摘要:

THE problem of the humane slaughtering of -T animals for food is one which has exercised many members of the medical and veterinary professions. It is of direct concern to men of science, first because certain relevant facts which are in dispute can only be settled by rigorously scientific experiment, and secondly, because the ethical principles involved have received a much enhanced significance from the work of Darwin and other zoologists. The discussion recently opened at King's College, London, by Profs. McCunn and Smythe, of the Royal Veterinary College, under the chairmanship of Prof. Julian Huxley, affords an occasion for putting before the readers of NATURE the more important of the facts relating to the slaughterhouse. In all matters which involve a conflict between ethical principles and economic interests the relevant facts are apt to become entangled in a good deal of special pleading, and in the present case there are certain points upon which even scientific authorities are not in agreement; but although the necessity for further inquiry of a rigorously scientific character is generally recognised, a number of important facts may be regarded as definitely established. The most recent authoritative documents for these are the reports issued by the London County Council on Feb. 15, 1923, and by the Public Health Department of the Corporation of London on April 2, 1925. Considerable importance attaches also to a paper read by Prof. G. H. Wooldridge before a meeting of the National Veterinary Medical Association and published, together with the discussion which followed it, in the Veterinary Record of Mar. 4, 1922; and to a report on the Jewish method of slaughtering by Prof. E. H. Starling and Sir Michael Foster, published by the Admiralty in 1904. The views of the meat traders were defended by Prof. Leonard Hill in the Lancet of Dec. 22, 1923, but the results of the demonstration arranged by them at Birmingham in November 1923 should be accepted with considerable reserve, so far, at all events, as the question of bleeding is concerned, since (according to Dr. W. J. Howarth, Medical Officer of Health to the Corporation of London) animals were " left on the floor for different intervals before the blood was allowed to be extracted." This incident emphasises the necessity for ensuring that such trials be controlled in every detail (including, by the way, the selection of the animals) by men trained in the rigour of scientific method.The old fashioned methods of slaughtering which are employed in the case of about fourteen million animals yearly in Great Britain are broadly as follows: Large animals before being killed are stunned with a poll-axe; pigs are hoisted with a chain attached to one hind leg and stuck, commonly without previous stunning; many calves and some pigs are first stunned with a hammer; occasionally sheep and lambs are similarly stunned, but usually they are lifted on to a ' crutch ' or trestle and stuck with a knife while conscious, after which their necks are broken by pressing back the head, the spinal cord being sometimes cut with the knife; Jewish slaughterers, for reasons of ritual, first throw the animal and then cut its throat in every case. The modern method, which is at present used for about one million animals yearly in Great Britain, consists in preliminary stunning with a specially designed pistol, after which the animal must be immediately bled.From the humane point of view the superiority of the pistol over the poll-axe has been placed beyond serious question by the experiments conducted on behalf of the Corporation of London by the Medical Officer of Health (Dr. W. J. Howarth), the Superintendent of the Metropolitan Cattle Market (Mr. J. R. Hayhurst), and the Veterinary Surgeon at the Central Meat Market (Lieut.-Col. T. Dunlop Young). These officers found, in a number of trials with careful and experienced slaughtermen, that it took on the average 2-49 blows with the poll-axe to stun a bull, 1-23 blows to stun a steer, 1 27 to stun a cow, and 1-55 to stun a large sow or boar. With careless or less experienced slaughtermen the results would have been still less favourable. On the other hand, with a particular captive-bolt pistol, 542 bovines were stunned with 543 shots and 712 swine were stunned with 715 shots. Starling and Foster found that when the throat is cut with exceptional skill (in the Jewish method) the duration of consciousness, as tested by corneal reflex and by purposiveness of movement, varies from 5 to 40 seconds, with an average in the neighbourhood of 20 seconds. The qualitative superiority of the pistol over the knife, from the humane point of view, may be regarded as established, though there is some difference of opinion as to the quantitative aspect of the matter. However, Sir Arthur Mayo-Robson has described an important post-mortem test which does not appear to have been applied in the investigations under consideration: it consists in examining the meninges. Dr. Pfister, Director of the Zurich Abattoir, has found that when animals have been stunned before killing their meninges are normal, whereas in animals killed without stunning, as many millions are in Great Britain, the meninges are intensely congested, a fact which proves that suffering has occurred. Finally, the use of the knife has to be learned by practising upon living animals. The captive-bolt pistol does not involve danger to the slaughterman or to bystanders, and its use calls for only such reasonable care as may fairly be demanded from a tradesman. The meat traders' federation collected for the London County Council inquiry 15 examples of alleged accidents occurring with 'humane killers' between 1913 and 1920, but of these 5 turned out to be cases of suicide and 4 to be otherwise irrelevant. Of 5 genuine and 1 suspectedly genuine accidents, 5 occurred with pistols of the free-bullet as distinct from the captive-bolt type, and in the remaining case the type of pistol was not specified.There are, however, other considerations which cannot be quite so easily dismissed. The most difficult of these is the allegation that pigs do not bleed so freely when shot as when killed by the old-fashioned methods, and that shot pigs are therefore less valuable for the manufacture of export bacon. It is also alleged that the flesh of shot pigs is more liable to be disfigured by 'blood splash.' The Corporation of London's research negatives the second of these allegations but leaves the first undecided: not only scientific authorities but also those engaged in the trade are divided on the subject, and further trials are called for. Doubtless a great deal depends on the precautions taken to promote bleeding immediately after shooting. In any case, it should be borne in mind that in large factories the pigs, when hoisted, are attached to a travelling conveyer, and owing to the weight of the animal the pressure of the chain on the leg will cause suffering, apart from the use of the knife. In the case of sheep the difficulty is somewhat different. If a sheep be lifted on to the crutch and then shot, its struggles are said to make manipulation of the pistol more difficult than that of the knife. If, on the other hand, it be shot on the ground, the labour of lifting it on to the crutch afterwards.is increased. Thus a 7-handed gang slaughtering 100 sheep a day might need an extra hand, whose wages would possibly amount to 128. 6d. a day. The increased cost of production would therefore be about Id. per sheep, or 0-025 pence per lb. of mutton. Such a small expense should not be allowed to obstruct thedoing of what is clearly just and right; Switzerland, Holland, Germany, Sweden, and Denmark have set an example which Great Britain could follow. In the Jewish method of slaughter, which is governed by a traditional ritual, the animal is first cast, after which its throat is cut with exceptional skill and elaborate precautions. From the humane point of view throat-cutting is not so satisfactory as stunning, but the most serious objection to this method is the preliminary casting, which in the opinion of Starling and Foster involves definite cruelty, sometimes of a serious character. The Jews are by nature and tradition a humane race, and it should not be impossible for their experts to devise some modification of the procedure which will satisfy all the requirements of the situation. Indeed, so recently as Mar. 17 an important test was held at Brixton of a new apparatus designed by Mr. H. Weinberg to obviate the cruelty involved in casting. It is understood that a number of veterinary surgeons who were present were satisfied that a great advance has been made, and it is to be hoped that mercenary interests will not prevent Mr. Weinberg's apparatus from receiving a more extensive trial.The compulsory training and licensing of slaughtermen is a pressing requirement, for while most slaughtermen are fully trained before they use the poll-axe, there is no adequate provision for the enforcement of this elementary precaution against the infliction of unnecessary suffering. But perhaps the most serious defect of our slaughtering system, both on humane and on hygienic grounds, is the lack of adequate control and inspection of slaughterhouses. In the more advanced of the Continental countries, private slaughterhouses have been extensively replaced by public abattoirs, but unfortunately in Great Britain private slaughterhouses still exist, and their licences have a capital value which opposes a strong vested interest to the movement for reform. The financial cost of doing what is right in this case is by no means an inconsiderable one. Obviously, however, the element of fear can be much diminished in a properly designed public abattoir, which also facilitates supervision for humane and hygienic ends. Hence public abattoirs alone are tolerable in towns, while in country districts a rigorous system of inspection and control by public officers is called for. The hardship which would be inflicted on the "slink " trade in meat from tuberculous animals could be softened by a good system of insurance. It will be seen that while a very substantial body of facts may be regarded as established in connexion with humane slaughtering, there are other factsand particularly as regards the effect on the quality of bacon and the psychological element in the suffering of the animals-which call for authoritative investigation. It is essential that the experimental work involved should be carried out by disinterested scientific men, adequately familiar with the canons of scientific method. However, apart from prejudice and conservatism and the professional pride taken by slaughtermen in a highly skilled trade, which they have learned by long apprenticeship, the opposition to reform is based on mercenary considerations. Even if the shot pig should prove to be somewhat less valuable for export bacon than the pig which has been more painfully killed, the question will arise whether the economic motive should prevail over the ethical.The Ministry of Health proposes two alternative by-laws for adoption by local authorities, but does not enforce their acceptance. By-law 9a requires that all slaughterers except Jews shall stun the animal before killing it, except in the case of sheep. By-law 9b is similar, but it applies also to sheep and specifies the use of a mechanically operated instrument-that is, in practice, a pistol. Out of some 2000 local authorities only 226 (including the London County Council) have hitherto adopted the stricter by-law, though the number is growing in response to propaganda by the Royal Society for the Prevention of Cruelty to Animals, the Humane Slaughter of Animals Association, and other humanitarian bodies. The adoption of the by-law may put a district at an economic disadvantage in its competition with neighbouring districts for the patronage of butchers, many of whom are prejudiced against the pistol. The Sanitary Committee of the Corporation of London has therefore passed a resolution to the effect that the time is now opportune for the issue of definite regulations which should be of general application throughout Great Britain, and that " in order to secure uniformity such regulations should be issued as compulsory regulations by the Ministry of Health." Presumably the Government will hesitate to take the necessary action until it feels itself supported by a well-informed public opinion, but the subject is an unpleasant one, and the public naturally prefers to know as little of it as possible. In the face of this situation, no apology is needed for having brought it to the attention of scientific men, who are ex hypothesi opposed to obscurantism.

ISSN:0028-0836    

DOI:10.1038/119481a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE accusation is frequently levelled at scientific workers that they will give no thought or credence to the very real phenomena of the supernormal, and that this attitude of aloofness sits ill on those who profess the true scientific spirit. That there is truth in the charge can scarcely be gainsaid. When Sir Oliver Lodge pronounces on a modern development or even a modern speculation of molecular physics, the auditorium is filled with craning necks and assenting minds, but let him turn to the subject of materialisations or the afterlife, the scientific necks are relaxed and the minds closed. It is worth while inquiring why this conspiracy of hostile silence is maintained. It is a truism that trustworthy scientific work can be accomplished only by trained minds after elaborate preparation for a line of attack based on a close study of the problem. For in all circumstances the question at stake is the question of what is and what is not admissible evidence. The scientific process is the method of collecting and assembling that evidence, and no deduction will stand that allows of possible ambiguity or for which the evidence is not both necessary and sufficient. Even legal standards are not permissible. The final conclusion cannot be based on circumstantial evidence, nor does one give an electron the benefit of the doubt. The logic of the law court is not necessarily the logic of the laboratory.In these circumstances it is permissible to doubt that any individual, no matter how well intentioned, could sail into a notoriously difficult region of inquiry and produce almost immediately astounding results of full evidential value. Even were the individual a trained scientific investigator, there is a natural hesitancy in acceptance, for independent verification by other workers is a necessary and legitimate demand. The difficulty is accentuated when the scientist who undertakes or is present at the inquiry is constrained to work under conditions and limitations the full implications of which cannot be precisely appreciated. The phenomenon, he may be told, will take place only in darkness, or in dull red light, or in the presence of a particular individual or a group of individuals, or when a gramophone plays in the subdued light of a vacuum tube discharge, and so on. If, moreover, the events described as occurring, when accepted, would involve a complete reconsideration of the structure of mechanical processes, reluctance to admit that the evidence is above criticism is naturally intensified. These are the difficulties one encounters with most of the material in the publication before us. If the merest fraction of the evidence adduced in this small volume were to be admitted it would cause a revolution in scientific thought. In a lecture delivered at the National Laboratory of Psychical Research, Countess Wassilko Serecki describes the history-one is almost tempted to write the hysteria-and phenomenon of Eleonore Zilgun, a Rumanian peasant girl. In the presence of this girl inanimate objects become endowed with a will of their own, bricks fly about, dishes dash themselves to pieces, a stone jumps out of the river, is replaced and jumps out again, scratches and bites appear on her arm, cups are snatched from her hand by invisible powers, and so on. A great deal of the evidence for this is not direct but produced by the Countess from depositions of individuals abroad. Dr. R. J. Tillyard contributes a record of two s6ances conducted by a medium in Boston, Mass. Here darkness appears to be essential, and the medium goes into a trance. This is verified at intervals by red light. It would be interesting to have details of the verification of this trance condition conducted in such difficult circumstances, but they are not provided. A gramophone plays a negro melody and a voice-immediately referred to as 'Walter's ' voice-talks " freely and wittily " apparently from inside a cabinet. The humour does not, however, appear to be very deep. A flower basket-rendered luminous-moves about high up in the room, rocked by 'Walter,' we are told, but no evidence is adduced about 'Walter' beyond the voice, or as to whether the basket was actually rocked by him.Much could be said about this kind of science, but restraint is desirable. Numerous questions naturally suggest themselves. If a brick can fling itself through a window, what reliance can be placed on the prediction of the total eclipse in June ? What reliance can be placed on the performance of any machine ? Alternatively, if, as experience shows, full reliance can be placed on a multitude of such predictions, what reliance can be placed on the evidence about the brick ? Scepticism becomes charity indeed. There is here a frank conflict of evidence, and until it is resolved the scientist's natural inclination is to turn back to the restful haven of verified knowledge. If there are inconsistencies in his own field, if for the moment he cannot reconcile solar mechanics withthe mechanics of the electron, his past experience has at least taught him that with patience these troubles will be smoothed. Consistency of behaviour of his material, however, is implicit in his method of approach. Such an assumption may possibly prove to be ill-founded, and the selfpropulsion of the brick through the window, referred to above, may ultimately prove to be the actual disturber of his mental peace. But his malaise in the presence of such a phenomenon-if true-goes deeper than this. " If the material with which I have to deal," he says, " is not consistent in its behaviour, how can I study the question at all ? " It seems to be inevitable in experiments in this field of inquiry-if they can be called experimentsthat a great deal must depend on the good faith of the medium. There is always the lurking suspicion that, consciously or unconsciously, the observers are being deluded-a factor utterly foreign to any class of physical experiment. This suspicion is traceable not so much to the fact that, in the past, trickery has been exposed in the performances of such individuals, as to the fact that results are claimed of a nature antagonistic to the tacit philosophy of the physicist. To meet this difficulty, one of the first tests that ought to be performed should be to determine the precise conditions under which a medium can be dispensed with. Quite obviously, the smaller the number of persons actually essential to an experiment, the greater the confidence in the result. Is it not possible for the National Laboratory of Psychical Research to produce the details of a single and convincing experiment that could be performed by any competent scientific worker in his own laboratory, as simple, say, as measuring the period of a pendulum ? If ' levitations ' are as frequent as they are claimed, this should not be impossible. The writer has frequently tried such experiments alone, but always in vain. What are the conditions that will ensure success ? Surely, after so many years' experimentation by devotees of the cult, including many eminent men, this must be known very accurately. All the tests described in the publication under review are so complex that instead of carrying conviction they arouse suspicion. It is the simple test that is required.There is, however, another-and possibly more important-factor that repels the scientist: it is the implications and assumptions inherent in the descriptions of these uncanny doings. If a voice is heard speaking from a box, is it necessary to assume it has an owner, 'Walter'? In a court of law it might be a legitimate assumption to make, and it might in conceivable circumstances be sufficient to hang a man, but in the description of a scientific experiment, why imply the existence of an 'owner' to the voice and by identifying it with 'Walter' ? Even assuming the accuracy of the phenomenon, which in the circumstances one would be far from doing, there are numerous possible working hypotheses of a more normal type than that of 'spirits.' When Sir Richard Paget makes his hands speak, one does not assume that the voice belongs to a spirit, even if it does call itself 'Walter.' Men of science have learnt that words are treacherous things, that false ideas of an ignorant past are dragged in at each turn, so they have learned to talk in symbols, with a clear-cut (1, 1) correspondence between idea and symbol. But the language of supernormal behaviour-and the very phrase itself is dangerous-is not yet sufficiently divorced from mystery and superstition, not yet sufficiently definite and precise, to ensure that the pet theories and vague beliefs of its devotees are not foisted on the unwary inquirer as he receives his description of the phenomena. If the National Laboratory of Psychical Research can produce a simple laboratory experiment, capable of being performed by a careful and trained scientist under conditions that he himself can guarantee and control, it would go further towards producing the revolution in thought which the Council so earnestly desires than volumes of ' evidence' of the type given in the present issue of its Journal.

ISSN:0028-0836    

DOI:10.1038/119484a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

(1) THE monumental treatise which Profs. T Levi-Civith and Amaldi are engaged in writing on rational mechanics (to use the comprehensive title established on the Continent) is divided into three volumes, which deal respectively with kinematics and statics, dynamics of systems possessing a finite number of degrees of freedom, and dynamics of continuous systems. The second volume is divided into two parts, to the second of which are reserved the general questions properly belonging to rigid dynamics and the subjects of canonical equations of motion and the principle of Hamilton and Jacobi. The plan of the first part of the second volume is as follows: The first two chapters discuss the motion of a particle constrained to move on a given curve and on a given surface. The third chapter deals with problems of gravitational attraction. General theorems on momentum, energy, and work are treated in Chapter iv. D'Alembert's principle and Lagrange's equations occupy Chapter v., and the volume closes with a chapter on stability of motion and small oscillations.Chapter iii., which is mainly concerned with celestial mechanics, contains interesting applications to planetary orbits according to Einstein's law of gravitation and to electronic orbits according to Bohr's atomic theory. The motion of electrons in an electromagnetic field also furnishes interesting examples. It is, indeed, a refreshing change to discover so little space devoted to questions better fitted to exercise a student in integration than in dynamical principles. Into the time-worn problems to which so large a proportion of any work on dynamics must be consecrated it would be difficult to introduce much originality of treatment. Yet throughout this work, Profs. Levi-Civith and Amaldi have succeeded in revivifying these 'dry bones' by a continual slight novelty, most stimulating to the reader. The work is planned on generous and comprehensive lines and covers ground scarcely touched in any similar treatise. It even contains a fair number of exercises for the student.(2) Prof. Moulton's short account of some methods of external ballistics discusses the three main problems of the effects of air resistance, rotationof the projectile, and minor factors such aswinds, on the projectory. The effect of air resistance is studied by the methods of finite differences, extensively used by Bashforth in England during the last century. The effect of abnormal air densities, variations in gravity, winds, etc., is studied by the method of perturbations, so widely used in astronomy. The effect of rotation is discussed by means of the classical equations of Euler. The book contains no reference to the pioneer work of Bashforth or to the work of Siacci. Few of the methods given appear to be new, and a remarkable new method due to Whitehead (" Graphical Solution from High-Angle Fire," Proc. Roy. Soc., 1918) is not mentioned. It seems that the title of the book is scarcely an accurate description of its contents. Considerable interest therefore attaches to an ingenuous admission in the introduction. " In view of the complete independence of the present developments from those that have gone before, no attempt has been made to treat the question historically, nor even to connect these results with those of earlier writers." This is an explanation, if not an excuse.

ISSN:0028-0836    

DOI:10.1038/119485a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE science of animal nutrition is concerned Twith the principles underlying the economical transformation of the produce of the soil into articles of human diet like meat and milk. The elucidation of these principles depends on a knowledge of two sets of factors: first, the nutritive requirements of the different classes of farm stock for the purposes of maintenance and of production (e.g. growth, fattening, and milk production); and secondly, the capacity of the various feeding stuffs for supplying these requirements. It is instructive to note how these problems have been attacked in Germany and the United States on one hand, and in the Scandinavian countries on the other. In Germany the wellknown investigations conducted by Kellner on fattening oxen in the respiration calorimeter have led to the formulation of a system of starch values, in which the productive or, more strictly speaking, the fattening value of a feeding stuff is defined in terms of pounds of starch. Kellner's system has been widely adopted in Britain, where, within limits, it has given useful results, though criticism of the method at the present time is not lacking. Armsby in the United States, also working with fattening oxen in a respiration calorimeter, has evolved a system of net energy values in which the productive value of a feeding stuff is stated in terms of therms of energy.In northern Europe, however, where dairy cows, and not fattening oxen, have been mainly employed in feeding investigations, it has been the custom to take milk production as a measure of the productive value of a feeding stuff. Experiments on these lines were first started by Fjord at Copenhagen so long ago as 1885, and since 1898these have been continued and expanded in a series of fundamental researches carried out by Nils Hansson at Stockholm. From the results of these feeding trials came the conception and development of the Scandinavian food unit system, which is now accepted as the basis of feeding in Sweden, Denmark, Norway, Finland, Poland, and other countries. This system, based on Hansson's data, has undoubtedly, in its application to feeding practice, achieved a larger measure of success in northern Europe than has any other system in any other country, and to its adoption must be attributed in no small degree the vast growth of the butter export trade of Denmark and the enormous increase in milk production in Sweden and other northern lands. Prof. Hansson's main work, " Handbok i Utfodringslara," was published in three parts and contained a detailed account of the development and application of the food unit system. The present volume appeared in 1922 under the title of " Husdjurens Utfodring " and brought together all the essential features of the " Handbook " in carefully condensed form. Unfortunately, not many English workers are able to read Swedish with any degree of ease, and this fact probably explains the somewhat tardy recognition of Hansson's ideas in Britain. The translation of " Husdjurens Utfodring " into German is the direct outcome of a widespread desire among German nutritional scientific workers to know more about a feeding system which has proved so successful in other countries.The treatment of the subject is characterised by the simplicity and logical clearness for which Hansson's publications are justly. celebrated. The first section opens with an account of the composition and digestibility of feeding stuffs, the concluding chapter of this section dealing with the different methods of assessing productive values. The English reader will be particularly interested in the comparative account of the Hansson food unit, the Kellner starch value, and the Armsby net energy value. In the second section the nutritive properties of the individual feeding stuffs are dealt with, while the third and concluding section is devoted to a thorough consideration of the scientific principles underlying the nutrition of calves and other young animals, of dairy cows and fattening oxen, of sheep, pigs, goats, and horses. The tables at the end of the book constitute a praiseworthy feature. Table I. gives the average composition and digestibility of a very large number of feeding stuffs, together with their productive values in terms of food units, starch values, and milk-producing values. In Table II. the nutritive requirements of all classes of farm stock are recorded in great detail. It is to be hoped that the translation of Hansson's treatise into English will not long be delayed. Affording as it does a fresh and hopeful outlook on the problems of the economical feeding of farm animals, especially of dairy cattle, it should prove a worthy companion volume to the well-known treatises of Kellner and Armsby and the more recently published text-book of the Cambridge worker, Prof. T. B. Wood. It should be read with interest and profit not only by the investigator in this domain of science, but also by all stockbreeders who are desirous of rearing their animals in accordance with accepted scientific principles.

ISSN:0028-0836    

DOI:10.1038/119486a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

Tnis is an interesting study of the relation of the various beliefs which men have held at different times to their conduct of life. The method of treatment begins with the biological study of belief, pointing out how, although we cannot tamper experimentally with our fellows in regard to the main issues of human life, yet Nature does not shrink from exposing men to the most searching tests. Various beliefs are discussed which are concerned with topics of high emotional value, such as bereavement, unsatisfied love, and ungratified ambition, and it is pointed out and examples are given of the way in which the attitudes and beliefs of the individual have a strongly subjective note. In the latter part of the book, man's general belief concerning the mechanism of Nature and the order of the cosmos is discussed. Here again the personal viewpoint is noted. The question of the mental health of the individual and the group depends largely on the underlying scheme of values.The book concludes with a discussion of what the author terms inferior beliefs about health, such as Christian science. Although admitting the personal comfort in some cases, he maintains that any increased efficiency is largely due to adopting the healthy attitude that, even when there is some physical ailment, it is often better to ignore it and to go on playing the game of life. He also points to the danger of inferior beliefs about social problems, such as that of the optimist who talks of universal peace and often denies the existence of harsh realities and hatreds. The belief in the spiritual order of the universe is an important driving force, but it must also be associated with the workaday world. Although tolerant ofvarious beliefs, Prof. Campbell's conclusion is that instead of discovering something absolute in the realm of belief, one finds that beliefs are the tools of life rather than rare intellectual products to be cherished carefully for themselves.

ISSN:0028-0836    

DOI:10.1038/119487a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is encouraging to find that these important lectures by one of the most prominent authorities on spectroscopy, delivered under the auspices of the University of London, are now accessible to all in English. They deal with the spectra of hydrogen and helium, and then proceed to the study of complex spectra such as manganese, iron, nickel, and palladium in the light of Pauli's " Principle of Uniqueness." The third lecture gives some muchneeded information concerning the structure of crystals, from the point of view of the quantum theory. The translation is carefully done, but errs on the side of literalness. The translation of Grundzustand as 'ground state' is scarcely English, while abgeschlossen as applied to systems of elements is self-contained ' rather than ' completed,' and 'quantize ' is rather more exotic than ' quantify' would be.

ISSN:0028-0836    

DOI:10.1038/119488c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT will doubtless be a surprise to many readers of NATURE, as it was to me, to hear that the element mercury is obtained in the distillation of coal tar. This fact was recently brought to my notice by Mr. W. Kirby, of the South Metropolitan Gas Co., who kindly provided me with a sample for examination of its isotopic constitution. He informs me that the mercury appears in the lightest of the fractions distilled and occurs to the extent of about one part in seven millions of undistilled tar. Its accumulation in any reasonable quantity will, therefore, take place only in a plant arranged for continuous fractionation.It was my first intention to compare its density with that of ordinary mercury, and if any appreciable difference was detected to submit it to analysis by the mass-spectrograph, but a favourable opportunity having occurred, I have been able to perform the latter operation under advantageous conditions. The discharge bulb was washed with carbon dioxide until all trace of the spectrum of mercury had disappeared. A portion of the sample was then introduced. This operation was more troublesome than I expected; but ultimately the bulb was flooded with the vapour and a number of mass-spectra were obtained, while the mercury spectrum was predominant in the discharge. On these the groups of isotopic lines were absolutely indistinguishable, both in position and intensity relations, from those of ordinary mercury described in NATURE, Aug. 8, 1925.

ISSN:0028-0836    

DOI:10.1038/119489a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

OF that famous palæolithic implement which the French call a ‘coup-de-poing,’ the function is still unknown and disputed; it was once called a ‘celt,’ and is still regarded by some experts as the head of a once hafted ax; others, like the late M. Commont, have argued that it was used as a scraper; and still others maintain that it is an ax without a helve.In order not to do violence to the feelings of some of our friends by forcing upon them a name which expresses a view from which they differ, I have suggested, as non-committal and non-combative, the use of a proper name; thus following the example of physicists, who speak of a watt or a volt. The name I proposed is that of the famous Frenchman, who did such splendid service with the ' coup-depoing ' in his fight over the antiquity of man. I allude, of course, to Jacques Boucher de Crevecceur de Perthes. From this full title I chose his family name of Boucher. This is not a Christian name, as my friend Mr. Balfour supposes, and my authority for saying this is our distinguished colleague, the Foch professor of French.A second objection raised by Mr. Balfour in his interesting review (NATURE, Feb. 12, p. 226), is that Mr. Neville Jones has misapplied the name. I do not think he has; but this is nothing to the point, for he distinctly asserts that he uses the word ' boucher' as equivalent to the French 'coup-de-poing.' Admiring as I do the consistent courtesy of Mr. Balfour, which is not confined to his friends, I feel sure he will not wish to introduce into our nomenclature a term like 'hand-ax,' which is eminently controversial and has not even the advantage of elegance. Who would speak of a knife-blade without a handle as a 'hand

ISSN:0028-0836    

DOI:10.1038/119490a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. J. B. S. HALDANE'S interesting letter on the above (NATURE, Mar. 5) reminds me that in 18861 made experiments on the influence of carbon monoxide, as well as of other gases (carbon dioxide, hydrogen, nitric oxide, nitrous oxide, sulphur dioxide, and hydrogen sulphide), on the vitality of three specific micro-organisms, namely,Bacillus pyocyaneus, Finkler's spirillum, and Koch's spirillum of Asiatic cholera. The results were published in theProceedings of the Royal Society(vol. 45, pp. 292–301), but a brief reference to them may not be out of place now, inasmuch as they bear on this matter of the toxicity of gases.The method of experiment consisted in exposing the several organisms, in the form of gelatin-peptone plate-cultures, to an atmosphere of the particular gas, a corresponding control-plate of the same culture being simultaneously incubated in atmospheric air. The behaviour of the three microbes in question in respect of carbon monoxide may be gathered from the following experimental results: BACILLUS PYOCYANEUS. When the above carbon monoxide plates were further incubated in air, 100,821 colonies made their appearance. Thus the carbon monoxide had had practically no permanent toxic effect on the bacilli distributed in the culture which had been exposed for a period of 7 days to the gas. KocH's SPIRILLIJM CHOLERAE ASIATIC.M. Number of colonies developing from 1 c.c. of culture Air-plates (after 4 days' incubation). 52,020 CO-plates (after 7 days' incubation). 19,494On subsequent further incubation of the carbon monoxide plates in air during 4 days, no increase in the number of colonies took place. FINLER'S SPIRILLUM. Air-plates CO-plates (after 3 days' (after 7 days' incubation), incubation). Number of colonies de. veloping from 1 c.c. of culture 4574 2 On further incubation of the carbon monoxide plates in air during 4 days, the number of colonies rose to 501.Thus in both cases, and especially in that of the Finkler spirilla, a large proportion of the individuals had been killed or rendered incapable of multiplication into colonies by exposure to the gas. It may be of interest to add that plates incubated in atmospheres of nitric oxide, sulphuretted hydrogen, and sulphur dioxide respectively developed no colonies, nor were any developed afterwards on placing the plates in air-chambers. These three micro organisms are therefore rapidly and permanently poisoned by the gases in question.Interest, again, attaches to the behaviour of the organisms exposed to nitrous oxide (NO). The B. pyocyaneus developed no colonies in this gas, but afterwards in air almost as many colonies made their appearance as on the control air-plates. Koch's spirilla, in nitrous oxide, developed nearly one-third of the number of colonies present on the air controlplates, a further but only slight increase taking place on their transference to air. In the case of Finkler's spirilla, in nitrous oxide, the number of colonies was about one-seventh of that on the air-plates, whilst the further colonies which appeared after transference to air brought the total to about one-fifth of the number on the air-control. The effect of nitrous oxide on Air-plates CO-plates (after 4 days' (after 7 days' incubation). incubation). Number of colonies developing from 1 c-c. of culture 113,978 0these three micro-organisms is thus very similar in character to that exerted by carbon monoxide.An atmosphere of carbon dioxide, again, prevented the development of any colonies on the plate-cultures of all three organisms, and only in the case of B. pyocyaneus did any appear on transference to air, and then only to the extent of about one-twelfth of the number present on the control air-plates. In reviewing the record of these experiments made forty-one years ago, it is obvious how greatly the investigation could be extended in various directions. Thus, for example, it would be particularly interesting to ascertain the deportment of sub-cultures made from the colonies appearing on plates which had been exposed to the toxic gases. By pursuing such experiments through a succession of generations it might be possible to arrive at 'strains ' of the organisms endowed with the capacity to resist the inhibiting action of a particular gas. Again, differences in behaviour towards a given toxic gas might be made a means of discriminating between otherwise similar organisms, and thus adding yet one more to the already overwhelming number of tests employed in bacteriological diagnosi

ISSN:0028-0836    

DOI:10.1038/119491a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE statement (NATURE, Feb. 19, p. 300) that the chemical laboratory opened in 1828 in University College, London, is the oldest public chemical laboratory in Britain can scarcely be accepted without qualification, in view of the fact that the University of Oxford had built a laboratory fitted for chemical studies so early as 1683, and that this remained in use until superseded in 1848 by Dr. Daubeny's new laboratory at Magdalen College.The use that was made of it was intermittent, and the modern practice of class teaching necessitating the multiplication of sets of apparatus had not been evolved; but still the possibility for a person to witness an experiment, even if he did not wish to make it himself, was there. In those early days the University of Oxford appears to have done little for chemical studies beyond the initial provision of the laboratory and of "the Alkanor and Great Reverberatory" furnaces, and larger utensils such as the great alembic, barrel and worm, with which it was equipped. Smaller earthen and glass vessels and chemicals appear to have been the private property of the laboratory assistant for the time being, who was permitted to increase a very meagre salary by selling to experimenters chemical preparations " at easie rates " and by taking payment for the performance of experiments himself.Notwithstanding the non-existence of any special university teachers of chemistry, useful practical instruction had been given in connexion with courses of public lectures in the laboratory at various times during the eighteenth century. The auditors were largely composed of medical students, with a sprinkling of the more intelligent members of the general public, who, like Princess Anne in 1683, entered the laboratory to see experiments " to their great satisfaction "; and some of the more curiousminded of these would doubtless have sought to try the experiments themselves. Dr. John Freind, described as well skilled in practical chemistry, in 1704 began courses of Prcelectiones Chymnicw in the laboratory, which were partly based on experimental work there, and were printed and reprinted for the next twenty years. Richard Frewin was among those who acted as assistant, and it is not unlikely that there too Dr. John Wall, the inventor of Worcester china, may have learnt his chemical manipulation. George Wingfield has left a written record of the methods of analysis in vogue in 1759, and in 1781 a considerable class of divines is reported to have waded " considerably deep in chemistry." Contemporary notes taken four years later by a pupil of Dr. Martin Wall show the distinctly practical trend of the instruction given, and from 1788 until 1793 the celebrated Dr. Beddoes, later patron to young Humphry Davy, drew to the Ashmolean "the largest classes known in the University since the thirteenth century." It was the period when the work of Sadler, the aeronaut, also helped to popularise chemical experiments in Oxford. Between 1803 and 1822 the existence of the laboratory made it possible for the first Aldrichian professor of chemistry, Dr. Kidd, to deliver courses of from twenty-six to thirty lectures on the subject of his chair during the winter terms, but owing to the lateness of the hour, 7 P.-M, it was unlikely that much work was done in the laboratory by his students. One, at any rate, the poet Shelley, is known to have continued experiments in his untidy rooms in college, while the professor himself worked in the University laboratory at his own researches. Doubtless the dim light of the few candles, or oil lamps, which would have been the only source of illumination then available, as well as the grime of ages on the vaulted ceiling of the laboratory, enhanced that appearance of gloom which has been so often remembered by our visitors during the early years of the nineteenth century, and which was unsuited for the critical operations of analytical chemistry as then practised. But it was not before 1848 that the old laboratory was superseded in Oxford, and the fact remains that for over a hundred and fifty years the Ashmolean had provided England with its first public university laboratory, " the designe of this building being not onlie to advance the studies of true and real philosophy, but also to conduce to the uses of life and the improvement of medicine."

ISSN:0028-0836    

DOI:10.1038/119492a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature