The following additional observations on the comparative structure of the eye-ball, are intended chiefly to illustrate the philosophical anatomy and physiology of the capsules forming the Canal of Petit, and of the Marsupium Nigrum; yet as I have here taken notice of several other points in the comparative anatomy of the eye, the memoir may be considered as supplementary to those formerly read to this learned Society, and which it did me the honour to insert in its Transactions. I have stated in the first of those essays, that I had been led to inquire into the structure of the Eye, partly as connected with researches into the comparative anatomy of all the organs of sense, but more particularly with a view to elucidate the nature and distribution of the nervous system. I did not presume to think that any remarkable peculiarities in the structure of this most interesting organ, had escaped preceding anatomists; but though I found this to be true, in so far as regards the structure of the eye in most of the mammalia, it yet appeared that the same organ in other vertebral animals had by no means been investigated, or at least describedj with the same care.

In the year 1818, my attention was accidentally directed to the subject of water in crystallised bodies, by the explosion of a crystal of Topaz, which I had exposed to a red heat, for the purpose of expelling its colouring matter. This violent disruption of the specimen, which was shivered into a thousand films, of extreme tenuity, arose from the expansion of the imprisoned fluid, and induced me to institute a series of experiments, for the purpose of determining the nature of the fluid, the form of the cavities which contained it, and the arrangement of these cavities in reference to the crystalline form of the mineral.

As the following anomalous case relating to the vision of colours, appears to possess some remarkable peculiarities, I have considered it of sufficient importance to be submitted to the Royal Society of Edinburgh.

J. B., aged 60 years, served in early life an apprenticeship to a farmer; but, disliking agricultural pursuits, became a tailor, and afterwards entered into the Navy, and served in several general actions. After quitting the sea-service, he resumed his trade, and in the employment of which he now continues. From his childhood, it appears, he was unable to point out colours by their proper names; or, excepting in a few cases, to distinguish one colour from another. From the nature of his avocation, this circumstance must have often been to him the source of much inconvenience; and during his whole life, he has found the utmost embarrassment from it.

The following observations, which I have the honour to present to the Society, have arisen out of an inquiry into the structure and distribution of the nervous system throughout the animal creation. It will readily be imagined, that the nerves supplied to the organs of sense, did not fail strongly to attract my attention, and that those belonging to so important an organ as the eye, were considered by me as worthy of the most minute investigation. It was impossible to proceed in this inquiry without submitting the organ itself to a very careful examination, in executing which, several important facts presented themselves, which I believed to be novel, at least, to lead to views respecting the physiology of the eye, different from those generally adopted. It became my duty to search into authors of the present and of the past age, and to collect into view whatever had been previously written on the subject; but leisure being altogether wanting for such an undertaking, I have thought it best to describe what I have myself seen.

Since the perfecting of a Natural Arrangement has become the grand object of scientific pursuit, it has been found necessary to enter more minutely than was required by an artificial system, into modifications of structure and function. Botanists have no longer rested satisfied with observing plants in their fully developed forms, but have also had recourse to several other periods in the existence of vegetable life, the observance of which gives much insight into the organisation of the individual. Of these there is none more important than germination, which is often the only means afforded for ascertaining the structure of the seed. This is the case with all the cryptogamic tribes, the seeds of which are generally so minute, that many of them must be brought together before they be distinctly visible.

In the month of September last (1822), when becalmed in my cutter in the Kyles of Bute, I accidently landed on the most northerly of the Burnt Isles, a small group that stretches across the Kyle or narrow channel between Bute and Argyleshire.

From the appearance of a ridge nearly covered with turf, I imagined at first that kelp had been formerly burnt here, but on examining it more narrowly I discovered that it was caused by the remains of a vitrified fort.

Although I possess a collection of specimens of Chalcedony, made expressly with the view to enable me to form some plausible theory of its formation; and; although my cabinet contains a variety of forms, perhaps unequalled in any other collection, I have, for many years, refrained from describing them, because the oftener I contemplated my specimens, the less able I found myself to apply any single agent, so that its operations alone could account for their forms. It is, indeed, very long since I entertained the opinion, that no hypothesis founded on the separate agency of heat or of water, could be satisfactory to speculative minds; and that geologists could never account for the formation of individual minerals, or of the rocks containing them, without combining the power of heat with that of water. But even this combination, though it can be easily conceived capable of forming many of the productions of the mineral kingdom, leaves numerous phenomena unexplained.

Few cabinets of minerals contain so many of the rare substances, which were discovered in Greenland, by Sir Charles Giesècke', and perhaps none in equally interesting varieties, as that of Mr Allan. The most prominent of them hare been examined both in a mineralogical and chemical point of view, and some described as particular species. Mineralogy is already indebted for Allanite, Sodalite, Eudialyte, and Gieseckite, to the zeal of die indefatigable explorer of Greenland, and the subsequent labours of Dr Thomson and Professor Stromeyer; and it is probable that the number of new species from this source will yet be increased upon farther examination.

My Dear Sir,

The Vertebra which I now send to you, was found about two years ago, on the property of Mr Mackenzie of Hilton, in Strathpeffer, county of Ross; and that gentleman desires me to present this interesting relic of some cetaceous animal to the Royal Society of Edinburgh.

Alexander Wilson, M. D., late Professor of Practical Astronomy in Glasgow College, was a younger son of Patrick Wilson, town-clerk of St Andrew's, and was born there in 1714. He was very young when his father died, and was afterwards brought up by the care of his mother, Clara Fairfoul, a person much respected for her prudence, virtue, and piety.

Having received the usual education at the different schools, he entered to the College of St Andrew's, where he made great proficiency in literature and the sciences, and, after completing a regular course of studies, was admitted to the degree of Master of Arts in his 19th year.

About the end of the year 1821, when I was engaged in the examination of the Family of the Zeolites, Mr Heuland was so obliging as to send me a variety of Stilbite from a Calamine mine at Altenberg near Aix-la-Chapelle. Upon comparing its optical structure with that of the Stilbites, it was manifest that it had no connection with this class of crystals, and that it constituted a new mineral species. Upon mentioning this result to Mr Brooke, this acute mineralogist was of opinion that it was the Silicate of Zinc. Mr Heuland had been led to regard this substance as a Stilbite, in consequence of having received it as such from Major Petersen; but, particularly, from finding in the collection of Mr C. H. Turner, a single crystal of the same substance attached to Carbonate of Zinc, and bearing the annexed figure, with an inscription in the handwriting of the Abbé Hauy, stating it to be a new variety of Stilbite, to which he gave the name of Stilbite Duovigesimale.

A. Justly celebrated Naturalist was of opinion, “that every “distribution of mineral bodies, which is instituted before the “determination of the species, must be mere confusion; while, “after having established it, according to fixed principles, no “kind of distribution can be absolutely faulty.” The distribution itself varies, along with the different principles of classification, introduced for the purpose of obtaining a systematic arrangement, conformable to the views of Natural History, of Chemistry, or of other sciences; but the Species remains that unique and unalterable point to which every system, and in fact every inquiry, must be referred, if we wish to avail ourselves of the prerogatives of the human mind, and preserve our information in a scientific form.

The public attention, animated by scientific controversy, has of late years been much directed to Geological subjects; and the certainty of many important facts, has in consequence been ascertained beyond dispute, which were formerly unknown, or at least involved in such obscurity, that no person could have ventured to assert them, without being charged with extravagance. But though, no doubt, many branches of this science still remain to be investigated, such inquiries may now be said to have acquired a considerable degree of consistency and interest, from the substantial basis upon which they have been found to rest.

My dear Sir,

I request you will do me the favour of submitting to the Royal Society the accompanying observations made at Paramatta and Sydney. Those of the Comet, together with the elements inferred from them, are exclusively Mr Rumker's, to whom it is impossible for me to give adequate praise, either for zeal, assiduity, or intelligence. In order to have a better chance of observing the transit of Mercury over the Sun's disk, I proceeded to Sydney, about 15 miles from hence, and I am happy to say that we had a most propitious day throughout for the observations, and that the near agreement of them at both places tends to confirm their accuracy, as well as to increase their value.

A box Chronometer having lately come into my possession, exhibiting remarkable proofs of strong and active Magnetism, I was induced to examine it particularly, and to ascertain the intensities of its different parts, by means of an apparatus resembling that employed by Coulomb, and which was capable, from its very delicate construction, of indicating the existence of the minutest traces of attraction.

The following paper contains the results of a series of inquiries, which lead to the conclusion, that the mineral called Smaragdite by Saussure, does not form a species of its own; but that this name has been given to a compound of certain varieties of two distinct species, Augite and Hornblende, the natural-historical species of paratomous and hemiprismatic Augite-spar.

Owing in part to the slight degree of resemblance prevailing among its varieties, the authors who have described them differ so essentially in opinion, that I am obliged to go into various details, both respecting the external appearance of the mineral itself, and of the opinions of mineralogists, in order to afford a correct view of the natural-historical species, to which these varieties belong, since this is the basis upon which every system, and, indeed, all accurate information in natural history, is founded, and the fixed point to which the one and the other must be referred.

The two Comets which are the subject of this communication were discovered at Paramatta; the first by Mr Rumker, and the second by our countryman Mr Dunlop.

The elements of both have been calculated from the observations of Mr Rumker and Mr Dunlop, by Mr George Innes, Aberdeen, and Mr James Gordon, A. M.

The most simple and obvious use of the Trigonomentrical Tables, is to find the logarithmic sine, tangent, &c. corresponding to a given angle; and, reversely, the angle corresponding to a given sine or tangent. However, in their more general application, we have often to find a logarithmic cosine, having given the corresponding sine, or the contrary; also the sine or cosine from a given tangent, and, in these cases, it may be of no consequence to know the exact angle.

It is universally admitted, that, in the present advanced stage of Meteorological Science, nothing would be more desirable than complete and accurate registers of the indications of Meteorological Instruments,—more especially of the Thermometer, Barometer, and Hygrometer, such registers being cotemporaneously kept at numerous places, and at various elevations on the earth's surface. Many are the obstacles, however, which have been found opposed to such an acquisition.