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of experimental science-teaching will not be much longer excusable for lack of suitable laboratory manuals. Mr. Arey's book consists of brief directions for seventy experiments in the several departments of physics, with suggestive questions as to what is shown by each experiment. The right-hand pages are left blank, or contain forms for entering the results of observations. The experiments are adapted to pupils in secondary schools, and are characterized by involving measurements, the author being convinced that "vastly greater mental discipline will be derived by the student from quantitative experiment" than from qualitative. It has been a part of the author's plan, also, to devise inexpensive apparatus with which results may be obtained sufficiently accurate to point conclusively to the law under consideration. Directions for making many pieces of this apparatus are appended to the book. The text is illustrated with fifty-six figures.

are supplied in this volume with a great deal of practical knowledge concerning the chief chemical and physical characters of the materials and processes that they use. There are other books that treat of the pigments employed, but this deals also with painting-grounds (paper, plaster, stone, wood, and canvas), with vehicles and varnishes, and with methods and results. In describing the materials which artists use, the sources from which they are obtained are told, and in many cases the mode of preparing them is given. Tests for purity and genuineness, that take but little time or apparatus, have also been inserted. Chapters that will contribute to the durability of the artist's work are those on the permanency of pigments, and the conservation of pictures and drawings. Exact knowledge in regard to permanency is furnished in the chapter containing results of trials by Mr. F. W. Andrew, Prof. Rood, Prof. Hartley, and by Dr. Russell and Captain Abney, as reported to the South Kensington Museum. The volume is adequately indexed, and its mechanical work is excellent.

monograph on the grasses, here translated, was contributed to the great German work on the Natural Families of Plants, edited by Drs. Engler and Prantl. The book consists of a botanical key to the Gramineæ, through which are interspersed full descriptions and cuts of the economically important species. The grass family includes a large number of plants which are of great value as furnishing food for man and for his domestic animals, as well as supplying a great variety of products used in the arts and in medicine. Among these are Indian corn, sugar-cane, bamboo, the grains, and the fodder grasses. The opening chapter gives an account of the general structure, morphology, and physiology of the Gramineæ. The translators have added an introduction, giving an example of how a botanical key is used, a full glossary, and an index, in order to make the volume more useful as a text-book in agricultural colleges. The illustrations number over a hundred.

Messrs. Black issue this little volume as the first of a series under the general title Science in Plain Language, the design of which is to impart the general results of scientific investigation in common language, and without a great deal of detail. The book consists of about twenty short articles grouped under four heads. Those in the first group deal with evolution and primeval man, those in the second are devoted to the lowest living organisms, the third contains papers on color in plants and animals, and in the fourth various movements in plants are described. Each essay is complete in itself, yet their subjects are so selected that they are all connected, and all unite to form a general picture of the evolution and general phenomena of life.