The author's object was, 1st, To confirm and extend the investigations of Gruby concerning the mycodermatous vegetations growing in the crusts of the cutaneous disease called Porrigo lupinosa;—2d, To describe a plant he had himself found growing on the living membrane and tubercular matter of Phthisis pulmonalis;—3d, To describe the structure of a plant found infesting the skin and gills of the gold-fish;—and, 4th, To inquire into the pathological state which furnishes the conditions necessary for the growth of fungi in living animals.

The author, after briefly stating the results of his Experimental Inquiries, published on this subject in 1829, proceeded to describe two instances which had recently come under his notice, illustrative of the solvent action of certain terrestrial waters on lead, and of the danger of using this metal for conducting water in pipes, unless with a due regard to the circumstances which promote or prevent its corroding property.

Referring to the nerves of touch, as distributed to the points of the fingers, the author proceeded to shew that something more was necessary than the exposure of the nerve. For example, the tongue being the most perfect organ of touch, resulting from the fine supply of nerves, is yet incapable of receiving certain impressions;—so that although it could distinguish the finest hair, so fine as not to be felt by the finger, yet if applied to the artery at the wrist, it conveys no sense of pulsation.

In this paper the author pointed out that the force, which had protruded granite and other matter among the strata, could not have been the same in point of time with that which broke up the crust of the earth into its present shape; because the matter in veins which we now see exposed to view on the faces of precipices, having been fluid at the time of protrusion, must have run out of the fissures on the rock being raised up.

The district proposed to be described, in so far as it was studied by the author in two journeys in 1839 and 1841, is an out-lyer or appendage to the main Alpine chain, which occupies a considerable portion of the old province of Dauphiné, and the modern departments of the Hautes Alpes and Isére. It is bounded, roughly, by the rivers Arc and Isére on the north, and by the Durance and the Drac in other directions. Its nucleus is essentially granitic, against which sedimentary deposits of limestone, of different ages, and especially of lias and chalk, repose in highly elevated or contorted strata; and it not unfrequently happens, that the dislocation of strata has been so great, that the gneiss or granite rocks are superimposed upon the secondary formations.

This grass of the genus Holcus was stated to be new to the British Flora, since no mention of it is made in the works either of Sir James Smyth or Sir William Hooker; and as the author was unable to find it noticed in the continental works, he proposed for it the name of Biaristatus, as illustrative of the species. Several specimens gathered in the neighbourhood of Edinburgh were exhibited, and the characters by which it differed from Holcus mollis and Holcus lanatus were pointed out.

After referring to the labours of those anatomists who had verified Malpighi's doctrine of the follicular nature of gland ducts, the author alluded to Purkinje's hypothesis of the secreting function of the nucleated corpuscules of these organs. In a rapid sketch of the results of inquiries since the appearance of Müller's work “De Penitiore Structura Grlandularum,” and more particularly of the observations of Henle and others on the closed vesicles which are situated at the extremities of certain ducts, Mr Goodsir stated, that no anatomist had hitherto “proved that secretion takes place within the primitive nucleated cell itself, or had pointed out the intimate nature of the changes which go on in a secreting organ during the performance of its function.”

This Memoir is the prosecution of a subject on which the author had previously touched in a paper which is printed in the seventh volume of the Transactions of the Cambridge Philosophical Society. It has for its object the investigation of the quantity of light which is received on a screen of unlimited dimensions, after passing through a certain aperture, or suffering reflexion at two mirrors. The end for which the investigation is undertaken is to ascertain the constant which must be introduced in using Huygens's principle.

In this paper, the author, after having noticed the ordinary quarantine classification of substances, into susceptible, non-susceptible, and doubtful, states as the result of his inquiries conducted in Turkey and the Mediterranean, that the distinctions involved in this arrangement have been made in a very unsatisfactory manner, not after careful research and deliberation, but rather during a period of panic, and hastily, in comparatively remote and ignorant times, and by men, for the then state of knowledge, ill qualified for the task, even had they entered upon it with all the calmness and caution that the subject required.

Professor Forbes observed that, in his communication to the Royal Society on the Conductivity of Soils for Heat, on the 20th December last (see Proceedings, page 343*), he had referred to the separation of the conductivity and specific heat, which are involved in the results of the thermometric experiments on subterranean temperature. In order to eliminate the effect of specific heat, M. Regnault of Paris (well known by his experiments on this subject) undertook, at the request of M. Elie de Beaumont, to ascertain the specific heats of the soils in which the different sets of thermometers are sunk.

Referring to a communication made by him to the Society on the 1st February 1841 (see Proceedings, page 322), the author reminded the Society that he had then endeavoured to account for certain anomalous facts observed by Dr Richardson, connected with solar radiation in the Polar Regions, by adverting to the intense radiating effect of a covering of snow. The disappearance of this snowy covering in the month of May, the author had observed to be synchronous with the anomalous diminution of solar radiation, ascertained by a blackened thermometer, in the months of June and July, compared with the months of April and May.

The author endeavoured to prove, from the recorded facts stated by different writers, that the crystalline particles of which the ice of glaciers is composed do not sensibly enlarge after being consolidated into compact ice; that the crystals have been shewn to be fully and perfectly formed in the course of a few nights in the Polar Regions; and that they have a position perpendicular to the layer of ice which they form,—their length being thus determined by the thickness of that layer.

The author, after adverting to the methods of investigating the subject, generally and specially, and expressing preference for the latter method; and, after pointing out how desirable it is in inquiries of an obscure nature, to find out instantiœ crucis, brings forward and details some facts, which he considers as such, on the question of the contagion of plague.

The minerals in question are the Phakolite of the Bohemian Mittelgebirge, and Caporcianite, a newly discovered mineral, first observed by Dr Savi, in a copper-mine at Caporciani, in the valley of Cæcino. The author found, that in point of composition, Caporcianite belongs to that division of the zeolites, which comprehend Analcine, Ledererite, Potash-harmotome, Chabasie, and Levyn, and whose constitution is represented by the mineralogical formula r S2+3 AS2 + z A q,—z being a variable quantity, r representing the variable monatomic bases, and A & S alumina and silica.

An examination of these specimens seemed to prove, that the leaves of the China tea-plant, cultivated at the same plantation with the tea-plant of Assam, are considerably less, and somewhat thicker, but otherwise so exactly similar, that the two plants may well be mere varieties of the same species,—an opinion now generally adopted by botanists in India. The specimens further illustrated the doctrine deduced from recent investigations in India, that the different kinds of green and black tea are made from the leaves of one species of plant, collected at different periods of their development.

The author noticed a variety of facts which were in direct opposition to the common notions entertained on the subject; and which led to the conclusion, that the chief object to be kept in view, was to destroy all sound that did not go directly from the source of sound to the ears of the audience, by preventing reflection. He described the plan of the Hall now building at the Assembly Rooms, the form of which is crucial, owing to the space on which it stands having been limited, and the necessity for connecting it with the pre-existing apartments; and he stated that he would have preferred a square, with the orchestra somewhat retired on one side.

There exists in several northern continental countries a peculiar kind of grouse, called by foreign naturalists Tetrao medius, on account of its exhibiting, as it were, a combination of the characters of the wood-grouse or capercailzie on the one hand, and of the black-cock on the other. It is never found except in countries inhabited by the two species last named; and as it presents a union of their characters, several naturalists have inferred that it is not itself a distinct kind, but a hybrid, resulting from the casual intercourse of the other two.

**** I Have the pleasure to send you two papers: the first on the changes, which the moment of a magnetical needle or bar undergoes as a function of the elapsed time, and of the variations of the temperature; the second, in the German language, is an extract of a letter to Professor Kupffer of St Petersburg, exhibiting the changes of the time of 300 horizontal vibrations, in Christiania, of my invariable magnetical cylinder, made by Dollond in 1819, from 1820 to 1839.