An interesting and valuable work, in which the science of teaching is treated in a philosophical and practical manner, and a sketch is given of a school to be established on the principles developed in his pages. Mr. Sands takes the view that education, mental and physical, is but the absorption of surrounding elements into the mind and body-an arrangement and assimilation of materials so as to incorporate them into the being to whose nourishment they are applied, just as the tree or plant assimilates to its growth and subsistence the materials which it draws from the air and the soil; and his theory of teaching is based on these truths.-N. Y. Times We commend it to the thoughtful consideration of all, but especially of our public men. * * * Commissioners of Schools and others charged with youthful training may advantageously consider the reflections.-N. Y. Evening Post