(2.) On the Application of the Chemical Rays of Light to the Purposes of Pictorial Reproduction. By Sir J. F. W. HERSCHEL, K.H., F.R.S.

On the Action of the Rays of the Solar Spectrum on Vegetable Colours, and on some New Photographic Processes. By the Same.

On Certain Improvements on Photographic Processes, and on the Parathermic Rays of the Solar Spectrum. By the Same.

Philosophical Transactions, 1839-43. (3.) Researches on Light in its Chemical Relations. By ROBERT HUNT, F.R.S. Second Edition. 1854.

(4.) The Journal of the Photographic Society. Edited by H. W. DIAMOND, M.D., F.S.A. Vols. I.-X. 1853-66. (5.) The Photographic News. Edited by G. WHARTON SIMPSON, M.A. Vols. I.

IX. 1858-65.

(6.) The Year-Book of Photography.

-66.

1861

(10.) L'Art de la Photographie. Par Dis

DERI. 1862.

that it is the recognized, unerring recorder of science, the auxiliary of the law, the willing assistant of the painter and the sculptor, for whom it does yeoman's service, the art itself is without a history. The records of its first days, although scarcely reaching beyond the present generation, are meagre and fragmentary. To the initial facts upon

which it is based we find occasional allo

A cen

sions as early as the sixteenth century, some of the alchemists regarding solar action as one source of the transmutation of metals, a conclusion doubtless derived from their observation that chloride of silver, known to them as luna cornua, was changed in colour by the rays of the sun. tury later, in 1777, the illustrious chemist, Scheele, records some interesting experiments on the same properties in this salt; but his discoveries remained dead facts, without application; and it was not until the commencement of the present century that the possibility of drawing by sunlight assumed a definite shape in men's minds.

In 1802, Thomas Wedgwood, the son of the celebrated potter, published in the Journal of the Royal institution An account of Method of Copying Paintings upon Glass, and of making Profiles by the Agency of Light upon Nitrate of Silver;' Obs rvations.' by Sir Humphry Davy, who had assisted in the experiments, accompanying the paper. In the brief but interesting record of their experiments, after learning that muriate of silver' was found to be more sensitive than nitrate of silver, that white leather when prepared was more sensitive than paper, and that although the images

of the camera obscura could not be secured

(12.) Photography: Its History, Position, and Prospects. A Lecture. By the Hon. J. WILLIAM STRUTT. 1865.

(13.) Researches on Solar Physics. By WARREN DE LA RUE, Ph.D., F.R.S.; BALFOUR STEWART, M.A., F.R.S.; and

BENJAMIN LOEWY. 1865.

WITH photography as a prominent fact of the day, essentially belonging to the nineteenth century, everybody is familiar. Its origin, growth, and variety of application have had no parallel in the history of the graphic and pictorial arts. But notwithstanding that its results are to be found in every part of the civilized globe, amongst the most cherished treasures of every home,

the fatal fact, that no attempts that have been made to prevent the uncoloured parts of the copy or profile from being acted upon by light have as yet been successful.' They had discovered but half the spell; the pictures could not be fixed. The agency they had invoked continued its work until the images first produced by its aid were destroyed by its continued action, and a blackened sheet of paper was all thát rẻmained. Although these efforts were unsuccessful, and the idea seemed for soine time abandoned, yet from this time we find the science of the sunbeam gaining increased attention, and the Transactions of the Royal Society and other learned bodies began to furnish trustworthy records of the researches into the chemical action of the solar rays, which initiated photography as a science,

and immediately preceded its advent as an

art.

It is somewhat curious to note that, whilst the actual history of photography is a thing of yesterday, we find premonitions of such a mode of delineation at a period long anterior to its existence, either as a fact or a subject of research. In Fénelon's Fables, under the title of Voyage Supposé, 1690,' a visit to the Island of Wonders is described, a country in which no painter dwelt, but when a portrait or picture was desired, the reflection of the object was obtained in a liquid placed in gold or silver vessels; the water shortly congealed and retained permanently the image which had been mirrored on its surface.* In 1760, Tiphaigne de la Roche, in a singular book, with a tile annagrammatized from his own name into Giphanie à Babylone, supposed himself transported into the palace of the genii of the elements, and there learns that these genii can arrest and retain the reflected images of objects made in the 'twinkling of an eye.' Cloth was prepared with a subtle adhesive material, which shone like a mirror, and possessed the power to retain on its viscous surface the momentary images reflected there, and being dried in the dark the picture became ineffaceable. The problems involved in such a method of securing the fleeting images of objects, the dreamer proposed for the solution of the philosophers of his day.†

confined to a period scarcely less recent, as almost all the elements employed in the first step taken in obtaining a photograph-the production of the negative — are of recent discovery. The sensitive salts, without the aid of which a negative is impossible, consist of iodides and bromides, and the now indispensable vehicle is collodion; chlorides being now used only in the secondary operation of printing. Iodine, the primary element, was unknown until 1812, when it was discovered by M. Courtois, of Paris. Bromine, an imperatively necessary aid to successful work, was not discovered until 1826, whilst collodion is a still younger child of chemical science. Other of the agents commonly used in photography are of recent origin; but these we have mentioned are the very bases on which the art rests, not simply in its existing modes, but in any form we know in which it could be used as the accurate registrar of transient effects, or to secure pictures of objects in life and motion. Thus photography, as a practical fact, came into existence almost as soon as the agents upon which its practice depends were known to science.

"Il n'y avait aucun peintre dans tout le pays, mais quand ou voulait avoir le portrait d'un ami, un beau paysage, ou un tableau, qui representat quelque autre objet, un mettait à l'eau dans de grande 'bassins d'or et d'argent; puis ou opposait cette eau à l'objet qu'on voulait peindre. Bientôt l'eau, se congelant, devenait comme une glacé de miroir, ou l'image demeurait ineffaçable. Ou l'emportait ou l'ou voulait, et c'était un tableau aussi fidele que les plus poli glacés de miroir.” — Les Fa

bles de Fénelon.

"It is curious to observe, in passing, the frequency of these coincidences, or poetic previsions of scientific discovery. The anticipatory allusions of Darwin to the advent of steam have been often quoted. In a number of the Guardian, issued a century and a half ago (Tuesday, July 28th, 1713), there is an account cited of a Chimerical Correspondence between two friends by the help of a certain loadstone which had such a virtue in it, that if it touched two several needles, the other, though at ever so great a distance, moved at the same time and in the same manner as a dial-plate provided with letters, to which the needles might point, which enabled the friends to communicate with each other instantly, and hold conversation when separated by continents. The similarity between this conception and the actual working of the elec tric telegraph is almost startling.

Nicéphore de Niepce commenced his labours in 1814, with a view to give a permanent embodiment to the fleeting images of the camera obscura. Led by what suggestions or inducements we know not, his researches were directed to a channel totally different from that to which his predecessors had given attention. They had experimented with certain salts of silver: he turned his attention to the behavior of certain resins when submitted to the action of light. Dr. Wollaston had, in 1803, discovered that gum guaiacum was singularly sensitive to the action of the solar ray; but no practical result had flowed from his discovery. The amateur chemist at work in his quiet laboratory at Chalons, steadily laboured at the problem he sought to solve, until success crowned his effort, and he finally produced the first sun pictures which were not of a fleeting char acter, and in which the productive cause, light, did not in its turn become the destructive agency. His process has since been superseded, but the principle he dis

in a solid form, or in a state of solution in a liquid?' Daguerre's pictures were produced on iodised silver plates: by what steps he arrived at this discovery, and at what period success crowned his efforts, we have no certain record. That he pursued his labours with a zeal inexplicable to the matter-offact people by whom he was surrounded, and that he was more fortunate in his domestic relations than was Bernard Pallisy, the potter, we have reason to believe, Nevertheless, we hear of Daguerre's wife consulting a medical friend on the symptoms of insanity in ber husband which such a devotion to a chimera implied. That he pursued his labours somewhat empirically we have also reason to believe, groping with more sagacity than knowledge, supported in his efforts by that high faith in an unseen possibility which is often born of strong desire. A history of the processes of thought, and the experimental efforts of a comparatively unscientific man in conducting such an investigation, and the grounds of the faith which sustained him through years of fruitless search for an unknown thing in an unknown region, would have been most interesting and instructive. His greatest discovery appears to have been the result of happy chance. Working with plates of silver which had been submitted to the fumes of iodine, he strove to obtain an image on the camera which should be visible and permanent. Heart-sick with disappointment, he put away in a cupboard which contained a heterogeneous assemblage of ehemicals his broken spells and fruitless eharms the tablets which bore no record of the image to which they had been submitted on the camera, Taking up one of these tablets one day in order to clean it and recommence experiments upon it, to his surprise he found a perfectly delineated picture thereon. The circumstance was incomprebensible: no picture had been there when the plate was put away; but here in its minutest detail was the image to which the plate had been submitted. The operation was repeated with like success. few hours in the magic cupboard produced a picture on the iodised tablet which showed no trace of anything of the kind before. After long and puzzling search, a vessel containing mercury, a substance which slowly vaporises at the ordinary temperature of the atmosphe e, was found to be the cause. The action of light on the iodide of silver, although not made apparent by any visible change, had actually impressed a latent image on the surface, sufficient to determine, the deposition of the vapours of mercury on

A

certain parts where light had acted, and thus bring out or develop a picture. We can understand at this stage of his researches the earnestness with which he wrote to Niepce urging him to experiment with iodine, although afraid to say how much he had himself already discovered. At length complete success was attained: a certain means of arresting and retaining the beau tiful but hitherto evanescent transcripts of nature presented by the camera obscura was discovered, and it only remained to the happy discoverer to bring it before the public and receive his reward.

In January, 1839, the discovery of M. Daguerre was first announced to the world, and specimens of the results were exhibited, the modus operandi being still preserved secret. The French Government at once entertained the project of rewarding the discoverer, and in the following June a bill received the Royal assent which gave to M. Daguerre a pension of 6,000 francs annually, and to M. Niepce, jun., a pension of 4,000 francs annually, that the new art might be presented a gift to the world. The savans of France were elate alike at the novelty and brilliancy of the discovery. Two of the most distinguished men of the time appeared as sponsors for the youngest and most beautiful child of science. M. Arago, in the Chamber of Deputies, and M. Gay Lussac, in the Chamber of Peers, introduced the subject with glowing eloquence. M. Arago was pre-eminently enthusiastic on the aid which such a power would lend to science. To copy,' he said, the millions and millions of hieroglyphics which entirely cover. to the very exterior, the great monuments at Thebes, Memphis, Carnac, &c., would require scores of years, and legions of artists. With the Daguerrotype a single man would suffice to bring to a happy conclusion this vast labour.' M. Paul Delaroche declared that the pictures carried to such perfection certain of the essential principles of art, that they must become subjects of study and observation, even to most accomplished

artists.'

Thus in the month of August, 1889, the new discovery was published to the world. It was received with enthusiasm, and rapidly adopted as a means of delineation, portraiture being its most early and extensive application. England alone failed to partake freely of this gift to the world,' M. Daguerre having entered into negotiations which secured a patent in this country whilst the question of his claims was under the attention of the French Government.

Daguerrotypes have now passed out of