To make Plates for the Daguerreotype—Determining the Time of Exposure
in the Camera—Instantaneous Process for Producing
Daguerreotype—Galvanizing the Daguerreotype Plate—Silvering
Solution—Daguerreotype without Mercury—Management of Chemicals—Hints
and Cautions—Electrotyping—Crayon Daguerreotypes—Illuminated
Daguerreotypes—Natural Colors in Heliography—Multiplying Daguerreotypes
on one Plate—Deposit in Gilding—Practical Hints on the Daguerreotype.
TO MAKE PLATES FOR THE DAGUERREOTYPE.
I do not give the method employed by our regular plate manufacturers;
this is not important, as the operator could not possibly profit by it
from the fact of the great expense of manufacturing. The following will
be found practical:
Procure a well planished copper plate of the required size, and well
polish it, first with pumice stone and water, then with snake stone,
jewelers’ rouge. Plates can be purchased in a high state of preparation
from the engravers. Having prepared the copper-plate, well rub it with
salt and water, and then with the silvering powder. No kind answers
better than that used by clock-makers to silver their dial-plates. It
is composed of one part of well washed chloride of silver, five parts
of cream of tartar, and four parts of table salt. This powder must be
kept in a dark vessel, and in a dry place. For a plate six inches by
five, as much of this composition as can be taken up on a shilling is
sufficient. It is to be laid in the centre of the copper, and the
figures being wetted, to be quickly rubbed over every part of the
plate, adding occasionally a little damp salt. The copper being covered
with the silvering is to be speedily well washed in water, in which a
little soda is dissolved, and as soon as the surface is of a fine
silvery whiteness, it is to be dried with a very clean warm cloth. In
this state the plates may be kept for use. The first process is to
expose the plate to the heat of a spirit flame, until the silvered
surface becomes of a well-defined golden-yellow color; then, when the
plate is cold, take a piece of cotton, dipped in very dilute nitric
acid, and rub lightly over it until the white hue is restored, and dry
it with very soft clean cloths. A weak solution of the hydriodate of
potash, in which a small portion of iodine is dissolved, is now passed
over the plate with a wide camel’s hair brush. The silver is thus
converted, over its surface, into an ioduret of silver; and in this
state it is exposed to light, which blackens it. When dry, it is to be
again polished, either with dilute acid or a solution of carbonate of
soda, and afterwards with dry cotton, and the smallest possible portion
of prepared chalk: by this means a surface of the highest polish is
produced. The rationale of this process is, in the first place, the
heat applied dries off any adhering acid, and effects more perfect
union between the copper and silver, so as to enable it to bear the
subsequent processes. The first yellow surface appears to be an oxide
of silver with, possibly, a minute quantity of copper in combination,
which being removed leaves a surface chemically pure.
Another Method.—The best and simplest mode with which we are acquainted
is to divide an earthenware vessel with a diaphragm: one side should be
filled with a very dilute solution of sulphuric acid, and the other
with either a solution of ferroprussiate of potash, or muriate of soda,
saturated with chloride of silver. The copper plate, varnished on one
side, is united, by means of a copper wire, with a plate of zinc. The
zinc plate being immersed in the acid, and the copper in the salt, a
weak electric current is generated, which precipitates the silver in a
very uniform manner over the entire surface.
Another Method.—A piece of brass or of polished copper, brass is
preferred, is perfectly planished and its surface made perfectly clean.
A solution of nitrate of silver, so weak that the silver is
precipitated slowly, and a brownish color, on the brass, is laid
uniformly over it, “at least three times,” with a camel’s hair pencil.
After each application of the nitrate, the plate should be rubbed
gently in one direction, with moistened bitartrate of potassa, applied
with buff. This coat of silver receives a fine polish from peroxide of
iron and buff. Proofs are said to have been taken on it, comparable
with those obtained on French plates.
M. SOLIEL’S PROCESS FOR DETERMINING THE TIME OF EXPOSURE IN THE CAMERA.
M. Soliel has proposed the use of the chloride of silver to determine
the time required to produce a good impression on the iodated plate in
the camera. His method is to fix at the bottom of a tube, blackened
within, a piece of card, on which chloride of silver, mixed with gum or
dextrine, is spread. The tube thus disposed is turned from the side of
the object of which we wish to take the image, and the time that the
chloride of silver takes to become of a greyish slate color will be the
time required for the light of the camera to produce a good effect on
the iodated silver.
INSTANTANEOUS PROCESS FOR PROCURING DAGUERREOTYPES.
The following method of producing Daguerreotypes has by some been named
as above. Most experienced operators have been long acquainted with the
effect of the vapor of ammonia upon the chemically coated plate. I will
here insert Mr. W. H. Hewett’s plan of proceeding. This gentleman, in
referring to it (published in 1845), says:
“This improvement consists in using the vapor of ammonia, as an object
to accelerate the action of light upon the plate. The effect is
produced upon a simple iodized plate, but still more upon a plate
prepared in the ordinary way, with both iodine and bromine. By this
means, the author obtained impressions instantaneously in the sunshine,
and in five to ten seconds in a moderate light; and he hopes to be able
to take moving objects. It can be applied by exposing the prepared
plate over a surface of water, to which a few drops of ammonia have
been added (sufficient to make it smell of ammonia); or the vapor can
be introduced into the camera during the action. In fact, the presence
of ammonia, in the operating-room, appears to have a good effect, as it
also neutralizes the vapors of iodine and bromine that may be floating
about, and which are so detrimental to the influences of light upon the
plate.”
GALVANIZING THE DAGUERREOTYPE PLATE.
In consideration of the importance of galvanized plates, I shall
endeavor to give as plain and concise a manner of manipulation as
possible. For some time it was a question among the operators
generally, as to the beneficial result of electrotyping, the
Daguerreotype plate, but for a few years past our first operators have
found it a fact, that a well electro-silvered surface is the best for
producing a portrait by the Daguerreotype.
From my own experiments, I have found that a plate, by being
galvanized, can be rendered more sensitive to the operation of the
light in proportion of one to five, viz.: if a plate as furnished by
the market, be cleaned, polished, coated and exposed in the camera, if
the required time to freely develop an impression be ten seconds, a
similar plate prepared in like manner and galvanized, will produce an
equally well-defined image in eight seconds. In connection with this
subject, there is one fact worthy of notice; a plate with a very heavy
coating of pure silver, will not produce an equally developed image, as
a plate with a thinner coating, hence the thin coating, providing it
entirely covers the surface, is the best, and is the one most to be
desired. The experiment is plain and simple. Let the slate receive a
heavy or thick coating by the electrotype, then polish, coat, expose in
the usual manner, and the result will be a flat, ashy, indistinct
impression; when, on the other hand, the thin coating will produce a
bright, clear and distinct image, with all the details delineated.
The style of battery best for the purpose has been, and now is, a
question of dispute among operators; some preferring the Daniell
battery to Smee’s. Some claim the superiority of the first from its
uniformity of action; others, of the latter, for its strength. I
consider either good, and for the inexperienced would prefer the
Daniell. This is more simple in its construction, while it has
certainty in action. The more skillful electrotyper would prefer
Smee’s, and this is the one most generally in use. I would remark that
the plan of galvanizing plates should be followed by every operator,
and when once thoroughly tested, no one will abandon it.
SILVERING SOLUTION.
To any desired quantity of chloride of silver in water add, little by
little, cyanide of potassium, shaking well at each addition, until all
the cyanide is dissolved. Continue this operation, and add the cyanide,
until all the precipitate is taken up and held in solution.
This solution is now ready for the plate-cup. Enough water may be added
to cover any sized plate when held perpendicular in the cup. The
strength of the solution may be kept up by occasionally adding the
chloride of silver and cyanide of potassium. There should alway be a
very little excess of the cyanide.
The plate should be well cleaned and buffed, and the solution well
stirred before it is immersed. Care should be observed to keep the
solution clean, and allow no particle of dust to come in contact with
the surface of the plate. The plate is now to be attached to the pole
of the battery.
After remaining a short time, it assumes a blue color; take it out,
rinse freely with pure water, then dry with a spirit lamp, and it is
ready for buffing. Buff and coat in the usual manner. Some operators
are in the practice of immersing the plate in the solution and buffing
twice. This additional silvering is no improvement wherever there has
been a proper first coating.
Sometimes the operator is troubled with streaks or scum on the plate.
This may arise from three causes, all of which experience must teach
the experimenter to avoid; first, too great an excess of cyanide in the
solution; second, a lack of silver; third, the current too strong.
Another annoyance arises from the solution being dirty and the dirt
collecting on the surface. When this is the case, the dirt is sure to
come in contact with the surface of the plate as it is plunged into the
solution, and the result is a scum that it is difficult to dispose of.
This can be prevented only by frequent filtering. One thing should
always be borne in mind in electrotyping Daguerreotype plates—that in
order to secure a perfectly coated surface, the plate should be
perfectly cleaned. In this point, many who have tried the electrotype
process have failed, attributing their ill success to other than the
proper cause.
DAGUERREOTYPES WITHOUT MERCURY.
The following process possesses some interest, and is worthy a trial
from operators. M. Natterer, of Vienna, discovered a process for
obtaining proofs on iodized plates with the chloride of sulphur,
without the use of mercury. A plate of silver is iodized in the usual
manner, and then placed on the top of a vessel six or eight inches
high, having at the bottom, in a small cup, a few drops of chloride of
sulphur; it should remain exposed to the action of the vapor until the
sombre yellow color is changed to a red, after which it is brought to a
focus in the camera, where it is exposed to the light in the camera,
for about the time necessary to produce an ordinary daguerreotype. The
plate is then taken out and examined in the camera by the light of a
candle. It often occurs that no trace of the image is as yet
perceptible, but if the plate is heated by placing over a spirit lamp
the unprepared side, or if left for some time in the dark, or, lastly,
if exposed only a few seconds to a weak, dimmed light, the positive
picture then appears with all its shades. Of these three modes of
bringing out the image, the second is superior to the others.
MANAGEMENT OF CHEMICALS.
It is necessary, first of all, to know that you have a chemical which
is capable of producing good results when in skillful hands. For this
reason it is best to prepare your own quick, after some formula which
is known to be good. Those quick-stuffs which contain chloride of
iodine are noted for their depth of tone while they probably operate
with less uniformity than those which are destitute of it. For
operating under ordinary circumstances, especially with an inferior
light, probably no accelerator is more quick and sure than Wolcott’s.
It also produces a very fine, white pleasing picture, though lacking
that depth of impression so much to be desired. The dry quick operates
with surety, and its use is simple and easy, producing an impression
much like Wolcott’s. For those having a good and permanent light,
however, we would recommend a chemical giving more body to the
impression.
There is a class of accelerators called sensitives, claiming to work in
from three to ten seconds, which, however, will be found very little,
if any, more sensitive than this. We frequently work it with the
ordinary coating in twelve and fifteen seconds. The manner in which the
sensitives are worked is by coating very light. In this way, a flat,
shallow picture is obtained in a few seconds; and the same can be done
with any of the more volatile quicks.
It is a fact not generally known, that a plate coated in a light
chemical room is more sensitive than when coated in darkness. By
admitting a free, uniform light, and exposing the plate to it a few
seconds after coating, then timing short in the camera, a very light,
clear impression is obtained. The time in the camera is reduced in
proportion to the previous action of light. The shades, of course, are
destroyed, and the tone injured; still, for taking children, we have
succeeded better by this method than by the use of “sensitives.” The
discovery of this principle was accidental, while operating where the
direct ray s of the sun, entering the window just before sunset, fell
on the curtain of our dark room, rendering it very light within.
The selection of iodine is not unimportant. Reject, at once, that which
has anything like a dull, black, greasy appearance; and select that
which is in beautiful large crystalline scales, of a purple color, and
brilliant steel lustre.
Solarization, and general blueness of all the light parts of the
picture, were formerly great obstacles to success, though now scarcely
thought of by first-class artists. Beginners in the art, however, are
still apt to meet with this difficulty. It is occasioned by dampness in
the iodine box, which causes the plate to become coated with a
hydro-iodide of silver, instead of the iodide. The remedy is in drying
your iodine. If in summer, you can open your box and set it in sunshine
a few minutes; or if in winter, set it under a stove a short time. The
true method, however, is to dry it by means of the chloride of calcium.
It has such a remarkable affinity for water, that a small fragment
placed in the open air, even in the dryest weather, soon becomes
dissolved.
Take one or two ounces of this chemical, heat it in the drying bath, or
in a hot stove, to perfect dryness; place it in a small glass toy dish,
or large watch crystal, and set it in the centre of your iodine box.
Take this out and heat to dryness every morning. Adopt this process,
and with your mercury at a high temperature, you will never be troubled
with blue pictures.
Young operators are apt to impute all want of success in operating to
their chemicals, even though the cause is quite as likely to be
elsewhere. Failure is quite likely to occur from dampness in the buffs,
or in the polish; it is therefore necessary to be constantly on the
guard in this quarter. With a view to this, always scrape your buffs
with a dull knife, or with one blade of your shears, the first thing in
the morning, and after brushing them thoroughly, dry them, either in
the sun, by a stove, or in the buff-dryer. It is equally important that
the polish and the brush should be kept dry.
Want of success may arise from vapors of iodine or bromine in the
camera box, mercury bath, or even in the buffs. It is incredible how
small a quantity of these vapors will affect the effect of light when
coming in contact with the plate, after or during the exposure in the
camera. It is therefore necessary to be cautious not to mix chemicals,
nor open your boxes or bottles in your room, but take them out to do
it. Never hurry the operation through from lack of confidence in the
result. The fact of anything being out of order, forms no excuse for
slighting the process. If unsuccessful, do not pursue the same course
every trial, but vary with a view to detect the cause of the
difficulty.
In case of a long series of failures, institute a regular course of
investigation, after this manner, commencing where the trouble is most
likely to occur:
1. Are the plates well cleaned?
2. Is the iodine dry? If the impressions come out blue, you may rest
assured it is not. Take out the iodine, wipe and dry the box, and dry
the calcium.
3. Is the quick battery of the right strength? If dry, it must change
the plate in from six to fifteen seconds. If any of the chloride of
iodine class, it may vary from five seconds to a minute. Begin by
coating light, and increase on each trial, observing the effect. If the
light side of the picture seems loth to come out, and shows no contrast
with the dark side, it is to be inferred that your battery is too
strong, and must be reduced with water or set out in the open air for a
few minutes, with the lid off. If working an old battery, never renew
very strong, or it will work dark and heavy. A battery, to work well,
should be gradually losing strength, but never gaining. An old battery,
however, may be quickened up and made to work well for some time, by
adding five of six drops of sulphuric acid, repeating the quantity as
often as necessary, providing always that acid be not used in
manufacturing the quick.
4. Have the plates lost their sensitiveness by being many times exposed
to mercury? Clean and burn them; but if French plates, burn light, or
you spoil them.
5. Are the buff s dry and clean? Examine the plate critically after
buffing to detect any appearance of scum or film on the surface. If so,
the longer you buff the more it shows. Scrape and dry the buffs
thoroughly.
6. Is the mercury free from scum and dirt? If not, filter. Is it also
far enough from the coating boxes? Should be at least three feet, and
kept covered.
7. Is the mercury sufficiently heated? This is important. Long
exposure, however, will answer the same purpose.
8. Are your lenses clean, and in proper place?
9. Are the tablets in focus with the ground-glass? If you can attribute
the failure to none of these, mix a new box of some other kind of
quick, say the dry, for instance. If you fail in the same manner here,
take time, wash your buffs, overhaul all the chemicals, and start anew.
Do not be discouraged.
There is no day so dark but that the sun will shine again. We will
close with this brief summary of advice:
Clean your plates. Keep everything dry. Keep the mercury hot. Follow
these instructions carefully, and you must succeed.
HINTS AND CAUTIONS.
First of all, cleanliness should be observed. When there is dust or
dirt about your room, particularly about the work-bench, failures will
be frequent; for the smallest particles of rotten-stone, when allowed
to come in contact with the buffs, will produce scratches on the
surface of the plate, which very much injures the operation, and often
causes failures.
Dust flying about the room is injurious, if allowed to fall on the
plate, either before or after it has been coated, as it causes black
spots which cannot be removed.
The polished plate should not be allowed to come in contact with a
strong current of air, for it tends to oxidize the surface. Breathing
on the surface should also be avoided, for the same reason.
The plate should, in all cases, be buffed immediately before using, and
not allowed to stand any length of time. It should be held with the
polished face downward.
It is always best that the plate should be of the same temperature of
the atmosphere in the room.
Keep the camera and mercury-bath perfectly free from the vapors of
iodine and bromine; for the presence of the slightest degree of either
of the above will injure the impression in no small degree. As a
preventive, let the camera be exposed to the sun or fire for a few
minutes in the morning.
Filter your mercury often, to keep the surface free from film and dust.
The hyposulphite solution should be filtered through sponge every time
it is used.
The direct rays of light must not enter the camera in conjunction with
those reflected from the object; or the picture will be veiled, and the
color of the plate changed to a thick green.
If the plate be iodized only to a light-yellow, the result might be of
a bluish or grey tinge: and this is generally the case, when the quick
is new and strong, and there is an excess of it on the plate, and yet
not enough to form the bromide iodide of silver; in which case it would
wholly spoil the impression.
Your iodine will be found to operate more successfully, when the time
required for coating the plate does not fall short of fifteen seconds,
or exceed one minute.
Too quick coating can be avoided by using less iodine in your box. In
the summer months, when the weather is 80 deg. and over, one quarter of
an ounce, or even less, will work to advantage.
ELECTROTYPING.
I am indebted to Mr. J. H. Fitzgibbons for the following process, which
he employed in producing the excellent specimens he exhibited at the
Crystal Palace:
“I shall endeavor to lay down in as comprehensive a manner as possible
the method by which I have been enabled to produce the most
satisfactory results. I use a Smee’s battery (another kind will do).
After filling the cell, of common size, nearly full with water; add
about quarter of an ounce of sulphuric acid. Mix this well, and let it
stand for about three hours, or until the action of the battery becomes
weak, when it is in order to work with a very uniform action. Put one
pound of sulphate of copper in one quart of water; stir it until the
sulphate of copper is all dissolved, and then add one half ounce of
sulphuric acid and a quarter of an ounce of nitric acid. This solution,
well mixed, should be filtered, and it is ready for use. It is very
important that the solution should be kept clean, clear, and free from
all foreign substance. The above quantity of this solution will be
found sufficient for electrotyping a dozen of the sixth-size plates.
When it is required to be strengthened, it is only necessary to add a
little of the sulphate of copper.
“With the battery prepared as above, and the solution of sulphate of
copper in a vessel of proper dimensions to receive your plate, connect
the galvanic current, and immerse the impressioned plate, letting it
remain until a thin film of copper has been formed, then the battery
can be strengthened, and the impression will be of sufficient thickness
to be removed in from eight to twelve hours. An old Daguerreotype plate
attached to the opposite pole of the battery (copper side towards the
face of the plate to be electrotyped), will answer the same purpose as
the silver-plate.
“The great difficulty in taking an electrotype impression, and
preserving the original, has been attributed to the battery being too
powerful. I am led to believe from practice that the principal
difficulty has been in the Daguerreotype plate itself, for if we use an
impression that has been taken but a few days, and taken in the usual
way, we will find it difficult to succeed without spoiling both the
copy and original, and so also with an old impression.
“I have found the most certain method to be as follows:—Coat the
Daguerreotype plate as usual, except use less of the accelerators, the
proportion of iodine coating being greater, of course the time of
exposure in the camera will be lengthened. Mercurialize it at about a
temperature requiring to develop the image, from six to eight minutes,
at least. Gilding the Daguerreotype has much to do towards producing a
good electrotype copy. This should be done by applying a little heat,
and gilding very slowly, giving a coating of gold with the greatest
possible uniformity. By this method, I have been enabled to produce any
number of proofs. I have produced a dozen from one impression, and it
remains as perfect as when first taken.
“By a little judgment and care the operator will be enabled to produce
the electrotype copy of the Daguerreotype plate without any difficulty.
The electrotype copy should be immediately put under a glass and sealed
in the same manner as the ordinary Daguerreotype.”
CRAYON DAGUERREOTYPES.
This process is patented in the United States, by J. A. Whipple, of
Boston, and of course no honorable person will use it for his own
benefit without purchasing a right.
A white back-ground is generally employed, the object being to blur the
lower portion of the plate, leaving the head of the subject in relief.
Every Daguerreotypist is familiar with the fact that a motion of any
body between the camera and the sitter will cause a “blur.” Cut a piece
of thin paper and scallop it, making a semicircle. This is kept
straight by means of a wire frame, and it is to be moved in front of
the lower part of the body of the sitter during the time of exposure of
the plate in the camera. Develop over mercury as usual, and the result
will be a crayon Daguerreotype.
Another method is to have a wheel with a hole cut through it of a
diameter of about 12 inches. This hole is so cut as to leave teeth
resembling those of a large saw. This wheel is so arranged that it can
be turned around, which should be done during the time of exposure in
the camera. It must be placed between the camera and the sitter, and at
such a distance from the camera as to allow such proportion of the body
of the sitter be seen upon the ground-glass as is desired. It will be
readily seen that by turning this wheel during the operation will
produce the same result as the paper being moved in the other method.
The teeth make the “blur.” The side of the wheel towards the camera may
be black, by which means the result will be a dark instead of a light
border.
ILLUMINATED DAGUERREOTYPES.
This process is also patented, and the remarks on the preceding subject
will apply in this case. The plate is prepared and exposed as in the
usual method of the Daguerreotype. A white back-ground is employed. Let
the head of the sitter come in the middle of the plate, and before
exposing it to the vapors of mercury, put a small mat or diaphragm,
having a small hole through it, over or directly on the surface of the
plate. This diaphragm should be bevelled, and the bevel should be
towards the surface of the plate; this, in order to prevent too sharp a
line on the impression. It will be readily seen that if an impressioned
plate so covered is placed over the mercury, it will be developed on
such portions only as are exposed. The principle is so familiar that
further explanations are unnecessary.
NATURAL COLORS IN HELIOGRAPHY.
This subject is worthy the attention of every operator. The following
process is so plain and easy of trial that any Daguerreotypist can try
it. This is as given by Mr. James Campbell, and was published in
Humphrey’s Journal of the Daguerreotype and Photographic Arts, vol. 5,
page 11. Mr. Campbell has done much to further the process announced by
M. Neipce, and his experiments have proved highly successful.
The following is submitted as worthy of trial:
“The proper preparation of the chloridated plate, to enable it to
receive colored impressions is an object of the first importance to
those wishing to experiment on it, and consequently requires particular
notice. The plate may be prepared by making it the positive pole of a
battery, and letting it at the same time be immersed in chlorine water.
The negative pole should be a slip of platinum. All the colors may be
produced from a plate so prepared if the chlorine and water are in the
right proportions; but generally one color or the other predominates,
according to the amount of chlorine in the liquid. By adding the
chlorides of strontian, uranium, potassium, sodium, iron, or copper to
the liquid, various effects may be produced, and these bodies will be
found to produce the same color on the plate that their flame gives to
alcohol.
“The honor of this discovery is due to M. Neipce. Copper gives a
variegated flame; hence many colors may be impressed on a plate
prepared with a solution of its chloride.
“M. Neipce recommends a solution of the mixed chlorides of copper and
iron, and it is with these, that I have been most successful. As the
chlorides of copper and iron are not much used in the arts, they are
not generally found for sale in the shops; and it may be well to
furnish those not much versed in chemistry with an easy method of
preparing them.
“They may be made directly from either metal by dissolving it in
hydrochloric acid; but they may be formed by a cheaper method, and by
which also the acid fumes are avoided.
“Sulphate of iron or copper, or both together, may be dissolved in
water and then neutralized with common crude potash, or its carbonate
or bicarbonate—known commonly as pearl ash and saleratus. If either of
the latter be used, there will be formed sulphate of potash and a
carbonate of the metal used, and there will also be a considerable
effervescence of carbonic acid, which will, if care is not taken, cause
the mixture to run over the vessel. After the copper or iron salt is
neutralized, which is known by its ceasing to effervesce, the carbonate
of the metal will settle slowly, and will at first nearly fill the
vessel. The supernatant fluid, which is sulphate of potash in solution,
may now be carefully poured off, and its place filled with water; this
operation should be repeated several times until the water which passes
off is tasteless. The carbonate of the metal rapidly changes to an
oxide by contact with the air, and it will generally be found, when it
is sufficiently washed, that it is at least half oxide. On adding
hydrochloric acid cautiously to the mixture, a chloric of the metal
will be formed, and carbonic acid will be evolved from the remaining
carbonate. The chloride formed is soluble; but as there are two
chlorides of these metals, and we wish to produce the one which
contains the most chlorine, it is best to add the acid cautiously until
the solution is decidedly acid. After filtering the solution, it is fit
for use; and it should be preserved in well-stoppered bottles. The
water used should be rain or distilled water.
“About one part of the mixed chlorides should be used to three or four
of water.
“The battery may be either Smee’s, Daniell’s, or Grove’s; if of either
of the former, it should be of two series; if of the latter, one cup is
sufficient.
“The plate on being immersed in the liquid, almost instantly takes a
violet color. It should be allowed to remain from two to five minutes,
according to the strength of the battery, and until it becomes nearly
black. It should now be carefully washed, and afterwards heated over a
spirit lamp until it takes a cherry-red color, and it is then ready for
exposure in the camera. Before speaking of exposing the plate, it may
be well to speak of some difficulties which the inexperienced operator
may find in preparing it. If the battery is not in good order, and a
sufficient current is not passed through the solution, the plate will
become coated—and apparently almost as well as when the battery is
working well—but on exposure it will give a negative picture, and but
little colored; while if the battery is in good order, the impression
is invariably positive.
“Sometimes on heating the plate after washing, the surface is covered
with spots or assumes a variegated appearance. This indicates that the
solution is impure, or that the plate have not been thoroughly washed
and are still contaminated with the soluble chlorides which are
contained in the solution.
“From the fact that the plate if prepared with positive electricity
gives a positive picture, while it prepared otherwise it gives a
negative, it is evident that electricity plays an important part in
this process. The same is true to some extent with the compounds formed
with iodine, bromine, and fluorine.
“On heating the plate, the brown coating of chloride melts into a
translucent enamel, and the heat should be withdrawn when a cherry-red
color is produced. It the heat is continued longer, the plate assumes a
lighter color, and becomes less sensitive; and the enamel will finally
scale off. To produce a picture by the ordinary process of M. Neipce,
unaccelerated, it should be exposed for from three to five hours to
sunlight in the camera, though pictures may be procured by contact, in
from fifteen to thirty minutes.”
MULTIPLYING DAGUERREOTYPES ON ONE PLATE.
I have produced some interesting specimens of the Daguerreotypic art,
by exposing in the camera only a portion of the sensitive plate to the
action of light. When on the exposed portion an image is formed, then
taking the tablet into the dark room, change ends and expose the
sensitive portion, and produce another image, developing as usual. This
plan is adapted for taking likenesses for lockets. Two images can be
presented as sitting side by side, by covering half the plate with
black paper, and exposing as before. In this manner we have been
enabled to surprise persons by exhibiting their portrait on the same
plate with a stranger’s. Daguerreotypists must be cautious in
practicing this, as it might not be agreeable to the parties whose
likenesses are together, by the above process. It is impossible to
produce an impression without a line being seen where the edge of the
paper prevented the operation of the light.
I have recently seen a fine specimen produced by another plan, which
far exceeds the above, there being no line, or any peculiarity denoting
two exposures. The specimen referred to, was a gentleman represented on
one plate by two full length portraits. This was produced by using a
black velvet for the background. The plate was exposed sufficient time
to produce one impression, and then the gentleman assumed another
position, and is repeated as looking at himself. From the fact that the
time required to develop black velvet being so much longer than that
for producing a portrait, we are enabled to produce the above
interesting results.
DEPOSIT IN GILDING.
Regarding specks from bad water, I would remark that gilding should be
made only with distilled water. Thus made, it produces very little
deposit, even by long keeping. It therefore preserves its original
strength, and works with great uniformity.
Every grain of deposit contains at least 7-10 its weight of gold,
easily discoverable by the blowpipe. Such gilding is continually
deteriorating, which with good chloride and distilled water may be
prevented. Distilled water should also be used for the hyposulphite.
and for cleaning plates. Any good, clear water may be afterwards used
for washing off, with equally good results. I am very rarely troubled
with specs, and deem this as the main reason.
With a portable still attached to a cooking stove, I obtain half a
gallon of water per hour, and with very little trouble. A small tin
retort or still connected with a Leibig’s condenser, would not add much
to the “traps” of the travelling operator, and save him many a
disreputable specimen.—T. J. BAILEY.—Humphrey’s Journal.
PRACTICAL HINTS ON THE DAGUERREOTYPE.
The following is from Humphrey’s Journal, vol. 5, and from the pen of
Dr. WM. HARRINGTON, one of the most able writers upon the subject of
the Daguerreotype in this country:
THE CAUSE OF THE DIFFICULTY THAT SOMETIMES OCCURS TO PREVENT THE
PRODUCTION OF A CLEAR IMPRESSION UPON A DAGUERREOTYPE PLATE.
Beyond all doubt this is traceable to dampness. Truly this is not a new
thought; but where does this dampness come from? How does it originate,
and where is it located? Generally it has been referred to a point
entirely remote from its real location.
This dampness exists particularly upon the surface of the plate; is
obviously derived immediately from the atmosphere; and is owing to a
certain relative temperature of the plate with the hygrometric
condition of the atmosphere.
Whenever this relation exists between the plate and atmosphere, a
precipitation of moisture takes place upon the surface of the plate,
which render all efforts at polishing impracticable. This interference
is not confined to the buffing operation alone, but sometimes is
discoverable even in the ordinary process of scouring. Every one at all
experienced in this art will remember that it is not always an easy
matter for him, by scouring, to bring his plate to the desired lustre.
All his efforts become unavailing; the more he rubs, the duller the
surface of his plate appears; and although he renews his cotton
repeatedly, still he is obliged to content himself with an
unsatisfactory finish.
This relative condition is not confined to any particular season of the
year, nor to any certain thermometric temperature; but may occur in
summer as well as in winter; the weather being warm or cold, wet or
dry, clear or cloudy, raining or shining. Under any of these
circumstances, if the relation of the plate and atmosphere be such as
to invite upon the plate a precipitation of humidity from the
atmosphere, the prospect of producing a clear impression is quite
problematical.
It is reasonable to expect this occurrence from the fact that metal is
a good radiator, and radiation reduces the temperature of a metallic
body below that of the atmosphere. Consequently, if this relative
condition happens, the result will be as I have stated.
Bodies may be colder than the atmosphere and yet derive no moisture
from it; while at the same time the driest atmosphere is not devoid of
moisture, but will part with it under certain conditions.
Assuming for granted that this relative condition between the plate and
atmosphere, disposing the former to receive the humidity of the latter,
constitutes the great obstacle the operator has to contend with in
producing, a clear proof upon the plate, the remedy naturally suggests
itself, and is very simple. It consists in merely heating the plate
above the temperature of the atmosphere, previous to polishing, and
retaining that temperature during the operation. Various measures might
be devised to effect the desired object; one of which consists of a
sheet-iron box, heated from the inside by a spirit-lamp, upon the top
of which are to be kept the plates ready to undergo the process of
being polished; the blocks of the swing or any other vice; or the iron
bed belonging to Lewis’s vice.
In cold weather, when it is necessary to keep a fire in the preparation
room, all of the above may be so arranged in the vicinity of the fire
as to receive the requisite degree of heat for the purpose specified.
This part of the subject, however, is left entirely for the ingenuity
of the operator. No matter by hat means he accomplishes the object; all
that is required is to heat the plate above the temperature of the
atmosphere and retain that heat during the process of polishing.
Since the adoption of this method, in connection with my partner, T. J.
Dobyns, even in this humid climate of ours, when everything in the room
is dripping with moisture, it has been attended with invariable
success.
CHOICE OF PLATES, ETC.
In the great catalogue of complaints made by operators, none is more
common than that alleged against the quality of plates in general use.
Although the greatest diversity of opinion exists upon this subject,
nevertheless the plates of every manufactory share in this universal
condemnation.
To be sure it cannot be denied but that this necessary article of
utility in the photographic art has undergone a sad deterioration in
quality owing to the increasing demand and great reduction in price—the
plates of the present day being by no means so heavily coated with
silver as formerly—but the complaint alluded to is not predicated so
much upon the thinness of silver as upon a mysterious something which
has conferred upon the plates the epithet of not good.
That this complaint is in a great measure groundless appears evident
from the fact that while, with the same brand of plates one operator
can work successfully, another encounters the greatest difficulty;
while one is able to produce beautifully clear and altogether
satisfactory results, the other labors under the troublesome annoyance
of innumerable specks, large dark insensitive patches and brown
map-like portions, together with divers other blemishes, sufficient to
prevent him from obtaining anything like a tolerable impression.
From this wide difference in the results of the two operators using
identically the same article, it is but reasonable to conclude that the
complaint is founded in error; while the inference is no more than
just, that the fault may be traced to a want of practical skill on the
part of the complaining operator himself; rather than to the inferior
quality of the plates.
The question, then, whether the plates are unfit for use, or whether
those who pronounce them so understand how to use them, appears to be
satisfactorily answered. It therefore becomes a matter worthy of
investigation, to ascertain what superior judgment and skill one
operator possesses over another which enable him to work successfully a
quality of plate, pronounced by the other entirely useless.
Suppose we make a critical examination of one of the repudiated plates.
From its external appearance we have little hesitation in pronouncing
it to be French; indeed, this presumption is strongly corroborated by
the fact that it is ornamented upon one of its corners with a brand to
designate the manufactory from which it emanated.
Upon close inspection we cannot fail to notice a striking peculiarity
upon the surface; the roughness is very remarkable; the planishing
hammer has left amazingly visible indications of its busy work. One
would suppose the manufacturer intended the surface of the plate to
represent the undulations of the sea, instead of that smooth and level
character so strongly recommended by M. Daguerre.
Such a plate necessarily requires at the hand of the operator
considerable labor before the surface is in a proper condition to
receive a suitable polish from the buffer. The least reflection in the
world should teach any one that so long as the undulatory character
continues upon the surface of the plate, it is in a very imperfect
condition for buffing, because the buffer cannot touch every point
equally; the elevated portions alone receiving a high degree of polish
while the depressed portion, from their roughness acting as nuclei,
gather dust, rouge, and other foreign bodies, so detrimental to
sensitiveness. The secret of the superior judgment and skill of one
operator over another, is intimately connected with this point: his
success depends very much upon the first process of cleaning the plate.
Let us examine the manipulation of the complaining operator. He takes
one of these plates and gives it a careful scouring with rotten-stone
and alcohol or any other liquid preferred for this part of the
operation—that is, he gives it what he terms a careful scouring—very
gently indeed because, from the frequent trials he is in the habit of
making in the camera, he fears he will rub the silver entirely away
before he succeeds in obtaining a good impression. The dark patches,
specks, and granular appearance resulting entirely from the unevenness
of the surface of the plate, look like copper to him, and he is
surprised that he should have rubbed away the silver so soon,
particularly by such delicate handling.
The judgment and experience of the successful operator, however, teach
him that scouring injures a plate less than buffing. He knows that
unless the hammer marks be obliterated, he cannot by the buffer produce
a surface of uniform polish and sensitiveness, without which a fair
proof is extremely doubtful; he knows that the time employed in the
preliminary operation of cleaning the plate properly is economy.
There is a style of French plates in the market, denominated heavy,
which are truly excellent, if properly managed. Much patience, however,
is required to remove the marks of the hammer; but with tripoli and
alcohol the surface is readily cut down, and the plate is then
susceptible of a beautiful black lustre by polishing with the buffer.
The complaining operator could not succeed by his own method with one
of the plates; he would encounter all manner of clouds and other
unaccountable phenomena; he would imagine this plate entirely worn out
before it was half cleaned, and soon fix in his own estimation the
reputation of the heavy plate.
In making a choice of plates, therefore, it would appear to be a matter
of perfect indifference with an experienced operator what kind he would
use, except so far only as the labor required in cleaning them was to
be taken into consideration.
The distinction between a scale plate, a Scovill No. 1, S. F., heavy A,
star, crescent, eagle, or any other brand, consists in the superior
finish of some, and the thinness of the silver in the cheaper
qualities.
Consequently, let the complaining operator but employ the diligence
inculcated in this article, to clean his plate thoroughly, so as to
bring it to a perfectly even and level surface, and he will seldom be
troubled with specks, clouds, dark patches, and the host of other
obstacles which heretofore have tormented him.