already appeared on the same subject, in various publications: but we cannot dismiss this long paper without giving our cordial testimony to the care and ability by which it is characterized. An Account of "The Sulphur," or " Souffrière" of the Island of Montserrat. By Nicholas Nugent, M. D., &c. - These sulphureous exhalations, which are very strong, issue from various fissures and crevices of a decomposed porphyritic rock. Though Dr. Nugent could perceive no indication of a crater, the intense heat which accompanies the discharge of these vapours may very probably be volcanic, because old craters are often filled up; or a certain degree of volcanic heat may be supposed to exist, without producing all the effects of a formal eruption. It Observations on the Wrekin, and on the Great Coal-field of Shropshire. By Arthur Aikin, Esq., M.G.S.-Under the term Wrekin, Mr. Aikin includes that line of hills of which it is the most conspicuous. The red sand-stone-rock of this district, which extends into other counties, consists principally of rather fine grains of quartz, with a few spangles of mica, cemented by clay and oxyd of iron, but possessing little cohesion. rises at an angle of between ten and twelve degrees; and its southern extremity in Shropshire rests on highly elevated strata of grauwacke. The series of coal-formation, which commences immediately adjacent to the red sand-stone, occupies a length of about six miles, and two in its utmost breadth. It is composed of the usual strata, which are not fewer than 86 in number; of which the 31st and 33d are coarse-grained sand-stone, entirely penetrated by petroleum. These strata are interesting, as furnishing the supply of petroleum that issues from the tar-spring at Coalport. By certain geologists, this reservoir of petroleum has been supposed to be sublimed from the beds of coal that lie below; an hypothesis not easily reconcilable to present appearances, especially as it omits to explain how the petroleum in the upper of these beds could have passed through the interposed bed of clay so entirely as to leave no trace behind; it is also worthy of remark that the nearest coal is only six inches thick, and is separated from the above beds by a mass ninetysix feet in thickness, consisting of sand-stone and clay-strata, without any mixture of petroleum.' The other strata and beds. of coal are duly particularized, but seem to present no unusual appearances. At the south-eastern extremity of the district, two parallel ranges of lime-stone run nearly north-east and south-west; that which lies most easterly being indicated by a line of hills, rising to five or six hundred feet above the level of the Severn, and consisting consisting of beds of lime-stone and sand-stone, rising to the north-west. This lime-stone is characterized by the madrepores. which it contains, particularly the catenaria, or chain-coral, by the pentacrinite, by small ammonites, by a few bivalve shells, and especially by the natural joints of the strata being often lined by flesh-coloured tabular heavy spar. Detached lumps of galena are often found on the surface, and a few small veins of the same mineral have been traced in various parts, but chiefly near the southern extremity, where it comes in contact with the coal-formation.' The average height of the western range scarcely exceeds three hundred feet above the bed of the Severn, forming an unbroken ridge, and containing multitudes of tubulites and other coraline remains, but, as far as the author could observe, no heavy spar. Its elevated portion is intimately connected with an unstratified green-stone trap, which forms two principal deposits, and exhibits several varieties. A regularly stratified bed of quartz-grit rises in a north-westerly direction, at an angle of 55°, where it rests on the Wrekin and Caer-Caradoc, but, in the intermediate space, at an angle of about 40°. It consists of quartz, in rounded grains, from the size of a pin's head to that of an egg. Beneath it is a very extensive bed of clay-stone, or compact felspar; for, in different places, it assumes the cha racter of both. Under this clay-stone, an unstratified trapformation, consisting chiefly of rocks of felspar and greenstone, constitutes the great mass of the Wrekin and the adjoining hills. When the horn-blend and felspar are intimately mixed in the green-stone, the rock usually becomes amygda loidal. Of these amygdaloids one is of remarkable beauty, forming large masses on Caer-Caradoc, but which has not yet found a place in the works of systematic mineralogists. It consists of a dull carthy basis, formed by an intimate mixture of dark bluish green hornblende, with flesh-red felspar, inclosing globular concretions of greenish-yellow radiated glassy actynolite, a quarter of an inch or more in diameter; smaller connections of quartz, intimately mixed with actynolite, and therefore nearly in the state of prasium, together with concretions and irregular veins of foliated white calcareous spar. The trap-formation itself does not seem to correspond with any of those described by mineralogical writers; and its essential characters are, its unconformableness with the transition-slate on which it rests, -the great abundance of clay-stone, both massive and vesicular, which it contains, and the presence of actynolitic amyg daloid.' - A Chemical Account of an Aluminous Chalybeate Spring in the Isle of Wight. By Alexander Marcet, M.D. F.R.S. M.G.S., &c. &c.-It appears, from Dr. Marcet's numerous observations and experiments, that the mean specific gravity of this water is 1007,5, and that each pint of it contains, of carbonic acid gas, three-tenths of a cubic inch, sulphate of iron 41,4 alumine 31,6 lime IC,I Hence, in point of strength, this water is reckoned superior to any analogous mineral-spring in Great Britain, those of Hartfell and Horley not excepted; and it is probable that in many instances it will be found expedient to drink the water in a diluted state; whilst in others, when it may be desirable to take in a small compass large doses of these saline substances, it will be preferred in its native undiminished strength.' A Sketch of the Geology of some Parts of Hampshire and Dorsetshire. By J.F. Berger, M.D., &c. - Independently of the -chalk-hills, which occupy a considerable portion of the district in question, various other strata or beds occur, of which the nature and general arrangement constitute the principal object of this memoir. In travelling from London to Southampton, by Bagshot, &c., flint-gravel, either in loose sand or in loam, may be traced to New Alresford, a distance of 57 miles; where the chalk is found in situ, but, at five or six miles S,S.W. from Winchester, gives place to the flint in loam. The flintpebbles are rounded; much smaller than those that are im bedded in the chalk; and they exhibit a semi-transparency, approaching to that of amber. Another formation, which, is seen in the Isle of Wight, is that of quartzose loose sand, including coarse hard ferruginous sand-stone, potter's clay, and a coaly bituminous matter, which burns with a weak flame, and emits a smell somewhat analogous to that of Bovey coal. A marl-rock, varying in texture and colour, occupies a considerable extent along the coast.-The cliffs of the south-western and southern coast of the Isle of Wight are composed of a coarse-grained sand-stone, disposed in strata of several yards in thickness, which alternate with coarse shelly lime-stone, and thin layers of chert. In many instances, Dr. Berger has observed the passage of the sand-stone into chert, and of the latter into a beautiful transparent chalcedony. Nearly in the same situation, and also in the islands of Portland and Pur beck, beck, is found the coarse shelly lime-stone, which the author has reason to believe is by no means so rare as it was at first supposed to be. The Doctor's remarks on this mineral substance are highly deserving of perusal but we must refrain from transcribing them. A bed of oviform lime-stone, or oolite, may be observed in the quarry of Wind Spit, in Purbeck; and another, still more extensive, to the north-west of the Isle of Portland. The Kimeridge coal lies between strata of slate-clay, which gradually pass into bituminous shale.Such are little more than the general titles of Dr. Berger's observations. Notice respecting the Geological Structure of the Vicinity of Dublin; with an Account of some rare Minerals found in Ireland. By William Fitton, M.D.-The district here particularized might, till lately, have been regarded as virgin soil in the eyes of the geologist; and the present memoranda, which seem to have originated with the late Rev. Walter Stephens, are recommended both by their novelty and their importance: since, besides pointing out the boundaries of the lime-stone and granite tracts, they make us acquainted with the occurrence of some rare and valuable mineral substances which were not formerly supposed to exist in Ireland. Among these we remark tin-stone, gold, the grey ore of manganese, earthy black cobalt ore, Vesuvian, grenatite, beryl, Andalusite, indurated talc, hollow spar, pitch-stone, granular sulphate of barytes, and barellite. On the Mineralogy of the Malvern Hills. By Leonard Horner, Esq., Sec. Geol. Soc. The Malvern hills consist of an uninterrupted chain, about nine miles in length, extending nearly in a straight line from north to south; their greatest breadth not exceeding two miles, and the elevation of the Herefordshire Beacon, the highest of the range, being 1444 feet above the level of the sea. Felspar, horn-blend, quartz, and mica, form various compound rocks in the chain: but these ingredients are blended in very different proportions, and in few instances with such minuteness as to give the internal structure a homogeneous appearance. The vegetation, however, which covers these hills, and the disintegrated state of those masses of rock which are laid open by quarrying, present very serious diffieulties in the way of investigation. The stratified rocks, which occupy the country to the westward, rise, in some places, to a considerable height, on the side of the range. In various parts of the chain, Mr. Horner met with epidote (pistazite of Werner), which, till lately, was believed to be a rare fossil. We cannot enter into the more particular details with which this intelligent observer has favoured the public. J Notice Notice accompanying a Section of Heligoland, drawn up from the Communications of Lieutenants Dickinson and McCulloch, of the Royal Engineers. By John McCulloch, M. D., &c.-ACcording to report, currently received among the inhabitants, this island has, by encroachments of the sea, been reduced within the last century from eleven miles in length to its present dimension of one mile. It seems to consist of strata of indurated clay, alternating with beds of grey lime-stone, with traces of copper-ore dispersed through them.Belemnites, and other fossil remains, both calcareous and flinty, are also found on the shore; and the clay strata often contain consis derable quantities of pyrites, together with carbonized and pyritaceous wood." Observations on some of the Strata in the Neighbourhood of Loudon, and on the Fossil Remains contained in them. By James Parkinson, Esq., M.G.S.-This is a very valuable communi cation, which strongly tends to confirm several important posis tions relative to the history of organized remains, imbedded in the carth; and it forms an interesting supplement to the au thor's very respectable volumes on the same subject. His present statements, however, are not easily reducible to such a concise form as to suit our legitimate bounds; and we must therefore, though reluctantly, refer our readers to the orie ginal paper. Memoir on Bardiglione or Sulphate of Lime, containing a Sketch of a Theary of the true Nature of Plaster, as well as of its Properties; in order to determine the Differences that exist between it and Bardiglione. By the Count de Bournon, F. R.S., &c. [Translated from the original French manuscript,]-We have no where met with a more detailed and accurate account of this modification of sulphate of lime, than the present paper affords, Though composed of the same principles with plaster, manifestly differs from the latter in some respects; because gypsum, when changed to the state of plaster by calcination, rapidly absorbs water, and by that absorption acquires consistency: whereas Bardiglione, either before or after calcina tion, has not any action whatever on water, and, if reduced to powder before it is mixed with that fluid, its particles still retain their state of division. As this difference cannot arise from the nature of the principles entering into combination, or from the manner in which they are proportioned to each other, it must necessarily arise from the mode of arrangement of the constituent molecules which form the integrant molecules." The Count endeavours, and with his usual acuteness, and in genuity, to support this conclusion; and we should gladly conour in his sentiments, were we perfectly satisfied with res gard |