A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



"To the solid ground 

 Of A'ature trusts the mind which builds for aye. " — WORDSWORTH 



MACMILLAN & CO., Publishers, 22 Bond St., NEW YOBK. 



'OL. 21 

 No. 14 



THURSDAY. FEBRUARY 5, if 



Price 15 Cents 

 Annual Subscription $6 



D. APPLETON & CO.'S 



RECENT SCIENTIFIC PUBLICATIONS. 



1IM) IN THE LOWER ANIMALS, IN HEALTH 

 AND DISEASE. BtfW. Lauder Lindsay, M.D., F.R.S.E., 

 In two volumes. Svo, cloth, $4. 



I'lIK CHEMISTRY, |OF COMMON LIFE. By the late 

 Professor James F. W. Johnston. A New Edition, revised, enlarged, 

 and brought down to the Present Time, by Arthur Herbert Church, 

 M.A., Oxon., author of "Food: its Sources, Constituents, and Uses." 

 Illustrated with Maps and numerous Engravings on Wood. In one 

 volume, 121110, 593 pages, cloth, $2. 



THE PATHOLOGY OF HIND. BEING THE THIRD 



EDITION OF THE SECOND PART OF "THE PHYSIOLOGY 



lTHOLOG\ OF MIND,' RECAST, ENLARGED, AND 



REWRITTEN. By Henry Maudsley, M.D., author of " Body and 



Mind," ." Physiology of the Mind," etc. 1 vol., iamo, cloth, 580 



a, $2. 



BRA8MU8 DAK WIN. By Ernst Krause. Translated from 

 by W. S. Dallas. With a Preliminary Notice by Charles 

 i\rwin. With Portrait and Woodcuts. 1 vol., tamo, cloth, $1.25. 



rlllC EVOLUTION OF MAN. A POPULAR EXPOSITION 

 I PRINCIPAL POINTS OF HUMAN ONTOGENY 

 AND PHILOGENY. From the German of Ernst Haeckel, Pro- 

 fessor ID the U Diversity of Jena. With. numerous Illustrations. In 2 

 vols., i2mo, clotl\ $5. 



noliKHV CHROMATICS, with APPLICATIONS TO ART 

 IV With 130 Onginal Illustrations, and Frontispiece 

 in Color?. By Ogden N. Rood, Professor of Physics in Columbia Cil- 

 lege. tamo, cloth, $2. 



THE HUMAN SPECIES. By A. Dt Quatrefaces, Professor 

 of ADthropology in the Museum of Natural History, Paris. lamo, 

 cloth, $r. 



THE DATA;0F ETHICS. BEING THE FIRST PART OF I 

 THE "PRINCIPLES OF MORALITY." By Herbert Spencer. 

 121110, cloth, $r.5o. 



•OLAR LIGHT AND HEAT: THE SOURCE AND THE I 

 SUPPLY. Gravitation : with Explanations of Planetary and Molecular | 

 Forces. By Zach. Allen, LL.D. With Illustrations. 8vo, cloth, 

 ♦■SO- 



MANUAL |OF POWER, FOR MACHINES. SHAFTS, AND 

 BELTS. With a History of Cotton Manufacture in the United States. 

 By Samuel Webber, C.E. Svo, cloth, $3.50. 

 THE SPEAKING' TELEPHONE, ELECTRIC LIGHT, 

 AND GTHER RECENT ELECTRICAL INVENTIONS. By 

 George S. Prescott. New edition, with 200 additional pages, includ- 

 ing illustrated descriptions of all of Edison's inventions. 214 illustrations. 

 8vo, cloth, $4. 



A GLOSSARY OF HIOLOCilC A L, ANATOMICAL, 

 AND PHYSIOLOGICAL TERMS. By Th 

 vo, cloth, $1. 



THE MOON : HER MOTIONS, ASPECT, SCENERY, and PHYS- 

 CONDITIONS, with TWO LUNAR PHOTOGRAPHS 

 and many ILLUSTRATIONS. By Richard A. Proctor. New 

 edition. i2mo, cloth, $3.50. 



A TREATISE ON CHEMISTRY. ByH. E. Roscob, F.R.S., 

 andC. ScHORLEMMBR, F.R.S., Professors of Chemistry in Ow 

 Manchester, England. Vol. II. Part I.— METALS. With numerous 

 Illustrations. 1 vol., 8vo, cloth, $3. 



THE STUDY OF ROOKS. AN ELEMENTARY TEXT- 

 BOOK IN PETROLOGY. With Illustrations By Frank Rutley, 

 of the English Geological Survey. i6mo, cloth, $r.7S. 



COOLEVS CYCLOPAEDIA OF PRACTICAL RE- 

 CEIPTS, and COLLATERAL INFORMATION IN THE 

 ARTS, MANUFACTURES, PROFESSIONS, and Ik 

 eluding MEDICINE, PHARMACY, and DOMESTIC El 

 Sixth edition. Revised and partly rewritten by Richard V. Tusot 

 Professor of Chemistry and Toxicology in the Royal Vetetinary Colleg* 

 In 2 vols. Vol. I. 8vo. clolh, $4.50. 



THE FAIRY-LAND OF SCIENCE. By Arabella B 

 Buckley, author of "A Short History of Natural Science," etc. With 

 numerous illustrations. i2mo, clolh, $1.50. 



FREEDOM IN SCIENCE AND TEACHING. From the 

 German of Ernst Haeckel. With a Prefatory Note by T. H. Hux. 

 lev, F.R.S. nmo, cloth, Jr. 



OCEAN WONDERS. A COMPANION FOR THE SEASIDE. 

 By William E. Damon. With numerous illustrations, tamo, cloth, $1.50. 



D. APPLETON & CO., Publishers, 1, 3, and 5 Bond Street, New York. 



