Produced by David Garcia, Simon Gardner and the Online Distributed Proofreading Team at https://www.pgdp.net Transcriber's Note: Minor inconsistencies in spelling, punctuation and formatting are retained as in the original. Where detailed corrections have been made on the text these are listed at the end of this document. Disclaimer: This is a work of historical interest only and much of the scientific content has been superseded. There are numerous experiments described in this book which are hazardous and should not be attempted. Advice given on handling toxic substances, electrical apparatus etc. should not be followed. Do not try this at home! * * * * * COMMON SCIENCE NEW-WORLD SCIENCE SERIES _Edited by John W. Ritchie_ * * * * * SCIENCE FOR BEGINNERS By _Delos Fall_ TREES, STARS, AND BIRDS By _Edwin Lincoln Moseley_ COMMON SCIENCE By _Carleton W. Washburne_ HUMAN PHYSIOLOGY By _John W. Ritchie_ SANITATION AND PHYSIOLOGY By _John W. Ritchie_ LABORATORY MANUAL FOR USE WITH "HUMAN PHYSIOLOGY" By _Carl Hartman_ * * * * * EXERCISE AND REVIEW BOOK IN BIOLOGY By _J. G. Blaisdell_ PERSONAL HYGIENE AND HOME NURSING By _Louisa C. Lippitt_ SCIENCE OF PLANT LIFE By _Edgar Nelson Transeau_ * * * * * ZOOeLOGY By _T. D. A. Cockerell_ EXPERIMENTAL ORGANIC CHEMISTRY By _Augustus P. West_ * * * * * _NEW-WORLD SCIENCE SERIES_ _Edited by John W. Ritchie_ COMMON SCIENCE _by_ _Carleton W. Washburne_ _Superintendent of Schools, Winnetka, Illinois_ _Formerly Supervisor in Physical Sciences and Instructor in Educational Psychology_ _State Normal School_ _San Francisco, California_ _ILLUSTRATED_ WITH PHOTOGRAPHS AND DRAWINGS _Yonkers-on-Hudson, New York_ WORLD BOOK COMPANY 1921 WORLD BOOK COMPANY THE HOUSE OF APPLIED KNOWLEDGE Established, 1905, by Caspar W. Hodgson YONKERS-ON-HUDSON, NEW YORK 2126 PRAIRIE AVENUE, CHICAGO