INDEX 



nineteenth century, 44-87 ; dis- 

 covery of Ceres, by Piazzi, 44 ; of 

 Pallas and Vesta, by Gibers, 44, 

 47; and of Juno, by Harding, "47 ; 

 Hencke's discovery of a fifth as- 

 teroid is followed by a thorough 

 investigation of the asteroidal sys- 

 tem, 47 ; how the asteroids are 

 accounted for, 47, 48 ; discovery of 

 Neptune, predicated by Bessel and 

 Leverrier, is accomplished by Dr. 

 Galle, 48, 49 ; Leverrier's predica- 

 tion of a trans-Neptunian planet, 

 49 ; discovery of the moons of 

 Mars by Professor Hall, 49 ; dis- 

 covery of Saturn's crape ring, 49, 

 50 ; Saturn's rings discussed and 

 their nature determined, 50 ; theo- 

 ries regarding the acceleration of 

 the moon, and how it is accounted 

 for, 50-53 ; speculations regarding 

 comets and the discovery of their 

 nature and constituents, 53-60 ; the 

 study of double stars by William 

 and John Herschel and others, 

 63-65 ; star distance determined, 

 65-69 ; and star motion, mass, and 

 brightness reckoned, 69, 70 ; solar 

 and sidereal investigations by 

 means of the spectroscope, 70-76 ; 

 discovery of " invisible " or dark 

 stars, 74-76 ; triumphs of celestial 

 photography, 76-83, 285, 286; 

 Lockyer's " meteoric hypothesis," 

 83-86 ; speculations as to the po- 

 tentialities of the stellar universe, 

 86, 87 ; some unsolved solar and 

 telluric problems, 435-442. 



Atomic theory, discovery and devel- 

 opment of, 252-262. 



Atoms, Boscovich's speculations re- 

 garding, 241 ; their combining 

 weights determined and the method 

 of expressing them invented, 254, 

 255, 259, 260 ; law of the specific 

 heat of, 260-262 ; establishment of 

 the law of valency, 269-275 ; their 

 character and properties investi- 

 gated, 275-278 ; Prout's theory of 

 the atomic weights and compound 

 nature of the elements, 278-280, 

 283-287; some unsolved problems 

 regarding, 447-449. 



Auenbrugger von Auenbrog, his in- 

 vention of the percussion method 

 for studying disease, 355. 



Aurora, the, speculations regarding 

 cause of, 162-167. 



Auscultation, its discovery and de- 

 velopment as an aid to diagnosis, 

 356, 359. 



Avogadro, Amadeo, his hypothesis as 

 to the numbers of ultimate par- 

 ticles in volumes of gases, and his 

 invention of the term " molecule " 

 as the unit of physical structure, 

 258, 269. 



BACTERIA, investigations relating to, 

 379-386. 



Baer, Karl Ernst von, his anatomi- 

 cal researches, 337. 



Bary, Heinrich Anton de, his dis- 

 covery of the identity of the ani- 

 mal and vegetable cell, 340. 



Bastian, Henry Charlton, revives 

 Pouchet's theory of " spontaneous 

 generation," 320. 



Beaumont, Elie de, his contention as 

 to the origin of mountains, 130, 145. 



Behring, Dr., his discoveries in serum- 

 therapy, 392. 



Bell, Sir Charles, his epochal psy- 

 chological discovery, 401, 402. 



Bernard, Claude, his study of the 

 pancreas, 347 ; his discovery of the 

 glycogenic function of the liver, 

 351, 352; his discoveries relating 

 to the nervous system, 405, 406. 



Bernoulli, Daniel, originator of the 

 kinetic theory of gases, 242, 243. 



Berthollet, Claude Louis, aids in 

 the development of a new chemistry, 

 32 ; his theory of chemical com- 

 bination, 255. 



Berzelius, Johan Jacob, confirms 

 and advocates Dalton's atomic the- 

 ory, 256, 259 ; his extension of the 

 binary theory and establishment of 

 theoretical chemistry, 264, 265, 267, 

 268. 



Bessel, Friedrich Wilhelm, predicts 

 the existence of a trans-Uranian 

 planet, 48 ; his successful measure- 

 ment of the parallax of a star, 66 ; 

 his discovery of " invisible" stars, 74. 



