Transcriber Note: Text emphasis denoted as _Italics_ and =Bold=.
VOL. II. JUNE 1, 1851. NO. 2.
=THE=
=DAGUERREIAN JOURNAL:=
=Devoted to the Daguerrian and Photogenic Arts.=
Also, embracing the Sciences, Arts, and Literature.
[Illustration]
S. D. HUMPHREY AND L. L. HILL, EDITORS.
NEW-YORK:
PUBLISHED SEMI-MONTHLY, AT $3 PER ANNUM, IN ADVANCE.
NO. 311 BROADWAY.
SUBJECT TO NEWSPAPER POSTAGE.--See 3d page cover.
=CONTENTS.=
Some experiments and remarks on the changes which bodies are
capable of undergoing in darkness, and on the agent producing
these changes, by Robert Hunt, 33
Railroad to the Pacific, 35
Experiments on the colored films formed by iodine, bromine, and
chlorine, upon various metals, by Augustus Waller, M. D., 36
Iodine with silver and copper, 39
Bromine with silver and copper, 40
Chlorine with silver and copper, 40
Iodine with titanium, 40
Bromine with titanium, 40
Chlorine with titanium and copper, 40
Iodine with bismuth and silver, 40
Iodine with mercury, 40
Bromine with mercury and copper, 41
Chlorine with mercury and copper, 41
Bromine with lead, 41
Iodine with iron, 41
The American electric telegraph, 42
Iron pavement, 43
Claudet's specification, 44
Interesting experiment with strychnia, 48
Editorial--Operation of light on silver surfaces, 49
Letter from L. L. Hill, 50
Papers of S. A. Wolcott, 51
The natural colors in photography, 52
Our Daguerreotypes--Butler--E. Long--L. M. Ives--N. E. Sissons--
J. D. Wells, 53
Submarine telegraph between England and France, 53
Action of solutions of chlorides and air on mercury, 55
The heat of combinations, 55
Daguerreotype, by John Johnson, 56
Galvanized Daguerreotype plates, 57
Answers to Correspondents, 58
Advertisements, 59
Artists' Register, 63
* * * * *
=S. J. THOMPSON,=
WOULD most respectfully announce to the public, that he has one of
the best sky-lights in the United States, and is prepared to execute
Daguerreotypes. Likenesses of all sizes, put up in every style of the Art.
No. 57 State-street, Albany, N. Y.
21y
* * * * *
=J. H. WHITEHURST'S=
=ELECTRO DAGUERREOTYPES,=
_Galleries, 207 Baltimore Street, Baltimore,_
Broadway, New York, 77 Main street, Richmond, Va., Main street, Norfolk,
Va., Sycamore street, Petersburg, Va., Main street, Lynchburg, Va.,
Pennsylvania Avenue, Washington city. Likenesses taken equally well in all
weather.
2tf
* * * * *
=J. D. WELLS,=
DAGUERREIAN ARTIST, No. 6 Kirkland's Block, Main Street; Northampton,
Mass. Likenesses taken by a sky-light connected with a beautiful
side-light. Pictures put up in all styles of the Art. Plates, Cases,
Lockets, Frames, and all kinds of Daguerreotype Stock for sale.
2-3
* * * * *
=J. E. MARTIN,=
"EXCELSIOR ROOMS" Jefferson Avenue and Odd Fellows' Hall, Detroit.
Daguerreotype Likenesses taken in every style of the Art.
21y
* * * * *
=HARRISON'S CAMERAS.=
The attention of those about purchasing instruments, is directed to the
following recommendation from one of the oldest operators in the country,
and one who has been "tried in the furnace" of experience:
Waterbury, Ct., April 1, 1851.
C. C. Harrison,
_Dear Sir_,--It affords me much pleasure, after giving the instrument
I purchased of you last week a fair trial, and having had eleven years
experience as an operator, to be enabled to bear testimony to the
superiority of your Cameras over all others, not excepting those made
by "Voightlander & Sohn," for the sale of which I was sometime agent at
Boston.
Yours respectfully,
Albert Litch,
Formerly of the firm of Litch & Whipple,
Boston, Mass.
* * * * *
=THE=
=DAGUERREIAN JOURNAL.=
=======================================================
Vol. II. NEW YORK, JUNE 1, 1851. No. 2
=======================================================
=SOME EXPERIMENTS AND REMARKS=
=ON THE CHANGES WHICH BODIES ARE CAPABLE OF UNDERGOING=
=IN DARKNESS, AND ON THE AGENT PRODUCING THESE CHANGES.=
BY ROBERT HUNT.
[Concluded.]
With the view of testing Dr. Draper's results, I carefully iodized two
silver plates and exposed them to light. I then placed them so that half
of one plate was covered by half of the other, and allowed them to remain
in the dark 1-24th of an inch apart for four hours. On mercurialization
I could not detect the slightest difference between the covered and
uncovered portions of either of the plates.
Another silver plate was iodized and exposed to light. It was then placed
in the dark wish a sensitive plate which had been carefully kept from the
light, 1-16th of an inch above it, and a small engraving placed between
them. They were allowed to remain thus for six hours. When exposed to the
vapor of mercury, the plate which had been subjected to the light whitened
all over, and the space occupied by the engraving was distinctly marked
by lines of vapor thicker than the other parts. The plate which had been
preserved in the dark was scarcely at all influenced by the vapor, except
on those parts which had been touched by the supports of card-board on
which it rested. These were so arranged that no radiation could have
influenced those parts of the plates.
An iodized silver plate was placed in the dark with a little fine string
coiled over parts of it, and a polished silver plate supported 1-8th of an
inch above it. After four hours both plates were subjected to mercurial
vapor. On the iodized plate the deposit of vapor was uniform, although
slight; but on the superposed plate of silver a strong and beautiful image
of the string on the under plate became visible. I found that neither of
the two iodized plates had lost their sensitiveness by the operations to
which they had been subjected in the dark.
Hoping to detect some evidence of the process by which these singular
results were produced, I instituted a series of experiments, of which the
following are some of the most interesting results.
A. A silver plate was iodized, a piece of card was placed upon it, and a
well-polished mercurial plate (amalgamated copper) was suspended 1-8th of
an inch above it, and left in this state for a night. The space on the
silver plate corresponding with the mercurial plate, except under the
card, was nearly freed of its iodine, which had evidently combined with
the mercury on the upper plate. On exposing the mercurial plate to the
vapor of mercury the image of the card was rendered visible, the vapor
covering every part of the plate except that opposite the card. The silver
plate received the vapor only on those parts which were not influenced by
the mercurial plate. The upper plate was suspended by strings; these were
faithfully imaged on both plates; by a thick line of mercurial vapor on
the under plate, by the absence of it in the upper one.
B. An iodized _silvered_ plate was exposed to light until brown, and a
mercurial plate suspended above it for twelve hours. The browned silver
plate was _whitened_, and all the irregularities of the mercurial plate
strikingly marked on it: the mercurial plate was slightly tarnished. On
rubbing the silvered plate it was found that the silver was removed more
readily over the whitened portion, but had lost none of its adhesion in
other parts.
C. Over an iodized silver plate, plates of gold, platina, silver, brass,
copper, copper amalgamated, and zinc were placed at the distance of
1-8th of an inch. After three hours the amalgamated plate had made a
decidedly visible impression on the silver one. On exposure to vapor, the
mercury lodged on every part of the plate except that affected by the
mercurial plate; some irregularities were observed, but none which could
be decidedly traced to the other metals in juxtaposition. I have some
evidence that different metals near each other seriously interfere with
each other's influence.
D. A mercurial plate was iodized, and another mercurial plate placed 1-8th
of an inch above it. The upper plate became covered with a bright yellow
film; and on exposing them to mercurial vapor, marks became apparent which
corresponded with those in the opposite plate.
E. A silver plate was iodized and placed in the dark with an engraving,
face down, upon it. An amalgamated copper plate was laid on this, and
left for fifteen hours. The mercurial plate was reddened, and on exposure
to the vapor of mercury, a very nice impression of the engraving was
brought out, it having been effected through the thickness of the paper.
On the silvered plate the space covered by the paper was well marked;
but vaporization produced no trace of the engraving. The space beyond
the paper was rendered white. It was curious that both plates had
several spots which corresponded, particularly two, distinguished by
a well-defined circle and a comet-like appendage, in length ten times
the diameter of the circle. These spots could not be traced to anything
visible in the print or either of the plates, and must, I think, be
referred to some electrical influence. I find it indeed commonly the
case, that the plates, after being subjected to these kind of experiments
a few times, become mottled, or present on their polished faces all the
appearances of a finely-grained wood, and in this state they are less
susceptible of receiving any impression than when not so.
F. A silver plate was iodized and placed upon an engraving laid on a
brightly polished mercurial plate, and left in the dark for twenty-four
hours. The mercurial plate was turned brown, and the silver plate was left
in the same state as if it had been exposed to sunshine, being _brown and
black_. Neither of these plates gave a copy of the picture.
G. A mercurial plate was iodized, and above it was placed a plate of
polished iron, a disc of paper being first laid on the mercurial plate,
and they were left in this state for some hours. On exposing the iron
plate to mercurial vapor, it was abundantly lodged over that space
opposite the paper disc, but not at all on the other parts. The mercurial
plate was attacked by vapor over every part but that which the paper disc
protected.
Lead and zinc plates were used instead of the iron one, with nearly
similar results.
H. A Daguerreotype was taken, and without removing the iodine a mercurial
plate was placed a little above it, and left for ten hours. When removed,
well-defined traces of the Daguerreotype picture were evident on the
mercurial plate, which leads me to hope that by careful manipulation we
may succeed in multiplying these beautiful productions by an easy method.
I became desirous of ascertaining whether the mercurial plates would
produce any change upon the precipitated iodide of silver. I find by many
experiments, that if the iodide of silver is pure, no more change is
produced than is produced upon it by diffused light; but if it is rendered
sensitive by a trace of the nitrate of silver, it is then darkened as by
solar influence.
Sensitive iodide of silver being placed upon a plate of glass, a mercurial
plate was fixed 1-8th of an inch above it. In three days the iodide of
silver had become a deep brown, almost a black, and the mercurial plate
was covered with the yellow iodide of mercury. Nitric acid dissolved
the dark portion of the silver salt, as did also ammonia, on which was
formed Faraday's oxide of silver, thereby proving the change, either by a
primary or a secondary process, of the iodide into the oxide of silver.
This experiment has been repeated at least a dozen times, and always with
the same results. If a little heap of the iodide of silver is placed
under a mercurial plate, it is exceedingly interesting to witness the
gradual formation of the very beautiful colored rings on the mercury in
the progress of its conversion into an iodide. By prolonged action the
yellow iodide passes into the bright red biniodide of mercury. I have
some experiments now in hand, which convince me that similar chemical
changes are to be effected through considerable spaces. I have succeeded
in decomposing the iodide of copper and the iodide of gold by mercurial
plates placed nearly a quarter of an inch above them.
I have an extensive record of results similar to those I have now
detailed, all of them showing that the changes brought about by this
mysterious agent, whether it be heat, light, or an undiscovered element,
cannot be referred to those rays which the admirable researches of Sir
John Herschel have shown to be the operative ones in producing the
photographic phenomena which have so interested the world by their
novel beauty, and which professor Draper includes within his general
term--tithonicity. With regard to the detithonizing influence of the gases
mentioned by Dr. Draper in his paper in your March number, I can only
consider the results, which I find to be as he has stated, as the simple
reconversion of the decomposed iodide of silver into another definite
chemical compound. An iodized plate is exposed to light, the iodide of
silver or other sensitive salt is decomposed, and in a state to receive
mercurial vapor. It is now passed through an atmosphere of iodine, of
chlorine, of bromine, or of nitrous gas. Chemists are well aware of the
surprising energy with which these bodies attack the metals, consequently
the exposure of a moment is quite sufficient to convert the surface which
has undergone a change, into an iodide, chloride, bromite, or nitrite of
silver. I certainly cannot see the necessity of going so far out of our
way for an explanation of this effect as Dr. Draper has done.
I fear I have already occupied too much of your valuable space, or I might
be inclined to trespass further. I shall, however drop my pen for the
present, again assuring you that I only desire to keep the image of Truth
which is just shadowing our path, as free as possible from mists which
might in any way obscure it.--_Philosophical Magazine_, 1843.
* * * * *
Railroad to the Pacific.--Forest Shepherd, of Sacramento City, says it is
now ascertained almost beyond doubt, that a railroad can be constructed
from the Mississippi to the Pacific, without crossing any mountains, or
meeting more impediment from snow than between Albany and Boston.
* * * * *
=EXPERIMENTS ON THE COLORED FILMS=
=FORMED BY IODINE, BROMINE, AND CHLORINE UPON VARIOUS METALS.=
BY AUGUSTUS WALLER, M. D.
In a paper presented by me to the Academy of Sciences of Paris, an extract
from which may be seen in the _Comptes Rendus_ for October 5, 1840, I
first demonstrated the error committed in ascribing to the iodide of
silver alone the power of fixing the vapors of mercury, after it had been
exposed to the action of light. Instead of this property being exclusively
confined to a film of iodide of silver, as obtained in the process of M.
Daguerre, I found that it existed in many other substances when presented
to the action of light in the state of thin films, viz. by the bromide
and chloride of silver; by the oxide, bromide, iodide and chloride of
copper, and some others; all these, however, possessing less sensibility
than the iodide of silver of Daguerre, and therefore less available for
the reproduction of the images of the camera than the compound originally
discovered by that gentleman. The iodide of Daguerre was found already too
little sensitive to the influence of light in this climate, especially
when applied to the reproduction of the image of animate objects, so that
those films discovered by me seemed still less suitable to be employed
for that purpose; this objection has, however, been completely removed by
recent improvements, more particularly those of M. Claudet, who effected
this principally by combining the original discovery of Daguerre with
those mentioned above as having been subsequently made by myself. Pursuing
the first stage of Daguerre's process, he obtained the film of iodide of
silver, and added to this another film of bromide, either in a simple
state,--as practised in my experiments published more than six months
before--or after two of these substances had been combined together, as
the chloride of iodine and the bromide of iodine, which he was the first
to employ.
These colored films, however, merit attention independently of the
purposes to which they may be applied in photography: the beauty of some
of the phenomena themselves is peculiarly attractive; the numerous changes
of color they undergo, either by a variation in the thickness of the film,
or by the action of light, assign them a place among the most curious
facts of science, and the extreme facility with which they are obtained
adds to the interest they excite.
Impressed with these ideas, I was induced to pursue a train of
investigation on this subject; among the results of which, one of the most
interesting was a new method of making colored rings, like those generally
known under the name of "Newton's colored rings," on many of the metals,
by the same chemical process as that employed for forming the films of
uniform thickness in photography. In order to procure these colored
rings, and at the same time to show the identity of the origin of the
colors with those of the ordinary transparent films, that is, as residing
simply in the thickness of the lamina and not dependent on the ordinary
cause of color, we have but to place a piece of iodine on a well-polished
surface of silver or copper, and in a short time we find around the iodine
a series of colored zones of the various tints of the spectrum, and
approaching in a greater or less degree to the form of a circle, according
as they have been more or less disturbed in their formation by currents
of the surrounding air. In order that they may be perfectly regular, as
large as possible, and with tints undisturbed by the action of light, it
is necessary to place a piece of iodine in the centre of a well-polished
plate, as before described; this is then to be shaded by an opake screen
superimposed a few lines from the surface to cause the vapors which would
otherwise ascend and partially escape, to expand over its silver surface.
Colored rings may be formed in the same manner by bromine and chlorine and
the various combinations of these bodies with each other, except that for
those that are gaseous or liquid it is requisite to pay a little attention
to the manner of disengaging them on the surface of the metal, either by
passing them through a glass tube, or by some other contrivance easy to
execute.
These rings correspond to those formed by reflected light in Newton's
experiments, with this difference, however, that in the colored films of
the soap bubble, and in those formed by the glass lenses, the thinest film
is in the centre; whilst in these rings, obtained by chemical action, it
exists at the circumference, as is the case with the colored rings of
Nobili. In watching the formation of these phenomena, at first are seen
two or three very small circles, which appear almost as soon as the iodine
and the metal are placed in contact with each other; as the experiment
continues, the circumference of these circles become gradually greater;
whilst the external colors extend themselves over a great space, those of
the centre grow fainter; red and green now only remain visible, and these
at last, when the film has attained a certain thickness, in their turn
also give place to a dull coating of brown.
The formation of these rings evidently depends on the vaporization of the
iodine from the solid nucleus. The variety in color and extent of these
zones is caused by the difference between the strength of the vapor at the
centre and the circumference of the iodic atmosphere whilst expanding over
so large a surface. In the metal thus combining with the vapor, we have
to consider,--1, the force of the vapor of different distances from the
centre; 2, the obstacle which a film of iodine, once formed, opposes to
any further action between the iodine and the metal.
This experiment may be varied in different ways: two pieces of iodine
of about the same size, placed at a small distance from each other on a
silver plate, form separate colored circles, until these come in contact
at their circumferences, when the two systems will slowly coalesce and
produce one common outline of the form of an ellipsis.
As the colors formed on various metals by the above-mentioned agents are
very similar to one another, it may be sufficient to examine in particular
those produced on silver by iodine.
The external film of the iodide of silver rings, which corresponds to the
central black spot in those of Newton, is completely invisible, it being
impossible to perceive any difference between the parts so covered and
those where the metal is intact; but by exposing half the plate to the
influence of light, whilst the other part remains covered, the silver is
then found darkened far beyond the limits of the external gold-colored
zone, where previously the surface was perfectly clear. The dark film
thus rendered apparent is now liable to be rubbed off by the slightest
friction, whereas before it was very adherent to the subjacent surface.
The first zone is of a pale gold color, which assumes a deeper tint as
the thickness of the film increases: the second zone is blue, the third
white: after these appear the different colors of the spectrum in regular
succession, as in the films studied by Newton and others, viz. yellow,
orange, red, blue green, yellow &c.
The presence of the golden-colored zone in the place mentioned is worthy
of remark, as in the tables of Newton of the colors presented by films
of various thicknesses, the blue is stated as immediately following the
black. The same gold film is the first which appears on most metals when
their surface is attacked in this manner. Chlorine and bromine on silver;
oxygen on steel; chlorine and bromine on titanium, bismuth, &c., commence
their colors in the same way. Copper, however, is in one respect an
exception, this metal first becoming of a dark red, which increases to a
ruddy brown and then changes into blue. This deviation is fully accounted
for by the color of the copper itself. With this single particularity,
this metal undergoes the same alterations as the others.
The action of light on the different colors of the iodide of silver is
very interesting: the most correct way of studying this is to protect one
half of a system of colored rings by an opake screen, while the other half
is exposed for a short time to the influence of the solar rays. The golden
zone undergoes the greatest change; at first it grows darker, then red,
and at length is converted into a beautiful green. The blue film, which
comes next in thickness, suffers considerable alteration in its tint,
assuming a much deeper and more brilliant shade; the rest of the colors
appear to be similarly affected by the action of light, though to a very
slight degree, acquiring a trifling accession in their brilliancy. It has
already been remarked that light destroys the adherence of the external
invisible film; the same thing obtains with the second or gold-colored
film, which turns green, _but only to a certain depth_ of the film, as may
be proved by slightly rubbing the part thus altered; the green color is
then seen to disappear, and beneath the pulverulent portion thus removed
is found the gold color, having almost the same appearance as before the
plate had been exposed. As this experiment may be repeated several times
with the same results, it shows to how inconceivably small a depth the
light has acted to produce this effect.
To ascertain what would take place on augmenting the thickness of the
portion turned green, and the adherence of which was destroy ed, a piece
of iodine was placed on the plate so that its vapor, by expanding,
might arrive upon the green, at the same time the whole being kept from
the light; the result was that the additional film combined with the
one already existing, producing a blue, being the color which would
have resulted by the combination of the unaltered yellow films. I have
found no chemical substance possessing the power of arresting, or in
any way influencing these changes of color; strong adds, provided they
do not attack the silver--for then, of course, the experiment would be
destroyed,--and alkalies in concentrated solution, allow the action of
light to go on as usual. The hyposulphate of soda, and ammonia in solution
have no longer the power of dissolving the green film as they had before
the action of light.
When the plate is left still longer exposed, after the changes above
stated have taken place, the colors become more faint, and within the
zone of green a white cloudy film is caused by the light, which, as it
increases, veils the spectral colors beneath.
The knowledge we at present possess in chemistry of the affinities with
which different bodies are endowed for combining with each other is but
very imperfect, and the causes which complicate most chemical phenomena
are so numerous, that it is scarcely possible to compare any two chemical
actions to each other. Most of the facts upon which chemical science is
founded, are acquired either by bringing the two bodies destined to act on
each other into contact by dissolving them in a liquid, or by subjecting
them to a temperature more or less elevated.
In the first of these methods, we are so far from being able to calculate
the force of the chemical powers called into play, that Berthollet was
induced to deny the existence of chemical power in the various phenomena
of solution and precipitation of saline substances, and according to him
what is called insolubility in a body is merely the result of its strength
of cohesion, an entirely physical property.
When the intervention of caloric is required, the effects are still more
complicated, as they vary according to the intensity of the heat employed,
and the time its action is exerted; besides, the chemical action, when
it does take place, is frequently so instantaneous that it is impossible
in our present state of science to imagine any means by which it might
be measured. In the combination of the three bodies, iodine, bromine
and chlorine, with the metals, however, most of these objections cease
to exist, or may be easily avoided. As their vapors combine with the
metallic surfaces at the ordinary temperature, they are all of them in
the same circumstances in that respect; and if the temperature should be
required more elevated, the gasiform state of these substances, iodine not
excepted, enables us to submit the metals to be experimented upon all at
the same time to the same influence. If, therefore, it were possible to
reduce the metallic substances into fine powders the particles of which
were of the same dimensions, by acting upon them with either of these
vapors, an idea might be formed of the affinities which produce their
binary compounds by the increased weight acquired by the powders in this
process; but the difference which exists in the physical properties of
the various metals would preclude the possibility of any near approach
to accuracy in this mode of proceeding; but by acting on the polished
metallic surfaces, as in the preceding experiments, all the advantages
offered by the process with the powders are included, whilst several of
the difficulties are removed.
As the film of the compound augments, it undergoes the various changes of
color which take place in all transparent films, thus affording a means of
ascertaining the absolute thickness obtained in different circumstances,
when it would be difficult to detect the slightest difference in weight
by means of the most delicate balance. The depth of this coating may be
ascertained when either the index of refraction of the compound itself is
known, or if the angle of polarized light is given by means of the law
discovered by Sir David Brewster, between the tangent of the angle of
polarization, and the index of refraction. The most convenient way which
occurred to me of performing these experiments, was the employment of a
bell-glass within which some iodine is fixed at the top; this apparatus
being placed over the metal to be acted on, the experiment may be watched
in all its progress, and the action can be retarded or accelerated at
pleasure by varying the interval of the iodine from the metal, or by
interposing at some distance from its surface a disc of paper so as to
cause the vapors of iodine to pass through it. Bromine may be made use of
likewise by pouring a few drops of it over some carded cotton, and using
it in a similar manner with the iodine. In respect to chlorine, it is most
convenient to disengage it slowly by dropping a little sulphuric acid upon
some chlorinated lime.
In illustration of the objects of this mode of experimenting, I will
aduce some of the results it has given me with various metals. Some of
the experiments below were performed before I had the idea of watching
the progress of the combination through a transparent medium; they are
therefore less exact than they might otherwise have been: but I have
preferred stating them as I had inserted them in my note-book before I
had conceived any idea as to their probable utility in the elucidation of
chemical affinity, and when I intended them for other purposes, which I
shall hereafter explain.
_Iodine with Silver and Copper._
1st change. Silver--pale gold.
" Copper--assumes a darker red.
" Silver--blue.
2nd do. Copper--blue.
" Silver--white.
3rd do. Copper--white.
" Silver--yellow.
4th do. Copper--yellow more extended than on the silver.
" Silver--Orange.
5th do. Copper--Red.
" Silver--blue, bluish-red.
" Copper--red, with a tinge of green on some parts.
" Silver--greenish blue.
" Copper--red, tinged with green.
" Silver--green.
" Copper--orange.
" Silver--yellowish green.
" Copper--orange tending to red.
" Silver--yellowish green.
" Copper--orange-red.
" Silver--red.
" Copper--dull green.
" Silver--red.
" Copper--green.
" Silver--deep green.
" Copper--dull red.
_Bromine with Silver and Copper._
5th change. Copper--sensibly darkened.
" Silver--unchanged.
" Copper--deep red.
" Silver--unchanged.
" Copper--red, blue.
" Silver--pale gold.
" Copper--white, orange of the 2d order.
" Silver--yellow.
" Copper--green of the 1st order, red 3rd order.
" Silver--blue.
_Chlorine with Silver and Copper._
The affinity of chlorine with silver is much inferior to that which it
possesses for copper.
_Iodine with Titanium._
Iodine at the common temperature has no action upon this metal.
_Bromine with Titanium._
Bromine, when the surface of this substance is perfectly dry, has no more
action upon it than iodine; but if it have a slight coating of moisture,
as is formed by merely condensing on it the vapor of the breath, the
colored films are formed without difficulty by the vapors of bromine.
Their appearance is the same as those of the iodide of silver, viz. gold,
deep gold, blue, white, yellow, orange, red, &c.
_Chlorine with Titanium and Copper._
Titanium has a stronger affinity than it has for either of the preceding
vapors. The combination takes place when the metallic surface is either
dry or moist.
Copper--much reddened.
Titanium--not affected.
Copper--passed through several of the spectral orders of red and green
until it arrived at almost its last changes of colors.
Titanium under the same action received a dull film, which viewed
obliquely showed red, green, yellow.
Silver, exposed to the same influence as the two former, had yellow in the
centre and blue more externally.
_Iodine with Bismuth and Silver._
Silver--pale gold.
Bismuth--some parts yellow, others not attacked.
Silver--blue, white, yellow-orange.
Bismuth--blue, yellow, orange.
In the action of iodine on bismuth, the influence of the physical
condition of metallic surface is very manifest. The crystaline texture of
this metal may be perceived, and the difference of its hardness admits,
to a certain point, of being measured by the difference of the color of
the films that are formed on various points; while most parts are yellow,
there exist others of an angular outline which remain still unattacked;
the same difference is remarked in the other stages of the combination.
_Iodine with Mercury._
It is impossible to estimate the affinity between mercury and iodine by
means of the colored films, because, on combining, these two substances
merely cause a dirty white appearance on the surface of the latter.
Their combining affinity appears to be considerable, for when exposed
together with silver the action produced with both was red at the edges,
little altered in color; on the rest of its surface a dull white film,
in the midst of which were seen several dark spots, where the metal was
apparently unaltered.
_Bromine with Mercury and Copper._
1st. Mercury--gold color.
" Copper slightly darkened.
2nd. Mercury--blue.
" Copper dark red.
3rd. Mercury--green on some parts.
" Copper white.
After this the copper underwent its usual changes of color on prolonging
the action of the vapor of bromine, but the color of the mercury suffered
no further change.
_Chlorine with Mercury and Copper._
Mercury--a slight film.
Copper no alteration of color.
Mercury--deep gold color.
Copper deep red on some parts, blue on others.
Mercury--red tinged with blue.
Copper blue, white.
Mercury--blue.
Copper same as before.
"With respect to the bromide and chloride of mercury, it is necessary
to view them obliquely in order to perceive all the changes of color
they undergo; for if looked at perpendicularly, there is seen on both
a dull uneven film of white which reflects none of the above colors:
consequently, to avoid any error, the copper must be inspected under the
same angle.
_Bromine with Bismuth and Silver._
Silver--pale gold.
Bismuth--not apparently changed.
Silver--deep gold, blue.
Bismuth--yellow, blue.
Silver--blue, yellow.
Bismuth--dull colorless film.
_Chlorine with Bismuth and Silver._
Bismuth is slowly attacked with chlorine gas, much in the same way as with
iodine and bromine in vapor.
_Bromine with Lead._
At the common temperature neither bromine nor chlorine forms colored films
upon this metal, which it is very difficult besides to bring to any high
state of polish on account of its softness. But when lead is heated, as
over the flame of a spirit-lamp, the vapors of bromine then form very fine
colored films, which are in succession gold, deep blue, &c.
_Iodine with Iron._
These two may be made to form colored films when combined rapidly
together, but generally a dull coating without any spectral color is
obtained, on account of the deliquescence of that salt.
Until we know the index of refraction of the different films enumerated,
it would be impossible to give a correct table of the combining powers
in the experiments that have been detailed; nor is the table of the
relative thickness of transparent plates as it has been transmitted to
us by Newton, sufficient in the present instance, if any great degree of
precision be required. Besides these objections, it is necessary before
leaving this subject to pass in review several others inseparable from the
mode of performing the experiments themselves. The principal circumstances
complicating these experiments and liable to vary in different
observations, are,--
First, the hardness of the metal acted upon; 2ndly, the obstacle opposed
to the continuation of chemical action by the inert film formed upon the
metal; 3rdly, the force of the vapors that attack the metal. The influence
of the texture of the metallic surface on chemical action is most evident
when bismuth is the metal employed. Here the chemical action may be
seen to commence on small isolated portions of the surface, which have
already assumed a deep gold color, before other parts are in the least
changed, from the natural appearance of the metal. To determine how far
this might influence the formation of the iodide of silver, a silver coin
was exposed to iodine with a piece of pure silver; as the former was so
much the harder of the two, it was naturally supposed that the chemical
action would be slower in exerting itself on it than on the latter. This,
however, was not the case, as may be seen by the following statement of
the result of the experiment:
Silver coin--pale gold color.
Pure silver--pale gold.
Silver coin--deep gold.
Pure silver--deep gold.
Silver coin--light blue.
Pure silver--light blue.
Silver chin--yellow.
Pure silver--blue, white, yellow not visible.
Silver coin--yellow, red at edges.
Pure silver--yellow, no red edges.
Silver coin--red, blue at edges.
Pure silver--yellow, no red apparent.
The intensity of the resistance offered by the different films of iodide
of silver to a continuation of the chemical combination, may be determined
by noting the moment at which the various spectral tints make their
appearance.
Color of the film of iodide of silver.
' "
0 50--beginning to darken.
2 0--pale gold.
4 40--deep gold.
6 40--orange blue.
7 30--blue.
9 30--light blue.
11 30--commencement of yellow.
18 30--orange red.
20 15--blue.
22 55--deep blue.
24 40--green.
28 0--yellowish green.
30 25--ruddy brown.
40 10--green.
46 30--green.
50 10--red.
53 15--green.
By comparing the thickness of the colors with the space of time required
for their production, it will be found, however imperfect the table given
by Newton may be when applied to this subject, that towards the end of
the experiment above given, the chemical combination is retarded by the
presence of the inert film, and that to obtain the same thickness of film
as at the commencement, about double the time is required.
The third cause of error may be avoided by operating with vapors of about
the same force. In those described, the average time employed in passing
to the maximum was generally about half an hour; if that were not taken
into consideration, different results might be obtained.
In regard to chlorine, there exists another cause of complication--the
affinity which it possesses for water; for when disengaged in the ordinary
manner, chlorine carries with it a certain quantity of water which may
very much alter the results of the experiment.--_Philosophical Magazine,_
1842.
* * * * *
=THE AMERICAN ELECTRIC TELEGRAPH.=
In each of the countries of Europe where the Electric Telegraph is
established, viz.: Britain, France, Germany, and Russ a, the people seem
anxious to claim for one or more of their own countrymen some merit
in connection with the invention. The English speak of Wheatstone and
Bain; the French of Le Sage; the Germans of Steinheil and Siemen; and
the Russians of Schilling or Jacobi. Most of these inventors have their
agents or representatives in different countries, ready on every suitable
occasion to speak or write in behalf of their principal.
The inventor of the American Electric Telegraph has, we believe, no
agent in Europe; and no person there who has any special interest in
promoting the introduction of his system. The adoption of it by the
Prussian government for great distances, as decidedly the best which it
could obtain, after advertising extensively in Europe, is, therefore,
the more remarkable; and especially, as the only knowledge which the
Prussians possess of the American system seems to have been derived from
one imperfectly acquainted with its powers; for we can account in no other
way for the fact that Siemen's needle apparatus is adopted for short
distances; Morse's instruments being clearly superior to Siemen's, or to
any other needle apparatus, for short as Well as for long distances; since
they are much more rapid in their motion, and have, besides, the advantage
of making a permanent record on paper, instead of merely indicating to the
eye by an evanescent sign. No one using the telegraph in America, would
think of employing a needle apparatus in any of its operations.
In addition to the evidence of the high estimation of the American
Telegraph by Europeans, furnished by this adoption of it in Prussia,
we learn also from an elaborate work on Telegraphs by Dr. H. Schellen,
recently published in Dusseldorf, that it is now introduced into other
countries on that continent. Dr. S. says: "Of late the Morse Telegraphs
are much used in Europe, viz: in England; between Hamburg and Cuxhaven;
between Bremen and Bremer-haven; in Prussia, Austria, Bavaria and
Hanover." Dr. S. might have added also that it is used in Turkey. Among
the advantages of the American Telegraph, Dr. S. says, is its "quickness
in making and marking the signs upon paper. * * * _It records under the
hand of a skilful operator 100 to 120 letters, in the same time in which
the best needle telegraphs are able to indicate 20._"
While the superiority of the American Electric Telegraph to all others is
thus acknowledged by Europeans, they do not seem to be aware that the date
of the American invention is also prior in point of time to that of any of
their own electric telegraphs. They very naturally regard the date of the
patent as the date of the invention, because in every country in Europe
the patent is given to the person who first promulgates the invention in
that country; and it is not safe, therefore, in Europe, for an inventor to
permit others to know any thing of his invention until he has patented it.
But in America, where the law permits no one to take out a patent but the
inventor, he is perfectly safe in communicating the knowledge of what he
has done, and even in publicly exhibiting his invention, before he takes
out his patent, provided he secures himself by a caveat, and does not
offer it for sale, or permit it to go into common use.
The inventor of the American Electric Telegraph, it is well known,
exhibited his instruments in operation in the N. Y. University, in the
presence of hundreds of our citizens in September, 1837, and privately to
his friends at various times as far back as November 1835, although his
first patent was not secured until 1838. No one claims for the inventions
of either Wheatstone or Steinheil a date prior to 1837; and when European
writers on the telegraph come to understand our laws, and the error into
which they have fallen, by confounding the date of the American invention
with the patent, they will no doubt do our country the justice to admit
its claims to priority as well as to _superiority_.--_N. Y. Observer._
* * * * *
Iron Pavement.--Iron is daily coming into more general use for almost
every purpose. A letter from Paris, of a late date says:
"A new pavement, to upset the Macadam and other inventions of the kind,
has been proposed by Mr. Tobard, who intends paving, in this way, the
streets and boulevards of Paris. This gentlemen has proved, by figures,
that melting iron is only worth 11 francs in Paris, 7 francs in Belgium,
and 4½ francs by 100 kilogrammes in England, whilst the stone costs 25
francs in London, 15 francs in Paris, and 8 and 10 francs in Belgium. This
new mode of pavement will be grooved, in order not to become slippery, and
it is said that the electricity occasioned by the rolling of the carriages
will prevent rust. Here is a new field open to industry."
CLAUDET'S SPECIFICATION.
Sealed 21st November, 1843.
We give the following as copied at the Patent Office in London. Many of
our Daguerreotypists have enquired of us in relation to the patents on the
Daguerreotype in England.
To Autoine Jean Claudet, of High Holborn, in the county of Middlesex,
glass merchant, for an invention of improvements in the process and
means of obtaining the representation of objects of nature and
art,--being a communication. [Sealed 21st November, 1843.]
These improvements consist in rendering the Daguerreotype picture
susceptible of producing, by printing, a great number of proofs or copies;
thereby transforming it into a complete engraved plate.
The process is established on the following facts, which have come to the
knowledge of the inventor:--
1st. A mixed acid, composed of water, nitric acid, nitrate of potassa, and
common salt, in certain proportions, being poured upon a Daguerreotype
picture, attacks the pure silver, forming a chloride of that metal, and
does not effect the white parts, which are produced by the mercury; but
this action does not continue long. Then, by a treatment with ammonia
(ammonia containing already chloride of silver in solution, is preferable
for this operation), the chloride of silver is dissolved, and washed
off, and the metal being again in its naked state, or cleansed from the
chloride, it can be attacked afresh by the same acid. This acid acts
better warm than cold.
2d. As all metallic surfaces are soon covered (when exposed to the
atmosphere) with greasy or resinous matters, it is necessary, in order
that the action of the acid upon the pure silver should have its full
effect, for the surface to be perfectly purified; this is effected by the
employment of alcohol and caustic potash.
3d. When a Daguerreotype picture is submitted to the effects of a boiling
concentrated solution of caustic potash, before being attacked by the
acid, the state of its surface is so modified that the acid spares or
leaves, in the part which it attacks, a great number of prints, which form
the grain of the engraving.
4th. When the effects of the acid are not sufficient, or, in other words,
it is not bitten deep enough, the effect is increased by the following
process:--Ink the plate as copper-plate printers do, but with a siccative
ink; when the ink is sufficiently dry, polish the white parts of the
plate, and gild it by the electrotype process; then wash it with warm
caustic potash, and bite it in with an acid, which will not attack the
gold, but only the metal in those parts which having been protected by the
ink, have not received the coating of gold. By these means the engraving
is completed, as by the acid alone it is not generally bitten in deep
enough.
5th. To protect the plate from the effects of wear, produced by the
operation of printing, the following process is employed: The surface of
the plate is covered with a thin coating of copper, by the electrotype
process, before submitting it to the operation of printing; and when
that pellicle or coating of copper begins to show signs of wear, it
must be removed altogether, by plunging the plate in ammonia, or in a
weak acid, which, by electro-chemical action, will dissolve the copper,
without effecting the metal under it; the plate is then coppered again,
by the same means, and is then ready for producing a further number of
impressions. This re-coating operation may be repeated as many times as
may be required. The following is the description of the whole process,
which is divided into two parts, consisting of a preparatory and printing
process.
_Preparatory Engraving._--For this operation which is the most delicate,
it is necessary to have--1. A saturated solution of caustic potash. 2.
Pure nitric acid at 36° of the barometer of Beaumé (spec. grav. 1·333).
3. A solution of nitrate of potassa, composed of 100 parts of water, and
5 parts of nitrate, by weight. 4. A solution of common salt, composed
of water 100 parts, and salt 10 parts by weight. 5. A weak solution of
ammoniacal chloride of silver, with an access of ammonia. The ammoniacal
chloride of silver must be diluted with 15 or 20 parts of pure water. In
the description of the process, this solution will be called ammoniacal
chloride of silver. 6. A weak solution of ammonia, containing 4 or 5
thousandths of liquid ammonia. This solution will be called ammoniacal
water. 7. A weak solution of caustic potash, containing 4 or 5 thousandths
of the saturated solution, which will be called alkaline water. 8. A
solution composed of water 4 parts, saturated solution of potash 2 parts,
alcohol 1 part, all in volume. This solution will be called alcoholized
potash. 9. Acidulated water, composed of water 100 parts, and nitric acid
2 parts, in volume. Besides, it is necessary to have three capsulæ or
dishes, made of porcelain, large enough to contain the plate, and covered
with an air-tight piece of ground plate glass, and two or three more
capsulæ, which do not require to be covered; two or three glass funnels,
to wash the plate; and two or three glass holders, in the shape of a spoon
or shovel, by which the plate is supported when put in and taken out of
the solution, without touching it with the fingers.