‘The Council of the Royal Society desire to record in their minutes the grief which they have felt in the death of James D. Forbes, Esq., lately Principal of St Andrews University, and their sense of the loss thus sustained—of one who was so great an ornament to science, and so long and so intimately connected with this Society. As a scientific inquirer, and as an academical instructor, the name of Dr Forbes will be held in reverence by all who knew him, or who benefited by his exertions; and it is a subject of deep regret that he should be cut off in the prime of life, and the scientific world deprived of his services at a time when his appointment as Principal of St Andrews University had placed him in a position where, if life and health had allowed, he might, by his further labours, have added to his own reputation and to the range of scientific discovery.

This paper, after a short introduction upon previous publications and experiences, describes in a plain and practical manner four steps of improvement recently made in the centrifugal governor of an equatorial driving clock; and touches on

1. The number of the pendulums;

2. Their weight and momentum;

3. Their chronometric principle; and

4. The intensification of the effect of gravity upon them, chiefly to increase the promptitude and energy of the centrifugal action.

An amusing and instructive example of the way in which logicians are accustomed to dogmatise upon the theory of sciences that they do not understand, is afforded by Mr Mill's explanation of the nature of geometrical reasoning.

Those who remember that Mr Mill assures Dr Whewell that he has conscientiously studied geometry (Logic, 7th ed. I. 270), will probably find some difficulty in believing that the demonstration of Euc. I5, which Mr Mill offers as an illustration of the justice of his theory of geometrical reasoning, depends on the axiom, that triangles, having two sides equal each to each, are equal in all respects. Such, nevertheless, is the case; and when one sees this absurdity pass unmodified from edition to edition of Mr Mill's Logic, and when even Mansel, Mr Mill's watchful enemy, tells us that “against the form of the geometrical syllogism, as exhibited by Mr Mill, the logician will have no objections to allege” (Mansel's Aldrich, 3d ed., p. 255), one cannot but think that logic would make more progress if logicians would give a little more attention to the processes they profess to explain.

Before proceeding to the special subject of this address, I have thought that it might be of interest to the Society to lay before them a brief outline of the history of geological map-making in Scotland, previous to the time when the task was undertaken by the Geological Survey. I do not, indeed, presume to enter upon any general retrospect of the literature of Scottish geology, but will content myself with selecting for remark a few of the more eminent contributors, on whose labours the present general geological maps of the country are based. These maps are compiled from the results obtained by many different geologists, working independently during the last fifty or sixty years. Some of the men whose researches have in this way been made ase of, never themselves produced any map, but their descriptions of the districts traversed by them served afterwards as a basis for the maps of others.

In this paper the author described in the adult human heart certain vestiges of structures which, during fœtal life, exist in an entire and perfect state. At birth, however, these, ceasing to be of use, generally disappear.

In allusion, first, to the Eustachian valve, he exhibited (and illustrated by the annexed sketch, fig. 1), an apparently unique specimen—obtained in his dissecting-rooms about six years ago—namely, a very large and reticulated Eustachian valve, prolonged at its middle third in the form of a semi-insulated cribriform fibrous lamina, taking a crescentic form continuously throughout, and after a valvular manner ending at the distance of three-sixteenths of an inch from the crest or rim of entrance of the superior vena cava.

In taking cranial capacity as a ground of comparison between the Anthropoids and Man, he gave some measurements of skulls contained in the Museum. The capacity of the cranial cavity in the Gorilla skeleton belonging to the Museum is 29 cubic inches. Considerably larger gorilla skulls, however, have been measured. The smallest healthy adult human skulls in the Museum are those of two Andaman Islanders. Of these, one has a cranial capacity of 75·5 cubic inches, and the other a capacity of 72 cubic inches. Next to these comes a Peruvian skull; its cranial cavity measures 76 cubic inches. The smallest healthy adult human skull measured by Morton was also that of a Peruvian, whose cranial capacity measured only 58 cubic inches.

Graham, in continuing his exhaustive researches on diffusion, has recently examined the relation of gases to various colloid septa. The remarkable discovery of Deville and Troost of the permeability of platinum and iron by hydrogen at a red heat, he lias expanded into a general examination of the relative rates of passage, at high temperature, of the various gases through different metallic septa. Further, he has proved that different metals have a specific occluding power over certain gaseous elements, retaining them in combination at low temperatures, although the absorption took place at a red heat. Of the many astonishing discoveries made during the course of these investigations, probably the most remarkable is the occlusion of hydrogen by palladium. This metal, whether in the form of sponge or hammered foil, when heated and cooled in an atmosphere of hydrogen, absorbed between six and seven hundred times its volume—increasing to the enormous occlusion of 982 volumes, when the metal used had been deposited by voltaic action.

This is an abstract of the first of two papers on the subject, prepared for the Society.

Physical bodies may be held, in accordance with chemical science, to consist of aggregations, either of material atoms, or of atomic circles, or centres of force.

There are certain exhibitions of physical power observed in connection with those atomic bodies, the laws and actions of which are in the highest degree worthy of study. Mr Wyld calls power exhibited in this way, free an-atomic or tranmissible power.

It having been shown by one of us that formic acid is produced by the union of carbonic acid and nascent hydrogen, it occurred to the authors to try whether other gases might not be made to unite directly with nascent hydrogen. Such experiments gave the prospect of being of especial interest in the case of nitrogen, as it was possible the synthesis of ammonia might thus be effected by the direct union of nitrogen and hydrogen.

In this paper the author drew attention to the nature of the process of Chemical Exchange (including substitution, double decomposition, and some cases of direct addition and subtraction), as a process by which the number of relations in which any given atom stands is unaffected. He pointed out the connection between this process and the notion of chemical structure, and discussed the nature of those chemical processes in which the number of relations of an atom is increased or diminished.

This paper is a compilation and discussion of all the best determinations of the sun's mean distance and parallax within the last few years, and up to the present time. The comparative weights to be given to the different observations or results are entered into at length, on principles which are stated, and a final mean of the whole is arrived at, giving for the solar parallax 8·″877. This is then compared with the result of the so-called Great Pyramid Sun Distance, which, combined with the best modern determination of the size and shape of the earth, gives a parallax of 8·″876.

That the temperature of the child is not the same as that of the adult has long been a generally acknowledged fact, but wherein and to what extent it differs is a point on which definite information is wanting. With the object of determining this point, the author took advantage of the opportunities afforded by a residence in the Edinburgh Maternity Hospital, to note the temperature of a number of children at the time of birth, and at frequently repeated intervals during the first few days of extra-uterine life. The result of these observations was to show that the child at birth partook of the temperature of the mother—that as soon as it commenced its separate existence the heat imparted by the parent was no longer maintained, but was rapidly lost, till, in a few hours (the exact period varying in different cases), the thermometer indicated a temperature one, two, three, or even six degrees below the normal standard of the adult.

The earliest condition of the embryonic vascular system, as described by Wagner and other embryologists, consists of a venovascular chain of sinuses along the ventral surface of the serous or animal lamina of the embryonic germ disc, which, being suddenly arrested by a large projection of the germ vesicle at the anterior part beyond the vascular and mucous lamina, causes a stagnation in the form of a conical sac, whose apex points forward below the head of the embryo at that time consisting of the mesocrane and procrane, with the visceral segments of the face-kist, and exhibiting three facial clefts.

In Part I., read 16th March 1868, in which was discussed the Mean Pressure of the Atmosphere over the Globe for July, January, and the year, the method by which the Isobaric Charts were constructed was detailed at length. Since March 1868, valuable additional information has been obtained from Australia, New Zealand, Tasmania, Africa, South America, the west coast of North America, Iceland, and from a few isolated stations in Europe and Asia. The period for the British Islands has been extended so as to include the eleven years from 1857 to 1867.

The author's former views on American storms were first alluded to—i.e., that the phenomena could only be accounted for on the supposition that there were two distinct currents. Instead of these being parallel, they were more nearly at right angles to each other. The southerly current on the eastern axis of storms brought up heat and moisture from the Gulf of Mexico, causing the barometers to fall. The west or north-west wind, on the other hand, cleared the southerly current away, causing the temperature everywhere to fall and the barometer to rise.

It was explained that this deposit, known in Scotland as Till or Boulder-Clay, prevails also in Ireland, the Isle of Man, England (north of the Thames), Denmark, and Sweden, though much less abundantly in these last countries. It exists also in the Hudson's Bay districts, and at the south extremity of South America.

It had been a subject of perplexity to geologists ever since attention was drawn to it, fifty years ago, by Sir James Hall of Dunglass, whose papers are in the Transactions of this Society.

About the year 1840 a theory was started to account for the boulder-clay, and other phenomena allowed to be connected with it, by the action of glaciers.

The affinities of the order Lentibulariaceæ having hitherto been somewhat obscure, the author undertook the investigation of the floral organogeny of P. vulgaris, in the hope of being able to throw some light on the subject.

A plant of P. vulgaris, examined during the flowering season, exhibits a short axis with “radical” leaves spreading as a rosette, and terminated by an unstalked umbel of ebracteate flowers.