classes should be carried on so that the Government grant be earned," is a non sequitur; at all events until the Science and Art Department award grants for distinctively technical subjects under the new Technical Instruction Act. We cannot help thinking that if due weight is allowed to these considerations the estimate of 15s. a head will be Largely raised (unless compensation be sought by cutting down some of the more expensive trade classes); and as we suppose the endowment cannot be much increased, the number of students to be provided for must be necessarily diminished. In fact, the whole scale on which Mr. Plumbe has calculated the requirements of the Institute may have to be somewhat revised. To those who consider large numbers all-important, this may seem deplorable, but we are convinced that the Committee of the South London Polytechnic will prefer the interests of efficiency to those of temporary display. One other matter which we notice with some surprise and regret is the apparent omission in the plans to provide committee-rooms and other accommodation which can be utilized by local working men's organizations. We referred in our former article to the importance of making the Institutes real working-class centres, and the reply of the Charity Commissioners to the deputation from the London Trades Council on the subject was supposed to be favourable to the provision in connection with each Institute of rooms which could be utilized on moderate payment by various working-class societies which now too often have to meet in public-houses. The omission of any such provision in the plans for Battersea is a serious blemish on the scheme, which, however, can easily be corrected, as soon as pointed out. The Committee will have a great opportunity, which it as to be hoped they will use aright, of providing the inhabitants of South London with a technical and recreative Institute, which in its close adaptation to local needs may serve as model for all such Institutes in the future. A GEOLOGICAL MAP OF THE ALPINE CHAIN. viz. those occupied by that crystalline series which, whatever may be its age, in the Alps always underlies any sedimentary rock to which a date can be assigned. The principle of coloration agrees very nearly with that suggested by the International Geological Congress at Bologna. Crimson denotes the deep-seated igneous rocks of the more acid type, dull green the more basic ; two slightly different shades of red represent respectively the older (and in most cases more acid) volcanics and the newer volcanics. Four colours are employed to express the "crystalline schist" series: one, for the Central gneiss and some of the oldest mica-schists; another, for the less coarsely crystalline (and probably newer) mica-schists, together with calc-schists, chlorite-schists, &c.; a third, for certain crystalline schists, phyllites, and clay-slates of uncertain geological age; and marbles are indicated by a deep blue. Palæozoic rocks (exclusive of Permian) are coloured purple, the different series being distinguished by symbols; pale brown denotes Permian; tints of blue represent the Triassic and Jurassic strata; green signifies Neocomian and Cretaceous; orange the older Tertiary, flysch having a separate tint; one shade of yellow is used for Miocene and Pliocene; another for Diluvial and Alluvial deposits-the former a word of misleading origin, which ought to have long since disappeared from geological nomenclature. Very wisely, Dr. Noë has included in his map something more than the Alps. Not only do we find the Jura, but also this region is extended far enough in the direction of Dole to exhibit the remarkable exposure of the old crystalline floor, north of that town. On the right bank of the Rhine, in the neighbourhood, of Sackingen, a considerable strip of crystalline rock is shown, the end of the great Schwarzwald massif; and north of the Eastern Alps we find the crystalline rocks indicated as they uprise from beneath the Miocene on the left bank of the Danube, as, for example, near Linz, and again at Pressburg. The geological colours also are carried down the east coast of the Adriatic as far as Spalato, so that the connection of the Istrian and Dalmatian Alps with the main chain is made perfectly clear. Unfortunately, however, Dr. Noë has not applied the same treatment to the Apennines, though their connection with the Alpine chain cannot be of less geological importance, GOOD, and in some cases even elaborate, geological for he brings the colours to an abrupt end a few miles maps exist for parts of the Alps; but one to exhibit the chain as a whole, without being on a scale so large as to be unwieldy or so small as to be indistinct, has been hitherto a desideratum. This has now been supplied by Dr. Noë. The scale adopted is 1 in 1,000,000, or about 16 miles to the inch, which very well satisfies both the above conditions. A glance at the list of authorities which have been consulted indicates that Dr. Noë has had no easy task; for in Alpine geology there are indeed consellors enough, but their multitude is not strength, for they are so often at variance. At the present stage of knowledge, the chartographer must be content, in dealing with the crystalline schists using that term in a rather wide sense), to colour his map petrographically-that is to say, he must, as far as possible, record facts and avoid theories. Dr. Noë has endeavoured, though not with complete, success, to render his maps petrographical in the parts where doubt might arise, west of Savona. In one or two respects the above system of coloration seems open to criticism. The tint and the lines used to indicate mountain land are productive of some confusion, and increase the difficulty of identifying the colours, without, as we think, producing a compensating advantage. The use of three colours for the Trias-Rhætic seems a disproportionate subdivision when only one is allotted to Neocomian-Cretaceous. We are, however, disposed to differ more seriously-though only occasionally-from Dr. Noë as to his use of the colours for the divisions of the crystalline schists. One of these is made too inclusive, because it is applied to clay-slates and phyllites as well as to rocks which must be admitted to be crystalline schists. Granted that there is sometimes a difficulty in separating these in the field, we fail to see the propriety of deliberately effacing the distinction. Fortunately, however, this confusion, owing to the scale of the map, does not seriously mislead the student, but we are more perplexed to discover the reasons which have led in some cases to the separation of the crystalline members of this group from certain of those in the other, and presumably older group, which is defined as consisting of "mica-schists calc-mica-schists, chlorite-schist, &c. To the latter are referred the schists-calcareous, micaceous, and chloritic -near Windisch-Matrei; to the former the great belts north and south of the Tauern range, which, for instance, occur respectively near Mittersill and Lienz. We cannot understand on what grounds these are distinguished. Further, the great group of schists which sweeps along on the eastern flank of the watershed of the Franco-Italian Alps, as, for example, near the Mont Genèvre, has the same colour as those of Windisch-Matrei; but petrographically they appear to us inseparable from the other group. By some geologists, as is well known, the "lustrous schists" have even been mapped (erroneously no doubt) as altered Trias. Still, though we venture to dissent occasionally from Dr. Noë, and think that in all probability a wider personal knowledge of the Alps would have led him occasionally to modify a conclusion and to avoid some slight inconsistencies, we cannot conclude this notice without expressing our sense of the very great value of his work. He has placed a really good general map of the Alps within the reach of all students, for the price at which it is sold is surprisingly low. The map is accompanied by a useful descriptive pamphlet, to which Prof. Suess has written a short preface. OLD AGE. T. G. BONNEY. Old Age. By George Murray Humphry, M.D., F.R.S, (Cambridge: Macmillan and Bowes, 1889.) IN spite of pessimistic philosophies, man still regards life as worth living, and trusts to attain to a good old age, however miserable his life may seem to impartial critics. This desire, of course, is a necessary condition of human existence, and the destruction of it would entail the extinction of the human race-a contingency, however, which is never likely to arise. Hence, we have no doubt that this volume will be eagerly scanned by innocent persons who are still in hopes of finding some panacea which will enable them to attain the desired length of days. But, alas, the number of their somatic cell generations is already fore-ordained in the germ from which they were developed ; and no rule of life can increase this. No man by taking much thought can add a cubit to his stature, nor a decade to the predestined span of his existence. Yet the facts gathered together in this book may afford some hints as to the best way of attaining just this limit. On p. 135, et seq., Prof. Humphry reviews the chief characteristics in the mode of life of the favoured subjects of the work. He begins by saying that the results of the collective investigation respecting old age, "have not been such as to evolve anything very novel or startling, or to give rise to any fresh theories with regard to longevity and the means of attaining it," but only to "show that the maxims and laws which common-sense would dictate hold good, that the real elixir vita 13 to be found in the observance of them, and that, as a genera. rule, those persons live the longest who might be expected to do so." The author also emphasizes the fact of the all-impriance of inherited predisposition among the factors that tend towards producing longevity, and shows that nearly all the subjects of the returns came of a long-lived stock. In most of them, too, the body was well-proportioned and developed, brain development fair, and there was a remarkable absence of degenerative changes in the arteries and cartilages. According to the author, ther essential characteristic is that all parts of the body are so well balanced, that the senile decay of function goes on in them all simultaneously, and at an equal rate, so that, e.g., the vascular system is not overloaded and overworked by a too vigorous digestive apparatus, nor the vessels worn out by an over-excitable nervous and cardiac mechanism, so that if we could induce all our organs "to arrange This not to be avoided change, So as to change together," we should have gone far towards attaining the secret of long life. Most of the persons described were temperate, taking little alcohol and meat, and lived active open-air lives There are one or two startling exceptions to the former rule, however; such as the centenarian who "drank like a fish all his life," and several others who had always indulged pretty freely in stimulants. Another point that Prof. Humphry lays stress on is the fact that most of these people were early risers, and could do with little sleep. It seems that the anabolic processes are more complete and regular when they are accomplished quickly. Apropos of this, he quotes with approval the dictum of the Duke of Wellington: "When one turns in bed, it is time to turn out." In discussing the general aspects of his subject, he shows that old age may be said to be a product of civilization, the law of the "weakest to the wall" being altered by the growth of sympathy, and of love for others But the continued existence of old people among communities may (partly, at all events) be accounted for on more utilitarian principles. Weismann remarks: "It [old age] is obviously of use to man, for it enables the old to care for their children, and is also advantageous in enabling the older individuals to participate in human affairs, and to exercise an influence upon the advancement of intellectual powers, and thus to influence indirectly the maintenance of the race." Thus we see the production of old age could be sc counted for simply on the laws of natural selection among nations. The fertility of these long-lived individuals is also above the normal (the average of children born to each, whether man or woman, being six), and many of them seem to have borne or begotten children to an advanced age. This, again, is in accordance with the view advocated by the biologist just quoted-viz. that a lengthening of life is connected with the increase in the duration of reproduction. The effects of this fertility of long-lived people must give their stock an advantage in the race for existence, so that one would expect their number, in proportion to the rest of the population, gradually to increase. The last chapter gives a short account of the maladies of old people, and is chiefly of medical interest. Besides the general account of the subject, Prof. Humphry gives all the analyses of the British Medical Association returns, which furnish the material for the book. There are several good photographic illustrations: the frontispiece, portraits of a man and his wife (both over 101 years), and others, representing sections through the neck of the thigh-bone, and the jaw of old people. With regard to the femur, Prof. Humphry points out that there is no foundation for the generally accepted idea that the head in old people sinks to or below the level of the great trochanter, and the illustration certainly bears out his criticism. Perhaps the happiest feature of the book is its optimism. "It is satisfactory to note how many of the very aged are in good possession of their mental faculties -taking a keen interest in passing events, forming a clear judgment upon passing events, and full of thoughts for the present and future welfare of others." An old age like this is worth striving to attain, although one may never be free from the dread of dying "from the head downwards," and so lingering on in "Second childishness and mere oblivion, Sans teeth, sans eyes, sans taste, sans everything." E. H. S. THE ELEMENTS OF ASTRONOMY. The Elements of Astronomy. By Prof. C. A. Young, Ph.D., LL.D. (Boston and London: Ginn and Co. 1890.) THIS ~HIS is a valuable addition to the existing text-books of astronomy for the use of those who intend to study the subject seriously. It has much in common with the same author's larger work on "General Astronomy" (see NATURE, vol. xxxix. p. 386), but we are assured that it is not merely an abridgment, but has been worked over with special reference to a high-school course. It is assumed that the students have mastered the ordinary elementary subjects, and are acquainted with elementary algebra and geometry. The book covers quite as much ground as can be expected for an elementary course, although many of the subjects are merely glanced at. Practically everything, with the exception of the more difficult problems of mathematical astronomy, is considered more or less. The opening chapters deal with definitions, the geometry of the sphere, and the determination of latitude and longitude. Chapters on the earth's dimensions and motions, the moon, sun, planets, comets, stars, and nebulæ, then follow. An appendix includes topics which might be considered beyond an elementary book, but are still of sufficient importance to form part of a high-school course. Astronomical physics receives a fair share of attention, but here the book is necessarily more open to criticism than in the parts dealing with well-established facts and principles. There are few general text-books which treat this important branch of astronomy in a satisfactory manner, and it is perhaps not to be wondered at, as the constantly increasing number of new observations necessitate considerable changes in our ideas. As far as a consideration of the facts is concerned, however, Prof. Young has done his work admirably, but this cannot be said of his treatment of the various conclusions which have been drawn from them. In his introduction, Prof. Young tells us that he has tried to treat every subject in such a way as "to discourage narrow and one-sided ways of looking at things, and to awaken a desire for further acquisition." However he may succeed with his readers, it does not seem that he has altogether taken this lesson to heart himself, for we find him dismissing suggestions without a complete hearing. For instance, in connection with the theory that sun-spots are formed by the downrush of cool materials into the photosphere (p. 130), he states that it is not easy to reconcile this view with the distribution of the spots over the sun's surface. Further enquiry on his part, however, would have shown him that the theory in its extended form suggests that the spot-forming material is mainly formed of vapours which have condensed in the cool outer layers of the sun's atmosphere (in the same way as water-vapour condenses in our own), and also gives an explanation of the way in which the material may be localized over the spot-zones. The author is notably cautious with regard to new things, but we are surprised to find that he continues to adopt Secchi's classification of star spectra (p. 317), seeing that it does not satisfactorily treat bright-line stars like y Cassiopeiæ, and those of Orion which give almost continuous spectra. The classifications suggested by Vogel and Lockyer both have the advantage of detail, and the latter is certainly the most philosophical. On p. 318 it is stated that stars of Secchi's fourth type usually "show a few bright lines," in addition to the carbon absorption bands, an idea of Secchi's which was shown to be erroneous several years ago. The book is abundantly illustrated, and most of the diagrams are excellent. Fig. 119, however, gives a very bad impression of the spectrum of a nebula, the three bright green lines being represented as almost equidistant, whereas they practically form a triplet. A useful "Uranography" is given at the end. This embraces the more important celestial objects in the northern hemisphere and some degrees south, and is accompanied by a series of star maps. In the maps a convenient system of indicating magnitudes is adopted, but it has the disadvantage of destroying the appearances of the constellations for rapid identification. A. F. OUR BOOK SHELF. Physiology of Bodily Exercise. By Fernand Lagrange, M.D. (London: Kegan Paul, Trench, and Co., 1889.) THIS book at first sight reminds one of the saying that a German takes a year to make a research, and a week to write an account of it, while a Frenchman takes a year to write a book on one week's work. The only original part consists of a few experiments on the influence of fatigue in producing increased excretion of urates in the urine. The author ascribes most of the ill effects of seriously mislead the student, but we are more perplexed to discover the reasons which have led in some cases to the separation of the crystalline members of this group from certain of those in the other, and presumably older group, which is defined as consisting of "mica-schists calc-mica-schists, chlorite-schist, &c. To the latter are referred the schists-calcareous, micaceous, and chloritic -near Windisch-Matrei; to the former the great belts north and south of the Tauern range, which, for instance, occur respectively near Mittersill and Lienz. We cannot understand on what grounds these are distinguished. Further, the great group of schists which sweeps along on the eastern flank of the watershed of the Franco-Italian Alps, as, for example, near the Mont Genèvre, has the same colour as those of Windisch-Matrei ; but petrographically they appear to us inseparable from the other group. By some geologists, as is well known, the "lustrous schists "have even been mapped (erroneously no doubt) as altered Trias. Still, though we venture to dissent occasionally from Dr. Noë, and think that in all probability a wider personal knowledge of the Alps would have led him occasionally to modify a conclusion and to avoid some slight inconsistencies, we cannot conclude this notice without expressing our sense of the very great value of his work. He has placed a really good general map of the Alps within the reach of all students, for the price at which it is sold is surprisingly low. The map is accompanied by a useful descriptive pamphlet, to which Prof. Suess has written a short preface. OLD AGE. T. G. BONNEY. Old Age. By George Murray Humphry, M.D., F.R.S, (Cambridge: Macmillan and Bowes, 1889.) IN N spite of pessimistic philosophies, man still regards life as worth living, and trusts to attain to a good old age, however miserable his life may seem to impartial critics. This desire, of course, is a necessary condition of human existence, and the destruction of it would entail the extinction of the human race-a contingency, however, which is never likely to arise. Hence, we have no doubt that this volume will be eagerly scanned by innocent persons who are still in hopes of finding some panacea which will enable them to attain the desired length of days. But, alas, the number of their somatic cell generations is already fore-ordained in the germ from which they were developed ; and no rule of life can increase this. No man by taking much thought can add a cubit to his stature, nor a decade to the predestined span of his existence. Yet the facts gathered together in this book may afford some hints as to the best way of attaining just this limit. On p. 135, et seq., Prof. Humphry reviews the chief characteristics in the mode of life of the favoured subjects of the work. He begins by saying that the results of the collective investigation respecting old age, "have not been such as to evolve anything very novel or startling, or to give rise to any fresh theories with regard to longevity and the means of attaining it," but only to 'show that the maxims and laws which common-sense would dictate hold good, that the real elixir vita is to be found in the observance of them, and that, as a general rule, those persons live the longest who might be expected to do so." The author also emphasizes the fact of the all-import ance of inherited predisposition among the factors that tend towards producing longevity, and shows that nearly all the subjects of the returns came of a long-lived stock In most of them, too, the body was well-proportioned and developed, brain development fair, and there was a remarkable absence of degenerative changes in the arteries and cartilages. According to the author, their essential characteristic is that all parts of the body are so well balanced, that the senile decay of function goes on in them all simultaneously, and at an equal rate, so that, e.g., the vascular system is not overloaded and overworked by a too vigorous digestive apparatus, nor the vessels worn out by an over-excitable nervous and cardiac mechanism, so that if we could induce all our organs "to arrange This not to be avoided change, So as to change together," we should have gone far towards attaining the secret of long life. Most of the persons described were temperate, taking little alcohol and meat, and lived active open-air lives. There are one or two startling exceptions to the former rule, however; such as the centenarian who "drank like a fish all his life," and several others who had always indulged pretty freely in stimulants. Another point that Prof. Humphry lays stress on is the fact that most of these people were early risers, and could do with little sleep. It seems that the anabolic processes are more complete and regular when they are accomplished quickly. Apropos of this, he quotes with approval the dictum of the Duke of Wellington: "When one turns in bed, it is time to turn out." In discussing the general aspects of his subject, he shows that old age may be said to be a product of civilization, the law of the "weakest to the wall" being altered by the growth of sympathy, and of love for other But the continued existence of old people among come munities may (partly, at all events) be accounted for on more utilitarian principles. Weismann remarks: "It [old age] is obviously of use to man, for it enables the old to care for their children, and is also advantageous in enabling the older individuals to participate in human affairs, and to exercise an influence upon the advancement of intellectual powers, and thus to influence indirectly the maintenance of the race." Thus we see the production of old age could be ac counted for simply on the laws of natural selection among nations. The fertility of these long-lived individuals is also above the normal (the average of children born to each, whether man or woman, being six), and many of them seem to have borne or begotten children to an advanced age. This, again, is in accordance with the view adv cated by the biologist just quoted-viz. that a lengthening of life is connected with the increase in the duration o reproduction. The effects of this fertility of long-lived people must give their stock an advantage in the race for existence, so that one would expect their number, in proportion to the rest of the population, gradually to increase. The last chapter gives a short account of the maladies of old people, and is chiefly of medical interest. Besides the general account of the subject, Prof. Humphry gives all the analyses of the British Medical Association returns, which furnish the material for the book. There are several good photographic illustrations: the frontispiece, portraits of a man and his wife (both over 101 years), and others, representing sections through the neck of the thigh-bone, and the jaw of old people. With regard to the femur, Prof. Humphry points out that there is no foundation for the generally accepted idea that the head in old people sinks to or below the level of the great trochanter, and the illustration certainly bears out his criticism. than in the parts dealing with well-established facts and principles. There are few general text-books which treat this important branch of astronomy in a satisfactory manner, and it is perhaps not to be wondered at, as the constantly increasing number of new observations necessitate considerable changes in our ideas. As far as a consideration of the facts is concerned, however, Prof. Young has done his work admirably, but this cannot be said of his treatment of the various conclusions which have been drawn from them. In his introduction, Prof. Young tells us that he has tried to treat every subject in such a way as “to discourage narrow and one-sided ways of looking at things, and to awaken a desire for further acquisition." However he may succeed with his readers, it does not seem that he has altogether taken this lesson to heart himself, for we find him dismissing suggestions without a complete hearing. For instance, in connection with the theory that sun-spots are formed by the downrush of cool materials into the photosphere (p. 130), he states that it is not easy to reconcile this view with the distribution of the spots over the sun's surface. Further enquiry on his part, however, would have shown him that the theory in its extended form suggests that the spot-forming material is mainly formed of vapours which have condensed in the cool outer layers of the sun's atmosphere (in the same way as water-vapour condenses in our own), and also gives an explanation of the way in which the material may be localized over the spot-zones. The author is notably cautious with regard to new things, but we are surprised to find that he continues to adopt Secchi's classification of star spectra (p. 317), seeing that it does not satisfactorily treat bright-line stars like y Cassiopeia, and those of Orion which give almost continuous spectra. The classifications suggested by Vogel and Lockyer both have the advantage of detail, and the latter is certainly the most philosophical. On p. 318 it is stated that stars of Secchi's fourth type usually "show a few bright lines," in addition to the carbon absorption HIS is a valuable addition to the existing text-books bands, an idea of Secchi's which was shown to be erroneous several years ago. Perhaps the happiest feature of the book is its optimism. "It is satisfactory to note how many of the very aged are in good possession of their mental faculties -taking a keen interest in passing events, forming a clear judgment upon passing events, and full of thoughts for the present and future welfare of others." An old age like this is worth striving to attain, although one may never be free from the dread of dying "from the head downwards," and so lingering on in "Second childishness and mere oblivion, Sans teeth, sans eyes, sans taste, sans everything." E. H. S. THE ELEMENTS OF ASTRONOMY. THIS is a valuable addition to the existing text-books study the subject seriously. It has much in common with the same author's larger work on "General Astronomy" (see NATURE, vol. xxxix. p. 386), but we are assured that it is not merely an abridgment, but has been worked over with special reference to a high-school course. It is assumed that the students have mastered the ordinary elementary subjects, and are acquainted with elementary algebra and geometry. The book covers quite as much ground as can be expected for an elementary course, although many of the subjects are merely glanced at. Practically everything, with the exception of the more difficult problems of mathematical astronomy, is considered more or less. The opening chapters deal with definitions, the geometry of the sphere, and the determination of latitude and longitude. Chapters on the earth's dimensions and motions, the moon, sun, planets, comets, stars, and nebulæ, then follow. An appendix includes topics which might be considered beyond an elementary book, but are still of sufficient importance to form part of a high-school course. Astronomical physics receives a fair share of attention, but here the book is necessarily more open to criticism The book is abundantly illustrated, and most of the diagrams are excellent. Fig. 119, however, gives a very bad impression of the spectrum of a nebula, the three bright green lines being represented as almost equidistant, whereas they practically form a triplet. A useful "Uranography" is given at the end. This embraces the more important celestial objects in the northern hemisphere and some degrees south, and is accompanied by a series of star maps. In the maps a convenient system of indicating magnitudes is adopted, but it has the disadvantage of destroying the appearances of the constellations for rapid identification. OUR BOOK SHELF. A. F. Physiology of Bodily Exercise. By Fernand Lagrange, M.D. (London: Kegan Paul, Trench, and Co., 1889.) THIS book at first sight reminds one of the saying that a German takes a year to make a research, and a week to write an account of it, while a Frenchman takes a year to write a book on one week's work. The only original part consists of a few experiments on the influence of fatigue in producing increased excretion of urates in the urine. The author ascribes most of the ill effects of |