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4 45 23 7 59 14 31 6 DISPLACEMENT OF RADIANT POINTS.-The late Dr. J. Kleiber left behind him a paper "On the Displacement of the Apparent Radiant Points of Meteor Showers due to the Attraction, Rotation, and Orbital Motion of the Earth." The paper appears in the March number of Monthly Notices of the R.A.S. The three principal causes of displacement mentioned in the title are treated separately, and the theory is illustrated by a consideration of the Perseid and Andromedid radiants. More than twenty years ago Schiaparelli developed formulæ for determining the amount of displacement of a radiant point due to the attraction of the earth. The effect of the attraction is to diminish the zenith-distance of every radiant and leave its azimuth unchanged. The corrections to be applied to the co-ordinates of the Perseid and Andromedid radiants on account of this disturbing cause were computed by Dr. Kleiber, and are given in his paper. It is shown that the latter swarm affords a good example of the displacement of a radiant due to the attraction of our planet. The rotation of the earth produces a small aberration of radiants, never amounting to more than 1 in the latitude of Greenwich. With regard to the earth's orbital motion, Dr. Kleiber found that it is sufficient to explain the displacement of 57° in right ascension, and 10° in declination, observed by Mr. Denning in the case of the Perseid swarm. And, after the proper corrections have been applied, it appears that of the forty-nine radiants catalogued by Mr. Denning as belonging to the Perseid shower, "forty-six lie within a circle described about the cometary radiant with a radius of 2°." This important result settles definitely the question as to the reality of the shift of radiant points.

TWO NEW VARIABLES IN CEPHEUS.-Mr. Paul S. Yendell, in the Astronomical Journal, No. 258, communicates the discovery of two variables of long period in Cepheus. One of them, D.M. 50° 2769, has a range of variation of a full magnitude (58 mag. to 6'8 mag.) in about a year. An interesting point is that "the star is apparently subject, especially near its maxima, to sudden and considerable fluctuations in light, often 33 The amounting to several steps from one night to the next. star No. 8594 of Chandler's "List of Stars probably Variable" has been proved to be variable. The period is about 348 days, and the light-range about o'7 mag., from 6'2 mag. to 6'9 mag.

ON THE VARIATION IN LATITUDE.-At the Paris Academy on March 28, M. Faye said :-"The question of the variability of latitudes has lately occupied the minds of astronomers and geodetists to a large extent. The Academy will hear with interest that this question appears to be settled in the affirmative by some observations that the Geodetical Association has recently had made at Honolulu. Whilst at Berlin, Prague, and Strasburg, the latitude increased o" 04 from June to September, and afterwards decreased o"I or o" 2 to December, and then diminished o"13 to January, at Honolulu it varied in the opposite direction-that is, it fell about o"3 from June to September, and increased o"13 from December to January."

THE INSTITUTION OF NAVAL ARCHITECTS.

THE annual spring meeting of the Institution of Naval Architects was held on Wednesday, Thursday, and Friday of last week, the President, the Earl of Ravensworth, occupying the chair during the whole of the sittings excepting that of Thursday evening, when Admiral Sir John Hay presided. The programme was not quite so long as usual, the Council of the Institution having come to the conclusion-wisely, we thinkthat it would be more desirable to have fewer papers and devote more time to their respective consideration. As it is now settled that the Institution is always to hold two meetings in the year, there is a chance of relief to what was always a congested programme when the business of the whole year was crowded into a single session. Where the summer meeting is to be held this year is not yet settled, but it is to be hoped that some place in

the provinces will be selected, as it is right that the great shipbuilding centres of the Kingdom, of which London is not one, should be visited by the leading shipbuilding institution.

The following is a list of the papers read, in the order in which they were taken :-On divisional water-tight bulkheads as applied to steamers and sailing-vessels, by B. Martell, Chief Surveyor Lloyd's Register of Shipping; on steadying vessels at sea, by J. I. Thornycroft; notes on some recent experiences with H.M. ships, by W. H. White, C.B., F.R.S.; a ram vessel and the importance of rams in war, by Commander E. B. Boyle, R. N.; whale-back steamers, by F. C. Goodall; on an approximate rule for the vertical position of the centre of buoyancy, by S. W. F. Morrish; on balancing marine engines and the vibration of vessels, by A. F. Yarrow; some notes on the strength of steamers, by A. Denny; on the transverse stability of ships, and a rapid method of determining it, by W. Hök; notes on experiments with inflammable and explosive atmospheres of petroleum vapour, by J. H. Heck; on the theoretical effect of the race rotation on screw propeller efficiency, by R. E. Froude; performance of three sets of engines belonging to the second-class cruisers recently added to H.M. Navy, as calculated from the full-power steam trials, by Mr. J. G. Liversidge, R. N.

It is evident that the space at our command will not permit us to give anything approaching a full description of a meeting that occupied five sittings, some of them of over four hours' duration; and we will therefore concentrate our attention upon those points more especially within our scope. Mr. Martell's paper was one of great value, but it was treated from a purely constructive point of view. There are, it may be remarked in passing, some very nice mathematical and physical considerations involved in the study of the theory of bulkheads. was pointed out by Dr. Elgar during the discussion, but up to the present we are not aware that the matter has been approached in a philosophic spirit. Before that can be done, certain experimental data must be obtained, and it will then remain for the mathematician to apply the canons of his science to the elucidation of the problems involved.

This

Mr. Thornycroft's paper on the steadying of vessels at sea was an account of some investigations and experiments carried out by one of our most scientific and careful mechanical engineers. Mr. Thornycroft has a steam-yacht, the Cecile, of 230 tons displacement. With this vessel he proceeded to make experiments with a view to reducing the rolling motion in a sea-way. The Cecile, it should be stated, is a bad roller, or, rather, a difficult vessel to prevent from rolling, as she has large metacentric height and a flat floor; in other words, she has considerable stability. In this vessel Mr. Thornycroft fitted, under the cabin floor, a shaft, which was free to turn completely round its axis, and to this was keyed a mass of ballast weighing 8 tons. The shaft had a crank, which was actuated by an hydraulic motor. In this way the ballast could be moved out from the centre line of the ship, so as to counteract the rolling motion. The movement of the weight had naturally to be provided for by some automatic arrangement, and this was sup plied by a short-period pendulum placed near the centre of gravity of the ship, and actuating the valves of the motor. So far, all is simple enough, but here the difficulties commence. The inertia of the heavy mass of ballast will cause some loss of time, as only a limited force could be used for its control, and Mr. Thornycroft sets himself the task of overcoming this difficulty. He therefore introduced a second pendulum, of long period, which tends to move the ballast in an opposite direction to the first pendulum, and this enables the apparatus to discriminate between the angular motion of the water and that of the vessel. Mr. Thornycroft found, however, that the long-period pendulum is rather a delicate instrument, and its function can best be served by a cataract arranged to always slowly return the ballast to the centre. This device has the effect of accelerating the phase of motion, which in some cases is required. Unfortunately, at this point Mr. Thornycroft's description breaks off. The mechanism by which the motion of the pendulum is made to govern the movement of the weight was described by Mr. Beauchamp Tower, who has seen it in operation, as "the greatest intellectual treat to all who appreciated the niceties of mechanical design." This intellectual treat was denied to the members of the Institution, for the mechanism was not described further than that it was an electrical device. Those, however, who have attempted to work with pendulums on board

ship will be sure that Mr. Tower did not exaggerate the ingenuity of its inventor; and we hope some day to have the details made public, more especially as the Director of Naval Construction-who was another of the favoured few who had seen the apparatus at work-stated that he felt sure it would Eave a wide application for other purposes than that for which it was originally devised. As a result, in a heavy sea in the Channel, the apparatus reduced a roll of 18° each way to one of 9 each way.

Mr. W. H. White's paper on recent experiences with H.M.'s ships had of course been looked forward to with considerable expectation and interest. The Director of Naval Construction has the art by which he can render interesting almost any subject upon which he writes. Probably, however, the paper was disappointing to many engineers, who were misled by the title into the belief that the great forced-draught and leaky-tube question was going to be fought out. As a matter of fact, Mr. White only referred to the boiler problem in order to inform his audience that he was going to say nothing about it; and the chief point to which he turned his attention was the influence of shallow water upon the trial trip speeds of modern vessels. In past times when speeds were more moderate, the Stokes Bay measured mile did well enough, but now that vessels have to be tried to 20 knots and over, the depth of water is wholly insufficient. Most of the measured miles on which ships are tried have an insufficient depth of water, the notable exception being the Skelmorlie course on the Clyde, which appears to be everything that can be desired, the water being both sheltered and deep. The Humber course is apparently the worst, as it is shallow in depth and very much exposed. In connection with this matter, an amusing incident arose during the discussion on Mr. White's paper.

A patriotic Scots shipbuilder had been exulting in the superiority of the Scottish mile over all those on the English coast. He was followed by a Hull constructor, who acknowledged the excellence of the Skelmorlie trial ground, "which," he said, "doubtless largely accounted for the very excellent results attained by Clyde-built vessels." To return, however, to Mr. White's paper; he gives an instance of two sister vessels tried on the Maplin mile at different states of the tide. The variation in depth of water was 9 feet on 42 feet, and with the same power indicated there was a difference of half a knot in speed. The cruiser Edgar, in Stokes Bay, with 12 fathoms of water, required 13,260 horse-power to attain 20 knots; whilst in water 30 fathoms deep she reached 21 knots with 12,550 horsepower. In running from the Nore to Portsmouth, the first-class cruiser Blenheim made 20 knots with 15,750 indicated horse-power in water 9 fathoms deep. On the same trip, when the vessel got into water of 22 to 36 fathoms, the speed rose to 214 knots with practically the same horse-power. In this instance the estimated loss due to the shallower water was 3000 horse-power. Other examples were given by the author, and by other naval architects during the discussion, the most notable perhaps being that narrated by Mr. Philip Watts, the chief of the Elswick Ship Yard, who gave his experience with the Italian cruiser Pimonte, the results being very similar to those of the Blenheim. It is evident that depth of water has a far greater influence on speed trials than has hitherto been generally supposed, and it should be remembered that the smaller vessels, such as torpedo-boats, suffer almost as much as the larger craft. A vessel travelling at a given speed has to carry a wave of dimensions corresponding to the speed, whether the vessel be large or small, so that the size of the vessel does not affect the depth of water required, except in the important detail that a big vessel's keel is nearer the bottom than that of a small one. Vibration was another subject upon which Mr. White treated, but this question was so much more fully dealt with by Mr. Yarrow in the evening, that we may pass on to the paper of the latter contributor; skipping the three intervening, which were of less general interest

These

Mr. Yarrow's paper on balancing marine engines and the vibration of vessels was undoubtedly the great feature of the meeting, as was his paper last year on the construction of marine boilers. Unfortunately it is impossible to give a good idea of Mr. Yarrow's lecture-for it was more than a paper-without the aid of the views by which it was illustrated. were thrown, by means of the lantern and electric light, on a large screen erected for the purpose. As everyone knows who has been present on the trial trip of a torpe lo-boat, the vibration in these little craft is excessive. The enormous power exerted by the engines, the rapidity of their reciprocations, and the slight

as

and elastic nature of the hull construction, all combine to render the deck of a torpedo-boat, travelling at her best speed, a most unpleasant position; especially when the spray is driven in sheets across the deck, and the white-hot cokes are at intervals emitted from the chimney. It is natural, therefore, that the question of vibration should be attacked, and to a great extent solved, by one of our two great torpedo-boat builders. Mr. Yarrow, some time ago, came to the conclusion that it was the reciprocating weights of the engines that caused vibration. There was long a general belief that the propeller was the origin of nearly all vibration in screw vessels, and the belief still largely exists; but those best acquainted with the subject have for some time known it to be erroneous. If the blades of a screw be properly balanced, and in other respects if the propeller is as well made as the screws of torpedo-boats have to be, there will be little difference in the amount of vibration whether the screw be in position or taken off, provided the engines are running at the same speed in both cases. Mr. Yarrow has proved these facts most conclusively by an elaborate series of trials made with working models and also with an actual torpedo-boat. The principal model represented to scale a three crank tri-compound engine. This was hung in a frame by means of spiral springs. The weights of their pistons and other moving parts were ordinarily arranged in a torpedo-boat's engines. The model was caused to work by means of a thin and flexible steel wire, so that no motion other than a rotary movement, could be conveyed to the apparatus. When the model was caused to work, at a given speed, the movement was excessive. In this way was very clearly brought out the fact, already known to engineers, that the vibration of a boat is at its maximum when the revolutions of the engine synchronize with the natural period of vibration of the boat. It will be seen that a boat or ship, like any other elastic structure, say a girder or a tuning-fork, will have a period of vibration natural to it. The reciprocations of the engine pistons cause a certain number of impulses to be communicated to the hull, and if the number of vibrations and the impulses are either one a multiple of the other, then the vibration will be excessive. This has been thoroughly proved by experience, and it has been the aim of builders of high-power vessels of light scantling to fit screws so designed that at maximum speeds the vibrations and revolutions of the engine will not synchronize. In Mr. Yarrow's model the elasticity of the hull was represented by the stiff spiral springs by which the model engine was suspended. Having shown the way in which the reciprocating weights of the engines acted so detrimentally, Mr. Yarrow next proceeded to explain the manner in which he overcame the difficulty. Attached to the model were weights, which he termed bob-weights. These were so placed as to balance the natural reciprocating parts of the engine. They were actuated by eccentrics, and could be put in and out of gear as required. With the bob-weight in operation, the effect was most marked, the model being perfectly steady at any rate of movement. The bob-weights have, of course, to be of the proper weight, and must be accurately placed in the longitudinal plane of the engine, otherwise the balance would be destroyed. This was shown by Mr. Yarrow with the model. He had first thought that a good effect might be obtained by making all three pistons of equal weight-the low-pressure piston is naturally far heavier than the others—but little benefit was obtained in this way. One of the most interesting parts of the lecture was the photographic pictures of torpedo-boats thrown on the screen by the magic lantern. These pictures were among the best of the kind we have ever seen. The boat was moored in the West India Docks so as to get still water, and a calm day was chosen. The propeller was removed so that the engines ran free. The first photograph was taken with the engine in its ordinary condition, no bob-weights being attached. By previous experiment the number of revolutions that caused the most vibration had been ascertained; we believe 240 per minute was the number, and the engines were run at that speed. The boat was therefore caused to vibrate excessively, and the effect was clearly shown by the waves or ripples thrown off from the side. These were beautifully marked in the photograph, the pattern caused by the intervening wave series being very curious. Many pictures were given illustrating various wave phenomena due to different combinations, one of the most interesting being that in which vibration was caused by one of Mr. Yarrow's assistants springing on the stern 240 times a minute; an athletic feat of no mean order, and one which required considerable training.

Another series of photographs, taken broadside, very clearly showed, by means of the wave motion, the nodes of vibration due to the period; the straight and the broken water line being well defined. When the bob-weights were attached, this phenomenon was naturally not present, as the vibration was destroyed. Our description has extended so far beyond our proper allotment of space, that we have not been able to describe the "vibrometer" which Mr. Yarrow has devised, and by which he obtains automatic records of the vibrations of a vessel. This instrument, if not absolutely accurate, has been proved quite sufficient for the purpose. On the whole, one can hardly doubt, after hearing Mr. Yarrow's lecture, that he has found a practical solution to the vibration difficulty, which threatened to become one of such serious dimensions, not only in torpedo craft but passenger steamers, in these days of high speed and steel hulls.

Mr.

The other papers we must pass over very briefly. Denny's monograph on the strength of steamers consisted virtually of a table with some explanatory notes. It represented a large amount of work, and will prove of great use to naval architects. Mr. Hök's contribution added another to those many "rapid methods" which from time to time are brought forward, but none of which have, so far as we are aware, yet superseded the older methods of calculating stability. Mr. Heck's paper was a useful contribution, explaining some simple methods he had devised for arriving at the state of the atmosphere in petroleum steamers.

On Friday the first paper taken was that of Mr. Froude, who may be safely described as our first living authority on the screw propeller in its scientific aspect. It will be remembered that the author has of late read a series of papers on this subject before the Institution. During the discussion on his contribution of last year Mr. Thornycroft suggested that some of the conclusions arrived at might be modified by the rotation of the race, and it was in order to elucidate this point that the investigation was undertaken. The present paper is the outcome of this. It would be useless to attempt to abstract, ever so briefly, a paper on so abstruse a subject as this; in fact, up to the present time we have not been able to give the day's preliminary study which Mr. Froude's papers require before we can fairly get a grasp of their drift. We should perhaps have hardly had the courage to make this admission had not two such past masters of the subject as Mr. Thornycroft and Mr. Macfarlane Gray confessed that they had devoted a day to the study of the paper, and still were not in a position to discuss it. The paper by Mr. Liversidge was the last read, and led to a short discussion, in which no point of special interest arose.

FOURTH ANNUAL REPORT OF THE DELEGATES OF THE OXFORD UNIVERSITY MUSEUM.

THE Delegates of the University Museum have presented their Report to Convocation for the year 1891. This Report consists of two parts: (1) the General Report of the Delegates, properly so called; and (2) the Departmental Reports of the Professors and Lecturers teaching within the Museum precincts. The Delegates call attention to the improved accommodation provided, or in course of being provided, for the several departments of Comparative Anatomy, Zoology, Geology, and in the Pitt-Rivers Museum. These new and improved buildings will be fully available before the end of 1892. The result will be, in the Comparative Anatomy Department, by altering the old dissecting room, to utilize it for convenient and welllighted rooms for laboratory and museum work. The Geological Department, which has long been inadequately accommodated, will be enlarged by a long working-room and a store room above. Two spacious store-rooms have likewise been provided for the department of Zoology and the housing of the Hope Collection. A Curator's room has also been provided for the PittRivers Collection, and additional facilities for the arrangement and storage of specimens.

The dissecting-room, lecture-theatre, museum, and assistants' and working rooms required for the department of Human Anatomy are in course of erection. They are expected to be available for use early in 1893.

Among the Professors' Reports, the Regius Professor of Medicine regrets that the University authorities have not seen

their way to provide, even on a modest scale, a Bacteriological Laboratory for the use of his department. But under the supervision of Dr. Carl Menge, recommended by Prof. Virchow, a small laboratory has been arranged in the limited space devoteri to the department of Medicine. The apparatus was purchased in Berlin, and Dr. Menge, freed from duties abroad, conducted a class during the long vacation in the technique of Bacteriology. This class was not only attended by several gentlemen who had passed the M.B. examination, but interested many of the medical practitioners in Oxford.

Sir H. Acland hoped to investigate the condition of the waters in and about the Isis and Cherwell, in connection with the larger inquiry as to the bacterial condition of the water supplied to London, but for various reasons this investigation is for the present left in abeyance.

The Linacre Professor of Comparative Anatomy divides his report into two subdivisions: (1) the care and development of the collections illustrating the comparative anatomy and classification of animals placed in the court of the Museum, and (2) the administration of the laboratories and lecture-room assigned to his department.

In the first subdivision the Professor remarks that the specimens are rather stored in cases than "exhibited.". By the aid of competent assistants, however, he hopes that the more typical specimens may be set out and labelled in a thoroughly demonstrative manner, after that introduced by Prof. Flower at the British Museum. A special case, illustrating the chief treasure of the Oxford Museum, viz. the head and foot of Ashmole's Dodo, is being made ready, and also a series of specimens, casts, and drawings, to exhibit the interest and importance of the six fossil jaws of Mammals from the Stonesfield Slate.

"The task of doing justice to the valuable collections belonging to the University, by adequately exposing, labelling, and arranging, some in exhibition cases, and by carefully recording and storing others, where they shall be readily accessible for the purposes of the student, is no light one. Even with a full staff of assistants it would take several years, and could never be 'finished,' any more than the books of the Bodleian Library could be finally arranged and left so for the admiration of future generations. The Natural History collection of the University requires constant care, special curators, and consequently a considerable annual expenditure, just in the same way as does its collection of books, though the former at present does not require so large a sum for its proper administration as does the latter. I have therefore to report that I have not sufficient funds at my disposal for carrying out the arrangement of the collections under my care with efficiency, or with reasonable promptitude."

The second part of the report shows the number of students attending the laboratory and lecture rooms. The number averages about thirty per term, and in addition to the ordinary lectures, informal meetings are held in which recently published memoirs on embryological and morphological subjects are discussed. Dr. Benham, Mr. Goodrich, Mr. Minchin, and Mr. E. B. Poulton and others have assisted the Professor in these informal classes.

The Curator of the Pitt-Rivers Museum gives a long catalogue of additions to his department, and remarks that the various series of musical instruments have been so far as possible completed, with labels, sketches, maps, &c. The weaving and barkcloth series has been re-arranged, and similarly the series of masks, primitive boat models, and the fire-making series, which is one of the most typical in the collection.

The Report of the Lecturer on Human Anatomy has reference principally to the construction of the new laboratories referred to in the Delegates' Report. The Lecturer in the course of the summer vacation visited the medical schools of Strassburg, Munich, Freiburg, Vienna, Buda-Pest, and Brussels, in order to observe the most approved methods of teaching and museum arrangement, and also to inspect the recently built anatomical institutes of these various centres of medical education, with the view of using the information so obtained in the fitting up of the new Laboratory.

The remaining reports do not present any points of special interest. They include reports from the Hope Professor of Zoology, the Professor of Experimental Philosophy, the Waynflete Professor of Chemistry (who has had ninety-eight individual students at work under his direction during the year), and the Professors of Geology, Mineralogy, Geometry, Natural Philosophy, and of the Reader in Anthropology.

SOCIETIES AND ACADEMIES.

LONDON.

Royal Society, March 31.-"The Abductor and Adductor Fibres of the Recurrent Laryngeal Nerve." By J. S. Risien Kassell, M. B., M. R. C. P. Communicated by Prof. V. Horsley, F. R.S. (From the Pathological Laboratory of University College, London.)

The first part of the following research consists in the separation and isolation of the different bundles of nerve fibres of which the nerve trunk is composed, electrical excitation of each separate bundle, and observation of the effects produced on the vocal cords by such excitation.

Exposure of the different bundles of nerve fibres, under exactly similar circumstances, to the drying influence of the external air, with observation of the relative duration of vitality possessed by the different bundles, forms the second part of the investigation.

Other methods were next instituted to control the results of the foregoing, and the first of these, constituting the third part of this work, consisted in tracing by post-mortem dissections each bundle of nerve fibres separated in the nerve trunk to its termination in the mucous membrane or in a muscle of the Larynx.

The next control method consisted in exposing the muscles of the larynx immediately after death, and direct observation of them during excitation of the separate bundles of nerve fibres, this being controlled by occasional excitation of individual muscles themselves. This forms the fourth part of the investigation. The fifth or last part of the research served as a third control method, and consisted in observations of the muscular degenerations which followed division of one or other bundle of nerve fibres in the nerve trunk, three weeks after such division. The results of these experiments show clearly:

(1) That the abductor and adductor fibres in the recurrent laryngeal nerve are collected into several bundles, the one distinct from the other, and each preserving an independent course throughout the nerve trunk to its termination in the muscle or muscles which it supplies with motor innervation, a condition of things, the possibility of which was suggested by Dr. Semon more than ten years ago, from the evidence of pathological facts.

(2) That while in the adult animal simultaneous excitation of all the nerve fibres in the recurrent laryngeal nerve results in adduction of the vocal cord on the same side, abduction is the effect produced in a young animal by an exactly similar procedure. (3) That when the abductor and adductor fibres are exposed to the drying influence of the air under exactly similar circumstances, the abductors lose their power of conducting electrical impulses very much more rapidly than the adductors-in other words, they are more prone to succumb than are the adductors-a fact which has for long been recognized and insisted on by Dr. Semon as being the case in the human subject, and in support of the truth of which that observer has adduced so many powerful arguments. (4) That, even in the young dog, the abductor nerve fibres, though perserving their vitality much longer than in the case of the adult animal, nevertheless in the end succumb before the adductor fibres.

(5) That this death commences at the point of section of the nerve, and proceeds gradually to its peripheral termination, and does not take place in the whole length of the nerve simultaneously.

(6) That it is possible to trace anatomically the abductor and adductor fibres throughout the whole length of the recurrent laryngeal nerve to their termination in the one or other group of laryngeal muscles, and that these fibres appear to bear a fixed relationship to each other throughout their course, the abductors being situated on the inner side of the nerve or that next to the trachea, while the adductors are on the outer side.

(7) That it is possible to so accurately separate these two sets of fibres in the nerve trunk that excitation of either of them evokes contraction of the abductor or adductor muscles, as the case may be, without evoking any contraction whatever in the muscle or muscles of opposite function

(8) That the bundle of nerve fibres concerned with one function may be divided without injury to that concerned with the opposite function, and that such division is followed by atrophy and degeneration of the muscles related to that function without any such changes being detectable in the muscles related to the opposite function.

Further, it is clear that the theory advanced by Mackenzie, and which has since found favour with many, viz. that possibly

the reason why the abductor fibres succumb before the adductor in affections of the nerve is because they are more superficially and circumferentially arranged, while the adductor fibres are situated deep in the substance of the nerve, is shown by these experiments to be entirely erroneous.

One point which is difficult to explain is why there should be so marked a difference between the recurrent laryngeal nerve of a young and that of an adult dog, as regards the respective predominance of abductor or adductor representation in the trunk of the nerve. Possibly the reason why the abductor influence is in the ascendency in the young dog is because the power of phonation is still imperfectly developed, and with it both the muscle and nerve fibres subserving this function are also imperfectly developed, while the function of respiration is from the beginning fully developed, and with it the muscle and nerve fibres connected with that function. That the reverse should be the case in the adult animal may well be due to the fact that phonation is perfectly developed, while respiration has become so automatic that very feeble stimuli are necessary to keep it going. "Interference with Icterus in Occluded Ductus Choledochus." By Vaughan Harley, M. D.

This paper is one of considerable biological-pathological interest, as it gives an experimental explanation of the strange discovery made by Kufferath, in 1880, that by placing a ligature on the thoracic-duct, the jaundice-producing effects of an occlusion of the common bile duct could be instantly arrested-which fact Kufferath did not so much as even attempt to explain; and no other physiologist having either confirmed or negatived the statement, far less offered any explanation of it, there were two problems requiring to be solved when Dr. Vaughan Harley entered upon the investigation :

(1) Does ligaturing the thoracic duct actually prevent the jaundice which otherwise inevitably occurs after occlusion of the common bile-duct?

(2) If it does, how can such a remarkable phenomenon be explained? seeing that the chyle-transmitting thoracic duct has no apparent physiological connection with the ductus choledochus.

Kufferath only kept the animals he operated upon alive from I to 24 hours-a period of time far too short to admit of any important morphological changes occurring, which could yield a clue to the mystery. Hence the first thing was to try and find a means of keeping the animals experimented upon alive for much longer periods of time, after both ducts had been ligatured. This was successfully done by feeding the dogs on fat-free food, containing only small proportions of proteids. It was found that when so fed dogs could not only be kept alive for weeks, but even months; and, what was stranger still, they even gained in weight.

The non-appearance of jaundice after ligature of the bile-duct when the chyle-duct was also tied, appeared remarkable from the fact that it was by all believed that both bile pigments and bile acids were always absorbed by the blood capillaries from the bile ducts; whereas it is now shown experimentally, in this paper by Dr. Vaughan Harley, that the blood capillaries have absolutely nothing whatever to do in the matter, and that, contrary to what has been up till now imagined, the pent-up bile is solely absorbed from the bile-ducts by lymphatics, and carried by them into the general circulation by the circuitous route of the thoracic duct.

Dr. Vaughan Harley has further demonstrated experimentally that, if a sufficient length of time is allowed to elapse after ligaturing the thoracic duct, bile pigment and bile acid again appear in the urine just as if the thoracic duct had not been ligatured at all, and that this arises from the fact that collateral lymphatics shoot out from the thoracic duct at a point below the ligature, and convey its contents into the right innominate vein. Hence he says that the three following conclusions may be drawn from the results obtained from his experiments :

(1) That bile existing in the bile-ducts can only reach the blood through the intervention of the lymphatics.

(2) Seeing that lymphatics surround the liver blood-vessels, one is forced to believe that bile pigment and bile acid cannot pass through the endothelium of the blood capillaries in the liver; or, perhaps, even throughout the body. The fact that bile reaches the blood when it has escaped into the peritoneal cavity is no argument against this view. For in that case it reaches the blood through the lymphatics of the diaphragm.

(3) After the left thoracic duct of the dog has been ligatured for some time, collateral lymphatics are opened up or developed from it leading into the right innominate vein.