This work is believed to be very opportune, since no elementary work on the subject has been issued for over a quarter of a century. It represents the modern aspects of the science. It is adapted to the use of advanced students, and will meet the needs of members of the National and State Weather Services who wish to acquaint themselves with something more than methods of observation. The essential theories of modern Meteorology are presented in such form that the student shall perceive their logical connection, and shall derive from their mastery something of the intellectual training that comes with the grasp of well-tested conclusions. The charts of temperature, pressure, winds, etc., are reduced from the latest available sources, while the diagrams freely introduced through the text are for the most part new. A.W. Greeley, retired Brigadier General U.S.A., and formerly Chief of Signal Office, Washington: "A valuable and timely contribution to scientific text-books." Winslow Upton, Professor of Astronomy, Brown University: "The best general book on the subject in our language." Wm. B. Clark, Professor of Geology, Johns Hopkins University: "An excellent book and of great value to the teacher of meteorology." David Todd, Professor of Astronomy, Amherst College: "Clear, concise, and direct. To teach meteorology with it must be a delight." MOLECULES AND THE MOLECULAR THEORY OF MATTER Department of Special Publioation. By A. D. RISTEEN. 8vo. Cloth. Illustrated. viii + 223 pages. Retail price, $2.00 This work is a complete popular exposition of the molecular theory of matter, as it is held by the leading physicists of today. Considerable space is devoted to the kinetic theory of gases. Liquids also are discussed, and solids receive much attention. There is also a division discussing the methods that have been proposed for finding the sizes of molecules, and here, as elsewhere throughout the book, the methods described are illustrated by numerical examples. The last division of the book touches upon the constitution of molecules. The subject is everywhere treated from a physical standpoint. END OF AN INTRODUCTION TO CHEMICAL SCIENCE INFORMATION ABOUT THIS ELECTRONIC EDITION The original edition of this text was published by Ginn and Company, Publishers, Boston, U.S.A. in 1896. The typography was by J.S. Cushing and Co., Boston and the Presswork was by Ginn and Co., Boston. The book was "Entered according to Act of Congress, in the year 1887, by R.P. Williams, in the Office of the Librarian of Congress, at Washington." This electronic text was prepared by John Mamoun with help from numerous other proofreaders, including those associated with Charles Franks' Distributed Proofreaders website. Thanks to R. Zimmerman, D. Starner, B. Schak, K. Rieff, D. Kokales, N. Harris, K. Peterson, E. Beach, W.M. Maull, M. Beauchamp J. Roberts and others for proofing this e-text.