PHILOLOGY English Grammar (1634), reprinted and edited by A. Eichler (Halle, 1910), Tupper's The Riddies of the Exeter Book (Boston, 1910), and the continuation of Dr. Murray's Oxford English Dictionary. Lannert's Investigation into the Language of Robinson Crusoe as Compared with That of Other 18th Century Works (Upsala, 1910) completes our list. are Philipon's Les Ibères: Etude d'histoire, d'archéologie et de linguistique (Paris, 1909), the late Whitley Stokes's A Supplement to Thesaurus Palæohibernicus (Halle, 1910), and the third volume of Camille Jullian's remarkable Histoire de la Gaule (Paris, 1910), a veritable mine for the philologist. The late Professor Strachan's Introduction to Early Welsh (ManROMANCE PHILOLOGY. The most absorbing chester, 1909), containing a middle Welsh topic in Romance philology has been the bitter reader and glossary, supplies a long-felt want. attack of Rajna and Cloëtta in behalf of the Mention should also be made of O'Maille's Lanold school on the revolutionary doctrines of guage of the Annals of Ulster (Manchester, Bédier. Notwithstanding these objections, schol- 1910), Bergin's Stories from Keating's History ars are now agreed that Bédier has proved in of Ireland, edited with notes and glossary his Légendes épiques, by means of his remark (Dublin, 1910), Duanaire Finn, the Book of the able discoveries, that the jongleurs and monks Lays of Fionn, edited and translated by E. Macse sont entendus pour exploiter les traditions Neill (London, Irish Texts Society, 1908), and carolingiennes." Behrens' Beiträge zur fran- Marstrander's Fleadh Dúin na nGéadh ocus Cath zösischen Wortgeschichte und Grammatik Muighe Ráth, edited with introduction and (Halle, 1910) is a careful work. Les Mélanges glossary (Christiania, 1910). In Welsh, we de Philologie romane et d'histoire litt. offerts note the following: Arthur Jones's History of à M. Maurice Wilmotte on the 25th anniversary Gruffydd ap Cynan, with translation and notes of his professorship (2 parts, Paris, 1910) (Manchester, 1910) and Anwyl's The Poetry of contains contributions from almost all the fa- the Gogynfeirdd, with an introduction to the mous Romance scholars of Europe. Mario study of Old Welsh Poetry (Denbigh, 1909). Roques has published the first part of Gaston G. P. Williams's The Preverbal Particle Re in Paris, Mélanges de Litt. franç. du Moyen Age Cornish (Halle, 1908) and Jamieson's Diction (Paris, 1910). The last fascicule of the monu- ary of the Scottish Language, revised by Dr. mental Atlas linguistique de la France of Gil- Longmuir and Mr. Metcalfe (London, 1910), liéron and Edmont (Paris, 1910) also appeared. should not be omitted. Finally Lindsay's Early Faral's Les Jongleurs en France au Moyen Age Irish Minuscule Script (Oxford, 1910) is of (Paris, 1910) and Beck's Les Mélodies des importance for both philology and paleography. Troubadours (Paris, 1910) are both epochmaking works. Devic's supplement to Littré's Dict. de la Langue franç. (Paris, 1910), Lecomte's Le Parler Dolois (Paris, 1910), and Westerbled's Baro et ses dérivés dans les langues romanes (Upsala, 1910) are worthy of note. The Rumanian Academy's Dictionarul Limbii Române, which has now reached its 5th fascicule, supplies a long-felt want. Trabalza's Storia della grammatica italiana (1908) is a remarkable work in which philosophy, philol ogy, pedagogy and aesthetics are combined. Bertoni's study on Buvalelli, Trovatore bolognese (1908) and Frisoni's Dizionario genovese-italiano e italiano-genovese (Genoa, 1910) are useful. In Provençal, we note Levy's Provenzalisches Supplement Wörterbuch (Leipzig, 1910), containing additions and corrections to Raynouard's Lexique roman, and Wechssler's Das Kulturproblem des Minnesangs (vol. I, 1909). In Spanish, Pidal published the series of lectures given at Johns Hopkins University under the title L'épopée espagnole (Paris, 1910). Plaza y Salazar's Etimologias vascongadas del Castellano (Bilbao, 1910) is useful, if controlled. Professors Todd and Weeks of Columbia University, with the coöperation of a number of professors of other American universities, have founded the Romanic Review, a quarterly journal devoted to research in the field of early Romance languages and literatures. The first volume appeared during the year 1910. This is the first review in English devoted entirely to this field. CELTIC PHILOLOGY. The Celtic scholars have been active. The indefatigable Holder published the 19th lieferung of the third volume of his Altkeltischer Sprachschatz (Leipzig, 1910); and Thurneysen completed the Texte mit Wörterbuch of his Grammatik. The second volume of Déchelette's monumental Manuel d'Arché ologie préhistorique celtique et gallo-romaine also appeared (Paris, 1910). Other notable works PHILOSOPHY. RECENT TENDENCIES. The keen interest in philosophy which has marked the end of the nineteenth and the beginning of the twentieth centuries may be said to be growing instead of diminishing. Ever since the reaction had set in against post-Kantian speculation, the theory of knowledge has been assiduously studied, and the history of philosophy, which received such an impetus from Hegel, has been pursued with diligent care. But for many years after the rise of the natural sciences and their mechanical interpretations of the universe, metaphysics assumed an apologetic tone or did not speak at all. The period of diffidence now seems to have passed, and there is intense activity in all the fields of philosophy, in metaphysics, ethics, æsthetics, the philosophy of law, the philosophy of religion, as well as in epistemology and the history of philosophy. We note that this activity is not restricted to any one of the civilized nations and that the thinkers of different countries are coöperating more and more in the solution of problems; even the Germans, who have shown a tendency, for many years, to ignore the writings of their English and American contemporaries, are beginning to discuss and translate their works. It is even held by some that the philosophical hegemony is passing out of the hands of the Germans; however that may be, the present leaders of philosophy in France, Italy, England, and America are producing works of merit. We also note that the occupation with philosophical problems is becoming more popular among mathematicians and natural scientists, as well as among students in other branches of knowledge, and that the insufficiency of the materialistic conception of the world is acknowledged, at least among the leaders of science. OPPOSING SCHOOLS. Within the domain of epistemology, which is still the most important subject of study, the controversy between the idealists, on the one hand, and the pragmatists, realists, empiricists, and pluralists, on the other, has not come to an end. The death of the greatest figure in the radical camp, Professor William James (q. v.), occurred during the year and caused universal sorrow. A group of younger American philosophers has promulgated a "platform of the realists," which formed the chief topic of discussion at the last meeting of the American Philosophical Association, where, also, many papers were read upon this question. The differences between the idealists and prag. matists are more thoroughgoing than those between idealists and realists, concerning, as they do, the problems of the nature and origin of knowledge, the criterion of truth, and the entire structure of experience. In spite of the attacks, however, which have been made upon it, objective idealism may still be regarded as the dominant theory: the result of the controversy has been a clarification of ideas and a greater emphasis upon phases of experience which had been more or less neglected. وو LITERATURE OF RECENT MOVEMENTS. A notable article by A. Chiappelli on "The Vital Tendencies in Contemporary Philosophy (Revue Philosophique, March, 1910) throws much light on the present situation. The following books also discuss the recent movements: Fabbricotti, Appunti critici di filosofia contem poranea; Thilly, Contemporary American Philosophy in Studies in Language and Literature; Walker, Theories of Knowledge: Absolutism, Pragmatism, Realism; Lyman, Theology and Human Problems: A Comparative Study of Absolute Idealism and Pragmatism as Interpreters of Reality; A. Chiappelli, Daila critici al nuovo idealismo; L. Chiappelli, La filosofia dell' assoluto in Inghelterra e in America; de Laguna, Dogmatism and Evolution; Schinz, Anti-Pragmatism; O'Sullivan, Old Criticism and New Pragmatism; A. W. Moore, Pragmatism and its Critics; Bawden, Principles of Pragmatism; Switalski, Der Wahrheitsbegriff des Pragmatismus nach William James; Gillouin, Henri Bergson; Dolson, The Philosophy of Henri Bergson (articles in Philosophical Review, November, 1910, January, 1911); Archambault, Emile Boutroux. An English translation of Bergson's (the leader of the French opposition to idealism) Time and Free Will has appeared, and a translation of his Matière et mémoire is an nounced. Schiller, the English humanist, has republished his Riddles of the Sphinx. Moore, The Process of Abstraction; Brunswig, Das Vergleichen und die Relationserkenntniss; Lechalas, Etude sur l'espace et la temps; Bauch, Das Substanzproblem in der griechischen Philosophie; Cassirer, Substanzbegriff und Funktionsbegriff; Berkeley, Mysticism in Modern Mathematics. Pillsbury, The Psychology of Reasoning; Verworrn, Die Mechanik des Geisteslebens, and McCabe, The Evolution of Mind, will also prove helpful in connection with a study of epis temological problems, as will also many of the books to be mentioned under the head of metaphysics, and historical works like the following: Cohen, Kants Begründung der Ethik, 2d greatly enlarged edition; Goldschmidt, Zur Wiedererkennung kantischer Lehre; von Aster, Immanuel Kant; Wenley, Kant and his Revolu tion; Tocco, Studi kantiani; Jünemann, Kantiana; Haering, Der Duisburgsche Nachlass und Kants Kriticismus um 1775; Wiegershausen, Aenesidem-Schulze; v. Zynda, Kant-ReinholdFichte; Cunningham, Thought and Reality in Hegel's System; MacTaggart, Commentary on Hegel's Logic; Lasson, Beiträge zur Hegelforschung. A long-desired translation of Hegel's Phenomenology of Mind has been published by Baillie. The dictionary of philosophy (Wörterbuch der Philosophie) by F. Mauthner, which is appearing serially, will prove useful in all branches of philosophy. CONSTRUCTIVE PHILOSOPHY. In the field of constructive philosophy, philosophy as Weltan schauung, or metaphysics, a number of interesting works have appeared. Rehmke, who be longs to the group of so-called "immanent philosophers" led by Schuppe in Germany, presents a system of objective idealism in his Philosophie als Grundwissenschaft. According to him, philosophy must say good-bye to phenomenalism, subjectivism, and relativism, and base itself upon the solid ground of reality. Another idealistic book, which, however, would serve as a good corrective to the preceding, is Varisco's I massimi problemi, offering a theory similar to the monadism of Leibnitz, but purged, as Professor Taylor, its reviewer in Mind, thinks, "of the worst features of Leibnitz's doctrine, the absence of real interaction between the monads, the pre-established harmony, and the rigid determinism." De Cyon, the well-known physiologist, declares in his Dieu et science that while the "soul" is intimately bound to the functioning of our organs, the "spirit" or mind WORKS ON LOGIC AND EPISTEMOLOGY are: is independent of these organs, not subject to Dorner, Encyklopädie der Philosophie; Kern, mechanical laws, but capable of unlimited activDas Erkenntnissproblem und seine kritische ity, which is creative in the true sense of the Lösung; Dürr, Erkenntnisstheorie; Rau, Das term. Other books are: a translation of JeruWesen des menschlichen Verstandes und Be- salem's Introduction to Philosophy, a popular wusstseins; Wodehouse, The Presentation of elementary text which has passed through five Reality; Bonnucci, Verità e realità; Ramousse, German editions; Lindsay, The Fundamental Essai d'une théorie scientifique du concept de Problems of Metaphysics; Dewing, Life as vérité; Häberlin, Wissenschaft und Philosophie; Reality; Petrone, Il diritto nel mondo della Delvolvé, Rationalisme et tradition; Lüdemann, spirito; Snowden, The World a Spiritual SysDas Erkennen und die Werturteile; Lodge, Rea- tem; Herrick, The Metaphysics of a Natson and Belief; Wilhelm Wundt, Die Prin- uralist; Lieder, Die psychische Energie und ihr cipien der mechanischen Naturlehre, second edi- Umsatz; Cohn, Ueber das Denken. Among the tion; Volkmann, Erkenntnisstheoretische Grund- contributions on the philosophy of nature may züge der Naturwissenschaften; Natorp, Die be mentioned: a translation of Ostwald's logischen Grundlagen der exacten Wissen Natural Philosophy; Frost, Naturphilosophie; schaften; Oswald Külpe, Erkenntnisstheorie Keyserling, Prolegomena zur Naturphilosophie; und Naturwissenschaft; Lourié, Die Principien Wundt, Die Principien der mechanischen Nader Wahrscheinlichkeitsrechnung; Paulhan, La turlehre; Lorentz, The Theory of Electrons; logique de contradiction; A. Sidgwick, The Hort, Der Entropiesatz; Darbon, Explication Application of Logic; Bode, An Outline of mécanique et la nominalisme; Duclaux, La Logic; Meinong, Ueber Annahmen; T. V. chimie de la matière vivante; Auerbach, PHILOSOPHY 583 PHILOSOPHY Ektropismus oder die physikalische The rich, Die Bestrafung des Motivs; Brugeilles, orie des Lebens; Stohr, Der Begriff des Lebens. Le droit et la sociologie; Lévy, La sociétié et Also of interest and value will be: Zeller, l'évolution juridique; Small, The Meaning of Kleine Schriften; Wundt, Kleine Schriften; Social Science; Ellwood, Sociology and Modern B. Russell, Philosophical Essays; Stumpf, Phil- Social Problems; Le Bon, La psychologie osophische Reden und Vorträge; Correspond- politique et la defense sociale; Fouillée, La ance de Renouvier et Secrétan; Lodge, Rea- démocratie politique et sociale en France; son and Belief; Planck, Die Einheit des physi- Samuelson, The Human Race; Haddon, The kalischen Weltbildes; Moon, The Relation of Races of Man; Wetham, The Family and the Medicine to Philosophy; translation of Houlle- Nation; Gaston, La femme dans l'histoire; vigne's The Evolution of the Sciences; Schnei- Kisch, The Sexual Life of Woman; Ellis, der, Die Grundgesetze der Descendenztheorie Studies in the Psychology of Sex; Coit, Woman in ihrer Beziehung zum religiösen Standpunkt; in Church and State; Odum, Social and Mental Seward, Darwin and Modern Science; Dewey, Traits of the Negro. The Influence of Darwin on Philosophy, and other Philosophical Essays; J. A. Thomson, Darwinism and Human Life; Baldwin, Darwin and the Humanities; Le Dantec, La stabilité de la vie. Étude enérgetique de l'évolution des espèces; Hart, Phases of Evolution and Heredity; Reid, The Laws of Heredity; Herbert, The First Principles of Heredity; De Vries, Intracellular Pangenesis. MORAL INSTRUCTION. The following deal with moral instruction, a subject to which greater attention is being given every year: DeGarmo, Ethical Training; Hart, Critical Study of Current Theories of Moral Education; Sully, Teacher's Handbook of Psychology; Gaultier, La vraie éducation; Namas, La pédagogie sociale de P. Bergemann; Roehrich, Philosophie de l'éducation; Cellérier, Esquisse d'une science pédagogique; Mendousse, Du dressage à l'éducation; Lemaître, La mentale de l'adolescent; Talbot, The Education of Women; Carreño, La educación sexual. ÆSTHETICS. Of works in æsthetics we note: Volkelt, System der Aesthetik, vol. III; Croce, Problemi di estetica; Babbitt, A New Laokoön; Paschal, Esthétique nouvelle; Prandtl, Die Einfühlung; d'Udine, L'art et le geste; Lewkowitz, Hegels Aesthetik im Verhältniss zu Schiller; Eckwitz, Nietzsche als ETHICS. The literature on ethics is large and is turning more and more to the study of special problems. The following deal mainly with theoretical problems: Muirhead, Elements of Ethics, 2d edition; Leonhardt, L'évolution. Doctrine de liberté; Parodi, Le problème moral et la pensée contémporaine; Piat, La morale du bonheur; Nicholson, The Concept Standard; E. Wentscher, Der Wille; Ach, Ueber den Willensakt und das Temperament; Fite, The Individual; McConnell, The Duty of Altruism; Sawicki, Das Problem der Persönlichkeit und Künstler. des Uebermenschen; Krieck, Persönlichkeit und Kultur; Bovet, La conscience de devoir dans l'introspection provoquée; Künzle, Ethik und Aesthetik. in HISTORY OF PHILOSOPHY. The history of philosophy shows the usual large number of productions. Besides the books already cited in connection with other fields, we mention: PRACTICE. The following are concerned with Windelband, Lehrbuch der Geschichte der Philquestions of practice: Everyday Ethics (a series osophie, 3d edition; Reyes, Historia de la filoof lectures delivered at Yale University); Pol- sofia y terminologia filosófica; Cushman, Belock, Hygiene of the Soul; Bryce, Hindrances ginner's History of Philosophy, 2 vols.; Eisler, to Good Citizenship; Justice Wanted: Modern Geschichte des Monismus; Hibben, The PhilThoughts on Social Problems (edited by O. O.); osophy of the Enlightenment; Rupp, Ueber Jones, The Working Faith of a Social Re- Klassiker und Philosophen der Neuzeit; Sanformer; Melin, L'organisation de la vie tayana, Three Philosophical Poets (Lucretius, privée; Lazzati, Liberté de conscience et liberté Dante, and Goethe); Forsyth, English Philde science; Rüstow, Der Lügner; Dromard, osophy; Inouyé, Confucian Philosophy Les Mensonges de la vie intérieure; Angell, Japan; Goebel, Die vor-sokratische PhilosoThe Ethics of Animal Experimentation. A phie; Werner, Aristote et l'idéalisme platonumber of excellent books have appeared on nicien; Joyau, Épicure; Bréhier, Chrysippe; the history of ethics and the history of moral Guthrie, The Philosophy of Plotinus; Endres, ideals: T. C. Hall, The History of Ethics Petrus Damiani; Bauemker, Beiträge zur within Organized Christianity; Bussell, Mar- Geschichte der mittelalterlichen Philosophie; cus Aurelius and Later Stoics; Hicks, Stoic Neumark, Geschichte der Jüdischen Philosophie and Epicurean; Adams, Israel's Ideal; King, im Mittelalter; Grundfeld, Die Lehre vom The Ethics of Jesus; A. Alexander, The Ethics göttlichen Willen bei den jüdischen Religionsof St. Paul; Monod, Nouvelles esquisses de philosophen; Lutz, Die Psychologie Bonamorale évangélique; H. C. Taylor, The Media- venturas; Kercher, Raymundus Lullus; Serval Mind; Schlatter, Die philosophische Arbeit seit Cartesius in ihrem ethischen und religiösen Ertrag; Cohen, Die Begründung von Kants Ethik; Kelly, Kant's Ethics and Schopen hauer's Criticism. F. B. Jevons, The Idea of God in Early Religions, and Hobert, La religion de la Grèce antique, may also be consulted with profit. tillanges, St. Thomas d'Aquin, two volumes; Péladan, La philosophie de Léonard de Vinci; Douglas, The Psychology and Philosophy of P. Pomponazzi; Wolff, F. Bacon und seine Quellen; Hamelin, Le système de Descartes; St. Cyres, Pascal; Alberti, Die Grundlagen des Systems Spinozas; Dunin-Borkowski, Der junge Spinoza ; Lempp, Das Problem der SOCIAL PHILOSOPHY. Worthy of mention Theodicee bei Leibniz; Mackinnon, The Phialso in this connection are works on legal, losophy of John Norris; Pryer, Cabanis; political, social, and sociological problems Katzer, Luther und Kant; Bolland, Schelling, which have a bearing on ethical questions: Hegel und Fechner en de nieuwe Theosophie ; Bosanquet, The Philosophical Theory of the Heller, Die Weltanschauung A. von НитState; Carreño, Filosofía del derecho; Char- boldts; Gwinner, Schopenhauers Leben, 3d mont, La renaissance du droit naturel; Fried- edition; Covotti, La vita e il pensiero di A. Schopenhauer; Keyserling, Schopenhauer als The extent of this latter deposit is as yet Verbilder; Mühlethaler, Die Mystik bei Schop- unknown. The price of radium has been conenhauer; Ziegler, Das Weltbild Hartmanns; siderably reduced. The sale of the element in The Letters of John Stuart Mill, edited by the form of the barium chloride salt was auElliot; Barzellotti, Monte Amiata e il suo pro- thorized by the Austrian government, which feta (Lazzaretti); Remacle, La philosophie de has taken the trade into its own hands. The S. S. Laurie. English translations of the price is now 400 kronen or $80 per milligram works of Aristotle and Nietzsche have been ap- (one-sixtieth of a grain). The substance is put pearing during the year. up in brass capsules, partly lined with lead, upon which the salt is deposited. An opening in the capsule, covered by a mica plate, permits the use of the radium for therapeutic purposes, without opening the capsule. PHOSPHATES. See FERTILIZERS. PATIONAL DISEASES. PHOTOTHERAPY. As familiarity with the Roentgen ray increases and technique improves, new uses are constantly being found for this agent, especially in the field of medical and surgical diagnosis. According to Finckh, 150 patients with suspicious stomach symptoms were examined at Tübingen University, and the presumptive diagnosis of cancer was confirmed by means of the X-ray before any tumor could be perceived by manual examination through the abdominal wall. Adler was able to photograph ulcers of the stomach and duodenum by means of the X-ray, after first administering to the patient a certain amount of subcarbonate of bismuth. The bismuth is deposited on the ulcerated surfaces, and a dim shadow of the outline of the ulcer shows in the photographic plates. Tumors of bones, pus cavities, aneurisms and the outlines of the abdominal organs can now be made out from negatives taken with the Roentgen ray, by those skilled in the reading of these plates. This agent was extensively used to designate purulent processes in the accessory sinuses of the nose and in the bony structures about the ear. As a means of treatment, the rays are being restricted to certain chronic skin diseases, such as lupus and eczema, and in superficial cancer. A bank for the storage and rental of radium to physicians and scientists was established in London. Portions of 50 milligrams of radium, having a value of $4000, could be hired for periods of time at the rate of $200 for one day's use, and one-half per cent. of the value for each subsequent day. PHYSICAL EDUCATION. See EDUCATION IN THE UNITED STATES; and UNIVERSITIES AND COLLEGES. PHYSICS. As has generally been the case during recent years, the most striking advances in physics have been made in those sections which deal with the ultimate constitution of matter, such as radioactivity and the electrical phenomena in gases, and light. A great deal of the work in any experimental science, and particularly in its older and more developed branches, is necessarily of a statistical character, and not so interesting and novel as the work on new theories and phenomena, although of great importance to the science as a whole. ac RELATIVITY THEORY. No entirely new quisition of great importance has been made in the domain of theoretical physics during the past year, but the applications of the relativity theory have been greatly extended. It is proper to note that the fundamental and even revolutionary significance of this theory is beRADIUM. It is now believed that radium coming more widely understood and accepted. emanations are not essentially different from The theory was evolved from the efforts of those of the X-ray in their external therapeu- physicists, particularly Lorentz and Einstein, tics. Independently of each other, Wolff and to explain satisfactorily the failure of the Friedländer investigated the effect of radium extremely careful experiments which had been emanations on tuberculosis, and reached the made in the attempt to discover some influence conclusion that no bactericidal action could be upon optical phenomena caused by the motion shown. In Wolff's experiments, cultures of the of the earth through the ether. Assuming that bacillus, subjected to the action of radium, there is some fundamental principle back of still proved virulent, and killed animals in- these failures, the relativity theory postulates oculated with them. He also applied radium that motion of matter has meaning only when to tuberculous glands in animals, with com- it is motion as referred to some other portion plete failure to reduce them, even under ir- of matter, and that to speak of absolute motion radiations intense enough to produce severe or motion through a universal ether is meaning. inflammation of the skin. less. This amounts to giving up the ether, for The supply of this rare metal, hitherto de- a mechanical conception of which many of the rived almost exclusively from the mines in most brilliant scientists have long labored, but Bohemia, was increased during 1910 by the in vain. 66 This discovery of two new sources of production. ATOMIC THEORY OF RADIATION. No direct The most important was that in Cornwall, and conclusive experimental test of the atomic England, where a pitchblende, comparative rich theory of radiation has yet been brought to a in this element, has already yielded 550 milli- successful completion. 'light-bundle grams of pure radium. The importance of this hypothesis, which explains some phenomena new source of supply will be understood when that appear to conflict with the older theory it is remembered that, according to Sir Wil- of radiation, is one of the most important adliam Ramsay, there are only 5500 milligrams vances of recent years. It has long been conof radium in the world, apart from the Corn- sidered that the emission of radiation from wall product. A new process was also devised any body is due to some sort of electrical vibraby which the element could be extracted from tion in some of its very small constituent the pitchblende within two months. The sec- parts. According to the older theory each source of supply was found in Por- such vibration causes radiant energy to travel tugal, near Guarda, in the bed of a stream. out in all directions. According to the "light ond new Among the interesting suggestions regarding the matter of nomenclature was the proposal to use the name " curie to designate the "amount of radium emanation in equilibrium with one gram of radium." bundle hypothesis the energy from a single compared. A comparison of standards in use vibration is concentrated in certain units, each at different laboratories has revealed errors in contained in a definite volume, and proceeding their supposed content of radium as great as 20 from the source in a straight line. per cent. in some cases. The committee on An ingenious experimental test of this has standards recommended the adoption of a defbeen attempted by Dr. N. Campbell. Accord- inite standard, and Mme. Curie has undertaken ing to the "atomic" theory of radiation, the to prepare a standard containing 20 milligrams beams of radiation proceeding in two different of radium in a suitable sealed tube. Such a directions from a source would be made up of standard can be used for comparison without "bundles of energy from different vibrators. opening the tube, by measuring the intenSuppose the mean intensities of these beams sity of the rays from it. It is proposed were equal, there would yet be momentary that all national laboratories, such as the differences in their intensities, and it can be Bureau of Standards at Washington, obtain shown that if the emission were in accordance sub-standards compared with this international with the "atomic theory of radiation" the mean standard. fluctuation of the difference would not be zero, while on the older theory it should. Campbell tried to test this, measuring the intensities of the light beams by the photo-electric currents which flowed from a sodium-potassium alloy when the light fell on its surface in a high METALLIC RADIUM. The year 1910 witnessed vacuum. The theory developed for the experi- another interesting event in the history of radment was partly confirmed, and Campbell ium. It has hitherto been known only in the found that the number of electrons liberated form of some of its salts, but this year Mme. by one of the hypothetical "light-bundles" Curie and A. Debierne have obtained metallic would be about 3, which agrees with the results radium. They electrolysed some chloride of deduced from other theoretical grounds. But radium, using a mercury cathode, and obtained the main object of the experiment was not fully an amalgam of radium. This amalgam was attained because of the impossibility of finding then freed from mercury by careful heating a suitable light source, so that direct evidence in an atmosphere of hydrogen in a quartz that light is sent out in discrete units of tube. The residue, metallic radium, had a energy remains still to be sought for. shining white color, and when heated to volatilization attacked the quartz tube. It decomposed water, and when exposed to air blackened rapidly, forming probably a nitride of radium. For further details concerning radium, see the articles CHEMISTRY and PHоTOTHERAPHY. In this connection the results obtained during the past year by O. Stuhlmann are of interest. He passed a beam of light through a film of platinum so thin as to be translucent, and compared tne photo-electric effect, that is, the number of electrons thrown out of the surface of the metal by the radiation, at the side of the film on which the light fell, with that at the other side, from which the light emerged. He found the photo-electric effect 17 per cent. greater on the emergent side, that is, when the electrons are torn out of the metal more of them are thrown off in the direction in which the light is traveling than in the opposite direction. This lack of symmetry is in accord with the light-bundle theory, but the difference is larger than can readily be explained on the older theory of light. RADIOACTIVITY. Probably the most im portant event of the year in its relation to the science of radioactivity was the meeting of the Second International Congress of Radiology and Electricity at Brussels in September, attended by about five hundred physicists and medical men. The meeting of so many men interested in the new and growing science could not fail to give a strong stimulus to work in this field. The recommendations adopted by the Congress lead toward greater uniformity and definiteness in the science, particularly in the important matters of physical standards and nomenclature. RADIOACTIVE RECOIL. The recently discovered phenomenon of radioactive recoil has received due attention during the past year. This phenomenon consists of the expulsion of atoms of the radioactive disintegration product from a layer of the parent material, which is due to the fact that when an atom of the latter disintegrates with the expulsion of a or B particles, equal and opposite momenta, in accordance with the principles of mechanics, are given to the atom of the product and to the particles. Hence if a particle is emitted toward the interior of the active layer the "recoilatom" is given a velocity, small because of its greater mass, away from the surface of the layer. Working with the "recoil atom" of radium B, obtained from a layer of radium A, Russ and Makower, and Makower and Evans have measured the deflections which it suffers in passing through electric and magnetic fields. The directions of these deflections indicate that the "recoil atoms" of radium B are positively charged. Their velocity as determined from the deflections and the known field strengths agrees with that computed from the relative masses of the atom of radium ß and of the a particle (from which it recoils) and the velocity of the latter. It was pointed out that a number of the quantities measured in investigations in radioactivity (for example; the volume of the radioactive emanations, the heating effects of radio- Wertenstein has found that the distance the active substances, the rate of production of "recoil atom" of radium B moves in a gas behelium, and the rate of emission of y and B fore being stopped (its "range") is inversely particles) can now be determined with a fair proportional to the pressure of the gas, and degree of accuracy. But the value of any one would at atmospheric pressure be about 0.12 milof these measurements depends upon the ac- limetre. By depositing very thin layers of silver curacy of the radium standard with which the over a layer of the radioactive material it was radioactive substance under investigation is found that most of the recoil atoms 66 |