MISCELLANY.
Fossil Wood in Flint. —An interesting specimen of this kind, which is in the Oxford collection, has lately been described and figured in a paper by Professor Phillips. The nodule of flint, which, when broken across, disclosed the contained wood, was of an elongated oval form, and had the uneven and knotted surface which frequently indicates aggregation on a sponge. The fractured surface showed partial change of color by watery action from without, and many variations of tint within, arising from some original differences in the composition of the mass. The color was, on the whole, somewhat lighter than is common in flints of the "Upper Chalk." Examined with a lens, it showed traces of spicula and other organic bodies; but it was impossible to trace through the mass a distinct spongy structure. The wood lay in the centre, and the figure of the flint was, in a general sense, conformed to it, and embraced it equally on all sides. There was a certain distinctness of color in the flint [{564}] where it lay in contact with the wood. The wood was a fragment worn and rounded in some of the prominent parts, and looked like a small portion of a pine branch which had been exposed to rough treatment, so as to present a wasted surface deprived of the bark. It was entirely siliceous, and exhibited its vegetable structure most perfectly. Traversing the woody fibres were several short, tubular masses swollen at the end, and marked more or less plainly with transverse rings. These Professor Phillips supposed to be flint moulds of cavities left by boring shells, probably Teredinidae. It would appear that these animals must have begun their operations in a young state on the wood, when it was reduced to its present form and size; for the moulds which remain in their holes appear to be quite small at the surface, and to expand internally. The writer of the paper becomes absolutely poetical in his speculations upon the remnant of extinct vegetation which he described. He writes: "Far away from the Cretaceous Sea of Albion, among the mountains previously uplifted in the West, from which had flowed the great river of the Wealden, we see a forest of coniferous trees. Whirled and broken to fragments by the rushing stream which received their decaying stems, the ruins of the forest reach the sea, and some few pieces float far from the shore beyond the area of deposited mud and drifted sand. Attacked by xylophagous mollusks, and sinking to the ocean bed, one, at least, serves as the nucleus for organic growth and accretion." Professor Phillips does not here refer to ordinary accretion; he conceives of the block as first surrounded by organic matter, and then, when buried in the cretaceous deposit, serving as a centre of attraction for siliceous solutions, such as have more than filled to solidity the tissues of sponges.—Popular Science Review.
The Removal of Neuralgic Pain. —It has lately been stated in some of the French journals that Dr. Caminiti, of Messina, has discovered a remedy for certain forms of neuralgia. A patient of his had long been suffering from trifacial neuralgia; she could not bear to look at luminous objects, her eyes were constantly watering, and she was in constant pain. Blisters, preparations of belladonna, and hydrochlorate of morphine, friction with tincture of aconite, pills of acetate of morphine and camphor, subcarbonate of iron, etc., had been employed with but partial success, or none whatever. At length Dr. Caminiti, attributing the obstinacy of the affection to the variations of temperature so frequent in Sicily, adopted the expedient of covering all the painful parts with a coating of collodion containing a certain proportion of hydrochlorate of morphine. This treatment was perfectly successful; the relief was instantaneous and permanent, and the coating fell off in the course of one or two days.
The Maltese Fossil Elephant. —The curious pigmy pachyderm whose remains were some time ago discovered in the Maltese bone-caves, has been indefatigably investigated by its original discoverer, Dr. Leith Adams. This gentleman has recently met with further relics of the fossil elephant in several new localities. He met with its teeth in great quantities in a cavern near Crendi. In a gap, evidently at one time the bed of a torrent, he has discovered the teeth and bones of thirty more individuals. The skeletons are met with jammed between large blocks of stone in a way which shows clearly that the carcases must have been hurled into their present situations by violent floods or freshets. Dr. Adams has now almost completed the skeleton of this wonderful little representative of an order which, till this discovery was recorded, had been commonly termed gigantic. Dr. Adams concludes, from his numerous inquiries, that the Maltese elephant did not exceed the height of a small pony.
The Volcanic District of Chili. —Some short time since, M. Pissis, the great explorer of South American geology, transmitted to M. Elie de Beaumont an elaborate description of the volcanic regions of Chili. He found the volcano of Chillans again in a state of eruption. This is a very rare circumstance in the volcanoes of the Andes, where the eruptions generally succeed each other only at very long intervals. The present eruption, which is much more extensive than the last one, commenced toward the end of last November, at a new point, situated about 200 metres below the summit of the grand cone, the new cone having toward the end of January attained a height of fifty [{565}] metres. The lava, escaping by two apertures near the summit, had already reached the vast glacier surrounding this massive volcano. The grand cone, which was covered with snow during the eruption, had the appearance of being completely bare, yet the snow had not been melted, but was covered with a great quantity of projected substances, which formed a layer over the snow of many decimetres in thickness. The alternation of glaciers with layers of scoriae are frequently met with in the volcanic cones of the Andes; wherever natural clefts occur, a great number of these layers may be seen successively superposed. The volcano of Antuco, visited last year, had been in eruption on a small scale in 1863. As no solid bodies were being projected at the time of his visit, M. Pissis was enabled to examine the interior of the crater, and, favored by a strong westerly wind, to observe it without being annoyed by the acid vapors which escape in abundance. The principal column of vapor proceeded from an aperture nearly circular, being recognized as that through which the lava had escaped. Its diameter was only from four to five feet.
Transferring Photographs to Metal for Printing—Some months since we called attention to some very promising experiments in this direction, conducted by Mr. Woodbury, of Manchester. These have resulted in a process recently patented, which is likely to assume a very important position in the arts. Mr. Fox Talbot has the merit of first pointing out the facta upon which it is based. This gentleman, to whom photographers too often forget how much they owe, discovered in connection with one of his photo-engraving processes that gelatine when dissolved in hot water, if mixed with bichromate of potash or ammonia, dried, and exposed to the action of light, would become insoluble—a result due to the decomposition of the alkaline bichromate and the liberation of chromic acid. It will at once, therefore, be seen that a coat of the bichromated gelatine on a glass or metal plate placed under a negative and exposed to light, would, when subjected to the action of hot water, be dissolved away in some parts, and in other parts unaffected, thus producing a photographic positive in relief. Acting on these facts, Mr. Woodbury takes the image in relief so produced, and either by mechanical pressure with some soft metal, such as type metal, or by the usual process of electrotyping, produces an intaglio impression therefrom. A properly prepared ink, formed with gelatine and some black or other colored pigment, is then passed over the plate, with which the impression is filled up even to the surface. Of course the gradations of relief in the bichromatic gelatine print form gradations of depth in the metal intaglio, in which again the ink, being transparent, forms gradations of blackness proportioned to its varying thicknesses. When this ink is transferred to paper, delivered as a jelly is from its mold, the delicate tints, the deepest shadows, and the intermediate gradations of the photographic negative are faithfully reproduced. In preparing the relievo, two ounces of gelatine are dissolved in six of water, and to this is added three-quarters of an ounce of lump sugar. Four ounces of a solution containing sixty grains of bichromate of ammonia to the ounce being added to this, the whole is then, while quite warm, strained. A plate of glass is next covered with a sheet of talc temporarily fixed by a few drops of water; the talc is coated with the above, and being sensitive to light, is placed in the dark to set. This done, the coated talc is removed, a negative laid over the talc, and exposed to light in the usual way, the only change being that of causing the light to pass through a glass condenser and fall on it in a parallel direction. The hot water is then applied as above stated. In order to insure perfect flatness while the cast is being taken, the talc side of the film should be again fastened to a plate of glass with Canada balsam. Mr. Woodbury calculates that with three or four presses going, these mechanically printed photographs could be produced at the rate of 120 per hour. Apart from ordinary purposes, the process can be applied to glass for transparencies; to china for burning in with enamel colors; to the production, at a cheaper rate, of porcelain transparencies, etc., etc. At present the prints exhibited are said to lack clearness; and the high relief of the extreme darks is also objected to.—Popular Science Review.