In a previous paper the hypothesis propounded by Kapteyn that the stars are moving in two streams was examined by considering the proper motions of stars which were moving more than 20″ a century. By a graphical method the directions of these two streams were found with results in fair agreement with those found by Kapteyn and Eddington by other methods and with different material. It was evident from that paper that it would be possible in a large percentage of cases to say with tolerable certainty to which stream individual stars of large proper motion belonged.

§1. The main object of this paper is to point out a method of applying hydrodynamic solutions already obtained to the solution of problems relating to flexural vibrations of thin elastic rods.

According to Kirchhoffs law every body in a state of pure temperature radiation absorbs those rays which it emits, and the ratio of the coefficient of absorption to the coefficient of emission is constant for all bodies. In many cases which do not come under the category of temperature radiation —for example, a sodium flame—the wave-lengths emitted are also absorbed. It is thus possible that a fluorescing substance, in addition to its ordinary absorption, may absorb while fluorescing those wave - lengths that it fluoresces. From a photometric study of fluorescent uranium glass Burke stated he had discovered such an effect. A cube the edges of which measured 1 cm., transmitted while fluorescing only 57 per cent, of the light it transmitted when not fluorescing, the measurements being made, of course, on light of the wave-length emitted during fluorescence. Nichols and Merritt investigated the subject in detail, obtained a similar result for fluorescein, using a Lummer-Brodhun spectrophotometer, and found that the additional absorption produced during fluorescence—or, to give it its usual name, fluorescence absorption—possessed many strange properties; for example, it did not follow the exponential law. Camichel repeated Burke's work with two different experimental arrangements, and found no effect; he also obtained no effect with fluorescein. Miss Wick, using the same apparatus and working in the same laboratory as Nichols and Merritt, confirmed their results for resorufin. For a full description of the work of these observers and an account of the present state of the question, together with the necessary references, the fourth volume of Kayser's Spectroscopie (1908), pp. 963–973, should be consulted.

If the electrodes of an induction coil be placed at such a distance that a spark will not pass easily, then the introduction of a dielectric between the poles will greatly facilitate the sparking, provided the dielectric be placed near or against the positive pole, but will not have this effect if placed against the negative pole. Experiments were made with mica, sulphur, glass, and ebonite, etc.

An extract of the seeds of Strophanthus sarmentosus appears to be an important ingredient of the arrow-poison of Nigeria and other parts of West Africa. While some of the other ingredients of this arrow-poison may possess toxic power, others of them have little or no toxicity and are introduced into the arrow-poison with the object, apparently, of rendering it more viscous and adhesive or with a superstitious intention.

1. When kidney or liver tissue is immersed in a saline solution containing chloroform, degenerative changes take place similar to the normal necrobiotic changes but very much more rapid. In the case of the kidney the glomeruli are not affected for a very considerable time.

2. When chloroform is administered through the respiratory passages a considerable degree of degeneration is only occasionally found in the kidney and liver cells. It is more marked in some cases than in others where a similar amount of chloroform was given to animals of a similar size. This may be associated with the very varying rate at which the drug is eliminated, as shown by Miss Lindsay (loc. cit.). The degree of change in the liver was never great. In the kidney there is frequently cloudy swelling, and occasionally desquamation of the epithelium of the ascending and descending tubules.

3. Where the drug is given by the stomach the mortality is great and the changes observed in the organs are marked. In all cases there is evidence of the toxic action of the drug. In the animals most affected, the structure of the liver is almost entirely lost, nothing remaining of the lobules but a shell of liver cells enclosing a cheesy debris.

In the kidney the drug acts in a similar way, the degree of degeneration being somewhat less than in the liver.

The glomeruli are but little affected even in the worst cases.

4. When the drug is given hypodermically the changes are similar to those observed when the drug is given by the stomach. The liver is again more affected than the kidney.

On the whole, however, chloroform does not appear to be quite so destructive to the liver tissue when administered in this form.

5. The marked action of the drug upon the liver, whether administered by the stomach or hypodermically, is probably accounted for by the “anchoring” action referred to by D. Noël Paton (1). It would be interesting to know if there is evidence of a similar action on the part of the kidney cells to account for the extensive degenerative change frequently observed there.

6. The result of these observations helps to explain the different effects of chloroform on hepatic metabolism. When given by the respiratory passages it is rapidly eliminated, produces no marked histological changes, and the metabolic disturbances are slight; but when given by the mouth and hypodermically it is more slowly eliminated, has more time to produce its toxic action, and the metabolic disturbances are pronounced.

In a future paper the action of chloroform upon the blood corpuscles will be dealt with.

The minimum resistance to deformation, and the inclination of the surfaces of sliding, are given for any system of stress in a body, supposing internal friction to be operative.

The effect of internal friction in various cases of combined loading, and the value of the coefficient have been calculated from experimental data. The results do not allow of a definite value being assigned to μ for steel.

Certain differences in the behaviour of ductile and of brittle bodies, when loaded, are pointed out.

An expression for the equivalent bending moment of a shaft submitted to simultaneous bending and twisting, when internal friction is allowed for, is given.

The effect of the friction of the crushing plates upon the yield point of short compression specimens has been investigated.

With plates harder than the material under test, the end friction causes an increase in the apparent yield point. This increase is calculated as 18 per cent. for wrought iron and mild steel, 20 per cent. for cast iron, and 50 to 200 per cent. for stones, bricks, and concrete. These figures, except the first, may apply almost equally well to the crushing strength, but they require experimental support. The corresponding inclinations of the surfaces of shearing are 37° for wrought iron and steel, 36° for cast iron, and 27° to 15° for stones, etc. The first value is seldom obtained, but the others agree fairly well with average experimental results.

When the crushing plates are of material softer than that under test, the lateral flow of the former diminishes the apparent strength of the specimen. With stones crushed between lead plates the strength is calculated as 0·35 to 0·15 of that obtained when iron or steel plates are employed. Experiments give 0·65 to 0·43 as the value of this ratio, but the specimens do not rupture by shearing in the manner contemplated.

The total crushing load of a short specimen of cast iron is increased by diminishing the length of the piece, but the crushing stress per unit of area is simultaneously decreased.

§ 1. The theory of group-velocity has been developed by Stokes, Osborne Reynolds, Lord Rayleigh, and later by Professor Lamb. The application of the theory to light-waves was made by Gouy and Lord Rayleigh, and its importance in this connection was emphasised by Professor Schuster in his paper “On Interference Phenomena,” Phil. Mag., vol. xxxvii., 1894.

While working at another subject I evolved a very simple piece of apparatus which on trial was found to be very sensitive to the penetrating rays of radioactive substances, so I have recently diverted my work from its original direction to study and improve this piece of apparatus. The principle of the action of the instrument is not new, as it depends on the fact discovered by Professor C. T. R. Wilson, that ions in air supersaturated with water vapour become centres of condensation when the supersaturation is sufficiently great.

I.—Nous avons vu, récemment, que les Macrwridœ, dans l'état actuel de nos connaissances, sont représentés par une espèce à l'intérieur du Cercle Polaire Arctique et par deux espèces à l'intèrieur du Cercle Polaire Antarctique.

My last communication in reference to the history of Jacobians dealt with the period 1815–1841 (Proc. Roy. Soc. Edin., xxiv. pp. 151–195). The present paper continues the history up to 1860.

Neptune's satellite was discovered by Mr Lassel of Liverpool in 1846. This satellite differs from the other planets and satellites, except those of Uranus, in the direction of its motion, which is from east to west. After the satellite had been observed for a few years, it was pointed out by Mr Marth that the node and the inclination of its orbit were slowly changing. These changes were explained by Tisserand and Newcomb as arising from the spheroidal shape of Neptune. The observations prior to 1892 have been discussed by Dr Struve in the Mémoires de l'Académie Impérials des Sciences de St Pétersbourg, viie série, tome xlii. No. 4. Since then a large number of valuable observations have been made at American observatories, especially by Prof. Barnard, and at Greenwich Observatory.

M. Melitensis is virulent to a greater or less degree for all the usual laboratory animals — guinea-pigs, rabbits, rats, mice, dogs, and monkeys — and by means of suitable passages its virulence for any particular species can be considerably exalted.

The discussion as to the homologies existing between the sound-conducting apparatus of the mammalia and certain elements of the lower jaw and branchial skeleton of fishes has occupied the attention of numerous authors. In fact the question may be considered as a classic, dating as it does to at least 1778, when Geoffry published his Dissertations sur l'organe de l'ouie de l'homme, des reptiles, et des poissons. From that time until 1898—from Geoffry to Gaupp—the contributions to the literature upon this subject constituted an enormous amount. Inasmuch as Gaupp has given a detailed and masterly review of the literature up to the time of his work (1898), and since Fuchs thoroughly covered the ground seven years later, I shall not undertake that task in the present communication. Moreover, as this paper is in the nature of a preliminary report upon the entire developmental history of the skull in the horse, I shall not here review in detail the contributions to the literature since the time of Fuchs' account (1905)

Dr Pettersson has recently published a paper on “Gezeitenaehnliche Bewegungen des Tiefenwassers” (Publications de Circonstance, No. 47), in which he describes certain movements in the deep waters of the Skagerak observed in January, February, and March 1909 at the Swedish station Bornö, in the Gullmarfjord, lat. 58° 24′ N., long. 11° 33′E. The observations were taken daily at 12.30 p.m. by means of soundings made through the ice. The diagram accompanying this paper is a reproduction of a diagram prepared by Dr Pettersson, and shows the observed variations in the position of the isotherms and isohalines. No observations appear to have been made on 7th, 8th, 10th, and 11th February, nor from 15th to 18th March, so that there are large interpolations on the diagram. Fig. 1 is a map of the Skagerak, the point of observation being marked by a cross.

It has long been known that the male and the female human genital tract contain not only organs characteristic of their sex proper, but also certain parts of the opposite sex in a less developed but yet perfectly definite form. Thus the female genital tract is made up of, not only its characteristic organs, the ovaries, tubes, uterus, etc., but also the epoophoron (parovarium) and its duct, the equivalent of the epididymis and ductus epididymis of the testis. In the same way, the human male has his characteristic sexual organs and also the appendix testis and prostatic utricle, the representatives of the fimbriated end of the Fallopian tube and of the lower end of the vaginal tract (hymen mainly, but varying).

One of the authors having made an experimental investigation on the currents produced in a trough of water by a blast of air driven along the surface of the water, it was desired to test the correctness of his deductions by actual observations in a large lake. Loch Ness was chosen on account of its length and uniformity of basin, as it was thought that the length and narrowness of the loch would lead to clearly defined currents being set up in the lake. The sequel showed, as in the case of observations on seiches, that it would have been better to confine attention to a smaller lake, for a twofold reason, (1) because in a large lake the difficulties of observations are much greater than in a small lake during stormy weather, and in very deep lakes the difficulties in the way of obtaining a fixed point from which to use the current meter are formidable, and (2) because it would seem from a few observations made in Loch Garry (Ness Basin) that currents are more defined and more regular in small than in great lakes.

Different experimenters on the degree of hydrolysis of amphoteric electrolytes in acid solution have obtained very discordant results, according to the method they employed.

The object of the present paper is to make some advance in the theory of those skew determinants that have the elements of the diagonal all equal. A few results on determinants of more general form and on related subjects are given incidentally.