As it is my intention soon to publish, in various works on Natural History, the observations on the Botany of India which I made during my residence there, I wish to place on record an account of the opportunities which I enjoyed of making such observations, with the view of explaining to the Botanist where he may find the various collections which I made in different parts. I also wish to explain the geographical terms that I shall employ, in giving an account of the places where I found each species. For this purpose I prefer using the ancient Sanscrita names, both as being more scientific, and as being more likely to remain permanent; for, after a lapse of many ages, they continue to be known to all Hindus of learning, while each new invasion or revolution sinks into immediate oblivion the mushroom appellations imposed by modern rulers, whether Muhammedans or Christians.

It seems extraordinary, that no one should have undertaken a geological survey of Roxburghshire, more especially as the counties to the east and west of it have been examined, and accounts of their formations were published some years ago. It cannot be from its uninteresting character, that the intervening district has been neglected; for it presents as great a variety of apparently distinct formations, as there are in the adjoining counties of Dumfries and Berwick; and some of these have long been the special subjects of speculation and controversy among geologists. The British Association, in the Report of its Meeting held at Cambridge in 1833, propounded the following questions for geological inquiry.

The presentation to the Royal Society of Edinburgh of results relating to the decennial period, derived from observations of magnetic declination made during nearly a quarter of a century at Trevandrum, has seemed to me a favourable occasion for a determination of the mean duration of this period. Upon the explanation of the decennial variations depends the solution of several important problems in solar and terrestrial physics, and the first step towards this result is to ascertain the true mean duration of the period. Two markedly different results have been obtained, each of which has been accepted by men of the highest scientific reputation.

1. This paper consists of two parts, the first of which is confined to describing the experiments performed; while in the second it is attempted to connect these with certain theoretical views regarding Radiant Heat.

2. The experiments were made with a fourfold object; at least, for the sake of clearness, it is well to class them into four distinct groups:—

Group I. Contains those experiments in which the quantities of heat radiated from polished plates of different substances, at a given temperature, are compared with the quantity radiated from a similar surface of lamp-black, at the same temperature.

II. Those in which the quantities of heat radiated at the same temperature, from polished plates of the same substance, but of different thicknesses, are compared with one another.

III. Those in which the radiations, from polished plates of different substances at any temperature, are compared with that from lampblack at the same temperature, with regard to the quality or nature of the heat radiated.

IV. Those in which the same comparison is made between the radiations from polished plates of the same substance, but of different thicknesses.

On account of the treacherous character of the natives of the Solomon Group, no extensive geological observations have ever been made in these islands since the period of their discovery by the Spaniards three centuries ago. For this reason my excursions in these regions were not free from personal risks; in many places they were considerably curtailed, and in some places they had to be abandoned altogether. Fortunately, however, I was able to make a detailed examination of several of the smaller islands, the natives of which had been first conciliated by the kindly tact of Lieut.-Commander C. F. Oldham, to whom I am indebted for much assistance in my pursuits. But from the circumstances in which I was placed, both on board and on shore, it was necessary, in order to accomplish much, to dare a little.

In the report on Oceanic Circulation, based on the observations made on board H.M.S. “Challenger,” and other observations, which was published in the beginning of 1895 as an Appendix in the Summary of Results, Second Part Challenger Reports, the specific gravities dealt with were all at the standard temperature of 60° Fahr., the standard density being that of distilled water at 39°·2 (4° C). By this method of treatment the question of the salinity or saltness of the water is approximately stated, unquestionably one of the most important questions affecting the physics of the ocean. But the movement of the water, or oceanic circulation, as resulting from different densities, can only be represented by stating, not the specific gravity reduced to the uniform temperature of 60°, but the specific gravity at the observed temperature at all points in the ocean at which observations are made. In this paper these specific gravities are viewed in their relations to the circulation of the waters of the ocean.

No subject of modern scientific inquiry is more important than the series of deposits in which geology comes in contact with the period of human history. This must be my apology for some of the seemingly trivial details contained in the following paper. When these observations were begun, nothing could be further from my thoughts than any reference to the antiquity of man. But I shall perhaps best introduce the subject by simply narrating the way in which I was led forward step by step, till the whole inquiry assumed the form in which it is here presented.

The river Tilt is a principal branch of the Tay, which rises on the borders of Aberdeenshire, and runs towards the south-west, through the north-eastern part of the county of Perth. A portion of the valley along its course, for about ten miles above Blair of Atholl, is called Glen Tilt.

The adjacent country presents the common character of the Highlands. It is mountainous and rugged, and the surface, except in the lower parts of the valleys, is chiefly covered with heath. Peat-moss frequently occurs.

The present paper is based on the study of a suite of fossils collected in 1898 by Dr W. S. Bruce, during a cruise with Major Andrew Coats in the Barents Sea, on board the yacht Blencathra.

The fossils were found in situ in a cliff at the extremity of Cape Cherney, a promontory situated on the west coast of Southern Nowaja Semlja, in Iat. 70° 49' and long. 56° 37'. Contrary to what often obtains in the case of materials collected by explorers, they are all from the same bed, a fact which greatly increases the value of the collection, as there is thus no possibility of a mixing of forms from different horizons.

The town of Ardrossan is built largely upon the 15-feet beach which to the north and south of the promontory is a well-marked terrace of sand and gravel, but on the promontory itself is represented by a rocky shelf rarely exceeding 12 feet in height. The promontory owes its origin to a great extent to the igneous rock of the Castlehill and the Inches, which has offered more resistance to marine denudation than the neighbouring sandstones. The railway to West Kilbride runs for some distance along the 50-feet beach, while the 100-feet beach is represented by an irregular accumulation of sand and gravel some distance inland.

The Memoir now submitted to the Society, while it details the chief events in the life of a man who occupied a distinguished place in the literature of Scotland, at a period when it had attained a high reputation, cannot claim to be so complete as might be desired. His life was prolonged for several years after nearly all of his early friends had passed away; and since his death many papers have been destroyed or have fallen aside, which would now be of the greatest interest.

Whilst in this way much has been lost that might have given greater completeness to these pages, still, the recent publication of the Diary of his friend Dr Carlyle of Inveresk, has furnished many additional details, and afforded further evidence of the estimation in which he was held by his literary associates.

Several letters selected from the lives of his distinguished friends, and from the Manuscript Collection of the University, in addition to information derived from the short notices of his life already printed, have afforded the materials for preparing this sketch of one, whose career was more varied, while his public labours and literary connections were not less important and extensive, than those of any of his contemporaries.

To understand the physico-chemical processes associated with migmatisation is an interesting petrological problem. New developments in microfluidics and chaotic mixing experiments have helped us to better perceive these processes from the migmatic rocks of the Proterozoic Chotanagpur Granite Gneiss Complex (CGGC), eastern India. The migmatic rocks of CGGC have preserved folded leucocratic veins in amphibolites representing viscous folding. The viscous folding phenomenon occurred due to the interaction between leucosome and melanosome. Based on textural features and mineral chemical data interpretations, we infer that when granitic and pegmatitic magmas intruded the gneissic rocks and amphibolites of our study area, diffusion of heat and volatiles from the hotter felsic magmas to the colder country rocks initiated partial melting in the amphibolites, forming melanosomes. After their formation, the highly viscous felsic magmas veined into the melanosomes, by progressively melting them and then interacting, leading to chaotic mixing dynamics. The development of chaotic mixing allowed the leucosome to venture into the melanosome as veins by stretching and folding dynamics. As the leucocratic veins or leucosome traversed through the partially molten rock or melanosome due to advection, the veins underwent viscous folding owing to the exertion of compressional stress brought about by the viscosity difference between the two mediums. The occurrence of viscous folding exponentially increased the contact area between the leucosome and the melanosome, eventually leading to enhanced diffusion and augmented mixing between the two mediums. Evidence of mixing through elemental diffusion is well documented by the compositions of amphibole and biotite occurring in the leucosome and melanosome. These minerals show substitution of magnesium and ferrous ion that show linear variation between the endmember compositions.

Within the context of the work and achievements of James Croll, this paper reviews the records of direct observations of glacial landforms and sediments made by Charles Lyell, Archibald and James Geikie and James Croll himself, in order to evaluate their contributions to the sciences of glacial geology and Quaternary environmental change. The paper outlines the social and physical environment of Croll's youth and contrasts this with the status and experiences of Lyell and the Geikies. It also outlines the character and role of the ‘Glasgow School’ of geologists, who stimulated Croll's interest into the causes of climate change and directed his focus to the glacial and ‘interglacial’ deposits of central Scotland. Contributions are outlined in chronological order, drawing attention to: (i) Lyell's high-quality observations and interpretations of glacial features in Glen Clova and Strathmore and his subsequent rejection of the glacial theory in favour of processes attributed to floating icebergs; (ii) the significant impact of Archibald Geikie's 1863 paper on the ‘glacial drift of Scotland’, which firmly established the land-ice theory; (iii) the fact that, despite James Croll's inherent dislike of geology and fieldwork, he provided high-quality descriptions and interpretations of the landforms and sediments of central Scotland in order to test his theory of climate change; and (iv) the great communication skills of James Geikie, enhanced by contacts and evidence from around the world. It is concluded that whilst direct observations of glacial landforms and sediments were critical to the long-term development of the study of glaciation, the acceptance of this theory was dependent also upon the skills, personality and status of the Geikies and Croll, who developed and promoted the concepts. Sadly, the subsequent rejection of the land-ice concept by Lyell resulted in the same factors challenging the acceptance of the glacial theory.

In 1823 and 1826 I communicated to the Society two papers on the nature and properties of two immiscible fluids, which I discovered, in contact with each other, in the cavities of topaz and other minerals. Although the facts contained in these papers were of so extraordinary a nature as to be received with scepticism by some, and with ridicule by others, yet I am not aware that, during the twenty years which have elapsed since their publication, any person has either repeated my observations, or advanced a single step in the same path of inquiry. In shewing to strangers some of the leading phenomena of the two new fluids, my attention has been frequently recalled to the subject; but it was not till last spring, when I discovered cavities in topaz filled with the most beautiful crystals of various form, that I was induced to undertake a new investigation of their nature and properties.

The theoretical determination of the longitudinal seiches of a lake was reduced by Professor Chrystal to the finding of those solutions of the differential equation

which vanish at x = 0 and x = a.

Here x denotes the area of the surface of the lake from one end up to any transverse section, and ranges from 0 to a, a being the total area of the surface of the lake; p(x) denotes the product of the area of the transverse section at x and its breadth at the free surface; λ=σ2/g, σ being the “speed” of the periodic motion and g the acceleration due to gravity; V denotes the total volume of water which has passed the section up to the time t.

Teilia Quarry, from which the fossils described in this paper have been collected, is situated about a quarter of a mile north-east of the village of Gwaenysgor, which is distant about five miles from Rhyl and one from Prestatyn.

The geology of the district has been fully described by Mr G. H. Morton, F.G.S., from whose paper the following notes are compiled:—

A considerable part of North Flintshire is occupied by a great development of limestone, which is generally referred to in writings on the subject as “Carboniferous Limestone.” It forms a tract of hilly ground, some of the higher points rising to a height of over 800 feet. These limestones lie immediately beneath the Cefn-y-Fedw sandstones, and occupy a hollow of considerable extent in Silurian strata.

The research of James Croll on the nature of Ice Ages led him into a detailed investigation of ocean currents. By the early 1870s he had calculated from first principles the quantities of heat delivered by ocean currents to high latitude areas and he understood how this heat supply may have altered drastically during ice ages. The publication of his many papers on ocean currents as well as his book, Climate and Time, coincided with Challenger expedition that, in 1872, embarked on a 4-year voyage of scientific exploration of the world's oceans. The expedition was crucially important for Croll since it enabled him to test his theories of ocean circulation using real data. His novel theories of ocean circulation based on this information conflicted with the established views popularly advocated by William Carpenter but they ultimately prevailed. In the many writings of Croll on ocean currents, we encounter, as with other areas of his research, numerous remarkable ideas many decades ahead their time.

The attempt to account for the behaviour of gases by attributing their apparently continuous pressure to exceedingly numerous, but nearly infinitesimal, impacts on the containing vessel is probably very old. It certainly occurs, with some little development, in Hooke's tract of 1676, Lectures de potentiâ restitutivâ, or of Spring; and, somewhat more fully developed, in the Hydrodynamica of D. Bernoulli, 1738. Traces of it are to be found in the writings of Le Sage and Prévost some 80 or 90 years ago. It was recalled to notice in 1847 by Herapath in his Mathematical Physics, and applied, in 1848, by Joule to the calculation of the average speed of the particles in a mass of hydrogen at various temperatures. Joule expressly states that his results are independent of the number of the particles, and of their directions of motion, as also of their mutual collisions.

The experiments described in this paper were commenced with the view, not only of determining the absolute thermal conductivity of nickel, but also of comparing the results found by Forbes's and Ängstrom's methods for the same specimen. Although some readings were taken for Ängstrom's method, that part of the investigation was not completed, because it was found that the experimental errors — unavoidable, on account of the necessity of measuring rapidly changing temperatures—would be too great for the results to be of any value. The thermal conductivity of a portion of the bar of nickel used for Forbes's method was determined by a direct method involving the determination only of steady temperatures, and the results so obtained are given in the latter portion of this paper.