Discovery 



SCIENTIFIC SIDE-LIGHTS 



174 



at the time upon a residue, obtained by 

 evaporating one of the mineral waters of 

 Germany. In that water they knew the un- 

 known metal was concealed, but vast quanti- 

 ties of it had to be evaporated before a resi- 

 due could be obtained sufficiently large to 

 enable ordinary chemistry to grapple with 

 the metal. They, however, hunted it down, 

 and it now stands among chemical sub- 

 stances as the metal rubidium. They subse- 

 quently discovered a second metal which they 

 called caesium. Thus, having first placed 

 spectrum analysis on a sure foundation, 

 they demonstrated its capacity as an agent 

 of discovery. Soon afterwards Mr. Crookes, 

 pursuing the same method, discovered the 

 bright green band of thallium, and obtained 

 the salts of the metal which yielded it. The 

 metal itself was first isolated in ingots by 

 M. Lamy, a French chemist. TYNDALL Lec- 

 tures on Light, lect. 6, p. 195. (A., 1898.) 



848. DISCOVERY CONFIRMS CON- 

 JECTURE The Antarctic Continent. The 

 cold of the antarctic regions was conjectured 

 by Cook to be due to the existence of a large 

 tract of land between the seventieth degree 

 of south latitude and the pole. The justness 

 of these and other speculations of that great 

 navigator have since been singularly con- 

 firmed by the investigation made by Sir 

 James Ross in 1841. He found Victoria 

 Land, extending from 71 to 79 S. latitude, 

 skirted by a great barrier of ice, the height 

 of the land ranging from 4,000 to 14,000 

 feet, the whole entirely covered with snow, 

 except a narrow ring of black earth sur- 

 rounding the huge crater of the active vol- 

 cano of Mount Erebus, rising 12,400 feet 

 above the level of the sea. The position of 

 a mountainous territory of such altitude, so 

 near the pole, and so obvious a source of in- 

 tense cold, fully explains why Graham's and 

 Enderby's Land, discovered by Captain Bis- 

 coe in 1831-2 (between lat. 64 and 68 S.), 

 presented a most wintry aspect, covered even 

 in summer with ice and snow, and nearly 

 destitute of animal life. In corresponding 

 latitudes of the northern hemisphere we not 

 only meet with herds of wild herbivorous 

 animals, but with land which man himself 

 inhabits, and where he has even built ports 

 and inland villages. LYELL Principles of 

 Geology, bk. i, ch. 7, p. 99. (A., 1854.) 



849. DISCOVERY, LONG DELAY TO 



REALIZE Humanity Waiting. It is inter- 

 esting, and indeed pathetic, to observe how 

 long a discovery of priceless value to hu- 

 manity may be hidden away, or rather lie 

 openly revealed, before the final and appar- 

 ently obvious step is taken towards its prac- 

 tical application. In 1837, Schwann clearly 

 established the connection between putre- 

 faction and microscopic life; but thirty 

 years had to elapse before Lister extended 

 to wounds the researches of Schwann on 

 dead flesh and animal infusions. TYNDALL 

 Floating Matter of the Air, int., p. 9. (A., 

 1895.) 



850. DISCOVERY MISSED Stopping 

 with an Instance Failure of Generaliza- 

 tion. Again, at Paris, in 1849, with a view 

 to testing the asserted coincidence between 

 the solar D-line and the bright yellow beam 

 in the spectrum of the electric arc (really 

 due to the unsuspected presence of sodium ) , 

 Leon Foucault threw a ray of sunshine 

 across the arc and observed its spectrum. 

 He was surprised to see that the D-line was 

 rendered more intensely dark by the com- 

 bination of lights. To assure himself still 

 further, he substituted a reflected image of 

 one of the white-hot carbon-points for the 

 sunbeam, with an identical result. The 

 same ray was missing. It needed but an- 

 otHer step to have generalized this result, 

 and thus laid hold of a natural truth of the 

 highest importance; but that step was not 

 taken. Foucault, keen and brilliant tho he 

 was, rested satisfied with the information 

 that the voltaic arc had the power of stop- 

 ping the kind of light emitted by it; he 

 asked no further question, and was conse- 

 quently the bearer of no further intelligence 

 on the subject. CLERKE History of Astron- 

 omy, pt. ii, ch. 1, p. 170. (Bl., 1893.) 



851. DISCOVERY OF AMERICA NOT 

 AN ISOLATED EVENT Way Prepared by 

 Science. The discovery of the tropical re- 

 gions of America by Christopher Columbus 

 . . . cannot be regarded in the history of 

 the contemplation of the universe as one 

 isolated event. . . . That which im- 

 parted to the age of Columbus its peculiar 

 character of uninterrupted and successful 

 efforts toward the attainment of new dis- 

 coveries and extended geographical knowl- 

 edge was prepared slowly and in various 

 ways. The means which contributed most 

 strongly to favor these efforts were a small 

 number of enterprising men, who early ex- 

 cited a simultaneous and general freedom of 

 thought, and an independence of investiga- 

 tion into the separate phenomena of Nature ; 

 the influence exercised on the deepest sources 

 of mental vigor by the renewed acquaintance 

 formed in Italy with the works of ancient 

 Greek literature; the discovery of an art 

 which lent to thought at once wings of speed 

 and powers of perpetuity; and the more ex- 

 tended knowledge of eastern Asia acquired 

 by traveling merchants, and by monks who 

 had been sent on embassies to the Mogul 

 rulers, and which was diffused by them 

 among those nations of the southwest of 

 Europe who maintained extensive commer- 

 cial relations with other countries, and who 

 were therefore most anxious to discover a 

 nearer route to the Spice Islands. To these 

 means ... we must add the advance 

 in the art of navigation, the gradual per- 

 fection of nautical instruments, both mag- 

 netic and astronomical, and, finally, the 

 application of certain methods for the 

 determination of the ship's place. HUM- 

 BOLDT Cosmos, vol. ii, pt. ii, p. 240. (H., 

 1897.) 



