摘要:

GOVERNORS and other official representatives of the non-self-governing representatives the Crown, recent gathered together at the Colonial Office Conference of the function of scientific research in the development of the territories for which they are responsible, and the means by which this research is to be promoted. The outcome of their deliberations is the report on Colonial Scientific and Research Services which they approved and adopted on May 27, and is now available to the public in the published proceedings of the conference-the first of its kind. Prom the point of view of research, no more favourable time could have been chosen for this first conference. It has followed closely upon the visit of the Parliamentary Commission to East Africa in the latter part of 1924, the personal visit of the Under-Secretary of State for the Colonies to West Africa in 1926, the tour of Mr. Roy Wilson and Mr. Harry Snell to British Guiana this year, and the reports which were presented to Parliament at their conclusion, in all of which the dependence of economic development upon the creation of new knowledge and the application of existing scientific and technical knowledge was emphasised. Furthermore, it is only a few months since the Premiers and other representatives of the self-governing Dominions met, and were led to consider similar problems and approved a report of a sub-committee which they appointed on Empire research.The changed attitude of the Dominion premiers towards scientific research as manifested in that report was the subject of comment in these columns at the time. At the Imperial Conference in 1923 they sought for a solution of their economic problems in political expedients; three years later they decided to give science a trial. Upon this result the present political heads of the Colonial Office can be congratulated, for they have assiduously preached the gospel of science for the past two years. Under influence of the same stimulus, the representatives of the non-self-governing dependencies have reacted in the same way as the Dominion representatives. One of their first acts in conference was to appoint a committee under the chairmanship of Lord Lovat " to frame and submit a scheme, based on contributions to a common pool, for the creation of a Colonial Scientific and Research Service available for the requirements of the whole Colonial Empire, for the support of institutions required for that purpose, and for the increase of research and study facilities in connexion with the specialist services-of the Colonies generally."In the general statement of the problem the Committee has drawn largely upon, the information contained in the report of the Committee on Agricultural Research and Administration in the Non-Self-Governiiig Dependencies, of which Lord Lovat was also chairman. Its recommendations are almost identical with those put forward in that report, and follow the general principles enunciated in the report of the East Africa Parliamentary Commission for the effective prosecution and coordination of research. The modesty of its proposals, however, will be gauged from the fact that the scheme proposed for the reorganisation of the colonial agricultural services involves an annual expenditure of £175,000 in all, a considerable proportion of which is at present a charge on colonial revenues. This is a very small sum when regarded from the point of view of the needs of colonies covering a total area of roughly 2,000,000 square miles, the populations of which-mainly agricultural-number 50,000,000, controlled by thirty distinct administrations. It is illuminating to relate the cost of such a service to the exports from the colonies to the United Kingdom. These exports, mainly agricultural, have quadrupled in the last twenty years and amounted to £81,000,000 in 1925. In that year " they were greater than those from the whole of India, or from any single one of the self-governing Dominions." If the total agricultural exports of the colonials are taken into account, including rubber, the cost of the proposed service works out to ^ of a penny in the pound. The Committee states that so far " the aid of science has been but half-heartedly invoked," but it is difficult to see how this state of affairs is to be remedied with such meagre financial provision. The committee is well aware of the needs of research. It appreciates the fact that " there is severe and growing competition between the sources of raw materials and food-stuffs for the supply of the world's markets "; that " the ravages of diseases, particularly among the luxuriant conditions of tropical life, are ever increasing "; and that " science, and science alone, can enable us to increase production by improved methods, and, at the same time, combat successfully the diseases which these new methods bring in their train." It notes that the " United States, the area of which is one-third larger, and the population a little more than double that of our Colonial Empire, spends more than £4,000,000 annually on agricultural research"; and that Egypt spends nearly twice as much annually on agricultural entomology as the whole of the British colonial governments, most of which are faced with far graver problems than Egypt. Unfortunately, the committee gives no indication of the expenditure of France, Belgium, or Holland on agricultural research in their respective colonies; but we know that the Dutch maintain Buitenzorg splendidly while the Amani Institute is still lying derelict, untenanted, unstaffed; we know that the French are devoting much attention to the investigation of nagana (tsetse-fly disease in cattle), and are attempting to breed immune types, while we continue to starve the veterinary research stations in East Africa, and to expect the research staffs to devote a considerable proportion of their time to the preparation of sera for inoculating cattle against the various diseases which decimate the natives' herds.In view of the condition of affairs regarding research and research institutions and the scientific services generally, as disclosed in the various reports to which we have referred above, in fact, to the complacent indifference to science which characterises our colonial administration, and the statement of Lord Lovat's Committee that " there is no organisation whatsoever in the colonies which views the problems of science as a whole," we can but admire the forbearance of the committee in stating that it is anxious not to give the impression that it is trying to be dictatorial to the colonial governments. It is well, however, that it has obtained general consent to the establishment of a central fund maintained by contributions from the various colonies. This should ensure continuity of research, and safeguard the individual scientific officer against the excessive zeal of colonial governments to reduce their scientific staffs in times of financial stringency. The evident purpose of the committee's recommendations is to make the research services of the colonies attractive to the best type of worker, and this is certainly a great step forward. The committee felt itself unequal to the task, in the short time available, of formulating proposals for the creation of a unified research service, postulating as it does modifications in the organisations (existing and proposed), the creation of links between various sciences not only in the colonies but also through research organisations at, home and in the Dominions. That task is left for another committee, which will have the advantage of making its proposals after the Colonial Medical Research Committee, the Empire Forestry Conference, and other bodies have examined the problems confronting them. The Lovat Committee, however, is quite definite as regards the organisation of a colonial agricultural research service. It recommends that a central council should be constituted with a chairman (who should be a layman), a director (who should be a recognised man of science), and a deputy-director (who should have had administrative experience in the tropics). The formal channel of communication between the coul and the Secretary of State should be through the chairman. The members of the Council should be the directors of the Royal Botanic Gardens at Kew, of the Imperial Bureau of Entomology, and of the Imperial Bureau of Mycology, a chemist, and representatives of veterinary science, of the Imperiaf Institute, of the Colonial Office, and of the Empire Marketing Board. Liaison with the Medical Research Committee and any other research committee should be maintained either by co-opting a member of that committee as occasion required, or by creating an ad hoc committee of members of the bodies concerned to deal with borderline questions.The proposed constitution of the council is open to criticism. No reasons are given for the choice of chairman. What precisely is meant by a layman? Is he to be a man whose impartiality and sound judgment are to be guaranteed by his complete ignorance of science 1 Exception might be taken also to the selection of the scientific representatives. Presumably botany, mycology, entomology, and chemistry are regarded by the committee as the four sciences of most importance to agriculture. Two of them are mainly concerned with the pathological aspects of agricultural research, admittedly of importance, but certainly not so important as research in genetics aiming at the production of new varieties of plant and animal types resistant to disease. At least one geneticist should be added to the council. The claims of physicists to representation on the council are also strong. A physicist would be able to advise on most problems in connexion with the relationship of soil and climate to plant life as well as those concerned with the transport and storage of agricultural produce. If there is a fear that the council would be too unwieldy, the substitution of an agriculturist-say the director of Rothamsted Experimental Station-for the four scientific members proposed by the committee, would preserve its balance and not diminish its effectiveness as a council. Perhaps it is not too late, also, to suggest that an ex-.member of the Indian agricultural services should be given a seat on the council. Many of the difficulties which beset agriculturists in the colonies are identical with those which have already been successfully surmounted in India by the application of research, and it would be well for the council to have the advice of some one thoroughly familiar witb*the methods already successfully adopted there. A further point might also be considered. The principle of automatic retirement of members of advisory councils after a short term of years has already been applied to membership of the Medical Research Council and the Advisory Council for Scientific and Industrial Research. If the Colonial Agricultural Research Council is constituted as proposed, this principle could not be applied. The observations of the committee on the need for attracting the best talent to the colonial agricultural services will commend themselves to scientific workers as a whole. It must provide a career. " It must be well paid, and the financial prospects held out must be better than those which obtain at present." An officer entering the unified service must be liable to transfer, but he must be safeguarded against any losis on transfer. It is recommended that retiring benefits for the members of this service should be provided by a provident fund scheme. Transfers of research officers to the administrative side of agriculture would not then present any difficulties in this regard. Before the recommendations of the conference can be translated into facts, however, the committee which has just been appointed by the Secretary of State for the Colonies has to go fully into the question of finance and submit its proposals to the colonial governments. This procedure involves vexatious delay and might have been obviated.The tentative proposals of the committee on the unification of the various colonial research services need not be considered at this juncture. It will be time enough to deal with the matter when it is made the subject of a report by the further committee which is to be set up. The progress made in connexion with the agricultural research services will be studied with interest, and once the recommendation of the conference is made operative^ that the poorer colonies will be entitled to command the services of first-class men from the central pool - equally with those colonies with greater financial resources-provided their problems are of sufficient importance, no excuse will remain for their starving these essential services.

ISSN:0028-0836    

DOI:10.1038/120033a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WHILE we regard parts of this book as beneath the dignity of the science the art and the principles of which it professes to expound, we cannot repress some feeling of sympathy with the author for the courage he shows in resisting superior forces. We can admire Prof. Armstrong's defence of the name of ' oxygen,' we can appreciate his insistence that water acts chemically when dissolving salts: but is anything gained by crude lampoons on van't Hoff, Arrhenius, and Ostwald- and indeed on the whole school of modern physical chemistry founded on their work? The motif of the book appears to be that chemists are not only a perverse and unthinking crowd, easily hypnotised by any ' Nordic' magician who can work the spell of the integral calculus, but also, having been inoculated with the ionic virus, are unable to see the clear facts which Prof. Armstrong has been putting before their eyes for the last forty years. Why should this be? Probably the force of prejudice and of dictated belief has blinded them: they have not understood. The case must be presented again in a more comprehensive and definite way.The root of the trouble is twofold: people have never grasped that water is not the simple, neutral, self-satisfied body made up of an oxygen atom holding a hydrogen atom in each of its two hands- it is a far more complicated affair, a mixture of ' polyhydrones ' of various orders of complexity holding in solution simple ' hydrones ' (H2O), the capture of which by molecules of dissolved salt or acid alters the physical properties of the solvent; and, secondly, no chemical action can take place unless there is a tertium quid-usually conducting water-to form an electrolytic system through which the change occurs. The year 1885 must still be sodden with the tears of things. In that year Prof. Armstrong first preached the true doctrine to the Chemical Section of the British Association; in that year the conception of the dissociation of salts in dilute solution became known-to use Prof. Armstrong's phrase, " Arrhenius came forward as a Whole-Hogger "; and "in 1885 van't Hoff, assuming the character of the Hatter, invited us to a scientific Mad Tea Party, at which he out-hatted the Hatter." But even this combination of ' genius ' and ' youthful enthusiasm ' would not have prevailed alone to spread the ' joke '; it was carried far and wide by " floods of Ostwaldian ink." Is not this language a little reminiscent of a celebrated criticism of the Hallucinations and the ' Phantasiespielereien ' of a certain Dr. J. H. van't Hoff, and does not our modern Censor rather out-Kolbe Kolbe?Chemists can understand the protest against the idea that water, acting as a solvent, is a mere material vacuum-chamber affording room for the salt to dissociate; they can believe it is an active chemical substance, and that the action between salt and water is reciprocal. Here is a strong position to hold, but Prof. Armstrong is not content to hold it. The salt, or the acid, cannot react with water without an intervening electrolyte. '' Take,'' he says, " pure non-conducting water and pure non-conducting hydrogen chloride: they cannot react chemically, but they can form a couple by some mechanical ' attraction ' or process of ' distribution.' This couple (being an electrolyte?) can now bring about union between it and another pair of molecules to form a complex which splits up into two bodies-one, ' muriated hydrol," the other, ' hydrone chloride.' " We are given a picture of the process, which we partly reproduce: (i.) H Cl (ii.) H H\ cm. HO/ /CK o H2 The complex. Hydrone chloride. Muriated hydrol. H2 The couple with attracted molecules. So far the conception seems clear, but afterwards it is harder to follow. The two hydrogen chloride molecules have each incorporated a volatile hydrone molecule, and by so doing have altered the physical properties of the solvent; but one has to account for each molecule of hydrogen chloride producing double the effect of a neutral non-conducting molecule. It seemed at first sight that Prof. Armstrong considered the ' hydrone chloride ' molecule to be more readily acted on by hydrone than its sister hydrol, and we pictured a further process taking place:(ili.) (v.) /ci H /on HoO +OH=H20 +HC1. "\H \H Hydroue chloride. Hydronol. The hydrogen chloride liberated in the last equation would presumably repeat the cycle, so that finally for every HC1 molecule dissolved, one hydrone would be captured and held bound as ' muriated hydrol,' while two hydrones would be incorporated as hydronol which is represented as a stable molecule. That this is the interpretation meant by Prof. Armstrong seemed confirmed by his statement (p. 266) that the osmotic activity is to be attributed, in a dilute solution of hydrogen chloride, to the molecules of muriated hydrol and of hydronol. It will be noticed that in this interpretation every HC1 molecule dissolved affects three, and not two, hydronic molecules: but in the equation suggested on page 264 to account for the production of hydronol both the hydrone chloride and the muriated hydrol react with hydrone and all the hydrogen chloride is liberated: xCl HOH IL-. HaO C1H=H20 HO/ H + 2C1H + OH2. OH Hydronol. Hydrone Hydrcne, Muriated chloride. hydrol. If the two HC1 molecules liberated in this equation are free they would, presumably, repeat the original cycle until aZZ'the free hydrone was converted into ' hydronol.' But if they form the H complex C1H (labelled d on p. 263) and this is Cl unacted on by hydrone, then each HC1 molecule has only anchored one hydrone. Probably Prof. Armstrong can devise some way out of the difficulty which eludes us, or possibly we have been caught by a snag somewhere. When a man prides himself on his clear and forcible English, what are we to make of the following statements? On page 266 he writes: " This osmotic activity is to be attributed ... in a dilute solution of hydrogen chloride, for example, to the molecules of muriated hydrol and of hydronol, HC1 and H20 while on page 271 he says: " As the concentration is lowered, under H the influence of hydrone, the complex is more and more converted into hydronol. Ultimately the solution contains the solute only in the /R form HO together with an equal number of molecules of hydronol." The difficulties of following the hypothesis of electrolytic dissociation seem small in comparison.Similarly in all cases of oxidation, whether it be a solid or,a gaseous fuel that is burnt, hydrone is the sine qua non. Take that peculiar gas carbonic oxide. " It is commonly recognised," Prof. Armstrong writes, "that this gas cannot be burnt dry, but that the rate of combustion rises as the amount of hydrone in admixture with it is increased, up to a certain point; hydrone apparently plays a peculiarly active part in its combustion, primarily through incorporation into its being. In fact, it is difficult to think of hydrone as active in conjunction with carbonic oxide except by giving rise to formic acid; the two molecules cannot well grip each other at all with any other result." That carbonic oxide can directly ' grip ' with hydrone to form formic acid seems to be an advance on the doctrine that no chemical action can take place between two molecules unless there is a third and conducting body to act as go-between; but obviously in this instance, as with hydrogen chloride, the hydrone plays a double part. It can ' grip ' or ' disperse itself over' carbonic oxide, and then "given the initial production of formic acid, all else in the behaviour of carbonic oxide is clear."Prof. Armstrong complains that his work has not been appreciated, his explanations not heeded. " Since 1885," he writes, " my voice has been that of one crying in the wilderness." But the voice of one crying in the wilderness-as prophesied by Isaiah-surely was listened to. Are we not told that not only Jerusalem went out to hear, but " all Judsea, and all the region round about Jordan "? The voice has been heard, but is not the answer more nearly that pagan rejoinder, ' Credat Judaeus?

ISSN:0028-0836    

DOI:10.1038/120036a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the modest preface to this book, the author expresses his hope that it will be of use to those who engage in research on the subject he deals with, and at the same time form a reference book for advanced students in agriculture and veterinary science. We have confidence that his hopes will be fulfilled. Those who have learnt to value the care and accuracy which characterise all Mr. Hammond's work will find in this book increased reason for appreciation of those qualities in the author. It is not only a masterly exposition of the physiology of reproduction in the cow; it also deals in a truly scientific spirit with gynaecological problems of the first importance to members of the veterinary profession, and therefore to their clients, the practical breeders.The volume is divided into (1) a short account of the breeding season; (2) the oestrous cycle, which occupies the bulk of the book; (3) pregnancy; and (4) sterility. The method of investigation the author adopts will be best disclosed by a brief survey of the section on the oestrous cycle. Mr. Hammond examines the periodicity and rhythm of the oestrous cycle in relation to the time of year, the age, the state of fatness, the effect of drugs, the psychological1 effect of proximity of the bull, the effect of service of the bull, and the result of artificial removal of the corpus luteum; and wherever possible supports the conclusions he arrives at with elaborate tables of figures. The duration of oestrus he treats in a similar elaborate manner, and comes to the conclusion, which we think is justified by his records, that the length of the cycle and the duration of oestrus are correlated phenomena. But the main portion of this section is devoted to a detailed account of the physiological, anatomical, and histological changes which take place throughout the whole of the organs concerned with reproduction during the osstrous cycle, and with the mammary gland; a most painstaking and valuable piece of work.It is impossible to do justice, in a critical sense, in the space at our disposal, to what may be described as a monograph of more than eighty pages containing fourteen elaborate tables and illustrated by a prodigal number of drawings and photographs contllhed' in nineteen admirably executed plates. Much o£ it, of course, consists of a critical examination of work done by others, and when we add that the author's bibliography contains references to four hundred books and papers, some idea may be gained of the labour involved in the work. A welcome feature of this portion of the author's duties is his generous appreciation of the work of others and his judicial tolerance in criticism. We would assure him that the weight of his judgment is not decreased thereby. Mr. Hammond's account of the anatomical and histological changes which take place in the ovaries during the oestrous cycle are specially worthy of note, more particularly, perhaps, in relation to the Graafian follicle and to the corpus luteum. Much of this is new, and in some ways highly suggestive, while the tables and figures he gives are illuminating. With some of his general conclusions we are in entire accord, as, for example, in his refusal to accept the theory that the ripening of the Graafian follicle is the direct cause of menstruation. On the other hand, we have failed to convince ourselves of the truth of the view that the duration of the corpus luteum solely controls the length of the osstrous cycle, a view which he finds reason to accept.If we must particularise, however, it is Mr. Hammond's original work on the mammary gland, on its growth, the histology of its development during foetal life, and from birth to the age of puberty, and the relation of different forms of development to the production of milk, which strikes us as fraught with matter of special scientific importance and economic value. The section concerned with pregnancy contains a valuable resume' of the work of a host of observers on a variety of domesticated animals; it is, in fact, a comparative study of more considerable interest to the scientific worker than to the practical breeder, though of undoubted value to the veterinary student. Here and there, however, these observations have practical significance, as for example the correlation between the time when the proportion of foetus exceeds that of the foetal fluids, and the liability to infection with Bacillus abortus.The changes which take place in the uterine tissues during pregnancy are very fully described and of much interest; especially in regard to the destructive action of the foetal membranes on the cotyledons, and the attachment of the foetal placenta thereto by finger-like growths which eat their way into the tissues of the cotyledons, where they are interlocked by growths of the maternal connective tissue and do not project freely into blood lacunse. The occurrence of pustules on the internal surface of the amnion and their relation to the amount of mucus in the amniotic fluid is recorded, but beyond the fact that they are said to contain large quantities of glycogen and that they are temporary structures, nothing seems to be known of their metabolic function. It occurs to us that the association of their breakdown and the simultaneous cessation of the secretion of foetal fluids with the glandular phase of growth of the udder, are correlated phenomena which it might be worth while to investigate. In this section also the work done on the histological changes which take place in the udder, and the nature of its secretions at different stages of pregnancy, is of marked value. It is to. be hoped that the brief concluding chapter on sterility may be extended when a call is made for the next edition of the book. There is no subject associated with the breeding industry, especially the breeding of thoroughbred stock, of greater importance than this, and there is no subject of which both the man of science and the veterinary profession are more profoundly ignorant

ISSN:0028-0836    

DOI:10.1038/120037a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

PROBABLY few whose pursuits have not J- brought them into wide as well as intimate contact with Nature, can realise the extent to which the face of the globe has been modified by the restless activities of the human race. The modifying influence of man is more particularly experienced by the organic film which tends to cover, now thickly, now thinly, those portions of the surface of the earth which are capable of supporting life. Nowhere, perhaps, is this influence more noticeable than in the case of vegetation. For this reason plant ecologists have up to the present tended where possible to select for study the more ' natural ' types of vegetation, i.e. those least altered by man and his domestic animals. It is gradually coming to be realised, however, that many of the problems of agriculture, dealing as it does with ' semi-natural ' vegetation such as pastures, as well as with vegetation in its most ' artificial ' aspect, the crops of arable land, are really ecological problems. Though, however, no doubt ecology in the future will occupy a not unimportant position amongst the applied sciences, in this, as in other cases, pure science is fundamental. Such experiments, therefore, as that now in progress on a large scale in the Swiss National Park, are being watched by ecologists with considerable interest. The Swiss " Commission for Nature Protection " is to be congratulated on its decision to allow natural processes to operate in this area of upwards of fifty square miles, entirely free from the disturbing influence of man.1 Here man is content to stand aside, and merely to observe and record. The two works reviewed below deal with this great Nature reserve, but from very different points of view.(1) The first is merely a ' Nationalparkalbum ' of some fifty photographs by J. Feuerstein, with forewords by Prof. Schroter and H. Federer. Yet the album is worthy of its subject, for Herr Feuerstein is at once a skilled photographer and an enthusiast thoroughly familiar with the Park and its inhabitants. Artistically and technically the photographs reach a high standard; they are well reproduced, and most of them are of whole plate size. The photographs themselves possess considerable scientific interest. The landscapes give a good idea of the ecological character of the district, especially of the coniferous forests on the mountain slopes and the alpine zone above. There are some excellent photographs of a few well- known plants such as Ranunculus alpestris and Crocus albiflorus, and of a number of animals. The latter include the marmot, chamois, roe deer, ibex, foxes, and the kite and other birds. One particu larly attractive photograph shows an alpine hare seated on the snow. (2) The second of the two works under considera tion is an important contribution towards the scientific exploration of the Swiss National Park, dealing with the development of both soil and vegetation above the tree limit. The vegetation in question is well seen in several photographs in the ' Album.' Dr. Braun-Blanquet is responsible for the vegetational portion of the memoir, and Dr. Jenny, of the Agricultural-Chemical Labora tory, Zurich, for that devoted to soils. The work has gained greatly by this co-operation.The underlying thesis, well established by convincing evidence, is that soil and vegetation undergo a parallel genetic development. Both exhibit initial an 1 transitional stages, and both tend towards a more or less stable ultimate condition, the soil climax and the vegetation climax respectively. Soil development is primarily conditioned by climatic factors, especially temperature, precipitation, and evaporation. The combined action of these factors ultimately produces a definite soil type which occurs, under similar climatic conditions, on every geological or petrographical substratum where soil formation has progressed to the final stage. The soil type then is a function of climate, and it should be possible therefore to speak of a ' climatic climax ' in the case of soils, as we already do in the case of vegetation. In the humid climate of the alpine zone in the Central Alps the progression, owing to leaching and the accumulation of humus, is invariably from basic or weakly acid soils towards a strongly acid climax-the alpine humus soil. This order of development is irreversible. So far as plant succession is concerned, the gradual changes in soil reaction are accompanied by a struggle between the pioneer species characteristic of basic or less acid soils, and invaders capable of nourishing in increasingly acid soils. The climax community, on the strongly acid alpine humus soil, is dominated by Car curvula. There is thus a very close parallel between soil succession and plant succession. The authors regard the progressive changes occurring in the soil as the immediate cause of plant succession, the climate mainly affecting this succession indirectly through the soil. Another point of general interest is the apparently great importance of wind-borne dust. This dust aids in the building of soils; compensates to some extent for the leaching out of soluble salts -thereby, in the case under consideration, retarding plant succession; is a source of mineral nutriment for plants-indeed the chief source, according to the authors, in the case of shallow-rooted plants growing in acid humus soil; and finally, serves to infect the soil with spores and seeds. The authors quote the opinion of Treitz, expressed at the International Soil Conference at Prague (1924), to the effect that " the most important soil-forming and plant-forming climatic factor is the annually deposited amount of wind-borne dust." At first frankly sceptical regarding this somewhat sweeping generalisation, the authors investigated the matter for themselves, by collecting and therefore immobilising blown dust in ' rain totalisators,' placed at two elevations in the Val Cluoza. The results obtained were truly remarkable. At the upper station, for example, above the tree limit at an altitude of 2340 m, the dust was collected continuously for two years. The average deposition over this period worked out at about 6-46 tons of dust per acre per annum, of which about 1 -63 tons were CaCO3. Such heavy manuring by wind action alone seems almost incredible, but if true would justify the authors' opinion that alpine vegetation depends for its supply of mineral salts to a great extent on wind-borne dust. Similar experiments would be well worth carrying out in Great Britain. Hitherto, with the obvious exception of accumulations of wind-blown sand, little or no attention has been paid by ecologists to what seems likely to prove an important factor of the plant environment.The memoir contains a mass of careful detailed work which cannot be dealt with here, beyond saying that Dr. Braun-Blanquet has described and analysed a large number of plant associations forming the complex of communities leading to that dominated by Carex curvula. He has, moreover, attempted to group these associations into alliances, according to their floristic relationships. On the whole, the monograph is certainly on"e%f the best that has so far emanated from the Zurich school.

ISSN:0028-0836    

DOI:10.1038/120039a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MEDICAL psychology has had a long and varied history. In its earliest stages it dealt with magical and pseudo-religious phenomena, which it took at their face value. Even within the last century it remained mainly anecdotal, with a complacent acceptance of the miraculous and the supernormal. With the earlier investigations and writings of scientists still among us, such as Dr. Pierre Janet and Dr. Morton Prince, it passed into the stage of detailed descriptions of outstanding cases of mental abnormality, especially of hysterical cases with their startling characteristics of dissociation and susceptibility to hypnotism. Only within the last thirty years has it taken on the characteristics of a definite science- that of psychopathology-with a systematic classification of its subject matter and a set of general principles genuinely explanatory in nature. In the course of its development it has profited greatly by the advance of normal psychology, but is now reacting strongly upon the latter science, deepening its conceptions and revealing the presence of dynamic factors in the normal mind which would otherwise have remained unobserved and unsuspected. In Prof. W. McDougall's " Outline of Abnormal Psychology " we have the first serious attempt at a systematic and detailed text-book on the subject. It is a sequel to his already well-known " Outline of Psychology," and is written on the lines of general psychological theory there set forth. In a series of thirty-four chapters, all the main aspects and problems of the science are fully dealt with. Throughout the volume detailed descriptions of typical cases, to the number of sixty in all, are given, which furnish a solid empirical foundation to the theoretical superstructure. Although full accounts are given of the chief schools of thought in modern psychopathology, such as those of Janet, Morton Prince, Freud, Jung, and Adler, these are successfully pressed into service to illustrate the author's own systematic psychological theory, the vitality of which is shown by its power to assimilate much that is characteristic of each of them. In this respect McDougall is representative of a nourishing school of psychopathology and psychotherapy especially prominent in England at the present time.Certain minor points may be singled out for qualified criticism. The theory of causation of exaltation and depression (manic-depressive insanity), in terms of the instincts of self-assertion and self-abasement, would seem to be too simple. It does not allow for the large,part played by ' disappointment in love,* understood in the widest sense, often found in these cases when deeply investigated. Again, the author unduly minimises the correlation of pronounced hypnotic phenomena with those of hysterical dissociation. This is no doubt not unconnected with his readiness to accept at their face value the manifestations of alternating and multiple personality. This, in its turn, involves him in the necessity of producing an ingenious but singular theory of ' monads ' in telepathic relation with one another to explain the forms of internal communication and lack of communication within these split personalities. Such monads are different from their Leibnizian prototypes, since the latter ' had no windows.' Moreover, to bring in telepathy as a thoroughgoing explanatory factor in this way seems perilously near explaining ignotum per ignotius. We should bear in mind the alternative possibility that the phenomena of multiple personality may be in the main artefacts, due to the hypnotic methods of investigation and treatment employed by their observers. This would fit in with the fact that during the recent European War, in which severe forms of functional nervous derangement were produced by the thousand, no well-marked cases of multiple personality were reported or observed. Cases of extensive amnesia, fugues, etc., were numerous; but the first aim of the army doctors in the battle areas was to remove these amnesias and re-associate the patients as quickly as possible, so that the latter might be either returned to the line or sent down to the base with the minimum of delay. Moreover, we should not overlook the part played by drama, or rather melodrama, in producing well-marked phenomena of multiple personality.Finally, Prof. McDougall makes a vigorous onslaught upon the theory of ' abreaction' or psychocatharsis as a working off of pent-up emotion leading to recovery. But in explaining the beneficial results of this method as due to a re-association of the mind, he is only restating the theory of his selected opponent, set out in publications already some years old. The essence of his opponent's theory was that the re-arousal of disturbing emotional experiences with sensorial vividness was in certain cases alone adequate to produce a re-association of the mind with the requisite degree of completeness. The re-association must be an emotional one as well as an intellectual one. These matters are, however, of subsidiary importance. In its powerful sweep, firm grasp of detail, and vivid and lucid style, the book stands out as one of the most important contributions to psychopathology of the present time.

ISSN:0028-0836    

DOI:10.1038/120040a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

(1) ALTHOUGH Dr. Collinge modestly calls this a revised edition of his work of 1913, it is virtually a new book. In place of the twenty-nine species formerly considered, the feeding habits of seventy are now discussed in detail, a considerable number being sea-birds, which had no place in the earlier work. The data for most of the species have been extended, the volumetric system of analysis, now universally adopted in the United States of America, has been superimposed upon the numerical system, and the useful chapters dealing with general aspects of the economic relationships of birds have been added to and expanded. On the whole, it is surprising in how many cases an analysis of the food stuffs taken over a long period tells in favour of birds usually condemned as unmitigated pests, even although the statistics here given reckon against the bird much in the food content which can be of no agricultural value. The statistical methods adopted in such investigations still fall far short of scientific precision and leave the final judgment to personal interpretation with wide margins, but until better methods are evolved, Dr. Collinge's book will remain the standard British work on the subject. (2) For the average naturalist this third volume completes the most attractive and useful of the lesser books on British birds. As a practical guide to species it is less essential than its forerunners, since it deals mainly with rare and casual visitors. It is illustrated by many fine coloured drawings reduced from Lord Lilford's standard work. But it breaks new ground by introducing several chapters dealing with general aspects of British bird life, including a lengthy and excellent account of migration, and descriptions, family by family, of characteristic migratory and other habits. The sixteen ' sub species ' added to the British list since the earlier volumes appeared are here described, as well as two species since recorded for the first time from Great Britain.(3) The appeal of Mr. Thorburn's work rests largely upon the beautiful and accurate coloured plates, the finest of their kind, which make identifica tion of species a pleasure and a matter of compara tive simplicity. Since, except for a number of rare and closely related species, all the British birds appear in these 192 plates, descriptive matter has been reduced to a minimum, and the text is con fined to short accounts of range and characteristic habits.

ISSN:0028-0836    

DOI:10.1038/120041a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE Tsangpo River, the main source of the Brahmaputra, flows placidly, from west to east, across Tibet until it reaches the eastern end of the Himalayan range, and vanishes into a terrific gorge. The bottom of the gorge is 9680 feet above sea-level, and the peaks that hem it in on each side rise to more than 21,000 feet. The river emerges from the mountains some 35 miles away, and is then flowing south and west at an elevation of less than 2000 feet. There was, therefore, a chance that the gorge might conceal the most stupendous waterfall. Part of the gorge was explored by Bailey and Morshead in 1913, and most of the remainder by Captain Kingdon Ward and Lord Cawdor in 1924. No large falls were found, and it is now clear that none exists. The main purpose, however, of Captain Kingdon Ward's expedition was not the exploration of the gorge, but the collection of plants and seeds. In this corner of Tibet the climate varies from tropical to arctic, and from humid to arid, within a range of a few miles, and the flora varies with the climate. It is a wild garden stocked with countless species and varieties of flowers and flowering shrubs; hillsides blazing with rhododendrons; fields of lilies; meadows of primulas; giant snowpeaks above, and below the abyss, echoing with the thunder of the hidden river.The book is very modestly written, and the dangers and difficulties that were faced and surmounted in the gorge are mostly left to the reader's imagination. It is probable that they will not be fully realised until some other explorer attempts to follow in the footsteps of Captain Kingdon Ward and Lord Cawdor. The expedition owed much to the hospitality of the Tibetans, and to the courage arid endurance of the men and women who, at the risk of life and limb, carried their loads up and down the almost vertical cliffs of the gorge. The book is illustrated by excellent photographs, some of which must have been taken from very perilous positions. The last two chapters of the book are by Lord Cawdor, and give a short account of the natives of Eastern Tibet and their customs.

ISSN:0028-0836    

DOI:10.1038/120042b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ONE is accustomed to anticipate with some eagerness the publication of the annual reports on pure and applied chemistry by the Chemical Society and the Society of Chemical Industry, respectively. The eleventh volume (1926) of the latter series will occasion no disappointment. In fact, it is unusually comprehensive; it is readable and yet as full as ever of catalogued information, and, moreover, it has appeared promptly. It is not surprising that constant reference is made to the impression left by last year's dispute in the coal-mining industry on the progress of applied chemistry; however, the difficulties of that period have at least focussed attention on fuel economy, on more fruitful ways of using coal, and on the possibility of meeting future demands for liquid fuel. It is noteworthy that the period under review saw the establishment of the Institution of Fuel Technology and the Fuel Section of the Society of Chemical Industry. The fermentation industries, also, continue to grow in importance; the butyl alcohol-acetone fermentation is now being harnessed to the commercial production of hydrogen. Harington's work on thyroxin is recorded as the most notable advance in the chemistry of the hormones.

ISSN:0028-0836    

DOI:10.1038/120043a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THERE seems to be but very little published information regarding the subject of solid friction, and such as there is is chiefly concerned with the effects of lubrication at considerable velocities and at comparatively low pressures.I think, therefore, it is worth while to contribute a short note on some experiments which I have recently made, in which the pressure between the solids range from those ordinarily met with in mechanical practice up to the highest which the material can withstand 1 and in which the velocities are almost vanishingly small. A list of the materials tried and of their coefficients of friction is given below. Tho point worthy of remark is the small difference which exists between the coefficients for the various metals notwithstanding their strong contrasts in other respects. Another point which seems remarkable is that when the pressure is high, the presence of a lubricant nearly always increases instead of diminishing the coefficient of friction.2In these experiments a small plate of sapphire was always used as one of the pair of substances the mutual friction of which was to be determined, because, as was found after many trials, where one of the pair was so hard as to be free from any chance of being scratched, the coefficient depended solely on the properties of the softer material. FIG. 1.-Apparatus used in the measurement coefficient of friction, a, side elevation; b, plan; A, tray rolling on steel balls; S, sapphire plate; T, test piece; P, zero mark on tray; /, index; H, divided head, controlling spring balance.As mentioned in my letter published in NATURE of May 7, the sapphire plate "was carried on a tray which could be dragged literally under the loaded test piece by the action of a spring balance. The apparatus, somewhat improved, is shown in Fig. 1, a and 6. Fie. 2.-Diagram showing the results of two sets of experiments on the coefficient of friction of steel on sapphire. x Individual observations when the surfaces are dry. 0 " " in oil. The ratio ordinate/abscissa=coefficient of friction.The tray A was supported on three steel balls rolling on steel guides, and it was found that the resistance offered to the travel of the tray was less than a ten-thousandth of the load carried by it. In making an experiment the tray was brought to the zero position by turning the adjusting screw H of the spring balance until the mark P on the tray coincided with the index /.COEFFICIENT OF FBICTION BETWEEN METAL AND SAPPHIRE. Metal. Coefficient of Friction. Load. Pressure. Steel . . . f Pl-L" 0-10 0-11 ^ 00S Copper . ' I L 0-11 0-105 ° Of +3• tpIs Antimony . • { L 0-105 0-14 °a^ 02 Q Zinc . . • 1 L 0-105 0-115 •Sg^S ^J «*-t O Cadmium . . TI L' 0-10 0-125 ^*e »eS Tin . . . |]? 0-115 0-135 1^1 iH Aluminium . -; T I1-1 0-10 0-11 §-1a r^ P- S Bismuth . 'IT 0-095 0-075 ^ T3 ^&S § M2 o S 0- 10 ffl 4J -^ Lead . . T 1 lj 0-135 1 " " §§'§ Zinc -copper . | T 0-85 0-95 1 ^1" Tin-copper . ^,- 0-115 '0-125 S0 !§• s Antimony-copper } -^ 0-09 0-108 % s ! 1 — 1 ^ || O Cadmium-copper •[ ^ 0-09 0-115 03 I .a Aluminium-copper -j ^ 0-095 0-10 1 D indicates that the surfaces were clean and dry. L, lubricated. To make the zero definite a counter weight W was added to give an initial tension to the springs. The test piece with its appropriate load was then allowed to press on the sapphire and the tray (by means of a screw nut shown in the sketch) was shifted slightly in the direction to extend the balance spring. This screw was slacked back and the mark P again brought to coincide with / by turning the divided head H.The balance reading then gave the force which was just sufficient to cause sliding between the test piece and the sapphire. Tn Fig. 2 one complete experiment is plotted in detail, in order to show the kind of accuracy with which the relation between the tractive force and the load is determined by this method. All the experiments were plotted in the same way, and the order of accuracy is much the same on each. The average results are given in the table on p. 45.Lubrication was effected by putting a drop of heavy oil on the sapphire before placing the test piece in position. Some very general causes must underlie the approximate equality of all these coefficients, but the explanation would require a knowledge (which does not at present exist) regarding the intimate conditions at solid boundaries. 1 An" example of friction at destructive pressures is presented by the driving-band on tlie projectiles of large guns. The great volume of smoke which ' smokeless ' powder produces when such guns are fired consists almost entirely of powdered driving-band, i.e. of finely divided copper.2 The effect of a ' drop ' in the saucer iu preventing a cup from slipping is very

ISSN:0028-0836    

DOI:10.1038/120044b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN a letter to NATURE (vol. 119, p. 558; April 16, 1927, hereafter cited asloc. cit), Messrs. Davisson and Germer have communicated the results of some very interesting experiments on the scattering of electrons from single crystals of nickel. They show that the distribution of scattered electrons, which have only lost a small fraction of their energy, depends on the voltage, and is in accordance with the symmetry of the crystal. The authors explain their results approximately on the basis of the Einstein - de Broglie theory of the wave electron, in a similar manner to that suggested by Elsasser (Naturwiss.,13, p. 711, 1925) in explanation of earlier experiments of Davisson and Kunsman (Phys. Rev.,22, p. 243, 1923). In particular, the explanation given is that electrons of velocityvare scattered by the nickel crystal in very nearly the same directions as those in which an electromagnetic wave of wave - length λe=h/mvwould be diffracted by the cross grating formed by the uppermost layer of atoms in the face of the crystal—in this case, a (111) face which has been etched by vaporisation.The alteration in intensity (with varying voltage) of the reflection with maximum at 50° in the {111} azimuth for 54. volt electrons [loc. cit.,~Fig. 1] is not explained by diffraction at a cross grating. There is another control which brings out the one reflection as a maximum with the partial suppression of the neighbouring ones. The control is not the complete one which would be exercised by a space lattice. This would entirely suppress all reflections but the maximum. The necessary degree of control would be provided by the influence of a second cross grating lying beneath the first. The observed position of the maximum (i.e. at 54 volts, 50°) can then, however, be explained only by the assumption of a spacing between the two gratings equal to Kaj-\/3, where JC=0~66 or 1-16 and a/\/3 is the normal spacing of the {111} planes of a face-centred cubic lattice of constant a. At these distances the diffracted beams from the two layers are in phase for 54 volts. The two factors differ from one another in corresponding path length by one wave-length.It must be pointed out that the factor K is not quite the same for all reflections. The calculated maximum intensities for the various voltages in the neighbourhood of 54 volts for the above values of K are shown in the figure, compared with the observed maximum intensities [loc. cit. Fig. 1]. (No corrections have been applied for general scattering.) The positions of the maxima agree with those observed within the error of reading of the published curve. The agreement in height of the maxima is almost equally satisfactory in the two sets. There is a possible preference for K- 1-16, as the existence or non-existence of a peak may be a better criterion than the comparison of intensities. It may be necessary to take a slight effect from the third layer into account.The variation of intensity with azimuth in co-latitude 50° has also been calculated [loc. cit. Fig. 2], The ratio of the maxima {111}: {100} has been calculated to be 4: 1; that of the observed values, making allowance for general scattered radiation, being of the order 2:1. This agreement is satisfactory when it is realised that atom factors for the gratings will have to be taken into account.Fig. 1. The reflections in azimuths {111} and {100} for 110 volts are not explained by diffractions in a cross-grating parallel to (111). On the suggestion of Prof, von Laue that faces other than (111) were present on the etched surface, the diffractions from the cross gratings parallel to a few of the most probable subsidiary faces were calculated. The assumption of the existence of faces {111} would explain the reflection in the {111} azimuth, giving a value of n(\mvlh)=2(].-QG). The reflection in the {100} azimuth can possibly be explained as a diffraction of the same type in the {111} faces of minute twin crystals, which are rotated through 60° on the surface of the main crystal. It is reasonable to assume that an alteration in the lattice is to be found near the surface of a crystal. *oo Whether an increase or a decrease takes place seems to be an open question. An application of the electron lattice theory of Haber would suggest that the nickel atoms would be repelled, and the spacing increase (cf. Madelung, Phys. Zeits., 20, p. 494, 1919). The point is, however, not very clear. That the surface of **>an etched crystal is not perfectly plane, and that many faces of the order of ten to a few hundred atoms in extent are present, is also to be expected. It is not profitable to carry the discussion further on the basis of the results which could be communicated in the scope of a letter to NATUBB. The agreement of these results with calculation seems to ** indicate that the phenomenon can be explained as a diffraction of waves in the outermost layers of the crystal surface. It also appears, which' may be even more important, that a complete analysis of the results of such experiments will give valuable information as to the conditions prevailing in the actual surface of the crystal, and that a new method has been made available for the investigation of the structure of crystals in a region which has up to the present almost completely escaped observation. Calculations on the above lines will be continued when a more detailed account of the experiments is available.In conclusion, the writer wishes to express his thanks to Prof. M. von Laue for the very kind interest which he has taken in discussing this p

ISSN:0028-0836    

DOI:10.1038/120046a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature