ences, in some instances, that may be drawn from them in explaining the practices of the most successful breeders. It is believed that a systematic statement of what is already known in the practice of the art is of greater importance, at the present lime, than any new truths, as it must furnish the only consistent foundation for future progress and improvement. The numerous cases that have been collected to illustrate the various topics under discussion have been compiled, as far as possible, from original sources, and presented in their original form—preferences, in nearly all cases, being given to the works from which they are quoted. This feature of the work will be of interest to the student who wishes to study the subject in greater detail, as it will, to some extent, serve as an index to authorities that may be profitably consulted. In the limits of a popular work it is of course impossible to treat each topic exhaustively, and the attempt has been made to present only such an outline of the principles of the art as would be required in a text-book for students, or a work of reference for farmers."
Outlines of Ontological Science; or, A Philosophy of Knowledge and of Being. By Henry N. Day, author of "Psychology," "Logic," "Ethics," etc. New York: G. P. Putnam's Sons. Pp. 441. Price, $1.75.
The present work is an attempt to grapple with the profoundest problems of philosophy by determining the nature and limits of genuine knowledge, and to determine the relations and interdependences of its several parts. The author claims for his book nothing of novelty in its design, but alleges, as a reason for undertaking it, that "the recent rapid developments of science, both mental and physical, with their widely-diversified results, seem to invite a fresh endeavor in this direction, as they furnish new facilities and helps for prosecuting it." As might be expected from the point of view here taken, modern scientific and philosophical ideas are brought under review and estimated, the result being, as we gather from the writer, that fundamental questions of speculative inquiry have not been much disturbed by modern research. In his last chapter on "Cosmogony" the author takes up the doctrine of evolution, which he says is philosophically "mere hypothesis," "irreconcilable with facts claimed to be ascertained by science," "repugnant to reason," and "as a theory of causal agency in the cosmos is a failure."
Life in Other Worlds: including a Brief Statement of the Origin and Progress of Life in our World. By Adam Miller, M. D. With an Appendix of Three Sermons by Rev. H. W. Thomas, D. D. Chicago: Fox, Cole & Co. Pp. 282, Price, $1.50.
A book of multifarious speculations, theological, historical, moral, astronomical, and physical. The author says that it was originally written with no intention of publication, but he got so much comfort out of the contemplations it embodies that he was impelled to print it. He remarks, "With a hope that some one who will read these pages will find encouragement for a union in the great future with friends that have gone before, as well as for an acquaintance with the millions of happy spirits who have passed through the vale of sorrow to their final home, I submit this work to a generous public." Our attention has been especially called to the author's three chapters on "Solar Light and Heat," in which he differs from the ideas that men of science are in the habit of taking. The cause of solar heat he holds to be the refraction of light, and says: "The atmosphere that surrounds our earth is in the form of a concavo-convex lens. The aqueous vapor in the upper regions of the atmosphere is intensely cold, yet, acting on the rays of light like a cold-water lens, produces heat; and here is the secret of solar temperature on the earth, and the change in temperature is caused by the varying angles at which the solar rays strike the atmosphere. I repeat, it cannot be denied that refraction of the rays of light will produce heat. The heat at the focus of a 32-inch lens exceeds almost every kind and intensity of heat known to terrestrial chemistry. Again, it cannot be denied that the earth's atmosphere is a refracting medium, and that as such it is capable of producing heat from rays of light."
The book is printed on tinted paper, and contains a portrait of the author.
Filtration of Potable Water. By Prof. William Ripley Nichols. From Massachusetts Health Reports, 1878. Pp, 90.
The author of this valuable report considers the subject of filtration under the three heads of "Artificial Filtration on the Large