摘要:

X NGLING in the slow-running rivers of England ByA affords recreation for an ever-increasing number of artisans and other responsible citizens of our large industrial centres. Inexpensive opportunities of health-giving open-air amusements in the limited time they have available are becoming fewer as the population increases and greater distances have to be traversed before arriving beyond the outskirts of the cities. Since it is upon the health and contentment of the city and industrial workers that the prosperity of the country has come to rest, it has become a duty of the nation to conserve the facilities for this tranquil and pleasant pastime quite as much as to conserve the more valuable salmon and trout fisheries, all of which suffer from the effects of pollution by industrial and other effluents more and more as time goes on. With these objects in view, the Standing Committee on River Pollution was appointed in 192i, and, with the help of local sub-committees, and a growing weight of public opinion, it has already accomplished a great deal towards checking an increase in pollution, and in some cases in ameliorating the existing conditions. The problem with which the Committee is faced is not a simple one; it is not obvious how, in many cases, an industrial effluent can be rendered harmless, or sufficiently non-toxic and clear, so as not to damage life in the river or the amenities of the country side. Every such effluent must go somewhere or the industry be dislocated; its satisfactory treatment in the space available at reasonable cost frequently provides matter for research.An interesting problem of the moment is the satisfactory treatment and disposal of the large volume of water used for washing and transportation in the new beet-sugar factories. This wash water, besides dirt, contains organic matter in solution and suspension which, although comparatively harmless to fish life on leaving the factory, may become harmful owing to the development of toxic substances during the decomposition of the organic matter. It is often easy enough to determine whether a river is polluted, but quite another matter to gauge the extent to which life in the river will be damaged. Fish utilise as food a large number of organisms, animals as well as plants. The larger animals, such as the fresh-water shrimp and insect larvae, which serve as food for many species of fish, in turn feed on smaller animals and plants. In many cases the dependence of one on the other is direct and obvious: in others less so. The presence or absence of vegetation, even of the smallest forms such as diatoms, may play a considerable role in determining the conditions of life in a river, quite apart from their actual food value, since they afford harbourage to animals and assist in the self-purification of the water. hence it is clearly not the direct physiological effect of a polluting effluent upon fish alone which has finally to be determined, but its effect, if any, upon some necessary link in the food-chain and upon the flora.The need for the solution of problems such as these before satisfactory legislation can be introduced to cope with river pollution is obvious, and has been felt in countries other than England. In 1920 the Dutch Government established a central institute at the Hague for experimental work in connexion with waste waters generally, from which advice is now sought by local authorities administering the law against pollution of the canals and waterways, and by industrial associations seeking the most economical means of treating their effluents. In the United States many rivers are grossly polluted; for example, the river carrying the Chicago sewage is stated to be devoid of dissolved oxygen for a distance of twenty miles. There the question of rational legislation is beginning to attract attention, and many specific problems are presenting themselves. Since the laws of the country have allowed the rivers to be treated as a public sink, and in consequence vested interests in them as such have developed, it will doubtless be a difficult and very expensive task to cope with their purification. In Great Britain numerous surveys of rivers have been carried out and local pollutions investigated during the last five years by Dr. E. C. Jee, the technical adviser to the Standing Committee on River Pollution, and by several scientific workers resident in various districts. Upon the results of this work, action has been taken in a number of cases and has led to the abatement of nuisances, and the fact that sources of pollution are being investigated at intervals and reported upon undoubtedly acts as a deterrent against increased pollution in other cases.Besides this necessary survey work and investigation of local problems, a small scientific staff at the Fisheries Experimental Station, Alresford, have begun several lines of research fundamental to a proper scientific attack of many existing problems. With the final object of undertaking a complete biological survey of a river with particular reference to the effect of various pollutions upon the normal fauna and flora, methods have been evolved which aim at providing a quantitative, or, at any rate, comparable, measure of the abundance of life in different rivers or in the same river at different times of the year. Preliminary work showed that by far the greater proportion of the animal life (in the upper waters of the Itchen) lived either on the bottom or among the weeds which clothe it; ordinary dredges did not yield a representative sample. To obtain a representative sample of the smaller animals a frame with gauze bottom containing stones, etc., similar to the river bottom, was left for a week in the river, and the organisms which had migrated into it were then picked out and counted. It is anticipated that the various methods evolved will be of service in the examinations of polluted rivers, and also that results obtained will finally provide a valuable basis for comparison. Fish found dead are frequently posted to Alresford for examination, and as our present knowledge of fish disease is fragmentary and the fish often arrive after decomposition has commenced, giving rise to symptoms which may easily be mistaken for those produced in a fresh fish by poisoning, an attempt is being made to obtain further accurate knowledge of post-mortem conditions, particularly histological changes in the gills and alimentary canal due to poisoning.The need for investigations of a general nature is amply borne out; the Standing Committee on River Pollution in its recent report 1 states that it is " constantly faced with the lack of scientific knowledge necessary to devise a method of dealing with a particular effluent," and advocates the appointment of sufficient technical staff to elucidate, not only in the laboratory, but also by experiments at the source of pollution, the scientific questions which at present have no answer. The future of many rivers in Great Britain is clearly in the hands of the chemist and biologist, for it is upon accurate knowledge such as they alone can obtain that any satisfactory legislation must rest. The longer the necessary efforts to tackle the pollution problem in a comprehensive manner is put off, the more difficult and the more expensive will be the task and the greater the risk of failure.To allow the serious pollution which exists at present in some British rivers to continue more or less unchecked and to grow, which it undoubtedly will tend to do as the population and industries increase, is an evil greater than can be expressed in terms of decreased monetary value of the fisheries. Increased demands on the water supply in towns and cities as they enlarge have also to be considered. From before the time of Isaac Walton the rivers of England have been part of the nation's playground, a playground put to greater use as the population becomes denser, a heritage to preserve-unpolluted.I "River Pollution and Fisheries. A non-technical report on the work during 1925 of the Standing Committee on River Pollution." Ministry of Agriculture and Fisheries, London. 1a26. Price 6d.

ISSN:0028-0836    

DOI:10.1038/119001a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

LTHOUGH there is no reference to W. H. Prescott A in this book, its title, "The Indian Sphinx," and the author's frequent references to himself as the Oedipus who is solving the riddle, suggest thatPrescott's famous book " The Conquest of Mexico," which was published in I843, had made a stronger impression upon him than he is prepared to admit. Both in the introduction and the lengthy appendix, Prescott gave an impressive summary of the evidence which forced him to admit, although it is clear he was very reluctant to do so, " that the coincidences are sufficiently strong to authorise a belief that the civilisation of Anahuac was in some degree influenced by that of Eastern Asia." At the same time, perhaps from having read Robertson's History, he was puzzled to account for the scores of arbitrary likenesses between the customs and beliefs of ancient Mexico and Asia. Thus he wrote: "Was it [the pre-Columbian civilisation of Mexico]indigenous ? or was it borrowed in some degree from the nations in the Eastern World ? If indigenous, how are we to explain the singular coincidence with the East in institutions and opinions ? If Oriental, how shall we account for the great dissimilarity in language, and for the ignorance of some of the most simple and useful arts, which, once known, it would seem scarcely possible should have been forgotten ? This is the riddle of the Sphinx, which no Oedipus has yet had the ingenuity to solve." If there were any real scientific discipline in ethnology, one might have hoped that Prescott's two difficulties having now been removed by the advancement of knowledge during the intervening eighty years (which have also added a vast accumulation of evidence in corroboration of the clear implications of the statement in " The Conquest of Mexico ")., the way would be clear for the frank admission of the diffusion of culture from eastern Asia. But in ethnology emotion still counts for more than reason: or perhaps it would be more explicit to say that the Newtonian principles of inductive reasoning, by basing theories on observed facts, have not yet penetrated into the subject, which is still under the sway of the deductive methods of Descartes. For in ethnology-and Prof. Imbelloni's treatise is a conspicuous illustration of the point-the dominating principle is still to force the evidence into conformity with certain catch-phrases that are called ' natural laws,' the idles innes of Descartes, the Elementargedanke of Bastian, the universal symbols of Freud, et cetera, from which a long line of philosophers, starting with Turgot in I75i, have been striving to rescue the study of mankind and make a real science of it.For the introduction of confusion into the fascinating problem of the origin of the pre-Columbian civilisation of America, as indeed into all ethnological doctrine, the chief blame must be attributed to Dr. William Robertson, Principal of the University of Edinburgh, whose famous " History of America " was published in 1777. He seems to have been the first to give wide currency to the Cartesian ideas that are so popular in ethnology to-day. " When the people of Europe unexpectedly discovered a New World, removed at a vast distance from every part of the ancient continent which was then known, and filled with inhabitants whose appearance and manners differed remarkably from the rest of the human species, the question concerning their original became naturally an object of curiosity and attention. The theories and speculations of ingenious men with respect to this subject would fill many volumes: but are often so wild and chimerical that I should offer an insult to the understanding of my readers if I attempted . . . to enumerate or refute them." After mentioning some of these speculations he adds: " though they rest upon no better foundation than the casual resemblance of some customs, or the supposed affinity between a few words in their different languages, much erudition and more zeal have been employed to little purpose, in defence of the opposite systems."Hence, without bothering to examine the evidence, the Scottish historian fell back on the device of formulating a law. " Were we to trace back the ideas of other nations to that rude state in which history first presents them to our view, we should discover a surprising resemblance in their tenets and practices; and should be convinced that, in similar circumstances, the faculties of the human mind hold nearly the same course in their progress, and arrive at almost the same conclusions." I have made these quotations from the work of this eighteenth-century divine because they represent the stock-in-trade of those who claim the independence of American culture to-day. Hence they shed some light upon the interesting psychological problem of why theories that are in such flagrant conflict with the evidence should continue to be respected. The explanation is provided by the history of these fallacies. Although Robertson wrote his book more than twentyfive years after Turgot (who had acquired the Newtonian discipline of reasoning from Sigorgne, his teacher of mathematics), Scotland, as Buckle pointed out in his " History of Civilisation," still remained under the influence of Descartes and the deductive method. These ethnological fallacies were floating about for another century without being taken seriously, until in i871 Sir Edward Tylor adopted them from Adolf Bastian, the arch-enemy of biological evolution, and gave them a fashionable and attractive veneer by calling them " evolution." By this strange irony more than fifty years ago, ethnology was put into the fetters of Cartesian scholasticism. These historical facts help us to understand how such a book as " The Indian Sphinx " could have been written.The problem of the pre-Columbian civilisation of America, with which the book deals, is of crucial importance. Not only was it responsible, as I have just indicated, for shaping ethnological theory in the past, but also at the present it is the supreme test of clear thinking. It is becoming a habit on the part of those who defend the principle of the independent development (in other words, spontaneous generation) of culture, to pretend that they do not deny the reality of diffusion. But the American problem demands a plain answer to the question whether or not any cultural influence was conveyed across the Pacific Ocean during the first ten centuries of the Christian era. Did Mexico, Central America, and Peru derive the germs of their civilisation from Cambodia and Java fifteen centuries ago, or was it a wholly indigenous creation of the Maya and preInca peoples ? That is the clear-cut issue. In this large treatise the various theories, ancient and modern, that relate to the origin of American civilisation are submitted to critical examination. In the first two-thirds of the book the author pours scorn on all theories of diffusion, adopting the extreme form of Bastian's theory of psychic unity. When the resemblances between cultures in different areas seem to put too great a strain on this speculation, he falls back on the biological theory of convergence. Hence it comes as a shock to the reader when on p. 279 he throws the Elementargedanke overboard and becomes an outand-out diffusionist. He has no doubt thatthe South America were derived from Polynesia. The magic wand that seems to have effected this wonderful transformation is the fact that the name for an 'axe' (toki) and the mode of fashioning the implements are essentially identical in Oceania and South America. But having convinced himself of this fact he then proceeds to discover identities in other arts, customs, beliefs, and languages, and adopts whole-heartedly the methods he has been ridiculing in the preceding 270 pages ! This admission, however, creates new difficulties for Prof. Imbelloni. If certain words in the languages of Tonga, Samoa, and Tahiti are identical with those used in Peru, much more definite affinities can be detected in the languages of Indo-China and India. The derivation of the cultures of Oceania from India is widely admitted. Hence he is committed to the linking up of pre-Columbian American culture with that of India, which in the light of recent discoveries is known to be genetically related to those of Elam, Sumer, and Egypt. These links are all now well established, as Prof. Breasted has recently pointed out.After an incomplete survey of the discussions of the seventeenth and eighteenth centuries, more than a hundred pages are devoted to certain modern speculations regarding connexions between America and Mesopotamia by way of Siberia and Turkestan, in the course of which essays on the evolution of the horse and the geographical distribution of the grape vine are introduced. The author examines and severely criticises Posnansky's attempt to apply to the ancient American pyramids astronomical methods for estimating their age somewhat analogous to those used by Sir Norman Lockyer in the cases of Stonehenge and Egyptian temples. Posnansky's calculation for Tiahuanacos gives a date of A.D. I200, which seems not unreasonable: but Imbelloni says it is based on a series of errors. Prof. Imbelloni's most scathing denunciations, however, are reserved for Part iii. of his book, in which he pours ridicule on what he calls " the Manchester School" and upon the present reviewer in particular. The bulk of this criticism follows the lines with which readers of NATURE have been made familiar during the last fifteen years, in particular in the discussion of the conventionalised elephant heads on the Copan stela (see NATURE, November 25 and December i6, I925, and January 27, i9i6; also the interludes by Dr. Forbes and Mr. Robson in August 2 and September I3, I924). As Prof. Imbelloni is not acquainted with anything that I have written on these matters since I922 (most of his knowledge of my work having been derived from Dr. Germain's review in L'Anthropologie of that year), I need only direct his attention to the full statement on the elephant-problem in my book "Elephants and Ethnologists " (1924). But Prof. Imbelloni's indignation with me would be quite excusable if I had ever expressed the preposterous views he attributes to me when he says I pretend the Mayas and Peruvians came from Egypt ! The confusion of race and culture vitiates in fact a large part of this entertaining book.Prof. Imbelloni has rendered a very useful service in emphasising the remarkable identities between certain features of Mycenaean and Mexican architecture (Plate III.), Egyptian and Peruvian balsas (Plate XI.) (of which, unaware of the various memoirs I have written on ancient shipping, he seems to think I am ignorant), the monstrous figures (Plates XIV. and XV.) with projecting tongue in Italy, Polynesia, and Mexico (and he might have added India, Indo-China, and Indonesia), the wonderful terraces of the Philippines and Peru (Plate XVI.), et cetera. But it is very surprising that such striking illustrations of identity in arbitrary detail should be used as illustrations of convergence in that part of the book which is expounding the principle of the diffusion of culture from Polynesia to America. At the present time scarcely any two believers in 'independent development' are in agreement as to the areas which are independent the one of the other. Prof. Imbelloni's book gives a new reshuffling. To illustrate the extent of these discrepancies I might mention that on the day his book came into my hands there also arrived a work by Prof. James H. Breasted, who admits the reality of diffusion from Egypt throughout the Old World, but refuses to admit any outside influence in America. Prof. Imbelloni denies diffusion in the Old World but admits that from the Pacific to America.If we allow the negative parts of the two views to neutralise one another and admit the cases both writers have established by positive evidence, I think we shall arrive at the truth.

ISSN:0028-0836    

DOI:10.1038/119003a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIS monograph on a subject of outstanding in1terest will commend itself under its sectional title to a wide circle of workers as an important and timely critical survey. The author's treatment of the matter, however, is much more comprehensive than might be inferred from the title, for it embraces the full perspective, and the work is consequently a contribution to natural history, and, beyond the phenomenal aspects of plant life, to general philosophy. The scope of the monograph, in fact, is first to set out the very considerable chemistry of lignin resulting from the investigations of some three hundred workers whose researches are critically reviewed in the text, and then to re-examine the scientific material thus accumulated, critically selected and co-ordinated by the author, in relation to the several sections of the science of botany, systematic (classification), physiology, structure and histology, to modern conceptions of the ultimate structure of the forms of matter, to the scientific technology of industry, and thus implicitly to the philosophy of the hurhan story, intimately interrelated as it is with that of plant life and evolution. The philosophic note is struck early in a critical discussion of the well-known methods of identifying lignin in plant tissues, and the resulting definition of " Das genuine Lignin " as distinct from the NI lignins isolated by chemical treatment, which are either synthetic derivatives or modified forms of the actual or original lignin, the degree of change associated with the reaction mechanism of the process of separation requiring to be estimated, but necessarily by a method which is inconclusive in respect of the actual relationship. It certainly leaves undefined the mode of union of lignone to cellulose in the ligno-celluloses; and the author's treatment of this problem in the later chapters will impress upon the chemist of objective mentality the obvious but much-ignored consideration that the synthetical operations of the plant in respect of its organised cell structures are not of the order of reversible reactions of his systematic text-books.A short outline of the work in sequence of chapters is necessary to characterise more closely its scope. Chaps. i.-iii. are concerned with (I) the identification of lignin in situ; (2) the isolation by various methods, direct (conversion to derivatives rendered soluble) and indirect (breakdown of associated cellulose to soluble products); (3) analysis, that is, elementary composition and estimation of 'adjective ' substituting groups, and a critical comparison of the numerous ' lignins ' thus separated with the genuine or ideal lignin of the organism. Chaps. iv.-vii. deal with the further special chemistry of lignin: conversion to synthetical derivation involving reactions of OH, CH= CH, CO and COOH groups, esters, ethers, halogen derivatives, condensations with phenols, reactions with oxidants and hydrogenants: hydrolyses and alkali fusions. This expose of the 'pure' or rather detached chemistry of lignin, occupying the first two hundred pages, is the author's critical digest of the literature of the subject of the period 1900–1926 (January I), a delimitation set out in the preface. It is accurate and exhaustive of the period though not of the subject matter, for the antecedent period (i875–1900) contributed quantitative methods of fundamental value as such, but of further import when interpreted as establishing the conception of ' ligno-cellulose ' by contrast with a cellulose extrinsically' encrusted 'with lignone matter. Moreover, it was clearly indicated, both a priori and on exact data, that the prototypes of the ligno-celluloses are the simpler structural forms of annual growths; whereas those of perennial structures are much more complex as such and by reason of secondary interior modification and condensations. The later research work dealt with in the present volume is largely devoted to the latter more complex types, which has inevitably complicated the treatment of the subject.To resume on the author's sequence of subject matter: in Chaps. viii.-xi. the subject is developed in terms of biochemical science and illuminated by a sustained argument which shapes the matter, treated in all its related aspects, to the satisfactory issue of converging proofs of definite theory. The subject of these chapters is lignification as an organic process: first, in relation to systematic botany; that is, to the grades of differentiated organic structure from the Thallophytes, with the first appearance of lignification in the Pteridophytes, to the most highly elaborated Phanerogams.Histological investigation has already recognised an ascending series of types of lignification in close correlation with the evolution of structure; but the author points the way to a positive biochemical treatment of this enormous range of material, hitherto classified certainly without direct reference to lignification. As an illustration of such biochemical method, he briefly discusses the prolonged investigations of Carl Mez, applying his sero-diagnostic processes to the exploration of generic affinities (Bot. Arch. Kinigsberg, I9ii et seq.), pointing out, however, that the method is indirect and otherwise subject to error. It is clear that the body of exact knowledge of lignin, the subject of the preceding chapters, supplies a basis of re-investigation of the vegetable kingdom, by indirect method, which he predicts will establish Ligninbildung as a critical index of evolutionary development; and outside this objective of science such re-investigation promises a number of collateral developments. In the next chapter, ix., under the sub-title " Entwicklungs-Mechanik," the organic process implicitly postulated is considered in relation to its factors. Lignification is a primary vital effect, but developed paradoxically pari passu with loss of vitality and cessation of growth. But the author refers to a ' post-mortem ' activity which supervenes, a respiratory consumption of oxygen at the expense of elaborated cell-wall material; the removal of oxygen followed by complicated condensations, yields as a final product the lignin or lignone complex. It is suggested that the arena and basis of these transformations is the middle lamella of the cell-wall, and evidence of the contributing functions of its pectic components is afforded by the special chemistry of this group of carbohydrate derivatives established by later researches which are fully discussed.In further development of the conception of the lignin-cellulose complex or ligno-cellulose as a biologic unity or individual, the author boldly grapples with the problem of cellulose constitution. While giving full value to chemical methods and results, attention is rather directed to the physical-biological interpretations of Rbntgen spectrographs, to the ultimate configuration of an anisotropic colloid, as a ' cristallite ' in evolution to organic form through micellar growth. This text definitely formulates a cellulose lattice and a penetration of the isotropic lignone so intimate as to represent a pseudomorph. Chap. x. deals with the transformations of the lignocelluloses and generally of cellulosic structures in fulfilment of ultimate natural functions.In regard to lignone proper, this is characterised by its well-known extraordinary resistance to reaction, and the only change in living structures which can be traced is in contributing to the formation of phyto-melan. The enormous range of breakdown processes which result in humus, peat, and the various grades of coal, are discussed with general reference to lignin, and also the author's theoretical conceptions in the foregoing text, with reference both to cellulose, pectins and hemi-celluloses, and to the constitution of the lignone complex.Chap. xi., under the title " Theorien uber Lignin," is a concentrated summary; that is, the author's conclusions on the whole matter. Chap. xii., and last, is particularly noteworthy. The subject is the technology of lignin and gives the author's scientific rationale of the leading industrial processes for the treatment of ligno-ceoses, such as destructive distillation, pulp manufacture by both acid and alkaline processes, partial resolution of ligno-cellulose structures (cereal straws) to serve as cattle food-stuffs, the production of sugar from wood and wood residues. Avoiding details of the manufacturing processes, the author applies his reasoned conceptions both of the proximate and of the ultimate constitution of ligno-cellulose matter to the elucidation of the reaction mechanism of the several industrial processes. This discussion has distinction as a critical illustration of the sound method of applying science to industry.In applying, in effect, the most modern and apparently recondite principles of modern science, the text of this chapter should be extraordinarily stimulating to those engaged in industry; not merely in perfecting routine operations but also in devising developments towards realising the progress inevitably suggested by discussion in relation to first principles. It will be clear from the foregoing that the author has produced a work based on an unusual range of appreciative study of the sciences in their most recent developments contributing to the elucidation of the general theme, which, primarily indicated by its title, extends to the natural history of the vegetable kingdom.We note in the text a considerable contribution of original investigations, which will probably be the subject of special publications in scientific journals. Lastly, the author is restrained in his criticisms of the researches of his fellow-workers; but a careful study of this work suggests that a notable proportion of the more speculative theories which they endeavour to establish will be excised from the student's memorabilia.

ISSN:0028-0836    

DOI:10.1038/119005a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

C INCE its foundation in 1767, officers and surveayors S of the Survey of India have accompanied every military expedition with which India has been connected. In order to provide a reserve of surveyors for war it has been the policy, as in most other countries, to employ army officers during peace time on the ordinary mapping of the country, so that they may be available at the outbreak of war to provide maps always required during the progress of military operations, though never so much as under the conditions which obtain to-day. There is no essential difference between peace and war mapping except that in the former case the work is of a more deliberate character, while in war it has, of necessity, to adapt itself to the exigencies of military operations. Until the recent War, tactical topographical maps on a scale of a half or one inch to the mile sufficed, but now trench warfare imposes much larger scales. Artillery maps, also on large scales, require to be of the highest order of accuracy to be of any practical value, while accurate control is required for the location of enemy guns. These new duties have largely enhanced the importance of the surveyor's work in war.On the outbreak of the War the Survey of India found itself in a position to provide, at once, officers and surveyors proficient in their art ready to take the field in accordance with its long-standing traditions. As the War went on, the call for officers became so insistent for survey and other duties that of the 54 regular officers employed in the Survey of India, 49 went on active service outside India. Of these eight were killed-all officers of the Royal Engineersand eleven wounded. Of the 44 civilian officers who took part in the War, two were killed and two wounded. In addition, five Indian surveyors and 44 khalasis lost their lives in the service of the Empire. The volume before us is a record of the operations carried out by the officers and surveyors in Mesopotamia, Kurdistan, Macedonia, Arabia, Persia, Palestine, East Africa, and Afghanistan. These explorations and surveys were accomplished in face of many difficulties and in every variety of terrain, from the icy highlands of Central Asia to the waterless deserts of Persia and Arabia. The total area thus explored by members of the department, often in unknown and unmapped regions, is almost comparable to that of Europe, while trustworthy new surveys, based on fixed points, covered an area more than twice that of Great Britain. In addition to a graphic description of the adventures that befell the surveyors in many lands, there is much valuable technical information to be found in the reports as to the methods of survey adopted, suitable to the different situations which presented themselves, and as to the climatic and political difficulties encountered.The larger portion of the volume is naturally devoted to operations in Mesopotamia and Persia, where by far the greater part of the mapping was carried out. It is a record of intense devotion to duty on the part of officers and surveyors; nor must we forget the Indian survey khalasi, whose devotion to duty, whether in peace or war, though occupying but a humble sphere, ranks high among the servants of Government. A roll of honour is included, and there are a number of photographs illustrating the different types of country concerned, as well as a series of index maps showing the areas actually surveyed. On the whole, this is a most interesting history of survey in war, and its production reflects the greatest credit on all concerned.

ISSN:0028-0836    

DOI:10.1038/119007a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

AN account of the second conference of the Institut International de Chimie Solvay, held in Brussels on April i6–24, I925, has already appeared in these columns (May 23, 1925, p. 8I7). It is therefore only necessary to note briefly the publication of the official report of the conference. This includes individual reports by Sir William Hardy, Sir William Bragg, Prof. W. L. Bragg, and M. Duclaux, on the structure of primary films, of crystals, and of solid colloids, and reports by Prof. Lowry, Prof. Swarts, M. Tiffeneau, Prof. Perrin, Prof. Job, Dr. Rideal, Dr. E. F. Armstrong, Prof. Moureu, Prof. Armstrong, M. Duclaux and Prof. Euler on various aspects of the mechanism of chemical change. These reports, with the somewhat lively discussions which followed them, make up a volume of nearly 700 pages, which will be read with interest by many of those who did not enjoy the privilege of attending the Conference. The publication of so full a report represents a vast amount of work on the part of the editors, and they are to be congratulated on the successful completion of their task. The only obvious criticism of their work is that in the index to the volume they have introduced two novel examples of multiple personality, by ascribing one report to MM. M. Eric et K. Rideal, and another to the triple authorship of MM. Thomas, Martin et Lowry. One constructive suggestion may be made. Since the reports were first written in English or French, according to the nationality of the author, it would be a real advantage to be able to read them in the original language rather than in a necessarily imperfect translation. The printing of the final report in alternating French and English sections would surely not be a serious handicap to Belgian and French readers, whilst to English and American readers it would give a guarantee of authenticity and precision of phrasing that would be of even more value than the greater facility of reading in one's mother-tongue instead of in a foreign languag

ISSN:0028-0836    

DOI:10.1038/119008a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the Research Items in NATURE for September 18 and in correspondence in the issues of October 23 and November 20, attention has been directed to experimental work by Willey and Rideal (Jour. Chem. Soc., July 1926) which led them to suggest that active nitrogen consists of metastable molecules having an energy of about 42,500 cal. per gm.-mol. ( =about 2 volts).Such a view is, however, difficult, if not impossible, to reconcile with spectroscopic data. Ludlam and Easson have pointed out one type of difficulty in the case of the production of such a line as that at x2o6i in the iodine spectrum, which requires an energy of some I50,000 cal. for its excitation. In reply to this, Mr. Willey has suggested that a quasi-stable molecule may first be formed (such as N2,2)-presumably by impact of an active nitrogen molecule and an iodine molecule-the energy of which may be released by a second active nitrogen molecule and the total energy should be adequate to excite the iodine line. This, however, is scarcely possible, for the maximum energy which the break-up of the above semi-stable molecule could yield is that of the active nitrogen molecule which produced its formation. When this is added to the energy of the impinging active molecule it only gives as available energy of excitation twice that of a single active nitrogen molecule (which would, according to Willey and Rideal, be 85,000 cal.). In practice, the energy available for exciting the iodine line will be still less by the amount required to dissociate first the iodine molecule. As an alternative Mr. Willey suggests that the excited NO molecules which yield the p and y groups of the afterglow spectrum may be responsible for excitation of the line. In this particular case this is just possible, although it is near the limit which these molecules can possess. The (o, o) band of the p group requires almost 6 volts for its production, and even taking the extreme case that an excited NO molecule is loaded with vibrational energy up to the point of dissociation, its available energy would be only 7–9 volts or i82,000 cal. (vide Birge and Sponer, PhyF. Rev., vol. 28, p. 283, 1926). In general, therefore, activated NO molecules cannot account for all the spectra which active nitrogen is known to be capable of exciting.In accordance with the views expressed by Birge, Sponer, and others, it seems highly probable that active nitrogen is really atomic nitrogen, which is equivalent to an energy of II-4 volts (=263,000 cal.), and this appears as radiation in the ordinary process of recombination. Contrary to the implication of Mr. Willey in his letter to NATURE (November 20), this evaluation of the energy is not based primarily on the ability of active nitrogen to excite other spectra but on the nature of its own spectrum (i.e. the a group). The peculiar limitation of the first positive band spectrum, which it comprises, receives a natural explanation on the assumption that about II quanta of vibrational energy (=2-I volts) in addition to the 9.3 volts of electronic energy, are sufficient to effect dissociation of the N2 molecule. Consequences which follow from this have been verified by quite different lines of experiment (vide Birge and Sponer, loc. cit.). In explanation of their theory that active nitrogen consists of metastable molecules excited to about 2 volts, Rideal and Willey write that " to effect this excitation it appears that the molecule has to be excited to a high level (II-5 volts) but the electronic energy rapidly disappears after departure of the gas from the discharge zone...." This can scarcely be the case, for 2 volts energy are inadequate to account for the afterglow spectrum (a group), more especially as we now know that the final electronic state of the molecule after this emission is 8-o volts above the norma

ISSN:0028-0836    

DOI:10.1038/119009b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MANY cases are known in which the results of reciprocal crosses between green and variegated plants fail to agree. In all these cases the progeny reproduce the appearance of the female parent alone. Cases are also known in which a cross made one way between two true breeding green races results in variegation, whereas in the reciprocal cross the appearance of variegation is either deferred to a later generation or is absent. We know that the female contributes all, or the greater part, of the cytoplasm, and it has therefore been supposed that the cytoplasm, or its inclusions, is partly or wholly responsible for this difference in inheritance. Can this difference in the contribution of the male and female account for the dissimilar results of reciprocal crosses in other characters than variegation ?In crosses between the Tall and Procumbent races of Linum usitatissimum a peculiar abnormality (male sterility) occurs in the F2, and is inherited as a simple Mendelian recessive (Bateson and Gairdner, Jour. of Gen., II, 3, i92i). This character only appears when Procumbent is the female parent in the original cross. No male-steriles occur in Fi or F2 of the reciprocal cross of Tall by Procumbent. Male sterility, then, only appears when there is cytoplasmic continuity from Procumbent. We suggest that this difference in inheritance is due to a dissimilarity in the cytoplasms of Procumbent and Tall. Individuals of the Fi, and later generations resulting from the cross of Procumbent by Tall, would have cytoplasm contributed by Procumbent, whereas the progeny of the reciprocal cross would have Tall cytoplasm. Though a particular Procumbent gene, or group of genes, reacts normally in both cytoplasms, the corresponding factor, or factors, in the Tall, when homozygous in Procumbent cytoplasm, gives rise to male-steriles. This may be shown diagrammatically thus:Tall (a X Procumbent F I +~~~~~~~~~~ Fl i) F2 A) (9) (e 1: 2: 1 (all hermaphrodites) PIP Procumbent E] f Tall i9 1 I H, F2 [TT 2 P: P 2:' (mal e -sterile) (hermaphrodites) Mtale T T )X Procumbent (heterozygous j| hermaphrodites) Male-sterile ETiX Tall H (male-steritles) 0 =cytoptasnic constituent of the Tall. l= , , Procumbent. T =a gene, or group of genes, of the Tall. P =a corresponding gene, or group of genes, of the Procumbent.It will be noted that male-steriles crossed with the pure Tall race give only male-steriles. Hence the Tall race was considered by Dr. Bateson to be heterozygous for the element determining hermaphroditism, this element passing solely to the ovules, the pollen being devoid of it. Such phenomena of unlikeness in the genetical constitution of pollen and ovules Dr. Bateson called anisogeny, in opposition to isogeny, the normal state in which they are equivalent. The example of anisogeny in flax he attributed to somatic segregation occurring at the formation of male and female organs. In the course of last year, however, he considered the possibility of applying a scheme similar to that above described and illustrated, but, owing to two or three inconsistencies in the experimental material, he was not wholly satisfied with it. The inconsistencies remain; but critical evidence is now available in flax, which, though incompatible with the original interpretation, is in perfect harmony with that now proposed. Additional evidence is also provided by a similar case of anisogeny in Geranium, observed here by W. C. F. Newton and Miss A. Sverdrup (unpublished). It is perhaps needless to say that the present scheme does not apply to Matthiola, -or at least does not do so in any simple form.

ISSN:0028-0836    

DOI:10.1038/119010a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

AT the beginning of June 1926 a quantity of wood heavily infected with Teredo (probably allTeredo norvegica), taken from the experimental rafts moored near the Plymouth breakwater, was placed in one of the tanks in the Plymouth laboratory. It was left undisturbed for almost four months, and when examined at the end of September was found covered with fæcal deposits consisting of wood fragments cut away by the shell valves of Teredo and passed out by way of the exhalent siphons. These deposits were, on the average, rather less than half an inch thick, and when they were washed away there were revealed, projecting from the wood, great numbers of fine calcareous tubes, which on closer examination proved to occur always in pairs and to project from the openings of the burrows formed by the shipworms. Plainly the tubes had been formed around the siphons of the Teredo. They were of varying length, depending presumably on the thickness of the deposits, the longest being some two-fifths of an inch. The general appearance of the wood is shown in Fig. I.Photo.] [A. J. 5miith.FIG. 1.-Portion of wood badly infected with Teredo norvegica. The white objects are the protruding calcarerous siphonal tubes which appeared after the f.cal deposits had been washed off. In several cases the paired tubes can plainly be distinguished. Normally the external openings of the tubes of Teredo are very difficult to distinguish, consisting of a pair of minute openings ringed with calcareous matter out of which project the siphons and within which these are immediately withdrawn on stimulation. The presence of faecal deposits, which had accumulated to an abnormal degree owing to the lack of water currents to remove them, would tend to obstruct the passage of the siphons and so endanger the life of the animals within. The response of the animals to this abnormal and dangerous state of affairs was to lay down calcareous tubes around the siphons, which by this means were able to maintain free contact with the water.Dr. W. T. Calman has directed my attention to the fact that the giant shipworm, Kuphus arenarius, which lives vertically embedded in the mud of mangrove swamps in the Pacific, normally has the siphons encased in this manner, a fact which was known to Rumphius so far back as I74i, and was figured by him (as Solen arenarius) in his " D'Amboinsche Rariteitkamer." This animal lives normally under conditions in which the Teredo in the Plymouth tank lived for some four months, namely, in constant danger of being suffocated by accumulating deposits-in one case of mud, in the other of faecal matter. This accidental production of calcareous siphonal tubes in Teredo is therefore of some considerable interest, since it provides a very striking case of an immediate and highly successful response by an animal to changed environmental conditions; a response, moreover, which has taken the form of a permanent adaptation in related animals living under conditions very similar to those accidentally produced

ISSN:0028-0836    

DOI:10.1038/119011b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WITH regard to Prof. Volterra's interesting article, “Fluctuations in the Abundance of a Species considered Mathematically,” in NATURE of October 16, page 558, I may be permitted to point to certain prior publications on the subject, of which Prof. Volterra seems to be unaware. The general theory as well as a number of special cases have been set forth in “Elements of Physical Biology” (published by Williams and Wilkins, Baltimore, 1925), in which work a considerable number of references to the journal literature are given. Among other things Prof. Volterra's diagram “Fig. 2” will be found on page go of the book cited; the expression for the period of isochronous small oscillations in the case of two species is also found on the same page. Prof. Volterra refers to certain applications of his analysis to problems of sea fisheries, to a passage in Darwin's “Origin of Species,” to extinction of species, to pathogenic germs, and to parasitology. An application to sea fisheries is found in the book cited on page 95; to a passage in Herbert Spencer on page 61; to the extinction of species on pages 94, 95; to pathogenic germs on pages 77, 79, 147et seq.; to parasitology on page 83.The effect of introducing a third species into a system of two species is discussed on page 94; the effect on equilibrium of changing various factors is treated in Chap. xxii., " Displacement of Equilibrium, " and, in particular, the effect on equilibrium between food and feeding species is analysed on page 289. The distinction between oscillatory and aperiodic systems, and its relation to certain quadratic forms, is referred to on pages 146, 148, and I59. It would be gratifying if Prof. Volterra's publication should direct attention to a field and method of inquiry which apparently has hitherto passed a

ISSN:0028-0836    

DOI:10.1038/119012a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE eggs of the coleopteran fire-fly,Luciola gorhami, found in the plains of the Punjab, have proved to be objects of rare value for the study of the problem of the origin of yolk. There are two kinds of yolk in these eggs: albuminous and fatty. The former arises directly from nucleolar extrusions of a remarkable type. At a very early stage in the growth period the nucleolus shows signs of intense activity and buds off numerous round bodies of different sizes, which are thrown out in the cytoplasm. The nucleolus continues to throw out these extrusions until the very last stage in oogenesis. At the beginning of this process the extrusions migrate towards the periphery of the egg-cytoplasm, where they grow in size, perhaps at the expense of food materials derived from the follicle cells.The whole process is reminiscent of what has been described in the cockroach and certain Hymenoptera by Hogben (Proc. Roy. Soc., I920, A, and I920, B) and in Saccocirrus by Gatenby (Quart. Jour. Micr. Sci., I922). Nucleolar extrusions preceding the appearance of albuminous yolk have, of course, been described in some other eggs, e.g. Lithobius (King, Scient. Proc. Roy. Dub. Soc., I924, and Nath, Proc. Camb. Phil. Soc. Biol. Sci., 1924) and Buthus and Euscorpius (Nath, Proc. Roy. Soc., I925), etc., but in Luciola it is noteworthy that the process of nucleolar budding lasts practically throughout oogenesis, and the process of the growth of nucleolar extrusions into the albuminous yolk spheres can be studied with diagrammatic clearness. The origin of the fatty yolk from the Golgi elements is no less clear. The latter exist in the form of rings and crescents. The rings might also be appropriately described as vacuoles (cf. ' vacuome' theory of Parat), with a sharp chromophilic rim and a central chromophobic substance (idiosome). When the solid osmicated fat spheres are decolorised in turpentine they also show a chromophilic rim and a central chromophobic substance, exactly like the Golgi rings. On further decolorisation they appear like clear vacuoles.We emphasise this morphological similarity between the Golgi rings and the fatty yolk spheres. It seems clear that the fat spheres arise directly from the Golgi rings, in the interior of which free fat, not miscible with the general cytoplasm, is deposited. In the undifferentiated germ cells the Golgi apparatus exists in the form of about four rings lying on the edge of the nuclear membrane, and we further emphasise the remarkable and unique fact that the Golgi rings of some germ cells are saturated with free fat long before the egg is differentiated from other cells.

ISSN:0028-0836    

DOI:10.1038/119013c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature