摘要:

THE invitation sent out by the National -T Union of Scientific Workers to all those who have made science their vocation, to assist in building up an organisation which shall be fully representative of their various interests, may appear to some to be superfluous. They may argue that the functions which it is proposed this representative body should perform come within the scope of the legitimate activities of existing bodies, the various learned societies, propagandist bodies like the British Association and the British Science Guild, and the professional institutions the members of which are engaged in the teaching and practice of science. Others, while prepared to agree with the statement that none of the existing bodies is fully representative of science and the scientific worker, may feel that this is an advantage rather than a disadvantage, in that it is conducive to the freest expression of the will of the individual. They may fear that the establishment of a code of professional ethics, for example, might result in the growth of a narrow professionalism>deadly to the spirit of science. A hundred years ago similar objections were raised to the formation of the British Medical Association. Some qualified physicians, surgeons, and apothecaries on one hand, and all the quacks on the other, regarded this body with the greatest disfavour, the former because they resented the implication that the existing bodies were not allsufficient and wished to safeguard their right to control their respective branches of the medical profession, the latter because they were fearful of the material consequences to themselves. Yet it cannot be seriously suggested that the peculiar form of professionalism which was established mainly through the initiative and instrumentality of the British Medical Association has not been of the greatest advantage to the members of that profession and even more to the public. It must be acknowledged that the type of professionalism which insists that the results of ameliorative research should be made available to the whole world, which insists also that the discoverers themselves shall not derive any immediate and direct pecuniary benefit from them, is expressive of the highest ideals of service and calculated to attract to the profession some of the finest spirits of the age. Neither can it be said that the prestige of the Royal Society of Medicine, the Royal College of Physicians or the Royal College of Surgeons, or the faculties of medicine of the universities of Great Britain suffered through the activities of the democratically constituted body: actually their prestige was enhanced. The medical profession is practically a self-governing body, members of the profession predominate on the General Medical Council, and the Government puts large funds at the disposal of the Medical Research Council, most of the members of which, and the chief administrative officer, are also members of the medical profession. Moreover, they act in an executive capacity, and not merely an advisory capacity like the scientific members of the Committee of the Privy Council for Scientific and Industrial Research. The suggestion that the proposed body for science is superfluous is disposed of by the signatories and supporters of the present appeal: among them are some who have held or are at present holding high offices in learned societies and professional institutions. In another category is the vague fear that such a body would tend to warp the spirit of the individual scientific worker or restrain his freedom of action in any way. Much would depend on the character of the restraint. It might quite reasonably recommend its members not to apply for appointments where low initial salaries were not compensated for by the prospects of a moderate competency later, or where other conditions of service were notoriously bad. But it is difficult to imagine in what other ways it would fetter the judgment of an individual. It can scarcely be imagined that it would demand a thirty-six-hour week, or that it would exhibit that peculiar vice of modern trade-unionismthe excessive demarcation of function-or even that it would proscribe certain types of research. It is obvious that it must do none of these things. On the contrary, one of its most'important tasks might be the freeing of research workers in certain industrial undertakings and government departments and State-aided institutions from many of the unnecessary and irritating restraints from which they suffer to-day-conditions which are only possible because of the lack of organisation among the victims. Just as the British Medical Association broke down the narrow professionalism and exclusiveness of the older sectional organisations, so could the proposed body promote unity among the many distinct and overlapping sectional bodies in science.It is a little unfortunate that the general newspapers, in commenting on the appeal, have unduly stressed its material aspect, and almost entirely ignored the wider aims outlined. Naturally, a body which exists for the purpose of furthering and protecting the interests of scientific workers must do all in its power to bring about an improvement of the salaries and other conditions of service of its members. The shortage of men and women of the first rank for research has been noted in nearly every report on scientific research which has lately been published, and this shortage is attributed to the slender material attractions of a career which demands not only a rare type of mind, but also the utmost perseverance and selftraining. Amateurs of the type of Cavendish and Darwin are few in number. The ranks of research workers have now to be filled by those to whom science must be a profession. " Human nature," stated the Observer last Sunday, " would have to be more exalted than it is to secure that the highest gifts would always be devoted to the service of knowledge for a reward much lower than accrues to mediocre grades of business ability." Clearly, it is the duty of the profession of science to ensure that the value put upon its services is sufficient to attract the highest type of recruit. More is, however, demanded. Scientific workers must be valued not only for their achievements in harnessing the forces of Nature to the service of man, for giving him a greater measure of control over his environment by their successes in the combat against the diseases which afflict human beings, animals, and plants; for the material blessings they bestow on communities, or for the potency of the lethal weapons they have devised. They must be valued for their greatest achievement, the habit of mind which their patient and persevering observations and inquiry has engendered. They can bring to the examination of world problems an outlook which cannot rest content with partial and incomplete solutions. Hitherto, they have been denied the opportunity of directing or sharing the control of the affairs of a civilisation for which they are mainly responsible. Again, the remedy lies with scientific workers themselves. They could, if they were united in a great resolve, make the nation understand the contributions they have to offer to its problems, social problems, industrial problems, problems of finance. It is essentially their function, and not primarily that of a government department, to state the aims and the needs of science, and how best those needs can be met. It is their paramount duty to insist that science should be adequately represented in the councils of the nation, and they could best accomplish that end if they presented the appearance of a disciplined force instead of unorganised or inchoate and impotent factions.It may be thought that unity in science will be best accomplished by the formation of a federal council upon which the various learned societies and professional institutions can be represented, rather than by a body aiming at becoming representative of these varied interests on the basis of individual membership. Scientific workers must realise, however, that to be effective, a federal council must have executive authority. It must be in a position, should the necessity arise, to take action involving each and all of the constituent bodies without direct reference to them: in other words, the constituent bodies must delegate large powers to their representatives. The breakdown of the Conjoint Board of Scientific Societies was largely due to the reluctance of the various societies to grant their representatives any such authority; and, in the end, to the Royal Society deciding not to support an appeal to Government for increased aid for the publication of scientific papers. Other attempts to obtain concerted action by the various societies have been equally unfortunate. On the other hand, if scientific workers are of opinion that a representative body able to speak with the authority of the majority of men and women professionally qualified for scientific service by their university degrees or other qualifications, is desirable for the advance of science and civilisation, they should make their wishes known.

ISSN:0028-0836    

DOI:10.1038/119341a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

G EOPHYSICS has now its 'Lehrbuch'; at vG any rate, it has two-fifths of one at the moment of writing, and the remaining instalments are promised for an early date. lty that no single author can cover the whole subject has been met by obtaining the collaboration of a number of authors, and the whole is under the editorship of Prof. B. Gutenberg, whose distinguished work has already led to great advances in seismology and the study of the propagation of sound. The first two parts are by Profs. A. Born, E. A. Ansel, A. Sieberg, J. Bartels, and Gutenberg himself. The opening chapter consists of three pages on cosmogony by Born, and gives short summaries of the nebular and planetesimal hypotheses of the origin of the solar system. It is rather unfortunate in mentioning work of mine in support of the planetesimal hypothesis; though the hypothesis I favour starts with the same initial assumptions as the planetesimal hypothesis, to the authors of which I have often expressed my indebtedness, it happens that the principal modification I have found necessary consists in dispensing with the planetesimals, and consequently a different name is needed for the theory I have advocated. The author decides that the primitive earth was fluid; this agrees with my own views, but not with the original form of the planetesimal hypothesis.Prof. Born then gives a condensed account of the classification of rocks, with much useful information about their composition, mechanical properties, and thermal conductivity. Such information in an accessible form has long been needed; most analysts seem to think that it is much less important to know the density of a rock than whether it contains 0 3 or 0 5 per cent. of titanium. On p. 8 aluminium has somehow escaped mention as a constituent of felspars. The composition and radioactivity of meteorites are then described, and Prof. Born goes on to the abundance of the chemical elements in the crust. The greater density and basicity of suboceanic rocks in comparison with continental ones are brought out. Data concerning radioactivity are given, but thorium contents are given only for basalts. A very good account of methods of determining geological time follows; De Geer's method for post-glacial time is included. The main geographical features of the earth are described in the next chapter.There is a remark on p. 52 that the melting-point of basaltic rocks at atmospheric pressure is about 200°-300° C. lower than that of granite ones, which is given as 11000. F. W. Clarke gives 12400 for granite, and values from 1060° to 12500 for basalt (" Data of Geochemistry," 1924, 298-301). J. H. L. Vogt gives 1250° for the crystallization point of gabbro, which is chemically similar to basalt, and 10000 for granite (" Economic Geology," 1926, 207-233). The latter estimates refer explicitly to dry material, but it seems to be generally believed by geologists that in natural conditions the melting-point of granite is more affected by water than that of basic rocks. A reconsideration of the data on this question is overdue; such a conflict of opinion on some of the most important experimental data of geophysics should not be allowed to persist. A useful discussion of gravity and isostasy by Prof. Ansel follows. The account of the differences between the Airy, Pratt, and Hayford views of isostasy is clear and good, and there is a short account of the figure of the earth. The method of reduction of gravity observations is described, with special application to European data.Movements of the crust are then treated by Prof. Born. Those on a continental scale are treated shortly, and then there is a description of the processes involved in the formation of mountains, with many excellent illustrations and accounts of relevant experiments. Pp. 122-125 are concerned with objections to the contraction hypothesis in general, not merely to the thermal contraction hypothesis. All seem to me quite unsound. One is that the strength required in the crust if it is to support itself like an arch without resting on the interior is many times the crushing strength of rock materials. Of course: but who has said that the crust had to become detached from the interior before it could be crumpled ? Phenomena of denudation and vulcanism are discussed in the next two chapters, mainly quantitatively. The section on earthquakes in relation to geology is by Prof. Sieberg. It is concerned mainly with macroseismic data; there are several striking illustrations showing the fractures, rotations, and other disturbances produced in the neighbourhood of an earthquake. In addition to the ordinary scales of intensity, Prof. Sieberg gives one of his own adapted to disturbances felt at sea. The relations of earthquakes to volcanic and tectonic disturbances, and the physical processes involved in earthquakes, are then treated at considerable length.The chief types of seismographs are described by Gutenberg in the next chapter. A novelty is an account of the torsion seismograph of Anderson and Wood, which depends on a cylinder mounted on a vertical wire in such a way that its centre of mass is not on the wire. Horizontal disturbances of the ground displace the wire and cause the cylinder to rotate about it. Then Gutenberg proceeds to consider the information yielded by the records of distant earthquakes. Most of his work on this subject has already been published, but not in so convenient a form, and it is so important that a connected account of it is invaluable. On pp. 245-6 tables derived from observation show the times of transmission of the direct P and S waves through the earth. These times are mostly rather shorter than those obtained by Zoppritz and still used as a basis for reductions by Turner; the differences for P reach about 12 seconds when the epicentral distance is 90°, while those for S are on the whole rather less. Gutenberg's times have been derived from a discussion of many more earthquakes than were available when Zoppritz wrote, and have been supplemented by the amplitudes of the displacements observed, which afford a valuable check on the times measured directly. In addition, he has used these times to calculate the times of transmission of the various other waves theoretically possible. Following up some earlier work of R. D. Oldham, Gutenberg has found that the earth has an extensive central core where the S (distortional) wave is not transmitted, and the P (compressional) wave travels much more slowly than in the outer parts. This opens up the possibility that any wave incident on the boundary of this core will be broken up into three new waves-compressional waves in both shell and core, and a distortional wave in the shell. Waves incident on the outer surface, again, in general give rise to both compressional and distortional reflected waves. The waves transmitted into the core can undergo further separations when they emerge from it, so that on the whole a very complex picture is presented of the motion produced by a single earthquake shock. In the figure on p. 247 there are 16 curves showing the times of transit of waves to different distances; originally only three of these were empirical, and all the others are direct inferences from these three by means of the ordinary laws of wave propagation. I believe I am right in saying that every one of these curves has been verified by tracing the derived waves on actual records. Near earthquakes and surface waves are then discussed, with several other interesting seismological questions, and Prof. Gutenberg then passes on to water waves and tides. The bodily tide, precession and nutation, and the variation of latitude are well, if somewhat briefly, discussed. The last twenty-three pages form the beginning of Dr. Bartels' article on terrestrial magnetism and related phenomena.That the book should be in the possession of every geophysicist need scarcely be said. Nevertheless one feels at times that the authors' style is cramped for lack of space, and that geophysics is too large for one text-book, even one of a thousand pages. Still the amount of information compressed into the first four hd pages is astonishing.

ISSN:0028-0836    

DOI:10.1038/119343a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

USUALLY, if one wants to discover detailed U and comprehensive statistics concerning all kinds of educational machinery from primary, secondary, technical, and art schools to libraries, and even theatres, they must be sought in many (and often elusive) publications. Here they appear in one volume-a recommendation in itself. It would be easy, of course, to succumb to the usual temptation presented by such a volume, namely, to compare its figures with those available in Great Britain. That is, however, a temptation we shall resist for three reasons. First, it is very difficult to make trustworthy comparisons where various parts of the machinery and their several objectives do not exactly correspond to those in Britain. Secondly, considerations of space would force us to select only those parts of the machinery in which we are specially interested; and, lacking the exact correspondence already mentioned, we would merely confirm the haters of statistics in their sweeping assertion that figures can be made to prove anything. The third reason, however, is the most important. It is that the idea behind this volume is not merely the presentation of many figures which uncontrolled enthusiasts may use to show how much more should be done in the fields which interest them most, or which railers against taxes may use to show in what manner public money is wasted. Nor is it, in the slightest degree, a defence of administration. It is a definite recognition that departmental statistics afford no real evidence of the intellectual progress of a country.Not yet is it sufficiently realised that education is a process by no means confined to the school. There are libraries and pictures; theatres and cinemas; churches and museums; books and companions: there are also thoughtless parents and heedless employers; and who will doubt the enormous influence of the Press ? All these, and countless other important and often unnoticed influences, go to make up the forces which determine intellectual progress. Only when their interlacing and interdependent qualities become more clearly perceived will the waste and sprawling disorder of the methods by which we try to advance become capable of scientific handling and direction. To the question of how is this perception to be achieved, there are doubtless as many answers as there are difficulties to be overcome; and one of the many difficulties arises out of our inevitable drive towards specialisation-in education no less than in other fields. As the specialist becomes. more immersed in his own developing activities, he, often becomes less inclined to do more towards cooperation than to utter phrases of pious generalisation in public, while in private he is apt to become contemptuous of what he regards as intrusion. To criticise this attitude too severely is futile. It is, after all, quite Comprehensible and is based upon a sound enthusiasm which is of vital importance to the swift destruction of the varied barriers against man's completer knowledge of his environment. Nevertheless, it must never be forgotten that specialisation achieves its highest value only by reason of its relationship to the great unity of knowledge which serves mankind. In Great Britain the tendency to draw together activities in order to obviate lonely and superfluous endeavour has recently found practical expression-particularly in the direction of securing a clearing-house for all kinds of specialised information -in the formation of the Association of Special Libraries and Information Bureaux. On the statistical side, it is in the category of such movements that we would place the present volume. It does not pretend to be so complete as might be desired. It is, indeed, frankly admitted that the lack of certain information makes the work fall short of the ideal which has inspired it. Its value, however, cannot be over-estimated, and we shall look forward to the next volume (1924-25) which is already promised. In the meantime we cannot do better than conclude by quoting a passage from the introduction:" Une publication comme celle-ci fait comprendre a quel point nous sommes loin de donner au public les renseignements qui serviraient a 6valuer la grandeur et la nature de la production francaise dans les sciences, les arts, les iettres et l'enseignement et en g6n6ral l'importance de l'activitd intellectuelle de la France. L'Institut International de Coop6ration Intellectuelle a fait savoir qu'il demanderait a tons les Etats de bien vouloir examiner les moyens de multiplier les releves statistiques relatifs a, la vie intellectuelle, suivant im plan qu'il leur proposera. II est certain que l'apparition simultan6e de statistiques bien faites sur l'activit6 intellectuelle de chaque pays pourrait singulinrement servir au progres gen6ral."

ISSN:0028-0836    

DOI:10.1038/119345a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

(1) OF recent years the application of potentiometric methods to the determination of conditions of equilibria in aqueous solutions as well as to quantitative analysis has assumed proportions of no inconsiderable magnitude, and has thus created a demand for text-books on the subjects. To English readers the appearance of the second edition in English of Michaelis's well known volume will prove a welcome addition to the textbooks, few in number, which are universally appreciated. It is unfortunate that in this edition the erroneous calculations of Ghosh, pp. 117-120, on the conductivity of strong electrolytes, have not been eliminated or replaced by those of Milner and Debye and Hfickel. The book is specially valuable, as it is the only one of which the reviewer is aware in which the various types of electrification which can be produced at interfaces are described and discussed. In biology, at least, phase boundary membrane and electrokinetic potentials appear to be of the greatest significance. (2) The volume of Kolthoff and Furman covers a somewhat different field. Here emphasis is laid on the more recent work on oxidation reduction potentials as well as the employment of metal electrodes in volumetric potentiometric analysis. The book is very well written and the conditions necessary for accurate work fully described. Possibly the weakest portion of the text is the descriptive portion in Chapts. vii. and viii. There are many simple and accurate potentiometers now on the market, such as that constructed by the Cambridge Instrument Co. designed specially for this work. These are now employed almost universally in research laboratories and works, and a short description of such might well replace some of the more complicated but no more accurate systems described. It is interesting to note that adsorption of precipitating ions may cause quite serious errors in the end points of various volumetric titrations in which precipitates are formed.(3) Kopaczewski has confined himself to the potentiometric and colorimetric methods for the determination of hydrogen ions. The theoretical discussion on the nature of electrolytic dissociation and on the various activity coefficients is treated very inadequately, whilst the remainder of the book, chiefly experimental in character, follows the usual course.

ISSN:0028-0836    

DOI:10.1038/119346b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIS monograph, dealing with the general 1theory of relativity, has a particular interest of its own in so far as it deals with a novel application of a recent generalisation of M. Cartan to the dynamics of the ether. Besides a brief historical introduction of three pages, and an appendix of nine pages on the technique of space and time measurements, there are two chapters, one of nearly thirty pages, dealing with the geometry of the spaces of the relativity theories, and another of nearly twenty pages dealing with the application of the principle of least action to the theories of gravitational and electromagnetic fields. The first chapter works out, by traditional methods, the generalisation of M. Cartan already referred to, in which the components rig of the affine connexion in Weyl's geometry are no longer assumed to be symmetric in the two lower indices. Consequently a new true tensor arises, namely, the torsion Ails rijt FiPj, which plays an important part in the geometry of the generalisation of Weyl's space. The second chapter, which is the novel part of the monograph, introduces an action integral after the fashion of Mie and Weyl, in which the action density is assumed, initially, at all events, to be a function of two tensors of the second order: one, the skew symmetric electromagnetic tensor, which is the rotation of the contracted components of the affine connexion, Fkjk, and the other, the gravitational tensor, which is the symmetric part of the contracted Riemann-Christoffel tensor, R,.The ether thus defined is deduced from a Riemann space by a projective conformal transformation, and that the vector potential of the electromagnetic tensor, apart from a numerical factor, can be identified with the contracted torsion tensor A, = AR'jk. With the action density so far defined as a function merely of the electromagnetic and gravitational tensors, the ether is empty, that is, devoid of electric charge and current. When, however, the action density in addition is an explicit function of the contracted torsion tensor, the current vector appears as the partial differential coefficient of the action density with respect to the new tensor. A plausible assumption as to the form of the action density in the general case leads to an energy tensor of the usual type, with a part representing the electromagnetic energy, another part representing the electronic energy, and generally a third complementary part, which has the character of a pressure. The additional hypothesis that the action density depends mainly on the gravitation potentials, gi, whilst the influence of the electromagnetic and current terms is comparatively small, leads to the results that (1) the Lorentz electrodynamics holds, (2) the atoms are bounded universes with constant total curvature, and (3) the complementary energy is absent, both in the ether and the atoms. The monograph is very concise, but offers no particular difficulty for readers familiar with the technique of the general theory of relativity. For such readers it will prove to be most interesting.

ISSN:0028-0836    

DOI:10.1038/119347a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THANKS to the courtesy of the Editor of NATURE, we are able to reply at once to the very kindly expressed criticism of Prof. Brauner. He considers that there is a possible source of error in our recent determination of the atomic weight of silver owing to the loss of traces of silver, by volatilisation, during its final melting in hydrogen. It is certain that, at the temperature of 900°, silver does give off some vapour, but we are convinced that no silver left the weighed tube. The silica tube was 17 cm. in length, not more than half of which was heated in the furnace. The rest, shielded from the heat of the furnace by asbestos board, together with the ground joint and narrow glass tube, has a length of 20 cm. They were kept cool by fanning during the whole time of the experiment. The current of hydrogen was very slow, about one bubble in 3 seconds.It is not possible that the silver, which may volatilise at 9000, should escape in the state of vapour. If it escaped at all, it must have been in the form of fine particles of solid metal, and it seems almost inconceivable that no deposit should ever have been observed throughout the eight years during which the experiments have been going on. In the last eighteen determinations the same pair of silica and glass tubes has been used, and microscopic examination fails to reveal any trace of deposit on the part of the silica tube which was cooled, or in the glass tube. A more certain proof, however, is given by the weighings. In each determination the silver was melted several times in the silica tube until its weight was constant to one or two hundredths of a milligram. If there had been any such loss as Prof. Brauner has suggested, such constancy could never have been attained; the weight of the tube would have shown a constant diminution. The knowledge of the atomic weight of silver is, as Prof. Brauner says, of such importance, that we have begun a new series of experiments to investigate the volatility and condensibility of silver

ISSN:0028-0836    

DOI:10.1038/119348b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN previous papers on the origin of the auroral spectrum, and recently in a letter to NATURE of Dec. 4, 1926, I have directed attention to the existence of a second green line lying in the region of about λ5230, which should correspond to the line, or rather group of lines, N2of the spectrum from solid nitrogen.As stated in my letter to NATURE, this second auroral line is usually extremely faint and has only occasionally been observed with spectroscopes; in consequence, various observers have found values of the wave-length which differ within fairly wide limits. On account of the faintness of the line, and also of the fact that the usual photographic plates have a minimum of sensitiveness in this region, I was not able during the early years of my work to obtain this line on my plates.On a spectrogram made last autumn, however, on a panchromatic plate, I obtained for the first time, after an exposure of forty northern-light hours, this second line; but it was too faint for accurate measurements. The wave-length obtained was 5223. After this spectrogram had been taken I was able to obtain a sensitiser which gave the plates a high sensitivity in the region wanted. The first exposure with this plate was made in a small spectrograph with fairly high light power and a broad slit. It was exposed at the Geophysical Institute of Tromso for fifteen effective northern-liglt hours. On this spectrogram, which gave the ordinary auroral lines much over-exposed, I also now obtained this second green line very well marked on the plate.The accompanying reproduction (Fig. 1) shows the strong green auroral line marked by a, the second green line by b, and the strongest lines of the negative band spectrum by c, d, e. It will be noticed first of all that the second green line is not sharp; although much weaker than the other lines, it covers a greater part of the spectrum. Measurements showed the breadth of the second green line to be 0-22 mm., while that of the other lines, although more strongly exposed, was only 0-15 mm.From this we can conclude that what is called the second green line is not a single line, but consists of a group of lines. As stated in my previous letter to NATURE, this is also the case with the N2 line from solid nitrogen. This fact, which has also been confirmed by McLennan, was taken by him to be an argument against my theory. We see, however, that the spectrogram obtained for the second green line, on the contrary, in this respect has confirmed my view with regard to the origin of the auroral spectrum. On account of the small dispersion and the broad slit we cannot at present find the wave-length of the He NL&l5 a FiG. 1. various components of the second green line; we have only been able to measure the wave-length of the maximum and limits of the band obtained by our plate. The limits are X\5220-5269, and for the maximum we find X5238. On account of the small dispersion, errors of a few angstroms are not excluded. Comparing this result with those obtained for the luminescence from solid nitrogen, it is of interest to notice that when small quantities of solid nitrogen are condensed in a solid system of inert gases, we find one of the components of N2, which in certain cases is dominant, to have wave-lengths of XX5236-5239, which within the limits of experimental errors correspond to the wave-length found for the maximum of the second green auroral line

ISSN:0028-0836    

DOI:10.1038/119349b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

PROF. JOHNSTONE'S letter in NATURE of Feb. 26 suggests an analogy. I happen for my sins to be gifted with very poor mathematical powers. Like him, also, on this account I “feel that I may be missing something that will help in an understanding” of the scientific problems with which mathematics are concerned. But I donottherefore attempt to belittle mathematical physics as Prof. Johnstone attempts to belittle the results of Mendelism.He asks " what are the fundamentals of genetics ? The 1fundamentals of genetics to date are, I take it, the laws of segregation, independent assortment, and linkage; the proof that the chromosomes carry the genes, and that the genes are arranged in linear order; the genetical results of heteroploidy and chromosome aberrations; the individuality of the chromosomes (as, of course, complicated by crossing-over); the normaT chromosomal determination of sex; the theory of genie balance; the facts concerning multiple allelomorphs, and multiple, modifying, and lethal factors; the new insight provided by neo-Mendelian methods into speciescrosses and into the effects of inbreeding and crossbreeding; the origin of certain variations by pointmutation, chromosome-mutation, genome-change, deficiency, duplication, balanced lethals, and abnormal crossing-over; the demonstration that Mendelism and biometrics are not opposed; the fact that no development is possible at all in the absence of at least one haploid set of chromosomes; the demonstration that genes often determine the rate of definite developmental processes. There are doubtless other points which I have forgotten in this hasty survey; but it is absurd to imply that this is not a very considerable achievement and an " ample foundation " for future work. Prof. Johnstone and Prof. Walker both seem to think that the sum of the genes cannot be responsible for the development of the " organism as a whole " or large characters such as the head. But has Liverpool never heard of Boveri's experiments on disperm sea-urchin eggs, published exactly twenty years ago ? It may be at present impossible to understand how the sum of the genes is responsible for the development of the organism as a whole, but Boveri made it reasonably certain that it is actually the case.However, the work of the experimental embryologists, of Child, and of Goldschmidt, is at last beginning to give us an insight into the how of this problem -but only by building on the Mendelian foundation which Prof. Johnstone scorns. I would refer critics to Goldschmidt's new book (" Physiologische Theorie der Vererbung ") and to a brief critical summary of my own (NATURE, Feb. 23, 1924) as showing how the obvious difficulties of the situation may perhaps be surmounted. I hope to summarise some of the recent work on the relations of hereditary constitution to developmental physiology in an article in NATURE in the near future. Meanwhile I would merely ask Prof. Johnstone whether he, like Prof. No6l Paton, wants to leave on one side all the results of Mendelian work in our attack upon the problem of heredity and its relation to the development of the organism as a whole ? That is the only meaning I can attach to his concluding sentences; and it appears to me to be a counsel of despair. Prof. Walker says (NATURE, Jan. 29, p. 161) that Dobell 'proved' that hereditary characters could not be controlled by chromosomes in certain Protozoa. The main reason advanced by Dobell concerned sex, and was that the Protozoa in question were haploid during all their sexually differentiated phase. If Prof. Walker had been better acquainted with genetical literature he would have remembered that almost simultaneously with Dobell's 'proof,' Wettstein was demonstrating experimentally, and conclusively, the control of sex by chromosomes in another group of organisms in which sex is displayed in the haploid phase-the mosses. Dobell's a priori arguments were never even theoretically valid, and long since fell to the ground on confrontation with actual fact.As to Tornier:-If Prof. MacBride chooses to believe that experiments on developmental physiology, unaccompanied by breeding, have any direct bearing on heredity, I fear I cannot argue with him; to my mind, Tornier's work has just as much (or as little) bearing on the origin of mutations as has that of Driesch or Jenkinson or Child. For the information of readers of NATURE, however, it should be recorded that Berndt (Zts. Ind. Abst. Vererb., 36, 1925) has repeated Tornier's goldfish work, and has also bred goldfish, on a large scale, and fails to verify either Tornier's facts or conclusions save in a few negligible deta

ISSN:0028-0836    

DOI:10.1038/119350a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WERNER'S conception of coordinated groups and of auxiliary valency has been extraordinarily useful in classifying and in elucidating the configurations of complex metallic compounds. Although many salts of this class, such astris-ethylenediamine cobaltic chloride [Co(NH2.CH2.CH2.NH2),]Cl3, have been resolved into optically active components, no proof has hitherto been given that an auxiliary valency linking can render a carbon atom asymmetric. This interesting proposition has been now established by the further study of the recently described salt, tetrachloro(triaminopropane monohydrochloride)platinum, PtCl4, NH2.CH2.CH(NH2).CH2.NH2, HCl, obtained by the action of the αβγ-triaminopropane hydrochloride on chloroplatinic acid (Mann,Jour. Chem. Soc., 129, 2681; 1926).In the new salt the components, PtCl4 and two of the NH2-groups with some of the associated carbon and hydrogen atoms, must lie inside the co-ordinated group, whilst the third NH2-group must protrude therefrom. It has now been found that the salt can be resolved into optically active components by the aid of silver dand i-camphorsulphonate. The two salts, I-base d-acid, and d-base I-acid, have thus been obtained in an optically pure state; the hydrochlorides regenerated from these salts give molecular rotations of 5020 and + 5010 respectively for the mercury green line in aqueous solution at 156. It is clear, therefore, that the constitution of the hydrochlorides must be represented by the following formula: CH2 . NH2, HCl C1 Cl\ ,I-NH2-CH Pt, I Cl/ "NH2-CH2L2 Cl In the above formula the enantiomorphism of configuration is associated with asymmetry of the middle or /3-carbon atom of the triaminopropane molecule; this asymmetry arises from the attachment of the aand /3-amino-groups to the platinum atom by auxiliary valencies. This is the first case to be recorded in which asymmetry of a carbon atom results from the operation of auxiliary valencies.The new type of molecular enantiomorphism now disclosed will no doubt appear among numerous complex metallic compounds and, indeed, a complex copper salt, analogous in constitution to the above platinum salt, has been already prepared (loc. cit.). We are now engaged on the further investigation of these and other related compoun

ISSN:0028-0836    

DOI:10.1038/119351b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

A NUMBER of spectra of zirconium ores and oxides have been examined for persistent lines of hafnium, using the wave-lengths for this latter element given by Hansen and Werner (NATURE, 112, 618; 1923). The most persistent lines observed—three of which were found in all spectra examined—are at wave-lengths2773 40, 2866 35, and 2919-55 angstroms, of which the first is the most persistent. Other lines slightly less persistent are 2516 85, 2887 15, 2898&25, 2904 40, (2904'80), 2940-80, 2964 85, 3194 20. (The line 2904 80 is uncertain on account of a strong zirconium line nearby. The hafnium line and its neighbour 2904 40 are possibly a pair like those at 2513 00 and 2512 70. The line 2904-40 is very persistent, but the shorter pair are not.) On account of the shortness of the range of Hansen and Werner's wave-lengths, none of these lines may safely be considered to be true raies ultinmes, but their persistence may have some practical utility. In this regard it may be remarked that the crude ores are but slightly more difficult of examination than are fairly pure oxides, in spite of the richness of the preponderant spectra involved. With moderate dispersion (XX 70002100 on a 10-inch plate) and good focus, the number of blends involving strong hafnium lines in the region studied is small and for analytical purposes probably of little moment. In using the ores and oxides of zirconium in a carbon arc, satisfactory spectra were not frequently obtained unless the arc carried enough current to be noisy. When satisfactory zirconium spectra were got there was no uncertainty about the hafnium traces, repeated exposures giving concordant results. Of the ores at hand the richest was of Wisconsin origin, being surpassed only by concentrates from a Carolina ore which was not available in crude state. In addition to the commoner elements in the ores, scandium appeared strongly in several cases.Regularities in the spectrum of hafnium, to which the persistent lines should be a guide, have not yet appeared satisfactorily. The arc spectrum should be of odd multiplicity; McLennan, McLay, and Smith (Proc. Roy. Soc. London, ii2, 76; 1926), applying Hund's principles, make the lowest arc term a triplet F. Inspection of Hansen and Werner's wave numbers beginning with the differences between the most per sistent observed lines reveals a number of apparent triplets, and several triplet combinations having satisfactory intensities and the latter meeting possible inner quantum restrictions. Lacking confirmation such as Zeeman effect, these regularities seem, however, too conjectural to deserve recording at pres

ISSN:0028-0836    

DOI:10.1038/119352b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature