mysterious to the ancients; both possess a strange power of attraction and repulsion, and these tendencies are selective, the amber for light bodies only, the magnet affecting naught else but iron or its like. Did not such action partake of the nature of an intelligence, and to what else could it be ascribed than the presence of a soul in amber and lodestone? In such attraction and repulsion they recognized both Love and Hate, and it becomes easily apparent that the "Intellectual Rise" here chronicled has touched upon the profoundest concepts of philosophy.

A potent charm for the cure of all manner of bodily ills was thought to reside in the magic amber and lodestone. From the times of the Samothracian priests, the medical quack has flourished and fattened on the credulous faith of people in the miraculous healing power of magnetic and electric belts, rings, pills, and so on through the list of traps for the unwary. It is a singular fact that both in the development of electricity and chemistry the first practical application was made in the attempted healing of bodily ills. It is difficult to explain the vitality of the belief in the healing efficacy of magnetism and electricity. This persistence certainly is no argument for the healing-power of such devices, but is rather evidence of the persistence of superstition and belief in diabolism.

The passage from poetic speculation to a concrete science did not occur until the close of the sixteenth century. In this change, the names of Gray and Gilbert stand as landmarks. Bacon, Galileo, Hooke, and Boyle, all contributed to gather the grains of fact from what had hitherto been so largely legendary. Other bodies were found to possess the attractive power of amber under favorable conditions. Substances were divided into electrics and non-electrics, and the behavior of such under excitation was studied. Magnetic phenomena were carefully studied. Later, Otto von Guericke discovered how to generate considerable quantities of static electricity by a rubbed sulphur globe; and von Kleist was as much dismayed by the shock that marked the discovery of the Leyden jar, as the world was surprised. Then electrical experiments became the fad, and monks, nuns, courtiers, and soldiers were repeatedly and indiscriminately shocked. A rich vein of humor runs through the descriptions of these times. The medical quack took fresh courage, and plied the gullible public with vigorous activity. We read of the marvellous cures of a certain

Flemish physician, Van Helmont, who worked wonders with the "Balsamick Emanations of the Sympathetick Unguent or Powder." Magnetic remedies abounded, which were famed for curing even at great distance. Here we note the rise of the conception of communication at distance by magnetic or electric means. Telepathy was firmly believed in, and one may readily discern the beginnings of modern hypnotic suggestion in those times.

But even at that period a wonderful idea was slowly taking form in the minds of the more thoughtful. Men began to dream of transmitting intelligence through space, germs of thought which have developed into the electromagnetic telegraph and telephone. A great generalization remained to be established, the identity of the electric spark with the lightning; and with this master-stroke of Franklin the chronicle of "The Intellectual Rise in Electricity" comes to an end. The final lesson of the author is worthy of note:

"Man-made systems may fall, apostles of degeneration may find, in the things which make up the environment of the hour, signs of impending decay. But he who turns to the history of intellectual endeavor in the study of nature will learn that when mind thus faces the purity of the Infinite, it does not and cannot degenerate. Rather will he see in the constant effort to reveal the truth an influence always making for good,—always neutralizing the tendency to evil, always vast in uplifting power.

Dr. Benjamin has done his work well. He has brought to his task the scientific training of the specialist in electricity, the resources of a private library considered without an equal in the country, and a literary style that is both elevated and charming. The work is free from mathematics and technicalities, and is as entertaining as a romance. W. M. STINE.

THE CAVE-DWELLERS OF YUCATAN.*

The examination of the earth accumulations upon the floors of caves in Europe has given important evidence to the archæologist. Ancient men used the caverns as homes, and in them are found to-day layers and heaps of rubbish that accumulated during this occupancy. Bones of animals that were used as food, rude tools and implements, charcoals of ancient fires, are among the objects found. From their evidence it is known that in France and England man was contemporaneous with the mammoth, the

*THE HILL CAVES OF YUCATAN. By Henry C. Mercer. With illustrations and map. Philadelphia: J. B. Lippincott Co.

woolly rhinoceros, the cave-bear, the reindeer,

creatures now extinct, or found only in districts remote from these; that man in Western Europe was at first a savage, with the crudest tools and weapons; that he was capable of progress, and that he made improvement, the steps in which may be traced. All this has been clearly proved.

Comparatively little careful exploration has been made of American caverns. What has been done is quite largely the work of Mr. Henry C. Mercer, who has recently studied caves in Pennsylvania, West Virginia, Virginia, Illinois, Kentucky, and Tennessee. The results are interesting and important, but cannot be presented here. The exploration of these caves suggested investigation of those of Yucatan. Everyone knows of the curious ruins left in that peninsula by the Mayas. A strange culture is shown by them and by the relics found with them. Was this culture indigenous, growing up in Yucatan itself, or was it introduced in full development? Mr. Mercer believed that an examination of the caves would solve the question. Fortunately, means for the enterprise were not wanting. Mr. John White Corwith offered the funds for the investigation, and with Mr. Mercer and a small party of helpers spent some months last year in the field. The results of the trip are presented in Mr. Mercer's volume on "The Hill Caves of Yucatan."

The physical geography of Yucatan is at once peculiar and simple. The country is largely one of limestones, and these are almost honeycombed with subterranean channels and chambers. Of high mountains there are none; a low ridge was the mass in which lay the caves examined. It presented no cliffs or rock walls. Caves like those of France and England, of Tennessee and Pennsylvania, do not seem to exist there. Those found are described as "A very striking class of underground chambers from fifty to three hundred and fifty feet in diameter and from fifteen to seventy feet high, more or less brightly lit by round openings in the ceiling-ten, twenty, and fifty feet in diameter. Through these skylights fragments of the original crust had fallen, forming piles of loose stones on the cave floor. . . . Where the rock pile was high enough, banana trees and tropical evergreens growing upon it swept the brink of the chasm with their boughs, making strange rattlings when the wind blew. Sometimes the subterranean groves lay far beneath the surface in rotundas inaccessible from above. Then they were first seen after a long clamber underground, like gardens beneath the vaultings of sombre passages. Doves built their nests in high ledges by the skylights, and animals found refuge under the rock heaps, where Indians had built blinds of loose stones to stalk them."

The

Such were the caves to be examined. work was often difficult. The fallen rock masses were frequently so numerous, so large, and so closely packed, that the excavation had to be abandoned long before the original floor of the cave was reached. It was soon evident that these caves had never been to any great extent either homes or burial places. But for all that, they contained the evidence sought. Yucatan has little surface water, few streams, and no great rivers. But underground water abounds, and these caves contain a fairly full and reliable supply. Man to-day comes to them for water, and he must have done the same ever since the peninsula has been inhabited. Never living here continuously, he has always been a frequent visitor and camper. Though relics are neither as abundant or varied in the earth-layers upon these floors as they are in the French caves, they occur, and are ample.

Twenty-nine caves were visited. "Thirteen had archæological significance; six yielded valuable, and three decisive, results." The excavations at Oxkintok, Loltun, and Sabaka showed a single layer of rubbish, consisting of potsherds, stone tools and weapons, charcoal, and bones of animals and birds, some of which had served as food. The objects found do not indicate vast antiquity, do not prove the coexistence in Yucatan of man and extinct species of animals, do not show a progress in culture.

In closing his study, Mr. Mercer arrives at three conclusions, which may be stated in his own words:

"First. That no earlier inhabitant had preceded the builder of the ruined cities in Yucatan.

"Second. That the people revealed in the caves had reached the country in geologically recent times.

"Third. That these people, substantially the ancestors of the present Maya Indians, had not developed their culture in Yucatan, but had brought it with them from somewhere else."

These conclusions appear justified by the evidence. It is now desirable that similar studies should be made in Central and Southern Mexico, and in Guatemala and other parts of Central America. Mr. Holmes's interesting study of "Early Man in Mexico" appears to show a progressive culture in the Valley of Mexico, and legends of Nahuatl and other tribes tell of successive populations in various portions of the Isthmian Area. Examination of caves in the regions suggested, such as Mr. Mercer has made in Yucatan, might yield most valuable results.

FREDERICK STARR.

SOME PHASES OF THE SCIENCE OF MIND.*

Different in subject and scope as are the five volumes included in this review, an important bond of community between them is none the less apparent; and this consists of their common bearing upon the rigorous study of mental phenomena, that forms one of the striking features of contemporary thought. For, apart from the anatomists, zoologists, and physiologists, who are enlarging the facts and interpret ing the results of their own specialties as a selfsufficient and independent pursuit, there exists a body of students ready to take up so much of these data as can be utilized in the exposition and investigation of psychological problems. And what is true of the relations between the sciences that deal with the body and those that deal with the mind, is true, though in different ways and degrees, of anthropology and philology, of psychiatry and sociology. Indeed, we may be said to have completed the circle of the sciences, beginning with the days when all knowledge was one, and that one philosophy, and slowly developing to the formation of the several sciences into independent groups; and now realizing, in the light of this vast accumulation of fact-material, the essential interrelation and interdependence of the many specialties. The various sciences represent the directions of our interests and the limitations of each man's powers, quite as much as they represent groups of facts naturally or logically separated from other groups of facts.

Professor Donaldson's work on "The Growth of the Brain" is devoted to a systematic and discriminating account of the growth-changes in the nervous system, accompanying and forming so essential a factor of the march from birth to death. To give this account its maximum significance, the introductory chapters describe the main factors of cell and body growth; and for the proper comprehension of the bearing of these changes, a clear and telling exposition of the architecture and function of nerve tissues is introduced. The volume thus does more than it promises, for it gives the facts of braingrowth a carefully wrought and attractive setting.

*THE GROWTH OF THE BRAIN. A study of the nervous system in relation to education. By Henry Herbert Donaldson, Professor of Neurology in the University of Chicago. "The Contemporary Science Series." London: Walter Scott. Charles Scribner's Sons, New York.

LECTURES ON HUMAN AND ANIMAL PSYCHOLOGY. BY Wilhelm Wundt. Translated from the second German edition, by J. E. Creighton and E. B. Titchener. London: Swan Sonnenschein & Co. Macmillan & Co., New York.

OUTLINES OF PSYCHOLOGY. Based upon the results of experimental investigation. By Oswald Külpe, Professor of Philosophy in the University of Würzburg. Translated from the German, by Edward Bradford Titchener, Sage Professor of Psychology in the Cornell University. London: Swan Sonnenschein & Co. Macmillan & Co., New York.

STUDIES IN THE EVOLUTIONARY PSYCHOLOGY OF FEELING. By Hiram M. Stanley. London: Swan Sonnenschein & Co. Macmillan & Co., New York.

THE BEGINNING OF WRITING. By Walter James Hoffman, M.D. The Anthropological Series. New York: D. Appleton & Co.

Our knowledge of the nervous system has recently progressed quite rapidly, but the records of the progress are difficult of access in scattered papers and technical journals, and require the elimination of contradictory data and accidental variations before their significance is revealed. So readable and at once so scholarly an account of the essential facts of neurology, embodying these recent advances, is itself an important acquisition to the literature of the subject.

It is in the results of the main problem under discussion that the reader will probably be seriously disappointed; he will find it difficult to carry away any very definite conclusion regarding brain changes and individual variations in brain structure. He appreciates the interpretation of the several tables of comparisons of cranial capacity and the like; he realizes the many sources of error and chances for misinterpretation and loose inferences in the treatment of the subject for these are clearly set before him; but he cannot escape the suspicion that the positive outcome of the discussion, though not to be ignored, is none the less disappointing. For this he must blame, not the author, but the present condition of the subject. It is in many ways an unfortunate time to attempt the grouping of the facts into an orderly whole, and particularly to present them in a form suitable for a semi-popular scientific series. The many tables and curves, the cautious preliminary discussions and careful considerations of sources of error, it is to be feared, will deter the layman, while calling out the admiration of the fellow specialist. Pioneer work is necessarily unsatisfactory from an artistic point of view. A quarter of a century hence the time may be riper for the preparation of such an essay on the growth of the brain as the average reader may desire, but will not find in the present volume. However, although the keystone will be the most conspicuous, the other stones are quite as essential to the strength of the structure.

Before leaving this volume, we must give a moment's notice to its sub-title "a study of the nervous system in relation to education." The growthchanges of the nervous system are obviously fundamental in all that process which we call education; and in the last two chapters of the work, the educational bearings of the whole are ably set forth. It is true that these educational applications are based as much upon other facts as upon those treated in the volume, and even more so; but they tell very plainly the lesson that neurology teaches. They show how apt we are to exaggerate the importance of formal education and technical acquisition, and how slight this may be when compared with unconscious absorption and the unfoldment of natural dispositions; they show that no discussion of the effects of educational methods can be considered complete that does not take into account the changes in the nervous system by which all such processes are conditioned. Our knowledge of such relations is lamentably imperfect in detail, but the attempt

to interpret educational changes in neurological terms is in itself most helpful, and gives additional importance to the volume under discussion.

Professor Wilhelm Wundt is widely known to English readers as a pioneer and a leader in the development of modern psychology and as the founder of the first laboratory for the experimental study of mental phenomena; yet the present is the first volume of his writings to appear in an English translation. These lectures on "Human and Animal Psychology" were first published over thirty years ago, being one of the very earliest contributions to the experimental field; in 1892 the author revised and rearranged the older lectures, and from this second edition Professors Creighton and Titchener, of Cornell University, have prepared their translation. Of all of Professor Wundt's writings, this volume is best suited for translation, because it is adapted to a wider reading public, and covers, in a less didactic and detailed manner than his more formal treatises, the chief problems of mental science. The first group of lectures considers the facts and interpretation of sense-impressions. The discussion of the measurement of intensities of sensation and of the methods of gaining a knowledge.of space-dimensions are particularly fully and interestingly treated. A second group of chapters takes up the time-relations of mental phenomena, considering the rapidity of mental processes, the range of consciousness, the fluctuations of attention, the nature of associations, and the like. Besides the lectures which treat of the nature of animal activities, there are also discussions of abnormal states, dreams, hypnotism, and allied phenomena; of the development of the will and its relation to reflex, automatic, and expressive movements; of the fundamental theories connecting bodily and mental states; and more less incidentally of a variety of interesting psychological problems.

It is thus apparent that the lectures cover a very wide range; but there is little attempt to give the various topics a definite setting in a coördinated general conception. In each of the groups of problems considered, a few problems are selected as typical, and are treated with considerable detail, their relations to other almost equally important topics being left without notice. This defect is perhaps to be ascribed to the lecture form of the work, but will often leave the general reader at sea regarding the significance of what he has read. Indeed, the reader to whom the volume will be most helpful is one who has some elementary acquaintance with scientific psychology, and is willing to make some effort to extend that acquaintance, and at the same time demand a readable and impressive exposition. This class of readers does not include the largest share of those who will be tempted to scan the title-page with a view of perusal, but it is large enough to sanction the labors of translation; nor should the demands of the rapidly increasing number of professed students be ignored.

The revision of a course of lectures prepared in

the budding-time of an expanding science could hardly have been an easy task; and the result, as the author confesses, is not free from the architectural defects and compromises inherent in the modernizing of an old structure. Distinctly new topics, that have come into prominence within recent years, are introduced; other lectures are omitted; and very generally new facts and experiments are substituted for the old ones. But in spite of all these changes the volume does not adequately represent the methods and results of the movement to which Professor Wundt has so largely contributed. Welcome as the volume undoubtedly is as an addition to the psychological shelves of our libraries, private and public, it must be recommended with an explanation of its relative historical importance, and of the plan of its modernization.

The translation is both readable and accurate qualities not so often combined as to need no commendation; here and there the harsh Teutonic technical phrases are insufficiently disguised, or unusual words used when more familiar ones are in vogue. But these minor imperfections entirely disappear in the general excellence of the whole.

Professor Külpe's "Outlines of Psychology" is a product of the Leipzic school of psychology; the author was for several years an assistant to Professor Wundt, and dedicates the volume to his master. It is in some respects a compendium of Wundt's larger work the resemblances of arrangement and treatment, of theory and perspective, being many and striking, but in the main deserves to be regarded as an original exposition of psychological problems from the experimental point of view. It is to be regretted that the author has not availed himself of the convenience of a preface to explain the special purposes of the volume, the class of readers to whom it is addressed, and the basis of selection of the particular problems selected and omitted. The "psychologies" of an earlier period were mostly expositions of individual systems, or the tenets of a school; more recently a "psychology" has come to represent the particular group of problems, treated from this or that point of view, in which the author is specially interested. It may be seriously questioned whether the progress of a science depending upon such contributions alone would be rapid or certain. It would be foolish to question the right of any scientific worker to express his own convictions upon the main problems of his science in a way most satisfactory to himself, and, indeed, a frank acknowledgement of this individualistic motive upon the title-page would often ward off a severe but justifiable criticism of the work; but from the point of view of a disinterested zeal in the advance of science it may be confidently maintained that a general discountenancing of such works would be a wholesome corrective to a natural excess. Many a work of ability, and replete with expositions of originality and importance, repels rather than attracts, because it is entitled "principles" or "outlines" of psychology, instead of "some contribu