摘要:

THE appearance of the first index volume, T covering the whole of the abstracts in pure and applied chemistry issued during 1926 under the direction of the Bureau of Chemical Abstracts, is a notable achievement. Marking, as it does, the completion of the first period in what promises to be a valuable co-operative and unifying enterprise, it represents a definite British contribution to the armoury of chemical knowledge and research. So far as the fields of physical, inorganic and organic chemistry, biochemistry, and chemical technology are concerned, few investigations of real importance, few new facts or measurements, few patents of chemical processes, can have failed to be reported in the abstracts on which this index is based. Since the rate of advance in any branch of knowledge so largely depends on an adequate acquaintance with the experimental results and theoretical views which form the starting-point of any new research, the efficiency of the abstracting and indexing service is a matter which closely concerns every investigator, teacher, and student. Since 1871 the Chemical Society has undertaken, on a systematic and extensive scale, the preparation and publication of abstracts of papers in pure physical, inorganic, organic, analytical, mineralogical, and biological chemistry; besides the annual indexes, collective indexes have been issued covering the periods 1841-72, 1873-82, 1883-92, 1893-1902, 1903-12, and 1913-22. The Society of Chemical Industry has similarly surveyed applied chemistry since 1882, and has published collective indexes for the periods 18821895 and 1896-1905.Naturally, a considerable amount of material appeared in both publications, and from time to time tentative efforts were made in the direction of collaboration. Real co-ordination, however, was initiated only in 1924, when the Bureau of Chemical Abstracts, composed of four representatives from each of the two societies, was constituted with the object of securing, so far as might be possible, unification of the two sets of abstracts. Ever since the Bureau was established, Prof. J. C. Philip has acted as independent chairman, and the new organisation has also had the advantage of the advice, in an honorary capacity, of Mr. A. J. Greenaway, formerly editor of the Journal of the Chemical Society. The regular staff of the Bureau consists of an editor, Mr. T. F. Burton, supported by eight specialist assistant editors, each in charge of an appropriate branch, and a large staff of abstractors, as well as an expert indexer. The publication as a whole, composed of two sections dealing with abstracts in pure and applied chemistry, is now known as " British Chemical Abstracts A and B, respectively. At the outset, the possibility of co-operation with the American Chemical Society with the object of producing one chemical abstract publication in the English language was thoroughly explored, but progress in this direction proved to be impracticable. The Bureau then proceeded, with what patience and persuasiveness one can only surmise, to secure consent to a common format for the two sections of the abstracts, and a joint index. Thanks to the Chemical Society's action in giving up its wellknown octavo format, agreement was reached in 1925 and the new scheme was initiated in January 1926. From that date onwards both A and B abstracts have been published-the former monthly, the latter fortnightly-in double column quarto, the overlap has been eliminated, and the A abstracts (pure chemistry) rearranged and paginated continuously, whilst the type and set up of the B abstracts (applied chemistry) have been brought into conformity with the A section. The first year of this new arrangement has now been completed by the publication of the index part, consisting of 430 pages. It has been necessary to adjust differences in the two systems of indexing previously employed, and to deal with some 50,000 index cards, so that the Bureau may be excused if the publication, which is to serve as a model, appears later than was hoped.The index qua index requires little comment. It is based on the nomenclature and arrangement adopted by the Chemical Society; it includes a list of patents and a list of the journals abstracted; but not, unfortunately, a formula index, that expensive luxury. In two respects, perhaps, the service offered to the chemist by " British Chemical Abstracts " is such as to merit his special attention. In the first place, it offers him abstracts which are admittedly second to none in accuracy; it is the policy of the Bureau that, so far as is practicable, the abstracts shall be prepared by abstractors and examined by editors who have specialised knowledge of the subject concerned. The degree of detail permitted in the abstracts depends to some extent on the accessibility of the original publication to British chemists, but every new substance is specifically mentioned. In the second place, promptness in the publication of abstracts is regarded as being of primary importance, and " British Chemical Abstracts," when compared with other similar publications, proves to have an excellent record in this matter.According to the list at the end of the index, some 400 journals come directly or indirectly under the review of the Bureau's staff. It is of course financially impossible at present to spread the net so wide as does the corresponding American publication; moreover, it is doubtful whether much advantage would accrue from the inclusion of a large amount of ephemeral, borderline, and even non-chemical matter. A systematic survey of all possible sources of information is, however, made, and certainly there can be very little valuable information that escapes the attention of the Bureau and its staff. Much of the so-called borderline material is of course abstracted by other bodies-scientific and trade societies and research associations-the scope of which, although sufficient for their own purposes, is admittedly incomplete. It might conceivably be possible to secure some measure of effective co-ordination or co-operation between the Bureau and such organisations as would result in financial advantage as well as economy of effort on the part of the user. The Bureau would no doubt welcome constructive criticism, and give the most careful consideration to any suggestions calculated to enhance the value of its publications. a British Chemical Abstracts issued by the Bureau of Chemical Abstracts. Index, 1926. Pp. 430. (London: Society of Chemical Industry.)

ISSN:0028-0836    

DOI:10.1038/119805a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THOSE who desire to gain some knowledge T about the attractive inhabitants of Sarawak will find what they require in this interesting and informative book by Dr. Hose. All the information here given about the natives, and much besides, will be found in the " Pagan Tribes of Borneo," by Dr. C. Hose and Dr. W. McDougall. The serious student cannot afford to neglect the older work, but sufficient material will be found in the new book to satisfy most other readers. Owing to his long residence in the country, his intimate and sympathetic knowledge of most of the tribes, and his friendship with many individuals, Dr. Hose not only writes with authority, but also is able to handle his multitudinous facts with ease and to bring out the essential points of material and social culture, besides giving a good insight into the mental and moral characteristics of the more important peoples. The value of the book is enhanced by the very numerous and beautiful photographs, which were mostly taken by the author and do really illustrate the text. A certain number, including two of the four coloured plates, appeared in the older work, but many are new and all are appropriate. There is a useful map of tribal distributions. Dr. Hose deals at the beginning with Borneo when it was inhabited solely by hunters and collectors of jungle produce. Then cultivation (more particularly of rice), metal-working, the building of long houses, and many other cultural elements were introduced; most of the aboriginal population assimilated these to a greater or lesser extent, and this congeries of tribes has beenn amed the Klemantans by Dr. Hose. Certain groups, however, persisted in the old way of life; these are the Punan and allied wanderers in the jungle. Later migrations of people with a similar culture, but more highly organised socially and possessing greater physical and mental FIG. 1.-Iban women dancing virility, were those of the Kayan-Kenyah peoples, whose cultural affinities with tribes in northern Burma and in Assam have often been noted. These are the most advanced of the true Borneans, and it is with them that the book mostly deals; they appear to have entered Borneo from the south. The north was affected by the invasion of the Murut, who, Dr. Hose thinks, came from the Philippines or from Annam. They were not a water folk, and are supposed to have introduced terrace cultivation, the buffalo, and various distinctive weapons and customs; they do not use the blow-pipe. The last migration, which is estimated to have occurred less than 300 years ago, was that of the Iban, or 'Wanderers' (the so-called Sea-Dayaks), who under Malay leadership raided the north-west and penetrated up numerous rivers, a turbulent crowd glorying in head-hunting. There appears, however, to have been an earlier immigration of the same stock, but of gentle manners and more settled habit.The great resources of Borneo attracted the Chinese more than a thousand years ago, and at intervals they claimed a partial suzerainty. Before the Mohammedan Malays became dominant in Brunei it was a Bisayan kingdom under Buddhist sovereigns. Indo-Javanese influence made itself felt, more especially in the west, of which traces still persist. Pigafetta in 1521 was the first European to visit Borneo, and various abortive attempts to settle in the island were made by with the heads of enemies at a festival. (From "Natural Man.") Europeans in the seventeenth century. The Dutch eventually established themselves in the south, and in 1839 the brilliant and adventurous James Brooke arrived on the north coast and shortly afterwards became Rajah of Sarawak. He instituted a policy of administration than which nothing could be better for the local conditions; this has been successfully followed by Rajah Sir Charles Brooke and the present Rajah, Sir Charles Vyner Brooke. The policy has always been to interfere as little as possible with native custom and belief, but necessarily life and property had to be made secure. As an example of the care for the people, it may be noted that many years before the rubber boom of 1910-11, Para rubber seeds had been imported and the natives were encouraged to plant rubber for their own profit. The Rajah caused notices to be published that the natives were at full liberty to appropriate forest lands for this purpose, which would remain their property so long as they took care of the trees and worked the rubber properly. He also ordered that no sales of rubber plantations should be effected without the approval of the Government, and thus prevented exploitation by outsiders. The administration of subject races, more particularly those in Africa, is a topic which is now being widely discussed. The method adopted in Papua has proved most excellent for peoples of very backward culture, and that employed in Sarawak is as admirable for somewhat more advanced peoples.

ISSN:0028-0836    

DOI:10.1038/119806a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ALTHOUGH not actively engaged as a teacher, I1-~ the author has done a considerable service to education in writing a book on photosynthesis as he understands it. The educational value of this book, however, lies not only in the actual information it gives on -what may be called the more descriptive physiological aspects of the phenomenon, but also on the broadness of outlook displayed in the treatment of the whole subject. With commendable thoroughness the author has put a very liberal interpretation upon the word ' photosynthesis,' and has drawn into his purview a number of aspects which might perhaps scarcely have been expected to have received the careful consideration which he has given them. Thus the cosmic and economic aspects of the problem are dealt with at considerable length, and are amplified and illustrated by numerical data which contribute materially to a proper appreciation of their significance; likewise the purely chemical and physical aspects are dealt with in a very lucid and thorough manner. It is by adopting this very comprehensive attitude towards the subject that the author points the way to future progress, for the reader will realise that many gaps in our knowledge of chemistry and physics need to be filled before there can be much hope of a better understanding of the process of assimilation of carbon by green plants. The book is divided into seven chapters which are, in effect, complete monographs of the various aspects of the question with which they deal, being supplied with continual references to original literature. From the point of view of the teacher or the advanced student, this is altogether excellent, since the book may be confidently relied upon to present a complete account of our present knowledge of the subject concerned. To the less experienced student this wealth of information may perhaps be a little embarrassing, more particularly as the author has an occasional tendency to break away from a subject and to return to it again later, which makes it necessary for the student to connect the various pieces together before he can get the continuous story.The opening chapter, entitled " The Origin of Organic Matter and the Cosmical Function of Green Plants," is one of particular interest. There is probably no other book in which such a complete account of this aspect of the subject is to be found; the author has here collected together a mass of data with regard to solar radiation and the disposal by the leaf of the solar energy incident upon it, and illustrates it graphically in a very convincing manner. Here also will be found a comprehensive discussion of the solubility of carbon dioxide in fresh and sea water and its significance to aquatic plants, as well as a discussion of the economic aspects of the utilisation of the solar energy stored by the products of photosynthesis. Many of the data furnished in this very interesting chapter are culled from American sources which, though possibly easily accessible, are not familiar to the average reader. The second chapter deals with " The Nature of Photosynthesis as Determined by Observations of Gas Interchange and the Formation of Organic Matter." This is by far the longest chapter in the book, and is the one which will appeal more particularly to the plant physiologist. Describing first the path of the gaseous interchange at the surface of the leaf and the work of Brown and Escombe, the author passes on to a consideration of the carbon dioxide content of the soil atmosphere and of natural waters. After carefully distinguishing between the terms 'photosynthetic ' and ' respiratory quotient,' he introduces the principle of limiting factors. In discussing the effect of light he wisely administers a much-needed warning to those who may still be in need of itand, sad to say, there are still a good many-in the following words: " . . . there is no sense in considering the photosynthetic activity in different coloured light without at the same time determining the energy relations of the light employed." Attention is also directed to the fact that " the method of measuring the rate of photosynthesis by the appearance of starch in the leaf cannot be considered as being very accurate," since the formation of starch is itself not dependent upon the presence of light. He also administers the coup de grdce to one other much-cherished idea by the statement that " there is apparently no relation between photosynthetic efficiency and the absorption bands of chlorophyll." After dealing successively with each of the various limiting factors in detail, the chapter is brought to a close with an account of the more recent work of Plaetzer, Harder, and Warburg on the 'compensation point,' that is to say, the light intensity at which the respiratory and photosynthetic activities compensate each other.In Chapter iii., entitled " The Products of Photosynthesis," the author gives a fairly exhaustive description of the occurrence and character of such carbohydrates as are found in the leaf, and may therefore be regarded as being, at any rate potentially, primary products of photosynthesis, and on these grounds excludes from this description such substances as trehalose, raffinose, melicitose, etc. Here also will be found a good summary of the vexed question of what is the first product of photosynthesis. The succeeding chapter gives a very clear account of the methods of measuring photosynthetic activity. In Chapter v. the author sets forth in characteristically thorough manner the various hypotheses regarding the steps in photosynthesis. He says of Baeyer's theory that " it is a good suggestion of a possible mechanism of photosynthesis," but of recent work purporting to support the formaldehyde theory he says: " Condensing formaldehyde with strong alkalies or through the action of ultra-violet light and obtaining a great mixture of substances of which only a small per cent is in many cases hexose sugar, will, even to the most optimistic chemist, appear as a rather far cry to the method by means of which the plant forms glucose."Chapter vi., on the energy relations in photosynthesis, contains a valuable summary of all the more recent work on this difficult subject, while Chapter vii. gives a fairly detailed but well-summarised account of the methods of isolating the various leaf pigments, including the separation of chlorophyll a and -b; there is also a section devoted to the chloroplast. There is a considerable number of misprints, more particularly of plant names, one of the most peculiar distortions being that of Heleodea for Elodea on p. 85. The book provides, however, most interesting and inspiring reading; it is impartially critical, and frequently indicates the direction in which further work is desirable. The author has produced a work for which teachers both of plant physiology and of chemistry should be very grateful.

ISSN:0028-0836    

DOI:10.1038/119808a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IT is probably recognised by every one that the I main interest in physics of to-day lies in the study of the atom. Much of the information with regard to the atom has been obtained by studying spectra; chemistry, magnetism, X-ray scattering, etc., play only a subsidiary part. We must admit, however, that our spectroscopic material is now more or less exhausted, and that we must look for fresh sources of information. Much may be said in support of the opinion that magnetism will open a new way by which to approach the study of the structure of the atom. The atom is essentially an electromagnetic system which consists of a positively charged nucleus with negative electrons revolving round it. If the atomic number of the atom is given with its nuclear charge, and if the electrons arrange themselves round the nucleus in a definite way, then this arrangement of the electrons practically fixes all physical and chemical properties of the given element.The magnetic field is probably the only practical weapon by means of which we may hope to change the motion and arrangement of the electrons in the atom, and thus influence all the physical and chemical properties of the atom. In only a very few cases at the present time do we find that the influence of the magnetic field on the properties of the atom is noticed. This is because the influence of the available fields is too weak to produce a marked change in the properties of the atom, and our present methods of magnetic research are not sufficiently refined to study them. The most easily observed magnetic phenomenon is the Zeeman effect, and this has a tremendous influence on the present theory of the structure of the atom. It is possible that the difficulty of experimenting in magnetism, and the small amount of trustworthy experimental work done, account for the fact that magnetism has been somewhat neglected. During the last few years, however, a considerable amount of research has taken place, and new methods of approaching the subject have been developed, and we now have to recognise a marked advance in magnetism.It is on this account that we have to welcome Dr. Stoner's book, especially as it attempts to give an account of our present knowledge of theoretical and experimental magnetism from the point of view of its relation to the structure of the atom. The task of writing such a book, the counterpart of which has not before been published in any language, is indeed difficult; and in his preface Dr. Stoner himself admits the difficulty. The material which an author of a book on magnetism has at his disposal is very large, but the great amount of contradiction in experimental as well as in theoretical work makes the problem of selection very considerable. In his preface Dr. Stoner states, " Prominence is given to the work which is thought to be of most important and lasting value," and the difficulty of selection may be illustrated by the following example. In Chapter xii. (p. 273, para. 4), Glaser's experiments are described at length, and in Chapter xv. they are well discussed. A few weeks before Dr. Stoner's book appeared, however, Glaser's experiments were repeated by Lehrer by a more refined method (Z. fuir P., vol. 37), and it was shown that the increase of atomic diamagnetic susceptibility at low pressures in diamagnetic gases, as observed by Glaser, is almost certainly due to experimental error. This example is given, not to criticise Dr. Stoner's work, but simply to illustrate the difficulty of his undertaking.On the whole, we must agree with Dr. Stoner's choice and with the manner in which he has put together the material at his disposal. The experimental and theoretical parts of the book are well divided; it is free from heavy mathematics; the subject is well brought up-to-date, and the references which follow each chapter are very valuable. Dr. Stoner also gives a brief account of electrodynamics, the quantum theory, and other work which has been done on the structure of the atom, so as to enable the unprepared reader to follow the main subject of the book. We scarcely consider that such a brief account is sufficient to impart the preliminary knowledge necessary to follow the subject of the book-it can be regarded only as a means of recalling certain facts with regard to electrodynamics and the quantum theory to the mind of the reader who is already acquainted with them. It is doubtful whether it is really advisable to include this account in the book.In general, the book is of more use to the experimentalist than to the theoretical research student. A close study of it reveals one or two slips and misunderstandings, but none of a very serious nature. Attention may be directed to one of these, and that is on p. 196, where Dr. Stoner makes some calculations on the gyromagnetic effect. In this connexion the equations (9.2) are wrong, as the author puts the sign of equality between two expressions which cannot be equal. On the following page he himself suggests that this may be 'wholly wrong,' and so it is. It is probable that as magnetism attracts more and more attention, and as its importance in the study of the atom increases, we shall soon have more books published on this subject. Dr. Stoner's book is, however, the first on this subject, and we welcome it as a very good commencement and as an important contribution to our present literature on magnetism.

ISSN:0028-0836    

DOI:10.1038/119809a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. KENNETH LINDSAY, who was Labour TV I candidate at a recent parliamentary election in Oxford, has written a very instructive study of the adequacy of the provision made for scholars to pass upwards from the elementary school to higher places of education, and the use made of it. He quotes with justifiable scepticism Lord Birkenhead's recent dictum that " the number of scholarships from the elementary to the secondary school is not limited, awards being made to all children who show capacity to profit "; and examines the actual facts carefully in four or five selected districts-London, Oxfordshire, Warrington, Wallasey, with a shorter account of Bradford. The book is an interesting illustration of the fact that, however small and technical the point of departure may be, if the argument is pursued faithfully, a survey of all the connected fields is gained. This is especially true of sociology, and Mr. Kenneth Lindsay, by his thoroughness and acuteness, manages to give us a fairly complete sociological picture of London and some of the other places simply by following the record of the scholars proceeding from the elementary to the secondary schools in the area. The main conclusions may be very briefly summarised. The ladder of which Lord Birkenhead spoke affects at most 20 per cent. of the elementary school population; 80 per cent. go no further in their scholastic education. It also appears quite clearly that the minority who do pass on are mainly from the lower middle class of clerks and small traders, and that their children by their continued education are enabled to remain or rise a little higher in the same class. Individual cases are mentioned of the sons of manual workers who become professors or civil servants, but it is abundantly proved that the mass of the workers are untouched by the secondary system. The root of the difficulty is poverty. Even if more secondary and central schools were provided, the need of the parents for their children's earnings would prevent any large number taking advantage of them.To Mr. Kenneth Lindsay this fact points to a much more generous subvention from the State towards the maintenance of scholars: he indicates his own belief in an all-round allowance to parents. From the educational point of view the book will incline most of us to the solution just advocated in the Report of the Consultative Committee on Adolescent Education, namely, the gradual raising of the universal school age to fifteen years as economic conditions permit, that is, concentrating more on the improvement of the education of all than on a large immediate increase either in secondary schools or in scholarships.

ISSN:0028-0836    

DOI:10.1038/119810a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIS volume, the last of the series prepared by Col. Addison to illustrate the manifold activities of the corps of Royal Engineers during the recent European War, covers a wide range of activities. It shows in what manner the corps rose from 1569 officers and 23,521 other ranks (including Territorials) in August 1914 to 11,830 officers and 225,540 other ranks in August 1918. The mere list of units included in 1918 shows what the developments in warfare had brought under the control of the corps: water boring, sound ranging, tunnelling, gas and anti-gas methods, meteorology, land drainage, forestry, laundry, cinema and camouflage were amongst the many which the engineerin-chief had to organise and supply with stores. The subject of most general interest in this volume is the account of the camouflage service. Once again we see the shattered tree near Burnt Farm, and we learn that Colonel Solomon drew its bark from the King's Park at Windsor. It is not without some amusement that we note that for purposes of R.E. the artists in the Camouflage section were rated as painters and the sculptors as plasterers. From the chapter on the organisation of engineer intelligence and information emerges the somewhat startling fact that none of the maps supplied to the Army by the French staff recorded the existence of the unfinished Canal du Nord.The chapters on concrete defences, on forward communications (duckboard tracks, decauville, mule tracks, plank roads, etc.) and on machinery, workshops (with the wonderful list of articles manufactured by the R.E. during the War), and electricity have their own special interest and might serve as a very useful text-book for engineers engaged in pioneer work in the outposts of civilisation. The concluding chapters on searchlights, inundations (our own and the enemy's), and training schools help further to illustrate the magnitude of the whole task of organising the engineering services required in the War and the success with which the task was accomplished.

ISSN:0028-0836    

DOI:10.1038/119811a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIS study of a group of Indian-white-negro crosses is a sociological and eugenic study of a group which has lived in the same locality in Virginia for more than a hundred years. It originated from a white-Indian union, with later introductions of 'mean-white' and negro strains. The group consists of about five hundred individuals in an area approximately eight miles long by four miles broad. They are mostly living on the land. The original white family, judging from its social and economic position, was probably above the average. The descendants are almost without exception below the low white in average ability. One hundred and forty-five pages of the book are taken up with a history of the individuals so far as it has been possible.to recover it, and this is followed by certain deductions from the data as to fecundity, consanguinity, legitimacy, and the like. As a sociological record this material has value; but as a scientific study it leaves much to be desired. The fact that a large number of the females have been prostitutes, and that white men from outside have resorted, and continue to resort, to the area, introduces an element of uncertainty into the data. Further, it is to be regretted that advantage has not been taken of such a promising opportunity to examine on anthropological and genetic lines such exceptional material for the study of a number of problems relating to heredity, inter-breeding, and racial crossing.

ISSN:0028-0836    

DOI:10.1038/119812c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE news of the dangerous floods at Memphis, Tennessee, inevitably invites a comparison with its Egyptian namesake. The modern town was laid out in 1819 (soon after the evacuation of the surrounding territory by the Chickasaw Indians) by three men, John Overton, Andrew Jackson, and James Winchester, who gave it the name of the most ancient of the great capitals of Egypt because of the similarity in the geographical positions of the two sites. They realised that the American site enjoyed an advantageous position at the head of the navigable waters of the Mississippi, and from that they doubtless hoped—and time has amply justified their hope—to derive the great commercial future for their new city which a like position at the apex of the Nile Delta had secured for Egyptian Memphis throughout a period of three thousand years.It seems possible, however, that the founders of the town had forgotten the implicit warning of Herodotus, who made his headquarters at Memphis when he visited Egypt in the latter half of the fifth century B.c. Speaking of the foundation of that city in the dim beginnings of Egyptian history, he tells us (as the priests had told him) how the river had originally flowed right under the western cliffs-as it might be the Chickasaw Bluffs in Tennesseeand how, in order to secure a larger area of low-lying irrigable land, the reigning king dammed the Nile and turned it into the middle of the valley between the two desert ranges, and then let it rejoin its bed at the apex of the Delta. He goes on to say that " to this day " (his day) the point at which the river was thus bent out of its old course was guarded by the Persians-then ruling Egypt-" with the greatest care," and was strengthened every year. " For if the river were to burst out at this place, and pour over the mound (i.e. the dam), there would be danger of Memphis being completely overwhelmed by flood." We have no exact information as to the nature of the defences thus so carefully manned by the Persians, though we may feel tolerably certain that they consisted simply in the earth banks which are almost as old in conception as the Nile mud itself and are still to be seen throughout the length of Egypt to-day. But the Greek historian's account has been verified and very happily supplemented by modern excavation. Herodotus tells us of a "camp of the Foreigners." Sir Flinders Petrie, who dug at Memphis for several years before the War, guessed that this referred to the mixed levies of the Persians; and in his first season's work he struck a building which, as he had calculated, turned out to be this very camp. It lay on the south-east edge of the, town, precisely where we should expect to find the " army of occupation " whose main business was to secure the city from flood. Memphis was at this time the commercial centre of Egypt as well as being its capital, and it was natural that the Persians should keep a strong armed force in this outpost of their empire. The size and heterogeneous nature of this force is attested by large numbers of small terracotta figures representing men of all nations, from the Scythians on the north-west to a Mongolian type coming from farther India, thus indicating the extreme limits of the Persian sway. The Egyptian, we know, was from the earliest times fond of caricature, and these figurines, though showing the influence of the Greek artists then fashionable in Egypt, are definitely the work of native craftsmen. An interesting feature is the absence of women among the foreign types, although Egyptian women occur fairly frequently. The explanation is clear enough. Memphis had become for a time the Cologne of Egypt-if one may be permitted the anachronism-and the army of occupation, consisting of units many of whom were thousands of miles from their native lands and who doubtless despaired of seeing their own homes again, followed the natural course and took wives from among the native women. That these should in their turn become a butt for the jesting hands of their fellow-countrymen is not surprising. Thus to the bald remarks of the ancient historian archaeology has added such convincing details as these models of the very soldiers, whose 'foreign service' for a considerable period was the comparatively 'light fatigue' of patrolling and repairing the dams of Memphis.Such a strict watch was still kept up at every Nile flood until a few years ago, when the irrigation works of the British engineers put the water under more perfect control, and thus practically removed the danger from flooding. Centuries of experience of the vagaries of the Nile floods, and perhaps a cautious instinct inherited from those earliest days of human occupation of the Nile valley, when every acre of cultivable land had to be won from Nature with great hardship and risk, must have made the Egyptians more than usually careful of their dykes. At all events it is interesting to note that throughout the five millennia of its history, during which we frequently hear of looting and partial destruction by conquering armies, there is no record, so far as I am aware, of the flooding of the town of Memphis. Yet its modern namesake, although advantageously situated on the hills forty feet above the river, and in spite of all the resources of modern science, is suffering this grievous calamity little more than a century after its foundat

ISSN:0028-0836    

DOI:10.1038/119813b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

TEMPTING though it is to deal with Prof. Huxley's personal references to myself and others, as they have no bearing upon the argument, I would return to my protest against his dogmatic statements about doubtful matters.Among " the fundamentals of genetics to date" (NATURE, Mar. 5, p. 350) Prof. Huxley gives "the proof that the chromosomes carry the genes, and that the genes are arranged in linear order," and "the individuality of the chromosomes." The 'genes' are of course the factors of Mendelian heredity. I think I am right in saying that they are assumed to be small particles arranged in regular order in the chromosomes, each representing a particular character. Also it is apparently assumed that all characters are represented by genes. Now the usual mode of distribution of the chromosomes between dividing cells before fertilisation, provides a perfect mechanism for the distribution of the 'genes ' according to the 'Neo-Mendelian' theory, but this mode of distribution is not universal in connexion with fertilisation, as I have already pointed out (NATURE, Jan. 29, p. 161). The continuous individuality of the chromosomes from generation to generation of cells and whole organisms may be a fact in some cases, but is very doubtful in others. They appear only during the process of mitosis in most organisms. Several investigators of repute (e.g. Child, Biol. Bull., vols. 12, 13, 1907; vol. 18, 1910; vol. 21, 1911) claim that amitosis occurs among the cells destined to produce gametes. Personally, I think there is some other explanation than amitosis for these appearances, but until this and the other points to which I have referred are demonstrated, the individuality of the chromosomes must remain as an attractive working hypothesis.While in breeding experiments certain groups of characters do appear in the individuals of consecutive generations in the Mendelian manner, the great majority of characters are common to all the individuals of a race or even many races, and any such mechanism as is provided by the chromosomes for the distribution of Mendelian characters would prove an obstacle were these common characters represented by unit factors arranged in regular lines in the chromosomes. Moreover, certain breeding experiments suggest that similar characters (e.g. colour) may blend when races geographically widely separated are crossed, but segregate in the case of local variants (Prout and Bacot, Proc. Roy. Soc., B, vol. 81, 1909; Entomologist's Record, 15 and 16, 1906; Trans. Entomol. Soc. Lond., 1906; Proc., 1907). Blending of such important characters as the number of the vertebrae occurs in crosses between Salmo salar, trutta and fario. The progeny are fertile and there is apparently no segregation (Walker, "Hereditary Characters," 1910). "Very frequently, if not always, the character that has once been crossed has been affected by its opposite with which it was mated and whose place it has taken in the hybrid," and "Everywhere unit characters are changed by hybridism " (Davenport, " Inheritance in Poultry," p. 80, 1906). Many other instances might be cited. The theory seems to me the most probable which requires least in the way of assumption. That recent variations are transmitted in the Mendelian manner; that they are always tending to blend more and more if they are preserved from generation to generation; and that racial characters, derived originally from individual variations, are produced through the general potentialities of the cell for development within definitely restricted limits, seems to me to require less in the way of assumption and to agree more easily with known facts than what is now put forward as the " Neo-Mendelian Chromosome Theory."That the chromosomes are concerned in the transmission of the potentialities for developing Mendelian characters is an attractive and probably useful working hypothesis, and so long as Prof. Huxley and " the whole body of those engaged upon genetical research" treat this and the other hypotheses involved as useful " conceptions and theories " (as he now calls them, NATURE, April 30, p. 639) and not as 'laws' and proven facts, no one can complain. "If therefore the Reader expects from me any infallible deductions, or certainty of Axioms, I am to say for myself, that these stronger Works of Wit and Imagination are above my weak Abilities. Wherever he finds that I have ventur'd at any small Conjectures, at the causes of things I have observed, I beseech him to look upon them only as doubtful Problems, and uncertain Ghesses, and not as unquestionable Conclusions, or matters of unconfutable Science " (Robert Hooke, Micrographia, 1665 (Preface)).

ISSN:0028-0836    

DOI:10.1038/119814a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. TIBYRIÇÁ's formula, which amounts to the statement thatM− 2αis divisible by 8, may be interpreted in the following manner. Every atomic number of the elements from 2 (helium) to 21 (scandium) may be represented by the expression 2 + 8d+v, wheredis an integer from 0 to 2 andvan integer from 0 to 4, equal to the valency of the element. This is supposed to be due to the arrangement of the electrons in layers; the first complete layer consisting of two, the second and third of eight electrons each; the valency being an excess above or a deficit below a complete layer. The elements with +vare often described as positive, those withvas negative. In any compound of two atoms in which the atomic number of one contains +v, and that of the other containsv, the total ‘molecular number,’M, will be 2 × 2 + 8(d+d′), wheredandd′ may be the same or different. Similarly, in a compound containing α atoms, with the sum of the + valencies equal to that of the − valencies, the total molecular number will be α×2 + 8(d+d′+etc.), where (d+d′+etc.) is an integern. This is Mr. Tibyriçá formula. In minerals, which are compounds, consisting only of elements with numbers from 2 to 21, all combination is between elements with + valency (including for this purpose the tetrads) and those with − valency, and their valencies are all satisfied. The only exception of which I am aware is carbon monoxide, which undoubtedly exists in a natural state.So far, the element hydrogen has been left out of consideration. Its atomic number, 2 + 8 x 0 I = 1, satisfies the same conditions as do the other elements up to 21, but though it has a valency of 1, it behaves as an element with + valency and combines with elements with valency, instead of those with + valency; thus water or ice would not satisfy Mr. Tibyrica's formula. For M 2a = 2 + 8 6 = 4, which is obviously not divisible by 8 If the elements of an even number of molecules of water be present in a molecule and the other elements present satisfy the formula, the mineral as a whole will do so. But if only the elements of an odd number of molecules of water be present, it will not. Thus, if tavistockite have the formula Al2Ca3(OH)6(PO4)2, Mr. Tibyriq's formula would not apply. ForM=231 and 2a=54; so that M-2a =234-54=180, which is not divisible by 8. But it appears that in calculating the number of atoms, a, he does not include atoms of hydrogen, though he includes their atomic number in calculating M. Consequently for water M-2a=2+8-2=8; so that for minerals with an odd multiple of the elements of water, M

ISSN:0028-0836    

DOI:10.1038/119815c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature