摘要:

THE Lancashire cotton industry is, as is well known,in a somewhat parlous condition; and one important factor involved is that it has not control over its supplies of raw material. About one-third is grown in Egypt and south America, and two-thirds are from the uniated States; but the cotton of these two sections is so different that two separate industries deal with it in Lancashire. The first appears to be fairly prosperous; but the larger industry, dependent on the United States supply, is in trouble. This supply fluctuates enormously, and demands from elsewhere are increasing rapidly. During the past five years the crop has varied from 11 to 18 million bales; cotton mills are springing up in many countries, and those in America alone now require about half the crop. These figures indicate sufficiently how precarious is the position of the bulk of the Lancashire cotton mills. This state of affairs has, however, been long predicted; and more than twenty years ago a British Cotton Growing Association was formed, to encourage growing American cotton within the Empire, chiefly by assistance in marketing the produce. Since t%e War, matters have become acute; and about fle fears ago a much more ambitious scheme was launclled, namely, the Empire Cotton Growing Corporation, which sought to stimulate the mill owners to united action, by a levy of 6d. on each bale of cotton entering Great Britain. When the participation of a large proportion of the mill owners was secured, the Government endowed the movement with close on one million pounds, saved through the control of the Egyptian cotton during the War; and an Act of Parliament was passed sanctioning the levy for five years. This period is now terminating; and the Lancashire industry concerned is about to be sounded as to whether the levy should be continued.It will be of interest to note how this Corporation, mainly composed of business men, has set about its task. A central office was opened in London, a library collected, and an excellent quarterly journal started. Senior officers were sent on surveys of various parts of Africa, India, and Australia, and their reports have been freely circulated. In Africa the transport problem dominates, and large sums of money have been spent on improving communications. In India a large model estate has been assisted and financed in the Punjab, for the encouragement of growing American cotton; and in Australia pound;3000 a year has been given for five years for founding cotton stations. The most interesting point, however, is the appreciation of the Corporation of the need for scientific work. A entral Research Institute has been built in Trinidad, and ,the local College liberally subsidised. A number of post-graduate scholarships kare been given on a generous scale to encourage recruitment, and four research institutions in Great Britain have received pound;1000 a year for five years, to assist in training these men. Senior officers, largely with Indian cotton experience, were engaged to start the work in the colonies, and the trained men have been drafted out in succession. In the circumstances, judging by the annual reports now coming in, progress has been remarkably rapid; although it is recognised that it will be many years before the goal is reached of making the Empire self-sufficient as to its cotton requirements. It is to be hoped that the Lancashire mill owners will vote for a further five-year period of the levy. The ball has been setrolling, but there are many obstacles in its path; and the co-operation of this powerful and broad-minded Corporation cannot be overThe most interesting point, however, is the appreciation of the Corporation of the need for scientific work. A entral Research Institute has been built in Trinidad, and ,the local College liberally subsidised. A number of post-graduate scholarships kare been given on a generous scale to encourage recruitment, and four research institutions in Great Britain have received pound;1000 a year for five years, to assist in training these men. Senior officers, largely with Indian cotton experience, were engaged to start the work in the colonies, and the trained men have been drafted out in succession. In the circumstances, judging by the annual reports now coming in, progress has been remarkably rapid; although it is recognised that it will be many years before the goal is reached of making the Empire self-sufficient as to its cotton requirements. It is to be hoped that the Lancashire mill owners will vote for a further five-year period of the levy. The ball has been setrolling, but there are many obstacles in its path; and the co-operation of this powerful and broad-minded Corporation cannot be over estimated.

ISSN:0028-0836    

DOI:10.1038/120645a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE two works which are the subjects of this review both arrive at the conclusion that birth-control is a necessity, but whereas Prof. Karl Pearson desires it in the interests of the future generation, Dr. Marie Stopes demands it in order to relieve the over-harassed mother. (1) Prof. Karl Pearsons pamphlet is a reprint of a lecture delivered to elementary school teachers; we congratulate him heartily on his descent from the clouds of the higher statistics, and his determination to talk plain common sense which every one can understand. He shows in the most convincing manner that certain repulsive deformities like lobster-claw, and certain dangerous weaknesses like hamophilia or bleeding, are handed on from generation to generation; he says that in a primitive state of society individuals afflicted with these taints would never have been allowed to survive, much less to marry. He points out that such weaklings are only preserved in the mawkish atmosphere of sentimental sympathy which is developed in our civilisation, and that in the history of humanity advance has come not from the persistence of old civilisations, but from the irruption of virile races reared in a hard cradle who had overwhelmed the effeminate civilisations which they encountered and appropriated as much of their culture as they saw fit.Prof. Pearson is less happy in his remarks on the relation of religion to eugenics. It is true, as he says, that the biological function of religion is to assure the solidarity of the tribe, and that the powerful taboos of primitive religion concerned themselves largely with the three great events in human life birth, marriage, and death, He thinks,with the late Sir Francis Galton, that eugenic principles will never prevail until they have behind them the driving force of religious sentiment; he calls therefore for a modification of religious sanctions which will make the marriage of those marred with physical and mental defect to be as great an offence against religion as murder and adultery, unless those so married consent to have no children. Prof. Pearson, however, forgets that primitive man obeyed the taboos not so much from fear of his fellow-tribesmen as from dread of the supernatural intervention of the higher powers in whom be fervently believed. From Prof. Pearsons contemptuous remarks about God it is clear that he does not share this belief, and without it religious sentiments are impossible. The idealistic and high- minded may have regard to the interests of the race when their individual interests collide with them, though personally we doubt it, but the hope that the lazy and self-indulgent will pay any attention to the interests of posterity, if to use an American phrase they can get away with it, is idle. Least of all will they be deterred by a make-believe religious sentiment if they have ceased to believe in God. While in general we agree with Prof. Pearsons views, certain difficulties occur to us. Hamophilia, for example, manifests itself in men but is transmitted through women, Now could we seriously expect a healthy, vigorous young woman to abstain from marriage with an equally healthy young man because her great - great- great - grandfather had suffered from hemophilia and she might be a transmitter of the taint? Again, whilst we cordially admit that to prevent defectives from having children would be a great gain, these defectives constitute at the worst a small percentage of the population: the really great menace comes from the over-propagation of the idle and thriftless, who would not be classed as either physically or mentally defective. To support the children of this class the thrifty are taxed to the bone. The birth endowment for which Prof. Pearson calls is already infull action in this case; it seems to us that the compulsory sterilisation of the thriftless when they bring into the world more children than they can support, would do more for society than the segregation of defectives. (2) Dr. Marie Stopess book consists in a history of the various varieties of birth-control and especially of contraception. She recalls to our memory the fact emphasised by Prof. Carr-Saunders thatbirth-control in the form of infanticide and abortion has been practised by all races of men since time immemorial, and that even drugs which prevented conception were known in antiquity. She does a useful service in demolishing the legend, sedulously propagated by a certain coterie, that the legality of birth-control was established by Bradlaughs fight for it. She shows convincingly that the very pamphlet in connexion with which Bradlaugh was prosecuted had been sold for years without let orhindrance, and that the police only interfered when the publisher added to it several indecent illustrations. Bradlaughs intervention, so far from helping the cause of birth-control, really hindered it, since it caused it to be associated in the minds of the public with his unpopular atheistic views.Dr. Stopes seems to think that Carr-Saunders has disposed of the arguments of Malthus. Never was there a greater illusion Maithuss main position stands to-day as an impregnable rock, and has indeed since Darwins time become a commonplace of biology. The fact that Malthus did not foresee the expansion of our food-supply by the exploitation of then undiscovered agricultural areas is irrelevant; this merely postpones for a limited time the advent of the crisis which he predicted and which has already arrived in overpopulated countries like India and China.Dr. Stopes gives an elaborated and detailed account of the physiology of sexual intercourse and of the relation to it of the various methods of birthcontrol now in use, giving of course prominence to that which she recommends. It would be entirely out of place to discuss these methods in the columns of NATURE, but Dr. Stopes raises several points of considerable physiological interest which may be mentioned here. She maintains that the male sexual discharge, in addition to the fertilising spermatozoa, contains a hormone the absorption of which is most beneficial to a womans health. A priori this seems not unlikely, but it is an exceed- ingly difficult matter to prove, and when one views the healthy, vigorous unmarried women around one, it is rather difficult to believe. Then Dr. Stopes stresses the fact that in the emotions accompanying coition, there is a female crisis which is reached later than the male crisis, and that when this is not attained the woman is left in an unsatisfied and irritated condition which, often repeated, leads to marital unhappiness and makes a shipwreck of the marriage. Whilst the normal reader must experiencea shock in finding these intimate matters discussed in such detail and in such plain language by a woman, and whilst the reviewer must admit that he sympathises with this feeling of shock, there are certain considerations which give him pause before he indulges in condemnation of the author. Some years ago, in the common-room of a certain college, the reviewer happened to be the only biologist present when one of Dr. Stopess books (Married Love) was discussed. He was immediately challenged to give his opinion on it, and he replied that while it seemed to him that this book could only have been written by a person entirely devoid of reticence, yet that it would do good in giving information about physiological matters such as the female crisis, which could be obtained nowhere else. To his amazement and stupefaction, two of his questioners, both scientific men and both married, confessed an utter ignorance of the very existence of a female crisis Dr. Stopes gives figures to show that the chances of survival of the children decrease with the rapidity of succession of pregnancies, and the cases selected from her records give ample evidence of the fearful wreckage of womens health which results from overbearing. Part of the book is given up to incisive replies to the various attacks which have been made on Dr. Stopes, and the reviewer must confess that in these replies she has his entire sympathy. When the urgent necessity of birth-control by some method is becoming evident not only to biologists but also to economists and even to politicians, it can only be described as hypocrisy on the part of the Church to condemn practicable methods and recommend abstinence and selfcontrol to the ordinary man in the street who lives with his family in cramped quarters. That there is inherent wickedness in the sexual process itself is a superstition worthy only of the darkest Middle Ages and reflecting an outlook on the world which no rational man can now uphold.In conclusion, we can only say that Dr. Stopess book is a compendium of most valuable theoretical and practical information on the all-important subject of birth-control.

ISSN:0028-0836    

DOI:10.1038/120646a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

CONFRONTED with this volume, for which the only adjective at all appropriate is colossal,one can appreciate the feelings of the rustics before Goldsmiths schoolmaster: And still they gazd, and still the wonder grew That one small head could carry all he knew.Dr. Sartons amazing erudition, equalled only by his energy, is fittingly accompanied by a breadth of sympathy and interests due in part to his personal history, of which he gives some details. A Belgian by birth, of mixed French and Flemish ancestry, he married an Englishwoman and has since become American by adoption. His work on the history of science was begun near Ghent, but on the outbreak of war in 1914 he was forced to abandon his home and to bury all his manuscripts in the garden. Fortunately, the in vadcr overlooked this buried treasure, and the papers were safely recovered in 1919. To the minds eye, the vision of Dr. Sarton digging up buried knowledge from its hiding-place is symbolic, for he has devoted his whole life to this very task, and the first-fruits of his labours are now presented to us. First - fruits may seem a particularly inept word to describe the book now before us, which many a scholar would be more than content to have to his credit as the sole product of his working years. Yet to its author it is but the foundation- stone of an imposing building the plan of which he sketches as follows. There are to be altogether three series of books. The first series will consist of a purely chronological survey of the history of science (a term which, as interpreted by Dr. Sarton, has a wide significance), from the earliest times to the present day, in units of half a century. The present volume is the first of this series, and seven or eight more of the same size are projected. The second series will give surveys of different types of civilisation and will run to about eight volumes. The third series will deal with the evolution of special sciences, in eight or nine volumes, namely, (1) logic and mathematics; (2) physical sciences; (3) biological sciences (4) sciences of the earth; (5) anthropological . and historical sciences; (6) medical sciences; (7) educational sciences; (8) philosophy; and (9) general index. Of this vast field, Dr. Sarton hopes himself to cover the first series down through the eighteenth century, parts of the second series dealing with Semitic and Far Eastern civilisations, and the second volume of the third series. If this ambitious programme is realised, as every one will hope it may he, Dr. Mellor will have to look to his laurels! Not content with his linguistic attainments, Dr. Sartori light-heartedly undertook, as a mere trifle in passing, the study of Arabic under Prof. J. R. Jewett and Dr. D. B. Macdonald: there were giants in the earth in those days.The chronological survey in this introductory volume begins with the dawn of Greek and Hebrew knowledge in the ninth and eighth centuries B.C., and ends with the time of Omar Khayyam (second half of eleventh century AD.). Each half-century, from the fourth century B.C. onwards, is given a separate chapter and is christened with the name of its most representative man; thus 250 200 B.C. is called The Time of Archimedes, while AD. 800 850 bears the name of the mathematician AlKhw¤rizmi. This simple device is remarkably efficient in helping the memory to assimilate the chronological sequence, and its adoption must be regarded as a stroke of genius. Especially for medieval times, our memory of dates is too often lamentably vague, and yet we must acquire an adequate sense of the succession of men and events if our mental pictures of the progress of science are to be accurate. Dr. Sarton rightly insists upon the essential importance of strict chronology, so far as it can be ascertained, and has chosen his chapter titles for mnemonic purposes; we should find it difficult, he justly says, to remember that such or such a man flourished in the first half of the ninth century, and such or such another in the second half of the same century, but we can more easily recall that the former flourished at about the same time as Al-Khw£rizmi, while the other will naturally cling in our memory to the personality of Al-R£zi. It has seemed necessary to dwell upon this point, because a casual glance at the book might give the impression that it is solely a work of reference, whereas in point of fact it contains much to be read and remembered. Each section is provided with a brief introduction or summary and a critical review of the relevant literature. The wealth of bibliographical detail is frankly stupendous, and in those sections which we have tested, very little of real importance has been omitted; though we noticed, for example, that H. H. Joachims article on AristotlesConception of Chemical Combination was not mentioned in the list of authorities quoted in the paragraph on Aristotelian chemistry. Such occasional lapses are inevitable, and serve merely to throw into higher relief the sound and careful scholarship and painstaking industry which Dr. Sarton has brought to bear upon his researches.Of especial value are those sections devoted to Chinese science. Hitherto, information respecting the scientific attainments of this people has been very difficult to collect, and even when collected its value and trustworthiness could not always be properly estimated. It is probable that a fuller knowledge of early Chinese work would cause us radically to modify some of our present opinions on the development of the sciences particularly chemistry, as urged by Prof. Partington and a systematic survey of the subject is urgently required. Dr. Sarton has provided an excellent starting-point in his collation and valuation of the critical literature available, and perhaps European or Oriental scholars may now be stimulated to undertake the necessary labour. 1t7 seems certain that such labour would be well repaid.Similar care has been bestowed upon the accounts of Muslim science, about which more is known, but of which there has been no comprehensive synthesis, most investigators having chosen particular topics for intensive study rather than a broad survey of all the various aspects. Dr. Sarton gives us the materials for such a survey and has pointed out the salient features. He has also taken pains to transliterate proper names accurately, a merit which is conspicuous by its absence in most histories of science, and the lack of which is not merely provoking but often seriously misleading. The history of politics and that of art have been deliberately omitted on the ground that these subjects have already been adequately treated by others. Prehistoric times are also omitted for the present, since the rapid advance of archaology in recent years suggests that a short postponement may enable a much more satisfactory account to be given later.Dr. Sarton expresses the hope that his sketch of the vast panorama of two thousand years of intellectual progress may hell) to guide the activity of a large number of scholars, by allowing them to undertake special investigations of particular topics without losing a sense of proportion and perspective. That his hope will be realised cannot be doubted, but we believe he will do more than prevent a loss of sense of perspective: he will convey it to those who have never possessed it and will render applicable to the history of science the words of the Pervigilium Veneris:"Cras amet qui nunquam amavit; Quique amavit eras ame

ISSN:0028-0836    

DOI:10.1038/120648a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIS much-anticipated book is described as a revision of Youngs Manual of Astronomy, although, as stated in the preface, the scope of the new work is somewhat more extensive than that of the former Manual, and intermediate between this and the General Astronomy. Th classical works of Young have long been the best volumes of their kind, except for the fact that they have been out-of-date on the physical side, and no more appropriate task could have been undertaken by their illustrious authors successors at Princeton than that which they have now brought to fulfilment. So numerous and radical have been the advances of the last few decades that it has been found necessary practically to re-write the book, with an inevitable increase in length. The result, it may be said at once, is worthy of its prototype. The two volumes deal respectively with The Solar System and Astrophysics. This is probably the most satisfatory method of dividing the subject of astronomy for treatment as a whole, although the more minute classification given in the introduction to the book is inconsistent with it, in the sense that it is impossible to assign each of the six branuhes mentioned therein definitely to either the solar system or astrophysics. No method of dividing and subdividing astronomy is entirely satisfactory, for astronomy deals with a universe and not a multiverse, and the science has progressed far enough for that fact to emerge and confound the would-be analyst. The preient cleavage into two volumes cannot evade a number of phenomena notably the sun, which it ha to split into two parts. In the first volume the treatment of this body is mainly descriptive; it is chiefly an account of the sun as seen through the telescope. The second volume deals with the examination of the sun by the spectroscope and bolometer.The contents of the first volume may be summarised as follows. After a brief introduction, astronomical systems of measurement are described, leading up to astronomical instruments and the problems of practical astronomy. The earth, moon, and sun are then discussed, with a separate chapter on eclipses. Between the consideration of C C the planets in general and the separate consideration of individual planets, a chapter of 49 pages, on celestial mechanics, is inter polated. The final chapter deals with comets and nieteors and the origin of the solar system. Volume 2 begins with a chapter on the analysis of light, after which the solar spectrum and the suns light and heat are dealt with. A chapter on atomic theory and astrophysics makes possible a general consideration of the stars and their various characteristics, including double and variable stars. Then follows a discussion of star clusters, the milky way, and the nebuhe, and the work concludes with two chapters on the constitution and evolution of the stars. An appendix to each volume contains useful data, and each chapter includes a number of exercises for the student. It is intended that the first volume shall be mastered before the second is approached a plan which has been adopted as a result of many years experience in lecturing. It is with diffidence that one ventures to question the conclusion of the distinguished authors on this matter, but it should perhaps be said that the reviewer has found it more satisfactory to introduce all the principles and instruments of investigation before dealing with the bodies to which they are applied. In the treatment here adopted the spectroscope and its applications are not introduced until the second volume is reached, with the result that the accounts of several phenomena, begun in the first volume, have to be completed in the second. Perhaps no general rule can be laid down in the matter, and in any case both volumes are available together for the teacher to deal with as he pleases.The treatment is comprehensive, clear, and, needless to say, accurate, The book is suitable for the beginner with only an elementary knowledge of physics and mathematics, but includes, never- theless, a little mathematical work (printed in smaller type) in the astrophysics volume which the elementary student is invited to omit. The use of the calculus has been completely avoided. The book appears to us to be undoubtedly the best text-book of general astronomy now available. The only criticism of a general character which we can make is that there are occasional lapses in English, of which two examples, taken from volume 1 , will be sufficient. On p. 53 we read: CC In the coelodollar;tat the plane of the mirror is parallel to that of the polar axis. The words that of should, obviously, be removed. Again, on p. 164, a paragraph is headed Method of Determining the Size of the Moons Orbit, that is, its Distance and Parallax. The distance and parallax dealt with are, of course, the moons, not those of its orbit. We have, however, noticed no serious ambiguity arising from this cause, The book is clearly printed and well and copiously illustrated, although the reproduction (Fig. 190) of Sir Norman Lockyers flash spectrum, obtained in India in 1898, is very disappointing.

ISSN:0028-0836    

DOI:10.1038/120649a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

DR. McGowAns investigation of these blood diseases originated from a series of observations on leucosis in fowls and iron deficiency as it occurs in pigs. The similarity between the former condition and the pernicious anamia - myelogenous leucamia group of diseases in human beings was apparent, and it was considered that their common association with iron deficiency in morbid conditions of the hamatopoietic system might shed light on some of the problems of human blood disease. Commencing with the demonstration of leucosis as a definite pathological syndrome with several different causal factors, it is postulated that the similar syndrome iii human beings has likewise a fundamental pathogenesis. It is considered that this is a modified hyperplasia due to an irritative condition and ending in some eases in sclerosis or aplasia of the bone-marrow. In those eases of pernicious amemia in which no definite irritative factor, such as tapeworm or specific poison, is recognised, it is suggested that there has been some general infection which has damaged the bone-marrow. The association with iron deficiency is through the metabolic fuiiction of the liver in preparing iron and fat for the production of erythrocytes. The aplastic form of amemia has its cause in the failure of the poisoned liver to carry out this function, apart from the toxic changes in the bone-marrow. Iron deficiency is considered to be due to deficiency in milk of iron relative to protein or growth-stimulating substance and to the growth potential of the young animal.The whole subject is presented with unusual lucidity, and Dr. McGowans conclusions will be of considerable interest to students of pathology and comparative medicine.

ISSN:0028-0836    

DOI:10.1038/120650a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. BIGGS has rendered a distinct service to physicists by preparing this short account of Schrodinger's theory. Beginning with the hypotheses of Louis de Broglie, out of which the subject has developed, he traces the evolution of the idea that wave-mechanics bears to classical mechanics the same relation as wave-optics bears to rayoptics, and obtains the partial differential equation for the sb-waves, proceeding then to its applications in spectroscopy. The style is lively and readable, the points are well made, and altogether no better introduction to the latest phase of the quantum theory can be desired. We may perhaps offer two slight criticisms: the translation of Eigenwerte by special values seems particularly unfortunate for those who dislike characteristic values or autovalues, the term double numbers may be suggested: and the mathematical treatment of the hydrogen-atom problem is greatly simplified, as Prof. Eddington pointed out some time ago in a letter to NATURE, by referring to the known properties of the Wk,m functions.

ISSN:0028-0836    

DOI:10.1038/120651c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

HAVING regard to the apparent importance of the discovery recently announced in letters from Messrs. J. P. T. Burchell and J. Reid Moir (NATURE, Aug. 20 and Sept. 24, 1927), and to the publicity which the matter has received in the Press, we considered it advisable to examine the several localities indicated. This we have now done. We had no difficulty in identifying the various sites, although some inaccuracies in the descriptions suggest that these were written from memory, and not from adequate notes taken on the spot.The western or seaward side of the promontory called Rosses Point, the site of Mr. Burchells rock- shelter, has three projections of limestone jutting into the sea, with areas of sand between. Mr. Burehell does not state on which of these projections his rock-shelter is situated, but says that it has a south -westerly aspect. We found on the middle projection a small undercutting of the cliff, facing south-west, which might conceivably have been a fallen-in rock-shelter; it is about 100 yards to the south of the lighthouse. But in no other way does it correspond to Mr. Burchells description; there are no fallen blocks upon its floor. The only hollow which agrees with the description in this respect, and in dimensions, is on the southern projection; but it faces magnetic north. It is about 1QO yards north of the ladies bathing-place. Mr. Burchell describes an Early Neolithic Raised Beach, consisting of powdered shells to a depth of one foot as covering what remains of the roof of his rock-shelter. No such feature exists above the roof of either of the rock-hollows just referred to. Indeed, there is no Raised Beach of any date in the district. The only covering above both of the hollows is a layer of gravelly soil, formed by disintegration of the limestone in situ, mixed with wind- borne sand and occasional fragments of shells. These shells were doubtless carried up by gulls, as is still being done. They are of species now common in the bay (Mya arenaria, Soln Biliqua, Ostrea edulis, Mactra solida). About twenty yards to the south of the hollow on the middle projection there is a flattened heap of fragmentary oyster-shells, possibly accumulated by human agency; these are within reach of high waves, and certainly do not form a raised beach.We could not detect any trace of the boulderclay in a hollow of which the outer margin of the Raised Beach is said to lie. Boulder-clay occurs on the northern end of the Rosses Point promontory, where, however, there are no shelters; and also on its southern shore, under the modern village. The large cave four feet high on Coney Island lies underneath the lower of the twin beacons at the north corner of the island. We consider that its existence is clearly due to recent undermining of the massive limestone of the low cliff, by erosion of the softer underlying shales. The masonry foundation of an earlier beacon (not more than fifty years old) now overhangs the face of the cliff above the cave by about three feet, and the beacon has had to be moved inland in consequence. This shows that the process of erosion is still actively in progress.It is inconceivable that caves of this kind and in such a situation could have persisted from Mousterian times, They are in an area that was severely glaciated by ice passing from the land out to sea. The pronouncedly jointed and bedded character of the rocks would in these circumstances give rise to excessive plucking, as is indeed evidenced by the sections below the houses of the village, where the thick masses of boulder-clay are crowded with large angular blocks of limestone. Any pre-glacial cave would thus have been obliterated. Moreover, there is abundant evidence, all along the coast, of rapid marine erosion; and any such shelters would have been washed away. even since Neolithic times. Similar hollows are still in process of formation indeed, it seemed to us doubtful whether the hollows under consideration were in existence at all a hundred years ago. Their floors are at such a level that they are uninhabitable, as the sea invades them at every tide; and there is no evidence that they were ever at a higher level. We see no reason to accept the statement that any of the countless stones littered upon the beach of Coney Island were drifted out of the cave. Among the infinity of shapes which these stones present, there are some resembling choppers, scrapers, and other tools; but in no greater proportion than might be seen on any other limestone beach.As to the implements described by Messrs. Burchell and Moir, we offer the following observations. In the first place, Mousterian is not Early Paheolithic; and Mousterian implements are not, as a rule, of impressive size. Moreover, we are at a loss to understand the meaning of the term patination as applied to limestone. Weathering produces a change of surface colour, hut this is not patination. Secondly, we find it impossible to understand why the hypothetical cave-dwellers made their implements of so unsatisfactory and unusual a material as limestone, when an inexhaustible supply of chert was available. Beds of chert, in many places up to six inches in thickness, form at least half of the bulk of the rocks about Rosses Paint.Thirdly, limestone, as is well known, and as we confirmed by experiments on the spot, does not break with a conchoidal fracture. Fourthly, although we found some stones which closely resembled in outline those illustrated by Mr. Burchell, careful search in all of the sites failed to reveal a single object which could be accepted as undoubtedly a human artefact of any kind whatsoever, or of any date. There was nothing in any of the sites but ordinary beach material, derived from the splintery rock of the neighbourhood.At l3allyconncll we found two sites agreeing generally with Mr. Burchells description. In each of these the boulder-clay is excessively stony, containing hundreds of thousands of fragments of all shapes and sizes. These are broken with sharp angular fractures, especially in the lower part of the deposit: and it would not be difficult, if any one chose to spend a few hours on the unprofitable task to collect a large number of fragments bearing a superficial resemblance to artificially formed implements. But having regard to the geological history of the area, and to the nature of the boulder-clay deposits themselves, we could not admit the possibility of any of the stones thus collected being artefacts. In view of the serious nature of the claims made byMr. Burchell, we feel that he should be called upon to substantiate them on the spot preferably in the presence of a competent jury of geologists and archaologists, selected by some neutral body. We feel also that Mr. Reid Moir should be requested to demonstrate to the same jury the possibility of manufacturing, from the material available at Rosses Point, Levallois scrapers (or any other sort of tool) by the complicated process which he describes.Until these things have been done, we must express and maintain a complete disbelief in the authenticity of this alleged discovery.

ISSN:0028-0836    

DOI:10.1038/120652a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN 1925 I reported to an oyster company that “in 1924–25 the whelk-tingle (Ocinebra (Murex) erinacea) was very abundant and very destructive. In my experiment ‘A,’ fully half of the brood of 1924 were found bored by the whelk-tingle, and it was obvious that most of the young oysters had been attacked in the early summer of 1925, since many of those bored had put on new growth.”The results obtained in the experiment quoted may be taken as roughly representative of what had happened in the beds. In the following year, 1926, there were strong indications that quite 50 per cent. of a good spatfall on the beds had been eaten by the whelk-tingle. Murex is fought on the beds by the dredgermen bringing in on extra payment clumps of spawn, as well as the living adult animal, but the rate of destruction is probably much less than the rate of increase, so that the pest is growing worse. Relief from this pest cannot, therefore, be obtained economically by oyster-producers in the present state of knowledge. It is common knowledge, however, among experi. enced practical oyster - producers that the whelk- tingle and it is interesting to record Echinus miliaris also is almost annihilated on beds after a severe winter. Unless, therefore, a new method of capturing Murex can be found, those oyster-producers who are handicapped by swarms of the pest, cannot expect abatement of the damage they cause until a very hard winter is experienced.It occurred to me that if one knew enough about the habits of Murex, it would be possible to estimate its negative economic value as an oyster-destroyer, and offset this against the increased cost of production of oysters, i.e. expenditure on extra wages, incurred in its destruction. For example, if individual Murex eat on the average one brood oyster a month during nine months of the year, and brood oysters are being bought at one penny each to lay on the beds, then the negative value of a Murex at the beginning of the period of nine months is about ninepence per annum. If Murex eats on the average more or less than one oyster brood per month, its negative value will be more . or less than that amount. Suppose the negative value be sixpence per annum, then a man catching Murex at the rate of 40 per day, and being paid wages at the rate of lOs. per day, would be increasing the potential value of the stock of the beds. In order to obtain some information on this subject, I carried out a few experiments this year to confirm a few previous ones made in 1922. The results of these experiments show that (a) of 15 oysters bored and eaten by Murex, the average time taken was about 57 days; (b) of 10 brood oysters bored, but not eaten, the average time taken was 4 1 days, but if one case of 13 days be omitted, the average time works out at about 31 days; (c) of 8 brood oysters nearly bored through and abandoned, the average time taken was about 45 days. These latter cases were probably special ones, where the shell was too thick or the borer became too weak to corn- plete its work. These preliminary experiments show that Murex can attack and devour an oyster brood from 1 to 2 inches long in 5 to 6 days. In the sea, or under better conditions than are possible in a laboratory removed from the oyster beds, this period will probably be reduced by reason of the better average condition of the borer, and the probability that once the oyster is bored, and consequently opened in the sea, other animals will share in the feast with the borer. I have not had the opportunity of finding out how frequently one and the same Murex attacks and destroys oysters, and suggest that this problem, as well as that of finding a new and efficient and cheap method of capture on the beds, may be advocated as a special piece of economic research. If Dr. Dodgson, at the Government Fisheries Experimental Station at Conway, i eventually successful in producing oyster spat by the million, these will have to be put out in the sea to grow, and to withstand the attacks of natural enemies. Unless, therefore, beds can be found where Murex is a negligible factor, it may be anticipated that the spat produced under artificial conditions will be destroyed in greater numbers than natural spat. The problem is thus an important one in oyster culture.In the experiments mentioned above it was found that Murex attacks small oysters at almost any place on either the flat or convex side; the borer may sit on the oyster, or it may successfully attack it by lying on its back with the prey firmly held over it by means of the foot. (See the photo reproduced in Fig. 1, for which I am indebted to Mr. A. J. Smith.) Oysters are frequently attacked and abandoned; they may be abandoned for unknown reasons when partly bored, or after a complete boring if either a chamber, or a loose horny layer (see Orton and Amirthalingam, J.M. B.A., 14, 4; 1927), is encountered; or if the oyster is in a poor or pathological condition. There is probably a limit to the depth beyond which Murex of a given size cannot use its mechanical boring apparatus, but this limit is greater than 3 millimetres. The shells of oysters rarely attain a thickness of 3 millimetres at even the age of three or four years. In 1922 Murex attacked brood oysters throughout the period of the experiments from the end of January to the middle of March; this year similar results were obtained from July to the middle of October, the whole period of the observations.Murex, however, like Purpura lapillus, feeds on barnacles as well as oysters, and some individuals in my experiments have preferred to attack and eat barnacles when there were oysters in the same dishes. In this years experiments it was found that Murex attacked Balanudollar; perforatus, a large species of barnacle (see Fig. 1 on the right), Balanus crenatus, and another unidentified barnacle, either by boring a hole through the shell or directly through the operculum, and the time taken to destroy B. perforatus was similar to that spent on boring and eating oysters. The smaller balanids are eaten at a much quicker rate. In the sea Murex probably eats all kinds of acorn barnacles. Thus barnacles, when present in abundance on oysters, a condition so frequently deplored by oyster cultivators, protect the more valuable animal by offering themselves as a first source of food to either Murex or Purpurci lcspillus, the smooth whelk-tingle. One individual of Purpura attacked and ate an oyster in my experiments, but this species clearly prefers barnacles, without confining itself, however, to either oysters or barnacles. Murex will also attack Crepidula, as I have found by experiment, but it is either unaware from strangeness of the value of Crepidula as food, or incapable of attacking it easily; a few bored shells of Crepidula have been picked up from oyster beds, but in these instances the borer may have been either Murex or Purpura. It might, however, be possible to introduce into the Thames Estuary oyster beds a natural borer enemy of Crepidula as a means of keeping down that pest, but it would be necessary first to discover whether that particular borer attacked oysters, i.e. 0. eclulis.It is an interesting fact that Murex may return to complete its work of boring an oyster, time after time, even after it has been forcibly removed from its prey. In one case I removed an individual from its boring four times, and laid it on its back each time not less than 1 cm. away from the boring; it returned to the same boring each time like a dog returning to a bone. In other cases individuals have returned to their boring after respectively two removals and one removal from both oysters and barnacles, while in some few instances the Murex has not returned after being removed.The middle West Mersea lVlurex is laid on its back holding by its sucker-like foot and boring an oyster spat. The left-hand Murex is also on its back holding and boring an oyster brood; both are from West Mersea. The right-hand Murex, from the Fal estuary, is itself covered with small barnacles and is eating, after having bored, a Plymouth Balanus perforatus. (Photo of the living animals in sea-water by Mr. A.

ISSN:0028-0836    

DOI:10.1038/120653b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

SINCE 1924, Joyet-Lavergne,1working with plants and Protozoa, has been developing the view that in general female sexual cells are more reducing than male as judged by their effects on the colours of dyes; recently2he considers that they contain more reduced glutathione because they give the colour reactions of this substance more strongly. In 1922, Manoilov3developed a ‘test for sex’ in plants by an elaborate treatment of dyes of the rosaniline series as a result of which the female side was made to display the deeper colour, that is, the reverse of the Joyet-Lavergne effect; Satina and Demerec4have confirmed and developed this test, applying it to animal tissues, and amongst others to the cladoceran Crustacea Moina and Daphnia.5More recently, Falk and Lorberblatt,6working again with animals (mammalian ovary and testis), have demonstrated that the test depends on an oxidation phenomenon, the more complicated Manoilov technique being replaceable by the oxidation of colourlessp-leucaniline in the presence of sufficient ferric chloride by which the female side again produces the deeper colour ofp-rosaniline and is therefore apparently more oxidising than the male; Falk and Lorberblatt also report an ‘interesting parallelism’ in that the extract of testis which they used was found to have considerable reducing power as shown by Tunnicliffe's method of estimating glutathione7whilst the ovarian extract had none, and Sir Frederick Hopkins tells me that this disparity has been long familiar to him.In 1923 (unpublished work) I myself found that the shore-crab Carcinus when inflicted with the parasite Sacculina (in which case the males are apt to assume a feminine appearance) suffered a diminution of sulphur and the nitroprusside reaction distinctive of glutathione, and have since demonstrated the same phenomenon in several ways Although I have never found clear evidence of a normal sexual difference in the content of glutathione in Carcinus, it has become apparent that the assumption of feminine characters by the male goes hand-in-hand with the decrease of its nitroprusside reaction and is therefore perhaps associated with the removal of a substance of a disulphide type which may be of considerable importance in tissue oxidations. On applying the Manoilov, and the Falk and Lorberblatt, and other tests of the same nature described below, I find that parasitised male crabs invariably display a relatively female reaction whether their external morphology be modified or not; at the same time it was evident from the first that glutthione is not solely responsible for the reactions, because they can be procured from the blood in which the nitroprussidcs test fails to indicate the presence of reduced glutathione. The dye tests for sex which I have employed on various crustacea, Cancer and Carcinus (l3rachyura), Homarus, Pandalus 2 spp., and Crangon (Macrura) Gammarus (Amphipoda) in various physiological states, sexual immaturity, parasitism (by Sacculina, Portunion, or Phryxus), and hunger, as well as on the diacious plant Mercurialis annua, may be summarised as follows(1) The direct action of an extract on the dye (p-rosaniline). The female side is typically the more reducing, that is, the Joyet-Lavergne effect, (2) Oxidation of the reduced dye (p - leucaniline) by a minimal quantity of oxidising agent (ferric chloride or hydrogen peroxide) in the presence of tissue extracts. The extracts are inhibitory to the oxidation, apparently through combining with the oxidising agent, and female extracts are typically more effective than male, i.e. the Joyet-Lavergne effect produced with the leueo-dye. This test is more obvious than the Joyet-Lavergne and more cOnstant than the remainder. (3) Oxidation of p-leucaniline by excess of oxidising agent in the presence of extracts. The in- hibitory effect observed under (2) is now destroyed, and the female side usually presents the deeper colour of dye. Evidently there are at least two factors which set up the oxidation conditions of the extracts, and a reducing factor which is present in greater force in females is destroyed by the oxidising agent.This is the Falk and Lorberblatt test. (4) Destruction of p - rosaniline by potassium prmanganate in the presence of tissue extracts.Potassium permanganate enters into combination with the extractives, quantitatively more so in female extracts which may therefore be considered the more reducing, the remainder is free to destroy the dye, and does so more rapidly in the case of males probably because they remove less permanganate. It is necessary to destroy the excess of permanganate by introducing a reducing agent, sodium thiosuiphate or allyl thiocarbamide (thiosinamine) but these apparently do not themselves decolorise such dye as may be unacted upon, except on very kng standing or heating. This is the Manoilov test; it is, in general, the most brilliant of the series.(5) Schiffs rosaniline and sulphur dioxide test for aldehydes. Minute quantities of aldehydes (which restore the colour to this colourless compound) are very rarely present in fresh extracts, and then usually in males. If the solution be heated, the colourless compound dissociates and the full colour of the dye appears, to disappear again by recombination on cooling if the whole of the sulphur-dioxide be not boiled away; in the presence of tissue extracts the same phenomenon takes place, but (typically) on the male side the colourless compound is reformed much more slowly and less readily, which may possibly indicate that a factor which is capable of combining with and so removing sulphur-dioxide is more predominant in the male sex. The tests may be applied either to aqueous (tnchioracetic acid) or alcoholic extracts, but with the exception of No. 5 they are more successful when the reaction is strongly acid; I have failed to confirm Falk and Lorberblatts observation that the presence of protein greatly enhances the disparity between the sexes, at least in trichloracetic acid extracts. Alcoholic extracts still exhibit differences after keeping for eighteen months, but dried tissues do not keep well.It must be clearly understood that the tests are so delicate that some noticeable difference between two extracts is almost always observed, and that equally differences can often be discovered between two samples of the same extract as a result of faults in technique; moreover, biological conditions such as nutrition and maturity themselves produce profound effects and may be compared by these tests one with another, so that the distinction between a pair of extracts which differ only in sex is occasionally not at all obvious and still more frequently is reversed. I cannot subscribe to the view that these methods are tests for sex they are tests for certain oxidising or reducing properties in the setting up of which more than one chemical factor plays a part, although they are undoubtedly closely associated with sex and also with other biological con

ISSN:0028-0836    

DOI:10.1038/120654a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is, of course, well known that for satisfactory work in any branch of microscopy, excellence of the optical parts of the apparatus is a prime essential. In the article referred to, however, it was intended, as was suggested near the beginning of the article, to discuss only the mechanical construction of the various instruments. Any detailed reference to the method of illumination, which is undoubtedly an item of considerable importance in metallurgical microscopy, was also thereby excluded. When referring to items to which the user might attach importance because they suited his particular method of working. the writer had in mind the various methods of illumination employed, including the universal vertical illuminator fitted to the Beck instrument, which permits of the use of various types of transparent and of opaque refleetor which are easily interchangeable and easily adjustable in every required direction. Reference was also made in the article to the wide range of adjustment of the elements of the illuminating system provided by the British instruments. These adjustments facilitate the use of the methods of illumination mentioned by Mr. Beck; but, as was suggested, the method of obtaining the adjustments might be improved.In the production by ordinary engineering methods of the optical bench of the elongated triangular prism type, a certain manufacturing tolerance is necessary on the angle of the prism. A manufacturing tolerance is necessary also on the angle of the saddle. If shake is to be avoided, no such tolerance can be permitted on either of these components. The geometrically mounted saddle will fit the triangular prism at any part of its length without shake, even though a reasonably large manufacturing tolerance has been allowed in the angle of the prism. When the saddle is in use, the forces brought to bear on it are not great; the relative movement of the saddle and the prism is not great; and the wear is thus not severe. The area of the contact surfaces need therefore not be at all large. A properly designed clamp for the saddle should produce a pressure uniformly distributed amongst the five points. The only result of this departure from the geometric principle is to set up strains in the saddle. For effective clamping these strains need not be great, and the ordinary saddle is sufficiently robust to withstand them without perceptible deformation. With regard to the focussing adjustments, it may be pointed out that the stage is subjected to varying loads. Frequently, fairly heavy objects are placed onit. These loads are effective on an overhanging stage whether the coarse adjustment is clamped or not. There are, certainly, various ways in which the necessary movements and adjustments of the several parts of the photomicrographie apparatus may be obtained, The method selected should be such as is likely to be most efficient in use, and the design such as to be capable of being satisfactorily made at a reasonable cost.

ISSN:0028-0836    

DOI:10.1038/120655b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature