THURSDAY, JANUARY 7, 1904. THE CRITICAL STATE. Le Point critique des Corps purs. Pp. viii+255. (Paris: C. Naud, 1904.) OF F late numerous attacks have been made on the commonly accepted theories relating to the conditions which obtain at the critical temperature of pure substances, and though the assailants may have received little support, or even attention, from the mass of their physical brethren, it is time that certain questions relating to the critical state were more definitely settled. In the opening chapter of this work the author discusses the general case of the evaporation of liquids at temperatures up to their critical point, leading up to the statement, which opens the second chapter, that the theories of Andrews and Van der Waals are insufficient to explain the observed phenomena. For instance, Battelli has attempted to prove that the temperature at which the meniscus disappears in a sealed tube containing alcohol is a function of the concentration of the alcohol in the tube. The experimental results are quoted; they are as follows: of ether, fairly inA very Similar results were obtained in the case but it is difficult to see how they may be terpreted as supporting the author's views. small quantity of impurity would be quite sufficient to account for these abnormal, but by no means concordant results. The experiments of Galitzin are next quoted to prove that the temperature of disappearance and reappearance of the meniscus is dependent not only on the mean density of the substance in the tube, but also on the dimensions of the latter. Sealed tubes containing ether were heated slowly to 200° C., maintained at that temperature for twenty minutes, and then allowed to cool slowly. A maximum difference of 0.9° C. between the temperatures at which the meniscus disappeared and reappeared again was observed, and as no evidence to the contrary is forthcoming, there is no reason for assuming that the temperature difference is not due to the lagging of the temperature of the liquid in the capillary tube after that of the bath. It is further remarked that, if one repeatedly heats and cools such a tube, the meniscus tends to reappear after each operation at a lower point in the tube. That this is not observed when the tube is shaken is highly significant. In the succeeding chapters the various methods which have been applied to the determination of the critical constants are described and criticised, theoretical questions being discussed as they occur. Opening with an account of Andrews's experiments, and the development of his method at the hands of Ramsay, Young, and others, the author leads up to a discussion on the application of the modified gas equation to the calculation of the critical constants from the data for the isothermals. As an example, he takes Sarrau's attempt to employ Clausius's equation to calculate the critical constants of hydrogen from Amagat's determinations of the compressibility of that gas. The results are, of course, wide of the mark, but it is interesting to note that Wroblewski, who investigated the isothermals of hydrogen between +100° C. and 182° C., obtained, by means of a similar equation, a very fair approximation of their values. In chapter vi. the author discusses the effect of the gravity of the substance under investigation on the density at different levels in the capillary tube. Here again our knowledge of the subject is very scanty, and experimental evidence is required to support the theoretical results of Gouy and others who have treated the subject mathematically. Particularly interesting accounts of special series of researches are given in the succeeding chapters. Olszewski's determination of the critical pressure of ethylene, oxygen, and hydrogen is described in detail, and the theory of the method, which is not dealt with in the original paper, is explained by means of a diagram. This piece of work is important, as it involves a new method for the determination of critical pressures, and gives us the only published experimental data for the critical pressure of hydrogen. Some of the methods described by the author as élégantes mais pur précises " are interesting, as they furnish suggestions which may be applied to other problems. The behaviour of mixtures, which could not be entirely omitted from the work, is briefly discussed, and diagrams are given illustrating the graphical method of treating the results. A table of critical constants occupies several pages. The final section of the book deals with the theories which have been put forward to account for the apparent irregularities in the behaviour of pure substances, and the deviation from the simple laws hitherto supposed to govern the phenomena which take place at the critical point. The existence of two kinds of molecules, gasogenic and liquidogenic, which persist in the vapour phase, was first suggested by de Heen, and has recently received support from Traube and others. As was long ago pointed out by Sir G. Stokes, de Heen's theory demands that the pressure of a saturated vapour of a pure substance, like that of a mixture, must be dependent on the relative masses of the liquid and vapour phases, and this is contrary to all experience. Modifications of this theory, involving an idea of a definite equilibrium dependent only on temperature between the two kinds of molecules, may be more easily tenable; but, as the author suggests, the existence of liquidogenic molecules, having only a transitory existence in the vapour phase, and dissociating slowly into gasogenic molecules, would account for most of the phenomena which have been observed. There are two obvious sources of error in measure ments of the kind described in this work. In the first place the substances must be of a very high degree of purity, and as the author justly remarks, there is usually no evidence that this has been the case. In the second, the difficulties experienced in maintaining temperatures which do vary at a greater rate than 0.002° per minute are enormous, and in dealing with substances enclosed in thick-walled capillary tubes, the temperature difference might be in some cases of the same order as the observed abnormalities were the temperature less steady. Whatever may be the fate of the new theories or the opinion as to the value of some of the experiments on which they are based, we are indebted to the author for collecting and arranging this mass of information, and for bringing the points at issue so clearly before the scientific world. M. W. T. THE B.M. HAND-LIST OF BIRDS AND CATALOGUE OF EGGS. WH A Hand-List of the Genera and Species of Birds. Vol. iv. By R. B. Sharpe. Pp. xii+391. (London : Printed by Order of the Trustees, 1903.) Catalogue of the Collection of Birds' Eggs in the British Museum (Nat. Hist.) Vol. iii. By E. W. Oates and S. G. Reid. Pp. x+349; 10 plates. (London: Printed by Order of the Trustees, 1903.) /HEN the publication of the valuable "HandList" was commenced, it was considered that the work would be completed in four volumes. The fourth volume is, however, before us, and the author's task is far from being ended. This, as stated in the preface by the director of the Museum, is due to the unexpectedly large amount of space occupied by the Passeres (or Passeriformes, as the author prefers to call them), the number of named species of which group has been largely augmented during the progress of the work. Accordingly, in order to keep the present one of moderate dimensions, it has been decided to complete the work in five, in place of four, volumes. The fifth and concluding volume, it is satisfactory to learn, is in a forward state, and will probably be issued shortly. Our opinion of the high value of this work having been already expressed in our notices of the earlier volumes, it need not be repeated here, although we must again state that it would have been an improvement had the dates of publication of the generic names been introduced. We are, moreover, debarred from criticising the right of certain forms and groups to specific or generic rank, for the author in this instance has been bound to follow the arrangement adopted in the "Catalogues." Ladak (p. 147) a part of that system. Then, again, on p. 149 we find Murree (Murri) described as being in the eastern Himalaya. The author's spelling of that name as Murri-is, moreover, without justification. Many years ago the Indian Government decreed that the names of well-known places were to be spelt in the old-fashioned way. If this ruling be followed, Murree is the proper orthography; if, however, the Hunterian system be followed, it should be Mari; Dr. Sharpe's "Murri" is neither one system nor the other. If the proof-reading had been done a little more carefully, certain discrepancies in the printing of names might also have been avoided. We should not have had, for instance, in one place Amur-land (p. 138) and in another Amurland (p. 339), or Somali Land (p. 12) and Somali-land (p. 293), or Szechuen (p. 8) and Sze-chuen (p. 322), or Damara Land (p. 22) and Damara-land (p. 331). Again, we believe that Gansu (p. 321) and Kansu (p. 323) are one and the same. Finally, we do not like the phrase (p. 259) “ Arctic and Subarctic regions of both hemispheres," which, although no doubt etymologically correct, sounds somewhat ambiguous. 46 The In regard to the third volume of the "Catalogue of Birds' Eggs," the most notable feature is its dual authorship, or, to be precise, that it is written by Mr. E. W. Oates, assisted by Captain Savile Reid. explanation of this is to be found in the preface, where it is stated that, owing to the ill-health of Mr. Oates, it had been found necessary to entrust the completion of the work to other hands. In the case of this volume the MS. was left in a forward state by Mr. Oates, and has been revised, together with the proofs, by Captain Reid, who has also incorporated in the text references to recently acquired specimens. The present volume commences with the parrots, and includes the whole of the so-called " picarian birds, together with a considerable number of the passerines, that is to say, from the Pteroptochidæ and Formicariidae to the bulbuls (Pycnonotida). From what has been written above, it is scarcely necessary to add that the plan followed in this volume is the same as in its predecessors. Now that a change of authorship has taken place, we may suggest that the value of the work would be decidedly increased if the characteristics of the eggs of the different families and genera were given in some detail in the volume yet to come. As it is, no regular rule seems to have been followed in this respect, and it is therefore quite impossible to gather of what value are egg-characters in classification. The exquisite plates illustrating this volume are, like those in its predecessors, reproduced from sketches by Mr. H. Gronvöld. Although the number of the plates is somewhat less than in vol. ii., the number of eggs figured is (owing to their smaller size) much greater. It may be added that small eggs, like those figured in this volume, form much more attractive octavo plates than is the case with the larger ones depicted in the earlier volumes, and whichever of the two authors is responsible for the grouping of the specimens figured he is to be congratulated, from an artistic point of view, on the result. As a rule, eggs which have not previously been figured are selected for illustration. and, later on, it is said of him, "Then the tireless The total number of species catalogued in this volume is 907, and the number of eggs 8474; the latter are, however, very unevenly distributed among the various species, of many of which there is but a single egg in the collection. This is the case, for instance, with three out of the four species of " frog-mouths catalogued, and likewise with many of the kingfishers, | United States." cuckoos, and humming-birds. The collection is especially rich in eggs of the common cuckoo, associated in a large number of cases with the clutches laid by their involuntary fosterparents. After remarking on their variability in size, the authors state that the cuckoo's eggs likewise present a considerable range of diversity in colour and the character of the marking, although the great majority approach in these respects to the eggs of the meadowpipit and skylark. Eggs of this type constitute the great bulk of the series in the collection. Some, however, like those associated with the eggs of Ruticilla phoenicurus, are blue, while one closely resembles that of a chaffinch. Curiously enough, cuckoos' eggs from hedge-sparrows' nests are of the ordinary type, and show no tendency to become blue. Altogether, the collection includes cuckoos' eggs taken from no less than forty-one different species of birds, ranging in size from a shrike to a fire-crest. Did space permit, many other interesting points connected with öology might be mentioned; as it is, we must bring our remarks to a close with the expression of our opinion of the great interest of this unique work. R. L. MODERN SCIENCE POPULARISED. New Conceptions in Science. By Carl Snyder. Pp. xii+362. (London and New York: Harper and Brothers, 1903.) Price 7s. 6d. net. IN N the absence of any preface, it is necessary for the reader to form his own opinions as to the aim or object of the book considered as a whole. This, evidently, is to arouse an interest in scientific work among unscientific people by telling the story of the discoveries of the day in unscientific language. We have here portraits of the man that weighed the crown of King Hiero, of the man that broke the atom into ions, of the man that caught and fought the deadly microbe, and other pioneers of science introduced in terms somewhat suggestive of those we have used above. Several of the illustrations show the discoverers at work in their own laboratories, and remind us that this book hails from the same land, which in recent years has flooded our breakfast tables with portraits of literary men writing articles by the side of revolving bookcases. We have spoken of the book as being written in unscientific language, but it would be better to describe the language as unconventional, unorthodox, and very funny to an English mind. As instances, we may quote "chips of atoms" as applied to corpuscles; Marconi is described as having "since the Salisbury Plain trials with kites, taken to the water wholly,' are use certain enlightened countries which still Réaumur's scale.) "If like this mechanical eye our eyes were sensitive to these electrical waves, then we might watch the progress of a play in Buenos Ayres or have witnessed the struggles at Peking." "Those who were reared to the ideas of Clerk Maxwell, regarding electricity as a wave and wobble in the highly hypothetical ether, have not failed to implant upon the new theory their collective feet." clip through Light and other waves are stated to space at 184,000 miles per second.' Dolbear picturesquely remarks, we could some way get a 'kick' on the ether, space navigation would be easy. It does not seem impossible that we shall be able to do this within another hundred or two hundred years." "If, as Prof. The book is not confined to physical science alone. It contains a chapter on Prof. Loeb's discovery of artificial parthenogenesis, another on the nature of life, in which is suggested the possibility of reversing the life processes and growing backward, and a chapter headed "The Spirit Rappers, the Telepaths and the Seriously speaking, the most imGalvanometer." portant chapter is undoubtedly that dealing with "America's Inferior Position in the Scientific World." In it, among other points, the author urges the necessity of founding an institution like our Royal Institution in America, and directs the attention of his fellow countrymen to their general backwardness in research. We over here are apt to think of the American man of science as being pretty well off in view of the large number of universities existing in the United States, and the large number of chairs attached to each of them, which should result in the individual professors having far more time for research work than they have in this country. If, however, the author succeeds in impressing on his fellow countrymen the need of devoting further endowments for the furtherance of research work pure and simple, the book will not have been written in vain. The danger is that the important part played in science by long formulæ involving dx's and dy's, inverted deltas and signs of integration will be overlooked. G. H. B. substance, and to treat them as examples of "tropisms" is not warranted by any considerations advanced in the book or known to the present writer. The concluding chapters deal with varieties and abnormalities of minds, and many valuable hints are given as to the special treatment of individuals de increasing very rapidly. This book is designed to introduce them to the study of the subject, and may be warmly recommended to them, but it is worthy of the attention of the professional psychologist also. The special features of the book are the freshness and clearness of the treatment, and the novel arrangement of mental phenomena under the three heads sensitive-manded of the teacher and parent. Among all the ness, docility, and initiative. Prof. Royce thus ignores the traditional divisions of the subject, which, though merely survivals from the old and misleading faculty-psychology, have largely determined the mode of treatment of most modern writers. By so doing he is enabled to treat every mental process as a whole having cognitive, conative and affective aspects. Though not himself an experimenter or a physiologist, Prof. Royce fully and generously admits the importance of physiological and experimental psychology, and recognises that the advance of the subject represented by this book is largely due to modern work by those methods; his sketch of the functions of the nervous system and his numerous references to physiological considerations are altogether admirable and judicious, and he shows how greatly experimental methods have furthered our analysis of mental processes. Here and there throughout the chapters practical deductions of the first importance to teachers are clearly and soundly drawn; for example, it is admirably shown how "differentiation of the simultaneous slowly results from the repeated acts, and from the powers of discrimination which have been cultivated in connection with them," and there follows the maxim, "Undertake to systematise this differentiation of consciousness through fitting series of successive deeds." the One of the most novel features is the treatment of the feelings. While agreeing with Wundt in regarding the classification of feelings into the two groups, pleasant and unpleasant, as very inadequate, Prof. Royce does not accept that author's six classes, but regards feelings of quiescence and of restfulness as two classes of antagonistic feelings correlative with the pleasant and unpleasant. In the chapter on conditions of mental initiative, the importance of this distinction is fully illustrated. It is there forcibly shown how "mental initiative" depends upon "a certain overwealth of persistent activities" not immediately adaptive and not necessarily pleasant, and it is asserted that "all such activities are characterised by the feeling of restlessness. In their physical aspects they are examples of the 'tropisms' of Loeb." This last statement is difficult to accept. In the introduction Prof. Royce shows that he has been much impressed by the phenomena of "tropism" as manifested by lowly organisms, and he seems to feel that the conception of the "tropism " is of great importance for psychology. But the later references to the subject do little to justify the expectations thus aroused. In the case of the "overwealth of persistent activities" which are so important for mental growth, it would seem to be truer to say that they are examples of "irritability," the fundamental property of all living many books on psychology, there is none that with. OUR BOOK SHELF. Animal Studies: a Text-book of Elementary Zoology for Use in High Schools and Colleges. By David Starr Jordan, V. L. Kellogg, and Harold Heath, of Leland Stanford Jr. University. Pp. 459; 259 figures. (New York and London: Appleton and Co., 1903.) Price 5s. net. 66 THIS is an interesting and delightful text-book of elementary zoology, combining some parts of “ Animal Life" and " Animal Forms," in the same series, with new material on classification, extinct forms, geographical distribution, special adaptations, instincts, and economic value. Beginning with chapters on the conditions of animal life and the principles of classification, the volume takes a survey of the most important classes from Protozoa to mammals. Then follow chapters on life-histories, the struggle for existence, adaptations, animal communities, commensalism and parasitism, protective resemblances and mimicry, the special senses, instinct and reason, and so on. When we compare a school-book on geography of a quarter of a century ago with the best modern school geography, we seem to breathe a different atmosphere, and so it is when we compare the natural history for schools which was in circulation twenty-five years ago with this lively, up-to-date, well thought-out, beautifully illustrated, and, in short, well adapted modern school text-book of zoology. We quote, in illustration of its educational value. one example :-" At one time we had two adult monkeys, Bob' and 'Jocko,' belonging to the genus Macacus, neither with the egg-eating instinct, and a baby monkey, Mono,' of the genus Cercopithecus, whose inherited impulses bore a distinct relation to feeding on eggs, just as the heredity of Macacus taught the others how to crack nuts or to peel fruit. To each of these monkeys we gave an egg, the first that any of them had ever seen." The result of the experiment was in the highest degree instructive. Mono cracked the egg against his upper teeth, made a hole in it, and sucked it. "Then holding the eggshell up to the light and seeing that there was no longer anything in it, he threw it away." He treated all subsequent eggs in the same expert fashion, while "Bob" and "Jocko "treated their eggs like nuts, and therefore ineffectively. We recommend this book strongly; it is simple but not superficial, it is both interesting and instructive; it is written with an educational perspective. It is particularly desirable in elementary books that every the standard of accuracy in this volume is a high one. general statement should be critically scrutinised, and We are not, however, prepared to accept every statement, e.g. that fur-seals "absorb the water needed through pores in the skin." J. A. T. Das Zeisswerk und die Carl-Zeiss-Stiftung in Jena. Ihre wissenschaftliche, technische und soziale Entwickelung und Bedeutung, für weitere Kreise dargestellt von Felix Auerbach (Prof. a.d. Universität). Pp. vi+124. (Jena: Gustav Fischer, 1903.) THIS short popular account of the optical works in Jena will be of interest to a wide circle of readers. Of the successful application of science to industry no more striking illustration can be found than in the history of the Zeiss firm, with its aim of "scientific exactness and perfection of workmanship," while to many the description of the present organisation of the undertaking, and the socialistic features of the charter under which it is now controlled, will no less appeal. The early efforts of Carl Zeiss towards the improvement of the microscope, his adoption of Abbe as scientific partner, and the revolution in the optical theory of the instrument due to Abbe's work, are dealt with in some detail. The need, emphasised by Abbe's investigations, of greater variety in the character of optical glass, to render possible the removal of the chief detects of lens systems, led to the foundation, in 1884, of the glass works of Otto Schott, and from this year we may date an enormous advance in the construction of optical instruments, with a further development of the Jena industry. This brings us to an account of the existing organisation, and a description of the main departments, with details and illustrations of many of the most important and best known instruments, as well as of the workshops and buildings. The latter part of the work deals with the social and socialistic aspects of the present system of administration. In 1891, some four years after the death of Carl Zeiss, Abbe devised his rights of property in the optical and glass works to the undertaking itself, and originated the statute, under which, after receiving in 1896 the legal sanction of the Duke of Saxony, the "CarlZeiss-Stiftung" is now controlled. Particulars are given of the statutory standing of the employés, the system of profit-sharing, the regulation of hours of work, the pension scheme, as well as of institutions founded for the benefit of the workmen, and benefactions to the university and to the town. In addition to Carl Zeiss and Abbe other personalities connected with the undertaking, Schott, Czapski, Straubel, Pulfrich, &c., are briefly characterised, and with these names may be also mentioned that of the old foreman, August Löber, to whom the firm is indebted for many improvements in technical detail. Reasons Against the Theory of Evolution. By Thomas Woods, M.D., M.R.C.S.L., L.R.C.S.I., &c. Pp. viii+52. (London: W. R. Russell and Co., n.d.) THE author of this booklet may have perfectly definite convictions as to the truth or falsity of the theory of evolution, but he has hardly succeeded in making his attitude towards the doctrine clear to his readers. object, the preface informs us, is to notice some occurrences, said to be due to evolution, the contrivances for which must have been pre-arranged, and therefore could not have been the result of accidental circum His stances. "If," he proceeds, "Evolution results from ' circumstances and surroundings,' pre-arrangement, of course, cannot have occurred, and if it can be shown that such pre-arrangement has in any instance taken place the whole thing must fall." This can only mean that the author considers himself in a position to disprove the existence of evolution in toto. But, on the other hand, we read that "if we regard Evolution as one of the means made use of, we may not err." We do not see how these statements are to be reconciled. Considering, however, the title of the essay, and the whole tone of the author's remarks, we shall probably be doing him no injustice if we put him down as a root and branch opponent of the theory as commonly understood. His leading argument appears to be this-facts such as the grouping of the planets of the solar system, the freezing and boiling points of water, and, in the organic world, the provision made by nature for the welfare of unborn offspring, with other similar conditions, seem to stand in definite relation with the existence of life on the earth; these conditions must have been pre-arranged, and therefore It is scarcely necessary to evolution is impossible. In point out that the argument is a non sequitur. estimating the evidence for and against evolution, it is absolutely immaterial to inquire whether the conditions under which it is supposed to have taken place are or are not the result of " pre-arrangement." ́ Dr.. Woods claims in an appendix to have anticipated Favre and Silberman in laying the foundations of thermochemistry. It is unfortunate that in entering the lists of biological controversy he has omitted to acquaint himself with the elementary conditions of the evolutionary problem. Lessons in Physics. By Lothrop D. Higgins, Ph.B. Pp. vii+379; with plates and diagrams. (Boston, U.S.A., and London: Ginn and Co., 1903.) Price 45. 6d. IT is rather difficult to "place" this book. At the end there is a glossary in which (amongst more difficult. ones) words are defined such as these:-absorb (to. take in), alter (to change), constant (always the same), detect (to find out), enlarge (to make larger). Apparently, then, the pupil is not expected to be certain about words of two syllables. We, accordingly, look for great simplicity in the text, especially as the author In his preface trusts that the explanations "have been made with a care which should render them unusually clear and simple." We open the book at random at the first section on magnets, and find the following definition as the first sentence :-"A Magnet is a body sɔ acted upon electrically that it has the power to exert magnetic force." We open on p. 319, and we find Ohm's law based upon the relative values of E.M.F. and current in the primary and secondary of an induction coil. We open again at p. 250, and learn, in explanation of the rainbow, that "the sunlight passes through some thin clouds whose particles of water refract the rays, and the spectrum is formed on other clouds or reflected to the eye. The first 120 pages, on mechanics, appear to be the best part of the book. There are several remarkably pretty plates. The Certainty of a Future Life in Mars. Being the Posthumous Papers of Bradford Torrey Dodd. Edited by L. P. Gratacap. Pp. iv + 266. (New York: Brentano's, 1903.) THE planet Mars has been the subject for many works of fiction, and in the present volume we have another addition to the list. The main idea of the train of thought in these pages is that upon each planet the possibilities of development just attain to the margin of the next higher stepin mental evolution. Thus in Venus the period of sense develops to the possibility of the period of science, but does not attain it. On the earth the period of science develops to that of spirit, while the latter is only reached in the planet Mars. On this assumption souls of different degrees move from planet to planet. The chief characters in this story are Mr. Dodd, his. wife and son (the author of these papers). The father and son work out a system of wireless telegraphy, and' |