Disko Island, (see Plate XV ), is situated in front of a bay in the continent of Greenland, within Davis' Strait, known by the name of Disko Bay, which is sometimes called, particularly in the old Dutch charts, Sydost Bay. This name is derived from an immense curvature, screened by innumerable islands, made in the continent by the sea. Disko Island is situated in 69° 14ʹ of N. latitude. It is distant from the continent towards the south 12 German miles; on the west and north it is surrounded by the sea of Davis' Strait; and on the east, it is separated by a narrow sound, distinguished by the name of Waygat by the Dutch, and by the Greenlanders Ikareseksoak. It stretches northward from 69° 14ʹ to 70° 24ʹ; and its greatest breadth, which is from Fortune Bay on the west, to Flakkerhuk, so named by the Dutch, on the east, is 10 German miles.

In this paper I propose submitting to the Society some observations on the nature and history of the Marsh Poison, which, under the title of Marsh Miasmata, or Malaria, has ever been acknowledged as the undisputed source of Intermittent Fevers, and is believed, with good reason, to be the exciting cause of the whole tribe of Remittent Fevers;—of Endemic Fever, in fact, in every form, and in every part of the world.

During the summer of the present year (1820), while navigating with the ship Baffin, the icy sea in the immediate neighbourhood of West Greenland (the east side), several extremely curious appearances of distant objects, produced by the reflective and refractive properties of the atmosphere, were observed.

On the 19th of February last, I had the honour of reading to this Society, some notices of the mode of working and polishing granite, by the natives of India.

One object of that paper was, from a view of the immense masses, which Indian artists are still in the habit of rendering obedient to their simple instruments, to deduce the probability of the similarity, if not of the identity, of the means now in use among them, with the processes by which the architects of the ancient world, raised the stupendous monuments which we still see in existence; and, as an instance of the very recent exercise of these arts, I mentioned the erection of a granite obelisk near Seringapatam, to the memory of the late Josiah Webbe, Esq. who died in the year 1805.

The variety of Apophyllite to which I have given the name of Tesselite, from the beautiful combination of tesselæ which it exhibits in polarised light, is one of the most singular substances in the mineral kingdom. The agency of that species of light, indeed, seemed necessary to the developement of its peculiar structure; but I have since succeeded in confirming and extending my former results, by the application of the microscope; and have been led to observe several new phenomena, which not only throw much light on the structure and properties of this curious mineral, but which affect the fundamental principles of crystallography.

Those who have devoted much of their attention to mathematical inquiries, must have had frequent occasion to admire mire the unexpected and intimate connection which subsists between branches of their science apparently the most remote and unconnected with each other; and repeated observation will have convinced them, that no researches, however recondite or abstruse, should be neglected, because they appear to stand isolated and detached from the body of the science. These reflections appear to have been felt with strongest force, by those who have most contributed to its advancement, and were particularly insisted on by Maclaurin, in the Preface to his Geometria Organica. The present Paper will add another example, to instances already numerous, of the latent affinity between departments of mathematics, usually regarded as the most opposite.

The value of the Chronometer for finding the Longitude at Sea, being, by the experience of many years trial, fully established, I am induced to offer to the Royal Society some remarks on the change of rate observed in this instrument, when on ship-board. This change of rate, that had usually been supposed to arise from the motion of the ship, has recently heen attributed, by Mr Fisher, who accompanied Captain Buchan in his Voyage towards the North Pole in the year 1818, ‘to the magnetic action exerted by the iron in the ship upon ‘the inner rim of the Chronometer's balance, which is composed of steel.’ I apprehend, however, that it will be very easy to show, that although the alteration of rate may be, and most probably is, owing to magnetism, yet the magnetic action of the iron in the ship, excepting in cases where chronometers are placed in immediate contact with large masses of iron, can contribute but in a very small degree to the error in question.

The communication received from Dr Dyce chiefly consists of a description of a singular affection of the nervous system, and mental powers, to which a girl of sixteen was subject immediately before puberty, and which disappeared when that state was fully established. It exemplifies the powerful influence of the state of the uterus on the mental faculties; but its chief value arises from some curious relations which it presents to the phenomena of mind, and which claim the attention of the practical metaphysician. The mental symptoms of this affection are among the number of those which are considered as uncommonly difficult of explanation. It is a case of mental disease, attended with some advantageous manifestations of the intellectual powers; and these manifestations disappearing in the same individual in the healthy state.

The figures, sculptured in full relief, and here represented by the four drawings in Plate XXIV., are idols brought from India in the year 1800, by Francis Simpson, Esq., which I had the honour of presenting to the Society at his request.

According to information with which I have been favoured by gentlemen conversant with the literature of India, these idols are Cali, Suria and Buda.

Of the various rocks of which the Earth's surface is composed, there are some which present very satisfactory indications of their origin; while others, when considered in that respect, seem to be placed almost beyond the reach of hypothesis. The Granite and Trap rocks, by extending their ramifications among their contiguous neighbours, distinctly avow, not only a subsequent formation, but, in many instances, they present the most unequivocal marks of an igneous origin. The Limestones and Sandstones, however, are equally constant in their indications of aquatic deposition, although, at the same time, the assistance of another agency may sometimes be inferred, when their consolidation and position are taken into the question. Of all the rocks with which I am acquainted, there is none whose formation seems to tax the ingenuity of theorists so severely, as the White Limestone or Chalk, in whatever respect we may think fit to consider it.

The title which I have given to this paper, is, perhaps, faulty, and apt to lead the imagination to expect a description of the various forms of those sea-weeds which clothe the channel of the deep;—the arrangement of the species, as depending on the soil and depth of water, the food which they yield to the various creatures that browse upon them, and the protection they afford to such as take refuge among their leaves and branches. Very different, however, is the scene which I propose to describe,—a bed of peat-moss, covered by the sea at every full tide, but indicating, by the appearances which it exhibits, that its present low level is different from its original position. In other words, it is a geological phenomenon, occurring in the Frith of Tay, similar to the one observed on the Lincolnshire coast, which, in 1796, was examined by the late Sir Joseph Banks and Dr Joseph Correa de Serra, and described by the latter in the Transactions of the Royal Society of London for 1799, p. 145, under the title, “On a Submarine Forest, on the East Coast of England.” I venture to prefix the same title to this paper, which I now offer to the consideration of the Royal Society of Edinburgh, aware of its impropriety, but urged by the wish to connect similar phenomena by the common terms employed in their description.

In a Paper on Vision through coloured Glasses, which I had lately the honour of submitting to the Society, I pointed out the advantages of coloured media in Microscopical and Telescopical observations. Having experienced the great utility of Green and Red lenses, in developing vegetable structures that required to be examined with high powers, I was anxious to derive from this new principle all the advantages which it appeared to possess. In attempting to do this, it became necessary to ascertain the power of giving distinct vision, which belonged to each separate colour of the spectrum, and though I had stated in my former paper, ‘that it was difficult to discover ‘any reason why one coloured medium should be preferred ‘to another, provided each of them transmits equal quantities ‘of homogeneous light;’ yet it was desirable to put this theoretical opinion to the test of direct experiment.

My dear Sir,

As I see by a notice in your Journal, No. 13., which has just reached my hands, that your attention has been occupied by the phenomena of Coloured Flames, and the Absorption of Coloured Light by Diaphanous Bodies; and that you have been successful in the very valuable discovery of a manageable flame, discharging a homogeneous yellow light of an invariable character, I shall perhaps be excused, while the contents of your paper are unknown to me more particularly, for stating some phenomena Which I have myself observed, relative to this highly interesting department of physical optics.

In compliance with your request, I send you a few notes of some of the principal geological facts I observed in Faroe, which may serve as a supplement to Sir George Mackenzie's and Mr Allan's accounts of these islands, which, as far as they extend, I found perfectly correct.

The Coal in Suderoe, which was not visited by them, is situated between two thick beds of hard clay, resembling the Clunch-clay of this country; to which succeed beds of trap. In some parts, pieces of petrified wood are very abundant in the superincumbent clay, and also nodules of ironstone; and in the coal, pieces of wood resembling charcoal. The coal has the same degree of inclination as the other beds, dipping towards the south-east, at an angle of about 4° or 5°; being the same as the dip in the other islands, excepting in part of Myggenæas, where it is much greater, being near 45°.

The interesting discoveries of Oersted, and the subsequent researches of Ampere, Arago, Davy, and Von Buch, which promise to throw a clearer light on the mysterious nature of Galvanism and Magnetism, induced us to undertake, and pursue conjunctly, a series of Electro-magnetic experiments. In prosecuting our inquiries in this new branch of scientific investigation, we have observed various interesting facts, some of which appeared to us new, while others did not seem to have been detailed so fully as their importance merited.

The following conjectures concerning the Analogy observed in the formation of some of the Tenses of the Greek Verb seem worthy of farther inquiry; for, if well founded, they may be useful towards establishing juster rules for the formation of the Tenses in some instances; and, particularly, they will account for certain forms of the Verb in Homer and Hesiod, which, being apparent violations of the usual analogy, have perplexed the grammarians, and reduced them to the necessity of assuming imaginary new Presents, without authority, and for no other reason, but to account for such anomalous forms.