1. During recent years increased attention has been paid to the question of measuring or estimating the extent or degree of disturbance in the earth's magnetic field. Two distinct purposes have been kept in view. The first and more general is to provide some measure of disturbance capable of use as a means of correlating terrestrial magnetic change with other geophysical or cosmical phenomena; in particular, solar phenomena. The second seeks to assign to each Greenwich day a numerical value for the degree of disturbance on that day, so that a selection may be made in each month of a certain number of days on which the terrestrial field has been least or most disturbed. The immediate object here is to secure comparability between results—particularly diurnal inequalities—obtained at different magnetic observatories.

The Jurassic to Cretaceous strata exposed in the Rollrock Section, Sverdrup Basin, Arctic Canada, represent one of the northernmost continuous outcrops spanning this poorly understood transition. The Oxfordian–Valanginian mudstones of the Rollrock Section were deposited in a shallow marine environment and, as such, provide the ideal lithology to investigate the response of high latitude dinoflagellate cyst populations to the frequent environmental perturbations of this time. Using a multivariate statistical approach, distinct palaeoecologically significant groups are identified and directly linked to time and palaeoenvironments, allowing for the reconstruction of underlying long term palaeoenvironmental trends. These palaeoenvironmental trends are identified to be driven by sequence stratigraphic cycles. For the first time, fourth order sequences are recorded from this pivotal period in the Sverdrup Basin and reveal an additional level of short term climatic events that complicate the identification of long term trends. The relationship existing between marine phytoplankton and climate is utilised to decipher the interplay of long-term and short-term climate fluctuations, distinguishing them from evolutionary trends. Two groups of dinoflagellate cysts, identified by process morphology, are recorded to act as environmental proxies. High percentages of proximochorate dinoflagellate cysts, such as Trichodinium erinaceoides, indicate more proximal, high energy, nutrient rich conditions and are dominant in fourth order transgressive systems tracts. High percentages of chorate dinoflagellate cysts, such as Oligosphaeridium complex, signify distal, low energy, nutrient depleted conditions and are dominant in fourth order highstand systems tracts.

A brief account of the weather of this period as regards temperature was read before the Royal Society last year. It was drawn up at the request of Professor Balfour, to accompany his paper “On the Remarkable State of Vegetation in the Edinburgh Botanic Garden in December 1863.”

From the 26th of October to the end of December the weather was in every way remarkable. Though frost occurred in the end of October and beginning of November it was not severe, and the temperature continued on the whole seasonable till the 12th of November. From this date till the end of the month it ranged unprecedently high, being 9° above the average temperature of the season. It then fell for the next ten days, but on no occasion below the average; and again rose considerably above the average during the week ending with the 18th of December. Under this genial weather vegetation in the open air advanced rapidly to a state of forwardness not usually seen till the month of March. In December 245 plants were in flower in the Gardens in the open air, and of these 35 were spring flowers. The frost which had occurred was insufficient to damage, to any material extent, 210 autumn-flowering plants; and the high temperature of November, which was as high as what ordinarily occurs in the beginning of May, brought the spring flowers prematurely into bloom, so that there was to be seen the rare spectacle of sweet peas and hepaticas flowering together.

My main purpose in the following short paper is to publish figures illustrating some of the more important facts of the early development of myotomes and motor nerves in Lepidosiren. The bearing of some of the observations of nerve development upon current theories renders it particularly desirable that they should be illustrated by untouched photographs of the sections. A few photographs illustrating the more important stages in the development of the motor nerve trunks are given on Plate I. For the preparation of the photographs here published, as well as several others, I am indebted to the skill of my friend Dr T. H. Bryce, and of Mr Fingland, our University photographer.

My first precise views of the structure of the Tunicata were formed by the perusal of Mr Huxley's masterly papers dealing with the anatomy of Salpa, Pyrosoma, Doliolum, and Appendicularia, in the Phil. Trans. for 1851, Part II.; and I have since had abundant opportunity of verifying all the important facts, made known by that original observer, in the papers to which I have alluded.

Having thus acknowledged my guide in this field of research, I can scarcely claim much originality as relates to pure anatomy; but I hope that the method here adopted, in opening up this interesting subject, will be found in keeping with nature, as it is the result of much study and practical investigation.

The subject to which I have to invite the attention of the Society this evening is one of no modern origin, the name of Hippocrates, amongst others of the fathers of medicine, being commonly associated with it. There is, indeed, perhaps no branch of medical inquiry whose history dips more deeply into the obscure pages of antiquity. The influence of weather upon disease and mortality has been acknowledged as a potent external force in every age, from that eminently speculative and credulous period when physicians professed to receive their diagnostic as well as their therapeutic inspirations from the stars, down to our own day. And yet there is perhaps no question in the whole cycle of medical sciences which has made slower progress than the one we have now to consider. People believe that the weather affects them. They speak of its influence, sometimes commendingly, more frequently with censure, on the most trivial occasions; but beyond a few commonplace ideas, the result of careless observation, or perhaps acquired only traditionally, they seldom seek a closer acquaintance with the subject. Our language teems with medico-meteorological apophthegms, but they are notoriously vague. The words which are most commonly employed to signify the state of the weather at any given time, possess a value relative only to the sensations of the individual uttering them. The general and convertible terms—bitter, raw, cold, severe, bleak, inclement, or fine and bracing, convey no definite idea of the condition of the weather; nay, it is quite possible that we may hear these several expressions used by different persons with reference to the weather of one and the same place and point of time. In order, then, to render medico-meteorological researches more trustworthy, we must be careful to employ, in the expression of facts, such symbols only as have a corresponding value in every nation.

Dear Sir,

Part of my promise has been accomplished in a former letter, in which I gave you the fullest account I could of the springs of boiling water that rise in the valley of Rykum. It now remains for me to send you a description of those we visited in the neighbourhood of Haukadal.

These last are the most remarkable in the island, and the eruptions of water from some of them so astonishing, that I doubt whether any adequate idea of their effect can be given by description. Abler pens than mine might fail probably in attempting to do justice to such wonderful phenomena. The objects, however, are so highly interesting in themselves, that even the simplest narrative that can be given of them will be read with more than ordinary attention.

The problem which bears the name of the Italian geometer Malfatti, by whom it was first proposed and solved, has long attracted the attention and exercised the ingenuity of mathematicians, and has been made the subject of many careful and elaborate researches.

The great attention which has been bestowed upon this problem has arisen partly from its intrinsic difficulty, but chiefly on account of the extreme simplicity of the solution finally obtained by Malfatti, which seemed to open new views of geometrical research, and gave reason to hope that simple solutions might in like manner be found of many other geometrical problems usually accounted very difficult or insoluble.

The prostates or spermiducal glands form a prominent feature in the anatomy of the large family of the Megascolecidæ. Occurring in the neighbourhood of the termination of the sperm-ducts, they assume one of two forms, the tubular or the lobular. In the first, the gland typically takes the form of a bent, undulating, or coiled tube, cylindrical, with a single central lumen; in the second, it consists of a loosely or tightly packed aggregate of lobules, each with its ductule. The prostatic duct is in the first case a continuation of the glandular tube; in the second, the duct is formed by the union of the ductules; in both cases it is as a rule firm and muscular.

The determination by experiment of the thermo-electric relations of any one substance belonging to the electromotive series to all other such substances is sufficient to fix all mutual thermo-electric relations among these. The first endeavour of the experimenter is then to obtain as convenient a substance for this purpose as possible. In investigating charcoal and certain alloys, we have in almost all cases employed one or other of two alloys of platinum and iridium, which have been already used by Professor Tait for a like purpose. The wires we used were the same which he discusses in his “First Approximation to a Thermo-Electric Diagram,” under the names of M and N. Their complete freedom from oxidation, their elasticity, and the high temperatures of their fusing points, rendered them peculiarly suitable for thermo-electric investigations through long ranges of temperature.

Generally both the M and N wires were firmly bound, each by its one extremity to the end or ends of the wire or wires respectively which were under investigation, in a multiple junction. This triple or, as it was in some cases, quadruple junction constituted the “hot junction.” The free extremities of the wires thus united were each bound to a moderately thin copper wire by very thin wire of the same metal, and the copper wires were led from these “cold junctions” to a commutator, which was in connection with a galvanometer. The commutator consisted of an arrangement of small mercury pools, into which the galvanometer and circuit wires, carefully amalgamated to ensure contact, dipped. All the junctions were formed in the manner indicated above, namely, by tightly binding the extremities of the wires together by thin copper wire.

One of the writers' main aims has been to help to prepare the way for a new approach to problems in which the natural occurrence of forsteritic olivines is a vital factor. Variation in their shapes and textural relations in minor intrusions, lavas and melts is examined and the historical development of concepts of their growth and resorption, particularly in magmas, is traced. Particular attention is focused on the olivines of picritic, minor intrusions. It is concluded that in the interpretation of olivine shapes there has been discrimination in favour of magmatic resorption rather than skeletal crystallization. From a wide and detailed survey of forsteritic olivines it is established that they tend to grow rapidly and that their phenomenal variation in habit and shape is probably due to a specific growth sensitivity to slight environmental differences. Concepts of the physical conditions leading to skeletal crystallization are briefly reviewed and discussed.

In this paper, theorems which are extensions of the following, are discussed:—

We define J[n] (λ, x) as

In this expression

The area embraced in this paper consists of that part of Pembrokeshire which lies to the north and north-east of St Bride's Bay. Bounded on the west by St George's Channel and on the north by Cardigan Bay, it extends to the north-east as far as the mouth of the river Teifi, near Cardigan.

That part of the country which lies in the immediate neighbourhood of St David's has, through the laborious researches of the late Dr Hicks and others, become well-known to geologists, and may now be regarded as classic ground. The solid geology of this promontory has given rise to much discussion, and has, perhaps, attracted more attention than that of any other part of the Principality. The reason for this great interest is to be sought in the facts that the rocks of this area are of a very great antiquity, and that the sedimentary series contain the remains of some of the earliest organic forms yet found in the earth's crust, whilst the igneous rocks are also displayed in great abundance and variety, and present us, in the words of Sir Archibald Geikie, with “the oldest well-preserved record of volcanic action in Britain.”

A few years ago, a memoir on high-water marks on the banks of the Rivers Earn and Teith, in Perthshire, by the Rev. Thomas Brown, was read in our Society, and published in our Transactions.

The only other Scotch geologist, so far as I know, who has alluded to the existence of river terraces, much above the level of existing floods, is the late Dr Robert Chambers. In his work, entitled “Ancient Sea Margins,” Dr Chambers specifies many Scotch rivers, in the valleys occupied by which, he had seen terraces, at considerable heights above the rivers and above the sea.

Muscovite is so easily recognised by its optical properties that the only cases which seemed to me to call for analysis were those which, from being possessed of characteristic colour, were of special interest. Of these the most singular is a variety found rarely in the great vein of Ben Capval, Harris; it occurs in crystals of a peculiar green tint, the crystals are small and have somewhat of a pearly lustre.