Page:Popular Science Monthly Volume 42.djvu/872

850 effects are given, and an index is appended. The text is concise and clear, and the book can not fail to be of use to those interested in the art of bronzing, or to students of metallurgy.

This work aims to present in considerable fullness, yet with suitable brevity, the principal content of the leading systems and partial systems of philosophy in modern times, together with a reasonable amount of information regarding philosophical authors and works. It aims to show, in a general way at least, the historical connections of systems, or to exhibit the historical continuity of modern philosophical thought, and further, to furnish materials and stimulus to the student for the study of the higher genesis and final values of ideas and systems. Modern philosophy, according to the author's definition, as distinguished from mediæval philosophy, is occupied with the immanent and concrete rather than the transcendent and abstract; with the natural and the human rather than with the unnatural and the superhuman. As distinguished from ancient philosophy, it is occupied with the subject rather than with the object; with thought, rather than with being. It may be divided into three great periods, of which the first was one predominantly of reception and appropriation—though with considerable self-assertion as against mediævalism; the second, a period of original effort, very largely destructive or negative—toward previous philosophy as well as toward the object of thought generally; and the third as a period of equal originality and more constructive or synthetic effort. Psychologically speaking, those periods are periods of sense (receptive), understanding (analytic), and reason (synthetic); logically they are regarded as periods of thesis, antithesis, and synthesis. Their dates are from the middle of the fifteenth to the beginning of the seventeenth century, thence to the third quarter of the eighteenth century, and thence down to the present. An apparently disproportionate amount of space is given to certain recent systems, because they have not as yet become commonly known through other histories of philosophy. Closing with a brief glance at American philosophy, the author finds that the study of the science has been more seriously undertaken than ever before in our higher institutions—for its own sake and independently of theological influences; and that it seems safe to predict a vigorous future for it here.

Such lovers of Nature as Thoreau, Ruskin, and the poets give us exquisite pictures of her varied moods and phases; but men of science vie with them in their enthusiasm and even in charm of expression. Throughout this volume are found many fine descriptions of natural scenery culled from various sources, and most vivid and glowing of all are those of the naturalists. For the introduction, the author has prepared a calendar of the special charms of each month, and encourages us to closer observation by premising that the lover of Nature is always young and can never be dull! None can gainsay his claim that science has given us a greater possibility of enjoyment in revealing two new worlds of beauty—the infinitely great and the infinitely little.

Animal life offers many problems for our study—the extremes of temperature at which animals can exist, their metamorphoses, modifications of growth, mimetic coloring, and modes of communication. Not only do many animals possess in a more acute degree the senses known to us, but it is possible that they also have others of which we can form no conception. It has been proved that the ultra-violet rays which are invisible to us are perceived by some of the lower species, while others have organs richly endowed with nerves indicative of uses wholly unlike those of man. Curious questions arise in considering the development of gnats and the reproduction of zoöphytes and infusoria. We can no longer define individuality with them, and some species are theoretically immortal.

Among plants it is found that the reasons for their variation are more wonderful than the old myths invented to explain them. The woods and fields are full of mysteries. Trees, like human beings, may have chosen associates; the larch and arolla grow