The Equatorial of the Royal Observatory, Edinburgh, is still in October 1887, unfinished, blocked against use, and entirely unusable. This lamentable outcome of so many years, is simply the consequence of the necessary funds for finishing and working the instrument having been withheld by Government, after they had been promised by the Board of Visitors, printed again and again in much detail, and thought to have been obtained.

Green's dynamics of polarisation by reflection, and Stokes's dynamics of the diffraction of polarised light, and Stokes's and Rayleigh's dynamics of the blue sky, all agree in, as seems to me, irrefragably demonstrating Fresnel's original conclusion, that in plane polarised light the line of vibration is perpendicular to the plane of polarisation; the “plane of polarisation” being defined as the plane through the ray and perpendicular to the reflecting surface, when light is polarised by reflection.

In the Proceedings of the Royal Society of Edinburgh, vol. xiv. [No. 123], pp. 97–106, there is a paper of mine under the above title. I wish in the present memoir to communicate to your distinguished Society further details relative to these investigations. The principle of these researches is to find some germicidal agent capable of destroying the microbes of disease, which have been proved to reside in the blood, and are the causes (directly or indirectly) of certain contagious diseases. At the same time, an aqueous solution of such an agent, while destroying the microbes of disease, must have very little or no detrimental action upon the blood. Having found such a substance, the rationale is to inject (hypodermically) a solution of the microbe-destroyer directly into the blood. By so doing, the destruction of the pathogenic organisms in situ would be the result.

Indian cattle have, with few exceptions, jet black skins. The hair is frequently white, grey, brown, or black, but only in rare cases are the skins white. The animals having white skins are weakly, if not unhealthy, are liable to blister with the sun, and contract after a time a form of leprosy.

In this paper the author described the pineal body in the walrus and in Phoca vitulina and Macrorhinus leoninus, in which animals, but more especially in the walrus, it is of larger size than is usual in mammalia. In one walrus it measured 30 mm. (1.18 inch) in length and 18 mm. (0.7 inch) in its greatest transverse diameter; in another it was 29 mm. long, 13 mm. broad, and 13 mm. in vertical diameter. It rested on the superior vermiform process of the cerebellum, and was visible between the two diverging hemispheres of the cerebrum when the brain was looked at from above. [The paper is printed in extenso in the Journal of Anatomy and Physiology, January 1888, and as a part of the ‘Report on the Seals’ collected by H.M.S. ‘Challenger,’ Part LXVIIL, 1888.]

Within the limits of the experiments, which were for t from 0° C. to 15° C, and forp from 1 to 3 tons-weight per square inch, it was found that the average compressibility of water per atmosphere may be fairly represented by

a formula which, while very convenient for application in the hydrostatic equations, extends to the whole range of temperature and pressure ordinarily occurring in nature.

The phosphines have, comparatively speaking, been little studied, and most of our information concerning them is due to the investigations of only two or three observers. There are consequently many points in their history which require examination, and the object we had in making the present research was to extend our knowledge of them as a group. We experimented in the benzyl series for several reasons, among which we may mention the following

In the fourth Mémoire of his celebrated Relation des Expériences, published in 1847, Regnault gives cogent reasons for preferring the air thermometer before any other as the instrument by means of which temperatures may be defined, and high temperatures determined. The thermodynamic researches of Sir William Thomson have furnished an absolute thermodynamic definition of temperatures ; and the experimental researches of Dr Joule and Sir William Thomson have established the practical agreement of Regnault's air thermometers with the thermodynamic scale of temperatures. Lastly, the air thermometer is at present the only instrument, with the exception of a mercurial thermometer which has been compared with an air thermometer, by means of which temperatures higher than, say, 150° C. or 200° C. can be determined within 3° C. or 4° C.*

The imaginaries of Algebra have done good service during the process of discovery of the principles of quaternions. Now that those principles have been founded on the basis of operations on real lines, we must no more admit as the equivalent of a unit-vector. Vectors, and unit-vectors, by their very definition, represent real lines, each of given direction and length, and a real quantity cannot be represented by an imaginary one.

In a paper communicated to the Berlin Academy on 27th July 1882, Kronecker pointed out that certain sets of minors of any axisymmetric determinant are connected by a linear relation, or, as I have tried to put it more definitely in the present title, that certain aggregates of minors are equal to zero. This discovery has attracted considerable attention in Germany, as the list of papers herewith given suffices to show.

In the course of verifying some of the mathematical work in the third instalment of Professor Tait's paper on the Kinetic Theory, the following simplification of his proof of Maxwell's theorem occurred to me.

The object of this communication is to exhibit and describe to the Royal Society a number of flint-glass globes having remarkable internal cavities produced during cooling. Along with these globes there is exhibited for comparison one globe having no perceptible internal cavity.

The making of these globes was shown to me by Mr John Griffin, manager of the St Rollox Flint Glass Works, Glasgow.

The globe having no internal cavity is marked A. A set of globes, four in number, are marked B1 B2, B3, B4, and the sixth globe is marked C.