Authorities on the action of medicinal substances agree in including convulsions among the effects on man of belladonna, and of its active principle, atropia. Similar effects are described as occurring when large doses of these substances are administered to dogs, rabbits, and other mammals, and to various birds. The recent remarkable progress of our knowledge of the exact and ultimate physiological action of many medicinal substances is greatly due to investigations that have been made on animals of a lower type of organisation; and, accordingly, numerous observers have instituted experiments with atropia on such animals, and especially on frogs. Hitherto, however, convulsions and tetanus have not been described among the effects of atropia-poisoning in cold-blooded animals.

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.

The following experiments, in continuation of our research on the discharge of electricity, were made in Professor Tait's Laboratory during the College Session 1878–79, and papers briefly describing the results were read before the Society on 6th January 1879 and 19th July 1880.

The general proposition in the theory of commensurables is to determine the conditions under which lines, surfaces, or solidities, connected with prescribed figures or forms, may have their ratios expressible by integer numbers.

The attention of geometers must have been drawn to this subject by the contemplation of incommensurable lines: the altitude of an equilateral trigon is incommensurable with the base; the diagonal of a square incommensurable with the side, and so on. And, when the two sides of a right angle are expressed by two numbers, the hypotenuse is, in the great multitude of cases, incommensurable with the sides: thus, if the sides be 5 and 7 inches respectively, the length of the subtense cannot be accurately expressed either in integers or fractions. However, when the sides are 3 and 4 units, the hypotenuse is exactly 5 of the same units.

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.

It is a fundamental principle in Algebra, that a problem admits of solution, when the number of independent equations is equal to that of the unknown quantities. If simple expressions only occur, the answers will always be found in numbers, either whole or fractional. But if the higher functions be concerned, the values of the unknown quantities will commonly be involved in surds, which it is impossible to exhibit on any arithmetical scale, and to which we can only make a repeated approximation. Hence the origin of that branch of analysis which is employed in the investigation of those problems, where the number of unknown quantities exceeds that of the proposed equations, but where the values are required in whole or fractional numbers. The subject is not merely an object of curiosity; it can be applied with advantage to the higher calculus. Yet the doctrine of indeterminate equations has been seldom treated in a form equally systematic with the other parts of algebra. The solutions commonly given are devoid of uniformity, and often require a variety of assumptions. The object of this paper is to resolve the complicated expressions which we obtain in the solution of indeterminate problems, into simple equations, and to do so, without framing a number of assumptions, by help of a single principle, which, though extremely simple, admits of a very extensive application.

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.

Dear Sir,

Some time ago I promised to send you the result of a series of observations, made to determine the situation of this place. Having, however, been much hurried of late, I am only able at present to transmit you the determination of the latitude, deduced from a series of observations of the sun's meridian zenith distances. With respect to the longitude, as soon as it is in my power, I will reduce some observations of occultations, and of the late solar eclipse, and send you the results.

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.”

The following experiments and observations have been undertaken with a view to discovering the means by which Tarsonemus is transmitted from one bee to another. It is obvious that a stage of the parasite exists outside the bee, and that there are also several possibilities (which may occur). One is the passage from bee to bee within the hive either directly or through the medium of frames or combs. Another, also within the hive, where the mites may in wandering upon the frames enter the cells and invade the body of the developing larvæ or pupæ, and in this way be present in the bee when it hatches. A third possibility is that whereby foraging infected bees may leave the mite upon flowers, vegetation generally, drinking grounds, or other situations, to be picked up later by other bees chancing to visit these. Crawling or dead bees may in a similar manner prove to be a source of infection through the contamination of the ground about the hive or of the actual hive itself.

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.

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.

The very curious Parasitic Crustacean, the structure and larval form of which we propose to consider in the following communication, we obtained in the month of August last, in considerable numbers, in the branchial pouches of a Lophius piscatorius, which we captured at Whitby in Yorkshire.

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.

Notwithstanding the intimate connexion which has long been known to exist between magnetism and electricity, we may safely say, that, only fifteen years ago, the announcement of the excitation of a luminous spark from a natural magnet would have been received with astonishment and even with incredulity.

After the great discovery of electro-magnetism, in 1819, by Professor Oersted, the extreme improbability of such a discovery was indeed removed; but, even after that period, until the recent researches of our distinguished countryman Mr Faraday, every attempt having failed to procure the feeblest trace of electricity from the obdurate magnetic mass, so striking a result, which comes home to the comprehension of those least accustomed to interest themselves in the less palpable results of scientific enquiry, could scarcely have been looked for with any degree of confidence.

Interferometry, a technique widely used in physics to study radiation fields, has been applied to the investigation of dowsing. Pairs of horizontal linear components, typically some metres in length and a metre or so apart, and parallel in a vertical plane, produce patterns of lines that can be mapped by dowsing rods. The lines are parallel to each other and to the components, and are equally spaced. The spacing of the lines depends on the length, separation and composition of the components. The existence of the patterns shows that the dowsing field is wave radiation. Since there is no detectable difference between patterns produced by pairs of components made of good electrical conductors such as copper, and those produced by good insulators such as uPVC, it is concluded that the radiation field is not electromagnetic. Furthermore, aluminium and tin behave differently from copper and steel. The spacing of the lines has been found to depend on time of year. It increases rapidly in late April and falls rapidly in late November; in between these times it appears to be relatively stable except for an isolated maximum in early March. It shows a high degree of repeatability from year to year.

Of all known examples in physical science, of simplifying, and at the same time “precisionising” some of its fundamental data, which might otherwise fall to be entangled in high numbers, none has been happier than Fraunhofer's application of the letters of the alphabet to certain chief lines in the solar spectrum. Happy both in its conception by the inventor, and its universal acceptance since then by the world. Whence it comes to pass now, that in every country, whoever observes the solar spectrum at all, with whatever instrument, large or small, diffracting or refracting, and whether he holds to the undulatory, or any other theory of light, and catalogues spectral lines either in Wave-lengths or Wave-numbers, or merely in terms of the brass scale screwed to his instrument by a maker,—yet whenever he speaks of the line A, or B, or C, or any other so named by Fraunhofer, he singles out thereby from among thousands, exactly the same identical line which any and every other spectroscopist alludes to under the same simple letter.

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.