KEY AND INDEX 



is one universal principle of development for the 

 elementary parts of organisms, however differ- 

 ent, and this principle is the formation of cells." 



Von Guericke, Otto, ii, 211. Born at Magde- 

 burg, Prussia, Nov. 20, 1602; died at Hamburg, 

 May n, 1686. Celebrated German natural phi- 

 losopher. He invented the air-pump in 1650. He 

 constructed the "Magdeburg hemispheres" two 

 hollow hemispheres which, when placed together 

 and exhausted could not be pulled apart by teams 

 of horses. 



Von Kleist, Dean, ii, 280. A physicist of Ca- 

 min, Pomerania, who in 1745 invented the Ley- 

 den jar. This discovery is sometimes credited 

 to Musschenbroek, then one of the foremost 

 teachers of Europe; but there is no doubt that 

 von Kleist's discovery antedated Musschen- 

 broek's by a few months. 



Von Mohl, Dr. Hugo, iv, 123. Born at Stutt- 

 gart, Wiirtemberg, April 8, 1805; died Tubingen, 

 April i, 1872. German botanist. Noted for his 

 studies on the cell contents, and for his invention 

 of the word protoplasm, to designate the "phys- 

 ical basis of life." 



Wallace, Alfred Russel, iv, 172. Born at Usk, 

 Monmouthshire, England, Jan. 8, 122; English 

 naturalist. On July I, 1858, simultaneously with 

 Darwin, he announced the theory of natural se- 

 lection, although Darwin's theory had been an- 

 nounced privately a year before. 



Watson, William, ii, 284. An English physi- 

 cist. He coined the word "circuit" as used in 

 electricity. In 1747, in an experiment of conduct- 

 ing a current of electricity across London Bridge, 

 using the water of the Thames to complete the 



