The Sun.
London, England, 1864-09-30 00:00:00

A New Step in Photography.

Few of the arts show such signs of vitality as the

infant one of photography. It would be strange,
indeed, if an art which has so much novelty and

marvel about it, which gives to idlers the most

graceful amusement, and to workers the most

splendid results, which interests equally the man of
science and the lover of art, which yield not merely
a livelihood, but immense gains to many who prac•
tise it, and which is, nevertheless, in its infancy,
should not display great vigour and make continual
progress. One more step of a mighty progress we
chronicle to.day—a step that, though small in itself,
is of immense importance and amounts to a revolu-
tion in photography. It is the step by which now

at last we can produce a permanent print• English-

men and Frenchmen have hitherto carried off the

chief honours of discovery in photographic science ;
but this last discovery is the work of a German. To

explain more clearly what he has accomplished, we
propose to state as rapidly as possible what has
been already done in the science.
It is not very long since Wedg wood and Davy
failed to fix the image which sunlight impresses, and
had long been known to impress upon any surface
impregnated with nitrate of silver. Documents exist
which prove that though pictures on silvered paper
were obtained about the commencement of the pre•

sent century, no means could be found to fix the
fleeting image. Disheartened by continual failure,
our men of science Ist photography go to sleep, and
nothing effectual was done in it until, excited by
the discoveries and speculations of Niepce de St.

Victor and others, Daguerre obtained pictures on
metal plates that promised permanence. The ap-
plication of vapour of iodine to the silvered plate
gave the daguerrotype image, and this process was
the pioneer of all the so-called "negative'' pro•

ceases now used in photography. Scarcely had the
beautiful process of Daguerre been made public
when our own countryman, Mr Fox Talbot, made
a farther step in advance—one which at once gave
a great practical value to the photographic art ; he
discovered the means of producing upon paper so-
cllled positive images of the objects to be pictured.
Independently of Daguerre, he had succeeded in

producing negative images on paper—that is,
images in which the conditions of light and shad:,
are the reverse of those existing in nature, the
shadows being represented by lights, and the lights
by shadows. He now succeeded in printing from
this negative any number of positive images in

which the lights were lights and the shadows

shadows. It was a vast stride, and that which fol-
lowed was also vast. It was recommended by Le

Grey that collodon should be used as the vehicle for
the sensitive salts which, spread out in a film, re-

ceive the sun picture. The practical mind of Archer
seized the idea, and, spreading the collodion on a
glass plate, discovered the means of obtaining very
much increased delicacy of detail—a negative pica
ture of far greater value than paper could possibly
produce. Thenceforward to the present time vari-

ous improvements have been made in the process
of taking the original negatives. Greater sensitive-
ness and, as a consequence, greater rapidity of
action have been imparted to the collodion film ; and
this negative process now ?eaves little to be desired,
ssve and except one thing—the means of impressing
the sensitive surface instantaneously with any kind
of picture. Instantaneous pictures of great beauty
have been obtained, and chiefly by Colonel Stuart
Wortley, but they are for the most part confined to

the representations of objects brilliantly lighted
Save for this defect of instantaneousness, the method
of taking negatives on a film of collodion spread
over glass is well nigh perfect.
It is in the process of transferring the negative
image into a positive one many times repeated that
the chief difficulty of photography now arises. A
perfect negative having been obtained,it is necessary
to print off hundreds and thousands of copies on
paper. The paper itself, and the materials with
which it is prepared, as the albumen and the
nitrate of silver, vary not a little in their action—
vary, indeed, so much it is rare to get 20 copies
of any individual photograph that shall be all
alike. Worst of all, the materials used in the pre.
paration of the prints contain within themselves
the elements of destruction. The most important
materials used in the preparation of paper for prints
ing positives are albumen and nitrate of silver. A
fi!tn of albumen lies upon the paper, and the surface
of it is prepared with silver to receive the print,
which is then submitted to various washing pro-
cesses in order to render it as permanent as possi-
ble. All questions of permanence, however, it is
difficult to establish, and when we come to consider
them we are reminded ef the wise youth mentioned
in every Greek Delectus, who, hearing that ravens
live a hundred years, kept one to see if it were true.
Unfortunately it is not necessary to wait so long in
order to discover that the great majority of photo-
graphic prints are certainly doomed, and that the
chances are against all in which silver and albumen
are used. Nitrate of silver is so difficult to work,
and so uncertain in its effects, besides being expene
sive, that men of science have long been on the
lookeout for some other metallic salt that would take
its place. The nitrate of uranium has been tried, the
ammonio-citrate of iron, the chloride of gold, and so
on, but hitherto with little success. The nitrate of
uranium seemed to promise permanence in the re-
sults which it gave, but these results were attained
with great difficulty, and were only in rare in-
stances of a fine quality.
The new process which has been discovered in
Germanyeby Herr Wothly, and from him has been
named" wothlytype," discards nitrate of silver, and
discards albumen. For the former it uses a double
silt of uranium, the name of which is at present
kept secret; for the latter it uses collodion. We
have explained that by the ordinary method the
paper to be printed is sized with albumen, and the
surface of the albumen receives the silver prepara-
tion, which is sensitive to the light, and shows the
printed image. The paper thus does not receive
the image, but is, as it were, a mere bed on which
lies the material that does receive it. By the subs
stitution of collodion for albumen a different result
is reached. In the first place, the film of collodion
on the paper yields a beautiful smooth surface on
which to receive the image, and the result is that
pictures are printed on it with wonderful delicacy.
In the second place, the collodion before it is
washed upon the paper is rendered sensitive by
being combined with the salt of uranium. The
sensitiveness, therefore, is not on the surface
alone of the collodion film; it is in the film
itself, and so completely passes through it that
even if it be peeled away from the paper the
image which it received will be found on the paper
beneath. The vehicle thus employed is not less
superior to all others yet known for printing the
positive image on paper than it is to all others yet
known for receiving the negative image on glass.
The metallic salt which combines with it has also
rare merits. In the first place, the manipulations
are very simple and easy—far more so than in the
silver-printing process, and thus the labour saved
is considerable. Next, the paper, when rendered
sensitive for printing, or "sensitizer?," as the phoe
tographers say, keeps perfectly for two or even
three weeks—an immense boon to amateurs, who
can thus have their stock of printing paper "sen-
sitized" for them, whereas at present, when the
paper receives the sensitive preparation, it has to
be used almost immediately, and will sot keep
more than a day or; two. Thirdly, the colour and
tone obtained are very various, including every
shade that can be got by the ordinary silver
plan; but, in addition, it has the advantage of being
able to print any number of impressions of exactly
the same colour, and of doing away with all such
difficulties as show themselves in meatiness and irre-
gular toning. The precision of result is a great
point. By the silver process the results are never
certain, and even when a print comes out perfect
from the frame the subsequent process of washing
and fixing go seriously to alter it. Lastly, the per-
manent character of the new method is very remark-
able. Nobody seems to know exactly why the old
silver process gives way—whether it be on account
of the albumen, or the nitrate of silver, or the hypo-
sulphite of soda. We only know that so many of the
prints prepared by the old method fall away, that
no reliance can be placed on those which seem to
stand firm. We know how apt silver is to tarnish,
and especially in atmospheres that abound in theem
compounds of sulphur, Sumo photographers se