In repeating some of the beautiful experiments of Professor Plateau, on the Equilibrium of Liquid Films, contained in seven Memoirs, published in the “Transactions of the Royal Belgic Academy,” and in prosecuting my experiments on the colours of the soap-bubble, I observed several new phenomena which may have escaped the notice of the Belgian philosopher.

In plunging a wire cube in a solution of soap, and lifting it up vertically, Professor Plateau found that there was formed within it a polyhedron, as shown in Plate XXXIV. Fig. 1, consisting of twelve similar liquid films adhering by capillary attraction to the twelve wires which compose the cube, and a small quadrangular film suspended in the middle of them. In many cases M. Plateau found that the vertical quadrangular film was often horizontal, as in Fig. 2; and M. Van Rees discovered, that by blowing very lightly upon one of its sides it was reduced to a simple line, and then reproduced in a horizontal position, from which it could be blown again into a vertical position, as in Fig. 1.

That excellent Geometer the late Dr Matthew Stewart, as long ago as the year 1746, published his book of General Theorems, all of them, except the first five, without the demonstrations. As I do not find that any demonstration of them has ever been made public, I may perhaps flatter myself that what I now communicate to this Society will not be wholly unacceptable. The demonstrations given are of the propositions relating to the sums of the squares, and of the fourth powers of lines drawn in a certain manner, and are selecled from the rest, as most connected with one another. The theorems that respect the cubes and other higher powers, may afford materials for another paper, should this meet with the approbation of the Society.

During a short visit I paid to Oxford in the month of June last I had the opportunity of examining, by the kind permission of Professor Moseley, a number of specimens of Bdellostoma Forsteri, which were some of a large number brought from the Cape by Mr Adam Sedgwick of Trinity College, Cambridge. This examination showed what, from the close affinity of the two forms, was naturally to be expected, namely, that the structure of the reproductive system and the development of the reproductive elements in Bdellostoma were very closely similar to the structure and development of the corresponding parts in Myxine. A short time ago I described before the Society some ovarian eggs of Myxine, obtained at the beginning of the present year, which were approaching maturity. In these eggs there were slight projections at the poles, and on the surface of the projecting parts a number of papillæ. The projections were caused by the growth of a number of threads from the vitelline membrane within the ovarian capsule, and the papillæ were the separate elevations produced by the threads.

The area lying between the north of Britain and the Faeröe Islands is classical in the annals of Marine Zoology, not only from the fact that the first systematic deep-sea investigations undertaken by this country were carried out there, but also from the number of new and remarkable types of animal life which have been first found in that region. Speaking only of the Echinoderm fauna, in justification of these remarks, it will suffice to mention the discovery of such forms as Phormosoma and Porocidaris amongst Echinoids, and of Hymenaster, Korethraster and Zoroaster amongst Asteroids.

The bearing which the subject of the following communication has upon the much-vexed question of the unity of the human species, and the inferences which may be drawn from it in relation thereto, invest it with an importance which would not otherwise belong to it.

The position which the question I allude to at present occupies is this. On the one hand, the advocates of the view that all men are not of the same species, but that they compose a genus consisting of many species, maintain that the parasites which infest the different races of man are distinct; and because we usually find that distinct species of parasites are allotted respectively to the different species of the lower animals, they infer that the same rule must hold with man, and that therefore each different race possessing a distinct parasite must be a distinct species.

Sir Isaac Newton's theory of the colours of natural bodies, is perhaps the most ingenious and lofty of all his speculations. It was devised, however, at a time when the doctrine of light had made comparatively but little progress, and before the discovery of various principles on which the colours of bodies must depend, or by which, at least, they must be extensively modified. The different dispersive powers of transparent substances;—the irrationality of the spectrum;—the action of striated surfaces;—the decomposition of polarised light;—the reflection of coloured light at the confines of equally refracting media;—and the absorption of common and of polarised rays,—are principles which embrace within their individual range a great variety of facts to which the Newtonian theory of colours bears no relation.

The following improvement on the construction of the thermometer, by which it is fitted to mark the lowest or the highest point to which the fluid has attained in the absence of the observer, is due to John Rutherford, M. D. of Middle Balilish. This gentleman communicated it to me some time ago, and accompanied the description with one of his thermometers. The contrivance is so very simple and ingenious, that it well deserves to be made public. I therefore, by permission of the author, beg leave to lay an account of it before the Royal Society.

The experiments which form the subject of the present communication were carried out two years ago, and supplement results already published. A brief note of some of the results was read before the Society in June 1904, and was also read before the British Association Meeting at Cambridge in August of the same year.

The previous paper discussed the effect of high temperature on the relation between electrical resistance and magnetization when the wire was magnetized longitudinally, that is, in the direction in which the resistance was measured.

The present results have to do with the effect of high temperature on the relation between resistance and magnetization when the magnetization was transverse to the direction along which the resistance was measured.

In February 1831 the late Mr Witham read to the Royal Society of Edin burgh, a paper of much interest on two fossil trees of great size which had been brought to light, the one in 1826, and the other in 1830, during the excavations carried on in Craigleith sandstone quarry, in the immediate neighbourhood of our city. In March of the same year this paper, with the addition of several chemical analyses of the fossils, was read also before the Natural History Society of Northumberland. In 1833 he included his observations on these fossils in a separate and more comprehensive treatise on “The Internal Structure of Fossil Vegetables found in the Carboniferous and Oolitic Deposits of Great Britain.” The main purpose of Mr Witham's researches—in addition to an accurate description and delineation of natural objects previously little investigated—was to show that fossil vegetables in the oolitic and carboniferous formations were not, as had been generally supposed prior to his researches, always ferns, tree-ferns, lycopodiums, and other acrogenous plants, but on the contrary many of them woody exogenous trees, showing longitudinal ligneous bundles, transverse medullary rays, concentric annual layers, and other characters belonging to the intimate organisation of our existing forest trees. Mr Witham even went so far as to identify the structure of the Craigleith fossils with that of our modern pines, and to assign them to two separate species.

As it appeared to me, when I first began, in 1759, to deliver in this University a public course of lectures on Anatomy and Surgery, that the structure of the oblique muscles had not been sufficiently examined, nor even the number of them attended to by authors, and that some of their chief purposes or effects had been ent rely overlooked by them, I endeavoured then, and in every course of lectures since that time, to direct very particularly the attention of students to those subjects.

(1.) In February 1850, I laid before the Royal Society of Edinburgh a paper, in which the laws of the pressure and expansion of gases and vapours were deduced from the supposition, that that part of the elasticity of bodies which depends upon heat, arises from the centrifugal force of the revolutions of the particles of elastic atmospheres surrounding nuclei, or atomic centres. A summary of the results of this supposition, which I called the Hypothesis of Molecular Vortices, was printed in the Transactions of this Society, volume xx., as an introduction to a series of papers on the Mechanical Action of Heat; and the original paper has since appeared in detail in the Philosophical Magazine.

In determining the solubility of salts and other bodies in alcohol, it is desirable to operate with a spirit wholly free from water. But anhydrous or absolute alcohol is formed with difficulty, even by the most improved process—that of Richter. In rectifying alcohol from chloride of calcium, as recommended by Richter, I have never obtained it under the specific gravity 0.798 at the temperature of 60°, by a single distillation; but upon rectifying this product again from new chloride of calcium, I generally succeeded in reducing it to 0.796, which is the specific gravity of the standard alcohol of that chemist. The following experiment illustrates this process.

The history of the newer sciences presents many instructive examples of the progress of the human mind in developing the germs of natural knowledge, and building on a single observation entire departments of science. Few pursuits indeed are more interesting, even to the student of immaterial nature, than in the perusal of such a history to trace the footsteps of the several investigators, and to mark how far, and by what means,—whether by new methods or by greater patience of research,—each successive observer advanced the inquiry. We see the human mind, as it were, set free from the trammels of time, and developing its resources on a large and continuous scale, not limited by the powers of one intellect, the length of one life, or the means of one station. We see, at the same time, what varied gifts and opportunities are necessary for the elucidation of a single subject; how these gifts, though not all imparted to one man or to one generation, are yet wisely and beneficently bestowed on the entire species; and how all are thus enabled to co-operate, either in unfolding abstract truth, or in drawing forth those practical results which directly conduce to the amelioration and comfort of all.

The St David's Head Intrusion, exposed in North Pembrokeshire, is a tholeiitic sill up to 570 m thick, comprising principally mafic gabbros, which are in part layered. Layering varies from the centimetre to the metre scale. A range of gabbroic compositions is present, defining seven major petrological types, which are cut by thin silicic (aplitic) veins.

Log–log plots of incompatible elements from the various lithological units indicate that all of the rocks in the intrusion are petrogenetically linked, although a variety of processes has been operative. Roach (1969) considered the quartz gabbros and dolerites, which form an envelope around the other units, to relate most closely to the parental composition. However, the least evolved compositions in the intrusion are from the xenolithic laminated olivine gabbros, although these mafic compositions are due primarily to the presence of abundant, mafic, cognate xenoliths. These xenoliths are thought to relate to an earlier episode of crystal accumulation in a high-level magma chamber. The various laminated gabbros reflect crystal accumulation in situ after magma emplacement, leading in certain layers to extreme enrichments in Fe, Ti, and V, related to high modal proportions of cumulus ilmenite. Further in situ crystallisation led to differentiation of the residual liquid, producing more silicic gabbros with well-developed granophyric textures, the granophyre reflecting the silicic residuum. Extreme differentiation, possibly combined with expulsion of silicic residual liquid during crystal accumulation and compaction, resulted in the cross-cutting aplite veins.

Three different types of layering are present in the intrusion. Firstly, preferred orientation of tabular minerals in the laminated gabbro units is thought to result from discrete sedimentation episodes from a convecting magma chamber. Secondly, macrorhythmic modal layering up to 1 m thick consists of an alternation of relatively ilmenite-rich and ilmenite-poor layers in the laminated gabbro units, although the reason for the modal variation is not certain. Thirdly, a centimetre-scale felsic–mafic microrhythmic layering is present in the envelope quartz gabbros and dolerites, which is similar to the inch-scale layering in the Stillwater Igneous Complex. This layering is thought to relate to metasomatic reaction in the gabbro in the presence of water at a late magmatic stage. Overall, these various lithological units themselves define a large-scale layering in the intrusion.

Combined, the petrological and geochemical data suggest that the St David's Head Intrusion was not emplaced in a single event. Rather, a series of magma pulses, of contrasting compositions but petrogenetically linked, was intruded. Some of the chemical variations now seen existed prior to emplacement, indicating the former presence of high-level crustal magma chambers, while other variations developed as a result of in situ crystallisation processes and related chemical differentiation.

The chemistry of the colouring matters has, perhaps, scarcely as yet met with the extended and complete investigation which the importance of the subject, in a theoretical and practical point of view, appears to deserve. The attention of chemists has been almost exclusively directed to the study of a comparatively small number of these substances, such as indigo, logwood, and the colouring matters of the lichens, which have been well and completely investigated; while the remaining, and by far the more extensive class, has received only a very partial and imperfect examination. To the latter, however, belong some of the most important of our dyes; and among others, the most valuable and indispensable of all, madder namely, the chemistry of which forms a problem as yet very far from being solved, but which chemists have shewn little disposition to submit to a thorough and searching investigation; and this disinclination seems to continue, notwithstanding that ground has been broken on the subject by the important observations of Robiquet, Kuhlmann, Runge, and others, which, though extremely incomplete, serve at least to indicate the importance of the results it is likely to afford, and to clear away the preliminary difficulties by which the commencement of such an investigation is surrounded.

We consider the reinterpretation of Bethia by Bassett et al. (2008) to be flawed in several regards. Details of the pedicle rootlets and wrinkles strongly imply a soft-tissue structure rather than calcified sheath. The ornament is unusual, but equally so under either an orthide or a plectambonitoidean model. The reinterpretation of the ‘deltial plates’ as ‘chilidial plates’ is likely correct, but argues against a plectambonitoidean affinity by implying that the pedicle emerges between the valves. Other arguments presented in favour of a plectambonitoidean affinity are also discussed; we consider them unpersuasive. Finally, we contend that Bethia is sufficiently well characterised to deserve a taxonomic name.

Hydrocarbon migration mechanism into a reservoir is one of the most controversial in oil and gas geology. The research aimed to study the effect of supercritical carbon dioxide (СО2) on the permeability of sedimentary rocks (carbonates, argillite, oil shale), which was assessed by the yield of chloroform extracts and gas permeability (carbonate, argillite) before and after the treatment of rocks with supercritical СО2. An increase in the permeability of dense potentially oil-source rocks has been noted, which is explained by the dissolution of carbonates to bicarbonates due to the high chemical activity of supercritical СО2 and water dissolved in it. Similarly, in geological processes, the introduction of deep supercritical fluid into sedimentary rocks can increase the permeability and, possibly, the porosity of rocks, which will facilitate the primary migration of hydrocarbons and improve the reservoir properties of the rocks. The considered mechanism of hydrocarbon migration in the flow of deep supercritical fluid makes it possible to revise the time and duration of the formation of gas–oil deposits decreasingly, as well as to explain features in the formation of various sources of hydrocarbons and observed inflow of oil into operating and exhausted wells.

Brachiopod taxonomy is based on descriptions of shell morphology and key characters, but diagenesis generally modifies or erases some of them, hindering brachiopod identification. Brachiopods that are taxonomically related usually present shells with similar appearance but can differ in size (i.e., Rhynchonellata). Some aspects of morphology – for example the angular measurement of the curvature of the shell or details of shell microstructure – could aid taxonomic identification. Gigantoproductids, which lack a robust taxonomy, have the largest shells among brachiopods and are ideal for this kind of study because of their gigantic size and morphological variability. Furthermore, they have a great abundance and worldwide distribution during the mid-Carboniferous. More than 700 samples have been collected from Sierra Morena (Spain), Montagne Noire (France) and Adarouch (Morocco) identifying up to six gigantoproductid genera: Globosoproductus, Semiplanus, Kansuella?, Latiproductus, Gigantoproductus and Datangia. Microstructural features from 170 thin sections belonging to gigantoproductid ventral valves have been studied, and six crystal morphologies have been distinguished within the tertiary layer: subhorizontal, imbricated, crenulated, acicular, short and long columnar morphologies. Moreover, 23 complete shells from all genera have been selected to investigate shell size and curvature. Results from this study emphasise that shell size, curvature and crystal shape are taxa-related. Finally, a remarkable morphological change in the gigantoproductid populations from the western Palaeo-Tethys occurred during the Viséan–Serpukhovian, from thin-shelled genera with subhorizontal morphology (Viséan) to thick-shelled genera with a tertiary layer consisting of long columnar crystals (Serpukhovian). This study proves that microstructure, maximum thickness and shell spiral characterisation are robust characters when applied to gigantoproductid taxonomy, but also have great potential in other brachiopod groups.

Open palates with large interpterygoid vacuities are a diagnostic characteristic of temnospondyl amphibians, the most species-rich group of early tetrapods. Aside from their functional roles, several other aspects of such vacuities, such as their variation and spatial relationships relative to the orbits, have received only scarce attention. The present work examines patterns of shape and size changes in the orbits and vacuities of temnospondyls using a time-calibrated phylogeny of 69 temnospondyl taxa and 13 additional early tetrapod ‘outgroups' (colosteids, an embolomere, ‘microsaurs' and nectrideans). Orbit and vacuity outlines are quantified in a comparative framework using standard eigenshape analyses. In addition, we employ a series of ratios of linear measurements of both orbits and vacuities, and subject them to a phylogenetic principal component analysis in order to evaluate their proportional changes relative to the skull and to one another. Finally, we examine rates of evolutionary change and their associated shifts for shape and size for both structures, and assess the strength and significance of the correlations between these two variables using phylogenetic generalised least squares analyses. Although orbits and vacuities have fairly simple outlines, they both reveal complex models of proportional change across the temnospondyl phylogeny. These changes exhibit strong phylogenetic signal, that is, trait covariance among taxa is predicted by tree topology. We discuss the hypothesis that, early in tetrapod evolution, the functional role of the vacuities was related to the accommodation of the anterior jaw muscles. Only later in evolution did such vacuities serve to accommodate the eye muscles only.