The Intematkmdt Scientijic ISeries. — (Continued.) 



19. ANIMAL PARASITES AND MESSMATES. By ProfesBor P. J. Van Ben- 

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80. FERMENTATION. By Professor P. SohCtzenbekgbb. With 28 Illustra- 



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21. THE FIVE SENSES OF MAN. By Professor Julius Bernstein, Univer- 

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82. THE THEORY OP SOUND IN ITS RELATION TO MUSIC. By Pro- 

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



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



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 26. EDUCATION AS A SCIENCE. By Alexander Bain, LL. D. $1.75. 



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



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



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



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

 89. THE ATOMIC THEORY. By Professor A. Wurtz. Translated by E. 



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EXISTENCE. By Professor Karl Semper, University of Wiirzburg. 



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



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



132 Dlustrations. $1.60. 

 as. GENERAL PHYSIOLOGY OF MITSCLES AND NERVES. By Professor 



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



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36. SUICIDE : An Essay in Comparative Moral Statistics. By Professor Henry 



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 87. THE FORMATION OF VEGETABLE MOULD, THROUGH THE AC- 

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