June 16, 1899. J 



SCIENCE. 



841 



ers of the wave theory of light, which plays 

 so important a part in modern physics. It 

 was left to later generations to appreciate 

 his merits in this respect and to discover 

 that he had anticipated many points for 

 which Fresnel was given the credit. Sir 

 Humphry Davy's tenure of the professor- 

 ship was nearly coextensive with his scien- 

 tific life. Engaged in 1801, he immediately 

 proved himself not only a lecturer of sin- 

 gular charm, but a most skilful and prolific 

 investigator. His most far-reaching re- 

 searches were probably those on the chem- 

 ical agencies of electricity, for it was in the 

 course of them that he decomposed the 

 alkalies by a strong electrical current, thus 

 not only discovering the metals sodium and 

 potassium, but laying the foundations of 

 electrolytical chemistry, a science whose 

 industrial applications are now becoming 

 more numerous and important every day. 

 In addition, he made many researches in 

 pure chemistry, and his work in the phil- 

 osophy of flame led to the famous invention 

 of the miner's safety lamp. The third of 

 this triumvirate, Michael Faraday, entered 

 the service of the Institution as assistant in 

 the laboratory and rose to be its chief orna- 

 ment and support. His scientific output 

 during the 50 years in which he labored is 

 quite unequalled for range and quality, in- 

 cluding, as it does, researches in alloys, new 

 organic compounds, optical glass, the lique- 

 faction of gases, regelation, the action of 

 metals on light, magnetism and diamag- 

 netism, the magnetization of light, and the 

 induction of electrical currents. The place 

 of honor must undoubtedly be assigned to 

 his work in the last department, not only 

 because of its enormous theoretical sig- 

 nificance, but also on account of the prac- 

 tical results of which it has been the start- 

 ing point ; it forms the foundation of the 

 huge and increasing fabric of modern elec- 

 trical engineering. 



Another distinguished name in the annals 



of the Royal Institution is that of John 

 Tyndall, who for 34 years maintained the 

 traditions of the place as a brilliant lecturer 

 and expei'imentalist. His researches were 

 numerous and varied, the main ones rela- 

 ting to heat, to sound and to the behavior of 

 small particles, such as compose dust, 

 whether of living or dead matter. Of the 

 first the difficult investigation of the ab- 

 sorption by gaseous bodies of invisible radia- 

 tion is the most important, but his book 

 on ' Heat considered as a Mode of Motion ' 

 is a classic which shows to advantage his 

 splendid power of popular scientific exposi- 

 tion. In sound some of his most interesting 

 work, that on the laws governing the audi- 

 bility of foghorns and other signals in thick 

 weather, was done as scientific adviser to 

 the Trinity Board, a position in which he 

 succeeded his friend and colleague Faraday, 

 while his inquiries on atmospheric dust 

 yielded results of great value alike to the 

 physicist and the biologist. Tyndall was 

 succeeded, both at the Eoyal Institution and 

 the Trinity House, by Lord Rayleigh, who 

 is universally recognized as one of the ablest 

 mathematical physicists now living. Doubt- 

 less he is best known popularly in connec- 

 tion with the discovery of argon, but, in fact, 

 his scientific reputation i-ests upon investi- 

 gations of the most abstruse and difficult 

 kind and upon practical achievements, 

 among which the isolation of a new gas 

 takes a secondary place. Of the men who 

 followed Faraday in the chair of chemistry 

 all are still at work. The first. Sir Edward 

 Franklin, perhaps, in strictness should not 

 be called a successor of Faraday, since he 

 never held the Fullerian professorship, 

 which was bestowed on Faraday for life, 

 but he was appointed professor of chemistry 

 when the latter's failing health obliged him 

 to give up lecturing, and in the laboratory 

 of the Royal Institution he carried out some 

 of those researches on orgauo-metallic com- 

 pounds which stamped him as one of the 



