By tearing thin sheets from the surface of decalcified bones, Sharpey first demonstrated the lamellar nature of bone, and also that these lamellæ have a fibrous structure.

The fibres, consisting of two sets crossing each other, were thought to be interwoven in each lamella, and contiguous fibrous laminæ to be separated from each other by a homogeneous ground substance in which the lime salts were mainly situated; alternations of fibrous and homogeneous layers giving rise to the appearance of lamellation.

From the researches of V. Ebner and my own investigations, the matrix is undoubtedly throughout fibrous, the lamellar appearance being due to an alternation of layers in which the directions of the fibres differ.

The two eggs of the Great Auk which I now exhibit were bought in Dowell's Auction Rooms rather more than a month ago, and formed part of a collection of “birds' eggs, shells, and other natural history specimens” which was disposed of among a lot of miscellaneous property belonging to a legal gentleman of this city. This small collection of eggs had been in the possession of the owner for about thirty years, and the two eggs in question had been purchased by his father from another collector in Edinburgh— a Mr Little—in whose possession it is thought, from collected and trustworthy evidence, the specimens had been at least other thirty years. These eggs, therefore, have probably not changed hands more than once during a period of fifty or sixty years. The present owner of the specimens, Mr Small, animal preserver, George Street, purchased the lot at the sale for £1, 12s., and has since taken great pains to establish the few facts I have stated regarding their history.

The experiment which forms the subject of this communication was originally devised as an illustration of the explanation of all kinds of microphone receivers, suggested by the beautiful experiments of Mr Blyth, on loose contacts. My idea was to replace Mr Blyth's heated point of metal by a continuous portion of the circuit which should act in the same manner.

It was obvious, for two reasons, that this part must be of small diameter; 1st, in order that the resistance, per unit of length, might be great enough to make the variation of the heating sufficient to cause sensible longitudinal extension; 2d, in order that the section might be small enough to allow sensible cooling in, say the of a second. I had reason beforehand to believe that the second of these conditions could be fulfilled in practice; because, I found in my experiments on Ohm's Law (Brit. Ass. Rep. 1876, p. 58, et seq.) that, when currents of two different strengths alternated, even with great rapidity (60 times per second) in a fine wire, the resistance was sensibly higher during the passage of the stronger current.

The plans and calculations in this paper are now more than two years old, but the author has only lately, by the kindness of Professor Tait, found opportunity to carry them out in practice.

A discussion is given of the different methods of applying the telephone to accurate measurement, and mention is made of the points which the author thinks have been missed by most of those who have worked in this way hitherto.

A common principle runs through all telephonic null methods, viz., that the balance may be dependent on the frequency of the interrupted current or may be independent of it. In the latter case there are in general more than one condition of balance, and in the former case, although one will very often suffice, two may occasionally be necessary. In the former class of cases we get relations between electric quantities of the same dimension, in the latter relations between quantities of different dimensions, e.g., between coefficients of induction and resistances: so that when the frequency is known we can find a coefficient of induction in terms of a resistance, and so on.

The object of the present paper is to describe the results obtained and the mode of experimenting adopted in some determinations which I have made of the specific heats of solutions of salts. These experiments form part of a series which I am at present carrying out on the physical changes produced when salts are dissolved in different amounts of their solvents. From such an investigation I believe much information may be gained regarding the nature of solution.

The method of experimenting adopted in the experiments described below was that of mixtures; but as regards the mode in which the exact amount of heat added to the solution was measured, it differed from any process with which I am acquainted. This peculiarity consisted in using as heater a thin glass bottle of about 50 cubic centimetres capacity, and furnished with a long glass neck, just wide enough to allow an ordinary mercury-in-glass thermometer to pass through. This bottle was nearly filled with mercury, in which was immersed the bulb of a sensitive thermometer, and thus the temperature of the mercury in the bottle could be read off at any instant. The graduation of this thermometer was to fifths of a degree centigrade, and had been compared with the Kew standards. The distance between two consecutive divisions of its scale was about one millimetre.

The sounding machine of which the annexed figure is a representation, is intended for use at considerable depths while the ship is proceeding on her course. It is therefore necessarily capable of indicating the depths independently of the length of sounding line or wire used. It possesses the further great practical advantage, that when it has served its purpose once it is immediately available for another sounding.

It indicates primarily the extent to which a given volume of air at atmospheric pressure has been condensed by the column of water to which it has been subjected. As the law of the compression of air is known, the depth reached by the instrument is at once deduced.

The experiments related in this paper were undertaken with a view to determine, by actual observation, the effect produced on solids by hydraulic pressure. The instrument used consists of a hydraulic pump, which communicates with a steel receiver capable of holding instruments of considerable size, and also with a second receiver of peculiar form. This receiver consists essentially of a steel tube terminated at each end by thick glass tubes fitted tightly. It is tapped at the centre with two holes, the one to establish connection with the pump and the other to admit a pressure-gauge or manometer. The steel tube may be of any length, being limited only by the extent of laboratory accommodation at disposal. The tube which I am using at present has a length of a little over six feet and an internal diameter of about three-tenths of an inch. The solid to be experimented on must be in the form of rod or wire, and must, at the ends, at least, be sufficiently small to be able to enter the terminal glass tubes, which have a bore of 0·08 inch, and an external diameter of 0·42 inch. The length of the rod or wire is such that, when it rests in the steel tube, its ends are visible in the glass terminations.

After considering the analogy which exists between the arts of writing and of signalling, the author proceeded to discuss what alphabet is the most suitable where the physical agent is not electricity. If we choose for elementary signals two qualities of the agent of communication A and B, which can be produced independently of one another, then the agent can be put into four states, viz., 1st, having the quality A, but not the quality B; 2d, having the quality B, but not the quality A; 3d, having both the qualities A and B; 4th, having neither of the qualities A and B. One of these states is required to separate letter from letter, and word from word; the fourth state where the agent is undifferentiated, is the one naturally adapted for the purpose. From the remaining three states we can get 3 permutations of one signal, 9 permutations of two signals, 27 permutations of three signals.

At our last meeting Professor Chrystal showed us that a fine platinum wire attached to a stretched disc of skin could act as an electric telephone receiver for the sounds of a violin. The wire was included in a galvanic circuit, and the variations of current were made by a microphone attached to the violin. The account he gave of this interesting experiment was that the receiving wire became extended by the heat of the current either as it was established or suddenly increased by the microphone, and correspondingly shortened on the current ceasing. These extensions and contractions were rendered audible by the disc. A similar demonstration with a like commentary was made by Mr Preece to the Royal Society of London, an account of which was published in “Nature” (June 10). Mr Preece got his wires to speak. At the first May meeting of this Society in 1878 I discussed the subject of the sounds emitted by fine wires, giving passage to intermittent currents. I found that the ordinary thread telephone gave us an easy means of hearing these sounds in non-magnetic metals. De la Rive had heard them in 1845, but since his time no one had been able to hear them, and they were almost looked on as apocryphal. I attached the thread of the skin or paper telephone transversely to the sounding wire, and not directly, as Professor Chrystal has done, for the simple reason that I found that the transverse method gave equally good results with very much less trouble. The cause in both cases seemed to me the same, viz., an internal molecular click which marked the setting in and stoppage of the current.

Subepiphysal Bone Growth. —Two processes must be noticed in this connection.

1st, The replacement of the neck of the cartilaginous head or epipliysis by cancellous tissue as an accompaniment to the rise of the epiphysis caused by the growth of the cartilage forming its neck.

The cartilage is channelled by the advancing marrow, the rows of cartilage capsules being opened up.

The opening up of the rows of cartilage capsules results from the presence of a capillary blood-vessel forming the head of the column of marrow which lies in immediate contact with the next unopened capsule (Ranvier). The close proximity into which the pabulum is thus brought with the cartilage corpuscle in the unopened capsule nearest it causes it to grow rapidly and absorb the surrounding cartilage, this occurring, quickest in the direction of least resistance that is, towards the marrow.

The nature of this paper may he understood from the following headings:—

(1.) The making and placing of the new thermometers.

(2.) Practically described by Mr Thomas Wedderburn.

(3.) The problem with the old thermometers.

(4.) Their next use in level fluctuations.

(5.) Their employment by Sir Wm. Thomson.

(6.) Their subsequent demonstration of the cycle of supra-annual waves of heat and cold.

(7.) The published predictions in 1872 for 1878–80.

(8.) The spoiled predictions in 1877, under the influence of erroneous sun-spot dates.

(9.) The rectified predictions in 1879, when the true date of sunspot minimum was ascertained by direct observation.

(10.) How to obtain correct dates for future sun-spot minima.

Four distinct sources of sound were noticed in the course of the experiments.

1. The variation of the longitudinal tension of the wire, owing to variation in the heating, still appears to be the most likely explanation of the action of the wire telephone, when a very fine wire of ordinary metal is used. Experiments were tried with induction coils of various sizes, the violin and microphone being put into the primary circuit and the fine wire telephone into the secondary. It was found that the sound diminished as the spark-giving power of the coil increased. With Professor Tait's large induction coil no sound at all could be obtained, when the secondary was closed through the most sensitive wire I possess.

The species enumerated in this paper belong to the two orders Phillopoda and Decapoda.

Of the Phyllopods, the author describes two species of Ceratiocaris (Salter), which differ from their Upper Silurian allies in the enormously-developed abdomen and in the small size of the carapace, also in the comparative insignificance of the side spines of the tail compared with the telson. As far as the author is aware, these are the first obtained from the Calciferous Sandstone series, although carapaces of Ceratiocaris have been got from the Mountain Limestone of England. (C. Scorpioides, 1½ to 2 inches long; C. elongatus, 5 to 8 inches long.)

The work described in this paper consists of rather careful measurements, but under low dispersion only, of the spectra of twenty gas-vacuum tubes, generally of different gases and illuminated by small induction sparks, but seen very brightly by the end-on method of viewing.

A comparison of the different spectra thus obtained follows, and some curious results are elicited as to the prevalence of certain impurities among gases, as well as alterations and even transformations of some of them with time and use.

These facts are contained chiefly in Appendix 1 and Appendix 2; while a third appendix, kindly contributed by Professor Alexander Herschel, contains some further observations of his with the same apparatus but higher dispersion introduced. See his account of the same.

In a note on “The Effect of Heat on an Infusible, Impalpable Powder,” by Professor P. G. Tait, in the Proceedings of the Royal Society of Edinburgh, vol. ix. p. 298, for the year 1876–77, Professor Tait points out that such a powder becomes very fluid under the action of heat, and behaves in many respects in the same way as a liquid would do—viz., convection currents are distinctly to be observed, and small particles of the powder are thrown up from the surface, in the same manner as we perceive little drops of water thrown up from the surface of a glass of soda-water. And Professor Tait then asks the question—If, supposing we had two such infusible, impalpable powders, would they diffuse into one another as do gases and liquids ? This is a question which as yet has not been answered. Professor Tait and I have been engaged in some experiments on the subject for some time, but the difficulties (chemical and physical) to be overcome are much greater than at first sight appear, and at present we are unable to say definitely whether they do so or not. But I think an answer may be obtained from another source. In some recent experiments I had occasion to have a number of Berlin porcelain crucibles and amorphous carbon in an impalpable powder kept in contact with each other at very high temperatures for from ten to twelve hours, with the following effect, that, although the crucibles did not become fused, but retained their exact original form, yet the carbon found its way to a considerable distance into the crucible, and some of the particles penetrated the crucible throughout. This was not a case, therefore, of fusion and mechanical mixture.

Since the publication of the first part of this preliminary report (Proc. Roy. Soc. Edin., 1879–80, p. 458), I have received some additional specimens of Ascidians belonging to the “Challenger” collection, and including the following ASCIDIADÆ

Ascidia cylindracea, n. sp.

External appearance. —Shape nearly cylindrical; posterior end rounded and wider than truncated anterior end; ventral edge nearly straight, dorsal slightly concave. Attached by base and lower half of left side. Both apertures at anterior end; branchial towards ventral side, sessile; atrial on dorsal edge, forming a rounded projection; both distinctly lobed. Surface smooth. Colour yellowish-grey. Length, 2 cm.; breadth, 1·2 cm.

The planets move round the sun in ellipses, in such a manner that the radii vectores describe areas proportional to the times. Now, by means of parallel lines, we can always project an ellipse upon a plane surface so as to make the projection circular, and thus we have to consider the motion of a point in the circumference of a circle, describing round an excentric point areas proportional to the times. The angle AOQ is called, very inappropriately, the excentric anomaly; I prefer to call it the angle of position. If we suppose a point M to move uniformly along the circumference, with the periodic time of the planet, and to have reached M when the actual projection of the planet is at Q, it is clear that the sector AOM must be equivalent to the area ASQ. The angle AOM is the mean anomaly.