Discovery that the disease pellagra was due to faulty diet made by Joseph Goldberger, _German Jew_ ... typhus and typhoid fever distinguished by Alfred Stillé, _Swede_ ... human blood classified in different types by Karl Landsteiner, _Austrian Jew_ ... research work in combatting syphilis and yellow fever by Hideyo Noguchi, _Japanese_. Expert on infantile paralysis and meningitis is Simon Flexner, _German Jew_ ... first removal of human ovary by Ephraim MacDowell, _Scot_ ... one of the famous authorities on plastic surgery is V. Kazanjian, _Armenian_ ... world authority on venereal disease is Vecki Victor, _Yugoslav_ ... Edward Trudeau, _French_, began sanatorium treatment for tuberculosis ... Clifford Beers, _English-Netherlander_, founder of mental hygiene movement. Discovery that mosquitoes carried yellow fever made by Walter Reed, _English_ ... malaria driven out of Panama by General William C. Gorgas, _Scotch-Irish-Netherlander_ ... first hospital in colonies founded by Dr. Thomas Bond, _Welsh_. _Physics_ [Illustration] Our great electrical wizards have been: Joseph Henry, _Scotch-Irish_, who helped to invent the telegraph ... Charles Steinmetz, _German-Polish_, mathematical genius and electrical scientist, who had one of the world’s most inventive minds ... Thomas Edison, _Scot-Netherlander_, who invented electric light bulb and phonograph ... Michael Pupin, _Yugoslav_, who perfected tuning-in mechanism of radio.... Nicola Tesla, _Yugoslav_, who made extensive use of electrical power possible ... Vladimir Karapetoff, _Armenian_, inventor of electrical devices. Most distinguished physicist on light rays is Albert A. Michelson, _German Jew_ ... on x-rays, Arthur H. Compton, _English_ ... on cosmic rays, Robert Millikan, _Scotch-Irish_ ... outstanding investigator of Röentgen ray is Mihran Kassabian, _Armenian_ ... through work on electrotechnics, expansion of telephonic and telegraphic communication made possible by E. F. W. Alexanderson, _Swede_ ... John Kruesi, _Swiss_, helped Edison develop electric incandescent lamp, dynamo, and phonograph. _Astronomy_ [Illustration] First observatory put up by Ephraim Williams, _Welsh_ ... many of our early-day almanacs based on astronomical studies and computations of David Rittenhouse, _German-Welsh_ ... Lick Observatory, California, and Yerkes Observatory, Wisconsin, founded by James Lick and Charles Yerkes, _Germans_ ... for pictures of many of the stars, Dorothy Klumpke, _German_, achieved much fame ... famous mathematician and everyday almanac maker was Benjamin Banneker, _Negro_, who also helped L’Enfant, _French_, to lay out Washington, D. C. _Chemistry_