here the importance of the numerous references to the literature is especially valuable.

The translation should he in the hands of everyone interested in the subject of catalysis, as in the judgment of this reviewer it is the most helpful book available on this subject.

J. C. W. FRAZER Tne J o n ~ s HOPEINS Ulrrwsslrv

B A L n M o a s . M * ~ ~ * N D

SOILLESS GROWTH oa PLANTS. CarletOx Ellis and Miller W. Swaney. Reinhold Publishing Corporation, New York City. 1938. 14.5 X 23 cm. 155 pp. 58 figs. (including 3 color plates). $2.75.

In view of the recent growth of popular interest in "hydro- ponics" or aquaculture this simply written, but authoritative and informative, little volume should meet with a warm welcome. I t treats not only of methods of water-culture, hut also of growth in mineral aggregates and other neutral media, fed by nutrient solutions.

The first chapter is devoted to a non-technical exposition of the essentials of the chemistry of plant life. With this background even the amateur horticulturist of no technical training whatever should be able to follow intelligently the discussion that follows. Specific formulas are given, and practical mechanical accessories are described and fully illustrated. The hobbyist and amateur experimenter are wisely advised to use simple and inexpensive equipment, and to devise and construct that which best suits their own needs.

The "trace" elements (such as boron, manganese, and so forth) as well as the so-called plant hormones, are briefly discussed. The effects of light and of various gases are also outlined.

The advantages and limitations of soilless culture are fairly and conservatively stated. Several commercial developments are mentioned. The reader is warned against unscrupulous er- ploitation by equipment and nutrient sellers, and should have no difficulty between "gyp" and honest dealers in the light of the information which this little volume places a t his disposal.

Format, illustrations, and typography are excellent. There is an index and a few blank pages for memoranda.

OTTO REINMUTE

Bnsrc GERMAN FOR SCIENCE STUDENTS. M. L. Barker, Uni- versity of Edinburgh. Third edition. Chemical Publishing Co. of New York, Inc., New York City, 1937. xiii + 186 pp. 15 X 23 cm. $2.50.

According to the preface, "The present book is the outcome of the author's practical experience in teaching university students to acquire a 'reading knowledge' of German for the purposes mentioned above," i . e.. . . . "learn enough German to enable him (1) to give in English the gist of the German passage set in his final B.S. paper, and (2) to understand German articles in books and periodicals dealing with his special subject or research work.' "

Part I (forty-seven pages) devotes twenty-two pages to an introduction which includes all the grammar (conjugations, declensions, and so forth) in the book and all thirty-one verses of chapter one of Genesis with appropriate vocabulary. An English translation of each verse is presented beside the German text. The remaining twenty-five pages of Part I have short German passages relating to the history of civilization an the left-hand page (with vocabulary as footnotes) and an English translation on the right-hand page. The author states, "The introduction and Part I provide the student with the material necessary for acquiring a vocabulary of approximately six hundred fifty of the first thousand basic German words, i. e., 'those words which are actually of most frequent occurrence in the writings of the German people.' " Part I1 (eighty pages) consists of German scientific passages on the left-hand side and an English transla- tion on the right with vocabulary as footnotes. Of Part I1 twenty-two pages are devoted to chemistry, ten to zoSogy, eight

to botany, fourteen to physics, ten to mathematics, and sixtear to medicine. One page is devoted to twenty-eight common German abbreviations, another to twenty-nine technical terms in chemistry and a third to a few very elementary ideas on in- organic chemistry nomenclature. The next twenty-nine pages are devoted to vocabulary and the h a 1 twenty-four pages to reproducing German passages set in papers for the final B.S. examinations in various fields of science. One page is given to "Practical hintson the pronunciation of German."

This book is not intended for use in class work and is not suit- able for this purpose. It does fulfill the objectives stated in the preface in a very condensed hut effective fashion. The scientific passage selections are well made, mostly from standard texts and of German of moderate difficulty, and the English transla- tions follow the German text very closely hut, despite this fact. are in excellent English. From the treatment of pages like those on common technical terms in chemistry and on nomenclature i t is obvious that the author is not a chemist and probably not trained in the sciences. A chemist would not be content with such elementary and incomplete treatment of these topics. For the penon who must acquire a reading knowledge of German by his own efforts, this book should prove very useful. I t is doubtful whether the American student will get much value from the passages from B.S. examinations, as those passages commonly given in language examinations in American universities for graduate degrees are much longer and usually more difficult German.

The hook is well manufactured and exceptionally free from erron, as the reviewer failed to h d a single error. The space arrangement of the text is not too good, as twenty-four pages were noted that were over half blank and about an equal number had too much unused space.

TUK FOUNDATIONS oa N~TRITXON. Mary Swarte Rose, Columbia University. Third edition. The Macmillan Company, New York City. 1938. xi + 625 pp. 116 figs. 14 X 21.5 cm. 8.50.

The third edition of TEDE FOUNDATIONS OP NUTRITION, like i ts predecessors, presents in an accurate and readable form the story of the development of the science of nutrition and its practical application. I t should serve equally well as a guide to food selection for the intelligent layman and as a text for the college student of food and nutrition.

The new chapter on "Vitamins of Undetermined Significance in Human Nutrition" comprises a timely addition. It serves to present to the beginner and those unfamiliar with the extensive vitamin literature evidence for the multiplicity of the B complex. It presents lucidly and briefly the necessary experimental work upon which this evidence is based. There will be some difference of opinion as to the wisdom of designating ribotlavin vitamin G. This objection is particularly justifiable in making an appraisal of the tables in the appendix. Few of the animal assays for the G value of foods can be said to be determinations of riboflavin only.

The summaries at the end of the chapters on the contributions to the diet made hy various types of food materials is a valuable addition to the hook. Such a summarization is most useful to the lay person with hut a casual interest in foods and their im- portance in the diet. For the more careful student of nutrition there is sufficient detail in the subject matter of these chapters to afford a thorough understanding of the reasons far the variations in biologicalvalue of individual foods and different classes of foods.

This book is admirably written and will undoubtedly find favor among new readers, as well as among those familiar with the preceding editions.

E. V. MCC~LLUM