graphically the variations of the principal magnetic and meteorological elements and of earth movements, in addition to a self-registering "Beckley rain gauge and other automatic apparatus. The tables, containing hourly and mean values, have been carefully prepared on the Greenwich pattern, and are, therefore, quite clear and convenient for reference. Mr. Claxton prints the results of an interesting investigation of the degree of accuracy of self-registering maximum and minimum thermometers. He finds that maximum thermometers read higher in a horizontal position than when inclined to the horizon; the excess may amount to 1° F. Also, that the indications of spirit minimum thermometers are untrustworthy, owing chiefly to evaporation of the spirit. They should be used in conjunction with an ordinary mercurial thermometer. A PAPER on Britain's place in foreign markets is contributed to the Economic Journal for September by Prof. A. W. Flux. The author has had considerable difficulty in drawing up statistics owing to the great discrepancies which he finds in the returns from different countries. He, however, considers that the market for British goods in Germany, France, and the United States, though narrowed by the tariff policy of the third, is still of great importance, and is expansive in some degree except in the case of the United States. In all three cases, however, the trade done by other countries as a whole has grown faster than their trade with us. DURING March, 1903, several excursions were made to the Phlegræan fields of Naples by Dr. G. de Lorenzo and Sir Archibald Geikie. At the suggestion of the latter the former has now published a short history of volcanic activity in this region (Rendiconto Naples Academy, May to July). Dr. de Lorenzo divides the volcanic formations into three periods, the first being represented by the pipernoid tufa of the Campagna and by conglomerate and breccia at Cuma, Camaldoli and Procida, the second by the yellow tufa of Posilipo, Nisida, Pozzuoli, Capodimonte, &c., and the trachitic masses of the Vomero, and the third period by the eruptions of the Solfatara, Monte Nuovo, the Lago d'Agnano and similar formations. IN the Rendiconto of the Naples Academy for March and April, Prof. Orazio Rebuffat describes some interesting and simple experiments with radium salts. When a glass rod was rubbed with wool in the common way for producing electric sparks the author found that if the experiment was performed in a medium containing a radium salt a luminous glow followed the wool, and when the finger was brought near the excited glass a glow was again seen. By taking a vacuum tube and opening connection with a small tube containing a salt of radium, and then rubbing the outside of the glass tube with wool, a brilliant glow was seen within. By means of this experiment Prof. Rebuffat considers it possible to demonstrate the production of emanations from radium preparations of very feeble activity. DR. R. VON LENDENFELD, of Prague, has published in Globus, lxxxv., 24, a discussion of the melting of glaciers in winter. The author considers that the earth's interior heat is incapable of accounting for any considerable part of the phenomenon; indeed, he only attributes about 3 per cent. to 6 per cent. of the result to this cause. Another cause which may account for a further 1 per cent. is the slow conduction of the summer heat to the interior. The main cause of the melting is attributed to the heating of the ice by the work done in its descent. This work is converted into heat in overcoming friction, viscosity, and similar resistances, just as in Joule's classical experiments. A further increase in the internal melting during the winter is probably due to the pressure produced by the winter snows. A SPECIAL report of the seventy-sixth meeting of the German Association of Naturalists and Physicians is contained in the number of the Physikalische Zeitschrift for October 20. The meeting was held at Breslau from September 18 to 24, and the physical papers include the following:-E. Hoppe, constitution of magnets; H. Hartl, lecture apparatus; C. Pulfrich, coast surveying, &c.; P. Müller, vacuum apparatus; C. Dieterici, energy of water and its vapour; W. Scheffer, stereoscopic problems; A. Köhler, photomicrography by ultra-violet light; J. Stark, mercury lamps of quartz glass; O. Lummer and P. Weiss, n-rays; W. Nernst, chemical equilibria at high temperatures; L. Grunmach, properties of emanium and liquid nitrous oxide; A. Wehnelt, negative ions from incandescent metallic oxides; O. Lummer, resolution of fine spectrum lines; W. Schmidt, models of wave motion; H. T. Simon, a phasemeter; M. Reinganum, molecular volumes of halogen salts; L. Graetz, radiations from hydrogen peroxide; J. Rosenthal, Sprengel pumps; W. Stern, tone-variators; K. Schreber, explosion motors, also force, weight and mass; G. Bredig and F. Epstein, kinetics of adiabatic reactions; and E. Meyer, combustion engines. In addition a discussion took place on mathematical and scientific teaching in the higher schools, including addresses by K. Fricke, F. Klein, F. Merkel, and G. Leubuscher. In the general meetings papers were read on the Ice age by Messrs. Brückner, Meyer and Partsch, on the Antarctic expedition by Prof. Gazert, and on biological mechanics by Prof. Roux. commerce. THE scientific methods which have characterised Japanese operations in the Far East are not the only results of the well developed system of education which the last thirtyfive years has seen established in Japan. Some fifty years ago Japan was a hermit nation more than five centuries behind the times, to-day she constitutes a new and important factor in the problem of the distribution of the world's The story of the foreign commerce of Japan since the restoration of imperial authority in 1868 is told by Mr. Yukimasa Hattori in Nos. 9 and 10 of series xxii. of the Johns Hopkins University Studies in Historical and Political Science, copies of which have reached us. Mr. Hattori considers his subject under three headings: the volume of trade, the character of Japan's commerce, and the geographical distribution of trade. Two remarks towards the end of his paper will show the conclusions to which Mr. Hattori has come. "Japan must rely on industrial development rather than on agriculture, and must try to excel in the quality of the goods produced rather than in quantity." "Japan possesses all the advantages necessary to make her a great manufacturing country. Her people possess exceptional skill, and labour is relatively cheap coal is abundant, and the raw material is easily obtainable either at home or in the neighbouring countries." Those readers who have followed the steps in Japan's development since 1868 will be prepared to agree with Mr. Hattori that his country is but "at the very beginning of beginnings" of what will yet be seen. A SECOND edition of Mr. Drinkwater Butt's "Practical Retouching" has been published by Messrs. Iliffe and Sons Ltd., at is. net. MESSRS. MACMILLAN AND Co., LTD., have in the press an English translation of Dr. Cohnheim's " Chemistry of the Proteids," prepared with the author's sanction from the second edition of that work by Dr. Gustav Mann, of the physiological laboratory at Oxford, and author of Physiological Histology." Dr. Cohnheim's book, which, in its second edition, has been entirely re-modelled, deals with all recent advances made in analysing and synthetising proteids. Several special features have been introduced into the English translation, and some of the chapters have been re-written. AN English edition of Prof. Weismann's "Evolution Theory," which has been translated, with the author's cooperation, from the second German edition (1904) by Prof. J. Arthur Thomson, of Aberdeen University, and his wife, will be published in two volumes by Mr. Edward Arnold toward the end of this month. To commemorate the twenty-fifth anniversary of the founding of the firm of Burroughs, Wellcome and Co., Mr. Henry S. Wellcome is arranging an exhibition of historical objects in connection with the history of medicine, chemistry, pharmacy, and the allied sciences, the object being to illustrate the art and science of healing in all ages. The date of the opening of the exhibition is not yet fixed. THE Cambridge University Press will publish very shortly in the Cambridge Biological Series " Morphology and Anthropology," by Mr. W. L. H. Duckworth. The volume will present a summary of the anatomical evidence bearing on the problem of man's place in nature. The Cambridge University Press has also in preparation "Studies from the Anthropological Laboratory in the University of Cambridge," by Mr. Duckworth. THE November number of the Popular Science Monthly is devoted entirely to the St. Louis Congress of Arts and Science. The representative administrative board, it will be remembered, adopted the plan proposed by Prof. Münsterberg, of Harvard University, to hold one congress of the arts and sciences which should attempt to promote and demonstrate the unity of science. An appreciation of the work of this international congress, interspersed with portraits of representative men of science from various parts of the world, is contributed by Mr. W. H. Davis, of Lehigh University, one of the secretaries. A selection from the addresses given at the congress completes an interesting Bumber of the magazine. OUR ASTRONOMICAL COLUMN. ENCKE'S COMET (1904 b).—A telegram from Prof. Max Wolf to the Astronomische Nachrichten (No. 3975) states that on October 28 the ephemeris published by M. Kaminsky in No. 3973 of that journal needed corrections of 118.24, and, further, that the magnitude of the comet was 12.5. Visual observations have not, as yet, been fruitful. Prof. E. Millosevich vainly sought for this object on September 15 and October 5. DESLANDRES'S FORMULA FOR THE LINES IN THE OXYGEN BAND SERIES.-Referring to a note on the results obtained by Mr. O. C. Lester concerning the oxygen bands in the solar spectrum, which appeared in these columns on October 20, Prof. Deslandres directs attention to the fact that a modification of his first formula (viz. N=a+bn2), equivalent to that now proposed by Mr. Lester, was publisted by him in his original (Comptes rendus, August, 1886) and succeeding memoirs on this subject. Mr. Lester's statement that the first law requires the me ñcation which he proposes is obviously justified, but he appears to have omitted to study the original memoirs, and to have accepted the epitomised and generally known results as being complete. This does not, however, lessen the im portance of the valuable experimental results he obtained in measuring the old and new bands on his large dispersion photographs. ANNUAL REPOrt of the CapE OBSERVATORY.-In the report of the Cape Observatory for 1903 Sir David Gill records several important additions to and modifications of the instrumental equipment. The work of the new transit circle has been greatly facilitated, and the results improved by the adaptation of a Repsold automatic transitting device to the instrument. The line-of-sight spectroscope which is used in connection with the Victoria telescope has been re-modelled, and an extremely delicate thermostatic arrangement has been fitted so that the temperature of the prism box can be maintained constant, within 10°-05 F., during a three or four hours' exposure. In the astrophysical department several stellar spectra have been completely reduced in the region à 4200 to λ 4580, and those of Canopus and Sirius have been discussed in connection with the corresponding terrestrial origins of their lines. The results of the line-of-sight work have been made more trustworthy by measuring only those lines which, on traversing either the thin or the thick ends of the prisms, show no relative displacement, and a Phoenicis has been shown to have a very large radial velocity. In December this star was apparently receding from us at the rate of 105 km. per second. A large amount of routine work in connection with the maintenance of an efficient time service and the completion of the Cape zone for the astrographic chart was accomplished during the year. Important operations were also carried out in connection with the geodetic survey of South Africa, whilst the Government survey of the Transvaal and the Orange River Colony and the topographic survey of South Africa have been planned, the former having been commenced. THE TRANSITION FROM PRIMARY TO SECONDARY SPECTRA.Some very interesting experimental results, obtained with the idea of determining as definitely as possible the points at which, under various conditions, the primary is replaced by the secondary spectrum in gases, are published by Mr. P. G. Nutting in No. 2, vol. XX., of the Astrophysical Journal. The general method was to determine what current capacity caused the above named change when either the wave-length, the pressure, the nature of the gas, the inductance or the resistance was altered, and this was called the "critical capacity." Among other results the experiments showed that this critical capacity is a function of the wave-length, and that it increases slightly as the pressure decreases down to about 1 mm. of air, when it suddenly becomes infinite. All the elements tested have the same critical capacity for the same wave-length and pressure, although the critical point is more marked in some elements than in others. The introduction of inductance always relatively weakens the secondary and strengthens the primary spectrum, although no amount of inductance will completely annul the effects of capacity. Resistance acts similarly to inductance. The critical capacity of any vapour in a mixture of vapours was shown to be the same as when no other gases were present. NEW BUILDINGS OF THE UNIVERSITY OF LIVERPOOL. The George Holt Physics Laboratory. THE George Holt Physics Laboratory, which was declared open by Lord Kelvin on November 12, will be valued by the University of Liverpool as a magnificent addition to its fabric, as well as a memorial to one of the wisest and most generous supporters of that college from which the university has been developed. The laboratory covers an area of 9600 square feet, and has an average height of 55 feet. The architects are Messrs. Willink and Thicknesse, of Liverpool, with whom there is associated Prof. F. M. Simpson, now of University College, London. The external walls, which are very substantial, are built in best common brick with broad courses of red brick and dressings of Storeton stone. The base ment floors are asphalte on a bed of concrete resting on the continuous rock which is the foundation of the whole building. All the upper floors are fire-proof; they consist of a bed of concrete which encases a lattice-work of steel girders, and supports a layer of coke breeze, upon which tongued and grooved pitch-pine boards are stuck down with bitumen and nailed. The resulting surface is both noiseless and steady, and the whole building is made very rigid by the girders employed. In the basement there is a large workshop, fully fitted with machine tools, store-rooms, a room containing a liquid air plant, a furnace room, an accumulator room, a room for the custody and comparison of standards, and a number of research rooms in which extra steadiness, complete darkness, or constancy of temperature can be respectively secured. On the ground floor, close to the entrance hall and cloakrooms, are the doors of the large lecture theatre, a smaller class-room, and a large laboratory for elementary students. This floor also contains the preparation room, the apparatus FIG. 1-The George Holt Physics Laboratory, Liverpool. room, and a sitting-room, office, and private laboratory for the professor. The first floor is set apart for the teaching of senior students. It contains two large students' laboratories, four smaller rooms suitable for optical and acoustical experiments, a students' workshop, a library, and two sittingrooms for demonstrators. The second floor consists almost entirely of research rooms of various sizes. Of these some are designed for special purposes, such as spectroscopy, but the majority are planned so as to be adaptable to as great a variety of needs as possible. A photographic dark room is provided on each floor; that in connection with the preparation room is adapted for the making of lantern slides and enlargements. There is also a small observatory on the roof, containing a four-inch equatorial telescope. An electrically driven lift, working in the centre of a tower, is available for the conveyance of heavy apparatus from floor to floor. It can also be used to give access for experimental purposes to all points of two vertical walls which extend to the full height of the tower, about 75 feet. In another part of the laboratory access over a horizontal distance, about 90 feet, nearly equal to the whole length of the building, is secured. The rooms are heated by low pressure hot water, and are ventilated by an exhaust fan in the roof. They are adequately supplied with gas, with sinks to which hot and cold water are led, with electric power from the corporation mains, and with wires from a switch-board in the basement to which the accumulators are connected. The wiring is run in wood casing on the surface of the walls; all pipes are fully exposed, and, wherever a floor or wall is pierced, an opening is left through which further permanent or temporary connections can be made as required. The apparatus and preparation rooms have galleries round them, so that their whole wall-space is rendered available for cupboards and drawers. Special devices have been adopted for the ready darkening of the lecture theatre, and for the provision of rigid points of attachment above the whole length of the lecture table. The counter-shafting in the workshop is supported so as to be entirely independent of the rest of the building, and thus silence and freedom from vibration are secured. The erection of the laboratory was rendered possible by the munificence of a small body of donors, Mrs. and Miss Holt, Sir John Brunner, the late Sir Henry Tate, the executors of the late Rev. J. H. Thom, Mr. Alfred Booth, Mr. Holbrook Gaskell, Mr. J. W. Hughes and Mr. John Rankin, who together subscribed the sum of 23,600l., which by the addition of interest has increased to 25,900l. The cost of the building, with furniture and fittings, is 21,600l. A sum of 1200l. has already been spent upon machinery and new apparatus, and thus about 3000l. is available for the completion and maintenance of its equipment. It is hoped that the general scheme according to which the laboratory is arranged will prove favourable to simplicity and economy of administration, and will allow teaching and research to flourish side by side, not hampering but supporting each other. New Medical Buildings of the University of Liverpool. The new medical buildings opened at Liverpool on November 12 go far to complete the university school of medicine in that city in a thoroughly efficient and modern manner. They provide accommodation chiefly for the subjects of anatomy, surgery, and materia medica, the school of dental surgery and the school offices, and forensic medicine. There are four full floors to the building, and the ground plan is of an L shape. One limb of the L-shaped figure joins the fine Thompson-Yates laboratories opened six years ago for physiology and pathology. The other limb forms a wing ending freely towards the north. In the angle of junction of the two portions of the building are placed large theatres, one on the ground floor for surgery, the other upstairs for human anatomy. The pitch of the benching is steep, and the lighting is extremely good from a series of long windows following the curve of the rounded angle of the building. In the wing, lighted by windows east and west, is a spacious museum for anatomical preparations. Above this is a large room for dissection, especially well lighted from the east. An excellent theatre for operative surgery forms a feature of the surgical equipment. In addition to the theatres, museum, and dissecting room are rooms for a library, and for smaller classes than those the theatres are intended to accommodate. In the front portion of the building is the medical faculty meeting room for transacting the business of the faculty and of its various committees, also for meetings of the veterinary board which manages the newly started university school of veterinary medicine. Next to the medical faculty meeting room is the spacious room providing an office for the Dean of the faculty. No effort or expense has been spared in making the construction at once durable, well lighted within, and handsome from the exterior. Admirable lighting has been secured throughout, even to the basement rooms, which are particularly good, so as to provide a much needed reading room for students. The erection was begun three years ago, and part of the building has already been in occupation for more than a year. The architects are Messrs. Waterhouse, of London, who have designed most of the older buildings of the university. The group of medical school buildings now in use have cost altogether about 80,oool., including, with the building opened on Saturday, the Thompson-Yates laboratory and the Johnston laboratory. The Chancellor of the university, Lord Derby, formally inaugurated the new buildings on the same afternoon as Lord Kelvin opened the new university laboratory for physics. With these fresh additions to its accommodation and teaching equipment, and with the fine new laboratories for zoology and for electrical engineering now rapidly nearing completion, the University of Liverpool will rank among the best provided university institutions in the country. PROF. MENDELÉEFF ON THE CHEMICAL THE last half-volume (eightieth) of the new Russian Encyclopædic Dictionary contains a remarkable paper by Prof. Mendeléeff on the chemical elements, of which the following is a slightly abridged translation. Together with the articles on matter and on the periodic law, which Mendeléeff contributed to previous issues of the same dictionary, and a paper, "An Attempt at a Chemical Comprehension of the World's Ether," published in a Russian review, this article represents the fundamental physical and chemical conceptions of the great chemist as they now appear in connection with the discoveries of recent years. Mendeléeff passes next to the so-called rare Leaving aside historical details concerning them, he remarks that it is the more necessary to dwell upon them as they complete to a great extent our knowledge of the "Our information about them, he conperiodic law. 66 tinues, can also, in our opinion, contribute towards explaining the relations between the phenomena and the substances in nature; because for the understanding of a multitude of natural phenomena it is necessary to resort to the conception of the so-called luminiferous ether, which by all means must be considered as a ponderable substance, and consequently must have its place in the system of elements, inasmuch as it reminds us of the properties of helium, argon, and other similar elements. The conception of the ether was resorted to at the outset exclusively for explaining the phenomena of light, which, as is known, can be best understood as the result of vibrations of the ether. However, later on, ether, considered as being distributed throughout the universe, was resorted to in order to explain, not only electrical phenomena, but also gravitation itself. In consequence of that, a very great importance has to be attributed to the ether; and as it cannot be considered as anything but ponderable matter, we are bound to apply to it all the conceptions which we apply to matter in general, including also the chemical relations. But as, at the same time, we are bound to admit that this matter is not only distributed throughout stellar space (in order to explain the light which reaches us from the stars), but also penetrates all other substances; and as also we must admit that the ether has no capacity of entering into chemical reactions, or of undergoing any sort of chemical condensation, therefore the above mentioned elements, helium and argon, which are characterised precisely by the absence of that property of entering into chemical reactions with other substances, show in this respect a certain similarity with the ether.'" transformed into helium." "Notwithstanding the extremely small quantities of radium occurring in nature, Madame Curie has succeeded in obtaining a compound of it, and in establishing its kinship with barium, as also in finding its atomic weight to be near 224, which permits us to complete the periodic system of elements by placing radium in the second group, in the 12th row, in which we have already thorium and uranium, the ores of which are possessed of radio-activity.2 Human thought," he begins, "has always endeavoured to simplify the immense variety of phenomena and substances in nature by admitting, if not the full unity of the fundamental elements (Democritus, Epicurus), at least the existence of a limited number of elements capable of producing all the variety of substances. In antiquity this tendency often resulted even in confusing the phenomena Referring further to radium, Mendeléeff remarks that with the substances (earth, water, air, and fire)." there can be no doubt as to its being a separate element, Since the time of Lavoisier such a confusion has become extremely rare in nature. As to the emanation of helium certainly impossible: the substances are sharply separated by radium, and the presence of the helium spectrum in the from the phenomena which are associated with them. spectrum of radium, he explains these facts by the occlusion Of course, there may be partial returns to the old of helium in a compound of radium, and considers that view. However, Mendeléeff continues, "" the solidity" nothing gives us reason to think that radium should be of the now prevailing conception as to the profound difference existing between substances and phenomena is the result of such a mass of coordinated knowledge that it cannot be shattered in the least even if a small portion of the men of science return to the " dynamism of old which endeavoured to represent matter also as one of the forms of phenomena. Consequently we are bound now to recognise the substances (the masses) and the phenomena (the moveents) as two quite separate, independent categories, such a space and time, the substance of which our thought has not yet penetrated, but without which it cannot work. Ts, for example, we are far yet from understanding the cause of gravitation, but with its aid we understand 1 178 phenomena, even though up till now it is not sure evident whether attraction acts through the aid of ntervening medium or represents a fundamental force which acts at a distance. Progress in the understanding rature depends, therefore, not upon our reducing everyting to one final conception-to one principle of all prir pies - but in reducing the great variety of substances «d phenomena which act upon our senses to a small number of recognised fundamental conceptions, even though these he be disconnected. One of such conceptions is that of the recognised chemical elements. The simplest way of conceiving matter in this case is consider it as the result of combinations of elements h themselves are matter; and the phenomena as the reits of movements which are the property of these ments or their aggregations. It was from this point of view that the conceptions were elaborated as to the tion, not only between phenomena and substances, be also between simple bodies and elements; because the option of a simple body implies the idea of an im*bility of transforming certain bodies into other bodies, the conception of a chemical element is merely deterd by the desire of diminishing the number of subes which are required for explaining the great variety the latter." "As to argon and its congeners-neon, krypton, and xenon these simple gases, discovered by Ramsay, differ from all the known elements in that, up till now, notwithstanding the most varied attempts, they could not be brought into combination with any other substance, or with each other. This gives them a separate place, quite distinct from all other known elements in the periodic system, and induces us to complete the system by a new separate group, the group zero, which precedes group i., the representatives of which are hydrogen, lithium, sodium, and so on. "The placing of these elements in a new group is fully supported by the atomic weights which are deduced for these gases on the basis of their densities, if we admit that the molecule of each of them contains but one atom. 1 "About this resemblance between argon and helium and the substance of the world's ether I have already written in a separate article entitled 'An Attempt at a Chemical Comprehension of the Ether,' in the review Messenger and Library of Self-Education, in the first four numbers of 1903. This article was translated into German in the Prometheus of 1503 by M. Tshulok, and into English by M. Kamenskiy under the title 'A Chemical Conception of the Ether' (Longmans, Green and Co., London, 1904). I must, however, remark that the German translation is a complete one, but that the editors of the English translation have omitted the introductory general philosophical remarks about the fundamental distinction between substances (masses), forces (energy), and spirit. This omission deprives the article of the realistic meaning which I intended to give it by introducing ether into the system of elements." 2 "Some later researches lead us to believe that the atomic weight of radium is slightly above the figure found by Madame Curie, but it seems to me that it still remains doubtful whether the conclusion of Madame Curie has to be altered." Thus, helium must be placed before lithium, and argon before potassium, as is seen from the table, into which radium has also been introduced. In this table there are, in the group zero, two unknown elements, x and y, which have been introduced for two reasons: first, because in the corona of the sun, above the region of incandescent hydrogen, there has been noticed an element which has an independent spectrum, and therefore is named coronium; and although it is yet unknown (helium was also first characterised by Crookes as an element, on account of the independence of its spectrum), it must have a density, and consequently an atomic weight, both smaller than those of hydrogen (in the table, this element is marked as y); and secondly, because there is no reason to believe that the system of elements is limited in the direction of the lightest ones by hydrogen. The presence of the elements x and y in the group zero makes us think that the elements which correspond to these positions in the system will be distinguished by the absence, in a high degree, of the capacity of chemical combination a property which belongs also, as has been already pointed out, to helium, argon, and their analogues. Row о ception of the chemical elements is connected in the most intimate way with the generally received teachings of Galileo and Newton about the mass and the ponderability of matter, as also with the teaching of Lavoisier concerning the indestructibility of matter, the conception of the ether originates exclusively from the study of phenomena and the need of reducing them to simpler conceptions. Amongst such conceptions we held for a long time the conception of imponderable substances (such as phlogiston, luminous matter, the substance of the positive and negative electricity, heat, &c.), but gradually this has disappeared, and now we can say with certainty that the luminiferous ether, if it be real, is ponderable, although it cannot be weighed, just as air cannot be weighed in air, or water in water. We cannot exclude the ether from any space; it is everywhere and penetrates everything, owing to its extreme lightness and the rapidity of motion of its molecules. Therefore such conceptions as that of the ether remain abstract, or conceptions of the intellect, like the one Group zero Group I. Group II. Group III. Group IV. Group V. Group VI. Group VII x I y H=1008 2 He=40 Li=7'03 Be=9'1 B=110 C=12'0 3 Ne 199 Na=23'05 Mg=24°1 | Al=270 4 Ar=38 K = 39'1 Ca=401 Sc=441 Ti=48'1 V=51'4 Cu=63'6 Zn=65'4 | Ga=700 Ge=72'3 As=750 Se=79 Br=79'95 5 7 8 Xe=128 Cs=132'9 Ba=137'4 La=139 Ce=140 9 66 "The same property must be attributed to the substance of the ether, which must possess, moreover, an extremely low density, and consequently a very great rapidity of motion of its molecules, in order to have the possibility of escaping from the spheres of attraction, not only from the atmosphere of the earth, but also from the atmospheres of our sun and other suns the masses of which are greater than that of ours. The researches concerning the double stars prove that the masses of the stars which we know do not exceed the mass of our sun more than thirtytwo times, while in other cases they are equal to it; therefore, if we attribute to the ether the properties of gases, we must admit, on the basis of the kinetic theory of gases, that its specific gravity must be very much smaller than the specific gravity of hydrogen. order that the ether may escape from the sphere of attraction of stars the mass of which is fifty times greater than the mass of the sun, it must, while it chemically resembles argon and helium, have an atomic weight not more than 0.000 000 000 053 (and a density, in relation to hydrogen, half as large, as I have proved in the above mentioned article on ether). The very small value of this figure already explains why there is little hope of isolating the substance of the ether in the near future, as it also explains why it penetrates all substances, and why it is condensed in a small degree, or collects in a physicomechanical way, round ponderable substances-being mostly condensed round immense masses as that of the sun or of stars.' (--) In conclusion, Mendeléeff indicates that while the con 1 "It is worth noting that all the incandescent, self-luminous celestial bodies are immense as regards their masses, in comparison with the cooler bodies like the earth or the moon; perhaps this depends upon the dis tribution of the ether, which is condensed precisely round such very big masses as the sun and the stars. It is also worth noticing that the atomic weights of radium, as also of thorium and uranium, are very great in comparison with those of the other elements." Th=232 U=239 which also leads us to the very teaching about a limited number of chemical elements out of which all substances in nature are composed." WELSH CONFERENCE ON THE TRAINING OF TEACHERS. THE Welsh National Conference on the Training of Teachers was held in Shrewsbury on November 10 and 11, and although no special reference was made to science teaching, still the subject of education is now in a fair way to be considered a science, since it has been included as a section of the British Association. The conference was convened by the Central Welsh Board and the University of Wales, and in addition to these bodies, representatives attended from every county education authority in Wales, from every type of educational institution, from the National Executive of Welsh Councils and from all the associations of masters and mistresses. Upwards of 200 delegates attended in all, most of whom remained throughout all four sessions. At the first session, which was devoted to "The Special Aspect of the Problem of Training Presented in Wales,' |