July 10, 1908] 



SCIENCE 



53 



composed of matter at all, it must be in that 

 sub-atomic condition characteristic of the 

 manifestation of electricity. The corona 

 from its very appearance suggests a streaming 

 out from the sun of attenuated matter, or of 

 force. That a repellant force actually ema- 

 nates from the sun is shown by the solar 

 action upon the tails of comets, always turn- 

 ing them from itself. It seems to have been 

 fairly weU established that all substances are 

 radio-active, differing only in degree in the 

 possession of this property. It is but a step 

 further to conclude that all celestial bodies 

 are sending out emanations of matter in the 

 most attenuated state, and that these effects, 

 in the case of the sun, become visible as 

 the solar corona. Following this trend of 

 thought, we may safely assume that the earth 

 and moon each has its own corona. The 

 aurora borealis then may be an exhibition of 

 our corona shining by its own light, the angle 

 at which the sun strikes the corona being such 

 as to preclude the reflection of sunlight to the 

 observer's eye. The zodiacal light might be 

 explained as being due mainly to sunlight 

 reflected from our own coronal matter. As 

 in this case we should not be viewing the earth 

 corona by its own light, the flickering effect 

 of the northern light would not be prominent. 



The hypothesis here offered seems to ac- 

 count for the puzzling mixed spectra of the 

 so-called zodiacal light. It further explains 

 the existence of the shafts high in the north 

 and the undecided character of the light, on 

 the evening of March 27. Both the zodiacal 

 and auroral theory utterly fail to account for 

 these. Wandering into the domain of con- 

 jecture, it is interesting to speculate whether 

 the solar, terrestrial and lunar coronas are 

 identical in nature. If they are not, it would 

 seem to indicate that radio-activity was a 

 function of the heat of the radiating body, 

 and we might expect the spectra to group 

 themselves in the order named as regards 

 simplicity. If the spectra should prove to be 

 the same, we might fairly conclude that cor- 

 onal material is the final form of disintegra- 

 ting matter, as a nebula is the first form. 

 WiLMOT E. Ellis 



Fort Tekby, N. Y. 



QUOTATIONS 

 THE CAVENDISH LABORATORY 



Lord Eayleigh, as chancellor of the Uni- 

 versity of Cambridge, performed his first 

 official act by opening the new wing of the 

 Cavendish Laboratory, which Lord Eayleigh, 

 as a Nobel prize-man, presented to the uni- 

 versity. The ceremony was all the more in- 

 teresting because, as Professor J. J. Thomson 

 observed, it occurred upon the anniversary of 

 the opening of the original Cavendish Labora- 

 tory, which the university owed to the gener- 

 osity of the seventh Duke of Devonshire, who 

 was chancellor in 1874. During the thirty- 

 four years that have elapsed since the found- 

 ing of the laboratory. Lord Eayleigh has been 

 closely connected with it, and the physical 

 research which it was designed to promote. 

 His interest in it, indeed, began, as he re- 

 marked yesterday, before it existed. He had 

 then become acutely aware of the scientific 

 destitution of the university, and of the diffi- ■ 

 eulty of acquiring systematic scientific train- 

 ing. Much good work had been done in phys- 

 ical research, but it had to be carried out by 

 earnest students either in their own houses or 

 in some college where the equipment was more 

 meager than students of the present day can 

 easily realize. Lord Eayleigh's activity in 

 seeking a remedy for that state of things was 

 much greater than might be inferred from his 

 characteristically modest remark that he had 

 some share in urging Clerk-Maxwell to accept 

 the appointment of professor of experimental 

 physics. That brilliant man's tenure of the 

 post was niot a long one, and on his lamented 

 death in 1879 Lord Eayleigh succeeded him 

 as Cavendish professor. During the five years 

 of his professorship Lord Eayleigh carried out 

 some fundamental researches with results 

 which more recent investigations have only 

 corroborated. Since that time the post has 

 been held and adorned by Professor J. J. 

 Thomson; but Lord Eayleigh's interest in the 

 laboratory and its work has been continuous 

 and keen. The extension which he has given 

 to its accommodation was very urgently 

 needed on account of the steady growth in the 



