22 SEPTEMBER 1900, Page 26

Eiententary Studies in Chemistry. By Joseph Torrey, jun. (A. Constable

and Co. Gs. net.)—Mr. Torrey is an instructor in Harvard University. It is specially interesting, therefore, to see what demands lie makes on behalf of the subject which he pro- fesses. The time he demands for chemistry is "at least five, and preferably six, hours per week." He also requires that the student should already have a knowledge of "elementary physics, geometry, and algebra."—We have received Part II. of A Treatise on Zoology, edited by E. Ray Lankester (A. and C. Black, 15s. net), containing "Great Divisions of the Metazoa," by the editor; " Porifera," by E. A. Minchin, M.A.; " Hydromeduste and Scyphomedusse," by G. H. Fowler, BA.; and "Anthozoa and Ctenophora," by G. C. Bourne, M.A.