The new researches seek to determine the motion of the liquid threads, that motion varying with the depth when water flows over a plain surface. These researches are too technical to be described here, but as they are of very great importance both practically and theoretically, it may be useful to mention that a translation of the abstract appended to Colding's paper has been printed. Colding has applied his results in the study of ocean currents. Floating Breakwaters.—Mr. T. Cargill has proposed the use of a particular form of floating iron breakwater, in preference to the immense expensive solidmasonry structures now employed. He supposes the influence of the waves not to extend to a greater depth than 15 feet from the surface. To break the force of the waves he proposes an iron floating structure composed of sections each 100 feet in length. Each section is in the shape of a triangular wedge with the apex towards the sea. The wedge is right angled and has one horizontal and one sloping surface. The horizontal surface is nearly level with the water. The section is composed of a series of screws of lattice wrought-iron framework. The theory is that in passing through these screws the waves would be gradually disintegrated and strained of their violence. The idea of floating breakwaters is not new, and many plans of such structures have been proposed, and in one or two cases they have been tried, but without success. Nothing but experiment can determine whether Mr. Cargill's designs would accomplish the end proposed in a practical manner.

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Domestic Steam Engines.--MM. Mignon and Rouart, of Paris, are supplying, on the system of M. Fontaine, a small domestic steam-motor, of 1 to 1 horse power. They are intended to be employed in driving lathes, sewing-machines, pumps, jewellers' tools, &c. If the use of these engines becomes general, it will affect many industries by enabling the workmen to labour at home at a variety of employments which now are carried on in large shops. The steam is raised by gas. The boilers are vertical tubular boilers, with Bunsen burners. The products of combustion can be led to an ordinary chimney. The boiler holds water enough for several hours' work, so that it does not require constant feeding, but can be filled up twice a day. There is a self-acting arrangement for regulating the gas flames. The machine weighs about 2 cwt., and costs 500 francs.-Paris Correspondent of "Engineering."

Strains on Arches-Mr. W. Bell has communicated to the Institution of Civil Engineers a paper on the determination of the stresses in metallic arches under unsymmetrical loads by combining graphic methods and calculation. The paper is one of great interest.

Pneumatic Despatch.-At the Institute of Civil Engineers, Mr. Siemens read a most interesting paper on his system of pneumatic despatch tubes now in use in Berlin, and also in London between the General Telegraph Office and Charing Cross. Mr. Siemen's system differs in principle from that originally introduced by Mr. D. K. Clarke. On Mr. Clarke's system a single tube was used between any two points, the carriers containing the messages being blown through in one direction and drawn back in the other by exhausting the air before them. Hence, in this system, the direction of the current of air is reversed at intervals. On Mr. Siemens' system a pair of tubes are laid down, one taking the carriers in one direction, the other

those in the other direction, and the current of air is a steady continuous current always flowing in one direction. Along the line of pipes are stations at which carriers containing messages can be introduced into or taken out of the circuit, and a beautiful piece of apparatus has been contrived by which the carriers can be introduced into or taken out of the tubes almost instantaneously, and without in any way interfering with the steady flow of the air-current. In order to prevent any possibility of the blocking up of the tubes by two carriers jamming, an electrical system is adopted, like the block system of railways, by which each station telegraphs on the arrival and departure of each carrier, and the station to which it is sent prepares to receive it. Although, of course, the passage of the carriers through these tubes is very slow compared with the speed of electricity, yet as some thirty messages fully written out can be sent in each carrier, it is found quicker and cheaper to use pneumatic tubes than to use electric wires in cases where the number of messages to be sent daily is very great. Mr. Siemens even thinks that in large towns we shall ultimately employ the pneumatic system to distribute the letters from the Branch to the General Post Office, and vice versa. He thinks that if a complete pneumatic system were in operation in London between the post offices, every letter might be delivered at its destination an hour after being posted.

As a subsidiary invention Mr. Siemens has perfected a new form of steamjet for exhausting the air from the tubes. As an engine with its boilers and air-pumps is an expensive item in the erection of a system of pneumatic tubes, it appeared to him that some cheap substitute was desirable, even if its efficiency were less than that of an engine and air-pumps. He has found such a substitute in the well-known steam-jet, but he has so improved that instrument that now its efficiency appears to be very little less than that of an engine with exhausting cylinders.

MEDICAL SCIENCE.

Abnormal Larynx.—Sir Duncan Gibb described some very curious forms of the above at the late meeting of the British Association. In one he described a rare instance of absence of both arytenoid cartilages in a girl of 18. Likewise, one in which the epiglottis possessed the shape of a trefoil leaf, and two others in boys of fissure of the same cartilage.

The Ohio Twins.-These are said to surpass in peculiarity the Siamese twins and the "Two-headed Nightingale," recently exhibited in town. The "Lancet" says, that the Ohio twins have been examined by Drs. Williams and Little, and they are described as being united in a direct line from the occiput downwards along the spine. On one side are perfectly developed hips, thighs, legs, and feet. On the other side there is one large, imperfectly formed leg, presenting the appearance of the consolidation of two legs. There are eight toes on this limb, two of which have the appearance of great toes, being much larger than the others. Each child has a well-formed head and features, good arms and hands, lungs, heart, liver, stomach, &c. The lower portion of the trunk is said to be common to both. While these

physicians were making their examination both cried, but, a few minutes after, one went to sleep, while the other remained awake. When either head would cry the perfect leg which was nearest that head kicked and drew up, while the leg nearest the other head remained quiet. When either cried, the toes on the imperfect foot would move, but the limb remained stationary.

Metamorphosis of Tissue while Fasting.-At a recent meeting of the Naturwissenschaftlichen Klasse of the Viennese Academy of Sciences, Prof. Seegen communicated a series of investigations upon the metamorphosis of albumen during fasting, which are thus given by the "Lancet." The subject of his experiments was a young girl, who, in consequence of a stricture of the œsophagus, was only able to consume very small quantities of nourishment. During a whole month the daily ingesta amounted to but 35 grammes of milk, and about 20 c.c. of water. A teaspoonful of this mixture was taken at intervals of about an hour. After lasting for four weeks, the difficulty of swallowing gradually disappeared, and the quantity of milk swallowed rose to 210 grammes per diem. The most important results obtained were the following:-1. The quantity of urine excreted daily amounted to 185 c.c. It was of very dark colour, possessed a strong acid reaction, and frequently deposited a considerable quantity of urates. 2. The amount of urea excreted daily, on an average of twelve days, was 8.9 grammes = 4·1 N. The amount of N. ingested with the milk was 0.29 gramme; the excess of N. excreted, therefore, amounted to 38 grammes. This quantity of nitrogen is contained in about 25 grammes of dry albumen, and the patient must thus have used up that weight of the dry albumen of her own body. The chief tissue furnishing this would of course be the muscles, and if that amount of dry albumen be calculated as coming from fresh muscle, 112 grms. of the latter would be used up. 3. The excretion of water is not covered by the water of the metamorphosed tissue. The organism, therefore, is dryer or poorer in water during fasting. 4. With increased supply of food the excretion of water through the urine rose, whilst the excretion of urea remained almost unchanged. 5. The metamorphosis of the albuminates during fasting, so far as they are represented by the excretory products of the urine, bears the proportion to the normal metamorphosis of 1: 4 or 1:5.

Inoculation of Cancer in the Lower Animals.—At the meeting of the British Association in Edinburgh, Dr. John Chiene read a paper entitled "An Experimental Inquiry into some of the Results of Inoculation in the Lower Animals." The paper described a series of experiments, in which rabbits were inoculated with cancerous matter obtained from the human subject. The result may be shortly stated in the following words:-(1) That cancer cannot be produced in rabbits; (2) that cysts, containing cheesy matter, arise at the points of inoculation; (3) that these cysts do not differ from the local appearances which arise after the application of any irritant to the subcutaneous tissue of the rabbit.

The Functions of the Uvula.-A paper on this subject was read at the meeting of the British Association at Edinburgh, by Sir Duncan Gibb, Bart. Anatomists describe the action of the uvular muscle as an elevator which shortens the uvula. It is, however, a sentinel to the fauces, especially in

the act of deglutition; for when any substance comes into contact with it, it excites the action of all the neighbouring muscles until it is got rid of. But it possesses a function of not less importance, in holding the soft palate tense and firm in the medial line against the wall of the pharynx during the act of deglutition itself, and thus prevents the passage upwards of fluid or solid substances behind the nose. This was supported by experiments upon a person who had lost the bones of the nose, permitting of a view of the action of the soft palate from its nasal aspect during deglutition with or without food. Under either circumstance, a double arch was seen in the form of two convex swellings, held in a state of firm tension by the action of the uvula passing down the centre of the soft palate, with its end resting flat against the wall of the pharynx. The tension ceased the moment that the constrictors of the pharynx had fully exerted their influence over the substances swallowed. Whilst the uvula has its special uses in the act of deglutition, it exerts a not less decisive influence upon the voice when uttered in a very loud tone, or in singing the higher registers, in both sexes. Then its character as a levator or shortener is exerted. If this power is impaired by removal of the muscular (not the membranous) end, then the singing powers are damaged. Some remarks were made upon elongation of the uvula and its effects, a distinction being made between its elongated membranous end and the true muscular tip, which should not be meddled with. Speech, the author said, was modulated by the soft palate and uvula, and the motor power of the latter is unquestionably exerted in pronouncing the letters K, Q, and X, with their associations, more especially the gutturals of the various languages.

Sir Thomas Watson on the Treatment of Cholera. - The "British Medical Journal" contains a communication from Sir Thomas Watson on the subject-now exciting so much attention-of cholera. Sir Thomas has altered his opinions as to the treatment of this disease. The following concluding passage will show this effectually:-"In the face of this and of much similar evidence, I feel bound to say that the rules laid down by Dr. Johnson for the treatment and prevention of diarrhoea and cholera seem now to me safer and better than the less discriminating advice. which heretofore I gave you : 'whenever a suspicion arose that cholera was present in the community, not to try, in cases of diarrhoea, to carry off the presumed offending matter, but to quiet the irritation and to stop the flux as soon as possible, by astringents, aromatics, and opiates.' No doubt, the true indication of treatment is, to stop the flux as soon as possible; but this may sometimes be best effected (as also in 'crapulous diarrhoea,' and in the summer cholera of Sydenham) by carrying off the offending matter.'"

Muscle-grafting.-Skin-grafting came into fashion a few years since, and has made much progress among advanced surgeons. Now muscle-grafting appears to be making its way. The New York Medical Journal for November contains an article upon the subject by Dr. B. Howard, and relates some interesting cases in which, by grafting, he obtained increased power of healing in several wounds. These were cases in which skin-graft had been first attempted, but without sufficient success. The paper is of some importance.

Nucleated Blood-cells in the Leucaemia of Infants.-Dr. Neuman has done

what none of his predecessors have attempted-he has found the white blood-corpuscles in the blood of a living patient, by puncturing with a needle for a drop of blood. Besides numerous colourless granular cells of 0.005-0·012 mm. in diameter, which under healthy circumstances present no nuclei, there were found single homogeneous, pale-yellow cells of 0·006-8 mm. in diameter, with a colourless round or spindle-shaped nucleus, or with numerous granules (remains of nuclei). By the addition of acetic acid, these latter cells lost their colour, and within their contour, which appeared as a fine circular line, the somewhat yellowish-tinged nuclei and granules stood out with a sort of fatty glitter. Dr. Neuman is inclined to regard the presence of these transition forms between colourless and coloured blood-cells, which are produced by the diseased marrow of the bones, as a diagnostic sign of the disease of the marrow in leucemia, since in a normal state they are found only in the marrow, and there is no evidence that in leucomia they occur also in other organs, provided they are not carried into the same. In proof of this, he asserts that he has found nucleated cells in the general circulation of newly-born infants at term, and not alone (as has already been made known) in the pancreas, spleen, liver, and bony marrow. How long they remain after birth is not certain; they were absent in a child which died of peritonitis, sixteen days after birth.

Passage of the White Blood-corpuscles through the Vessels.-Dr. Norris, Professor of Physiology in Queen's College, Birmingham, presented lately a valuable paper on this subject to the Royal Society. It is abstracted in the Monthly Microscopical Journal for November. Briefly, his conclusion may be summed up thus: 1st. Both white and red corpuscles pass out of the vessels through apertures which can neither be seen before their ingress into or egress from the vessel wall, but only during the period of transit. 2nd. An essential and primary step in the process is, that the corpuscles shall adhere, or, more properly, cohere to the wall of the vessel. 3rd. These cohering corpuscles shall subsequently be subjected to pressure from

within.

The Epithelium of the Cornea and its Regeneration.-The Lancet, which has of late years adopted the excellent custom of occasionally translating good papers from foreign journals devoted to histology, recently gave an account of a paper in Virchow's Archiv, by J. Arnold, and an opposition paper by Dr. H. Heiberg, of Copenhagen, on the above subject. Arnold's conclusion is that the new cells which replaced the old, when these had been detached, were derived from a finely-granular blastema that changes into protoplasm, and that in this protoplasm the new cells arise by a process of free cell-formation. The correctness of this conclusion is contested by Dr. Heiberg, who maintains the view that young cells are developed from the old, in which certain changes have taken place. His mode of procedure was to scratch the surface of the cornea with a cataract needle in animals (frogs, birds, rats), and, after the lapse of from eighteen to forty hours, to remove the eye and examine the cornea both by means of fresh sections and after careful preparation in solutions of chloride of gold (maceration for from three to five minutes in a one-half per cent. solution of the salt). In certain preliminary experiments it was found that the injured