摘要:

IT is satisfactory to note from the Fifth Annual Report of the Safetykjli££ResearchBoard, just issued, that pwichs ef an imjofteint character are being jpfflfHy Bur^eck*aila Especially that the Board appears wkmg4i wider view of its duties than was sJ^one time the case. It has been pointed out more than once that the tendency of the Research Board was to trust too implicitly to laboratory investigations, and that as an almost necessary consequence many of the researches were confined to chemical or physico-chemical problems. What is particularly needed to-day is investigation of mechanical problems. These are of such a nature that their proper investigation can be carried out only in the pit, and laboratory work can do little more than give an indication of the direction in which the researches would need to be prosecuted. The most fertile cause of underground accidents is still, as it has been for many years, that occasioned by falls of ground; an investigation, sufficiently complete and searching to enable suitable remedies to be suggested, is necessarily a lengthy and wearisome one, and one which can only be carried out underground. It is, therefore, gratifying to observe that investigations of this type are being actively pursued. The results obtained by the dynamometer-prop, the object of which is to measure the actual roof pressures experienced in the mine, will be looked forward to with great interest, though every experienced miner knows that it is not the amount of pressure only which matters; a roof which weighs heavily, but can be so controlled as to take advantage of that very weighting for the purposes of coal getting, is likely to be a source of much less danger than the roof which presses less heavily, but is apt to break tip without warning.Among the reports of results of investigations issued during the course of the year was an exceedingly valuable one on the East Midland Coalfield, in which the results obtained by steel props were recorded and their more general adoption, at any rate on an experimental scale, was advocated. Such props are attracting considerable attention, and it is to be hoped that the Safety in Mines Research Board will continue to investigate the respective advantages and drawbacks of the different types of props which are being put on the market. It may be noted that the Board has had tests_ carried out on quartered props, which show that these props are as strong as round props of the same sectional area. It may be doubted whether it was worth while carrying out these tests, seeing that the subject has been fully dealt with in Germany, and the German reports show exactly the same conclusion as has been reached in Great Britain (see Gliickauf, 1926, p. 1409). It is, however, some satisfaction to find that the results which have been obtained by the British and German investigators have led to identical conclusions. Another subject on which the Safety in Mines Research Board is initiating an investigation, is wire ropes, and this may be described as an investigation of first-rate importance. It is true that colliery accidents due to the failure of wire ropes are exceedingly rare, and that they stand almost at the opposite end of the scale to that which accidents from falls of ground occupy. Nevertheless, it may fairly be said that there is no article in common everyday use about which our ignorance is so profound as is the case with the wire rope, and any information concerning wire ropes will be eagerly welcomed. No fault can be found with the objects of the wire rope com mittee, namely, to discover means of prolonging the life of the rope and of foretelling probabilities of failure; but the method which the committee proposes to adopt, namely, to examine samples cut off from the ends of winding ropes when re-capping takes place, is decidedly open to objection. *Whilst it is a fact that winding ropes very rarely fail at the cappingg, it is nevertheless certain that the end of the rope where it enters the capping is liable to much more severe corrosion than any other part of the rope; where ropes are capped by running in white metal, local galvanic action may be expected, and, in any event, this is the point at which acid water, however produced, is most liable to accumulate. On the other hand, the end of the rope is never exposed to bending stresses, which affect every other portion of the rope as it passes over the pit-head pulleys and round the winding drum. These stresses, with the consequent alternation of stress, are bound to have a more or less injurious effect upon the rope, and this effect will be entirely missed by investigations confined to the end of the winding rope. There is no doubt that winding and haulage ropes constitute a vast field for investigation, and it is highly satisfactory to learn that a systematic attack upon these problems has now been commenced. Among other researches of importance is one upon the improvement of the lighting efficiency of safety lamps, both electric and flame lamps, and the report certainly suggests that a very considerable measure of success has already been attained. The publication of the full account of this work will be looked forward to with much interest. Researches upon coal dust and firedamp explosions and upon mining explosives are, of course, being steadily continued. Naturally, this aspect of the work is very closely connected with operations at the Buxton Research Station, the official opening of which took place only a few weeks ago. There is no doubt that the geographical position of this station is an immense improvement upon Eskmeals, and the experience gained by the latter station will no doubt have been fully utilised in the design of the new station, so that this may be fully equal to all the work required of it, both as a testing station and as a research station.Important results may be expected from the electrical researches in progress, the ultimate object of which is to obtain electrical appliances which shall be absolutely safe for use in underground work even in fiery pits. Other subjects which are briefly dealt with in this report arc researches on the spontaneous combustion of coal and the investigation of certain defects in mine rescue apparatus, which have been found in practice to cause inconvenience; the report indicates that remedies for these defects will in all probability be forthcoming as the result of these researches. There is a brief reference to the constitution and the work done by the Health Advisory Committee, which has now been brought into closer relationship with the Safety in Mines Research Board by the appointment of Sir Edward Troup as chairman of both. The report contains two interesting appendices, one being a programme of the researches of the Board which are either in progress or under consideration, and the second a report on the co-operative researches that are being carried on jointly by the United States Bureau of Mines and the Safety in Mines Research Board. It is sincerely to be hoped that this scheme of cooperation will be further extended until it embraces all the researches carried on in all the coal-mining countries of the world upon objects identical with those of the British Safety in Mines Research Board.1 Mines Department. Fifth Annual Report of the Safety in Mines .Research Board, including a Beport of Matters dealt with by the Health Advisory Committee, 1926. Pp. 55. (London: H.M. Stationery Office.) 9d. ne

ISSN:0028-0836    

DOI:10.1038/120249a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE third and final volume of " The Forests of India " is divided into two parts, the first of which deals with the period 1871-1900, and contains brief descriptions of the main features which affected progress in forestry in the different provinces. The period covered by this section of the book corresponds more or less to a definite stage in the development of Indian forestry. It is the period of reservation and demarcation of an area to be permanently maintained under forest. In reading Part 1 of this volume it is important to realise that India is not homogeneous. Apart from differences in geographical, topographical, and climatic conditions, which result in different forest types and therefore different forest values, the provinces themselves were in varying stages of development and had different histories. Different forms of land tenure existed, and the people differed in local customs and methods of cultivation. Prof. Stebbing devotes a separate chapter to each province and gives us an outline of the difficulties to be overcome.In all countries the history of progress in forestry is the history of the education of the people, and in . India a second factor existedgthe need for educating the civil authorities. All through w.e find instances where the latter were antagonistic, or at least unsympathetic, to the Forest Department, and although this may appear to be an unusual feature, it has its explanation in what is described as " a supersensitiveness on the part of the civil authorities on the question of the rights of property " and their reluctance to interfere unnecessarily with local customs. Examples are quoted where this attitude was undoubtedly carried to extremes; but considering the past history of India, this feature was largely unavoidable and its delaying effect may not have been unduly great. The factors which were primarily responsible for progress were economics, and examples are to be found in most provinces. The visible effects of the destruction of forests on the water supply and erosion, the increasing demand for and the diminishing supply of cheap fuel and timber, were the things which finally convinced local governments of the need for defining a policy with reference to forest areas.During the thirty years under review, India was fortunate in having at its disposal the services of three very able Inspectors - General, Brandis, Schlich, and Ribbentrop. Prof. Stebbing quotes largely from the reports of these officers, particularly those of Brandis, whose energy and driving powers were amazing. It is impossible to deal with all the aspects of the developments which are mentioned in Prof. Stebbing's book; but perhaps the most striking fact is the dependence of progress on the close cooperation between the Chief Forest Officer and the local government on one hand, and on the maintenance of friendly relations between the Divisional Forest Officer and the local inhabitants on the other. Where these two conditions exist, the progress of education goes on smoothly and with the least delay.In other branches of forestry developments were also taking place. In Burma, the United Provinces, and the hill divisions of the Punjab, forests were being worked under regular ' working plans,' and in Ajmer-Merwara and the plains of the Punjab we find the first attempts to re-afforest areas, where the destruction of forests had proceeded too far. By the end of the last century the progress was such that the area under forest compared favourably with that in other countries in Europe and elsewhere, the general lines of forest policy had been definitely laid down in all provinces, and the forest service was firmly established. Part 1 of this volume is a striking tribute to the first three Inspectors - General.In Part 2, Prof. Stebbing deals with developments between 1901 and 1925, and in the opening chapter he gives a short review on the administration of India during this period. In the following chapter, which is devoted to forest administration, he points out how sylviculture, working plans, utilisation, and research now take precedence over reservation, protection, and forest legislation. On p. 262, while acknowledging the debt owed to the first three German Inspectors-General, he would have us believe that the very rapid progress in recent years dates from the change to English Inspectors-General and, in particular, from the inauguration of the Imperial Research Institute in 1906. If this is to imply that the formation of a research branch is the cause of the rapid development, this is an opinion which will not be accepted by many forest officers in India, and it is preferable to continue to look upon the progress made as a natural evolution governed by economic factors, such as the growth of Indian industries and the stimulus of the War. The figures on p. 622 in the chapter on yield and revenue for imports of railway sleepers, which increased 'in value from less than Rs30,000 in 1919 to nearly Rs40,00,000 in 1923, speak for themselves. The sanction of the large sum of money for the new Research Institute was feasible only on account of the economic need for expansion in research, particularly in the branch of forest economy. We find the same rap d advance in other branches, sylviculture, working plans, and utilisation, the splitting-up of territorial charges and increases in staff, due not to forest research but to the forests becoming economically more important to India.The chapter on forest research is of particular interest and well illustrated by photographs, which give some idea of the scale on which the new Research Institute is equipped. The author also deals with advances in sylviculture, afforestation, -fire-protection, working plans, and exploitation, and in Chap. xiii. discusses forest education and the training of probationers for the Indian Forest Services. In this chapter he expresses opinions which will not find favour with all, particularly on the subject of " training under subsidised German Forest Officers " and on the value of tours on the continent of Europe. On the question of Indianisation and the future training of Indian probationers, now 75 per cent, of the annual recruitment at Dehra Dun, Prof. Stebbing appears pessimistic. In Chapter xvi., on sylviculture, he admits that "at the present day work on as high a plane as anything on the continent of Europe is to be seen in India." He proceeds to qualify this statement by "the proviso that these methods have been so far only applied to a comparatively small area," and gives it as his opinion that " India is not yet in a position to.afford as valuable a training ground as exists in Europe, because with few exceptions no Indian forest has yet passed through a whole rotation." Some of those who have had experience in teaching forestry at Dehra Dun and have also re-visited continental forests, will be inclined to think that Prof. Stebbing has been too emphatic on this point. Whatever views are, however, held on this point, it is now the accepted policy of Government to train three-quarters of the future probationers in India, to be followed by a visit to the continent after three years in a division, and, as is pointed out, it rests with those responsible for the selection of the right type of probationer and for the control of the new training centre, whether the future is to be retrogressive or otherwise. Prof. Stebbing's book contains a vast amount of information on all aspects>ofo Indian forestry and is essentially a historical record of a department of which India may justly feel proud. It is as a history rather than as a critical work that the book is of value. Little need be said on the arrangement of the book or the subject matter. The author has had to deal with a large subject, covering a period of time during which conditions were changing very rapidly. He must have experienced considerable difficulty hi selecting from the mass of official reports and papers those which could most suitably be included to illustrate half a century of forest progress.Prof. Stebbing is to be congratulated on having compiled a history, which gives so many concrete facts about one of the departments the activities of which are carried on far from the public eye, and on the excellent photographs with which the book is illustrated. In his preface the author expresses the hope that he has been able to show that the Indian Service can take rank with some of the most organised forest services in Europe, and those who read his book will agree that he has achieved his object.

ISSN:0028-0836    

DOI:10.1038/120251a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ONE of the most formidable obstacles to the progress of science at the present day is the manner in which it is progressing. The continuous increase in the number of research workers and in the scope of their investigations cannot be a source of unalloyed satisfaction to the earnest seeker after knowledge, who before ever he begins a research must delve long and laboriously in the files of countless periodicals in order to discover just where he should begin. There are abstracts, it is true, but they are seldom adequate; in practice one finds them chiefly useful in facilitating reference to the papers really relevant to one's purpose. From this point of view they are often extremely valuable, but from time to time in the development of a subject the need becomes urgent of a pause to review the results obtained and to consolidate the advances made. It is a difficult task, demanding much labour, critical judgment, and breadth of vision. A mere compilation is not enough, for in the study and co-ordination of so many researches numerous problems are bound to arise which call for immediate investigation with the object of removing discrepancies or establishing generalisations. Yet the compiler must exercise a nice discrimination in embarking on such researches, for publication cannot be long delayed if the work is to be up-to-date and not unduly littered with " notes added in proof." Obviously, then, it is not a task to be undertaken lightly; but on the other hand, if well done, it should be of inestimable value, not only to the worker in the particular region surveyed but also to those in neighbouring fields as well. The time was undoubtedly ripe for such a review of band spectra. In the last ten years a rich harvest of results has been reaped, but scarcely garnered, and the phenomena in question are of such a complex character that no survey could be adequate unless planned on a rather considerable scale. For this reason the National Research Council did wisely in entrusting the task to a committee rather than to an individual. In the present case the consequent loss of homogeneity is certainly outweighed by the gain in authoritativeness. There are five contributors: two of them (Kemble and Page) deal with the theoretical side of the subject, and the other three (Colby, Birge, and Loomis) mainly with the experimental, under the headings of infra-red absorption bands, electronic bands, the isotope effect, and fluorescent band spectra.The second of these sections is by far the largest, comprising in fact more than half the book. This is natural enough, since bands of the electronic type (i.e. involving changes of electron configuration) are both the most complex in structure and the most accessible to investigation. Prof. Birge's task must have been an exceedingly difficult one, particularly in view of the rapid progress which has recently been made in the interpretation of optical bands, but he would probably be far from regretting the undertaking, for the researches which presented themselves in the course of the work have had some notable results. For example, they led him to the recognition of the essential similarity between molecular and atomic electron transitions, a conclusion of great importance and fruitfuliiess. Congratulations are due to him upon an extremely valuable piece of work. The other sections also contain much that is interesting and suggestive. In the account of infra-red absorption bands (Colby) one would have been grateful for a little more information concerning the far infra-red region, so full of difficulty and promise. The section on fluorescent band spectra (Loomis) deals actually with that of iodine only, but the facts described are certainly of sufficient interest to justify the allocation of a whole chapter to them. It seems to the writer that the discussion here is not quite so easily followed as could be wished, but this may be a merely personal difficulty. Chapter v., also by Loomis, is a very useful account of-the isotope effects occurring in band spectra. Up to the present these observations have served mainly to confirm band spectrum theory, the isotopic constitution of the elements being already well established, but it is not improbable that they may find wider applications in the future.The final chapter, by Prof. Kemble, is a masterly survey of certain theoretical aspects of the subject. The account of Hund's recent work on bands will be found particularly valuable, and the section on the Zeeman effect also calls for special mention, providing as it does a basis for discussion and extension of the rather perplexing results already obtained in this connexion. One of the most valuable features of the Report is the systematic notation scheme which has been used throughout. Progress would be greatly facilitated if this were universally adopted by writers on the subject. The volume is admirably produced, and misprints are very few. There is a reference to the " first measurement " of the MgH band A5211 as by Watson and Rudnick (instead of by Fowler), but this may be nothing more than a slight ambiguity of construction. The bibliography, whilst professedly incomplete, is very extensive, but it is a great pity that no index is provided.

ISSN:0028-0836    

DOI:10.1038/120252a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE need for an inexpensive book on sex addressed to the interested layman and written by a trained biologist has long been recognised. It is true that there are many popular books dealing with this subject, written during recent years by sincere enthusiasts whose chief claim to authorship would appear to be an irresistible yearning to help their fellow-women; but the extent of the ignorance of established biological fact and the easy disregard of scientific method exhibited by these authors have forced the professional and responsible biologist to accept the task of democratising the knowledge that he possesses. Biology, and especially sex-physiology, is the field in which any and every one exercises his or her opinions. The chemist or physicist can speak of his science without interruption, for in it there still is magic, but let the sex-physiologist speak and his voice is at once drowned in violent controversy. Impressionistic, anecdotal, uncritical doctrine, born of desire and supported by insufficient and inexact observation, denies the logical inferences of dispassionate experimentation, and the people, eager for information and for guidance, are led along the road that leads to disappointment and disillusionment, while the eyes of many still remain blinded by hope. To the general public sex is still, in spite of the abundant fruits of the last five-and-twenty years of most profitable research, one of the great mysteries. It is high time that the layman should be told that, though as yet all concerning the details of the processes of sex-determination and sex-differentiation is not known, it is the case that the salient and significant features of these processes are already apprehended. The study of the chromosomes and of the internal secretions has revealed the precision and the wonder of the mechanisms concerned, and the advance in knowledge concerning sex has been such that already it is possible to control the expression of certain of its aspects. It is desirable that this knowledge should be placed before the public, whose lives are continually affected in one way or another by one or more of the various manifestations of sexuality; it is desirable that there should be made available a fair statement of current scientific opinion concerning sex; it was high time that some professional biologist, well equipped for the task and with a flai$ for interpreting scientific terminology into language readily understood by the man in the street and the woman in the home, should place his services at the disposal of those who desire to learn.Mr. J. R. Baker, provoked by the manifest need for such an exposition, has discussed the facts adequately, frankly, and rationally. In his book, addressed to students of biology and of medicine, the subject matter is well chosen and well arranged and the language is simple. It is written especially for those who Ipok to others for their creed. Among the well-sustained conclusions of many authorities are dispersed the personal opinions of the author concerning not only the biological but also the anthropological, psychological, and sociological aspects of his subject, and it is not always easy to distinguish between generally accepted facts and reasonable but personal point of view concerning the possible implication of these facts in relation to human affairs. The author writes with courage and with competence as one willing to accept the responsibilities of leadership and as one who sees the goal of human endeavour. In his praiseworthy attempt to democratise scientific knowledge he has deliberately avoided meticulous accuracy and any profound consideration of elaborate detail, and so the real significance of the general principles of the subject is not obscured. Since his teaching cannot be reconciled with the preferences and prejudices of the multitude who dedicate their activities to the dissemination of their own speculative but attractive theories and methods of controlling sex, the author must not expect that his teaching will be as widely followed as it deserves to be. He has, however, the satis faction of having written a book that must be of great value to any one who, being eager to hear of what is known and of what is reasonable, seeks to sit at the feet of somebody who himself has contributed quite notably to our knowledge of sex.

ISSN:0028-0836    

DOI:10.1038/120253a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the preface to this volume the author refers to the four lectures on religion delivered in King's Chapel, Boston, during February 1926, in which the train of thought which was applied to science in his Lowell Lectures of the previous year (" Science and the Modern World ") is here applied to religion. It is stimulating to read this book from the pen of one who can speak with such authority and experience in the realms of mathematics, science, and philosophy. The work is divided into four chapters, the first of which, " Religion in History," begins with the definition of religion: the theme developed is that religion is solitariness." Collective enthusiasms, revivals, institutions, churches, rituals, bibles, codes of behaviour, are the trappings of religion, its passing forms. They may be useful, or harmful; they may be authoritatively ordained, or merely temporary expedients. But the end of religion is beyond all this. . . . What should emerge from religion is individual worth of character." The emergence of religion is traced and four factors are exhibited-ritual, emotion, belief, rationalisation. " The bible is by far the most complete account of the coming of rationalism into religion," and the effect of travelling and trading facilities eventually produce a world-consciousness. The same growth can in essence be traced in India and China. In the last section of this chapter rational religion is described as the wider conscious reaction of men to the universe in which they find themselves. Generality is the salt of religion.The dogmas of such religions as Christianity and Buddhism, especially with regard to the problem of evil, form the subject of the second chapter, " Religion and Dogma." The contrast is seen in Buddhism as a metaphysic generating a religion, whereas Christianity has always been a religion seeking a metaphysic. The life of Christ is not an exhibition of overruling power; its glory is for those who can discern it and not for the world. Its power lies in its absence of fprce. It has the decisiveness of a supreme ideal, and that is why the history of the world divides at this point of time. There are three concepts on which religion is founded, namely, that of the value of an individual for itself, that of the value of the diverse individuals of the world for each other, and lastly, that of the value of the objective world. To the query of value and the attainment of light, comes the answer that religion is world-loyalty. In the greatest of all religious dogmas-What do you mean by ' God '?-there are three simple renderings of this concept: the first that of the eastern Asiatic concept of an impersonal order, and then the Semitic concept of a definite personal entity, and lastly the pantheistic concept. If the modern world is to find God, it must find Him through love and not through fear; the author emphasises the help of St. John in this direction, rather than the God of vengeance. The third chapter is metaphysical and leads up to God and the moral order: value and the purpose of God, body, and mind. The fact of the instability of evil is the moral; order in the world. The order of the world is no accident,; value, beauty, zest of life, peace of life, and the mastery of evil are all bound together, and the religious insight is the grasp of this truth in relation to the completed ideal of harmony, which is God.Finally, Prof. Whitehead investigates the application to religion of a contrast between ' dogmatic' and 'empiric.' Again, the divergence of the two traditions of Buddhism and Christianity is traced, with a reference to absolute idealism as a reaction for Buddhist metaphysics on the part of Western mentality. Meanwhile science had appeared as a third organised system of thought, and both Christianity and Buddhism, having unduly sheltered themselves from each other, were unable to reveal the requisite flexibility of adaptation demanded by the rise of science. Such men as Origen and Erasmus in the Christian Church have, at any rate, recognised the central importance of this adaptability. The book closes, with references to the nature of God as the complete conceptual realisation of the realm of ideal forms. The kingdom of heaven is God. God in the world is the perpetual vision of the road which leads to the deeper realities, God upon Whose wisdom all forms of order depend. It is certainly to be hoped that Prof. White-head's work will be carefully studied by all who mould current theological opinion.

ISSN:0028-0836    

DOI:10.1038/120254a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

CAST iron has a very limited literature in comparison with steel, and it is only lately that any considerable attention has been given to its scientific study, although isolated workers have attempted from time to time to elucidate its complex problems. The author of this little book has an extensive practical experience of the subject, and has been responsible for several improvements in technical practice. He therefore speaks with authority on matters concerning the foundry. Cupola and moulding practice are not dealt with, and the book is devoted to the chemical and physical characteristics of cast iron in their relation to its use in the foundry. The chemistry is not always correct, but the errors will not mislead the practical reader to any "serious extent. The vexed question of the relations between sulphur and manganese deserves more detailed; consideration than it receives here, but it is a Jj"pint on which an author scarcely dares to be dogmatic. In view of the author's personal experience, it is surprising that so little is said of casting in permanent moulds, especially by the centrifugal process, whilst one also misses a discussion of the various methods now adopted, mainly on the suggestion of German inventors, for obtaining strong and tough irons by heating the mould or by using high casting temperatiires, after controlling the chemical composition according to definite rules. Maurer's diagram is open to objection because it does not take into account the varying thickness of castings, but it is a useful guide, and can be modified to give graphical methods of calculating compositions which have proved to be of real use in the foundry, so that it should have been mentioned. The statement concerning vis cosity on p. 275 is incorrect, and is based on a misunderstanding. The work of Wimmer on the viscosity of molten cast iron was perhaps published too late for inclusion.

ISSN:0028-0836    

DOI:10.1038/120255a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

DR. HOGABTH has published his Sohweich Lectures for 1924 practically in the form in which they were delivered before the British Academy, his reason being that owing to the still imperfectly published state of the results of excavation, the time has not yet come for fuller treatment. In this he has been wise, for, well argued as are his conclusions, his method of treatment in lecture form serves to emphasise their still extremely tentative character. His kings of the Hittitcs are those of the Biblical narrative, the rulers of the southern Hittites, to whom reference occurs in the Chronicles of the historic age as holders of States to the north of Palestine in the earlier period of the Jewish monarchy. His purpose has been to illustrate their civilisation and to try to discover their origin and racial character. The evidence upon which Dr. Hogarth draws is that imperfectly published, as already stated, from the sites of Zenjirli, Sakjegeuzi, and Carchemish. In discussing the connexion with the Cappadocian Hittite, Dr. Hogarth is inclined to see a common origin rather than a direct connexion. For this origin he suggests we should look towards the east at the early part of the second millennium B.C. with a leaning towards its identification with the Mitanni. Dr. Hogarth by no means minimises our lack of knowledge bf this people, and his readers will fully agree as to the need for exploration of the northern area of Mesopotamia, in which their influence was dominant, before we arc likely to deal with any approach to finality in this and the other problems which he discusses.

ISSN:0028-0836    

DOI:10.1038/120256b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE present section of this work deals with animal and plant physiology and biochemistry, and consists of tables extracted from papers published during the years 1917-1922, arranged under appropriate headings. Very varied information may be found within its pages. Thus weight-relationships, the chemical composition of organisms and their organs and tissue fluids, and the toxicities of drugs are all included. The greater part deals with plant physiology and chemistry, but data on enzymes and the biochemistry of vegetable products are frequently of use to animal physiologists. The data are given in French, but the table of contents is also given in English, German, and Italian. They are compiled from a selected list of about sixty different journals. The work should be useful for quick reference on any particular subject.

ISSN:0028-0836    

DOI:10.1038/120257c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN theProceedings of the Anatomical Society of Great Britain and Ireland, just published in theJournal of Anatomy, there is a record (page 498) of a communication by Prof. H. H. Woollard on the innervation of voluntary muscle, which is of unusual importance from its bearing upon a question that is a matter of widespread controversy at the present moment. My purpose in directing attention to Dr. Woollard's observation, however, is not so much to emphasise its intrinsic significance as to suggest the possibility of an interpretation other than that adumbrated in his preliminary note.FIG. 1.-Dr. Woollard's preparation of a rabbit's muscle showing double irinervation. For more than fifty years the problem has been discussed whether striated muscle has a double nerve supply (in addition, of course, to the sensory nerves connected with the muscle spindles). Interest in this question has been revived during recent years by the observations of Prof. Boeke, of Utrecht, who claims that each individual muscle fibre is provided with two nerves, a modullated somatic fibre and a non-modullated fibre, which he oo regards as being sympathetic in origin. ' 15~-Wheii, in 1879, Tcheriev directed attention to the fact that the two types of efferent fibres, which twenty years previously Lionel Beale and others had detected in motor nerves, proceeded to different kinds of terminals, the medullated (Beale's " dark-bordered fibres") to the end-plates of Kuehne, and tho non-medullated (Beale's " fine pale fibres ") to grape-like endings, little attention was paid to the observation. For the opinion was then current that the fine muscle-fibres-even perhaps the spindles-and their nerves were the embryonic forms of the larger muscle fibres and their medullated nerves (see Koelliker's Croonian Lecture in 1862). In 1909 and the succeeding years Boeke revived interest in the matter onco more. He dissented from the earlier observations by claiming that both kinds of nerves proceeded to the same muscle fibres. Then the matter began to attract widespread attention, which was largely due to the fact that the attempt was being made to interpret tho phenomena of muscle torie in terms of the assumed sympathetic nature of the non-medullated nerves. After Prof. Boeke brought his preparations to London in 1921, my colleague J. P. Hill suggested to the late Prof. Kulchitsky, who had just come to work in this Department, the desirability of investigating once more the problem that had been the subject of his first original work thirty years earlier.In 1924, Kulchitsky published the results of this new research on the innervation of the muscles in snakes, in which he demonstrated once more, as Tcheiiev and many others had done previously, that the two types of nerves did not pass to the same muscle fibres. In other words, he was unable to discover any muscle fibre receiving both kinds of nerve fibres. Hence there emerged a sharp conflict between the results obtained by Boeke on tho extrinsic muscles of the eye in mammals and by Kulchitsky on the subcutaneous muscle of the body in snakes. During the last three years the qxiestion of the innervation of striated muscle has become a matter of acute controversy.>Doubt has been thrown upon the existence of non-medullated fibres in motor nerves, and in particular upon the claim that the non-medullated fibres were derived from the sympathetic; and alternatively the suggestion has been made that the type of innervation found by Kulchitsky in tho snake might not be found in mammals. Using tho methylene blue method of Staining, Dr. Woollard (after a very prolonged and laborious search) has been able to demonstrate (see Fig. 1) in the case of the superior rectus muscle of the rabbit, a double innervation conforming to that described by Kulchitsky in the case of the snake. The rabbit's eye-muscle, like that of the snake's body, consists of two kinds of fibres, coarse and fine. In both cases the coarse fibres are more than double the diameter of the fine fibres, and whereas the coarse fibres receive medullated nerves proceeding to typical end-plates, the finer muscle fibres receive only non-medullated nerves proceeding to grape-like endings, placed epilemmally upon the muscle fibres. Moreover, these endings are disposed in such a way (a number of them being connected with a single nerve fibre widespread on several muscle fibres) as to make it impossible that they could develop intq the ordinary end plates. Incidentally, the new observations of Kutchitsky and Woollard that the medullated fibres end hypolemm-ally and the non-medullated epilemmally, settle once for all the old dispute of sixty years ago (Kuehne, Koelliker, Beale, Margo, Bouget, Naunyn, and Bngel-mann) as to whether motor nerve fibres did or did not perforate the sarcolemma. As some do and others do not, each group of controversialists had some evidence to support their claims.The importance of Dr. Woollard's demonstration lies in the fact that it removes once for all the doubt as to the existence of this type of double innervation in mammals. It also proves that the two types of muscle fibres (and associated nerve fibres) are morphologically distinct one from the other. In his communication, however, Dr. Woollard lays particular emphasis on the fact that he has found this type of double innervation only in the case of the eye-muscles and not in any other part of the body. It is important, however, not to lose a sense of perspective in estimating the meaning of this observation. In 1882, Dr. L. Bremer, of the University of Strasbourg, described (Archiv. f. mikr. Anatomie, Bd. 21) non-medullated nerves ending in the muscles of the tongue and limbs in the frog (see in particular his figures 13 and 20) in precisely the same-manner as Dr. Woollard has depicted in the case of the eye-muscles of the rabbit. The coincidence is most striking and significant.In view of these facts, especially when taken in conjunction with the difficulty Dr. Woollard himself experienced in discovering such endings in the eye-muscles, the failure to obtain satisfactory proof of the presence of such nerve fibres in other mammalian muscles should not be assumed to imply their absence. When they are found so widespread in the muscles of the trunk, limbs, and tongue of amphibia and reptilia and in the ocular muscles of mammals, there is a presumption that one is dealing with a morphological fact that applies to all striated muscles. But it remains for future research to provide conclusive evidence for or against this morphological inference -a problem that Dr. Woollard proposes to investigate in the University of Adelaide.

ISSN:0028-0836    

DOI:10.1038/120258a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is a well-established fact that copper, gold and silver, in the native state, exhibit twinning on the octahedral plane.I have recently examined, by means of X-rays, structures in aluminium which resemble lamellar twinning, and a sample of native copper which contained large well-marked lamellar twins. Such structures are always to be found in copper and its alloys, as well as gold and silver, if the metal has been worked and annealed, but are rarely found in cast metals. In aluminium they are rarely met with, although this metal has the same crystal lattice. The orientation in both parts of the ' twin ' were determined. Two samples of aluminium were investigated, which showed the same relationship existing between them. These appeared to have one dodecahedral plane in common, but the one could only be derived from the other by turning one upside-down and rotating through an angle of 60°. The plane of junction between the crystals had no relation to the crystal structure of either. This was also the case in the copper sample. Here there appeared to be no important crystal plane or direction which was common to both parts. It has always been assumed that the banded structure in these metals represented twinning on the octahedral planes of the crystal, but the examples quoted above show that this is not always so. It will, of course, be necessary to compare a number of samples of all the metals mentioned with the view of arriving at any definite conclusions

ISSN:0028-0836    

DOI:10.1038/120259a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature