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Mallory and Wright's Pathologic Technic Cloth, $2.25 net SEVENTH This work gives the technic of bacteriologic methods, bacteriology of various diseases, histologic Octavo of 555 pages, with 180 illustrations. By FRANK BURR MALLORY, M.D., Pathologist to the Boston City SIGN AND MAIL THIS ORDER FORM TODAY W. B. SAUNDERS COMPANY, West Washington Square, Phila. Books That Have a Real Message for You Epidemiology and Public Health By Victor C. Vaughan, M.D., LL.D., Chairman of the Division on Medical Sciences of the National Research Council. Assisted by Henry F. Vaughan, M.S., Dr. P. H., and George T. Palmer, M.S., Dr. P. H. In 3 vols. Vol. I ready, 700 pages, illustrated. Price, per volume. . . . ..$9.00 A text and reference book for physicians, students of hygiene and sanitation, and others. One of the most important contributions to the science of epidemiology, public health, and state medicine made in a decade. A study of the prevalence of respiratory affections among school children and their association with school ventilation and the seasonal changes in weather. This study was conducted jointly Mysticism, Freudianism, and Scientific Psychology By Knight Dunlap, Professor of Experimental Psychology in Johns Hopkins University. 150 pages. Price, cloth....$1.50 Analyzes the current Freudian movement in detail, and states in the light of analysis the fundamental principles of presentday psychology. Written in popular style. Psychopathology By Edward J. Kempf, M.D., Formerly Clinical Psychiatrist to St. Elizabeths Hospital, Washington. 762 pages, 97 illustrations. Price, cloth..... $9.50 One of the most important contributions ever made to the study of human behavior. An epoch-making book, and one that is being discussed by scientific men. Presented to physicians, psychologists, sociologists, psychopathologists, teachers, lawyers, judges, custodians and directors of educational, military and custodial institutions to assist them to a clearer understanding of the abnormal or potentially abnormal individual. by Bureau of Child Hygiene of N. Y. City Dept. of Health and Hygiene the New York State Comm. on Ventilation. Sex and Sex Worship By O. A. Wall, M.D., Ph.G., Ph.M., 625 pages, with 375 illustrations. Price, cloth...... ..$8.50 A scientific treatise on sex, its nature and function, and its influence on art, science, architecture, literature, and religion, with special reference to sex worship and symbolism. The Sexual Life By C. W. Malchow, M.D., 318 pages. Price, cloth.....$3.00 Recommended by the American Association of Social Hygiene in its reading course. Designed for advanced students and the professions; embracing the natural sexual impulse, normal sexual habits and propagation, together with sexual physiology and hygiene. By Clair E. Turner, Asst. Prof. of Biology and Public Health, Mass. Institute of Technology; Chapters by Dean Rice, Tufts Dental College; Introduction by Wm. T. Sedgwick, Sc.D., Prof. of Biology and Public Health, Mass. Institute of Technology. 400 pages, 52 illustrations. Price, cloth.......$4.00 Turner has written a book on hygiene along entirely new lines and it is different from anything heretofore published. Physiological Chemistry By Sidney W. Cole, M.A., Trinity College, Cambridge, England. Introduction by Prof. F. G. Hopkins, M.B., D.Sc., F.R.C.P., Professor of Biochemistry, Trinity College, Cambridge. 350 pages, 5 x 81⁄2, illustrated. 5th edition, enlarged. Price, cloth. ..$4.50 New fifth edition, completely revised. The book is practical -the text was worked out step by step at the laboratory bench at Cambridge University, England. Modern methods of biochemistry are given. ▷ You should order copies of these important books today through your bookseller or direct from the publishers. Also request a copy of our complete catalogue of medical, dental, scientific, pharmaceutical, and nursing publications. Mention “Science” when writing or ordering. New York City: Grand Central Terminal Entered in the post-office at Lancaster, Pa., as second-class matter, under the act of March 3, 1879 TEACHERS WANTED An Associate Professor in Physics, $2600; Associate Professor of Biology, $2400; Professor of Zoology and Geology, $2500; teacher of General Science in High School, $2000; Assistant in Zoology, $1800. The Interstate Teachers Agency, New Orleans, La. Marine Biological Laboratory WOODS HOLE, MASS. Biological Material 1. Zoology. 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