In drawing up this abstract, I have somewhat enlarged the plan followed in those formerly communicated to the Society. In order to represent more accurately the progress of the seasons, every month is here divided into three parts, and the state of the barometer and thermometer is given for each of these divisions.

The Cnoc Rhaonastil dolerite boss on Islay, NW Scotland represents a body of alkali-olivine basalt magma which differentiated at low pressure and in situ, from dolerite through teschenite to minor nepheline-syenite. The syenites occur as isolated pods and pegmatitic schlieren within the leucodolerite, and have an exotic mineralogy including Zr-aegirine, Zr-arfvedsonite, Ca-catapleiite, zirconolite and aenigmatite. Fluor-apatite occurs as an accessory phase in the dolerite, but becomes more abundant within the teschenite and syenites. Total REE contents within apatites in the dolerites are typically low (σREE = 0·57–3·21 wt.% oxide), the highest REE contents occurring in irregular, deuterically altered rims and internal patches. The REE-enriched rims also have slightly elevated SiO2 contents at 0·81–0·95 wt.%, suggesting that the substitution scheme Ca2++P5+ ⇔ REE3++Si4+ was operating. These apatites have up to 0·08 wt.% Cl and 3·7 wt.% F, with most being almost pure end-member fluor-apatite. The majority of the teschenite apatites show the least REE-enrichment (σREE = 0·27–0·45 wt.%), coupled with low Na (<0·12 wt.%) and low SiO2 (<0·39 wt.%) contents. However, within the syenites two distinct populations of apatite exist. The first, most common, variety consists of unzoned, low-REE apatites (max. 3·1 wt.% σREE, again in irregular rims and patches), whereas the second variety is often complexly zoned, and has variably enriched zones up to a maximum σREE content of 42 wt.%; this is by far the most REE-enriched natural fluor-apatite so far reported from the British Isles. The REE-enriched zones are often less than 3 μm wide, and have Na content up to 5·4 wt.% Na2O, implying that the substitution scheme Na+ + REE3+⇔2Ca2+ dominated over the more typical scheme involving Si4+ which operated in the dolerites and teschenite. Other zones are either variably enriched in Y (up 2·1 wt.% Y2O3) or Th (up to 0·85 wt.% ThO2). However, there is no correlation between Y and REE contents, suggesting that crystallographic factors were involved in apatite Y and REE partitioning. The REE-rich apatites have very low Cl content (<0·04 wt.%), but high F concentrations (<2·8 wt.%). It is believed that these strongly enriched apatites crystallised under disequilibrium conditions from isolated, variably REE-enriched domains, within the fluid-rich residual syenitic magma. These domains may have been generated by the prior crystallisation of monazite, Ca-catapleiite or zirconolite, which can be found as small inclusions within albite and interstitial analcime. The dynamic process of slumping of the denser teschenite back into the leucodolerite crystal mush is believed to have played an important role in the release of deuteric fluids and the concentration of residual magmas.

About ten months ago, I had the honour of communicating to the Royal Society, a description of a new instrument for ascertaining the Magnetic Dip. Having made very considerable improvements in the apparatus, by means of which some curious results on the magnetic laws, especially those that relate to the production and annihilation of magnetism in iron, have been obtained,—I now beg leave to submit to the Society a drawing and description of my improved instrument, together with an outline of some of the most interesting experiments made with it. Many of the results appear to me to be new; if so, their importance will be my excuse for repeating some parts of the description given in the former paper. It has been long known that iron might be rendered magnetical by percussion; but I am not aware that the precise effect of position has ever been suggested, I remain, &c.

The celebrated Bouguer was the first who discovered the important fact, that the eye can detect a very small difference between two similar illuminated surfaces, when viewed at the same moment,—the only principle which has yet been applied with any degree of success, in determining the relative illuminating powers of artificial flames. The following is perhaps the most commodious application of this principle, to determine the relative illuminating powers of different artificial lights, particularly of coal and oil gas. The instrument, or photometer, which I employ for this purpose, is extremely simple. It consists of a rectangular box, about an inch and a half, or two inches square, open at both ends, and blackened within for the purpose of absorbing the stray-light.

In the following Paper, it is proposed to illustrate more fully the hint explanatory of certain atmospheric colours, given in a notice of the remarkable red hue of condensing steam, communicated on the 21st January. Since that time, I have examined with care the principal authors who have adverted to the subject of the colour of the sky generally, and of the redness of sunset in particular; and since, in the course of that research, I have found much to confirm, and little to modify, the view which I have already taken of the subject, I hope that the present Paper may be considered as a fit appendix to my former experimental notice. It will be recollected that in it I stated the singular fact, that steam does not pass at once from the state of invisible pellucid vapour to that of a misty white cloud, such as issues from the spout of a tea-kettle; but that an intermediate stage occurs, in which it is coloured, even very highly, giving to transmitted light a hue varying from tawny yellow up to intense smoke-red. I then observed, that, since this phenomenon does not require steam of high tension for its production, it is very probable that the tints of sunset and of artificial lights seen through certain fogs, may be owing to the absorptive action of watery vapour in this critical condition.

On the Fossil Plants collected during the Sinking of the Shaft of the Hamstead Colliery, Great Barr, near Birmingham.

The area comprised in the county of Stafford embraces five coal fields—

I. The Goldsitch Moss Coal Field, in the extreme north-east of the county.

II. The Cheadle and Churnet Valley Coal Field.

III. The Wetley and Shafferlong Coal Field.

IV. The Coal Field of the Potteries.

V. The South Staffordshire Coal Field.

The three first mentioned are of small extent, and as I know little of their fossil flora they are omitted from this series of papers on the Carboniferous Flora of the Staffordshire Coal Fields.

I, however, devote a separate communication to the fossil plants met with while sinking the shaft of the Hamstead Colliery, Great Barr, as a considerable part of the rocks passed through during this operation is clearly Upper Coal Measures, not Permian, as has been generally stated. The palæontological evidence, therefore, becomes of special importance in determining the age of the red shales occurring in the upper part of this sinking, which have been usually mapped as Permian.

In examining the changes which light undergoes during its passage through transparent bodies, we not only receive information respecting the properties of that mysterious agent; but we are in some measure made acquainted with the composition of the substances themselves, and with the manner in which their ingredients are combined. The optical phenomena, therefore, which bodies exhibit in their action upon light, are so many tests, to which the philosopher may have recourse, either in supplying the place of chemical analysis, or in correcting and modifying its results. A difference in the optical properties of two bodies, is generally an infallible indication of a difference in their elementary principles; and whatever confidence we may place in the skill of the chemist, or in the accuracy of his methods, the mind can never rest satisfied with the results of an analysis which is directly opposed by optical phenomena.

Of these gigantic thermometers, with their bottle-sized bulbs, their long capillary intermediate tubes, and their upper enlarged bores for scale-reading purposes, an account of their construction and being placed in position for observation on June 26, 1879, is to be found in Part II. Vol. XXIX. of the Transactions of the Royal Society, Edinburgh, for 1879–80, and it is only proposed in the present place to give an account of their performances since that time.

It is well known that no satisfactory demonstration has ever been given of Fermat's celebrated theorem, which asserts that the equation an = bn + cn is impossible, if a, b, c, are whole numbers, and n is any whole number greater than 2. In Legendre's Théorie des Nombres, he demonstrates the cases of n = 3, n = 4, and n = 5, the latter only in his Second Supplement. In Crelle's Mathematical Journal, ix. 390, M. Dirichlet, a mathematician of Berlin, has demonstrated the case of n = 14, but I am not aware whether his demonstration is considered successful. Legendre informs us (Second Supplement, p. 3) that the Academy of Sciences, with the view of doing honour to the memory of Fermat, proposed, as the subject of one of its mathematical prizes, the demonstration of this theorem; but the Concourse, though prolonged beyond the usual term, produced no result.

Although a few papers have been published a number of years ago on the genus Ephedra, the authors have treated the subject mainly from a systematic standpoint. Thus, while the characters of the floral organs have been carefully examined and described, the structure and character of the vegetative organs have only received passing reference. It is proposed in the following notes to undertake the study of the histology of the vegetative organs, and thereafter to ascertain how far this knowledge applies to the determination of species. The following notes deal with the histology of the primary stem.

In the second volume of the Asiatic Researches, an extract is given from the Surya Siddhanta, the ancient book which has been long, though obscurely, pointed out as the source of the astronomical knowledge of the Brahmins. The Surya Siddhanta is in the Sanscrit language: It is one of the Sastras, or inspired writings of the Hindoos, and is called the Jyotish, or Astronomical, Sastra. It professes, as we learn from Mr Davis, the ingenious translator, to be a revelation from heaven, communicated to Meya, a man of great fanctity, about four millions of years ago, toward the close of the Satya Jug, or of the Golden Age of the Indian mythologists; a period at which man is said to have been incomparably better than he is at present; when his stature exceeded twenty-one cubits, and his life extended to ten thousand years.

The notice which, at the suggestion of Dr Brewster, is now to be laid before the Society, respecting a remarkable shower of hail which lately fell in Orkney, has been drawn up partly from conversations with Richard Caithness, a plain but intelligent country man, who possesses a small farm at Hunday in the island of Stronsa, and whose property suffered severely from the shower; and partly from subsequent correspondence with the Reverend William Taylor of Stronsa, whose house lay in the track of the cloud, and with Mr Robert Lindsay, Student of Divinity, who had an opportunity of witnessing the effects of the hail at Lopness, on the neighbouring island of Sanda, when the shower was nearly exhausted. They agree in all important particulars; but even at the risk of some repetition, their own words shall, as often as possible, be employed.

The morning of the 24th of July 1818, was, in Orkney, clear and warm, with a slight air of wind at due south.

In February 1909 Mr John Thompson, Hull, forwarded to me for identification, along with species of Hydroids, specimens of a “Pedicellina,” which he was unable to identify with any known British form. These specimens proved to be of particular interest; and although a first consignment was dead on arrival in Edinburgh, Mr Thompson was successful in obtaining additional specimens, which, having travelled safely, were kept under observation in a living state for a week, when they were preserved for more detailed examination. Cocaine was found to be the most successful narcotising agent.

From the point of view of its function, a nerve fibre is a conductor of nervous impulses, and as such is the path of communication between two structures, the one situated in the central nervous system, and the other in the periphery. In the mixed nerve, such as the sciatic, the nerve fibres are distinguished as afferent or as efferent, according as they conduct impulses originating at the periphery, and received by a cell in the central nervous system, or vice versâ. It has long since been shown that nerve fibres are capable of conducting impulses in either direction, but normally, from their anatomical connections, the individual nerve fibres are conductors for impulses only in the one or in the other direction. This is proved by the Wallerian method of investigation, as on severance of the posterior spinal root distal to the ganglion only certain fibres degenerate and the conductivity of the nerve only for afferent impulses is lost, while the severance of the anterior root is followed by the degeneration of the remainder with loss of functions depending on efferent impulses.

We have examined the sample of spirits, which was sent by Dr Hunter of York to the Royal Society, and we have read the account of the experiment on the sermentation and distillation of carrots by which the said spirit was produced. The experiment was made by Mr Thomas Hornby, druggist in York, with one ton and eight stone of carrots, which, after being exposed to the air a few days to dry, weighed 160 stone, and measured 42 bushels; they were washed, topped and tailed, by which they lost in weight 11 stone, and in measure seven bushels; being then cut, they were boiled with the proportion of 24 gallons of water to one third of the above quantity of carrots, until the whole was reduced to a tender pulp, which was done in three hours boiling.

When any one of the following tables has been given in the past to an extent useful at the present time, it will be found by the computer that the necessary volume is only with difficulty accessible and hardly ever to be purchased. That these tables are obviously useful is perhaps all that need be said in justification of their more extended computation.

Every mineralogist is conversant with some of the facts relative to the subject of this paper. Some of the observations enumerated, are comparatively new, as the attention of naturalists has been only of late more particularly directed towards these facts. Others, which I have had an opportunity of collecting myself, I trust will not be considered uninteresting, as they tend materially to rectify certain ideas connected with the determination of the mineralogical species, the most important branch of natural-historical research.

The usual methods of obtaining pure phosphoric acid by the oxidation, with nitric acid, or by combustion, of pure phosphorus, are well known; but, although they yield a pure product, yet, as the phosphorus must be prepared from phosphoric acid, it is obvious that we shall derive a great advantage from any method of purifying easily and cheaply the phosphoric acid from bones, instead of first reducing it to phosphorus, and then re-oxidizing it. In practice, phosphorus is made from the superphosphate of lime, and it is from the same salt that phosphoric acid may be most economically prepared.

The following observations may serve to illustrate and confirm the opinion now very generally adopted by Anatomists and Physicians, That an affection of one hemisphere of the brain, whether from internal disease or external accident, produces its morbid symptoms on the opposite side of the body.