BIOGRAPHICAL INDEX 



English clergyman and inventor. About 1589 

 he invented a knitting machine which would 

 knit at a rate more than ten times faster than 

 could be done by hand. The English hand- 

 knitters opposed the use of this invention, and 

 it was not until after the death of the inventor 

 that his machine was put to practical use. 



Leeuwenhoek, Anthony van, ii, 179. Born at 

 Delft, Netherlands, Oct. 24, 1632; died at Delft, 

 Aug. 26, 1723. Dutch microscopist and natural- 

 ist. Discovered microbes in the secretions of the 

 mouth in 1683. He also discovered red blood- 

 corpuscles, spermatozoa, and the capillary cir- 

 culation of the blood. 



Leibnitz, Gottfried Wilhelm von, ii, 197. Born 

 at Leipsic, July 6, 1646; died at Hanover, Nov. 

 14, 1716. German philosopher and mathemati- 

 cian. Called, with reason, "a universal genius." 

 He was the inventor of the differential and in- 

 tegral calculus. He conceived the theory that 

 the entire universe is composed of individual 

 centers, or monads, and deduced the doctrine 

 of pre-established harmony. His influence on 

 the scientific thought of his time was very 

 marked. 



Leidy, Joseph, iv, 207. Born at Philadelphia, 

 Sept. 9, 1823; died April 30, 1891. American 

 naturalist. In 1827 he discovered the cyst of 

 "Trichina spiralis" in pork. He made impor- 

 tant discoveries and wrote extensively on the 

 subject of extinct vertebrate fauna. 



Leonardo, Vinci, da, i, 129; ii, 47. Born at 

 Vinci, Italy, 1452; died near Ambrosie, France, 

 May 2, 1519. Famous Italian artist, architect, 

 musician, and scientist. Perhaps the most uni- 



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