international undertakings, such as the Catalogue of Scientific Literature, the Geodetic Association, and the Geological Congress.

The association meets every three years. To these meetings each constituent academy may send as many delegates as may be found convenient. For the discussion of special questions the assembly divides itself into a scientific section and a literary section.

In each of these sections, as well as in the plenary meetings comprising both sections, each academy has only one vote, At each triennial assembly the next meeting place is chosen. In the intervals between the meetings the affairs of the association are placed in the hands of a council on which each academy is represented by two members or one, according as it comprises both a literary and scientific section or only one of them. The resolutions passed by the association are not binding on the constituent academies, who maintain their liberty of adopting or rejecting them.

The Association of Academies suffers unavoidably from a certain want of homogeneity, owing to differences in the constitution of its component bodies. Most Continental academies contain both literary and scientific sections, and at the organising meeting held at Wiesbaden, marked attention was directed to the fact that there was no body in England that could be considered as representative of literary studies. If matters had been left as they stood then, this country would have been altogether unrepresented as regards half the activity of the association. Efforts were made in consequence to take a more liberal view of the branches of knowledge coming within the range of the Royal Society, and to include literary subjects. Very unfortunately, in my opinion, these efforts failed, and a charter was granted to the British Academy, which has now been included as a separate body among the list of academies forming part of the association. While in this respect we have been at a certain disadvantage, the constitution of the Royal Society has the great advantage of being truly representative of the Empire. In France, on the other hand, no one can belong to the Academy of Sciences who is not domiciled in Paris. Similarly, although Germany possesses four Royal academies (Berlin, Göttingen, Leipzig, Munich), each of them is confined, as regards ordinary members, to its own locality, so that a professor of the Universities of Bonn or Heidelberg, however eminent he may be, could not become a member of any of these academies. Neither in France nor in Germany can the academy therefore be called truly representative. The disadvantages which may arise from this defect have been minimised by adopting a rule that the International Association of Academies may appoint committees for the discussion of special questions, and that members of these committees need not be members of any of the constituent academies. This to a large degree obviates what would otherwise be a considerable difficulty. Nevertheless, I believe that the circumstances to which I have directed attention form the only impediment in the way of handing over to the Association of Academies the ultimate control of every new international undertaking, and even the charge of some of those already established. It is highly desirable that we should work towards this end. An energetic enthusiast may easily start a new enterprise, and Governments are appealed to from different sides for help and support. There ought to be some authoritative body to whom the Governments could apply for advice. Overlapping and waste would thus be avoided.

It is not my desire to disguise the difficulties which have sometimes been encountered in providing for joint undertakings on a large scale. Whether national or international, combined work between men of different temperaments always requires some suppression of personality. Even stronger feelings may be involved when a central office or bureau has to be selected which specially distinguishes one locality. The advantage gained by the locality is often one of appearance rather than of reality, for these central offices should be the servants rather than the masters of the undertaking. In order to prevent national feeling being aroused by any preference given to one nation, it has been customary in some cases to have a. president who belongs to a different country from that of

the director of the Central Bureau; there are also a vicepresident and a secretary, all belonging to different nations. It is thought that such a distribution of office may assist in preserving harmony. I believe that this is the case, but sometimes at the risk of impaired efficiency. It cannot be denied, however, that the seat of the central office of an important undertaking confers a certain dignity, and it is quite natural that a country should feel some pride in the distinction.

England on the whole has not done so badly. We should not forget that in a great portion of the world all clocks strike the same minutes and seconds. Before long all civilised countries (except Ireland) will have adopted the Greenwich meridian for their standard of time, and we may rightly, therefore, call Greenwich the central bureau of universal time.

The offices of the International Catalogue and both the central and computing bureaux of the Solar Union are situated in this country, and if we have not secured an even larger share of the onerous but honourable duties incumbent on such offices the fault is our own. The questions which at the present moment more especially require combined treatment are those of geo-physics, a subject for which very inadequate provision has been made in England. Our earthquake observations almost entirely depend on the self-devotion of one man, and the Meteorological Office, which might reasonably be expected to take charge of certain portions of the work, such as atmospheric electricity, is kept in a state of chronic poverty, and has to restrict itself to work of the most pressing necessity.

Germany, having a large number of well-equipped stations for geodetic, magnetic, and aeronautic work, naturally reaps the reward when the offices of an international undertaking have to be chosen which shall be attached to flourishing institutions in charge of men possessing the leisure and qualifications for the work.

No serious advance will be made in our own country in this respect until our universities pay more attention to the subject of terrestrial physics. This would involve the establishment by the universities of separate laboratories or institutions, to which their present funds could not be applied. The matter wants consideration in detail, and should be carried out according to a homogeneous scheme which would prevent wasteful repetition in different places. But I feel certain that until we have trained up a number of students who possess an adequate knowledge of questions of meteorology, geodetics, terrestrial magnetism, seismology, the position which this country will take in international organisation cannot be a leading one, though it may be, and, indeed, owing to private efforts, is at the present moment, one of which we need not be ashamed.

and

Finally, I must lay stress on one aspect of the question which I hope may induce us to attach still greater importance to international undertakings. The cooperation of different nations in the joint investigation of the constitution of the terrestrial globe, of the phenomena which take place at its surface, and of the celestial bodies which shine equally upon all, directs attention to our common interests and exposes the artificial nature of political boundaries. The meetings in common discussion of earnest workers in the fields of knowledge tend to obliterate the superficial distinctions of manner and outward bearing which so often get exaggerated until they are mistaken for deepseated national characteristics.

I am afraid I have only given a very inadequate account of the serious interests which are already involved in international scientific investigations. But if I may point once more to Indian meteorology, and remind you of the vital importance of an effective study of the conditions which rule the monsoon, you will, I think. realise how impossible it is to separate scientific and national interests. The solution of this particular problem requires an intimate cooperation with Central Asia and Siberia a cooperation which has been easily secured. I do not wish to exaggerate the civilising value of scientific investigation, but the great problems of creation link all humanity together, and it may yet come to pass that when diplomacy fails-and it often comes perilously near failureit will fall to the men of science and learning to preserve the peace of the world.

UNIVERSITY AND EDUCATIONAL INTELLIGENCE.

THE Technical High School of Prague will celebrate its hundredth anniversary in November next. Prof. Wilhelm Gint has been appointed rector for the year 1906-7.

ON July 4, the honorary degree of Sc.D. of Dublin University was conferred upon Colonel David Bruce, C.B., Mr. E. T. Whittaker, F.R.S., Astronomer Royal of Ireland, and Sir A. E. Wright, F.R.S.

PROF. C. GRAEBE has tendered his resignation of the professorship of inorganic, organic, and technical chemistry in Geneva University, to take effect from October 1, after which date Prof. Graebe will be an honorary professor of the University.

THE cost of the new metallurgical institute now being erected in connection with the Technical High School at Aachen will be met chiefly by the voluntary contributions of the Rhine and Westphalian metallurgical industries; the sum set apart for the actual buildings is 500,000 marks. At the recent laying of the foundation stone, Generaldirector Springomm, as president of the Verein deutscher Eisenhüttenleute, expressed the sympathy and best wishes of the society with the undertaking.

MR. F. C. FORTH, principal of the Municipal Technical Institute, Belfast, has sent us a copy of an interesting article on the compilation of technical students' records reprinted from the Journal of the Department of Agriculture and Technical Instruction for Ireland (vol. vi., No. 3). The system advocated of chronicling for ready reference data relative to students' attendances, marks, and successes has been devised to meet the requirements of a large technical institute, and as it has now stood the test of two years' working, the description of it should prove a valuable guide to other technical institutions.

SCARCELY a week passes without an announcement in the American papers of some handsome contribution to higher education from public-spirited citizens. In the last issue of Science received we notice that at the commencement of Brown University it was announced that 32.400l. had been subscribed for the John Hay Memorial Library, thus securing the additional gift of 30,000l. by Mr. Andrew Carnegie. Mr. D. W. Goodspeed, secretary of the board of trustees of the University of Chicago, has announced a gift of 52.000l. from Mr. John D. Rockefeller for current expenses for the year beginning July 1. At the recent commencement of Olivet College gifts aggregating 53,000!. were announced. Of this amount 43,000l. applies toward the Carnegie endowment, leaving only 7000l. to be raised to ensure receiving Mr. Carnegie's gift of 50,000l. By the will of the late Prof. George A. Wentworth, of Phillips Exeter Academy, 2000l. is bequeathed to the academy.

THE new Code of regulations for public elementary schools marks a great advance on similar publications of a few years ago. The detailed schedules of former years, with their minute instructions as to the work of separate standards, are discontinued. Great prominence is given to a few broad educational principles, on which all successful school practice must be based. The new code, in fact, supplemented by the recently published excellent suggestions for teachers, provides just that necessary official guidance which should suffice to enable properly trained teachers to adapt their procedure and curriculum to local conditions and requirements. The tendency exhibited by the central authority to give efficient teachers a freer hand is satisfactory, and we welcome it. A new scheme of arithmetic is included in the Code, and it reflects the movement started by the British Association to eliminate from school arithmetic all fanciful problems of little everyday use, and to introduce practical measurements at an early stage. The scheme in the new Code puts such measurements in the Fifth Standard work, but omits to state definitely in the same section that such practical work with a scale of inches and tenths, or centimetres and millimetres, is the most satisfactory and natural introduction to decimals.

Decimals are, of course, included in the scheme, but the apparent omission referred to makes it appear that the study of decimals is to be postponed until vulgar fractions and mensuration have been mastered. Though the formal study of decimals may be deferred until the Sixth Standard is reached, the use of a decimally-divided scale for measurements should certainly form part of the work in the Fifth Standard at least, if not at an earlier stage. Mensuration without decimals is an anachronism; and the Board of Education ought to state, through its inspectors or otherwise, that use should be made of scales divided into tenths, in the measurements of rectangles and rectangular solids, and of triangles, included in the course prescribed.

From the examination of the cross-sections of the lumbosacral-coccygeal cord of the Macaque monkey (Macacus sinicus), it is seen that:

(1) The maximum section area of the cord, of the white substance as a whole, as well as of the dorsal and the ventro-lateral columns, is found in the fourth lumbar region.

(2) The maximum section area of the grey substance as a whole, and of the dorsal and the ventral horns, is found in the fifth lumbar region.

(3) Reckoning the cross-sectional area of the cord as 100, the maximum percentage of the white substance as a whole, and of the dorsal and the ventro-lateral columns, is found in the first lumbar region.

(4) The maximum percentage of the grey substance is reached in the first coccygeal region.

(5) Reckoning the total area of the grey substance in each cross-section of the cord as 100, the maximum percentage of the dorsal horns is found in the third coccygeal region, and that of the ventral horns in the fifth lumbar region.

January 18. Observations on the Life-history of Leucocytes." By C. E. Walker. Communicated by Prof. C. S. Sherrington, F.R.S.

January 25." On the Origin of the Sertoli, or Footcells of the Testis." By C. E. Walker and Miss Alice L. Embleton. Communicated by Prof. C. S. Sherrington, F.R.S.

In animals, those cells set aside to produce definite sexual elements go through two divisions, the first and second maiotic (heterotype and homotype) divisions, and are then, without any further division, converted directly into spermatozoa. The same thing happens in the maturation of the ovum. No post-maiotic (post-homotype) divisions have hitherto been recorded.

In plants, on the other hand, after the second maiotic division has occurred, an apparently unlimited number of generations may be produced of cells that have gone through the maiotic phase, and consequently possess only half the somatic number of chromosomes. In the first of the above papers, the occurrence of maiotic phenomena is recorded among the leucocytes and the cells which are their immediate ancestors. According to these observ ations, after the first and second maiotic divisions have occurred, they are followed by an indefinite number of generations of cells possessing only half the somatic complement of chromosomes. The first maiotic division is preceded by amitosis and mitosis of the somatic character, just as happens in the testes of many animals, if not in all. It must be remembered that in certain plants only a few of the cells which have gone through the maiotic phase ever become sex cells. The others may form tissues having somatic characters and functions. This parallel between certain vegetable cells and ieucocytes is carried further by the observations recorded in the second of the above papers. Here it is stated that at an early stage in the develop

ment of the testis, before the tubules or pockets are formed, it is impossible to discriminate between the cells destined to become foot-cells and the leucocytes or their immediate ancestors in the same animal.

Among these cells, also, divisions are seen where the chromosome number is half what is found in the somatic cells. The conclusion drawn from this is that the undifferentiated cells which surround the male ova, and which eventually form both the foot-cells and the walls of the pockets or tubules of the testis, are derived from leucocytes or have immediately common ancestors. If these observations be correct, we have, therefore, animal cells which, though reduced, form tissues possessing somatic characters and functions known to happen in plants.

The bearing of these observations upon the cancer problem is obvious when the fusion between leucocytes and tissue cells recorded elsewhere is borne in mind.

May 17. Some Physical Constants of Ammonia: a Study of the Effect of Change of Temperature and Pressure on an Easily Condensible Gas." By Dr. E. P. Perman and J. H. Davies. Communicated by Principal E. H. Griffiths, F.R.S.

(1) The vapour density of ammonia at o° has been found to be 0-77085 (mass of 1 litre in grams at latitude 45°), previous results being 07708 by Guye and 0.7719 by Le Duc.

(2) When the ammonia and the glass vessel were thoroughly dried no appreciable adsorption of ammonia by glass, or condensation of ammonia on the surface of glass, was found to take place.

(3) From density determinations at different temperatures, the coefficient of expansion of ammonia has been deduced as 0.003914 between o° and -20°, and 0.003847 between 0° and 100°.

(4) From Rayleigh's determination of the compressibility of ammonia and our own value for the density, the molecular weight of ammonia has been calculated as 17-030, and the atomic weight of nitrogen as 14.007.

(5) Incidentally, the density of air free from water vapour and carbon dioxide has been determined as 1.2920 (lat. 45°).

(6) The deviation from Dalton's law for a mixture of approximately equal volumes of air and ammonia has been found to be about 1 part in 1000.

(7) The pressure-coefficient of ammonia has been determined, the pressure being atmospheric at 15°. Between 0° and -20° the coefficient was 0.004003, and between o° and 98° it was 0.003802.

The determination of the vapour pressure of liquid ammonia was repeated at some of the lower temperatures, using pure ammonia, in order to obtain an accurate value for its boiling point. From the results, the boiling point of liquid ammonia at 760 mm. pressure was found to be -335 C.

June 7. On the Osmotic Pressures of some Concentrated Aqueous Solutions. By the Earl of Berkeley and E. G. J. Hartley. Communicated by W. C. D. Whetham, F.R.S.

This communication gives an account of measurements of osmotic pressures of aqueous solutions of cane sugar, dextrose, galactose, and mannite. The method adopted is that briefly outlined by us in vol. 1xxiii., Roy. Soc. Proc. A gradually increasing pressure is placed upon the solution (which is separated from the solvent by a semipermeable membrane) until the solvent, which at first flows into the solution, reverses its direction, and is squeezed out. The pressure, when there is no movement of the solvent, is considered to be the osmotic pressure. Owing to the difficulty of determining the exact point at which no movement takes place, and for other reasons, the experiments are carried out so as to enable an observation to be made of the rate of movement of the solvent, both when the pressure on the solution is just below and when just above the turning-point pressure. The osmotic pressure is deduced from these rates. The range of pressures covered by the experiments is from 12 atmospheres.

to 135

making the copper ferrocyanide membranes, and it is pointed out that with the best membranes, in most cases, a small quantity of solution comes through during the experiment. It is shown that even a small leak causes

a considerable lowering of the observed pressure, hence the final results accepted are those where the leak was least.

Attention is directed to the fact that the osmotic pressures of cane-sugar solutions, when measured directly and when calculated from their vapour pressures, agree to within 3 per cent.

Zoological Society, June 19.-Sir Edmund G. Loder, Bart., vice-president, in the chair.-The nudibranchs of southern India and Ceylon, with special reference to the collections and drawings preserved in the Hancock Museum at Newcastle-on-Tyne: Sir Charles Eliot. This paper was an attempt to settle the synonymy of various Nudibranchiata of the Indo-Pacific with the help of Kelaart's drawings and the collections made by him and Walter Elliot, and now preserved at Newcastle. It also contained some new information as to the anatomy of several species (particularly Platydoris formosa, P. papillata, Doriopsilla miniata, Kalinga ornata, and several Pleurophyllidiida). An account of the Entomostraca taken during a bathymetrical survey of the New Zealand lakes, and a comparison of this fauna with that of the English lakes: Dr. G. S. Brady.-A paper dealing with the higher Crustacea obtained during the above-mentioned survey: Prof. C. Chilton. A classification of the Selachian fishes: C. T. Regan. The author stated that the Selachii were regarded as entitled to rank, at least, as a well-marked subclass, and he divided them into two principal groups, viz. Trematopnea and Chasmatopnea, the latter including the single order Holocephali.-An account of the polyclad Turbellaria from the Cape Verde Islands collected by Mr. C. Crossland: F. F. Laidlaw. The collection shows that, on the whole, the fauna of this region of the Atlantic agrees closely with that of the Mediterranean so far as the polyclads are concerned. The most interesting of the sixteen or seventeen species represented in the collection are, perhaps, a species of Anonymus (of which several specimens were taken) and Traunfelsia elongata, gen. et sp. nov. The latter is an elongated form remarkable for the possession of marginal tentacles, which are not usually associated with a long, narrow body in this class. A unique feature in this genus is the presence of a pair of alveolar glands, each with a long duct opening on either side of antrum masculinum. The genus is referred to the Diposthiida of Woodworth.-A large unknown marine animal observed off the coast of Brazil during a cruise in the Earl of Crawford's yacht the Valhalla : E. G. B. Meade-Waldo and M. J. Nicoll (see p. 202).

Royal Microscopical Society, June 20.-Dr. Dukinfield H. Scott, F.R.S., president, in the chair.-The structure of some Carboniferous ferns: Dr. D. H. Scott. The author pointed out the change which had taken place during the last three years in our conception of the Carboniferous ferns. So many examples of fern-like plants were now known to have borne seeds, or were suspected of having been seed bearers, that comparatively few undoubted ferns were left, and it was questioned whether, at least in the Lower Carboniferous, true ferns existed. One family, the Botryopterideæ, was admitted to be well represented in Lower as well as Upper Carboniferous times, and Mr. Newell Arbor had proposed to establish a group of Primofilices to include this and other primitive ferns of the Palæozoic age. The object of the communication was to give a few illustrations of this ancient race of ferns. The Botryopterideæ were first described, beginning with the type-genus Botryopteris. The genus Zygopteris was next considered. A new genus from the Lower Coal-measures of Lancashire, for which the name of Botrychioxylon was proposed, was then described. Two or three other examples of the family having been noticed, Dr. Scott described certain annulate fern sporangia. The germination of spores within a sporangium was demonstrated, and this sporangium had quite recently been identified as belonging to

Chemical Society, June 21.-Prof. R. Meldola, F.R.S., president, in the chair.-The Cleve memorial lecture: Prof. T. E. Thorpe.-The constituents of the essential oil from the fruit of Pittosporum undulatum: F. B. Power and F. Tutin. The results show that the oil contains d-pinene, d-limonene, esters of valeric, formic and other acids, a sesquiterpene, palmitic acid, and a phenol.-Mobility of substituents in derivatives of B-naphthol J. T. Hewitt and H. V. Mitchell.-The decomposition of nitrocellulose: O. Silberrad and R. C. Farmer. The decomposition products are ethyl nitrate, ethyl nitrite, ethyl alcohol, nitric and nitrous acids, ammonia, formic, acetic, butyric, dihydroxybutyric, oxalic, tartaric, isosaccharinic, and hydroxypyruvic acids. Carbohydrates were also present. Note on gunpowder and bullets made about 1641, recently discovered in Durham Castle: O. Silberrad and W. 'S, Simpson. The gunpowder was found to approximate closely in composition to the black powder now used in this country. The ingredients had been merely ground and mixed together. It seems probable that this powder was of Prussian origin. The constitution of acetone : Miss M. Taylor. The results prove that acetone does not behave either towards sodium or Grignard's reagent as isopropenyl alcohol, CH,.C(OH): CH,.-Diazo-derivatives of the mixed aliphatic aromatic w-benzene-sulphonylaminobenzyl amines G. T. Morgan and Miss F. M. G. Micklethwait.-Influence of substitution on the formation of diazoamines and aminoazo-compounds, part v.-s-Dimethyl4 6-diamino-m-xylene: G. T. Morgan and A. Clayton. -Improved apparatus for the determination of molecular weights P. Blackman.

:

on

Linnean Society, June 21.-Dr. A. Smith Woodward, F.R.S., vice-president, in the chair.-A contribution to the botany of southern Rhodesia: Miss L. S. Gibbs. The collections on which the report was based were obtained in August to October, 1905, at the end of the dry season. The air is dry and the sun's rays very strong, temperature from 80° to 90°, so that the country presented a burnt-up aspect, and the trees were bare, except a few evergreens. The veld is systematically burnt, to promote young growth for cattle-food, to the detriment or destruction of trees and shrubs. Distribution of species is wide, and the present paper tends to a confirmation, with many new records. Twenty-three new species are described, amongst the more interesting being the grass Erianthus teretifolius, Stapf, and a characteristic Elephantorhiza.-The authentic portraits of Linnæus: W. Carruthers. The author recalled the fact that in 1889 he made the subject the chief topic of his address at the anniversary meeting on May 24 of that year; he subsequently visited Sweden, Germany, and the Netherlands to inspect the originals, and read a paper detailing his results at the general meeting held November 19, 1891; a transcript of his remarks had been prepared, but did not satisfy him, and nothing was published. The approaching bicentenary celebration of the birthday of Linnæus, for which the Swedes have been making extensive preparations, had induced him to revise his old transcript, and add some recently ascertained facts, which he now submitted to the society.-Plantæ novæ Daweanæ in Uganda lectæ : Dr. Otto Stapf. Mr. M. T. Dawe, officer in charge of the Forestry and Scientific Department of the Uganda Protectorate, made an expedition from Entebbe, through Buddu and the western and Nile provinces of that territory. His collections were transmitted from time to time to Kew, and his report was issued as a Blue-book (1906, Cd. 2904) last April; it gave an account of his journey, with some rough illustrations of specially noteworthy plants. Much new light is thrown on distribution, and new species are described, amongst them the new genus of Rutacea, Balsamocitrus, Stapf, and a new species of Warburgia (Canellaceae). appendix, Mr. Dawe gives a summary of his report on the vegetation of the country traversed. The genitalia of Diptera: J. Hopkinson. The structure of bamboo leaves : Sir Dietrich Brandis.

As an

Physical Society, June 22.-Prof. J. Perry, F.R.S., president, in the chair.-The effect of radium in facilitating the visible electric discharge in vacuo: 5. A. C. Swinton.

It has been shown by Edison, Fleming, and others that the passage of the electric discharge in vacuo is much facilitated by heating the kathode. More recently it has been shown that the passage of the discharge is still further facilitated by coating the heated kathode with oxides of the alkaline metals. It is generally held that the efficacy of the hot oxides in this direction is due to their giving off negatively-charged ions or corpuscles. The author therefore decided to ascertain whether similar effects could be obtained by painting the kathode with radium, and as radium gives off corpuscles when cold, it was anticipated that it might not be necessary to heat the kathode. Using a continuous current up to 400 volts pressure, this was found not to be the case, the radium having no appreciable effect in producing a visible discharge. When the radium-coated kathode was heated to redness, the radium was found to have a very marked action in facilitating the production of a luminous discharge. Experiments were made which proved that the mere presence of radium in the tube was insufficient to produce the effect, and, furthermore, it was found that the tube would only allow visible discharges to pass in the direction that made the radium-treated electrode the kathode, the tube acting as a unidirectional valve in the same way as do tubes with kathodes coated with oxides.-The effect of the electric spark on the actinity of metals: T. A. Vaughton. It has been pointed out by several observers that some metals, such as aluminium, cadmium, zinc, magnesium, &c.. although not radio-active in the ordinary sense of the word, yet have the power of affecting a photographic plate. The electric spark has a remarkable influence on this actinity,' in some cases causing an increase, and in others apparently diminishing it. The alteration is not merely momentary, but remains for months. It is, however, quite superficial, and may be removed by slightly rubbing the surface of the metal with emery-paper. In the case of aluminium sparked with gold, the direction of the current does not make much difference in the actinity of the sparked plate, but in the case of other couples the difference is very marked. For example, if a cadmium strip is sparked with antimony, the cadmium being connected with the positive terminal, the cadmium becomes very active photographically, not only on the spot sparked, but all over its surface. If, however, the cadmium is connected with the negative terminal and sparked with a positive terminal of antimony, the cadmium remains very slightly more active than if not sparked at all.-The dielectric strength of thin liquid films: Dr. P. E. Shaw. The range of voltage used in the experiments is from 25 to 400, and the corresponding spark-lengths vary from about 0.15 to б.0 μ (μ=0.001 mm.) for the insulating liquids used. The apparatus employed for measuring length is the micrometer designed by the author for measuring gauges (Proc. Roy. Soc., April). The substances used were olive oil, castor oil, linseed oil, rape oil. turpentine, fusel oil, oil of resin, cod-liver oil, neat's-foot oil, paraffin, transformer oil, the homologous series CH, CH, CH, CH,,, and armacell, ohmaline and Sterling varnishes. The best insulators are paraffin and transformer oil, though for these, as for all commercial oils, great care was taken to remove water and acid by prolonged heating to 110° C., and treating with potassium carbonate. No simple connection can be traced between specific inductive capacity and dielectric strength.-The effect of electrical oscillations on iron in a magnetic field: Dr. W. H. Eccles. In attempting to make precise measurements of the effect of high-frequency oscillations on iron held magnetised by a magnetic field, two main difficulties are met. The one is that arising from the fact that the oscillatory currents induced on the surface of the iron investigated shield the inner layers, and thus make the mass of iron affected a variable quantity. The other difficulty arises in the matter of producing oscillations of determinate and invariable character. The author has endeavoured to meet the first difficulty by using oscillations so feeble that they affected only the outermost lavers of the iron wires employed, and these even only slightly. The second difficulty has been met by using the oscillations produced in an open insulated solenoid by a single small measurable spark passed to one end of the solenoid.

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14

EDINBURGH.

Royal Society, June 18.-Dr. Munro, vice-president, in the chair.-A study of the dietaries of students' residences in Edinburgh: Dr. Isabella Cameron. The objects of the investigation were to compare the dietary of the middle classes with that of the working classes, which had already been carefully studied, to ascertain how far this diet conformed to the various standard diets, and to investigate the question of the reduction of cost through combination.

The dietaries of four men's residences and one women's residency were studied for one week, which was equivalent to 1129 men for one day. The average amount consumed per man per diem was:-proteids, 143 grams; fats, 138 grams; carbohydrates, 511 grams; fuel value, 3973 calories. The expenditure came to fully is. 2d. per day per man, nearly double the cost of the average labouring man's diet. When compared with similar institutions in America, the Edinburgh residences were found to consume more proteid and carbohydrate, but less fat. There was also less waste. The theory of epidemics: Dr. John Brownlee. The growth and decay of an epidemic seemed to depend on the acquisition of a high degree of infectivity at the start, this infectivity being then lost at a rate expressible mathematically as an exponential. This truth was realised by Dr. Farr, but the subject did not seem to have been pursued with any definite scientific aim. Dr. Brownlee had subjected various epidemic statistics to mathematical analysis, and had found that the curves representing their growth and decay could be well represented by Prof. Karl Pearson's curve of type iv. The correspondence was very close, except in the neighbourhood of the vertex. The general conclusion was that the condition of the germ had much more to do with the causation of an epidemic than the constitutional peculiarity of the persons affected at the moment. There was no evidence in favour of the idea that the epidemic ended because of the lack of susceptible persons.-The plant remains in the Scottish peat mosses, part ii. Francis J. Lewis. This part had to do with the Scottish Highlands, the preceding part having discussed the peats of the Lowland Uplands. These Highland peat mosses began later than the Lowland mosses, and did not show the intercalated Arctic condition after the retreat of the ice-sheet. The bottom layers in the mosses in Caithness and Inverness had Arctic plants, but these were lacking in the Skye mosses, which accordingly were shown to have begun still later. The succession of layers was broadly similar to the succession already made out in the Lowland mosses, but in the Highland peats of recent age there were two distinct dry woodland mosses full of trunks of Pinus sylvestris, separated by a layer of sphagnum moss. The peat deposits over Scotland thus showed a definite succession of changes which could be correlated with the later stages of the Glacial epoch.

PARIS.

Academy of Sciences, June 25.-M. H. Poincaré in the chair. The formation of endothermic compounds at high temperatures: M. Berthelot. According to the current thermodynamical theories, endothermic compounds can be formed and are stable at high temperatures. The author criticises the experimental observations adduced in support of this view, and concludes that no exact observation has been brought forward establishing, either in principle or in fart, that very high temperatures can cause a reversal of chemical affinity by directly forming endothermic compounds by simple heating.-The generalised problem of Dirichlet and Fredholm's equation: Emile Picard.-The radio-activity of gases evolved from the water of thermal springs: P. Curie and A. Laborde. The data given in a previous paper are corrected, and some additional determinations given for some new springs.-The action of steam upon sulphides at a red heat. The production of native metals: Armand Gautier. The sulphides of iron give rise to magnetic iron oxide, sulphuretted hydrogen and hydrogen. In the case of lead sulphide, taken as a type of the sulphide of a metal which does not decompose water, the primary products would appear to be lead, sulphuretted hydrogen and sulphur dioxide, the two latter substances reacting to give free sulphur. Copper sulphide gave copper, sulphur dioxide, and

hydrogen. These experimental facts are applied to the consideration of volcanic phenomena.-The condensation of BB-dimethylglycidic ester with sodio-malonic ester. Syntheses of terebic and pyroterebic acids: A. Haller and G. Blanc. Dimethyl-glycidic ester, heated on the water bath with olide-4, and this, boiled with hydrochloric acid, gives terebic sodio-malonic ester, gives 4-methyl-2: 3-dicarboxyl-pentanacid, the latter being characterised by its conversion into isocaprolactone and pyroterebic acid. The external work

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created by the statical and dynamical actions of the internal work of the motor muscle: A. Chauveau.-The treatment of pulmonary tuberculosis by serotherapy: MM. Lannepathogenic Trypanosomes: longue, Achard, and Gaillard.-The identification of attempts at diagnosis: A. Laveran and F. Mesnil. The serum of an animal which has acquired immunity against a particular trypanosome frequently possesses to a high degree specific properties which can be utilised for the identification of trypanosomes. The authors give a detailed account of experiments made in this connection, and show that the application of this method is not without difficulties.-The indication for the anti-tuberculous vaccination of young ruminants by the alimentary canal: S. Arloing. Details of experiments on young goats are given from which the author concludes that complete immunisation can be effected by the aid of human or bovine tubercle bacilli, suitably modified, introduced into the alimentary canal.-M. Gernez was elected member in the section of physics in the place of the late M. Pierre Curie.-The deformation of certain tetrahedral surfaces G. Tzitzéica.-A theorem of algebraic surfaces of the nth order: G. B. Guccia.-Differential equations of the second order and first degree the general integral of which is uniform: M. Gambier.-Diminution of velocity and change of trim of ships by the reflex action of water on the bottom: E. Fournier.-A simplified study of the effects of capacity of alternating current cables: A. Blondel.-Interferential photography: the variation of the incidence polarised light: M. Ponsot.-An arrangement position of minimum deviation: P. Lambert.-A simple permitting of placing simultaneously several prisms in the method for the study of the movements of metallic vapours in the oscillating spark: G. A. Hemsalech, The sparks are blown on one side by a current of air of known velocity, resulting in curved lines in the spectrum, from measurements of which the tangential velocities of the metallic vapours can be determined.-The methods of photographing the absorption lines of the colouring matters of the blood: Louis Lewin, A. Miethe, and E. Stenger. Details of the apparatus used are given. The present note contains no results. The heat of formation of carbonyl-hydroferrocyanic acid J. A. Muller. The heat of combustion, determined in the calorimetric bomb, was 3444 calories per gram, from which the heat of formation was calculated as -122 cal. The kathodic phosphorescence of europium diluted with lime. Study of the ternary system lime-gadolina-europia: G. Urbain. The refractive index of substances dissolved in other solvents than water: C. Chéneveau. Results are given for solutions of lithium chloride in water, methyl and ethyl alcohols, and in glycerol.The variations in state undergone by amorphous carbon under the influence of a sudden variation of temperature: O. Manville. The variation in state was measured by the alteration in the temperature at which the carbon commenced to give carbon dioxide in a current of oxygen.-The double sulphate of iridium and potassium, Ir,(SO,), 3K,SO, Marcel Delépine. The properties of the substances formed by the action of hydrochloric acid upon certain metallic silicides: M. Boudouard. These substances contain hydrogen, and may be regarded as mixtures in variable proportions of silicoformic anhydride and silico-oxalic hydrate. The crystallography of iron: F. Osmond and G. Cartaud.-The action of oxygen on rubidium-ammonia: E. Rengade. The three metals potassium, cæsium, and rubidium, dissolved in liquid ammonia, give in presence of oxygen a white dioxide and a yellow tetroxide. Potassium and cæsium give in addition a dark trioxide, but there is no evidence of the formation of an analogous oxide of rubidium.-Researches on the pyrazolones: new methods of synthesis: Ch. Moureu and J. Lazennec. The reaction between the arylpropiolic esters and hydrazine, forming