INDEX 



Wassermann, Professor A. von, 



his tentative cancer cure, 167, 



231. 

 Water, its purification with the 



ultraviolet ray, 242. 

 Weighing the worlds, -Chapter III, 



60. 

 Wellman, Mr., makes attempt to 



fly across the ocean in his dirig- 

 ible balloon, 291. 

 Wireless telegraph, 305. 

 Wireless telephone, developed by 



De Forest, 310. 

 Wireless transmission of pictures, 



317. 

 Wonders of the modern world, 



seven chief, 323. 



Wood, Prof. T. B., his experi- 

 ments in Mendelian heredity 



with sheep, 197. 

 Warden, the U. S. S., stabilized 



by the Sperry gyroscope, 269. 

 Working wonders with a top, 



'Chapter IX, 255. 

 World, has it turned upside down ? 



12. 

 Worlds, weighing the, Chapter II, 



00. 

 Wright, Sir Almroth, his estimate 



of vaccine therapy, 208; his 



discovery of opsonins and the 

 opsonic index, 215; extends 

 the vaccine method to many 

 diseases, 216; his clinics at St. 

 Mary's hospital, 220. 



Wright, Wilbur and Orville, in- 

 ventors of the aeroplane; first 

 to make a successful flight, 297; 

 the devices that made their suc- 

 cess possible, 298 ; all subsequent 

 aeroplanes built on principles 

 developed by them, 299. 



X-ray, liberates ions in a gas, 127. 



Yellow fever, transmitted by mos- 

 quito of the genus stegomyia, 

 249. 



Young, Charles A., his formula 

 for weighing a planet, 82. 



Zeeman effect, what it is, 104; 

 shows that light is an electric 

 phenomenon, 105. 



Zeeman, Professor Peter, his dis- 

 covery of the Zeeman effect, 105. 



Zeppelin, Count von, his first 

 dirigible balloon, 288; later 

 types, 289; his passenger air- 

 ships, 293. 



Zsigmondy, developer of ultra- 

 microscope, 232. 





