Specific gravity 3.585.

Connemara Garnet.-Occurs in rhombic dodecahedrons with bevelled edges; faces of crystals have a metallic lustre, colour resembling bronze. The matrix appears to consist of the same mineral mixed with epidote.

On the Composition of Jet. By THOMAS H. ROWNEY, Ph.D., F.C.S., Prof. of Chemistry, Queen's College, Galway.

The following results were obtained by the analysis of two specimens of jet and of a very pure coal, a portion of a fossil plant:

On Waterproof and Unalterable Small-arm Cartridges. By T. SCOFFern.

On a New Form of Blowpipe for Laboratory Use.
By Dr. HERMANN SPRENGEL.

Mr. SYMONS exhibited some forms of Alkalimeters suggested by Mr. Wiers.

On Thiotherine, a Sulphuretted Product of Decomposition of Albuminous Substances. By Dr. THUDIchum.

On the Occurrence of Poisonous Metals in Cheese.
By Professor Voelcker.

The author stated that he had detected both copper and zinc in cheese in some specimens copper, in others zinc, and in some both copper and zinc were found. The description of cheese in which these poisonous metals were found was double-Gloucester cheese. Skimmed-milk cheese, which was likewise examined for copper and zinc, did not contain any metallic impurity. Stilton, and other varieties of cheese, have not as yet been examined; it must not therefore be inferred that cheese made in other districts than Gloucestershire contains poisonous metals. Inquiry in the dairy districts of Gloucestershire and Wiltshire has led to the discovery that in many dairies in these counties sulphate of copper, and sometimes sulphate of zinc, are employed in the making of cheese. The reasons for which these prejudicial salts are added to the cheese are variously stated. Some persons added sulphate of zinc with a view of giving new cheese the taste of old; others employed sulphate of copper for the purpose of preventing the heaving of cheese. Dr. Voelcker also stated that he had found alum in Gloucester cheese, and mentioned that he had learnt that in some dairies alum was employed to effect a more complete separation of the caseine from the whey.

On the Causes of Fire in Turkey-red Stoves. By Dr. W. WALLACE.

GEOLOGY.

Notes on two newly discovered Ossiferous Caves in Sicily.
By Baron F. ANCA.

FOUND in the Grotta de Olivella, near Palermo. Molar of Eleph. Africanus (the existing species), amidst bones and teeth of an extinct species of Hippopotamus, both in a well-marked fossil state, and infiltrated with hydrate of iron.

Grotta de San Feodora. Molar of Eleph. Africanus, with abundant remains; upper and lower jaws of Hyæna crocuta, determined by M. Lartet.

Facts go to prove continuity of land between Sicily and the African continent, probably along the line of the Adventure Bank of Admiral Smyth, stretching between Capo Bono, the promontory of Tunis and Marsala. The Admiral found only 75 fathoms sounding upon the bank; but a deep sea to the north and to the south. Proofs of continuity with Sicily are found at Malta.

Details respecting a Nail found in Kingoodie Quarry, 1843.
By Sir DAVID BREWSTER, K.H., D.C.L., F.R.S.

On the Stratigraphical Position of certain Species of Corals in the Lias. By the Rev. P. B. BRODIE, M.A., F.G.S.

The author first alluded to the exact position of a species of Coral found in the Hippopodium bed near Cheltenham, and another locality near Evesham, where the same form was equally abundant. Another and distinct genus, a Montlivaliia allied to M. Stutchbury, was procured in the same bed in Warwickshire, associated with numerous other fossils, and a section of the pit was given. Other and distinct species of Corallines, one of which from Gloucestershire belongs to the genus Cladophyllia, were known to occur lower down in the Lima beds,' the probable position of the fine Isastraa Murchisoni, found occasionally in Worcestershire and Warwickshire. One or more additional species have been met with in the bottom beds of the Warwickshire Lias, which had not been previously observed so low down. The divisions of the Lias, which seem to be characterized by the presence of Corals, are-1, the Hippopodium bed; 2, the Liina bed; 3, the White Lias; and 4, the Guinea bed. So that it would appear that Corals are more numerous in the Lias than has been usually supposed, and that they occupy certain zones in it, which future investigations may show to be as well marked and distinctive as that of any other particular organisms.

A few Corals have been recorded from the Upper Lias, but they are smaller and less frequent than the above.

On the Velocity of Earthquake Shocks in the Laterite of India.

By JOHN ALLAN BROUN, F.R.S.

Mr. Mallet's interesting observations on the velocity of earthquake shocks had drawn my attention to the subject; and when earthquakes were remarked in Travancore, the part, South of India, where I resided, I endeavoured to add something to our knowledge of the subject.

Four earthquakes were perceived in Travancore during the year 1856; that to which I am about to allude was observed at the Trevandrum Observatory, August 22, where the commencement of the shock was noted accurately by the Observatory clock, at 4h 25m 10s of Trevandrum mean time. The magnets in the magnetic observatory were dancing up and down with sharp jerks, but without any change of mean positions; a vessel containing water was wetted highest on the points to W.N.W. and E.S.E. The vibration of the bifilar magnet was 3'0 scale divisions a few minutes after the shock. On the 11th of the same month a shock had been felt at Trevandrum, and I had addressed a circular to several persons in the district for information as to the time, direction, and character of the shock: this circular had drawn attention to the questions of interest in connexion with such shocks. One gentleman at Quilon (thirty-seven miles N.W. of Trevandrum) was writing an account of the former shock when the shock of August 22nd occurred. Four gentlemen and one lady noted the time of the shock at Quilon; these times were as follows:-Mr. D'Albed'yhll and Mr. Newas (same watch), 4h 20m; Capt. Carr, 4h 25m; Mr. Stone, 4h 19m; Mrs. Wilkins, 4h 16m. A box chronometer by Dent was sent by me to Quilon, for the purpose of comparing it with the different watches or clocks used in the determination of the time of the shock: the rate of the chronometer was +8 seconds, and the error was determined before and after the comparisons, which were made August 27th. The following are the facts connected wth the observations:-Mr. Newas had set his watch, on the 17th of August, to 6h 0m at sunrise; allowing for the height of the chain of Ghats where the sun rose, I have computed that sunrise must have been about 3 minutes before six o'clock: the watch had been allowed to run down after the shock, so that it could not be compared with the chronometer. Supposing the watch without any marked rate, the Trevandrum mean time of the shock was 4h 18. Mr. Stone had set his watch August 17, by the time of the Trevandrum Observatory (where a ball is dropped daily at eleven o'clock). When compared with the chronometer, it had gained 3 35 giving a daily rate of about +215; so that on the 22nd the error of the watch must have been about 1m 47, and the shock must have occurred about 4h 171m Trevandrum mean time. This is by far the most important observation; the others can be considered only as approximate determinations. Capt. Carr's watch was found fourteen minutes fast of Trevandrum time on the 27th; supposing the rate zero, the time of shock was 4h 11". Mrs. Wilkins's clock had been compared with the mess clock of the native regiment at Quilon, which was regulated by persons proceeding from Trevandrum, with the Observatory time, and which was found correct when compared with the chronometer. Mrs. Wilkins's clock was three minutes slow of Trevandrum mean time, making the time of the clock 4h 19m. The four observations, therefore, corrected to Trevandrum mean time, gave—

There can be no doubt that Mr. Stone's observation is the most trustworthy, as his time depends on two comparisons with the Trevandrum Observatory, viz. on the 17th and 27th; and the deduced error for the middle of the interval (the 22nd) cannot be far from the truth. Mr. Newas's observation, which agrees with it within about a minute, depends wholly on the observation for the sunrise; it is so far confirmatory. Rejecting Capt. Carr's observation, as differing too much from the others, the mean of the remaining three is 4h 183TM.

If we suppose the shock to have travelled in the direction from Quilon to Trevan

drum, which does not differ much from that indicated by the vessel of water, and take the distance at thirty-seven miles, we obtain a velocity of propagation of 470 feet per second; and if we take the latest result at Quilon, or 4h 19m, we have still a velocity of only 530 feet per second--little more than three-fifths of that found by Mr. Mallet in wet sand. If we take the W.N.W. as the direction of propagation of the shock, or any other than that direct from Quilon, the velocity will of course be diminished. It should be remarked that the laterite, which forms the upper stratum (about 30 feet deep) between Quilon and Trevandrum, is a clayey rock, in a semi-pasty condition of perhaps the lowest degree of elasticity; and the laterite reposes in some places on strata of sand and clays.

On the Course of the Thames from Lechlade to Windsor, as ruled by the Geological Formations over which it passes. By the Rev. J. C. CLUTTERBUCK, M.A.

The tortuous course of the Thames between Lechlade and Windsor shows that there must be some physical cause which obliges it to deviate from the straight line it would naturally take to its outfall. This is found in the obstructions encountered in its passage over or through the various strata. From Lechlade to Sandford the river finds its bed in the Oxford clay; it then passes through a narrow gap in the middle oolite to the Kimmeridge clay, holds its course on that clay, under the escarpment of the Iron-sand in Nuneham Park, turns the escarpment at Culham, passes to the Gault at Appleford, touches a ledge of the Iron-sand at Clifton Hampden, returns to the Gault, enters the Greensand near its junction with the Thame stream, passes to the Chalk, in which it finds its bed to the point,-which is the limit proposed for consideration. The natural obstructions are found at the junction of the different strata. The quantity of water flowing down the river, whether issuing in perennial springs, or thrown from the surface in flood, is due to the geological condition of the district. The tributaries or feeders discharge more or less of perennial or flood water, as they carry the water from permeable or impermeable strata. The flooding of the district necessarily affects the sanitary condition of Oxford. The city itself is placed on a bed of gravel, overlying the Oxford clay, the surface of which undulates so that the water is stanked back in the gravel; it was cutting through one of these undulations, in carrying out the Jericho drainage, that deprived many wells in Oxford of their water. As this bed of gravel extends beyond the limits of the city, on the subsidence of the floods, the water filtrates through the gravel, and thus noxious evaporation is diminished. Considerable accumulations have raised the bed of the river in many places, evidence as to the date of which is found in antiquities which have been discovered when constructing locks or weirs, or in dredging for gravel. At Sandford, arms of the time of Charles I. have been found 8 feet below the riverbed, relics of greater antiquity and at various depths have often been found in other places, where the bed of the river has been raised, or, as in some cases, entirely changed its course. The phenomenon of the formation of ice at the bottom of the stream, when the temperature falls to 20 Fahr., and the transportation of stones from the bottom by the ice rising to the surface, adds to the natural obstructions in the stream, and hinders the passage of the flood-waters by which so much damage has been done at various times in the neighbourhood of Oxford. The paper, which entered into full details, was illustrated with a map, sections, and diagrams.

Photographs of a Paddle of Pliosaurus of great size, found at Kimmeridge, were exhibited by Mr. R. DAMON, of Weymouth.

Remarks on the Elevation Theory of Volcanos.
By Professor DAUBENY, M.D., F.R.S.

This paper was chiefly intended as a protest against the assumption of certain geologists, that because it had been shown, more especially by Sir Charles Lyell in his memoir published in the Philosophical Transactions' for 1858, that sheets of compact lava have been formed on steep inclines, it therefore followed, that all volcanic mountains have been built up by a series of successive eruptions.

Not denying that this explanation may serve for the oldest, as it certainly does for the more recent beds, which constitute such mountains as Etna and Vesuvius, the

author contended that it is not applicable to the celebrated case of Jorullo, as described by Humboldt, nor yet to the volcanic islands thrown up in deep water at various times during the historical period.

He was also disposed to refer the four trachytic Puys near Clermont, in Auvergne, as well as the still loftier Cones composed of the same material in the Andes, which Humboldt describes, rather to the upheaval of a softened mass of rock, than to the outburst of liquid lava.

He appealed also to the crater-lakes in the Eifel country and elsewhere, as furnishing cases of upheaval, even where no lava had been ejected; and argued, that so long as the idea of paroxysmal action continued to be entertained with reference to rocks in general, it was probable that volcanic countries, above all others, would be subject to such operations.

On the Mode of Flight of the Pterodactyles of the Coprolite Bed near Cambridge. By the Rev. J. B. P. DENNIS, F.G.S.

Coprolitic remains of Pterodactyle bone have afforded an opportunity of studying its microscopic characters, and this had led to the present attempt to show from the analogy of other flying animals, from the different modes of flight among birds, from the apparent adjustment of the haversian canals thereunto, and the harmonious perfection of the skeleton with the adaptation of the pectoral muscle to the same (so that even the humeral process of its attachment has its marked characteristics), that these and other analogies lead to the inference that considerable knowledge even of the mode of flight of this extinct reptile may be obtained from the study of its microscopical bone structure. In elucidation of this subject, a brief account was given of the structure of the wing-bones of a bird, and of the mode of flight of the Gull, a bird distinguished for its elasticity and endurance on the wing, and in other respects very suitable for illustrating the subject.

A description was then given of fragments of Pterodactyle bone obtained by Mr. Barrett from the coprolite bed, most of which were portions of wing-bones of very thin texture. It was also shown that the Pterodactyle required not to be encumbered with muscular legs, and thus the vastus was only sufficiently developed to enable the animal to spring from the ground preparatory to flight (as the form of the femur also seemed to indicate); also the biceps, semitendinosus, &c., or their analogues, did not require any great development; while the gastrocnemius, as it would assist in the spring, was probably on that account fairly represented. The pectoral muscle, following the saurian type, must have been less voluminous than that of birds, flatter, with its greatest development in front, and in position comparing somewhat with that muscle in gulls and owls, birds of elastic but not rapid flight. The Pterodactyle was also shown to agree more with birds than with bats, especially in its omoplate, while the absence of a fercula implied no similar volume of muscle; the bones in like manner were permeated by air, or if some were not, they were yet filled with a light fatty substance or marrow to give additional strength to their light texture; and though the natural weakness of its muscular powers was considerable in comparison with birds, yet this was balanced by an extremely light framework, the weight of which predomi nated in front, where the muscular force was more directly antagonistic; and above all, the admirable microscopic structure of its bone eminently conduced to its powers of flight. Delicate in the extreme to the unassisted eye, when examined under the microscope, the bone is found to contain numerous and large haversian canals in a very marked degree, comparing in their arrangement with those seen in the wing-bones of gulls; also lacunæ well displayed, larger than those of a bird of flight, long and fusiform. From this correspondence of the characters of the haversian canals, of which illustrations were given, an inference seems capable of being drawn in reference to the flight of these large Pterodactyles, which, if they did not possess the dash of the falcon or the impetuosity of the wood-pigeon, yet sailed gracefully over primæval seas with a lightness and buoyancy, as it would seem, analogous in some degree at least to the conspicuous grace of the gulls, which are the present ornament of our coasts. So in every respect is seen the wisdom displayed in the adaptation of means, each inadequate in itself, and the result is the production of one of the strangest anomalies, of which, if we had not had the clearest testimony, the imagination would have failed to picture, a true Pterosaurian, in some respects perhaps more wonderful in its construction than bats or even birds, and being as fully capable of flight as they, teaching