11 round the shorter axis, and weighed 4 pounds. One end of it was somewhat flattened, as if it had, whilst in a soft state, come in contact with some hard substance. Its whole surface was covered with a blackish, vitrified-looking crust, about one-twentieth of an inch in thickness, whilst the interior resembled a greyish-white soft sandstone, diffused through which were minute brilliant metallic particles, about the size of small pin-heads. It crumbled readily under the fingers; and when reduced to powder, the metallic particles could all be abstracted from it by a magnet. Its specific gravity was 3.512. Hydrochloric and nitric acid acted violently upon it, with evolution of sulphuretted hydrogen gas, and solution of the metallic particles.

Its analysis was conducted by digesting it with heat, in nitrolydrochloric acid, leaving the insoluble earthy silicates: precipitating the iron as peroxide by an excess of ammonia, which gave a pale sapphire-blue solution: then evaporating to dryness, igniting to expel the ammonia salt: dissolving the residue in nitric acid, and precipitating the nickel as oxide by potash. Neither cobalt nor chromium were detected by qualitative methods. After the action of nitro-hydrochloric acid, sulphur floated on the liquid, and, moreover, much sulphur was given off as sulphuretted hydrogen.

Aerolites, from the Myhee Caunta.-On the 30th of November 1842, at 4 P.M., some Khoonbees were sowing grain between the villages of Jeetala and Mor Monree, in the Myhee Caunta, to the northeast of the city of Ahmedabad, when they heard a noise or report like the firing of heavy guns, four or five times; this sound came from the east, and was instantly followed by a violent gale of wind, and the fall of a number of stones,—of these the Khoonbees picked up one that fell on the edge of their field; it weighed about When first taken up, it smelt strongly of gunpowder. The people broke it to pieces, and kept them as curiosities. One of the fragments having fallen into the hands of a Karkoon, he brought it to Captain G. Fulljames, Commandant of the Goozerat Irregular Horse, who transmitted a small portion of the stone to the Bombay Geographical Society. This fragment presented so exactly the appearance of the foregoing aërolite from Dharwar, that it might have been taken for a portion of it; presenting the same dark vitrified surface, the greyish-white siliceous interior, with the brilliant metallic particles diffused through it. Its specific gravity was somewhat less than that of the preceding aërolite, being 3.360. The portion which was placed in my hands for analysis, was unfortunately too small to

*Professor Giraud's MS. leaves blank space in place of weight.-Edit.

afford other qualitative results; these, however, pointed to its close resemblance to the Dharwar stone, for with the earthy silicates it contained sulphur, iron, and nickel.

Meteoric iron from Singhur, near Poona in the Deccan.-The hill fort of Singhur has, of late years, during the hot season, become a favourite resort of European officers, stationed at Kirkee and Poona, from which latter place it is about fourteen miles distant. The fort, situated upon a basaltic hill, is at an elevation of about 2000 feet above the surrounding plain, and 4500 above the level of the sea.

In November 1847, as some workmen were improving the ascent to the fort, they stumbled upon a mass of what they supposed to be iron ore, lying upon the surface of the ground; but from its being so totally unlike any rock in the neighbourhood, they took it as a curiosity to the Rev. Mr Reynolds, the chaplain of Kirkee, who was at the time residing at Singhur. Mr Reynolds, struck with its singular locality and appearance, transmitted it to Dr Buist, the secretary to the Bombay Geographical Society, from whom I received it for

examination. The mass is of an irregular three-sided prismatic form, tapering and conical at the ends. It is 12 inches long; and at its broadest parts the sides are from 5 to 5 inches across. It weighs 31 lb. 4 oz. The specific gravity of the several pieces that have been detached from the mass, varies from 4.720 to 4.900. The whole surface is of ferruginous colour, with here and there bright metalliclooking portions, of the colour and appearance of malleable iron. One of its sides is highly vesicular, as if gases had been extricated from it, whilst solidifying from a state of fusion; another of its sides is less vesicular than this; and the third is flattened and metallic-looking, as if it had been beaten with a sledge-hammer, or had fallen while soft upon a hard surface. On boring into the mass for the purpose of obtaining portions for analysis, it was found to have large irregular vesicular-surfaced cavities in its interior, and the walls of these, as well as the borings (which were powdery), were of a deepslate colour, or almost black.

On having a portion of one of its extremities cut off, small, yellowish-white, earthy-looking bodies, about the size of peas, were observed sparingly scattered through and embedded in the iron. The mass is so exceedingly tough, that portions could not be detached from it by the hammer, and it was found necessary to heat it before a piece could be cut from it. It is malleable, powerfully attracts the magnet, but has no magnetic poles, as some masses of meteoric iron have been found to possess. The analysis of the borings, taken from a depth of three inches, gave of—

The strict resemblance of this specimen, both in physical and chemical properties, to the many recorded examples of meteoric iron, leave no doubt regarding its nature.

Its vesicular surface indicates a state of fusion, which the power of the native furnaces of this country is quite inadequate to produce in iron of such toughness and malleability; and, moreover, its constituent nickel, so near the average proportion of five per cent., points distinctively to its meteoric origin.

Like the Siberian meteoric iron, described by Pallas, when heated strongly, it became brittle, refused to extend under the hammer, and broke into grains; and, like the Brazilian specimen described in the Philosophical Transactions, it gave abundance of sparks when struck with a steel hammer.

M. ALCIDE D'ORBIGNY on Living and Fossil Molluscs.

Among the zoologists whose labours have contributed most to increase our acquaintance with the relations which ancient faunas bear to the animals of the present epoch, M. Alcide d'Orbigny occupies a place in the first rank. This skilful naturalist has published, within these few years back, a series of works,* which, taken together, may be said to form an epoch in the history of zoology and paleontology. Studying each natural group of the great and important class of mollusca in succession, and comparing these animals in the different geological periods, and in the existing world, he has reached results of the highest interest. We shall here explain the most important of these, selecting more especially such of them as are connected with those principles of paleontology which we have often had occasion to lay before our readers.

We shall first bring forward the following considerations on the geographical distribution of living molluscs. No one

* M. d'Orbigny's works of which we chiefly wish to speak, are his Paleontologie Française (already consisting of upwards of 170 livraisons,) which is devoted to the fossil molluscs of France; his Paleontologie Etrangère, the companion of the former; his History of Living and Fossil Molluscs, a work which will be of immense utility, if it be completed. He promises, besides, a Cours de Paléontologie Generale et Appliquée.

ever enjoyed better opportunities of studying these animals in every point of view, than M. d'Orbigny. His early years were spent on the shores of the ocean, while a journey of seven years' duration in South America, and immense collections, have furnished him with numerous points of comparison. "The geographical distribution of molluscs is of great importance, because, proceeding from the known to the unknown, it is calculated to make known to paleontology, by the laws which regulate the geographical distribution of living beings, what has taken at the different epochs of animals appearing on the globe. I shall here mention, in a general way, some of the principal results with which my numerous investigations on this subject have already furnished me.

"The study of terrestrial animals has proved to me that the species, restricted by limits more or less extensive, were distributed each according to special* zones of temperature, complicated, nevertheless, by influences determined by the orographic form of continents and their phytographic composition. In general, the number of species decreases in proportion as we recede from the warm regions and approach the cold regions.†

"The study of marine pelagic animals, or such as belong to deep seas, has in like manner demonstrated to me that of the cephalopods, notwithstanding the number of species which pass indifferently from one ocean to another, more than two-thirds of each sea are peculiar to it. These numbers evidently prove, that the limits of fixed habitation still exist in respect to animals, which their power of locomotion, and pelagic habits, would distribute throughout every sea, if Cape Horn on the one hand, and the Cape of Good Hope on the other, were not, in their southern position, altogether beyond the torrid zone, which nearly all the species inhabit, and thus form a barrier which they are unable to pass. have, therefore, the certainty that uniformity of temperature,

We

* See my observations on this subject, Mollusques de mon Voyage dans l'Amerique Meridionale, p. 215.

Same work.

Memoir read to the Academy of Sciences, 19th July 1841, and inserted in the Monographie des Céphalopodes Acétabulifères. Introduction.

more than any other agents, is the true basis of the geographical distribution of the animals of the high seas. We may add, that they are found to be more complicated in their forms, and more numerous in species, the nearer we approach the warm regions. The pteropods, although more indifferent as to temperature, have afforded me the same general results,* with respect to their geographical distribution in the

oceans.

"The investigations which I have in like manner undertaken, although much more difficult, in order to become acquainted with the laws which regulate the geographical distribution of the molluscs of sea-coasts, have led me to curious results. I have ascertained, for example, the action of three different influences,-currents, temperature, and the orographical configuration of coasts.

"We thus perceive, that if currents, by their long-continued action, have a tendency to spread the molluscs of coasts beyond their natural limits of latitude, when they carry them to a distance from a continent, or round a cape advanced in the direction of the pole,--or when they suddenly leave the coasts under the warm regions, we must ascribe to them, on the other hand, the isolation and establishment of local faunas.

I have likewise ascertained that, notwithstanding the active influence of currents, the passive action of heat is everywhere felt in a very marked manner, by forming collections of species in more or less restricted limits of latitude.

"The orographical configuration of the coasts of oceans, by offering conditions of existence more or less favourable to littoral molluscs, according to their genera, exercises also immense influence on the zoological composition of the faunas which inhabit them.

"From the combined effect of these three kinds of influences we may infer, with certainty, that the laws which

* Memoir read to the Academy of Sciences in 1835, and inserted in the molluscs of my Voyage dans l'Amerique Meridionale, p. 68.

See my Memoir, laid before the Academy of Sciences in November 1844, and printed in 1845 in the Annales des Sciences Naturelles.