GENERAL INDEX 



Wyoming, the largest schooner 

 ever constructed, 7, 61. 



XENOPHANES, founder of the 

 famous Eleatic School, 1, 114, 

 127; his theories concerning 

 the creation, 1, 128; the ear- 

 liest paleontologist, 1, 120. 



Xiphilinus, his account of the 

 battle between the Romans 

 and the hostile Quadi, 1, 297. 



X-ray, discovered in 1895, 6, 97. 



Yankee, experimental attacks 

 upon, by submarines, 7, 116. 



Yersin, famous for his re- 

 searches in the prevention and 

 cure of cholera, 6, 184. 



Young, Dr. Thomas, and the 

 wave theory of light, 3, 215- 

 225; his extraordinary pre- 

 cocity, 3, 216; his "theory 

 of light and colors," 3, 217; 

 his experiments with , mi- 

 crometers, 3, 222; his doc- 

 trine of the interference of un- 

 dulations, 3, 223; his wave 

 theory endorsed by Fresnel 

 and Arago, 3, 226; deter- 

 mined opposition to his wave 

 theory by French scientists, 

 ibid.; final acceptance of his 



wave theory by the French 

 academy, 3, 227; his theories 

 about ether, 3, 285; decipher- 

 ment of the Rosetta Stone, 4, 

 290; professor of natural 

 history in Royal Institution, 

 6,35; wave theory of light, 6. 

 36; his interpretation of 

 Franklin's theory of electric- 

 ity, 6, 150. 



ZENKER, his theory on color- 

 photography, 8, 236. 



Zenon, discovery of, 6, 87. 



Zeppelin, Count, the dirigible 

 balloons of, 7, 265. 



Zero, absolute, approach to the, 

 5, 69; probable form of all 

 matter at, 5, 70. 



Zoological classification, Profes- 

 sor Haeckel's work in sys- 

 tematizing, 6, i 68. 



Zoology at the close of the 

 eighteenth century, 4, 99. 



Zoology, Ernst Haeckel and the 

 New, Chapter VI, 5, 144. 



Zoology, the new, Ernst Haeckel 

 and, 5, 144; import of the 

 study of, 6, 1 66; fundamental 

 conception of , 6, 167; Haeckel 

 the recognized leader in, 6, 

 171. 



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