lar expositions which have appeared in recent years, in which the principles of the science and their application to the arts have been told in plain, simple, and attractive language. Already the popular literature of the subject is large, and keeps pace with the advance in industrial and technical uses. Of recent contributions of this character the work of M. Guillemin is one of the most notable. The work covers a general exposition of the science of electricity and magnetism, and then brief and concise descriptions of apparatus and appliances. In the division devoted to the industrial applications, the subjects considered are—the mariner's compass, lightning-conductors, telegraphy, the telephone, microphone, and the radiophone, electric clock-work, motors, transmission of power, electric lighting, electro-plating, and various minor applications. In an appendix Prof. Thompson gives a brief account of the modern views of the nature of electricity, based upon the researches of Faraday and Maxwell.
The book is handsomely got up, printed in large type, on heavy calendered paper, with wide margins, and is very fully illustrated.
Mental Suggestion. By Dr. J. Ochorowicz, with a Preface by Charles Richet. New York: The Humboldt Publishing Company. Pp. 361. Price, $2.
As we gather from the concluding chapter of this work, by mental suggestion is meant a "dynamic correlate" sent forth by thoughts in every direction. Thoughts do not travel; "no substance is carried hither or thither, but a wave is propagated and modified more and more according to the different natures and the different resistances of the media it traverses" It is mental action at a distance, upon subjects which have to be in a proper rapport or relation to the acting thought. By it the phenomena of hypnotism, occultism, which it does not favor but banishes, and kindred mysteries are supposed to be accounted for. According to Dr. Richet's interpretation, the theory means that "independently of any phenomenon appreciable by our normal senses or by our normal perspicacity, how quick soever it may be supposed to be, there exists between the thought of two individuals a correlation such as chance can not account for." Dr. Ochorowicz sets forth a multitude of facts which have been observed by himself and by sundry experimenters, criticises them vigorously and seeks to eliminate the difficulties that might arise from fraud or chance, and to present the conclusions which seem to be established. Yet Dr. Richet does not maintain that his argument produces conviction, but only doubt. "So strong in its action upon our ideas is the influence of routine and of habit," which have taught us to ignore the conclusions to which the phenomena would lead an unprejudiced mind. "But," Dr. Richet adds, "whatever the opinion ultimately formed as to the reality of mental suggestion, it ought not, I think, to influence one's judgment as to M. Ochorowicz's book. Everybody, it seems to me, must recognize his sincerity, his perseverance, and his contempt for ready-made opinions. One feels that he has a passionate love of truth." The body of the work consists largely of citations of incidents apparently or really illustrating the doctrine of mental suggestion, with the author's criticisms and comments upon them, and the conclusions drawn from them.
Solutions. By W. Ostwald. Translated by M. M. Pattison Muir. London and New York: Longmans, Green & Co. Pp. 816. Price, $3.
The volume here offered to chemists is a portion of the author's Lehrbuch der allgemeinen Chemie, a second edition of which was issued toward the end of 1890. Sufficient reason for its translation and publication by itself is given in the appearance and rapid growth during the last three or four years of van 't Hoff's theory of solutions. An authoritative statement of this theory, together with a systematic setting forth of the great mass of facts about solutions that have been accumulated, has obvious value for chemists at the present time. The eminent rank of the translator among English chemists, together with the fact that he has had the co-operation of the author in preparing this version, insures that the treatise has lost nothing in the process of translation. It has, in fact, gained the benefit of some slight revisions, and some additions from memoirs published in the first half of 1891.
