摘要:

THE War brought into painful prominence certain facts regarding the resources and distribution of commodities, animal, vegetable, and mineral, which had indeed long been known, but the real significance of which in such a period of stress had not been fully grasped by any one of the Powers concerned. The waste of time, man-power, and material involved in the efforts made to overcome the resulting difficulties created a profound impression, from which flowed a stream of resolutions and good intentions. Meanwhile the years are slipping by and there is yet little indication of an Empire policy regarding minerals and metals. While it is obvious that the development and conservation of the resources of the British Empire in plant and animal life require all the care and attention that can be given them, the case of minerals is peculiar. It is generally admitted that there is, in accessible form, enough of every mineral in the world to enable its inhabitants to carry on along present lines for a great period of time; but the distribution is unequal, the demand for certain minerals may at any moment overstep the known resources, new sources have to be discovered, and when they have been found and exploited they cannot be rejuvenated or replaced.One of the lessons of the War was the need for each nation to be fully aware, in detail, of its own resources in minerals and of the means available for rendering them fit for industrial purposes and munitions of war; to be aware also of its actual relations with the rest of the world with respect to resources, transport, marketing, and treatment of minerals. The official statistics available to Governments are practically limited to those of production and of movements, represented by imports and exports. Such statistics, though better than none and essential for certain purposes, convey a totally erroneous conception of the actual resources of a territory; they throw no light on those available for future exploitation; they are always too late to indicate the significance of new finds; and they contain no reminder of the reserves that are fairly accurately known but are not exploited under the fiscal or commercial conditions that are prevalent at the time of their publication. For many years the United States, through its Geological Survey, and later, the Bureau of Mines, has done good service, not solely to its own nationals, by the publication of elaborate statistics relating to the mineral resources of the States, with such figures as could be assembled regarding other countries, and frequently enlivened by informative reviews of the industry in specific minerals. It was not unnatural, therefore, on ground so well prepared, that Spurr's " Political and Commercial Geology," in 1920, should have stimulated the two leading institutions of American miners and metallurgists to form a joint committee under the chairmanship of Prof. C. K. Leith, to consider and report upon foreign and domestic mining policy and industrial preparedness (" International Control of Minerals." New York, 1925). This Committee enunciated certain propositions "in the interest of efficient and conservational use of the world's mineral resources and in minimising international difficulties arising from the discovery, development, transportation, and marketing of mineral resources." The propositions put forward cannot be discussed here; in the main, they are equally applicable to any great State. In other quarters there is evident the same desire that these problems should be attacked; quite recently, from Germany, comes a proposal for the formation of an " International Institute of Mines." As things are at present, however, it is more practicable to restrict the field of action to States or federations of States.The matter has recently been taken up with vigour by Sir Thomas Holland: in a presidential address in 1925 (Trans. Inst. Min. and Met., 34, 1925, pp. xliv-lxiii), he directed attention to the possibility of shortages of certain base metals in the not very distant future; in 1926, at the Royal Society of Arts (" International Interests in Raw Materials," Jour. Roy. Soc. Arts, 75, 1926, pp. 42-61), he enlarged upon the need fot investigation and collection of data regarding the natural resources of the British Empire; this has been followed up by his paper, a " Proposed Review of the Mineral Resources of the Empire," read before the Institution of Mining and Metallurgy on April 21, part of which is printed elsewhere in this issue. In this paper Sir Thomas proposes that: "In each of the Dominions and, if possible, in each of the larger Colonies, committees of specialists should be appointed and entrusted with the duty of reviewing for each large State or unit of area its mineral resources and smelting capabilities, having in mind the desirability of accumulating, in addition to the ordinary official statistics of production and movement, the essential data necessary for the formulation of an economic policy, as well as for obtaining the information required to institute measures designed to secure military safety."These proposals are now under discussion in London, and, if approved, it is intended to submit them, with such modifications as may be deemed desirable, for further discussion by the second Empire Congress of Mining and Metallurgy to be held in Canada this autumn. Should the Congress adopt the scheme and proceed to put it into being, there will be for the first time within the British Empire an organisation for the collection of live data and for the prompt examination and elucidation of their implications by men with knowledge of the facts. The essence of the plan is decentralisation: in each territorial unit, whatever it may be, the special committee would be responsible for the collection and consideration of data within its ambit, and its methods would be those best suited to the local circumstances and special problems. The co-ordinating bodies would be the constituent members of the Empire Council of Mining and Metallurgical Institutions, established at the first Congress, held at Wembley in 1924, in order that each may benefit by the experience of the others, and especially in order that correlation and subsequent economic co-operation by the various Governments may be facilitated at future Imperial conferences of the kind recently held in London.It is suggested that reports of progress made by the special committees in the Dominions during the next three years should be discussed at the Empire Mining and Metallurgical Congress, which will be arranged to follow that to be held at Montreal this year. The International Geological Congress has shown that it is possible, even with a very loose organisation, to assemble information of a most valuable character on specific subjects, exemplified in the reports on the world resources of coal and iron. The scheme to be laid before the Empire Congress in Canada is more far-reaching: it involves the consideration not only of the mineral resources and their development and treatment in the units of the British Empire, but also of the changing interactions, as adjustments take place due to new discoveries, new methods, new migrations of material, the growth of new industrial centres, and the consequences of political action. In short, to fulfil its functions properly, the proposed organisation must be not only alive but also assured of a prolonged life. The territorial committees will have to concern themselves with such questions as the conservation of minerals; the encouragement of prospecting; the support of the geological survey, keeping it in touch with realities and advising on the choice ofareas ripe for intensive geological investigation; the elimination of wasteful methods of mining, and of movement of ore; and the consideration of suitable centres for refining and smelting. The local mining laws should be critically examined with the view of simplification and, so far as possible, unification. Statistics should be analysed and presented in more useful form. The discussion of these and other matters would be carried on by the Congress and Empire Council from the point of view of Empire requirements. Amongst the larger questions might appear that of State ownership of minerals, the inclusion of mining in the public utility services, the accumulation of reserve stocks, fiscal interrelations, etc., which cannot be dealt with by the official and State-aided organisations already existing for the collection and publication of mineral statistics.While such an organisation as the Imperial Mineral Resources Bureau will doubtless continue to function usefully, the scheme outlined by Sit Thomas Holland would be far more effective in securing the essential details promptly and their consideration by specialists actually in touch with the ramifications of the industry. It is only by some such process that the great industries of mining and metallurgy can be brought into a position from which they can speak with full authority to their several Governments, and thus influence the creation of sound domestic and Empire politics.

ISSN:0028-0836    

DOI:10.1038/119625a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is always interesting and sometimes profitable to turn for a moment from the achievements of to-day to contemplate the difficulties, struggles, and aspirations of the pioneer in some special field of scientific endeavour. To do so, however, is not always a simple matter, since it often entails a laborious search through the publications of various learned societies; and, at the end of the search, a feeling that something of importance may after all have been missed. When, however, the whole of the written work of some specialist has been collected together and republished in one volume, it can be studied at any time with the greatest facility. All those who are interested in the history and development of the reflecting telescope have cause for satisfaction in that this collation of scientific work has been effected in recent years in the case of two of the most distinguished pioneers in the construction and improvement of that instrument.In 1912 the collected scientific papers of Sir William Herschel were published by the Royal and Royal Astronomical Societies. Among these papers is one which gives a fairly full account of the construction and working of that great 40-foot reflector which may justly be described as the world's first giant telescope, destined not to be doubled in aperture for 130 years. It is only to be regretted that Herschel published very few details of the purely optical part of his work. Fortunately, however, he did commit to writing a very full account of his methods of figuring specula; and, as this manuscript is still extant, it is to be hoped that it may yet one day be published. We have now before us the scientific papers of William Parsons, third Earl of Rosse, brought together and published in one volume by his son, the Hon. Sir Charles Parsons. These papers, considered in relation to the work of Herschel, may be said to constitute the next chapter in the history of the reflecting telescope. Unlike Herschel, Lord Rosse had no special reason for reticence with regard to his methods, and the full account which he gives of his many optical experiments, successful and unsuccessful alike, makes very interesting reading. Thus, the first paper of the series, written in the days before he had fully mastered the art of figuring his specula to a paraboloid, describes a simple and ingenious method of reducing the aberrations of a spherical surface. This he accomplished by casting a speculum in two concentric parts, with a small space between them. The two parts were then worked together to what was, optically, a single spherical surface. The resulting spherical aberration was then reduced by drawing back the central portion by means of three fine screws. It is rather surprising to read that this apparently crude method proved successful in a mirror having a focal ratio of only 1 to 4; but, as the aperture of this speculum was only 6 in., it seems unlikely that it was called upon to bear very high powers. Yet its maker was so satisfied with it that he declared his intention of constructing one (in three pieces) so large as 18 in. in diameter. But no such instrument is afterwards mentioned, and it appears that Lord Rosse soon turned instead to more promising methods of improving, and more particularly enlarging, his specula.In this connexion many of Lord Rosse's experiments were directed towards increasing the rigidity of metallic mirrors, and at the same time reducing their weight. To this end he tried the expedient of casting some specula of moderate size with backs braced by straight ribs, and some others with backs of a cellular structure. The results were not altogether successful, and it is interesting to note that similar experiments made on glass mirrors in recent years have also failed to justify expectations. Most noteworthy, however, of all Lord Rosse's experiments are of course those connected with the casting and figuring of really large specula. The primary difficulty was the successful annealing of large masses of speculum metal in which the copper content was relatively low; for only to such mirrors was it possible to impart a really brilliant and lasting polish. While this difficulty was still outstanding, Lord Rosse turned for a time to an alternative expedient-that of building up a speculum of a number of thin plates of a highly reflective but brittle composition. These plates were soldered side by side to a stout backing of brass, so compounded as to have as nearly as possible the same coefficient of expansion. Except for diffraction effects, caused by the intervals between the plates, this built-up speculum, of 3 ft. diameter, seems to have been entirely successful.Meanwhile a solution to the annealing problem had been found. It consisted in the casting of specula on a bed of hoop-iron packed tightly on edge. This promoted the rapid and regular cooling of the metal from below upwards, and by its means Lord Rosse was able successfully to cast specula of 6 ft. diameter. Two of these were eventually cast for use in the great reflector which marked the crowning point of the efforts of this tireless experimenter. The actual figuring of these great masses of metal, weighing three or four tons apiece, seems, strangely enough, to have presented comparatively little difficulty. It was of course necessary to devise special grinding and polishing machinery, all of which is fully described and illustrated in the papers; but previous experience with smaller specula had apparently done much to smooth the way for this greater undertaking. Much more serious was the difficulty of so mounting the finished mirror as to free it from the risk of flexure. However, this difficulty was almost completely met by mounting the speculum on a series of triangles, supported by levers, after the plan devised by Thomas Grubb. The design and erection of a mounting for the great telescope gave plenty of scope to the engineering ability of its constructor; and it is here worth remarking that the entire instrument was from first to last the product of local labour, under the instruction of Lord Rosse himself, and that the total cost was only £8000. The actual work done with the great telescope, especially in revealing for the first time the spiral structure of certain nebulae, is a matter of astronomical history, and need not here be described. One point, however, brought out clearly in the detailed description of the telescope's performance, seems worthy of emphasis in view of statements sometimes to be found in less authoritative accounts. We refer to the defining power of the great speculum, which has often been described as being of a distinctly inferior order. That there were many occasions when, in the climate of Ireland, such a telescope would perform but poorly, will be readily understood by all who have worked with large apertures; also it appears that flexure was occasionally a source of trouble; but, on the other hand, it is equally clear, from details given here and there in the papers, that the telescope did at times perform splendidly, even under high powers, which it certainly could not have done had the figure of the speculum been appreciably defective.The volume closes with some interesting extracts from the correspondence of Lord Rosse bearing on the early history of the ' ironclad.' Apart from any value they may have had at the time they were written, they serve to illustrate the versatility of this remarkable man; and it seems worth remarking that they were destined to be by no means the last contributions of the Parsons family to the science of marine engineering

ISSN:0028-0836    

DOI:10.1038/119627a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

(1) DR. SCHUEPP'S own contributions to our I-' understanding of the part played by the plant meristem are a guarantee that this section of the new handbook of plant anatomy is in safe hands. He points out that after a period, from 1870 until1880, when the meristem, and especially the growing point, was the centre of botanical interest, the subject has somewhat fallen into the background, to be brought forward again to-day, to some extent, in the attempt to understand some of the phenomena of graft hybridisation and especially periclinal chimeras. It is interesting, therefore, to see how concepts that were formulated in an earlier period of botanical activity fare when made the basis of treatment in a modern monograph of the subject. Dr. Schiiepp presents the subject as a problem requiring elucidation from the viewpoint of causal anatomy, but he is not inclined to attach great significance to attempts to explain cell division, its order and direction, along the lines of simple physical laws, as foreshadowed to some extent by Berthold in his "StUdien fiber Protoplasmamechanik." He discusses the different types of apical meristem of the vascular cryptogam and the flowering plant, finding a transition between the apical cell of the former and the uniform meristematic tissue of the latter in the initial cells of the apex of the axis of the Lycopodiales and Gymnosperms. The initial cell is not an apical cell, because it is not characterised by special size, form, or manner of division, but it is a cell or group of cells from which all the tissues of the growing region derive. In the Gymnosperms, Haustein's distinctions of dermatogen, periblem, and plerome cannot hold, even the dermatogen showing occasional periclinal divisions, and the result of the discussion is evidently to minimise their importance in the complex construction of the Angiosperm apex. For the root another distinction of ' cap ' and ' core ' is drawn, the cell series in these two regions arising from the ' urmeristem ' by a different order of cell division, which affects their symmetry as derivatives of the active apical meristem. Root systems are then classified according to the relative share these two tissues play in the differentiated root; the cap may only form the root cap-on the other hand, it may form every tissue from the outside of the root cap down to the endodermis.Embryonic meristems are also briefly discussed, Soneges being chiefly followed here, but the monograph is mainly valuable for its clear and critical discussion of the activity of the apical meristems of shoot and root. It is interesting to see that the theory that the endodermis acts as a tissue-absorbing pocket, in advance of the growing point of the secondary root, is given on the authority of the earlier workers without comment, though it has been thoroughly negatived by Friedrich Lenz (in 1910-11) and is not supported by any modern experimental work so far as is known to the reviewer. (2) Prof. Guttenberg has made a very full compilation of the literature in a somewhat artificially delimited field of plant anatomy. Naturally the treatment is of adult tissues, without consideration of development, and from a strictly teleological viewpoint. The classification adopted in the same field by Haberlandt is followed without alteration.Tissues involved in active movements such as dehiscence or growth mechanisms, etc., are first distinguished from tissues concerned in passive movements, such as the floating mechanisms of water-dispersed seeds and fruits. Tissues concerned in active movements are classified as dead or living tissue systems. In the dead systems those depending upon hygroscopic movements in anisotropic wall systems are distinguished from mechanisms such as the fern annulus, which depend upon the cohesive pull upon elastic walls, exerted by the gradual diminution of the water content in cells full of water. There is a very brief discussion of growth curvatures, as these are not usually associated with special tissue systems. A brief description of stomatal movement is found amongst living tissue systems associated with movement; this discussion is restricted to the effect of the histology of the guard cells and other special cells upon the movement mechanism. A very complete bibliography is included. (3) In this monograph Prof. Miehe passes in review many of the puzzling facts associated with the capacity for reproduction, especially vegetative propagation, of the plant. He then suggests that the capacity of a cell to construct new protoplasm and then multiply by division, in other words, the meristematic properties of the cell, may be a function of its content in a special type of protoplasm, the ' archiplasm.' Cells of the permanent tissue, incapable of reproduction, are then deficient in this 'archiplasm.' Prof. Miehe terms them' ergoblasts 'as compared with the potentially reproductive ' archiplasts,' which in the meristeiA of a growing point may be massed in an 'archenchyma.' This new viewpoint evidently admits of a re-interpretation of well-known phenomena in terms of a new phraseology, but as the 'archiplasma ' cannot be recognised save by its effects on reproduction, and as no new experimental method of attack is suggested, it.is questionable if it does much more. It at least puts upon recordProf. Miehe's view that all living cells of the plant cannot be regarded as ' totipotent 'in reproduction, a viewpoint towards which Vochting's experiments had led him.This theoretical conception of the ' archiplasm' is applied in a very brief general review of reproduction and regeneration in the plant. The subject is one on which generalised statements are difficult to make, and two are noted to which exception can certainly be taken, namely, the statements (p. 37) that adventitious roots arising upon shoots always appear in the pericycle, and (p. 39) that the phellogen is a tissue which is never associated with the origin of buds.

ISSN:0028-0836    

DOI:10.1038/119628a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ALL those who are well acquainted with recent psychological thought must turn with unusual interest to a comprehensive expression of the views of Dr. William Brown. This they will find set forth in the volume now offered to us, which-to use the author's own words-is " an attempt to obtain a synoptic view of personality, as considered from the standpoints of the various sciences-especially from those of psychology, psycho-pathology, and philosophy." Besides these three sciences, however, there might well have also been made a claim for physiology. For from this latter it is that Dr. Brown first embarks upon his course, and in a definitely anti-mechanistic direction. "Although the body," he says, " does obey physical and chemical laws, processes nevertheless go on in it which are inexplicable in those terms." Among the non-mechanical characteristics of bodily conduct he enumerates " spontaneity," " persistence of action after the stimulus producing the action has disappeared," " the coming to an end of the activity after a certain purpose has been achieved," " the power of learning by experience," the action of " the organism as a whole "; in short, the fundamental fact that " all animal behaviour is purposive."Turning to the point of view of psychology, we find that the author rather curiously trisects this into " psychology " pure and simple, " experimental psychology," and " child psychology." Dominating the first of these three divisions comes for him the conception of the mind " as a system of interests, with emotional reactions, showing different degrees of unity in the systems of subordinate unities; these systems being incorporated in wider systems, and these wider systems again being incorporated in still wider systems, till at last one has a total system dominated by one allsatisfying interest." As for " volition," this he takes to consist of " the whole character in action with the sentiment of self-respect in command." In his second or " experimental " division of psychology we come upon an assortment of such topics as psycho-physical methods, cutaneous sensibility, visual experience, mental variation, and mathematical ability. His third and last division, that which deals with the child, is most notable for warning that undesirable juvenile propensities should be counteracted, not by " repression," but instead either by " substitution or else by " sublimation." From the author's next scientific point of view, that of psycho-pathology, he strongly defends the distinction that has been drawn between " organic " and " functional " nervous disorders. As regards the latter, he urges that "physical and physiological methods of treatment have shown themselves thoroughly inadequate to cope with the situation." In their place he recommends, not so much " psycho-analysis " in particular, as rather IC deep analysis " in general. This supplies a procedure whereby to resolve the abnormal systems of interests called " complexes," as also possibly the normal systems called " sentiments." Here and indeed almost throughout he is greatly influenced by the teachings of Freud, which he either admiringly accepts or else sharply contests. An example of the critical attitude is his emphatic rejection of the belief that a young child has ever present a strong feeling of hostility towards the parent of like sex. He further repudiates the suggestion that the unity of the mind has been proved to be a comparatively late mental product. On the contrary, he says, " the results of psychological analysis itself show an underlying thoroughgoing unity."The author's third or philosophic point of view brings him to the topic of ethics; and here he ranges himself on the side of the intuitionist school. Turning, next, to the theory of evolution, he proceeds to combat the " aimless freedom of spontaneous activity and pure duration " advocated by Bergson, and would substitute in its place the " real freedom of deliberate choice." Then follows his treatment of the problem which appears to have for him the deepest interest of all; it is thatof religion, which he defines as an attitude " of personal relationship towards the universe." This leads him, finally, to the region of mysticism, where his counsel is that we should seek to transcend time and in such wise follow the exhortation of Aristotle " to be immortal as far as possible even in this life." On the whole, Dr. Brown ranges over an extraordinarily wide field. But for so doing he can at least claim the high sanction: Wer vieles bringt, wird manchem etwas bringen.

ISSN:0028-0836    

DOI:10.1038/119630a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

Z OOLOGY has been suffering during recent years under the unjust and wholly undeserved criticism that it does not readily lend itself to experiment and is therefore, in this respect, inferior to botany as a subject for inclusion in the school curriculum. It is true that there is still a tendency to lay too much stress on structures and to neglect the functions served by those structures, but this is the fault of the teachers rather than the subject. Prof. Dakin's book is at once a complete justification of the right of zoology to be considered as an experimental subject for school work, and a guide to the teacher as to how the relative claims of function and structure can be adequately met in their courses. Function is the dominating note of the book and, except for a chapter specially devoted to the Protozoa, the subject matter is arranged under the headings of the various functions of animals and not undet the customary systematic groups. In dealing with any one function, the author has given just so much structural detail of the organs concerned as is necessary for a proper comprehension of their uses, and has saved much valuable space by the free use of carefully annotated drawings and diagrams to impart the details of anatomy. Among the most valuable parts of the book are the experiments, which are carefully outlined in each chapter, for practical demonstration of the physiological processes underlying function. The material chosen for these experiments is readily obtainable and easy to manipulate; the experiments themselves are simple and the apparatus inexpensive. With these as their guide, teachers should have little difficulty in making intelligible, even to their younger pupils, the life processes of the living animal. They will at least be able to make zoology a living science.The book is intended mainly as a guide to the study of animals through their functions, but in order to meet the needs of laboratories where one type is studied at a time in the practical classes (and this must inevitably be the case in most school laboratories), the author has assembled in the index all references to a particular type under one heading, so that the book readily lends itself for use as a practical text-book from the systematic point of view. Special praise must be accorded to the illustrations. Not only are they clearly and beautifully reproduced, but also they have been chosen with great care, and in nearly all cases have been modified and specially annotated. Their value has been enhanced enormously thereby. Prof. Dakin has, in our opinion, abundantly justified the preparation and publication of this book. It strikes a new note in text-books of zoology, and should prove of incalculable help to teachers of biology in schools, while university teachers will find much in it of real use for their intermediate courses. It is the most refreshing and stimulating text-book, from the teachers' point of view, that has been published for some time. The Oxford Press deserves special commendation, not only for the admirable way in which the book has been produced, but also for its remarkably low price.

ISSN:0028-0836    

DOI:10.1038/119631a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ELECTRICAL contractors form a very important section of the engineering industry. It is curious, therefore, that so few books are published to meet their needs. It is necessary that they should know the best method of organising their businesses, preparing estimates, reading and supplying specifications, and preparing schemes for lighting, heating, and power. They have also to know the best materials to use in given cases. We think that this book under notice will be found of practical use to contractors. In an introduction, stress is laid on the importance of good workmanship. To have cheap materials properly installed by a conscientiously competent workman is much preferable to having good materials casually and carelessly installed. Screwed steel conduit, for example, even when of the best quality, does not signify a safe installation if improperly fitted up. Special care has to be taken when choosing switches for bathrooms, kitchens, cellars, and so on. It is specially important also that the ' earthing ' of the conduit be efficiently done. Useful information is given on illumination work, the number of foot candles required for all kinds of lighting being specified. The methods of installing electrical signs are described. We are told that the well-known 'neon' illumination of the Coliseum, Charing Cross, London, and the enormous Daily Mail sign at Blackfriars Bridge over the Thames, consume only 22 and 15 units per hour respectively. The high-tension side of these signs, which operates at pressures not less than 2000 volts and is consequently dangerous, is erected by the makers themselves. It is pointed out that it is sometimes advantageous to work the electric bells in a house from the alternating current supply.

ISSN:0028-0836    

DOI:10.1038/119632b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

A USEFUL compilation, of which the first two parts have appeared, is in course of publication. It is a catalogue of all plants collected in Siam, with a full record of collectors' specimens, references to literature and synonymy, together with occasional notes by the author, who has critically examined, wherever possible, the type specimens and other specimens quoted. The local Siamese and Malay names are given. No new species are recorded, though very many of those listed have been described by the author himself in the Kew Bulletin from material supplied by recent collectors, chiefly. Dr. A. F. G. Kerr, Mrs. D. J. Collins, and members of the Siam Forest Service. The geographical situation of Siam lends special importance to its flora, for it is a focus for intrusive plants from south-west China, Burma, and the Malay Peninsula. Possibly also (with the adjacent countries which go to make up Indo-China) it has been a centre from which certain species have been disseminated. It must, therefore, have a considerable bearing on the floristic relationship of those different regions.

ISSN:0028-0836    

DOI:10.1038/119633b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

DURING recent years X-ray analysis has been successfully applied to the investigation of long-chain organic compounds. The method seems especially adapted to the study of polymorphism of such substances (Piper, Malkin, and Austin,Jour. Chem. Soc., 1926; 2310. G. M. de Boer, NATURE, Jan. 8, 1927. J. Thibaud,C.R., 184, 24, 96; 1927).The easiest method to follow is to make a thin film of the substance on a glass strip (by melting or by crystallising from a solution) and to use this as a 'turning crystal' in the X-ray spectrograph. By exposing the film to monochromatic X-rays, rather sharp lines are obtained, which are due to a long spacing present in the micro-crystalline film. This long spacing is a beautiful characteristic of the modifications of the substance which sometimes gives information not so well afforded by an investigation of other physical constants as the heat of transformation. In continuation of such former work, I have studied in this manner the influence of temperature on the modifications of the odd and even saturated fatty acids. For this purpose the preparation was placed inside a small thermostat, which was mounted on the crystal table of the spectrograph. For the passage of the X-rays the thermostat was fitted with two windows covered with goldbeater skin. By electric heating it was possible to obtain temperatures from room temperature up to 600, the temperature being measured with a mercury thermometer.Using copper Ka radiation, photographs were taken at different temperatures showing the lower orders of reflection of the long spacing. The distance between the third and fifth orders was measured, and from this the spacing was calculated. The data obtained with the odd acids, which behave differently in general from the even acids, are summarised in the following table:\Acid MeltingPnint. TransiticPoint. I Spacing cf the Mcdification. IAt Lower Temp. At Higherremp. °c.C. flu. flu, Au. I Au.a. zuiH015112202 013112,02017115502 28-241-2 521606 1732 4454 30-1 ..35-1 31-5 39.7 [ 35.9 .. 40225-4 298 I34.4 387At the transition point, the 1-modifications pass into the a-modification and vice versa. The presence of two 3-modifications in the table needs some further explanation:At the lower temperature, in the case of Cn and C1, all specimens showed the '13I-spacing,' whereas films of C, and C17 always showed the '13,s-spacing.' It was possible, however, to obtain in some ways films of C, showing not only the pibut also the PsI-spacing, and films of C, showing, besides the Oiu-spacing, also the 3i-spacing. When these films, however, after first being transformed into the a-modification, were again cooled down below the transition temperature, the a-lines of course disappeared, but only lines due to one 1-modification reappeared. In the case of C, this was the 13,-modification, in the case of C, the Iin-modification. From this we may conclude that the 13-modification is the stable one of C01 and the 13,1of C,. It must be observed, however, that heating the preparation for several hours at about 20 below the transition point did not seem to have any influence on the relative intensities of the lines due to the two ,13-spacings. This proves that if it should be possible to transform immediately the less stable form into the more stable one, the rate of this transformation at least must be very slow.Pm. 1.-Spacing constants as a function of the number of C-atoms of the molecule. The dotted lines relate to the even acids, and the continuous lines to the odd acids. Though several trials were made under different conditions, I never succeeded in observing a l131-modification of C, or a 13-modification of C,7.For some of the even fatty acids Piper has found three different modifications at room temperature which he calls A-, B-, and C-modifications. According to Piper, these modifications are independent of the temperature, their occurrence depending only on the way the preparation is obtained. In the present investigation, however, I could show that these modifications are also influenced in a. certain way by temperature. For example, starting with a preparation of palmitic acid, which showed at room temperature three modifications at the same time (spacings A 41.2; B 39 5; C 35-8 A.U.) and heating at 450 for three hours, the B-lines had nearly disappeared, the A-lines persisted in about the same intensity, whereas the C-lines had much increasedRaising the temperature to 500 for two hours, the Aand B-lines both had wholly disappeared, whereas only C-lines appeared on the plate. Raising againthe temperature to 590, no further changes occurred. On cooling down again to room temperature, a photograph was obtained identical with that at 590; no A or B spacing reappeared. In the case of stearic acid, starting with a film which showed only the B-lines at room temperature, after heating to 550 only the C-lines were observed. In the case of capric and laurie acid, only the C-modification was found at room temperature, which remained unchanged when heating at some degrees below the melting temperature.Thus the even fatty acids seem to have only monotropic modifications of which the C-modification is the stable one. In the accompanying diagram (Fig. 1) the spacings observed are plotted against the number of carbon atoms of the corresponding molecule. So far there seems to be no simple relation between the spacings of the even and the odd acids.Our results seem to confirm some suggestions already given by Garner (Garner, Madden, and Rushbrooke, Jour. Chem. Soc., 1926; 2491). I have to thank Mr. J. A. Prins for much helpful advice during the course of the work.In conclusion, I wish to express my thanks to Prof. P. E. Verkade, of Rotterdam, for supplying several pure fatty acids, and to Prof. W. E. Garner, of London, who put some pure heptadecylic acid at my disposal

ISSN:0028-0836    

DOI:10.1038/119634a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

KAMMERER'S untimely death has confronted us with three problems, seeming intrinsically interwoven, but, as it appears now, distinct enough to be dealt with separately: they are—(1) The motives of his suicide; (2) the mystery of the ‘doctored’ specimen; (3) the validity of the original experiments on the nuptial pads in Alytes. The first question is chiefly psychological, the second criminal, while only the third concems biological science proper. Whilst we can conjecture the motives of Kammerer's weariness of life (see Moniatische Monatshefte, ii, 401, Nov. 1926; R. Wettstein, Neue Freie Presse, Dec. 16, 1926), we are at a loss as to the person who may have injected specimens with Indian ink or with what intention this may have been done. It seems not impossible that Mr. W. C. Kiplinger's suggestion is correct and that the injection was intended to enhance a faded appearance in order to get a good photograph, although the existence of other doctored specimens does not seem to be in favour of this version. A picture was taken in September 1922, not in the Biologische Versuchsanstalt, but in the photographic studio Reiffenstein, of the well-known specimen, and only from thence onwards do the mis-statements begin. On the other hand, up to 1919 the descriptions and figures of nuptial pads in Alytes given by Kammerer do not fit in with this specimen. We are therefore able to exempt any one who died before 1919, or had no contact with the Institute after that year, from any suspicion at having made the injection; for example, Dr. F. Megussar, who was killed at the Wolhynian front on Aug. 3, 1916 (see Archiv fkr Entwickl.-mech., 42, 222; 1917).We have been able to collect five proofs that in his original papers Kammerer was not hampered by the doctored specimen which has invalidated his remarks on the same subject in his books " Inheritance of Acquired Characteristics" (1924) and "Neuvererbung" (1925). By comparing dates and photographs we can now formulate these proofs even before the new experimental evidence which Kammerer's collaborators in Moscow are trying to get is available: the proofs are as follows: (1) In Kammerer's original papers the nuptial pad in Alytes is described and pictured as being " on the dorsal side of the thumb and on the thumb-ball " (1909, p. 516, fig. 26a), " on the dorsal and radial side of the first fingers " (1919, p. 336), and " across the thumb-ball on the whole internal side of the fore-arm to near the elbow" (p. 337, tb. x, fig. 2), in accord with the general appearance of nuptial pads. Even in 1923, when Kammerer showed a lantern slide of the critical specimen before the Zoological Society of London, he did not mention the disposition of the nuptial pad on the whole palm of the hand (see Bateson, NATUfLE, Dec. 22, 1923, and letter to Przibram). It was not until the photographs of this specimen were used in his books (1924, p. 53, fig. 9 to the right; 1925, fig. 9, facing p. 20) that Kammerer mentions and defends the untoward position of the pad in the palm and on the outer border of the last (fourth) finger.(2) The photograph in his original paper (1919, tb. x. fig. 2), taken by E. B. Congdon (see ib. p. 369) in Kammerer's and my presence in 1913 (letter of Congdon, professor at the Chulalangkara Medical School, Bangkok, Jan. 8, 1927), shows a narcotised Alytes with nuptial pads on the radial side of hand and arm. (3) The drawings by Kaspar of microtome sections (Kammerer, 1919, p. 370, tb. 11, figs. 7, 9), and the photos thereof by Prof. H. Joseph (ib. tb. 10, fig. 4), relate to skin taken in 1913 (see ib. p. 331) from the hands of Alytes in Kammerer's presence by Olga Kermauner, sister of Prof. Kermauner, of the University of Vienna, now married to Mr. Critikos. This lady histologist herself prepared all the slides and remembers having been struck by the difference in those of the water-bred Alytes as compared with the normals from the beginning (letter by Mrs. Olga Critikos, 914 Leland Ave., Chicago, Dec. 15, 1926).(4) Comparing the known forms of nuptial pads in other species as to their horny spicules (Lataste, Meisenheimer, Harms, Kandler, etc.) with these drawings and photos of Alytes, there seems to be full specificity of these structures. Even the sections of Bombina maxima, the nearest approach to Alytes, can easily be distinguished from the photographs and drawings which Dr. Noble (Museum, New York) has sent me. The species B. maxima was not known to Kammerer and has never been kept alive at our Institute (see list of animals, Zeitschrift biol. Technik ft. Methodik, 3, 163; 1913, p. 214). (5) The histological features of Kammerer's sections of nuptial pads in Alytes are furthermore identical with those of a specimen found in Nature by R. Kandler (Jenaische Zeitschrift, 6o, 175; 1924, tb. x. fig. 12) with rudimentary nuptial pads. The strati fication and relative nuclear sizes of the said sectionsare also exactly duplicated by those of sections taken from normal Alytes (Kammerer, 1919, tab. 11, figs. 1, 2, and photographs sent by Dr. Noble).These five proofs being each conclusive and independent of each other, I should think the nuptial pads in water-bred Alytes must be seriously taken into consideration, unless some one should offer another explanation of the coincidence of the five points raised

ISSN:0028-0836    

DOI:10.1038/119635b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the very sympathetic notice of my book, “Plant Nutrition and Crop Production,” in NATURE of Mar. 26, p. 454, the reviewer raises the interesting question how far science has actually helped in increasing the production of food. Statistics show that, in spite of the scientific work, the yield of wheat per acre in England is not much greater than it was fifty years ago, and it is implied that scientific work has in practice achieved little, however interesting its results may have been from other points of view.The statement is partly true, but the conclusion is entirely wrong. There are several ways in which food production may be assisted by science, among them: (1) increasing the output per acre of land, (2) increasing the output per man-hour of labour, (3) increasing the area of cultivated land. The great development of transport during the past fifty years led to the opening up of new countries, and made the third of these possibilities the easiest; it was consequently adopted. The extension in area of cultivated land has proceeded pare passu with the growth of the population, and there are still, as there were fifty years ago, some two acres of cultivated land for each civilised human being. There has been no pressing necessity, and therefore no economic inducement, to increase output per acre. The great increase in rates of farm wages, however, has compelled an increased output per man-hour of labour, and this has been accomplished. In 1881 on a farm of careful management and careful records it took 117 man hours to grow one ton of wheat; in 1921 only 82 hours were needed. Equally marked changes have taken place in the root crops.Further,'science has greatly increased the certainty of crop yields: catastrophes are things of the past. In 1844 potato blight came to the British Isles, and for forty years its depredations were almost unchecked. It caused the appalling Irish famine of 1845-46, and between 1877 and 1880 its damage in Ireland alone was estimated at £20,000,000. The committee of inquiry set up in 1880 reported that all witnesses, scientific and practical, believed it to be hopeless to prevent the spread of the disease once it had set in. All this is changed; an effective fungicide now keeps the disease in bounds so that it is no longer feared.By common consent the worst season of the last century for the wheat crop was 1879, when the persistent wetness and high rainfall completely baffled the farmers of Great Britain. The financial losses were appalling, and the season was long remembered with dread in the countryside. During the present century there have already been three years of higher rainfall, 1903, 1912, and 1924, than 1879, but there was no agricultural crisis. Of course there were losses, but they did not compare with those of 1879, and they are already almost forgotten. The statement, frequently made, that yields have not increased, is only partially true. Wheat is commonly taken as the test crop, but this is unfair. It was formerly the most important crop on the farm, but now it is much less important. The high yields of fifty years ago were attained by abundance of cheap labour; to-day this method is not available. New methods have been devised which pay the labourer several times the old wages and which yield at least as much produce per acre. More direct comparison can be made by taking crops in which we have been self-supporting over the whole period and for which therefore the relative importance in the farm economy has not diminished. Precise statistics of average yields are difficult to obtain, but trustworthy experts fifty years ago put the yield of potatoes at about 61 tons per acre under good farming conditions. Now, however, a good farmer would expect 10 tons per acre, and could reasonably hope for more. Similar increases can be recorded for some of the fruit and market garden crops, as well as the important cucumber and tomato crops.It is freely admitted, of course, that science has not been the only factor at work. The makers of implements, and fertilisers and feeding-stuffs, seedsmen, the country school teacher, and the farmers themselves have all played their part, but it is impossible to deny that science has largely contributed to the result. Finally, scientific work has demonstrated that this intensification of production is possible for all farm produce. At the present time much of the knowledge remains unused in regard to certain items such as wheat, lower qualities of meat, etc., because the alternative method of increasing the area of cultivated land still remains open and is cheaper. But obviously this will not always be the position, and it is perhaps the crowning achievement of agricultural science that it is steadily working at methods of intensification, knowledge of which will be imperative directly the area of cultivated land has reached its l

ISSN:0028-0836    

DOI:10.1038/119636a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature