Tfw International SdentiJUi Series. — (Continued.) 



i9. ANIMAL PARASITES AND MESSMATES. By Professor P. J. Van Ben- 

 EDEN, University of Louvain. With 83 Illustrations. %\ .50. 



20. FEKMENTATION. By Professor P. SohOtzenbebgeb. "With 38 Ulustra- 

 tions. $1.50. 

 ' 81. THE FIVE SENSES OF MAN. By Professor Julius Beenstein, Univer- 

 sity of Halle. With 91 Illustrations. $1.75. 



82. THE THEOEY OF SOUND IN ITS EELATION TO MUSIC. By Pro- 

 fessor PiETRo Blaserna, Royal University of Eome. With numerous 

 Illustrations. $1.50. 



23 STUDIES IN SPECTRUM ANALYSIS. By J. Nobman Locktek, F. E. S. 

 With 7 Photographic Illustrations of Spectra, and 52 other Elastrations. 

 $2.50. 



24. A HISTOEY OF THE GROWTH OF THE STEAM-ENGINE. By Pro- 

 fessor K. H. Thueston, Cornell University. With 163 Illustrations. $2.60. 

 28. EDUCATION AS A SCIENCE. By Alexandee Bain, LL. D. $1.75. 



20. STUDENTS' TEXT-BOOK OF COLOR ; or. Modem Chromatics. With 

 Applications to Art and Industry. By Professor Oqden N. Eoob, Colum- 

 bia College. With 130 Illustrations. $2.00. 



27. THE HUMAN SPECIES. By Professor A.» de Quatkefages, Museum of 



Natural History, Paris. $2.00. 



28. THE CRAYFISH : An Introduction to the Study of Zoology. By T. H. 



Huxley, F. R. S. With 82 Illustrations. $1.75. 



29. THE ATOMIC THEOEY. By Professor A. Wurtz. Translated by E. 



Cleminshaw, F. C. S. With Illustrative Chart. $1.60. 



30. ANIMAL LIFE AS AFFECTED BY THE NATURAL CONDITIONS OF 



EXISTENCE. By Professor Karl Sempee, University of Wflrzbnrg. 

 With 106 Illustrations and 2 Maps. $2.00. 

 81. SIGHT : An Exposition of the Principles of Monocular and Binocular Vision. 

 By Professor Joseph Le Contb, LL. D., University of California. With 

 133 Illustrations. $1.50. 



■52. GENERAL PHYSIOLOGY OF MUSCLES AND NERVES. By Professor 



I. Rosenthal, University of Brlangen. With 75 Illustrations. $1.50. 

 33. ILLUSIONS : A Psychological Study. By James Sully. $1.50. 



34 THE SUN. By Professor C. A. YogNs, College of New Jersey. With 83 

 Illustrations. $2.00. 



36. VOLCANOES ; What they Are and What they Teach. By Professor John 



W. JuDD, F. E S., Eoynl School of Mines. With 96 Illustrations. $2.00. 

 86. SUICIDE: An Essay in Comparative Moral Statistics. By Prof essor Heney 

 ■MoBSEiLi, M. D., Eoyal University, Turin. With 4 Statistical Maps. 

 $1.75. 



37. THE FOEMATION OF VEGETABLE MOULD, THROUGH THE AC- 



TION OF WORMS. With Observations on their Habits. By Charles 

 Dartvin, LL. D., F. E. S. With 16 Illustrations. $1.60. 



