It may be proper to preface these specimens of a new Art by a brief
account of the circumstances which preceded and led to the discovery of
it. And these were nearly as follows.
One of the first days of the month of October 1833, I was amusing myself
on the lovely shores of the Lake of Como, in Italy, taking sketches with
Wollaston’s Camera Lucida, or rather I should say, attempting to take
them: but with the smallest possible amount of success. For when the eye
was removed from the prism—in which all looked beautiful—I found that the
faithless pencil had only left traces on the paper melancholy to behold.
After various fruitless attempts, I laid aside the instrument and came to
the conclusion, that its use required a previous knowledge of drawing,
which unfortunately I did not possess.
I then thought of trying again a method which I had tried many years
before. This method was, to take a Camera Obscura, and to throw the image
of the objects on a piece of transparent tracing paper laid on a pane of
glass in the focus of the instrument. On this paper the objects are
distinctly seen, and can be traced on it with a pencil with some degree of
accuracy, though not without much time and trouble.
I had tried this simple method during former visits to Italy in 1823 and
1824, but found it in practice somewhat difficult to manage, because the
pressure of the hand and pencil upon the paper tends to shake and displace
the instrument (insecurely fixed, in all probability, while taking a hasty
sketch by a roadside, or out of an inn window); and if the instrument is
once deranged, it is most difficult to get it back again, so as to point
truly in its former direction.
Besides which, there is another objection, namely, that it baffles the
skill and patience of the amateur to trace all the minute details visible
on the paper; so that, in fact, he carries away with him little beyond a
mere souvenir of the scene—which, however, certainly has its value when
looked back to, in long after years.
Such, then, was the method which I proposed to try again, and to
endeavour, as before, to trace with my pencil the outlines of the scenery
depicted on the paper. And this led me to reflect on the inimitable
beauty of the pictures of nature’s painting which the glass lens of the
Camera throws upon the paper in its focus—fairy pictures, creations of a
moment, and destined as rapidly to fade away.
It was during these thoughts that the idea occurred to me…how charming it
would be if it were possible to cause these natural images to imprint
themselves durably, and remain fixed upon the paper!
And why should it not be possible? I asked myself.
The picture, divested of the ideas which accompany it, and considered only
in its ultimate nature, is but a succession or variety of stronger lights
thrown upon one part of the paper, and of deeper shadows on another. Now
Light, where it exists, can exert an action, and, in certain
circumstances, does exert one sufficient to cause changes in material
bodies. Suppose, then, such an action could be exerted on the paper; and
suppose the paper could be visibly changed by it. In that case surely
some effect must result having a general resemblance to the cause which
produced it: so that the variegated scene of light and shade might leave
its image or impression behind, stronger or weaker on different parts of
the paper according to the strength or weakness of the light which had
acted there.
Such was the idea that came into my mind. Whether it had ever occurred to
me before amid floating philosophic visions, I know not, though I rather
think it must have done so, because on this occasion it struck me so
forcibly. I was then a wanderer in classic Italy, and, of course, unable
to commence an inquiry of so much difficulty: but, lest the thought should
again escape me between that time and my return to England, I made a
careful note of it in writing, and also of such experiments as I thought
would be most likely to realize it, if it were possible.
And since, according to chemical writers, the nitrate of silver is a
substance peculiarly sensitive to the action of light, I resolved to make
a trial of it, in the first instance, whenever occasion permitted on my
return to England.
But although I knew the fact from chemical books, that nitrate of silver
was changed or decomposed by Light, still I had never seen the experiment
tried, and therefore I had no idea whether the action was a rapid or a
slow one; a point, however, of the utmost importance, since, if it were a
slow one, my theory might prove but a philosophic dream.
Such were, as nearly as I can now remember, the reflections which led me
to the invention of this theory, and which first impelled me to explore a
path so deeply hidden among nature’s secrets. And the numerous researches
which were afterwards made—whatever success may be thought to have
attended them—cannot, I think, admit of a comparison with the value of the
first and original idea.
In January 1834, I returned to England from my continental tour, and soon
afterwards I determined to put my theories and speculations to the test of
experiment, and see whether they had any real foundation.
Accordingly I began by procuring a solution of nitrate of silver, and with
a brush spread some of it upon a sheet of paper, which was afterwards
dried. When this paper was exposed to the sunshine, I was disappointed to
find that the effect was very slowly produced in comparison with what I
had anticipated.
I then tried the chloride of silver, freshly precipitated and spread upon
paper while moist. This was found no better than the other, turning
slowly to a darkish violet colour when exposed to the sun.
Instead of taking the chloride already formed, and spreading it upon
paper, I then proceeded in the following way. The paper was first washed
with a strong solution of salt, and when this was dry, it was washed again
with nitrate of silver. Of course, chloride of silver was thus formed in
the paper, but the result of this experiment was almost the same as
before, the chloride not being apparently rendered more sensitive by being
formed in this way.
Similar experiments were repeated at various times, in hopes of a better
result, frequently changing the proportions employed, and sometimes using
the nitrate of silver before the salt, &c. &c.
In the course of these experiments, which were often rapidly performed, it
sometimes happened that the brush did not pass over the whole of the
paper, and of course this produced irregularity in the results. On some
occasions certain portions of the paper were observed to blacken in the
sunshine much more rapidly than the rest. These more sensitive portions
were generally situated near the edges or confines of the part that had
been washed over with the brush.
After much consideration as to the cause of this appearance, I conjectured
that these bordering portions might have absorbed a lesser quantity of
salt, and that, for some reason or other, this had made them more
sensitive to the light. This idea was easily put to the test of
experiment. A sheet of paper was moistened with a much weaker solution of
salt than usual, and when dry, it was washed with nitrate of silver. This
paper, when exposed to the sunshine, immediately manifested a far greater
degree of sensitiveness than I had witnessed before, the whole of its
surface turning black uniformly and rapidly: establishing at once and
beyond all question the important fact, that a lesser quantity of salt
produced a greater effect. And, as this circumstance was unexpected, it
afforded a simple explanation of the cause why previous inquirers had
missed this important result, in their experiments on chloride of silver,
namely, because they had always operated with wrong proportions of salt
and silver, using plenty of salt in order to produce a perfect chloride,
whereas what was required (it was now manifest) was, to have a deficiency
of salt, in order to produce an imperfect chloride, or (perhaps it should
be called) a _subchloride_ of silver.
So far was a free use or abundance of salt from promoting the action of
light on the paper, that on the contrary it greatly weakened and almost
destroyed it: so much so, that a bath of salt water was used subsequently
as a fixing process to prevent the further action of light upon sensitive
paper.
This process, of the formation of a subchloride by the use of a very weak
solution of salt, having been discovered in the spring of 1834, no
difficulty was found in obtaining distinct and very pleasing images of
such things as leaves, lace, and other flat objects of complicated forms
and outlines, by exposing them to the light of the sun.
The paper being well dried, the leaves, &c. were spread upon it, and
covered with a glass pressed down tightly, and then placed in the
sunshine; and when the paper grew dark, the whole was carried into the
shade, and the objects being removed from off the paper, were found to
have left their images very perfectly and beautifully impressed or
delineated upon it.
But when the sensitive paper was placed in the focus of a Camera Obscura
and directed to any object, as a building for instance, during a moderate
space of time, as an hour or two, the effect produced upon the paper was
not strong enough to exhibit such a satisfactory picture of the building
as had been hoped for. The outline of the roof and of the chimneys, &c.
against the sky was marked enough; but the details of the architecture
were feeble, and the parts in shade were left either blank or nearly so.
The sensitiveness of the paper to light, considerable as it seemed in some
respects, was therefore, as yet, evidently insufficient for the purpose of
obtaining pictures with the Camera Obscura; and the course of experiments
had to be again renewed in hopes of attaining to some more important
result.
The next interval of sufficient leisure which I found for the prosecution
of this inquiry, was during a residence at Geneva in the autumn of 1834.
The experiments of the previous spring were then repeated and varied in
many ways; and having been struck with a remark of Sir H. Davy’s which I
had casually met with—that the _iodide_ of silver was more sensitive to
light than the _chloride,_ I resolved to make trial of the iodide. Great
was my surprise on making the experiment to find just the contrary of the
fact alleged, and to see that the iodide was not only less sensitive than
the chloride, but that it was not sensitive at all to light; indeed that
it was absolutely insensible to the strongest sunshine: retaining its
original tint (a pale straw colour) for any length of time unaltered in
the sun. This fact showed me how little dependance was to be placed on
the statements of chemical writers in regard to this particular subject,
and how necessary it was to trust to nothing but actual experiment: for
although there could be no doubt that Davy had observed what he described
under certain circumstances—yet it was clear also, that what he had
observed was some exception to the rule, and not the rule itself. In
fact, further inquiry showed me that Davy must have observed a sort of
subiodide in which the iodine was deficient as compared with the silver:
for, as in the case of the chloride and subchloride the former is much
less sensitive, so between the iodide and subiodide there is a similar
contrast, but it is a much more marked and complete one.
However, the fact now discovered, proved of immediate utility; for, the
iodide of silver being found to be insensible to light, and the chloride
being easily converted into the iodide by immersion in iodide of
potassium, it followed that a picture made with the chloride could be
_fixed_ by dipping it into a bath of the alkaline iodide.
This process of fixation was a simple one, and it was sometimes very
successful. The disadvantages to which it was liable did not manifest
themselves until a later period, and arose from a new and unexpected
cause, namely, that when a picture is so treated, although it is
permanently secured against the _darkening_ effect of the solar rays, yet
it is exposed to a contrary or _whitening_ effect from them; so that after
the lapse of some days the dark parts of the picture begin to fade, and
gradually the whole picture becomes obliterated, and is reduced to the
appearance of a uniform pale yellow sheet of paper.
A good many pictures, no doubt, escape this fate, but as they all seem
liable to it, the fixing process by iodine must be considered as not
sufficiently certain to be retained in use as a photographic process,
except when employed with several careful precautions which it would be
too long to speak of in this place.
During the brilliant summer of 1835 in England I made new attempts to
obtain pictures of buildings with the Camera Obscura; and having devised a
process which gave additional sensibility to the paper, viz. by giving it
repeated alternate washes of salt and silver, and using it in a moist
state, I succeeded in reducing the time necessary for obtaining an image
with the Camera Obscura on a bright day to ten minutes. But these
pictures, though very pretty, were very small, being quite miniatures.
Some were obtained of a larger size, but they required much patience, nor
did they seem so perfect as the smaller ones, for it was difficult to keep
the instrument steady for a great length of time pointing at the same
object, and the paper being used moist was often acted on irregularly.
During the three following years not much was added to previous knowledge.
Want of sufficient leisure for experiments was a great obstacle and
hindrance, and I almost resolved to publish some account of the Art in the
imperfect state in which it then was.
However curious the results which I had met with, yet I felt convinced
that much more important things must remain behind, and that the clue was
still wanting to this labyrinth of facts. But as there seemed no
immediate prospect of further success, I thought of drawing up a short
account of what had been done, and presenting it to the Royal Society.
However, at the close of the year 1838, I discovered a remarkable fact of
quite a new kind. Having spread a piece of silver leaf on a pane of glass,
and thrown a particle of iodine upon it, I observed that coloured rings
formed themselves around the central particle, especially if the glass was
slightly warmed. The coloured rings I had no difficulty in attributing to
the formation of infinitely thin layers or strata of iodide of silver; but
a most unexpected phenomenon occurred when the silver plate was brought
into the light by placing it near a window. For then the coloured rings
shortly began to change their colours, and assumed other and quite unusual
tints, such as are never seen in the “colours of thin plates.” For
instance, the part of the silver plate which at first shone with a pale
yellow colour, was changed to a dark olive green when brought into the
daylight. This change was not very rapid: it was much less rapid than the
changes of some of the sensitive papers which I had been in the habit of
employing, and therefore, after having admired the beauty of this new
phenomenon, I laid the specimens by, for a time, to see whether they would
preserve the same appearance, or would undergo any further alteration.
Such was the progress which I had made in this inquiry at the close of the
year 1838, when an event occurred in the scientific world, which in some
degree frustrated the hope with which I had pursued, during nearly five
years, this long and complicated, but interesting series of
experiments—the hope, namely, of being the first to announce to the world
the existence of the New Art—which has been since named Photography.
I allude, of course, to the publication in the mouth of January 1839, of
the great discovery of M. Daguerre, of the photographic process which he
has called the Daguerreotype. I need not speak of the sensation created
in all parts of the world by the first announcement of this splendid
discovery, or rather, of the fact of its having been made, (for the actual
method made use of was kept secret for many months longer). This great
and sudden celebrity was due to two causes: first, to the beauty of the
discovery itself: secondly, to the zeal and enthusiasm of Arago, whose
eloquence, animated by private friendship, delighted in extolling the
inventor of this new art, sometimes to the assembled science of the French
Academy, at other times to the less scientific judgment, but not less
eager patriotism, of the Chamber of Deputies.
But, having brought this brief notice of the early days of the
Photographic Art to the important epoch of the announcement of the
Daguerreotype, I shall defer the subsequent history of the Art to a future
number of this work.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Some time previously to the period of which I have now been speaking, I
met with an account of some researches on the action of Light, by Wedgwood
and Sir H. Davy, which, until then, I had never heard of. Their short
memoir on this subject was published in 1802 in the first volume of the
Journal of the Royal Institution. It is curious and interesting, and
certainly establishes their claim as the first inventors of the
Photographic Art, though the actual progress they made in it was small.
They succeeded, indeed, in obtaining impressions from solar light of flat
objects laid upon a sheet of prepared paper, but they say that they found
it impossible to fix or preserve those pictures: all their numerous
attempts to do so having failed.
And with respect to the principal branch of the Art, viz. the taking
pictures of distant objects with a Camera Obscura, they attempted to do
so, but obtained no result at all, however long the experiment lasted.
While therefore due praise should be awarded to them for making the
attempt, they have no claim to the actual discovery of any process by
which such a picture can really be obtained.
It is remarkable that the failure in this respect appeared so complete,
that the subject was soon after abandoned both by themselves and others,
and as far as we can find, it was never resumed again. The thing fell
into entire oblivion for more than thirty years: and therefore, though the
Daguerreotype was not so entirely new a conception as M. Daguerre and the
French Institute imagined, and though my own labours had been still more
directly anticipated by Wedgwood, yet the improvements were so great in
all respects, that I think the year 1839 may fairly be considered as the
real date of birth of the Photographic Art, that is to say, its first
public disclosure to the world.
‐‐‐‐‐‐‐‐‐‐‐‐‐‐
There is a point to which I wish to advert, which respects the execution
of the following specimens. As far as respects the design, the copies are
almost facsimiles of each other, but there is some variety in the tint
which they present. This arises from a twofold cause. In the first place,
each picture is separately formed by the light of the sun, and in our
climate the strength of the sun’s rays is exceedingly variable even in
serene weather. When clouds intervene, a longer time is of course allowed
for the impression of a picture, but it is not possible to reduce this to
a matter of strict and accurate calculation.
The other cause is the variable quality of the paper employed, even when
furnished by the same manufacturers—some differences in the fabrication
and in the _sizing_ of the paper, known only to themselves, and perhaps
secrets of the trade, have a considerable influence on the tone of colour
which the picture ultimately assumes.
These tints, however, might undoubtedly be brought nearer to uniformity,
if any great advantage appeared likely to result: but, several persons of
taste having been consulted on the point, viz. which tint on the whole
deserved a preference, it was found that their opinions offered nothing
approaching to unanimity, and therefore, as the process presents us
spontaneously with a variety of shades of colour, it was thought best to
admit whichever appeared pleasing to the eye, without aiming at an
uniformity which is hardly attainable. And with these brief observations
I commend the pictures to the indulgence of the Gentle Reader.
[PLATE I. PART OF QUEEN’S COLLEGE, OXFORD.]