I t is now more than fifteen years ago that specimens of a new and mysterious art were first exhibited to our wondering gaze. They consisted of a few heads of elderly gentlemen executed in a bistre-like colour upon paper. The heads were not above an inch long, they were little more than patches of broad light and shade, they showed no attempt to idealise or soften the harshnesses and accidents of a rather rugged style of physiognomy -- on the contrary, the eyes were decidedly contracted, the mouths expanded, and the lines and wrinkles intensified. Nevertheless we examined them with the keenest admiration, and felt that the spirit of Rembrandt had revived. Before that time little was the existence of a power, availing itself of the eye of the sun both to discern and to execute, suspected by the world -- still less that it had long lain the unclaimed and unnamed legacy of our own Sir Humphry Davy. Since then photography has become a household word and a household want; is used alike by art and science, by love, business, and justice; is found in the most sumptuous saloon, and in the dingiest attic -- in the solitude of the Highland cottage, and in the glare of the London gin-palace in the pocket of the detective, in the cell of the convict, in the folio of the painter and architect, among the papers and patterns of the millowner and manufacturer, and on the cold brave breast on the battle-field. The annals of photography, as gathered from the London Directory, though so recent, are curious. As early as 1842 one individual, of the name of Beard, assumed the calling of a daguerreotype artist. In 1843 he set up establishments in four different quarters of London, reaching even to Wharf Road, City Road, and thus alone supplied the metropolis until 1847. In 1848 Claudet and a few more appear on the scene, but, owing to then existing impediments, their numbers even in 1852 did not amount to more than seven. In 1855 the expiration of the patent and the influence of the Photographic Society swelled them to sixty-six -- in 1857 photographers have a heading to themselves and stand at 147. These are the higher representatives of art. But who can number the legion of petty dabblers, who display their trays of specimens along every great thoroughfare in London, executing for our lowest servants, for one shilling, that which no money could have commanded for the Rothschild bride of twenty years ago? Not that photographers flock especially to the metropolis; they are wanted everywhere and found everywhere. The large provincial cities abound with the sun's votaries, the smallest town is not without them; and if there be a village so poor and remote as not to maintain a regular establishment, a visit from a photographic travelling van gives it the advantages which the rest of the world are enjoying. Thus, where not half a generation ago the existence of such a vocation was not dreamt of, tens of thousands (especially if we reckon the purveyors of photographic materials) are now following a new business, practising a new pleasure, speaking a new language, and bound together by a new sympathy. For it is one of the pleasant characteristics of this pursuit that it unites men of the most diverse lives, habits, and stations, so that whoever enters its ranks finds himself in a kind of republic, where it needs apparently but to be a photographer to be a brother. The world was believed to have grown sober and matter-of-fact, but the light of photography has revealed an unsuspected source of enthusiasm. An instinct of our nature, scarcely so worthily employed before, seems to have been kindled, which finds something of the gambler's excitement in the frequent disappointments and possible prizes of the photographer's luck. When before did any motive short of the stimulus of chance or the greed of gain unite in one uncertain and laborious quest the nobleman, the tradesman, the prince of blood royal, the innkeeper, the artist, the manservant, the general officer, the private soldier, the hard-worked member of every learned profession, the gentleman of leisure, the Cambridge wrangler, the man who bears some of the weightiest responsibilities of this country on his shoulder, and, though last, not least, the fair woman whom nothing but her own choice obliges to be more than the fine lady? The records of the Photographic Society, established in 1853, are curiously illustrative of these incongruities. Its first chairman, in order to give the newly instituted body the support and recognition which art was supposed to owe it, was chosen expressly from the realms of art. Sir Charles Eastlake therefore occupied the chair for two years; at the end of which the society selected a successor quite as interested and efficient from a sphere of life only so far connected with art and science as being their very antipodes, namely, Sir Frederick Pollock the Chief Baron of England. The next chairman may be a General fresh from the happy land where they photograph the year round; the fourth, for aught that can be urged to the contrary, the Archbishop of Canterbury. A clergyman of the Established Church has already been the editor to the journal of the society. The very talk of these photographic members is unlike that of any other men, either of business or pleasure. Their style is made of the driest facts, the longest words, and the most high-flown rhapsodies. Slight improvements in processes, and slight varieties in conclusions, are discussed as if they involved the welfare of mankind. They seek each other's sympathy, and they resent each other's interference, with an ardour of expression at variance with all the sobrieties of business, and the habits of reserve; and old-fashioned English mauvaise honteÊ is extinguished in the excitement, not so much of a new occupation as of a new state. In one respect, however, we can hardly accuse them of the language of exaggeration. The photographic body can no longer be considered only a society, it is becoming 'one of the institutions of the country.' Branches from the parent tree are flourishing all over the United Kingdom. Liverpool assists Norwich, Norwich congratulates Dublin, Dublin fraternises with the Birmingham and Midland Institute, London sympathises with each, and all are looking with impatience to Manchester. Each of these societies elect their officers, open their exhibitions, and display the same encouraging medley of followers. The necessity too for regular instruction in the art is being extensively recognised. The Council of King's College have instituted a lectureship of photography. Photographic establishments are attached to the Royal Arsenal at Woolwich; a photographic class is opened for the officers of the Royal Artillery and Engineers; lectures are given at the Royal Institution, and popular discourses at Mechanics' Institutes. Meanwhile British India has kept pace with the mother country. The Photographic Society at Bombay is only second in period of formation to that of London. Calcutta, Madras, Bengal, and minor places all correspond by means of societies. The Elphinstone Institution has opened a class for instruction. Nor is the feeling of fellowship confined to our own race. The photographic and political alliance with France and this country was concluded at about the same period, and we can wish nothing more than that they may be maintained with equal cordiality. The Duke de Luynes, a French nobleman of high scientific repute, has placed the sum of 10,000 francs at the disposal of the Paris Photographic Society, to be divided into two prizes for objects connected with the advance of the art, -- the prizes open to the whole world. The best landscape photographs at the Eciteposition des Beaux Art were English, the best architectural specimens in the London Exhibition are French. The Exhibition at Brussels last October was more cosmopolitan than Belgian. The Emperors of Russia and Austria, adopting the old way for paying new debts, are bestowing snuff-boxes on photographic merit. These are but a few of the proofs that could be brought forward of the wide dissemination of the new agent, and of the various modes of its reception, concluding with a juxtaposition of facts which almost ludicrously recall paragraphs from the last speech from the throne; for while our Queen has sent out a complete photographic apparatus for the use of the King of Siam, the King of Naples alone, of the whole civilised world, has forbidden the practice of the works of light in his dominions! Our chief object at present is to investigate the connexion of photography with art -- to decide how far the sun may be considered an artist, and to what branch of imitation his powers are best adapted. But we must first give a brief history of those discoveries which have led to the present efficiency of the solar pencil. It appears that the three leading nations the French, the English, and the Germans -- all share in the merit of having first suggested, then applied, and finally developed the existence of the photographic element. It may not be superfluous to all our readers to state that the whole art in all its varieties rests upon the fact of the blackening effects of light upon certain substances, and chiefly upon silver, on which it acts with a decomposing power. The silver being dissolved in a strong acid, surfaces steeped in the solution became encrusted with minute particles of the metal, which in this state darkened with increased rapidity. These facts were first ascertained and recorded, as regards chloride of silver, or silver combined with chlorine, in 1777, by Scheele, a native of Pomerania, and in 1801, in connexion with nitrate of silver, by Ritter of Jena. Here therefore were the raw materials for the unknown art; the next step was to employ them. And now we are at once met l y that illustrious name to which we have alluded. Sir Humphry Davy was the first to make the practical application of these materials, and to foresee their uses. In conjunction with Mr. Thomas Wedgwood, only less eminent than his brother Josiah, Sir Humphry succeeded, by means of a camera obscura, in obtaining images upon paper, or white leather prepared with nitrate of silver -- of which proceeding he has left the most interesting record in the Journal of the Royal SocietyÊ for June, 1802. Their aim, as the title shows, was not ambitious; but the importance lay in the first stain designedly traced upon the prepared substance, not in the thing it portrayed. In one sense, however, it was very aspiring, if colour as well as form were sought to be transferred, as would appear from their attempt to copy coloured glass; otherwise it is difficult to account for their selecting this particular material.1 Besides showing the possibility of imprinting the forms of objects thus reflected in the camera, the paper in question proceeds to describe the process since known as 'Photographic Drawing,' by which leaves, or lace, or the wings of insects, or any flat and semi-transparent substances, laid upon prepared paper, and exposed to the direct action of the sun, will leave the perfect tracery of their forms. But having thus conjured up the etherial spirit of photography, they failed in all attempts to retain it in their keeping. The charm once set agoing refused to stop -- the slightest exposure to light, even for the necessary purposes of inspection, continued the action, and the image was lost to view in the darkening of the whole paper. In short, they wanted the next secret, that of rendering permanent, or, in photographic language, of fixingÊ the image. Here, therefore, the experiment was left to be taken up by others, though not without a memento of the prophetic light cast on the mind's eye of the great elucidator; for Sir Humphry observes, 'Nothing but a method of preventing the unshaded parts of the delineation from being coloured by the exposure to the day is wanted to render this process as useful as it is elegant.' Meanwhile, in 1803, some remarkable experiments were made by Dr. Wollaston, proving the action of light upon a resinous substance known in commerce as "gum guaiacum;" and in due time another workman entered the field who availed himself of this class of materials. The name of Joseph Nicphore de Nipce is little known to the world as one of the founders of the now popular art, his contributions being exactly of that laborious and rudimental nature which later inventions serve to conceal. He was a French gentleman of private fortune, who lived at Chlon-sur-Saone, and pursued chemistry for his pleasure. Except also in the sense of time, he cannot be called a successor to Davy and Wedgwood; for it is probable that the path they had traced was unknown to him. Like them, however, he made use of the camera to cast his images; but the substance on which he received them was a polished plate of pewter, coated with a thin bituminous surface. His process is now rather one of the curiosities of photographic history; but, such as it was, it gained the one important step of rendering his creations permanent. The labours of the sun in his hands remained spell-bound, and remain so still. He began his researches in 1814, and was ten years before he attained this end. To M. Nipce also belongs the credit of having at once educed the high philosophic principle, since then universally adopted in photographic practice, which put faith before sight -- the conviction of what must be before the appearance of what is. His pictures, on issuing from the camera, were invisible to the eye, and only disengaged by the application of a solvent which removed those shaded parts unhardened by the action of the light. Nor do they present the usual reversal of the position of light and shade, known in photographic language as a negativeÊ appearance; but whether taken from nature or from an engraving, are identical in effect, or what is called positives. But though, considering all these advantages, the art of Heliography, as it was called by its author, was at that early period as great a wonder as any that have followed it, yet it was deficient in those qualities which recommend a discovery to an impatient world. The process was difficult, capricious, and tedious. It does not appear that M. Nipce ever obtained an image from nature in less than between seven to twelve hours, so that the change in lights and shadows necessarily rendered it imperfect; and in a specimen we have seen, the sun is shining on opposite walls. Deterred probably by this difficulty from any aspirations after natural scenes, M. Nipce devoted his discovery chiefly to the copying of engravings. To this he sought to give a practical use by converting his plate, by means of the application of an acid, into a surface capable of being printed by the ordinary methods. Here again he was successful, as specimens of printed impressions still show, though under circumstances too uncertain and laborious to encourage their adoption. Thus the comparative obscurity in which his merits have remained is not Difficult to comprehend; for while he conquered many of the greater difficulties of the art, he left too many lesser ones for the world to follow in his steps. To these reasons may be partially attributed the little sensation which the efforts of this truly modest and ingenious gentleman created in this country, which he visited in 1827, for the purpose, he states, of exhibiting his results to the Royal Society, and of rendering homage of his discovery to his Britannic Majesty. A short memorial, drawn up by himself, was therefore forwarded, with specimens, to the hands of George IV.; but a rule on the part of the Royal Society to give no attention to a discovery which involves a secret proved a barrier to the introduction of M. Nipce's results to that body. Dr. Wollaston was the only person of scientific eminence to whom they appear to have been exhibited; and, considering their intrinsic interest, as well as the fact of his being in some sort their progenitor, it is difficult to account for the little attention he appears to have paid them. M. Nipce therefore returned to his own country, profoundly convinced of the English inaptitude for photographic knowledge. In the mean time the indiscretion of an optician revealed to the philosopher of Chlon the fact that M. Daguerre, a dioramic artist by profession, was pursuing researches analogous to his own in Paris. This led to an acquaintance between the two, and finally to a legal partnership in the present pains and possible profits of the new art. M. Nipce died in 1833 without, it seems, contributing any further improvement to the now common stock; and M. Daguerre, continuing his labours, introduced certain alterations which finally led to a complete change in the process. Suffice it to say that, discarding the use of the bituminous varnish, and substituting a highly polished tablet of silver, he now first availed himself of that great agent in photographic science, the action of iodine, by means of which the sensitiveness of his plate was so increased as to render the production of the image an affair of fewer minutes than it had previously been of hours. At the same time the picture, still invisible, was brought to light by the application of the fumes of mercury, after which a strong solution of common salt removed those portions of the surface which would otherwise have continued to darken, and thus rendered the impression permanent. Here, therefore, was a representation obtained in a few minutes by a definite and certain process, which was exquisitely minute and clear in detail, capable of copying nature in all her stationary forms, and also true to the natural conditions of light and shade. For the fumes of mercury formed minute molecules of a white colour upon those parts of the iodised tablet darkened by the light, thus producing the lights to which the silver ground supplied the shades. In 1839 the results of M. Daguerre's years of labour, called after himself the Daguerreotype, came forth fully furnished for use; and in the June of that year gave rise to a remarkable scene in the French Chambers. The question before the deputies was this: MM. Daguerre and Nipce jun. (for the partnership gave all the advantages of M. Daguerre's discovery to the son of his late colleague) were possessed of a secret of the utmost utility, interest, and novelty to the civilised world -- a secret for which immense sacrifices of time, labour, and money had been made, but which, if restricted by patent for their protection, would be comparatively lost to society. A commission had therefore been appointed by the French Government to inquire into its merits, and the secret itself intrusted to M. Arago, who succeeded at once in executing a beautiful specimen of the art. Thus practically convinced, he addressed the Chamber in a speech which is a masterpiece of scientific summary and philosophic conclusion. He pointed out the immense advantages which might have been derived, "for example, during the expedition to Egypt, by a means of reproduction so exact and so rapid." He observed that "to copy the millions and millions of hieroglyphics which entirely cover the great monuments at Thebes, Memphis and Carnac, &c., would require scores of years and legions of artists; whereas with the daguerreotype a single man would suffice to bring this vast labour to a happy conclusion." He quoted the celebrated painter De la Roche in testimony of "the advantage to art by designs perfect as possible, and yet broad and energetic -- where a finish of inconceivable minuteness in no respect disturbs the repose of the masses, nor impairs in any manner the general effect." The scene was French in the highest sense -- at once scientific, patriotic, and withal dramatic, -- France herself treating for the creations of genius on the one hand, and on the other dispensing them, "a gift to the whole world." It was repeated in the Chamber of Peers, who, in addition to other arguments addressed to them by M. Gay-Lussac, were reminded, with a true French touch, that 'even a field of battle in all its phases may be thus delineated with a precision unattainable by any other means !" The result was that a pension of 10,000 francs was awarded for the discovery -- 6000 to M. Daguerre, 4000 to M. Nipce. The seals which retained the secret were broken, and the daguerreotype became the property of the world. We unwillingly recall a fact which rather mars the moral beauty of this interesting proceeding, viz. that by some chicanery a patent for the daguerreotype was actually taken out in England, which for a time rendered this the only country which did not profit by the liberality of the French Government. The early history of photography is not so generous in character as that of its maturity. It may be added that all that has been since done for the daguerreotype are improvements in the same direction. It has that mark of a great invention -- not to require or admit of any essential deviation from its process. Those who have contributed to perfect it are also of the same race as the inventor. The names of M. Fizeau and M. Claudet are associated with its present state. The first, by using a solution of chloride of gold, has preserved the daguerreotype from abrasion, and given it a higher tone and finish; while M. Claudet, who has variously contributed to the advance of the art, by the application of chloride of bromine with iodine, has accelerated a hundredfold the action of the plate; at the same time, by a prolongation of a part of the process, he has, without the aid of mercury, at once converted the image into a positive, the silver ground now giving the lights instead, as before, of the shades of the picture. We may now turn to England, and to those discoveries which, though less brilliant in immediate result, yet may be said to have led to those practical uses which now characterise the new agent. The undivided honour of having first successfully worked out the secret of photography in England belongs to Mr. Fox Talbot. He also is a private gentleman, living in the country, and pursuing chemical researches for his own pleasure. In his case it. may be strictly said that he took up the ground to which Davy and Wedgwood had made their way. Paper was the medium he adhered to from the beginning, and on which he finally gained the victory. We have no account of the repeated essays and disappointments by which this gentleman advanced step by step to the end in view. All we know is that the French success on metal and the English success on paper were, strange to say, perfectly coincident in date. Daguerre's discovery was made known in Paris in January, 1839; and in the same month Mr. Fox Talbot sent a paper to the Royal Society, giving an account of a method by which he obtained pictures on paper, rendered them unalterable by light, and by a second and simple process, which admitted of repetition to any extent, restored the lights and shadows to their right conditions. This announcement fell, like the pictures of light themselves, upon ground highly excited in every way to receive and carry it forward. It was immediately taken up by Sir John Herschel, who commenced a series of experiments of the utmost practical importance to photography and science in general, one of the first results of which was the discovery of the hyposulphate of soda as the best agent for dissolving the superfluous salts, or, in other words, of fixing the picture. This was one of those steps which has met with general adoption. Another immediate impulse was given by a lecture read at the London Institution in April, 1839, and communicated by the Rev. J. B. Reade, recommending the use of gallic acid in addition to iodide or chloride of silver as a means of greatly increasing the sensitiveness of the preparation. Again, Mr. Robert Hunt, since known as the author of the work that heads this article, published at the British Association at Plymouth, in 1841, another sensitive process, in which the ferrocyanate of potash was employed; and in 1844 the important use of the protosulphate of iron in bringing out, or, as it is termed, developingÊthe latent picture. Other fellow-labourers might be mentioned, too, all zealous to offer some suggestion of practical use to the new-born art. Meanwhile Mr. Fox Talbot, continuing to improve on his original discovery, thought fit in 1842 to make it the subject for a patent, under the name of the calotype process. In this he is accused of having incorporated the improvements of others as well as his own, a question on which we have nothing to say, except that at this stage of the invention the tracks of the numerous exploring parties run too close to each other to be clearly identified. As to the propriety of the patent itself, no one can doubt Mr. Fox Talbot's right to avail himself of it, though the results show that the policy may be questioned. For this gentleman reaped a most inadequate return, and the development of the art was materially retarded. In the execution of a process so delicate and at the best so capricious as that of photography, the experience of numbers, such as only free-trade can secure, is required to define the more or less practical methods. Mr. F. Talbot's directions, though sufficient for his own pre-instructed hand, were too vague for the tyro; and an enlistment into the ranks of the "Pilgrims of the Sun" seldom led to any result but that of disappointment. Thus, with impediments of this serious nature, photography made but slow way in England; and the first knowledge to many even of her existence came back to us from across the Border. It was in Edinburgh where the first earnest, professional practice of the art began, and the calotypes of Messrs. Hill and Adamson remain to this day the most picturesque specimens of the new discovery. It was at this crisis that a paper published in the "Philosophical Transactions" of May, 1844, by Mr. George Cundell, gave in great measure the fresh stimulus that was needed. The world was full of the praise of the daguerreotype, but Mr. Cundell stood forth as the advocate of the calotype or paper process, pointed out its greater simplicity and inexpensiveness of apparatus, its infinite superiority in the power of multiplying its productions, and then proceeded to give those careful directions for the practice, which, though containing no absolutely new element, yet suggested many a minute correction where every minutia is important. With the increasing band of experimentalists who arose -- for all photographers are such now ensued the demand for some material on which to receive their pictures less expensive than the silver plate, and less capricious than paper. However convenient as a medium, this latter, from the miscellaneous nature of its antecedents, was the prolific parent of disappointment. Numerous expedients were resorted to render it more available -- it was rubbed, polished, and waxed, but, nevertheless, blotches and discolorations would perpetually appear, and that at the very moment of success, which sorely tried the photographic heart. The Journal of the Society sends up at this time one vast cry of distress on this subject, one member calling unto another for help against the common enemy. Under these circumstances many a longing eye was fixed upon glass as a substitute; and numerous experiments, among which those by Sir John Herschel were the earliest and most successful, were tried to render this material available. But glass itself was found to be an intractable material; it has no powers of absorption, and scarcely any affinities. The one thing evidently needed was to attach some transparent neutral coating of extreme tenuity to its surface, and in due time the name of Nipce again appears supplying the intermediate step between failure and success. M. Nipce de St. Victor, nephew to the inventor of heliography, is known as the author of the albumen process, which transparent and adhesive substance being applied to glass, and excited with the same chemical agents as in the calotype process, is found to produce pictures of great beauty and finish. But, ingenious as is the process, and often as it is still used, it fails of that unsurpassable fitness which alone commands universal adoption. The amalgamation of the substances is tedious and complicated, and the action of the light much slower. The albumen process was a great step, and moreover a step in the right direction; for it pointed onward to that discovery which has reduced the difficulties of the art to the lowest sum, and raised its powers, in one respect at all events, to the highest possibility, viz. to the use of collodion. The Daguerre to this Nipce was a countryman of our own Mr. Scott Archer -- who is entitled to fame not only for this marvelous improvement, but for the generosity with which he threw it open to the public. The character of the agent, too, adds interest to the invention. The birth and parentage of collodion are both among the recent wonders of the age. Gun-cotton -- partly a French, partly a German discovery -- is but a child in the annals of chemical science; and collodion, which is a solution of this compound in ether and alcohol, is its offspring. Its first great use was, as is well known, in the service of surgery; its second in that of photography. Not only did the adoption of this vehicle at once realise the desires of the most ardent photographer -- not only, thus applied, did it provide a film of perfect transparency, tenuity, and intense adhesiveness -- not only was it found easy of manipulation, portable and preservable -- but it supplied that element of rapidity which more than anything else has given the miraculous character to the art. Under the magician who first attempted to enlist the powers of light in his service, the sun seems at best to have been but a sluggard; under the sorcery of Nipce he became a drudge in a twelve-hours' factory. On the prepared plate of Daguerre and on the sensitive paper of Fox Talbot the great luminary concentrates his gaze for a few earnest minutes; with the albumen-sheathed glass he takes his time more leisurely still; but at the delicate film of collodion which hangs before him finer than any fairy's robe, and potent only with invisible spells -- he literally does no more than wink his eye, tracing in that moment, with a detail and precision beyond all human power, the glory of the heavens, the wonders of the deep, the fall, not of the avalanche, but of the apple, the most fleeting smile of the babe, and the most vehement action of the man. Further than this the powers of photography can never go; they are already more nimble than we need. Light is made to portray with a celerity only second to that with which it travels; it has been difficult to contrive the machinery of the camera to keep pace with it, and collodion has to be weakened in order to clog its wheels. While these practical results occupied the world, more fundamental researchers had been carried on. By the indefatigable exertions of Sir John Herschel and Mr. Hunt the whole scale of mineral and other simple substances were tested in conjunction with tried and untried chemical processes, showing how largely nature abounds with materials for photographic action. Preparations of gold, platinum, mercury, iron, copper, tin, nickel, manganese, lead, potash &c. were found more or less sensitive and capable of producing pictures of beauty and distinctive character. The juices of beautiful flowers were also put into requisition, and papers prepared with the colours of the Corchorus japonica, the common ten-weeks' stock, the marigold, the wallflower, the poppy, the rose, Senecio splendens, &c., have been made to receive delicate though in most cases fugitive images. By these experiments, though tending little to purposes of utility, the wide relations and sympathies of the new art have been in some measure ascertained, and its dignity in the harmonious scale of natural phenomena proportionably raised. When once the availability of one great primitive agent is thoroughly worked out, it is easy to foresee how extensively it will assist in unravelling other secrets in natural science. The simple principle of the stereoscope, for instance, might have been discovered a century ago, for the reasoning which led to it was independent of all the properties of light, but it could never have been illustrated, far less multiplied as it now is, without photography. A few diagrams, of sufficient identity and difference to prove the truth of the principle, might have been constructed by hand for the gratification of a few sages, but no artist, it is to be hoped, could have been found possessing the requisite ability and stupidity to execute the two portraits, or two groups, or two interiors, or two landscapes, identical in every minutia of the most elaborate detail, and yet differing in point of view by the inch between the two human eyes, by which the principle is brought to the level of any capacity. Here, therefore, the accuracy and insensibility of a machine could alone avail; and if in the order of things the cheap popular toy which the stereoscope now represents was necessary for the use of man, the photograph was first necessary for the service of the stereoscope. And while photography is thus found ready to give its aid to other agencies, other agencies are in turn ready to cooperate with that. The invention now becoming familiar to the public by the name of photo-galvanic engraving is a most interesting instance of this reciprocity of action. That which was the chief aim of Nipce in the humblest dawn of the art, viz. to transform the photographic plate into a surface capable of being printed, which had been bona fide realised by Mr. Fox Talbot, M. Nipce de St. Victor, and others, but by methods too complicated for practical use, is now by the co-operation of electricity with photography done with the simplicity and perfection which fulfil all conditions. This invention is the work of M. Pretsch of Vienna, and deserves a few explanatory words. It differs from all other attempts for the same purpose in not operating upon the photographic tablet itself, and by discarding the usual means of varnishes and bitings in. The process is simply this. A glass tablet is coated with a gelatine diluted till it forms a jelly, and containing bichromate of potash, nitrate of silver and iodide of potassium. Upon this when dry is placed, face downwards, a paper positive, through which the light, being allowed to fall, leaves upon the gelatine a representation of the print. It is then soaked in water, and while the parts acted upon by the light are comparatively unaffected by the fluid, the remainder of the jelly swells, and rising above the general surface gives a picture in relief, resembling an ordinary engraving upon wood. Of this intaglio a cast is now taken in gutta-percha, to which the electro process in copper being applied, a plate or matrix is produced bearing on it an exact repetition of the original positive picture. All that now remains to be done is to repeat the electro process, and the result is a copper plate, in the necessary relieve, of which, as the company who have undertaken to utilise the invention triumphantly set forth, nature furnishes the materials, and science the artist, the inferior workman being only needed to roll it through the press. And here, for the present, terminate the more important steps of photographic development, each in its turn a wonder, and each in its turn obtained and supported by wonders only a little older than itself. It was not until 1811 that the chemical substance called iodine, on which the foundations of all popular photography rest, was discovered at all; bromine, the only other substance equally sensitive, not till 1826. The invention of the electro process was about simultaneous with that of photography itself. Gutta-percha only just preceded the substance of which collodion is made; the ether and chloroform, which are used in some methods, that of collodion. We say nothing of the optical improvements purposely contrived or adapted for the service of the photograph -- the achromatic lenses, which correct the discrepancy between the visual and chemical foci; the double lenses, which increase the force of the action; the binocular lenses, which do the work of the stereoscope; nor of the innumerable other mechanical aids which have sprung-up for its use; all things, great and small, working together to produce what seemed at first as delightful, but as fabulous, as Aladdin's ring, which is now as little suggestive of surprise as our daily bread. It is difficult now to believe that the foundations of all this were laid within the memory of a middle-aged gentleman, by a few lonely philosophers, incognizant of each other, each following a glimmer of light through years of toil, and looking upward to that Land of Promise to which beaten tracks and legible handposts now conduct an army of devotees. Nevertheless, there is no royal road thrown open yet. Photography is, after all, too profoundly interwoven with the deep things of Nature to be entirely unlocked by any given method. Every individual who launches his happiness on this stream finds currents and rocks not laid down in the chart. Every sanguine little couple who set up a glass-house at the commencement of summer, call their friends about them, and toil alternately in broiling light and stifling gloom, have said before long, in their hearts, "Photography, thy name is disappointment!" But the photographic back is fitted to the burden. Although all things may be accused in turn -- their chemicals, their friends, and even Nature herself -- yet with the next fine day there they are at work again, successively in hope, excitement, and despair, for, as Schiller says, -- "Etwas frchten, und hoffen, und sorgen

Muss der Mensch fr den kommenden Morgen." Notes to Part 1 An account of a method of copying paintings upon glass and making profiles by the agency of light upon nitrate of silver, with observations by Humphry Davy. To Part 2 This essay originally appeared under the title "Photography," by Lady Elizabeth Eastlake, from The London Quarterly Review, No. 101, April 1857, pp. 442-468.