摘要:

IN July 1915 the Government announced the appointment of a special committee of the Privy Council and the establishment of a permanent official organisation for the promotion of scientific and industrial research. As an integral part of the organisation " a small Advisory Council, composed mainly of eminent scientific men and men actually engaged in industries dependent upon scientific research," was established by Order in Council. There already existed large national responsibilities for the conduct of scientific inquiry in connexion with the fighting services, agriculture, fisheries, and medicine, but save for the last, these were subordinate activities of ministries with many other responsibilities. The unique feature of the new organisation lay in the fact that it definitely put the scientific man in the saddle, for all proposals for allocating the funds placed at the disposal of this body stand referred to the Advisory Council. The need for such an organisation was forced upon Great Britain by the sudden realisation of its dependence on foreign countries for certain essential raw materials and manufactured goods, particularly those goods which were based upon the application of scientific discoveries to industrial processes. It was realised, moreover, that our industrial ascendancy had been challenged, if not wrested from us, by the capacity for organisation displayed by our commercial rivals, particularly Germany, and that organisation could only be met by counter-organisation.It was in this spirit that the idea of the cooperative industrial research associations was conceived. As the Advisory Council remarked at the time: " so long as the Englishman treats his business house as his business castle, . . . with his hand against the hand of every other baron in his trade and no personal interest in the foreign politics of his industry as a whole, it will be as impossible for the State to serve him, whether by research or other means, as it would have been for King Stephen to conduct a campaign abroad. In the main the State can only effectively help those who help themselves."The essential individualism of the average English industrialist was accompanied by a lack of appreciation of the function of systematic scientific research. A managing director of a manufacturing firm, and regarded as typical, informed the Advisory Council that he had no interest in research which did not produce tangible results within a year. In the face of this attitude the Advisory Council came to the conclusion that it would have to " expend a good deal of attention and money upon convincing the manufacturing world in general that scientific research is a paying proposition," and that unless the generality of British firms could be induced to alter their attitude it would have failed profoundly in one of its appointed tasks. Little, however, could be done until 1918. In the years following 1916, when the whole energies of the nation were bent to one purpose, and the whole of the existing supply of scientific workers were either engaged at the front or in urgent national services at home, it was difficult to put any policy involving individual firms into effect. Even if the Advisory Council had had the time at its disposal and could have gained the ready acceptance by individual manufacturers of a policy of co-operative research, it was confronted with the serious difficulty of finding the research workers. Some industries, temporarily impressed with the need for men of scientific training, could not obtain them. To meet this demand, the Department instituted, a few months before the Armistice, a system of maintenance allowances to suitable students to spend two years in scientific research under direction at a university. Thus it was hoped to re-establish "a body of scientific workers of the highest rank for purely scientific work, and to enable men who intended to make some branch of industry their profession to equip themselves for scientific work in industry." In the same year, 1918, from a Million Fund put at the disposal of the Advisory Council, the first co-operative research associations were started, those for the scientific instrument and photographic industries in July, and the first of the textile research associations, that for the woollen and worsted industry, in October. In all, twentyseven research associations have been formed under the State-aided scheme, twenty-three of which survive.It was hoped and contemplated when the scheme was inaugurated that the industrial research associations would become self-supporting within five years-that that period would be sufficiently long to convince the subscribing firms of their utility. But some of the associations have gone into liquidation through lack of support, and most of the others, even the most successful, are still in receipt of grants. Two reasons are advanced for this by the Advisory Council: the difficult conditions during the post-War years, continued political and social unrest throughout Europe with its consequent trade depression, and the continued apathy of many of the subscribers towards research, many of them regarding their subscriptions to the associations as contributions to a benevolent organisation to be reduced or withheld in bad times. Individualism of the old order has still to be broken down. British manufacturers as a whole have still to realise that co-operation is not the negation of individual effort, but that, on the contrary, it raises initiative to a higher power. Too few regard scientific research as an insurance against industrial bankruptcy. In too many instances, moreover, the subscribing firms have not the capacity to appreciate the research work which is being done. They are intellectually incapable of understanding their own problems. They confuse research with invention. Other factors also operate against the research associations. They are competing with private consultants, many of whom have a wealth of experience and knowledge at their command, and have long enjoyed the confidence of their clients. Then again, many industrial firms prefer either to do most of their own research, if necessary submitting special problems to members of university staffs. Some of the most enlightened industrialists subscribe to the research associations, not with the primary object of submitting their principal and most promising problems to them, but rather for the purpose of obtaining information regarding the problems confronting other industrialists. The problems they refer to the research associations are often of greater academic than practical importance.Considering the state of public opinion and the industrial unrest which prevailed at the time when most of the research associations were started, it must be confessed that the Advisory Council was unduly optimistic in expecting the associations to become self-supporting within five, or even ten, years. This is most evident in those industries in which the scientific principles underlying the processes of manufacture are little understood. The textile industries, for example, have been brought to a high standard of efficiency as the result of experience and manipulative skill, but little is known of the physical qualities of the materials used or the precise nature of the properties required in the ultimate product. Knowledge of the latter must be combined with acquaintance with the former. The research workers are therefore faced with the initial necessity of acquiring knowledge of the processes before they can hope to secure the confidence of the industries. Laboratory research is in itself a tedious process; further experimentation with small-scale plant is usually necessary before the final and more costly stage is reached of experimenting on a full commercial scale. The fact was recognised by the Advisory Council that nothing short of a revolutionary change in our industrial processes, based upon fundamental research, would raise British industries from the slough into which they had fallen, but the time-lag between a scientific discovery of practical importance and its industrial application was much underestimated. Commenting on a memorandum submitted by the Department of Scientific and Industrial Research, the Committee of Industry and Trade stated that: "The results so far achieved by the Research Associations as a whole . . . have been for the most part rather of an educational value to the industries concerned than of a kind which can be assessed in terms of actual monetary saving or gain. . . . The initial period of five years . . . has in fact proved too short a period in the case of most of the associations to yield practical results sufficiently clear and striking to convince the sceptics within the industry of the money value to their businesses of fundamental scientific research."There is another aspect of the matter which the Advisory Council overlooks. A large number of young and enthusiastic research workers were attracted to the service of these associations, not so much by high initial salaries as by the promised interest of the work, and the prospects held out to them. Most of them fondly imagined that a change of attitude on the part of industry had brought the associations into being. But many have spent some of the best years of their life in trying to combat the prejudice against ' science ' which still exists, working under difficulties throughout, and now are faced with the possibility of their work and knowledge being relegated to the limbo of forgotten enterprises. Can the State afford to lose the results of the work of these men because industries are not yet sufficiently aware of their responsibilities to the nation ? This is a question which will have to be decided before the second period of five years has elapsed. We cannot agree that it is only the industrialists themselves who are concerned with industrial research. The conduct of industry is of supreme importance to the nation as a whole. The doctrine that " the future of research associations must rest with the industries concerned, since the State cannot be expected to support indefinitely organisations instituted primarily for the benefit of the industries themselves," as enunciated by the Department, cannot be accepted. In comparison with countries like Germany-which has had far more post-War difficulties to contend with than Great Britain-and the United States, Great Britain's expenditure on industrial research is almost trifling. If industry will not equip itself for the task, it is the bounden duty of the State to decide what industrial research is required. The method of raising the funds for the purpose is a matter for the State to decide. It has already been suggested that firms should be forced to contribute to the specialised research affecting their activities. This may not be equitable, since industrial research, like pure research, is the concern of the nation as a whole. It may be found desirable to change the character of the existing associations, to group them differently or to have them centred in the various universities scattered throughout the country. Whatever is decided, the beginning, for that is all it is, is sufficiently promising to justify increased rather than diminished effort to bring home to the country as a whole the fundamental importance of research on a magnificent scale.Rather more than ten years have elapsed since Sir Frank Heath forsook his studies of Chaucer and Canterbury pilgrims to become one of the leaders in the great pilgrimage of research. He has had to meet many difficulties. The hostility of many men of science who resented the entry of a State department into the scientific and academic world had to be fought: the apathy of industry had to be overcome. He is now about to hand over his responsibilities to Mr. H. T. Tizard, but he retires with the consciousness that his name is inevitably associated with the most successful experiment in administration to which the War gave birth.

ISSN:0028-0836    

DOI:10.1038/119589a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT always arouses one's suspicions if a timehonoured institution which we have known all our days, and know to be the outcome of an immemorial growth, suddenly announces that it has become quite new. Or. if a certain number of its workers set up the claim to a new and inspired method of working, we are apt, and often rightly, to regard them as charlatans or ' bolsheviks,' or whatever may happen to be the fashionable word for a dangerous revolutionary at the time. So it was, and in that case rightly, with those who promised us a new heaven and a new earth as a result of the War, and so in the minds of many is it likely to be with those who are now talking of a new history. The phrase is chiefly current on the western side of the Atlantic, and if we are not mistaken it has been most, if not first, used by one of the two authors of the beautiful work entitled " The Human Adventure," which has just appeared in two volumes, by Prof. J. H. Breasted, the eminent Egyptologist, and Prof. J. H. Robinson. Prof. Robinson, who writes the second volume, on medieval and modern times, is principally identified with this new gospel of history, but Prof. Breasted, who supports him with a massive knowledge of archaeology and the ancient world, is at one in thinking that history in our time has entered into another and far more important phase of its development. What, then, are these recent changes ? Are they sufficient to make us think that history has put on a substantially new character ? What are the bearings of this new history, new at least in the minds of some who study and teach it, and how far do these two volumes by Messrs. Breasted and Robinson fulfil the ideals that they set before them ?The inquiry, as we might expect before starting, very soon reveals itself as closely similar to that into the evolution of any other great branch of human activity. Take, for comparison, religion, or science, or art. They seem in their fully developed form to differ so widely from their first beginnings that we are apt to think them entirely changed and that we have achieved, or are on the threshold of, a religion or a science-new in kind. Yet, looking back, we can trace a continuous growth and always find somewhere an earlier germ of what we thought was quite new. So in this appearance of a 'new' history one can find antecedents and authority in the works of previous thinkers for all the new ideas and material that are now coming in with a flood. Thucydides and Herodotus could give us examples enough; what is new is the amplitude of the material, the spread of a similar spirit of inquiry from one branch or nation to another; above all, the valiant attempt to see all the facts as part of one process the understanding of which is a matter of essential and transcendent importance for civilised men. Understood in this sense, we may well allow the claim of a 'new history' to its professors and gratefully acknowledge our debt to Messrs. Breasted and Robinson for their contribution to it in these volumes. The distinguishing points in the outlook on history which these books so admirably illustrate are mainly these. In the first place, and dominating all the rest, the story is regarded as that of civilisation as a whole, and not merely of the political development, whether of one nation or of any grouping of nations. This involves not omitting wars or the building of states, but seeing these activities as part of the larger process through which mankind has passed from the state of isolation, ignorance, and collective powerlessness in which we first discover our human ancestors, to the comparative unity and vast collective power and knowledge in which we now live.Three aspects of history at once emerge into prominence as soon as this point of view is taken. One is the importance of the fundamental early inventions and advances in culture which archeology has lately been revealing with a striking similarity from all quarters of the globe. Prof. Breasted is satisfactorily emphatic on this side of his subject, and puts first ploughing, the use of metals, and the invention of writing and the calendar, among the benefits which the ancient Egyptians conferred on their neighbours. It will be noticed that the priority which he assigns to Egypt, not only over the west but also over all the civilisations farther east, lends support to the recent school which turns to Egypt as the nursery of all civilisation. It should also be remembered that such particular questions as the relations between Egypt and Babylonia, or the antiquity and originality of the civilisations of India and China, are detailed matters for further research. They do not affect the main position of putting I in their due place these and other aspects of man's contact with Nature as well as with his fellow-man. Following the same line of thought into later times, the new outlook in history lays stress on the vital importance of the evolution of scientific thought in building up mankind. In this, again, as we might expect, our authors show a right appreciation of the relation of the facts, although one would be glad to see more space assigned to that aspect of progress which has hitherto received practically no treatment at all in general histories. Thus Mr. Robinson points out that the scientific advance which began to be rapid in the seventeenth century, produced also a general spirit of reform which has dominated the west ever since; and in a concluding chapter he shows the supreme importance of scientific thinking in promoting the forward-looking habit, based upon continuity with the past. It would be interesting to trace how it is precisely this spirit which inspired the reforming monarchs of the eighteenth century-Frederick the Great, Joseph II., and the rest. The limitations of their success, and the limitations, equally marked though due to other causes, of the philosophers of the Revolution, form one of the most interesting and instructive studies in history, far outweighing the glamour of Napoleon's career, which still occupies the forefront of the stage even in such enlightened books as these. Napoleon, and many like him, passed over the world as a hurricane, clearing away, no doubt, much illfounded vegetation and structures; but the work of the thinkers goes on steadily all the time, correcting its mistakes and bringing at last to fruition ideas that ignorance and passion may impede for generations.It will be understood at once that as soon as we transfer our main attention in history to the general growth of civilisation, rather than the political development of particular States, our view gains in universality as well as continuity with the past. The things that matter most are those which we share with others and not those which divide or distinguish us. It all turns on that, and the acceptance of this fundamental truth does not involve the lowering ofmankind to a level of dull and monotonous mediocrity. Eminences will remain, and may be just as beautiful and varied if they arise from a broad and well-based plateau as if they stand isolated and likely to be submerged in a rising ocean. The fundamental facts of civilisation are of this common and connecting kind. Not only in their inventions and their arts of life, but also in their maxims of morality and their earliest ideas of religion, we find ourselves at home when we trace origins, whether in India and China or in Mexico and Peru. Going back we come together, and going forward we may hope to integrate history and the world at large in the same spirit, a spirit not of uniformity or of degradation, but of a common humanity, realising itself in varied forms.On this matter again it must be saidthat Prof. Robinson might have imported a little more of the 'eternal spirit ' in looking at his facts without depriving them of a tittle of their interest and actuality. The League of Nations is made to appear in his pages as if it were merely as a part of the Treaty of Versailles, a sequel useful and important, but only a sequel, of the War. It is that of course, but, sub specie aeternitatis, it is far more. It is the necessary sequel of the process of unifying the world, in which science and its applications had played so large a part, both in the "Conquest " and the " Ordeal " of civilisation. The "Ordeal " is in fact the question whether the achievements of science in the mechanical sphere are to be used for the furtherance or the destruction of the civilisation which has been conquered; the sharpened razor and the more massive hammer will be the more destructive to life if they are not wisely governed; and wisdom, like science, is a collective thing, the highest manifestation of common sense. The League of Nations, whether there had been a great war or not, must have been born, and was being born, to give voice to this common sense. One would have welcomed a little more explicit statement of these truths in the second volume, and a little less of somewhat personal matters in the post-War chapters; even the excellent and almost full-length portrait of Mr. Ramsay MacDonald does not reconcile one to this want of balance.On the whole, however, the work in both volumes is well done and is unquestionably the best popular presentation of general history which we have yet acquired in English. Prof. Robinson is more fluent and philosophic; Prof. Breasted is more solid, and adds more to our knowledge. But he does it in the most attractive way, with admirable pictures, maps, and cross references. The work is a notable step forward in the much-needed operation of informing the general public of the latest results of historical research into the ancient world and of the new and broader outlook in the modern.

ISSN:0028-0836    

DOI:10.1038/119591a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THlS book is a welcome addition to the AL rapidly growing mass of astronomical literature. It is, in the main, well arranged, clearly written, and adequately supplied with excellent illustrations and diagrams. There is nothing revolutionary or in any way unconventional in its general plan, and while the most recent researches have been taken into account, the author has not yielded to the temptation of ascribing to intrinsic importance the relative prominence which may actually arise only from their nearness. The book may be generally recommended as an accurate and interesting outline of present-day astronomy. It is unfortunate, however, that Prof. Fath has attempted the impossible task of achieving two irreconcilable results in a single volume. His work is intended both as a text-book and as a book for the general reader. The characteristics of successful works of these two types under our present system of education are antagonistic. A text-book must be primarily an. aid in preparing for examinations, and should therefore present knowledge in the form of ' quanta ' which can be reproduced on the examination paper in a period of twenty or thirty minutes. It must draw a perfectly sharp line between what is known and what is unknown, and concentrate attention entirely on the former. This is very regrettable, but it is nevertheless true. The general reader, on the other hand, is interested in astronomy only in relation to life as a whole. He does not want chapter and verse, but only broad results and lines of thought. In brief, while the text-book should describe the individual pebbles on the shore, the book for the general reader should deal only with the relation of those pebbles to the undiscovered ocean of truth from which they have been retrieved.Prof. Fath's book necessarily suffers from the attempt to unite these two classes of work. As a text-book it lacks something of the precision which is desirable. The treatment of the subject matter is in parts somewhat sketchy, and is almost entirely non-mathematical. It is true that the book is intended for college freshmen, but the college curriculum which includes the teaching of the principles of refraction of light and the methods of determining time, latitude, etc., to students with no knowledge of the rudiments of trigonometry, is open to severe criticism. There is, too, a complete absence of suggestions for practical exercises. It is most desirable that students-and especially beginners-should be encouraged to do things for themselves, and even in those colleges unprovided with simple spectroscopes, transit and equatorial instruments, a great deal may be done with the old-fashioned celestial and terrestrial globes. It will be noticed that these defects of the text-book are merits of the book for the general reader, who, however, will not welcome the division of the chapters into short numbered paragraphs, each with its own heading. Allowing for the impossibility of his aim, however, Prof. Fath has probably made as satisfactory a compromise as is possible. A book may fall short of its ideal and still be extremely valuable. We regret that Prof. Fath did not confine himself to a single purpose or, better still, write two books -but we do not wish to convey the impression that the book is a failure. It will probably be found most useful to the secondary school teacher who, not having to teach astronomy as a definite subject, is yet sufficiently interested in the wider aspects of education to keep his pupils in touch with the general principles and achievements of the most humanistic of sciences. The general reader also who is not repelled by the text-book-like appearance of the paragraphs will read the volume with both pleasure and profit. About two-thirds of the book is concerned with the solar system, so the older astronomy has not been neglected for the more sensational developments of the new. Having regard to the four subdivisions of astronomy defined in paragraph 6, however, the uninstructed reader will probably conclude that the observation of the planets belongs to astrophysics. A fifth subdivision-descriptive astronomy-might well have been included.There are the few inevitable mistakes, of which only the more serious need be mentioned. Since a paragraph has been devoted to the ' spectrum: of a comet, it should have been stated that the spectra of the head and tail differ from one another. The proposed classification of the nebulae on the basis of spectral type alone is scarcely satisfactory, and the term ' disintegration ' of matter, which is used throughout to indicate the probable source of stellar energy, does not convey the true idea of annihilation. The reader who has had faith in the ingenuity of men of science will be surprised by the statement on p. 39 that a con verging and a diverging meniscus (not here sc called) " cannot be distinguished by their names alone." Finally, Fig. 31 is an almost incredibly erroneous diagram, in which rays of light are suddenly deviated in the midst of a homogeneous medium. It is the most striking example we have met with of the danger of thinking in terms of single rays instead of pendils of light. The book is well produced, and contains few misprints 21 lb., however, is an excessive weight for a book of 307 pages.

ISSN:0028-0836    

DOI:10.1038/119593a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

N ONE of the foreign guests of the Mineralogical 1N1 Society on the occasion of its recent fiftieth anniversary was more heartily welcome than Prof. Niggli of Zurich. It is therefore with especial interest that we open the new and greatly enlarged edition of his text-book of mineralogy in two handsome volumes. The first of these, which deals with the general principles of the subject, is not only a monument of industry and research, but it also displays everywhere the resources and originality of the author. It deals with crystallography at considerable length, paying especial attention to the atomic configuration, as revealed by the Rontgen rays. More stress than usual is laid on the physical characters of crystals, though, as may be supposed, it is their optical properties that are treated in the greatest detail. The principles of crystal chemistry are carefully explained, and space is even found for the subject of glasses and colloids.The student who has mastered the contents of this volume will have acquired an undoubted mastery of the theory of the subject, though it may be open to question whether it is best for him to owe his training to one great compilation, however accurate, logical, and complete it may be. He might get a broader grasp of the subject if he studied, under the guidance of his teacher, the expositions of different workers who have made themselves responsible for recent advances. There would then be less danger of his adopting stereotyped methods of treatment. Some years ago, Prof. Hilton introduced the principle of ' rotatory inversions ' in describing the symmetry of certain classes of crystals: that is to say, rotations resulting in the coincidence of all crystallographic lines, but with the directions reversed of lines having different properties in opposite directions. This valuable conception, based on the nature of crystal structure, has been since extended to the relation between the component parts of some twinned structures, but it finds no place even in this most comprehensive of text-books.The second volume, dealing with the individual minerals, is no less remarkable. In it, also, special stress is laid on crystallography, which is treated in a somewhat original manner. Crystals belonging to systems with relatively low symmetry are considered to be distorted examples of forms with higher symmetry and classified accordingly. Thus a group of cubic and ' hypocubic ' crystals includes not only fluor, which is cubic, but also calcite, which is rhombohedral. Curiously enough, Prof. Niggli does not place the monoclinic baryto-calcite in the same category in spite of the remarkable resemblance of its crystallisation to that of the rhombohedral carbonates. The felspars, too, are referred to hypocubic axes. Pyroxenes are, as one would expect, hypotetragonal, and amphiboles hypohexagonal. These and other similar affinities have long been recognised and were studied in detail by Fedorov. Indeed, the author might have noted an additional link between the cubic and trigonal systems in the fact that fluor and halite, though cubic in their angles and optical characters, exhibit occasionally a development of faces which seems to indicate rhombohedral or even lower trigonal symmetry. But the use of such affinities as the basis of a classification, cutting across the established systems and classes of crystals, which the author still recognises, and branching out into intricate subdivisions, is calculated to confuse the student, while those who are already familiar with crystallographic principles experience a sense of bewilderment when they have struggled through the volume. Yet it undoubtedly contains a store of interesting facts and suggestions. With all its idiosyncrasies this remarkable book should be found on the shelves of every teacher of mineralogy and crystallography, but he will probably hesitate to place it in the hands of the members of his classes.

ISSN:0028-0836    

DOI:10.1038/119595a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

METHODS of soil investigation are now so numerous and varied that a volume including some description of the more important of these fills a definite gap. The features of special soil types are not dealt with, but as a preliminary the procedures adopted in soil surveying and sampling are outlined, together with methods of classification and mechanical analyses. Analytical methods for the determination of various soil constituents are given in detail, special attention being devoted to the preparation of equipment. The physics and biology of the soil are not dealt with so fully, but sufficient is given to direct the attention of the student to the main aspects of the problems involved. The bibliographies are conveniently placed at the end of the various sections, but consist mainly of references to American papers. Numerous laboratory experiments are suggested and outlined wherever possible, with the intention of supplying training on a good working basis for the determination of the characteristics of whatever soils may come under consideration.

ISSN:0028-0836    

DOI:10.1038/119596c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is generally assumed that coral reefs are still growing, and when the outer slope is fairly well covered with living corals there seems to be no doubt about the matter. Yet in Tahiti and the adjacent island of Moorea there is no doubt that even with a fair abundance of living coral, the reefs are slowly going back.Pending the publication of a full account, the following are evidences for this unexpected conclusion: (1) The form of the outer slope, its regularity and smoothness, absence of all sand and debris-down to 10 or 12 fathoms it is absolutely clean.(2) Its being cut into by trenches at short intervals. These are very clearly under erosion, their vertical sides and flat bottoms being scoured clean of every growth. These extend from where the surf breaks just under the raised edge of the reef to 10 fathoms, where they open out on to the general slope. For the lower 7 or 8 fathoms of their course they lie at the bottom of, ravines the sides of which are covered with corals to exactly the same extent as the open slopes,. but for all that, growth has not sufficed to make the ravine's sides vertical or anywhere near that. These trenches are not in the least like outgrowing tongues or buttresses; they do not resemble at all those described and mapped in the Report on Funafuti, for example. (3) The strong scour on these slopes is shown also by the fact that it is the corymbose Madreporas (Acropora), which are the dominant corals, this form of growth being a special modification for the purpose of raising the colony above the fatal sand rasp of the bottom. This became clear to me from my experiments with pearl oysters in the Red Sea. These corals are all, as it were, planted out at intervals of a foot or two over the surface, never riotously crowded as on the reefs of the Red Sea or the lagoon reefs of Tahiti.(4) Coral growth ends quite definitely at from 10 to 12 fathoms down, instead of the usual 30 fathoms or more. (5) The final and conclusive proof is that some of the stones which lie in the trenches are rounded pieces of basalt from the hills. One finds such stones at intervals on any part of the reef, on both sides of the lagoon, either lying on the eroded outer flat or bedded into the vertical walls of the shoreward lagoon reefs. It is clear that the reef was originally continuous from shore to edge, and that the lagoon is a comparatively recent secondary formation. The stones on the outer slope would have been buried deeply in coral if there had been any extension of the reef seawards since the opening of the lagoons cut off the supply from the island. They prove more than that growth has come to a standstill since that event, for the stones could not lie on this slope for long: they must in time be swept downwards. Those now in view have been exposed comparatively recently by the erosion of the coral in which they were embedded.(6) Though there is no coral rock in all Tahiti raised above sea-level so high as to be dry land, there is in three places in Moorea. (One of these was reported as coral to Capt. Cook by his officers, but Agassiz was so badly served as to be told that the rock was volcanic.) All three are on the outer sides of islets of coral sand on the reefs, and near the outer edge, and all were originally the outer shallow part of the lagoon floor, which is now two feet above water level and in an extraordinarily perfect state of preservation. Their position so near the present reef-edge affords another proof that there has been no extension seawards since that lowering of the ocean surface which left these lagoon floors dry, and exposed the shelves along the foot of cliffs in so many islands of the Pacific, the Marquesan and Society Islands included. (7) Unlike the other islands of the group, Tahiti is not completely surrounded by a 'barrier' reef. (The reason for the use of inverted commas is given above.) There are no surface reefs for miles off the north-eastern corner of the island, but soundings show that the reefs are there, but under about 5 fathoms of water. These might be (1) reefs growing up which have not yet reached the surface; (2) reefs submerged by local subsidence, but the chart itself shows clearly that they are not; (3) parts of an original shelf upon which all the reefs were founded. The examination of the shores within them shows that there was once the usual maritime flat here as round the rest of the island, which has now disappeared, leaving relics here and there to show its former existence, and the comparison of the reefs themselves with those which reach the surface shows that they are exactly the same but for the removal of the upper five fathoms or so.I find it difficult to account for this reduction in the vigour of coral growth, but one factor has probably been the laterisation of basalt, its conversion from hard rock to that red clay so conspicuous on the slopes, which in floods causes all the streams to run red. This does not, however, seem possible as the whole explanation, and there may be biological changes involved, such as in the species of coral dominant, the balance between the organisms which build and those which destroy reef material, or even in coral physiology. In Tahiti and Moorea, at any rate, it is clear that the age of corals is past. Is it possible that this is true of the world in general ? In 1902 the writer showed that the great reef of tropical East Africa is nothing but a shelf cut by the sea into the great mass of raised coral which forms these coasts; in the Red Sea, part of the breadth of the reefs is formed in the same way and part by the growth which has occurred since the elevation, but where the distinction can be made out the latter is comparatively small. In reading most descriptions of reefs one is struck by the disproportion between the amount of growing material present now and the huge structure raised by growth in the past.The possibility that the latest of the coral ages is now passing or passed, introduces another complication into this ever-fascinating study, and the possibilitv of former extensions of the present surface reefs is one to be borne in mind in future investigations. I desire to acknowledge the assistance received from the Government's Grant Committee of the Royal Society and the managers of the Balfour Fund of this University, which made possible the exploration of which this is the more important result.

ISSN:0028-0836    

DOI:10.1038/119597a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE letter of Prof. Harkins, concerning some of the methods used for measuring surface tension,1contains a statement about the ring method which may mislead the reader; and the addition of a few words to it may therefore be worth while.My efforts in the past five years have tended to emphasise the importance of a phenomenon which had been overlooked so far, namely, the decrease in the surface tension of colloidal solutions as a function of the time. Although a few exceptions have been found, the great majority of colloidal solutions obey this law, including dyes, proteins, metallic sols, gums, etc. It was known that the static value of the surface tension was different from the dynamic value, but it was generally agreed that the adsorption in the surface layer took place almost instantaneously.' The study of the delayed adsorption, which can be followed step by step over periods of hours through the consequent decrease in the surface tension, can obviously only be observed by using a method permitting a proper control of the time. As the surface tension of a colloid solution begins to decrease as soon as it is no longer stirred, its value depends on the time elapsed since the last stirring. By using the instrument which I call for short a 'tensiometer, according to a technique first described in 1922 and improved in 1925,a it was possible to obtain the values of the surface tension about 1/10 of a second after the stirring. These values, for sodium oleate solutions diluted to 1/25,000, were only slightly less than the value of the surface tension of pure water, namely, 68 to 69 dynes at 20° C. Measurements taken at ten seconds' interval showed the decrease which, under the conditions of the experiments (2 c.c. in watch glasses), took place proportionally to the time. After thirty seconds the value was 55 dynes, and after one minute, 42 dynes. The curve expressing the decrease then assumed a logarithmic shape, and the static value was attained, in this case in five minutes, at 36 6 dynes. At higher dilutions, the time required to reach the static value is greater; for example, at 1/100,000 under the same experimental conditions, the static value was equal to 32 1 dynes and was reached in twelve minutes. Itis obvious that the time required to reach the equilibrium depends on three main factors: concentration, mobility of molecules (function of the viscosity of the solution), and ratio vurface of vollume the container. It may vary with different solutions in watch-glasses (2 c.c.) from twenty minutes (pure serum) to three hours or more (serum diluted 10,000 to 20,000 times).Such measurements are very easy and simple to perform with good accuracy by means of the tensiometer. If a drop method, even though highly improved, were used, it would require waiting two or three hours, sometimes more, for every drop to form and fall. If it be assumed that three drops were sufficient to obtain a satisfactory accuracy, which is an optimistic view to say the least, this would mean, with one instrument, six hours instead of two, or nine hours instead of three, and an accurate control of this time would be exceedingly difficult. The determination of a complete adsorption isotherm would require days. Moreover, the estimation of the total adsorbing area, which is an important factor, would not be an easy matter and would involve the calculation of the surface of the drop itself. I have shown' that under certain conditions absolute minima of the value of the surface tension are observed at very high dilutions (at 1/750,000, 1/1,220,000, and 1/1,390,000 in the case of 2 c.c. of sodium oleate in watch-glasses), and that these minima can be shifted by altering the area of the adsorbing surfaces (by adding glass beads, for example). The hanging-drop method does not readily lend itself to such experiments. Another interesting phenomenon was described in 1922,5 namely, the 'antagonistic action ' of one colloid upon another. When a strongly surfaceactive substance, such as sodium oleate, is added to a solution of colloids with larger molecules or particles (proteins, metallic sols), a sudden drop in the surface tension is observed, as would be expected, but this drop is immediately followed by a rapid rise which can be followed step by step with the tensiometer, and, under certain conditions, the original surface tension is reached after seven minutes. When measurements are made every thirty seconds, a perfect adsorption isotherm is obtained.6 It is doubtful whether this phenomenon could be studied at all with any drop-weight method. Yet it is important, since it gives a method whereby adsorption may be studied quantitatively with great ease and rapidity, and whereby the area of adsorbing surfaces may be evaluated. This problem is being investigated at present in our laboratory.A slight modification of the tensiometer makes it possible to measure interfacial tensions.7 With this instrument we have obtained adsorption isotherms at the interface between paraffin oil and sodium oleate solutions, as a function of time; I the action of temperature at the interface between water and ethyl ether and water-carbon disulphide was also investigated with great facility, and gave positive temperature coefficients. I have mentioned a few of the results which were found as a direct consequence of the use of the ring method improved so as to render it practical and very rapid. In the biological field this method has enabled us to study the processes of immunity in animals, and to reach certain conclusions which are not devoid of interest. On the other hand, the absolute value of the surface tension of water obtained without any correction with the du NoUy tensiometer agrees within ±0-1 dyne with the values published by the best authors (72-6 dynes at 18° C.). Furthermore, although criticised by some, the ring method has nevertheless in recent years aroused so much interest that Prof. Harkins himself, whose authority in this field is unchallenged, has found it necessary to give it a great deal of attention, and leads us to hope that he and his collaborators will soon be able to give a corrected formula which will reduce the errors to less than 0-1 per cent. This correction, although uncalled for in the case of water and most aqueous solutions, will undoubtedly establish the superiority of the ring method over all others, so far as convenience, rapidity, reliability, and adaptability to different problems are concerned. I trust I have made it clear that it has already scored in the particular case of colloi

ISSN:0028-0836    

DOI:10.1038/119598a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ONE of the most difficult problems which confronts all investigators who have to deal with man as a worker, is the assessment of his fitness to produce. The accurate determination of the degree of fitness of the man to perform his work has never been satisfactorily elucidated, so that reliance is placed most frequently on the measure of his productiveness as shown, say, by the number of articles produced, the quality of his work, the time taken to perform selected operations, alterations in skill of performance, etc. Further, when it is desired to refer to any alteration, either by way of enhancement or diminution, in the individual's capacity to carry on any particular operation, it is generally said that the man'sefficiencyis increased or diminished.It is true that modern usage, as indicated by the "New English Dictionary," for example, authorises a definition of the word efficiency as " fitness or power to accomplish, or success in accomplishing, the purpose intended"; and as another meaning it gives " efficient powers or capacities." Colloquially the word efficiency is commonly used, with perhaps even wider significance, as a synonym for power to perform, for the conduct of business with energy and with the minimum of waste, not only on the part of single individuals but also of groups of workers. It has, of course, long been recognised that the term efficiency is neither a scientific nor, in the light of modern knowledge, an apt one by which to refer to the individual's change in capacity. The engineer has appropriated to his own technical vocabulary a word which had long been in common use, and as a result it has come to have a very definite connotation in engineering, and even in physiological, science. When used by the engineer it is, as a rule, qualified by some adjective indicative of the particular type of efficiency to which he is referring. Thus he may speak of mechanical or thermal or thermodynamic efficiency.The physiologist, too, has investigated the efficiencyin the engineering sense it would be the over-all thermal efficiency-of the human body and has arrived at very definite results. While it is open to question whether a mode of calculation suitable in the case of the development of energy in a mechanical apparatus, like a steam engine, is applicable to the series of metabolic processes common to the human body, where, it must be remembered, food serves not only for yielding energy but also for the repair of tissue waste, no serious objection can perhaps be taken, provided the limitations of the method are kept in mind. As an alternative to the displacement of the term efficiency from the engineer's vocabulary, a feat which would be practically impossible of accomplishment, we must be prepared either to use the word with a double significance or else find a substitute. It is clear that the common usage of the term in connexion with everyday labour of all kinds cannot be justified. We have no right to refer to the increased or diminished efficiency with which a man performs a specific piece of work if we, at the same time, take no cognisance of the data which must be determined before the actual efficiency of production may be considered. The use of the word efficiency is then simply a loose colloquial way of referring to a general condition of human wellbeing with absolutely no reference whatsoever to the true scientific meaning of the term.When we speak of efficiency in this general way, what we want to express is, that the individual in question is performing his work in the most effective and useful fashion. In other words, the idea we wish to convey has nothing to do with that other determinable factor involved in man's productive powers, namely, the ratio of his energy expenditure in the form of useful work to his intake of energy or to his total expenditure of energy, but simply with the degree of effectiveness with which the work is done. In view, then, of the confusion of ideas which must arise when the same word is employed to define two very different types of phenomena in man, it is suggested that it would be best to employ two words. Let the word efjiciency be confined, whether fully justified or no, to the ratio of the energy exchange in the performance of work, but in order to cover the much wider field, where there are no special but innumerable general physiological or physical determinants, and where we wish to speak of enhanced or diminished capacity to perform, it is suggested that a word like effectivity might be more fitly employed. Such a word commits us to no underlying single series of physiological phenomena, but is perfectly general, and refers merely to the sum total of the factors which lead to effective production, and it can therefore be suitably applied to a wide range of activities of individuals or groups of individuals. The word has been selected as the most suitable from a number of alternatives, all, more or less, expressing the same general idea.As a practical illustration of the difference between "efficiency " and " effectivity " one of the experiments which I published in conjunction with Prof. F. G. Benedict may be cited. We determined the efficiency of a highly trained subject doing most strenuous work on a bicycle ergometer for more than 4 hours. His efficiency at the start was 23 1 per cent., and in the observation made just before the experiment ended, due to the impending collapse of the subject, it was 213 per cent. One can state, then, in this extreme example, that although there was but a small reduction in the subject's efficiency, his effectivity at the end was nil. It may be remarked in conclusion that certain of the German workers have found the same difficulty, but, so far as I am aware, none of them has suggested a term to cover the idea which it is desired to express. Effectivity, if it find acceptance, might be utilised by German workers as 'Effektivitdt.'

ISSN:0028-0836    

DOI:10.1038/119599a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the discussion in NATURE (Jan. 22, p. 120, and Mar. 12, p. 392), Mr. McKeehan has taken exception to statements of Carpenter and Tamura in a paper on the above subject on the grounds that the method of formation of twins depicted by them brings atom centres too close together. Twinning by reflection about a plane is considered, and the discussion hinges on the precise location of this plane with reference to the planes of atoms. Geometrically, a twin crystal of this type consists of two individuals united symmetrically about a plane, which is not one of systematic symmetry but is a possible crystal face (Tutton, “Crystallography and Practical Crystal Measurement,” 2nd ed. vol. 1, p. 500, where it is also stated that the plane of twinning is “usually one with low indices and indeed very often a primary face”). In view of the improbably small distance of approach of atoms required by Carpenter and Tamura's hypotheses, it appeared to be worth while examining the effect of adding to the above geometrical law of twinning thephysicalconditions (1) that the reflection plane can only be one such that the operation of twinning does not bring atom centres closer to one another than the closest distance of approach of atoms in either component of the twin, and (2) that the components of the twin have in common at least one plane of atoms. Briefly, these conditions imply minimum stress and maximum continuity of structure.Subject to these assumptions, it may be shown that for a simple cubic lattice, twinning of the type considered can only take place about {100$, 110$, 4111t or 4200$, of which the first two and the last are systematic planes of symmetry and lead only to cases of parallel growth in holohedral forms. For a body-centred cube such as a-iron there is no plane, other than 4100$, 4110$, 4200$, which fulfils condition (1), but 4211$ requires a very small compression and might be permissible. For a facecentred cube, {111$ is the only plane other than 4100$, 4110$, 12001 and 4220$. In the case of the diamond structure the only plane other than symmetry planes is that mentioned by Mr. McKeehan (NATURE, Jan. 22), namely, a plane parallel to 4111$ cutting the cube diagonal at a distance ⅛th of its length from the origin and bisecting a line joining two atoms which are separated by the closest distance of approach-the co-ordinates of the atoms being 000, O½½½o½½½o. ¼¼¼ ¼¾¾ ¾¼¾¾¾¼ In this structure the components of the twin have two planes of atoms in common, and the reflecting plane lies midway between them. So far as the metals which crystallise on a facecentred cubic lattice are concerned, the above results seem to be correct. Gold, silver, copper, lead, platinum, and iridium are stated by Dana to twin about 4111$. Diamond and silicon also twin on this plane. Iron is stated to twin on 4111$, contrary to the result obtained above; but as this material passes through a transformation in cooling, the existence of twinning in the a-modification would have to be confirmed by X-ray measurements. I understand that twins are rarely, if ever, observed in the body-centred cubic metals.The application of the above hypothesis to the case of compounds is too complicated to be dealt with here; but sodium chloride and potassium chloride, in which the atoms are situated at the corners of a simple cube, ought to twin on 4111$, as they are in fact observed to do (Groth). The case of calcite can be derived from this, for when the sodium and chlorine atoms are replaced by calcium and carbon respectively and the cube distorted to a rhomb, {100E becomes a possible twin plane and is commonly observed. In general each case would have to be considered separately in conjunction with a knowledge of the s

ISSN:0028-0836    

DOI:10.1038/119600a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN order to find experimental support for the theory of X-ray diffraction in liquids put forward some three years ago by C. V. Raman and K. R. Ramanathan (Proc. Indian Association for the Cultivation of Science, vol. 8, p. 127, 1923), extensive studies have been undertaken in the authors' laboratory of the phenomena observed when a pencil of monochromatic X-rays passes through a layer of fluid, particularly with the view of determining how the effects are influenced by the physical condition and the chemical nature of the substance under investigation. The photographs here reproduced (Fig. 1,aandb) were obtained in the course of work on this line by one of us (C. M. Sogani) and represent the X-ray liquid haloes of hexane and cyclo-hexane respectively. The fluids were contained in cells with very thin walls of mica, and theK-radiation of copper from a Shearer X-ray tube was used.FIG. 1.-X-ray thraction haloes of liquids. a, Rexane; b, cyclo-hexane. The differences between the two patterns are sufficiently striking; cyclo-hexane shows a bright and sharply defined halo with a very clear dark space within, while hexane, on the other hand, shows a less intense and relatively diffuse halo, the inner margin of which is not sharply terminated but extends almost up to the direction of the incident rays. These differences indicate very clearly the effect of the geometrical form of the molecules on the X-ray scattering by a liquid. From an X-ray point of view, cyclo-hexane consisting of ring-formed-though arbitrarily orientated-molecules has a nearly homogeneous structure, while on the other hand the elongated shape and varying orientations of the molecules in hexane cause it to be much less homogeneous in X-ray scattering. This explanation is supported by the observation that the diffraction halo of benzene resembles very closely that of cyclo-hexane.It is very interesting to contrast these facts with the optical behaviour of the three liquids with regard to the scattering of ordinary light. Optically, hexane and cyclo-hexane are far more nearly similar to each other, and differ strikingly from benzene, the depolarisation of the scattered light being small for hexane and cyclo-hexane and relatively large for benzene. Here, evidently, the geometrical form of the molecule is of much less importance than its chemical character. Further studies of the liquid-haloes for various organic substances of the aromatic and aliphatic series, and specially with the long-chain compounds, are in progress.

ISSN:0028-0836    

DOI:10.1038/119601a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature