3. This method was modified as follows:-
:-

A steel spring, strongly clamped at one end, was arranged so that its free end could be bent back to touch a hinged upright connected with a tambour; the recording tambour was in connection as in method 2. By pulling on the spring by the index-finger (the corresponding thumb being at the fixed point of resistance) the vibratory movements of tetanic muscles are communicated through the spring to the air, and so to the recording tambour. The graphic representation of this is very similar to that in 2.

The figures in a typical set of tracings were 9, 6·6, 10, 113, 14, 17, 13, 117, 18. The average of a large number of experiments was 12.5 vibrations per second.

4. In this, the apparatus was as in 3, except that the myogram was taken on a rotating cylinder, which also oscillated transversely seventeen times per second. The tracing was in places identical with that obtained when one combines two wave-systems whose periods are as 1: 2; in other places there was a perfectly simple wave-form.

It is contrary to all we know to suppose that the tetanus had twice the rate of the cylinder-viz. 34; the contrary must be true.

If, then, the tetanus had at times a rhythm of 8.5 per second, and at times rose to 17, the mean is 12.75.

5. By a method employing a carbon resistance pile (upon which the muscle was pressed) in the primary circuit of the inductorium, a capillary electrometer in the secondary, and viewing the electrometer through a stroboscopic card, a rate of 12 per second was estimated.

6. By experiments with the microphone, on which the muscle was laid, the rest of the connections being as in 5, the rate was fixed at 12-15.

7. By the microphone laid over the contracting biceps, and a frog's gastrocnemius stimulated by secondary shocks (the microphone being in the primary circuit of inductorium), a rate of 8-15 was estimated, or an average of 11.5 vibra tions per second.

The average of these and very many other experiments is 12.5 per second.

3. On Mirror Writing. By Professor F. J. ALLEN.

4. On a Model of the Cochlea. By JOHN G. M'KENDRICK, M.D., F.R.S., Professor of Physiology in the University of Glasgow.

Professor M'Kendrick exhibited a working moded intended to illustrate the mechanism of the cochlea, devised by himself, with the aid of valuable suggestions by Professor Crum Brown. It consisted of a water-tight glass tank divided into two compartments by a horizontal glass diaphragm. At the end of each compartment a round hole was cut and covered with an india-rubber membrane. The upper hole represented the fenestra ovalis, and the lower the fenestra rotunda. The horizontal glass plate had two holes cut, each of which was supplied with an indiarubber membrane, and on each membrane there was a steel watch-spring tuned to vibrate at a certain rate. The vibrations of the two springs were as 2: 1. An arrangement was used for imitating the movements of the stapes, consisting of a rod caused to oscillate horizontally by an eccentric wheel. In this way pendular vibrations were transmitted by the fenestra ovalis, and it was shown that when the number of pushes made by the base of the stapes corresponded to the period of spring A, spring A began to vibrate; if the number of pushes was increased a ceased to move; and when the pushes reached the period of B, the latter began to move. Finally, by an appropriate harmonic motion, the wave form of two vibrations, 2:1 was transmitted to the fenestra ovalis, and both springs vibrated whejius period of A was reached, thus showing that the apparatus analysed thesignation wave-form. The model generally supported the Helmholtz-Hensen Medicine.

cochlea. Professor M'Kendrick stated that the Royal Society had enabled him tə continue the investigation, and that a more refined apparatus was in course of construction.

5. On some Physiological Applications of the Phonograph. By JOHN G. M'KENDRICK, M.D., F.R.S., Professor of Physiology in the University of Glasgow.

Professor M'Kendrick exhibited one of the newest forms of the phonographs of the Edison-Bell Corporation, and by the aid of a large resonator adapted to it by himself he was able to cause the instrument to speak so loudly as to be distinctly heard throughout the large room in which the Section met. He explained the mechanism of the instrument, and showed how it might be adapted for recording the voices of two persons at one time, and for transmission of speech to a distance, by using along with it a microphone in a telephonic circuit. He also described attempts he had made to register the voice curves by means of a small and light lever running along the grooves and recording on a small smoked cylinder travelling at a slow rate, and he exhibited curves obtained in this way. His method was quite different from that employed by Professor Hermann, of Königsberg. These curves showed long undulations, at periods of about one second, with the speech curves superposed on these. He also explained methods by which the phonograph might be used for recording respiratory and cardiac sounds, and he stated that, whilst he had been as yet unable to record cardiac sounds, he had obtained several respiratory curves, and also the sound of the ticking of a watch. He announced his intention of continuing the investigation with more delicate apparatus.

6. On Trophic Changes in the Nervous System.

By JUSTUS GAULE, Professor of Physiology, University of Zürich. The author has been able by experiments upon the inferior cervical ganglion of the sympathetic to bring about changes in different organs, especially in the biceps and psoas muscles. As the result of further research, he is able to follow out the trophic effect from the spot where the operation is performed up to the organ which subsequently undergoes change. The pathway of this trophic effect passes through the spinal cord; the author in previous communications had already pointed this out as the probable pathway, and now this supposition has been confirmed by microscopical examination. It has been found that the path is marked out by changes of a trophic nature in the nervous system, passing from the point of section to the organ which undergoes change. It was necessary in order to remove any doubt to perform the experiment in such a way that the injury caused by the operation could have little or no part in bringing about the changes in the nervous system.

At last it was found that the trophic changes took place throughout the whole length down to the biceps or psoas muscles when a special nerve scarcely visible to the naked eye was cut away with scissors from its ganglion. This nerve joins the ganglion near the spot where one of the accelerator nerves arises. When the operation is performed in this way the injury is so slight that if the section does not involve the right part of the nerve there are practically no after-effects to be observed in the animal. We must therefore attribute to a special trophic influence those changes which can be observed after the section of the nerve has been properly performed. The changes can be classified according to the different parts of the trophic path in which they lie:

Those of (1) the sympathetic ganglion; (2) the rami communicantes; (3) the spinal ganglia and posterior roots; (4) the spinal cord; (5) the anterior roots and nerve-trunks; (6) the smaller divisions of the nerves in muscle; (7) the nerveendings in muscle; (8) and lastly those of the muscle itself.

The changes in each of these parts are of so special a nature that it is impossible to give a short general description of them. In general the changes are of such a kind as if the operation caused some substance to be formed or to soak into the ganglion, and then spread along its nervous connections, bringing about changes in the chemical conditions of the cells of the tissues until the cells are more or less completely destroyed. The alteration spreads along the natural pathways only as long as they are intact; every experiment therefore which destroys the connection produces no trophic effect. It appears that a spread of this injurious substance is possible both in the special ganglia and in the grey substance of the spinal cord, for the number of altered cells is far greater in the case of the spinal ganglion than in that of the sympathetic ganglion. In the grey substance of the spinal cord the change is seen to spread, not only from the posterior to the anterior horns, but also in the direction from above downwards. In those places where the change has reached the anterior horns it spreads through the anterior nerve-roots, and thus arrives at the muscles. At least one finds in the fibres of the nerves which supply the biceps muscle characteristic changes throughout the whole course of the nerves down the brachial plexus to the muscle.

7. On the Development of Kidney. By JOHN BERRY HAYCraft, M.D., Professor of Physiology, University College, Cardiff.

The epithelium of the kidney tubules is originally derived from that of the ureter and Wolffian duct, as taught by Kölliker. In the rabbit the ureter branches in the kidney blastema into six or eight tubules, ending in peripheral dilatations, the primitive renal vesicles. These vesicles divide again and again as the kidney grows, keeping to the extreme cortex, and their stalks forming the collecting tubules. All the primary branches of the ureter and many of the above-named collecting tubules become evaginated to form the pelvis. From the primary renal vesicles the rest of the tubules grow out as solid and then hollow processes and the Bowman's capsule is moulded on a bend of its own tubule, and is not invaginated by a glomerulus. After birth the primary renal vesicles shrink down to the size of an ordinary tubule, but at birth they may be seen as dilatations of the collecting tube when it reaches the extreme cortex and turns round into the region of the convoluted tubules.

FRIDAY, AUGUST 10.

The President, Professor E. A. SCHÄFER, F.R.S., delivered the following address:

BEFORE beginning the subject-matter of my address I had conceived it to be necessary, appearing before you as we do as a new Section, to offer some sort of apology for our presence. But, on looking up the history of the Association, I find that my task is somewhat different. If I have any apology to offer at all it is that the Section of Physiology has ceased to appear for many years.

The British Association was founded at York in 1831; and at the subsequent meeting, which was held in this very city of Oxford, amongst other Sections which were established, was one for Anatomy and Physiology. Now, when we consult the records of this Section we are struck with the fact that Medicine early shows a marked preponderance. Thus, in 1833 a physician, Dr. Haviland, is selected as President for the Section; and the secretaries are Dr. H. J. H. Bond, who was Regius Professor of Physic in the University of Cambridge from 1851 to 1872; and Mr. (afterwards Sir) G. E. Paget, who succeeded Dr. Bond in the Regius Professorship. This preponderance soon came to be recognised in the designation of the Section, for in 1835 we find it entitled Section E, Anatomy and Medicine.

As time went on the interests of medical men became gradually more absorbed in the rapidly growing British Medical Association; and in 1841 the medical title was dropped, and the Section came to be called simply Physiology, which title it retained until 1847. Under that designation the Section has now been revived.

The fact that Physiology as a separate Section in this Association was allowed to lapse for so long a period is not remarkable when we remember that during the first half of this period Physiology as a science was practically nonexistent in this country. The teachers of Physiology were, almost without exception, practising physicians and surgeons, and even when a professor was expected to devote his time to the teaching of Physiology he was not expected to devote part of that time to the prosecution of physiological research. During all these years, fron 18:33 to 1847, we do not find amongst the officers of the Section any actual working physiologists. Most of the officers were distinguished medical men, with an anatomist here and there amongst them. Far be it from me to say that there was no actual work being done in Physiology at this time; for Charles Bell and Marshall Hall were engaged in elucidating the functions of the nervous system; whilst Bowman, Wharton Jones, and others were producing good and permanent work in various other departments of Physiology. Their labours, however, were isolated, and formed but oases in the Sahara of neglect into which the pursuit of Physiology had fallen in this country; and this during a period when it was being pursued with signal success and activity both in Germany and France.

After 1847 a revival of Physiology began to manifest itself even here; and this was followed by the establishment, from time to time, of a sub-section to Section D, which was devoted to Physiology, and had a special President. Whether, however, owing to their subordinate character, or from some other reason, these sub-sections had not usually any great measure of success, and for the last twelve years they have been wholly dropped. During that period Physiology has only twice been represented in the Chair of Section D, and has usually had no secretarial representation. This decadence of Physiology in the British Association during the last eleven or twelve years is the more remarkable because it is obviously not due to any want of outside activity in regard to the subject; for during this period we find an extraordinary revival of interest in physiological research, a revival which in its most active stage dates from about twenty-five years ago, but still some twenty or thirty years later than the corresponding revival in France and Germany. I have taken the trouble to prepare a list of prominent physiological workers who flourished during the thirty years prior to 1870. My list comprises, in all, thirty. Of these, four are English, five French, and twenty-one German or Dutch. Of the four English working physiologists not one is a teacher of Physiology. Of the five French and twenty-one German all are recognised teachers. It was not, in fact, until it came to be understood that teaching and work in Physiology, as in all branches of science, ought in the main, to be successful, to go hand in hand, that the science had any possibility of revival.

Let us glance for a moment at the history of the revival of Physiology in this country as compared with its revival in Germany. In each country the revival may be said to have been largely due to the influence of one teacher. In Germany the teacher was Johannes Müller; in this country, William Sharpey. Both of these remarkable men were pupils of Rudolphi, who was Professor of Anatomy and Physiology in Berlin until 1833. It is stated regarding Rudolphi that he was an enemy to subjective speculation in biological science: he looked on the so-called philosophy as mistaken and futile in its application to the phenomena of the animal economy, and based his physiology chiefly, and perhaps rather exclusively, on the study of the animal structure.' The influence of Rudolphi is apparent in both Müller and Sharpey.

Miller was born in 1801, Sharpey in 1802 ; they were therefore of about the same age. But Müller's scientific and intellectual development was more rapid than that of his contemporary. Thus we find that already in 1826, when he was but twenty-five years old, Müller attained so great a reputation as to be made Professor Extraordinary in the University of Bonn; and before very long he was promoted to the grade of Ordinary Professor there. In 1833, whilst still a

young man, he was called to the chair of Anatomy and Physiology at Berlin, which had just become vacant by the death of his master and friend, Rudolphi. Sharpey, on the other hand, occupied himself until 1829 with perfecting both his general and his special anatomical education. It was not until 1830 that he published his first essay in anatomical and physiological research entitled 'On a Peculiar Motion excited in Fluids by the Surfaces of Certain Animals'-observations which were preliminary to the discovery of the existence of cilia in vertebrates. And it was not until 1836 that he was called to the newly instituted professorship of Anatomy and Physiology in University College, London, which he filled for so many years with such signal success. Both of these distinguished men owed, there is no doubt, their success as teachers of Physiology to their early anatomical training. The general anatomical bent of Johannes Müller is evidenced by the fact of his scientific work being turned so much in the direction of Comparative Anatomy and Physiology. And Sharpey, although great, and deservedly great, as a teacher of Physiology, remained to his dying day, above all, an anatomist. Physiologists of this school are rare at the present day; but it is probable that in some respects the progress of Physiology may suffer thereby. Helmholtz began his public career as professor of Anatomy; but it would be unfair to attach too much weight to this particular incident in the case of so many-sided a man as the great Berlin Professor of Physics. Nevertheless, the necessity of a close and careful training in Anatomy for those who are afterwards to work at or to teach Physiology is so important that I do not hesitate to say that the younger physiologists who neglect the study of Anatomy will find that before very long they must abandon the pursuit of many byways of Physiology which might otherwise be followed up with manifest advantage.

We

The influence of Johannes Müller upon the revival of the pursuit of Scientific Physiology in Germany, and indeed generally, cannot be overestimated. have only to look at the names and eminence of his pupils in order to recognise the immense influence which his teaching has exerted upon the progress of Physiology ever since his time. Some of these pupils are still amongst us, others have joined the majority. But the pupils of these men, again, are now great names in many departments of our science, and through them we cannot fail to recognise the influence which was exerted by this truly great man.

We may say the same in almost identical words of William Sharpey. The practical pursuit of Physiology in this country has mainly radiated from the centre where Sharpey taught. Michael Foster was his pupil. The physiological investigations of Burdon-Sanderson were assisted and encouraged by him. From Sharpey, therefore, we may trace the rise of the great school of Physiology at Cambridge, and we have only to look at the magnificent laboratory which has been erected here to observe a monument of the influence of the same teacher. And there have emanated either directly from the physiological school established by Sharpey at University College, or indirectly from those at Cambridge and Oxford, many of the most active teachers and workers in Physiology in the kingdom.

In these respects there is much in common between the revival of Physiology in Germany and in this country. In other respects, however, the two cases have been entirely under different conditions. There its revival, in common with that of science generally, has been assisted and stimulated by the active and beneficent co-operation of every German State. Here, also in common with science generally, it has had to make its way against every conceivable obstacle; and almost without assistance, either moral or material, from the Government or from public bodies. But not only has it not met with assistance, there have been actual obstacles placed in the way of teaching and work in Physiology. Some have been unintentional, others intentional. As an instance of the unintentional may be mentioned the practice which has obtained in medical schools and on examining boards a practice which, I am happy to say, is gradually being discarded-of appointing as teachers and examiners in Physiology men who may have a good general knowledge of the science, yet with whom it is not the business of their lives, and who cannot, therefore, be expected to be as familiar with its details, and as absorbed in its interests, as those who devote their entire time and attention to its pursuit.