KEY AND INDEX 



220; his attention directed 

 to the subject of photography, 

 8, 223; inventor of the 

 daguerreotype process, 8, 

 224. 



Daguerreotype perfected by 

 Louis Daguerre in 1839, 4, 

 70; 8, 224. 



Daimler, German inventor, who 

 applied a high-speed oil en- 

 gine to the automobile in 

 1884, 6, 140; used the gasoline 

 motor for the practical pro- 

 pulsion of a tricycle, 7, 157. 



D'Alembert, Jean le Roud, 

 determined the ratio of the 

 attractive forces of the sun 

 and moon, and the mutation 

 of the axis of the earth, 8,15. 



Dalton, Chemistry Since the 

 Time of, Chapter III, 4, 38. 



Dalton, John, and the atomic 

 theory, 4, 38-46; first con- 

 ception of the chemical atom, 

 4, 39; his theory disputed, 4, 

 41; his theory adopted, 4, 

 44 ; predicted the liquefaction 

 of gases, 5, 40. 



Daniell, John Frederick, pro- 

 duced the cell which bears his 

 name, 3, 236. 



Dark Age, Science in the, Chap- 

 ter I, 2, 3. 



Darwin, Charles Robert, his 

 Origin of Species, 3, 95; his 

 work a revelation to the 

 geological world, 3, 96; his 

 work on doctrine of evolu- 

 tion, 4, 167; his most avail- 

 able field, 4, 1 68; years spent 

 in gathering facts, 4, 171; 

 joint paper of, and Wallace, 



resented to the Linnaean 

 ociety of London, 4, 173; 

 makes converts of Hooker, 

 Lyell, and Huxley, 4, 174; en- 

 tombed in Westminster Abbey, 

 4. 178; statue of, in Museum 

 of Natural History, 6, 9; 

 computations as to the earth's 

 ultimate fate, 5, 212. 

 Darwin, Dr. Erasmus, his theory 

 concerning the aurora bore- 

 alis, 3, 173; concerning the 



vapor of water, 3, 177; and 

 vegetable respiration, 4, 94- 

 99; his Botanic Garden, 4, 

 147; his Zob'nomia and Temple 

 of Nature, 4, 148; his ex- 

 pression of the idea of organic 

 evolution, ibid.; at his death 

 his idea of transmutation of 

 species still an unsubstan- 

 tiated dream, 4, 149. 



Darwinian theory, its develop- 

 ment, 4, 1 66; greatest scien- 

 tific conception of the nine- 

 teenth century, 6, 241. 



Davenport, Thomas, has the 

 distinction of building the 

 pioneer electric road, 7, 178. 



Davenports, English potters 

 who early produced wares of 

 superior quality, 9, 232. 



Da Vinci, Leonardo, his theories 

 concerning the creation sim- 

 ilar to those expressed by 

 Xenophanes two thousand 

 years before, 1, 129; sketches 

 of flying-machines by, 7, 227. 



Davy, Sir Humphry, produced 

 the first electric lamp, 3, 234; 

 his own account of his experi- 

 ments, 6, 220; showed that 

 labor may be transformed into 

 heat, 3, 255; his experiment 

 of melting ice by friction, 3, 

 277; heat a manifestation of 

 motion among particles of 

 matter, 3, 294; and electro- 

 chemistry, 4, 46-53 ; brilliant 

 researches with his voltaic 

 battery, 4, 47; his famous 

 Bakerian lecture 4, 48; his 

 theory of binary composition 

 of chemical compounds, 4,53; 

 experiments in the mysteries 

 of respiration, 4, 93; experi- 

 ments with nitrous oxide, 4, 

 209-212; professor of chem- 

 istry in Royal Institute, 6, 34; 

 his science of electro-chem- 

 istry, 6, 36; experiments with 

 low temperatures, 6, 40; his 

 suggestion results in produc- 

 tion of liquid chlorine, 6, 41; 

 experiments upon gases, 6, 

 42; challenged the theory of 



