I deem no apology due for introducing to the notice of the Royal Society the subject of the present paper. The close and accurate criticism which distinguishes modern scholarship has allied all branches of knowledge in a common scientific system; and the laws which regulate the development of human society are now recognised as being not less inexorable than those of which the operation on material objects is the more frequent theme in this room. To exhume the forms and types of ancient society, to subject them to close analysis, to identify their prototypes and trace their evolution in our modern life is not less a scientific study than to dig out the nodules of remote ages from those ancient records the rocks, and to subject them to that analysis which detects their identity with forms of life still extant. But with this difference in our present inquiry : the forms of existence of which the nodule is the representative have transmitted their characteristics through so great a succession and variety of forms as to make their identity with, or even relation to, any modern type distinguishable in most cases only by subtle processes of analysis; they are themselves callous and dead, and have no direct contact with the life of the present day; but the systems of ancient society have not undergone that process of extinction and disintegration in transmitting their characteristics; it is less in the alembic that decomposes than by the scalpel that exposes, that their characteristics are discoverable; they do touch, and that often closely, the living present, and there is danger therefore that in the search for ancient truth a nerve may be sometimes touched that may send a thrill into living organisms in our modern society, aflame as some of these are at present with fevered sensation and debate.

In this paper an anatomical peculiarity was described which is occasionally found both in Man and the Cetacea. It is not due to a bifurcation of the shaft of a single rib at its vertebral end into two heads, but to the fusion of what ought to have been the shafts of two distinct ribs into a common body, and it invariably occurs at the apex of the thorax. Although the author had long been familiar with dried specimens from the human body in the Anatomical Museum of the University of Edinburgh, two cases which he now describes were the first that he had seen in the subject itself in the course of nearly thirty years' experience as a teacher of anatomy, and it is remarkable that they should both have occurred within a few months of each other. A third specimen occurred in a skeleton in the possession of one of his pupils, Mr Minas S. P. Aganoor.

Professor Tait laid upon the table a series of Photographs of Astronomical Instruments made at the new works of the Geneva Society for the Manufacture of Scientific Instruments. These photographs ware sent by the Astronomer-Royal for Scotland.

It is narrated that a physician, having given cogent reasons to show that there could be no recovery, and somewhat disconcerted by the return of sound health, yet maintained the cogency of his pathological arguments. The present may be a new edition of the same story; however, we shall advance the arguments, and leave it to futurity to tell whether there be any patient at all.

This apparatus will be best understood by a reference to the figures. The bell-jar A (fig. 1) rests, during filtration, on a square block of hard wood c, 25 cm. square by 25 mm. thick, over which is laid a sheet of vulcanised rubber d of good quality, and not less than 3 mm. thick. In the centre is a circular disk e also of hard wood, 13 cm. in diameter and about 20 mm. thick, which is held in position by four strong brass screws which pass down through the rubber into the square block below.

When a current of electricity is sent through a dynamo machine in the same direction as the current flows when the dynamo is being used as a generator, then the field magnets are polarised in their normal manner, and the magnetism of the armature is such as to cause it to rotate in the opposite direction to that in which it turns when generating a current. The dynamo now acts as a motor. If now the current be sent through the dynamo in the opposite direction, the field magnets are polarised in the opposite manner, i.e., a north pole is found where a south pole was before. The same is true of the magnetism of the armature.

In an ordinary simple Ascidian, where both the branchial and atrial apertures are at or near the anterior extremity of the body, the region lying between them—the interoscular area of Laeaze-Duthiers—is small in extent, and contains three important structures, the nerve ganglion, the neural gland, and the dorsal tubercle, lying close together. The ganglion in such a case is elongated dorsoyentrally, and gives off nerves at its two extremities, one set ventrally and anteriorly towards the branchial aperture, and the other set dorsally and posteriorly towards the atrial.

When we try to define, from a purely geometrical point of view, the rigidity of a system of points, we are inclined to consider the invariability of the mutual distances of the points a sufficient definition. But when we take this definition as a starting point, in the problem of expressing the finite displacements of the system, we soon discover that the invariability of the distances is not sufficient for insuring the invariability of the relative positions of the points.

The unrestricted problem, “To find the form assumed by an elastic system when subjected to. known strains,” is one of those mechanical problems which baffle the powers even of the modern calculus. It is only when the change of form is exceedingly small that we can obtain approximate results. In the simplest case—that of a straight uniform elastic body—there is, so far as I know, no complete solution; and thus I venture to suppose that the following remarks may not be devoid of interest:—

The difficulties attending the measurement of the electrical resistance of electrolytes are well known, the rapid growth of the polarisation of the electrodes especially preventing the application of the ordinary Wheatstone Bridge method. The polarisation may be kept down by using alternating currents, as was done by Kohlrausch; and this method is no doubt the most general and most accurate which has yet been applied.

That the electrical resistance of palladium is increased by hydrogenisation has long been known, but the lack of any very definite information induced me to investigate the matter last winter.