EULOGY ON ARTHUR AUGUSTE DE LA RIVE. 197 



atmosphere, having for center the magnetic pole. By transmitting 

 through a rarifled gas an electrical discharge around the pole of a 

 strong magnet, he caused a luminous ring to appear, animated with a 

 movement of rotation around this same pole. This experiment is so 

 beautiful that it must be admired even by those physicists, now few in 

 number, who consider that the aurora is derived from a source far beyond 

 the terrestrial atmosphere, and attribute to it a cosmical origin. He 

 writes thus to me, only a short time before the attack of illness which 

 caused his death: "Assist me in defending a theory, which I believe to 

 be founded upon incontestable facts, and which was advocated by Frank- 

 lin and Arago when there was less evidence in its favor. The investi- 

 gators who study only the brilliant and occasional auroras of our lati- 

 tudes, should also take into consideration those less radiant that appear 

 almost every day in the polar regions. I do not know a single observer, 

 placed in our extreme northern countries, who does not support the 

 views I have adopted. Surely it is much iu their favor that they are 

 advocated by men who live in the midst of the phenomena; and shall 

 we abandon them because they are opposed by those who witness these 

 remarkable appearances only occasionally, and under the influence of 

 surprise and astonishment which must more or less aflect the judgment 

 concerning them 1 " 



At the equator, the silent magnetic agitations are replaced by electri- 

 cal storms, accompanied by thunder and rain, marking, so to say, the 

 course of the sun ; and if there is a constant manifestation of auroral 

 phenomena, more or less distinct at each pole, there is always an orange 

 tint, of greater or less intensity, at some point of the equator. What 

 purpose do they serve, these electric manifestations, continually exhib- 

 ited throughout the atmosphere of the earth ? We are not yet in a con- 

 dition to say, but De La Rive has thrown much light upon the question. 



When, a hundred years ago, Priestley discovered oxygen, the agent 

 of combustion and respiration, medicine found a valuable auxiliary, and 

 enthusiasts saw iu it a means of prolonging life. The experiments of 

 M. Bert, however, proved that this vital air, if inhaled into the lungs in 

 a pure state, was a mortal poison. This same oxygen, as soon as it is 

 electrized, shows that it is accompanied by a very odorous substance, 

 blackening colored bodies, irritating violently the respiratory organs, 

 and converting animal products into saltpeter. This is the ozone M 

 Scuonbein, the celebrated professor of Basle, found at times in the 

 atmosphere, particularly when the latter was electrized by thunder- 

 clouds. Auguste De La Rive and his learned friend M. de Mariguac 

 maintained that ozone is a modification of oxygen, a conclusion ren- 

 dered incontestable by our two eminent associates, IVUVI. Fr6my and 

 Becquerel, jr. 



If pure oxygen is deadly in its effects, mingled with the air that sur- 

 rounds us, it supports life; and if oxygen, ozenized, is a poison, in mod- 



