INDEX 



Latour, Cagniard, discoverer of pep- 

 sin, 347 ; his microscopical re- 

 searches, 376. 



Laurent, Augustus, his work in or- 

 ganic chemistry, 266, 268. 



of the compound microscope, 327, 

 328 ; his discovery of the true form 

 of red blood corpuscles, 329 ; liis 

 discovery and development of anti- 

 sepsis in surgery, 382-386. 



Lavoisier, Antoine Laurent, his chem- ! Lockyer, J. Norman, his "meteoric 



ical experiments and discoveries, 

 26, 31-33; his tragic fate and the 

 triumph of his doctrines, 33-35 ; 

 his experiments on respiration, 40. 



" Law of octaves," the, its discovery 

 and development, 280, 283. 



Leeuwenhoek, Antonius von, his mi- 

 croscopical researches, 329, 376. 



Leidy, Joseph, his discoveries of the 



hypothesis," 83-86 ; his endorse- 

 ment of the theory that our so- 

 called elements have a compound 

 nature, 286, 287 ; his theory of 

 solar heat, 439. 



Lodge, J. Oliver, his theory of two 

 ethers, 235. 



Logan, William I., his geological in- 

 vestigations in Canada, 139. 



Tertiary period in the Rocky Moun- Long, Crawford W., his investiga- 

 tain region and the truth they teach, tions of the anaesthetic properties of 

 114-121; his investigation of the! ether, 373. 374. 

 Trichina spiralis, 363. j Lotze, Rudolf Hermann, his advocacy 



Lenz, Professor, first proposer of j of psycho-physiology, 409. 



gravitation as the cause of oceanic Louis, Pierre Charles Alexandre, his 



circulation, 180. 

 Le Sage's hypothesis of the cause of 



gravitation, 443-445. 

 Leuckart, Karl Georg Friedrich Ru- 



dolf, 



his investigations of 

 stpiralis, 363, 364. 



the 



Leverrier, Urbain Jean Joseph, his 

 calculations lead to the discovery 

 of Neptune, 48, 49 ; his further cal- 

 culations as to the location of a 

 hypothetical planet known as Vul- 

 can, 49. 



Liebig, Justus von, foremost among 

 the workers in organic chemistry, 

 266, 268, 274 ; his important chem- 

 ical researches, 346, 347 ; discovers 

 the source of animal heat, 349 ; 

 opposes Pasteur's doctrine of fer- 

 mentation, 376, 379. 



Life, some unsolved problems of cos- 

 mic and telluric, 449-453. 



Light, how regarded in the eighteenth 

 century, 24 ; establishment of the 

 undulatory theory of, 192-204, 223; 

 Helmholtz's electro-magnetic the- 

 ory of, 227, 228. 



Liquefaction of air, of carbonic-acid 

 gas, hydrogen, and of other perma- 



nent gases, 249 ; the question as to 

 the liquefaction of air in our outer 

 atmosphere, 250. 

 Lister, Sir Joseph, his improvement 



468 



introduction of the " statistical 

 method " into the practice of med- 

 icine, 360. 



Lubbock, Sir John William, advocates 

 the Darwinian theory of natural 

 selection, 313. 



Lyell. Charles, the apostle of uniform- 

 "itarianism, 99-102, 125, 126, 130; 

 convinced by Darwin, endorses the 

 transmutation theory, 107, 108, 

 313 ; his advocacy of the glacial 

 theory, 131, 132; his citation of a 

 fact from Playfair which is undis- 

 puted, 153; his aid sought by 

 Darwin in the publication of his 

 Origin, of Species, 307, 309. 



MAGKNDIE, FRANCOIS, his services in 

 the rational practice of medicine, 

 359, 360; his studies of the ner- 

 vous system, 400, 402. 



Magnetism, its relations to electricity 

 discovered, and the science of mag- 

 neto-electricity founded, 207-209. 



Magneto-electricity, Faraday estab- 

 lishes and develops the science of. 

 208, 209. 



Malthas, Thomas Robert, how his 



Population aided Darwin 

 in formulating his theory of the 

 origin of species by natural selec- 

 tion, 305, 306. 



