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written as it were in bubbles of gas. Hence, as he shows, we have the cause of the effervescence produced by the immersion of a piece of bread in champagne. This curious subject has been recently studied by M. Ludwig Moser of Berlin, who has arrived at several very important conclusions, which our limits prevent us from giving, otherwise than in the following abbreviated form :

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to the surface, under certain conditions, | images may be formed upon the traces of remains there for a long time. "During words by gaseous bodies-the letters being the cold weather," says Dr. Draper, "last winter (1840-1841) I, produced such an image on the mirror of my heliostate: It could be revived by breathing on the metal many weeks afterwards, nor did it finally disappear until the end of several months." Dr. Draper has also shown that a series of spectra may co-exist on a phosphorescent surface (sulphuret of lime), and after remaining latent for a length of time, will come forth in their proper order on raising If the surface of a solid body has been the temperature of the surface. Place a touched in any particular part by anokey, for example, on a phosphorescent sur-ther body, it acquires the property of face, and make that surface glow by a gal- precipitating on the touched part all vapors vanic discharge between charcoal points for which adhere to it, or which combine two or three minutes-the image of the key chemically with it, differently from what it will of course be seen after removing it. If does on the untouched part. the surface, kept in the dark for a day or This result was obtained with all bodies two, be now inspected, no image will be such as glass, metals, resins, wood, pastevisible, but when laid upon a piece of warm board, &c., and in order to produce the iron a spectral image of the key will be effect absolute contact was not necessary; seen. Take a similar plate similarly im- a shilling held above mercury and then pressed by a key, but whose image has not breathed upon gave the image of the shilbeen involved, and having set before the ling, as when it was laid upon a plate of surface another object, such as a metallic glass and subsequently breathed upon. ring, discharge at a short distance a Leyden Mercurial vapor, and that of iodine, acted jar. The phosphorus will shine all over exactly like the vapor of water. except on the portion shaded by the ring. phenomenon of the Daguerreotype was proThis image of the ring soon disappears to-duced without the intervention of light, for tally; but if the plate is set upon a piece the experiments were equally successful by of warm iron it will speedily begin to glow, night as by day, and consequently "conthe image of the ring will be first reproduced, tact is capable of imitating the action of and as it fades away the spectral form of the light." key will gradually unfold itself, and then

vanish.

Hence the

After

After showing, by experiment, that “the violet rays continue the action commenced Invisible traces of written words have by contact," he examines the action of light been rendered visible in several curious upon plates of silver, copper, and glass. phenomena of crystallization. Dr. Draper A clean and highly polished plate of observed, that if we draw a line on the silver, having a pattern cut out of paper interior of a glass-receiver containing cam-suspended over it, without touching it, was phor, and if we expose the receiver to the sun after it is exhausted of its air, the line described will be stellated with crystals of camphor. If we make a solution of a few grains of sulphate of magnesia, and three of carbonate of ammonia, in an ounce and a half of water-or, what Dr. Waller prefers, of ten grains of phosphate of soda instead of the sulphate of magnesia-and spreading this solution upon a plate of glass (or upon quartz or agate), write with a pen upon the glass, the words will become visible (by the deposition of crystals,) both on the glass and on the surface of the fluid! Dr. Waller, to whose interesting paper we refer our readers-(Phil. Mag., Feb., 1846, vol. xxviii., p. 94)-has shown that similar

exposed to the sun for some hours.
being cooled, it was held over mercury
heated to about 60° of Reaumur, when a
clear image of the pattern was produced by
the mercurial vapor." From these, and
other experiments, Moser concludes, "that
light acts on all bodies; and that its influ-
ence may be tested by all vapors that ad-
here to the surface or act chemically upon
it ;" and that "the same modification is
produced upon plates when vapors are con-
densed, as when light acts upon them."
M. Moser has endeavored to explain these,
and various other phenomena, on the hypo-
thesis "that every body is self-luminous,
and emits invisible rays of light," and that
when two bodies are sufficiently approxi-

mated, they reciprocally depict each other The heat must on no account be so great as to by means of the invisible rays which they volatilize the mercury."-Phil. Mag., vol. xxi., p. 467.-Researches, p. 237.

emit.

vapor

of which attacks the white

The plate is then placed in a mercury box, the parts of the copy, and gives a faithful but indistinct image. It is then exposed to the free from mercury, and by blackening them vapor of iodine, which attacks the parts gives a perfectly black picture.

M. Knorr has shown that these images of vapor, and simply by the action of heat. may be produced without any condensation The copper-plate is heated to the degree at which it begins to change color, and the plates and medals withdrawn, distinct when the spirit-lamp is extinguished, and impressions of them are found penetrating to a considerable depth into the surface of

the metal.

Mr. Hunt, who dissents from this hypothesis, has described several experiments in which the phenomena are produced by heat, and he has given the name of Thermography to this process of copying engravings on metallic plates, regarding the phenomena, "if not directly the effect of a disturbance of the latent caloric, as at least materially influenced by the action of heat." Mr. Hunt placed on a well-polished copperplate a sovereign, a shilling, a large silver medal, and a penny, and when the plate had been gently warmed by a spirit-lamp, cooled, and exposed to the vapor of mercury, each piece left its impression, the sovereign and the silver medal being most distinct, and the lettering in each copied. A bronze medal gave its picture, though placed th Dr. Karsten of Berlin has obtained still of an inch above the plate. When the copper-plate was made too hot to be hanmore interesting results by the agency of dled, it gave impressions in the following upon a glass-plate, and this plate upon a common electricity. If a medal is placed order of intensity, gold, silver, bronze, cop-metallic one, and if the medal is subjected per, the mass of the metal materially influencing the result, and the impressions from of the medal, capable of being developed to discharges of electricity, a perfect image the gold and silver being permanent. The by mercury or iodine, will be received upon heat of the sun's rays produced analogous the glass; and if several glass plates are effects, the calorific rays alone influencing interposed between the medal and the the result. In this way Mr. Hunt copied metallic-plate, an image of the medal will printed pages and engravings on iodized be formed on the upper surface of each of paper, by mere contact and exposure to the plates of glass. heat, and he found that this could be done even at considerable distances between the object and its copy. By amalgamating the surface of the paper according to the following process, he was at length enabled to copy from paper line-engravings, wood-aqueous vapor. cuts, and lithographs, with surprising ac

curacy.

"A well polished plate of copper is rubbed over with the nitrate of mercury, and then well washed, to remove any nitrate of copper which may be formed; when quite dry, a little mercury, taken upon soft leather or linen, is well rubbed over it, and the surface washed to a perfect mirror. The sheet to be copied is placed smoothly over the mercurial surface, and a sheet or two of soft clean paper being placed upon it, it is pressed into equal contact with the metal by a piece of glass or flat board. In this state it is allowed to remain for an hour or two The time may be considerably shortened by applying a very gentle heat for a few minutes to the under surface of the plate.

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which we have been considering arise from M. Fizeau is of opinion that the images slight layer of organic matter, volatile, or at least capable of being carried off by Professor Grove has David Brewster, having succeeded in formadopted the same general view, and Sir ing very fine pictures upon glass, by the entrance of nitrate of silver into its pores, regards all these images as the result of the absorption of matter, emanating from one body and received into the pores of another. Hence he has been led to the following general conclusions:-"That all bodies throw off emanations in greater or less abundance, in particles of greater or less size, and with greater or less velocities-that these particles enter more or less into the pores of solid and fluid bodies, sometimes resting near their surface, sometimes effecting a deeper entrance, and sometimes permeating them altogether-that the pro

differences of temperature-by great heat*

See Transactions of the Cornwall Polytechnic So-jection of these emanations is aided by ciety, 1842. London and Edinburgh Philosophical Magazine, October, 1840, and December, 1842, vol. xxi., p. 462, and Researches, &c., p. 223.j

* The colored films produced upon steel and

-by vibratory action-by friction-by | tered by power, consecrated by piety, and electricity, in short, by every cause which hallowed by affection, their choicest proaffects the forces of aggregation, by which ductions have been preserved by the libethe particles of bodies are held together; rality of individuals, and the munificence of and that these emanations, when feeble, kings-while the palaces of sovereigns, the show themselves in the images of Fusinieri, edifices of social life, the temples of religion, Draper, Hunt, Moser, Fizeau, Knorr, Kar- the watch-towers of war, the obelisks of sten, and Zantedeschi"-when stronger, in fame, and the mausolea of domestic grief, certain chemical changes which they pro- remain under the blue cupola of nature's duce-when stronger still, in their action museum, to attest by their modern beauty, on the olfactory nerves, causing smell, and or their ruined grandeur, the genius and when thrown off most copiously and rapidly, taste of their founders. To the cultivation in heat, affecting the nerves of touch-in and patronage of such noble arts, the vanity, photogenic action, dissevering and re-com- the hopes, and the holiest affections of bining the elements of matter, and in phos- man stand irrevocably pledged; and we phorescent and luminous emanations, ex- should deeply deplore any invention or disciting the retina and producing vision." covery, or any tide in the nation's taste, Before we conclude this part of our sub-which should paralyse the artist's pencil, or ject, we must give a brief notice of a very remarkable invention of M. Martens, by which an extensive panoramic view, amounting even to an angle of 150°, may be taken by the Daguerreotype. The object-glass is fixed upon a pivot, and put in motion by an endless screw, so as to present a narrow aperture in front of it, in succession, to the landscape or group of figures to be copied. When the long iodized plate, curved cylindrically, is placed in the apparatus, the cover is taken from the object-glass, and the handle is turned slowly and steadily round, slowly when a dark object is in the field, and quickly when a luminous object is there. By means of a common achromatic object-glass, one inch and four-tenths in diameter, views have been produced thirty-three sister arts shall simultaneously adeight centimetres long and twelve wide; and these views, one of which we have seen, are as perfect as if they had been taken by the common camera.

Having thus given our, readers a brief account of the history and processes of the two sister arts which constitute photography, we must now endeavor to estimate the advantages which they have conferred upon society, and which may yet be expected from their future progress. The arts of architecture, sculpture, and painting, have in every age called into exercise the loftiest genius and the deepest reason of man. Fos

other metals by heat are obviously the material radiations from the metal uniting with the oxygen of the atmosphere.

* Professor Zantedeschi, of Venice, has shown that metals pass into a radiant state-are reflected like light and heat, and return into a concrete state in virtue of chemical affinity.-Ricerche Fisico

chimico Fisiologiche sulla Luce, chap. iv. Venezia.

1846. Folio.

stay the sculptor's chisel, or divert into new channels the genius which wields them. Instead of superseding the arts of design, as some have feared, photography will but supply them with new ideas-with collections of costume, with studies of drapery and of figures, and with scenes in life and nature, which, if they possess at all, they possess imperfectly, and without which art must be stationary, if she does not languish and decline. Sentiments analogous to these have been more professionally expressed by M. Delaroche, a distinguished French artist, and we believe also by Mr. Eastlake, the highest authority in England; and if a new era be now seen in our horizon, with all the promise of an auroral dawn, in which the

vance to perfection, it will be by the agency of photography-importing nature herself into the artist's studio, and furnishing to his imagination an exuberance of her riches.

In sculpture, advantage has not yet been taken of the peculiar help which is offered to her by photography. All the elements of statuary, and all the forms and proportions of a living figure, may be obtained from a number of azimuthal representations, or sectional outlines, taken photographically: and by means of a binocular camera, founded on the principle of Mr. Wheatstone's beautiful stereoscope, two of these azimuthal sections may be combined into a solid, with all the lights and shadows of the original figure from which they are taken. Superficial forms will thus, at his command, stand before the sculptor in three dimensions, and he may thus virtually carry in his portfolio the Apollo Belvidere and the gigantic Sphynx, and all the statuary of the Louvre and the British Museum.

or the "shepherd's fold."* But though it is only Palestine in desolation that a modern sun can delineate, yet the seas which bore on their breast the divine Redeemer, and the everlasting hills which bounded his view, stand unchanged by time and the elements, and, delineated on the faithful tablet, still appeal to us with an immortal interest †

But while the artist is thus supplied with every material for his creative genius, the public will derive a new and immediate advantage from the productions of the solar pencil. The homefaring man, whom fate or duty chains to his birth-place, or imprisons in his fatherland, will, without the fatigues and dangers of travel, scan the beauties and wonders of the globe, not in the fantastic or deceitful images of a hurried But the scenes which are thus presented pencil, but in the very picture which would to us by the photographer have not merely have been painted on his own retina, were the interest of being truthful representahe magically transported to the scene. tions: they form, as it were, a record of The gigantic outline of the Himalaya and every visible event that takes place while the the Andes will stand self-depicted upon his picture is delineating. The dial-plate of borrowed retina-the Niagara will pour out the clock tells the hour and minute when it before him, in panoramic grandeur, her was drawn, and with the day of the month, mighty cataract of waters-while the flam- which we know, and the sun's altitude, ing volcano will toss into the air her clouds which the shadows on the picture often supof dust and her blazing fragments.* The ply, we may find the very latitude of the scene will change, and there will rise before place which is represented. All stationary him Egypt's colossal pyramids, the tem-life stands self-delineated on the photoples of Greece and Rome, and the gilded graph: The wind, if it blows, will exhibit mosques and towering minarets of Eastern its disturbing influence-the rain, if it falls, magnificence. But with not less wonder, and will glisten on the housetop--the still with a more eager and affectionate gaze, will clouds will exhibit their ever-changing he survey those hallowed scenes which faith forms-and even the lightning's flash will has consecrated and love endeared. Paint-imprint its fire-streak on the sensitive taed in its cheerless tints Mount Zion will blet. stand before him "as a field that is ploughed," Tyre, as a rock on which the fisherman dry their nets-Gaza, in her prophetic "baldness"-Lebanon with her cedars prostrate among the "howling firs;" -Nineveh "made as the grave," and seen only in the turf that covers it ;--and Babylon the Great, the Golden City, with its impregnable walls, its hundred gates of brass, now sitting in the dust," cast up as an heap," covered with "pools of water," and without even the "Arab's tent"

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To the physical sciences Photography has already made valuable contributions. Mr. Ronalds, Mr. Collen, and Mr. Brooke have, with much ingenuity, employed it at Kew and at Greenwich to record the variations of meteorological and magnetical instruments in the absence of the observer, and Mr. Brunel has Daguerreotype pictures taken of the public works which he is carrying on, at stated times, so as to exhibit their progress, and give him as it were a power of superintendance without being personally present. Sir John Herschel and other philosophers have obtained from photography much important information respecting the properties of the solar spectrum, and Dr. Carpenter has applied it with singular success in executing beautiful

An accomplished traveller, who ascended Mount Etna in order to take Talbotype drawings of its scenery, placed his camera on the edge of the crater, in order to get a representation of that interesting spot. No sooner was the camera fixed, and the sensitive paper introduced, than a partial eruption took place, which drove the traveller from his camera in order to save his life. When the eruption ceased, he returned to collect the fragments of Dr. Keith has brought home with him from the his instrument, when, to his great surprise and de- Holy Land, about thirty Daguerreotypes of its most light, he found that his camera was not only unin-interesting scenery, executed by his son, Dr. George jured, but contained an excellent picture of the crater and the eruption!

The drawings in the Excursions Daguerriennes, taken from the sun-pictures in the splendid gallery of M. Lerebours, contain 114 plates, representing scenes and public buildings in America, Algeria, England, Egypt, France, Spain, Italy, Greece, Russia, Sardinia, Sweden, Switzerland, Savoy, Nubia, Syria, and Palestine.

Keith, and which are now engraving for publication. Since this note was printed, we have received, and now have before us, fourteen of these beautiful engravings, representing Mount Zion, Tyre, Petra, Hebron, Askelon, Gerash, Cesarea, Ashdod, and other interesting places.

† See Lond. and Edin. Phil. Magazine, Feb., 1846, vol. xxviii., p. 73; and Phil. Trans., 1847, pt. 1., pp. 59, 69, and 111.

drawings of objects of natural history, as | likeness, which to the filial and parental exhibited in the solar microscope. heart must become a precious possession.

If the solar pencil fails in its delineations These observations, which apply princiof female beauty, or of the human counte- pally to the Talbotype, were at one time nance when lighted up with joy and glad- especially applicable to the Daguerreotype ness, or beaming with the expression of portraits, when the sitter sat long, and feeling or intelligence, it yet furnishes to when a pallid whiteness characterized all its the domestic circle one of its most valued productions. The improvement of the art, acquisitions. The flattering representa- however, in the shortness of the sitting, in tions of the portrait-painter, which delight the tone of light and shadow, and the prous for awhile, lose year after year their like- cess of coloring the picture, has been so ness to the living original, till time has ob- great that the Daguerreotype portraits literated the last fading trace of the resem- have all the beauty of the finest miniatures, blance. The actual view of the time-worn and are at least faithful if not flatterreality overbears the recollection of early ing representations of female beauty.* beauty, and the work of the painter, though The Talbotype will, we doubt not, make it be a valuable production of art, has lost its domestic charm. In the faithful picture by the sun, on the contrary, time adds but to the resemblance. The hue of its cheek never grows pale. Its unerring outline changes neither with age nor with grief, and the grave and sombre, and perchance un- countenance.† gainly, picture grows even into a flattering

the same start towards perfection; and when a fine grained paper shall be made, and a more sensitive process discovered, we shall have Talbotype portraits the size of life, embodying the intellectual expression as well as the physical form of the human

From Tait's Magazine.

FEMALE AUTHORS.-No. II.

MRS. ELIZABETH BARRETT BROWNING.

BY GEORGE GILFILLAN.

IN selecting Mrs. Hemans as our first spe-, more? Secondly, because the premise is cimen of Female Authors, we did so avowedly, because she seemed to us the most feminine writer of the day. We now select Mrs. Browning for the opposite reason, that she is, or at least is said by many to be, the most masculine of our female writers.

To settle the respective spheres and calibres of the male and the female mind is one of the most difficult of philosophical problems. To argue, merely, that because the mind of woman has never hitherto produced a "Paradise Lost," or a (( Principia," it is therefore for ever incapable of producing similar masterpieces, seems to us unfair, for various reasons. In the first place, how many ages elapsed e'er the male mind realized such prodigies of intellectual achievement? And do not they still stand unparalleled and almost unapproached? And were it not as reasonable to assert that man as that woman can renew them no

granted-that woman has not-does the conclusion follow, that woman cannot excogitate an argument as great as the "Principia," or build up a rhyme as lofty as the "Paradise Lost?" Would it not have been as wise for one who knew Milton only as the Milton of "Lycidas" and "Arcades," to have contended that he was incapable of a great epic poem? And is there nothing in Madame De Stael, in Rahel the Germaness, in Mary Somerville,

* As examples of the perfection of Engravings from Daguerreotype portraits, we may mention those of the Duke of Wellington and Dr. Chalmers, from Daguerreotypes executed by M. Claudet.

† Our scientific readers will find a very interesting section on the literature of the chemical rays, Litterratur der chemischen lichtstrahlen, by Dr. Karsten, in the Fortschritt der Physik im Jahre 1845: Dargestellt von der physikalischen Gesellschaft zu Berlin. Redigirt von Dr. G. KarSTEN, pp. 226–298. Berlin, 1847.

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