摘要:

TOHANN HEINRICH PESTALOZZI died at e Brugg, Switzerland, on Feb. 17, 1827; and in the hundred years which have passed since then, a great change has taken place in educational thought and practice. Especially is this so in the province of school science, a growth almost entirely of the latter part of the nineteenth century. But as with all growths, we must search for the roots in the history of a far earlier period than this; and then we discover what science teachers owe to the pioneers of old, one of whom, Pestalozzi, will always hold an honoured place. During the Middle Ages, when Aristotelian doctrines dominated intellectual thought and the grammar schools in England were precluded by their statutes from teaching any but grammatical subjects, there were already many people alive to the fact that a knowledge of science would be of advantage to the rising generation. They were not, however, thinking of science as we understand it to-day; all they advocated was a study of the scientific works of the classical authors, and by the middle of the seventeenth century a few, but very few, schoolmasters endeavoured to emphasise books of this nature.Following the rise of modern science, and about the time of the foundation of the Royal Society (1662), a few pioneers urged a reform of the school curriculum in the direction of science teaching. But whether it was Comenius in his wide embracing encyclopedic fashion urging complete reform, or Milton and Cowley advocating a closer study of scientific Latin and Greek books, or Hartlib and Petty emphasising the need of school science of a practical nature, little success attended their labours. Their schemes were all premature; the English grammar schools were not allowed by law to teach science until 1840. A hundred years after the beginning of the scientific movement came Rousseau, with his vigorous revolutionary doctrines, bent on making his ]tmile a model youth. The old order was to be swept away and JEmile's education was to proceed on novel lines. Amongst other things he must learn science, not book science, but practical, everyday science. No pedant was to teach him, he must teach himself: " Let him not be taught science, let him discover it." No book for IImile but that of the world, for books " only teach us to talk about things we know nothing about." Wordiness in education must disappear, and in its place come things, a first-hand acquaintance with things, so bringing into use the boy's powers of observation, reasoning, and invention. At the time, in 1762, when " 1mile " was published, Pestalozzi was a student at the University of Zurich. He was enraptured with the book, and became ensnared in the revolutionary ideas of his hero Abandoning in turn his course of study for the ministry and for the law, he turned to farming, where his idealism was rewarded with bankruptcy. He then became schoolmaster, a profession he was to follow until his death in 1827.In this short article we are not concerned with his general views on teaching or with the methods he devised or adopted. It is enough to say that he believed that the true basis of knowledge was sensory experience, and that education should be based on personal, first-hand observation. Out of this grew the familiar object lessons of the nineteenth century, and these are of great significance in the history of science teaching. For during them much scientific information was imparted to the children, since Pestalozzi and his numerous followers took for the subject matter familiar and interesting objects. The pupils learnt to look at things more closely, to examine plants, animals, and inanimate objects. Pestalozzi, it may be recalled, had had experience in farming, and it seenfs highly probable that in the lessons he himself gave, agricultural topics would frequently be mentioned. Occasionally excursions were made into the surrounding districts, when, under the supervision of the teacher, many interesting titbits of natural history were learnt. But unfortunately this science, if such it can be termed, was taught generally without plan and was of a haphazard nature. It was largely of the demonstrative type, where the attention of the child was directed to some particular part or property of the object, the name of which, when given by the teacher, was repeated aloud and memorised. Such lessons had for their chief function the teaching of words, not science. In addition, however, to the smattering of scientific information which he gave in this manner, Pestalozzi included physics and chemistry in the curriculum of the school at Munchunbuchsee, and, in the " Report to Parents," special mention was made of science teaching, thus: "We are also trying at the same time to organise the teaching of experimental science. So far we have demonstrated to the boys the principal facts concerning Electricity and Magnetism and the behaviour of certain gases. We are, in this connection, trying to establish a satisfactory course of instruction in the language of physical science. A local doctor gives weekly lessons in this direction to the older children with the aid of excellent apparatus in his possession."Natural history was also taught, for, as he pointed out, almost every child is sure to be familiar with " half a dozen mammals, and as many birds, fishes, insects, amphibians, and worms." In short, he endeavoured to connect the course with the things the boys could see around them, such as the behaviour and structure of the common animals and plants. All this Pestalozzi was doing, whilst in England and most other countries little, if any, attention was being paid to science in the schools. It is rather significant that many schools, when first introducing science, did so in a similar manner. For example, Dr. Arnold, of Rugby, persuaded the boys to collect specimens of rock, etc., from their neighbourhood to form a science museum, and his successor, Dr. Tait, invited a local physician to give lessons similar to these suggested by Pestalozzi.The latter had no misgivings on how science should be taught, as the following extract from "How Gertrude Teaches Her Children " shows: " All science teaching that is dictated, explained, analysed by men who have not learnt to think and speak in accordance with the laws of Nature, all science teaching of which the definitions are forced, as if by magic, into the minds of children, like a Deus ex machina, or rather are blown into their ears by a stage prompter, so far as it does, this must necessarily sink into a miserable burlesque of education." Pestalozzi's influence on science teaching rests, however, on his object lessons, for they were widely imitated in England, largely owing to Dr. Mayo and his sister. After Dr. Mayo's return from visiting Pestalozzi he opened a school at Epsom and later at Cheam, and in time the Home and Colonial Infant School Society's training college resulted. Here intending teachers were trained to give these object lessons. Further, the two Mayos published books on methods of teaching, the most important for our present purpose being Miss Mayo's " Lessons on Objects." In it were given typical object lessons on numerous scientific subjects, and these served as models to numerous teachers. Lessons of this type became very common in England, especially in the elementary schools, and for many years, in fact until the introduction of Lowe's Revised Code in 1861, they were the only means by which children at such schools were brought into touch with science. But the lessons departed from the model of Pestalozzi, and readers of Dickens will recall the type of lesson Bitzer of " Hard Times " had to endure with his " Quadruped, graminivorous forty teeth, etc.," or the one Nicholas Nickleby caught Squeers giving. Pestalozzi's influence was not confined to the elementary schools, however, and many secondary schools taught object lessons often with the idea of giving scientific information. Thus, from its foundation in 1832, University College School, London, made use of Miss Mayo's book on " Lessons on Objects," but not for long, since it was found, as Dickens saw later, that these lessons tended to degenerate into a mere explanation of hard words, and hence they were soon discontinued at this school. Yet though Pestalozzi did little to establish modern school science-the science of his day was not sufficiently organised to serve as a school subject, whilst he himself was chiefly interested in young children-his name must be revered by science teachers because of his patient research into better methods of teaching.

ISSN:0028-0836    

DOI:10.1038/119377a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE author of this book is lecturer on 1 economics in the University of Reading. The work is one which, in our opinion, is of firstclass importance, written in a most interesting style, and we heartily commend it to all our readers. It is difficult within the compass of a review to give an adequate idea of the value of its contents. It deals with a subject which has caused acute controversy, and still awakens intense emotion in the minds of many of our countrymen-namely, the so-called industrial revolution. Although the author approves of the use of this term, and indeed states that the industrial revolution was of such magnitude as to dwarf all political revolutions, yet we think that the word revolution is misapplied in this case. This word has always been held to denote a violent upheaval and overturning of the social order by insurgence from within; but the industrial revolution was merely an extremely rapid evolution due to purely natural causes, as the author convincingly shows; and it had declared itself, shown all its characteristic features, and accomplished much of its course before any political change took place at all. The popular conception of this change, which still figures largely in Socialist literature (we remember hearing it expounded with great vehemence by the late Mr. Hyndman in 1890), was that it involved the seizing of the common land of the poorer people by the landlords, whilst the dispossessed were then transformed from freeholders into tenants-at-will or driven into the towns, where they were ' exploited' at starvation pay by greedy manufacturers. It was, so far as we can recollect, Dean Inge who first forced on public attention the fact that this change was accompanied by an enormous and rapid increase in our population. The Dean's estimate was that the population of England had increased by 30 per cent. between 1700 and 1800, and by 300 per cent. between 1800 and 1900; it is with the causes and time of beginning of this increase that our author first sets herself to deal.The first census of England was made in 1801, but various sources of information exist from which fairlv trustworthy estimates of the population at earlier dates can be made. The author weighs the evidence, and comes to the conclusion that at the beginning of the eighteenth century the population of England was 51 millions; that it decreased during the first decade and then began to rise, and that it showed a net increase of one million by 1750, but that between 1750 and 1820 the population doubled itself. The rapid increase therefore began long before the invention of the steam engine, and before the expansion of manufacturing industries. It must obviously have been due either to immigration, or to an increase in the fertility of marriage, or to a fall in the death-rate. The author proves that the last was the real cause, and that it was not an increase on the longevity of adults which took place, but a fall in the infantile death-rate. She goes on to show that amongst primitive peoples population is regulated by an appalling wastage of child life. Persia, for example, is a country without motors, railways, or manufactures; there is widespread peasant proprietorship and few large towns -yet in some districts 85 per cent. of the children die before attaining the age of ten years, and in other districts only one child in ten attains maturitv. In this, man resembles the lower animals, for the greater part of ' natural selection ' takes place at the expense of the young. Now in the sixteenth, seventeenth, and eighteenth centuries, but especially during the first two, England was ravaged by diseases formerly supposed to be tropical. The exact nature of some of these was obscure, because distinct diseases were confounded together under the name of plague, but bubonic plague, typhus, typhoid, dysentery, malaria (ague), and above all, smallpox, were rampant. Smallpox attacked chiefly the young, and few children escaped it. About the middle of the eighteenth century, inoculation as a remedy was introduced, to be followed soon afterwards by vaccination. The author shows that inoculation was in most cases an effective and not very dangerous remedy, since it was performed with an attenuated virus, and in one respect it excelled vaccination, because it was never necessary to repeat it.Thus the main reason for the increase was the gradual improvement of medical science, but this was coupled with the better development of agriculture and a regular and more nutritious supply of food. Food began to be grown for trading with other districts, not merely for the support of a particular district; this was rendered possible by the development of better roads. The author throws scorn on the idea that the medieval peasant proprietor lived under idyllic conditions. He was miserably housed, and he worked for unthinkable hours for a pittance. When the harvest failed there was no means of bringing food from elsewhere, and the peasant starved, or died from diseases which attacked him owing to his weakened condition brought on by eating rotten grain. One of the diseases which decimated the population was scurvy. Since there was no means of feeding cattle during the winter, the majority were slaughtered every autumn and their flesh salted. The stringency of the game laws is said to have been due to the determination of the feudal lords to avert scurvy by having fresh meat during the winter, so they alone were allowed to hunt game and to keep pigeons. But in the middle of the eighteenth century root crops were introduced from Holland, and thereafter cattle were kept alive during the winter. The common on which the peasant had grazing rights and from which he collected firewood was unenclosed waste. The author gives a vivid picture of how incredibly large and unproductive this waste was when enclosure began. Agriculture could only be improved by bringing a large part of it under cultivation, and there is no evidence to show that this enclosure was detrimental to the peasant. For when really productive farming began there was regular employment for more men, and a comparison of villages in districts with and without enclosure shows that the population increased faster in the former than in the latter. What the peasant hated was a change in his habits; he preferred to starve under old conditions to which he was accustomed rather than to prosper under the new ones.The author emphasises the fact that during the eighteenth century, though there was little political liberty as embodied in the right to vote, there was abundant personal and intellectual liberty. To the freedom of initiative, to the prevalence of the doctrine of laissez-faire-in a word, to private enterprise-she attributes the major part of the influences which produced modern England. At the beginning of the century Northumberland was as wild and unenclosed as the backwoods of Canada, and the enterprising farmers who settled in its valleys, cleared the timber, and brought the ground under cultivation were as truly adventurous pioneers as the merchant adventurers of Queen Elizabeth.Of course, as the steam engine came into use our manufacturing capacity increased enormously, and there was a steady drift into the towns which has continued ever since. A favourite theory has been that the peasants were lured from their healthy homes in the country into the slums of the towns, where they rotted and died. Now the author shows that the medieval city was in reality a festering sore. To contemporary writers cities were known as devourers of population. Our cathedrals, so beloved by the medievally-minded amongst us, arose in the midst of narrow, unspeakably dirty lanes from which air and light were shut out by overhanging upper stories, with no sewers except an open drain in the middle of the street, into which all rubbish, including human exereta, was flung from the windows. Herds of pigs wandered about fattening on this garbage, and proposals of the rich to pave the streets and remove the rubbish were resented by the poor as an invasion of their privileges. Truly the medieval circle of ideas which the reactionaries would restore if they could, was one of dirt and primitive superstition. But in the eighteenth century, when the drift to the towns began, advancing medical science had begun to discover the necessity for a better water supply; the streets were wider and better paved, and the garbage was removed. Far from perfect as the habitations of the work people undoubtedly were, they were better than the dwellings they left behind in the country, and population grew in the towns by increase of births over deaths. The myth that the workmen were ' exploited ' by the payment of scandalously low wages is also exploded by the author. As she says, there never was a time when native talent and initiative amongst the workmen had greater opportunities. Early machinery was costly, wasteful, and constantly breaking down, and workmen with skill, common sense, and adaptability could practically demand their own price. Those who got the minimum wage and deserved no more were those who were only fit for routine operations. Just as daring private enterprise built up our agriculture, so it founded our manufactures. On it all England's greatness is founded, and by it, though sorely hampered and embarrassed, we still are borne.The perusal of this book leaves us with some curious reflections. This unspeakably filthy medieval society from which we have slowly emerged succeeded to a Roman civilisation-a civilisation with paved roads carved with superb engineering across hill and dale; with properly constructed sewers, and with a plentiful supply of pure water carried on wonderful aqueducts. Houses were provided with ' central heating ' on much the same plan as that now to be adopted in Liverpool Cathedral, and above all, with properly constructed baths. This civilisation can be traced through Rome to Greece and back to Crete, and possibly eventually to Egypt. Yet this age-long civilisation, which must have appeared to its contemporaries as securely founded and permanent as the orbit of Nature itself, succumbed to the attacks of northern barbarians, and not until the middle of the nineteenth century did we reach the same level as that achieved by Rome. Washing was eschewed in the Middle Ages as a heathen luxury. So late as 1801 a London doctor stated that his patients amongst 'ladies and gentlemen' washed their hands every day, but did not wash their bodies from year to year. The Anglo-Saxon St. Dunstan is said to have given proof of his holiness by the fact that when he shook his sleeves as he sat at board, 'maggots' escaped from them.The Mediterranean civilisation once penetrated to the south of Africa. Like the Roman civilisation in Britain, it was overwhelmed by barbarians, and its remains, overbuilt by the kraals of Kaffirs, are to be seen until this day. Our twentiethcentury civilisation, if the private enterprise which upholds it is undermined, might suffer a like fate.

ISSN:0028-0836    

DOI:10.1038/119379a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

OF the excellence of Major Cheesman's journey 0 into the deserts of eastern Arabia there can be no question. He travelled down the Persian Gulf from Basra to Bahrain, and from there to the little port of Oqair, on the Arabian coast; there he met camels, sent down for him by the ruler of eastern Arabia, Abdul Aziz ibn Saud, whom he had already met, and to whom he carried a personal letter from Sir Percy Cox. The camels took him, his baggage, and his Baghdadi servant to Hufuf, an oasis which has already been visited by several European travellers. The purpose of the expedition was to collect mammals and birds, and, where necessary, to fix the position of places astronomically, and to make compass traverses when passing over unmapped routes; the traveller's purpose was to work his way south from Hufuf towards the empty quarter of Arabia, unvisited by Europeans, unknown to most Arabs, and only recently brought under the suzerainty of the conquering ibn Saud, leader of the Wahhabis. Cheesman was delayed nearly three months in Hufuf in mid-winter; he occupied his time collecting the fauna and making a map as unobtrusively as possible, but he was handicapped by the season, for the resident birds were not breeding, and there was no through migration; the insects were presumably hibernating, if we may judge from his scanty collection and from what we know of their behaviour at the same season in Mesopotamia.At length, on February 8, he left Hufuf and travelled 150 miles south over unknown country, most of it hard desert of an extreme type, until he reached the wells of Jabrin. He is the first European to see the Al Murra Arabs at home; he has brought back a route map, and established the position of the Wadi Sahba, which is now dry at all seasons, but formerly carried water from the highlands of western Arabia right across the peninsula to the Persian Gulf. He has also brought home a good collection of birds and mammals, and of observations on their habits, and a number of specimens of insects, plants, and rocks. So much for the journey, already described in the Geographical Journal. The present book is delightful when it describes the author's observations on bird, beast, or man, and the conclusions which follow immediately from them. There is, for example, an excellent chapter on the water supplies of desert animals, though we think that the author is too much inclined to look for actual water in the form of dew, and that he does not realise the high proportion of water which is held in fragments of dry vegetation. There are also some most interesting notes on gerbilles of the genus Meriones, which prove to be diurnal, and not nocturnal like other gerbilles. We think that the author could have written a book of more permanent value had he included a general account of Nature in Mesopotamia and the islands of the Persian Gulf; he knows more about these countries than any other field naturalist, and he has wandered over them in all directions and at all seasons, collecting and observing. The raw materials for such a study are available in a long series of systematic papers by various specialists in the Jour. Bombay Nat. Hist. Society. The present book contains no reference to any of the author's previous travels, except a reprint of an account of a journey along the shores of the Gulf from Oqair to Salwa, and for this reason is a little unsatisfying. So far as the last journey is concerned, the unknown country covered was between Hufuf and Jabrin, and that journey only occupied a fortnight; the same featureless track was covered twice, and a general account of it would be easier to read than the transcript of diary which is given. But even as it stands the book is full of life and vigour and observation, and it makes delightful reading.When the author gets away from his own observations, however, his zoology becomes surprisingly ' loose.' One may quote his own italicised sentence: " I think the development of a colour as evidenced most clearly in a subspecies is the result of an influence which I will call subspecific desire, operating through generations of that subspecies, for that particular tone." It is clear from the context that he does, in fact, attribute the colour of animals to volition, and that the exercise of the will is thought to be most potent when the bird is nesting, except that predatory species do their ' wishing' when they are stalking their prey. With regard to protective coloration, the author is strictly orthodox, so much so that he brings forward no fresh arguments in favour of the theory; instead of doing so he talks in general about willow grouse, and mallard, and desert birds, and trout, and lizards, and nightjars (which almost shut their eyes, because they know how conspicuous the eye would otherwise be !). Every one admits that the majority of desert animals, in the widest sense of the word, are coloured so that they resemble the soil on which they are found; in some cases the degree of resemblance is very high, in many much less so; but the theory that this similarity of colour is protective is not generally accepted nowadays, because it does not appear to cover more than a fraction of the facts. It is difficult to apply it to the strictly nocturnal animals, and still more difficult to fit it to the subterranean pocket gophers of California and Arizona, and other subterranean mammals and reptiles, many of which exhibit a high degree of resemblance to the soil in which they live. Moreover, if the facts are faced without prejudice, it will be found that a proportion of diurnal desert creatures are black, and this is true in the Old World, America, and Australia; examples occur in birds, and grasshoppers, beetles, flies, and other creatures.The devout believer in protective coloration will tell us that none of these black creatures needs protection, and that explanation is enough for him; but those who are inquisitive, perhaps agnostic, may reasonably ask why all the creatures which do not need 'protection' should agree to wear black. Even among the facts recorded by Cheesman himself, one can find examples of animals to which the theory of protective coloration cannot be applied. In Arabia, and in many parts of the Old and New World deserts, the bats are much more sand-coloured than their relatives in other climates; moreover, this tendency, which is observable in the less extreme deserts -for example, Mesopotamia-is increased in the intense climate of Hufuf and other similar places. It appears that nothing but an act of faith could carry the true believer over such an obstacle as this, for we can scarcely suppose that a pale bat is protected from a (hypothetical) owl, or that its paleness assists it in pursuing moths (also ' protected ') by moonlight. We understand that the author left for Abyssinia before the book passed through the press, but that does not explain the multitude of inaccuracies which it contains. He was probably wise to adopt a simple system of transliteration from Arabic, suited to the general reader, but his use of it is quite inconsistent. For example, he writes suq and booma, though both have the same long u in the original tongue; on the other hand, he writes suq and burr, using the same English vowel to represent different sounds. He commonly transliterates the Arabic letter Khe by Kh, consistently with general usage, but he also uses k in ' Jebel Akdhar,' and h in 'Hashm.' " The ibn Shaikh " is an unnatural mongrel between the English " The Shaikh's Son," and the Arabic " Ibn esh Shaikh." One gathers that when Cheesman bade farewell to the Amir at Jabrin, both were so much overcome that they forgot their grammar; one said " we am so pleased you came," and the other ohorussed, " I are so pleased to have met you." Neither 'Brinjal' nor 'Jird' are words known to the educated English reader, and as one is Hindustani and the other Persian, there seems no justification for their use here, particularly as English equivalents of both are available. The illustrations from the author's photographs are admirable, and they serve to show what excellent results may be obtained with a minimum of apparatus and trouble. They were all obtained with a quarter-plate Kodak, and the films were developed four months after they were taken, in England. The scientific results of the expedition have been dealt with by specialists, and their accounts are all reprinted as appendices; the result is that all that is known of the fauna of this part of the world is contained in this one volume. There is an adequate index and an excellent map, reprinted from the Geographical Journal.

ISSN:0028-0836    

DOI:10.1038/119381a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

(1) TWENTY-TWO years ago the first Optical 1-Convention, defined as a conference of opticians " to discuss questions of interest and to promote the general welfare of the Trade," was held in London under the presidency of Sir Richard Glazebrook. It amply fulfilled the expectations of those members of the Optical Society whose prescient minds foresaw the advantages that might accrue to the science and practice of optics. Seven years later, Prof. Silvanus P. Thompson, the president of the second Convention, held in 1912, in his address to the members declared: " We are met here to exchange views, to deliberate, to discuss, to learn from one another and from the material objects we have been able to bring together in an Optical Exhibition, anything and everything which can stimulate our thoughts, widen our information, or concentrate or harmonise our activities in matters optical."After a further lapse of fourteen years the third Convention, presided over by Sir Frank Dyson, has recently been held. During that period of fourteen years the optical industry has experienced an extraordinary expansion followed by prolonged postWar depression. But however subdued the present state of the industry may be, there is no apparent abatement of the interest in optics. This is manifested by the two large volumes which embody the proceedings of the Convention. Containing as they do more than ninety papers, some of them miniature treatises, dealing with every aspect, they constitute the largest and most comprehensive addition to the literature of practical and theoretical optics that has ever been made at one time. Surveying, and particularly that latest development, aerial surveying, forms the subject of fourteen papers. There are ten devoted to visual optics and eleven to photometry. Optical computation takes a prominent place, but only the geometrical aspects of the question have received much attention: practical trigonometrical methods such as are used by the manufacturer still receive little consideration from the mathematicians. For the first time there are included several excellent historical papers.Since the date of the second Convention the foundations of optics have been overturned and the builders still lack some necessary material for their reconstruction. Only one paper on this basic subject is included. There is also only one paperfortunately an authoritative one-which deals with that one-time popular instrument, the microscope. So large a number of papers delivered in so short a time has resulted in a discussion of unduly limited extent; it amounts to about 13 per cent. of the material. In 1905 there was a 22 per cent. discussion, and in 1912, 18 per cent. The index is scarcely adequate. The illustrations are generally good, but the cover is unattractive. In this respect it would be well in future to depart from the bad example of the 1905 Proceedings.(2) This catalogue is no mere enumeration of the instruments of British origin exhibited at the Optical Convention of 1926. It records the important advancement that has been made by the optical industry since the date of the last Convention; it is a record of advancement that is remarkable when it is realised that all products of purely war character have been excluded. It also serves as an index to which future progress will be referred. More than sixty British firms who participated in the exhibition have contributed descriptions of the instruments and optical materials produced or supplied by them. These descriptions are devoid of salesmanship claims and are of special interest, as they express the essentially practical opinions of the manufacturers themselves.Instruments are well classified under seventeen groups, of which by far the most extensive is that devoted to the microscope, which receives so little attention in the Proceedings of the Convention. Ophthalmic apparatus and surveying instruments occupy second and third place respectively. Of the five additional sections, one is devoted to experiment and research, and another to an account of the very valuable collection of historical instruments and books. The catalogue is well produced, and should be studied by all engaged or interested in the optical industry.

ISSN:0028-0836    

DOI:10.1038/119383a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

W TE learn from the preface that this translaV V tion of Schmidt's " Kurzes Lehrbuch der organischen Chemie " arises from the encouraging results that attended the adoption of the German original as a text-book for the advanced students in the University of Edinburgh, and indeed the translator has done his work so admirably and produced so readable a book that there can be no question that it also will find a similar welcome in other English-speaking universities. It is the type of book that the teacher can recommend with confidence to the more ambitious second-year and pass students in organic chemistry, and, in so far as any single text-book can meet the ever-growing requirements of the honours students of a university, this book will prove both helpful and useful. Following a general introduction of 68 pages, the book treats of the chemistry of the carbon compounds in 687 pages under the three sections (1) the aliphatic or fatty compounds, (2) the carbocyclic compounds, and (3) the heterocyclic compounds. It is obvious that in so limited a space the treatment of so vast a subject could not be wholly adequate, and in this respect the general introduction is perhaps the weakest part of the book; the description of 'the methods of qualitative and quantitative analysis, for, example, is condensed into seven pages and unrelieved by any diagrams. In the three main sections, the chemistry of the hydrocarbons and their derivatives is discussed under their respective headings in the usual order, and one of the most valuable features of the book is the introduction of numerous sub-sections dealing with special groups of compounds-of natural or synthetic origin-as they fall within the category of the compounds under discussion. Some of these are of special interest, as for example those dealing with the polypeptides, with rubber, with the depsides, with the tannins, and with the vegetable alkaloids; the last forms a valuable monograph on the chemistry of these important compounds.Judging from the numerous references to recent literature, the book has been carefully brought up-to-date, and it is surprising, therefore, to find no reference to the replacement of ' benzine ' as a dry cleaning solvent by the chlorinated derivatives for acetylene; no mention of the preparation of synthetic methyl alcohol from water gas; no reference to the now extensive use of thionyl chloride in the preparation of acid chlorides; and no mention of the iodonium bases. In the preface the author states that " although the greater number of references to German literature contained in the original have been retained, some progress has been made towards the inclusion of representative English and American work "; it is therefore to be hoped that when further progress in this direction has been made, many of the unfortunate omissions from the present edition may be rectified, as for example Werner's work on the chemistry of urea, and Armstrong's and Wynne's classical researches on the chloro-derivatives of naphthalene. Whilst the text is singularly free from errors, the following have been noted: p. 99, line 6 (from bottom), for " arsenite " read " arsinate "; p. 118, line 14, the equation should read PhONa + (CH,)2SO4 =PhOMe+NaMeSOl; p. 122, line 11 (from bottom), for P/ read /p3f'; p. 131, line 8, for "monobromoacetamide " read " acetbromamide "; p. 199, line 22, the middle formula is faulty; p. 476, line 12, for "boiling " read " melting "; p. 142, the formation of " aldehyde resin " is characteristic of acetaldehyde only. Finally, the reviewer would like to register a mild protest against the printing in formal text books of laboratory slang terms as "to combust," even if, on its first appearance, the offender be shielded by apologetic inverted commas.

ISSN:0028-0836    

DOI:10.1038/119384a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

FIFTEEN years ago, America's entire dependence upon imported potash led her to initiate a survey of possible home sources of this essential substance, which was scarcely completed when the breaking out of the War emphasised the importance of developing domestic resources. In pre-War days, Germany practically held the monopoly of the world's potash supply, but afterwards, when France obtained possession of the Alsatian mines, an agreement was made whereby Germany dealt with 62-5 per cent. and France with 37-5 per cent. of American and other demands for potash. In 1922 the world consumption was 1,600,000 tons of potash salts, far below the limit of producing capacity of Germany alone. At present the price is below pre-War rates, and this has caused in America an almost entire deflation of the development of the potash industries which had arisen during the War period. America's need is to push the domestic production of potash to such a point as to secure the possibility of the production of full home supplies in case of war. Kelp is a valuable asset, as iodine and potash can be obtained as by-products from the manufacture of kelpehar, a very active decolorising carbon. Other sources of supply which can be exploited successfully are surface lakes, subterranean deposits, silicates, industrial wastes (both organic and inorganic), and cement-mill flue dust, the last being a very important potential source. Ninety per cent. of the potash entering American markets goes to agriculture, but the ten per cent. is of equal importance in that it is required for many industries. The feasibility of the recovery of sufficient potash from available home resources has been demonstrated, and the immediate problem is that of perfecting the methods employed and rendering the recovery process an economic proposition.

ISSN:0028-0836    

DOI:10.1038/119385c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WHILE this work is primarily and confessedly taxonomic, the authors have brought together most of the scattered information on the Aspergilli, and have given a comprehensive survey of the genus from a few different points of view. Part I. deals with such different aspects as culture methods, morphology, and special physiology of these forms. A very interesting chapter is devoted to enzymatic activities, and their economic significance in the production of acids, sake, taka diastase, etc., while their pathogenic importance in reference to man, birds, and insects is treated in another. Part 2 of the book is devoted to a taxonomic revision of the whole genus based on the examination of large numbers of forms from natural substrates, and the 350 strains which the authors have grown in pure cultures in their own laboratory. While the sixty-six odd accepted species of Aspergilli have been considerably multiplied, an attempt has been made by the authors to indicate real relationships in the presentation of their various groups, and the diagnostic scheme in their keys has been so arranged as to bring together closely allied forms. A fairly exhaustive bibliography is appended to the work, which forms a welcome addition to current mycological literature.

ISSN:0028-0836    

DOI:10.1038/119386b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

I WISH to bring forward one or two additional results on this subject in supplement to my letter published in NATURE of Nov. 27, 1926.In the first place, I found that the green visual band, extinguished by heat, recovers to some extent as the excited vapour moves on to a cold part of the tube. This effect has been satisfactorily photographed. As emphasised in published papers, the main part of the band spectrum covers the whole region on the less refrangible side of the resonance line X2537, at which point it abruptly begins.I now find that the 'forbidden' line X2270 is present on the plate, and that a separate stretch of band spectrum reaches from this point to the band X2345. In the region of wave-length less than X2270, and also in the region between X2345 and X2537, the background of the spectrum is quite dark. Prof. Takamine has suspected that the band X2345 was associated in some way with the 'forbidden' line, and he suggested to me some time ago to look for this line in the excited vapour. It was not to be seen on the negative then available. My present negative has been made with an improved technique, and exposed for as much as 100 hours. I do not think it has been suspected before that a stretch of continuous spectrum begins at X2270, and connects up with X2345 and the associated bands of intermediate wave-length.

ISSN:0028-0836    

DOI:10.1038/119387a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE problem of the practical differentiation of species in Nature stands so much in need of experimental work, that the recently published paper by Dr. J. W. Heslop Harrison on an apparently successful attempt to influence the hereditary instincts of a sawfly (Proc. Roy. Soc.,Series B, vol. 101, pp. 115–126) will be read with interest, and I am induced to offer one or two critical remarks.This sawfly, Pontania salicis, is stated to feed on many species of Salix, but in any given locality to restrict itself habitually to some one (not the same) species, although several others may be equally plentiful. I do not dispute the statement, but in the whole of the Lepidoptera I have never heard of a similar instance. Salix, in particular, supports a large number of Lepidoptera, but in general the only discrimination made is between the roughand smooth-leaved species (probably influenced by touch rather than taste), and again the choice of S. repens by certain species seems due rather to the superior shelter afforded by the dwarf habit. Also the Pontania is a gall-maker; and the case of gall-producers, where complicated reactions ensue between insect and plant, may be specially difficult to understand. In the experiments the change was produced immediately. and was completely established in three years; there must be some quite unusual element here. From this single and quite exceptional case, however, Dr. Harrison proceeds to deduce what he calls a new principle of evolution, which I understand to be that in phytophagous insects (for example) pairs of allied species are produced by the accidental transference of larva from the usual food-plant to an adjacent allied plant, or even to one usually associated with it but not allied. Several pairs of species of Lepidoptera are instanced as suitably associated " in Britain," as, for example, Cerura bicuspis and C. furcula, but this argument is wholly fallacious, involving the assumption that one of the species originated here; both range over the whole of northern and central Europe and Asia, and the circumstances of their origin are entirely problematical. But is there anything new in the principle ? All lepidopterists are aware that not merely pairs, but also whole groups of species, tend strongly to feed on allied and associated plants, and this would appear to be probable on any theory of the mechanism of evolution; and microlepidopterists in particular have long ago suggested that the closely similar species in such genera as Phthorimaea and Lithocolletis, each attached to its own food-plant, originated as phytophagic races.The trouble is that no one has yet evolved a new species by this means; and I shall be very much surprised if, when this is accomplished, it proves to require only three generations of the insect. But even this achievement will not go very far to explain the formation of species in the Lepidoptera. A very large proportion of these (such as most of the very common British Caradrinidin) have larvae which feed either on grasses generally or on miscellaneous low plants almost indiscriminately, and without any variation resulting except perhaps of size; and a further large class feed on dead wood and dry vegetable refuse. The same influences which have resulted in the multiplication of species in these groups must be supposed equally efficient in the groups which are more specialised in their tastes and, subtracting their effect, not much will remain for that of the food-plant. I have even recorded ("Exotic Microlepidoptera," vol. 2, p. 521) the case of two Indian species of Bactra, separable with difficulty, known only from series reared together from larvae feeding on the same individual plants in the same way at the same tim

ISSN:0028-0836    

DOI:10.1038/119388a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN 1923, Bohr (Z. f. Phys., 13, P. 117; 1923) directed attention to the fact that the usual formulæ of the older quantum theory might not be strictly applicable to atoms which are subjected to intense radiation fields of high frequency, such as those of ordinary light. Schrödinger (see particularly equation 16,Ann. d. Phys., 81, p. 109; 1926) has formulated the differential equation for the ψ-function of an atom exposed to a harmonic electric force, and from this the allowed values of the quantityEappearing in the equation may be determined. In such a case, however, the physical interpretation ofEis doubtful, though it seems highly probable that it represents the (average) energy of the disturbed atom. Thus we cannot be certain that the equationE1E2=hν is correct for calculating the frequencies emitted by such an atom. Whatever be the final formulation of the theory, it seems reasonable to suppose that the energy levels of atoms in sources at very high temperatures may be modified by the electric and magnetic fields of the radiation from the source itself.Mr. W. Kuhn (Z. f. Phys., 38, p. 440; 1926) devised an interesting experiment for detecting changes in the energy levels of sodium atoms illuminated with wave-lengths near the D lines, and performed it in collaboration with Mr. R. de L. Kronig. By analogy with the classical theory of dispersion, such wavelengths should be capable of producing disturbances quite large compared with those produced by wavelengths much farther from the resonance lines. Briefly, the experiment consisted in studying the D line absorption of sodium vapour illuminated by a suitable continuous background, (1) when it was also illuminated by the broadly reversed D lines from a very intense sodium source, and (2) without this intense illumination. The temperature of the absorption vessel was so regulated that wave-lengths extending about 0 03 A.U. on either side of the centre of a D line were absorbed and the temperature of the intense source was such that the reversal was about 0 06 A.U. wide. The effective radiations lay mainly at a distance between 0 03 and 0 06 A.U. from the centres of the D lines, so that the total range of wave-lengths utilised in the neighbourhood of either D line was about 0 06 A.U. Kuhn states that an approximate computation indicates the possibility of a shift of 0 15 A.U. for the D lines in absorption, due to the alteration of the energy levels of the sodium atom. He gives no details of his calculations. Therefore no statement can be made here as to the way in which the phase differences of the monochromatic constituents of the incident light were taken into account. But leaving aside all theoretical questions, the experimental result was that no such broadening or shift could be detected. It is the purpose of this note to point out that if such an effect exists, it should bereadily possible to detect it in the solar spectrum, or better, in the spectra of very hot stars. To show this we note that the intensity of the yellow sodium light used by Kuhn corresponds to an energy density in the light beam of 400 x 900/c ergs per c.c. For an atom at the surface of the sun we may suppose as a rough approximation that the effective energy density corresponds to about five-sixths of the energy density of isotropic black body radiation. That is, if we consider a unit cube in which the atom is placed, we see that black body radiation of the temperature appropriate to the sun streams in through five sides of this cube, since about one-half of the total solid angle is subtended by the sun at this position. Calculating from Planck's formula, the energy density of black body radiation carried in a wave-length interval of 0(06 A.U. units at the position of the D lines, we find the value 3.4 x 106/c ergs per c.c. This must be doubled to take account of radiations in the neighbourhood of both D lines. The result, 6-8 x 106/c ergs per c.c., is twenty times as large as the figure given by Kuhn.Kuhn's calculation of the change in energy levels depended upon the assumption that the atoms are subjected to an electric force E obtained from the equation Energy density= E2/4-. This is open to considerable question. In calculating the actual electric force acting upon an atom, it may be necessary to take the microscopic structure of the wave front into account. Looking at the question from the point of view of the theory of unidirectional quanta (simply for the sake of convenience), it seems reasonable to suppose that many of the absorbing atoms may not be affected at the moment of absorption by any quantum belonging to the intense beam. This objection may also be applied to speculations on the possibility that atoms are oriented by the electric and magnetic fields of incident radiation, an idea which is sometimes invoked to explain the polarisation of resonance radiation in cases which do not yield to the usual theories. Arguments based on analogy with Huyghehs' principle in classical optics could no doubt be given to show that the detailed structure of the wave fronts may be neglected; but the attitude adopted here consists essentially in questioning the validity of such evidence.Further, it should be remembered that in Kuhn's experiment (uni-directional illumination) only half the energy density is effective in producing a polarisation of the atoms parallel to a given direction in a plane normal to the beam. A similar factor must be applied for atoms in celestial sources, but since we are interested only in the order of magnitude of the effects, we shall not discuss the matter further. It may be that an effect of this kind exerts a detectable influence on wave-lengths in celestial sources. Whatever the verdict may be, the question can only be settled by those familiar with the complexities of astrophysical spectroscopy. Such an effect cannot be easily disentangled from those due to other physical disturbances. The question should certainly be considered in future discussions of the Einstein red shift and of peculiar motions in the line of si

ISSN:0028-0836    

DOI:10.1038/119389b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature