The Mayor of Lyons hopes to secure as complete a collection as possible of papers relating to the war, so that students and investigators of diverse subjectsmeteorologist or historian, hygienist or sociologist will eventually regard it as the central bureau for their own particular studies of the times through which which we are now passing. All branches of human activity having relation to war questions or problems will be embraced by the library, and no article or other publication will be considered too unimportant for inclusion. It is hoped that authors of all contributions upon these subjects will send copies of their works to the Bibliothèque de la Guerre of the city of Lyons, and will co-operate in other ways to make the collection complete. UNTIL recent years the personal side of academic scientific history has not attracted with us the general attention that its human interest deserves. A notable exception is, however, afforded by the accounts given in the biographies of Lord Kelvin of the relations between Glasgow and Cambridge in his early days. A very interesting narrative of about ten years later has now appeared in the form of a notice of G. M. Slessor, of Queens' College, senior wrangler of 1858, and for a few years professor at Belfast, a mathematician of well-known achievement, whose high promise was cut off by early death at the age of twenty-eight. The biography, accompanied by a striking portrait, is in the Aberdeen University Review for June, 1915; it is written by the Master of Emmanuel, Dr. P. Giles, largely from material contributed by Sir James Stirling, F.R.S., who was a pupil and friend of Slessor, and was himself an Aberdonian senior wrangler a few years later. It may be commended to the notice of all concerned with the preservation of the scientific and academic personal records of the period. BOOKS RECEIVED. Chemistry of Familiar Things. By S. S. Sadtler. Pp. xiii+320. (Philadelphia and London: J. B. Lippincott Co.) 7s. 6d. net. A Text-Book on Practical Mathematics for Advanced Technical Students. By H. L. Mann. Pp. xii+487. (London: Longmans and Co.) 7s. 6d. net. Metropolitan Water Board. Eleventh Report on Research Work, together with Index to Research Reports. Nos. i.-x., inclusive. By Dr. A. C. Houston Pp. 52+vii. (London.) How Belgium is Fed. Pp. 28. (London: National Commission for Relief in Belgium.) The National Physical Laboratory. Report for the Year 1914-15. Pp. 136. (Teddington.) The National Physical Laboratory. Collected Researches. Vol. xii., 1915. Pp. iv + 173+ plates. (London Harrison and Sons.) 125. 594 594 596 596 601 601 601 602 602 603 603 SOCIETIES AND ACADEMIES. PARIS. Academy of Sciences, July 19.-M. Ed. Perrier in the chair.-J. Boussinesq: The existence in our physicomathematical sciences of fundamental chapters still in the same rudimentary state as the dynamics of Aristotle.-Georges Lemoine : The catalysis of hydrogen peroxide in homogeneous media with acids and alkalis. Pure water acts as a catalyser on hydrogen peroxide. The addition of acids even in very small proportions, some ten-thousandths, reduces the rate of decomposition. Curves are given showing the relation between rate of decomposition and concentration of acid for sulphuric and hydrochloric acids. Alkalis accelerate the rate of decomposition, and the results of experiments with soda, potash, and lithia are given.-C. E. Guye and Ch. Lavanchy: The experimental verification of the Lorentz-Einstein formula by kathode rays of high velocity. Using the method of identical trajectories described in an earlier paper it was found that the Lorentz-Einstein formula on the variation of the inertia as a function of the velocity was verified with great precision by all the measurements.-E. Fleurent: Remarks on bread for prisoners of war. A method of preparing bread is described giving a product not liable to mould, and preserving its flavour intact even after keeping a month or longer in a moist, dark cupboard.-Louis Roule: Fish from the lower depths of the sea of the family of Brotulideæ in the North Atlantic.-E. Vasticar: The nuclear formation of the external auditive cells and of Deiters cells. NO. 2387, VOL. 95] The Royal Geographical Society's Work on the Recent Studies in the Dynamics of Living Matter. Our Astronomical Column: Astrographic Catalogue, Perth Section. The University Observatory, Oxford. A New Saccharimeter. (Illustrated.) Entomological Work in Canada. By H. M. L. The Government Scheme for the Organisation and University and Educational Intelligence Societies and Academies Books Received Editorial and Publishing Offices: MACMILLAN & CO., LTD., 605 609 610 610 ST. MARTIN'S STREET, LONDON, W.C. Advertisements and business letters to be addressed to the Publishers. Editorial Communications to the Editor. Telegraphic Address: PHUSIS, LONDON. Telephone Number: GERRARD 8830. THURSDAY, AUGUST 5, 1915. ionic charge. The latter includes an interesting account of the experiments of Perrin. Then follows a very complete discussion of ionisation by collision-a subject which the author has made A CHAPTER OF BRITISH SCIENCE. Electricity in Gases. By Prof. J. S. Townsend. peculiarly his own. Other chapters are devoted Pp. xv+496. (Oxford: Clarendon Press, 1915.) Price 14s. net. THE HE present book was written to appear as the first of six volumes of a handbook on Radiology, to be published in German under the editorship of Prof. Erich Marx. The translation of Rutherford's "Radio-active Substances and their Radiations" appeared nearly two years ago as the second volume of the series. The other volumes in preparation deal with kathode rays, X-rays, photoelectric effects, and the theory of electrons and X-rays. It was intended that the last two subjects should be treated by a number of well-known physicists, including Profs. H. A. Lorentz, P. Zeemann, Langevin, Einstein, Riecke and Sommerfeld. No doubt the publication of the later volumes has been delayed by the outbreak of war. The best-known work on the passage of electricity through gases is Sir J. J. Thomson's treatise, of which a second edition was published in 1906. This gave a very complete account of the work up to that date in this new department of physics. Since that time the growth of experimental facts has been so rapid that it would be difficult to treat the whole subject adequately within the compass of a single volume. Fortunately a number of small books have been published from time to time dealing with special topics, e.g. H. A. Wilson's "The Electrical Properties of Flames and Incandescent Solids," Townsend's "Ionisation by Collision," Sir J. J. Thomson's "Positive Rays," Kaye's "X-Rays," W. H. and W. L. Bragg's "X-Rays and Crystals," Crowther's "Molecular Physics," and Soddy's "Chemistry of the Radio-Elements." These have proved of great value and interest in giving a first-hand account of recent advances of our knowledge in these special departments. The present volume is mainly confined to a discussion of the properties of ions and the mode of conveyance of electricity through gases. The allied subjects of radio-activity, characteristic Xradiations, wave-lengths of X-rays, and thermionics, receive only passing mention, as they were to be treated in detail by other writers in subsequent volumes. After a preliminary discussion of the methods of production of ions in gases by different agencies, there follows a detailed discussion of the motion of ions in the electric field, the laws of their diffusion and recombination, and the methods of determining the to the discussion of the conditions and types of discharge between conductors of various shapes, and the passage of electricity through vacuum tubes. The final chapter gives an interesting review of the pioneer researches on the nature of the kathode and positive rays. Our information on the subject of ionisation and the passage of electricity through gases has grown so rapidly, and is in many respects so definite and complete, that the reader is liable to forget how modern the subject is, for the whole advance is included within a period of less than twenty years. It is instructive to note what a prominent part British science has taken in its development. Practically all the pioneer discoveries in this subject were made in the Cavendish laboratory, and it is of interest to recall briefly the more important features in this advance. Shortly after the discovery that X-rays imparted a transient electrical conductivity to gases, in 1896 J. J. Thomson and Rutherford showed that the results were simply explained on the assumption that the current through the gas was due to the movement of charged ions produced throughout the volume of the gas by the radiation. This theory was soon generally accepted, and has formed the starting point of subsequent advances. Then followed the work of Rutherford on the recombination of the velocity of ions. and the application of the ionisation theory to radio-activity. Zeleny discovered the difference in velocity between the positive and negative ion, and made the first accurate measurements of the mobilities. To this period belong the classical researches of C. T. R. Wilson on the ions as nuclei of condensation-investigations which have had such a remarkable development in recent years in making visible the processes occurring in the ionisation of gases by different types of radiation. Then followed the application of the ionisation theory to explain the conductivity of flame gases and flames by J. McClelland and H. A. Wilson, and later the investigations of H. A. Wilson and O. W. Richardson on the escape of negative electricity from glowing bodies. We can only refer in passing to the pioneer experiments of Townsend, J. J. Thomson, and H. A. Wilson on the magnitude of the charge carried by the gaseous ions. In 1898 Townsend began his well-known researches on the diffusion of ions, and on the ionisation of gases by collision The present volume is a very lucid and admirable exposition of our knowledge on this subject. The various theories which have been proposed and the experimental data are analysed with critical skill, and there are numerous original calculations added by the author himself. The mathematical theory of the subject is worked out with considerable detail, but is controlled at all points by careful consideration of the experimental data. The theory of the relation between current and voltage for ionised gases is mainly confined to the case of uniform ionisation, which, as is well known, presents many mathematical difficulties. No mention is made of the interesting cases that arise when the ionisation is nonuniform, or mainly confined to one electrode. Such cases often arise in experimental work, and it is important to direct the attention of the student to the marked differences in the currentvoltage curves which are exhibited under different conditions of distribution of the ionisation. While the author does not profess to discuss the whole of the large number of papers that have been published in this field, a clear account is given of all the more important investigations, and great care has been taken in the numerous references to literature. It is probable that many of those who have followed closely the rise of this subject will not in all cases agree with the relative importance tacitly assigned to practically independent investigations in this field; but this, after all, is largely a matter of personal opinion. We can strongly recommend the present work as a sound and valuable contribution to our knowledge of the development of a very interesting and important branch of modern physics. E. R. THE PRINCIPLE OF RELATIVITY. The Principle of Relativity. By E. Cunningham. Pp. xiv + 221. (Cambridge: At the University Press, 1914.) Price 9s. net. E VEN to the present day, the existence of the Principle of Relativity, which arose as a branch of physical theory, is somewhat trouble some to the individual physicist, owing to the efforts of his philosophical friends to obtain a precise account of its origin, treated from an historical point of view, which can emphasise the exact movement of thought leading to its adoption. The literature of the subject has been scattered in various periodicals, and so loaded with mathematical symbols that its appeal has been to a very limited audience, in spite of the real simplicity of all the ideas concerned. Three recent volumes will serve to remove this difficulty very effectually, and two of them possess the advantage of proceeding from entirely different points of view. The first, by Dr. Robb, has already been noticed in these columns, and the second is the volume by Mr. Cunningham now under review, which is designed to fill the gap specially indicated in our first sentence. The third, by Dr. Silberstein, already noticed also, is similar to Mr. Cunningham's, but is based on a different mathematical treatment. Mr. Cunningham's intention throughout has been to consider those aspects of the Principle which have a direct bearing on the practical questions of physics, without more recourse to mathematics than is absolutely essential for a really valuable consideration of these questions, and it may be said at once that the simplicity of the treatment is remarkable. The matter is put in a very interesting way throughout, and even to the non-mathematician the volume is not difficult to read. The first part gives a very lucid outline of the manner in which the Principle grew out of electrical theory, and one feature which must be recorded with satisfaction is the accuracy of the account, which does not share a tendency, noted in the case of several writers, to bestow too much of the scientific credit for the Principle on those who have worked out the details, at the expense of the real originators, one of whom belongs to this country. The space devoted to any problem is strictly commensurate with its importance. The author makes it clear in this section that there is a place for the Principle as a hypothesis supplementary to electrical theory, and on account of the necessary limits of that theory, independent of it. He avoids, at the same time, excursions into questions with metaphysical bearing. In the second part of the work an excellent account of Minkowski's two representations is given. The four-dimensional world of Minkowski is by far the most interesting development of the Principle, and, unfortunately, hitherto the most inaccessible in this country. This section is undoubtedly the most valuable part of the book for the general reader, and although it is essentially mathematical, the author has minimised the diffi culties as far as possible. Proofs of statements are printed in smaller type, and the general argument can be followed quite readily. Misconceptions of the position of the exponent of the Principle are frequent, and the exponent is not always free from blame. In these circumstances we welcome the explicit statement on p. 117—and the statement cannot be criticised-that while the Principle of Relativity cannot say what are the equations for bodies the motion of which is not uniform, it can say what they may be, and it therefore gives a powerful means of devising such equations to be tested by experiment. A similar definiteness is found in connection with the vexed problem of rotation. The third part of the work is devoted to the necessary modifications of mechanical theory, on the supposition that the Principle is universal. Fundamental points only are dealt with, to the welcome exclusion of a mass of material the interest of which is almost entirely academic. Very speculative developments, such as that of Einstein in connection with gravitation, are omitted, and the author is thereby enabled to give a very clear view of the real implications of the Principle. THE DEVELOPMENT OF MAN. Heredity and Environment in the Development of Men. By Prof. E. G. Conklin. Pp. xiv + 533. (Princeton: University Press; London : Oxford University Press, 1915.) Price 8s. 6d. net. AP DDRESSING a general audience rather than a scientific gallery, Prof. Conklin deals in six lectures with the development of Man. In the first chapter he shows that development is the result of intrinsic factors, implied in the organisation of the germ-cells, and of extrinsic factors, the environmental conditions. The germcell is a living individuality, and development is one of its functions. New materials and qualities appear in increasing complexity, and this is due to active combinations and interactions under environmental influence. The hereditary germinal organisation is very complex, but development is no mere unfolding or unpacking. It includes processes of "creative synthesis." The second chapter is devoted to the germcells and their organisation. "Development is progressive and co-ordinated differentiation of the germinal organisation, by which it is transformed into the adult organisation." Different kinds of substances are formed epigenetically; these are localised and isolated by intra-cellular movements and differential cytoplasmic divisions; and they are eventually transformed into various per manent structures. The third chapter deals with the modes of inheritance, with special reference to Man. "Blending" is still retained on trial, but it is shown that "the principles of Mendel have served as an Ariadne thread to guide science through the maze of apparent contradictions and exceptions in which it was formerly lost." In the next chapter the author treats of the influence of the environment, and is more than usually careful in his analysis. He distinguishes the different kinds of developmental stimuli, the different times of their operation, and their varied results. There is a useful recognition of functional activity as a factor in development. "Nurture," it is argued, means much as a condition of individual development, but little as a transforming factor in evolution. For Man, however, with his social heritage, the evolution of the environment must corroborate eugenic improvements of the breed. In this and in the next chapter, which is devoted to a consideration of eugenics, the author turns repeatedly to the idea that environmental changes, saturating into the germ-cells, may incite heritable variations in the germinal organisation. The discussion of eugenics is restrained and wise. It is possible to improve defective from reproducing; (2) by cultivating the human breed (1) by preventing the seriously pride of race, and discouraging voluntary infertility on the part of those who have a goodly heritage; (3) by increasing opportunities for early and favourable marriages; and (4) by carefully conserving the best human mutations or heritable variations. But along with these eugenic endeavours there must go improvements of environment and training including, preeminently, the development of control and goodwill. In the concluding pages Prof. Conklin explains how he, as a biologist, finds between the fatalistic and voluntaristic extremes a middle way which leads to action. We venture to commend the wise and stimulating discussion of the determinism involved in the creature's hereditary and nurtural relations and of the other side to this. The book is marked by sound judgment, firmness. and clearness of treatment, and a vigorous buoyancy. It is to be strongly recommended to those who wish to understand the facts of human development in their relation to the larger problems of human life. The volume is well got up, effectively illustrated, and provided with a carefully selected bibliography and an unusually good glossary as well as a full index. MATHEMATICAL CRYSTALLOGRAPHY. An Amateur's Introduction to Crystallography By Sir (from Morphological Observations). W. P. Beale, Bart. Pp. vii + 220. (London: Longmans, Green and Co., 1915.) Price 45. 6d. net. THIS HIS exposition of crystallography has been written by "an amateur" with the intention to help "other amateurs." Amateurs differ, however, very widely in the variety and extent of their interests and also in their keenness. The author has evidently had a mathematical training, and it is this aspect of the subject that specially appeals to him. Very few amateurs, such as those possessing a collection of minerals, would, we imagine, be anxious to begin by calculating the axial ratios of their crystals. They would rather wish to gain some insight into the general relations of the external forms and symmetry of crystals; and they would be repelled by pages of mathematical discussion and formulæ. Having produced such a work on crystallography, the author must no longer regard himself as a mere amateur, but as a serious crystallographer. For these reasons the book cannot be recommended to amateurs; it should, in fact, be carefully kept out of the reach of anyone who displays the slightest curiosity respecting crystals, otherwise the spark will surely be extinguished. On the other hand, the book will be of real value to the serious student who has already made some start in crystallography, for it will present the subject to him in a somewhat different light from that given in the ordinary text-books; and taking the two together the subject will no doubt be studied more intelligently. The author plunges into his theme by regarding a crystal as a geometrical polyhedron, and selecting three edges as axes of reference, he explains clearly how the positions of all the other surfaces of the solid are fixed in terms of the Millerian system of notation. Commencing with the most general (and difficult) case, namely that of the anorthic system, he leads the unfortunate reader through the maze of spherical triangles necessary for the calculation of the angles of inclination and the relative lengths of the axes of reference. The remaining systems of crystals are logically treated in turn, ending with the cubic. Here the important idea of symmetry is only incidentally touched upon. This is, however, treated rather more fully in the succeeding description of the merohedral forms belonging to each system. There is a long appendix on methods of calculation, and another on the drawing of crystals from the calculated elements. are The 136 illustrations (several of which repeated for convenience of reference) are a special feature and are entirely original. These are well and clearly drawn, and the method of giving the axes of reference in red adds still more to their clearness. There is a slight slip in fig. 64, whilst fig. 65 is quite wrong. The book is clearly printed in large type, and there are but few misprints; {hko}, etc., instead of {hko}, etc., however, recurs throughout the volume. OUR BOOKSHELF. L. J. S. The Medical Annual. A Year Book of Treatment and Practitioner's Index. Thirty-third year, 1915. Pp. cxx+830. (Bristol: J. Wright and Sons, Ltd.; London: Simpkin, Marshall and Co., Ltd., 1915.) Price 10s. net. THIS, the thirty-third annual issue of this publication, contains a summary of the year's (1914) contributions to medicine and surgery by a number of competent authorities. The exceptional lateness of the isue is accounted for by the strain and distraction of a great war, all the contributors, fully occupied as they are in normal times, having been working under exceptional stress from military duties and contingent work. The list of contributors is a sufficient guarantee of the accuracy and up-to-dateness of the information given. Thus we find an account of the latest work on typhus and cerebro-spinal fevers, both of topical interest at the present time. Trypanosomiasis is dealt with by the competent hand of Sir Leonard Rogers, and the article gives full information of the latest work on the parasitology and treatment of this important condition. About twenty pages are devoted to the important subjects of radio-activity, X-rays, and electro-therapeutics, and useful sections deal with the changes in the new British Pharmacopoeia of 1914. Special articles on naval and military surgery are included, together with references to personal experience in the treatment of wounds. A number of full-page and other illustrations are included, and form a special feature of the volume; they illustrate various disease conditions, details of surgical technique, surgical appliances, pathological features, etc. The two plates of skin eruptions in pellagra are beautiful examples of colour photography. The "Medical Annual" is a book eminently suited to the needs of the busy practitioner who desires to keep abreast with modern progress. and Wisconsin Geological Natural History Survey. Bulletin No. xxxiv. Economic Series, No. 16. Limestone Road Materials of Wisconsin. By W. O. Hotchkiss and E. Steidtmann. Pp. viii+137. (Madison, Wis. : Published by the State, 1914.) THIS bulletin has been published for the purpose of helping to conserve the expenditure of the "vast |