ELEMENTARY ELECTRICITY AND MAGNETISM. By DUGALD C. JACKSON, E. E., Prof. of Electrical Engineering, University of Wisconsin, and J. P. JACKSON, M.E., Prof. Electrical Engineering, Penna. State College. The Macmillan Company.

This volume will be appreciated by all persons who wish to acquire some knowledge of the subjects it presents. While the authors have written in an elementary way, every topic is as scientifically and exhaustively discussed as one would expect from an expert. In these days when electricity is applied so extensively, and when many employ it without adequate previous training as to its origin, its control, measurement, etc., the present volume comes as a reliable and trusty handbook. To chemists, who have not enjoyed a full training in physics, it cannot fail to recommend ifself. It is well written and well illustrated.

EDGAR F. SMITH. ENZYMES AND THEIR APPLICATION. By DR. JEAN EFFRONT, translated by S. C. PRESCOTT. Published by John Wiley & Sons, New York. The interest in enzymes is growing very rapidly. The sphere of their application is largely increased both in theoretical and industrial chemistry. Biology is probably the science that has profited most from the study of enzymes, and many problems that were in darkness for decades lose their mysteriousness in the light of the new discoveries of certain functions of enzymes.

But the results of all the new investigations were never summed up in a systematic, brief and popular form. Prof. Effront's book supplied that gap in the chemical literature, and Mr. Prescott's translation of the work under the title "Enzymes and their Application" will be welcomed by all interested in the subject.

The present volume deals chiefly with the enzymes of the carbohydrates, and briefly with the oxidases. In the following volume the proteolytic enzymes and toxines will be discussed.

The book being a summary of a course of lectures delivered at the Institute of Fermentation at the University of Brussels, it naturally has a more or less elementary character, and cannot be regarded as a reference or text-book. But all the greater is its value for one who seeks a general knowledge on the subject both from theoretical and practical standpoints. The theoretical problems are discussed in a very clear and comprehensive way. The

introductory chapter on the synthetic and analytic work of the living cell is perhaps a little too brief, but the question of the "Manner of Action of Diastase" is discussed exhaustively in the light of the recent researches in organic chemistry. The author criticises the theory that enzymes are not a substance but a property, and adduces all the evidence for the theory of the chemical nature of the action of enzymes.

The question of the individuality of enzymes the author answers in the affirmative.

The mode of preparation of the different individual enzymes, and the favorable and unfavorable condition for their action is discussed in considerable detail, and sufficient room is given to the theoretical explanation of the experimental and practical findings. It seems, however, that the reversibility of the action of ferments is omitted in all the theoretical considerations of the author, and yet they could explain a good many facts for the explanation of which the author resorts to much more complicated views.

The chapters on industrial application of the enzymes read, as interestingly as the theoretical discussions, and the book will undoubtedly be an inspiration to a good many workers in the line of biological chemistry.

The fact that the author verified most of the experimantal data of other investigators mentioned in the book makes the book all the more valuable.

Mr. Prescott deserves much credit for the good translation of the book. P. A. LEVENE.

REPRINTS OF SCIENCE CLASSICS NO. I. THE ANALYSIS OF AIR AND WATER, being selections from LAVOISIER'S ELEMENTARY TREATISE OF CHEMISTRY. Translated and annotated by C. E. LINEBARGER. 1902. Ravenswood, Chicago, Ill. The School Science Press. Double number, pp. 31.

Price, 10 cents.

The purpose of the little pamphlet before us is to place in the hands of pupils of high schools and colleges the exceedingly beautiful and clear account which Lavoisier gives of those experiments which first laid a secure foundation for our present knowledge of air and water. Dr. Linebarger's idea is a most happy one. It is difficult to think of anything better than this little booklet for riveting the attention and awakening the interest of beginners in scientific study. It is well worthy of perusal by older chemists

as well, for we all have much to learn from the great master of our science.

W. A. N. STUDIEN ZUR Kentniss der AbhängigkEIT DER VISCOSITÄT DER FLÜSSIGEN KÖRPER VON DER TEMPERATURE UND VON IHRER CHEMISCHEN CONSTITUTION. By Alexius Batschinski. 101 pp. 17 X 25 cm. Moscow.

1901.

Though large enough to be a monograph, this is really a reprint of a journal article. The author has previously called attention to the fact that with most liquids the product of the internal friction into the absolute temperature is a constant. Data are given showing the application of this law to one hundred and forty-four different substances. In general, the agreement is good; but anhydrides, acids, alcohols and water form exceptions. These are all substances which we consider as polymerized in the liquid state. WILDER D. BANCROFT.

THE EXPERIMENTAL STUDY OF GASES. BY MORRIS W. TRAVERS, D.Sc. New York: The Macmillan Co.

Dr. Travers' book confines itself to methods of experiment which have been useful in researches on the properties of gases and to a description of some of the more important of such researches. It does not contain lecture experiments, nor instruction for beginners. In the selection of topics, it is well balanced, and as complete as can fairly be demanded of its 320 pages; chapters on mercury pumps, on stop-cocks and other connections, on the collection and storage of gases, on reading instruments, and on calibration, have their due place. The chapters on the preparation of pure gases, on gas analysis, and on the determination of densities, are interesting and satisfactory, as are those on the relation of temperature, pressure, and volume, on vapor pressure and critical constants, and on specific heat.

The most interesting chapters, naturally, are those which have more or less to do with the newly discovered gases. That entitled "The Gases of the Helium Group" describes the method used in isolating argon, and that afterwards used to obtain it in considerable quantity, and narrates the steps which led to the discovery of helium, neon, krypton, and xenon. A chapter on the liquefaction of gases explains all the new principles which have been utilized and the new processes which have been used in liquefying gases since the time of the experiments of Pictet and of Cailletet. Here is found a clear account of Hampson's machine for liquefying air; it is stated that this machine will

begin to deliver liquid air in four minutes from the time of starting it. A method is fully described by which liquid hydrogen may be obtained without great difficulty. A chapter entitled "The Manipulation of Liquefied Gases" will be thought by many to be the most interesting in the book. It treats of the separation of gases in a mixture by fractional distillation. One such separation was that by which, from a hundred liters of atmospheric nitrogen, there was obtained a residue containing ten per cent. of neon and helium; in the air, there is but one or two parts of neon in a hundred thousand, and perhaps a tenth as much helium. Another such separation is that of fifteen liters of argon; diagrams make clear the course of the experiment, by which, after two final distillations at the temperature of liquid hydrogen, neon was obtained in quantity sufficient for the determination of its density. A third such fractional distillation was that applied to liquid air, by which krypton and xenon were obtained; the course of this experiment is also made clear by the aid of diagrams. A proper end of this subject is made by the chapter on spectrum analysis, which contains convenient tables, as well as a map, of the spectra of the new gases.

The reading of proofs was careful; no misprints have been noted more serious than Hildebrand twice for Hillebrand, and Gimmingham for Gimingham. Errors of fact are few and unimportant. Names of journals not published in England are cited somewhat carelessly; the Smithsonian Contributions to Knowledge appear as Proceedings of the Smithsonian Association, and the Annales de Chimie et de Physique is referred to in five different ways.

Dr. Travers' connection with the first workers on the new gases was so intimate, and his own part in some of the work was such, that he is especially well fitted to write this volume, which is a very welcome addition to scientific literature.

EDWARD W. MORLEY.

THE MANUFACTURE OF PAINT. BY J. CRUICKSHANK SMITH. London: Scott, Greenwood & Co. 1901. 200 pp. Price, $3.00 net.

This author seems to know very well the kinds of machinery in use in England for making the cheaper grades of paint, and the illustrations are intelligently chosen and well executed. is difficult for an American paint manufacturer to believe that modern high-class paint machinery has not yet found its way

into English factories, but very likely it is true. The only American machine described is one of the earlier forms of water-cooled mills; and the practical, technical points which one would like to find in a book of this sort, such as the values of different styles of dressing millstones for various kinds of work, the points of excellence to be aimed at in making particular paints, the nature and effect of the vehicles used, and the like, such things as these are very scantily touched upon. It seems remarkable that no mention is made of the practice of mixing oil with wet white lead without preliminary drying, a practice of great commercial importance. In general, the information conveyed to the reader seems to be of the sort obtainable from the makers of paint machinery, rather than from experts in paint manufacture; accurate and useful as far it goes, but lacking in real knowledge of the subject. The book is one which should be of interest and use to the beginner but is not complete enough to serve the advanced manufacturer. A. H. SABIN.

LEÇONS SUR LA THEORIE DES GAZ. L. BOLTZMANN; traduites par A. GALLOTTI. Paris: Gauthier-Villers. 1902. Price, 8 francs.

Boltzmann is one of the three great mathematicians to whom the development of the kinetic theory of gases is mainly due. The present volume contains a translation of the first half of his lectures, originally published in 1896 and 1898, and gives a systematic account of the mathematical results attained by the joint labors of Maxwell, Clausius and Boltzmann.

Professor Gallotti's translation is clear and accurate; some sentences are even more perspicuous than in the original. Professor Brillouin has furnished an historical introduction and some comments on certain steps in the mathematical discussions of the author. EDWARD W. MORLEY.

THE MANUFACTURE OF MINERAL AND LAKE PIGMENTS. BY DR. JOSEF BERSCH. TRANSLATED BY A. C. WRIGHT. London: Scott, Greenwood & Co. 1901. 476 pp. Price, $5.00 net.

This admirable book was evidently written by a thorough chemist who is also a practical color-maker. Not many technical points escape mention and the book is valuable not only for reference but for daily use. The chapters on "Black Pigments,' "Vermilion," and "Ultramarine," are especially valuable, as presenting an intelligible account of processes on which very little practical information is available.