The Evolution of Photography

THE DARK AGES

More than three hundred years have elapsed since the influence and actinism of light on chloride of silver was observed by the alchemists of the sixteenth century. This discovery was unquestionably the first thing that suggested to the minds of succeeding chemists and men of science the possibility of obtaining pictures of solid bodies on a plane surface previously coated with a silver salt by means of the sun’s rays; but the alchemists were too much absorbed in their vain endeavours to convert the base metals into royal ones to seize the hint, and they lost the opportunity of turning the silver compounds with which they were acquainted into the mine of wealth it eventually became in the nineteenth century. Curiously enough, a mechanical invention of the same period was afterwards employed, with a very trifling modification, for the production of the earliest sun-pictures. This was the camera-obscura invented by Roger Bacon in 1297, and improved by a physician in Padua, Giovanni Baptista Porta, about 1500, and afterwards remodelled by Sir Isaac Newton.

Two more centuries passed away before another step was taken towards the revelation of the marvellous fact that Nature possessed within herself the power to delineate her own beauties, and, as has recently been proved, that the sun could depict his own terrible majesty with a rapidity and fidelity the hand of man could never attain. The second step towards this grand achievement of science was the construction of the double achromatic combination of lenses by J. Dolland. With single combinations of lenses, such pictures as we see of ourselves to-day, and such portraits of the sun as the astronomers obtained during the late total eclipse, could never have been produced. J. Dolland, the eminent optician, was born in London 1706, and died 1762; and had he not made that important improvement in the construction of lenses, the eminent photographic opticians of the present day might have lived and died unknown to wealth and fame.

The observations of the celebrated Swedish chemist, Scheele, formed the next interesting link between the simple and general blackening of a lump of chloride of silver, and the gradations of blackening which ultimately produced the photographic picture on a piece of paper possessing a prepared surface of nitrate of silver and chloride of sodium in combination. Scheele discovered in 1777 that the blackening of the silver compound was due to the reducing power of light, and that the black deposit was reduced silver; and it is precisely the same effect of the action of light upon chloride of silver passing through the various densities of the negative that produces the beautiful photographic prints with which we are all familiar at the present time. Scheele was also the first to discover and make known the fact that chloride of silver was blackened or reduced to various depths by the varying action of the prismatic colours. He fixed a glass prism in a window, allowed the refracted sunbeams to fall on a piece of paper strewn with luna cornua—fused chloride of silver—and saw that the violet ray was more active than any of the other colours. Anyone, with a piece of sensitised paper and a prism, or piece of a broken lustre, can repeat and see for themselves Scheele’s interesting discovery; and anyone that can draw a head or a flower may catch a sunbeam in a small magnifying glass, and make a drawing on sensitised paper with a pencil, as long as the sun is distant from the earth. It is the old story of Columbus and the egg—easy to do when you are shown or told how.

Charles William Scheele was born at Stralsund, Sweden, December 19th, 1742, and died at Koeping, on lake Moeler, May 21st, 1786. He was the real father of photography, for he produced the first photographic picture on record without camera and without lens, with the same chemical compound and the same beautiful and wonderful combination of natural colours which we now employ. Little did he dream what was to follow. But photography, like everything else in this world, is a process of evolution.

Senebier followed up Scheele’s experiments with the solar spectrum, and ascertained that chloride of silver was darkened by the violet ray in fifteen minutes, while the red rays were sluggish, and required twenty minutes to produce the same result.

John Wm. Ritter, born at Samitz, in Silesia, corroborated the experiments of Scheele, and discovered that chloride of silver was blackened beyond the spectrum on the violet side. He died in 1810; but he had observed what is now called the fluorescent rays of the spectrum—invisible rays which unquestionably exert themselves in the interests and practice of photography.

Many other experiments were made by other chemists and philosophers on the influence of light on various substances, but none of them had any direct bearing on the subject under consideration until Count Rumford, in 1798, communicated to the Royal Society his experiments with chloride of gold. Count Rumford wetted a piece of taffeta ribbon with a solution of chloride of gold, held it horizontally over the clear flame of a wax candle, and saw that the heat decomposed the gold solution, and stained the ribbon a beautiful purple. Though no revived gold was visible, the ribbon appeared to be coated with a rich purple enamel, which showed a metallic lustre of great brilliancy when viewed in the sunlight; but its photographic value lay in the circumstance of the hint it afterwards afforded M. Fizeau in applying a solution of chloride of gold, and, by means of heat, depositing a fine film of metallic gold on the surface of the Daguerreotype image, thereby increasing the brilliancy and permanency of that form of photographic picture. A modification of M. Fizeau’s chloride of gold “fixing process” is still used to tone, and imparts a rich purple colour to photographic prints on plain and albumenized papers.

In 1800, Dr. Herschel’s “Memoirs on the Heating Power of the Solar Spectrum” were published, and out of his observations on the various effects of differently coloured darkening glasses arose the idea that the chemical properties of the prismatic colours, and coloured glass, might be as different as those which related to heat and light. His suspicions were ultimately verified, and hence the use of yellow or ruby glass in the windows of the “dark room,” as either of those coloured glasses admit the luminous ray and restrain the violet or active photographic ray, and allow all the operations that would otherwise have to be performed in the dark, to be seen and done in comfort, and without injury to the sensitive film.

The researches of Dr. Wollaston, in 1802, had very little reference to photography beyond his examination of the chemical action of the rays of the spectrum, and his observation that the yellow stain of gum guaiacum was converted to a green colour in the violet rays, and that the red rays rapidly destroyed the green tint the violet rays had generated.

1802 is, however, a memorable year in the dark ages of photography, and the disappointment of those enthusiastic and indefatigable pursuers of the sunbeam must have been grievous indeed, when, after years of labour, they found the means of catching shadows as they fell, and discovered that they could not keep them.

Thomas Wedgwood, son of the celebrated potter, was not only the first that obtained photographic impressions of objects, but the first to make the attempt to obtain sun-pictures in the true sense of the word. Scheele had obtained the first photographic picture of the solar spectrum, but it was by accident, and while pursuing other chemical experiments; whereas Wedgwood went to work avowedly to make the sunbeam his slave, to enlist the sun into the service of art, and to compel the sun to illustrate art, and to depict nature more faithfully than art had ever imitated anything illumined by the sun before. How far he succeeded everyone should know, and no student of photography should ever tire of reading the first published account of his fascinating pastime or delightful vocation, if it were but to remind him of the treasures that surround him, and the value of hyposulphite of soda. What would Thomas Wedgwood not have given for a handful of that now common commodity? There is a mournfulness in the sentence relative to the evanescence of those sun-pictures in the Memoir by Wedgwood and Davy that is peculiarly impressive and desponding contrasted with our present notions of instability. We know that sun-pictures will, at the least, last for years, while they knew that at the most they would endure but for a few hours. The following extracts from the Memoir published in June, 1802, will, it is hoped, be found sufficiently interesting and in place here to justify their insertion.

“White paper, or white leather moistened with solution of nitrate of silver, undergoes no change when kept in a dark place, but on being exposed to the daylight it speedily changes colour, and after passing through different shades of grey and brown becomes at length nearly black.... In the direct beams of the sun, two or three minutes are sufficient to produce the full effect, in the shade several hours are required, and light transmitted through different coloured glasses acts upon it with different degrees of intensity. Thus it is found that red rays, or the common sunbeams passed through red glass, have very little action upon it; yellow and green are more efficacious, but blue and violet light produce the most decided and powerful effects.... When the shadow of any figure is thrown upon the prepared surface, the part concealed by it remains white, and the other parts speedily become dark. For copying paintings on glass, the solution should be applied on leather, and in this case it is more readily acted on than when paper is used. After the colour has been once fixed on the leather or paper, it cannot be removed by the application of water, or water and soap, and it is in a high degree permanent. The copy of a painting or the profile, immediately after being taken, must be kept in an obscure place; it may indeed be examined in the shade, but in this case the exposure should be only for a few minutes; by the light of candles or lamps as commonly employed it is not sensibly affected.

“No attempts that have been made to prevent the uncoloured parts of the copy or profile from being acted upon by the light have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured, and even after repeated washings, sufficient of the active part of the saline matter will adhere to the white parts of leather or paper to cause them to become dark when exposed to the rays of the sun....

“The images formed by means of a camera-obscura have been found to be too faint to produce, in any moderate time, an effect upon the nitrate of silver. To copy these images was the first object of Mr. Wedgwood, in his researches on the subject, and for this purpose he first used the nitrate of silver, which was mentioned to him by a friend, as a substance very sensible to the influence of light; but all his numerous experiments as to their primary end proved unsuccessful.”

From the foregoing extracts from the first lecture on photography that ever was delivered or published, it will be seen that those two eminent philosophers and experimentalists despaired of obtaining pictures in the camera-obscura, and of rendering the pictures obtained by superposition, or cast shadows, in any degree permanent, and that they were utterly ignorant and destitute of any fixing agents. No wonder, then, that all further attempts to pursue these experiments should, for a time, be abandoned in England. Although Thomas Wedgwood’s discoveries were not published until 1802, he obtained his first results in 1791, and does not appear to have made any appreciable advance during the remainder of his life. He was born in 1771, and died in 1805. Sir Humphry Davy was born at Penzance 1778, and died at Geneva in 1828, so that neither of them lived to see the realization of their hopes.

From the time that Wedgwood and Davy relinquished their investigation, the subject appears to have lain dormant until 1814, when Joseph Nicéphore Niépce, of Chalons-sur-Saône, commenced a series of experiments with various resins, with the object of securing or retaining in a permanent state the pictures produced in the camera-obscura, and in 1824, L. J. M. Daguerre turned his attention to the same subject. These two investigators appear to have carried on their experiments in different ways, and in total ignorance of the existence and pursuits of the other, until the year 1826, when they accidentally became acquainted with each other and the nature of their investigations. Their introduction and reciprocal admiration did not, however, induce them to exchange their ideas, or reveal the extent of their success in the researches on which they were occupied, and which both were pursuing so secretly and guardedly. They each preserved a marked reticence on the subject for a considerable time, and it was not until a deed of partnership was executed between them that they confided their hopes and fears, their failures with this substance, and their prospects of success with that; and even after the execution of the deed of partnership they seem to have jealously withheld as much of their knowledge as they decently could under the circumstances.

Towards the close of 1827 M. Niépce visited England, and we receive the first intimation of his success in the production of light-drawn pictures from a note addressed to Mr. Bauer, of Kew. It is rather curious and flattering to find that the earliest intimation of the Frenchman’s success is given in England. The note which M. Niépce wrote to Mr. Bauer is in French, but the following is a translation of the interesting announcement:—“Kew, 19th November, 1827. Sir,—When I left France to reside here, I was engaged in researches on the way to retain the image of objects by the action of light. I have obtained some results which make me eager to proceed.... Nicéphore Niépce.” This is the first recorded announcement of his partial success.

In the following December he communicated with the Royal Society of London, and showed several pictures on metal plates. Most of these pictures were specimens of his successful experiments with various resins, and the subjects were rendered visible to the extent which the light had assisted in hardening portions of the resin-covered plates. Some were etchings, and had been subjected to the action of acid after the design had been impressed by the action of light. Several of these specimens, I believe, are still extant, and may be seen on application to the proper official at the British Museum. M. Niépce named these results of his researches Heliography, and Mr. Robert Hunt gives their number, and a description of each subject, in his work entitled, “Researches on Light.” M. Niépce met with some disappointment in England on account of the Royal Society refusing to receive his communication as a secret, and he returned to France rather hurriedly. In a letter dated “Chalons-sur-Saône, 1st March, 1828,” he says, “We arrived here 26th February”; and, in a letter written by Daguerre, February 3rd, 1828, we find that savant consoling his brother experimentalist for his lack of encouragement in England.

In December, 1829, the two French investigators joined issue by executing a deed of co-partnery, in which they agreed to prosecute their researches in future in mutual confidence and for their joint advantage; but their interchange of thought and experience does not appear to have been of much value or advantage to the other; for an examination of the correspondence between MM. Niépce and Daguerre tends to show that the one somewhat annoyed the other by sticking to his resins, and the other one by recommending the use of iodine. M. Niépce somewhat ungraciously expresses regret at having wasted so much time in experimenting with iodine at M. Daguerre’s suggestion, but ultimate results fully justified Daguerre’s recommendation, and proved that he was then on the right track, while M. Niépce’s experiments with resins, asphaltum, and other substances terminated in nothing but tedious manipulations, lengthy exposures, and unsatisfactory results. To M. Niépce, most unquestionably, is due the honour of having produced the first permanent sun-pictures, for we have seen that those obtained by Wedgwood and Davy were as fleeting as a shadow, while those exhibited by M. Niépce in 1827 are still in their original condition, and, imperfect as they are, they are likely to retain their permanency for ever. Their fault lay in neither possessing beauty nor commercial applicability.

As M. Niépce died at Chalons-sur-Saône in 1833, and does not appear to have improved his process much, if any, after entering into partnership with M. Daguerre, and as I may not have occasion to allude to him or his researches again, I think this will be the most fitting place to give a brief description of his process, and his share in the labours of bringing up the wonderful baby of science, afterwards named Photography, to a safe and ineffaceable period of its existence.

The Heliographic process of M. Niépce consists of a solution of asphaltum, bitumen of Judea, being spread on metal or glass plates, submitted to the action of light either by superposition or in the camera, and the unaffected parts dissolved away afterwards by means of a suitable solvent. But, in case any student of photography should like to produce one of the first form of permanent sun-pictures, I shall give here the details of M. Niépce’s own modus operandi for preparing the solution of bitumen and coating the plate:—