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In a previous paper (‘Philosophical Transactions,’ A, 1897, vol. 189, p. 137) we have drawn attention to the fact that the disturbance set up in a liquid by the impact of a rough sphere falling into it, differs in a very remarkable manner from that which follows the entry of a smooth sphere. In the present paper we describe further experiments, made with the object of ascertaining the reason of this difference, and give the conclusions reached. It appeared desirable, in the first place, to take instantaneous photographs of the disturbed liquid below the water-line. These were easily obtained by letting the splash take place in an approximately parallel-sided thin glass vessel (an inverted clock-shade) illuminated from behind. The liquid surface when undisturbed was about level with the middle of the camera-lens, which was focussed for the sphere when under water. The general arrangement of the optical apparatus will be suffi­ciently understood from the accompanying cut (fig. 1). The method of timing the illumination was that already described ( loc. cit. ).

This paper contains a further record of experiments which were begun at the same time as those recorded in my first paper. The method of interpreting results in the present paper is the same as that used in the first one, and is based upon the same working hypothesis, i. e. , Bateson and Punnett’s “Presence and Absence” hypothesis and Cuénot’s theory of colour. The cost of these experiments has been defrayed by a grant from the Government Grant Committee of the Royal Society. The Experimental Matings. (1) (a) Cr 4 × Cr 4 = Albino × Albino . Twenty pairs of albinoes were mated. There was a total offspring of 174 individuals, all albinoes. Some of these albinoes had a near albino ancestry, while others had a pigmented one. The details of the ancestry made be seen upon reference to the Table of Ancestry, pp. 390—391.

Although dry paper is widely used as a supporting and insulating material in telephone cables, the published data with regard to its specific inductive capacity (or permittivity) appear to be very meagre. For this reason Mr. Gavey, C. B., Engineer-in-Chief of the Post Office, asked us to investigate the matter, and sent for test a large number of samples of paper obtained from four different cable manufacturers. All the samples consisted of what is known as “chemical wood paper,” presumably free from lignified fibre. This type of paper, according to the Society of Arts Report on the Durability of Papers, is better in lasting quality than “mechanical wood paper” or paper made from straw, jute or esparto grass. Mr. Gavey, in addition, has kindly supplied the results of some tests on actual cables and further data for some of the samples of paper. This information is embodied in Part II of the present paper. Part I.–Tests on dry paper. One of the main difficulties in the testing of paper lies in the fact that it absorbs moisture so readily; and the presence of moisture has a large effect on the specific inductive capacity and an enormous effect on the insulation-resistance. The nature of these effects is well illustrated by the curve in fig. 6 (Part II, p. 204), which shows how the capacity increases and the resistance decreases as a well-dried cable is allowed to absorb moisture from the atmosphere.

In my former paper on this subject, I pointed out the existence of an element of strength in beams when subjected to transverse strain, which had been omitted in the generally admitted theory. The forms of beam employed in the experiments described in that paper were only of two kinds, namely, solid rectangular bars, and open beams or girders.

In the above-mentioned paper Mr. Ward communicates theoretical and experimental investigations which, as far as they are correct, are in their essential parts already published, and indeed somewhat more completely in three papers by Gouy and ourselves, the latter investigations having been suggested by Professor Kundt. Experiments on the rotation of the plane of polarisation of light by means of interrupted currents, like those of Bichat and Blondlot, are here excluded. Since the above-mentioned papers have not been noticed by Mr. Ward, and are hence probably not well known, it may be of interest to reproduce here their essential contents.

I Have to beg the indulgence of the Society to some minute details of anatomy, for the sake of those deductions which can be attained by no other means: and that a zeal for its cultivation may be preserved among us. There is an obvious practical benefit derived from anatomy, but the public do not comprehend its importance as a science. It is to the Royal Society that those who prosecute this science must look for countenance in their slow and painful investigations. Nine years ago, at the request of our late President, I submitted to the Society a paper on the Nervous System; in which I arranged the nerves strictly according to the anatomy, and illustrated the principles of the arrangement, by exhibiting the different functions of the Nerves of the Face. On presenting a second paper on the same part of the nervous system after so considerable a lapse of time, there will be some novelty both in the facts and in the illustrations; yet I have more gratification in showing that after the most minute inquiries in different countries, my positions drawn from the anatomy have been admitted, and my reasoning on the experiments, with one exception, found to be correct. Confident in the accuracy of my deductions from the anatomy of the fifth nerve, I had attributed to one of its branches a function which belongs to another branch of the same nerve. The subject will form a part of the present paper.

These experiments are a continuation of those described in my papers read February 26th, 1866 and February 7th, 1867. They were made during the Winter Session of 1866—67, in the same place, and with the same apparatus as the later experiments on the steel rod (see p. 150 of last paper), the observer being Mr. Zaccheus Walker, student of Engineering, who has been already mentioned as joint observer in the experiments on the steel rod. I personally inspected the apparatus from time to time, and assisted in the taking of those measurements which only required to be made once for all in the case of each rod. The weights, in air and water, of the portions of rods operated on, were observed by Mr. John Tatlock, Laboratory Assistant to Sir William Thomson, who also performed this portion of the labour in the previous experiments. The rods operated on in the experiments now to be described were three in number, and were of malleable iron, cast iron, and copper respectively, those previously operated on being of flint glass (two specimens), brass, and steel.

In a paper which the Royal Society did me the honour to publish in the last volume of its Transactions, I gave the analysis of 328 of the calculi contained in the cabinet of the Norfolk and Norwich Hospital; but was prevented from extending my observations over the whole series of specimens, from the cir­cumstance of the remainder not being then divided. Since that period, how­ever, the division of the whole has been effected; and I have therefore been able to complete the analysis, of which I have now the honour to lay the result before the Society. In my former paper I stated it as probable, that the proportions of the different descriptions of calculi, which formed the undivided part of the cabinet, would not differ materially from that of those which I had analysed; and this proves, in a considerable degree, to be the case. But it may be remarked, that some of the specimens which had been broken in the extraction, and whose interior had been considered as sufficiently exposed for the correct examination of all their laminæ, were found to exhibit some slight differences in their centres, on a more complete division.

1. In the paper recently communicated to this Society, Dr. Duffield has described a promising method of determining gravity at sea, but a somewhat fuller discussion on the theoretical side is required before an opinion of its capabilities and limitations can be formed. For this purpose it is more especially necessary to investigate the effects of the forced vibrations which may be imposed on the mercury in the apparatus by the vertical acceleration of the ship. 2. The problem of determining the period of free oscillation in a barometer tube is very simple, but in the present case three tubes are connected with each other, and at least two of the tubes are not of uniform section, but contain a portion with a narrow bore introduced to damp the oscillations.

In a former paper an examination was made of the nerves of the face; that part of the system was taken, as proving in a manner the least liable to exception, that two sets of nerves, hitherto undistinguished, possessed distinct powers; and that very different effects were produced when the muscles and integuments were deprived of the controuling influence of the one or of the other of these nerves. In that paper it was shown, that parts remote in situation, were yet united by the closest sympathy with the lungs. That by a division of one nerve, these organs could be severed from the other parts of the apparatus of respiration; and though rendered dead to the influence of the heart and lungs, were yet possessed of their other properties, such as sensibility and voluntary motion. In the present paper it is proposed to prosecute this sub­ject, by tracing the nerves which influence the motions of the trunk of the body in respiration, and to subject them to a similar enquiry.

In offering to the Royal Society the ensuing Supplement to my two former papers on the Law of Mortality, with subsequent remarks on invalidism, I am anxious to acknowledge that I have derived great advantage from the encouragement and persuasion of my esteemed brother-in-law, Sir Moses Montefiore, Bart., given me to endeavour to com­pile and publish some of my later observations on the subject; knowing that, though I felt flattered by the attention originally shown by scientific gentlemen to these papers, they appeared to me capable of advantageous illustrations. Therefore I may venture to hope that if this Supplement merit the attention of those interested in this branch of science, I may consider that he has added a mite further to entitle him to the good wishes of those who applaud him for his constant endeavours to promote the general interest of mankind—endeavours which he has shown to extend through Europe and Asia in the cause of humanity, and to be exercised at home in various ways, among which I notice his attention to the practice of Life, Fire, and Marine Assurance; he being the President of the Alliance British and Foreign Life and Fire Assurance Com­pany; of which I was the founding Actuary, and in which Institution, though retired from it, I feel greatly interested; it having been established about the year 1824 by the late N. M. de Rothschild, Esq., the late John Irving, Esq., the late Samuel Gurney, Esq., and Francis Baring, Esq., and himself conjointly with other gentlemen, and he being also President of the Alliance Marine Assurance Society, founded at the same time by them with him. Art. 1. In the year 1820 the Royal Society did me the honour to publish in their Transactions a paper of mine on the Analysis and Notation applicable to the valuation of Life Contingencies, in which I introduced a new and general notation, which appealed to me far more extensively useful, and more explanatory of its object, than any other notation I had met with; and in that paper I think I introduced a new manner of deal­ing with the subject, by offering an analysis, with examples of the extensive use of it, applicable to some of the most intricate questions which had up to that period met with anything like a proper solution; and showed, by selections from the treatise of Life Annuities of my late learned and much-respected friend, Francis Baily, Esq., a mode of solution of all the problems in chapter 8 of that work, depending on a particular order of survivorship; problems previously considered many years before, and presented by my late friend William Morgan, Esq., of the Equitable Society, to the Royal Society, and published in their valuable Transactions; and which had been since considered, in a learned work on Life Annuities, by my late respected friend Joshua Milne, Esq., with some ingenious notation with respect to those contingencies. But still, the solutions given to many of the problems, though there were but three lives con­cerned, were of such an intricate practical form, as to be in my opinion perfectly useless; especially on considering that it was necessary to obtain, by Tables of single and joint lives, by necessary interpolations, the required data; as the differences to be used for the interpolations, in consequence of the great irregularity of the numbers of those Tables, are so irregular as to throw great doubt on the necessary accuracy of the results. And I think the examples I gave of my method could leave no doubt as to the comparative simplicity which resulted from it, and consequently comparative utility of my analysis; an analysis which applies where there are more than three lives concerned, and, in fact, where there are any number of lives to be considered. And I may refer the reader to my solutions in that tract, to enable him to make the com­parison.

When the intricacy of the subject, on which my two last papers have been treating, is considered, it will not appear singular that a few supplementary articles should be given. The compression of the account of the experiments into a small compass, where many material circumstances must be left unnoticed, may throw some obscurity on the results, which can only be removed by examining the subject in a fuller ex­tent, and from various points of view. I hope the following illustration and additional explanations will have the effect of clearing up what may possibly to some appear obscure or doubtful, in either the first or second part of my paper, and serve also to make the conclusions, which in the second have been chiefly supported by prismatic experiments, directly applicable to such as have in the first been made by convex glasses. That the colours in all prismatic phenomena, which have been examined in the 44th, 45th, 46th, 47th, and 48 articles of my paper, are produced either by the interior critical separa­tion arising from the different reflexibility of the rays which cause the blue bow, or by the exterior critical separation arising from the different intromissibility of the rays which cause the red bow, has been so clearly and circumstantially proved that it can admit of no doubt; it may even be con­ceived by some that I have been too particular in giving the precise angles, when we see in the LectionesOptica , Sect. II. Par . 2, page 257, 258, how far Sir I. Newton has explained the blue bow ; but a sufficient reason for this minuteness was to give greater clearness to my explanation of the new pheno­menon of a red bow, which I have with equal precision de­scribed, and which by this means may be, step by step, compared with the production of the blue bow; but a sufficient reason for this minuteness was to give greater clearness to my explanation of the new phenomenon of a red bow, which I have with equal precision described, and which by this means may be, step by step, compared with the production of the blue bow. By this precaution I hoped to anticipate any objection that might occur, such as, for instance, that Sir I. N ewton has also explained the red bow which (it may be supposed) merely the converse of the blue bow. This conception, although N ewton no where speaks of a red bow, seems to be countenanced by what is said after he has shown that the blue bow is caused by the different reflexibility of the rays of light; for as he affirms that the red, orange, and yellow colours are transmitted, he contrives a method of proving it experimentally, by adding a second prism, placed under that which gives the blue bow, and thus making the transmitted rays visible. The full import of this Newtonian experiment will be considered in the following articles.

In a paper on the variations of the acidity of the urine in the state of health, I have, in the third section, given the effect of dilute sulphuric acid; in this Appendix I pur­pose to show the influence of other medicines on the variations of the acidity of the urine. III. ( b . ) The effect of caustic potash on the acidity of the urine was examined. The caustic potash of pharmacy varying much in its specific gravity from 1060 downwards, and in the proportion of carbonate of potash which it contains, some caustic potash perfectly free from carbonate, and of specific gravity 1072, containing, by Dr. Hofmann’s analysis, from 6·20 to 6·29 per cent, of potash, was used for the following experiments. It was taken in distilled water.

The researches detailed in the present paper were commenced in May 1871. The results arrived at were largely obtained from using the microscope. Similar but less brilliant and more scanty appearances can be obtained with the telescope; but the very high power and ready adaptability of the former confers some advantages not offered by the latter. In both, however, the same principles are illustrated. A cone of rays of small angular aperture having the object-glass for its base in each case engages the eyepiece and emerges parallel, and the eyepieces are similar in each.

A few remarks arising out of the perusal of this paper may perhaps not be considered as out of place on the present occasion. They are not meant as in any way impugning the author’s views of the laws determining the fracture and disruption of glacier masses, or their application to glacier-phenomena in general, but in relation to the somewhat mysterious process of regelation itself, and to those generally recognized and most remarkable facts of the gradual conversion of snow into more or less transparent ice, and the reunion of blocks and fissured or broken fragments, under the joint influence of renewed pressure and of that process (whatever its nature), into continuous masses. If regelation be really a process of crystallization, it seems exceedingly difficult to imagine how the molecules forming the cementing layer between two juxtaposed surfaces can at once arrange themselves conformably to the accidentally differing axial arrangements of those of the two surfaces cemented.

The principal object of this paper is the connexion of the results deduced in a former paper from the observations at the Royal So­ciety’s Apartments, with the observations at the Royal Observatory at Greenwich, in order to determine mean numerical values, and to establish the laws of periodic variation from this long series of obser­vations ; the two series of observations are here induced to one and the same series. The observations at the Royal Society having been discontinued between the years 1781 and 1786, it was necessary to supply this link in the series, more particularly as these years were distinguished by very severe weather, and their omission would have a sensible effect on the results. The deficient observations have been supplied by a comparison of the observations which were made at Somerset House, with the observations during the corresponding years made by Mr. Barker at Lyndon in Rutlandshire, from 1771 to 1799, cor­rections being thus obtained for reducing the Lyndon observations to those at Somerset House.

It is an admitted doctrine that the vital properties of motor and sensitive nerves disappear much sooner than those of muscles, after death, or when they are deprived of blood. Although founded on positive facts, this theory is not correct, these facts being capable of another interpretation. In the experiments made heretofore, other organs (such as the spinal cord and muscles) had been deprived of blood, at the same time with the sensitive and motor nerves.

The magical perfection of the designs delineated by light on the prepared tablets of M. Daguerre, and the extreme sensitiveness of his photographic material, render the discovery of inappreciable value to art and science. It appeared to me unfortunate, that a process which promised to improve our perceptions of the beautiful, and which placed in the hands of the scientific observer an instrument of wonderful delicacy, should have its utility circumscribed by its expense and inconvenience. Had the art of engraving the Daguerreotype tablets, or any other mode of multiplying copies of the original designs been discovered, nothing further would have been desired; but as it was, it appeared to be of the greatest importance, that means should be sought for of using some lighter and less expensive material.

Three years ago I gave a sketch of a theory of the passage of electricity through gases, in which it was assumed that in the gaseous discharge an atom carries a definite molecular charge just as in electrolysis (see Bakerian Lecture, ‘Roy. Soc. Proc.,’ vol. 37, p. 317). I showed how this molecular charge if constant might be measured, and I have since that time worked continuously in arranging for the necessary experiments.

In reasoning on the peculiar coloured dispersion operated on a portion of a beam of white light intromitted into a solution of sulphate of quinine, it occurred to me as a subject well worthy of inquiry whether the rays so selected for dispersion and thus singularly separated from the rest, were distinguished by any other peculiarity; whether in effect an analysis of the incident light into two distinct species qualitatively different had been performed, or merely a simple subdivision , such as takes place, for instance, in partial reflexion, as in the phenomena of the colours of thin plates. Another interesting subject of inquiry presents itself in the laws which regulate this singular mode of dispersion itself, which, for brevity, I shall venture to call (at least provisionally) epipölic ,from ϵπ'πo⋋ἠ , a surface, the seat of the dispersion being at or very near the intromitting surface. As regards the question of analysis, two modes of examination present themselves, viz. either,—1, by subjecting the dispersed portion of the light to experiment, or, 2, the residual portion, which, having escaped dispersion, preserves the unity of its direction; and on that account, as well as by reason of its vastly superior intensity, offers itself more readily to experimental inquiry.

THE following letter has been received from the Secretaries of the Society for publication in the hope that it may provoke discussion on a matter of some importance to the well-being of the Society. To the Secretaries of the Royal Society. Dear Sirs, In recent years a good deal of dissatisfaction has been expressed in the Society with the way in which papers have been ‘ read ’ before it. I do not think that those who read the papers have been entirely to blame, since, as far as I know, it has never been properly considered what the purpose of the reading is. It is easy to say that when someone has made an important discovery he is to tell the Society about it, but in fact hardly one paper in a hundred of those communicated is of this class. In the remaining ninety^nine cases the paper will consist of a small advance in some field of study, often very specialized study, of which the great majority of the audience is largely ignorant, and this evidently calls for different treatment. In giving his account, the speaker is usually embarrassed by the fact that among his audience there are a few experts in his subject, while the remainder have only a rather vague knowledge of it, and he (especially if he is a young man) tends to address the experts. Moreover, he is apt to assume that he may refer to any previous work in his subject as being familiar to the whole audience. The result is that he is incomprehensible to the great majority, and on the other hand the experts can hardly be expected to pronounce critical opinions on a paper which they have not seen in detail. No useful purpose on either side is achieved by this manner of reading papers.

In a paper inserted in the Philosophical Transactions I endeavoured to elucidate what appeared to me an important point in the wave-theory, viz. the connexion (first pointed out by Mr. Tovey) between certain conditions with respect to the arrangement of the ætherial molecules, and the rectilinear or elliptic form of the vibrations ; thus affording a criterion of their nature, in the respective cases, by the evanescence, or finite value, of certain terms in the equations. Since the publication of that paper I have been led to review the subject in connexion with the valuable illustrations given by Mr. Lubbock of the views of Fresnel, according to which it appears that the criterion just mentioned requires a material modification. I think it necessary therefore to submit to the Royal Society this short Supplement, in order to point out in what way the conclusions in my paper will be affected by these considerations.

The paper is based upon 55 dissections, 32 fœtal and 23 adult. The posterior thoracic is formed by the 5th, 6th, and usually the 7th. The 5th supplies the first two digitations, the 6th the next two, the 6th and 7th the lower five, or if there is no 7th, the 5th may supply three, and join the 6th for the remainder. The suprascapular is given off from the 5th, with or without a minute fibre from the 6th.

The distances between the parallels of latitude of the principal stations of the original English Arc, as used by Archdeacon Pratt in his paper “On the Effects of Local Attrac­tion*,” are taken from the second and third volumes of the “Account of the Trigono­ metrical Survey.” The correct distances, with the exception of that for Blenheim, are given at page 732 of the last published volume of the Ordnance Survey. They are as follows:- Fect Dunnose and Greenwich ........ 313716.9 Greenwich and Blenheim ........ 132802.0 Blenheim and Arbury Hill ......... 139837.4 Arbury Hill and Clifton ......... 450225.2 Clifton and Burleigh Moor ........ 406596.9 The distance, Greenwich to Bleinheim, is not altered, as there is no new determina­tion of that quantity. The quantities λ and μ, as used by Archdeacon Pratt, do not require alteration.

The influence of oxygen and carbonic acid on the living tissues, has been very little investigated, either by physiologists or practitioners of medicine. I have made a great many experiments on this subject, but will relate here merely a few of them, which are sufficient to show that oxidation of the spinal cord and nerves, as well as that of muscles, increases their vital properties, sometimes in a high degree.

The primary object of the machine is the construction of standard notes. It admits also of the accurate determination of tuning forks, &c., having pitch near that of any standard note of the machine, besides other applications.

I will merely indicate here the principal points of similitude between the effects of these two experiments. Some of the results here mentioned as observed after the section of the sympathetic nerve in the neck, have been discovered by Prof. Bernard; the others have been found by myself. As to the effects of the section of a lateral half of the spinal-cord, I have discovered all of them.

After premising a short history of the opinions of Galen, Dr. William Hunter, Mr. John Hunter, Professor Tiedemann, Professor Lobstein, and Professor Osiander, relative to the existence, course, and enlargement of the nerves of the uterus, the author adverts to his own researches on this subject, which commenced with his discovery, in April 1838, of the trunk of a large nerve accompanying the uterine vein, and of the great nervous plexus with which it was continuous. Of this discovery he gave an account to the Royal Society in a paper read on the 12th of December of the same year. In a subsequent paper, he described some large nervous ganglia situated at the neck of the uterus; and in the present appendix he describes other nervous structures of still greater size which presented themselves to him, on a still more complete dissection which he made of a gravid uterus at the full period of gestation. It appears from the results of these dissections that the human uterus possesses a great and extensive system of nerves, which enlarge during pregnancy, along with the coats, blood-vessels, and absorbents of that organ, and which after parturition resume their original condition. It is chiefly through the influence conveyed by these nerves that the uterus is rendered capable of performing its various functions, and by which sympathies are established between it and other parts of the system.

In an engraving annexed to Sir Everard Home’s first paper upon the above subject, a portion of bone is shown lying upon the scapula, which he considered as a portion of a rib accidentally brought there; but which he now finds to be nearly in its original situation, and is found to resemble nearly the clavicular bone in birds, as far as regards relative position. The bones of the sternum were first pointed out to the author by Mr. Buckland; and their discovery destroys the analogy between this fossil animal and cartilaginous fishes. On comparing the general form of the sternum with that of the Ornithorhynchus paradoxus , a general agreement was discovered between them: they differ in the fossil skeleton having a clavicular bone, which is wanting in the other, and in the Ornithorhynchus having a long process from the scapula, which the fossil bone wants.

This paper forms the continuation of that printed in the last volume of the Society’s Transactions, by the same author. In the present communication the author proceeds to show that the office of the respiratory apparatus is not confined to the changes produced upon the blood, but that the same actions are employed in subservience to other organs, and that they perform a variety of functions, as in the natural voice in articulate language, and in the expression of passion, as well as in the more familiar acts of smelling, coughing, sneezing, &c. Having established the proofs of the necessity of a number of remote parts being joined in the performance of these functions, he proceeds to show that there is a distinct class of nerves for this purpose. That these nerves depart from the same column of the spinal marrow, and diverge to all the parts of the frame, which are drawn into consent in the action of respiration.

The result obtained in the paper on the cell of the honey bee, read November 26, 1885, by which the side of one of the lozenges composing the cell was found to be three times the difference between the two parallel edges forming the sides of one of the trapeziums of the prism, gives a very simple method for constructing the figure as follows. On a straight line take a part AD, and lay off DC equal to twice AD, from D erect a perpendicular, and with radius AC = 3DA cut off DP; AC and AP are sides of the lozenge ACEP, which fulfils the required conditions. It is manifest that from this lozenge the remaining two lozenges and also the six trapeziums can he immediately constructed.

1. The Magnetic Observatory at Singapore. Twenty-seven anemometer curves. Eight magnetic observations for February 1841. Anemometer curves for March, April and May 1841. Magnetic observations made on the term-days in November and December 1840, and January 1841, with an abstract of the magnetic and meteorological instruments, from the commencement of December 1840 to the end of January 1841. Daily curves of certain magnetic instruments

In the paper referred to above, it was stated that the markings or dots upon the valves of the Diatomaceæ, are the optical expressions of depressions existing upon the valves. All those authors who have paid special attention to the Diatomaceæ, have considered the markings to denote cells; among these we find Ehrenberg, Kützing, Ralfs, Smith, and Quekett.

The author, in a paper published in the last volume of the Philosophical Transactions, gave the analysis of 328 calculi contained in the collection of the Norfolk and Norwich Hospital; and has been since enabled to complete the analysis of the 335 remaining specimens, which have now been divided. The results of the ana­lysis are given in a tabular form, exhibiting in the order of their occurrence from the centre, the consecutive deposits of the different materials of which the calculi are composed, according to the most prominent character of such material. The most remarkable cir­cumstance brought to light in the course of this investigation, is the discovery of the presence of silex in one specimen composed principally of oxalate of lime, and weighing about 5 grains. The particles of silex were very minute, and were imbedded in, and dif­fused through, the oxalate of lime. Three examples of a similar occurrence are quoted by the author. The paper concludes with a few remarks on the statistical conclusions stated in his former communication. He thinks there is reason to believe that the average number of calculous disorders in Scotland has been much underrated; on the other hand, the proneness to those complaints is very small in Ireland. A much larger proportion of calculous cases occurs in towns than in the country.

Since the communication above referred to was presented to the Royal Society, I have made a very minute dissection in alcohol of the whole nervous system of the young heifer’s heart. The distribution of the ganglia and nerves over the entire surface of the heart, and the relations of these structures to the blood-vessels and muscular substance, are far more fully displayed in these preparations than in any of my former dissections. On the anterior surface, there are distinctly visible to the naked eye ninety ganglia or ganglionic enlargements on the nerves, which pass obliquely across the arteries and the muscular fibres of the ventricles from their base to the apex. These ganglionic enlargements are observed on the nerves, not only where they are crossing the arteries, but where they are ramifying on the muscular substance without the blood-vessels. On the posterior surface, the principal branches of the coronary arteries plunge into the muscular substance of the heart near the base, and many nerves with ganglia accompany them throughout the walls to the lining membrane and columnse carneæ. From the sudden disappearance of the chief branches of the coronary arteries on the posterior surface, the nervous structure distributed over a consider­ able portion of the left ventricle is completely isolated from the blood-vessels, and on these, numerous ganglionic enlargements are likewise observed, but smaller in size than the chains of ganglia formed over the blood-vessels on the anterior surface of the heart. In the accompanying beautiful drawings, Mr. West has depicted with the greatest accuracy and minuteness the whole nervous structures demon­strable in these preparations on the surface of the heart. But the ganglia and nerves represented in these drawings constitute only a small portion of the nervous system of the heart, numerous ganglia being formed in the walls of the heart which no artist can represent. It can be clearly demonstrated that every artery distributed throughout the walls of the Uterus and Heart, and every muscular fasciculus of these organs, is supplied with nerves upon which ganglia are formed.

In the brief account of the transit instrument which I had the honour some time ago of presenting to the Royal Society, I stated the circumstance of the instrument's deviation from the meridian arising from the unequal expansion of its braces; but no instance was then given of the magnitude of such deviation. I now subjoin one. On the morning of Oct. 15, (civil reckoning) after observing the passage of Regulus, the southern shutters were accidentally left open, so that when I returned to observe the inferior culmination of the pole star, the sun was shining on the upper western brace, the object-glass of the instrument being towards the zenith. The effect of this was a retardation of more than 25 seconds in the star's passage, as will thus appear: I now view, with great suspicion, all the observations of the sun's transits, which I observed previously to the detection of that source of inequality which is the subject of the present, and of my former communication.

This communication is intended merely as a supplement to a for­mer paper on the same subject, printed in the Transactions of this Society, in which a deviation of the transit instrument from the plane of the meridian, arising from a difference of expansion in its braces, was pointed out. As no instance was there given of the magnitude of this deviation, one is here adduced in which the inferior passage of the pole star was found to have been retarded twenty-five seconds in consequence of the sun having been allowed to shine on the up­ per western brace, the object-glass of the transit being towards the zenith. The author adds, that in consequence of the detection of this source of inequality, he now views with great suspicion all his previous observations of solar transits.

In the abstract of Dr. Woods paper printed in the 'Proceedings’ for January 10th, the following remark occurs: “Mr. Joule published in the Philosophical Magazine for June 1852, a memoir proving exactly the same proposition, but giving me the merit of priority in a preliminary remark.” In justice to myself I must state that my actual words were— “I observe with pleasure that Dr. Woods has recently arrived at one of the results of the paper, viz. 'that the decomposition of a compound body occasions as much cold as the combination of its elements originally produced heat,’ by the use of an elegant experimental process described in this Magazine for October 1851. I ought, however, to remark, that previous to the year 1843 I had demonstrated ‘that the heat rendered latent in the electrolysis of water is at the expense of the heat which would otherwise have been evolved in a free state by the circuit.’ ”

Some months since I communicated to the Royal Society the result of observations on γ Draconis made with the water-telescope of the Royal Observatory (constructed expressly for testing the equality of the coefficient of sidereal aberration, whether the tube of a telescope be filled with air, as usual, or with water) in the spring and autumn of 1871. Similar observations have been made in the spring and autumn of 1872, and I now place before the Society the collected results. It will be remembered, from the explanation in the former paper, that the uniformity of results for the latitude of station necessarily proves the correctness of the coefficient of aberration employed in the Nautical Almanac.

The author states that, from a microscopical examination of the blood-vessels and circulation in the ears of the long-eared bat, he has ascertained that, different from what he had discovered to be the case in the wings, the veins of the ears are unfurnished with valves, and are not endowed with rythmical contractility, and that the onward flow of blood in them is consequently uniform.

In the First Part of the Philosophical Transactions for 1841,I have described and represented in two engravings the nervous ganglia, situated on the sides of the neck of the uterus, in which the great sympathetic and third sacral nerves unite, and from which branches proceed to the vagina, bladder, rectum, and the whole of the lower part of the uterus. In an Appendix to that paper, published in the Second Part of the Philosophical Transactions for 1842, there is contained a further account of the nervous structures situated on the fundus and body of the uterus, and an engraving in which the appearances they present at the full period of gestation have been ac­curately delineated. From the form, colour, vascularity, and general distribution of these structures, and from their branches actually coalescing, and being continuous with those of the great sympathetic and spinal nerves, I inferred that they were true nervous ganglionic plexuses, and formed the nervous system of the uterus enlarged during pregnancy. In a gravid uterus at the full period I have recently, and with still more care, traced the great sympathetic and spinal nerves into the two hypogastric ganglia, and from thence over both sides of the uterus to the fundus. A lens which magnified six diameters was employed in this dissection, which enabled me with unerung certainty to distinguish and to separate the nervous filaments from the fine cellular membrane by which they are so closely surrounded, and from all the other contiguous structures. In this minute dissection, many of the details of the nervous system of the uterus are more perfectly shown than in any previous dissection made by me, and they confiim, in the most complete manner, the accuracy of all that is contained in my previous communications on this subject to the Royal Society. To this preparation I can now appeal, as affording a perfect demonstration of the truth of all my statements respect­ing the ganglia and other nervous structures of the uterus.

The author inquires whether the peculiar coloured dispersion of white light intromitted into a solution of sulphate of quinine, is the result of an analysis of the incident light into two distinct species, or merely of a simple subdivision analogous to that which takes place in partial reflexion, as exemplified in the colours of thin plates. He endeavours to ascertain the laws which regulate this singular mode of dispersion, which for brevity he terms epipolic , on account of the proximity of the seat of dispersion to the intromitting surface of the fluid. It might have been expected that by passing the same incident beam successively through many such dispersive surfaces, the whole of the blue rays would at length be separated from it, and an orange, or red residual beam be left: but the author establishes, by numerous experiments, the general fact, that an epipolical beam of light , meaning thereby a beam which has been once transmitted through a quiniferous solution, and undergone its dispersing action, is incapable of farther undergoing epipolic dispersion. There were only two liquids, out of all those examined by the author, namely oil of turpentine and pyroxylic spirit, which, when interposed in the incident beam, act like the solutions of quinine in preventing the formation of the blue film: and the only solid in which the author discovered a similar power of epipolic dispersion, is the green fluor of Alston Moor, and which by this action exhibits at its surface a fine deep blue colour.

The erroneous date given in our paper for one of Professor Wolf’s maxima has already been corrected by us, and we give in the subjoined little Table the corrections of the few numerical data which are necessitated by the error of fixing the date of maximum at 1846·6 instead of 1848·6. Professor Wolf’s ratio A/B(p. 86). The differences derived from our own results are respectively +0·061, —0·107, and +0·047, that is, they are still much smaller, and agree singly better with the mean, than if Professor Wolf’s ratio were adopted; hence our conclusion is quite unaffected by this correction.

The interesting new definition of electronegativity put forward by Dr Walsh is open to the same sort of criticism as that which may be levelled at that of Pauling. As applied to an atom, the term ‘electronegativity’, in its original context, was surely a measure of its polar propensities. And both of these empirical definitions appear to preserve only the most tenuous of connexions with this connotation. It is true that A —H bond force constants appear to increase on going from left to right across the periodic table and that they decrease on going down. Deviations from bond additivity exhibit closely related regularities. We may observe that Mulliken's electronegativities ½( I + E ) behave in a similar fashion. But it is quite another thing to define electronegativities on the basis of such correlations. Indeed, the work reported by Dr Cottrell and Dr Sutton suggests that both Dr Walsh’s and Pauling’s data may be satisfactorily explained in terms of a purely homopolar effect. Professor Coulson has drawn attention to the very delicate position in which electronegativity theory now finds itself. It may therefore be of interest to the discussion if I may summarize an entirely theoretical approach to these problems which I have developed recently.

1. No systematic investigation on this subject has yet been attempted. The efforts made to group these materials in a series according to the charges generated when they are rubbed two at a time are of uncertain value because of (1) impurities of substance and surface, (2) indeterminate initial surface strains. Moreover, the general practice has been to rub the solids when held, one in each hand. A more reliable method is to mount the bodies in a mechanism which ensures that the same parts of them come into contact at each fresh stroke. In the present research, the elements, mostly metals, are those specified in the preceding paper. The textiles are made and cleansed as described in an earlier paper. Silk, cotton and linen in our experience behave reliably when fully cleaned. The other great textile material, wool, is more oily and cannot be readily cleansed; so is less trustworthy. We therefore at present confine ourselves to one animal and one vegetable textile, choosing the pure samples of silk and cotton specified in the above paper. Also filter paper, another convenient fabric, is used after being boiled in several lots of distilled water. As the silk and cotton are treated with boiling chloroform, we tried exhausting the filter paper in this solvent to see if such treatment affected the cellulose in any way; but no effect on the properties of the paper could be found.

The present paper is the third of a series dealing with the effects of freezing and drying on living amphibian muscle (1, 2). In this paper it is shown that simple drying of muscles causes the production of lactic acid, in amount identical with that produced by the corresponding degree of freezing (2). This finding confirms the view expressed in the earlier communications that the effects of freezing and drying are identical, the determining factor in each case being the removal from the muscle of a certain amount of water. Experimental Procedure . To ensure even drying throughout, it was necessary to use a thin muscle of regular geometrical form. The sartorius muscle of the frog was therefore chosen. The frogs were precooled for some hours at zero. The muscles were then carefully removed at their insertions, wiped on filter paper, and each individual muscle suspended by a silk thread of known weight (see later) in a stoppered bottle, over 0·72 per cent, sodium chloride solution. After standing at 0° C. for 24 hours, to allow of the removal of the lactic acid formed during the manipulation, the muscles were weighed, and rapidly dried by being suspended in bottles over solid calcium chloride. It has already been shown that this method of drying produces a uniform state throughout the muscle (1, p. 187). They were removed at intervals for weighing.

The difficulties attending continuous registration of electrical potential gradient of the atmosphere are very great; but it is not my intention in this paper to discuss these. My object is to call attention to the measuring part of an electrograph, and more especially to experiments made with an instrument that promises to be of considerable service in work of this kind. A recording voltmeter ought to have a uniform scale value over the range for which it is intended to be used, it must possess a high degree of insulation, and it ought to be capable of acting efficiently for long periods without having to be taken to pieces for cleaning. The general excellence of the Dolezalek electrometer and its high degree of mechanical symmetry suggested to me its use as a recorder, although I do not know that it has been tried before. The instrument was designed to measure very small differences of potential between the quadrants with a potential of, say, 100 volts on the needle. The first thing to ascertain was whether, with a fixed difference due to a single Weston cell, the sensitiveness could be reduced so that the movement of the needle would record, on a suitable scale, the potential applied to it. A trial suspension made of phosphor bronze proved successful, and a scale value of about 200 volts per centimetre was obtained on the photographic paper, which is carried on a drum 1 metre from the mirror attached to the needle Up to 500 or 600 volts the behaviour was excellent, but for higher potentials the needle began to tilt, and if a sudden change was made the needle generally discharged to the quadrants. Experience showed that it would have frequently to carry over 1000 volts. The needle was therefore loaded by prolonging the vertical axis to about 3 cms. beneath the needle, and adding at the end a small brass nut of about 1½ grm. It now carries 1100 volts with perfect safety and stability.

It has been shown in former papers that wood has the property of acting in the dark on a photographic plate, when placed in contact or in proximity to it. Not only does wood act in this way, but leaves, seeds, roots, bulbs, and, in fact, with only few exceptions, all vegetable substances act in a similar way. The more important bodies which are without this property are starch, cellulose, gum, sugar, pith, and pollen. To obtain this action on a plate it is necessary that the body used be tolerably dry, or else the moisture contained in it will act on the gelatine of the photographic plate and destroy the picture. The time necessary for the exposure to the plate varies from a few minutes to 18 hours or more. To quicken the action, heat may be applied, but the temperature must not be above 55º C., nor the time of exposure, under ordinary circumstances, longer than 18 hours, or the photographic film will be injured. Any ordinary rapid photographic plate may be used, and its development is exactly the same as that of an ordinary picture. The best and most general method of drying vegetable substances before exposing them to the photographic plate is to place them between pure white blotting paper and subject them to considerable pressure, say from 1 to 5 or 6 tons per square inch. This process has also the advantage of giving a second picture, for it is found that the liquid which has been expressed and absorbed by the blotting paper is capable of acting on a photographic plate, and that it gives a good representation of the plant from which it came (Plate 19, fig. 1, an oak leaf). Since different woods are capable of acting on a photographic plate it was to be expected that leaves, stems, flowers would do the same. This has been found to be the case, and the action has been traced from its commencement in the sprouting embryo of a plant till after its death. Postponing for the present the full discussion of the cause of this activity of vegetable matter on a photographic plate, it may be assumed as a working hypothesis that the active substance is hydrogen peroxide. As far as the activity of a plant goes, it is comparable with that of hydrogen peroxide. For instance, if one part of pure peroxide be dissolved in one million parts of water it is sufficient to enable the solution in 24 hours at ordinary temperatures, even when the plate is 1/8 inch above the liquid, to give a marked action on the plate; and, on the other hand, a seed leaf of a runner bean weighing only0·02 gramme can give a similar effect.

In extending our search for enzymes of the emulsin type, during the past two years, we have examined a large number of species of plants, using for the purpose the following method briefly referred to in the previous paper, as in most cases we found that active extracts could not be obtained directly from the leaf material. Usually, as soon as possible after it has been collected, we have placed the plant in a bottle with toluene, both in order to prevent the development of moulds and to give full opportunity to the enzymes within the cells to resolve the various hydrolytes with which they are associated. Such material can be dealt with at leisure. It is first cut up in a mincing mill and then dried—either directly or after it has been thoroughly washed to deprive it of soluble matter—best by exposure in a vacuum desiccator at air temperatures; the washed material has the advantage that little or no correction has to be applied subsequently, in the course of the analytical process, on account of soluble matter, such as reducing sugars and tannins, which disturb the result, if present. But in most cases washing diminishes the activity of the material. In determining the original activity of the plant material, it is, of course, necessary to dry it without washing. The dried material is finally prepared for use by grinding it to a fine powder in a coffee mill. Such powder apparently may retain its activity over long periods.