within his ken, and he gains a more vivid feeling and a keener conception of it. He measures the distance he has traversed, and values the worth of his own contemplations by the fullness of lucid clearness-which enlightens his faint view of the first principles of things, and by the depth of humble reverence with which he bows before the mysterious Power which created all!
"Concarneau (Finisterre), May, 1878."
The Microscope and its Revelations. By William B. Carpenter, M. D., F. R. S. Fifth edition. 848 pp. Price $5.50. Philadelphia: Lindsay & Blakiston, 1875.
This standard work on the microscope has been carefully revised by the author, so as to present the latest improvements in modern instruments. It also includes the new methods and principles of Dr. Royston-Piggott, which have lately been the subject of so much discussion among microscopists; it likewise gives the latest results of microscopical study. It is a volume of goodly size, containing 449 woodcut-illustrations, and 25 plates illustrative of its wide range of subjects, and forming a standard and complete guide to the use of the microscope. The author's object throughout is to direct the possessor of a microscope in the intelligent study of any department of natural history for which he may have a taste, or his circumstances afford him the facilities of pursuit; and, again, to meet the wants of those who, coming to the study of minute animal and vegetable life with no scientific preparation, yet want something more than a mere sight of them. Of his use of scientific terms the author says:
"Some... may think that he might have rendered his descriptions simpler by employing fewer scientific terms. But he would reply that he has had much opportunity of observing among the votaries of the microscope a desire for just such information as he has attempted to convey; and that the use of scientific terms cannot be easily dispensed with, since there are no others in which the facts can be readily expressed. As he has made a point of explaining these in the places where they are first introduced, he cannot think that any of his readers need find much difficulty in apprehending their meaning."
Dr. Carpenter recognizes the impossibility of keeping pace with the rapid extension of knowledge over every part of the constantly-widening field of microscopic research, to say nothing of furnishing an exhaustive treatise on each of its many departments, in the limited compass of his book, the original purpose of which is to impart general guidance, rather than special instruction; and, instead of attempting the impossibility of teaching his reader all there is to be learned, he is put in the way of learning it from that best of all teachers, experience. And so, in the applications of the microscope, the proportion of space allotted to the different departments has been determined more from their special interest to the amateur microscopist than their physiological importance, and more space and treatment in detail are given to subjects having no special sources of information than to such as are the subjects of special treatises.
The first five chapters, embracing 269 pages of the work, treat respectively of the principles of the microscope, its construction, accessory apparatus, management of the microscope, preparation of objects, etc., while the rest of the work is devoted to the practical applications of the microscope in the study of minute forms of animal and vegetable life, and its uses in geology, mineralogy, and chemistry.
Health; A Hand-book for Households and Schools. By Edward Smith, M. D., F. R. S., Author of "Foods," etc. 198 pages. Price $1.00. New York: D. Appleton & Co.
Under the general title of "The Popular Science Library," it is proposed to issue a series of neat and attractive volumes at the moderate and uniform price of a dollar each, that shall treat of the most important and interesting scientific subjects in a way suited for general readers. The books will be original, translations, reprints, and abridgments, with illustrations when necessary, and will take a free range in the selection of subjects, giving prominence to those that are practical, but aiming to represent all the aspects of science which are of general or of prominent interest. Dr. Smith's volume on "Health" was issued first, and is a plain, practical, useful book, which aims only to give valuable information for everybody, in a form which anybody can under-
