The author has extracted ptomaïnes from the urine of patients suffering from certain infectious diseases by the following method :— (a) A considerable quantity of urine was made alkaline by the addition of a solution of sodium carbonate, and then agitated with half its volume of ether, (b) The ethereal solution (after standing) was filtered, and agitated with a solution of tartaric acid. The tartaric acid combines with any ptomaïnes present, forming soluble tartrates ; and the solution of tartrates forms the lower layer of the liquid mass, (c) The tartaric acid solution (after being separated from the ether) was also made alkaline by the addition of sodium carbonate, and was once more agitated with half its volume of ether. (d) The ethereal solution (after standing) was separated, and the ether allowed to evaporate spontaneously, (e) The residue (after drying over sulphuric acid) was treated with water, an excess of pure calcium hydroxide added, and the mixture evaporated on a water-bath. The residue so obtained was treated with chloroform and filtered. The filtrate (after evaporation) yielded the ptomaïne in an isolated and a crystalline condition.

In October 1890, Dr Bramwell sent to the Laboratory a small quantity of urine, with a request that I should give him a report upon it. To him I am indebted for the opportunity of making the series of observations here recorded.

On examination, I found that the amount of proteid was enormous, and that it was made up almost entirely of a globulin :—

This condition of the urine persisted, with only slight changes, until the death of the patient.

The blood of the Invertebrata, like that of the Vertebrata, is not homogeneous. It consists of a transparent or semitransparent liquid, and a number of small, solid corpuscles which float in it.

In the higher animals the corpuscles are of two kinds—red and colourless; but in the Invertebrata there are, as a rule, only colourless corpuscles. The red blood of Annelids is different from the red blood of Vertebrates, inasmuch as the plasma is coloured, and the corpuscles are colourless in the former, while in the latter the plasma is colourless, and there are present coloured and colourless corpuscles.

The following method of treating the question occurred to me while Dr Muir was reading his paper at the last meeting of the Society. It seems to throw some new and curious light on the intrinsic nature of the problem. I have confined myself to an exceedingly brief sketch, but it is clear that the proposed mode of treatment opens a wide field of interesting work.

I have just seen in the Comptes Rendus (June 27) an account of some experiments, on this subject, made by M. Galopin in the laboratory of Professor Pictet. As the effects obtained by him seem to be somewhat greater than my own experiments had led me to expect, I was induced to repeat my calculations with the view of trying to account for the difference. Unfortunately, M. Galopin's work is confined to 500 atmospheres, a pressure which lies a little beyond the range of my experiments ; so that no very trustworthy comparison can be made. M. Galopin's results have one advantage over those of the direct experiments of the same kind which I made, inasmuch as he was able to use ordinary thermometers, while I employed thermo-electric junctions, in measuring the rise of temperature by compression. But they have a corresponding disadvantage, in the fact that mine were obtained instantaneously (by means of a dead-beat galvanometer) and required no correction; while his had to be corrected for the heat-equivalent of his apparatus to an amount not easy to estimate with accuracy.

The paper which I have the honour of presenting to you to-night is similar in construction to those I have previously brought under your notice on the For, Madi, and Waganda tribes.

As in former papers, I have written from notes of my own observations made when in the country and from information supplied me by people of the tribe. This time, however, in order to complete the description of the people, I have had recourse to the works published by Sir Samuel Baker, Dr Emin Pasha, Capt. Casati, and the late Dr W. Junker, and I have to acknowledge my indebtedness to these authors for information gleaned from their pages.

The proposition that “the only series of surfaces which, together, divide space into cubes are planes and their electric images” presented itself to me twenty years ago, in the course of a quaternion investigation of a class of Orthogonal Isothermal Surfaces (Trans. R.S.E., Jan. 1872). I gave a second version of my investigation in vol. ix., p. 527, of our Proceedings. Prof. Cayley has since referred me to Note vi., appended by Liouville to his edition of Monge's Application de l'Analyse á, la Géométrie (1850), in which the proposition occurs, probably for the first time. The proof which is there given is very circuitous; occupying some eight quarto pages of small type, although the reader is referred to a Memoir by Lamé for the justification of some of the steps. But Liouville concludes by saying :—“l'analyse précédente qui établit ce fait important 'est pas indigne, ce me semble, de l'attention des géométres.” He had previously stated that he had obtained the result “en profitant d'une sorte de hasard.” As Liouville attached so much importance to the theorem, and specially to his proof of it, it may not be uninteresting if I give other modes of investigation.

Sochaczewer has examined the olfactory organs in the Pulmogasteropoda. In these animals the organ of Semper, the pedal gland, and the tentacula have each been considered to have the function of an olfactory organ. Sochaczewer states that: (a) The organ of Semper is small in Helix, Avion, and Limnceus; but is well developed in Limax. In the last mentioned animal it has the form of four or five glandular lobate processes, which are set at the sides of the mouth. This organ is supplied with four nerve-fibres. The two median are muscular in character, while the lateral branches are the proper labiales, which give off, one on either side, fine nerve-branch to the glandular branches of the organ of Semper. The cells of the constituent lobes resemble the glandular cells of the salivary glands; in other words, this organ has not an olfactory function, (b) The pedal gland is an olfactory organ. It is well supplied with nerves; but experiments are difficult to try in such an organ, (c) The tentacula of Helix pomatia are not the seat of the olfactory organs. After having cut off the tentacula, and allowed the wounds to heal, he then placed the snails on a flat plate, the edge of which was smeared with turpentine. He says that both the mutilated and unmutilated specimens turned away from the edges, and he therefore concludes that this proves that the tentacula are not the seat of the olfactory organ.

I have already shown that the secretion of the five large cardiac sacs of the stomach of Uraster rubens contains uric acid; and consequently these sacs are considered to be the necessary apparatus for eliminating the nitrogenous products of the waste of the tissues, “it is possible that the uric acid arrived into the starfish's stomach in the interior of small mussels, &c., whose excretory organs contain that body, and of which as food the starfish appears to be very fond: anyhow, such a source of the uric acid must be eliminated before Griffiths’ conclusion can be accepted; for obviously, if the presence of urates were demonstrated in the gastric contents of an individual who had recently supped off oysters, it would by no means follow that the stomach was the organ whereby the individual excreted his urates.” Certainly not; but Mr Durham has overlooked the fact that if the uric acid had been introduced along with the food, I should also have found urea in the contents of the starfish's stomach; but I conclusively proved that urea was absent.

It appears to me that the form in which the definition or condition of uniform convergence is usually stated, is (to say the least) not easily intelligible. I call to mind the general notion : We may have a series, to fix the ideas, say of positive terms

the successive terms whereof are continuous functions of x, for all values of x from some value less than a up to and inclusive of a (or from some value greater than a down to and inclusive of a): and the series may be convergent for all such values of x, the sum of the series øx is thus a determinate function øx of x; but øx is not of necessity a continuous function; if it be so, then the series is said to be uniformly convergent; if not, and there is for the value x = a a breach of continuity in the function øx then there is for this value x = a a breach of uniform convergence in the series.

If the two ends of a strip of paper are pasted on one another after having twisted one of them through 180°, we obtain a surface with only one side. On the last meeting of the British Association Professor A. Crum Brown showed a model of a mathematical surface closely connected with it. This surface, with the common name of “marrowbone,” is the locus of the line AB (fig. 1), cutting a given circle C orthogonally and moving under the condition ∠ AOD = 2 ∠ BAE.

(1.) Of late years there has arisen a clique of vector analysts who refuse to admit the quaternion to the glorious company of vectors. Their high-priest is Professor Willard Gibbs. His reasons against the quaternion are given with tolerable fulness in Nature, April 2, 1891. His own vector analysis is presented in a pamphlet, “Elements of Vector Analysis, Arranged for the Use of Students in Physics—not Published” (1881–4). Mr Oliver Heaviside, in a series of papers published recently in the Electrician, and in an elaborate memoir in the Philosophical Transactions (1892), supports some of Gibbs's contentions, and cannot say hard enough things about the quaternion as a quantity which no physicist wants. Professor Macfarlane of Texas University sides with Heaviside in taking umbrage at a most fundamental principle of quaternions, and develops a pseudo-quaternionic system of vector algebra non-associative in its products.

The instruments exhibited were especially fitted for working with the “messenger,” a perforated weight which is allowed to glide down the line or wire at a suitable interval behind the apparatus which it is to act on. The apparatus immediately acted on in this case is a trigger, or disengaging hook, of very simple construction, which is attached independently to the line above the principal apparatus. Separating the arrangement for freeing the apparatus (whether thermometer or water-bottle or other instrument) has many advantages. Being very light, it can be attached to the line by twine, or to the wire by a small clamp; and the principal apparatus can be attached in any convenient way, without it being necessary to pay minute attention to the knots or hitches that may be required. Further, in almost all cases, the principal apparatus and the separate trigger are much cheaper than the two combined. The separate trigger was exhibited attached to two forms of water-bottle for collecting water at intermediate depths. In one, which is a modification of a bottle for collecting bottom water, and is figured and described in the Challenger Reports, Narrative, vol. i. p. 117, the weights, which are provided to fall down and rest on the india-rubber valves K and H in the figure, are suspended by a line or wire to the trigger, and when the messenger falls on the trigger the line is slipped and the weights fall on the valves, which are then fixed, and enclose the sample. The pressure on the valves may be equally well produced by springs.

Synthesis of Tetramethylsuccinic Acid.–Ethyl-potassium dimethylmalonate cannot be prepared from dimethylmalonic ether by following precisely the method which succeeded in all previous cases. When the ether is mixed, either at once or slowly, with the calculated quantity of caustic potash in alcoholic solution, half of the ether is completely saponified, while the other half is unacted on, only an insignificant fraction being half-saponified and converted into the ethyl-potassium salt. A good yield of the latter was, however, obtained by a modification of the process, the special points of which were great dilution with alcohol and low temperature

In a previous communication (see page 85) the remarkable changes of capacity of an iron tube when magnetised were described. In the present note it is proposed to record a few of the more striking results since obtained.

The investigation of the relations which subsist amongst various physical quantities, and which are exemplified in the different transformations of energy, is one of the most interesting investigations in the whole range of physics. On the other hand, the mathematical methods which are usually employed for this purpose are of such a nature as to be unavailable to any who are unacquainted with higher mathematical methods. It is one of the objects of the present note to point out how these relations may be worked out by means of the most elementary methods. For the notation of the calculus, though used below as a matter of convenience, is quite unnecessary, since we might use, e.g., small and capital type of the same letter to denote quantities of the same kind of different magnitudes.

At the beginning of the paper some observations made on the water particles in clouds on the Rigi on the 21st of May last are described. Previous observations with the fog-particle counter had shown that there is a relation between the density of a cloud and the number of water particles observed. On the occasion above referred to the number was very much greater than corresponded with the density. It is pointed out that the number of dust particles in the air which become centres of condensation depends on the rate at which the condensation is taking place, quick condensation causing a large number of particles to become active, slow condensation causing a small number; and that after the condensation has ceased a process of differentiation takes place, the larger particles, robbing the smaller ones of their water, owing to the vapour-pressure at the surface of drops of large curvature being less than at the surface of drops of smaller curvature. The particles in a cloud are by this process reduced in number, those remaining becoming larger and falling quicker, the cloud thus tending to become thinner by the reduction of the number of particles and by the falling of some of them. It is shown that the exceptional readings above referred to, obtained on the Rigi, were owing to the observations then made being taken in a new and rapidly-formed cloud, due to the strong wind blowing at the time causing a quick ascent and rapid cooling and condensation, the result being the formation of a large number of very small water particles. Though the number was very great, the particles were so small they were only just visible with great care with the magnifying power used in the instrument. Previous observations on cloud particles had been made in slowly-formed or in old clouds after the process of differentiation had been in play for some time, and after the drops had been reduced in number and increased in size.

The solution is effected by the method of Symmetric Functions.

By a preliminary transformation * the equations of the original system are put into the form