 1st, that it gives great brilliancy to 
 the lights, and the solarized parts become very white; 2nd, that, silver 
 being a photogenic metal, the plates may be easily reprepared for use by 
 rubbing with dry tripoli; 3rd, that if, over a picture, when taken from the 
 mercury, or after being fixed by silver, concentrated hyposulphite of soda 
 solution should be poured, and the liquid brought nearly to a boiling 
 point, the picture gradually assumes the richest tints, passing succes- 
 sively from yellow to red, and from red to blue; the zinc pole determines 
 these colours in the cold at the points near it, pictures already fixed by 
 chloride of gold giving the richest colours. 
 
FIXING THE PICTURE, 
 
 33 
 
 This process is not very unlike one proposed by Professor Page, of 
 New York. In a course of experiments made by him to determine the 
 effects of oxidation upon the surface of photographic pictures, that gen- 
 tleman arrived at some very beautiful results, and adopted the following 
 method for fixing, strengthening, and colouring his impressions. 
 
 After taking and washing his picture in the usual manner, he plunged 
 it in a bath of cupreous cyanide of copper , and by galvanic agency a very 
 light deposit of copper was precipitated upon it, only just sufficient to 
 change the colour of the plate; then washed very carefully with distilled 
 water, and heated over a spirit-lamp until the light parts assume a pearly 
 transparent appearance. He also found that, according to the depth 
 of oxidation produced upon the surface, various colours were the re- 
 sult ; and one remarkable effect is the great hardening of surface, and that 
 it is as little liable to change as the fixing by gold. 
 
 For landscapes we know that it has a pleasing effect ; and, by adopting 
 some of the recent inventions for stopping out the deposit of copper, the 
 green colour may be made to appear stronger wherever desired. In some 
 pictures a curious variety of colours is obtained, owing to the varying thick- 
 ness of the deposit of copper, which is governed by the thickness of the 
 deposit of mercury forming the picture. To succeed well in the fixing 
 and in the production of the pearly appearance, the picture in the first in- 
 stance should be carried as far as possible without solarization, the solu- 
 tion of the hyposulphite of soda employed should especially be pure and 
 free from the traces of sulphur , and the plate should be carefully washed 
 with distilled water both before and after it receives the deposit of copper. 
 
 Mr. Fox Talbot also describes a process for colouring the pictures by 
 the battery, not very unlike the process adopted by Mr. Page. It is as 
 follows : — 
 
 A smooth surface of steel, platina, or other suitable metal, is coated 
 with an extremely thin layer of silver. The silver is then made sensitive 
 to light, by the methods now well known, and a photographic image is re- 
 ceived upon it. The plate with the image is then placed in a horizontal 
 position, and a solution of acetate of lead in water, is poured upon it. A 
 galvanic current is then made to pass through the plate and the solution, 
 which causes a coloured film to precipitate upon the plate. 
 
 Also, a method of obtaining very thin silver plates or surfaces, for the 
 purpose of economy in the processes of photography in which such are 
 used, and also for the greater convenience of transport in travelling. For 
 this purpose he precipitates on a polished metal plate, a thin layer of 
 copper by the galvanic process, now well known by the name of electro- 
 type. He then cements or glues a sheet of paper or card to the back of 
 
 D 
 
34 
 
 PROCESS OF COLOURING. 
 
 this layer of copper, and when it is dry, removes the paper with the layer 
 of copper adhering. This copper is then silvered by dipping it into any 
 suitable solution of silver. 
 
 PROCESS OF COLOURING. 
 
 In our opinion colouring a beautifully delineated photographic picture 
 is akin to “painting the lily white,” or daubing an exquisite line en- 
 graving all over with gaudy colours. Possibly, however, the reader’s taste 
 does not quite conform with that of our own, in this particular, and he 
 may fancy that a slight colouring renders his picture yet more attractive 
 to the eye. W e, therefore, present him with such directions as will best 
 enable him to gratify his “liking” in this respect: — 
 
 Dissolve two or three grains of gum arabic in a wine glass of water, and, 
 subsequently, cast in a small quantity of carmine or other finely powdered 
 colour. Set aside the glass until the coarse particles have subsided (as 
 they will do in a few minutes) at the bottom of the vessel; then pour the 
 particles remaining in suspension through a sheet of white filtering paper, 
 and let this mixture continue undisturbed until it has become thoroughly 
 drained and dry, when it is “ fit for use.” When this colouring mixture 
 is required for use a small portion should be rubbed off with a fine camel’s 
 hair pencil, and delicately stencilled on that part of the picture’s surface 
 intended to be coloured. A few delicate touches of this prepared carmine 
 will suffice to colour the lips and cheeks of the portrait. The admixture 
 of carmine, with two thirds of equally fine powdered raw seinna forms a very 
 natural looking flesh colour, and another tint is obtained by using burnt 
 seinna; but for sallow and dark complexions, generally, the carmine had 
 better be dispensed with, and the seinna only used. Prussian blue, cobalt, 
 and ultra-marine are the best blue colours, and either mixed with an equal 
 quantity of chrome yellow, produces an excellent green. Chrome yellow 
 can also be used alone, but we have frequently found that pictures will 
 not readily take either a yellow or green, if not laid on slightly moistened 
 with spirit of wine. Ready prepared shells of gold and silver are ob- 
 tained at any colour vendors, but neither will adhere to the plate if not 
 moistened. 
 
 This mode of colouring is so far preferable to any other yet suggested, 
 that it admits of the easy and clean removal of over colouring , by the sim- 
 ple employment of a clean brush — an article which it is advisable to have ~ 
 constantly within hand reach. If, therefore, the complexion is painted 
 too rubicund, or the attire, and so forth, be spotted by droppings of flesh 
 colour,, either may be speedily removed by the brush or a small pair of 
 hollows — the portrait being thus preserved from spoiling, and the artist 
 
THE MULTIPLICATION OF PICTURES. 
 
 35 
 
 enabled to “put on” or “take off” the colour until he has produced the 
 desired effect. 
 
 All the colours should be prepared in the same mode as that prescribed 
 for carmine, and they should be kept very dry on the paper, so as to be 
 always ready for use. The highly polished and dark appearance of the 
 material precludes the effective employment of almost every other colour 
 than those above enumerated — these can be purchased, in the form of an 
 almost impalpable powder, of any artist’s colourman. 
 
 THE MULTIPLICATION OF PICTURES. 
 
 It has been urged as a very great objection that Daguerreotype pic- 
 tures do not admit, as the Calotype’s, of being re-produced or copied ; 
 but many improvements have suggested themselves to remove this diffi- 
 culty to the multiplication of a good or valuable proof. Perhaps the 
 best yet pointed out, was the last of Wolcott’s inventions, relating to a 
 camera, in which photographic pictures on polished plates may be copied 
 by the scattered light from the surface of the plate, that portion of the 
 light which is reflected from the polished surface at the same angle at 
 which the incident rays fall (according to the laws of reflection of 
 polished surfaces), being prevented from entering the lenses of the 
 camera ; and in which camera pictures that are distorted in the perspec- 
 tive, by reason of the camera in which it was taken making an improper 
 angle with the horizon, either accidentally, or in order to take in parts of 
 a view which otherwise would not be seen, may be copied in true 
 perspective. 
 
 If the glasses are placed at equal distances from the picture and the 
 plate on which they are to be copied, the copy will be equal in size to the 
 picture to be copied, and at any other distances, that will be the largest 
 which is farthest from the glasses. In all these changes the focal dis- 
 tance must be carefully preserved, by changing the position of the plate 
 on which the copy is to be made ; as the sum of the focal distances becomes 
 greater as the difference between the two focii increases. 
 
 To understand this arrangement for correcting the perspective, it must 
 be borne in mind, that in taking a photographic picture, as the end of 
 the camera nearest any object is more elevated, the upper part of the 
 object will be more contracted in the picture than the under part ; and 
 that if the same end of the camera is depressed, the reverse will take 
 place. Thus, a row of columns, instead of being all perpendicular, 
 would, in the one case, appear falling together, and in the other, to fall 
 outwards. As it often happens in consequence of some obstruction, that 
 distance enough from the object cannot be had to bring all the parts 
 within the field, unless the camera is thus elevated or depressed, a pic- 
 
 D 2 
 
36 
 
 THE MULTIPLICATION OF PICTURES. 
 
 lure in true perspective could never be made, unless the evil could be 
 corrected in the copy, as may be done. 
 
 The operation is as follows : — Place the picture, and a plate on which 
 the copy is to be made, in a frame, and in such manner, that the parts 
 which are perpendicular in the object shall be horizontal in the frame, 
 then bring the end of the picture, in which the perspective is contracted, 
 a little nearer the glasses, by causing it to turn on its axis ; then, sup- 
 posing the copy to be of the size of the original, turn the end of the 
 plate on which the copy is to be made to the same angle to the glasses 
 as the picture is, and in such direction, that the ends, both of the picture 
 and the plate for the copy which are nearest the glasses, shall both be on 
 the same side of the box. Now it will be seen, that by this arrangement 
 the parts of the picture which are nearest to the glasses will be copied on 
 to that part of the plate which is farthest from the glasses, and thereby 
 be copied larger than if the plates were parallel ; and that those parts of 
 the picture which are farthest from the glasses will be copied on that 
 part of the plate which is nearest to the glasses, and thus be copied 
 smaller than if they were parallel, thus correcting the perspective in the 
 copy. The proper angle to place the picture and plate, according to the 
 amount of distortion, can soon be determined by a few experiments. As 
 in the picture and plate, those parts which are nearest the glasses in the 
 one, are farthest in the other ; the focal distance is very nearly preserved. 
 The sizes of the plates or pictures, with regard to the focal distance, 
 should be such, that when they are adjusted to the proper focal distance, 
 either for pictures and plates of different sizes or for those of equal size, 
 the angles subtended from the glasses to the ends of the plate, be not 
 more than thirty degrees. For the convex lenses, common plate-glass 
 may be used ; the concave should be of the heavy flint, of a specific 
 gravity of about 3*5; and for a focal distance of about 7*7 inches, the 
 following proportions will perform very well. The side of the concave 
 glass next to the aperture, is plane and distant 79-100 of an inch ; the 
 other side of the concave, and also that side of the convex which is next 
 it, are made to a radius of 1 78-100; the other side of the convex is made 
 to a radius of 2 62-100 inches. The thickness of the concave in the 
 middle is 6-100 inch, and that of the convex is 56-100 inch, diameters 
 about l£ inch. If the pictures that are to be copied, have been 
 taken in a camera that did not contain a reflector, they would be 
 reversed, but the copy would be correct. A metallic plate has been 
 mentioned as the surface on which the pictures are to be copied, but any 
 material may be used that is properly prepared to receive an impression, 
 by light. The edge of the box should be so high, that a ray of light 
 
THE REPRODUCTION OF PICTURES BY THE ELECTROTYPE. 37 
 
 passing into the box close to that part, and falling on to the polished 
 surface of the picture close to its upper edge, shall, when reflected, be 
 thrown below the glasses. It having been found that the clearest blacks 
 in a picture are produced when the polish of the plate has been finished 
 by straight strokes in that direction, which will be horizontal in the pic- 
 ture, it becomes necessary in copying pictures formed on plates so 
 polished, to place them in the box in such a manner that the lines of the 
 polish shall be perpendicular; and in all cases, in whatever direction the 
 lines of polish in the picture are, they must be placed perpendicularly in 
 copying. In cases where the polish has been made in curved, or other- 
 wise than in parallel straight lines, that position should be chosen in 
 which the largest portion of the lines will be perpendicular, or most 
 nearly so; or, at all events, in which such will be the case in the most 
 important parts of the picture. 
 
 This position of the lines will cause the light which falls on the inclined 
 edges of the lines (the lines of the polish being only so many minute 
 furrows) to be reflected to that part of the box which is below the 
 glasses ; whereas if the light was allowed to fall at right angles to the 
 lines a large portion of it would be reflected from the lines into the 
 glasses. Every part of the inside of the box between the picture and 
 the partition, should be lined with black cotton velvet, or otherwise 
 blackened so as to prevent any injurious reflection of light. By these 
 means, if the polished surface of the picture were viewed from the place 
 occupied by the glasses no object or light from objects bright enough to 
 interfere with the operation would be perceived in it, and, of course, 
 there would not be much light to act on the plate or other material on 
 which the picture is to be copied, and thereby injure the copy, which it 
 is only intended should be made by scattering lights from the rough sur- 
 face produced by the adhesion of mercury, of which the picture is essen- 
 tially composed, being painted on the polished black ground of the plate. 
 
 His invention consists then in the mode of constructing cameras, con- 
 taining a chamber for the picture to be copied, and so constructed, that 
 if the picture were viewed from the place occupied by the glasses, no 
 object, or light from objects bright enough to prevent a distinct view of 
 all the parts of the picture, could be seen in the polished surface of the 
 picture. And also the mode of making cameras whereby a copy in true 
 perspective may be obtained from a picture not in perspective. 
 
 THE REPRODUCTION OP PICTURES BY THE ELECTROTYPE. 
 
 The plate must first be entirely divested of all traces of hyposulphite* 
 and is indispensable that it should be perfectly fixed by the chloride of gold. 
 
38 
 
 THE REPRODUCTION OF PICTURES BY THE ELECTROTYPE. 
 
 In general, operators are in a hurry to see the progress of the process. 
 We advise them to moderate that eagerness which is frequently the cause 
 of failure. They should always wait a few minutes before taking the 
 plate out of the bath; and, each time that it is done, care must be taken 
 not to leave it long in contact with the air, as a few minutes would suf- 
 fice to oxydize the surface to sucli a degree as to hinder the next deposite 
 from adhering to the first. 
 
 When the metallic coating is judged to be of sufficient thickness — and, 
 in this case, that of a stout card suffices — the plate should be rinsed co- 
 piously in water, and then dried either with saw-dust or blotting-paper. 
 
 If you wish to preserve on the plate the beautitul rosy hue of the mo- 
 ther-of-pearl opal, which the deposite should leave on its being taken out 
 of the bath, hasten the drying of it, after passing it once through the 
 water, by wetting it with spirits of wine, which you also dry up with 
 blotting-paper. 
 
 The separation of the deposite from the plate may be attended with 
 an accident which spoils them both. It often happens that a small drop 
 of liquid remains unperceived under the wax which covers the borders 
 of the plate, and that, at the instant when you lift up the deposite with 
 the blade of a knife, this drop works itself into the capillary space thus 
 formed, and wets the deposite and the plate, which are infallibly stained 
 if the liquid contains any remaining particles of the sulphate of 
 copper. 
 
 The most secure process for separating the two plates consists, when 
 the deposite is not too thick, in cutting with a pair of strong scissors all 
 round the edges of the two plates, which then separate with the greatest 
 facility. 
 
 The affinity of oxygen for copper being much greater than for silver, 
 the counter- proof must be withdrawn as soon as possible from the con- 
 contact of the air, by placing it in a skeleton frame; and above all, the 
 greatest care must be taken not to touch its surface. It is also necessary 
 to observe the nicest precaution in preventing all dust or other foreign 
 substances from lodging on the surface of the plate, otherwise the copy 
 would be found disfigured w r ith their corresponding traces. 
 
 Having thus explained the most essential conditions to be observed, we 
 will now enter into some further details of the operation. Lay hold of 
 the silvered plate by one of its sides, or, if a small plate, by one of its - 
 angles, and keep that part free from oxydation, in order to attach it to 
 the connecting wire of the trough, to which the positive pole (zinc) of 
 the battery is joined, and the whole is held fast with a binding-screw. 
 
 The back of the plate is then covered with a coating of varnish, com- 
 
ENGRAVING PHOTOGRAPHIC PLATES. 
 
 39 
 
 posed of one-third of essence of turpentine and two-thirds of beeswax, 
 or simply of beeswax alone, in order to avoid a useless deposite of cop- 
 per. Care must be taken that this coating of varnish, which should he 
 applied hot, should be of a certain thickness, and should not interpose 
 between the plate and the connecting wire of the precipitating trough, 
 or it would interrupt the metallic contact necessary to the success of the 
 operation. 
 
 The sulphate of copper solution must be carefully filtered, and it must 
 be saturated in cold water.* 
 
 When all is prepared, put the positive electrode (a copper plate which 
 dissolves in the trough) in connexion with the negative pole of the bat- 
 tery (carbon), and immerse it in the bath ; establish also a connexion 
 between the proof to be reproduced and the other pole (zinc), and when 
 firmly attached by means of one or more binding-screws, it must be 
 immersed in the bath, when it will immediately become covered with 
 copper. 
 
 The expense consists, therefore, only in the value of the copper depo- 
 sited; and when it is considered that, with so very small an outlay, you 
 may be able, after one or two experiments, to reproduce and multiply, 
 without any risk of failure, the finest photographic impressions (which 
 are always very much prized), with a very warm tone, and an admirable 
 degree of perfection; when you reflect that the same small apparatus 
 may serve for a number of other applications, one is really surprised 
 that it should not be more generally adopted. 
 
 ENGRAVING PHOTOGRAPHIC PLATES. 
 
 It was found that the parts over which the mercury had been de- 
 posited were deeply etched by the iodine, and a very important practical 
 advantage has been taken of this remarkable peculiarity, by the recent 
 attempts at etching the pictures. Professor Groves was the first to point 
 out a mode by the aid of an acid and a powerful voltaic current, and we 
 believe he succeeded in producing some pleasing results; hut a better plan 
 has been lately patented by Claudet, and is as follows : — 
 
 1. A mixed acid, composed of water, nitric acid, nitrate of potassa, and 
 common salt, in certain proportions, being poured upon a Daguerreotype 
 picture attacks the pure silver, forming a chloride of that metal, and does 
 not affect the white parts, which are produced by the mercury; but this 
 
 * In order to have a solution always ready, it will be well to keep it in a 
 large glass-bottle ; it will be known that it is sufficiently saturated, when 
 after having shaken it several times, the liquid ceases to dissolve the few 
 crystals of sulphate of copper which remain at the bottom in excess. 
 
40 
 
 EKGRAVING PHOTOGRAPHIC PLATES. 
 
 action does not continue long. Then, by a treatment with ammonia (am- 
 monia containing already chloride of silver in solution is preferable for 
 this operation), the chloride of silver is dissolved, and washed off, and the 
 metal being again in its naked state, or cleansed from the chloride, it can 
 be attacked afresh by the same acid. This acid acts better warm than cold. 
 
 2. As all metallic surfaces are soon covered, when exposed to the 
 atmosphere, with greasy or resinous matters, it is necessary, in order that 
 the action of the acid upon the pure silver should have its full effect, for 
 the surface to be perfectly purified; this is effected by the employment of 
 alcohol and caustic potash. 
 
 3. When a Daguerreotype picture is submitted to the effect of a boiling 
 concentrated solution of caustic potash, before being attacked by the 
 acid, the state of its surface is so modified that the acid spares or leaves, 
 in the parts which it attacks, a great number of points, which form the 
 grain of the engraving. 
 
 4. When the effect of the acid is not sufficient, or in other words, if it 
 has not bitten deep enough, the effect is increased by the following pro- 
 cess : — Ink the plate as copper-plate printers do, but with a siccative ink ; 
 when the ink is sufficiently dry, polish the white parts of the plate, and 
 gild it by the electrotype process ; then wash it with warm caustic potash, 
 and bite in with an acid, which will not attack the gold, but only the 
 metal in those parts which, having been protected by the ink, have not 
 received the coating of gold. By these means the engraving is com- 
 pleted, as by the action of the acid alone it is not generally bitten in deep 
 enough. 
 
 5. To protect the plate from the effects of wear, produced by the opera- 
 tion of printing, the following process is employed : — The surface of the 
 plate is covered with a very thin coating of copper, by means of the 
 electrotype process, before submitting it to the operation of printing; and 
 when that pellicle or coating of copper begins to show signs of wear, it 
 must be removed altogether, by plunging the plate in ammonia, or in a 
 weak acid which, by electro-chemical action, will dissolve the copper, 
 without affecting the metal under it; the plate is then coppered again, by 
 the same means, and is then ready for producing a further number of im- 
 pressions. This re-coating operation may be repeated as many times as 
 may be required. The following is the description of the whole process,, 
 which is divided into two parts, consisting of a preparatory and finishing - 
 process 
 
 Preparatory Engraving . — For this operation, which is the most deli- 
 cate, it is necessary to have, 1. A saturated solution of caustic potash. 
 
 2. Pure nitric acid at 36° of the areometer of Beaume (spec. grav. 1*333.) 
 
ENGRAVING PHOTOGRAPHIC PLATES. 
 
 41 
 
 3. A solution of nitrite of potassa, composed of 100 parts of water and 
 5 parts of nitrite, by weight. 4. A solution of common salt, composed of 
 water 100 parts, and salt 10 parts, by weight. 5. A weak solution of am- 
 moniacal chloride of silver, with an excess of ammonia. The ammonia- 
 cal chloride of silver must be diluted with 15 or 20 parts of pure water. 
 In the description of the process, this solution will be called ammoniacal 
 chloride of silver. 6. A weak solution of ammonia, containing 4 or 5 
 thousandths of liquid ammonia. This solution will be called ammoniacal 
 water. 7. A weak solution of caustic potash, containing 4 or 5 thou- 
 sandths of the saturated solution, which will be called alkaline water. 
 8. A solution composed of water 4 parts, saturated solution of potash 2 
 parts, alcohol 1 part, all in volume. This solution will be called alcoho- 
 lised potash. 9. Acidulated water, composed of water 100 parts, and 
 nitric acid 2 parts, in volume. Besides, it is necessary to have three cap- 
 sulae or dishes, made of porcelain, large enough to contain the plate, and 
 covered with an air-tight piece of ground plate-glass, and two or three 
 more capsulae which do not require to be covered; two or three glass fun- 
 nels, to wash the plate; and two or three glass holders, in the shape 
 of a spoon or shovel, by which the plate is supported when put in and 
 taken out of the solution, without touching it with the fingers. 
 
 The Daguerreotype plate is submitted to the engraving process, after 
 having been washed in the hyposulphite of soda, and afterwards in dis- 
 tilled water. 
 
 First process for biting in or engraving the plate . — The following solutions 
 must be put in the capsulae, in sufficient quantity, so as to entirely cover 
 the plate: — 1. Acidulated water. 2. Alkaline water. 3. Alcoholised 
 potash, in covered capsulae. 4. Caustic potash, in covered capsulae. 5. 
 Distilled water. 
 
 The plate being put upon the glass holder or spoon, is plunged in the 
 acidulated water, and agitated during a few seconds, then put into a glass 
 funnel, and washed with distilled water. It is taken again with the glass 
 spoon, and plunged in the capsula containing alcoholised potash. This 
 capsula is covered with its glass cover, and then heated, by means of a 
 spirit-lamp, to about 144° Fahrenheit. The plate must remain in the 
 capsula half an hour, during which the solution is heated now and then, 
 and agitated. During that time, the following acid solution, which will 
 be called normal acid , must be prepared; it is composed as follows : — Water 
 600 parts, nitric acid 45 parts, solution of nitrite of potassa 12 parts, solu- 
 tion of common salt 45 parts. These proportions are in volume. The 
 normal acid must be poured in a capsula, covered with its glass cover, 
 and a sufficient quantity must be kept in the bottle. 
 
42 
 
 ENGRAVING PHOTOGRAPHIC PLATES. 
 
 When the plate has been immersed in the alcoholised potash during 
 half an hour, it is taken out of the solution by means of the glass holder, 
 and immediately plunged in the alkaline water, and agitated pretty 
 strongly ; from thence it is put in distilled water. (A) 
 
 This being done, the plate is plunged in the acidulated water, and 
 moved about therein for a few seconds : it is then put into the normal acid. 
 When the plate has been immersed a few seconds in the acid, it is taken 
 out by means of the glass holder, taking care to keep it as much as pos- 
 sible covered with the solution, and it is immediately placed horizontally 
 upon a stand, and as much acid as the plate can hold is poured upon it 
 from the bottle; it is then heated with a spirit-lamp, but without attain- 
 ing the boiling point. During this operation it is better to stir or move 
 about the acid on the plate by pumping it, and ejecting it again, by means 
 of a pipette or glass syringe; after two or three minutes the acid is 
 thrown away, the plate is put in the glass funnel, and there well washed 
 with water, and afterwards with distilled water. (B) 
 
 Then, without letting the plate dry, it is put upon the fingers of the left 
 hand, and with the right hand some ammoniacal chloride of silver, which 
 is moved about the surface by balancing the hand, is poured upon it ; the 
 solution is renewed until the chloride, formed by the action of the acid, is 
 dissolved; the plate is then washed by pouring upon it a large quantity 
 of ammoniacal water, and afterwards some distilled water. (C) 
 
 Without allowing the plate to dry, it is then put in the caustic potash, 
 and the capsula being placed upon the stand, the potash is heated up to 
 the boiling point; it is then left to cool (D); and beginning again the 
 operations described from A to D, a second biting is obtained; and by re- 
 peating again the operations described in A and B, a third biting is pro- 
 duced. The plate is then dried; in this state the black parts of the plate 
 are filled with chloride of silver. 
 
 The plate is then polished until the white part^are perfectly pure and 
 bright. This polishing is done with cotton and 44 pounce” (pumice stone); 
 afterwards, the chloride of silver; filling the black parts, is cleansed by 
 the means described in B and C. The plate is then dried; but before 
 drying, it is well to rub the plate slightly with the finger, in order to take 
 off from the black parts any remains of an insoluble body which gene- 
 rally remain on it. The preparatory engraving is then finished, and the 
 plate has the appearance of a very delicate aqua-tint engraved plate, not 
 very deeply bitten in. 
 
 Nevertheless, if the operation has been well managed, and has been 
 successful, it is deep enough to allow the printing of a considerable num- 
 ber of copies. 
 
ENGRAVING PHOTOGRAPHIC PLATES. 
 
 43 
 
 Note. — Sometimes, instead of treating the plate with the boiling potash 
 in the capsula, a similar result may be obtained by placing the plate upon 
 the stand, covering it with the solution, and heating it by means of a 
 spirit-lamp, until, by evaporation, the potash becomes in a state of ignited 
 fusion. By this means the grain is finer, but the white parts are more 
 liable to be attacked. 
 
 Last operation of biting in . — This operation requires some of the re- 
 agents before named, and also, 
 
 1. A siccative ink, made of linseed oil, rendered very siccative by 
 boiling it sufficiently with litharge ; it may be thickened with calcined 
 lamp-black. 
 
 2. An electrotype apparatus, and some solutions fit to gild and copper 
 the plate. 
 
 Means of operating . — The plate must be inked as copper-plate printers 
 do, taking care to clean off the white parts more perfectly than usual; the 
 plate is then to be placed in a room sufficiently warm, until the ink is well 
 dried, which requires more or less time, according to the nature of the oil 
 employed. The drying of the oil may be hastened by heating the plate 
 upon the stand with the lamp, but the slow process is more perfect and 
 certain. 
 
 When the ink is well dried, the white parts are cleaned again by polish- 
 ing the plate with cotton and pounce, or any other polishing powder : a 
 ball of cotton, or any other matter, covered with a thin piece of caout- 
 chouc or skin, can be used for this purpose. When polished, the plate is 
 ready to receive the electro- chemical coating of gold, which will protect 
 the white parts. 
 
 Gilding . — The gilding is obtained by any of the various processes of 
 electrotyping which are known. The only indispensable condition is, that 
 the surface obtained by the precipitation must not be liable to be attacked 
 by any weak acid ; a solution answering this purpose is made of ten parts 
 (by weight) of ferrocyanide of potassium, one part of chloride of gold, 
 and 1000 parts of water, used with a galvanic battery. During the gild- 
 ing the plate must be turned in several positions, in order to regulate the 
 metallic deposit. In some cases the gilding may be made more perfect, 
 if the plate is covered with a thin coating of mercury before being put in 
 the gilding solution. 
 
 When the plate is gilded, it must be treated with the boiling caustic 
 potash, by the process already indicated for the preparatory engraving, 
 in order to cleanse it from all the dried oil or ink which fits the hollows. 
 The plate is then washed and dried, and when the oil employed has been 
 thickened with the lamp-black, the surface of the plate is rubbed with 
 
44 
 
 ENGRAVING PHOTOGRAPHIC PLATES. 
 
 crumb of bread, in order to cleanse and take off the black remaining; 
 then, the white parts being covered and protected by a varnish not liable 
 to be attacked, and the black parts being uncovered and clean, the plate 
 can be bitten in by aquafortis, according to the ordinary process used by 
 engravers. 
 
 This operation must be done upon the stand, and not by immersing the 
 plate in the solution. 
 
 Before this last biting-in, if the preparatory engraving has not suc- 
 ceeded well, and the plate still wants a sufficient grain, it can be given by 
 the various processes of aquatint engraving. 
 
 Before submitting the plate to the operation of printing, in order to 
 insure an unlimited number of copies, it is necessary, as before stated, to 
 protect it by a slight coating of copper, which is obtained by the electro- 
 type process; otherwise the printing would soon wear the plate. This 
 coating must be kept very thin, lest the fineness of the engraving, and 
 the polish of the white parts, should be destroyed. In this state the plate 
 can be delivered to the printer. 
 
 After a certain number of impressions have been obtained, it will be 
 perceived that the coating of copper is worn in some places ; then, this 
 coating must be removed, and a fresh one applied in its place. For this 
 purpose, the plate must be purified and cleansed by warm potash, and 
 plunged in a weak acid composed as follows: — Water, 600 parts; nitric 
 acid, 50 parts; nitrous acid of engravers, 5 parts; all in volume. This 
 acid will dissolve the coating of copper, and the plate being coppered again 
 by the same means as before, may be again submitted to the operation of 
 printing; and as nothing can prevent the success of a repetition of the 
 same operation, any number of impressions may be obtained. The coat- 
 ing of copper can also be removed by caustic ammonia. 
 
 The Daguerreotype plates engraved by this process, which constitute 
 the present invention, consist, — * 
 
 First, — in the discovery and employment of certain properties of a 
 mixture composed of nitric acid, nitrous acid, and hydrochloric acid, in 
 determined or fixed proportions. The two last-mentioned acids may be 
 employed either in a free state, or combined with alkaline or other basis. 
 This mixed acid has the property of biting the pure silver which forms 
 the black parts of the Daguerreotype picture, without attacking the white 
 parts formed by the amalgam of mercury. The result of the action of 
 the biting is to form on the black parts of the picture an insoluble chlo- 
 ride of silver; and this chipride of silver which when formed stops the 
 action of the acid, is dissolved by ammonia, which allows the biting to 
 continue. 
 
ENGRAVING PHOTOGRAPHIC PLATES. 
 
 45 
 
 Secondly, — in the discovery of certain properties of a warm solution of 
 caustic potash, and in the employment of the said solution, by which the 
 mercury forming the picture is better and deeper amalgamated with the 
 silver under it, so that many imperceptible points of the amalgam are 
 effected in such a manner that the acid has no action upon them. 
 
 Thirdly, — in the discovery and employment of a process which pro- 
 duces a grain favourable to the engraving,by which the biting on the plate 
 is rendered deeper. This is effected by filling the parts engraved with a 
 siccative ink, or any other substance, and then gilding the plate by the 
 electrotype process ; the gold is not deposited on the parts protected by 
 the ink. When the plate is gilded, the ink is cleansed by the caustic 
 potash, and the plate may be submitted to the effects of an acid which, 
 does not attack the coating of gold, but bites only on the silver in the 
 parts already engraved by the first operation. 
 
 Fourthly, — in the employment of a process by which the plate is pro- 
 tected from the wear of the printing operation. This is effected by 
 covering the plate before printing with a slight coating of copper by the 
 electrotype process, and when the coating begins to wear by printing, it 
 is removed by a weak acid, or by ammonia, which dissolves the copper 
 without affecting the silver under it. The plate is coppered again, and 
 after another printing the same operation is repeated, so that a con- 
 siderable number of copies may be printed without much injury to the 
 engraving. 
 
 We have in our possession an exquisite picture printed on paper from 
 one of these etched plates, and it is, indeed, equal to a very fine mezzo- 
 tinto, and from this specimen have, no doubt, but that, with a little 
 patient attention, some beautiful results may be obtained. 
 
 It was stated at the late meeting of the British association by Mr. 
 Goadby, that Claudet had fully established the successful application of 
 this process to the purposes of illustrating natural history, by copying 
 from nature, and engraving several delicate and difficult dissections of 
 the lower animals, particularly the nervous system of Aplysia and Tri- 
 tonia (the latter much magnified) and the nutrimental organs in situ of a 
 caterpillar. 
 
 Captain Ibbetson also employed a similar process for engraving micro- 
 scopic objects. He exhibited some plates of blood-globules, &c., pro- 
 cured in this way by Dr. Donne, of Paris. It must be observed, to 
 produce a very perfect specimen, that it generally requires to be finished 
 by the hand of the engraver, who has the advantage of a perfect , although 
 faint picture to work upon. 
 
 Tolerable positive pictures have been obtained without mercurializa- 
 
46 
 
 ENGRAVING PHOTOGRAPHIC PLATES. 
 
 iion, as will be seen in the following experiment by Mr. Hunt. After 
 exposing to light, a prepared photographic plate, it was placed in a vessel, 
 in which chlorine was very slowly forming, from manganese and muriatic 
 acid. In a short time the iodized surface, which had not been exposed 
 sufficiently long to undergo any change of colour, became perfectly black. 
 In this state, it was subjected to light, the effect of which was to whiten 
 the plate, with much rapidity. A few well conducted experiments in a 
 similar way may lead to unlooked-for results. 
 
 It is asserted by Mr. Hunt, upon the authority of Dr. Robinson, of 
 Armagh, that lunar light will not act chemically upon the prepared pho- 
 tographic plate; we are at a loss to imagine what Dr. Robinson could 
 have prepared his plates with, as we have repeatedly obtained an image 
 of the moon upon our plates in one minute, and in two, three, and five 
 minutes they have been completely solarized ; upon an occasion of a 
 plate remaining exposed for half-an-hour, we found that the image had 
 moved over the space of an inch leaving a solarized comet-like train, 
 very much over done (as it is technically termed) the whole length. 
 
 A. M. Martenz, of Paris, states that he has discovered the means of 
 carrying on the daguerreotype process on a gigantic scale. He can, he 
 says, daguerreotype an entire panorama, embracing 150 degrees ! ! His 
 process consists in curving the metallic plate, and causing the lens which 
 reflects the landscape to turn by clockwork. The lens* in turning, passes 
 over on one side the whole space to be daguerreotyped, and on the other 
 side moves the refracted luminous cone to the plate, to which the objects 
 are successively conveyed. 
 
 Mr. Fox Talbot suggested a very curious experiment which we should 
 be glad to hear the result of. He says, “ When a ray of solar light is 
 refracted by a prism, and thrown upon a screen, it forms there the very 
 beautiful coloured band known by the name of the solar spectrum. Ex- 
 periments have found that if this spectrum is thrown upon a sheet of 
 sensitive paper, the violet end of it produces the simple effect: and, what 
 is truly remarkable, a similar effect is produced by certain invisible rays 
 which lie beyond the violet, and beyond the limits of the spectrum, and 
 whose existence is only revealed to us by this action which they exert. 
 Now I would propose to separate the invisible rays from the rest, by 
 suffering them to pass into an adjoining apartment through an aperture 
 in a Trail or screen of partition. This apartment would thus become filled 
 (we must not call it illuminated ) with invisible rays, which might be 
 scattered in all directions by a convex lens placed behind the aperture. 
 If there were a number of persons in the room no one would see the 
 other; and yet, nevertheless, if a camera were so placed as to point in the 
 
THE CALOTYPE OH TALBOTYPE. 
 
 47 
 
 direction in which any one was standing, it would take his portrait and 
 reveal his actions; * * the eye of the camera would see plainly where 
 the human eye would find nothing hut darkness.” Erom this we would 
 infer that powerful chemical action may be exerted independent of light 
 Sir J. Herschel proposed the epithet of actino- chemistry, to distinguish this 
 chemical power from the light and heat with which it is associated, and 
 it would indeed appear from the phenomena connected with the actinic 
 influence, that we are on the eve of discovering some remarkable truths, 
 which will probably embrace all the changes which occur on the surface 
 of our globe ; since photography has taught us how to prepare a metal 
 plate, or a sheet of paper, which shall in a few seconds receive an im- 
 pression of a shadow , to which the permanence of an engraving can be 
 given, and thus we shall be enabled to hand down to future ages a picture 
 of the sunshine of yesterday, or a memorial of the haze of to-day, suck 
 are the results of recent investigation. 
 
 CHAPTER II. 
 
 THE CALOTYPE OR TALBOTYPE. 
 
 The art of photography is greatly indebted to Mr. Eox Talbot for its 
 present state of perfection. It must not be forgotten, as we have before 
 pointed out, that Mr. Talbot was the first who succeeded in fixing images 
 taken by the camera, and by super-position on paper; and that he has 
 steadily pursued his experiments until the perfection of the calotype has 
 rewarded his perseverance. Some of his recently published productions 
 are for minuteness of detail and beauty very little inferior to those taken 
 on silver plates. Several other inquirers have been labouring in the 
 same field, and the result of their researches has been the extraordinary 
 discovery, that all bodies are constantly undergoing changes under the 
 influence of the solar rays ; from the delicately sensitive film which is 
 formed on the silver plate to all the salts of the metals, and even to the 
 metals themselves, or plates of glass or stone, have been found capable of 
 receiving light impressed pictures. A shadow cannot fall upon any solid 
 body without leaving evidence behind it, in the disturbed and undisturbed 
 condition of its molecular arrangement of the parts in light or shade. It 
 is evident, then, that all bodies are capable of photographic disturbance, 
 
48 
 
 THE CALOTYPE OR TALBOTYPE. 
 
 and might be used for the production of pictures, did we but know the 
 methods by which the pictures might be developed, for it must be re- 
 membered that in all the best photographic processes the images 
 are invisible at first, and we are not without hope that at no very 
 distant time these means may be discovered. We shall now proceed 
 to give, in Mr. Talbot’s own words, the very latest improvements 
 he has published for the preparation of the calotype paper. The 
 only apparatus necessary for this purpose are a few wood frames, a trifle 
 smaller than the sheets of paper to be prepared, two or three soft camel’s 
 hair brushes, some sheets of white blotting paper, two or three glasses 
 for holding the solutions, and two glass stirring rods. 
 
 First Part of the Preparation of the Paper. — I dissolve 100 grains of 
 chrystallized nitrate of silver in six ounces of distilled water ; I wash one 
 side of the paper with this solution with a soft camel hair brush, and 
 place a mark upon that side by which to know it again. I dry the paper 
 cautiously at a distant fire, or else I leave it to dry spontaneously in a 
 dark place. Next I dip the paper in a solution of iodide of potassium, 
 containing 500 grains of that salt dissolved in one pint of water. I leave 
 the paper a minute or two in this solution. I then take it out and dip it 
 in water. I then dry it lightly with blotting paper, and finish drying it 
 at a fire, or else I leave it to dry spontaneously. All this process is best 
 done in the evening by candle-light. The paper thus far prepared may 
 be called, for the sake of distinction, iodized paper. This iodized paper 
 is scarcely sensitive to light, but nevertheless it should be kept in a port- 
 folio or some dark place till wanted for use. It does not spoil by keeping 
 any length of time, provided it is kept in a portfolio and not exposed to 
 the light. 
 
 Second Part of the Preparation of the Paper . — This second part is best 
 deferred until the paper is wanted for use. When that time is arrived I 
 take a sheet of the iodized paper and wash it with a liquid prepared in 
 the following manner. Dissolve 100 grains of chystallized nitrate of 
 silver in two ounces of distilled water; to this solution add one-sixth of 
 its volume of strong acetic acid; let this mixture be called a; dissolve 
 chrystallized gallic acid in distilled water, as much as it will dissolve 
 (which is a very small quantity); let this solution be called b. When you 
 wish to prepare a sheet of paper for use, mix together the liquids, a and 
 b, in equal volumes. This mixture I shall call by the name of galio- 
 nitrate of silver. Let no more be mixed than is intended to be used at 
 one time, because the mixture will not keep good for a long period. Then 
 take a sheet of iodized paper and wash it over with this gallo-nitrate of 
 silver with a soft camel hair brush, taking care to wash it on the side 
 
THE CALOTYPE OR TALBOTYPE. 
 
 49 
 
 which has been previously marked. This operation should be performed 
 by candle-light. Let the paper rest half a minute, and then dip it into 
 water, then dry it lightly with blotting paper; and lastly, dry it cau- 
 tiously at a fire, holding it at a considerable distance therefrom. When 
 dry the paper is fit for use; but it is advisable to use it within a few hours 
 after its preparation. 
 
 Note, that if it is so used immediately, the last drying may be dis- 
 pensed with, and the paper may be used moist. 
 
 Note 2. Instead of using a solution of gallic acid for the liquid, b, the 
 tincture of galls diluted with water may be used, but it is not so ad- 
 visable. 
 
 Use of the Paper . — The paper thus prepared, and which I name calo- 
 type paper, is placed in a camera obscura, so as to receive the image 
 formed in the focus of the lens. Of course the paper must be screened or 
 defended from the light during the time it is being put into the camera. 
 When the camera is properly pointed at the object, this screen is with- 
 drawn, or a pair of internal folding doors are opened, so as to expose the 
 paper for the reception of the image. If the object is very bright, or the 
 time employed is sufficiently long, a sensible image is perceived upon the 
 paper when it is withdrawn from the camera; but when the time is short, 
 or the objects dim, no image whatever is visible upon the paper, which 
 appears entirely blank. Nevertheless it is impressed with an invisible 
 image, and I have discovered the means of causing this image to become 
 visible. This is performed as follows: — I take some gallo-nitrate of 
 silver, prepared in the manner before directed, and with this liquid I 
 wash the paper all over with a soft camel hair brush. I then hold it 
 before a gentle fire, and in a short time (varying from a few seconds to a 
 minute or two) the image begins to appear upon the paper. Those parts 
 of the paper upon which light has acted the most strongly become brown 
 or black, while those parts on which light has not acted remain white. 
 The image continues to strengthen and grow more and more visible dur- 
 ing some time ; when it appears strong enough the operation should be 
 terminated and the picture fixed. 
 
 The Fixing Process . — In order to fix the picture thus obtained I first 
 dip it into water. I then partly dry it with blotting-paper, and then 
 wash it with a solution of bromide of potassium, containing 100 grains of 
 the salt dissolved in eight or ten ounces of water. The picture is then 
 washed with water and then finally dried. Instead of bromide of potas- 
 sium, a strong solution of common salt may be used, but it is less advis- 
 able. The picture thus obtained will have its lights and shades reversed. 
 With respect to the natural objects, viz., the lights of the objects are re- 
 
 E 
 
50 
 
 THE CALOTYPE Oil TALBOT l’PE. 
 
 presented by shades, aud vice versa . But it is easy from this picture to 
 obtain another, which shall be conformable to nature, viz., in which the 
 lights shall be represented by lights, and the shades by shades. It is only 
 necessary for this purpose to take a second sheet of sensitive calotype 
 paper and place it in close contact with the first, upon which the picture 
 has been formed. A board is put beneath them and a sheet of glass 
 above, and the whole is pressed into close contact by screws. Being then 
 placed in sunshine or daylight for a short time, an image or copy is 
 formed upon the second sheet of paper. This image or copy is often in- 
 visible at first, but the image may be made to appear in the same way 
 that has been already stated. But I do not recommend that the copy 
 should be taken on calotype paper ; on the contrary, I would advise that 
 it should be taken on common photographic paper. This paper is made 
 by washing good writing paper first with a weak solution of common salt, 
 and next with a solution of nitrate of silver. Since it is well known, hav- 
 ing been freely communicated to the public by myself in the year 1839, 
 and that it forms no part of the present invention, I need not describe it 
 here more particularly, although it takes a much longer time to obtain a 
 copy upon this paper than upon calotype paper, yet the tints of the copy 
 are generally more harmonious and agreeable. On whatever paper the 
 copy is taken it should be fixed in the way already described. After a 
 calotype picture has furnished a good many copies it sometimes grows 
 faint, and the subsequent copies are inferior. This may be prevented by 
 means of a process which revives the strength of the calotype pictures. 
 In order to this it is only necessary to wash them by candle-light with 
 gallo-nitrate of silver, and then warm them. This causes all the shades 
 of the picture to darken considerably, while the white parts are unaf- 
 fected. After this the picture is of course to be fixed a second time. The 
 picture will then yield a second series of copies, and a great number of 
 them may frequently be made. 
 
 Note. In the same way in which I have just explained that a faded 
 calotype picture may be revived and restored, it is possible to strengthen 
 and revive photographs which have been made on other descriptions of 
 sensitive photographic paper, but these are inferior in beauty, and more- 
 over the result is less to be depended on, I therefore do not recommend 
 them. 
 
 The next part of my invention consists in a mode of obtaining positive 
 photographic pictures, that is to say, photo-graphics, in which the lights 
 of the object are represented by lights, and the shades by shades. I have 
 already described how this may be done by a double process; but I shall 
 now describe the means of doing it by a single process: I take a sheet of 
 
THE CALOTYPE OR TALBOTYPE. 
 
 51 
 
 sensitive calotype paper and expose it to daylight, until I perceive a 
 slight but visible discolouration or browning of its surface, — this gene- 
 rally occurs in a few seconds. I then dip the paper into a solution of 
 iodide of potassium, of the same strength as before; viz., 500 grains to 
 one pint of water. This immersion apparently removes the visible im- 
 pression caused by the light — nevertheless, it does not really remove it; 
 for if the paper were to be now washed with gall-nitrate of silver, it would 
 speedily blacken all over. The paper, when taken out of the iodide of 
 potassium, is dipped in water, and then lightly dried with blotting paper. 
 It is then placed in the focus of a camera obscura, which is pointed at an 
 object. After five or ten minutes the paper is withdrawn and w r ashed 
 with gallo-nitrate of silver, and warmed as before directed. An image 
 will then appear of a positive kind ; namely, representing the lights of 
 the objects by lights, and the shades by shades. Engravings may be very 
 well copied in the same way, and positive copies of them obtained at once 
 (reversed, however, from right to left). Eor this purpose a sheet of calo- 
 type paper is taken and held in daylight to darken it, as before mentioned ; 
 but for the present purpose it should be more darkened than if it were 
 intended to be used in the camera obscura. The rest of the process is 
 the same. The engraving and the sensitive paper should be pressed into 
 close contact with screws or otherwise, and placed in the sunshine, which 
 generally effects the copy in a minute or two. This copy, if it is not suf- 
 ficiently distinct, must be rendered visible, or strengthened, with the 
 gallo-nitrate of silver, as before described. I am aware that the use of 
 iodide of potassium for obtaining positive photographs has been recom- 
 mended by others ; and I do not claim it here by itself as a new inven- 
 tion, but only when used in conjunction with the gallo-nitrate of silver; 
 or, when the pictures obtained are rendered visible or strengthened sub- 
 sequently to their first formation. In order to take portraits from the 
 life, I prefer to use for the object glass of the camera, a lens whose focal 
 length is only three or four times greater than the diameter of the aper- 
 ture. The person whose portrait is to be taken should be so placed that 
 the head may be as steady as possible, and the camera being then pointed 
 at it, an image is received on the sensitive calotype paper. I prefer to 
 conduct the process in the open air, under a serene sky, but without sun- 
 shine : the image is generally obtained in half a minute, or a minute. If 
 sunshine is employed, a sheet of blue glass should be used as a screen to 
 defend the eyes from too much glare, because this glass does not materi- 
 ally weaken the power of the chemical rays to affect the paper. The 
 portrait thus obtained on the calotype paper is a negative one ; and from 
 this a positive copy may be obtained in the way already described. 
 
52 
 
 THE CALOTYPE OK TALBOT l'PE. 
 
 Care must be taken to obtain paper of a very fine and even texture, 
 and perfectly free from all foreign matter in its substance, which would 
 cause blemishes in the picture. The best kind of paper is that called 
 blue wove post, and each sheet, preparatory to its being used, should be 
 carefully examined before a strong light, and those sheets rejected in 
 which any spots or uneven texture is observed. 
 
 This calotype paper is so exceedingly sensitive to the influence of light 
 that very beautiful copies of lace, feathers, leaves, pictures, or ancient 
 writing may be made by the light of a common gas-light, or an argand 
 oil lamp. Merely press the article to be copied against a piece of the 
 prepared paper, with a sheet of strong glass and expose them to the light 
 about four or five inches from the flame for the space of two or three 
 minutes. 
 
 Sir D. Brewster’s Improved Method of taking Positive 
 Calotypes, or Talbotypes. 
 
 In the method now in use the face of the negative Talbotype is 
 placed directly upon the side of the paper which lias been brushed 
 over with a solution of nitrate, or ammonia-nitrate, of silver, and which 
 is to receive the positive picture. In strong sunlight the picture is 
 thus taken very quickly ; but there is a roughness in the shades, 
 owing to the formation of black specks, which destroys the softness 
 of the picture, and in portraits gives a disagreeable harshness to the 
 human face. In order to remove this defect, the author first interposed 
 thin plates of glass, with their surfaces sometimes ground and sometimes 
 polished ; but, though the divergency or diffusion of the light, passing 
 through the negative picture, produced great softness in the positive , yet 
 the outlines were too indistinct, though the Talbotypes looked very well, 
 when placed at a distance. He then tried the effect of interposing a sheet 
 of writing paper, without the water-mark and of uniform texture. The 
 result of this experiment fully answered his expectations. The diffusion 
 of the light thus occasioned shaded off, as it were, all the sharp lines and 
 points, and gave a high degree of softness to the picture. The effect was 
 even improved by interposing two sheets of clean paper ; and, with a 
 very bright meridian sun, he found that three sheets may be used with 
 advantage. A similar effect may be obtained, in a smaller degree, by _ 
 placing the hack of the negative upon the positive paper, so as to cause 
 the light to traverse the thickness of the negative, and this may be com. 
 bined with one or more sheets of clean paper. This, of course, will be 
 appropriate only with portraits ; and it has the advantage (sometimes re- 
 quired) of making the figure look another way. To those who see the 
 
THE EERROTYPE. 
 
 53 
 
 experiments above described for the first time, the effect is almost magi- 
 cal ; and when the negative is removed, we see only a blank sheet of 
 white paper ; and our surprise is very great when, upon lifting this sheet, 
 we discover beneath it a perfect picture, which seems as it were to have 
 passed through the opaque and impervious screen. 
 
 Mr. Hunt’s Ferrotype 
 
 Is a very simple and exceedingly good process, easily managed, and 
 worthy the attention of the amateur, we will give it in Mr. Hunt’s own 
 words, as all that proceeds from a thoroughly practical man is of value 
 to the learner. 
 
 “All the photographic processes with which we are at present ac- 
 quainted, sufficiently sensitive for the fixation of the images of the 
 camera-obscura,) require the most careful and precise manipulation ; con- 
 sequently, those who are not accustomed to the niceties of experimental 
 pursuits, are frequently annoyed by failures. The following statement 
 will at once show the exceeding simplicity of the new discovery : — 
 
 Good letter-paper is first washed over with the following solution : — 
 A saturated solution of succinic acid, 2 drachms. 
 
 Mucilage of gum-arabic i *> 
 
 Water 1^ „ 
 
 When the paper is dry, it is washed over once with an argentine solution, 
 consisting of 1 drachm of nitrate of silver to 1 ounce of distilled water. 
 The paper is allowed to dry in the dark, and it is fit for use. It can be 
 preserved in a portfolio, and at any time employed in the camera. This 
 paper is a pure white, and it retains its colour, which is a great advan- 
 tage. At present I finddt necessary to expose this prepared paper in the 
 camera-obscura for periods, varying with the quantity of sunshine, from 
 two to eight minutes, although, from some results which I have obtained, 
 I am satisfied that, by a nice adjustment of the proportions of the ma- 
 terials, a much shorter exposure will suffice. When the paper is removed 
 from the camera, no trace of a picture is visible. We have then to 
 mix together 1 drachm of a saturated solution of sulphate of iron, 
 and 2 or 3 drachms of the mucilage of gum-arabic. A wide flat brush, 
 saturated with this solution, is now swept over the face of the paper 
 rapidly and evenly. In a few seconds the dormant images are seen 
 to develope themselves, and with great rapidity a pleasing negative pho- 
 tographic picture is produced. The iron solution is to be washed off as 
 soon as the best effect appears, this being done with a soft sponge and 
 clean water. The drawing is then soaked for a short time in water, and 
 may be permanently fixed by being washed over with ammonia, or, per- 
 haps, better with a solution of the hyposulphite of soda, care being taken 
 
54 
 
 THE IODIZED PAPER. 
 
 that the salt is afterwards well washed out of the paper. From the pic- 
 tures thus produced, any number of others, correct in position, and in 
 light and shadow, may be produced, by using the same succinated papers 
 in the ordinary way, from five to ten minutes in sunshine producing the 
 desired effect. 
 
 The advantages which this process possesses over every other must be, 
 I think, apparent. The papers are prepared in the most simple manner, 
 and may be kept ready by the tourist until required for use. They re- 
 quire no preparation previously to their being placed in the camera, and 
 they can be preserved until a convenient opportunity offers for bringing 
 out the picture, which is done in the most simple manner, with a material 
 which can be anywhere procured. 
 
 He has since made a brilliant improvement in the above process, it is 
 as follows : — 
 
 Having prepared the paper according to his directions, and submitted 
 it to the action of the sun’s rays in the camera, it must be removed and 
 dexterously immersed into a vessel containing a spiritous solution of the 
 essential oils of cassia and cloves ; and as soon as the spirit has pene- 
 trated the texture of the paper, which will be in the space of a few mo- 
 ments, it must be taken out, and with the quickness of thought, laid flat 
 on a piece of plate-glass, and kept pressed in that position by means of 
 blotting paper, saturated with the same solution* for an hour or two. The 
 result is, a picture beautifully delineated, with brilliant metallic lines of 
 silver, for wherever the nitrate remains unacted ux>on by the light and 
 other reagents made use of, the oils, (as in the new process for the manu- 
 facture of mirrors) throws down the silver in the metallic state. 
 
 IODIZED PAPER. 
 
 The expense of metallic plates aud their inconvenience, particularly to 
 travellers, renders it very desirable that some material, such as paper, 
 might be employed instead of them. Some very tolerable effects may be 
 produced upon silvered paper; but the pictures thus formed, want the 
 fine black surface, which is to contrast with the mercurial vapour, and 
 which forms the chief charm of a good Daguerreotype. Mr. Hunt first 
 pointed out the mode of preparing this paper, he says — 
 
 Any of the ordinary photographic papers, will darken by exposure to 
 brown or dark olive colour. Exposed to the vapour of iodine, the paper 
 becomes of a steel blue or violet colour. If subjected to solar influence 
 in this state, mercurial vapour attacks all the parts on which the light 
 has acted, in the same manner as it does the iodized metallic plate, giving 
 a tolerable picture. I also found, that perfectly pure oxide of silver, 
 spread on paper and iodized, was similarly disposed to receive the mer- 
 
THE IODIZED PAPER. 
 
 55 
 
 curial vapour, after it had been submitted to the sun’s rays. The yellow- 
 brown phosphate of silver, was also found to acquire additional sensitive- 
 ness under the influence of iodine, and to yield a tolerable picture when 
 exposed to the mercurial fumes. 
 
 Papers which were prepared, by first saturating them, with strong 
 solutions* of the nitrate of silver, and then exposed to phosphuretted 
 hydrogen gas, until , there was a complete revival of the silver over the 
 surface of the paper, were found to be acted upon by iodine, in a similar 
 way to the silver plates themselves, and for most purposes are capable of 
 being substituted for them. The pictures, when the papers are well 
 prepared, are formed as readily as upon the iodized plates, and are not 
 wanting in the beauty of their general effect, or in the delicacy of their 
 minute detail. It unfortunately happens that a considerable degree of risk 
 attends the preparation of the paper by this spontaneous inflammable gas. 
 
 Papers prepared in a similar way, substituting the sulphuretted for the 
 phosphuretted hydrogen, are in nearly all respects equal to them. Some 
 difficulties attend the preparation, but, by observing the following direc- 
 tions, papers of a very uniform dark grey surface may be prepared. 
 The paper is first soaked in a solution of the muriate of ammonia, 
 carefully wiped with cotton cloths, and then dried. It is next dipped in 
 a solution of nitrate of silver, dried in the dark, and then carried into a 
 vessel in which sulphuretted hydrogen is slowly forming. When it has 
 darkened to an iron brown, the paper must be passed through water 
 slightly impregnated with chlorine or muriatic acid, and again dried. It 
 is once more dipped into an argentine solution, and when dry, subjected 
 a second time to sulphuration. These papers are best iodized by draw- 
 ing them slowly over a saturated solution of any hydriodic salt, in which 
 is dissolved a considerable quantity of iodine ; care must be taken that 
 one side only of the paper is wetted. It is then dried near the fire, and 
 subjected in the camera to the solar agency. After mercurialisation, the 
 picture is fixed most effectually by a strong solution of common salt used 
 moderately warm. 
 
 If when these drawings are finished, they are placed in a solution of 
 corrosive sublimate, the images entirely disappear, but after a few mi- 
 nutes they are seen, as if by magic, unfolding themselves, and gradually 
 becoming far more beautiful than before — delicate lines, at first invisible 
 or barely seen, are now distinctly marked, and a rare and singular per- 
 fection of detail is given to the photograph. The picture is thus re- 
 stored by the agent which caused it to disappear, and it would appear 
 that the mercury on the paper, is slowly converted into a protochloride : 
 but the modus operandi is not, however, quite evident. 
 
*6 
 
 THE CHROMATYPE. 
 
 THE CHROMATYPE. 
 
 The process is so exceedingly simple, and the resulting pictures of so 
 very pleasing a character, that, although it is not sufficiently sensitive 
 for use in the camera-obscura, it will be found of the greatest value for 
 copying botanical specimens, engravings, or the like. 
 
 Good writing-paper is washed over with sulphate of copper in solution, 
 the strength of which is not of much importance. About one drachm to 
 an ounce of water is preferred ; when dry it is washed over with a mode- 
 rately [strong, but not saturated, solution of the bichromate of potash. 
 The paper, when dry, is fit for use, and it may be, I believe, kept for any 
 length of time in a portfolio, without its sensibility being in the least im- 
 paired. 
 
 When exposed to the sunshine, the first change is to a dull brown ; and 
 if checked in this stage of the process, we have a negative picture; but if 
 the action of light is continued, the browning gives way, and we have a 
 a positive yellow picture on a white ground. In either case, if the paper, 
 when removed from the sunshine, is washed over with a solution of 
 nitrate of silver, a very beautiful positive picture results. In practice it 
 will be found advantageous to allow the bleaching action to go on to some 
 extent: the picture resulting from this, will be clearer and more defined 
 than that which is procured when the action is checked at the brown 
 stage. To fix these pictures, it is necessary to remove the excess of 
 nitrate of silver, which is done by washing in pure water. If the water 
 contains any muriates, the picture suffers; and long soaking in such 
 water entirely destroys it: or if a few grains of common salt are added 
 to the water, the apparent destruction is very rapid. The picture is, 
 however, capable of restoration ; all that is necessary being to expose it 
 to the sunshine for ten minutes or a quarter of an hour, when it revives ; 
 but instead of being of a red colour, it becomes lilac, the shades of colour 
 depending upon the quantity of salt used to decompose the chromate of 
 silver. After this exposure, no fixing is required, the continued action of 
 light only still further improving the pictures. 
 
 Modification of the Chromatype . — If to a solution of the sulphate of 
 copper we add a solution of the chromate of potash — the neutral salt — a 
 brown precipitate falls very copiously, which is a true chromate of 
 copper. If this precipitate, after being well washed, is added to water 
 rendered tolerably acid by sulphuric acid, it is dissolved, and a dichromatic 
 solution is formed, which is, when spread upon paper, a pure yellow. A 
 very short exposure of the papers, washed with this solution, is quite 
 sufficient to discharge all the yellow from the paper, and give to it a per- 
 fect whiteness. If an engraving is to be copied, we proceed in the usual 
 
THE CHE03IATYPE. 
 
 57 
 
 manner ; and we may either bring out the picture by placing the paper 
 in a solution of carbonate of soda or potash, by which all the shadows are 
 represented by the chromate of copper ; or by washing the paper with 
 the nitrate of silver. It may sometimes happen that, owing to deficient 
 light, the engraving is darkened all over when the silver is applied; this 
 colour, by keeping, is gradually removed, and the lights come out clear 
 and sharp. The little excess of acid in the paper, acts upon the chro- 
 mate, which has been partially changed, and a pale yellow, instead of a 
 red salt, is formed. 
 
 If the chromate of copper is dissolved in ammonia, a beautiful green 
 solution results. If papers are prepared with this solution, they act 
 similarly to those last mentioned. If the pictures prepared as above 
 are washed with ammonia, they are nearly obliterated ; but upon expo- 
 sing them to the air and light, negative pictures of a pale blue colour 
 result. 
 
 All the salts of copper, undergo some change under the influence of the 
 solar radiations. The change is not in many cases apparent, but in some 
 it is so. If, however, a solution of any salt of copper is laid over paper, 
 and it be exposed to the sunshine, a change is brought about; and if after 
 it is removed from the light, it is washed with nitrate of silver, the 
 covered portion remains of its original colour, whilst the exposed parts 
 darken very considerably. The following salts afford really interesting 
 pictures: — Sulphate, muriate, nitrate, carbonate, acetate, oxalate, ammo- 
 nia-oxalate, tartrate, malate, chloride, bromide, and arseniate. We do not 
 doubt but by attention and experiment, some of these may afford very 
 valuable photographic preparations. At all events these results show the 
 immense field of inquiry which is opening before us. 
 
 A beautiful variation of the chromatype by Mr. Hunt. A neutral solu- 
 tion of the chloride of gold is mixed with an equal quantity of the bichromate 
 of potash. Paper is washed with this solution, and dried near the fire. On 
 exposing this paper to light, it speedily changes, first to a deep brown, 
 and ultimately to bluish black. If an engraving is superposed, we have 
 a negative copy, blue or brown, upon a yellow ground. If this photo- 
 graph is placed in clean water, and allowed to remain in it for some 
 hours, very singular changes takes place. The yellow salt is all dissolved 
 out, and those parts of the paper left beautifully white. All the dark 
 portions of the paper become more decided in their character, and ac- 
 cordingly as the solarization has been prolonged, or otherwise, or the light 
 has been more or less intense, we have either crimson , blue , brown , or deep 
 black , negative photographs of a most beautiful character. 
 
58 
 
 THE CTANOTYPE. 
 
 THE CTANOTYPE. 
 
 This name has been applied by Sir John Herschel to the whole class of 
 processes in which cyanogen forms a leading part, with a mixture, which 
 may pontain equal proportions of ammonia-citrate of iron and ferroses- 
 quicyanate of potash prepare a paper, and impress it with a picture, after 
 which throw it into water, and dry it; a negative blue picture will be pro- 
 duced. If this picture is washed with a solution of the protonitrate of 
 mercury, it is in a little time discharged. The mercurial salt being 
 thoroughly washed out, and the paper dried, the picture is susceptible of 
 restoration. If a smooth iron is passed over it somewhat hotter than is 
 used for ironing linen, but not sufficiently so as to scorch the paper, the 
 obliterated picture immediately reappears, not blue, but brown. However 
 carefully kept, these photographs fade after a few weeks and disappear. A 
 fresh application of heat restores them to full intensity. 
 
 This use of a mercurial salt led Sir John Herschel to devise an im- 
 provement on the cyanotype process, which affords much more certain 
 results and more decided pictures. One part by weight of the ammonia- 
 citrate of iron is dissolved in eleven parts of water, and this is mixed 
 with an equal quantity of a saturated cold solution of corrosive subli- 
 mate (bichloride of mercury). Before a precipitate has had time to form, 
 the solution is washed over paper (which should have rather a yellowish 
 than a bluish cast) and dried. This paper appears to keep well. It is 
 exposed to light till a faint, but perfectly visible picture is impressed. It 
 is then washed over as rapidly as possible with a broad flat brush dipped 
 in a saturated solution of prussiate of potash, diluted with three times its 
 bulk of gum water, so strong as just to flow freely without adhesion to 
 the lip of the vessel. Care is required to spread this wash with one ap- 
 plication, evenly, over every part of the paper. Beautiful pictures are 
 thus produced, which will immediately bear exposure to light tolerably 
 well, but which after a few days will bear strong sunshine uninjured. By 
 long keeping, details which were barely seen at first, come out with con- 
 tinally increasing intensity. 
 
 Wash a paper with a solution of the ammonia-citrate of iron and dry 
 it ; then wash it over with a solution of the ferrocyanate of potash ; 
 there is no immediate formation of true prussian blue, but the paper 
 rapidly acquires a deep purple colour. If in this state these papers are 
 exposed to light, they give positive pictures of great sharpness ; but 
 they possess this peculiarity — they darken again spontaneously on expo- 
 sure to the air in darkness, and are soon obliterated. The paper, how- 
 ever, remains susceptible to light, and capable of receiving other pic- 
 tures, which fade in turn. If these pictures are washed with ammonia 
 
THE CHRYSOTYPE. 
 
 59 
 
 or its carbonate, they are for a feAv moments obliterated, but they presently 
 reappear, with reversed lights and shades . “ In this state they are fixed, 
 
 and the ammonia, with all ^that it will dissolve, being removed by wash- 
 ing in water, their colour becomes a pure prussian blue, which deepens 
 much by keeping. If the solutions be mixed, there results a very dark 
 violet-coloured ink, which may be kept uninjured in an opaque bottle, 
 and will readily furnish by a single wash, at a moment’s notice, the posi- 
 tive paper in question, which is most sensitive when wet.” 
 
 Paper simply washed with the ferrosesquicyanuret of potassium, is 
 highly sensitive to light. Exposed to sunshine for about an hour, with 
 an engraving upon it, a beautiful negative photograph is the result 
 These are fixed by soaking in water in which a little suljdiate of soda is 
 dissolved, to insure the fixity of the prussian blue deposited. While dry 
 this cyanotype is dove-colour on a greenish yellow ground ; after wash- 
 ing, it becomes bright blue on a white ground. 
 
 Prepare a paper by washing, first, with a weak solution of ammonia- 
 citrate of iron, one part, by weight, of the salt to twenty parts of water, 
 and, when dry, with a saturated solution of the protonitrate of mercury. 
 When nearly dry expose it for twenty minutes or half an hour to the 
 light, and a faint photograph will result. If it is now wetted with water 
 and held for a few minutes in the sun, every part of the picture becomes 
 visible, each line assuming an inky blackness. Instead of water, the so- 
 lution of the nitrate of mercury may be used, and it possesses the advan- 
 tage of giving greater permanence to the picture than when it was ex- 
 cited by water only. 
 
 THE CHRYSOTYPE. 
 
 “ Paper is washed with a moderately concentrated solution of ammonia- 
 citrate of iron, and dried; the strength of the solution being such as to 
 dry into a good yellow colour, and not at all brown. In this state it is 
 ready to receive a photographic image, which may be impressed on it, 
 either from nature in the camera obscura, or from an engraving on a 
 frame in sunshine. The image so impressed, however, is faint, and some- 
 times hardly perceptible. The moment it is removed from the frame or 
 camera, it must be washed over with a neutral solution of gold, of such 
 strength as to have the colour of sherry wine. Instantly the picture 
 appears, not indeed at once of its full intensity, but darkening with great 
 rapidity up to a certain point, depending cn the strength of the solutions 
 used, &c. At this point nothing can surpass the sharpness and perfec- 
 tion of detail of the resulting photograph. To arrest this process, and to 
 fix the picture (so far at least as the agency of light is concerned), it is to 
 be thrown into water slightly acidulated with sulphuric acid, and well 
 
60 
 
 THE FLUOROTYPE. 
 
 soaked, dried, washed with hydrobromate of potash, rinsed, and dried 
 again.” 
 
 Subsequently the talented discoverer of this process recommended the 
 hydriodate of potash as superior to the hydrobromate as a fixing agent. 
 “ As soon as the picture is satisfactorily brought out by the auriferous 
 fluid, it is to be rinsed in spring water, which must be three times 
 renewed. It is then blotted off and dried, after which it is to be washed 
 on both sides with a somewhat weak solution of hydriodate of potash. If 
 there be any free chloride of gold present in the pores of the paper it 
 will be discoloured, the lights passing to a ruddy brown; but they 
 speedily whiten again spontaneously, or at all events on throwing it (after 
 lying a minute or two) into fresh water, in which being again rinsed and 
 dried, it is now perfectly fixed.” 
 
 If instead of a solution of gold the nitrate of silver is used, the picture 
 is brought out somewhat more slowly, and, as far as my own experience 
 goes, with much less beauty, whether we consider colour or detail. 
 
 THE FLUOROTYPE. 
 
 This process, which is characterised by its easy manipulation, and by 
 the sensibility of the papers when carefully prepared, consists in the 
 formation of a salt of silver, which must be considered as a fluo-bro- 
 mide of silver. It is at present somewhat difficult to say, which is the 
 most efficacious manner of proceeding ; but the difference, as it regards 
 the sensibility of papers, is so very trifling that this is not of much con- 
 sequence. The paper may be washed first, with the bromide of potas- 
 sium, and then with the fluate of soda ; or, which will be found on the 
 whole the best plan, the two salts may be united. The strength of the 
 solutions should be a6 follows : — 
 
 { Bromide of potassium 
 | Distilled water 
 ( Fluate of soda 
 \ Distilled water 
 
 20 grains. 
 
 1 fluid ounce. 
 5 grains. 
 
 1 fluid ounce. 
 
 Mix a small quantity of these solutions together when the papers are to 
 be prepared, and wash the paper once over with the mixture, and when 
 dry, apply nitrate of silver, in solution, 60 grains to an ounce of water. 
 These papers appear to keep for some weeks without injury, and they 
 become impressed with good images in half a minute in the camera. This 
 impression is not sufficiently strong to serve, in the state in which it is 
 taken from the camera, for producing positive pictures, but it may be 
 rendered so, by a secondary process. 
 
 The photograph is first soaked in water for a few minutes ; it is then 
 
THE FLUOROTYPE. 
 
 61 
 
 placed upon a slab of porcelain or stone, and a weak solution of the pro- 
 tosulphate of iron applied, which very readily darkens, all the parts on 
 which the light has acted, to a deep brown, and every object is brought 
 out with £reat sharpness. When the best effect is produced the process 
 must be stopped, or the lights suffer. All that is necessary is to soak the 
 paper in water, and then fix the drawing with hyposulphite of soda. This 
 process admits of numerous modifications. 
 
 Paper is prepared with bromide of potassium and nitrate of silver, in 
 such proportions that the nitrate is in very slight excess. When used, 
 it is washed over with a solution of 120 grains of nitrate of silver, and 
 placed wet in the camera. After being exposed for a second or two, the 
 light must be shut off, the camera carried into a dark room, and the paper 
 allowed to dry in the dark. When dry it is placed in the mercurial 
 vapour box; and heat being applied, the mercury is very slowly vapo- 
 rised. The picture now begins to develope itself, and gradually a most in- 
 tense photograph results. It often happens that the picture appears at 
 first clouded; but if the paper is carefully placed in the dark, it generally, 
 in the course of a few hours, gets clear. We have often procured most 
 beautiful pictures by this method, after an exposure to solar influence 
 during a second; and moving objects have been well defined, showing the 
 action to be almost instantaneous. Photographs thus procured are best 
 fixed, by soaking the paper in a weak solution of salt in water, and then 
 by brushing the paper over with the hyposulphite of soda. The great 
 difficulty to be overcome in this process, is the annoyance continually 
 arising, from the perfect blackness produced over every part of the paper 
 by the mercurial vapour. Often, when the best result appears to have 
 been attained, in an instant the delightful picture vanishes away, and a 
 sheet of blank blackness takes its place. It is not quite clear, to what 
 this can be attributed ; some kinds of paper are more liable to it than 
 others, from which it would appear that it arises from the condition of 
 the surface. I have, indeed, on some occasions been enabled to trace this 
 blackening, from a little downy pile standing out more prominently from 
 one part than another. 
 
 It will be found that papers prepared with a single wash of each of 
 the following solutions — 
 
 Bromide of potassium 50 grains, water 1 oz. 
 
 Nitrate of silver 100 grains, ditto — 
 may be used most advantageously for copying any fixed objects. They 
 require but a few minutes exposure, and at any time, the picture may be 
 brought out, by washing with the solution of gallic acid. These photo- 
 graphs, which possess all the requisites of good negative ones, may be 
 
62 
 
 THE FLUOKOTYFE. 
 
 ■well fixed, by washing with a weak solution of the bromide of po tassium 
 or with the hyposulphite of soda. 
 
 Papers washed with chloride of gold, freed from an excess of acid, are 
 slowly changed under the influence of ihe solar beams, a regularly in- 
 creasing darkness takes place, and the paper at length becomes purple 
 (Herscliel). I have observed that the first action of the light is to 
 whiten the paper, which has been rendered a pale yellow by the chloride. 
 If papers are removed from the light when thus bleached, it will be found 
 that a darkening action will gradually come on, and eventually devolope 
 the picture, which may be impressed on the paper. This process is much 
 quickened by placing the paper in cold water. 
 
 Chloride of gold with nitrate of silver gives a precipitate of a yellow 
 brown colour, possibly metallic double salts, in which the gold as well as 
 the silver is in the state of chloride. On glass this precipitate is but very 
 slightly sensitive, on paper it is blackened somewhat more speedily 
 (Herscliel). 
 
INDEX. 
 
 PAGE. 
 
 Accelerating Mixtures 19 
 
 “ “ Wolcott’s, &c 20 
 
 “ “ Claudet’s : 30 
 
 44 “ Process 19 
 
 Bromine, Chloride of 19 
 
 44 Water 19 
 
 Brewster’s late communication 52 
 
 Calotype Process 47 
 
 “ Sir D. Brewster’s improvement on 52 
 
 Camera, Yoitlander’s lenses for 27 
 
 “ Exposing the Plate in ~ 24 
 
 “ For Multiplication of Pictures 35 
 
 Chromatype, the 56 
 
 “ Hunt’s improvement on 57 
 
 Crysotype, the 59 
 
 Colouring Process 34 
 
 Copper, Salts of 57 
 
 Copying Camera 35 
 
 Cyanotype 58 
 
 Daguerreotype Process 13 
 
 “ On a Gigantic Scale, by M. Martenz, of Paris 46 
 
 Electrotype Process 37 
 
 Engrayhng or Etching Process 39 
 
 44 Illustrating purposes of 45 
 
 Ferroty'pe — Mr. Hunt’s 53 
 
 Fixing the Picture 31 
 
 44 The Silver Batii for 32 
 
 *• Mr. Page’s Process 33 
 
 44 Mr. Fox Talbot’s 33 
 
 44 New-salt for 32 
 
 Fluorotype 60 
 
 Gold, Chloride of, to prepare 32 
 
 44 Plates 10 
 
 44 Salt of 32 
 
INDEX, 
 
 * PAGE. 
 
 Hyposulphite Bath 31 
 
 “ Crystals, choice of 32 
 
 Images, Obliteration and Restoration of 30 
 
 Iodizing Process 16 
 
 “ Conducted in the Daylight 20 
 
 Iodized Paper Process 54 
 
 Lathe for Polishing 14 
 
 Light, the Great Variation of 25 
 
 “ Lunar Pictures taken by 46 
 
 “ Shaw’s Experiments on 22 
 
 “ Talbot’s Experiment on 46 
 
 Mercurializing Process 29 
 
 Multiplication of Pictures, by Wolcott’s Camera 35 
 
 “ “ by the Electrotype 37 
 
 “ “ by Etching 39 
 
 Patent, Injustice of 5 
 
 “ Invalidity* of 8 
 
 “ Suggestions for Avoiding it 9-10 
 
 “ Vice-Chancellor’s Judgment on the late Injunction ... 6 
 
 Photogenic Agent — A New Onb 11 
 
 Plates, How to Clean 14 
 
 “ Economical Production of 33 
 
 Portraits, Taking of 27 
 
 “ Choice of Back Grounds 28 
 
 Positive Pictures without Mercury 46' 
 
 Shaw’s Experiments on Light 23 
 
 Salt of Gold, new from Paris 32 
 
 Silver Bath 32 
 
 Silvered Paper, &c 10 
 
 Talbot’s Suggestion for a Curious Experiment with Light 46 
 
 Talbotype 47 
 
 Views, &c., to take 28 
 
 Wolcott’s Restoring Process 21 
 
 “ Mixture... 
 
spcxuu 
 
 5 
 
 mm 
 
 MGEITYCBffEt 
 
 WRY 
 
daguerreotype, Calotype, Sec. 
 
 AMATEURS IN THIS FASCINATING SCIENCE 
 
 how a favourable opportunity of gratifying their taste^ 
 
 MR. EGERTON, 
 
 (USING FREE TO SELL THE SUPERIOR LENSES AND APPARATUS OF 
 
 VOIGTLASDER AND LEREBOURS. ' 
 
 CHEMICALS, PLATES, . 
 
 fi* ' 
 
 Ami every requisite for carrying out the Photographic Art, 
 
 Parties made proficient in the process for <£3 3.9., either by personal 
 instruction, or by letter. 
 
 The French Liqueur llongroise, 5s. per bottle. 
 
 WOLCOTT’S MIXTURE, 5S. PER BOTTLE, THE BEST ACCELERATING 
 COMPOUND KNOWN. 
 
 i 
 
 NEW SALT OF GOLD FOR FIXING THE DAGUERREOTYPE 
 PICTURES, 5s. PER BOTTLE. :* • 
 
 KGERTON’S TRANSLATION OF LEREBOURS* TREATISE ON THE ART, 7S. 6(L 
 
 ORDERS BY POST PUNCTUALLY ATTENDED TO. 
 
 Lv Temple- street, Whitefriars, London. 
 
 London : Printed by W. M. Clark, 10 , Red Lion-court, .Fleet-street.