UNIVERSITY OF MANCHESTER. CHEMICAL DEPARTMENT. The SENATE propose to appoint two ASSISTANT LECTURERS and DEMONSTRATORS in CHEMISTRY. The appointments will be for three years, dating from September 29 next, at a salary of £125. Applications should be sent, on or before June 11, to the REGIstrar, from whom further particulars may be obtained. ARMSTRONG COLLEGE, NEWCASTLE-UPON-TYNE. LECTURESHIP IN BOTANY. The Council invite applications for this LECTURESHIP. The stipend will commence at £120 per annum, and rise by £10 per annum to £150. Candidates must send in their applications not later than June 16, 1906, to the undersigned, from whom further particulars may be obtained. F. H. PRUEN, Secretary. TO SCIENCE AND MATHEMATICAL MASTERS.-Immediate and September Vacancies.-Graduates and other well qualified Masters seeking posts in Public and other Schools should apply at once, giving full details as to qualifications, &c., to Messrs. GRIFFITHS, SMITH, POWELL & SMITH, Tutorial Agents (Estd. 1833), 34 Bedford Street, Strand, London. Immediate notice of all the best vacancies will be sent. OWEN'S SCHOOL, ISLINGTON. FORM MASTER required in September, Graduate, English, Mathematics, and two of the three following-Latin, French, German. The moder languages to be taught on the oral method. Good experience necessary. Also a fully qualified PHYSICS MASTER. The salaries generally commence at £150. Apply at once to the HEADMASTER, giving ful particulars of qualifications and experience, and copies of three recent testimonials, KING'S COLLEGE, LONDON. The Council invite applications for the post of SENIOR LECTURER Wanted, 3 or 4 in. Telescope with finder, tripod, &c., cheap.-"S.," 1 MARINA, Ramsgate. TYPE-WRITING UNDERTAKEN BY HIGHLY EDUCATED WOMEN ACCUSTOMED TO SCIEN. TIFIC MSS. (Classical Tripos, Intermediate Arts, Cambridge Higher Local, thorough acquaintance with Modern Languages). Research, Revision, Translation. 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Catalogues issued. References in all parts of the world. W. MULLER, Export Bookseller, 59 CASTLE STREET EAST, OXFORD STREET, LONDON, W. Sale by Auction. NEEDHAM MARKET, SUFFOLK. On the G. E. Railway, Main Line from London to Norwich. GARROD TURNER & SON will sell by Auction, by direction of the Executors of Mr. Henry Lingwood, deceased, at the "Chestnuts," the whole of the contents of the residence, including a fine COLLECTION of BRITISH BUTTERFLIES and MOTHS, comprising over 5000 Specimens of about 470 species set up in good condition in a Mahogany Cabinet with 40 drawers, also about 80 CASES of STUFFED BIRDS, all local specimens. Catalogues of the Auctioneers, Ipswich. BIRKBECK BANK ESTABLISHED 1851. Current Accounts. 2% Interest allowed on minimum monthly balances when not drawn below £100. Deposits. 21% Interest allowed on Deposit Accounts. Advances made. Stocks and Shares bought and sold. Apply C. F. RAVENSCROFT, Secretary, Southampton Buildings, High Holborn, W.C. THOUGHTS ON PERCEIVING. By E. H. AITKEN Author of "The Tribes on My Frontier," &c. New Impression. Large Crown Svo. 5/- net. CAMBRIDGE UNIVERSITY PRESS. NO MAN'S LAND. A History of Spitsbergen from its Discovery to the beginning of the Scientific Exploration of the Country. By Sir MARTIN CONWAY. Here the author tells the story of events in and on the coasts of Spitsbergen since its discovery in 1596. Year by year from early in the seventeenth century, Spitsbergen has been the scene of industries attracting adventurers of many nations, whose purposes, rivalries and fortunes are related. The book is illustrated with eleven full-page plates and has thirteen maps. IN INFECTIVE DISEASES. By ÉLIE METCHN!KOFF, Foreign Member of the Royal Society of London, Professor at the Pasteur Institute, Paris. Translated from the French by Francis G. Binnie, of the Pathological Department, University of Cambridge. "The book is most interesting reading.... Study of it is indispensable to all who are specially interested in the subject of immunity."-Lancet. "The Cambridge University Press has done a real service in publishing a translation of Elie Metchnikoff's volume." Westminster Gazette. Cambridge Biological Series. General Editor-A. E. SHIPLEY, M.A., F.R.S. Trees: A Handbook of Forest Botany for the Woodlands and the Laboratory By H. MARSHALL WARD, Sc. D., F.R.S.. Professor of Botany in the University of Cambridge. In six volumes. Vol. I. Buds and Twigs. Vol. II. Leaves. Vol. III. Flowers and 45. 6d. net Inflorescences. Crown 8vo. With numerous Illustrations. each. The remaining volumes will deal with Fruits and Seeds, Seedlings, and the Habit and Conformation of the Tree as a whole. "The work is one that cannot fail to appeal to all who are interested in the trees and shrubs of our woodlands."-Times. Grasses: A Handbook for use in the Field and Laboratory. By H. MARSHALL WARD, Sc. D., F.R.S., Fellow of Sidney Susse College, Professor of Botany in the University of Cambridge. With 81 figures. Crown 8vo. The Natural History of some Common Animals. By OSWALD H. LATTER, M.A., Senior Science Master at Charterhouse. Crown 8vo. 58. net. 65. "An excellent book, written by a man who is equally in his element whether he writes as an outdoor naturalist or as a laboratory student. This combination is by no means a common one, and it is just the combination that is wanted for a book of this kind."-Nature. London: CAMBRIDGE UNIVERSITY PRESS WAREHOUSE THURSDAY, MAY 24, 1906. ADOLF VON BAEYER'S COLLECTED WORKS. Adit von Baeyer's gesammelte Werke. Herausgegeben zur Feier des siebzigsten Geburtstages des Autors von seinen Schülern und Freunden. Erster Band, pp. cxxxii+990. Zweiter Band, pp. 1194. (Brunswick: F. Vieweg und Sohn, 1905.) AS S we examine these two splendid volumes we cannot but feel that no better way of commmorating the seventieth birthday of Adolf von Baever could possibly have been found than that of collecting together his researches and publishing them so that they might be studied in their entirety by all students of chemistry. The publication of the complete researches of an investigator who has had a profound influence on the scientific thought of his time has much to recommend it, since the collected works form not only a memorial to the investigator, but also enable others to gain an insight into the train of thought which preceded the gradual development of each important discovery. The present volumes have, moreover, a special interest since they have been produced under the personal supervision of Baeyer himself, with the result that the vast amount of work which he has accumulated during the fifty years of his active life is arranged in the manner which he himself wished and thought most suitable. These volumes contain as frontispiece a strikingly lifelike portrait of Baeyer. The introduction contains a most interesting sketch of Baeyer's life (1835-1905) from his own pen, which enables the reader to form a very vivid idea of the difficulties Baeyer had to en- | counter in the earlier days of his scientific career. Not only were the schools of chemistry which existed at that time few in number and the appliances even in¦ the best of them only of a very elementary kind, but research in organic chemistry was still quite in its fancy, and therefore every new development was the nature of pioneer work. Although in his grandfather's house Baeyer was in h. early years brought into contact with Paul Heyse, Geibel, Fontane, and other literary giants of the time, h showed no inclination towards literature, and soon began to develop a love for science by taking a keen interest in chemistry, botany, physics, and mathe Maties. In 1855 he decided to devote himself seriously to chemistry, and became a student in Bunsen's laboratory at Heidelberg at a time when Roscoe, Pebal, Lieben, Bellstein. Lothar Meyer, and others were working in the laboratory, and when Bunsen's reputation as a teacher and investigator was at its highest. His first original investigation was a continuation of the work of Bunsen and Roscoe on the combination of hydrogen and chlorine, and this, as well as his next research, on methyl chloride, were suggested by Bunsen. After this Baeyer worked entirely on his own initiative, and gradually laid the foundations upon which the great edifice of his life-work was subsequently raised. The papers collected together in the two volumes before us have been grouped by Baeyer under the following headings:-(1) The organic arsenic compounds; (2) the uric acid group; (3) indigo; (4) papers arising from the researches on indigo; (5) pyrrol and pyridine bases; (6) experiments on the elimination of water and on condensation; (7) the phthaleins; (8) the chemistry of the hydroaromatic compounds; (9) the terpenes; (10) nitroso-compounds; (11) furfurol; (12) acetylene compounds and the "Spannung's Theorie "; (13) peroxides; (14) the basic properties of oxygen; (15) dibenzalacetone and triphenylmethane; (16) various researches in the aromatic series; (17) various researches in the aliphatic series; (18) nomenclature; (19) diversa. The titles alone will serve to convey some idea of the immense range of subjects which have claimed the attention of Baeyer, and as we study each of these sections we meet always the same characteristics— great skill in overcoming experimental difficulties (often necessitating the working out of entirely new methods of attack), and great ability in deducing the correct theoretical explanation from the results of experiment. Within the necessarily limited space of this review it is, of course, impossible to discuss in any detail even the most far-reaching of Baeyer's discoveries or to attempt to follow their historical development. Attention may, however, be briefly directed to some characteristics of Baeyer's work which will probably strike the reader most as he studies the successive sections into which these researches are divided. The researches on uric acid, which date from 1860, are marvels of experimental skill, including, as they do, the discovery and characterisation of barbituric acid, violuric acid, and many other new members of this important group, and this at a time when the structure and relationship of the more important members of this section of organic chemistry were little understood. Baeyer was naturally interested in the problem of the synthesis of uric acid, and in 1863 he endeavoured to accomplish this by combining uramil with potassium cyanate, when he obtained pseudo-uric acid, an acid which contains one molecule of water more than uric acid itself. The synthesis was completed in 1895, when E. Fischer and L. Ach showed that pseudo-uric acid is converted into uric acid when it is melted with anhydrous oxalic acid. Of great interest, not only from a purely scientific, but also from the commercial point of view, are the sections on the phthaleins and on indigo. The researches on the phthaleins must have required exceptional skill, ingenuity and patience, because it must be remembered that this work was absolutely new, and, moreover, the substances belonging to this class are, at the present day, some of the most difficult to deal with experimentally. The well-known papers on indigo should be read in connection with a most interesting sketch of their historical development (p. xxxvii, which Baeyer himse'f has contributed. The labour entailed in carrying out these researches must have been very great, and it is instructive to read that, after a certain time, Baeyer became su wearied with indigo that he was quite unable to continue experimenting on the subject, and had to allow the various problems connected with the commercial development of his discoveries to pass into other hands. In search of fresh fields for investigation, Baeyer commenced an inquiry with the object of discovering whether carbon atoms, uncombined with hydrogen, are capable of uniting to form long chains, and, in order to determine this, he synthesised a number of poly-acetylene compounds, including tetracetylenedicarboxylic acid CO2H.CC-CC-C C-C=C.CO2H. This remarkable acid is quite colourless, but is readily blackened by the action of light, and compounds of this type were found to be so explosive that their further investigation had to be abandoned. One of the fruits of the consideration of the properties of these compounds was the enunciation of the wellknown "Spannung's Theorie," which has given rise to so much discussion, and proved to be of such value in suggesting new lines for experimental inquiry. Section viii., which Baeyer has placed directly after the phthaleins, deals with the chemistry of the hydroaromatic compounds and the constitution of benzol. These researches date from the year 1866 when, in conjunction with Graebe, Born, Mohs and others, he first investigated the behaviour of phthalic acid and terephthalic acid towards sodium amalgam. Baeyer repeatedly returned to this subject in later years, but it was not until 1888 that the epoch-making series of papers "Ueber die Constitution des Benzols" began with the exhaustive study of the products which are formed when terephthalic acid is reduced with sodium amalgam. These researches on the reduction products of the phthalic acids and of benzene itself are well known, but they have perhaps hardly received the close attention which they merit, owing partly, no doubt, to their difficult and intricate nature. The careful study of these papers will, however, more than repay the time spent, and to the young investigator they may well serve as an example of the patience and endurance which he must be prepared to face if he wishes to attempt the solution of a problem of really first-rate importance. It is perhaps a consequence of the study of these artificially prepared reduction derivatives of benzene that Baeyer was led to investigate that wonderful series of naturally occurring reduced benzene derivatives the terpenes-the constitution of which has offered one of the most difficult problems to the modern organic chemist. During the course of his experiments on the oxidation of substances which, like the terpenes, contain unsaturated closed chains, Baeyer commenced to experiment with Caro's acid, and, among many other interesting results, showed that this acid was a most valuable reagent for the conversion of ketones into lactones. Further experiments resulted in the discovery of the remarkable series of peroxidised substances of which benzoylhyperoxide and diethylperoxide may be taken as types, and led to a development of Collie and Tickle's important work on the tetravalent nature of oxygen and the oxonium theory. Baeyer's latest publications deal with the vexed question of the relation of colour to constitution, and are concerned especially with the reason for the coloured nature of certain salts derived from dibenzalacetone and from triphenylcarbinol. One of the most remarkable results of this investigation is the proof that the coloured salts of triphenylcarbinol are in reality esters possessing the properties of salts, and that they cannot be regarded as quinoid compounds. Baeyer is, at the present time, occupied with the further development of this important matter. It is impossible to close the volumes before us without marvelling at the immense amount of work which it is possible for one man to carry out, and without a deep impression of the enormous influence which the work of Baeyer has had on the development of modern chemistry. The list of papers published from Baeyer's laboratory occupies no less than sixty-three pages of closely-printed matter, and when we look at the names attached to these papers we are able to form some idea of the magnitude of the school which he has founded, and of the extent to which many of the greatest chemists of the day owe their training in research to Baeyer. W. H. PERKIN, JUN. A STANDARD TREATISE ON ELASTICITY. A Treatise on the Mathematical Theory of Elasticity. By A. E. H. Love. Second edition. Pp. xviii+ 552. (Cambridge: University Press, 1906.) Price 18s. net. INSTEAD of merely revising his former treatise, Prof. Love has written a new one; the result is that we have two works by the same author, in some ways contrasting, in others complementary. And as in the similar cases of Maxwell's "Electricity," and Thomson and Tait's "Natural Philosophy," the prudent will buy the new book without parting with the old. Naturally one feature in the new edition is the inclusion of important or interesting results obtained since the appearance of the earlier one. In some branches of mathematics the proportion of English workers is distressingly small; but in elasticity this is happily not the case, and the recent researches of Michell, Filon, Dougall, and others, besides those of veterans that need not be named, receive in these pages their due recognition. So also do those of their Continental confrères, more particularly Voigt; but it is hard to avoid the impression that the deaths of Kirchhoff and Hertz have left vacancies which have yet to be worthily filled. It is interesting to compare the historical introduction in its old form with its successor. The former was in some places controversial, and the author seems to have thought some of the statements too dogmatic, at any rate in form. However this may be, the new introduction is strictly impersonal, and shows clearly enough how recent physical theories and discoveries affect the subject of elasticity. A great deal of the polemic about the number of elastic constants was as illogical as the quarrel about vis viva. As an abstract mathematical theory, the 21-constant hypothesis is as legitimate as its rival and conversely; the question that interests physicists is which of the two, if either, best corresponds to the properties of elastic bodies. Saint-Venant rightly argued that this could not be settled a priori, but only by experiment; and at the present day his justification on this point is complete, although he was led to adopt the rari-constant theory by relying upon inconclusive experiments. As Prof. Love points out (pp. 14, 15) our views of the ultimate structure of matter are being profoundly modified, and until they are cleared up it is premature to propose an "atomic" theory of elasticity. Meanwhile we can make a working hypothesis by assuming the existence of a strain-energy-function which is a quadratic function of the components of strain. In all probability the ultimate theory, if we could only reach it, is kinematical; the stresses set up in a strained body being an aspect of a new distribution of kinetic energy in space. The results of the theory, as applied to the arts, are, of necessity, only approximate; and great care must be taken to see that, when an approximate solution has been obtained, it is really applicable to the concrete case. An excellent example is given on p. 140, relating to a sphere strained by its own gravitation. If we put in the numerical values of g, 。, P, and any reasonable values for A, μ, when the sphere in question is the earth, we find that the condition that Ur should be small for r>r>o cannot be satisfied, although this is one of the assumptions on which U has been calculated. This point was brought out in the previous edition (i. 220); it is a pity that this warning has been suppressed, though another, equally instructive, has been given. Again, take the condition (or conditions) for rupture taking place (pp. 117 sqq.). This cannot be given by the ordinary theory, which is only applicable when the elastic limit is not exceeded. Nevertheless, attempts have been made to express the condition in terms of the components of stress. This is entirely illogical, and hence, as usual, a contest between rival formulæ. It may, of course, happen that one formula, as against the other, may have a wider range of applicability; but it ought to be treated as purely empirical, and not rashly applied to untested cases. On this point the author might have been more dogmatic than he is. stress and strain in a curved shell, agreeing to that order with results of Mr. Basset's. In this, as in other parts of the book, the analysis is very elegant, and is given in sufficient detail for really competent readers to follow. But the author follows the general tendency now in vogue, of suppressing details of calculation, and emphasising results of practical value, rather than examples of mainly æsthetic interest. In his preface he expresses a hope that his book will be useful to engineers; how far they do so depends, of course, upon them as well as upon him. They will find among the subjects treated the buckling of plates, the collapse of boiler-flues, the whirling of shafts, the stability of slender columns, and other such things; it is to be hoped that they will also appreciate the general theory, as the author presents it. Every student, not an expert, should follow the advice given in the preface of proceeding to chapter v. as soon as possible. It is a great advantage that the author of this book is a mathematician of wide as well as accurate attainments. As an illustration, it will be enough to refer to p. 306, dealing with the torsion of a rectangular prism; it is at once clear that the author's knowledge of Fourier expansions is quite different from that of the average physicist. Similar examples of rigour free from pedantry may be found throughout the volume. At the end of the introduction occurs the sentence: "Most of the men by whose researches it [the mathematical theory of elasticity] has been founded and shaped have been more interested in Natural Philosophy than in material progress, in trying to understand the world than in trying to make it more comfortable." It may be added that most of the comfort we enjoy, and most of our civilisation that is worthy of the name, is due to men who have endured discomfort, in pursuance of ideal ends. Apart from the poets and the philosophers, where should we be? G. B. M. PROTEID CHEMISTRY. Chemistry of the Proteids. By Dr. Gustav Mann. Based on Prof. Otto Cohnheim's "Chemie der Eiweisskörper." Pp. xviii+606. (London: Macmillan and Co., Ltd.; New York: The Macmillan Co., 1906.) Price 158. net. A very interesting section is that on the deforma- DR. GUSTAV MANN started this work with the tion of plates. This is a famous problem, historically, and even lately gave rise to a controversy, now satisfactorily settled. To get a reasonably simple approximate solution some kinematical assumption must be made, and this must be compatible with the boundary conditions. Prof. Love pointed out that, strictly speaking, a vibrating plate with free edges cannot satisfy the condition that the middle surface is unstretched; Mr. Basset and Prof. Lamb showed that the boundary condition could be satisfied without supposing any considerable stretching except near the edge. An interesting statical illustration due to Lamb is given on p. 521. On p. 506 Prof. Love obtains, by a method of his own, second approximations for modest idea of producing an English translation of Prof. O. Cohnheim's well-known monograph on the chemistry of the albuminous substances. But it has developed into a volume of a much more ambitious nature, and has culminated in a book twice the size of that on which it is founded. The subject in many parts is treated much more fully, and a good deal of new matter introduced. In many places, moreover, Cohnheim's own views are adversely criticised, so that the present volume bears witness to the originality of the English author. Those who know Dr. Mann best as a histologist may be surprised that he should have the necessary knowledge to write on a subject at first sight so far |