"This work is more than a contribution to the stock of entertaining knowledge, though, if it only pleased, that would be sufficient excuse for its publication. But Dr. Pettigrew has given his time to these investigations with the ultimate purpose of solving the difficult problem of Aëronautics. To this he devotes the last fifty pages of his book. Dr. Pettigrew is confident that man will yet conquer the domain of the air."--_N. Y. Journal of Commerce._ "Most persons claim to know how to walk, but few could explain the mechanical principles involved in this most ordinary transaction, and will be surprised that the movements of bipeds and quadrupeds, the darting and rushing motion of fish, and the erratic flight of the denizens of the air, are not only anologous, but can be reduced to similar formula. The work is profusely illustrated, and, without reference to the theory it is designed to expound, will be regarded as a valuable addition to natural history."--_Omaha Republic._ IX. Responsibility in Mental Disease. By HENRY MAUDSLEY, M. D., Fellow of the Royal College of Physicians; Professor of Medical Jurisprudence in University College, London. 1 vol., 12mo. Cloth. Price, $1.50. "Having lectured in a medical college on Mental Disease, this book has been a feast to us. It handles a great subject in a masterly manner, and, in our judgment, the positions taken by the author are correct and well sustained."--_Pastor and People._ "The author is at home in his subject, and presents his views in an almost singularly clear and satisfactory manner.... The volume is a valuable contribution to one of the most difficult, and at the same time one of the most important subjects of investigation at the present day."--_N. Y. Observer._ "It is a work profound and searching, and abounds in wisdom."--_Pittsburg Commercial._ "Handles the important topic with masterly power, and its suggestions are practical and of great value."--_Providence Press._ X. The Science of Law. By SHELDON AMOS, M. A., Professor of Jurisprudence in University College, London; author of "A Systematic View of the Science of Jurisprudence," "An English Code, its Difficulties and the Modes of overcoming them," etc., etc. 1 vol., 12mo. Cloth. Price, $1.75.