After noticing Helmholtz's admirable discovery of the law of vortex motion in a perfect liquid, that is, in a fluid perfectly destitute of viscosity (or fluid friction), the author said that this discovery inevitably suggests the idea that Helmholtz's rings are the only true atoms. For the only pretext seeming to justify the monstrous assumption of infinitely strong and infinitely rigid pieces of matter, the existence of which is asserted as a probable hypothesis by some of the greatest modern chemists in their rashly-worded introductory statements, is that urged by Lucretius and adopted by Newton; that it seems necessary to account for the unalterable distinguishing qualities of different kinds of matter. But Helmholtz has proved an absolutely unalterable quality in the motion of any portion of a perfect liquid, in which the peculiar motion which he calls “wirbel-bewegung” has been once created. Thus, any portion of a perfect liquid which has “wirbel-bewegung” has one recommendation of Lucretius' atoms—infinitely perennial specific quality. To generate or to destroy “wirbel-bewegung” in a perfect fluid can only be an act of creative power. Lucretius' atom does not explain any of the properties of matter without attributing them to the atom itself.

Referring to the papers formerly read before the Society in 1863 and 1864, the author first noticed the Section at Errol, its stratigraphical position and fossils, more especially the skeleton of a seal which had been found in the clay. He then described more in detail the different deposits as they occur in the neighbourhood of Elie. Since the shore Section was described in 1863 two new Sections had been examined, and the position of the different beds more fully ascertained. One was in the railway cutting extending from Elie Bridge to the Railway Station, in which, when first laid open, the series of deposits was remarkably well displayed.

In a paper “On the Phenomena of thin Plates exposed to Polarised Light,” published in the Philosophical Transactions for 1841, the author observed certain motions and colours upon some of the volatile and fixed oils, the cause of which he did not attempt to discover. Their apparent similarity to the molecular movements and colours, described in a preceding paper, induced him to resume the subject.

When a drop of alcohol is placed upon an aperture the fifth of an inch in diameter or less, a concave lens will be formed upon it. As the alcohol evaporates, a very small plane film will appear in the centre, and will gradually increase till it fills the aperture.

When engaged, during the course of last summer, in the examination of the action of various medicinal and poisonous agents on blood, I observed the remarkable change in the colour of the blood of animals poisoned with nitrite of amyl. In every case in which I induced death by this agent the blood presented a dirty chocolate coloration, instead of the characteristic colour of normal blood. When examined by means of the spectroscope, this blood was found to present optical characters very different from those of ordinary blood, for the two well-marked absorption bands of 0 – hæmoglobin, or (as the readers of Professor Stokes' paper will know them better as) of scarlet cruorine, were found to be extremely faint, and only visible when comparatively thick layers of fluid were examined; whilst an additional and very faint absorption band in the red, occupying the same position as that of acid hæmatine, was seen.

It is often regarded almost as a matter of admission, on the part of the cultivators of social and political philosophy, that their subjects defy scientific treatment; and that, when they talk of tracing out laws of social wellbeing or progress, they use words which indicate, at most, a very faint analogy between the methods which they affect to follow, and those really employed in the physical sciences. The reproach to which they are exposed, on this ground, would never have arisen, or would not have been merited, had they habituated themselves and others to regard their subject, as a science, in the ordinary sense of an inquiry into nature, and not as a series of random observations, in which the contingent and the necessary, the permanent and the accidental, were hopelessly and inextricably mixed up.

The object of this paper was to controvert the views of Mr Grote as stated in his history of Greece and in his work on Plato. Professor Blackie, while admitting that the Sophists might have been somewhat hardly dealt with by certain extreme writers in modern times, and recognising gladly the view stated by Meiners and Hegel that their teaching was an important and necessary step in the intellectual development of Greece, nevertheless maintained that the current character of the Sophists, as handed down to us from ancient times, was in the main correct; and that all that could be said in defence of their teaching amounted to no more than a slight palliation of the charges brought against them by Plato and Aristophanes, not to an acquittal.

I have very great pleasure in presenting to the Society's museum a few very peculiarly-shaped stones or mineral concretions found near Carlisle, similar in external characters to those fairy stones found in Elwand Water, near Melrose, and described at a meeting of this Society, held 5th February 1866, by Sir D. Brewster. These stones or nodules were found about twenty years ago embedded in marl in a deep cutting at Wreay, five miles south of Carlisle, during the formation of the Lancaster and Carlisle Railway. They were found in great numbers by the workmen, but only in this particular cutting, and excited a great deal of curiosity at the time, but were soon laid aside and forgotten; and it was not until the account of those fairy stones described by Sir D. Brewster appeared, that my esteemed relative, Dr T. Barnes, F.R.S.E., remembered that he had them in his possession, and asked me to present them to the Society.

I have read with much interest Professor Tait's “Note on Determinants of the Third Order” in the Proceedings of this Session (pp. 59–61), and admire the method of discovering new properties of Determinants. I am not sure, however, that the properties, when discovered, are more difficult of proof by Determinant methods, and I venture to submit the following as simple and elementary:—

The first property, namely,

is true under greater generality, and the Determinant proof is the same as for the special case.

In many cases the best guarantee of the purity of a chemical substance is the method by which it has been prepared. If the processes are well devised and carefully conducted, they constitute in themselves a qualitative analysis on a large scale, the exactitude and reliability of which go far beyond what could be obtained by ordinary testing. This, however, does not apply to many organic preparations, and is eminently inapplicable in the case of compound ethers. If in the preparation of such an ether, we start with a pure alcohol and a pure acid, and carefully distil, wash, and redistil the ether produced, the product ultimately obtained may contain considerable quantities of alcohol, free acid, and water. The purity of a compound ether can be established only by direct Experiment. Free acid is easily tested for, and even quantitatively determined by the well-known acidimetric processes; the presence or absence of water may be proved by an elementary analysis, but an admixture of alcohol is not easily established.

The meconic acid group of substances has always been regarded as peculiarly interesting. Situated, as it is, on the ill-defined limits of the fatty and aromatic compounds, and exhibiting interesting isomeric relations with other organic substances, the structure and derivatives of the whole group afford ample scope for theoretical speculation. Meconic acid has always been considered a tribasic acid, which, by the successive elimination of two molecules of carbonic anhydride, yields first a dibasic and then a monobasic acid. But chemists now know that the basicity of an acid may be less than its atomicity, and that even the former cannot be deduced from the composition of one or two isolated salts, but only from a comprehensive view of all the salts and ethers of the acid. As now a general review of the salts and ethers of meconic acid seems to point to an acid with an atomicity greater than its basicity, and as any additional proof of this constitution would help to explain many abnormal decompositions in the series, the authors have investigated the action of the general reagents on these compounds that enable us to distinguish between the basic and alcoholic hydroxyls.

This paper contains some further details of the properties and composition of the substance mentioned in a former note (Proceedings, vi. 75).

The substance is produced by the action of dry ammonia gas on dichloracetone. A low temperature favours its formation. It forms colourless needles, generally radiating from central points. It is extremely unstable, and can only be preserved in an atmosphere of dry ammonia. In vacuo over sulphuric acid, even at a temperature of 0° C., it decomposes into ammonia, dichloracetone, and a viscous substance, which has a smell recalling that of acetamide. The same decomposition takes place in dry air. Hydrochloric acid converts it into dichloracetone and chloride of ammonium. It may be fused in an atmosphere of dry ammonia, and sublimes readily at temperatures far below its fusing point.

Monsieur,—Les semaines passées j'âi trouvé quelques faits dans le sel gemme et le spath d'Islande, que je prends la liberté de vous communiquer, parceque je m'imagine, qu'il n'y a personne au monde, qui saurait mieux apprécier la valeur des petites choses qui se sont offertes à moi.

Dans le sel gemme il y a un clivage ou passage multiple, omis à tort par les minéralogistes, qui jouit des propriétès singulières et qui jetera peut être quelque lumière sur le phénomène, de la “polarisation lamellaire.” Ce passage suit les faces du granatoëdre ou dodecaëdre régulier. En pressant un morceau carré, dont deux arètes opposées sont enlevées par la lime, on obtient par une pression modique un passage brillant suivant la diagonale.

The object of this paper was to show the true character of storms, illustrated by those of 2d, 3d, and 4th December 1863. It was pointed out that the mode usually adopted of laying down the isobarometric lines was calculated to present an erroneous view of their figure or form. The laying down representative lines in round numbers of 5 millemetres in each, or in two-tenths of an inch of barometric readings, lead deceptively to the conclusion that the areas of least pressure were circular or elliptical.

It was then shown that the lines of equal pressures were ribbed into the latitudinal line of minimum barometer, which was usually found running north and south, sometimes nearly straight, but often curved, with its convex side towards the east. The minimum line of barometer was easily fixed by consulting the self-registering barometers. The minimum line of barometer was shown to have been on the meridian of London at 8 a.m. of the 3d December, and apparently nearly straight from Algiers to the Orkney Islands.

In the year 1842 I discovered that the luminous and brilliant lines in the spectrum of certain flames, since called vapour lines, corresponded to certain dark lines in the solar spectrum.

This observation was made for the first time by the spectrum produced by the deflagration of nitre, and I afterwards found that this was a property belonging to every such flame.

This result was obtained from experiments made at St Andrews in 1842, on nearly 180 substances, deflagrated in a platina cup by a mixture of oxygen and coal gas. A notice of these experiments was read at the meeting of the British Association at Manchester in 1842. The journal containing them was laid before the Physical Section, and one or two of the more interesting results were published in the reports of the Association for that year.