tings that much of the life work of Archimedes 

 is known. Many of the mechanisms invented 

 by him are also described. 



Pouchet, M. F. A., iv, 180. A French scientist 

 who advocated the theory that organic beings 

 are generated about us constantly in the familiar 

 processes of putrefaction which are known to be 

 due to the agency of microscopic bacteria. In 

 1862 Louis Pasteur proved that this seeming 

 spontaneous generation is in reality due to the 

 existence of germs in the air. 



Prestwich, Sir Joseph, iii, 101. Born at Clap- 

 ham, London, March 12, 1812; died at Shore- 

 ham, Kent, June 23, 1895. Noted English geol- 

 ogist. With Mr. (afterward Sir John) Evans he 

 made important excavations and investigations 

 of fossil remains and prehistoric implements 

 found at Abbeville and other places in 1859. 

 His discoveries helped to establish the correct- 

 ness of the theory of evolution. 



Priestley, Joseph, iv, 20. Born near Leeds, 

 Yorkshire, March 13, 1733; died at Northumber- 

 berland, Pa., Feb. 6, 1804. Celebrated English 

 clergyman and natural philosopher. Noted for 

 his general experiments with gases, and in par- 

 ticular for his discovery of oxygen. He wrote 

 a "History of Electricity" at the suggestion of 

 Benjamin Franklin. 



Proust, Louis Joseph, iv, 41. Born at Angers, 

 J 755; died in 1826. French chemist. His work 

 led to the establishment of the principle that 

 chemical compounds are of fixed proportions, 

 however prepared. 



Ptolemy (Claudius Ptolemaeus), i, 267. Born 

 at Alexandria; died first half of Second Cen- 



